Commit Graph

46 Commits

Author SHA1 Message Date
Niklas Schnelle
4cdf2f4e24 s390/pci: implement minimal PCI error recovery
When the platform detects an error on a PCI function or a service action
has been performed it is put in the error state and an error event
notification is provided to the OS.

Currently we treat all error event notifications the same and simply set
pdev->error_state = pci_channel_io_perm_failure requiring user
intervention such as use of the recover attribute to get the device
usable again. Despite requiring a manual step this also has the
disadvantage that the device is completely torn down and recreated
resulting in higher level devices such as a block or network device
being recreated. In case of a block device this also means that it may
need to be removed and added to a software raid even if that could
otherwise survive with a temporary degradation.

This is of course not ideal more so since an error notification with PEC
0x3A indicates that the platform already performed error recovery
successfully or that the error state was caused by a service action that
is now finished.

At least in this case we can assume that the error state can be reset
and the function made usable again. So as not to have the disadvantage
of a full tear down and recreation we need to coordinate this recovery
with the driver. Thankfully there is already a well defined recovery
flow for this described in Documentation/PCI/pci-error-recovery.rst.

The implementation of this is somewhat straight forward and simplified
by the fact that our recovery flow is defined per PCI function. As
a reset we use the newly introduced zpci_hot_reset_device() which also
takes the PCI function out of the error state.

Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Acked-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-11-08 14:17:49 +01:00
Niklas Schnelle
4fe2049770 s390/pci: refresh function handle in iomap
The function handle of a PCI function is updated when disabling or
enabling it as well as when the function's availability changes or it
enters the error state.

Until now this only occurred either while there is no struct pci_dev
associated with the function yet or the function became unavailable.
This meant that leaving a stale function handle in the iomap either
didn't happen because there was no iomap yet or it lead to errors on PCI
access but so would the correct disabled function handle.

In the future a CLP Set PCI Function Disable/Enable cycle during PCI
device recovery may be done while the device is bound to a driver.  In
this case we must update the iomap associated with the now-stale
function handle to ensure that the resulting zPCI instruction references
an accurate function handle.

Since the function handle is accessed by the PCI accessor helpers
without locking use READ_ONCE()/WRITE_ONCE() to mark this access and
prevent compiler optimizations that would move the load/store.

With that infrastructure in place let's also properly update the
function handle in the existing cases. This makes sure that in the
future debugging of a zPCI function access through the handle will
show an up to date handle reducing the chance of confusion. Also it
makes sure we have one single place where a zPCI function handle is
updated after initialization.

Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-11-08 14:17:49 +01:00
Vasily Gorbik
e7456f7adb Merge branch 'fixes' into features
pci and string functions changes on features depend on changes from the
fixes branch.

* fixes:
  s390: add Alexander Gordeev as reviewer
  s390: fix strrchr() implementation
  vfio-ccw: step down as maintainer
  KVM: s390: remove myself as reviewer
  s390/pci: fix zpci_zdev_put() on reserve
  bpf, s390: Fix potential memory leak about jit_data

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-10-26 15:20:04 +02:00
Niklas Schnelle
6526a597a2 s390/pci: add simpler s390dbf traces for events
We often need to figure out what operations were performed in response
to an error or availability event. The operations are easily accessible
in s390dbf/pci_msg but the events have to be correlated with these from
either the kernel log or s390dbf/pci_err. Improve this situation by
logging the most important data from error and availability events that
is the FID, PEC and FH together with the operations.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-10-04 09:49:36 +02:00
Niklas Schnelle
a46044a92a s390/pci: fix zpci_zdev_put() on reserve
Since commit 2a671f77ee ("s390/pci: fix use after free of zpci_dev")
the reference count of a zpci_dev is incremented between
pcibios_add_device() and pcibios_release_device() which was supposed to
prevent the zpci_dev from being freed while the common PCI code has
access to it. It was missed however that the handling of zPCI
availability events assumed that once zpci_zdev_put() was called no
later availability event would still see the device. With the previously
mentioned commit however this assumption no longer holds and we must
make sure that we only drop the initial long-lived reference the zPCI
subsystem holds exactly once.

Do so by introducing a zpci_device_reserved() function that handles when
a device is reserved. Here we make sure the zpci_dev will not be
considered for further events by removing it from the zpci_list.

This also means that the device actually stays in the
ZPCI_FN_STATE_RESERVED state between the time we know it has been
reserved and the final reference going away. We thus need to consider it
a real state instead of just a conceptual state after the removal. The
final cleanup of PCI resources, removal from zbus, and destruction of
the IOMMU stays in zpci_release_device() to make sure holders of the
reference do see valid data until the release.

Fixes: 2a671f77ee ("s390/pci: fix use after free of zpci_dev")
Cc: stable@vger.kernel.org
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-10-04 09:49:10 +02:00
Niklas Schnelle
1f3f76812d s390/pci: improve DMA translation init and exit
Currently zpci_dma_init_device()/zpci_dma_exit_device() is called as
part of zpci_enable_device()/zpci_disable_device() and errors for
zpci_dma_exit_device() are always ignored even if we could abort.

Improve upon this by moving zpci_dma_exit_device() out of
zpci_disable_device() and check for errors whenever we have a way to
abort the current operation. Note that for example in
zpci_event_hard_deconfigured() the device is expected to be gone so we
really can't abort and proceed even in case of error.

Similarly move the cc == 3 special case out of zpci_unregister_ioat()
and into the callers allowing to abort when finding an already disabled
devices precludes proceeding with the operation.

While we are at it log IOAT register/unregister errors in the s390
debugfs log,

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-08-25 11:03:34 +02:00
Niklas Schnelle
0d9cf5d8c5 s390/pci: handle stale deconfiguration events
The PCIs event with PEC 0x0303 or 0x0304 are a request to deconfigure
a PCI function, respectively an indication that it was already
deconfigured by the platform. If such an event is queued during boot it
may happen that the platform has already adjusted the configuration flag
of the relevant function in the CLP List PCI Functions result. In this
case we might not have configured the PCI function at all and should
thus ignore the event. Note that no locking is necessary as event
handling only starts after we have fully initialized the zPCI subsystem
and scanned all PCI devices listed in the CLP result.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-04-30 17:17:00 +02:00
Niklas Schnelle
a7f82c3641 s390/pci: rename zpci_configure_device()
With zpci_configure_device() now always called on a device that has
already been configured on the platform level its name has become
misleading. Rename it to zpci_scan_configured_device() to signify that
the function now only handles the correct scanning of a newly configured
PCI function taking care of the special handling necessary for function
0 and functions parked waiting for a PCI bus that can't be created
without first seeing function 0.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-04-30 17:17:00 +02:00
Niklas Schnelle
14c87ba812 s390/pci: separate zbus registration from scanning
Now that the zbus can be created without being scanned we can go one
step further and make registering a device to a zbus independent from
scanning it. This way the zbus handling becomes much more natural
in that functions can be registered on the zbus to be scanned later more
closely resembling the handling of both real PCI hardware and other
virtual PCI busses like Hyper-V's virtual PCI bus (see for example
drivers/pci/controller/pci-hyperv.c:create_root_hv_pci_bus()).

Having zbus registration separate from scanning allows us to return
fully initialized but still disabled zdevs from zpci_create_device()
which can then be configured just as we would configure a zdev from
standby (minus the SCLP Configure already done by the platform).  There
is still the exception that a PCI function with non-zero devfn can be
plugged before its PCI bus, which depends on the function with zero
devfn, is created. In this case the zdev returend from
zpci_create_device() is still missing its bus, hotplug slot, and
resources which need to be created later but at least it doesn't wait in
the enabled state and can otherwise be treated as initialized.

With this we also separate the initial PCI scan using CLP List PCI
Functions into two phases. In the CLP loop's callback we only register
each function with a virtual zbus creating the latter as needed. Then,
after we have built this virtual PCI topology based on our list of
zbusses, we can make use of the common code functionality to scan each
complete zbus as a separate child bus.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-04-12 12:46:42 +02:00
Niklas Schnelle
652d40b2f8 s390/pci: fix DMA cleanup on hard deconfigure
In commit dee60c0dbc ("s390/pci: add zpci_event_hard_deconfigured()")
we added a zdev_enabled() check to what was previously an uncoditional
call to zpci_disable_device(). There are two problems with that. Firstly
zpci_had_deconfigured() is only called on event 0x0304 for which the
device is always already disabled by the platform so it is always false.
Secondly zpci_disable_device() not only disables the device but also
calls zpci_dma_exit_device() which is thus not called and we leak the
DMA tables.

Fix this by calling zpci_disable_device() unconditionally to perform
Linux side cleanup including the freeing of DMA tables.

Fixes: dee60c0dbc ("s390/pci: add zpci_event_hard_deconfigured()")
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-03-28 20:23:54 +02:00
Niklas Schnelle
95b3a8b401 s390/pci: move zpci_remove_device() to bus code
The zpci_remove_device() function removes the device from the PCI common
code core which is an operation dealing primarily with the zbus and PCI
bus code. With that and to match an upcoming refactoring of the
symmetric scanning part move it to the bus code.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-03-22 11:36:04 +01:00
Niklas Schnelle
2631f6b6f2 s390/pci: unify de-/configure for slots and events
A zPCI event with PEC 0x0301 for an existing zPCI device goes through
the same actions as enable_slot(). Similarly a zPCI event with PEC
0x0303 does the same steps as disable_slot().
We can thus unify both actions as zpci_configure_device() respectively
zpci_deconfigure_device().

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-03-22 11:36:04 +01:00
Niklas Schnelle
dee60c0dbc s390/pci: add zpci_event_hard_deconfigured()
Extract the handling of PEC 0x0304 into a function and make sure we only
attempt to disable the function if it is enabled. Also check for errors
returned by zpci_disable_device() and leave the function alone if there
are any.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-03-22 11:36:04 +01:00
Niklas Schnelle
0b13525c20 s390/pci: fix leak of PCI device structure
In commit 05bc1be6db ("s390/pci: create zPCI bus") we removed the
pci_dev_put() call matching the earlier pci_get_slot() done as part of
__zpci_event_availability(). This was based on the wrong understanding
that the device_put() done as part of pci_destroy_device() would counter
the pci_get_slot() when it only counters the initial reference. This
same understanding and existing bad example also lead to not doing
a pci_dev_put() in zpci_remove_device().

Since releasing the PCI devices, unlike releasing the PCI slot, does not
print any debug message for testing I added one in pci_release_dev().
This revealed that we are indeed leaking the PCI device on PCI
hotunplug. Further testing also revealed another missing pci_dev_put() in
disable_slot().

Fix this by adding the missing pci_dev_put() in disable_slot() and fix
zpci_remove_device() with the correct pci_dev_put() calls. Also instead
of calling pci_get_slot() in __zpci_event_availability() to determine if
a PCI device is registered and then doing the same again in
zpci_remove_device() do this once in zpci_remove_device() which makes
sure that the pdev in __zpci_event_availability() is only used for the
result of pci_scan_single_device() which does not need a reference count
decremnt as its ownership goes to the PCI bus.

Also move the check if zdev->zbus->bus is set into zpci_remove_device()
since it may be that we're removing a device with devfn != 0 which never
had a PCI bus. So we can still set the pdev->error_state to indicate
that the device is not usable anymore, add a flag to set the error state.

Fixes: 05bc1be6db ("s390/pci: create zPCI bus")
Cc: <stable@vger.kernel.org> # 5.8+: e1bff843cd s390/pci: remove superfluous zdev->zbus check
Cc: <stable@vger.kernel.org> # 5.8+: ba764dd703 s390/pci: refactor zpci_create_device()
Cc: <stable@vger.kernel.org> # 5.8+
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-03-15 19:10:56 +01:00
Niklas Schnelle
ba764dd703 s390/pci: refactor zpci_create_device()
Currently zpci_create_device() is only called in clp_add_pci_device()
which allocates the memory for the struct zpci_dev being created. There
is little separation of concerns as only both functions together can
create a zpci_dev and the only CLP specific code in
clp_add_pci_device() is a call to clp_query_pci_fn().

Improve this by removing clp_add_pci_device() and refactor
zpci_create_device() such that it alone creates and initializes the
zpci_dev given the FID and Function Handle. For this we need to make
clp_query_pci_fn() non-static. While at it remove the function handle
parameter since we can just take that from the zpci_dev. Also move
adding to the zpci_list to after the zdev has been fully created which
eliminates a window where a partially initialized zdev can be found by
get_zdev_by_fid().

Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09 15:57:04 +01:00
Niklas Schnelle
e1bff843cd s390/pci: remove superfluous zdev->zbus check
Checking zdev->zbus for NULL in __zpci_event_availability() is
superfluous as it can never be NULL at this point. While harmless this
check causes smatch warnings because we later access zdev->zbus with
only having checked zdev != NULL which is sufficient.

The reason zdev->zbus can never be NULL is since with zdev != NULL given
we know the zdev came from get_zdev_by_fid() and thus the zpci_list.
Now on first glance at zpci_create_device() one may assume that there is
a window where the zdev is in the list without a zdev, however this
window can't overlap with __zpci_event_availability() as
zpci_create_device() either runs on the same kthread as part of
availability events, or during the initial CLP List PCI at which point
the __zpci_event_availability() is not yet called as zPCI is not yet
initialized.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-01-27 13:00:48 +01:00
Niklas Schnelle
0b2ca2c7d0 s390/pci: fix hot-plug of PCI function missing bus
Under some circumstances in particular with "Reconfigure I/O Path"
a zPCI function may first appear in Standby through a PCI event with
PEC 0x0302 which initially makes it visible to the zPCI subsystem,
Only after that is it configured with a zPCI event  with PEC 0x0301.
If the zbus is still missing a PCI function zero (devfn == 0) when the
PCI event 0x0301 is handled zdev->zbus->bus is still NULL and gets
dereferenced in common code.
Check for this case and enable but don't scan the zPCI function.
This matches what would happen if we immediately got the 0x0301
configuration request or the function was included in CLP List PCI.
In all cases the PCI functions with devfn != 0 will be scanned once
function 0 appears.

Fixes: 3047766bc6 ("s390/pci: fix enabling a reserved PCI function")
Cc: <stable@vger.kernel.org> # 5.8
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-03 15:12:16 +01:00
Linus Torvalds
847d4287a0 s390 updates for the 5.10 merge window
- Remove address space overrides using set_fs().
 
 - Convert to generic vDSO.
 
 - Convert to generic page table dumper.
 
 - Add ARCH_HAS_DEBUG_WX support.
 
 - Add leap seconds handling support.
 
 - Add NVMe firmware-assisted kernel dump support.
 
 - Extend NVMe boot support with memory clearing control and addition of
   kernel parameters.
 
 - AP bus and zcrypt api code rework. Add adapter configure/deconfigure
   interface. Extend debug features. Add failure injection support.
 
 - Add ECC secure private keys support.
 
 - Add KASan support for running protected virtualization host with
   4-level paging.
 
 - Utilize destroy page ultravisor call to speed up secure guests shutdown.
 
 - Implement ioremap_wc() and ioremap_prot() with MIO in PCI code.
 
 - Various checksum improvements.
 
 - Other small various fixes and improvements all over the code.
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Merge tag 's390-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Vasily Gorbik:

 - Remove address space overrides using set_fs()

 - Convert to generic vDSO

 - Convert to generic page table dumper

 - Add ARCH_HAS_DEBUG_WX support

 - Add leap seconds handling support

 - Add NVMe firmware-assisted kernel dump support

 - Extend NVMe boot support with memory clearing control and addition of
   kernel parameters

 - AP bus and zcrypt api code rework. Add adapter configure/deconfigure
   interface. Extend debug features. Add failure injection support

 - Add ECC secure private keys support

 - Add KASan support for running protected virtualization host with
   4-level paging

 - Utilize destroy page ultravisor call to speed up secure guests
   shutdown

 - Implement ioremap_wc() and ioremap_prot() with MIO in PCI code

 - Various checksum improvements

 - Other small various fixes and improvements all over the code

* tag 's390-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (85 commits)
  s390/uaccess: fix indentation
  s390/uaccess: add default cases for __put_user_fn()/__get_user_fn()
  s390/zcrypt: fix wrong format specifications
  s390/kprobes: move insn_page to text segment
  s390/sie: fix typo in SIGP code description
  s390/lib: fix kernel doc for memcmp()
  s390/zcrypt: Introduce Failure Injection feature
  s390/zcrypt: move ap_msg param one level up the call chain
  s390/ap/zcrypt: revisit ap and zcrypt error handling
  s390/ap: Support AP card SCLP config and deconfig operations
  s390/sclp: Add support for SCLP AP adapter config/deconfig
  s390/ap: add card/queue deconfig state
  s390/ap: add error response code field for ap queue devices
  s390/ap: split ap queue state machine state from device state
  s390/zcrypt: New config switch CONFIG_ZCRYPT_DEBUG
  s390/zcrypt: introduce msg tracking in zcrypt functions
  s390/startup: correct early pgm check info formatting
  s390: remove orphaned extern variables declarations
  s390/kasan: make sure int handler always run with DAT on
  s390/ipl: add support to control memory clearing for nvme re-IPL
  ...
2020-10-16 12:36:38 -07:00
Niklas Schnelle
809fcfaf92 s390/pci: remove clp_rescan_pci_devices()
there is only one call site of clp_rescan_pci_devices() and
all the function does is call zpci_remove_reserved_devices()
followed by a duplicating clp_scan_pci_devices().
So inline the single call as a call to zpci_remove_reserved_devices()
and clp_scan_pci_devices() and remove the function.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-14 11:38:34 +02:00
Niklas Schnelle
afdf9550e5 s390/pci: fix leak of DMA tables on hard unplug
commit f606b3ef47 ("s390/pci: adapt events for zbus") removed the
zpci_disable_device() call for a zPCI event with PEC 0x0304 because
the device is already deconfigured by the platform.
This however skips the Linux side of the disable in particular it leads
to leaking the DMA tables and bitmaps because zpci_dma_exit_device() is
never called on the device.

If the device transitions to the Reserved state we call zpci_zdev_put()
but zpci_release_device() will not call zpci_disable_device() because
the state of the zPCI function is already ZPCI_FN_STATE_STANDBY.

If the device is put into the Standby state, zpci_disable_device() is
not called and the device is assumed to have been put in Standby through
platform action.
At this point the device may be removed by a subsequent event with PEC
0x0308 or 0x0306 which calls zpci_zdev_put() with the same problem
as above or the device may be configured again in which case
zpci_disable_device() is also not called.

Fix this by calling zpci_disable_device() explicitly for PEC 0x0304 as
before. To make it more clear that zpci_disable_device() may be called,
even if the lower level device has already been disabled by the
platform, add a comment to zpci_disable_device().

Cc: <stable@vger.kernel.org> # 5.8
Fixes: f606b3ef47 ("s390/pci: adapt events for zbus")
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-14 10:08:07 +02:00
Niklas Schnelle
2f0230b2f2 s390/pci: re-introduce zpci_remove_device()
For fixing the PF to VF link removal we need to perform some action on
every removal of a zdev from the common PCI subsystem.
So in preparation re-introduce zpci_remove_device() and use that instead
of directly calling the common code functions. This  was actually still
declared from earlier code but no longer implemented.

Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-08-17 13:17:25 +02:00
Niklas Schnelle
b76fee1bc5 s390/pci: ignore stale configuration request event
A configuration request event may be stale, that is the event
may reference a zdev which was already configured.
This can happen when a hotplug happens during boot such that
the device is discovered and configured in the initial clp_list_pci(),
then after initialization we enable events and process
the original configuration request which additionally still contains
the old disabled function handle leading to a failure during device
enablement and subsequent I/O lockout.

Fix this by restoring the check that the device to be configured is in
standby which was removed in commit f606b3ef47 ("s390/pci: adapt events
for zbus").

This check does not need serialization as we only enable the events after
zPCI has fully initialized, which includes the initial clp_list_pci(),
rescan only does updates and events are serialized with respect to each
other.

Fixes: f606b3ef47 ("s390/pci: adapt events for zbus")
Cc: <stable@vger.kernel.org> # 5.8
Reported-by: Shalini Chellathurai Saroja <shalini@linux.ibm.com>
Tested-by: Shalini Chellathurai Saroja <shalini@linux.ibm.com>
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-08-17 13:17:05 +02:00
Niklas Schnelle
3047766bc6 s390/pci: fix enabling a reserved PCI function
In usual IPL or hot plug scenarios a zPCI function transitions directly
from reserved (invisible to Linux) to configured state or is configured
by Linux itself using an SCLP, however it can also first go from
reserved to standby and then from standby to configured without
Linux initiative.
In this scenario we first get a PEC event 0x302 and then 0x301.  This may
happen for example when the device is deconfigured at another LPAR and
made available for this LPAR. It may also happen under z/VM when
a device is attached while in some inconsistent state.

However when we get the 0x301 the device is already known to zPCI
so calling zpci_create() will add it twice resulting in the below
BUG. Instead we should only enable the existing device and finally
scan it through the PCI subsystem.

list_add double add: new=00000000ed5a9008, prev=00000000ed5a9008, next=0000000083502300.
kernel BUG at lib/list_debug.c:31!
Krnl PSW : 0704c00180000000 0000000082dc2db8 (__list_add_valid+0x70/0xa8)
Call Trace:
 [<0000000082dc2db8>] __list_add_valid+0x70/0xa8
([<0000000082dc2db4>] __list_add_valid+0x6c/0xa8)
 [<00000000828ea920>] zpci_create_device+0x60/0x1b0
 [<00000000828ef04a>] zpci_event_availability+0x282/0x2f0
 [<000000008315f848>] chsc_process_crw+0x2b8/0xa18
 [<000000008316735c>] crw_collect_info+0x254/0x348
 [<00000000829226ea>] kthread+0x14a/0x168
 [<000000008319d5c0>] ret_from_fork+0x24/0x2c

Fixes: f606b3ef47 ("s390/pci: adapt events for zbus")
Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2020-06-29 16:26:28 +02:00
Pierre Morel
44510d6fa0 s390/pci: Handling multifunctions
We allow multiple functions on a single bus.
We suppress the ZPCI_DEVFN definition and replace its
occurences with zpci->devfn.

We verify the number of device during the registration.

There can never be more domains in use than existing
devices, so we do not need to verify the count of domain
after having verified the count of devices.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-28 13:49:47 +02:00
Pierre Morel
f606b3ef47 s390/pci: adapt events for zbus
Simplify the event handling.
Set the zpci state explicitly.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-28 13:49:46 +02:00
Pierre Morel
05bc1be6db s390/pci: create zPCI bus
The zPCI bus is in charge to handle common zPCI resources for
zPCI devices.

Creating the zPCI bus, the PCI bus, the zPCI devices and the
PCI devices and hotplug slots
done in a specific order:
- PCI hotplug slot creation needs a PCI bus
- PCI bus needs a PCI domain
  which is reported by the pci_domain_nr() when setting up the
  host bridge
- PCI domain is set from the zPCI with devfn 0
  this is necessary to have a reproducible enumeration

Therefore we can not create devices or hotplug slots for any PCI
device associated with a zPCI device before having discovered
the function zero of the bus.

The discovery and initialization of devices can be done at several
points in the code:
- On Events, serialized in a thread context
- On initialization, in the kernel init thread context
- When powering on the hotplug slot, in a user thread context

The removal of devices and their parent bus may also be done on
events or for devices when powering down the slot.

To guarantee the existence of the bus and devices until they are
no more needed we use kref in zPCI bus and introduce a reference
count in the zPCI devices.

In this patch the zPCI bus still only accept a device with
a devfn 0.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-28 13:49:46 +02:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Sebastian Ott
623bd44d3f s390/pci: improve pci hotplug
PCI hotplug events basically notify about the new state of a
function. Unfortunately some hypervisors implement hotplug
events in a way where it is not clear what the new state of
the function should be.

Use clp_get_state to find the current state of the function
and handle accordingly.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-06-28 07:32:12 +02:00
Markus Elfring
64a40c8400 s390/pci: Delete an unnecessary check before the function call "pci_dev_put"
The pci_dev_put() 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: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-07-18 10:17:24 +02:00
Sebastian Ott
9a99649f2a s390/pci: remove pdev pointer from arch data
For each PCI function we need to maintain arch specific data in
struct zpci_dev which also contains a pointer to struct pci_dev.

When a function is registered or deregistered (which is triggered by PCI
common code) we need to adjust that pointer which could interfere with
the machine check handler (triggered by FW) using zpci_dev->pdev.

Since multiple instances of the same pdev could exist at a time this can't
be solved with locking.

Fix that by ditching the pdev pointer and use a bus walk to reach
struct pci_dev (only one instance of a pdev can be registered at the bus
at a time).

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-02-23 08:56:16 +01:00
Sebastian Ott
8ead7efb63 s390/pci: set error state for unusable functions
We receive special notifications from firmware when an error was detected
and a pci function became unusable. Set the error_state accordingly to give
device drivers a hint that they don't need to try error recovery.

Suggested-by: Alexander Schmidt <alexschm@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-01-26 12:46:28 +01:00
Sebastian Ott
2a01bd1bd3 s390/pci: use pci_rescan_remove_lock
Make sure that we use the pci_rescan_remove_lock when we remove
or add functions from/to the bus.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-07-29 09:11:56 +02:00
Sebastian Ott
515f022e8b s390/pci: handle events for unused functions
Receiving error events for a pci function that's currently not in use
will crash the kernel. For example the procedure for FW upgrades might
include:
* remove the function from Linux
* apply FW upgrade
* rescan for new functions

Receiving an event during the FW upgrade will result in a use after free
when printing the functions name. Just print "n/a" in such cases.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-07-29 09:11:52 +02:00
Sebastian Ott
7fc611ff3f s390/pci: improve handling of hotplug event 0x301
Hypervisors may deliver event 0x301 not only for standby
but also for reserved devices.
Just handle event 0x301 regardless of the device's state.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-06-18 15:45:54 +02:00
Gerald Schaefer
896cb7e635 s390/pci: fix kmsg component
KMSG_COMPONENT has to be defined instead of COMPONENT.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-07-22 09:26:21 +02:00
Sebastian Ott
ca25f564c4 s390/pci: improve state check when processing hotplug events
Processing pci hotplug events can fail when a pci function is in an
unexpected state. This can happen when we already processed the
change associated with the hotplug event (especially when receiving
hotplug events during early boot).
Just ignore the event in this case.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-05-20 08:58:48 +02:00
Linus Torvalds
f479c01c8e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:
 "The bulk of the s390 updates for v3.14.

  New features are the perf support for the CPU-Measurement Sample
  Facility and the EP11 support for the crypto cards.  And the normal
  cleanups and bug-fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (44 commits)
  s390/cpum_sf: fix printk format warnings
  s390: Fix misspellings using 'codespell' tool
  s390/qdio: bridgeport support - CHSC part
  s390: delete new instances of __cpuinit usage
  s390/compat: fix PSW32_USER_BITS definition
  s390/zcrypt: add support for EP11 coprocessor cards
  s390/mm: optimize randomize_et_dyn for !PF_RANDOMIZE
  s390: use IS_ENABLED to check if a CONFIG is set to y or m
  s390/cio: use device_lock to synchronize calls to the ccwgroup driver
  s390/cio: use device_lock to synchronize calls to the ccw driver
  s390/cio: fix unlocked access of online member
  s390/cpum_sf: Add flag to process full SDBs only
  s390/cpum_sf: Add raw data sampling to support the diagnostic-sampling function
  s390/cpum_sf: Filter perf events based event->attr.exclude_* settings
  s390/cpum_sf: Detect KVM guest samples
  s390/cpum_sf: Add helper to read TOD from trailer entries
  s390/cpum_sf: Atomically reset trailer entry fields of sample-data-blocks
  s390/cpum_sf: Dynamically extend the sampling buffer if overflows occur
  s390/pci: reenable per default
  s390/pci/dma: fix accounting of allocated_pages
  ...
2014-01-20 09:23:31 -08:00
Sebastian Ott
fcf2f40293 s390/pci: obtain function handle in hotplug notifier
When using the CLP interface to enable or disable a pci device a
valid function handle needs to be delivered. So far our assumption
was that we always have an up-to-date version of the function handle
(since it doesn't change when the device is in use). This assumption
is incorrect if the pci device is enabled or disabled outside of our
control. When we are notified about such a change we already receive
the new function handle. Just use it.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-12-30 11:28:47 +01:00
Sebastian Ott
0c0c277692 s390/pci: set error state for unavailable functions
If we receive a notification that a pci function became unavailable we clean
up by removing the pci device. This can confuse the driver since the function
is already unaccessible. Improve this situation by setting an appropriate
error_state.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-12-16 14:37:55 +01:00
Sebastian Ott
704268925d s390/pci: fix removal of nonexistent pci bus
If we remove a pci bus after receiving a hotplug notification we need
to check if the bus is actually present (creation of the pci bus
during an earlier notification may have been failed).

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-12-16 14:37:54 +01:00
Sebastian Ott
aa3b7c2967 s390/pci: prevent inadvertently triggered bus scans
Initialization and scanning of the pci bus is omitted on older
machines without pci support or if pci=off was specified. Remember
the fact that we ran without pci support and prevent further bus
scans during resume from hibernate or after receiving hotplug
notifications.

Reported-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-12-16 14:37:54 +01:00
Sebastian Ott
d795ddad36 s390/pci: implement hotplug notifications
When the availability of a pci function has changed by means
outside of our control we receive an availability event.
Implement/improve the handling of these notifications.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-11-15 14:08:42 +01:00
Sebastian Ott
1f1dcbd4f2 s390/pci: message cleanup
Cleanup arch specific pci messages. Remove unhelpful messages and
replace others with entries in the debugfs.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24 17:17:15 +02:00
Sebastian Ott
1d57896638 s390/pci: split lpf
List pci functions is used to query and iterate over pci functions.
This function currently has 2 users - initial device discovery and
rescan after a machine check. Instead of having a multipurpose
function pass a callback which gets called for each pci function.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-08-30 08:57:17 +02:00
Jan Glauber
d0b0885316 s390/pci: performance statistics and debug infrastructure
Add support for reading the PCI function measurement block counters
provided by the hypervisor. Add two s390 debug features, one for
critical errors and one for tracing and provide wrappers to log data.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-12-14 10:01:17 +01:00
Jan Glauber
cbc0dd1f85 s390/pci: CHSC PCI support for error and availability events
Add CHSC store-event-information support for PCI (notfication type 2)
and report error and availability events to the PCI architecture layer.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-11-30 17:47:24 +01:00