- Drop device reference unconditionally in pcie_port_remove_service() to
fix resource leak (Uwe Kleine-König)
- Remove empty pcie_port_shutdown_service() callback (Uwe Kleine-König)
- Remove unnecessary bus_type check in pcie_port_bus_match() (Uwe
Kleine-König)
- Move pcie_port_bus_match() and pcie_port_bus_type to PCIe-specific
portdrv.c (Uwe Kleine-König)
- Remove unnecessary dev and dev->driver checks in portdrv .probe() and
.remove() (Uwe Kleine-König)
- Take advantage of pcie_port_bus_type.probe() and .remove() instead of
assigning them for each portdrv service driver (Uwe Kleine-König)
* pci/portdrv:
PCI/portdrv: Use bus-type functions
PCI/portdrv: Don't check for valid device and driver in bus callbacks
PCI/portdrv: Move pcie_port_bus_type to pcie source file
PCI/portdrv: Don't check for the driver's and device's bus
PCI/portdrv: Drop empty shutdown callback
PCI/portdrv: Fix potential resource leak
- Skip enabling ExtTag on VFs since that bit is Reserved and causes
misleading log messages (Håkon Bugge)
- Mark 3ware-9650SA Root Port Extended Tags as broken since 9650SA can't
handle 8-bit tags (Jörg Wedekind)
- Release domain number from the correct IDA when a PCI host bridge has no
parent device (Sergey Shtylyov)
- Initialize endpoint Read Completion Boundary to match Root Port,
regardless of ACPI _HPX (Håkon Bugge)
- Apply _HPX PCIe Setting Record only to AER configuration, and only when
OS owns PCIe hotplug but not AER, to avoid clobbering Extended Tag and
Relaxed Ordering settings (Håkon Bugge)
- Clear PCIe Root Status register with a write, not a read/modify/write
(Lukas Wunner)
* pci/enumeration:
PCI/PME: Replace RMW of Root Status register with direct write
PCI/ACPI: Restrict program_hpx_type2() to AER bits
PCI: Initialize RCB from pci_configure_device()
PCI: Check parent for NULL in of_pci_bus_release_domain_nr()
PCI: Mark 3ware-9650SA Root Port Extended Tags as broken
PCI: Do not attempt to set ExtTag for VFs
Correctable and Uncorrectable Error Status Registers on reporting agents
are cleared upon PCI device enumeration in pci_aer_init() to flush past
events. They're cleared again when an error is handled by the AER driver.
If an agent reports a new error after pci_aer_init() and before the AER
driver has probed on the corresponding Root Port or Root Complex Event
Collector, that error is not handled by the AER driver: It clears the
Root Error Status Register on probe, but neglects to re-clear the
Correctable and Uncorrectable Error Status Registers on reporting agents.
The error will eventually be reported when another error occurs. Which
is irritating because to an end user it appears as if the earlier error
has just happened.
Amend the AER driver to clear stale errors on reporting agents upon probe.
Skip reporting agents which have not invoked pci_aer_init() yet to avoid
using an uninitialized pdev->aer_cap. They're recognizable by the error
bits in the Device Control register still being clear.
Reporting agents may execute pci_aer_init() after the AER driver has
probed, particularly when devices are hotplugged or removed/rescanned via
sysfs. For this reason, it continues to be necessary that pci_aer_init()
clears Correctable and Uncorrectable Error Status Registers.
Reported-by: Lucas Van <lucas.van@intel.com> # off-list
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Lucas Van <lucas.van@intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/3011c2ed30c11f858e35e29939add754adea7478.1769332702.git.lukas@wunner.de
Previously program_hpx_type2() applied PCIe settings unconditionally,
which could incorrectly change bits like Extended Tag Field Enable and
Enable Relaxed Ordering.
When _HPX was added to ACPI r3.0, the intent of the PCIe Setting
Record (Type 2) in sec 6.2.7.3 was to configure AER registers when the
OS does not own the AER Capability:
The PCI Express setting record contains ... [the AER] Uncorrectable
Error Mask, Uncorrectable Error Severity, Correctable Error Mask
... to be used when configuring registers in the Advanced Error
Reporting Extended Capability Structure ...
OSPM [1] will only evaluate _HPX with Setting Record – Type 2 if
OSPM is not controlling the PCI Express Advanced Error Reporting
capability.
ACPI r3.0b, sec 6.2.7.3, added more AER registers, including registers
in the PCIe Capability with AER-related bits, and the restriction that
the OS use this only when it owns PCIe native hotplug:
... when configuring PCI Express registers in the Advanced Error
Reporting Extended Capability Structure *or PCI Express Capability
Structure* ...
An OS that has assumed ownership of native hot plug but does not
... have ownership of the AER register set must use ... the Type 2
record to program the AER registers ...
However, since the Type 2 record also includes register bits that
have functions other than AER, the OS must ignore values ... that
are not applicable.
Restrict program_hpx_type2() to only the intended purpose:
- Apply settings only when OS owns PCIe native hotplug but not AER,
- Only touch the AER-related bits (Error Reporting Enables) in Device
Control
- Don't touch Link Control at all, since nothing there seems AER-related,
but log _HPX settings for debugging purposes
Note that Read Completion Boundary is now configured elsewhere, since it is
unrelated to _HPX.
[1] Operating System-directed configuration and Power Management
Fixes: 40abb96c51 ("[PATCH] pciehp: Fix programming hotplug parameters")
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260129175237.727059-3-haakon.bugge@oracle.com
Pull non-MM updates from Andrew Morton:
- "panic: sys_info: Refactor and fix a potential issue" (Andy Shevchenko)
fixes a build issue and does some cleanup in ib/sys_info.c
- "Implement mul_u64_u64_div_u64_roundup()" (David Laight)
enhances the 64-bit math code on behalf of a PWM driver and beefs up
the test module for these library functions
- "scripts/gdb/symbols: make BPF debug info available to GDB" (Ilya Leoshkevich)
makes BPF symbol names, sizes, and line numbers available to the GDB
debugger
- "Enable hung_task and lockup cases to dump system info on demand" (Feng Tang)
adds a sysctl which can be used to cause additional info dumping when
the hung-task and lockup detectors fire
- "lib/base64: add generic encoder/decoder, migrate users" (Kuan-Wei Chiu)
adds a general base64 encoder/decoder to lib/ and migrates several
users away from their private implementations
- "rbree: inline rb_first() and rb_last()" (Eric Dumazet)
makes TCP a little faster
- "liveupdate: Rework KHO for in-kernel users" (Pasha Tatashin)
reworks the KEXEC Handover interfaces in preparation for Live Update
Orchestrator (LUO), and possibly for other future clients
- "kho: simplify state machine and enable dynamic updates" (Pasha Tatashin)
increases the flexibility of KEXEC Handover. Also preparation for LUO
- "Live Update Orchestrator" (Pasha Tatashin)
is a major new feature targeted at cloud environments. Quoting the
cover letter:
This series introduces the Live Update Orchestrator, a kernel
subsystem designed to facilitate live kernel updates using a
kexec-based reboot. This capability is critical for cloud
environments, allowing hypervisors to be updated with minimal
downtime for running virtual machines. LUO achieves this by
preserving the state of selected resources, such as memory,
devices and their dependencies, across the kernel transition.
As a key feature, this series includes support for preserving
memfd file descriptors, which allows critical in-memory data, such
as guest RAM or any other large memory region, to be maintained in
RAM across the kexec reboot.
Mike Rappaport merits a mention here, for his extensive review and
testing work.
- "kexec: reorganize kexec and kdump sysfs" (Sourabh Jain)
moves the kexec and kdump sysfs entries from /sys/kernel/ to
/sys/kernel/kexec/ and adds back-compatibility symlinks which can
hopefully be removed one day
- "kho: fixes for vmalloc restoration" (Mike Rapoport)
fixes a BUG which was being hit during KHO restoration of vmalloc()
regions
* tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (139 commits)
calibrate: update header inclusion
Reinstate "resource: avoid unnecessary lookups in find_next_iomem_res()"
vmcoreinfo: track and log recoverable hardware errors
kho: fix restoring of contiguous ranges of order-0 pages
kho: kho_restore_vmalloc: fix initialization of pages array
MAINTAINERS: TPM DEVICE DRIVER: update the W-tag
init: replace simple_strtoul with kstrtoul to improve lpj_setup
KHO: fix boot failure due to kmemleak access to non-PRESENT pages
Documentation/ABI: new kexec and kdump sysfs interface
Documentation/ABI: mark old kexec sysfs deprecated
kexec: move sysfs entries to /sys/kernel/kexec
test_kho: always print restore status
kho: free chunks using free_page() instead of kfree()
selftests/liveupdate: add kexec test for multiple and empty sessions
selftests/liveupdate: add simple kexec-based selftest for LUO
selftests/liveupdate: add userspace API selftests
docs: add documentation for memfd preservation via LUO
mm: memfd_luo: allow preserving memfd
liveupdate: luo_file: add private argument to store runtime state
mm: shmem: export some functions to internal.h
...
Pull PCI updates from Bjorn Helgaas:
"Enumeration:
- Enable host bridge emulation for PCI_DOMAINS_GENERIC platforms (Dan
Williams)
- Switch vmd from custom domain number allocator to the common
allocator to prevent a potential race with new non-VMD buses (Dan
Williams)
- Enable Precision Time Measurement (PTM) only if device advertises
support for a relevant role, to prevent invalid PTM Requests that
cause ACS violations that are reported as AER Uncorrectable
Non-Fatal errors (Mika Westerberg)
Resource management:
- Prevent resource tree corruption when BAR resize fails (Ilpo
Järvinen)
- Restore BARs to the original size if a BAR resize fails (Ilpo
Järvinen)
- Remove BAR release from BAR resize attempts by the xe, i915, and
amdgpu drivers so the PCI core can restore BARs if the resize fails
(Ilpo Järvinen)
- Move Resizable BAR code to rebar.c (Ilpo Järvinen)
- Add pci_rebar_size_supported() and use it in i915 and xe (Ilpo
Järvinen)
- Add pci_rebar_get_max_size() and use it in xe and amdgpu (Ilpo
Järvinen)
Power management and error handling:
- For drivers using PCI legacy suspend, save config state at suspend
so that state (not any earlier state from enumeration, probe, or
error recovery) will be restored when resuming (Lukas Wunner)
- For devices with no driver or a driver that lacks power management,
save config state at hibernate so that state (not any earlier state
from enumeration, probe, or error recovery) will be restored when
resuming (Lukas Wunner)
- Save device config space on device addition, before driver binding,
so error recovery works more reliably (Lukas Wunner)
- Drop pci_save_state() from several drivers that no longer need it
since the PCI core always does it and pci_restore_state() no longer
invalidates the saved state (Lukas Wunner)
- Document use of pci_save_state() by drivers to capture the state
they want restored during error recovery (Lukas Wunner)
Power control:
- Add a struct pci_ops.assert_perst() function pointer to
assert/deassert PCIe PERST# and implement it for the qcom driver
(Krishna Chaitanya Chundru)
- Add DT binding and pwrctrl driver for the Toshiba TC9563 PCIe
switch, which must be held in reset after poweron so the pwrctrl
driver can configure the switch via I2C before bringing up the
links (Krishna Chaitanya Chundru)
Endpoint framework:
- Convert the endpoint doorbell test to use a threaded IRQ to fix a
'sleeping while atomic' issue (Bhanu Seshu Kumar Valluri)
- Add endpoint VNTB MSI doorbell support to reduce latency between
host and endpoint (Frank Li)
New native PCIe controller drivers:
- Add CIX Sky1 host controller DT binding and driver (Hans Zhang)
- Add NXP S32G host controller DT binding and driver (Vincent
Guittot)
- Add Renesas RZ/G3S host controller DT binding and driver (Claudiu
Beznea)
- Add SpacemiT K1 host controller DT binding and driver (Alex Elder)
Amlogic Meson PCIe controller driver:
- Update DT binding to name DBI region 'dbi', not 'elbi', and update
driver to support both (Manivannan Sadhasivam)
Apple PCIe controller driver:
- Move struct pci_host_bridge allocation from pci_host_common_init()
to callers, which significantly simplifies pcie-apple (Marc
Zyngier)
Broadcom STB PCIe controller driver:
- Disable advertising ASPM L0s support correctly (Jim Quinlan)
- Add a panic/die handler to print diagnostic info in case PCIe
caused an unrecoverable abort (Jim Quinlan)
Cadence PCIe controller driver:
- Add module support for Cadence platform host and endpoint
controller driver (Manikandan K Pillai)
- Split headers into 'legacy' (LGA) and 'high perf' (HPA) to prepare
for new CIX Sky1 driver (Manikandan K Pillai)
MediaTek PCIe controller driver:
- Convert DT binding to YAML schema (Christian Marangi)
- Add Airoha AN7583 DT compatible and driver support (Christian
Marangi)
Qualcomm PCIe controller driver:
- Add Qualcomm Kaanapali to SM8550 DT binding (Qiang Yu)
- Add required 'power-domains' and 'resets' to qcom sa8775p, sc7280,
sc8280xp, sm8150, sm8250, sm8350, sm8450, sm8550, x1e80100 DT
schemas (Krzysztof Kozlowski)
- Look up OPP using both frequency and data rate (not just frequency)
so RPMh votes can account for both (Krishna Chaitanya Chundru)
Rockchip DesignWare PCIe controller driver:
- Add Rockchip RK3528 compatible strings in DT binding (Yao Zi)
STMicroelectronics STM32MP25 PCIe controller driver:
- Fix a race between link training and endpoint register
initialization (Christian Bruel)
- Align endpoint allocations to match the ATU requirements (Christian
Bruel)
Synopsys DesignWare PCIe controller driver:
- Clear L1 PM Substate Capability 'Supported' bits unless glue driver
says it's supported, which prevents users from enabling non-working
L1SS. Currently only qcom and tegra194 support L1SS (Bjorn Helgaas)
- Remove now-superfluous L1SS disable code from tegra194 (Bjorn
Helgaas)
- Configure L1SS support in dw-rockchip when DT says
'supports-clkreq' (Shawn Lin)
TI Keystone PCIe controller driver:
- Fail the probe instead of silently succeeding if ks_pcie_of_data
didn't specify Root Complex or Endpoint mode (Siddharth Vadapalli)
- Make keystone buildable as a loadable module, except on ARM32 where
hook_fault_code() is __init (Siddharth Vadapalli)"
* tag 'pci-v6.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (100 commits)
MAINTAINERS: Add Manivannan Sadhasivam as PCI/pwrctrl maintainer
MAINTAINERS: Add CIX Sky1 PCIe controller driver maintainer
PCI: sky1: Add PCIe host support for CIX Sky1
dt-bindings: PCI: Add CIX Sky1 PCIe Root Complex bindings
PCI: cadence: Add support for High Perf Architecture (HPA) controller
MAINTAINERS: Add NXP S32G PCIe controller driver maintainer
PCI: s32g: Add NXP S32G PCIe controller driver (RC)
PCI: dwc: Add register and bitfield definitions
dt-bindings: PCI: s32g: Add NXP S32G PCIe controller
PCI: Add Renesas RZ/G3S host controller driver
PCI: host-generic: Move bridge allocation outside of pci_host_common_init()
dt-bindings: PCI: Add Renesas RZ/G3S PCIe controller binding
PCI: Validate pci_rebar_size_supported() input
Documentation: PCI: Amend error recovery doc with pci_save_state() rules
treewide: Drop pci_save_state() after pci_restore_state()
PCI/ERR: Ensure error recoverability at all times
PCI/PM: Stop needlessly clearing state_saved on enumeration and thaw
PCI/PM: Reinstate clearing state_saved in legacy and !PM codepaths
PCI: dw-rockchip: Configure L1SS support
PCI: tegra194: Remove unnecessary L1SS disable code
...
- Enable PTM only if device advertises support for a relevant role, to
prevent invalid PTM Requests that cause ACS violations that are reported
as AER Uncorrectable Non-Fatal errors (Mika Westerberg)
* pci/ptm:
PCI/PTM: Enable only if device advertises relevant role
Introduce a generic infrastructure for tracking recoverable hardware
errors (HW errors that are visible to the OS but does not cause a panic)
and record them for vmcore consumption. This aids post-mortem crash
analysis tools by preserving a count and timestamp for the last occurrence
of such errors. On the other side, correctable errors, which the OS
typically remains unaware of because the underlying hardware handles them
transparently, are less relevant for crash dump and therefore are NOT
tracked in this infrastructure.
Add centralized logging for sources of recoverable hardware errors based
on the subsystem it has been notified.
hwerror_data is write-only at kernel runtime, and it is meant to be read
from vmcore using tools like crash/drgn. For example, this is how it
looks like when opening the crashdump from drgn.
>>> prog['hwerror_data']
(struct hwerror_info[1]){
{
.count = (int)844,
.timestamp = (time64_t)1752852018,
},
...
This helps fleet operators quickly triage whether a crash may be
influenced by hardware recoverable errors (which executes a uncommon code
path in the kernel), especially when recoverable errors occurred shortly
before a panic, such as the bug fixed by commit ee62ce7a1d ("page_pool:
Track DMA-mapped pages and unmap them when destroying the pool")
This is not intended to replace full hardware diagnostics but provides a
fast way to correlate hardware events with kernel panics quickly.
Rare machine check exceptions—like those indicated by mce_flags.p5 or
mce_flags.winchip—are not accounted for in this method, as they fall
outside the intended usage scope for this feature's user base.
[leitao@debian.org: add hw-recoverable-errors to toctree]
Link: https://lkml.kernel.org/r/20251127-vmcoreinfo_fix-v1-1-26f5b1c43da9@debian.org
Link: https://lkml.kernel.org/r/20251010-vmcore_hw_error-v5-1-636ede3efe44@debian.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Suggested-by: Tony Luck <tony.luck@intel.com>
Suggested-by: Shuai Xue <xueshuai@linux.alibaba.com>
Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com> [APEI]
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Bob Moore <robert.moore@intel.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morse <james.morse@arm.com>
Cc: Konrad Rzessutek Wilk <konrad.wilk@oracle.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Omar Sandoval <osandov@osandov.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In 2009, commit c82f63e411 ("PCI: check saved state before restore")
changed the behavior of pci_restore_state() such that it became necessary
to call pci_save_state() afterwards, lest recovery from subsequent PCI
errors fails.
The commit has just been reverted and so all the pci_save_state() after
pci_restore_state() calls that have accumulated in the tree are now
superfluous. Drop them.
Two drivers chose a different approach to achieve the same result:
drivers/scsi/ipr.c and drivers/net/ethernet/intel/e1000e/netdev.c set the
pci_dev's "state_saved" flag to true before calling pci_restore_state().
Drop this as well.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com> # qat
Link: https://patch.msgid.link/c2b28cc4defa1b743cf1dedee23c455be98b397a.1760274044.git.lukas@wunner.de
Pull pci fixes from Bjorn Helgaas:
- Cache the ASPM L0s/L1 Supported bits early so quirks can override
them if necessary (Bjorn Helgaas)
- Add quirks for PA Semi and Freescale Root Ports and a HiSilicon Wi-Fi
device that are reported to have broken L0s and L1 (Shawn Lin, Bjorn
Helgaas)
* tag 'pci-v6.18-fixes-5' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
PCI/ASPM: Avoid L0s and L1 on Hi1105 [19e5:1105] Wi-Fi
PCI/ASPM: Avoid L0s and L1 on PA Semi [1959:a002] Root Ports
PCI/ASPM: Avoid L0s and L1 on Freescale [1957:0451] Root Ports
PCI/ASPM: Convert quirks to override advertised link states
PCI/ASPM: Add pcie_aspm_remove_cap() to override advertised link states
PCI/ASPM: Cache L0s/L1 Supported so advertised link states can be overridden
Defective devices sometimes advertise support for ASPM L0s or L1 states
even if they don't work correctly.
Cache the L0s Supported and L1 Supported bits early in enumeration so
HEADER quirks can override the ASPM states advertised in Link Capabilities
before pcie_aspm_cap_init() enables ASPM.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Link: https://patch.msgid.link/20251110222929.2140564-2-helgaas@kernel.org
We have a Switch Upstream Port (2b:00.0) that has a PTM Capability, but
doesn't advertise support for any PTM roles:
Capabilities: [220 v1] Precision Time Measurement
PTMCap: Requester- Responder- Root-
Linux enables PTM without looking into what roles it actually supports, and
apparently the Port immediately sends PTM Requests even though it doesn't
support the PTM Requester role. The messages include an invalid bus number,
so the Root Port detects an ACS Violation (see the PCIe r7.0, sec 6.12.1.1,
implementation note):
pci 0000:2b:00.0: [8086:5786] type 01 class 0x060400 PCIe Switch Upstream Port
pci 0000:2b:00.0: PTM enabled, 4ns granularity
pcieport 0000:00:07.1: AER: Multiple Uncorrectable (Non-Fatal) error message received from 0000:00:07.1
pcieport 0000:00:07.1: PCIe Bus Error: severity=Uncorrectable (Non-Fatal), type=Transaction Layer, (Receiver ID)
pcieport 0000:00:07.1: device [8086:e44f] error status/mask=00200000/00000000
pcieport 0000:00:07.1: [21] ACSViol (First)
pcieport 0000:00:07.1: AER: TLP Header: 0x34000000 0x00000052 0x00000000 0x00000000
The TLP Header shows a 4 DW header, no data (001b) Msg with Local routing
(1 0100b) with Requester ID 0x0000 and PTM Request code (0x52).
Fix this by enabling PTM only if the following conditions are true (see sec
6.21.1 figure 6-21):
- Endpoint must advertise PTM Requester Capable
- Switch Upstream Port must advertise PTM Responder Capable
- Root Port must advertise PTM Root Capable
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[bhelgaas: commit log, comments]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20251112074614.1440266-1-mika.westerberg@linux.intel.com
- Enable all ClockPM and ASPM states for devicetree platforms, since
there's typically no firmware that enables ASPM (Manivannan Sadhasivam)
- Remove the qcom code that enabled ASPM (Manivannan Sadhasivam)
* pci/aspm:
PCI: qcom: Remove custom ASPM enablement code
PCI/ASPM: Enable all ClockPM and ASPM states for devicetree platforms
When platform firmware supplies error information to the OS, e.g., via the
ACPI APEI GHES mechanism, it may identify an error source device that
doesn't advertise an AER Capability and therefore dev->aer_info, which
contains AER stats and ratelimiting data, is NULL.
pci_dev_aer_stats_incr() already checks dev->aer_info for NULL, but
aer_ratelimit() did not, leading to NULL pointer dereferences like this one
from the URL below:
{1}[Hardware Error]: Hardware error from APEI Generic Hardware Error Source: 0
{1}[Hardware Error]: event severity: corrected
{1}[Hardware Error]: device_id: 0000:00:00.0
{1}[Hardware Error]: vendor_id: 0x8086, device_id: 0x2020
{1}[Hardware Error]: aer_cor_status: 0x00001000, aer_cor_mask: 0x00002000
BUG: kernel NULL pointer dereference, address: 0000000000000264
RIP: 0010:___ratelimit+0xc/0x1b0
pci_print_aer+0x141/0x360
aer_recover_work_func+0xb5/0x130
[8086:2020] is an Intel "Sky Lake-E DMI3 Registers" device that claims to
be a Root Port but does not advertise an AER Capability.
Add a NULL check in aer_ratelimit() to avoid the NULL pointer dereference.
Note that this also prevents ratelimiting these events from GHES.
Fixes: a57f2bfb4a ("PCI/AER: Ratelimit correctable and non-fatal error logging")
Link: https://lore.kernel.org/r/buduna6darbvwfg3aogl5kimyxkggu3n4romnmq6sozut6axeu@clnx7sfsy457/
Signed-off-by: Breno Leitao <leitao@debian.org>
[bhelgaas: add crash details to commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250929-aer_crash_2-v1-1-68ec4f81c356@debian.org
So far, the PCI subsystem has honored the ASPM and Clock PM states set by
the BIOS (through LNKCTL) during device initialization, if it relies on the
default state selected using:
* Kconfig: CONFIG_PCIEASPM_DEFAULT=y, or
* cmdline: "pcie_aspm=off", or
* FADT: ACPI_FADT_NO_ASPM
This was done conservatively to avoid issues with the buggy devices that
advertise ASPM capabilities, but behave erratically if the ASPM states are
enabled. So the PCI subsystem ended up trusting the BIOS to enable only the
ASPM states that were known to work for the devices.
But this turned out to be a problem for devicetree platforms, especially
the ARM based devicetree platforms powering Embedded and *some* Compute
devices as they tend to run without any standard BIOS. So the ASPM states
on these platforms were left disabled during boot and the PCI subsystem
never bothered to enable them, unless the user has forcefully enabled the
ASPM states through Kconfig, cmdline, and sysfs or the device drivers
themselves, enabling the ASPM states through pci_enable_link_state() APIs.
This caused runtime power issues on those platforms. So a couple of
approaches were tried to mitigate this BIOS dependency without user
intervention by enabling the ASPM states in the PCI controller drivers
after device enumeration, and overriding the ASPM/Clock PM states
by the PCI controller drivers through an API before enumeration.
But it has been concluded that none of these mitigations should really be
required and the PCI subsystem should enable the ASPM states advertised by
the devices without relying on BIOS or the PCI controller drivers. If any
device is found to be misbehaving after enabling ASPM states that they
advertised, then those devices should be quirked to disable the problematic
ASPM/Clock PM states.
In an effort to do so, start by overriding the ASPM and Clock PM states set
by the BIOS for devicetree platforms first. Separate helper functions are
introduced to override the BIOS set states by enabling all of them if
of_have_populated_dt() returns true. To aid debugging, print the overridden
ASPM and Clock PM states as well.
In the future, these helpers could be extended to allow other platforms
like VMD, newer ACPI systems with a cutoff year etc... to follow the path.
Link: https://lore.kernel.org/linux-pci/20250828204345.GA958461@bhelgaas
Suggested-by: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
[bhelgaas: tweak comments and dmesg logs]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250922-pci-dt-aspm-v2-1-2a65cf84e326@oss.qualcomm.com
When reporting an error, the AER driver prints the TLP Header / Prefix Log
only for errors enumerated in the AER_LOG_TLP_MASKS macro.
The macro was never amended since its introduction in 2006 with commit
6c2b374d74 ("PCI-Express AER implemetation: AER core and aerdriver").
At the time, PCIe r1.1 was the latest spec revision.
Amend the macro with errors defined since then to avoid omitting the TLP
Header / Prefix Log for newer errors.
The order of the errors in AER_LOG_TLP_MASKS follows PCIe r1.1 sec 6.2.7
rather than 7.10.2, because only the former documents for which errors a
TLP Header / Prefix is logged. Retain this order. The section number is
still 6.2.7 in today's PCIe r7.0.
For Completion Timeouts, the TLP Header / Prefix is only logged if the
Completion Timeout Prefix / Header Log Capable bit is set in the AER
Capabilities and Control register. Introduce a tlp_header_logged() helper
to check whether the TLP Header / Prefix Log is populated and use it in
the two places which currently match against AER_LOG_TLP_MASKS directly.
For Uncorrectable Internal Errors, logging of the TLP Header / Prefix is
optional per PCIe r7.0 sec 6.2.7. If needed, drivers could indicate
through a flag whether devices are capable and tlp_header_logged() could
then check that flag.
pcitools introduced macros for newer errors with commit 144b0911cc0b
("ls-ecaps: extend decode support for more fields for AER CE and UE
status"):
https://git.kernel.org/pub/scm/utils/pciutils/pciutils.git/commit/?id=144b0911cc0b
Unfortunately some of those macros are overly long:
PCI_ERR_UNC_POISONED_TLP_EGRESS
PCI_ERR_UNC_DMWR_REQ_EGRESS_BLOCKED
PCI_ERR_UNC_IDE_CHECK
PCI_ERR_UNC_MISR_IDE_TLP
PCI_ERR_UNC_PCRC_CHECK
PCI_ERR_UNC_TLP_XLAT_EGRESS_BLOCKED
This seems unsuitable for <linux/pci_regs.h>, so shorten to:
PCI_ERR_UNC_POISON_BLK
PCI_ERR_UNC_DMWR_BLK
PCI_ERR_UNC_IDE_CHECK
PCI_ERR_UNC_MISR_IDE
PCI_ERR_UNC_PCRC_CHECK
PCI_ERR_UNC_XLAT_BLK
Note that some of the existing macros in <linux/pci_regs.h> do not match
exactly with pcitools (e.g. PCI_ERR_UNC_SDES versus PCI_ERR_UNC_SURPDN),
so it does not seem mandatory for them to be identical.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/5f707caf1260bd8f15012bb032f7da9a9b898aba.1756712066.git.lukas@wunner.de
After a Fatal Error has been reported by a device and has been recovered
through a Secondary Bus Reset, AER updates the device's error_state to
pci_channel_io_normal before invoking its driver's ->resume() callback.
By contrast, EEH updates the error_state earlier, namely after resetting
the device and before invoking its driver's ->slot_reset() callback.
Commit c58dc575f3 ("powerpc/pseries: Set error_state to
pci_channel_io_normal in eeh_report_reset()") explains in great detail
that the earlier invocation is necessitated by various drivers checking
accessibility of the device with pci_channel_offline() and avoiding
accesses if it returns true. It returns true for any other error_state
than pci_channel_io_normal.
The device should be accessible already after reset, hence the reasoning
is that it's safe to update the error_state immediately afterwards.
This deviation between AER and EEH seems problematic because drivers
behave differently depending on which error recovery mechanism the
platform uses. Three drivers have gone so far as to update the
error_state themselves, presumably to work around AER's behavior.
For consistency, amend AER to update the error_state at the same recovery
steps as EEH. Drop the now unnecessary workaround from the three drivers.
Keep updating the error_state before ->resume() in case ->error_detected()
or ->mmio_enabled() return PCI_ERS_RESULT_RECOVERED, which causes
->slot_reset() to be skipped. There are drivers doing this even for Fatal
Errors, e.g. mhi_pci_error_detected().
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/4517af6359ffb9d66152b827a5d2833459144e3f.1755008151.git.lukas@wunner.de
According to Documentation/PCI/pci-error-recovery.rst, the following shall
occur on failure to recover from a PCIe Uncorrectable Error:
STEP 6: Permanent Failure
-------------------------
A "permanent failure" has occurred, and the platform cannot recover
the device. The platform will call error_detected() with a
pci_channel_state_t value of pci_channel_io_perm_failure.
The device driver should, at this point, assume the worst. It should
cancel all pending I/O, refuse all new I/O, returning -EIO to
higher layers. The device driver should then clean up all of its
memory and remove itself from kernel operations, much as it would
during system shutdown.
Sathya notes that AER does not call error_detected() on failure and thus
deviates from the document (as well as EEH, for which the document was
originally added).
Most drivers do nothing on permanent failure, but the SCSI drivers and a
number of Ethernet drivers do take advantage of the notification to flush
queues and give up resources.
Amend AER to notify such drivers and align with the documentation and EEH.
Link: https://lore.kernel.org/r/f496fc0f-64d7-46a4-8562-dba74e31a956@linux.intel.com/
Suggested-by: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/ec212d4d4f5c65d29349df33acdc9768ff8279d1.1755008151.git.lukas@wunner.de
Upon failure to recover from a PCIe error through AER, DPC or EDR, a
uevent is sent to inform user space about disconnection of the bridge
whose subordinate devices failed to recover.
However the bridge itself is not disconnected. Instead, a uevent should
be sent for each of the subordinate devices.
Only if the "bridge" happens to be a Root Complex Event Collector or
Integrated Endpoint does it make sense to send a uevent for it (because
there are no subordinate devices).
Right now if there is a mix of subordinate devices with and without
pci_error_handlers, a BEGIN_RECOVERY event is sent for those with
pci_error_handlers but no FAILED_RECOVERY event is ever sent for them
afterwards. Fix it.
Fixes: 856e1eb9bd ("PCI/AER: Add uevents in AER and EEH error/resume")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v4.16+
Link: https://patch.msgid.link/68fc527a380821b5d861dd554d2ce42cb739591c.1755008151.git.lukas@wunner.de
When Advanced Error Reporting was introduced in September 2006 by commit
6c2b374d74 ("PCI-Express AER implemetation: AER core and aerdriver"), it
sought to adhere to the recovery flow and callbacks specified in
Documentation/PCI/pci-error-recovery.rst.
That document had been added in January 2006, when Enhanced Error Handling
(EEH) was introduced for PowerPC with commit 065c635907 ("[PATCH] PCI
Error Recovery: documentation").
However the AER driver deviates from the document in that it never
performs a Secondary Bus Reset on Non-Fatal Errors, but always on Fatal
Errors. By contrast, EEH allows drivers to opt in or out of a Bus Reset
regardless of error severity, by returning PCI_ERS_RESULT_NEED_RESET or
PCI_ERS_RESULT_CAN_RECOVER from their ->error_detected() callback. If all
drivers agree that they can recover without a Bus Reset, EEH skips it.
Should one of them request a Bus Reset, it overrides all other drivers.
This inconsistency between EEH and AER seems problematic because drivers
need to be aware of and cope with it.
The file Documentation/PCI/pcieaer-howto.rst hints at a rationale for
always performing a Bus Reset on Fatal Errors: "Fatal errors [...] cause
the link to be unreliable. [...] This [reset_link] callback is used to
reset the PCIe physical link when a fatal error happens. If an error
message indicates a fatal error, [...] performing link reset at upstream
is necessary."
There's no such rationale provided for never performing a Bus Reset on
Non-Fatal Errors.
The "xe" driver has a need to attempt a reset of local units on graphics
cards upon a Non-Fatal Error. If that is insufficient for recovery, the
driver wants to opt in to a Bus Reset.
Accommodate such use cases and align AER more closely with EEH by
performing a Bus Reset in pcie_do_recovery() if drivers request it and the
faulting device's channel_state is pci_channel_io_normal. The AER driver
sets this channel_state for Non-Fatal Errors. For Fatal Errors, it uses
pci_channel_io_frozen.
This limits the deviation from Documentation/PCI/pci-error-recovery.rst
and EEH to the unconditional Bus Reset on Fatal Errors.
pcie_do_recovery() is also invoked by the Downstream Port Containment and
Error Disconnect Recover drivers. They both set the channel_state to
pci_channel_io_frozen, hence pcie_do_recovery() continues to always invoke
the ->reset_subordinates() callback in their case. That is necessary
because the callback brings the link back up at the containing Downstream
Port.
There are two behavioral changes resulting from this commit:
First, if channel_state is pci_channel_io_normal and one of the affected
drivers returns PCI_ERS_RESULT_NEED_RESET from its ->error_detected()
callback, a Bus Reset will now be performed. There are drivers doing this
and although it would be possible to avoid a behavioral change by letting
them return PCI_ERS_RESULT_CAN_RECOVER instead, the impression I got from
examination of all drivers is that they actually expect or want a Bus
Reset (cxl_error_detected() is a case in point). In any case, if they can
cope with a Bus Reset on Fatal Errors, they shouldn't have issues with a
Bus Reset on Non-Fatal Errors.
Second, if channel_state is pci_channel_io_frozen and all affected drivers
return PCI_ERS_RESULT_CAN_RECOVER from ->error_detected(), their
->mmio_enabled() callback is now invoked prior to performing a Bus Reset,
instead of afterwards. This actually makes sense: For example,
drivers/scsi/sym53c8xx_2/sym_glue.c dumps debug registers in its
->mmio_enabled() callback. Doing so after reset right now captures the
post-reset state instead of the faulting state, which is useless.
There is only one other driver which implements ->mmio_enabled() and
returns PCI_ERS_RESULT_CAN_RECOVER from ->error_detected() for
channel_state pci_channel_io_frozen, drivers/scsi/ipr.c (IBM Power RAID).
It appears to only be used on EEH platforms. So the second behavioral
change is limited to these two drivers.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/28fd805043bb57af390168d05abb30898cf4fc58.1755008151.git.lukas@wunner.de
Pull PCI updates from Bjorn Helgaas:
"Enumeration:
- Allow built-in drivers, not just modular drivers, to use async
initial probing (Lukas Wunner)
- Support Immediate Readiness even on devices with no PM Capability
(Sean Christopherson)
- Consolidate definition of PCIE_RESET_CONFIG_WAIT_MS (100ms), the
required delay between a reset and sending config requests to a
device (Niklas Cassel)
- Add pci_is_display() to check for "Display" base class and use it
in ALSA hda, vfio, vga_switcheroo, vt-d (Mario Limonciello)
- Allow 'isolated PCI functions' (multi-function devices without a
function 0) for LoongArch, similar to s390 and jailhouse (Huacai
Chen)
Power control:
- Add ability to enable optional slot clock for cases where the PCIe
host controller and the slot are supplied by different clocks
(Marek Vasut)
PCIe native device hotplug:
- Fix runtime PM ref imbalance on Hot-Plug Capable ports caused by
misinterpreting a config read failure after a device has been
removed (Lukas Wunner)
- Avoid creating a useless PCIe port service device for pciehp if the
slot is handled by the ACPI hotplug driver (Lukas Wunner)
- Ignore ACPI hotplug slots when calculating depth of pciehp hotplug
ports (Lukas Wunner)
Virtualization:
- Save VF resizable BAR state and restore it after reset (Michał
Winiarski)
- Allow IOV resources (VF BARs) to be resized (Michał Winiarski)
- Add pci_iov_vf_bar_set_size() so drivers can control VF BAR size
(Michał Winiarski)
Endpoint framework:
- Add RC-to-EP doorbell support using platform MSI controller,
including a test case (Frank Li)
- Allow BAR assignment via configfs so platforms have flexibility in
determining BAR usage (Jerome Brunet)
Native PCIe controller drivers:
- Convert amazon,al-alpine-v[23]-pcie, apm,xgene-pcie,
axis,artpec6-pcie, marvell,armada-3700-pcie, st,spear1340-pcie to
DT schema format (Rob Herring)
- Use dev_fwnode() instead of of_fwnode_handle() to remove OF
dependency in altera (fixes an unused variable), designware-host,
mediatek, mediatek-gen3, mobiveil, plda, xilinx, xilinx-dma,
xilinx-nwl (Jiri Slaby, Arnd Bergmann)
- Convert aardvark, altera, brcmstb, designware-host, iproc,
mediatek, mediatek-gen3, mobiveil, plda, rcar-host, vmd, xilinx,
xilinx-dma, xilinx-nwl from using pci_msi_create_irq_domain() to
using msi_create_parent_irq_domain() instead; this makes the
interrupt controller per-PCI device, allows dynamic allocation of
vectors after initialization, and allows support of IMS (Nam Cao)
APM X-Gene PCIe controller driver:
- Rewrite MSI handling to MSI CPU affinity, drop useless CPU hotplug
bits, use device-managed memory allocations, and clean things up
(Marc Zyngier)
- Probe xgene-msi as a standard platform driver rather than a
subsys_initcall (Marc Zyngier)
Broadcom STB PCIe controller driver:
- Add optional DT 'num-lanes' property and if present, use it to
override the Maximum Link Width advertised in Link Capabilities
(Jim Quinlan)
Cadence PCIe controller driver:
- Use PCIe Message routing types from the PCI core rather than
defining private ones (Hans Zhang)
Freescale i.MX6 PCIe controller driver:
- Add IMX8MQ_EP third 64-bit BAR in epc_features (Richard Zhu)
- Add IMX8MM_EP and IMX8MP_EP fixed 256-byte BAR 4 in epc_features
(Richard Zhu)
- Configure LUT for MSI/IOMMU in Endpoint mode so Root Complex can
trigger doorbel on Endpoint (Frank Li)
- Remove apps_reset (LTSSM_EN) from
imx_pcie_{assert,deassert}_core_reset(), which fixes a hotplug
regression on i.MX8MM (Richard Zhu)
- Delay Endpoint link start until configfs 'start' written (Richard
Zhu)
Intel VMD host bridge driver:
- Add Intel Panther Lake (PTL)-H/P/U Vendor ID (George D Sworo)
Qualcomm PCIe controller driver:
- Add DT binding and driver support for SA8255p, which supports ECAM
for Configuration Space access (Mayank Rana)
- Update DT binding and driver to describe PHYs and per-Root Port
resets in a Root Port stanza and deprecate describing them in the
host bridge; this makes it possible to support multiple Root Ports
in the future (Krishna Chaitanya Chundru)
- Add Qualcomm QCS615 to SM8150 DT binding (Ziyue Zhang)
- Add Qualcomm QCS8300 to SA8775p DT binding (Ziyue Zhang)
- Drop TBU and ref clocks from Qualcomm SM8150 and SC8180x DT
bindings (Konrad Dybcio)
- Document 'link_down' reset in Qualcomm SA8775P DT binding (Ziyue
Zhang)
- Add required PCIE_RESET_CONFIG_WAIT_MS delay after Link up IRQ
(Niklas Cassel)
Rockchip PCIe controller driver:
- Drop unused PCIe Message routing and code definitions (Hans Zhang)
- Remove several unused header includes (Hans Zhang)
- Use standard PCIe config register definitions instead of
rockchip-specific redefinitions (Geraldo Nascimento)
- Set Target Link Speed to 5.0 GT/s before retraining so we have a
chance to train at a higher speed (Geraldo Nascimento)
Rockchip DesignWare PCIe controller driver:
- Prevent race between link training and register update via DBI by
inhibiting link training after hot reset and link down (Wilfred
Mallawa)
- Add required PCIE_RESET_CONFIG_WAIT_MS delay after Link up IRQ
(Niklas Cassel)
Sophgo PCIe controller driver:
- Add DT binding and driver for Sophgo SG2044 PCIe controller driver
in Root Complex mode (Inochi Amaoto)
Synopsys DesignWare PCIe controller driver:
- Add required PCIE_RESET_CONFIG_WAIT_MS after waiting for Link up on
Ports that support > 5.0 GT/s. Slower Ports still rely on the
not-quite-correct PCIE_LINK_WAIT_SLEEP_MS 90ms default delay while
waiting for the Link (Niklas Cassel)"
* tag 'pci-v6.17-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (116 commits)
dt-bindings: PCI: qcom,pcie-sa8775p: Document 'link_down' reset
dt-bindings: PCI: Remove 83xx-512x-pci.txt
dt-bindings: PCI: Convert amazon,al-alpine-v[23]-pcie to DT schema
dt-bindings: PCI: Convert marvell,armada-3700-pcie to DT schema
dt-bindings: PCI: Convert apm,xgene-pcie to DT schema
dt-bindings: PCI: Convert axis,artpec6-pcie to DT schema
dt-bindings: PCI: Convert st,spear1340-pcie to DT schema
PCI: Move is_pciehp check out of pciehp_is_native()
PCI: pciehp: Use is_pciehp instead of is_hotplug_bridge
PCI/portdrv: Use is_pciehp instead of is_hotplug_bridge
PCI/ACPI: Fix runtime PM ref imbalance on Hot-Plug Capable ports
selftests: pci_endpoint: Add doorbell test case
misc: pci_endpoint_test: Add doorbell test case
PCI: endpoint: pci-epf-test: Add doorbell test support
PCI: endpoint: Add pci_epf_align_inbound_addr() helper for inbound address alignment
PCI: endpoint: pci-ep-msi: Add checks for MSI parent and mutability
PCI: endpoint: Add RC-to-EP doorbell support using platform MSI controller
PCI: dwc: Add Sophgo SG2044 PCIe controller driver in Root Complex mode
PCI: vmd: Switch to msi_create_parent_irq_domain()
PCI: vmd: Convert to lock guards
...
- Fix runtime PM ref imbalance on Hot-Plug Capable ports caused by
misinterpreting a config read failure after a device has been removed
(Lukas Wunner)
- Avoid creating a useless PCIe port service device for pciehp if the slot
is handled by the ACPI hotplug driver (Lukas Wunner)
- Ignore ACPI hotplug slots when calculating depth of pciehp hotplug ports
(Lukas Wunner)
- Simplify pci_bridge_d3_possible() and clarify comments (Lukas Wunner)
* pci/hotplug:
PCI: Move is_pciehp check out of pciehp_is_native()
PCI: pciehp: Use is_pciehp instead of is_hotplug_bridge
PCI/portdrv: Use is_pciehp instead of is_hotplug_bridge
PCI/ACPI: Fix runtime PM ref imbalance on Hot-Plug Capable ports
- Change aspm_disabled and aspm_force from int to bool (Hans Zhang)
- Initialize val at declaration (Hans Zhang)
* pci/aspm:
PCI/ASPM: Consolidate variable declaration and initialization
PCI/ASPM: Use boolean type for aspm_disabled and aspm_force
The PCIe port driver erroneously creates a subdevice for hotplug on ACPI
slots which are handled by the ACPI hotplug driver.
Avoid by checking the is_pciehp flag instead of is_hotplug_bridge when
deciding whether to create a subdevice. The latter encompasses ACPI slots
whereas the former doesn't.
The superfluous subdevice has no real negative impact, it occupies memory
and interrupt resources but otherwise just sits there waiting for
interrupts from the slot that are never signaled.
Fixes: f841522283 ("PCI: Use cached copy of PCI_EXP_SLTCAP_HPC bit")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v4.7+
Link: https://patch.msgid.link/40d5a5fe8d40595d505949c620a067fa110ee85e.1752390102.git.lukas@wunner.de
When a PCIe device detects an error, it logs the error locally and issues
an error Message routed to the Root Complex (PCIe r6.0, sec 6.2.5). If the
Root Port or RCEC supports AER and Linux has enabled the AER interrupt,
aer_isr() traverses the relevant devices and adds those with AER errors
logged to the aer_err_info.dev[] array for error logging and recovery.
If aer_isr() finds more than AER_MAX_MULTI_ERR_DEVICES devices with AER
errors logged, it silently ignores them, and those extra devices are not
included in the recovery flow.
Emit an error message if we find more than AER_MAX_MULTI_ERR_DEVICES
devices with AER errors logged.
Testing details at link below.
Signed-off-by: Akshay Jindal <akshayaj.lkd@gmail.com>
[bhelgaas: commit log, join error message]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250619185041.73240-1-akshayaj.lkd@gmail.com
- Simplify link bandwidth controller by replacing the count of Link
Bandwidth Management Status (LBMS) events with a PCI_LINK_LBMS_SEEN flag
(Ilpo Järvinen)
- Update the Link Speed after retraining, since the Link Speed may have
changed (Ilpo Järvinen)
* pci/bwctrl:
PCI: Update Link Speed after retraining
PCI/bwctrl: Replace lbms_count with PCI_LINK_LBMS_SEEN flag
Allow userspace to read/write log ratelimits per device (including
enable/disable). Create aer/ sysfs directory to store them and any
future AER configs.
The new sysfs files are:
/sys/bus/pci/devices/*/aer/correctable_ratelimit_burst
/sys/bus/pci/devices/*/aer/correctable_ratelimit_interval_ms
/sys/bus/pci/devices/*/aer/nonfatal_ratelimit_burst
/sys/bus/pci/devices/*/aer/nonfatal_ratelimit_interval_ms
The default values are ratelimit_burst=10, ratelimit_interval_ms=5000, so
if we try to emit more than 10 messages in a 5 second period, some are
suppressed.
Update AER sysfs ABI filename to reflect the broader scope of AER sysfs
attributes (e.g. stats and ratelimits).
Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats ->
sysfs-bus-pci-devices-aer
Tested using aer-inject[1]. Configured correctable log ratelimit to 5.
Sent 6 AER errors. Observed 5 errors logged while AER stats
(cat /sys/bus/pci/devices/<dev>/aer_dev_correctable) shows 6.
Disabled ratelimiting and sent 6 more AER errors. Observed all 6 errors
logged and accounted in AER stats (12 total errors).
[1] https://git.kernel.org/pub/scm/linux/kernel/git/gong.chen/aer-inject.git
[bhelgaas: note fatal errors are not ratelimited, "aer_report" ->
"aer_info", replace ratelimit_log_enable toggle with *_ratelimit_interval_ms]
Signed-off-by: Karolina Stolarek <karolina.stolarek@oracle.com>
Signed-off-by: Jon Pan-Doh <pandoh@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/20250522232339.1525671-21-helgaas@kernel.org
Spammy devices can flood kernel logs with AER errors and slow/stall
execution. Add per-device ratelimits for AER correctable and non-fatal
uncorrectable errors that use the kernel defaults (10 per 5s). Logging of
fatal errors is not ratelimited.
There are two AER logging entry points:
- aer_print_error() is used by DPC and native AER
- pci_print_aer() is used by GHES and CXL
The native AER aer_print_error() case includes a loop that may log details
from multiple devices, which are ratelimited individually. If we log
details for any device, we also log the Error Source ID from the Root Port
or RCEC.
If no such device details are found, we still log the Error Source from the
ERR_* Message, ratelimited by the Root Port or RCEC that received it.
The DPC aer_print_error() case is not ratelimited, since this only happens
for fatal errors.
The CXL pci_print_aer() case is ratelimited by the Error Source device.
The GHES pci_print_aer() case is via aer_recover_work_func(), which
searches for the Error Source device. If the device is not found, there's
no per-device ratelimit, so we use a system-wide ratelimit that covers all
error types (correctable, non-fatal, and fatal).
Sargun at Meta reported internally that a flood of AER errors causes RCU
CPU stall warnings and CSD-lock warnings.
Tested using aer-inject[1]. Sent 11 AER errors. Observed 10 errors logged
while AER stats (cat /sys/bus/pci/devices/<dev>/aer_dev_correctable) show
true count of 11.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/gong.chen/aer-inject.git
[bhelgaas: commit log, factor out trace_aer_event() and aer_print_rp_info()
changes to previous patches, enable Error Source logging if any downstream
detail will be printed, don't ratelimit fatal errors, "aer_report" ->
"aer_info", "cor_log_ratelimit" -> "correctable_ratelimit",
"uncor_log_ratelimit" -> "nonfatal_ratelimit"]
Reported-by: Sargun Dhillon <sargun@meta.com>
Signed-off-by: Jon Pan-Doh <pandoh@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/20250522232339.1525671-19-helgaas@kernel.org
Previously aer_get_device_error_info() and aer_print_error() took a pointer
to struct aer_err_info and a pointer to a pci_dev. Typically the pci_dev
was one of the elements of the aer_err_info.dev[] array (DPC was an
exception, where the dev[] array was unused).
Convert aer_get_device_error_info() and aer_print_error() to take an index
into the aer_err_info.dev[] array instead. A future patch will add
per-device ratelimit information, so the index makes it convenient to find
the ratelimit associated with the device.
To accommodate DPC, set info->dev[0] to the DPC port before using these
interfaces.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/20250522232339.1525671-17-helgaas@kernel.org
