linux-stable.git/drivers/pci, branch v6.3.2

PCI/PM: Extend D3hot delay for NVIDIA HDA controllers

2023-05-11T14:17:27+00:00

[ Upstream commit a5a6dd2624698b6e3045c3a1450874d8c790d5d9 ]

Assignment of NVIDIA Ampere-based GPUs have seen a regression since the
below referenced commit, where the reduced D3hot transition delay appears
to introduce a small window where a D3hot->D0 transition followed by a bus
reset can wedge the device.  The entire device is subsequently unavailable,
returning -1 on config space read and is unrecoverable without a host
reset.

This has been observed with RTX A2000 and A5000 GPU and audio functions
assigned to a Windows VM, where shutdown of the VM places the devices in
D3hot prior to vfio-pci performing a bus reset when userspace releases the
devices.  The issue has roughly a 2-3% chance of occurring per shutdown.

Restoring the HDA controller d3hot_delay to the effective value before the
below commit has been shown to resolve the issue.  NVIDIA confirms this
change should be safe for all of their HDA controllers.

Fixes: 3e347969a577 ("PCI/PM: Reduce D3hot delay with usleep_range()")
Link: https://lore.kernel.org/r/20230413194042.605768-1-alex.williamson@redhat.com
Reported-by: Zhiyi Guo 
Signed-off-by: Alex Williamson 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Tarun Gupta 
Cc: Abhishek Sahu 
Cc: Tarun Gupta 
Signed-off-by: Sasha Levin

PCI/EDR: Clear Device Status after EDR error recovery

2023-05-11T14:17:25+00:00

[ Upstream commit c441b1e03da6c680a3e12da59c554f454f2ccf5e ]

During EDR recovery, the OS must clear error status of the port that
triggered DPC even if firmware retains control of DPC and AER (see the
implementation note in the PCI Firmware spec r3.3, sec 4.6.12).

Prior to 068c29a248b6 ("PCI/ERR: Clear PCIe Device Status errors only if
OS owns AER"), the port Device Status was cleared in this path:

  edr_handle_event
    dpc_process_error(dev)                 # "dev" triggered DPC
    pcie_do_recovery(dev, dpc_reset_link)
      dpc_reset_link                       # exit DPC
      pcie_clear_device_status(dev)        # clear Device Status

After 068c29a248b6, pcie_do_recovery() no longer clears Device Status when
firmware controls AER, so the error bit remains set even after recovery.

Per the "Downstream Port Containment configuration control" bit in the
returned _OSC Control Field (sec 4.5.1), the OS is allowed to clear error
status until it evaluates _OST, so clear Device Status in
edr_handle_event() if the error recovery was successful.

[bhelgaas: commit log]
Fixes: 068c29a248b6 ("PCI/ERR: Clear PCIe Device Status errors only if OS owns AER")
Link: https://lore.kernel.org/r/20230315235449.1279209-1-sathyanarayanan.kuppuswamy@linux.intel.com
Reported-by: Tsaur Erwin 
Signed-off-by: Kuppuswamy Sathyanarayanan 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Sasha Levin

PCI: imx6: Install the fault handler only on compatible match

2023-05-11T14:17:24+00:00

[ Upstream commit 5f5ac460dfe7f4e11f99de9870f240e39189cf72 ]

commit bb38919ec56e ("PCI: imx6: Add support for i.MX6 PCIe controller")
added a fault hook to this driver in the probe function. So it was only
installed if needed.

commit bde4a5a00e76 ("PCI: imx6: Allow probe deferral by reset GPIO")
moved it from probe to driver init which installs the hook unconditionally
as soon as the driver is compiled into a kernel.

When this driver is compiled as a module, the hook is not registered
until after the driver has been matched with a .compatible and
loaded.

commit 415b6185c541 ("PCI: imx6: Fix config read timeout handling")
extended the fault handling code.

commit 2d8ed461dbc9 ("PCI: imx6: Add support for i.MX8MQ")
added some protection for non-ARM architectures, but this does not
protect non-i.MX ARM architectures.

Since fault handlers can be triggered on any architecture for different
reasons, there is no guarantee that they will be triggered only for the
assumed situation, leading to improper error handling (i.MX6-specific
imx6q_pcie_abort_handler) on foreign systems.

I had seen strange L3 imprecise external abort messages several times on
OMAP4 and OMAP5 devices and couldn't make sense of them until I realized
they were related to this unused imx6q driver because I had
CONFIG_PCI_IMX6=y.

Note that CONFIG_PCI_IMX6=y is useful for kernel binaries that are designed
to run on different ARM SoC and be differentiated only by device tree
binaries. So turning off CONFIG_PCI_IMX6 is not a solution.

Therefore we check the compatible in the init function before registering
the fault handler.

Link: https://lore.kernel.org/r/e1bcfc3078c82b53aa9b78077a89955abe4ea009.1678380991.git.hns@goldelico.com
Fixes: bde4a5a00e76 ("PCI: imx6: Allow probe deferral by reset GPIO")
Fixes: 415b6185c541 ("PCI: imx6: Fix config read timeout handling")
Fixes: 2d8ed461dbc9 ("PCI: imx6: Add support for i.MX8MQ")
Signed-off-by: H. Nikolaus Schaller
Signed-off-by: Lorenzo Pieralisi
Reviewed-by: Richard Zhu
Signed-off-by: Sasha Levin

PCI: qcom: Fix the incorrect register usage in v2.7.0 config

2023-05-11T14:16:47+00:00

commit 2542e16c392508800f1d9037feee881a9c444951 upstream.

Qcom PCIe IP version v2.7.0 and its derivatives don't contain the
PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT register. Instead, they have the new
PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2 register. So fix the incorrect
register usage which is modifying a different register.

Also in this IP version, this register change doesn't depend on MSI
being enabled. So remove that check also.

Link: https://lore.kernel.org/r/20230316081117.14288-2-manivannan.sadhasivam@linaro.org
Fixes: ed8cc3b1fc84 ("PCI: qcom: Add support for SDM845 PCIe controller")
Signed-off-by: Manivannan Sadhasivam 
Signed-off-by: Lorenzo Pieralisi 
Cc:  # 5.6+
Signed-off-by: Greg Kroah-Hartman

PCI: pciehp: Fix AB-BA deadlock between reset_lock and device_lock

2023-05-11T14:16:47+00:00

commit f5eff5591b8f9c5effd25c92c758a127765f74c1 upstream.

In 2013, commits

  2e35afaefe64 ("PCI: pciehp: Add reset_slot() method")
  608c388122c7 ("PCI: Add slot reset option to pci_dev_reset()")

amended PCIe hotplug to mask Presence Detect Changed events during a
Secondary Bus Reset.  The reset thus no longer causes gratuitous slot
bringdown and bringup.

However the commits neglected to serialize reset with code paths reading
slot registers.  For instance, a slot bringup due to an earlier hotplug
event may see the Presence Detect State bit cleared during a concurrent
Secondary Bus Reset.

In 2018, commit

  5b3f7b7d062b ("PCI: pciehp: Avoid slot access during reset")

retrofitted the missing locking.  It introduced a reset_lock which
serializes a Secondary Bus Reset with other parts of pciehp.

Unfortunately the locking turns out to be overzealous:  reset_lock is
held for the entire enumeration and de-enumeration of hotplugged devices,
including driver binding and unbinding.

Driver binding and unbinding acquires device_lock while the reset_lock
of the ancestral hotplug port is held.  A concurrent Secondary Bus Reset
acquires the ancestral reset_lock while already holding the device_lock.
The asymmetric locking order in the two code paths can lead to AB-BA
deadlocks.

Michael Haeuptle reports such deadlocks on simultaneous hot-removal and
vfio release (the latter implies a Secondary Bus Reset):

  pciehp_ist()                                    # down_read(reset_lock)
    pciehp_handle_presence_or_link_change()
      pciehp_disable_slot()
        __pciehp_disable_slot()
          remove_board()
            pciehp_unconfigure_device()
              pci_stop_and_remove_bus_device()
                pci_stop_bus_device()
                  pci_stop_dev()
                    device_release_driver()
                      device_release_driver_internal()
                        __device_driver_lock()    # device_lock()

  SYS_munmap()
    vfio_device_fops_release()
      vfio_device_group_close()
        vfio_device_close()
          vfio_device_last_close()
            vfio_pci_core_close_device()
              vfio_pci_core_disable()             # device_lock()
                __pci_reset_function_locked()
                  pci_reset_bus_function()
                    pci_dev_reset_slot_function()
                      pci_reset_hotplug_slot()
                        pciehp_reset_slot()       # down_write(reset_lock)

Ian May reports the same deadlock on simultaneous hot-removal and an
AER-induced Secondary Bus Reset:

  aer_recover_work_func()
    pcie_do_recovery()
      aer_root_reset()
        pci_bus_error_reset()
          pci_slot_reset()
            pci_slot_lock()                       # device_lock()
            pci_reset_hotplug_slot()
              pciehp_reset_slot()                 # down_write(reset_lock)

Fix by releasing the reset_lock during driver binding and unbinding,
thereby splitting and shrinking the critical section.

Driver binding and unbinding is protected by the device_lock() and thus
serialized with a Secondary Bus Reset.  There's no need to additionally
protect it with the reset_lock.  However, pciehp does not bind and
unbind devices directly, but rather invokes PCI core functions which
also perform certain enumeration and de-enumeration steps.

The reset_lock's purpose is to protect slot registers, not enumeration
and de-enumeration of hotplugged devices.  That would arguably be the
job of the PCI core, not the PCIe hotplug driver.  After all, an
AER-induced Secondary Bus Reset may as well happen during boot-time
enumeration of the PCI hierarchy and there's no locking to prevent that
either.

Exempting *de-enumeration* from the reset_lock is relatively harmless:
A concurrent Secondary Bus Reset may foil config space accesses such as
PME interrupt disablement.  But if the device is physically gone, those
accesses are pointless anyway.  If the device is physically present and
only logically removed through an Attention Button press or the sysfs
"power" attribute, PME interrupts as well as DMA cannot come through
because pciehp_unconfigure_device() disables INTx and Bus Master bits.
That's still protected by the reset_lock in the present commit.

Exempting *enumeration* from the reset_lock also has limited impact:
The exempted call to pci_bus_add_device() may perform device accesses
through pcibios_bus_add_device() and pci_fixup_device() which are now
no longer protected from a concurrent Secondary Bus Reset.  Otherwise
there should be no impact.

In essence, the present commit seeks to fix the AB-BA deadlocks while
still retaining a best-effort reset protection for enumeration and
de-enumeration of hotplugged devices -- until a general solution is
implemented in the PCI core.

Link: https://lore.kernel.org/linux-pci/CS1PR8401MB0728FC6FDAB8A35C22BD90EC95F10@CS1PR8401MB0728.NAMPRD84.PROD.OUTLOOK.COM
Link: https://lore.kernel.org/linux-pci/20200615143250.438252-1-ian.may@canonical.com
Link: https://lore.kernel.org/linux-pci/ce878dab-c0c4-5bd0-a725-9805a075682d@amd.com
Link: https://lore.kernel.org/linux-pci/ed831249-384a-6d35-0831-70af191e9bce@huawei.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215590
Fixes: 5b3f7b7d062b ("PCI: pciehp: Avoid slot access during reset")
Link: https://lore.kernel.org/r/fef2b2e9edf245c049a8c5b94743c0f74ff5008a.1681191902.git.lukas@wunner.de
Reported-by: Michael Haeuptle 
Reported-by: Ian May 
Reported-by: Andrey Grodzovsky 
Reported-by: Rahul Kumar 
Reported-by: Jialin Zhang 
Tested-by: Anatoli Antonovitch 
Signed-off-by: Lukas Wunner 
Signed-off-by: Bjorn Helgaas 
Cc: stable@vger.kernel.org # v4.19+
Cc: Dan Stein 
Cc: Ashok Raj 
Cc: Alex Michon 
Cc: Xiongfeng Wang 
Cc: Alex Williamson 
Cc: Mika Westerberg 
Cc: Sathyanarayanan Kuppuswamy 
Signed-off-by: Greg Kroah-Hartman

PCI: kirin: Select REGMAP_MMIO

2023-05-11T14:16:47+00:00

commit 3a2776e8a0e156a61f5b59ae341d8fffc730b962 upstream.

pcie-kirin uses regmaps, and needs to pull them in; otherwise, with
CONFIG_PCIE_KIRIN=y and without CONFIG_REGMAP_MMIO pcie-kirin produces
a linker failure looking for __devm_regmap_init_mmio_clk().

Fixes: d19afe7be126 ("PCI: kirin: Use regmap for APB registers")
Link: https://lore.kernel.org/r/04636141da1d6d592174eefb56760511468d035d.1668410580.git.josh@joshtriplett.org
Signed-off-by: Josh Triplett 
[lpieralisi@kernel.org: commit log and removed REGMAP select]
Signed-off-by: Lorenzo Pieralisi 
Cc: stable@vger.kernel.org # 5.16+
Signed-off-by: Greg Kroah-Hartman

Merge tag 'irq_urgent_for_v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-04-23T15:15:33+00:00

Pull irq fix from Borislav Petkov:

 - Remove an over-zealous sanity check of the array of MSI-X vectors to
   be allocated for a device

* tag 'irq_urgent_for_v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  PCI/MSI: Remove over-zealous hardware size check in pci_msix_validate_entries()

Merge tag 'pci-v6.3-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci

2023-04-20T22:36:23+00:00

Pull pci fix from Bjorn Helgaas:

 - Previously we ignored PCI devices if the DT "status" property or the
   ACPI _STA method said it was not present.

   Per spec, _STA cannot be used for that purpose, and using it that way
   caused regressions, so skip the _STA check (Rob Herring)

* tag 'pci-v6.3-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
  PCI: Restrict device disabled status check to DT

PCI: Restrict device disabled status check to DT

2023-04-20T18:30:14+00:00

Commit 6fffbc7ae137 ("PCI: Honor firmware's device disabled status")
checked the firmware device status for both DT and ACPI devices. That
caused a regression in some ACPI systems. The exact reason isn't clear.
It's possibly a firmware bug. For now, at least, refactor the check to
be for DT based systems only.

Note that the original implementation leaked a refcount which is now
correctly handled.

[bhelgaas: Per ACPI r6.5, sec 6.3.7, for devices on an enumerable bus, _STA
must return with bit[0] ("device is present") set]

Link: https://lore.kernel.org/all/m2fs9lgndw.fsf@gmail.com/
Fixes: 6fffbc7ae137 ("PCI: Honor firmware's device disabled status")
Link: https://lore.kernel.org/r/20230419193513.708818-1-robh@kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217317
Reported-by: Donald Hunter 
Reported-by: Vitaly Kuznetsov 
Tested-by: Donald Hunter 
Tested-by: Vitaly Kuznetsov 
Signed-off-by: Rob Herring 
Signed-off-by: Bjorn Helgaas 
Cc: Binbin Zhou 
Cc: Liu Peibao 
Cc: Huacai Chen

PCI/MSI: Remove over-zealous hardware size check in pci_msix_validate_entries()

2023-04-16T12:11:51+00:00

pci_msix_validate_entries() validates the entries array which is handed in
by the caller for a MSI-X interrupt allocation. Aside of consistency
failures it also detects a failure when the size of the MSI-X hardware table
in the device is smaller than the size of the entries array.

That's wrong for the case of range allocations where the caller provides
the minimum and the maximum number of vectors to allocate, when the
hardware size is greater or equal than the mininum, but smaller than the
maximum.

Remove the hardware size check completely from that function and just
ensure that the entires array up to the maximum size is consistent.

The limitation and range checking versus the hardware size happens
independently of that afterwards anyway because the entries array is
optional.

Fixes: 4644d22eb673 ("PCI/MSI: Validate MSI-X contiguous restriction early")
Reported-by: David Laight 
Signed-off-by: Thomas Gleixner 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87v8i3sg62.ffs@tglx