Commit Graph

71 Commits

Author SHA1 Message Date
Bjorn Helgaas
0caa17f5f2 Merge branch 'pci/misc'
- Convert PCIe capability PCIBIOS errors to errno (Bolarinwa Olayemi
  Saheed)

- Align PCIe capability and PCI accessor return values (Bolarinwa Olayemi
  Saheed)

- Replace http:// links with https:// (Alexander A. Klimov)

- Replace lkml.org, spinics, gmane with lore.kernel.org (Bjorn Helgaas)

- Update panic message to mention kzalloc(), not kmalloc() (Liao Pingfang)

- Move PCI_VENDOR_ID_REDHAT definition to pci_ids.h (Huacai Chen)

- Remove unused pci_lost_interrupt() (Heiner Kallweit)

* pci/misc:
  PCI: Remove unused pci_lost_interrupt()
  PCI: Move PCI_VENDOR_ID_REDHAT definition to pci_ids.h
  PCI: Fix error in panic message
  PCI: Replace lkml.org, spinics, gmane with lore.kernel.org
  PCI: Replace http:// links with https://
  PCI: Align PCIe capability and PCI accessor return values
  PCI: Convert PCIe capability PCIBIOS errors to errno
2020-08-05 18:24:16 -05:00
Bjorn Helgaas
2a7e32d054 PCI: Fix pci_cfg_wait queue locking problem
The pci_cfg_wait queue is used to prevent user-space config accesses to
devices while they are recovering from reset.

Previously we used these operations on pci_cfg_wait:

  __add_wait_queue(&pci_cfg_wait, ...)
  __remove_wait_queue(&pci_cfg_wait, ...)
  wake_up_all(&pci_cfg_wait)

The wake_up acquires the wait queue lock, but the add and remove do not.

Originally these were all protected by the pci_lock, but cdcb33f982
("PCI: Avoid possible deadlock on pci_lock and p->pi_lock"), moved
wake_up_all() outside pci_lock, so it could race with add/remove
operations, which caused occasional kernel panics, e.g., during vfio-pci
hotplug/unplug testing:

  Unable to handle kernel read from unreadable memory at virtual address ffff802dac469000

Resolve this by using wait_event() instead of __add_wait_queue() and
__remove_wait_queue().  The wait queue lock is held by both wait_event()
and wake_up_all(), so it provides mutual exclusion.

Fixes: cdcb33f982 ("PCI: Avoid possible deadlock on pci_lock and p->pi_lock")
Link: https://lore.kernel.org/linux-pci/79827f2f-9b43-4411-1376-b9063b67aee3@huawei.com/T/#u
Based-on: https://lore.kernel.org/linux-pci/20191210031527.40136-1-zhengxiang9@huawei.com/
Based-on-patch-by: Xiang Zheng <zhengxiang9@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Xiang Zheng <zhengxiang9@huawei.com>
Cc: Heyi Guo <guoheyi@huawei.com>
Cc: Biaoxiang Ye <yebiaoxiang@huawei.com>
2020-07-07 15:09:01 -05:00
Bolarinwa Olayemi Saheed
b91535812d PCI: Align PCIe capability and PCI accessor return values
The PCI config accessors (pci_read_config_word(), et al) return
PCIBIOS_SUCCESSFUL (zero) or positive error values like
PCIBIOS_FUNC_NOT_SUPPORTED.

The PCIe capability accessors similarly return PCIBIOS errors, but in
addition, they can return -EINVAL.  This makes it harder than it should be
to check for errors.

Return PCIBIOS_BAD_REGISTER_NUMBER instead of -EINVAL in all PCIe
capability accessors.

Suggested-by: Bjorn Helgaas <bjorn@helgaas.com>
Link: https://lore.kernel.org/r/20200615073225.24061-9-refactormyself@gmail.com
Signed-off-by: Bolarinwa Olayemi Saheed <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-06-26 13:50:41 -05:00
Patel, Mayurkumar
af65d1ad41 PCI/AER: Save AER Capability for suspend/resume
Previously we did not save and restore the AER configuration on
suspend/resume, so the configuration may be lost after resume.

Save the AER configuration during suspend and restore it during resume.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/92EBB4272BF81E4089A7126EC1E7B28492C3B007@IRSMSX101.ger.corp.intel.com
Signed-off-by: Mayurkumar Patel <mayurkumar.patel@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2019-10-18 17:05:42 -05:00
Mika Westerberg
984998e340 PCI: Make pcie_downstream_port() available outside of access.c
pcie_downstream_port() is useful in other places where code needs to
determine whether the PCIe port is downstream so make it available outside
of access.c.

Link: https://lore.kernel.org/r/20190822085553.62697-1-mika.westerberg@linux.intel.com
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2019-09-07 07:45:25 -05:00
Keith Busch
5180fd9135 PCI: Uninline PCI bus accessors for better ftracing
The PCI bus config accessors could be inlined into other accessor
functions, which makes it so they can't be traced.  Force them to never be
inlined so that ftrace can hook into these functions.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-10-04 16:37:37 -05:00
Bjorn Helgaas
c8afd5ef00 Merge branch 'pci/vpd'
- consolidate VPD code in vpd.c (Bjorn Helgaas)

* pci/vpd:
  PCI/VPD: Move VPD structures to vpd.c
  PCI/VPD: Move VPD quirks to vpd.c
  PCI/VPD: Move VPD sysfs code to vpd.c
  PCI/VPD: Move VPD access code to vpd.c
2018-04-04 13:28:40 -05:00
Bjorn Helgaas
df62ab5e0f PCI: Tidy comments
Remove pointless comments that tell us the file name, remove blank line
comments, follow multi-line comment conventions.  No functional change
intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-03-19 14:20:43 -05:00
Bjorn Helgaas
f0eb77ae6b PCI/VPD: Move VPD access code to vpd.c
Move the VPD-related code from access.c to vpd.c.  The goal is to
encapsulate all the VPD code and structures in vpd.c.

No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-03-19 13:06:11 -05:00
Bjorn Helgaas
ab8c609356 Merge branch 'pci/spdx' into next
* pci/spdx:
  PCI: Add SPDX GPL-2.0+ to replace implicit GPL v2 or later statement
  PCI: Add SPDX GPL-2.0+ to replace GPL v2 or later boilerplate
  PCI: Add SPDX GPL-2.0 to replace COPYING boilerplate
  PCI: Add SPDX GPL-2.0 to replace GPL v2 boilerplate
  PCI: Add SPDX GPL-2.0 when no license was specified
2018-02-01 11:40:07 -06:00
Bjorn Helgaas
7328c8f48d PCI: Add SPDX GPL-2.0 when no license was specified
b24413180f ("License cleanup: add SPDX GPL-2.0 license identifier to
files with no license") added SPDX GPL-2.0 to several PCI files that
previously contained no license information.

Add SPDX GPL-2.0 to all other PCI files that did not contain any license
information and hence were under the default GPL version 2 license of the
kernel.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-26 11:45:16 -06:00
Frederick Lawler
7506dc7989 PCI: Add wrappers for dev_printk()
Add PCI-specific dev_printk() wrappers and use them to simplify the code
slightly.  No functional change intended.

Signed-off-by: Frederick Lawler <fred@fredlawl.com>
[bhelgaas: squash into one patch]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-01-18 12:55:24 -06:00
Thomas Gleixner
714fe383d6 PCI: Provide Kconfig option for lockless config space accessors
The generic PCI configuration space accessors are globally serialized via
pci_lock. On larger systems this causes massive lock contention when the
configuration space has to be accessed frequently. One such access pattern
is the Intel Uncore performance counter unit.

Provide a kernel config option which can be selected by an architecture
when the low level PCI configuration space accessors in the architecture
use their own serialization or can operate completely lockless.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Bjorn Helgaas <helgaas@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: linux-pci@vger.kernel.org
Link: http://lkml.kernel.org/r/20170316215057.205961140@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-06-28 22:32:56 +02:00
Brian Norris
449e2f9e95 PCI: Make error code types consistent in pci_{read,write}_config_*
Callers normally treat the config space accessors as returning PCBIOS_*
error codes, not Linux error codes (or they don't look at them at all).  We
have pcibios_err_to_errno() in case the error code needs to be translated.

Fixes: 4b10388347 ("PCI: Don't attempt config access to disconnected devices")
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
2017-05-26 16:38:50 -05:00
Bjorn Helgaas
94f543b276 Merge branch 'pci/misc' into next
* pci/misc:
  PCI: Change pci_host_common_probe() visibility
  PCI: Fix typo pci_cfg_access_lock() comment
  PCI: Include pci.h for struct pci_ops definition
2017-04-28 10:34:14 -05:00
Bjorn Helgaas
9b70ae4951 PCI: Include PCI-to-PCIe bridges as "Downstream Ports"
A PCI/PCI-X to PCI Express bridge, sometimes referred to as a "reverse
bridge", is a bridge with conventional PCI or PCI-X on its primary side and
a PCI Express Port on its secondary (downstream) side.

That PCIe Port is a Downstream Port and could be connected to a slot, just
like a Root Port or a Switch Downstream Port.  Make pcie_downstream_port()
return true for them, so we can access the Slot registers in the PCIe
capability.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-04-19 07:44:51 -05:00
Brian Norris
0b131b1394 PCI: Fix typo pci_cfg_access_lock() comment
There is no pci_cfg_access_unlocked(). I think the author meant
pci_cfg_access_unlock().

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-04-04 12:02:57 -05:00
Keith Busch
4b10388347 PCI: Don't attempt config access to disconnected devices
If we've  detected the PCI device is disconnected, there is no need to
attempt to access its config space since we know the operation will fail.
Make all the config reads and writes return -ENODEV error immediately when
in such a state.

If a caller requests a config read to a disconnected device, return a data
value of all 1's.  This is the same as what hardware is expected to return
when accessing a removed device, but software can do this faster without
relying on hardware.

Tested-by: Krishna Dhulipala <krishnad@fb.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Wei Zhang <wzhang@fb.com>
2017-03-29 22:54:56 -05:00
Keith Busch
d3881e5015 PCI: Export PCI device config accessors
Replace the inline PCI device config read and write accessors with exported
functions.  This is preparing for these functions to make use of private
data.

Tested-by: Krishna Dhulipala <krishnad@fb.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Wei Zhang <wzhang@fb.com>
2017-03-29 22:48:52 -05:00
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
Bjorn Helgaas
4c2ae32d4c Merge branch 'pci/vpd' into next
* pci/vpd:
  PCI: Increase VPD access timeout to 125ms
2017-02-15 11:56:12 -06:00
Matthew R. Ochs
4f69bd16df PCI: Increase VPD access timeout to 125ms
The PCI core uses a fixed 50ms timeout when waiting for VPD accesses to
complete.  When an access does not complete within this period, a warning
is logged and an error returned to the caller.

While this default timeout is valid for most hardware, some devices can
experience longer access delays under certain circumstances.  For example,
one of the IBM CXL Flash devices can take up to ~120ms in a worst-case
scenario.  These types of devices can benefit from an extended timeout.

To support devices with a longer access delay, increase the timeout in
pci_vpd_wait() to 125ms.  The PCI specification is silent with respect to
VPD delays, therefore there is no concern for violating a threshold.

Tested-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
2017-02-03 11:16:30 -06:00
Bjorn Helgaas
cdcb33f982 PCI: Avoid possible deadlock on pci_lock and p->pi_lock
pci_lock is an IRQ-safe spinlock that protects all accesses to PCI
configuration space (see PCI_OP_READ() and PCI_OP_WRITE() in pci/access.c).

The pci_cfg_access_unlock() path acquires pci_lock, then p->pi_lock (inside
wake_up_all()).  According to lockdep, there is a possible path involving
snbep_uncore_pci_read_counter() that could acquire them in the reverse
order: acquiring p->pi_lock, then pci_lock, which could result in a
deadlock.  Lockdep details are in the bugzilla below.

Avoid the possible deadlock by dropping pci_lock before waking up any
config access waiters.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=192901
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-01-30 16:55:33 -06:00
Bjorn Helgaas
fb26592301 PCI: Warn on possible RW1C corruption for sub-32 bit config writes
Hardware that supports only 32-bit config writes is not spec-compliant.
For example, if software performs a 16-bit write, we must do a 32-bit read,
merge in the 16 bits we intend to write, followed by a 32-bit write.  If
the 16 bits we *don't* intend to write happen to have any RW1C (write-one-
to-clear) bits set, we just inadvertently cleared something we shouldn't
have.

Add a rate-limited warning when we do sub-32 bit config writes.  Remove
similar probe-time warnings from some of the affected host bridge drivers.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Enthusiastically-Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Shawn Lin <shawn.lin@rock-chips.com>	# rockchip
Acked-by: Thierry Reding <treding@nvidia.com>
2016-11-21 16:25:39 -06:00
Hariprasad Shenai
cb92148b58 PCI: Add pci_set_vpd_size() to set VPD size
After 104daa71b3 ("PCI: Determine actual VPD size on first access"), the
PCI core computes the valid VPD size by parsing the VPD starting at offset
0x0.  We don't attempt to read past that valid size because that causes
some devices to crash.

However, some devices do have data past that valid size.  For example,
Chelsio adapters contain two VPD structures, and the driver needs both of
them.

Add pci_set_vpd_size().  If a driver knows it is safe to read past the end
of the VPD data structure at offset 0, it can use pci_set_vpd_size() to
allow access to as much data as it needs.

[bhelgaas: changelog, split patches, rename to pci_set_vpd_size() and
return int (not ssize_t)]
Fixes: 104daa71b3 ("PCI: Determine actual VPD size on first access")
Tested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Casey Leedom <leedom@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-04-15 13:00:11 -05:00
Bjorn Helgaas
c521b014cd PCI: Sleep rather than busy-wait for VPD access completion
Use usleep_range() instead of udelay() while waiting for a VPD access to
complete.  This is not a performance path, so no need to hog the CPU.

Rationale for usleep_range() parameters:

  We clear PCI_VPD_ADDR_F for a read (or set it for a write), then wait for
  the device to change it.  For a device that updates PCI_VPD_ADDR between
  our config write and subsequent config read, we won't sleep at all and
  can get the device's maximum rate.

  Sleeping a minimum of 10 usec per 4-byte access limits throughput to
  about 400Kbytes/second.  VPD is small (32K bytes at most), and most
  devices use only a fraction of that.

  We back off exponentially up to 1024 usec per iteration.  If we reach
  1024, we've already waited up to 1008 usec (16 + 32 + ... + 512), so if
  we miss an update and wait an extra 1024 usec, we can still get about
  1/2 of the device's maximum rate.

Tested-by: Shane Seymour <shane.seymour@hpe.com>
Tested-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
2016-03-10 14:24:48 -06:00
Bjorn Helgaas
408641e93a PCI: Fold struct pci_vpd_pci22 into struct pci_vpd
We only support one flavor of VPD, so there's no need to complicate things
by having a "generic" struct pci_vpd and a more specific struct
pci_vpd_pci22.

Fold struct pci_vpd_pci22 directly into struct pci_vpd.

[bhelgaas: remove NULL check before kfree of dev->vpd (per kfreeaddr.cocci)]
Tested-by: Shane Seymour <shane.seymour@hpe.com>
Tested-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
2016-02-29 17:47:36 -06:00
Bjorn Helgaas
f1cd93f9aa PCI: Rename VPD symbols to remove unnecessary "pci22"
There's only one kind of VPD, so we don't need to qualify it as "the
version described by PCI spec rev 2.2."

Rename the following symbols to remove unnecessary "pci22":

  PCI_VPD_PCI22_SIZE	-> PCI_VPD_MAX_SIZE
  pci_vpd_pci22_size()	-> pci_vpd_size()
  pci_vpd_pci22_wait()	-> pci_vpd_wait()
  pci_vpd_pci22_read()	-> pci_vpd_read()
  pci_vpd_pci22_write()	-> pci_vpd_write()
  pci_vpd_pci22_ops	-> pci_vpd_ops
  pci_vpd_pci22_init()	-> pci_vpd_init()

Tested-by: Shane Seymour <shane.seymour@hpe.com>
Tested-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
2016-02-29 17:47:31 -06:00
Bjorn Helgaas
da00684723 PCI: Remove struct pci_vpd_ops.release function pointer
The struct pci_vpd_ops.release function pointer is always
pci_vpd_pci22_release(), so there's no need for the flexibility of a
function pointer.

Inline the pci_vpd_pci22_release() body into pci_vpd_release() and remove
pci_vpd_pci22_release() and the struct pci_vpd_ops.release function
pointer.

Tested-by: Shane Seymour <shane.seymour@hpe.com>
Tested-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
2016-02-29 17:47:24 -06:00
Bjorn Helgaas
64379079a9 PCI: Move pci_vpd_release() from header file to pci/access.c
Move pci_vpd_release() so it's next to the other VPD functions.  This puts
it next to pci_vpd_pci22_init(), which allocates the space freed by
pci_vpd_release().

Tested-by: Shane Seymour <shane.seymour@hpe.com>
Tested-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
2016-02-29 17:47:16 -06:00
Bjorn Helgaas
fc0a407e9e PCI: Move pci_read_vpd() and pci_write_vpd() close to other VPD code
pci_read_vpd() and pci_write_vpd() were stranded in the middle of config
accessor functions.  Move them close to the other VPD code in the file.
No functional change.

Tested-by: Shane Seymour <shane.seymour@hpe.com>
Tested-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
2016-02-29 17:47:11 -06:00
Hannes Reinecke
104daa71b3 PCI: Determine actual VPD size on first access
PCI-2.2 VPD entries have a maximum size of 32k, but might actually be
smaller than that.  To figure out the actual size one has to read the VPD
area until the 'end marker' is reached.

Per spec, reading outside of the VPD space is "not allowed."  In practice,
it may cause simple read errors or even crash the card.  To make matters
worse not every PCI card implements this properly, leaving us with no 'end'
marker or even completely invalid data.

Try to determine the size of the VPD data when it's first accessed.  If no
valid data can be read an I/O error will be returned when reading or
writing the sysfs attribute.

As the amount of VPD data is unknown initially the size of the sysfs
attribute will always be set to '0'.

[bhelgaas: changelog, use 0/1 (not false/true) for bitfield, tweak
pci_vpd_pci22_read() error checking]
Tested-by: Shane Seymour <shane.seymour@hpe.com>
Tested-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
2016-02-29 17:47:04 -06:00
Bjorn Helgaas
c5563887a9 PCI: Use bitfield instead of bool for struct pci_vpd_pci22.busy
Make struct pci_vpd_pci22.busy a 1-bit field instead of a bool.  We intend
to add another flag, and two bitfields are cheaper than two bools.

Tested-by: Shane Seymour <shane.seymour@hpe.com>
Tested-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
2016-02-29 17:46:57 -06:00
Bogicevic Sasa
ff3ce480e8 PCI: Fix all whitespace issues
Fix all whitespace issues (missing or needed whitespace) in all files in
drivers/pci.  Code is compiled with allyesconfig before and after code
changes and objects are recorded and checked with objdiff and they are not
changed after this commit.

Signed-off-by: Bogicevic Sasa <brutallesale@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-01-08 10:35:24 -06:00
Alex Williamson
da2d03ea27 PCI: Use function 0 VPD for identical functions, regular VPD for others
932c435cab ("PCI: Add dev_flags bit to access VPD through function 0")
added PCI_DEV_FLAGS_VPD_REF_F0.  Previously, we set the flag on every
non-zero function of quirked devices.  If a function turned out to be
different from function 0, i.e., it had a different class, vendor ID, or
device ID, the flag remained set but we didn't make VPD accessible at all.

Flip this around so we only set PCI_DEV_FLAGS_VPD_REF_F0 for functions that
are identical to function 0, and allow regular VPD access for any other
functions.

[bhelgaas: changelog, stable tag]
Fixes: 932c435cab ("PCI: Add dev_flags bit to access VPD through function 0")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
Acked-by: Myron Stowe <myron.stowe@redhat.com>
Acked-by: Mark Rustad <mark.d.rustad@intel.com>
CC: stable@vger.kernel.org
2015-09-24 17:06:32 -05:00
Alex Williamson
9d9240756e PCI: Fix devfn for VPD access through function 0
Commit 932c435cab ("PCI: Add dev_flags bit to access VPD through function
0") passes PCI_SLOT(devfn) for the devfn parameter of pci_get_slot().
Generally this works because we're fairly well guaranteed that a PCIe
device is at slot address 0, but for the general case, including
conventional PCI, it's incorrect.  We need to get the slot and then convert
it back into a devfn.

Fixes: 932c435cab ("PCI: Add dev_flags bit to access VPD through function 0")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
Acked-by: Myron Stowe <myron.stowe@redhat.com>
Acked-by: Mark Rustad <mark.d.rustad@intel.com>
CC: stable@vger.kernel.org
2015-09-24 17:06:32 -05:00
Mark Rustad
932c435cab PCI: Add dev_flags bit to access VPD through function 0
Add a dev_flags bit, PCI_DEV_FLAGS_VPD_REF_F0, to access VPD through
function 0 to provide VPD access on other functions.  This is for hardware
devices that provide copies of the same VPD capability registers in
multiple functions.  Because the kernel expects that each function has its
own registers, both the locking and the state tracking are affected by VPD
accesses to different functions.

On such devices for example, if a VPD write is performed on function 0,
*any* later attempt to read VPD from any other function of that device will
hang.  This has to do with how the kernel tracks the expected value of the
F bit per function.

Concurrent accesses to different functions of the same device can not only
hang but also corrupt both read and write VPD data.

When hangs occur, typically the error message:

  vpd r/w failed.  This is likely a firmware bug on this device.

will be seen.

Never set this bit on function 0 or there will be an infinite recursion.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alexander Duyck <alexander.h.duyck@redhat.com>
CC: stable@vger.kernel.org
2015-07-21 13:11:53 -05:00
Bjorn Helgaas
ffb4d60262 PCI: Add pcie_downstream_port() (true for Root and Switch Downstream Ports)
As used in the PCIe spec, "Downstream Port" includes both Root Ports and
Switch Downstream Ports.  We sometimes checked for PCI_EXP_TYPE_DOWNSTREAM
when we should have checked for PCI_EXP_TYPE_ROOT_PORT or
PCI_EXP_TYPE_DOWNSTREAM.

For a Root Port without a slot, the effect of this was that using
pcie_capability_read_word() to read PCI_EXP_SLTSTA returned zero instead of
showing the Presence Detect State bit hardwired to one as the PCIe Spec,
r3.0, sec 7.8, requires.  (This read is completed in software because
previous PCIe spec versions didn't require PCI_EXP_SLTSTA to exist at all.)

Nothing in the kernel currently depends on this (pciehp only reads
PCI_EXP_SLTSTA on ports with slots), so this is a cleanup and not a
functional change.

Add a pcie_downstream_port() helper function and use it.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-14 17:39:32 -05:00
Rob Herring
1f94a94f67 PCI: Add generic config accessors
Many PCI controllers' configuration space accesses are memory-mapped and
vary only in address calculation and access checks.  There are 2 main
access methods: a decoded address space such as ECAM or a single address
and data register similar to x86.  This implementation can support both
cases as well as be used in cases that need additional pre- or post-access
handling.

Add a new pci_ops member, map_bus, which can do access checks and any
necessary setup.  It returns the address to use for the configuration space
access.  The access types supported are 32-bit only accesses or correct
byte, word, or dword sized accesses.

Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
2015-01-22 13:59:45 -06:00
Yinghai Lu
7a1562d4f2 PCI: Apply _HPX Link Control settings to all devices with a link
Previously we applied _HPX type 2 record Link Control register settings
only to bridges with a subordinate bus.  But it's better to apply them to
all devices with a link because if the subordinate bus has not been
allocated yet, we won't apply settings to the device.

Use pcie_cap_has_lnkctl() to determine whether the device has a Link
Control register instead of looking at dev->subordinate.

[bhelgaas: changelog]
Fixes: 6cd33649fa ("PCI: Add pci_configure_device() during enumeration")
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-11-13 15:43:42 -07:00
Ryan Desfosses
227f064705 PCI: Merge multi-line quoted strings
Merge quoted strings that are broken across lines into a single entity.
The compiler merges them anyway, but checkpatch complains about it, and
merging them makes it easier to grep for strings.

No functional change.

[bhelgaas: changelog, do the same for everything under drivers/pci]
Signed-off-by: Ryan Desfosses <ryan@desfo.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-06-10 20:20:42 -06:00
Gavin Shan
d97ffe2368 PCI: Fix return value from pci_user_{read,write}_config_*()
The PCI user-space config accessors pci_user_{read,write}_config_*() return
negative error numbers, which were introduced by commit 34e3207205
("PCI: handle positive error codes").  That patch converted all positive
error numbers from platform-specific PCI config accessors to -EINVAL, which
means the callers don't know anything about the specific cause of the
failure.

The patch fixes the issue by converting the positive PCIBIOS_* error values
to generic negative error numbers with pcibios_err_to_errno().

[bhelgaas: changelog]
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Greg Thelen <gthelen@google.com>
2014-05-27 17:10:16 -06:00
Stephen Hemminger
3984ca1c6e PCI: Remove unused pci_vpd_truncate()
My philosophy is unused code is dead code.  And dead code is subject to bit
rot and is a likely source of bugs.  Use it or lose it.

This reverts db5679437a ("PCI: add interface to set visible size of
VPD"), removing this interface:

    pci_vpd_truncate()

[bhelgaas: split to separate patch, also remove prototype from pci.h]
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-01-13 11:14:43 -07:00
Bjorn Helgaas
fed2451512 PCI: Remove pcie_cap_has_devctl()
pcie_cap_has_devctl() does nothing, so remove it.  Simplicity over
consistency in this case.  No functional change.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-By: Jiang Liu <jiang.liu@huawei.com>
2013-08-28 20:51:39 -06:00
Bjorn Helgaas
6d3a1741f1 PCI: Support PCIe Capability Slot registers only for ports with slots
Previously we allowed callers to access Slot Capabilities, Status, and
Control for Root Ports even if the Root Port did not implement a slot.
This seems dubious because the spec only requires these registers if a
slot is implemented.

It's true that even Root Ports without slots must have *space* for these
slot registers, because the Root Capabilities, Status, and Control
registers are after the slot registers in the capability.  However,
for a v1 PCIe Capability, the *semantics* of the slot registers are
undefined unless a slot is implemented.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-By: Jiang Liu <jiang.liu@huawei.com>
2013-08-28 20:51:39 -06:00
Bjorn Helgaas
c8b303d020 PCI: Remove PCIe Capability version checks
Previously we relied on the PCIe r3.0, sec 7.8, spec language that says
"For Functions that do not implement the [Link, Slot, Root] registers,
these spaces must be hardwired to 0b," which means that for v2 PCIe
capabilities, we don't need to check the device type at all.

But it's simpler if we don't need to check the capability version at all,
and I think the spec is explicit enough about which registers are required
for which types that we can remove the version checks.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-By: Jiang Liu <jiang.liu@huawei.com>
2013-08-28 20:51:39 -06:00
Bjorn Helgaas
d3694d4fa3 PCI: Allow PCIe Capability link-related register access for switches
Every PCIe device has a link, except Root Complex Integrated Endpoints
and Root Complex Event Collectors.  Previously we didn't give access
to PCIe capability link-related registers for Upstream Ports, Downstream
Ports, and Bridges, so attempts to read PCI_EXP_LNKCTL incorrectly
returned zero.  See PCIe spec r3.0, sec 7.8 and 1.3.2.3.

Reference: http://lkml.kernel.org/r/979A8436335E3744ADCD3A9F2A2B68A52AD136BE@SJEXCHMB10.corp.ad.broadcom.com
Reported-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-By: Jiang Liu <jiang.liu@huawei.com>
2013-08-28 11:28:22 -06:00
Alex Williamson
969daa349f PCI: Fix PCI Express Capability accessors for PCI_EXP_FLAGS
PCI_EXP_FLAGS_TYPE is a mask, not an offset.  Fix it.

Previously, pcie_capability_read_word(..., PCI_EXP_FLAGS, ...) would
fail.

[bhelgaas:  tweak changelog]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org	# v3.7+
2013-02-15 11:46:24 -07:00
Myron Stowe
1c531d82ee PCI: Use PCI Express Capability accessor
Use PCI Express Capability access functions to simplify device
Capabilities Register usages.

Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-01-30 21:24:39 -07:00
Jiang Liu
8c0d3a02c1 PCI: Add accessors for PCI Express Capability
The PCI Express Capability (PCIe spec r3.0, sec 7.8) comes in two
versions, v1 and v2.  In v1 Capability structures (PCIe spec r1.0 and
r1.1), some fields are optional, so the structure size depends on the
device type.

This patch adds functions to access this capability so drivers don't
have to be aware of the differences between v1 and v2.  Note that these
new functions apply only to the "PCI Express Capability," not to any of
the other "PCI Express Extended Capabilities" (AER, VC, ACS, MFVC, etc.)

Function pcie_capability_read_word/dword() reads the PCIe Capabilities
register and returns the value in the reference parameter "val".  If
the PCIe Capabilities register is not implemented on the PCIe device,
"val" is set to 0.

Function pcie_capability_write_word/dword() writes the value to the
specified PCIe Capability register.

Function pcie_capability_clear_and_set_word/dword() sets and/or clears bits
of a PCIe Capability register.

[bhelgaas: changelog, drop "pci_" prefixes, don't export
pcie_capability_reg_implemented()]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-08-23 09:41:20 -06:00