After recovering from a PCI error through reset, affected devices are in
D0_uninitialized state and need to be brought into D0_active state by
re-initializing their Config Space registers (PCIe r7.0 sec 5.3.1.1).
To facilitate that, the PCI core provides pci_restore_state() and
pci_save_state() helpers. Document rules governing their usage.
As Bjorn notes, so far no file in "Documentation/ includes anything about
the idea of a driver using pci_save_state() to capture the state it wants
to restore after an error", even though it is a common pattern in drivers.
So that's obviously a gap that should be closed.
Reported-by: Bjorn Helgaas <helgaas@kernel.org>
Closes: https://lore.kernel.org/r/20251113161556.GA2284238@bhelgaas/
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Link: https://patch.msgid.link/077596ba70202be0e43fdad3bb9b93d356cbe4ec.1763746079.git.lukas@wunner.de
Commit 11502feab423 ("Documentation: PCI: Tidy AER documentation")
replaced the terms "PCI-E", "PCI-Express" and "PCI Express" with "PCIe"
in the AER documentation.
Do the same in the documentation on PCI error recovery. While at it,
add a missing period and a missing blank.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/db56b7ef12043f709a04ce67c1d1e102ab5f4e19.1757942121.git.lukas@wunner.de
Amend the documentation on PCI error recovery with specifics about
Downstream Port Containment and Advanced Error Reporting:
* Explain that with DPC, devices are inaccessible upon an error (similar
to EEH on powerpc) and do not become accessible until the link is
re-enabled.
* Explain that with AER, although devices may already be accessible in the
->error_detected() callback, accesses should be deferred to the
->mmio_enabled() callback for compatibility with EEH on powerpc and with
s390.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/61d8eeadb20ee71c3a852f44c863bfe0209c454d.1757942121.git.lukas@wunner.de
Amend the documentation on PCI error recovery to fix minor inaccuracies
vis-à-vis the actual code:
* The documentation claims that a missing ->resume() or ->mmio_enabled()
callback always leads to recovery through reset. But none of the
implementations do this (pcie_do_recovery(), eeh_handle_normal_event(),
zpci_event_do_error_state_clear()).
Drop the claim to align the documentation with the code.
* The documentation does not list PCI_ERS_RESULT_RECOVERED as a valid
return value from ->error_detected(). But none of the implementations
forbid this and some drivers are returning it, e.g.:
drivers/bus/mhi/host/pci_generic.c
drivers/infiniband/hw/hfi1/pcie.c
Further down in the documentation it is implied that the return value is
in fact allowed:
"The platform will call the resume() callback on all affected device
drivers if all drivers on the segment have returned
PCI_ERS_RESULT_RECOVERED from one of the 3 previous callbacks."
The "3 previous callbacks" being ->error_detected(), ->mmio_enabled()
and ->slot_reset().
Add it to the valid return values for consistency.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/ed3c3385499775fcc25f1ee66f395e212919f94a.1757942121.git.lukas@wunner.de
and fix all in-tree references.
Architecture-specific documentation is being moved into Documentation/arch/
as a way of cleaning up the top-level documentation directory and making
the docs hierarchy more closely match the source hierarchy.
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20230826165737.2101199-1-costa.shul@redhat.com
Change references to *.txt to *.rst to match the current filenames.
Link: https://lore.kernel.org/r/20230609222500.1267795-4-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
There are likely no users of this driver as the hardware has been
discontinued since 2010. Remove the driver and all references to it
in documentation.
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some new devices such as CXL devices may want to record additional error
information on a corrected error. Add a callback to allow the PCI device
driver to do additional logging such as providing additional stats for user
space RAS monitoring.
For CXL device, this is actually a need due to CXL needing to write to the
CXL RAS capability structure correctable error status register in order to
clear the unmasked correctable errors. See CXL spec rev3.0 8.2.4.16.
Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166984619233.2804404.3966368388544312674.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Replace "It" with "If", since it is a conditional statement.
Link: https://lore.kernel.org/r/20210531081215.43507-1-wesley.sheng@amd.com
Signed-off-by: Wesley Sheng <wesley.sheng@amd.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>
The method struct pci_error_handlers.error_detected() is defined and
documented as taking an 'enum pci_channel_state' for the second argument,
but most drivers use 'pci_channel_state_t' instead.
This 'pci_channel_state_t' is not a typedef for the enum but a typedef for
a bitwise type in order to have better/stricter typechecking.
Consolidate everything by using 'pci_channel_state_t' in the method's
definition, in the related helpers and in the drivers.
Enforce use of 'pci_channel_state_t' by replacing 'enum pci_channel_state'
with an anonymous 'enum'.
Note: Currently, from a typechecking point of view this patch changes
nothing because only the constants defined by the enum are bitwise, not the
enum itself (sparse doesn't have the notion of 'bitwise enum'). This may
change in some not too far future, hence the patch.
[bhelgaas: squash in
https://lore.kernel.org/r/20200702162651.49526-3-luc.vanoostenryck@gmail.comhttps://lore.kernel.org/r/20200702162651.49526-4-luc.vanoostenryck@gmail.com]
Link: https://lore.kernel.org/r/20200702162651.49526-2-luc.vanoostenryck@gmail.com
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The hardware has been declared EOL by the vendor more than 5 years ago.
What's more relevant to the Linux kernel is that the quality of this driver
is not on par with many other mainline drivers.
Cc: Manish Chopra <manishc@marvell.com>
Message-id: <20190617074858.32467-1-bpoirier@suse.com>
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert docs to ReST and add them to the arch-specific
book.
The conversion here was trivial, as almost every file there
was already using an elegant format close to ReST standard.
The changes were mostly to mark literal blocks and add a few
missing section title identifiers.
One note with regards to "--": on Sphinx, this can't be used
to identify a list, as it will format it badly. This can be
used, however, to identify a long hyphen - and "---" is an
even longer one.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> # cxl
Convert plain text documentation to reStructuredText format and add it to
Sphinx TOC tree. No essential content change.
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
