linux/arch/s390
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
..
appldata s390/appldata: use struct_size() helper 2020-06-29 16:32:34 +02:00
boot s390: support command lines longer than 896 bytes 2021-10-26 15:21:31 +02:00
configs s390: update defconfigs 2021-10-19 15:39:54 +02:00
crypto s390/archrandom: add parameter check for s390_arch_random_generate 2021-04-21 12:32:12 +02:00
hypfs s390: rename dma section to amode31 2021-08-05 14:10:53 +02:00
include s390/pci: implement minimal PCI error recovery 2021-11-08 14:17:49 +01:00
kernel s390 updates for the 5.16 merge window 2021-11-06 14:48:06 -07:00
kvm s390 updates for the 5.16 merge window 2021-11-06 14:48:06 -07:00
lib s390 updates for the 5.16 merge window 2021-11-06 14:48:06 -07:00
mm s390 updates for the 5.16 merge window 2021-11-06 14:48:06 -07:00
net s390: introduce nospec_uses_trampoline() 2021-10-26 15:21:29 +02:00
pci s390/pci: implement minimal PCI error recovery 2021-11-08 14:17:49 +01:00
purgatory s390: enable KCSAN 2021-07-30 17:09:23 +02:00
tools s390/disassembler: add instructions 2021-07-27 09:39:19 +02:00
Kbuild s390/numa: move code to arch/s390/kernel 2020-08-11 18:16:55 +02:00
Kconfig s390: make command line configurable 2021-10-26 15:21:31 +02:00
Kconfig.debug tracing: Refactor TRACE_IRQFLAGS_SUPPORT in Kconfig 2021-08-16 11:37:21 -04:00
Makefile s390: remove WARN_DYNAMIC_STACK 2021-09-15 14:29:21 +02:00