linux-stable.git/drivers/pci/hotplug, branch linux-6.10.y

pci/hotplug/pnv_php: Fix hotplug driver crash on Powernv

2024-09-12T09:12:59+00:00

[ Upstream commit 335e35b748527f0c06ded9eebb65387f60647fda ]

The hotplug driver for powerpc (pci/hotplug/pnv_php.c) causes a kernel
crash when we try to hot-unplug/disable the PCIe switch/bridge from
the PHB.

The crash occurs because although the MSI data structure has been
released during disable/hot-unplug path and it has been assigned
with NULL, still during unregistration the code was again trying to
explicitly disable the MSI which causes the NULL pointer dereference and
kernel crash.

The patch fixes the check during unregistration path to prevent invoking
pci_disable_msi/msix() since its data structure is already freed.

Reported-by: Timothy Pearson 
Closes: https://lore.kernel.org/all/1981605666.2142272.1703742465927.JavaMail.zimbra@raptorengineeringinc.com/
Acked-by: Bjorn Helgaas 
Tested-by: Shawn Anastasio 
Signed-off-by: Krishna Kumar 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20240701074513.94873-2-krishnak@linux.ibm.com
Signed-off-by: Sasha Levin

PCI: pciehp: Retain Power Indicator bits for userspace indicators

2024-08-11T10:57:59+00:00

commit 5560a612c20d3daacbf5da7913deefa5c31742f4 upstream.

The sysfs "attention" file normally controls the Slot Control Attention
Indicator with 0 (off), 1 (on), 2 (blink) settings.

576243b3f9ea ("PCI: pciehp: Allow exclusive userspace control of
indicators") added pciehp_set_raw_indicator_status() to allow userspace to
directly control all four bits in both the Attention Indicator and the
Power Indicator fields via the "attention" file.

This is used on Intel VMD bridges so utilities like "ledmon" can use sysfs
"attention" to control up to 16 indicators for NVMe device RAID status.

abaaac4845a0 ("PCI: hotplug: Use FIELD_GET/PREP()") broke this by masking
the sysfs data with PCI_EXP_SLTCTL_AIC, which discards the upper two bits
intended for the Power Indicator Control field (PCI_EXP_SLTCTL_PIC).

For NVMe devices behind an Intel VMD, ledmon settings that use the
PCI_EXP_SLTCTL_PIC bits, i.e., ATTENTION_REBUILD (0x5), ATTENTION_LOCATE
(0x7), ATTENTION_FAILURE (0xD), ATTENTION_OFF (0xF), no longer worked
correctly.

Mask with PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC to retain both the
Attention Indicator and the Power Indicator bits.

Fixes: abaaac4845a0 ("PCI: hotplug: Use FIELD_GET/PREP()")
Link: https://lore.kernel.org/r/20240722141440.7210-1-blazej.kucman@intel.com
Signed-off-by: Blazej Kucman 
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas 
Cc: stable@vger.kernel.org	# v6.7+
Signed-off-by: Greg Kroah-Hartman

PCI: hotplug: Remove obsolete sgi_hotplug TODO notes

2024-05-03T21:26:50+00:00

Commit c7532b601e77 ("PCI/hotplug: remove the sgi_hotplug driver") deleted
the driver.

Remove the remaining TODO notes as well.

Link: https://lore.kernel.org/r/26784ee39fbb3fbd0fe96508158d74419018e6ad.1714762038.git.namcao@linutronix.de
Signed-off-by: Nam Cao 
Signed-off-by: Bjorn Helgaas

PCI: hotplug: Document unchecked return value of pci_hp_add_bridge()

2024-05-03T21:25:52+00:00

Some hotplug drivers do not check the return value of pci_hp_add_bridge().
This may be problematic if the driver proceeds after pci_hp_add_bridge()
fails.

Link: https://lore.kernel.org/r/16a2442ea6ee896987a44df3ed509e4cfde44475.1714762038.git.namcao@linutronix.de
Signed-off-by: Nam Cao 
Signed-off-by: Bjorn Helgaas

s390/pci: introduce lock to synchronize state of zpci_dev's

2024-02-20T13:37:32+00:00

There's a number of tasks that need the state of a zpci device
to be stable. Other tasks need to be synchronized as they change the state.

State changes could be generated by the system as availability or error
events, or be requested by the user through manipulations in sysfs.
Some other actions accessible through sysfs - like device resets - need the
state to be stable.

Unsynchronized state handling could lead to unusable devices. This has
been observed in cases of concurrent state changes through systemd udev
rules and DPM boot control. Some breakage can be provoked by artificial
tests, e.g. through repetitively injecting "recover" on a PCI function
through sysfs while running a "hotplug remove/add" in a loop through a
PCI slot's "power" attribute in sysfs. After a few iterations this could
result in a kernel oops.

So introduce a new mutex "state_lock" to guard the state property of the
struct zpci_dev. Acquire this lock in all task that modify the state:

- hotplug add and remove, through the PCI hotplug slot entry,
- avaiability events, as reported by the platform,
- error events, as reported by the platform,
- during device resets, explicit through sysfs requests or
  implict through the common PCI layer.

Break out an inner _do_recover() routine out of recover_store() to
separte the necessary synchronizations from the actual manipulations of
the zpci_dev required for the reset.

With the following changes I was able to run the inject loops for hours
without hitting an error.

Signed-off-by: Gerd Bayer 
Reviewed-by: Niklas Schnelle 
Signed-off-by: Heiko Carstens

Revert "PCI: acpiphp: Reassign resources on bridge if necessary"

2023-12-15T20:55:10+00:00

This reverts commit 40613da52b13fb21c5566f10b287e0ca8c12c4e9 and the
subsequent fix to it:

  cc22522fd55e ("PCI: acpiphp: Use pci_assign_unassigned_bridge_resources() only for non-root bus")

40613da52b13 fixed a problem where hot-adding a device with large BARs
failed if the bridge windows programmed by firmware were not large enough.

cc22522fd55e ("PCI: acpiphp: Use pci_assign_unassigned_bridge_resources()
only for non-root bus") fixed a problem with 40613da52b13: an ACPI hot-add
of a device on a PCI root bus (common in the virt world) or firmware
sending ACPI Bus Check to non-existent Root Ports (e.g., on Dell Inspiron
7352/0W6WV0) caused a NULL pointer dereference and suspend/resume hangs.

Unfortunately the combination of 40613da52b13 and cc22522fd55e caused other
problems:

  - Fiona reported that hot-add of SCSI disks in QEMU virtual machine fails
    sometimes.

  - Dongli reported a similar problem with hot-add of SCSI disks.

  - Jonathan reported a console freeze during boot on bare metal due to an
    error in radeon GPU initialization.

Revert both patches to avoid adding these problems.  This means we will
again see the problems with hot-adding devices with large BARs and the NULL
pointer dereferences and suspend/resume issues that 40613da52b13 and
cc22522fd55e were intended to fix.

Fixes: 40613da52b13 ("PCI: acpiphp: Reassign resources on bridge if necessary")
Fixes: cc22522fd55e ("PCI: acpiphp: Use pci_assign_unassigned_bridge_resources() only for non-root bus")
Reported-by: Fiona Ebner 
Closes: https://lore.kernel.org/r/9eb669c0-d8f2-431d-a700-6da13053ae54@proxmox.com
Reported-by: Dongli Zhang 
Closes: https://lore.kernel.org/r/3c4a446a-b167-11b8-f36f-d3c1b49b42e9@oracle.com
Reported-by: Jonathan Woithe 
Closes: https://lore.kernel.org/r/ZXpaNCLiDM+Kv38H@marvin.atrad.com.au
Signed-off-by: Bjorn Helgaas 
Acked-by: Michael S. Tsirkin 
Acked-by: Igor Mammedov 
Cc:

Merge branch 'pci/field-get'

2023-10-28T18:31:05+00:00

- Use FIELD_GET()/FIELD_PREP() when possible throughout drivers/pci/ (Ilpo
  Järvinen, Bjorn Helgaas)

- Rework DPC control programming for clarity (Ilpo Järvinen)

* pci/field-get:
  PCI/portdrv: Use FIELD_GET()
  PCI/VC: Use FIELD_GET()
  PCI/PTM: Use FIELD_GET()
  PCI/PME: Use FIELD_GET()
  PCI/ATS: Use FIELD_GET()
  PCI/ATS: Show PASID Capability register width in bitmasks
  PCI: Use FIELD_GET() in Sapphire RX 5600 XT Pulse quirk
  PCI: Use FIELD_GET()
  PCI/MSI: Use FIELD_GET/PREP()
  PCI/DPC: Use defines with DPC reason fields
  PCI/DPC: Use defined fields with DPC_CTL register
  PCI/DPC: Use FIELD_GET()
  PCI: hotplug: Use FIELD_GET/PREP()
  PCI: dwc: Use FIELD_GET/PREP()
  PCI: cadence: Use FIELD_GET()
  PCI: Use FIELD_GET() to extract Link Width
  PCI: mvebu: Use FIELD_PREP() with Link Width
  PCI: tegra194: Use FIELD_GET()/FIELD_PREP() with Link Width fields

# Conflicts:
#	drivers/pci/controller/dwc/pcie-tegra194.c

Merge branch 'pci/hotplug'

2023-10-28T18:30:58+00:00

- Add driver for Ampere Altra Attention Indicators (D Scott Phillips)

* pci/hotplug:
  PCI: hotplug: Add Ampere Altra Attention Indicator extension driver
  PCI: acpiphp: Allow built-in drivers for Attention Indicators

PCI: hotplug: Add Ampere Altra Attention Indicator extension driver

2023-10-26T11:02:10+00:00

On Ampere Altra, PCIe hotplug is handled through ACPI. A side interface is
also present to request system firmware control of the hotplug Attention
Indicators. Add an ACPI PCI Hotplug companion driver to support Attention
Indicator control.

Link: https://lore.kernel.org/r/20230930002036.6491-2-scott@os.amperecomputing.com
Signed-off-by: D Scott Phillips 
[bhelgaas: mask domain to low 4 bits]
Signed-off-by: Bjorn Helgaas 
Acked-by: "Rafael J. Wysocki"

PCI: acpiphp: Allow built-in drivers for Attention Indicators

2023-10-25T18:05:37+00:00

Since the introduction of the attention callback in acpiphp, a non-zero
struct module *owner has been required in acpiphp_register_attention(). The
intent seemed to be that the core code could hold a refcount on the module
while invoking a callback.

This check accidentally precludes the possibility of attention callbacks to
built-in drivers.

Remove the check on `struct module *owner` in acpiphp_register_attention()
so attention callbacks can also be registered from built-in drivers.

Link: https://lore.kernel.org/r/20230930002036.6491-1-scott@os.amperecomputing.com
Signed-off-by: D Scott Phillips 
Signed-off-by: Bjorn Helgaas