Commit Graph

528 Commits

Author SHA1 Message Date
Saravana Kannan
8375e74f2b driver core: Add fw_devlink kernel commandline option
fwnode_operations.add_links allows creating device links from
information provided by firmware.

fwnode_operations.add_links is currently implemented only by
OF/devicetree code and a specific case of efi. However, there's nothing
preventing ACPI or other firmware types from implementing it.

The OF implementation is currently controlled by a kernel commandline
parameter called of_devlink.

Since this feature is generic isn't limited to OF, add a generic
fw_devlink kernel commandline parameter to control this feature across
firmware types.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200222014038.180923-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-04 17:58:48 +01:00
Saravana Kannan
1745d299af driver core: Reevaluate dev->links.need_for_probe as suppliers are added
A previous patch 03324507e6 ("driver core: Allow
fwnode_operations.add_links to differentiate errors") forgot to update
all call sites to fwnode_operations.add_links. This patch fixes that.

Legend:
-> Denotes RHS is an optional/potential supplier for LHS
=> Denotes RHS is a mandatory supplier for LHS

Example:

Device A => Device X
Device A -> Device Y

Before this patch:
1. Device A is added.
2. Device A is marked as waiting for mandatory suppliers
3. Device X is added
4. Device A is left marked as waiting for mandatory suppliers

Step 4 is wrong since all mandatory suppliers of Device A have been
added.

After this patch:
1. Device A is added.
2. Device A is marked as waiting for mandatory suppliers
3. Device X is added
4. Device A is no longer considered as waiting for mandatory suppliers

This is the correct behavior.

Fixes: 03324507e6 ("driver core: Allow fwnode_operations.add_links to differentiate errors")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200222014038.180923-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-04 17:58:47 +01:00
Saravana Kannan
77036165d8 driver core: Skip unnecessary work when device doesn't have sync_state()
A bunch of busy work is done for devices that don't have sync_state()
support. Stop doing the busy work.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200221080510.197337-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-04 13:46:03 +01:00
Saravana Kannan
21eb93f432 driver core: Call sync_state() even if supplier has no consumers
The initial patch that added sync_state() support didn't handle the case
where a supplier has no consumers. This was because when a device is
successfully bound with a driver, only its suppliers were checked to see
if they are eligible to get a sync_state(). This is not sufficient for
devices that have no consumers but still need to do device state clean
up. So fix this.

Fixes: fc5a251d0f (driver core: Add sync_state driver/bus callback)
Signed-off-by: Saravana Kannan <saravanak@google.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200221080510.197337-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-04 13:46:03 +01:00
Christian Brauner
3b52fc5d78 drivers/base/power: add dpm_sysfs_change_owner()
Add a helper to change the owner of a device's power entries. This
needs to happen when the ownership of a device is changed, e.g. when
moving network devices between network namespaces.
This function will be used to correctly account for ownership changes,
e.g. when moving network devices between network namespaces.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-26 20:07:25 -08:00
Christian Brauner
b8f33e5d76 device: add device_change_owner()
Add a helper to change the owner of a device's sysfs entries. This
needs to happen when the ownership of a device is changed, e.g. when
moving network devices between network namespaces.
This function will be used to correctly account for ownership changes,
e.g. when moving network devices between network namespaces.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-26 20:07:25 -08:00
Saravana Kannan
26e77708fd driver core: Allow device link operations inside sync_state()
Some sync_state() implementations might need to call APIs that in turn
make calls to device link APIs. So, do the sync_state() callbacks
without holding the device link lock.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20191114225646.251277-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-15 10:06:54 +08:00
Saravana Kannan
03324507e6 driver core: Allow fwnode_operations.add_links to differentiate errors
When add_links() still has suppliers that it needs to link to in the
future, this patch allows it to differentiate between suppliers that are
needed for probing vs suppliers that are needed for sync_state()
correctness.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20191028220027.251605-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-02 18:05:18 +01:00
Saravana Kannan
bcbbcfd572 driver core: Allow a device to wait on optional suppliers
Before this change, if a device is waiting on suppliers, it's assumed
that all those suppliers are needed for the device to probe
successfully. This change allows marking a devices as waiting only on
optional suppliers. This allows a device to wait on suppliers (and link
to them as soon as they are available) without preventing the device
from being probed.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20191028220027.251605-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-02 18:05:17 +01:00
Saravana Kannan
05ef983e0d driver core: Add device link support for SYNC_STATE_ONLY flag
Parent devices might need to create "proxy" device links from themselves
to supplier devices to make sure the supplier devices don't get a
sync_state() before the child consumer devices get a chance to add
device links to the supplier devices.

However, the parent device has no real dependency on the supplier device
and probing, suspend/resume or runtime PM don't need to be affected by
the supplier device.  To capture these cases, create a SYNC_STATE_ONLY
device link flag that only affects sync_state() behavior and doesn't
affect probing, suspend/resume or runtime PM.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20191028220027.251605-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-02 18:05:17 +01:00
Greg Kroah-Hartman
8f677bc819 Merge 5.4-rc5 into driver-core-next
We want the sysfs fix in here as well to build on top of.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-27 18:54:13 +01:00
Rafael J. Wysocki
65650b3513 cpufreq: Avoid cpufreq_suspend() deadlock on system shutdown
It is incorrect to set the cpufreq syscore shutdown callback pointer
to cpufreq_suspend(), because that function cannot be run in the
syscore stage of system shutdown for two reasons: (a) it may attempt
to carry out actions depending on devices that have already been shut
down at that point and (b) the RCU synchronization carried out by it
may not be able to make progress then.

The latter issue has been present since commit 45975c7d21 ("rcu:
Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds"),
but the former one has been there since commit 90de2a4aa9 ("cpufreq:
suspend cpufreq governors on shutdown") regardless.

Fix that by dropping cpufreq_syscore_ops altogether and making
device_shutdown() call cpufreq_suspend() directly before shutting
down devices, which is along the lines of what system-wide power
management does.

Fixes: 45975c7d21 ("rcu: Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds")
Fixes: 90de2a4aa9 ("cpufreq: suspend cpufreq governors on shutdown")
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.0+ <stable@vger.kernel.org> # 4.0+
2019-10-10 11:11:17 +02:00
Saravana Kannan
fc5a251d0f driver core: Add sync_state driver/bus callback
This sync_state driver/bus callback is called once all the consumers
of a supplier have probed successfully.

This allows the supplier device's driver/bus to sync the supplier
device's state to the software state with the guarantee that all the
consumers are actively managing the resources provided by the supplier
device.

To maintain backwards compatibility and ease transition from existing
frameworks and resource cleanup schemes, late_initcall_sync is the
earliest when the sync_state callback might be called.

There is no upper bound on the time by which the sync_state callback
has to be called. This is because if a consumer device never probes,
the supplier has to maintain its resources in the state left by the
bootloader. For example, if the bootloader leaves the display
backlight at a fixed voltage and the backlight driver is never probed,
you don't want the backlight to ever be turned off after boot up.

Also, when multiple devices are added after kernel init, some
suppliers could be added before their consumer devices get added. In
these instances, the supplier devices could get their sync_state
callback called right after they probe because the consumers devices
haven't had a chance to create device links to the suppliers.

To handle this correctly, this change also provides APIs to
pause/resume sync state callbacks so that when multiple devices are
added, their sync_state callback evaluation can be postponed to happen
after all of them are added.

kbuild test robot reported missing documentation for device.state_synced
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20190904211126.47518-5-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-04 17:30:19 +02:00
Saravana Kannan
e2ae9bcc4a driver core: Add support for linking devices during device addition
The firmware corresponding to a device (dev.fwnode) might be able to
provide functional dependency information between a device and its
supplier and consumer devices.  Tracking this functional dependency
allows optimizing device probe order and informing a supplier when all
its consumers have probed (and thereby actively managing their
resources).

The existing device links feature allows tracking and using
supplier-consumer relationships. So, this patch adds the add_links()
fwnode callback to allow firmware to create device links for each
device as the device is added.

However, when consumer devices are added, they might not have a supplier
device to link to despite needing mandatory resources/functionality from
one or more suppliers. A waiting_for_suppliers list is created to track
such consumers and retry linking them when new devices get added.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20190904211126.47518-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-04 17:29:50 +02:00
Saravana Kannan
372a67c0c5 driver core: Add fwnode_to_dev() to look up device from fwnode
It's often useful to look up a device that corresponds to a fwnode. So
add an API to do that irrespective of the bus on which the device has
been added to.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20190904211126.47518-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-04 17:29:50 +02:00
Linus Torvalds
1f7d290a72 Driver core patches for 5.4-rc1
Here is the big driver core update for 5.4-rc1.
 
 There was a bit of a churn in here, with a number of core and OF
 platform patches being added to the tree, and then after much discussion
 and review and a day-long in-person meeting, they were decided to be
 reverted and a new set of patches is currently being reviewed on the
 mailing list.
 
 Other than that churn, there are two "persistent" branches in here that
 other trees will be pulling in as well during the merge window.  One
 branch to add support for drivers to have the driver core automatically
 add sysfs attribute files when a driver is bound to a device so that the
 driver doesn't have to manually do it (and then clean it up, as it
 always gets it wrong).
 
 There's another branch in here for generic lookup helpers for the driver
 core that lots of busses are starting to use.  That's the majority of
 the non-driver-core changes in this patch series.
 
 There's also some on-going debugfs file creation cleanup that has been
 slowly happening over the past few releases, with the goal to hopefully
 get that done sometime next year.
 
 All of these have been in linux-next for a while now with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg Kroah-Hartman:
 "Here is the big driver core update for 5.4-rc1.

  There was a bit of a churn in here, with a number of core and OF
  platform patches being added to the tree, and then after much
  discussion and review and a day-long in-person meeting, they were
  decided to be reverted and a new set of patches is currently being
  reviewed on the mailing list.

  Other than that churn, there are two "persistent" branches in here
  that other trees will be pulling in as well during the merge window.
  One branch to add support for drivers to have the driver core
  automatically add sysfs attribute files when a driver is bound to a
  device so that the driver doesn't have to manually do it (and then
  clean it up, as it always gets it wrong).

  There's another branch in here for generic lookup helpers for the
  driver core that lots of busses are starting to use. That's the
  majority of the non-driver-core changes in this patch series.

  There's also some on-going debugfs file creation cleanup that has been
  slowly happening over the past few releases, with the goal to
  hopefully get that done sometime next year.

  All of these have been in linux-next for a while now with no reported
  issues"

[ Note that the above-mentioned generic lookup helpers branch was
  already brought in by the LED merge (commit 4feaab05dc) that had
  shared it.

  Also note that that common branch introduced an i2c bug due to a bad
  conversion, which got fixed here. - Linus ]

* tag 'driver-core-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (49 commits)
  coccinelle: platform_get_irq: Fix parse error
  driver-core: add include guard to linux/container.h
  sysfs: add BIN_ATTR_WO() macro
  driver core: platform: Export platform_get_irq_optional()
  hwmon: pwm-fan: Use platform_get_irq_optional()
  driver core: platform: Introduce platform_get_irq_optional()
  Revert "driver core: Add support for linking devices during device addition"
  Revert "driver core: Add edit_links() callback for drivers"
  Revert "of/platform: Add functional dependency link from DT bindings"
  Revert "driver core: Add sync_state driver/bus callback"
  Revert "of/platform: Pause/resume sync state during init and of_platform_populate()"
  Revert "of/platform: Create device links for all child-supplier depencencies"
  Revert "of/platform: Don't create device links for default busses"
  Revert "of/platform: Fix fn definitons for of_link_is_valid() and of_link_property()"
  Revert "of/platform: Fix device_links_supplier_sync_state_resume() warning"
  Revert "of/platform: Disable generic device linking code for PowerPC"
  devcoredump: fix typo in comment
  devcoredump: use memory_read_from_buffer
  of/platform: Disable generic device linking code for PowerPC
  device.h: Fix warnings for mismatched parameter names in comments
  ...
2019-09-18 10:04:39 -07:00
Linus Torvalds
4feaab05dc LED updates for 5.4-rc1
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Merge tag 'leds-for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED updates from Jacek Anaszewski:
 "In this cycle we've finally managed to contribute the patch set
  sorting out LED naming issues. Besides that there are many changes
  scattered among various LED class drivers and triggers.

  LED naming related improvements:

   - add new 'function' and 'color' fwnode properties and deprecate
     'label' property which has been frequently abused for conveying
     vendor specific names that have been available in sysfs anyway

   - introduce a set of standard LED_FUNCTION* definitions

   - introduce a set of standard LED_COLOR_ID* definitions

   - add a new {devm_}led_classdev_register_ext() API with the
     capability of automatic LED name composition basing on the
     properties available in the passed fwnode; the function is
     backwards compatible in a sense that it uses 'label' data, if
     present in the fwnode, for creating LED name

   - add tools/leds/get_led_device_info.sh script for retrieving LED
     vendor, product and bus names, if applicable; it also performs
     basic validation of an LED name

   - update following drivers and their DT bindings to use the new LED
     registration API:

        - leds-an30259a, leds-gpio, leds-as3645a, leds-aat1290, leds-cr0014114,
          leds-lm3601x, leds-lm3692x, leds-lp8860, leds-lt3593, leds-sc27xx-blt

  Other LED class improvements:

   - replace {devm_}led_classdev_register() macros with inlines

   - allow to call led_classdev_unregister() unconditionally

   - switch to use fwnode instead of be stuck with OF one

  LED triggers improvements:

   - led-triggers:
        - fix dereferencing of null pointer
        - fix a memory leak bug

   - ledtrig-gpio:
        - GPIO 0 is valid

  Drop superseeded apu2/3 support from leds-apu since for apu2+ a newer,
  more complete driver exists, based on a generic driver for the AMD
  SOCs gpio-controller, supporting LEDs as well other devices:

   - drop profile field from priv data

   - drop iosize field from priv data

   - drop enum_apu_led_platform_types

   - drop superseeded apu2/3 led support

   - add pr_fmt prefix for better log output

   - fix error message on probing failure

  Other misc fixes and improvements to existing LED class drivers:

   - leds-ns2, leds-max77650:
        - add of_node_put() before return

   - leds-pwm, leds-is31fl32xx:
        - use struct_size() helper

   - leds-lm3697, leds-lm36274, leds-lm3532:
        - switch to use fwnode_property_count_uXX()

   - leds-lm3532:
        - fix brightness control for i2c mode
        - change the define for the fs current register
        - fixes for the driver for stability
        - add full scale current configuration
        - dt: Add property for full scale current.
        - avoid potentially unpaired regulator calls
        - move static keyword to the front of declarations
        - fix optional led-max-microamp prop error handling

   - leds-max77650:
        - add of_node_put() before return
        - add MODULE_ALIAS()
        - Switch to fwnode property API

   - leds-as3645a:
        - fix misuse of strlcpy

   - leds-netxbig:
        - add of_node_put() in netxbig_leds_get_of_pdata()
        - remove legacy board-file support

   - leds-is31fl319x:
        - simplify getting the adapter of a client

   - leds-ti-lmu-common:
        - fix coccinelle issue
        - move static keyword to the front of declaration

   - leds-syscon:
        - use resource managed variant of device register

   - leds-ktd2692:
        - fix a typo in the name of a constant

   - leds-lp5562:
        - allow firmware files up to the maximum length

   - leds-an30259a:
        - fix typo

   - leds-pca953x:
        - include the right header"

* tag 'leds-for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds: (72 commits)
  leds: lm3532: Fix optional led-max-microamp prop error handling
  led: triggers: Fix dereferencing of null pointer
  leds: ti-lmu-common: Move static keyword to the front of declaration
  leds: lm3532: Move static keyword to the front of declarations
  leds: trigger: gpio: GPIO 0 is valid
  leds: pwm: Use struct_size() helper
  leds: is31fl32xx: Use struct_size() helper
  leds: ti-lmu-common: Fix coccinelle issue in TI LMU
  leds: lm3532: Avoid potentially unpaired regulator calls
  leds: syscon: Use resource managed variant of device register
  leds: Replace {devm_}led_classdev_register() macros with inlines
  leds: Allow to call led_classdev_unregister() unconditionally
  leds: lm3532: Add full scale current configuration
  dt: lm3532: Add property for full scale current.
  leds: lm3532: Fixes for the driver for stability
  leds: lm3532: Change the define for the fs current register
  leds: lm3532: Fix brightness control for i2c mode
  leds: Switch to use fwnode instead of be stuck with OF one
  leds: max77650: Switch to fwnode property API
  led: triggers: Fix a memory leak bug
  ...
2019-09-17 18:40:42 -07:00
Greg Kroah-Hartman
bfb3943bed Revert "driver core: Add support for linking devices during device addition"
This reverts commit 5302dd7dd0.

Based on a lot of email and in-person discussions, this patch series is
being reworked to address a number of issues that were pointed out that
needed to be taken care of before it should be merged.  It will be
resubmitted with those changes hopefully soon.

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Saravana Kannan <saravanak@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-27 21:41:16 +02:00
Greg Kroah-Hartman
33cbfe5449 Revert "driver core: Add edit_links() callback for drivers"
This reverts commit 134b23eec9.

Based on a lot of email and in-person discussions, this patch series is
being reworked to address a number of issues that were pointed out that
needed to be taken care of before it should be merged.  It will be
resubmitted with those changes hopefully soon.

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Saravana Kannan <saravanak@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-27 21:41:06 +02:00
Greg Kroah-Hartman
bcca686c11 Revert "driver core: Add sync_state driver/bus callback"
This reverts commit 8f8184d6bf.

Based on a lot of email and in-person discussions, this patch series is
being reworked to address a number of issues that were pointed out that
needed to be taken care of before it should be merged.  It will be
resubmitted with those changes hopefully soon.

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Saravana Kannan <saravanak@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-27 21:40:50 +02:00
Ingo Molnar
6c06b66e95 Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU and LKMM changes from Paul E. McKenney:

 - A few more RCU flavor consolidation cleanups.

 - Miscellaneous fixes.

 - Updates to RCU's list-traversal macros improving lockdep usability.

 - Torture-test updates.

 - Forward-progress improvements for no-CBs CPUs: Avoid ignoring
   incoming callbacks during grace-period waits.

 - Forward-progress improvements for no-CBs CPUs: Use ->cblist
   structure to take advantage of others' grace periods.

 - Also added a small commit that avoids needlessly inflicting
   scheduler-clock ticks on callback-offloaded CPUs.

 - Forward-progress improvements for no-CBs CPUs: Reduce contention
   on ->nocb_lock guarding ->cblist.

 - Forward-progress improvements for no-CBs CPUs: Add ->nocb_bypass
   list to further reduce contention on ->nocb_lock guarding ->cblist.

 - LKMM updates.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-08-22 20:52:04 +02:00
Joel Fernandes (Google)
c2fa1e1bfa driver/core: Convert to use built-in RCU list checking
This commit applies the consolidated hlist_for_each_entry_rcu() support
for lockdep conditions.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2019-08-13 14:28:47 -07:00
Greg Kroah-Hartman
e6aa640eb2 Merge 5.3-rc4 into driver-core-next
We need the driver core fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-12 07:37:39 +02:00
Linus Torvalds
36e630ed98 Driver core fixes for 5.3-rc4
Here are 2 small fixes for some driver core issues that have been
 reported.  There is also a kernfs "fix" here, which was then reverted
 because it was found to cause problems in linux-next.
 
 The driver core fixes both resolve reported issues, one with gpioint
 stuff that showed up in 5.3-rc1, and the other finally (and hopefully)
 resolves a very long standing race when removing glue directories.  It's
 nice to get that issue finally resolved and the developers involved
 should be applauded for the persistence it took to get this patch
 finally accepted.
 
 All of these have been in linux-next for a while with no reported
 issues.  Well, the one reported issue, hence the revert :)
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are two small fixes for some driver core issues that have been
  reported. There is also a kernfs "fix" here, which was then reverted
  because it was found to cause problems in linux-next.

  The driver core fixes both resolve reported issues, one with gpioint
  stuff that showed up in 5.3-rc1, and the other finally (and hopefully)
  resolves a very long standing race when removing glue directories.
  It's nice to get that issue finally resolved and the developers
  involved should be applauded for the persistence it took to get this
  patch finally accepted.

  All of these have been in linux-next for a while with no reported
  issues. Well, the one reported issue, hence the revert :)"

* tag 'driver-core-5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Revert "kernfs: fix memleak in kernel_ops_readdir()"
  kernfs: fix memleak in kernel_ops_readdir()
  driver core: Fix use-after-free and double free on glue directory
  driver core: platform: return -ENXIO for missing GpioInt
2019-08-10 12:20:02 -07:00
Saravana Kannan
8f8184d6bf driver core: Add sync_state driver/bus callback
This sync_state driver/bus callback is called once all the consumers
of a supplier have probed successfully.

This allows the supplier device's driver/bus to sync the supplier
device's state to the software state with the guarantee that all the
consumers are actively managing the resources provided by the supplier
device.

To maintain backwards compatibility and ease transition from existing
frameworks and resource cleanup schemes, late_initcall_sync is the
earliest when the sync_state callback might be called.

There is no upper bound on the time by which the sync_state callback
has to be called. This is because if a consumer device never probes,
the supplier has to maintain its resources in the state left by the
bootloader. For example, if the bootloader leaves the display
backlight at a fixed voltage and the backlight driver is never probed,
you don't want the backlight to ever be turned off after boot up.

Also, when multiple devices are added after kernel init, some
suppliers could be added before their consumer devices get added. In
these instances, the supplier devices could get their sync_state
callback called right after they probe because the consumers devices
haven't had a chance to create device links to the suppliers.

To handle this correctly, this change also provides APIs to
pause/resume sync state callbacks so that when multiple devices are
added, their sync_state callback evaluation can be postponed to happen
after all of them are added.

kbuild test robot reported missing documentation for device.state_synced
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20190731221721.187713-5-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-01 16:04:14 +02:00
Saravana Kannan
134b23eec9 driver core: Add edit_links() callback for drivers
The driver core/bus adding supplier-consumer dependencies by default
enables functional dependencies to be tracked correctly even when the
consumer devices haven't had their drivers registered or loaded (if they
are modules).

However, when the bus incorrectly adds dependencies that it shouldn't
have added, the devices might never probe.

For example, if device-C is a consumer of device-S and they have
phandles to each other in DT, the following could happen:

1.  Device-S get added first.
2.  The bus add_links() callback will (incorrectly) try to link it as
    a consumer of device-C.
3.  Since device-C isn't present, device-S will be put in
    "waiting-for-supplier" list.
4.  Device-C gets added next.
5.  All devices in "waiting-for-supplier" list are retried for linking.
6.  Device-S gets linked as consumer to Device-C.
7.  The bus add_links() callback will (correctly) try to link it as
    a consumer of device-S.
8.  This isn't allowed because it would create a cyclic device links.

Neither devices will get probed since the supplier is marked as
dependent on the consumer. And the consumer will never probe because the
consumer can't get resources from the supplier.

Without this patch, things stay in this broken state. However, with this
patch, the execution will continue like this:

9.  Device-C's driver is loaded.
10. Device-C's driver removes Device-S as a consumer of Device-C.
11. Device-C's driver adds Device-C as a consumer of Device-S.
12. Device-S probes.
14. Device-C probes.

kbuild test robot reported missing documentation for device.has_edit_links
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20190731221721.187713-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-01 16:04:13 +02:00
Saravana Kannan
5302dd7dd0 driver core: Add support for linking devices during device addition
When devices are added, the bus might want to create device links to track
functional dependencies between supplier and consumer devices. This
tracking of supplier-consumer relationship allows optimizing device probe
order and tracking whether all consumers of a supplier are active. The
add_links bus callback is added to support this.

However, when consumer devices are added, they might not have a supplier
device to link to despite needing mandatory resources/functionality from
one or more suppliers. A waiting_for_suppliers list is created to track
such consumers and retry linking them when new devices get added.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20190731221721.187713-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-01 16:04:13 +02:00
Muchun Song
ac43432cb1 driver core: Fix use-after-free and double free on glue directory
There is a race condition between removing glue directory and adding a new
device under the glue dir. It can be reproduced in following test:

CPU1:                                         CPU2:

device_add()
  get_device_parent()
    class_dir_create_and_add()
      kobject_add_internal()
        create_dir()    // create glue_dir

                                              device_add()
                                                get_device_parent()
                                                  kobject_get() // get glue_dir

device_del()
  cleanup_glue_dir()
    kobject_del(glue_dir)

                                                kobject_add()
                                                  kobject_add_internal()
                                                    create_dir() // in glue_dir
                                                      sysfs_create_dir_ns()
                                                        kernfs_create_dir_ns(sd)

      sysfs_remove_dir() // glue_dir->sd=NULL
      sysfs_put()        // free glue_dir->sd

                                                          // sd is freed
                                                          kernfs_new_node(sd)
                                                            kernfs_get(glue_dir)
                                                            kernfs_add_one()
                                                            kernfs_put()

Before CPU1 remove last child device under glue dir, if CPU2 add a new
device under glue dir, the glue_dir kobject reference count will be
increase to 2 via kobject_get() in get_device_parent(). And CPU2 has
been called kernfs_create_dir_ns(), but not call kernfs_new_node().
Meanwhile, CPU1 call sysfs_remove_dir() and sysfs_put(). This result in
glue_dir->sd is freed and it's reference count will be 0. Then CPU2 call
kernfs_get(glue_dir) will trigger a warning in kernfs_get() and increase
it's reference count to 1. Because glue_dir->sd is freed by CPU1, the next
call kernfs_add_one() by CPU2 will fail(This is also use-after-free)
and call kernfs_put() to decrease reference count. Because the reference
count is decremented to 0, it will also call kmem_cache_free() to free
the glue_dir->sd again. This will result in double free.

In order to avoid this happening, we also should make sure that kernfs_node
for glue_dir is released in CPU1 only when refcount for glue_dir kobj is
1 to fix this race.

The following calltrace is captured in kernel 4.14 with the following patch
applied:

commit 726e410979 ("drivers: core: Remove glue dirs from sysfs earlier")

--------------------------------------------------------------------------
[    3.633703] WARNING: CPU: 4 PID: 513 at .../fs/kernfs/dir.c:494
                Here is WARN_ON(!atomic_read(&kn->count) in kernfs_get().
....
[    3.633986] Call trace:
[    3.633991]  kernfs_create_dir_ns+0xa8/0xb0
[    3.633994]  sysfs_create_dir_ns+0x54/0xe8
[    3.634001]  kobject_add_internal+0x22c/0x3f0
[    3.634005]  kobject_add+0xe4/0x118
[    3.634011]  device_add+0x200/0x870
[    3.634017]  _request_firmware+0x958/0xc38
[    3.634020]  request_firmware_into_buf+0x4c/0x70
....
[    3.634064] kernel BUG at .../mm/slub.c:294!
                Here is BUG_ON(object == fp) in set_freepointer().
....
[    3.634346] Call trace:
[    3.634351]  kmem_cache_free+0x504/0x6b8
[    3.634355]  kernfs_put+0x14c/0x1d8
[    3.634359]  kernfs_create_dir_ns+0x88/0xb0
[    3.634362]  sysfs_create_dir_ns+0x54/0xe8
[    3.634366]  kobject_add_internal+0x22c/0x3f0
[    3.634370]  kobject_add+0xe4/0x118
[    3.634374]  device_add+0x200/0x870
[    3.634378]  _request_firmware+0x958/0xc38
[    3.634381]  request_firmware_into_buf+0x4c/0x70
--------------------------------------------------------------------------

Fixes: 726e410979 ("drivers: core: Remove glue dirs from sysfs earlier")
Signed-off-by: Muchun Song <smuchun@gmail.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Link: https://lore.kernel.org/r/20190727032122.24639-1-smuchun@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-30 18:44:47 +02:00
Greg Kroah-Hartman
f87da58b79 Merge branch 'generic_lookup_helpers' into driver-core-next
This was on a separate branch so that others can pull it in.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-30 13:26:39 +02:00
Suzuki K Poulose
6bf85ba9e5 drivers: Add generic helper to match any device
Add a generic helper to match any/all devices. Using this
introduce new wrappers {bus/driver/class}_find_next_device().

Cc: Elie Morisse <syniurge@gmail.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Nehal Shah <nehal-bakulchandra.shah@amd.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Shyam Sundar S K <shyam-sundar.s-k@amd.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # PCI
Link: https://lore.kernel.org/r/20190723221838.12024-7-suzuki.poulose@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-30 13:07:42 +02:00
Suzuki K Poulose
00500147cb drivers: Introduce device lookup variants by ACPI_COMPANION device
Add a generic helper to match a device by the ACPI_COMPANION device
and provide wrappers for the device lookup APIs.

Cc: Len Brown <lenb@kernel.org>
Cc: linux-acpi@vger.kernel.org
Cc: linux-spi@vger.kernel.org
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: linux-i2c@vger.kernel.org
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # I2C parts
Link: https://lore.kernel.org/r/20190723221838.12024-6-suzuki.poulose@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-30 13:07:42 +02:00
Suzuki K Poulose
4495dfdd61 drivers: Introduce device lookup variants by device type
Add a helper to match a device by its type and provide wrappers
for {bus/class/driver}_find_device() APIs.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-usb@vger.kernel.org
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20190723221838.12024-5-suzuki.poulose@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-30 13:07:42 +02:00
Suzuki K Poulose
67843bbaf3 drivers: Introduce device lookup variants by fwnode
Add a helper to match the firmware node handle of a device and provide
wrappers for {bus/class/driver}_find_device() APIs to avoid proliferation
of duplicate custom match functions.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: linux-usb@vger.kernel.org
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Joe Perches <joe@perches.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20190723221838.12024-4-suzuki.poulose@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-30 13:07:42 +02:00
Suzuki K Poulose
6cda08a20d drivers: Introduce device lookup variants by name
Add a helper to match the device name for device lookup. Also
reuse this generic exported helper for the existing bus_find_device_by_name().
and add similar variants for driver/class.

Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexander Aring <alex.aring@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Murphy <dmurphy@ti.com>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: linux-leds@vger.kernel.org
Cc: linux-rtc@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: linux-wpan@vger.kernel.org
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Stefan Schmidt <stefan@datenfreihafen.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20190723221838.12024-2-suzuki.poulose@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-30 13:07:41 +02:00
Rafael J. Wysocki
fb583c8eee driver core: Fix creation of device links with PM-runtime flags
After commit 515db266a9 ("driver core: Remove device link creation
limitation"), if PM-runtime flags are passed to device_link_add(), it
will fail (returning NULL) due to an overly restrictive flags check
introduced by that commit.

Fix this issue by extending the check in question to cover the
PM-runtime flags too.

Fixes: 515db266a9 ("driver core: Remove device link creation limitation")
Reported-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/7674989.cD04D8YV3U@kreacher
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-30 12:34:39 +02:00
Linus Torvalds
523634db14 libnvdimm fixes v5.3-rc2
- Fix duplicate device_unregister() calls (multiple threads competing to
   do unregister work when scheduling device removal from a sysfs attribute
   of the self-same device).
 
 - Fix badblocks registration order bug. Ensure region badblocks are
   initialized in advance of namespace registration.
 
 - Fix a deadlock between the bus lock and probe operations.
 
 - Export device-core infrastructure to coordinate async operations via
   the device ->dead state.
 
 - Add device-core infrastructure to validate device_lock() usage with
   lockdep.
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Merge tag 'libnvdimm-fixes-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm fixes from Dan Williams:
 "A collection of locking and async operations fixes for v5.3-rc2. These
  had been soaking in a branch targeting the merge window, but missed
  due to a regression hunt. This fixed up version has otherwise been in
  -next this past week with no reported issues.

  In order to gain confidence in the locking changes the pull also
  includes a debug / instrumentation patch to enable lockdep coverage
  for libnvdimm subsystem operations that depend on the device_lock for
  exclusion. As mentioned in the changelog it is a hack, but it works
  and documents the locking expectations of the sub-system in a way that
  others can use lockdep to verify. The driver core touches got an ack
  from Greg.

  Summary:

   - Fix duplicate device_unregister() calls (multiple threads competing
     to do unregister work when scheduling device removal from a sysfs
     attribute of the self-same device).

   - Fix badblocks registration order bug. Ensure region badblocks are
     initialized in advance of namespace registration.

   - Fix a deadlock between the bus lock and probe operations.

   - Export device-core infrastructure to coordinate async operations
     via the device ->dead state.

   - Add device-core infrastructure to validate device_lock() usage with
     lockdep"

* tag 'libnvdimm-fixes-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  driver-core, libnvdimm: Let device subsystems add local lockdep coverage
  libnvdimm/bus: Fix wait_nvdimm_bus_probe_idle() ABBA deadlock
  libnvdimm/bus: Stop holding nvdimm_bus_list_mutex over __nd_ioctl()
  libnvdimm/bus: Prepare the nd_ioctl() path to be re-entrant
  libnvdimm/region: Register badblocks before namespaces
  libnvdimm/bus: Prevent duplicate device_unregister() calls
  drivers/base: Introduce kill_device()
2019-07-27 08:25:51 -07:00
Rafael J. Wysocki
515db266a9 driver core: Remove device link creation limitation
If device_link_add() is called for a consumer/supplier pair with an
existing device link between them and the existing link's type is
not in agreement with the flags passed to that function by its
caller, NULL will be returned.  That is seriously inconvenient,
because it forces the callers of device_link_add() to worry about
what others may or may not do even if that is not relevant to them
for any other reasons.

It turns out, however, that this limitation can be made go away
relatively easily.

The underlying observation is that if DL_FLAG_STATELESS has been
passed to device_link_add() in flags for the given consumer/supplier
pair at least once, calling either device_link_del() or
device_link_remove() to release the link returned by it should work,
but there are no other requirements associated with that flag.  In
turn, if at least one of the callers of device_link_add() for the
given consumer/supplier pair has not passed DL_FLAG_STATELESS to it
in flags, the driver core should track the status of the link and act
on it as appropriate (ie. the link should be treated as "managed").
This means that DL_FLAG_STATELESS needs to be set for managed device
links and it should be valid to call device_link_del() or
device_link_remove() to drop references to them in certain
sutiations.

To allow that to happen, introduce a new (internal) device link flag
called DL_FLAG_MANAGED and make device_link_add() set it automatically
whenever DL_FLAG_STATELESS is not passed to it.  Also make it take
additional references to existing device links that were previously
stateless (that is, with DL_FLAG_STATELESS set and DL_FLAG_MANAGED
unset) and will need to be managed going forward and initialize
their status (which has been DL_STATE_NONE so far).

Accordingly, when a managed device link is dropped automatically
by the driver core, make it clear DL_FLAG_MANAGED, reset the link's
status back to DL_STATE_NONE and drop the reference to it associated
with DL_FLAG_MANAGED instead of just deleting it right away (to
allow it to stay around in case it still needs to be released
explicitly by someone).

With that, since setting DL_FLAG_STATELESS doesn't mean that the
device link in question is not managed any more, replace all of the
status-tracking checks against DL_FLAG_STATELESS with analogous
checks against DL_FLAG_MANAGED and update the documentation to
reflect these changes.

While at it, make device_link_add() reject flags that it does not
recognize, including DL_FLAG_MANAGED.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Saravana Kannan <saravanak@google.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Review-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/2305283.AStDPdUUnE@kreacher
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-25 13:31:18 +02:00
Dan Williams
87a30e1f05 driver-core, libnvdimm: Let device subsystems add local lockdep coverage
For good reason, the standard device_lock() is marked
lockdep_set_novalidate_class() because there is simply no sane way to
describe the myriad ways the device_lock() ordered with other locks.
However, that leaves subsystems that know their own local device_lock()
ordering rules to find lock ordering mistakes manually. Instead,
introduce an optional / additional lockdep-enabled lock that a subsystem
can acquire in all the same paths that the device_lock() is acquired.

A conversion of the NFIT driver and NVDIMM subsystem to a
lockdep-validate device_lock() scheme is included. The
debug_nvdimm_lock() implementation implements the correct lock-class and
stacking order for the libnvdimm device topology hierarchy.

Yes, this is a hack, but hopefully it is a useful hack for other
subsystems device_lock() debug sessions. Quoting Greg:

    "Yeah, it feels a bit hacky but it's really up to a subsystem to mess up
     using it as much as anything else, so user beware :)

     I don't object to it if it makes things easier for you to debug."

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/156341210661.292348.7014034644265455704.stgit@dwillia2-desk3.amr.corp.intel.com
2019-07-18 16:23:27 -07:00
Dan Williams
00289cd876 drivers/base: Introduce kill_device()
The libnvdimm subsystem arranges for devices to be destroyed as a result
of a sysfs operation. Since device_unregister() cannot be called from
an actively running sysfs attribute of the same device libnvdimm
arranges for device_unregister() to be performed in an out-of-line async
context.

The driver core maintains a 'dead' state for coordinating its own racing
async registration / de-registration requests. Rather than add local
'dead' state tracking infrastructure to libnvdimm device objects, export
the existing state tracking via a new kill_device() helper.

The kill_device() helper simply marks the device as dead, i.e. that it
is on its way to device_del(), or returns that the device was already
dead. This can be used in advance of calling device_unregister() for
subsystems like libnvdimm that might need to handle multiple user
threads racing to delete a device.

This refactoring does not change any behavior, but it is a pre-requisite
for follow-on fixes and therefore marked for -stable.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Fixes: 4d88a97aa9 ("libnvdimm, nvdimm: dimm driver and base libnvdimm device-driver...")
Cc: <stable@vger.kernel.org>
Tested-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/156341207332.292348.14959761496009347574.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-07-18 16:21:01 -07:00
Linus Torvalds
f632a8170a Driver Core and debugfs changes for 5.3-rc1
Here is the "big" driver core and debugfs changes for 5.3-rc1
 
 It's a lot of different patches, all across the tree due to some api
 changes and lots of debugfs cleanups.  Because of this, there is going
 to be some merge issues with your tree at the moment, I'll follow up
 with the expected resolutions to make it easier for you.
 
 Other than the debugfs cleanups, in this set of changes we have:
 	- bus iteration function cleanups (will cause build warnings
 	  with s390 and coresight drivers in your tree)
 	- scripts/get_abi.pl tool to display and parse Documentation/ABI
 	  entries in a simple way
 	- cleanups to Documenatation/ABI/ entries to make them parse
 	  easier due to typos and other minor things
 	- default_attrs use for some ktype users
 	- driver model documentation file conversions to .rst
 	- compressed firmware file loading
 	- deferred probe fixes
 
 All of these have been in linux-next for a while, with a bunch of merge
 issues that Stephen has been patient with me for.  Other than the merge
 issues, functionality is working properly in linux-next :)
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core and debugfs updates from Greg KH:
 "Here is the "big" driver core and debugfs changes for 5.3-rc1

  It's a lot of different patches, all across the tree due to some api
  changes and lots of debugfs cleanups.

  Other than the debugfs cleanups, in this set of changes we have:

   - bus iteration function cleanups

   - scripts/get_abi.pl tool to display and parse Documentation/ABI
     entries in a simple way

   - cleanups to Documenatation/ABI/ entries to make them parse easier
     due to typos and other minor things

   - default_attrs use for some ktype users

   - driver model documentation file conversions to .rst

   - compressed firmware file loading

   - deferred probe fixes

  All of these have been in linux-next for a while, with a bunch of
  merge issues that Stephen has been patient with me for"

* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
  debugfs: make error message a bit more verbose
  orangefs: fix build warning from debugfs cleanup patch
  ubifs: fix build warning after debugfs cleanup patch
  driver: core: Allow subsystems to continue deferring probe
  drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
  arch_topology: Remove error messages on out-of-memory conditions
  lib: notifier-error-inject: no need to check return value of debugfs_create functions
  swiotlb: no need to check return value of debugfs_create functions
  ceph: no need to check return value of debugfs_create functions
  sunrpc: no need to check return value of debugfs_create functions
  ubifs: no need to check return value of debugfs_create functions
  orangefs: no need to check return value of debugfs_create functions
  nfsd: no need to check return value of debugfs_create functions
  lib: 842: no need to check return value of debugfs_create functions
  debugfs: provide pr_fmt() macro
  debugfs: log errors when something goes wrong
  drivers: s390/cio: Fix compilation warning about const qualifiers
  drivers: Add generic helper to match by of_node
  driver_find_device: Unify the match function with class_find_device()
  bus_find_device: Unify the match callback with class_find_device
  ...
2019-07-12 12:24:03 -07:00
Suzuki K Poulose
65b6668234 drivers: Add generic helper to match by of_node
Add a helper to match device by the of_node. This will be later used
to provide wrappers to the device iterators for {bus/class/driver}_find_device().
Convert other users to reuse this new helper.

Cc: Alan Tull <atull@kernel.org>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: devicetree@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: linux-fpga@vger.kernel.org
Cc: linux-i2c@vger.kernel.org
Cc: linux-spi@vger.kernel.org
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Moritz Fischer <mdf@kernel.org>
Cc: Peter Rosin <peda@axentia.se>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Thor Thayer <thor.thayer@linux.intel.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-24 05:22:31 +02:00
Heikki Krogerus
dad9bb0178 driver core: Add helper device_find_child_by_name()
It looks like the child device is often matched with a name.
This introduces a helper that does it automatically.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-03 10:55:38 +02:00
Borislav Petkov
affada726c driver core: Clarify which counterparts to use to device_add()
It is not absolutely clear from the docs how the cleanup path after
device_add() should look like so spell it out explicitly.

No functional changes, just documentation.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 19:34:54 +02:00
Rafael J. Wysocki
36003d4cf5 driver core: Fix PM-runtime for links added during consumer probe
Commit 4c06c4e6cf ("driver core: Fix possible supplier PM-usage
counter imbalance") introduced a regression that causes suppliers
to be suspended prematurely for device links added during consumer
driver probe if the initial PM-runtime status of the consumer is
"suspended" and the consumer is resumed after adding the link and
before pm_runtime_put_suppliers() is called.  In that case,
pm_runtime_put_suppliers() will drop the rpm_active refcount for
the link by one and (since rpm_active is equal to two after the
preceding consumer resume) the supplier's PM-runtime usage counter
will be decremented, which may cause the supplier to suspend even
though the consumer's PM-runtime status is "active".

For this reason, partially revert commit 4c06c4e6cf as the problem
it tried to fix needs to be addressed somewhat differently, and
change pm_runtime_get_suppliers() and pm_runtime_put_suppliers() so
that the latter only drops rpm_active references acquired by the
former.  [This requires adding a new field to struct device_link,
but I coulnd't find a cleaner way to address the issue that would
work in all cases.]

This causes pm_runtime_put_suppliers() to effectively ignore device
links added during consumer probe, so device_link_add() doesn't need
to worry about ensuring that suppliers will remain active after
pm_runtime_put_suppliers() for links created with DL_FLAG_RPM_ACTIVE
set and it only needs to bump up rpm_active by one for those links,
so pm_runtime_active_link() is not necessary any more.

Fixes: 4c06c4e6cf ("driver core: Fix possible supplier PM-usage counter imbalance")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-20 11:18:07 +01:00
Rafael J. Wysocki
4c06c4e6cf driver core: Fix possible supplier PM-usage counter imbalance
If a stateless device link to a certain supplier with
DL_FLAG_PM_RUNTIME set in the flags is added and then removed by the
consumer driver's probe callback, the supplier's PM-runtime usage
counter will be nonzero after that which effectively causes the
supplier to remain "always on" going forward.

Namely, device_link_add() called to add the link invokes
device_link_rpm_prepare() which notices that the consumer driver is
probing, so it increments the supplier's PM-runtime usage counter
with the assumption that the link will stay around until
pm_runtime_put_suppliers() is called by driver_probe_device(),
but if the link goes away before that point, the supplier's
PM-runtime usage counter will remain nonzero.

To prevent that from happening, first rework pm_runtime_get_suppliers()
and pm_runtime_put_suppliers() to use the rpm_active refounts of device
links and make the latter only drop rpm_active and the supplier's
PM-runtime usage counter for each link by one, unless rpm_active is
one already for it.  Next, modify device_link_add() to bump up the
new link's rpm_active refcount and the suppliers PM-runtime usage
counter by two, to prevent pm_runtime_put_suppliers(), if it is
called subsequently, from suspending the supplier prematurely (in
case its PM-runtime usage counter goes down to 0 in there).

Due to the way rpm_put_suppliers() works, this change does not
affect runtime suspend of the consumer ends of new device links (or,
generally, device links for which DL_FLAG_PM_RUNTIME has just been
set).

Fixes: e2f3cd831a ("driver core: Fix handling of runtime PM flags in device_link_add()")
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-13 09:09:57 +01:00
Rafael J. Wysocki
e7dd40105a driver core: Add device link flag DL_FLAG_AUTOPROBE_CONSUMER
Add a new device link flag, DL_FLAG_AUTOPROBE_CONSUMER, to request the
driver core to probe for a consumer driver automatically after binding
a driver to the supplier device on a persistent managed device link.

As unbinding the supplier driver on a managed device link causes the
consumer driver to be detached from its device automatically, this
flag provides a complementary mechanism which is needed to address
some "composite device" use cases.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-01 10:04:08 +01:00
Rafael J. Wysocki
72175d4ea4 driver core: Make driver core own stateful device links
Even though stateful device links are managed by the driver core in
principle, their creators are allowed and sometimes even expected
to drop references to them via device_link_del() or
device_link_remove(), but that doesn't really play well with the
"persistent" link concept.

If "persistent" managed device links are created from driver
probe callbacks, device_link_add() called to do that will take a
new reference on the link each time the callback runs and those
references will never be dropped, which kind of isn't nice.

This issues arises because of the link reference counting carried
out by device_link_add() for existing links, but that is only done to
avoid deleting device links that may still be necessary, which
shouldn't be a concern for managed (stateful) links.  These device
links are managed by the driver core and whoever creates one of them
will need it at least as long as until the consumer driver is detached
from its device and deleting it may be left to the driver core just
fine.

For this reason, rework device_link_add() to apply the reference
counting to stateless links only and make device_link_del() and
device_link_remove() drop references to stateless links only too.
After this change, if called to add a stateful device link for
a consumer-supplier pair for which a stateful device link is
present already, device_link_add() will return the existing link
without incrementing its reference counter.  Accordingly,
device_link_del() and device_link_remove() will WARN() and do
nothing when called to drop a reference to a stateful link.  Thus,
effectively, all stateful device links will be owned by the driver
core.

In addition, clean up the handling of the link management flags,
DL_FLAG_AUTOREMOVE_CONSUMER and DL_FLAG_AUTOREMOVE_SUPPLIER, so that
(a) they are never set at the same time and (b) if device_link_add()
is called for a consumer-supplier pair with an existing stateful link
between them, the flags of that link will be combined with the flags
passed to device_link_add() to ensure that the life time of the link
is sufficient for all of the callers of device_link_add() for the
same consumer-supplier pair.

Update the device_link_add() kerneldoc comment to reflect the
above changes.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-01 10:04:08 +01:00
Rafael J. Wysocki
a1fdbfbb1d driver core: Do not call rpm_put_suppliers() in pm_runtime_drop_link()
Calling rpm_put_suppliers() from pm_runtime_drop_link() is excessive
as it affects all suppliers of the consumer device and not just the
one pointed to by the device link being dropped.  Worst case it may
cause the consumer device to stop working unexpectedly.  Moreover, in
principle it is racy with respect to runtime PM of the consumer
device.

To avoid these problems drop runtime PM references on the particular
supplier pointed to by the link in question only and do that after
the link has been dropped from the consumer device's list of links to
suppliers, which is in device_link_free().

Fixes: a0504aecba ("PM / runtime: Drop usage count for suppliers at device link removal")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-01 10:04:08 +01:00
Rafael J. Wysocki
15cfb09416 driver core: Fix adding device links to probing suppliers
Currently, it is not valid to add a device link from a consumer
driver ->probe callback to a supplier that is still probing too, but
generally this is a valid use case.  For example, if the consumer has
just acquired a resource that can only be available if the supplier
is functional, adding a device link to that supplier right away
should be safe (and even desirable arguably), but device_link_add()
doesn't handle that case correctly and the initial state of the link
created by it is wrong then.

To address this problem, change the initial state of device links
added between a probing supplier and a probing consumer to
DL_STATE_CONSUMER_PROBE and update device_links_driver_bound() to
skip such links on the supplier side.

With this change, if the supplier probe completes first,
device_links_driver_bound() called for it will skip the link state
update and when it is called for the consumer, the link state will
be updated to "active".  In turn, if the consumer probe completes
first, device_links_driver_bound() called for it will change the
state of the link to "active" and when it is called for the
supplier, the link status update will be skipped.

However, in principle the supplier or consumer probe may still fail
after the link has been added, so modify device_links_no_driver() to
change device links in the "active" or "consumer probe" state to
"dormant" on the supplier side and update __device_links_no_driver()
to change the link state to "available" only if it is "consumer
probe" or "active".

Then, if the supplier probe fails first, the leftover link to the
probing consumer will become "dormant" and device_links_no_driver()
called for the consumer (when its probe fails) will clean it up.
In turn, if the consumer probe fails first, it will either drop the
link, or change its state to "available" and, in the latter case,
when device_links_no_driver() is called for the supplier, it will
update the link state to "dormant".  [If the supplier probe fails,
but the consumer probe succeeds, which should not happen as long as
the consumer driver is correct, the link still will be around, but
it will be "dormant" until the supplier is probed again.]

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-01 10:04:08 +01:00
Rafael J. Wysocki
e2f3cd831a driver core: Fix handling of runtime PM flags in device_link_add()
After commit ead18c23c2 ("driver core: Introduce device links
reference counting"), if there is a link between the given supplier
and the given consumer already, device_link_add() will refcount it
and return it unconditionally without updating its flags.  It is
possible, however, that the second (or any subsequent) caller of
device_link_add() for the same consumer-supplier pair will pass
DL_FLAG_PM_RUNTIME, possibly along with DL_FLAG_RPM_ACTIVE, in flags
to it and the existing link may not behave as expected then.

First, if DL_FLAG_PM_RUNTIME is not set in the existing link's flags
at all, it needs to be set like during the original initialization of
the link.

Second, if DL_FLAG_RPM_ACTIVE is passed to device_link_add() in flags
(in addition to DL_FLAG_PM_RUNTIME), the existing link should to be
updated to reflect the "active" runtime PM configuration of the
consumer-supplier pair and extra care must be taken here to avoid
possible destructive races with runtime PM of the consumer.

To that end, redefine the rpm_active field in struct device_link
as a refcount, initialize it to 1 and make rpm_resume() (for the
consumer) and device_link_add() increment it whenever they acquire
a runtime PM reference on the supplier device.  Accordingly, make
rpm_suspend() (for the consumer) and pm_runtime_clean_up_links()
decrement it and drop runtime PM references to the supplier
device in a loop until rpm_active becones 1 again.

Fixes: ead18c23c2 ("driver core: Introduce device links reference counting")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-01 10:04:08 +01:00
Rafael J. Wysocki
5db25c9eb8 driver core: Do not resume suppliers under device_links_write_lock()
It is incorrect to call pm_runtime_get_sync() under
device_links_write_lock(), because it may end up trying to take
device_links_read_lock() while resuming the target device and that
will deadlock in the non-SRCU case, so avoid that by resuming the
supplier device in device_link_add() before calling
device_links_write_lock().

Fixes: 21d5c57b37 ("PM / runtime: Use device links")
Fixes: baa8809f60 ("PM / runtime: Optimize the use of device links")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-01 10:04:08 +01:00
Rafael J. Wysocki
f265df550a driver core: Avoid careless re-use of existing device links
After commit ead18c23c2 ("driver core: Introduce device links
reference counting"), if there is a link between the given supplier
and the given consumer already, device_link_add() will refcount it
and return it unconditionally.  However, if the flags passed to
it on the second (or any subsequent) attempt to create a device
link between the same consumer-supplier pair are not compatible with
the existing link's flags, that is incorrect.

First off, if the existing link is stateless and the next caller of
device_link_add() for the same consumer-supplier pair wants a
stateful one, or the other way around, the existing link cannot be
returned, because it will not match the expected behavior, so make
device_link_add() dump the stack and return NULL in that case.

Moreover, if the DL_FLAG_AUTOREMOVE_CONSUMER flag is passed to
device_link_add(), its caller will expect its reference to the link
to be dropped automatically on consumer driver removal, which will
not happen if that flag is not set in the link's flags (and
analogously for DL_FLAG_AUTOREMOVE_SUPPLIER).  For this reason, make
device_link_add() update the existing link's flags accordingly
before returning it to the caller.

Fixes: ead18c23c2 ("driver core: Introduce device links reference counting")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-01 10:04:08 +01:00
Rafael J. Wysocki
c8d50986da driver core: Fix DL_FLAG_AUTOREMOVE_SUPPLIER device link flag handling
Change the list walk in device_links_driver_cleanup() to a safe one
to avoid use-after-free when dropping a link from the list during the
walk.

Also, while at it, fix device_link_add() to refuse to create
stateless device links with DL_FLAG_AUTOREMOVE_SUPPLIER set, which is
an invalid combination (setting that flag means that the driver core
should manage the link, so it cannot be stateless), and extend the
kerneldoc comment of device_link_add() to cover the
DL_FLAG_AUTOREMOVE_SUPPLIER flag properly too.

Fixes: 1689cac5b3 ("driver core: Add flag to autoremove device link on supplier unbind")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-01 10:04:08 +01:00
Alexander Duyck
3451a495ef driver core: Establish order of operations for device_add and device_del via bitflag
Add an additional bit flag to the device_private struct named "dead".

This additional flag provides a guarantee that when a device_del is
executed on a given interface an async worker will not attempt to attach
the driver following the earlier device_del call. Previously this
guarantee was not present and could result in the device_del call
attempting to remove a driver from an interface only to have the async
worker attempt to probe the driver later when it finally completes the
asynchronous probe call.

One additional change added was that I pulled the check for dev->driver
out of the __device_attach_driver call and instead placed it in the
__device_attach_async_helper call. This was motivated by the fact that the
only other caller of this, __device_attach, had already taken the
device_lock() and checked for dev->driver. Instead of testing for this
twice in this path it makes more sense to just consolidate the dev->dead
and dev->driver checks together into one set of checks.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-31 14:20:53 +01:00
Yong Wu
0fe6f7874d driver core: Remove the link if there is no driver with AUTO flag
DL_FLAG_AUTOREMOVE_CONSUMER/SUPPLIER means "Remove the link
automatically on consumer/supplier driver unbind", that means we should
remove whole the device_link when there is no this driver no matter what
the ref_count of the link is.

CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-22 14:25:26 +01:00
Jerome Brunet
8a4b326911 driver core: silence device link messages unless debugging
On platforms making a fair use of regulators, the dev_info() messages
coming from the device link function are a bit too verbose. The amount
of message will increase further with the clock framework joining the
device link party.

These messages looks valuable for people debugging device link related
issues, so dev_dbg() looks more appropriate than dev_info().

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-22 14:25:26 +01:00
Wei Yang
570d020012 driver core: move device->knode_class to device_private
As the description of struct device_private says, it stores data which
is private to driver core. And it already has similar fields like:
knode_parent, knode_driver, knode_driver and knode_bus. This look it is
more proper to put knode_class together with those fields to make it
private to driver core.

This patch move device->knode_class to device_private to make it comply
with code convention.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18 16:55:48 +01:00
Linus Torvalds
b07039b79c Driver core patches for 4.21-rc1
Here is the "big" set of driver core patches for 4.21-rc1.
 
 It's not really big, just a number of small changes for some reported
 issues, some documentation updates to hopefully make it harder for
 people to abuse the driver model, and some other minor cleanups.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the "big" set of driver core patches for 4.21-rc1.

  It's not really big, just a number of small changes for some reported
  issues, some documentation updates to hopefully make it harder for
  people to abuse the driver model, and some other minor cleanups.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  mm, memory_hotplug: update a comment in unregister_memory()
  component: convert to DEFINE_SHOW_ATTRIBUTE
  sysfs: Disable lockdep for driver bind/unbind files
  driver core: Add missing dev->bus->need_parent_lock checks
  kobject: return error code if writing /sys/.../uevent fails
  driver core: Move async_synchronize_full call
  driver core: platform: Respect return code of platform_device_register_full()
  kref/kobject: Improve documentation
  drivers/base/memory.c: Use DEVICE_ATTR_RO and friends
  driver core: Replace simple_strto{l,ul} by kstrtou{l,ul}
  kernfs: Improve kernfs_notify() poll notification latency
  kobject: Fix warnings in lib/kobject_uevent.c
  kobject: drop unnecessary cast "%llu" for u64
  driver core: fix comments for device_block_probing()
  driver core: Replace simple_strtol by kstrtoint
2018-12-28 20:44:29 -08:00
Peter Rajnoha
df44b47965 kobject: return error code if writing /sys/.../uevent fails
Propagate error code back to userspace if writing the /sys/.../uevent
file fails. Before, the write operation always returned with success,
even if we failed to recognize the input string or if we failed to
generate the uevent itself.

With the error codes properly propagated back to userspace, we are
able to react in userspace accordingly by not assuming and awaiting
a uevent that is not delivered.

Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-06 16:07:43 +01:00
Ezequiel Garcia
186bddb28f kref/kobject: Improve documentation
The current kref and kobject documentation may be
insufficient to understand these common pitfalls regarding
object lifetime and object releasing.

Add a bit more documentation and improve the warnings
seen by the user, pointing to the right piece of documentation.

Also, it's important to understand that making fun of people
publicly is not at all helpful, doesn't provide any value,
and it's not a healthy way of encouraging developers to do better.

"Mocking mercilessly" will, if anything, make developers feel bad
and go away. This kind of behavior should not be encouraged or justified.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-06 13:57:03 +01:00
Kaitao cheng
f88184bfee driver core: Replace simple_strto{l,ul} by kstrtou{l,ul}
The simple_strto{l,ul} are deprecated, use kstrtou{l,ul} instead.

Signed-off-by: Kaitao cheng <pilgrimtao@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27 12:00:52 +01:00
Heikki Krogerus
59abd83672 drivers: base: Introducing software nodes to the firmware node framework
Software node is a new struct fwnode_handle type that can be
used to describe devices in kernel (software). It is meant
to complement fwnodes representing real firmware nodes when
they are incomplete (for example missing device properties)
and to supply the primary fwnode when the firmware lacks
hardware description for a device completely.

The software node type is really meant to replace the
currently used "property_set" struct fwnode_handle type. The
handling of struct property_set is glued to the generic
device property handling code, and it is not possible to
create a struct property_set independently from the device
that it is bind to. struct property_set is only created when
device properties are added to already initialized struct
device, and control of it is only possible from the generic
property handling code.

Software nodes are instead designed to be created
independently from the device entries (struct device). It
makes them much more flexible, as then the device meant to
be bind to the node can be created at a later time, and from
another location. It is also possible to bind multiple
devices to a single software node if needed.

The software node implementation also includes support for
node hierarchy, which was the main motivation for this
commit. The node hierarchy was something that was requested
for the struct property_set, but it did not seem reasonable
to try to extend the property_set support for that purpose.
struct property_set was really meant only for device
property handling like the name suggests.

Support for struct property_set is not yet removed in this
commit, but it will be in the following one.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-11-26 18:19:11 +01:00
Heikki Krogerus
7847a1455f ACPI / glue: Add acpi_platform_notify() function
Instead of relying on the "platform_notify" callback hook,
introducing separate notification function
acpi_platform_notify() and calling that directly from
drivers core when device entries are added and removed.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-11-26 18:19:11 +01:00
Heikki Krogerus
07de0e86fe drivers core: Prepare support for multiple platform notifications
Since it should be possible to support several hardware
description models at the same time (at least in theory),
for example ACPI and devicetree on a running system, the
platform notifications need to be handled differently.

For now a single "platform_notify" callback function was
used to notify the underlying base system which is in charge
of the hardware description when a new device entry was
added to the system, but that callback is available to only
a single base system at the time. This will add a function
device_platform_notify() and replace all direct
platform_notify() calls with it.

device_platform_notify() will first simply call the
platform_notify() callback, so this commit has no functional
affect, however, the idea is that individual base systems
will put their direct notification calls there instead of
using the platform_notify function pointer.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-11-26 18:19:11 +01:00
Linus Torvalds
a18d783fed Driver core patches for 4.19-rc1
Here are all of the driver core and related patches for 4.19-rc1.
 
 Nothing huge here, just a number of small cleanups and the ability to
 now stop the deferred probing after init happens.
 
 All of these have been in linux-next for a while with only a merge issue
 reported.  That merge issue is in fs/sysfs/group.c and Stephen has
 posted the diff of what it should be to resolve this.  I'll follow up
 with that diff to this pull request.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here are all of the driver core and related patches for 4.19-rc1.

  Nothing huge here, just a number of small cleanups and the ability to
  now stop the deferred probing after init happens.

  All of these have been in linux-next for a while with only a merge
  issue reported"

* tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits)
  base: core: Remove WARN_ON from link dependencies check
  drivers/base: stop new probing during shutdown
  drivers: core: Remove glue dirs from sysfs earlier
  driver core: remove unnecessary function extern declare
  sysfs.h: fix non-kernel-doc comment
  PM / Domains: Stop deferring probe at the end of initcall
  iommu: Remove IOMMU_OF_DECLARE
  iommu: Stop deferring probe at end of initcalls
  pinctrl: Support stopping deferred probe after initcalls
  dt-bindings: pinctrl: add a 'pinctrl-use-default' property
  driver core: allow stopping deferred probe after init
  driver core: add a debugfs entry to show deferred devices
  sysfs: Fix internal_create_group() for named group updates
  base: fix order of OF initialization
  linux/device.h: fix kernel-doc notation warning
  Documentation: update firmware loader fallback reference
  kobject: Replace strncpy with memcpy
  drivers: base: cacheinfo: use OF property_read_u32 instead of get_property,read_number
  kernfs: Replace strncpy with memcpy
  device: Add #define dev_fmt similar to #define pr_fmt
  ...
2018-08-18 11:44:53 -07:00
Linus Torvalds
9a76aba02a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
 "Highlights:

   - Gustavo A. R. Silva keeps working on the implicit switch fallthru
     changes.

   - Support 802.11ax High-Efficiency wireless in cfg80211 et al, From
     Luca Coelho.

   - Re-enable ASPM in r8169, from Kai-Heng Feng.

   - Add virtual XFRM interfaces, which avoids all of the limitations of
     existing IPSEC tunnels. From Steffen Klassert.

   - Convert GRO over to use a hash table, so that when we have many
     flows active we don't traverse a long list during accumluation.

   - Many new self tests for routing, TC, tunnels, etc. Too many
     contributors to mention them all, but I'm really happy to keep
     seeing this stuff.

   - Hardware timestamping support for dpaa_eth/fsl-fman from Yangbo Lu.

   - Lots of cleanups and fixes in L2TP code from Guillaume Nault.

   - Add IPSEC offload support to netdevsim, from Shannon Nelson.

   - Add support for slotting with non-uniform distribution to netem
     packet scheduler, from Yousuk Seung.

   - Add UDP GSO support to mlx5e, from Boris Pismenny.

   - Support offloading of Team LAG in NFP, from John Hurley.

   - Allow to configure TX queue selection based upon RX queue, from
     Amritha Nambiar.

   - Support ethtool ring size configuration in aquantia, from Anton
     Mikaev.

   - Support DSCP and flowlabel per-transport in SCTP, from Xin Long.

   - Support list based batching and stack traversal of SKBs, this is
     very exciting work. From Edward Cree.

   - Busyloop optimizations in vhost_net, from Toshiaki Makita.

   - Introduce the ETF qdisc, which allows time based transmissions. IGB
     can offload this in hardware. From Vinicius Costa Gomes.

   - Add parameter support to devlink, from Moshe Shemesh.

   - Several multiplication and division optimizations for BPF JIT in
     nfp driver, from Jiong Wang.

   - Lots of prepatory work to make more of the packet scheduler layer
     lockless, when possible, from Vlad Buslov.

   - Add ACK filter and NAT awareness to sch_cake packet scheduler, from
     Toke Høiland-Jørgensen.

   - Support regions and region snapshots in devlink, from Alex Vesker.

   - Allow to attach XDP programs to both HW and SW at the same time on
     a given device, with initial support in nfp. From Jakub Kicinski.

   - Add TLS RX offload and support in mlx5, from Ilya Lesokhin.

   - Use PHYLIB in r8169 driver, from Heiner Kallweit.

   - All sorts of changes to support Spectrum 2 in mlxsw driver, from
     Ido Schimmel.

   - PTP support in mv88e6xxx DSA driver, from Andrew Lunn.

   - Make TCP_USER_TIMEOUT socket option more accurate, from Jon
     Maxwell.

   - Support for templates in packet scheduler classifier, from Jiri
     Pirko.

   - IPV6 support in RDS, from Ka-Cheong Poon.

   - Native tproxy support in nf_tables, from Máté Eckl.

   - Maintain IP fragment queue in an rbtree, but optimize properly for
     in-order frags. From Peter Oskolkov.

   - Improvde handling of ACKs on hole repairs, from Yuchung Cheng"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1996 commits)
  bpf: test: fix spelling mistake "REUSEEPORT" -> "REUSEPORT"
  hv/netvsc: Fix NULL dereference at single queue mode fallback
  net: filter: mark expected switch fall-through
  xen-netfront: fix warn message as irq device name has '/'
  cxgb4: Add new T5 PCI device ids 0x50af and 0x50b0
  net: dsa: mv88e6xxx: missing unlock on error path
  rds: fix building with IPV6=m
  inet/connection_sock: prefer _THIS_IP_ to current_text_addr
  net: dsa: mv88e6xxx: bitwise vs logical bug
  net: sock_diag: Fix spectre v1 gadget in __sock_diag_cmd()
  ieee802154: hwsim: using right kind of iteration
  net: hns3: Add vlan filter setting by ethtool command -K
  net: hns3: Set tx ring' tc info when netdev is up
  net: hns3: Remove tx ring BD len register in hns3_enet
  net: hns3: Fix desc num set to default when setting channel
  net: hns3: Fix for phy link issue when using marvell phy driver
  net: hns3: Fix for information of phydev lost problem when down/up
  net: hns3: Fix for command format parsing error in hclge_is_all_function_id_zero
  net: hns3: Add support for serdes loopback selftest
  bnxt_en: take coredump_record structure off stack
  ...
2018-08-15 15:04:25 -07:00
Linus Torvalds
b018fc9800 Power management updates for 4.19-rc1
- Add a new framework for CPU idle time injection (Daniel Lezcano).
 
  - Add AVS support to the armada-37xx cpufreq driver (Gregory CLEMENT).
 
  - Add support for current CPU frequency reporting to the ACPI CPPC
    cpufreq driver (George Cherian).
 
  - Rework the cooling device registration in the imx6q/thermal
    driver (Bastian Stender).
 
  - Make the pcc-cpufreq driver refuse to work with dynamic
    scaling governors on systems with many CPUs to avoid
    scalability issues with it (Rafael Wysocki).
 
  - Fix the intel_pstate driver to report different maximum CPU
    frequencies on systems where they really are different and to
    ignore the turbo active ratio if hardware-managend P-states (HWP)
    are in use; make it use the match_string() helper (Xie Yisheng,
    Srinivas Pandruvada).
 
  - Fix a minor deferred probe issue in the qcom-kryo cpufreq
    driver (Niklas Cassel).
 
  - Add a tracepoint for the tracking of frequency limits changes
    (from Andriod) to the cpufreq core (Ruchi Kandoi).
 
  - Fix a circular lock dependency between CPU hotplug and sysfs
    locking in the cpufreq core reported by lockdep (Waiman Long).
 
  - Avoid excessive error reports on driver registration failures
    in the ARM cpuidle driver (Sudeep Holla).
 
  - Add a new device links flag to the driver core to make links go
    away automatically on supplier driver removal (Vivek Gautam).
 
  - Eliminate potential race condition between system-wide power
    management transitions and system shutdown (Pingfan Liu).
 
  - Add a quirk to save NVS memory on system suspend for the ASUS
    1025C laptop (Willy Tarreau).
 
  - Make more systems use suspend-to-idle (instead of ACPI S3) by
    default (Tristian Celestin).
 
  - Get rid of stack VLA usage in the low-level hibernation code on
    64-bit x86 (Kees Cook).
 
  - Fix error handling in the hibernation core and mark an expected
    fall-through switch in it (Chengguang Xu, Gustavo Silva).
 
  - Extend the generic power domains (genpd) framework to support
    attaching a device to a power domain by name (Ulf Hansson).
 
  - Fix device reference counting and user limits initialization in
    the devfreq core (Arvind Yadav, Matthias Kaehlcke).
 
  - Fix a few issues in the rk3399_dmc devfreq driver and improve its
    documentation (Enric Balletbo i Serra, Lin Huang, Nick Milner).
 
  - Drop a redundant error message from the exynos-ppmu devfreq driver
    (Markus Elfring).
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Merge tag 'pm-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "These add a new framework for CPU idle time injection, to be used by
  all of the idle injection code in the kernel in the future, fix some
  issues and add a number of relatively small extensions in multiple
  places.

  Specifics:

   - Add a new framework for CPU idle time injection (Daniel Lezcano).

   - Add AVS support to the armada-37xx cpufreq driver (Gregory
     CLEMENT).

   - Add support for current CPU frequency reporting to the ACPI CPPC
     cpufreq driver (George Cherian).

   - Rework the cooling device registration in the imx6q/thermal driver
     (Bastian Stender).

   - Make the pcc-cpufreq driver refuse to work with dynamic scaling
     governors on systems with many CPUs to avoid scalability issues
     with it (Rafael Wysocki).

   - Fix the intel_pstate driver to report different maximum CPU
     frequencies on systems where they really are different and to
     ignore the turbo active ratio if hardware-managend P-states (HWP)
     are in use; make it use the match_string() helper (Xie Yisheng,
     Srinivas Pandruvada).

   - Fix a minor deferred probe issue in the qcom-kryo cpufreq driver
     (Niklas Cassel).

   - Add a tracepoint for the tracking of frequency limits changes (from
     Andriod) to the cpufreq core (Ruchi Kandoi).

   - Fix a circular lock dependency between CPU hotplug and sysfs
     locking in the cpufreq core reported by lockdep (Waiman Long).

   - Avoid excessive error reports on driver registration failures in
     the ARM cpuidle driver (Sudeep Holla).

   - Add a new device links flag to the driver core to make links go
     away automatically on supplier driver removal (Vivek Gautam).

   - Eliminate potential race condition between system-wide power
     management transitions and system shutdown (Pingfan Liu).

   - Add a quirk to save NVS memory on system suspend for the ASUS 1025C
     laptop (Willy Tarreau).

   - Make more systems use suspend-to-idle (instead of ACPI S3) by
     default (Tristian Celestin).

   - Get rid of stack VLA usage in the low-level hibernation code on
     64-bit x86 (Kees Cook).

   - Fix error handling in the hibernation core and mark an expected
     fall-through switch in it (Chengguang Xu, Gustavo Silva).

   - Extend the generic power domains (genpd) framework to support
     attaching a device to a power domain by name (Ulf Hansson).

   - Fix device reference counting and user limits initialization in the
     devfreq core (Arvind Yadav, Matthias Kaehlcke).

   - Fix a few issues in the rk3399_dmc devfreq driver and improve its
     documentation (Enric Balletbo i Serra, Lin Huang, Nick Milner).

   - Drop a redundant error message from the exynos-ppmu devfreq driver
     (Markus Elfring)"

* tag 'pm-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (35 commits)
  PM / reboot: Eliminate race between reboot and suspend
  PM / hibernate: Mark expected switch fall-through
  cpufreq: intel_pstate: Ignore turbo active ratio in HWP
  cpufreq: Fix a circular lock dependency problem
  cpu/hotplug: Add a cpus_read_trylock() function
  x86/power/hibernate_64: Remove VLA usage
  cpufreq: trace frequency limits change
  cpufreq: intel_pstate: Show different max frequency with turbo 3 and HWP
  cpufreq: pcc-cpufreq: Disable dynamic scaling on many-CPU systems
  cpufreq: qcom-kryo: Silently error out on EPROBE_DEFER
  cpufreq / CPPC: Add cpuinfo_cur_freq support for CPPC
  cpufreq: armada-37xx: Add AVS support
  dt-bindings: marvell: Add documentation for the Armada 3700 AVS binding
  PM / devfreq: rk3399_dmc: Fix duplicated opp table on reload.
  PM / devfreq: Init user limits from OPP limits, not viceversa
  PM / devfreq: rk3399_dmc: fix spelling mistakes.
  PM / devfreq: rk3399_dmc: do not print error when get supply and clk defer.
  dt-bindings: devfreq: rk3399_dmc: move interrupts to be optional.
  PM / devfreq: rk3399_dmc: remove wait for dcf irq event.
  dt-bindings: clock: add rk3399 DDR3 standard speed bins.
  ...
2018-08-14 13:12:24 -07:00
Mark Brown
d22d59362b
Merge branch 'regulator-4.19' into regulator-next 2018-08-10 17:31:24 +01:00
Benjamin Gaignard
e16f4f3e0b base: core: Remove WARN_ON from link dependencies check
In some cases the link between between customer and supplier
already exist, for example when a device use its parent as a supplier.
Do not warn about already existing dependencies because device_link_add()
takes care of this case.

Link: http://lkml.kernel.org/r/20180709111753eucas1p1f32e66fb2f7ea3216097cd72a132355d~-rzycA5Rg0378203782eucas1p1C@eucas1p1.samsung.com

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-21 09:51:44 +02:00
Pingfan Liu
3297c8fc65 drivers/base: stop new probing during shutdown
There is a race window in device_shutdown(), which may cause
-1. parent device shut down before child or
-2. no shutdown on a new probing device.

For 1st, taking the following scenario:
         device_shutdown                        new plugin device
  list_del_init(parent_dev);
  spin_unlock(list_lock);
                                                  device_add(child)
                                                  probe child
  shutdown parent_dev
       --> now child is on the tail of devices_kset

For 2nd, taking the following scenario:
         device_shutdown                        new plugin device
                                                  device_add(dev)
  device_lock(dev);
  ...
  device_unlock(dev);
                                                  probe dev
       --> now, the new occurred dev has no opportunity to shutdown

To fix this race issue, just prevent the new probing request. With this
logic, device_shutdown() is more similar to dpm_prepare().

Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-21 09:51:44 +02:00
Dmitry Torokhov
9944e894c1 driver core: set up ownership of class devices in sysfs
Plumb in get_ownership() callback for devices belonging to a class so that
they can be created with uid/gid different from global root. This will
allow network devices in a container to belong to container's root and not
global root.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-20 23:44:35 -07:00
Benjamin Herrenschmidt
726e410979 drivers: core: Remove glue dirs from sysfs earlier
For devices with a class, we create a "glue" directory between
the parent device and the new device with the class name.

This directory is never "explicitely" removed when empty however,
this is left to the implicit sysfs removal done by kobject_release()
when the object loses its last reference via kobject_put().

This is problematic because as long as it's not been removed from
sysfs, it is still present in the class kset and in sysfs directory
structure.

The presence in the class kset exposes a use after free bug fixed
by the previous patch, but the presence in sysfs means that until
the kobject is released, which can take a while (especially with
kobject debugging), any attempt at re-creating such as binding a
new device for that class/parent pair, will result in a sysfs
duplicate file name error.

This fixes it by instead doing an explicit kobject_del() when
the glue dir is empty, by keeping track of the number of
child devices of the gluedir.

This is made easy by the fact that all glue dir operations are
done with a global mutex, and there's already a function
(cleanup_glue_dir) called in all the right places taking that
mutex that can be enhanced for this. It appears that this was
in fact the intent of the function, but the implementation was
wrong.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-16 13:42:02 +02:00
Shaokun Zhang
46d3a03781 driver core: remove unnecessary function extern declare
device_private_init is called only in core.c, extern declare is
unnecessary and make it static.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-16 13:32:20 +02:00
Vivek Gautam
1689cac5b3 driver core: Add flag to autoremove device link on supplier unbind
Add a flag to autoremove the device links on supplier driver
unbind. This obviates the need to explicitly delete the link
in the remove path.
We remove these links only when the supplier's link to its
consumers has gone to DL_STATE_SUPPLIER_UNBIND state.

Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Suggested-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-07-09 12:14:31 +02:00
Vivek Gautam
e88728f46c driver core: Rename flag AUTOREMOVE to AUTOREMOVE_CONSUMER
Now that we want to add another flag to autoremove the device link
on supplier unbind, it's fair to rename the existing flag from
DL_FLAG_AUTOREMOVE to DL_FLAG_AUTOREMOVE_CONSUMER so that we can
add similar flag for supplier later.
And, while we are touching device.h, fix a doc build warning.

Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-07-09 12:14:31 +02:00
Joe Perches
663336ee26 device: Add #define dev_fmt similar to #define pr_fmt
Add a prefixing macro to dev_<level> uses similar to the pr_fmt
prefixing macro used in pr_<level> calls.

This can help avoid some string duplication in dev_<level> uses.

The default, like pr_fmt, is an empty #define dev_fmt(fmt) fmt

Rename the existing dev_<level> functions to _dev_<level> and
introduce #define dev_<level> _dev_<level> macros that use the
new #define dev_fmt

Miscellanea:

o Consistently use #defines with fmt, ... and ##__VA_ARGS__
o Remove unnecessary externs

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-06 17:50:19 +02:00
pascal paillet
d8842211b6
driver core: Add device_link_remove function
Device_link_remove uses the same arguments than device_link_add. The Goal
is to avoid storing the link pointer.

Signed-off-by: pascal paillet <p.paillet@st.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-05 18:55:08 +01:00
Rafael J. Wysocki
47e5abfb54 PM / core: Fix supplier device runtime PM usage counter imbalance
If a device link is added via device_link_add() by the driver of the
link's consumer device, the supplier's runtime PM usage counter is
going to be dropped by the pm_runtime_put_suppliers() call in
driver_probe_device().  However, in that case it is not incremented
unless the supplier driver is already present and the link is not
stateless.  That leads to a runtime PM usage counter imbalance for
the supplier device in a few cases.

To prevent that from happening, bump up the supplier runtime
PM usage counter in device_link_add() for all links with the
DL_FLAG_PM_RUNTIME flag set that are added at the consumer probe
time.  Use pm_runtime_get_noresume() for that as the callers of
device_link_add() who want the supplier to be resumed by it are
expected to pass DL_FLAG_RPM_ACTIVE in flags to it anyway, but
additionally resume the supplier if the link is added during
consumer driver probe to retain the existing behavior for the
callers depending on it.

Fixes: 21d5c57b37 (PM / runtime: Use device links)
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: 4.10+ <stable@vger.kernel.org> # 4.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-06-14 10:01:52 +02:00
Linus Torvalds
ec064d3c6b Driver core changes for 4.18-rc1
Here is the driver core patchset for 4.18-rc1.
 
 The large chunk of these are firmware core documentation and api
 updates.  Nothing major there, just better descriptions for others to be
 able to understand the firmware code better.  There's also a user for a
 new firmware api call.
 
 Other than that, there are some minor updates for debugfs, kernfs, and
 the driver core itself.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the driver core patchset for 4.18-rc1.

  The large chunk of these are firmware core documentation and api
  updates. Nothing major there, just better descriptions for others to
  be able to understand the firmware code better. There's also a user
  for a new firmware api call.

  Other than that, there are some minor updates for debugfs, kernfs, and
  the driver core itself.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (23 commits)
  driver core: hold dev's parent lock when needed
  driver-core: return EINVAL error instead of BUG_ON()
  driver core: add __printf verification to device_create_groups_vargs
  mm: memory_hotplug: use put_device() if device_register fail
  base: core: fix typo 'can by' to 'can be'
  debugfs: inode: debugfs_create_dir uses mode permission from parent
  debugfs: Re-use kstrtobool_from_user()
  Documentation: clarify firmware_class provenance and why we can't rename the module
  Documentation: remove stale firmware API reference
  Documentation: fix few typos and clarifications for the firmware loader
  ath10k: re-enable the firmware fallback mechanism for testmode
  ath10k: use firmware_request_nowarn() to load firmware
  firmware: add firmware_request_nowarn() - load firmware without warnings
  firmware_loader: make firmware_fallback_sysfs() print more useful
  firmware_loader: move kconfig FW_LOADER entries to its own file
  firmware_loader: replace ---help--- with help
  firmware_loader: enhance Kconfig documentation over FW_LOADER
  firmware_loader: document firmware_sysfs_fallback()
  firmware: rename fw_sysfs_fallback to firmware_fallback_sysfs()
  firmware: use () to terminate kernel-doc function names
  ...
2018-06-05 16:29:19 -07:00
Mathieu Malaterre
6a8b55d7f2 driver core: add __printf verification to device_create_groups_vargs
__printf is useful to verify format and arguments. Remove the following
warning (with W=1):

  drivers/base/core.c:2435:2: warning: function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]

Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 16:59:21 +02:00
Wolfram Sang
13509860ef base: core: fix typo 'can by' to 'can be'
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 16:48:59 +02:00
Tetsuo Handa
84d0c27d62 driver core: Don't ignore class_dir_create_and_add() failure.
syzbot is hitting WARN() at kernfs_add_one() [1].
This is because kernfs_create_link() is confused by previous device_add()
call which continued without setting dev->kobj.parent field when
get_device_parent() failed by memory allocation fault injection.
Fix this by propagating the error from class_dir_create_and_add() to
the calllers of get_device_parent().

[1] https://syzkaller.appspot.com/bug?id=fae0fb607989ea744526d1c082a5b8de6529116f

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+df47f81c226b31d89fb1@syzkaller.appspotmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 16:37:46 +02:00
Feng Kan
494fd7b7ad PM / core: fix deferred probe breaking suspend resume order
When bridge and its endpoint is enumerated the devices are added to the
dpm list. Afterward, the bridge defers probe when IOMMU is not ready.
This causes the bridge to be moved to the end of the dpm list when
deferred probe kicks in. The order of the dpm list for bridge and
endpoint is reversed.

Add reordering code to move the bridge and its children and consumers to
the end of the pm list so the order for suspend and resume is not altered.
The code also move device and its children and consumers to the tail of
device_kset list if it is registered.

Signed-off-by: Toan Le <toanle@apm.com>
Signed-off-by: Feng Kan <fkan@apm.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-24 12:18:25 +02:00
Lukas Wunner
ead18c23c2 driver core: Introduce device links reference counting
If device_link_add() is invoked multiple times with the same supplier
and consumer combo, it will create the link on first addition and
return a pointer to the already existing link on all subsequent
additions.

The semantics for device_link_del() are quite different, it deletes
the link unconditionally, so multiple invocations are not allowed.

In other words, this snippet ...

    struct device *dev1, *dev2;
    struct device_link *link1, *link2;

    link1 = device_link_add(dev1, dev2, 0);
    link2 = device_link_add(dev1, dev2, 0);

    device_link_del(link1);
    device_link_del(link2);

... causes the following crash:

    WARNING: CPU: 4 PID: 2686 at drivers/base/power/runtime.c:1611 pm_runtime_drop_link+0x40/0x50
    [...]
    list_del corruption, 0000000039b800a4->prev is LIST_POISON2 (00000000ecf79852)
    kernel BUG at lib/list_debug.c:50!

The issue isn't as arbitrary as it may seem:  Imagine a device link
which is added in both the supplier's and the consumer's ->probe hook.
The two drivers can't just call device_link_del() in their ->remove hook
without coordination.

Fix by counting multiple additions and dropping the device link only
when the last addition is unwound.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-02-27 18:10:42 +01:00
Lukas Wunner
433986c2c2 PM / runtime: Update links_count also if !CONFIG_SRCU
Commit baa8809f60 (PM / runtime: Optimize the use of device links)
added an invocation of pm_runtime_drop_link() to __device_link_del().
However there are two variants of that function, one for CONFIG_SRCU and
another for !CONFIG_SRCU, and the commit only modified the former.

Fixes: baa8809f60 (PM / runtime: Optimize the use of device links)
Cc: v4.10+ <stable@vger.kernel.org> # v4.10+
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-02-12 11:12:58 +01:00
Linus Torvalds
ab486bc9a5 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
Pull printk updates from Petr Mladek:

 - Add a console_msg_format command line option:

     The value "default" keeps the old "[time stamp] text\n" format. The
     value "syslog" allows to see the syslog-like "<log
     level>[timestamp] text" format.

     This feature was requested by people doing regression tests, for
     example, 0day robot. They want to have both filtered and full logs
     at hands.

 - Reduce the risk of softlockup:

     Pass the console owner in a busy loop.

     This is a new approach to the old problem. It was first proposed by
     Steven Rostedt on Kernel Summit 2017. It marks a context in which
     the console_lock owner calls console drivers and could not sleep.
     On the other side, printk() callers could detect this state and use
     a busy wait instead of a simple console_trylock(). Finally, the
     console_lock owner checks if there is a busy waiter at the end of
     the special context and eventually passes the console_lock to the
     waiter.

     The hand-off works surprisingly well and helps in many situations.
     Well, there is still a possibility of the softlockup, for example,
     when the flood of messages stops and the last owner still has too
     much to flush.

     There is increasing number of people having problems with
     printk-related softlockups. We might eventually need to get better
     solution. Anyway, this looks like a good start and promising
     direction.

 - Do not allow to schedule in console_unlock() called from printk():

     This reverts an older controversial commit. The reschedule helped
     to avoid softlockups. But it also slowed down the console output.
     This patch is obsoleted by the new console waiter logic described
     above. In fact, the reschedule made the hand-off less effective.

 - Deprecate "%pf" and "%pF" format specifier:

     It was needed on ia64, ppc64 and parisc64 to dereference function
     descriptors and show the real function address. It is done
     transparently by "%ps" and "pS" format specifier now.

     Sergey Senozhatsky found that all the function descriptors were in
     a special elf section and could be easily detected.

 - Remove printk_symbol() API:

     It has been obsoleted by "%pS" format specifier, and this change
     helped to remove few continuous lines and a less intuitive old API.

 - Remove redundant memsets:

     Sergey removed unnecessary memset when processing printk.devkmsg
     command line option.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (27 commits)
  printk: drop redundant devkmsg_log_str memsets
  printk: Never set console_may_schedule in console_trylock()
  printk: Hide console waiter logic into helpers
  printk: Add console owner and waiter logic to load balance console writes
  kallsyms: remove print_symbol() function
  checkpatch: add pF/pf deprecation warning
  symbol lookup: introduce dereference_symbol_descriptor()
  parisc64: Add .opd based function descriptor dereference
  powerpc64: Add .opd based function descriptor dereference
  ia64: Add .opd based function descriptor dereference
  sections: split dereference_function_descriptor()
  openrisc: Fix conflicting types for _exext and _stext
  lib: do not use print_symbol()
  irq debug: do not use print_symbol()
  sysfs: do not use print_symbol()
  drivers: do not use print_symbol()
  x86: do not use print_symbol()
  unicore32: do not use print_symbol()
  sh: do not use print_symbol()
  mn10300: do not use print_symbol()
  ...
2018-02-01 13:36:15 -08:00
Sergey Senozhatsky
a52668c674 drivers: do not use print_symbol()
print_symbol() is a very old API that has been obsoleted by %pS format
specifier in a normal printk() call.

Replace print_symbol() with a direct printk("%pS") call.

Link: http://lkml.kernel.org/r/20171211125025.2270-10-sergey.senozhatsky@gmail.com
To: Andrew Morton <akpm@linux-foundation.org>
To: Russell King <linux@armlinux.org.uk>
To: Catalin Marinas <catalin.marinas@arm.com>
To: Mark Salter <msalter@redhat.com>
To: Tony Luck <tony.luck@intel.com>
To: David Howells <dhowells@redhat.com>
To: Yoshinori Sato <ysato@users.sourceforge.jp>
To: Guan Xuetao <gxt@mprc.pku.edu.cn>
To: Borislav Petkov <bp@alien8.de>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Thomas Gleixner <tglx@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
To: Vineet Gupta <vgupta@synopsys.com>
To: Fengguang Wu <fengguang.wu@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-am33-list@redhat.com
Cc: linux-sh@vger.kernel.org
Cc: linux-edac@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
[pmladek@suse.com: updated commit message]
Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-01-05 15:23:59 +01:00
Gimcuan Hui
93ead7c948 drivers: base: omit redundant interations
When error happens, these interators return the error, no interation should
be continued, so make the change for getting out of while immediately.

Signed-off-by: Gimcuan Hui <gimcuan@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-18 16:47:27 +01:00
Greg Kroah-Hartman
3282570990 driver core: Remove redundant license text
Now that the SPDX tag is in all driver core files, that identifies the
license in a specific and legally-defined manner.  So the extra GPL text
wording can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07 18:36:44 +01:00
Greg Kroah-Hartman
989d42e85d driver core: add SPDX identifiers to all driver core files
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the driver core files files with the correct SPDX license
identifier based on the license text in the file itself.  The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07 18:36:43 +01:00
Linus Torvalds
b9743042b3 Driver core patches for 4.15-rc1
Here is the set of driver core / debugfs patches for 4.15-rc1.
 
 Not many here, mostly all are debugfs fixes to resolve some
 long-reported problems with files going away with references to them in
 userspace.  There's also some SPDX cleanups for the debugfs code, as
 well as a few other minor driver core changes for issues reported by
 people.
 
 All of these have been in linux-next for a week or more with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the set of driver core / debugfs patches for 4.15-rc1.

  Not many here, mostly all are debugfs fixes to resolve some
  long-reported problems with files going away with references to them
  in userspace. There's also some SPDX cleanups for the debugfs code, as
  well as a few other minor driver core changes for issues reported by
  people.

  All of these have been in linux-next for a week or more with no
  reported issues"

* tag 'driver-core-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver core: Fix device link deferred probe
  debugfs: Remove redundant license text
  debugfs: add SPDX identifiers to all debugfs files
  debugfs: defer debugfs_fsdata allocation to first usage
  debugfs: call debugfs_real_fops() only after debugfs_file_get()
  debugfs: purge obsolete SRCU based removal protection
  IB/hfi1: convert to debugfs_file_get() and -put()
  debugfs: convert to debugfs_file_get() and -put()
  debugfs: debugfs_real_fops(): drop __must_hold sparse annotation
  debugfs: implement per-file removal protection
  debugfs: add support for more elaborate ->d_fsdata
  driver core: Move device_links_purge() after bus_remove_device()
  arch_topology: Fix section miss match warning due to free_raw_capacity()
  driver-core: pr_err() strings should end with newlines
2017-11-16 08:55:30 -08:00
Linus Torvalds
37cb8e1f8e DeviceTree for 4.15:
- kbuild cleanups and improvements for dtbs
 
 - Code clean-up of overlay code and fixing for some long standing memory
   leak and race condition in applying overlays
 
 - Improvements to DT memory usage making sysfs/kobjects optional and
   skipping unflattening of disabled nodes. This is part of kernel
   tinification efforts.
 
 - Final piece of removing storing the full path for every DT node. The
   prerequisite conversion of printk's to use device_node format
   specifier happened in 4.14.
 
 - Sync with current upstream dtc. This brings additional checks to dtb
   compiling.
 
 - Binding doc tree wide removal of leading 0s from examples
 
 - RTC binding documentation adding missing devices and some
   consolidation of duplicated bindings
 
 - Vendor prefix documentation for nutsboard, Silicon Storage Technology,
   shimafuji, Tecon Microprocessor Technologies, DH electronics GmbH,
   Opal Kelly, and Next Thing
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Merge tag 'devicetree-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull DeviceTree updates from Rob Herring:
 "A bigger diffstat than usual with the kbuild changes and a tree wide
  fix in the binding documentation.

  Summary:

   - kbuild cleanups and improvements for dtbs

   - Code clean-up of overlay code and fixing for some long standing
     memory leak and race condition in applying overlays

   - Improvements to DT memory usage making sysfs/kobjects optional and
     skipping unflattening of disabled nodes. This is part of kernel
     tinification efforts.

   - Final piece of removing storing the full path for every DT node.
     The prerequisite conversion of printk's to use device_node format
     specifier happened in 4.14.

   - Sync with current upstream dtc. This brings additional checks to
     dtb compiling.

   - Binding doc tree wide removal of leading 0s from examples

   - RTC binding documentation adding missing devices and some
     consolidation of duplicated bindings

   - Vendor prefix documentation for nutsboard, Silicon Storage
     Technology, shimafuji, Tecon Microprocessor Technologies, DH
     electronics GmbH, Opal Kelly, and Next Thing"

* tag 'devicetree-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (55 commits)
  dt-bindings: usb: add #phy-cells to usb-nop-xceiv
  dt-bindings: Remove leading zeros from bindings notation
  kbuild: handle dtb-y and CONFIG_OF_ALL_DTBS natively in Makefile.lib
  MIPS: dts: remove bogus bcm96358nb4ser.dtb from dtb-y entry
  kbuild: clean up *.dtb and *.dtb.S patterns from top-level Makefile
  .gitignore: move *.dtb and *.dtb.S patterns to the top-level .gitignore
  .gitignore: sort normal pattern rules alphabetically
  dt-bindings: add vendor prefix for Next Thing Co.
  scripts/dtc: Update to upstream version v1.4.5-6-gc1e55a5513e9
  of: dynamic: fix memory leak related to properties of __of_node_dup
  of: overlay: make pr_err() string unique
  of: overlay: pr_err from return NOTIFY_OK to overlay apply/remove
  of: overlay: remove unneeded check for NULL kbasename()
  of: overlay: remove a dependency on device node full_name
  of: overlay: simplify applying symbols from an overlay
  of: overlay: avoid race condition between applying multiple overlays
  of: overlay: loosen overly strict phandle clash check
  of: overlay: expand check of whether overlay changeset can be removed
  of: overlay: detect cases where device tree may become corrupt
  of: overlay: minor restructuring
  ...
2017-11-14 18:25:40 -08:00
Mark Rutland
6aa7de0591 locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE()
Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.

For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.

However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:

----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()

// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch

virtual patch

@ depends on patch @
expression E1, E2;
@@

- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)

@ depends on patch @
expression E;
@@

- ACCESS_ONCE(E)
+ READ_ONCE(E)
----

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-25 11:01:08 +02:00
Jeffy Chen
2ec1615017 driver core: Move device_links_purge() after bus_remove_device()
The current ordering of code in device_del() triggers a WARN_ON()
in device_links_purge(), because of an unexpected link status.

The device_links_unbind_consumers() call in device_release_driver()
has to take place before device_links_purge() for the status of all
links to be correct, so move the device_links_purge() call in
device_del() after the invocation of bus_remove_device() which calls
device_release_driver().

Fixes: 9ed9895370 (driver core: Functional dependencies tracking support)
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-20 16:33:13 +02:00
Rob Herring
0c3c234b95 of: wrap accesses to device_node kobject
In preparation to make kobject element in struct device_node optional,
provide and use a macro to return the kobject pointer. The only user
outside the DT core is the driver core.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-16 13:37:38 -05:00
Michal Suchanek
7521621e60 Do not disable driver and bus shutdown hook when class shutdown hook is set.
As seen from the implementation of the single class shutdown hook this
is not very sound design.

Rename the class shutdown hook to shutdown_pre to make it clear it runs
before the driver shutdown hook.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28 18:02:46 +02:00
Greg Kroah-Hartman
1af824f085 Merge branch 'bind_unbind' into driver-core-next
This merges the bind_unbind driver core feature into the
driver-core-next branch.  bind_unbind is a branch so that others can
pull and work off of it safely.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-22 12:00:15 +02:00
Dmitry Torokhov
57b8ff070f driver core: add devm_device_add_group() and friends
Many drivers create additional driver-specific device attributes when
binding to the device, and providing managed version of
device_create_group() will simplify unbinding and error handling in probe
path for such drivers.

Without managed version driver writers either have to mix manual and
managed resources, which is prone to errors, or open-code this function by
providing a wrapper to device_add_group() and use it with devm_add_action()
or devm_add_action_or_reset().

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-22 11:59:23 +02:00
Dmitry Torokhov
a7670d425b driver core: make device_{add|remove}_groups() public
Many drivers create additional driver-specific device attributes when
binding to the device. To avoid them calling SYSFS API directly, let's
export these helpers.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-22 11:59:23 +02:00
Josh Zimmerman
f77af15165 Add "shutdown" to "struct class".
The TPM class has some common shutdown code that must be executed for
all drivers. This adds some needed functionality for that.

Signed-off-by: Josh Zimmerman <joshz@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Fixes: 74d6b3ceaa ("tpm: fix suspend/resume paths for TPM 2.0")
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-07-07 09:49:24 +10:00
Linus Torvalds
974668417b driver core patches for 4.13-rc1
Here is the big driver core update for 4.13-rc1.
 
 The large majority of this is a lot of cleanup of old fields in the
 driver core structures and their remaining usages in random drivers.
 All of those fixes have been reviewed by the various subsystem
 maintainers.  There's also some small firmware updates in here, a new
 kobject uevent api interface that makes userspace interaction easier,
 and a few other minor things.
 
 All of these have been in linux-next for a long while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the big driver core update for 4.13-rc1.

  The large majority of this is a lot of cleanup of old fields in the
  driver core structures and their remaining usages in random drivers.
  All of those fixes have been reviewed by the various subsystem
  maintainers. There's also some small firmware updates in here, a new
  kobject uevent api interface that makes userspace interaction easier,
  and a few other minor things.

  All of these have been in linux-next for a long while with no reported
  issues"

* tag 'driver-core-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (56 commits)
  arm: mach-rpc: ecard: fix build error
  zram: convert remaining CLASS_ATTR() to CLASS_ATTR_RO()
  driver-core: remove struct bus_type.dev_attrs
  powerpc: vio_cmo: use dev_groups and not dev_attrs for bus_type
  powerpc: vio: use dev_groups and not dev_attrs for bus_type
  USB: usbip: convert to use DRIVER_ATTR_RW
  s390: drivers: convert to use DRIVER_ATTR_RO/WO
  platform: thinkpad_acpi: convert to use DRIVER_ATTR_RO/RW
  pcmcia: ds: convert to use DRIVER_ATTR_RO
  wireless: ipw2x00: convert to use DRIVER_ATTR_RW
  net: ehea: convert to use DRIVER_ATTR_RO
  net: caif: convert to use DRIVER_ATTR_RO
  TTY: hvc: convert to use DRIVER_ATTR_RW
  PCI: pci-driver: convert to use DRIVER_ATTR_WO
  IB: nes: convert to use DRIVER_ATTR_RW
  HID: hid-core: convert to use DRIVER_ATTR_RO and drv_groups
  arm: ecard: fix dev_groups patch typo
  tty: serdev: use dev_groups and not dev_attrs for bus_type
  sparc: vio: use dev_groups and not dev_attrs for bus_type
  hid: intel-ish-hid: use dev_groups and not dev_attrs for bus_type
  ...
2017-07-03 20:27:48 -07:00
Johan Hovold
4e75e1d7da driver core: add helper to reuse a device-tree node
Add a helper function to be used when reusing the device-tree node of
another device.

It is fairly common for drivers to reuse the device-tree node of a
parent (or other ancestor) device when creating class or bus devices
(e.g. gpio chips, i2c adapters, iio chips, spi masters, serdev, phys,
usb root hubs). But reusing a device-tree node may cause problems if the
new device is later probed as for example driver core would currently
attempt to reinitialise an already active associated pinmux
configuration.

Other potential issues include the platform-bus code unconditionally
dropping the device-tree node reference in its device destructor,
reinitialisation of other bus-managed resources such as clocks, and the
recently added DMA-setup in driver core.

Note that for most examples above this is currently not an issue as the
devices are never probed, but this is a problem for the USB bus which
has recently gained device-tree support. This was discovered and
worked-around in a rather ad-hoc fashion by commit dc5878abf4 ("usb:
core: move root hub's device node assignment after it is added to bus")
by not setting the of_node pointer until after the root-hub device has
been registered.

Instead we can allow devices to reuse a device-tree node by setting a
flag in their struct device that can be used by core, bus and driver
code to avoid resources from being over-allocated.

Note that the helper also grabs an extra reference to the device node,
which specifically balances the unconditional put in the platform-device
destructor.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-13 11:07:32 +02:00
Peter Rajnoha
f36776fafb kobject: support passing in variables for synthetic uevents
This patch makes it possible to pass additional arguments in addition
to uevent action name when writing /sys/.../uevent attribute. These
additional arguments are then inserted into generated synthetic uevent
as additional environment variables.

Before, we were not able to pass any additional uevent environment
variables for synthetic uevents. This made it hard to identify such uevents
properly in userspace to make proper distinction between genuine uevents
originating from kernel and synthetic uevents triggered from userspace.
Also, it was not possible to pass any additional information which would
make it possible to optimize and change the way the synthetic uevents are
processed back in userspace based on the originating environment of the
triggering action in userspace. With the extra additional variables, we are
able to pass through this extra information needed and also it makes it
possible to synchronize with such synthetic uevents as they can be clearly
identified back in userspace.

The format for writing the uevent attribute is following:

    ACTION [UUID [KEY=VALUE ...]

There's no change in how "ACTION" is recognized - it stays the same
("add", "change", "remove"). The "ACTION" is the only argument required
to generate synthetic uevent, the rest of arguments, that this patch
adds support for, are optional.

The "UUID" is considered as transaction identifier so it's possible to
use the same UUID value for one or more synthetic uevents in which case
we logically group these uevents together for any userspace listeners.
The "UUID" is expected to be in "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
format where "x" is a hex digit. The value appears in uevent as
"SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" environment variable.

The "KEY=VALUE" pairs can contain alphanumeric characters only. It's
possible to define zero or more more pairs - each pair is then delimited
by a space character " ". Each pair appears in synthetic uevents as
"SYNTH_ARG_KEY=VALUE" environment variable. That means the KEY name gains
"SYNTH_ARG_" prefix to avoid possible collisions with existing variables.
To pass the "KEY=VALUE" pairs, it's also required to pass in the "UUID"
part for the synthetic uevent first.

If "UUID" is not passed in, the generated synthetic uevent gains
"SYNTH_UUID=0" environment variable automatically so it's possible to
identify this situation in userspace when reading generated uevent and so
we can still make a difference between genuine and synthetic uevents.

Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25 18:30:51 +02:00
Viresh Kumar
35dbf4efb0 driver core: don't initialize 'parent' in device_add()
'parent' is always overwritten before getting used and there is no need
to initialize it with NULL.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:27:39 +02:00
Heiko Carstens
15c9e10d9a drivers core: remove assert_held_device_hotplug()
The last caller of assert_held_device_hotplug() is gone, so remove it again.

Link: http://lkml.kernel.org/r/20170314125226.16779-3-heiko.carstens@de.ibm.com
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-16 16:56:19 -07:00
Ingo Molnar
174cd4b1e5 sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>
Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:32 +01:00
Dan Williams
3fc2192410 mm: validate device_hotplug is held for memory hotplug
mem_hotplug_begin() assumes that it can set mem_hotplug.active_writer
and run the hotplug process without racing another thread.  Validate
this assumption with a lockdep assertion.

Link: http://lkml.kernel.org/r/148693886229.16345.1770484669403334689.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24 17:46:53 -08:00
Greg Kroah-Hartman
c7334ce814 Revert "driver core: Add deferred_probe attribute to devices in sysfs"
This reverts commit 6751667a29.

Rob Herring objected to it, and a replacement for it will be added using
debugfs in the future.

Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Reported-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-14 14:09:03 +01:00
Lukas Wunner
64df114887 driver core: Silence device links sphinx warning
Silence this warning emitted by sphinx:
include/linux/device.h:938: warning: No description found for parameter 'links'

While at it, fix typos in comments of device links code.

Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Silvio Fricke <silvio.fricke@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-05 15:02:20 +01:00
Ben Hutchings
6751667a29 driver core: Add deferred_probe attribute to devices in sysfs
It is sometimes useful to know that a device is on the deferred probe
list rather than, say, not having a driver available.  Expose this
information to user-space.

Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 17:22:23 +01:00
Rafael J. Wysocki
baa8809f60 PM / runtime: Optimize the use of device links
If the device has no links to suppliers that should be used for
runtime PM (links with DEVICE_LINK_PM_RUNTIME set), there is no
reason to walk the list of suppliers for that device during
runtime suspend and resume.

Add a simple mechanism to detect that case and possibly avoid the
extra unnecessary overhead.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-31 11:42:51 -06:00
Rafael J. Wysocki
21d5c57b37 PM / runtime: Use device links
Modify the runtime PM framework to use device links to ensure that
supplier devices will not be suspended if any of their consumer
devices are active.

The idea is to reference count suppliers on the consumer's resume
and drop references to them on its suspend.  The information on
whether or not the supplier has been reference counted by the
consumer's (runtime) resume is stored in a new field (rpm_active)
in the link object for each link.

It may be necessary to clean up those references when the
supplier is unbinding and that's why the links whose status is
DEVICE_LINK_SUPPLIER_UNBIND are skipped by the runtime suspend
and resume code.

The above means that if the consumer device is probed in the
runtime-active state, the supplier has to be resumed and reference
counted by device_link_add() so the code works as expected on its
(runtime) suspend.  There is a new flag, DEVICE_LINK_RPM_ACTIVE,
to tell device_link_add() about that (in which case the caller
is responsible for making sure that the consumer really will
be runtime-active when runtime PM is enabled for it).

The other new link flag, DEVICE_LINK_PM_RUNTIME, tells the core
whether or not the link should be used for runtime PM at all.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-31 11:42:51 -06:00
Rafael J. Wysocki
9ed9895370 driver core: Functional dependencies tracking support
Currently, there is a problem with taking functional dependencies
between devices into account.

What I mean by a "functional dependency" is when the driver of device
B needs device A to be functional and (generally) its driver to be
present in order to work properly.  This has certain consequences
for power management (suspend/resume and runtime PM ordering) and
shutdown ordering of these devices.  In general, it also implies that
the driver of A needs to be working for B to be probed successfully
and it cannot be unbound from the device before the B's driver.

Support for representing those functional dependencies between
devices is added here to allow the driver core to track them and act
on them in certain cases where applicable.

The argument for doing that in the driver core is that there are
quite a few distinct use cases involving device dependencies, they
are relatively hard to get right in a driver (if one wants to
address all of them properly) and it only gets worse if multiplied
by the number of drivers potentially needing to do it.  Morever, at
least one case (asynchronous system suspend/resume) cannot be handled
in a single driver at all, because it requires the driver of A to
wait for B to suspend (during system suspend) and the driver of B to
wait for A to resume (during system resume).

For this reason, represent dependencies between devices as "links",
with the help of struct device_link objects each containing pointers
to the "linked" devices, a list node for each of them, status
information, flags, and an RCU head for synchronization.

Also add two new list heads, representing the lists of links to the
devices that depend on the given one (consumers) and to the devices
depended on by it (suppliers), and a "driver presence status" field
(needed for figuring out initial states of device links) to struct
device.

The entire data structure consisting of all of the lists of link
objects for all devices is protected by a mutex (for link object
addition/removal and for list walks during device driver probing
and removal) and by SRCU (for list walking in other case that will
be introduced by subsequent change sets).  If CONFIG_SRCU is not
selected, however, an rwsem is used for protecting the entire data
structure.

In addition, each link object has an internal status field whose
value reflects whether or not drivers are bound to the devices
pointed to by the link or probing/removal of their drivers is in
progress etc.  That field is only modified under the device links
mutex, but it may be read outside of it in some cases (introduced by
subsequent change sets), so modifications of it are annotated with
WRITE_ONCE().

New links are added by calling device_link_add() which takes three
arguments: pointers to the devices in question and flags.  In
particular, if DL_FLAG_STATELESS is set in the flags, the link status
is not to be taken into account for this link and the driver core
will not manage it.  In turn, if DL_FLAG_AUTOREMOVE is set in the
flags, the driver core will remove the link automatically when the
consumer device driver unbinds from it.

One of the actions carried out by device_link_add() is to reorder
the lists used for device shutdown and system suspend/resume to
put the consumer device along with all of its children and all of
its consumers (and so on, recursively) to the ends of those lists
in order to ensure the right ordering between all of the supplier
and consumer devices.

For this reason, it is not possible to create a link between two
devices if the would-be supplier device already depends on the
would-be consumer device as either a direct descendant of it or a
consumer of one of its direct descendants or one of its consumers
and so on.

There are two types of link objects, persistent and non-persistent.
The persistent ones stay around until one of the target devices is
deleted, while the non-persistent ones are removed automatically when
the consumer driver unbinds from its device (ie. they are assumed to
be valid only as long as the consumer device has a driver bound to
it).  Persistent links are created by default and non-persistent
links are created when the DL_FLAG_AUTOREMOVE flag is passed
to device_link_add().

Both persistent and non-persistent device links can be deleted
with an explicit call to device_link_del().

Links created without the DL_FLAG_STATELESS flag set are managed
by the driver core using a simple state machine.  There are 5 states
each link can be in: DORMANT (unused), AVAILABLE (the supplier driver
is present and functional), CONSUMER_PROBE (the consumer driver is
probing), ACTIVE (both supplier and consumer drivers are present and
functional), and SUPPLIER_UNBIND (the supplier driver is unbinding).
The driver core updates the link state automatically depending on
what happens to the linked devices and for each link state specific
actions are taken in addition to that.

For example, if the supplier driver unbinds from its device, the
driver core will also unbind the drivers of all of its consumers
automatically under the assumption that they cannot function
properly without the supplier.  Analogously, the driver core will
only allow the consumer driver to bind to its device if the
supplier driver is present and functional (ie. the link is in
the AVAILABLE state).  If that's not the case, it will rely on
the existing deferred probing mechanism to wait for the supplier
driver to become available.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-31 11:36:20 -06:00
Linus Torvalds
9929780e86 Driver core patches for 4.9-rc1
Here are the "big" driver core patches for 4.9-rc1.  Also in here are a
 number of debugfs fixes that cropped up due to the changes that happened
 in 4.8 for that filesystem.  Overall, nothing major, just a few fixes
 and cleanups.
 
 All of these have been in linux-next with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here are the "big" driver core patches for 4.9-rc1. Also in here are a
  number of debugfs fixes that cropped up due to the changes that
  happened in 4.8 for that filesystem. Overall, nothing major, just a
  few fixes and cleanups.

  All of these have been in linux-next with no reported issues"

* tag 'driver-core-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (23 commits)
  drivers: dma-coherent: Move spinlock in dma_alloc_from_coherent()
  drivers: dma-coherent: Fix DMA coherent size for less than page
  MAINTAINERS: extend firmware_class maintainer list
  debugfs: propagate release() call result
  driver-core: platform: Catch errors from calls to irq_get_irq_data
  sysfs print name of undiscoverable attribute group
  carl9170: fix debugfs crashes
  b43legacy: fix debugfs crash
  b43: fix debugfs crash
  debugfs: introduce a public file_operations accessor
  device core: Remove deprecated create_singlethread_workqueue
  drivers/base dmam_declare_coherent_memory leaks
  platform: don't return 0 from platform_get_irq[_byname]() on error
  cpu: clean up register_cpu func
  dma-mapping: use vma_pages().
  drivers: dma-coherent: use vma_pages().
  attribute_container: Fix typo
  base: soc: make it explicitly non-modular
  drivers: base: dma-mapping: page align the size when unmap_kernel_range
  platform driver: fix use-after-free in platform_device_del()
  ...
2016-10-03 20:03:24 -07:00
Ming Lei
cebf8fd169 driver core: fix race between creating/querying glue dir and its cleanup
The global mutex of 'gdp_mutex' is used to serialize creating/querying
glue dir and its cleanup. Turns out it isn't a perfect way because
part(kobj_kset_leave()) of the actual cleanup action() is done inside
the release handler of the glue dir kobject. That means gdp_mutex has
to be held before releasing the last reference count of the glue dir
kobject.

This patch moves glue dir's cleanup after kobject_del() in device_del()
for avoiding the race.

Cc: Yijing Wang <wangyijing@huawei.com>
Reported-by: Chandra Sekhar Lingutla <clingutla@codeaurora.org>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 15:13:55 +02:00
Lukas Wunner
478573c93a driver core: Don't leak secondary fwnode on device removal
If device_add_property_set() is called for a device, a secondary fwnode
is allocated and assigned to the device but currently not freed once the
device is removed.

This can be triggered on Apple Macs if a Thunderbolt device is plugged
in on boot since Apple's NHI EFI driver sets a number of properties for
that device which are leaked on unplug.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31 00:28:29 +02:00
Mika Westerberg
55f89a8a45 driver core: Do not overwrite secondary fwnode with NULL if it is set
If multiple devices share single firmware node like it is case with MFD
devices, the same firmware node (ACPI) is assigned to all of them. The
function also modifies the shared firmware node in order to preserve
secondary firmware node of the device in question.

If the new device which is sharing the firmware node does not have
secondary node it will be NULL which will be assigned to the secondary node
of the shared firmware node losing all built-in properties.

Prevent this by setting the secondary firmware node only if the replacement
is non-NULL.

Print also warning if someone tries to overwrite secondary node that has
already been assigned.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-12-07 02:29:23 +01:00
Zhen Lei
56f2de81e0 of: to support binding numa node to specified device in devicetree
For now, in function device_add, the new device will be forced to
inherit the numa node of its parent. But this will override the device's
numa node which configured in devicetree.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 22:11:50 -07:00
Linus Torvalds
ae98207309 Power management and ACPI material for v4.3-rc1
- ACPICA update to upstream revision 20150818 including method
    tracing extensions to allow more in-depth AML debugging in the
    kernel and a number of assorted fixes and cleanups (Bob Moore,
    Lv Zheng, Markus Elfring).
 
  - ACPI sysfs code updates and a documentation update related to
    AML method tracing (Lv Zheng).
 
  - ACPI EC driver fix related to serialized evaluations of _Qxx
    methods and ACPI tools updates allowing the EC userspace tool
    to be built from the kernel source (Lv Zheng).
 
  - ACPI processor driver updates preparing it for future
    introduction of CPPC support and ACPI PCC mailbox driver
    updates (Ashwin Chaugule).
 
  - ACPI interrupts enumeration fix for a regression related
    to the handling of IRQ attribute conflicts between MADT
    and the ACPI namespace (Jiang Liu).
 
  - Fixes related to ACPI device PM (Mika Westerberg, Srinidhi Kasagar).
 
  - ACPI device registration code reorganization to separate the
    sysfs-related code and bus type operations from the rest (Rafael
    J Wysocki).
 
  - Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause,
    Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss).
 
  - ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups
    (Pan Xinhui, Rafael J Wysocki).
 
  - cpufreq core cleanups on top of the previous changes allowing it
    to preseve its sysfs directories over system suspend/resume (Viresh
    Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior).
 
  - cpufreq fixes and cleanups related to governors (Viresh Kumar).
 
  - cpufreq updates (core and the cpufreq-dt driver) related to the
    turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz).
 
  - New DT bindings for Operating Performance Points (OPP), support
    for them in the OPP framework and in the cpufreq-dt driver plus
    related OPP framework fixes and cleanups (Viresh Kumar).
 
  - cpufreq powernv driver updates (Shilpasri G Bhat).
 
  - New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen).
 
  - Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups
    and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean).
 
  - intel_pstate driver updates including Skylake-S support, support
    for enabling HW P-states per CPU and an additional vendor bypass
    list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao).
 
  - cpuidle core fixes related to the handling of coupled idle states
    (Xunlei Pang).
 
  - intel_idle driver updates including Skylake Client support and
    support for freeze-mode-specific idle states (Len Brown).
 
  - Driver core updates related to power management (Andy Shevchenko,
    Rafael J Wysocki).
 
  - Generic power domains framework fixes and cleanups (Jon Hunter,
    Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson).
 
  - Device PM QoS framework update to allow the latency tolerance
    setting to be exposed to user space via sysfs (Mika Westerberg).
 
  - devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect
    exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas).
 
  - System sleep support updates (Alan Stern, Len Brown, SungEun Kim).
 
  - rockchip-io AVS support updates (Heiko Stuebner).
 
  - PM core clocks support fixup (Colin Ian King).
 
  - Power capping RAPL driver update including support for Skylake H/S
    and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi).
 
  - Generic device properties framework fixes related to the handling
    of static (driver-provided) property sets (Andy Shevchenko).
 
  - turbostat and cpupower updates (Len Brown, Shilpasri G Bhat,
    Shreyas B Prabhu).
 
 /
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Merge tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI updates from Rafael Wysocki:
 "From the number of commits perspective, the biggest items are ACPICA
  and cpufreq changes with the latter taking the lead (over 50 commits).

  On the cpufreq front, there are many cleanups and minor fixes in the
  core and governors, driver updates etc.  We also have a new cpufreq
  driver for Mediatek MT8173 chips.

  ACPICA mostly updates its debug infrastructure and adds a number of
  fixes and cleanups for a good measure.

  The Operating Performance Points (OPP) framework is updated with new
  DT bindings and support for them among other things.

  We have a few updates of the generic power domains framework and a
  reorganization of the ACPI device enumeration code and bus type
  operations.

  And a lot of fixes and cleanups all over.

  Included is one branch from the MFD tree as it contains some
  PM-related driver core and ACPI PM changes a few other commits are
  based on.

  Specifics:

   - ACPICA update to upstream revision 20150818 including method
     tracing extensions to allow more in-depth AML debugging in the
     kernel and a number of assorted fixes and cleanups (Bob Moore, Lv
     Zheng, Markus Elfring).

   - ACPI sysfs code updates and a documentation update related to AML
     method tracing (Lv Zheng).

   - ACPI EC driver fix related to serialized evaluations of _Qxx
     methods and ACPI tools updates allowing the EC userspace tool to be
     built from the kernel source (Lv Zheng).

   - ACPI processor driver updates preparing it for future introduction
     of CPPC support and ACPI PCC mailbox driver updates (Ashwin
     Chaugule).

   - ACPI interrupts enumeration fix for a regression related to the
     handling of IRQ attribute conflicts between MADT and the ACPI
     namespace (Jiang Liu).

   - Fixes related to ACPI device PM (Mika Westerberg, Srinidhi
     Kasagar).

   - ACPI device registration code reorganization to separate the
     sysfs-related code and bus type operations from the rest (Rafael J
     Wysocki).

   - Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause,
     Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss).

   - ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups (Pan
     Xinhui, Rafael J Wysocki).

   - cpufreq core cleanups on top of the previous changes allowing it to
     preseve its sysfs directories over system suspend/resume (Viresh
     Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior).

   - cpufreq fixes and cleanups related to governors (Viresh Kumar).

   - cpufreq updates (core and the cpufreq-dt driver) related to the
     turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz).

   - New DT bindings for Operating Performance Points (OPP), support for
     them in the OPP framework and in the cpufreq-dt driver plus related
     OPP framework fixes and cleanups (Viresh Kumar).

   - cpufreq powernv driver updates (Shilpasri G Bhat).

   - New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen).

   - Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups
     and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean).

   - intel_pstate driver updates including Skylake-S support, support
     for enabling HW P-states per CPU and an additional vendor bypass
     list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao).

   - cpuidle core fixes related to the handling of coupled idle states
     (Xunlei Pang).

   - intel_idle driver updates including Skylake Client support and
     support for freeze-mode-specific idle states (Len Brown).

   - Driver core updates related to power management (Andy Shevchenko,
     Rafael J Wysocki).

   - Generic power domains framework fixes and cleanups (Jon Hunter,
     Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson).

   - Device PM QoS framework update to allow the latency tolerance
     setting to be exposed to user space via sysfs (Mika Westerberg).

   - devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect
     exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas).

   - System sleep support updates (Alan Stern, Len Brown, SungEun Kim).

   - rockchip-io AVS support updates (Heiko Stuebner).

   - PM core clocks support fixup (Colin Ian King).

   - Power capping RAPL driver update including support for Skylake H/S
     and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi).

   - Generic device properties framework fixes related to the handling
     of static (driver-provided) property sets (Andy Shevchenko).

   - turbostat and cpupower updates (Len Brown, Shilpasri G Bhat,
     Shreyas B Prabhu)"

* tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (180 commits)
  cpufreq: speedstep-lib: Use monotonic clock
  cpufreq: powernv: Increase the verbosity of OCC console messages
  cpufreq: sfi: use kmemdup rather than duplicating its implementation
  cpufreq: drop !cpufreq_driver check from cpufreq_parse_governor()
  cpufreq: rename cpufreq_real_policy as cpufreq_user_policy
  cpufreq: remove redundant 'policy' field from user_policy
  cpufreq: remove redundant 'governor' field from user_policy
  cpufreq: update user_policy.* on success
  cpufreq: use memcpy() to copy policy
  cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event
  cpufreq: mediatek: Add MT8173 cpufreq driver
  dt-bindings: mediatek: Add MT8173 CPU DVFS clock bindings
  PM / Domains: Fix typo in description of genpd_dev_pm_detach()
  PM / Domains: Remove unusable governor dummies
  PM / Domains: Make pm_genpd_init() available to modules
  PM / domains: Align column headers and data in pm_genpd_summary output
  powercap / RAPL: disable the 2nd power limit properly
  tools: cpupower: Fix error when running cpupower monitor
  PM / OPP: Drop unlikely before IS_ERR(_OR_NULL)
  PM / OPP: Fix static checker warning (broken 64bit big endian systems)
  ...
2015-09-01 19:45:46 -07:00
Linus Torvalds
17e6b00ac4 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "This updated pull request does not contain the last few GIC related
  patches which were reported to cause a regression.  There is a fix
  available, but I let it breed for a couple of days first.

  The irq departement provides:

   - new infrastructure to support non PCI based MSI interrupts
   - a couple of new irq chip drivers
   - the usual pile of fixlets and updates to irq chip drivers
   - preparatory changes for removal of the irq argument from interrupt
     flow handlers
   - preparatory changes to remove IRQF_VALID"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits)
  irqchip/imx-gpcv2: IMX GPCv2 driver for wakeup sources
  irqchip: Add bcm2836 interrupt controller for Raspberry Pi 2
  irqchip: Add documentation for the bcm2836 interrupt controller
  irqchip/bcm2835: Add support for being used as a second level controller
  irqchip/bcm2835: Refactor handle_IRQ() calls out of MAKE_HWIRQ
  PCI: xilinx: Fix typo in function name
  irqchip/gic: Ensure gic_cpu_if_up/down() programs correct GIC instance
  irqchip/gic: Only allow the primary GIC to set the CPU map
  PCI/MSI: pci-xgene-msi: Consolidate chained IRQ handler install/remove
  unicore32/irq: Prepare puv3_gpio_handler for irq argument removal
  tile/pci_gx: Prepare trio_handle_level_irq for irq argument removal
  m68k/irq: Prepare irq handlers for irq argument removal
  C6X/megamode-pic: Prepare megamod_irq_cascade for irq argument removal
  blackfin: Prepare irq handlers for irq argument removal
  arc/irq: Prepare idu_cascade_isr for irq argument removal
  sparc/irq: Use access helper irq_data_get_affinity_mask()
  sparc/irq: Use helper irq_data_get_irq_handler_data()
  parisc/irq: Use access helper irq_data_get_affinity_mask()
  mn10300/irq: Use access helper irq_data_get_affinity_mask()
  irqchip/i8259: Prepare i8259_irq_dispatch for irq argument removal
  ...
2015-09-01 14:33:35 -07:00
Grygorii Strashko
52cdbdd498 driver core: correct device's shutdown order
Now device's shutdown sequence is performed in reverse order of their
registration in devices_kset list and this sequence corresponds to the
reverse device's creation order. So, devices_kset data tracks
"parent<-child" device's dependencies only.

Unfortunately, that's not enough and causes problems in case of
implementing board's specific shutdown procedures. For example [1]:
"DRA7XX_evm uses PCF8575 and one of the PCF output lines feeds to
MMC/SD and this line should be driven high in order for the MMC/SD to
be detected. This line is modelled as regulator and the hsmmc driver
takes care of enabling and disabling it. In the case of 'reboot',
during shutdown path as part of it's cleanup process the hsmmc driver
disables this regulator. This makes MMC boot not functional."

To handle this issue the .shutdown() callback could be implemented
for PCF8575 device where corresponding GPIO pins will be configured to
states, required for correct warm/cold reset. This can be achieved
only when all .shutdown() callbacks have been called already for all
PCF8575's consumers. But devices_kset is not filled correctly now:

devices_kset: Device61 4e000000.dmm
devices_kset: Device62 48070000.i2c
devices_kset: Device63 48072000.i2c
devices_kset: Device64 48060000.i2c
devices_kset: Device65 4809c000.mmc
...
devices_kset: Device102 fixedregulator-sd
...
devices_kset: Device181 0-0020 // PCF8575
devices_kset: Device182 gpiochip496
devices_kset: Device183 0-0021 // PCF8575
devices_kset: Device184 gpiochip480

As can be seen from above .shutdown() callback for PCF8575 will be called
before its consumers, which, in turn means, that any changes of PCF8575
GPIO's pins will be or unsafe or overwritten later by GPIO's consumers.
The problem can be solved if devices_kset list will be filled not only
according device creation order, but also according device's probing
order to track "supplier<-consumer" dependencies also.

Hence, as a fix, lets add devices_kset_move_last(),
devices_kset_move_before(), devices_kset_move_after() and call them
from device_move() and also add call of devices_kset_move_last() in
really_probe(). After this change all entries in devices_kset will
be sorted according to device's creation ("parent<-child") and
probing ("supplier<-consumer") order.

devices_kset after:
devices_kset: Device121 48070000.i2c
devices_kset: Device122 i2c-0
...
devices_kset: Device147 regulator.24
devices_kset: Device148 0-0020
devices_kset: Device149 gpiochip496
devices_kset: Device150 0-0021
devices_kset: Device151 gpiochip480
devices_kset: Device152 0-0019
...
devices_kset: Device372 fixedregulator-sd
devices_kset: Device373 regulator.29
devices_kset: Device374 4809c000.mmc
devices_kset: Device375 mmc0

[1] http://www.spinics.net/lists/linux-mmc/msg29825.html

Cc: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 17:07:19 -07:00
Andy Shevchenko
3d060aeb72 driver core: implement device_for_each_child_reverse()
The new function device_for_each_child_reverse() is helpful to traverse the
registered devices in a reversed order, e.g. in the case when an operation on
each device should be done first on the last added device, then on one before
last and so on.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-07-28 08:50:42 +01:00
Jiang Liu
4a7cc83167 genirq/MSI: Move msi_list from struct pci_dev to struct device
Move msi_list from struct pci_dev into struct device, so we can
support non-PCI-device based generic MSI interrupts.

msi_list is now conditional under CONFIG_GENERIC_MSI_IRQ, which is
selected from CONFIG_PCI_MSI, so no functional change for PCI MSI
users.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Reviewed-by: Yijing Wang <wangyijing@huawei.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Stuart Yoder <stuart.yoder@freescale.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Alexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/1436428847-8886-10-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-22 18:37:43 +02:00
Rasmus Villemoes
a29fd614a6 drivers/base/core.c: use strreplace()
This eliminates a little .text and avoids repeating the strchr call when
we meet a '!' (which will happen at least once).

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-25 17:00:40 -07:00
Linus Torvalds
2481bc7528 Power management and ACPI updates for v4.1-rc1
- Generic PM domains support update including new PM domain
    callbacks to handle device initialization better (Russell King,
    Rafael J Wysocki, Kevin Hilman).
 
  - Unified device properties API update including a new mechanism
    for accessing data provided by platform initialization code
    (Rafael J Wysocki, Adrian Hunter).
 
  - ARM cpuidle update including ARM32/ARM64 handling consolidation
    (Daniel Lezcano).
 
  - intel_idle update including support for the Silvermont Core in
    the Baytrail SOC and for the Airmont Core in the Cherrytrail and
    Braswell SOCs (Len Brown, Mathias Krause).
 
  - New cpufreq driver for Hisilicon ACPU (Leo Yan).
 
  - intel_pstate update including support for the Knights Landing
    chip (Dasaratharaman Chandramouli, Kristen Carlson Accardi).
 
  - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann).
 
  - powernv cpufreq driver update (Shilpasri G Bhat).
 
  - devfreq update including Tegra support changes (Tomeu Vizoso,
    MyungJoo Ham, Chanwoo Choi).
 
  - powercap RAPL (Running-Average Power Limit) driver update
    including support for Intel Broadwell server chips (Jacob Pan,
    Mathias Krause).
 
  - ACPI device enumeration update related to the handling of the
    special PRP0001 device ID allowing DT-style 'compatible' property
    to be used for ACPI device identification (Rafael J Wysocki).
 
  - ACPI EC driver update including limited _DEP support (Lan Tianyu,
    Lv Zheng).
 
  - ACPI backlight driver update including a new mechanism to allow
    native backlight handling to be forced on non-Windows 8 systems
    and a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede).
 
  - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu).
 
  - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
    Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki).
 
  - Fixes related to suspend-to-idle for the iTCO watchdog driver and
    the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu).
 
  - PM tracing support for the suspend phase of system suspend/resume
    transitions (Zhonghui Fu).
 
  - Configurable delay for the system suspend/resume testing facility
    (Brian Norris).
 
  - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki).
 
 /
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Merge tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI updates from Rafael Wysocki:
 "These are mostly fixes and cleanups all over, although there are a few
  items that sort of fall into the new feature category.

  First off, we have new callbacks for PM domains that should help us to
  handle some issues related to device initialization in a better way.

  There also is some consolidation in the unified device properties API
  area allowing us to use that inferface for accessing data coming from
  platform initialization code in addition to firmware-provided data.

  We have some new device/CPU IDs in a few drivers, support for new
  chips and a new cpufreq driver too.

  Specifics:

   - Generic PM domains support update including new PM domain callbacks
     to handle device initialization better (Russell King, Rafael J
     Wysocki, Kevin Hilman)

   - Unified device properties API update including a new mechanism for
     accessing data provided by platform initialization code (Rafael J
     Wysocki, Adrian Hunter)

   - ARM cpuidle update including ARM32/ARM64 handling consolidation
     (Daniel Lezcano)

   - intel_idle update including support for the Silvermont Core in the
     Baytrail SOC and for the Airmont Core in the Cherrytrail and
     Braswell SOCs (Len Brown, Mathias Krause)

   - New cpufreq driver for Hisilicon ACPU (Leo Yan)

   - intel_pstate update including support for the Knights Landing chip
     (Dasaratharaman Chandramouli, Kristen Carlson Accardi)

   - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann)

   - powernv cpufreq driver update (Shilpasri G Bhat)

   - devfreq update including Tegra support changes (Tomeu Vizoso,
     MyungJoo Ham, Chanwoo Choi)

   - powercap RAPL (Running-Average Power Limit) driver update including
     support for Intel Broadwell server chips (Jacob Pan, Mathias Krause)

   - ACPI device enumeration update related to the handling of the
     special PRP0001 device ID allowing DT-style 'compatible' property
     to be used for ACPI device identification (Rafael J Wysocki)

   - ACPI EC driver update including limited _DEP support (Lan Tianyu,
     Lv Zheng)

   - ACPI backlight driver update including a new mechanism to allow
     native backlight handling to be forced on non-Windows 8 systems and
     a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede)

   - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu)

   - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
     Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki)

   - Fixes related to suspend-to-idle for the iTCO watchdog driver and
     the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu)

   - PM tracing support for the suspend phase of system suspend/resume
     transitions (Zhonghui Fu)

   - Configurable delay for the system suspend/resume testing facility
     (Brian Norris)

   - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki)"

* tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits)
  ACPI / scan: Fix NULL pointer dereference in acpi_companion_match()
  ACPI / scan: Rework modalias creation when "compatible" is present
  intel_idle: mark cpu id array as __initconst
  powercap / RAPL: mark rapl_ids array as __initconst
  powercap / RAPL: add ID for Broadwell server
  intel_pstate: Knights Landing support
  intel_pstate: remove MSR test
  cpufreq: fix qoriq uniprocessor build
  ACPI / scan: Take the PRP0001 position in the list of IDs into account
  ACPI / scan: Simplify acpi_match_device()
  ACPI / scan: Generalize of_compatible matching
  device property: Introduce firmware node type for platform data
  device property: Make it possible to use secondary firmware nodes
  PM / watchdog: iTCO: stop watchdog during system suspend
  cpufreq: hisilicon: add acpu driver
  ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handler
  cpufreq: powernv: Report cpu frequency throttling
  intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs
  intel_idle: Update support for Silvermont Core in Baytrail SOC
  PM / devfreq: tegra: Register governor on module init
  ...
2015-04-14 20:21:54 -07:00
Rafael J. Wysocki
97badf873a device property: Make it possible to use secondary firmware nodes
Add a secondary pointer to struct fwnode_handle so as to make it
possible for a device to have two firmware nodes associated with
it at the same time, for example, an ACPI node and a node with
a set of properties provided by platform initialization code.

In the future that will allow device property lookup to fall back
from the primary firmware node to the secondary one if the given
property is not present there to make it easier to provide defaults
for device properties used by device drivers.

Introduce two helper routines, set_primary_fwnode() and
set_secondary_fwnode() allowing callers to add a primary/secondary
firmware node to the given device in such a way that

 (1) If there's only one firmware node for that device, it will be
     pointed to by the device's firmware node pointer.
 (2) If both the primary and secondary firmware nodes are present,
     the primary one will be pointed to by the device's firmware
     node pointer, while the secondary one will be pointed to by the
     primary node's secondary pointer.
 (3) If one of these nodes is removed (by calling one of the new
     nelpers with NULL as the second argument), the other one will
     be preserved.

Make ACPI use set_primary_fwnode() for attaching its firmware nodes
to devices.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-03 23:23:37 +02:00
Benjamin Herrenschmidt
5590f3196b drivers/core/of: Add symlink to device-tree from devices with an OF node
So I've been annoyed lately with having a bunch of devices such as i2c
eeproms (for use by VPDs, server world !) and other bits and pieces that
I want to be able to identify from userspace, and possibly provide
additional data about from FW.

Basically, it boils down to correlating the sysfs device with the OF
tree device node, so that user space can use device-tree info such as
additional "location" or "label" (or whatever else we can come up with)
propreties to identify a given device, or get some attributes of use
about it, etc...

Now, so far, we've done that in some subsystem in a fairly ad-hoc basis
using "devspec" properties. For example, PCI creates them if it can
correlate the probed device with a DT node. Some powerpc specific busses
do that too.

However, i2c doesn't and it would be nice to have something more generic
since technically any device can have a corresponding device tree node.

This patch adds an "of_node" symlink to devices that have a non-NULL
dev->of_node pointer, the patch is pretty trivial and seems to work just
fine for me.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25 14:56:58 +01:00
Markus Elfring
5f0163a5ee driver core: Delete an unnecessary check before the function call "put_device"
The put_device() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25 13:52:35 +01:00
Joe Perches
d1f1052c52 device: Change dev_<level> logging functions to return void
No caller or macro uses the return value so make all
the functions return void.

Compiled x86 allyesconfig and defconfig w/o CONFIG_PRINTK

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-26 15:57:59 -08:00
Linus Torvalds
e6b5be2be4 Driver core patches for 3.19-rc1
Here's the set of driver core patches for 3.19-rc1.
 
 They are dominated by the removal of the .owner field in platform
 drivers.  They touch a lot of files, but they are "simple" changes, just
 removing a line in a structure.
 
 Other than that, a few minor driver core and debugfs changes.  There are
 some ath9k patches coming in through this tree that have been acked by
 the wireless maintainers as they relied on the debugfs changes.
 
 Everything has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
2014-12-14 16:10:09 -08:00
Sergey Klyaus
0cd75047de driver core: fix race with userland in device_add()
bus_add_device() should be called before devtmpfs_create_node(), so when
userland application opens device from devtmpfs, it wouldn't get ENODEV
from kernel, because device_add() wasn't completed.

Signed-off-by: Sergey Klyaus <Sergey.Klyaus@Tune-IT.Ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07 11:14:57 -08:00
Yijing Wang
e4a60d1390 sysfs: driver core: Fix glue dir race condition by gdp_mutex
There is a race condition when removing glue directory.
It can be reproduced in following test:

path 1: Add first child device
device_add()
    get_device_parent()
            /*find parent from glue_dirs.list*/
            list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
                    if (k->parent == parent_kobj) {
                            kobj = kobject_get(k);
                            break;
                    }
            ....
            class_dir_create_and_add()

path2: Remove last child device under glue dir
device_del()
    cleanup_device_parent()
            cleanup_glue_dir()
                    kobject_put(glue_dir);

If path2 has been called cleanup_glue_dir(), but not
call kobject_put(glue_dir), the glue dir is still
in parent's kset list. Meanwhile, path1 find the glue
dir from the glue_dirs.list. Path2 may release glue dir
before path1 call kobject_get(). So kernel will report
the warning and bug_on.

This is a "classic" problem we have of a kref in a list
that can be found while the last instance could be removed
at the same time.

This patch reuse gdp_mutex to fix this race condition.

The following calltrace is captured in kernel 3.4, but
the latest kernel still has this bug.

-----------------------------------------------------
<4>[ 3965.441471] WARNING: at ...include/linux/kref.h:41 kobject_get+0x33/0x40()
<4>[ 3965.441474] Hardware name: Romley
<4>[ 3965.441475] Modules linked in: isd_iop(O) isd_xda(O)...
...
<4>[ 3965.441605] Call Trace:
<4>[ 3965.441611]  [<ffffffff8103717a>] warn_slowpath_common+0x7a/0xb0
<4>[ 3965.441615]  [<ffffffff810371c5>] warn_slowpath_null+0x15/0x20
<4>[ 3965.441618]  [<ffffffff81215963>] kobject_get+0x33/0x40
<4>[ 3965.441624]  [<ffffffff812d1e45>] get_device_parent.isra.11+0x135/0x1f0
<4>[ 3965.441627]  [<ffffffff812d22d4>] device_add+0xd4/0x6d0
<4>[ 3965.441631]  [<ffffffff812d0dbc>] ? dev_set_name+0x3c/0x40
....
<2>[ 3965.441912] kernel BUG at ..../fs/sysfs/group.c:65!
<4>[ 3965.441915] invalid opcode: 0000 [#1] SMP
...
<4>[ 3965.686743]  [<ffffffff811a677e>] sysfs_create_group+0xe/0x10
<4>[ 3965.686748]  [<ffffffff810cfb04>] blk_trace_init_sysfs+0x14/0x20
<4>[ 3965.686753]  [<ffffffff811fcabb>] blk_register_queue+0x3b/0x120
<4>[ 3965.686756]  [<ffffffff812030bc>] add_disk+0x1cc/0x490
....
-------------------------------------------------------

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Weng Meiling <wengmeiling.weng@huawei.com>
Cc: <stable@vger.kernel.org> #3.4+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07 08:17:43 -08:00
Linus Torvalds
23971bdfff IOMMU Updates for Linux v3.18
This pull-request includes:
 
 	* Change in the IOMMU-API to convert the former iommu_domain_capable
 	  function to just iommu_capable
 
 	* Various fixes in handling RMRR ranges for the VT-d driver (one fix
 	  requires a device driver core change which was acked
 	  by Greg KH)
 
 	* The AMD IOMMU driver now assigns and deassigns complete alias groups
 	  to fix issues with devices using the wrong PCI request-id
 
 	* MMU-401 support for the ARM SMMU driver
 
 	* Multi-master IOMMU group support for the ARM SMMU driver
 
 	* Various other small fixes all over the place
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Merge tag 'iommu-updates-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull IOMMU updates from Joerg Roedel:
 "This pull-request includes:

   - change in the IOMMU-API to convert the former iommu_domain_capable
     function to just iommu_capable

   - various fixes in handling RMRR ranges for the VT-d driver (one fix
     requires a device driver core change which was acked by Greg KH)

   - the AMD IOMMU driver now assigns and deassigns complete alias
     groups to fix issues with devices using the wrong PCI request-id

   - MMU-401 support for the ARM SMMU driver

   - multi-master IOMMU group support for the ARM SMMU driver

   - various other small fixes all over the place"

* tag 'iommu-updates-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (41 commits)
  iommu/vt-d: Work around broken RMRR firmware entries
  iommu/vt-d: Store bus information in RMRR PCI device path
  iommu/vt-d: Only remove domain when device is removed
  driver core: Add BUS_NOTIFY_REMOVED_DEVICE event
  iommu/amd: Fix devid mapping for ivrs_ioapic override
  iommu/irq_remapping: Fix the regression of hpet irq remapping
  iommu: Fix bus notifier breakage
  iommu/amd: Split init_iommu_group() from iommu_init_device()
  iommu: Rework iommu_group_get_for_pci_dev()
  iommu: Make of_device_id array const
  amd_iommu: do not dereference a NULL pointer address.
  iommu/omap: Remove omap_iommu unused owner field
  iommu: Remove iommu_domain_has_cap() API function
  IB/usnic: Convert to use new iommu_capable() API function
  vfio: Convert to use new iommu_capable() API function
  kvm: iommu: Convert to use new iommu_capable() API function
  iommu/tegra: Convert to iommu_capable() API function
  iommu/msm: Convert to iommu_capable() API function
  iommu/vt-d: Convert to iommu_capable() API function
  iommu/fsl: Convert to iommu_capable() API function
  ...
2014-10-15 07:23:49 +02:00
Joerg Roedel
599bad38cf driver core: Add BUS_NOTIFY_REMOVED_DEVICE event
This event closes an important gap in the bus notifiers.
There is already the BUS_NOTIFY_DEL_DEVICE event, but that
is sent when the device is still bound to its device driver.

This is too early for the IOMMU code to destroy any mappings
for the device, as they might still be in use by the driver.

The new BUS_NOTIFY_REMOVED_DEVICE event introduced with this
patch closes this gap as it is sent when the device is
already unbound from its device driver and almost completly
removed from the driver core.

With this event the IOMMU code can safely destroy any
mappings and other data structures when a device is removed.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Jerry Hoemann <jerry.hoemann@hp.com>
2014-10-02 11:14:34 +02:00
Ben Hutchings
655e5b7c03 drivers/base: Fix length checks in create_syslog_header()/dev_vprintk_emit()
snprintf() returns the number of bytes that could have been written
(excluding the null), not the actual number of bytes written.  Given a
long enough subsystem or device name, these functions will advance
beyond the end of the on-stack buffer in dev_vprintk_exit(), resulting
in an information leak or stack corruption.  I don't know whether such
a long name is currently possible.

In case snprintf() returns a value >= the buffer size, do not add
structured logging information.  Also WARN if this happens, so we can
fix the driver or increase the buffer size.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 22:55:15 -07:00
Tejun Heo
33ac1257ff sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()
All device_schedule_callback_owner() users are converted to use
device_remove_file_self().  Remove now unused
{sysfs|device}_schedule_callback_owner().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-16 11:56:33 -07:00
Greg Kroah-Hartman
72099304ee Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()"
This reverts commit d1ba277e79.

As reported by Stephen, this patch breaks linux-next as a ppc patch
suddenly (after 2 years) started using this old api call.  So revert it
for now, it will go away in 3.15-rc2 when we can change the PPC call to
the new api.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: Stewart Smith <stewart@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-25 20:54:57 -07:00
Roland Dreier
aa0689b36b Revert "driver core: synchronize device shutdown"
This reverts commit 401097ea4b.  The
original changelog said:

    A patch series to make .shutdown execute asynchronously.  Some drivers's
    shutdown can take a lot of time.  The patches can help save some shutdown
    time.  The patches use Arjan's async API.

    This patch:

    synchronize all tasks submitted by .shutdown

However, I'm not able to find any evidence that any other patches from
this series were applied, nor am I able to find any async tasks that are
scheduled in a .shutdown context.

On the other hand, we see occasional hangs on shutdown that appear to be
caused by the async_synchronize_full() in device_shutdown() waiting
forever for the async probing in sd if a SCSI disk shows up at just the
wrong time — the system starts the probe, but begins shutting down and
tears down too much of the SCSI driver to finish the probe.

If we had any async shutdown tasks, I guess the right fix would be to
create a "shutdown" async domain and have device_shutdown() only wait
for that domain.  But since there apparently are no async shutdown
tasks, we can just revert the waiting.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-08 22:08:29 -08:00
Jiang Liu
5c764dfaef driver core: unexport static function create_syslog_header
Function create_syslog_header() is defined as static, so it should
not be exported.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-15 11:38:36 -08:00
Tejun Heo
ce8b04aa6c sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()
All device_schedule_callback_owner() users are converted to use
device_remove_file_self().  Remove now unused
{sysfs|device}_schedule_callback_owner().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07 15:42:41 -08:00
Tejun Heo
6b0afc2a21 kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers
Sometimes it's necessary to implement a node which wants to delete
nodes including itself.  This isn't straightforward because of kernfs
active reference.  While a file operation is in progress, an active
reference is held and kernfs_remove() waits for all such references to
drain before completing.  For a self-deleting node, this is a deadlock
as kernfs_remove() ends up waiting for an active reference that itself
is sitting on top of.

This currently is worked around in the sysfs layer using
sysfs_schedule_callback() which makes such removals asynchronous.
While it works, it's rather cumbersome and inherently breaks
synchronicity of the operation - the file operation which triggered
the operation may complete before the removal is finished (or even
started) and the removal may fail asynchronously.  If a removal
operation is immmediately followed by another operation which expects
the specific name to be available (e.g. removal followed by rename
onto the same name), there's no way to make the latter operation
reliable.

The thing is there's no inherent reason for this to be asynchrnous.
All that's necessary to do this synchronous is a dedicated operation
which drops its own active ref and deactivates self.  This patch
implements kernfs_remove_self() and its wrappers in sysfs and driver
core.  kernfs_remove_self() is to be called from one of the file
operations, drops the active ref the task is holding, removes the self
node, and restores active ref to the dead node so that the ref is
balanced afterwards.  __kernfs_remove() is updated so that it takes an
early exit if the target node is already fully removed so that the
active ref restored by kernfs_remove_self() after removal doesn't
confuse the deactivation path.

This makes implementing self-deleting nodes very easy.  The normal
removal path doesn't even need to be changed to use
kernfs_remove_self() for the self-deleting node.  The method can
invoke kernfs_remove_self() on itself before proceeding the normal
removal path.  kernfs_remove() invoked on the node by the normal
deletion path will simply be ignored.

This will replace sysfs_schedule_callback().  A subtle feature of
sysfs_schedule_callback() is that it collapses multiple invocations -
even if multiple removals are triggered, the removal callback is run
only once.  An equivalent effect can be achieved by testing the return
value of kernfs_remove_self() - only the one which gets %true return
value should proceed with actual deletion.  All other instances of
kernfs_remove_self() will wait till the enclosing kernfs operation
which invoked the winning instance of kernfs_remove_self() finishes
and then return %false.  This trivially makes all users of
kernfs_remove_self() automatically show correct synchronous behavior
even when there are multiple concurrent operations - all "echo 1 >
delete" instances will finish only after the whole operation is
completed by one of the instances.

Note that manipulation of active ref is implemented in separate public
functions - kernfs_[un]break_active_protection().
kernfs_remove_self() is the only user at the moment but this will be
used to cater to more complex cases.

v2: For !CONFIG_SYSFS, dummy version kernfs_remove_self() was missing
    and sysfs_remove_file_self() had incorrect return type.  Fix it.
    Reported by kbuild test bot.

v3: kernfs_[un]break_active_protection() separated out from
    kernfs_remove_self() and exposed as public API.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07 15:42:41 -08:00
Greg Kroah-Hartman
a9f138b0e5 Revert "kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers"
This reverts commit 1ae06819c7.

Tejun writes:
        I'm sorry but can you please revert the whole series?
        get_active() waiting while a node is deactivated has potential
        to lead to deadlock and that deactivate/reactivate interface is
        something fundamentally flawed and that cgroup will have to work
        with the remove_self() like everybody else.  IOW, I think the
        first posting was correct.

Cc: Tejun Heo <tj@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-13 14:05:13 -08:00
Greg Kroah-Hartman
a30f82b7eb Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()"
This reverts commit d1ba277e79.

Tejun writes:
        I'm sorry but can you please revert the whole series?
        get_active() waiting while a node is deactivated has potential
        to lead to deadlock and that deactivate/reactivate interface is
        something fundamentally flawed and that cgroup will have to work
        with the remove_self() like everybody else.  IOW, I think the
        first posting was correct.

Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-13 13:51:36 -08:00
Tejun Heo
d1ba277e79 sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()
All device_schedule_callback_owner() users are converted to use
device_remove_file_self().  Remove now unused
{sysfs|device}_schedule_callback_owner().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-10 16:03:19 -08:00
Tejun Heo
1ae06819c7 kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers
Sometimes it's necessary to implement a node which wants to delete
nodes including itself.  This isn't straightforward because of kernfs
active reference.  While a file operation is in progress, an active
reference is held and kernfs_remove() waits for all such references to
drain before completing.  For a self-deleting node, this is a deadlock
as kernfs_remove() ends up waiting for an active reference that itself
is sitting on top of.

This currently is worked around in the sysfs layer using
sysfs_schedule_callback() which makes such removals asynchronous.
While it works, it's rather cumbersome and inherently breaks
synchronicity of the operation - the file operation which triggered
the operation may complete before the removal is finished (or even
started) and the removal may fail asynchronously.  If a removal
operation is immmediately followed by another operation which expects
the specific name to be available (e.g. removal followed by rename
onto the same name), there's no way to make the latter operation
reliable.

The thing is there's no inherent reason for this to be asynchrnous.
All that's necessary to do this synchronous is a dedicated operation
which drops its own active ref and deactivates self.  This patch
implements kernfs_remove_self() and its wrappers in sysfs and driver
core.  kernfs_remove_self() is to be called from one of the file
operations, drops the active ref and deactivates using
__kernfs_deactivate_self(), removes the self node, and restores active
ref to the dead node using __kernfs_reactivate_self() so that the ref
is balanced afterwards.  __kernfs_remove() is updated so that it takes
an early exit if the target node is already fully removed so that the
active ref restored by kernfs_remove_self() after removal doesn't
confuse the deactivation path.

This makes implementing self-deleting nodes very easy.  The normal
removal path doesn't even need to be changed to use
kernfs_remove_self() for the self-deleting node.  The method can
invoke kernfs_remove_self() on itself before proceeding the normal
removal path.  kernfs_remove() invoked on the node by the normal
deletion path will simply be ignored.

This will replace sysfs_schedule_callback().  A subtle feature of
sysfs_schedule_callback() is that it collapses multiple invocations -
even if multiple removals are triggered, the removal callback is run
only once.  An equivalent effect can be achieved by testing the return
value of kernfs_remove_self() - only the one which gets %true return
value should proceed with actual deletion.  All other instances of
kernfs_remove_self() will wait till the enclosing kernfs operation
which invoked the winning instance of kernfs_remove_self() finishes
and then return %false.  This trivially makes all users of
kernfs_remove_self() automatically show correct synchronous behavior
even when there are multiple concurrent operations - all "echo 1 >
delete" instances will finish only after the whole operation is
completed by one of the instances.

v2: For !CONFIG_SYSFS, dummy version kernfs_remove_self() was missing
    and sysfs_remove_file_self() had incorrect return type.  Fix it.
    Reported by kbuild test bot.

v3: Updated to use __kernfs_{de|re}activate_self().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-10 14:01:05 -08:00
Rafael J. Wysocki
ecfbf6fd9c Driver core: Fix device_add_attrs() error code path
If the addition of dev_attr_online fails, device_add_attrs() should
remove device attribute groups as well as type and class attribute
groups before returning an error code.  Make that happen.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-18 15:50:16 -08:00
David Herrmann
bbc780f8ba driver core: fix device_create() error path
We call put_device() in the error path, which is fine for dev==NULL.
However, in case kobject_set_name_vargs() fails, we have dev!=NULL but
device_initialized() wasn't called, yet.

Fix this by splitting device_register() into explicit calls to
device_add() and an early call to device_initialize().

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08 18:25:10 -08:00
ethan.zhao
69df75334b drivers/base/core.c: output device renaming messages with dev_dbg().
Replace pr_debug() with dev_dbg().

Signed-off-by: ethan.zhao <ethan.kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 18:33:27 -07:00
Greg Kroah-Hartman
a6b01deda1 driver core: remove dev_bin_attrs from struct class
No in-kernel code is now using this, they have all be converted over to
using the bin_attrs support in attribute groups, so this field, and the
code in the driver core that was creating/remove the binary files can be
removed.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-06 00:01:47 -07:00
Greg Kroah-Hartman
bcc8edb52f driver core: remove dev_attrs from struct class
Now that all in-kernel users of the dev_attrs field are converted to use
dev_groups, we can safely remove dev_attrs from struct class.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-05 23:59:34 -07:00