linux/drivers/pci
Lukas Wunner 74ff8864cc PCI: hotplug: Allow marking devices as disconnected during bind/unbind
On surprise removal, pciehp_unconfigure_device() and acpiphp's
trim_stale_devices() call pci_dev_set_disconnected() to mark removed
devices as permanently offline.  Thereby, the PCI core and drivers know
to skip device accesses.

However pci_dev_set_disconnected() takes the device_lock and thus waits for
a concurrent driver bind or unbind to complete.  As a result, the driver's
->probe and ->remove hooks have no chance to learn that the device is gone.

That doesn't make any sense, so drop the device_lock and instead use atomic
xchg() and cmpxchg() operations to update the device state.

As a byproduct, an AB-BA deadlock reported by Anatoli is fixed which occurs
on surprise removal with AER concurrently performing a bus reset.

AER bus reset:

  INFO: task irq/26-aerdrv:95 blocked for more than 120 seconds.
  Tainted: G        W          6.2.0-rc3-custom-norework-jan11+
  schedule
  rwsem_down_write_slowpath
  down_write_nested
  pciehp_reset_slot                      # acquires reset_lock
  pci_reset_hotplug_slot
  pci_slot_reset                         # acquires device_lock
  pci_bus_error_reset
  aer_root_reset
  pcie_do_recovery
  aer_process_err_devices
  aer_isr

pciehp surprise removal:

  INFO: task irq/26-pciehp:96 blocked for more than 120 seconds.
  Tainted: G        W          6.2.0-rc3-custom-norework-jan11+
  schedule_preempt_disabled
  __mutex_lock
  mutex_lock_nested
  pci_dev_set_disconnected               # acquires device_lock
  pci_walk_bus
  pciehp_unconfigure_device
  pciehp_disable_slot
  pciehp_handle_presence_or_link_change
  pciehp_ist                             # acquires reset_lock

Link: https://bugzilla.kernel.org/show_bug.cgi?id=215590
Fixes: a6bd101b8f ("PCI: Unify device inaccessible")
Link: https://lore.kernel.org/r/3dc88ea82bdc0e37d9000e413d5ebce481cbd629.1674205689.git.lukas@wunner.de
Reported-by: Anatoli Antonovitch <anatoli.antonovitch@amd.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v4.20+
Cc: Keith Busch <kbusch@kernel.org>
2023-02-15 15:01:01 -06:00
..
controller phy-for-6.2 2022-12-19 08:40:58 -06:00
endpoint Merge branch 'remotes/lorenzo/pci/misc' 2022-12-10 10:36:40 -06:00
hotplug PCI: pciehp: Add Qualcomm quirk for Command Completed erratum 2023-02-14 11:47:49 -06:00
msi PCI/MSI: Provide pci_ims_alloc/free_irq() 2022-12-05 22:22:35 +01:00
pcie pci-v6.2-changes 2022-12-14 09:54:10 -08:00
switch PCI: switchtec: Prefer ida_alloc()/free() over ida_simple_get()/remove() 2022-06-09 12:28:21 -05:00
access.c PCI: Access Link 2 registers only for devices with Links 2022-11-04 10:38:11 -05:00
ats.c PCI: Enable PASID only when ACS RR & UF enabled on upstream path 2022-11-03 15:47:47 +01:00
bus.c PCI: Skip allocate_resource() if too little space available 2022-12-10 10:31:47 -06:00
doe.c PCI/DOE: Fix maximum data object length miscalculation 2022-11-16 14:26:46 -06:00
ecam.c
host-bridge.c
iov.c PCI/IOV: Fix wrong kernel-doc identifier 2022-03-07 12:06:10 -07:00
irq.c PCI: Check for alloc failure in pci_request_irq() 2022-11-21 16:55:18 -06:00
Kconfig genirq: Get rid of GENERIC_MSI_IRQ_DOMAIN 2022-11-17 15:15:20 +01:00
Makefile PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
mmap.c PCI: Remove pci_mmap_page_range() wrapper 2022-07-29 12:08:44 -05:00
of.c IOMMU Updates for Linux v5.19 2022-05-31 09:56:54 -07:00
p2pdma.c for-6.2/block-2022-12-08 2022-12-13 10:43:59 -08:00
pci-acpi.c PCI/ACPI: Use METHOD_NAME__UID instead of plain string 2022-11-07 15:22:52 -06:00
pci-bridge-emul.c PCI: pci-bridge-emul: Set position of PCI capabilities to real HW value 2022-08-25 12:07:56 +02:00
pci-bridge-emul.h PCI: pci-bridge-emul: Set position of PCI capabilities to real HW value 2022-08-25 12:07:56 +02:00
pci-driver.c PCI/PM: Remove unused 'state' parameter to pci_legacy_suspend_late() 2022-10-26 11:26:11 -05:00
pci-label.c
pci-mid.c
pci-pf-stub.c
pci-stub.c PCI: pci_stub: Set driver_managed_dma 2022-04-28 15:32:20 +02:00
pci-sysfs.c pci-v6.2-changes 2022-12-14 09:54:10 -08:00
pci.c PCI: Fix pci_device_is_present() for VFs by checking PF 2022-11-11 17:37:56 -06:00
pci.h PCI: hotplug: Allow marking devices as disconnected during bind/unbind 2023-02-15 15:01:01 -06:00
probe.c pci-v6.2-changes 2022-12-14 09:54:10 -08:00
proc.c PCI: Remove pci_mmap_page_range() wrapper 2022-07-29 12:08:44 -05:00
quirks.c PCI/DPC: Quirk PIO log size for certain Intel Root Ports 2022-09-27 18:13:18 -05:00
remove.c PCI: Assign PCI domain IDs by ida_alloc() 2022-11-08 11:14:18 -06:00
rom.c
search.c
setup-bus.c Revert "PCI: Distribute available resources for root buses, too" 2022-10-14 14:27:58 -05:00
setup-irq.c
setup-res.c PCI: Sanitise firmware BAR assignments behind a PCI-PCI bridge 2022-09-21 17:52:47 -05:00
slot.c
syscall.c
vc.c
vgaarb.c PCI/VGA: Replace full MIT license text with SPDX identifier 2022-03-09 18:31:34 -06:00
vpd.c
xen-pcifront.c xen/pcifront: move xenstore config scanning into sub-function 2022-10-07 07:36:44 +02:00