Commit Graph

1118 Commits

Author SHA1 Message Date
Bjorn Helgaas 13571584e1 Merge branch 'pci/resource'
- 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)

* pci/resource:
  PCI: Validate pci_rebar_size_supported() input
  PCI: Convert BAR sizes bitmasks to u64
  drm/amdgpu: Use pci_rebar_get_max_size()
  drm/xe/vram: Use pci_rebar_get_max_size()
  PCI: Add pci_rebar_get_max_size()
  drm/xe/vram: Use PCI rebar helpers in resize_vram_bar()
  drm/i915/gt: Use pci_rebar_size_supported()
  PCI: Add pci_rebar_size_supported() helper
  PCI: Improve Resizable BAR functions kernel doc
  PCI: Move pci_rebar_size_to_bytes() and export it
  PCI: Move pci_rebar_bytes_to_size() and clean it up
  PCI: Move Resizable BAR code to rebar.c
  PCI: Prevent restoring assigned resources
  drm/amdgpu: Remove driver side BAR release before resize
  drm/i915: Remove driver side BAR release before resize
  drm/xe: Remove driver side BAR release before resize
  PCI: Add kerneldoc for pci_resize_resource()
  PCI: Fix restoring BARs on BAR resize rollback path
  PCI: Free saved list without holding pci_bus_sem
  PCI: Try BAR resize even when no window was released
  PCI: Change pci_dev variable from 'bridge' to 'dev'
  PCI/IOV: Adjust ->barsz[] when changing BAR size
  PCI: Prevent resource tree corruption when BAR resize fails
2025-12-03 14:18:32 -06:00
Bjorn Helgaas 5c5b8751e5 Merge branch 'pci/err'
- 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 PM, 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)

* pci/err:
  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
2025-12-03 14:18:31 -06:00
Lukas Wunner a2f1e22390 PCI/ERR: Ensure error recoverability at all times
When the PCI core gained power management support in 2002, it introduced
pci_save_state() and pci_restore_state() helpers to restore Config Space
after a D3hot or D3cold transition, which implies a Soft or Fundamental
Reset (PCIe r7.0 sec 5.8):

  https://git.kernel.org/tglx/history/c/a5287abe398b

In 2006, EEH and AER were introduced to recover from errors by performing
a reset.  Because errors can occur at any time, drivers began calling
pci_save_state() on probe to ensure recoverability.

In 2009, recoverability was foiled by commit c82f63e411 ("PCI: check
saved state before restore"):  It amended pci_restore_state() to bail out
if the "state_saved" flag has been cleared.  The flag is cleared by
pci_restore_state() itself, hence a saved state is now allowed to be
restored only once and is then invalidated.  That doesn't seem to make
sense because the saved state should be good enough to be reused.

Soon after, drivers began to work around this behavior by calling
pci_save_state() immediately after pci_restore_state(), see e.g. commit
b94f2d775a ("igb: call pci_save_state after pci_restore_state").
Hilariously, two drivers even set the "saved_state" flag to true before
invoking pci_restore_state(), see ipr_reset_restore_cfg_space() and
e1000_io_slot_reset().

Despite these workarounds, recoverability at all times is not guaranteed:
E.g. when a PCIe port goes through a runtime suspend and resume cycle,
the "saved_state" flag is cleared by:

  pci_pm_runtime_resume()
    pci_pm_default_resume_early()
      pci_restore_state()

... and hence on a subsequent AER event, the port's Config Space cannot be
restored.  Riana reports a recovery failure of a GPU-integrated PCIe
switch and has root-caused it to the behavior of pci_restore_state().
Another workaround would be necessary, namely calling pci_save_state() in
pcie_port_device_runtime_resume().

The motivation of commit c82f63e411 was to prevent restoring state if
pci_save_state() hasn't been called before.  But that can be achieved by
saving state already on device addition, after Config Space has been
initialized.  A desirable side effect is that devices become recoverable
even if no driver gets bound.  This renders the commit unnecessary, so
revert it.

Reported-by: Riana Tauro <riana.tauro@intel.com> # off-list
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Riana Tauro <riana.tauro@intel.com>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Link: https://patch.msgid.link/9e34ce61c5404e99ffdd29205122c6fb334b38aa.1763483367.git.lukas@wunner.de
2025-11-24 16:58:33 -06:00
Ilpo Järvinen 9f71938cd7 PCI: Move Resizable BAR code to rebar.c
For lack of a better place to put it, Resizable BAR code has been placed
inside pci.c and setup-res.c that do not use it for anything.  Upcoming
changes are going to add more Resizable BAR related functions, increasing
the code size.

As pci.c is huge as is, move the Resizable BAR related code and the BAR
resize code from setup-res.c to rebar.c.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patch.msgid.link/20251113180053.27944-2-ilpo.jarvinen@linux.intel.com
2025-11-14 12:34:21 -06:00
Ilpo Järvinen 4687b3315a PCI/IOV: Adjust ->barsz[] when changing BAR size
pci_rebar_set_size() adjusts BAR size for both normal and IOV BARs. The
struct pci_sriov keeps a cached copy of BAR size in ->barsz[] which is not
adjusted by pci_rebar_set_size() but by pci_iov_resource_set_size().
pci_iov_resource_set_size() is called also from
pci_resize_resource_set_size().

The current arrangement is problematic once BAR resize algorithm starts to
roll back changes properly in case of a failure. The normal resource
fitting algorithm rolls back resource size using the struct
pci_dev_resource easily but also calling pci_resize_resource_set_size() or
pci_iov_resource_set_size() to roll back BAR size would be an extra burden,
whereas combining ->barsz[] update with pci_rebar_set_size() naturally
rolls back it when restoring the old BAR size on a different layer of the
BAR resize operation.

Thus, rework pci_rebar_set_size() to also update ->barsz[].

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Alex Bennée <alex.bennee@linaro.org> # AVA, AMD GPU
Link: https://patch.msgid.link/20251113162628.5946-3-ilpo.jarvinen@linux.intel.com
2025-11-14 12:32:47 -06:00
Dan Williams bcce8c74f1 PCI: Enable host bridge emulation for PCI_DOMAINS_GENERIC platforms
The ability to emulate a host bridge is useful not only for hardware PCI
controllers like CONFIG_VMD, or virtual PCI controllers like
CONFIG_PCI_HYPERV, but also for test and development scenarios like
CONFIG_SAMPLES_DEVSEC [1].

One stumbling block for defining CONFIG_SAMPLES_DEVSEC, a sample
implementation of a platform TSM for PCI Device Security, is the need to
accommodate PCI_DOMAINS_GENERIC architectures alongside x86 [2].

In support of supplementing the existing CONFIG_PCI_BRIDGE_EMUL
infrastructure for host bridges:

* Introduce pci_bus_find_emul_domain_nr() as a common way to find a free
  PCI domain number whether that is to reuse the existing dynamic
  allocation code in the !ACPI case, or to assign an unused domain above
  the last ACPI segment.

* Convert pci-hyperv to the new allocator so that the PCI core can
  unconditionally assume that bridge->domain_nr != PCI_DOMAIN_NR_NOT_SET
  is the dynamically allocated case.

A follow on patch can also convert vmd to the new scheme. Currently vmd is
limited to CONFIG_PCI_DOMAINS_GENERIC=n (x86) so, unlike pci-hyperv, it
does not immediately conflict with this new pci_bus_find_emul_domain_nr()
mechanism.

Link: http://lore.kernel.org/174107249038.1288555.12362100502109498455.stgit@dwillia2-xfh.jf.intel.com [1]
Reported-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Closes: http://lore.kernel.org/20250311144601.145736-3-suzuki.poulose@arm.com [2]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Link: https://patch.msgid.link/20251024224622.1470555-2-dan.j.williams@intel.com
2025-10-28 12:36:34 -05:00
Linus Torvalds 2f2c725493 pci-v6.18-changes
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Merge tag 'pci-v6.18-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci

Pull pci updates from Bjorn Helgaas:
 "Enumeration:

   - Add PCI_FIND_NEXT_CAP() and PCI_FIND_NEXT_EXT_CAP() macros that
     take config space accessor functions.

     Implement pci_find_capability(), pci_find_ext_capability(), and
     dwc, dwc endpoint, and cadence capability search interfaces with
     them (Hans Zhang)

   - Leave parent unit address 0 in 'interrupt-map' so that when we
     build devicetree nodes to describe PCI functions that contain
     multiple peripherals, we can build this property even when
     interrupt controllers lack 'reg' properties (Lorenzo Pieralisi)

   - Add a Xeon 6 quirk to disable Extended Tags and limit Max Read
     Request Size to 128B to avoid a performance issue (Ilpo Järvinen)

   - Add sysfs 'serial_number' file to expose the Device Serial Number
     (Matthew Wood)

   - Fix pci_acpi_preserve_config() memory leak (Nirmoy Das)

  Resource management:

   - Align m68k pcibios_enable_device() with other arches (Ilpo
     Järvinen)

   - Remove sparc pcibios_enable_device() implementations that don't do
     anything beyond what pci_enable_resources() does (Ilpo Järvinen)

   - Remove mips pcibios_enable_resources() and use
     pci_enable_resources() instead (Ilpo Järvinen)

   - Clean up bridge window sizing and assignment (Ilpo Järvinen),
     including:

       - Leave non-claimed bridge windows disabled

       - Enable bridges even if a window wasn't assigned because not all
         windows are required by downstream devices

       - Preserve bridge window type when releasing the resource, since
         the type is needed for reassignment

       - Consolidate selection of bridge windows into two new
         interfaces, pbus_select_window() and
         pbus_select_window_for_type(), so this is done consistently

       - Compute bridge window start and end earlier to avoid logging
         stale information

  MSI:

   - Add quirk to disable MSI on RDC PCI to PCIe bridges (Marcos Del Sol
     Vives)

  Error handling:

   - Align AER with EEH by allowing drivers to request a Bus Reset on
     Non-Fatal Errors (in addition to the reset on Fatal Errors that we
     already do) (Lukas Wunner)

   - If error recovery fails, emit FAILED_RECOVERY uevents for the
     devices, not for the bridge leading to them.

     This makes them correspond to BEGIN_RECOVERY uevents (Lukas Wunner)

   - Align AER with EEH by calling err_handler.error_detected()
     callbacks to notify drivers if error recovery fails (Lukas Wunner)

   - Align AER with EEH by restoring device error_state to
     pci_channel_io_normal before the err_handler.slot_reset() callback.

     This is earlier than before the err_handler.resume() callback
     (Lukas Wunner)

   - Emit a BEGIN_RECOVERY uevent when driver's
     err_handler.error_detected() requests a reset, as well as when it
     says recovery is complete or can be done without a reset (Niklas
     Schnelle)

   - Align s390 with AER and EEH by emitting uevents during error
     recovery (Niklas Schnelle)

   - Align EEH with AER and s390 by emitting BEGIN_RECOVERY,
     SUCCESSFUL_RECOVERY, or FAILED_RECOVERY uevents depending on the
     result of err_handler.error_detected() (Niklas Schnelle)

   - Fix a NULL pointer dereference in aer_ratelimit() when ACPI GHES
     error information identifies a device without an AER Capability
     (Breno Leitao)

   - Update error decoding and TLP Log printing for new errors in
     current PCIe base spec (Lukas Wunner)

   - Update error recovery documentation to match the current code
     and use consistent nomenclature (Lukas Wunner)

  ASPM:

   - Enable all ClockPM and ASPM states for devicetree platforms, since
     there's typically no firmware that enables ASPM

     This is a risky change that may uncover hardware or configuration
     defects at boot-time rather than when users enable ASPM via sysfs
     later. Booting with "pcie_aspm=off" prevents this enabling
     (Manivannan Sadhasivam)

   - Remove the qcom code that enabled ASPM (Manivannan Sadhasivam)

  Power management:

   - If a device has already been disconnected, e.g., by a hotplug
     removal, don't bother trying to resume it to D0 when detaching the
     driver.

     This avoids annoying "Unable to change power state from D3cold to
     D0" messages (Mario Limonciello)

   - Ensure devices are powered up before config reads for
     'max_link_width', 'current_link_speed', 'current_link_width',
     'secondary_bus_number', and 'subordinate_bus_number' sysfs files.

     This prevents using invalid data (~0) in drivers or lspci and,
     depending on how the PCIe controller reports errors, may avoid
     error interrupts or crashes (Brian Norris)

  Virtualization:

   - Add rescan/remove locking when enabling/disabling SR-IOV, which
     avoids list corruption on s390, where disabling SR-IOV also
     generates hotplug events (Niklas Schnelle)

  Peer-to-peer DMA:

   - Free struct p2p_pgmap, not a member within it, in the
     pci_p2pdma_add_resource() error path (Sungho Kim)

  Endpoint framework:

   - Document sysfs interface for BAR assignment of vNTB endpoint
     functions (Jerome Brunet)

   - Fix array underflow in endpoint BAR test case (Dan Carpenter)

   - Skip endpoint IRQ test if the IRQ is out of range to avoid false
     errors (Christian Bruel)

   - Fix endpoint test case for controllers with fixed-size BARs smaller
     than requested by the test (Marek Vasut)

   - Restore inbound translation when disabling doorbell so the endpoint
     doorbell test case can be run more than once (Niklas Cassel)

   - Avoid a NULL pointer dereference when releasing DMA channels in
     endpoint DMA test case (Shin'ichiro Kawasaki)

   - Convert tegra194 interrupt number to MSI vector to fix endpoint
     Kselftest MSI_TEST test case (Niklas Cassel)

   - Reset tegra194 BARs when running in endpoint mode so the BAR tests
     don't overwrite the ATU settings in BAR4 (Niklas Cassel)

   - Handle errors in tegra194 BPMP transactions so we don't mistakenly
     skip future PERST# assertion (Vidya Sagar)

  AMD MDB PCIe controller driver:

   - Update DT binding example to separate PERST# to a Root Port stanza
     to make multiple Root Ports possible in the future (Sai Krishna
     Musham)

   - Add driver support for PERST# being described in a Root Port
     stanza, falling back to the host bridge if not found there (Sai
     Krishna Musham)

  Freescale i.MX6 PCIe controller driver:

   - Enable the 3.3V Vaux supply if available so devices can request
     wakeup with either Beacon or WAKE# (Richard Zhu)

  MediaTek PCIe Gen3 controller driver:

   - Add optional sys clock ready time setting to avoid sys_clk_rdy
     signal glitching in MT6991 and MT8196 (AngeloGioacchino Del Regno)

   - Add DT binding and driver support for MT6991 and MT8196
     (AngeloGioacchino Del Regno)

  NVIDIA Tegra PCIe controller driver:

   - When asserting PERST#, disable the controller instead of mistakenly
     disabling the PLL twice (Nagarjuna Kristam)

   - Convert struct tegra_msi mask_lock to raw spinlock to avoid a lock
     nesting error (Marek Vasut)

  Qualcomm PCIe controller driver:

   - Select PCI Power Control Slot driver so slot voltage rails can be
     turned on/off if described in Root Port devicetree node (Qiang Yu)

   - Parse only PCI bridge child nodes in devicetree, skipping unrelated
     nodes such as OPP (Operating Performance Points), which caused
     probe failures (Krishna Chaitanya Chundru)

   - Add 8.0 GT/s and 32.0 GT/s equalization settings (Ziyue Zhang)

   - Consolidate Root Port 'phy' and 'reset' properties in struct
     qcom_pcie_port, regardless of whether we got them from the Root
     Port node or the host bridge node (Manivannan Sadhasivam)

   - Fetch and map the ELBI register space in the DWC core rather than
     in each driver individually (Krishna Chaitanya Chundru)

   - Enable ECAM mechanism in DWC core by setting up iATU with 'CFG
     Shift Feature' and use this in the qcom driver (Krishna Chaitanya
     Chundru)

   - Add SM8750 compatible to qcom,pcie-sm8550.yaml (Krishna Chaitanya
     Chundru)

   - Update qcom,pcie-x1e80100.yaml to allow fifth PCIe host on Qualcomm
     Glymur, which is compatible with X1E80100 but doesn't have the
     cnoc_sf_axi clock (Qiang Yu)

  Renesas R-Car PCIe controller driver:

   - Fix a typo that prevented correct PHY initialization (Marek Vasut)

   - Add a missing 1ms delay after PWR reset assertion as required by
     the V4H manual (Marek Vasut)

   - Assure reset has completed before DBI access to avoid SError (Marek
     Vasut)

   - Fix inverted PHY initialization check, which sometimes led to
     timeouts and failure to start the controller (Marek Vasut)

   - Pass the correct IRQ domain to generic_handle_domain_irq() to fix a
     regression when converting to msi_create_parent_irq_domain()
     (Claudiu Beznea)

   - Drop the spinlock protecting the PMSR register - it's no longer
     required since pci_lock already serializes accesses (Marek Vasut)

   - Convert struct rcar_msi mask_lock to raw spinlock to avoid a lock
     nesting error (Marek Vasut)

  SOPHGO PCIe controller driver:

   - Check for existence of struct cdns_pcie.ops before using it to
     allow Cadence drivers that don't need to supply ops (Chen Wang)

   - Add DT binding and driver for the SOPHGO SG2042 PCIe controller
     (Chen Wang)

  STMicroelectronics STM32MP25 PCIe controller driver:

   - Update pinctrl documentation of initial states and use in runtime
     suspend/resume (Christian Bruel)

   - Add pinctrl_pm_select_init_state() for use by stm32 driver, which
     needs it during resume (Christian Bruel)

   - Add devicetree bindings and drivers for the STMicroelectronics
     STM32MP25 in host and endpoint modes (Christian Bruel)

  Synopsys DesignWare PCIe controller driver:

   - Add support for x16 in devicetree 'num-lanes' property (Konrad
     Dybcio)

   - Verify that if DT specifies a single IRQ for all eDMA channels, it
     is named 'dma' (Niklas Cassel)

  TI J721E PCIe driver:

   - Add MODULE_DEVICE_TABLE() so driver can be autoloaded (Siddharth
     Vadapalli)

   - Power controller off before configuring the glue layer so the
     controller latches the correct values on power-on (Siddharth
     Vadapalli)

  TI Keystone PCIe controller driver:

   - Use devm_request_irq() so 'ks-pcie-error-irq' is freed when driver
     exits with error (Siddharth Vadapalli)

   - Add Peripheral Virtualization Unit (PVU), which restricts DMA from
     PCIe devices to specific regions of host memory, to the ti,am65
     binding (Jan Kiszka)

  Xilinx NWL PCIe controller driver:

   - Clear bootloader E_ECAM_CONTROL before merging in the new driver
     value to avoid writing invalid values (Jani Nurminen)"

* tag 'pci-v6.18-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (141 commits)
  PCI/AER: Avoid NULL pointer dereference in aer_ratelimit()
  MAINTAINERS: Add entry for ST STM32MP25 PCIe drivers
  PCI: stm32-ep: Add PCIe Endpoint support for STM32MP25
  dt-bindings: PCI: Add STM32MP25 PCIe Endpoint bindings
  PCI: stm32: Add PCIe host support for STM32MP25
  PCI: xilinx-nwl: Fix ECAM programming
  PCI: j721e: Fix incorrect error message in probe()
  PCI: keystone: Use devm_request_irq() to free "ks-pcie-error-irq" on exit
  dt-bindings: PCI: qcom,pcie-x1e80100: Set clocks minItems for the fifth Glymur PCIe Controller
  PCI: dwc: Support 16-lane operation
  PCI: Add lockdep assertion in pci_stop_and_remove_bus_device()
  PCI/IOV: Add PCI rescan-remove locking when enabling/disabling SR-IOV
  PCI: rcar-host: Convert struct rcar_msi mask_lock into raw spinlock
  PCI: tegra194: Rename 'root_bus' to 'root_port_bus' in tegra_pcie_downstream_dev_to_D0()
  PCI: tegra: Convert struct tegra_msi mask_lock into raw spinlock
  PCI: rcar-gen4: Fix inverted break condition in PHY initialization
  PCI: rcar-gen4: Assure reset occurs before DBI access
  PCI: rcar-gen4: Add missing 1ms delay after PWR reset assertion
  PCI: Set up bridge resources earlier
  PCI: rcar-host: Drop PMSR spinlock
  ...
2025-10-06 10:41:03 -07:00
Bjorn Helgaas fef3530379 Merge branch 'pci/capability-search'
- Simplify __pci_find_next_cap_ttl() by replacing magic numbers with
  #defines, extracting fields with FIELD_GET(), etc (Hans Zhang)

- Convert __pci_find_next_cap_ttl() to a PCI_FIND_NEXT_CAP() macro that
  takes a config space accessor function so we can also use it in cases
  where the usual config accessors aren't available (Hans Zhang)

- Similarly convert pci_find_next_ext_capability() to a
  PCI_FIND_NEXT_EXT_CAP() macro (Hans Zhang)

- Implement dwc, dwc endpoint, and cadence capability search interfaces on
  top of PCI_FIND_NEXT_CAP() and PCI_FIND_NEXT_EXT_CAP(), replacing the
  previous duplicated code (Hans Zhang)

- Search for capabilities in the cadence core instead of hard-coding their
  offsets, which are subject to change (Hans Zhang)

* pci/capability-search:
  PCI: cadence: Use cdns_pcie_find_*capability() to avoid hardcoding offsets
  PCI: cadence: Implement capability search using PCI core APIs
  PCI: dwc: ep: Implement capability search using PCI core APIs
  PCI: dwc: Implement capability search using PCI core APIs
  PCI: Refactor extended capability search into PCI_FIND_NEXT_EXT_CAP()
  PCI: Refactor capability search into PCI_FIND_NEXT_CAP()
  PCI: Clean up __pci_find_next_cap_ttl() readability
2025-10-03 12:13:14 -05:00
Mario Limonciello 299fad4133 PCI/PM: Skip resuming to D0 if device is disconnected
When a device is surprise-removed (e.g., due to a dock unplug), the PCI
core unconfigures all downstream devices and sets their error state to
pci_channel_io_perm_failure. This marks them as disconnected via
pci_dev_is_disconnected().

During device removal, the runtime PM framework may attempt to resume the
device to D0 via pm_runtime_get_sync(), which calls into pci_power_up().
Since the device is already disconnected, this resume attempt is
unnecessary and results in a predictable errors like this, typically when
undocking from a TBT3 or USB4 dock with PCIe tunneling:

  pci 0000:01:00.0: Unable to change power state from D3cold to D0, device inaccessible

Avoid powering up disconnected devices by checking their status early in
pci_power_up() and returning -EIO.

Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
[bhelgaas: add typical message]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://patch.msgid.link/20250909031916.4143121-1-superm1@kernel.org
2025-09-22 09:38:49 -05:00
Kees Cook 00e58ff924 PCI: Test for bit underflow in pcie_set_readrq()
In preparation for the future commit ("bitops: Add __attribute_const__ to generic
ffs()-family implementations"), which allows GCC's value range tracker
to see past ffs(), GCC 8 on ARM thinks that it might be possible that
"ffs(rq) - 8" used here:

	v = FIELD_PREP(PCI_EXP_DEVCTL_READRQ, ffs(rq) - 8);

could wrap below 0, leading to a very large value, which would be out of
range for the FIELD_PREP() usage:

drivers/pci/pci.c: In function 'pcie_set_readrq':
include/linux/compiler_types.h:572:38: error: call to '__compiletime_assert_471' declared with attribute error: FIELD_PREP: value too large for the field
...
drivers/pci/pci.c:5896:6: note: in expansion of macro 'FIELD_PREP'
  v = FIELD_PREP(PCI_EXP_DEVCTL_READRQ, ffs(rq) - 8);
      ^~~~~~~~~~

If the result of the ffs() is bounds checked before being used in
FIELD_PREP(), the value tracker seems happy again. :)

Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/linux-pci/CA+G9fYuysVr6qT8bjF6f08WLyCJRG7aXAeSd2F7=zTaHHd7L+Q@mail.gmail.com/
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20250905052836.work.425-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
2025-09-08 14:58:20 -07:00
Hans Zhang 4d909bf1a5 PCI: Refactor extended capability search into PCI_FIND_NEXT_EXT_CAP()
Move the extended Capability search logic into a PCI_FIND_NEXT_EXT_CAP()
macro that accepts a config space accessor function as an argument. This
enables controller drivers to perform Capability discovery using their
early access mechanisms prior to full device initialization while sharing
the Capability search code.

Convert the existing PCI core extended Capability search implementation to
use PCI_FIND_NEXT_EXT_CAP().

Signed-off-by: Hans Zhang <18255117159@163.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://patch.msgid.link/20250813144529.303548-4-18255117159@163.com
2025-08-14 15:03:45 -05:00
Hans Zhang 3c02084d8f PCI: Refactor capability search into PCI_FIND_NEXT_CAP()
The PCI Capability search functionality is duplicated across the PCI core
and several controller drivers. The core's current implementation requires
fully initialized PCI device and bus structures, which prevents controller
drivers from using it during early initialization phases before these
structures are available.

Move the Capability search logic into a PCI_FIND_NEXT_CAP() macro that
accepts a config space accessor function as an argument. This enables
controller drivers to perform Capability discovery using their early
access mechanisms prior to full device initialization while sharing the
Capability search code.

Convert the existing PCI core Capability search implementation to use
PCI_FIND_NEXT_CAP().  Controller drivers can later use this with their
early access mechanisms while maintaining the existing protection against
infinite loops through preserved TTL checks.

Signed-off-by: Hans Zhang <18255117159@163.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://patch.msgid.link/20250813144529.303548-3-18255117159@163.com
2025-08-14 15:03:40 -05:00
Hans Zhang 37d1ade896 PCI: Clean up __pci_find_next_cap_ttl() readability
Refactor the __pci_find_next_cap_ttl() to improve code clarity:

  - Replace magic number 0x40 with PCI_STD_HEADER_SIZEOF.
  - Use ALIGN_DOWN() for position alignment instead of manual bitmask.
  - Extract PCI capability fields via FIELD_GET() with standardized masks.
  - Add necessary headers (linux/align.h).

No functional changes intended.

Signed-off-by: Hans Zhang <18255117159@163.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Acked-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20250813144529.303548-2-18255117159@163.com
2025-08-14 15:03:34 -05:00
Linus Torvalds 0bd0a41a51 pci-v6.17-changes
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Merge tag 'pci-v6.17-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci

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
  ...
2025-08-01 13:59:07 -07:00
Bjorn Helgaas 29ccb7b97e Merge branch 'pci/resources'
- Restore VF resizable BAR state after reset (Michał Winiarski)

- Add pci_resource_num_to_vf_bar() and pci_resource_num_from_vf_bar() to
  convert between VF BAR number and the dev->resource[] index (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)

* pci/resources:
  PCI/IOV: Allow drivers to control VF BAR size
  PCI/IOV: Check that VF BAR fits within the reservation
  PCI/IOV: Allow IOV resources to be resized in pci_resize_resource()
  PCI/IOV: Add pci_resource_num_to_vf_bar() to convert VF BAR number to/from IOV resource
  PCI/IOV: Restore VF resizable BAR state after reset
2025-07-31 16:11:43 -05:00
Bjorn Helgaas 0e142889f4 Merge branch 'pci/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)

- 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
2025-07-31 16:11:42 -05:00
Lukas Wunner c2f9de5e2d PCI: Move is_pciehp check out of pciehp_is_native()
pci_bridge_d3_possible() seeks to forbid runtime power management on:

* Non Hot-Plug Capable PCIe ports which are nevertheless ACPI slots
  (recognizable as: bridge->is_hotplug_bridge && !bridge->is_pciehp)

* Hot-Plug Capable PCIe ports for which platform firmware has not granted
  PCIe Native Hot-Plug control to the operating system
  (recognizable as: bridge->is_pciehp && !pciehp_is_native(bridge))

Somewhat confusingly, the check for is_hotplug_bridge is in
pci_bridge_d3_possible(), whereas the one for is_pciehp is in
pciehp_is_native().

For clarity, check is_pciehp directly in pci_bridge_d3_possible()
(and in the other caller of pciehp_is_native(), hotplug_is_native()).

Rephrase the code comment preceding these checks to no longer mention
"System Management Mode", which is an x86 term inappropriate in generic
PCI code.  Likewise no longer mention "Thunderbolt on non-Macs", because
there is nothing Thunderbolt-specific about these checks.  It used to be
the case that non-Macs relied on the platform for Thunderbolt tunnel
management and hotplug, but they've since moved to OS-native tunnel
management (as Macs always have), hence the code comment is no longer
accurate.

There is a subsequent check for is_hotplug_bridge further down in
pci_bridge_d3_possible().  Change the check to is_pciehp because any
ports matching "bridge->is_hotplug_bridge && !bridge->is_pciehp" are
already filtered out at the top of the function.

Do the same for another check in acpi_pci_bridge_d3(), which is called
from pci_bridge_d3_possible() via platform_pci_bridge_d3().

No functional change intended.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/18b2c2110ad0f27a34b189d793310b9c4f2f24a0.1752390102.git.lukas@wunner.de
2025-07-29 11:45:39 -05:00
Lukas Wunner 6cff20ce3b PCI/ACPI: Fix runtime PM ref imbalance on Hot-Plug Capable ports
pci_bridge_d3_possible() is called from both pcie_portdrv_probe() and
pcie_portdrv_remove() to determine whether runtime power management shall
be enabled (on probe) or disabled (on remove) on a PCIe port.

The underlying assumption is that pci_bridge_d3_possible() always returns
the same value, else a runtime PM reference imbalance would occur.  That
assumption is not given if the PCIe port is inaccessible on remove due to
hot-unplug:  pci_bridge_d3_possible() calls pciehp_is_native(), which
accesses Config Space to determine whether the port is Hot-Plug Capable.
An inaccessible port returns "all ones", which is converted to "all
zeroes" by pcie_capability_read_dword().  Hence the port no longer seems
Hot-Plug Capable on remove even though it was on probe.

The resulting runtime PM ref imbalance causes warning messages such as:

  pcieport 0000:02:04.0: Runtime PM usage count underflow!

Avoid the Config Space access (and thus the runtime PM ref imbalance) by
caching the Hot-Plug Capable bit in struct pci_dev.

The struct already contains an "is_hotplug_bridge" flag, which however is
not only set on Hot-Plug Capable PCIe ports, but also Conventional PCI
Hot-Plug bridges and ACPI slots.  The flag identifies bridges which are
allocated additional MMIO and bus number resources to allow for hierarchy
expansion.

The kernel is somewhat sloppily using "is_hotplug_bridge" in a number of
places to identify Hot-Plug Capable PCIe ports, even though the flag
encompasses other devices.  Subsequent commits replace these occurrences
with the new flag to clearly delineate Hot-Plug Capable PCIe ports from
other kinds of hotplug bridges.

Document the existing "is_hotplug_bridge" and the new "is_pciehp" flag
and document the (non-obvious) requirement that pci_bridge_d3_possible()
always returns the same value across the entire lifetime of a bridge,
including its hot-removal.

Fixes: 5352a44a56 ("PCI: pciehp: Make pciehp_is_native() stricter")
Reported-by: Laurent Bigonville <bigon@bigon.be>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220216
Reported-by: Mario Limonciello <mario.limonciello@amd.com>
Closes: https://lore.kernel.org/r/20250609020223.269407-3-superm1@kernel.org/
Link: https://lore.kernel.org/all/20250620025535.3425049-3-superm1@kernel.org/T/#u
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Cc: stable@vger.kernel.org # v4.18+
Link: https://patch.msgid.link/fe5dcc3b2e62ee1df7905d746bde161eb1b3291c.1752390101.git.lukas@wunner.de
2025-07-29 11:45:10 -05:00
Sean Christopherson 5c0d0ee36f PCI: Support Immediate Readiness on devices without PM capabilities
Query support for Immediate Readiness irrespective of whether or not the
device supports PM capabilities, as nothing in the PCIe spec suggests that
Immediate Readiness is in any way dependent on PM functionality.

Fixes: d6112f8def ("PCI: Add support for Immediate Readiness")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: David Matlack <dmatlack@google.com>
Cc: Vipin Sharma <vipinsh@google.com>
Cc: Aaron Lewis <aaronlewis@google.com>
Link: https://patch.msgid.link/20250722155926.352248-1-seanjc@google.com
2025-07-22 18:02:44 -05:00
Michał Winiarski e200f4f7ea PCI/IOV: Allow IOV resources to be resized in pci_resize_resource()
Similar to regular resizable BARs, VF BARs can also be resized.

The capability layout is the same as PCI_EXT_CAP_ID_REBAR, which means we
can reuse most of the implementation, the only difference being resource
size calculation (which is multiplied by total VFs) and memory decoding
(which is controlled by a separate VF MSE field in SR-IOV cap).

Extend the pci_resize_resource() function to accept IOV resources.

See PCIe r6.2, sec 7.8.7.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20250702093522.518099-4-michal.winiarski@intel.com
2025-07-14 15:04:18 -05:00
Mario Limonciello 907a7a2e5b PCI/PM: Set up runtime PM even for devices without PCI PM
4d4c10f763 ("PCI: Explicitly put devices into D0 when initializing")
intended to put PCI devices into D0, but in doing so unintentionally
changed runtime PM initialization not to occur on devices that don't
support PCI PM.  This caused a regression in vfio-pci due to an imbalance
with its use.

Adjust the logic in pci_pm_init() so that even if PCI PM isn't supported
runtime PM is still initialized.

Fixes: 4d4c10f763 ("PCI: Explicitly put devices into D0 when initializing")
Reported-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Closes: https://lore.kernel.org/linux-pci/20250424043232.1848107-1-superm1@kernel.org/T/#m7e8929d6421690dc8bd6dc639d86c2b4db27cbc4
Reported-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Closes: https://lore.kernel.org/linux-pci/20250424043232.1848107-1-superm1@kernel.org/T/#m40d277dcdb9be64a1609a82412d1aa906263e201
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Tested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Link: https://patch.msgid.link/20250611233117.61810-1-superm1@kernel.org
2025-06-13 14:38:45 -05:00
Linus Torvalds 3719a04a80 pci-v6.16-changes
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Merge tag 'pci-v6.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci

Pull pci updates from Bjorn Helgaas:
 "Enumeration:

   - Print the actual delay time in pci_bridge_wait_for_secondary_bus()
     instead of assuming it was 1000ms (Wilfred Mallawa)

   - Revert 'iommu/amd: Prevent binding other PCI drivers to IOMMU PCI
     devices', which broke resume from system sleep on AMD platforms and
     has been fixed by other commits (Lukas Wunner)

  Resource management:

   - Remove mtip32xx use of pcim_iounmap_regions(), which is deprecated
     and unnecessary (Philipp Stanner)

   - Remove pcim_iounmap_regions() and pcim_request_region_exclusive()
     and related flags since all uses have been removed (Philipp
     Stanner)

   - Rework devres 'request' functions so they are no longer 'hybrid',
     i.e., their behavior no longer depends on whether
     pcim_enable_device or pci_enable_device() was used, and remove
     related code (Philipp Stanner)

   - Warn (not BUG()) about failure to assign optional resources (Ilpo
     Järvinen)

  Error handling:

   - Log the DPC Error Source ID only when it's actually valid (when
     ERR_FATAL or ERR_NONFATAL was received from a downstream device)
     and decode into bus/device/function (Bjorn Helgaas)

   - Determine AER log level once and save it so all related messages
     use the same level (Karolina Stolarek)

   - Use KERN_WARNING, not KERN_ERR, when logging PCIe Correctable
     Errors (Karolina Stolarek)

   - Ratelimit PCIe Correctable and Non-Fatal error logging, with sysfs
     controls on interval and burst count, to avoid flooding logs and
     RCU stall warnings (Jon Pan-Doh)

  Power management:

   - Increment PM usage counter when probing reset methods so we don't
     try to read config space of a powered-off device (Alex Williamson)

   - Set all devices to D0 during enumeration to ensure ACPI opregion is
     connected via _REG (Mario Limonciello)

  Power control:

   - Rename pwrctrl Kconfig symbols from 'PWRCTL' to 'PWRCTRL' to match
     the filename paths. Retain old deprecated symbols for
     compatibility, except for the pwrctrl slot driver
     (PCI_PWRCTRL_SLOT) (Johan Hovold)

   - When unregistering pwrctrl, cancel outstanding rescan work before
     cleaning up data structures to avoid use-after-free issues (Brian
     Norris)

  Bandwidth control:

   - 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)

  PCIe native device hotplug:

   - Ignore Presence Detect Changed caused by DPC.

     pciehp already ignores Link Down/Up events caused by DPC, but on
     slots using in-band presence detect, DPC causes a spurious Presence
     Detect Changed event (Lukas Wunner)

   - Ignore Link Down/Up caused by Secondary Bus Reset.

     On hotplug ports using in-band presence detect, the reset causes a
     Presence Detect Changed event, which mistakenly caused teardown and
     re-enumeration of the device. Drivers may need to annotate code
     that resets their device (Lukas Wunner)

  Virtualization:

   - Add an ACS quirk for Loongson Root Ports that don't advertise ACS
     but don't allow peer-to-peer transactions between Root Ports; the
     quirk allows each Root Port to be in a separate IOMMU group (Huacai
     Chen)

  Endpoint framework:

   - For fixed-size BARs, retain both the actual size and the possibly
     larger size allocated to accommodate iATU alignment requirements
     (Jerome Brunet)

   - Simplify ctrl/SPAD space allocation and avoid allocating more space
     than needed (Jerome Brunet)

   - Correct MSI-X PBA offset calculations for DesignWare and Cadence
     endpoint controllers (Niklas Cassel)

   - Align the return value (number of interrupts) encoding for
     pci_epc_get_msi()/pci_epc_ops::get_msi() and
     pci_epc_get_msix()/pci_epc_ops::get_msix() (Niklas Cassel)

   - Align the nr_irqs parameter encoding for
     pci_epc_set_msi()/pci_epc_ops::set_msi() and
     pci_epc_set_msix()/pci_epc_ops::set_msix() (Niklas Cassel)

  Common host controller library:

   - Convert pci-host-common to a library so platforms that don't need
     native host controller drivers don't need to include these helper
     functions (Manivannan Sadhasivam)

  Apple PCIe controller driver:

   - Extract ECAM bridge creation helper from pci_host_common_probe() to
     separate driver-specific things like MSI from PCI things (Marc
     Zyngier)

   - Dynamically allocate RID-to_SID bitmap to prepare for SoCs with
     varying capabilities (Marc Zyngier)

   - Skip ports disabled in DT when setting up ports (Janne Grunau)

   - Add t6020 compatible string (Alyssa Rosenzweig)

   - Add T602x PCIe support (Hector Martin)

   - Directly set/clear INTx mask bits because T602x dropped the
     accessors that could do this without locking (Marc Zyngier)

   - Move port PHY registers to their own reg items to accommodate
     T602x, which moves them around; retain default offsets for existing
     DTs that lack phy%d entries with the reg offsets (Hector Martin)

   - Stop polling for core refclk, which doesn't work on T602x and the
     bootloader has already done anyway (Hector Martin)

   - Use gpiod_set_value_cansleep() when asserting PERST# in probe
     because we're allowed to sleep there (Hector Martin)

  Cadence PCIe controller driver:

   - Drop a runtime PM 'put' to resolve a runtime atomic count underflow
     (Hans Zhang)

   - Make the cadence core buildable as a module (Kishon Vijay Abraham I)

   - Add cdns_pcie_host_disable() and cdns_pcie_ep_disable() for use by
     loadable drivers when they are removed (Siddharth Vadapalli)

  Freescale i.MX6 PCIe controller driver:

   - Apply link training workaround only on IMX6Q, IMX6SX, IMX6SP
     (Richard Zhu)

   - Remove redundant dw_pcie_wait_for_link() from
     imx_pcie_start_link(); since the DWC core does this, imx6 only
     needs it when retraining for a faster link speed (Richard Zhu)

   - Toggle i.MX95 core reset to align with PHY powerup (Richard Zhu)

   - Set SYS_AUX_PWR_DET to work around i.MX95 ERR051624 erratum: in
     some cases, the controller can't exit 'L23 Ready' through Beacon or
     PERST# deassertion (Richard Zhu)

   - Clear GEN3_ZRXDC_NONCOMPL to work around i.MX95 ERR051586 erratum:
     controller can't meet 2.5 GT/s ZRX-DC timing when operating at 8
     GT/s, causing timeouts in L1 (Richard Zhu)

   - Wait for i.MX95 PLL lock before enabling controller (Richard Zhu)

   - Save/restore i.MX95 LUT for suspend/resume (Richard Zhu)

  Mobiveil PCIe controller driver:

   - Return bool (not int) for link-up check in
     mobiveil_pab_ops.link_up() and layerscape-gen4, mobiveil (Hans
     Zhang)

  NVIDIA Tegra194 PCIe controller driver:

   - Create debugfs directory for 'aspm_state_cnt' only when
     CONFIG_PCIEASPM is enabled, since there are no other entries (Hans
     Zhang)

  Qualcomm PCIe controller driver:

   - Add OF support for parsing DT 'eq-presets-<N>gts' property for lane
     equalization presets (Krishna Chaitanya Chundru)

   - Read Maximum Link Width from the Link Capabilities register if DT
     lacks 'num-lanes' property (Krishna Chaitanya Chundru)

   - Add Physical Layer 64 GT/s Capability ID and register offsets for
     8, 32, and 64 GT/s lane equalization registers (Krishna Chaitanya
     Chundru)

   - Add generic dwc support for configuring lane equalization presets
     (Krishna Chaitanya Chundru)

   - Add DT and driver support for PCIe on IPQ5018 SoC (Nitheesh Sekar)

  Renesas R-Car PCIe controller driver:

   - Describe endpoint BAR 4 as being fixed size (Jerome Brunet)

   - Document how to obtain R-Car V4H (r8a779g0) controller firmware
     (Yoshihiro Shimoda)

  Rockchip PCIe controller driver:

   - Reorder rockchip_pci_core_rsts because
     reset_control_bulk_deassert() deasserts in reverse order, to fix a
     link training regression (Jensen Huang)

   - Mark RK3399 as being capable of raising INTx interrupts (Niklas
     Cassel)

  Rockchip DesignWare PCIe controller driver:

   - Check only PCIE_LINKUP, not LTSSM status, to determine whether the
     link is up (Shawn Lin)

   - Increase N_FTS (used in L0s->L0 transitions) and enable ASPM L0s
     for Root Complex and Endpoint modes (Shawn Lin)

   - Hide the broken ATS Capability in rockchip_pcie_ep_init() instead
     of rockchip_pcie_ep_pre_init() so it stays hidden after PERST#
     resets non-sticky registers (Shawn Lin)

   - Call phy_power_off() before phy_exit() in rockchip_pcie_phy_deinit()
     (Diederik de Haas)

  Synopsys DesignWare PCIe controller driver:

   - Set PORT_LOGIC_LINK_WIDTH to one lane to make initial link training
     more robust; this will not affect the intended link width if all
     lanes are functional (Wenbin Yao)

   - Return bool (not int) for link-up check in dw_pcie_ops.link_up()
     and armada8k, dra7xx, dw-rockchip, exynos, histb, keembay,
     keystone, kirin, meson, qcom, qcom-ep, rcar_gen4, spear13xx,
     tegra194, uniphier, visconti (Hans Zhang)

   - Add debugfs support for exposing DWC device-specific PTM context
     (Manivannan Sadhasivam)

  TI J721E PCIe driver:

   - Make j721e buildable as a loadable and removable module (Siddharth
     Vadapalli)

   - Fix j721e host/endpoint dependencies that result in link failures
     in some configs (Arnd Bergmann)

  Device tree bindings:

   - Add qcom DT binding for 'global' interrupt (PCIe controller and
     link-specific events) for ipq8074, ipq8074-gen3, ipq6018, sa8775p,
     sc7280, sc8180x sdm845, sm8150, sm8250, sm8350 (Manivannan
     Sadhasivam)

   - Add qcom DT binding for 8 MSI SPI interrupts for msm8998, ipq8074,
     ipq8074-gen3, ipq6018 (Manivannan Sadhasivam)

   - Add dw rockchip DT binding for rk3576 and rk3562 (Kever Yang)

   - Correct indentation and style of examples in brcm,stb-pcie,
     cdns,cdns-pcie-ep, intel,keembay-pcie-ep, intel,keembay-pcie,
     microchip,pcie-host, rcar-pci-ep, rcar-pci-host, xilinx-versal-cpm
     (Krzysztof Kozlowski)

   - Convert Marvell EBU (dove, kirkwood, armada-370, armada-xp) and
     armada8k from text to schema DT bindings (Rob Herring)

   - Remove obsolete .txt DT bindings for content that has been moved to
     schemas (Rob Herring)

   - Add qcom DT binding for MHI registers in IPQ5332, IPQ6018, IPQ8074
     and IPQ9574 (Varadarajan Narayanan)

   - Convert v3,v360epc-pci from text to DT schema binding (Rob Herring)

   - Change microchip,pcie-host DT binding to be 'dma-noncoherent' since
     PolarFire may be configured that way (Conor Dooley)

  Miscellaneous:

   - Drop 'pci' suffix from intel_mid_pci.c filename to match similar
     files (Andy Shevchenko)

   - All platforms with PCI have an MMU, so add PCI Kconfig dependency
     on MMU to simplify build testing and avoid inadvertent build
     regressions (Arnd Bergmann)

   - Update Krzysztof Wilczyński's email address in MAINTAINERS
     (Krzysztof Wilczyński)

   - Update Manivannan Sadhasivam's email address in MAINTAINERS
     (Manivannan Sadhasivam)"

* tag 'pci-v6.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (147 commits)
  MAINTAINERS: Update Manivannan Sadhasivam email address
  PCI: j721e: Fix host/endpoint dependencies
  PCI: j721e: Add support to build as a loadable module
  PCI: cadence-ep: Introduce cdns_pcie_ep_disable() helper for cleanup
  PCI: cadence-host: Introduce cdns_pcie_host_disable() helper for cleanup
  PCI: cadence: Add support to build pcie-cadence library as a kernel module
  MAINTAINERS: Update Krzysztof Wilczyński email address
  PCI: Remove unnecessary linesplit in __pci_setup_bridge()
  PCI: WARN (not BUG()) when we fail to assign optional resources
  PCI: Remove unused pci_printk()
  PCI: qcom: Replace PERST# sleep time with proper macro
  PCI: dw-rockchip: Replace PERST# sleep time with proper macro
  PCI: host-common: Convert to library for host controller drivers
  PCI/ERR: Remove misleading TODO regarding kernel panic
  PCI: cadence: Remove duplicate message code definitions
  PCI: endpoint: Align pci_epc_set_msix(), pci_epc_ops::set_msix() nr_irqs encoding
  PCI: endpoint: Align pci_epc_set_msi(), pci_epc_ops::set_msi() nr_irqs encoding
  PCI: endpoint: Align pci_epc_get_msix(), pci_epc_ops::get_msix() return value encoding
  PCI: endpoint: Align pci_epc_get_msi(), pci_epc_ops::get_msi() return value encoding
  PCI: cadence-ep: Correct PBA offset in .set_msix() callback
  ...
2025-06-04 11:26:17 -07:00
Bjorn Helgaas 3de914864c Merge branch 'pci/misc'
- Drop 'pci' suffix from intel_mid_pci.c filename to match similar files
  (Andy Shevchenko)

- All platforms with PCI have an MMU, so add PCI Kconfig dependency on MMU
  to simplify build testing and avoid inadvertent build regressions (Arnd
  Bergmann)

- Update driver path in PCI NVMe function documentation (Rick Wertenbroek)

- Remove unused pci_printk() (Ilpo Järvinen)

- Warn (not BUG()) about failure to assign optional resources (Ilpo
  Järvinen)

- Update Krzysztof Wilczyński's email address in MAINTAINERS (Krzysztof
  Wilczyński)

- Update Manivannan Sadhasivam's email address in MAINTAINERS (Manivannan
  Sadhasivam)

* pci/misc:
  MAINTAINERS: Update Manivannan Sadhasivam email address
  MAINTAINERS: Update Krzysztof Wilczyński email address
  PCI: Remove unnecessary linesplit in __pci_setup_bridge()
  PCI: WARN (not BUG()) when we fail to assign optional resources
  PCI: Remove unused pci_printk()
  Documentation: Fix path for NVMe PCI endpoint target driver
  PCI: Add CONFIG_MMU dependency
  x86/PCI: Drop 'pci' suffix from intel_mid_pci.c
2025-06-04 10:50:45 -05:00
Bjorn Helgaas df11586119 Merge branch 'pci/reset'
- Fix locking issue in the slot reset path (Ilpo Järvinen)

* pci/reset:
  PCI: Fix lock symmetry in pci_slot_unlock()
2025-06-04 10:50:02 -05:00
Bjorn Helgaas f377d9cb25 Merge branch 'pci/pm'
- Add pm_runtime_put() cleanup helper for use with __free() to
  automatically drop the device usage count when a pointer goes out of
  scope (Alex Williamson)

- Increment PM usage counter when probing reset methods so we don't try to
  read config space of a powered-off device (Alex Williamson)

- Set all devices to D0 during enumeration to ensure ACPI opregion is
  connected via _REG (Mario Limonciello)

* pci/pm:
  PCI: Explicitly put devices into D0 when initializing
  PCI: Increment PM usage counter when probing reset methods
  PM: runtime: Define pm_runtime_put cleanup helper
2025-06-04 10:50:01 -05:00
Bjorn Helgaas 68d0370e4e Merge branch 'pci/enumeration'
- Remove pci_fixup_cardbus(), which has no users left (Heiner Kallweit)

- Print the actual delay time in pci_bridge_wait_for_secondary_bus()
  instead of assuming it was 1000ms (Wilfred Mallawa)

- Revert 'iommu/amd: Prevent binding other PCI drivers to IOMMU PCI
  devices', which broke resume from system sleep on AMD platforms and has
  been fixed by other commits (Lukas Wunner)

- Restrict visibility of pci_dev.match_driver since it's no longer used
  outside the PCI core (Lukas Wunner)

* pci/enumeration:
  PCI: Limit visibility of match_driver flag to PCI core
  Revert "iommu/amd: Prevent binding other PCI drivers to IOMMU PCI devices"
  PCI: Print the actual delay time in pci_bridge_wait_for_secondary_bus()
  PCI: Use PCI_STD_NUM_BARS instead of 6
  PCI: Remove pci_fixup_cardbus()

# Conflicts:
#	drivers/pci/pci.h
2025-06-04 10:49:56 -05:00
Bjorn Helgaas f56278a46d Merge branch 'pci/devres'
- Remove mtip32xx use of pcim_iounmap_regions(), which is deprecated and
  unnecessary (Philipp Stanner)

- Remove pcim_iounmap_regions() and pcim_request_region_exclusive() and
  related flags since all uses have been removed (Philipp Stanner)

- Rework devres 'request' functions so they are no longer 'hybrid', i.e.,
  their behavior no longer depends on whether pcim_enable_device or
  pci_enable_device() was used, and remove related code (Philipp Stanner)

* pci/devres:
  PCI: Remove function pcim_intx() prototype from pci.h
  PCI: Remove hybrid-devres usage warnings from kernel-doc
  PCI: Remove redundant set of request functions
  PCI: Remove exclusive requests flags from _pcim_request_region()
  PCI: Remove pcim_request_region_exclusive()
  Documentation/driver-api: Update pcim_enable_device()
  PCI: Remove hybrid devres nature from request functions
  PCI: Remove pcim_iounmap_regions()
  mtip32xx: Remove unnecessary pcim_iounmap_regions() calls
2025-06-04 10:49:50 -05:00
Philipp Stanner 51f6aec99c
PCI: Remove hybrid devres nature from request functions
All functions based on __pci_request_region() and its release counter
part support "hybrid mode", where the functions become managed if the
PCI device was enabled with pcim_enable_device().

Removing this undesirable feature requires to remove all users who
activated their device with that function and use one of the affected
request functions.

These users were:
	ASoC
	alsa
	cardreader
	cirrus
	i2c
	mmc
	mtd
	mtd
	mxser
	net
	spi
	vdpa
	vmwgfx

all of which have been ported to always-managed pcim_ functions by now.

The hybrid nature can, thus, be removed from the aforementioned PCI
functions.

Remove all function guards and documentation in pci.c related to the
hybrid redirection. Adjust the visibility of pcim_release_region().

Signed-off-by: Philipp Stanner <phasta@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://lore.kernel.org/r/20250519112959.25487-3-phasta@kernel.org
2025-05-19 12:34:58 +00:00
Ilpo Järvinen 6ade6e81f8
PCI: Update Link Speed after retraining
PCIe Link Retraining can alter Link Speed. pcie_retrain_link() that
performs the Link Training is called from bwctrl and ASPM driver.

While bwctrl listens for Link Bandwidth Management Status (LBMS) to
pick up changes in Link Speed, there is a race between
pcie_reset_lbms() clearing LBMS after the Link Training and
pcie_bwnotif_irq() reading the Link Status register. If LBMS is already
cleared when the irq handler reads the register, the interrupt handler
will return early with IRQ_NONE and won't update the Link Speed.

When Link Speed update originates from bwctrl,
pcie_bwctrl_change_speed() ensures Link Speed is updated after the
retraining. ASPM driver, however, calls pcie_retrain_link() but does
not update the Link Speed after retraining which can result in stale
Link Speed. Also, it is possible to have ASPM support with
CONFIG_PCIEPORTBUS=n in which case bwctrl will not be built in (and
thus won't update the Link Speed at all).

To ensure Link Speed is not left stale after Link Training, move the
call to pcie_update_link_speed() from pcie_bwctrl_change_speed() into
pcie_retrain_link().

Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/linux-pci/aBCjpfyYmlkJ12AZ@wunner.de
Link: https://lore.kernel.org/r/20250514132821.15705-1-ilpo.jarvinen@linux.intel.com
2025-05-15 16:28:44 +00:00
Ilpo Järvinen 2389d8dc38
PCI/bwctrl: Replace lbms_count with PCI_LINK_LBMS_SEEN flag
PCIe BW controller counted LBMS assertions for the purposes of the Target
Speed quirk (pcie_failed_link_retrain()). It was also a plan to expose the
LBMS count through sysfs to allow better diagnosing link related issues.
Lukas Wunner suggested, however, that adding a trace event would be better
for diagnostics purposes, leaving only pcie_failed_link_retrain() as a user
of the lbms_count.

The logic in pcie_failed_link_retrain() does not require keeping count of
LBMS assertions, so replace lbms_count with a simple flag in pci_dev's
priv_flags.  The reduced complexity allows removing pcie_bwctrl_lbms_rwsem.

Since pcie_failed_link_retrain() runs before bwctrl is probed during boot,
the LBMS in Link Status register still has to be checked by the quirk.

The priv_flags numbering is not continuous because hotplug code added a few
flags to fill numbers 4-5 (hotplug and bwctrl changes are routed through in
different branches).

Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
[kwilczynski: squashed a fix to resolve build failures from
https://lore.kernel.org/all/20250508090036.1528-1-ilpo.jarvinen@linux.intel.com]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Link: https://patch.msgid.link/20250422115548.1483-1-ilpo.jarvinen@linux.intel.com
2025-05-15 08:38:40 +00:00
Mario Limonciello 4d4c10f763 PCI: Explicitly put devices into D0 when initializing
AMD BIOS team has root caused an issue that NVMe storage failed to come
back from suspend to a lack of a call to _REG when NVMe device was probed.

112a7f9c8e ("PCI/ACPI: Call _REG when transitioning D-states") added
support for calling _REG when transitioning D-states, but this only works
if the device actually "transitions" D-states.

967577b062 ("PCI/PM: Keep runtime PM enabled for unbound PCI devices")
added support for runtime PM on PCI devices, but never actually
'explicitly' sets the device to D0.

To make sure that devices are in D0 and that platform methods such as
_REG are called, explicitly set all devices into D0 during initialization.

Fixes: 967577b062 ("PCI/PM: Keep runtime PM enabled for unbound PCI devices")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Denis Benato <benato.denis96@gmail.com>
Tested-By: Yijun Shen <Yijun_Shen@Dell.com>
Tested-By: David Perry <david.perry@amd.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://patch.msgid.link/20250424043232.1848107-1-superm1@kernel.org
2025-05-05 18:04:44 -05:00
Ilpo Järvinen f3efb9569b PCI: Fix lock symmetry in pci_slot_unlock()
The commit a4e772898f ("PCI: Add missing bridge lock to pci_bus_lock()")
made the lock function to call depend on dev->subordinate but left
pci_slot_unlock() unmodified creating locking asymmetry compared with
pci_slot_lock().

Because of the asymmetric lock handling, the same bridge device is unlocked
twice. First pci_bus_unlock() unlocks bus->self and then pci_slot_unlock()
will unconditionally unlock the same bridge device.

Move pci_dev_unlock() inside an else branch to match the logic in
pci_slot_lock().

Fixes: a4e772898f ("PCI: Add missing bridge lock to pci_bus_lock()")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250505115412.37628-1-ilpo.jarvinen@linux.intel.com
2025-05-05 13:39:59 -05:00
Arnd Bergmann 8fe743b5eb PCI: Add CONFIG_MMU dependency
It turns out that there are no platforms that have PCI but don't have an
MMU, so adding a Kconfig dependency on CONFIG_PCI simplifies build testing
kernels for those platforms a lot, and avoids a lot of inadvertent build
regressions.

Add a dependency for CONFIG_PCI and remove all the ones for PCI specific
device drivers that are currently marked not having it.

There are a few platforms that have an optional MMU, but they usually
cannot have PCI at all. The one exception is Coldfire MCF54xx, but this is
mainly for historic reasons, and anyone using those chips should really use
the MMU these days.

Link: https://lore.kernel.org/lkml/a41f1b20-a76c-43d8-8c36-f12744327a54@app.fastmail.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patch.msgid.link/20250423202215.3315550-1-arnd@kernel.org
2025-04-23 15:40:30 -05:00
Wilfred Mallawa d24eba726a PCI: Print the actual delay time in pci_bridge_wait_for_secondary_bus()
Print the delay amount that pcie_wait_for_link_delay() is invoked with
instead of the hardcoded 1000ms value in the debug info print.

Fixes: 7b3ba09feb ("PCI/PM: Shorten pci_bridge_wait_for_secondary_bus() wait time for slow links")
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20250414001505.21243-2-wilfred.opensource@gmail.com
2025-04-17 15:24:20 -05:00
Alex Williamson bc0b828ef6 Revert "PCI: Avoid reset when disabled via sysfs"
This reverts commit 479380efe1.

The reset_method attribute on a PCI device is only intended to manage the
availability of function scoped resets for a device.  It was never intended
to restrict resets targeting the bus or slot.

In introducing a restriction that each device must support function level
reset by testing pci_reset_supported(), we essentially create a catch-22,
that a device must have a function scope reset in order to support bus/slot
reset, when we use bus/slot reset to effect a reset of a device that does
not support a function scoped reset, especially multi-function devices.

This breaks the majority of uses cases where vfio-pci uses bus/slot resets
to manage multifunction devices that do not support function scoped resets.

Fixes: 479380efe1 ("PCI: Avoid reset when disabled via sysfs")
Reported-by: Cal Peake <cp@absolutedigital.net>
Closes: https://lore.kernel.org/all/808e1111-27b7-f35b-6d5c-5b275e73677b@absolutedigital.net
Reported-by: Athul Krishna <athul.krishna.kr@protonmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220010
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250414211828.3530741-1-alex.williamson@redhat.com
2025-04-15 17:27:40 -05:00
Heiner Kallweit 74a70e80da PCI: Remove pci_fixup_cardbus()
Since 1c7f4fe86f ("powerpc/pci: Remove pcibios_setup_bus_devices()")
there's no architecture left setting pci_fixup_cardbus. Therefore remove
support from PCI core.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/8de7da4c-2b16-4ee1-8c42-0d04f3c821c6@gmail.com
2025-04-10 09:33:52 -05:00
Bjorn Helgaas dea140198b Merge branch 'pci/misc'
- Remove unused tools 'pci' build target left over after moving tests to
  tools/testing/selftests/pci_endpoint (Jianfeng Liu)

- Fix typos and whitespace errors (Bjorn Helgaas)

* pci/misc:
  PCI: Fix typos
  tools/Makefile: Remove pci target

# Conflicts:
#	drivers/pci/endpoint/functions/pci-epf-test.c
2025-03-27 13:15:05 -05:00
Bjorn Helgaas 38d42a6612 Merge branch 'pci/resource'
- Use pci_resource_n() to simplify BAR/window resource lookup (Ilpo
  Järvinen)

- Fix typo that repeatedly distributed resources to a bridge instead of
  iterating over subordinate bridges, which resulted in too little space to
  assign some BARs (Kai-Heng Feng)

- Relax bridge window tail sizing for optional resources, e.g., IOV BARs,
  to avoid failures when removing and re-adding devices (Ilpo Järvinen)

- Fix a double counting error for I/O resources, as we previously did for
  memory resources (Ilpo Järvinen)

- Use resource_set_{range,size}() helpers in more places (Ilpo Järvinen)

- Add pci_resource_is_iov() to identify IOV resources (Ilpo Järvinen)

- Add pci_resource_num() to look up the BAR number from the resource
  pointer (Ilpo Järvinen)

- Add restore_dev_resource() to simplify code that resources saved device
  resources (Ilpo Järvinen)

- Allow drivers to enable devices even if we haven't assigned optional IOV
  resources to them (Ilpo Järvinen)

- Improve debug output during resource reallocation (Ilpo Järvinen)

- Rework handling of optional resources (IOV BARs, ROMs) to reduce failures
  if we can't allocate them (Ilpo Järvinen)

- Move declarations of pci_rescan_bus_bridge_resize(),
  pci_reassign_bridge_resources(), and CardBus-related sizes from
  include/linux/pci.h to drivers/pci/pci.h since they're not used outside
  the PCI core (Ilpo Järvinen)

- Make pci_setup_bridge() static (Ilpo Järvinen)

- Fix a NULL dereference in the SR-IOV VF creation error path (Shay Drory)

- Fix s390 mmio_read/write syscalls, which didn't cause page faults in some
  cases, which broke vfio-pci lazy mapping on first access (Niklas
  Schnelle)

- Add pdev->non_mappable_bars to replace CONFIG_VFIO_PCI_MMAP, which was
  disabled only for s390 (Niklas Schnelle)

- Support mmap of PCI resources on s390 except for ISM devices (Niklas
  Schnelle)

* pci/resource:
  s390/pci: Support mmap() of PCI resources except for ISM devices
  s390/pci: Introduce pdev->non_mappable_bars and replace VFIO_PCI_MMAP
  s390/pci: Fix s390_mmio_read/write syscall page fault handling
  PCI: Fix NULL dereference in SR-IOV VF creation error path
  PCI: Move cardbus IO size declarations into pci/pci.h
  PCI: Make pci_setup_bridge() static
  PCI: Move resource reassignment func declarations into pci/pci.h
  PCI: Move pci_rescan_bus_bridge_resize() declaration to pci/pci.h
  PCI: Fix BAR resizing when VF BARs are assigned
  PCI: Do not claim to release resource falsely
  PCI: Increase Resizable BAR support from 512 GB to 128 TB
  PCI: Rework optional resource handling
  PCI: Perform reset_resource() and build fail list in sync
  PCI: Use res->parent to check if resource is assigned
  PCI: Add debug print when releasing resources before retry
  PCI: Indicate optional resource assignment failures
  PCI: Always have realloc_head in __assign_resources_sorted()
  PCI: Extend enable to check for any optional resource
  PCI: Add restore_dev_resource()
  PCI: Remove incorrect comment from pci_reassign_resource()
  PCI: Consolidate assignment loop next round preparation
  PCI: Rename retval to ret
  PCI: Use while loop and break instead of gotos
  PCI: Refactor pdev_sort_resources() & __dev_sort_resources()
  PCI: Converge return paths in __assign_resources_sorted()
  PCI: Add dev & res local variables to resource assignment funcs
  PCI: Add pci_resource_num() helper
  PCI: Check resource_size() separately
  PCI: Add pci_resource_is_iov() to identify IOV resources
  PCI: Use resource_set_{range,size}() helpers
  PCI: Use SZ_* instead of literals in setup-bus.c
  PCI: Fix old_size lower bound in calculate_iosize() too
  PCI: Allow relaxed bridge window tail sizing for optional resources
  PCI: Simplify size1 assignment logic
  PCI: Use min_align, not unrelated add_align, for size0
  PCI: Remove add_align overwrite unrelated to size0
  PCI: Use downstream bridges for distributing resources
  PCI: Cleanup dev->resource + resno to use pci_resource_n()
2025-03-27 13:14:45 -05:00
Bjorn Helgaas a7a8e7996c Merge branch 'pci/reset'
- Log debug messages about reset methods being used (Bjorn Helgaas)

- Avoid reset when it has been disabled via sysfs (Nishanth Aravamudan)

* pci/reset:
  PCI: Avoid reset when disabled via sysfs
  PCI: Log debug messages about reset method
2025-03-27 13:14:45 -05:00
Bjorn Helgaas e91c25c6fc Merge branch 'pci/pm'
- Allow PCI bridges to go to D3Hot on all non-x86 systems (Manivannan
  Sadhasivam)

* pci/pm:
  PCI: Allow PCI bridges to go to D3Hot on all non-x86
2025-03-27 13:14:44 -05:00
Bjorn Helgaas e9e224dadd Merge branch 'pci/enumeration'
- Enable Configuration RRS SV early instead of during child bus scanning
  (Bjorn Helgaas)

- Cache offset of Resizable BAR capability to avoid redundant searches for
  it (Bjorn Helgaas)

- Fix reference leaks in pci_register_host_bridge() and
  pci_alloc_child_bus() (Ma Ke)

- Drop put_device() in pci_register_host_bridge() left over from converting
  device_register() to device_add() (Dan Carpenter)

* pci/enumeration:
  PCI: Remove stray put_device() in pci_register_host_bridge()
  PCI: Fix reference leak in pci_alloc_child_bus()
  PCI: Fix reference leak in pci_register_host_bridge()
  PCI: Cache offset of Resizable BAR capability
  PCI: Enable Configuration RRS SV early
2025-03-27 13:14:43 -05:00
Bjorn Helgaas 67b9f18202 Merge branch 'pci/devres'
- Enlarge the devres table[] to accommodate bridge windows, ROM, IOV BARs,
  etc (Philipp Stanner)

- Validate BAR index in devres interfaces (Philipp Stanner)

* pci/devres:
  PCI: Check BAR index for validity
  PCI: Fix wrong length of devres array
2025-03-27 13:14:43 -05:00
Bjorn Helgaas 5a04a18b1a Merge branch 'pci/aer'
- Implement local aer_printk() since AER is the only place that prints a
  message with level depending on the error severity (Ilpo Järvinen)

* pci/aer:
  PCI/ERR: Handle TLP Log in Flit mode
  PCI: Track Flit Mode Status & print it with link status
  PCI/AER: Descope pci_printk() to aer_printk()
2025-03-27 13:14:42 -05:00
Manivannan Sadhasivam a5fb3ff632 PCI: Allow PCI bridges to go to D3Hot on all non-x86
Currently, pci_bridge_d3_possible() encodes a variety of decision factors
when deciding whether a given bridge can be put into D3. A particular one
of note is for "recent enough PCIe ports." Per Rafael [0]:

  "There were hardware issues related to PM on x86 platforms predating
   the introduction of Connected Standby in Windows.  For instance,
   programming a port into D3hot by writing to its PMCSR might cause the
   PCIe link behind it to go down and the only way to revive it was to
   power cycle the Root Complex.  And similar."

Thus, this function contains a DMI-based check for post-2015 BIOS.

The above factors (Windows, x86) don't really apply to non-x86 systems, and
also, many such systems don't have BIOS or DMI. However, we'd like to be
able to suspend bridges on non-x86 systems too.

Restrict the "recent enough" check to x86. If we find further
incompatibilities, it probably makes sense to expand on the deny-list
approach (i.e., bridge_d3_blacklist or similar).

Link: https://lore.kernel.org/r/20250320110604.v6.1.Id0a0e78ab0421b6bce51c4b0b87e6aebdfc69ec7@changeid
Link: https://lore.kernel.org/linux-pci/CAJZ5v0j_6jeMAQ7eFkZBe5Yi+USGzysxAgfemYh=-zq4h5W+Qg@mail.gmail.com/ [0]
Link: https://lore.kernel.org/linux-pci/20240227225442.GA249898@bhelgaas/ [1]
Link: https://lore.kernel.org/linux-pci/20240828210705.GA37859@bhelgaas/ [2]
[Brian: rewrite to !X86 based on Rafael's suggestions]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2025-03-20 16:33:33 -05:00
Philipp Stanner b1a7f99967 PCI: Check BAR index for validity
Many functions in PCI use accessor macros such as pci_resource_len(),
which take a BAR index. That index, however, is never checked for
validity, potentially resulting in undefined behavior by overflowing the
array pci_dev.resource in the macro pci_resource_n().

Since many users of those macros directly assign the accessed value to
an unsigned integer, the macros cannot be changed easily anymore to
return -EINVAL for invalid indexes. Consequently, the problem has to be
mitigated in higher layers.

Add pci_bar_index_valid(). Use it where appropriate.

Link: https://lore.kernel.org/r/20250312080634.13731-4-phasta@kernel.org
Closes: https://lore.kernel.org/all/adb53b1f-29e1-3d14-0e61-351fd2d3ff0d@linux.intel.com/
Reported-by: Bingbu Cao <bingbu.cao@linux.intel.com>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
[kwilczynski: correct if-statement condition the pci_bar_index_is_valid()
helper function uses, tidy up code comments]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: fix typo]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2025-03-14 10:35:12 -05:00
Bjorn Helgaas a7eb9124d9 PCI: Cache offset of Resizable BAR capability
Previously most resizable BAR interfaces (pci_rebar_get_possible_sizes(),
pci_rebar_set_size(), etc) as well as pci_restore_state() searched config
space for a Resizable BAR capability.  Most devices don't have such a
capability, so this is wasted effort, especially for pci_restore_state().

Search for a Resizable BAR capability once at enumeration-time and cache
the offset so we don't have to search every time we need it.  No functional
change intended.

Link: https://lore.kernel.org/r/20250215000301.175097-3-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
2025-03-10 13:41:47 -05:00
Bjorn Helgaas f4e026f454 PCI: Fix typos
Fix typos and whitespace errors.

Link: https://lore.kernel.org/r/20250307231715.438518-1-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2025-03-08 15:08:45 -06:00
Zhiyuan Dai 5af473941b PCI: Increase Resizable BAR support from 512 GB to 128 TB
Per PCIe r6.0, sec 7.8.6.2, devices can advertise Resizable BAR sizes up to
128 TB in the Resizable BAR Capability register.  Larger sizes can be
advertised via the Capability register, but that requires an API change.

Update pci_rebar_get_possible_sizes() and pbus_size_mem() to increase the
sizes we currently support from 512 GB to 128 TB.

Link: https://lore.kernel.org/r/20250307053535.44918-1-daizhiyuan@phytium.com.cn
Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2025-03-07 11:23:34 -06:00
Nishanth Aravamudan 479380efe1 PCI: Avoid reset when disabled via sysfs
After d88f521da3 ("PCI: Allow userspace to query and set device reset
mechanism"), userspace can disable reset of specific PCI devices by writing
an empty string to the sysfs reset_method file.

However, pci_slot_resettable() does not check pci_reset_supported(), which
means that pci_reset_function() will still reset the device even if
userspace has disabled all the reset methods.

I was able to reproduce this issue with a vfio device passed to a qemu
guest, where I had disabled PCI reset via sysfs.

Add an explicit check of pci_reset_supported() in both
pci_slot_resettable() and pci_bus_resettable() to ensure both the reset
status and reset execution are bypassed if an administrator disables it for
a device.

Link: https://lore.kernel.org/r/20250207205600.1846178-1-naravamudan@nvidia.com
Fixes: d88f521da3 ("PCI: Allow userspace to query and set device reset mechanism")
Signed-off-by: Nishanth Aravamudan <naravamudan@nvidia.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Raphael Norwitz <raphael.norwitz@nutanix.com>
Cc: Amey Narkhede <ameynarkhede03@gmail.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Yishai Hadas <yishaih@nvidia.com>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Cc: Kevin Tian <kevin.tian@intel.com>
2025-03-04 17:23:21 -06:00
Bjorn Helgaas 800ce277f4 PCI: Log debug messages about reset method
Log pci_dbg() messages about the reset methods we attempt and any errors
(-ENOTTY means "try the next method").

Set CONFIG_DYNAMIC_DEBUG=y and enable by booting with
dyndbg="file drivers/pci/* +p" or enable at runtime:

  # echo "file drivers/pci/* +p" > /sys/kernel/debug/dynamic_debug/control

Link: https://lore.kernel.org/r/20250303204220.197172-1-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
2025-03-04 16:44:43 -06:00