Revision tags: v6.6.25, v6.6.24, v6.6.23, v6.6.16, v6.6.15, v6.6.14, v6.6.13, v6.6.12, v6.6.11, v6.6.10, v6.6.9, v6.6.8, v6.6.7, v6.6.6, v6.6.5, v6.6.4, v6.6.3, v6.6.2, v6.5.11, v6.6.1, v6.5.10, v6.6, v6.5.9, v6.5.8, v6.5.7, v6.5.6, v6.5.5, v6.5.4, v6.5.3, v6.5.2, v6.1.51, v6.5.1, v6.1.50, v6.5, v6.1.49, v6.1.48, v6.1.46, v6.1.45, v6.1.44, v6.1.43, v6.1.42, v6.1.41, v6.1.40, v6.1.39, v6.1.38, v6.1.37, v6.1.36, v6.4, v6.1.35, v6.1.34, v6.1.33, v6.1.32, v6.1.31, v6.1.30, v6.1.29, v6.1.28, v6.1.27, v6.1.26, v6.3, v6.1.25, v6.1.24, v6.1.23, v6.1.22, v6.1.21, v6.1.20, v6.1.19, v6.1.18, v6.1.17, v6.1.16, v6.1.15, v6.1.14, v6.1.13, v6.2, v6.1.12, v6.1.11, v6.1.10, v6.1.9, v6.1.8, v6.1.7, v6.1.6, v6.1.5, v6.0.19, v6.0.18, v6.1.4, v6.1.3, v6.0.17, v6.1.2, v6.0.16, v6.1.1, v6.0.15, v6.0.14, v6.0.13, v6.1, v6.0.12, v6.0.11, v6.0.10, v5.15.80, v6.0.9, v5.15.79, v6.0.8, v5.15.78, v6.0.7, v5.15.77, v5.15.76, v6.0.6, v6.0.5, v5.15.75, v6.0.4, v6.0.3, v6.0.2, v5.15.74, v5.15.73, v6.0.1, v5.15.72, v6.0, v5.15.71, v5.15.70, v5.15.69, v5.15.68, v5.15.67, v5.15.66, v5.15.65, v5.15.64, v5.15.63, v5.15.62, v5.15.61, v5.15.60, v5.15.59, v5.19, v5.15.58, v5.15.57, v5.15.56, v5.15.55, v5.15.54, v5.15.53, v5.15.52, v5.15.51, v5.15.50, v5.15.49, v5.15.48, v5.15.47, v5.15.46, v5.15.45, v5.15.44, v5.15.43, v5.15.42, v5.18, v5.15.41, v5.15.40, v5.15.39, v5.15.38, v5.15.37, v5.15.36, v5.15.35, v5.15.34, v5.15.33 |
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#
723b5a9d |
| 01-Apr-2022 |
Niklas Schnelle <schnelle@linux.ibm.com> |
s390/pci: don't log availability events as errors
Availability events are logged in s390dbf in s390dbf/pci_error/hex_ascii even though they don't indicate an error condition.
They have also become
s390/pci: don't log availability events as errors
Availability events are logged in s390dbf in s390dbf/pci_error/hex_ascii even though they don't indicate an error condition.
They have also become redundant as commit 6526a597a2e85 ("s390/pci: add simpler s390dbf traces for events") added an s390dbf/pci_msg/sprintf log entry for availability events which contains all non reserved fields of struct zpci_ccdf_avail. On the other hand the availability entries in the error log make it easy to miss actual errors and may even overwrite error entries if the message buffer wraps.
Thus simply remove the availability events from the error log thereby establishing the rule that any content in s390dbf/pci_error indicates some kind of error.
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>
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Revision tags: v5.15.32, v5.15.31, v5.17, v5.15.30, v5.15.29, v5.15.28, v5.15.27, v5.15.26, v5.15.25, v5.15.24, v5.15.23, v5.15.22, v5.15.21, v5.15.20, v5.15.19, v5.15.18, v5.15.17, v5.4.173, v5.15.16, v5.15.15, v5.16, v5.15.10, v5.15.9, v5.15.8, v5.15.7, v5.15.6, v5.15.5, v5.15.4, v5.15.3, v5.15.2, v5.15.1, v5.15, v5.14.14, v5.14.13, v5.14.12, v5.14.11, v5.14.10, v5.14.9, v5.14.8, v5.14.7 |
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c122383d |
| 20-Sep-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
s390/pci: improve zpci_dev reference counting
Currently zpci_dev uses kref based reference counting but only accounts for one original reference plus one reference from an added pci_dev to its under
s390/pci: improve zpci_dev reference counting
Currently zpci_dev uses kref based reference counting but only accounts for one original reference plus one reference from an added pci_dev to its underlying zpci_dev. Counting just the original reference worked until the pci_dev reference was added in commit 2a671f77ee49 ("s390/pci: fix use after free of zpci_dev") because once a zpci_dev goes away, i.e. enters the reserved state, it would immediately get released. However with the pci_dev reference this is no longer the case and the zpci_dev may still appear in multiple availability events indicating that it was reserved. This was solved by detecting when the zpci_dev is already on its way out but still hanging around. This has however shown some light on how unusual our zpci_dev reference counting is.
Improve upon this by modelling zpci_dev reference counting on pci_dev. Analogous to pci_get_slot() increment the reference count in get_zdev_by_fid(). Thus all users of get_zdev_by_fid() must drop the reference once they are done with the zpci_dev.
Similar to pci_scan_single_device(), zpci_create_device() returns the device with an initial count of 1 and the device added to the zpci_list (analogous to the PCI bus' device_list). In turn users of zpci_create_device() must only drop the reference once the device is gone from the point of view of the zPCI subsystem, it might still be referenced by the common PCI subsystem though.
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>
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Revision tags: v5.14.6, v5.10.67, v5.10.66, v5.14.5, v5.14.4, v5.10.65, v5.14.3, v5.10.64, v5.14.2, v5.10.63, v5.14.1, v5.10.62, v5.14, v5.10.61, v5.10.60, v5.10.53, v5.10.52, v5.10.51, v5.10.50, v5.10.49 |
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#
4cdf2f4e |
| 07-Jul-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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 notificatio
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>
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#
4fe20497 |
| 07-Jul-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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 s
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>
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#
6526a597 |
| 15-Sep-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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 s390
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>
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#
4e32c4c7 |
| 20-Sep-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
s390/pci: improve zpci_dev reference counting
[ Upstream commit c122383d221dfa2f41cfe5e672540595de986fde ]
Currently zpci_dev uses kref based reference counting but only accounts for one original r
s390/pci: improve zpci_dev reference counting
[ Upstream commit c122383d221dfa2f41cfe5e672540595de986fde ]
Currently zpci_dev uses kref based reference counting but only accounts for one original reference plus one reference from an added pci_dev to its underlying zpci_dev. Counting just the original reference worked until the pci_dev reference was added in commit 2a671f77ee49 ("s390/pci: fix use after free of zpci_dev") because once a zpci_dev goes away, i.e. enters the reserved state, it would immediately get released. However with the pci_dev reference this is no longer the case and the zpci_dev may still appear in multiple availability events indicating that it was reserved. This was solved by detecting when the zpci_dev is already on its way out but still hanging around. This has however shown some light on how unusual our zpci_dev reference counting is.
Improve upon this by modelling zpci_dev reference counting on pci_dev. Analogous to pci_get_slot() increment the reference count in get_zdev_by_fid(). Thus all users of get_zdev_by_fid() must drop the reference once they are done with the zpci_dev.
Similar to pci_scan_single_device(), zpci_create_device() returns the device with an initial count of 1 and the device added to the zpci_list (analogous to the PCI bus' device_list). In turn users of zpci_create_device() must only drop the reference once the device is gone from the point of view of the zPCI subsystem, it might still be referenced by the common PCI subsystem though.
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> Signed-off-by: Sasha Levin <sashal@kernel.org>
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#
a46044a9 |
| 22-Sep-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
s390/pci: fix zpci_zdev_put() on reserve
Since commit 2a671f77ee49 ("s390/pci: fix use after free of zpci_dev") the reference count of a zpci_dev is incremented between pcibios_add_device() and pcib
s390/pci: fix zpci_zdev_put() on reserve
Since commit 2a671f77ee49 ("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: 2a671f77ee49 ("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>
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#
1f3f7681 |
| 16-Jul-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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_d
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>
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Revision tags: v5.13, v5.10.46, v5.10.43, v5.10.42, v5.10.41, v5.10.40, v5.10.39, v5.4.119, v5.10.36, v5.10.35, v5.10.34, v5.4.116, v5.10.33, v5.12, v5.10.32, v5.10.31, v5.10.30 |
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0d9cf5d8 |
| 09-Apr-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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
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>
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a7f82c36 |
| 09-Apr-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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 t
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>
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Revision tags: v5.10.27, v5.10.26, v5.10.25, v5.10.24, v5.10.23, v5.10.22, v5.10.21, v5.10.20, v5.10.19, v5.4.101, v5.10.18, v5.10.17, v5.11, v5.10.16 |
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14c87ba8 |
| 12-Feb-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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
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>
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652d40b2 |
| 24-Mar-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
s390/pci: fix DMA cleanup on hard deconfigure
In commit dee60c0dbc83 ("s390/pci: add zpci_event_hard_deconfigured()") we added a zdev_enabled() check to what was previously an uncoditional call to z
s390/pci: fix DMA cleanup on hard deconfigure
In commit dee60c0dbc83 ("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: dee60c0dbc83 ("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>
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Revision tags: v5.10.15, v5.10.14 |
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95b3a8b4 |
| 26-Jan-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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 c
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>
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Revision tags: v5.10 |
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2631f6b6 |
| 03-Nov-2020 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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 doe
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>
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Revision tags: v5.8.17, v5.8.16, v5.8.15, v5.9, v5.8.14, v5.8.13, v5.8.12, v5.8.11, v5.8.10 |
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dee60c0d |
| 16-Sep-2020 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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
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>
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0b13525c |
| 10-Mar-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
s390/pci: fix leak of PCI device structure
In commit 05bc1be6db4b2 ("s390/pci: create zPCI bus") we removed the pci_dev_put() call matching the earlier pci_get_slot() done as part of __zpci_event_av
s390/pci: fix leak of PCI device structure
In commit 05bc1be6db4b2 ("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: 05bc1be6db4b2 ("s390/pci: create zPCI bus") Cc: <stable@vger.kernel.org> # 5.8+: e1bff843cde6 s390/pci: remove superfluous zdev->zbus check Cc: <stable@vger.kernel.org> # 5.8+: ba764dd703fe 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>
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Revision tags: v5.8.9, v5.8.8, v5.8.7, v5.8.6, v5.4.62, v5.8.5, v5.8.4, v5.4.61, v5.8.3, v5.4.60, v5.8.2, v5.4.59, v5.8.1, v5.4.58, v5.4.57, v5.4.56, v5.8, v5.7.12, v5.4.55, v5.7.11, v5.4.54 |
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ba764dd7 |
| 22-Jul-2020 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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 separa
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>
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e1bff843 |
| 19-Jan-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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 smatc
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>
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38c74f2f |
| 10-Mar-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
s390/pci: fix leak of PCI device structure
commit 0b13525c20febcfecccf6fc1db5969727401317d upstream.
In commit 05bc1be6db4b2 ("s390/pci: create zPCI bus") we removed the pci_dev_put() call matching
s390/pci: fix leak of PCI device structure
commit 0b13525c20febcfecccf6fc1db5969727401317d upstream.
In commit 05bc1be6db4b2 ("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: 05bc1be6db4b2 ("s390/pci: create zPCI bus") Cc: <stable@vger.kernel.org> # 5.8+: e1bff843cde6 s390/pci: remove superfluous zdev->zbus check Cc: <stable@vger.kernel.org> # 5.8+: ba764dd703fe 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
075e3034 |
| 19-Jan-2021 |
Niklas Schnelle <schnelle@linux.ibm.com> |
s390/pci: remove superfluous zdev->zbus check
commit e1bff843cde62a45a287b7f9b4cd5e824e8e49e2 upstream.
Checking zdev->zbus for NULL in __zpci_event_availability() is superfluous as it can never be
s390/pci: remove superfluous zdev->zbus check
commit e1bff843cde62a45a287b7f9b4cd5e824e8e49e2 upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
bd37d9b9 |
| 22-Jul-2020 |
Niklas Schnelle <schnelle@linux.ibm.com> |
s390/pci: refactor zpci_create_device()
commit ba764dd703feacb5a9c410d191af1b6cfbe96845 upstream.
Currently zpci_create_device() is only called in clp_add_pci_device() which allocates the memory fo
s390/pci: refactor zpci_create_device()
commit ba764dd703feacb5a9c410d191af1b6cfbe96845 upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
0b2ca2c7 |
| 02-Nov-2020 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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
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: 3047766bc6ec ("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>
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809fcfaf |
| 21-Aug-2020 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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_
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>
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afdf9550 |
| 03-Sep-2020 |
Niklas Schnelle <schnelle@linux.ibm.com> |
s390/pci: fix leak of DMA tables on hard unplug
commit f606b3ef47c9 ("s390/pci: adapt events for zbus") removed the zpci_disable_device() call for a zPCI event with PEC 0x0304 because the device is
s390/pci: fix leak of DMA tables on hard unplug
commit f606b3ef47c9 ("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: f606b3ef47c9 ("s390/pci: adapt events for zbus") Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
2f0230b2 |
| 03-Aug-2020 |
Niklas Schnelle <schnelle@linux.ibm.com> |
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-introdu
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>
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