kernel/linux.git/drivers/pci/hotplug, branch v6.6.132

PCI: pnv_php: Fix surprise plug detection and recovery

2025-08-15T10:09:01+00:00

[ Upstream commit a2a2a6fc2469524caa713036297c542746d148dc ] The existing PowerNV hotplug code did not handle surprise plug events correctly, leading to a complete failure of the hotplug system after device removal and a required reboot to detect new devices. This comes down to two issues: 1) When a device is surprise removed, often the bridge upstream port will cause a PE freeze on the PHB. If this freeze is not cleared, the MSI interrupts from the bridge hotplug notification logic will not be received by the kernel, stalling all plug events on all slots associated with the PE. 2) When a device is removed from a slot, regardless of surprise or programmatic removal, the associated PHB/PE ls left frozen. If this freeze is not cleared via a fundamental reset, skiboot is unable to clear the freeze and cannot retrain / rescan the slot. This also requires a reboot to clear the freeze and redetect the device in the slot. Issue the appropriate unfreeze and rescan commands on hotplug events, and don't oops on hotplug if pci_bus_to_OF_node() returns NULL. Signed-off-by: Timothy Pearson [bhelgaas: tidy comments] Signed-off-by: Bjorn Helgaas Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/171044224.1359864.1752615546988.JavaMail.zimbra@raptorengineeringinc.com Signed-off-by: Sasha Levin

PCI: pnv_php: Work around switches with broken presence detection

2025-08-15T10:09:00+00:00

[ Upstream commit 80f9fc2362797538ebd4fd70a1dfa838cc2c2cdb ] The Microsemi Switchtec PM8533 PFX 48xG3 [11f8:8533] PCIe switch system was observed to incorrectly assert the Presence Detect Set bit in its capabilities when tested on a Raptor Computing Systems Blackbird system, resulting in the hot insert path never attempting a rescan of the bus and any downstream devices not being re-detected. Work around this by additionally checking whether the PCIe data link is active or not when performing presence detection on downstream switches' ports, similar to the pciehp_hpc.c driver. Signed-off-by: Shawn Anastasio Signed-off-by: Timothy Pearson Signed-off-by: Bjorn Helgaas Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/505981576.1359853.1752615415117.JavaMail.zimbra@raptorengineeringinc.com Signed-off-by: Sasha Levin

PCI: pnv_php: Clean up allocated IRQs on unplug

2025-08-15T10:09:00+00:00

[ Upstream commit 4668619092554e1b95c9a5ac2941ca47ba6d548a ] When the root of a nested PCIe bridge configuration is unplugged, the pnv_php driver leaked the allocated IRQ resources for the child bridges' hotplug event notifications, resulting in a panic. Fix this by walking all child buses and deallocating all its IRQ resources before calling pci_hp_remove_devices(). Also modify the lifetime of the workqueue at struct pnv_php_slot::wq so that it is only destroyed in pnv_php_free_slot(), instead of pnv_php_disable_irq(). This is required since pnv_php_disable_irq() will now be called by workers triggered by hot unplug interrupts, so the workqueue needs to stay allocated. The abridged kernel panic that occurs without this patch is as follows: WARNING: CPU: 0 PID: 687 at kernel/irq/msi.c:292 msi_device_data_release+0x6c/0x9c CPU: 0 UID: 0 PID: 687 Comm: bash Not tainted 6.14.0-rc5+ #2 Call Trace: msi_device_data_release+0x34/0x9c (unreliable) release_nodes+0x64/0x13c devres_release_all+0xc0/0x140 device_del+0x2d4/0x46c pci_destroy_dev+0x5c/0x194 pci_hp_remove_devices+0x90/0x128 pci_hp_remove_devices+0x44/0x128 pnv_php_disable_slot+0x54/0xd4 power_write_file+0xf8/0x18c pci_slot_attr_store+0x40/0x5c sysfs_kf_write+0x64/0x78 kernfs_fop_write_iter+0x1b0/0x290 vfs_write+0x3bc/0x50c ksys_write+0x84/0x140 system_call_exception+0x124/0x230 system_call_vectored_common+0x15c/0x2ec Signed-off-by: Shawn Anastasio Signed-off-by: Timothy Pearson [bhelgaas: tidy comments] Signed-off-by: Bjorn Helgaas Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/2013845045.1359852.1752615367790.JavaMail.zimbra@raptorengineeringinc.com Signed-off-by: Sasha Levin

PCI: pciehp: Don't enable HPIE when resuming in poll mode

2025-04-10T12:37:29+00:00

[ Upstream commit 527664f738afb6f2c58022cd35e63801e5dc7aec ] PCIe hotplug can operate in poll mode without interrupt handlers using a polling kthread only. eb34da60edee ("PCI: pciehp: Disable hotplug interrupt during suspend") failed to consider that and enables HPIE (Hot-Plug Interrupt Enable) unconditionally when resuming the Port. Only set HPIE if non-poll mode is in use. This makes pcie_enable_interrupt() match how pcie_enable_notification() already handles HPIE. Link: https://lore.kernel.org/r/20250321162114.3939-1-ilpo.jarvinen@linux.intel.com Fixes: eb34da60edee ("PCI: pciehp: Disable hotplug interrupt during suspend") Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner Signed-off-by: Sasha Levin

PCI: cpqphp: Fix PCIBIOS_* return value confusion

2024-12-09T09:32:25+00:00

[ Upstream commit e2226dbc4a4919d9c8bd9293299b532090bdf020 ] Code in and related to PCI_RefinedAccessConfig() has three types of return type confusion: - PCI_RefinedAccessConfig() tests pci_bus_read_config_dword() return value against -1. - PCI_RefinedAccessConfig() returns both -1 and PCIBIOS_* return codes. - Callers of PCI_RefinedAccessConfig() only test for -1. Make PCI_RefinedAccessConfig() return PCIBIOS_* codes consistently and adapt callers accordingly. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Link: https://lore.kernel.org/r/20241022091140.3504-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin

PCI: cpqphp: Use PCI_POSSIBLE_ERROR() to check config reads

2024-12-09T09:32:25+00:00

[ Upstream commit 87d5403378cccc557af9e02a8a2c8587ad8b7e9a ] Use PCI_POSSIBLE_ERROR() to check the response we get when we read data from hardware. This unifies PCI error response checking and makes error checks consistent and easier to find. Link: https://lore.kernel.org/r/20240806065050.28725-1-412574090@163.com Signed-off-by: weiyufeng Signed-off-by: Bjorn Helgaas Stable-dep-of: e2226dbc4a49 ("PCI: cpqphp: Fix PCIBIOS_* return value confusion") Signed-off-by: Sasha Levin

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

2024-09-12T09:11:36+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

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

2023-12-20T16:01:53+00:00

commit 5df12742b7e3aae2594a30a9d14d5d6e9e7699f4 upstream. 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: Signed-off-by: Greg Kroah-Hartman

Merge tag 'powerpc-6.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2023-08-31T19:43:10+00:00

Pull powerpc updates from Michael Ellerman: - Add HOTPLUG_SMT support (/sys/devices/system/cpu/smt) and honour the configured SMT state when hotplugging CPUs into the system - Combine final TLB flush and lazy TLB mm shootdown IPIs when using the Radix MMU to avoid a broadcast TLBIE flush on exit - Drop the exclusion between ptrace/perf watchpoints, and drop the now unused associated arch hooks - Add support for the "nohlt" command line option to disable CPU idle - Add support for -fpatchable-function-entry for ftrace, with GCC >= 13.1 - Rework memory block size determination, and support 256MB size on systems with GPUs that have hotpluggable memory - Various other small features and fixes Thanks to Andrew Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Athira Rajeev, Benjamin Gray, Christophe Leroy, Frederic Barrat, Gautam Menghani, Geoff Levand, Hari Bathini, Immad Mir, Jialin Zhang, Joel Stanley, Jordan Niethe, Justin Stitt, Kajol Jain, Kees Cook, Krzysztof Kozlowski, Laurent Dufour, Liang He, Linus Walleij, Mahesh Salgaonkar, Masahiro Yamada, Michal Suchanek, Nageswara R Sastry, Nathan Chancellor, Nathan Lynch, Naveen N Rao, Nicholas Piggin, Nick Desaulniers, Omar Sandoval, Randy Dunlap, Reza Arbab, Rob Herring, Russell Currey, Sourabh Jain, Thomas Gleixner, Trevor Woerner, Uwe Kleine-König, Vaibhav Jain, Xiongfeng Wang, Yuan Tan, Zhang Rui, and Zheng Zengkai. * tag 'powerpc-6.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (135 commits) macintosh/ams: linux/platform_device.h is needed powerpc/xmon: Reapply "Relax frame size for clang" powerpc/mm/book3s64: Use 256M as the upper limit with coherent device memory attached powerpc/mm/book3s64: Fix build error with SPARSEMEM disabled powerpc/iommu: Fix notifiers being shared by PCI and VIO buses powerpc/mpc5xxx: Add missing fwnode_handle_put() powerpc/config: Disable SLAB_DEBUG_ON in skiroot powerpc/pseries: Remove unused hcall tracing instruction powerpc/pseries: Fix hcall tracepoints with JUMP_LABEL=n powerpc: dts: add missing space before { powerpc/eeh: Use pci_dev_id() to simplify the code powerpc/64s: Move CPU -mtune options into Kconfig powerpc/powermac: Fix unused function warning powerpc/pseries: Rework lppaca_shared_proc() to avoid DEBUG_PREEMPT powerpc: Don't include lppaca.h in paca.h powerpc/pseries: Move hcall_vphn() prototype into vphn.h powerpc/pseries: Move VPHN constants into vphn.h cxl: Drop unused detach_spa() powerpc: Drop zalloc_maybe_bootmem() powerpc/powernv: Use struct opal_prd_msg in more places ...

Merge tag 'pci-v6.6-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci

2023-08-31T03:23:07+00:00

Pull PCI updates from Bjorn Helgaas: "Enumeration: - Add locking to read/modify/write PCIe Capability Register accessors for Link Control and Root Control - Use pci_dev_id() when possible instead of manually composing ID from dev->bus->number and dev->devfn Resource management: - Move prototypes for __weak sysfs resource files to linux/pci.h to fix 'no previous prototype' warnings - Make more I/O port accesses depend on HAS_IOPORT - Use devm_platform_get_and_ioremap_resource() instead of open-coding platform_get_resource() followed by devm_ioremap_resource() Power management: - Ensure devices are powered up while accessing VPD - If device is powered-up, keep it that way while polling for PME - Only read PCI_PM_CTRL register when available, to avoid reading the wrong register and corrupting dev->current_state Virtualization: - Avoid Secondary Bus Reset on NVIDIA T4 GPUs Error handling: - Remove unused pci_disable_pcie_error_reporting() - Unexport pci_enable_pcie_error_reporting(), used only by aer.c - Unexport pcie_port_bus_type, used only by PCI core VGA: - Simplify and clean up typos in VGA arbiter Apple PCIe controller driver: - Initialize pcie->nvecs (number of available MSIs) before use Broadcom iProc PCIe controller driver: - Use of_property_read_bool() instead of low-level accessors for boolean properties Broadcom STB PCIe controller driver: - Assert PERST# when probing BCM2711 because some bootloaders don't do it Freescale i.MX6 PCIe controller driver: - Add .host_deinit() callback so we can clean up things like regulators on probe failure or driver unload Freescale Layerscape PCIe controller driver: - Add support for link-down notification so the endpoint driver can process LINK_DOWN events - Add suspend/resume support, including manual PME_Turn_off/PME_TO_Ack handshake - Save Link Capabilities during probe so they can be restored when handling a link-up event, since the controller loses the Link Width and Link Speed values during reset Intel VMD host bridge driver: - Fix disable of bridge windows during domain reset; previously we cleared the base/limit registers, which actually left the windows enabled Marvell MVEBU PCIe controller driver: - Remove unused busn member Microchip PolarFlare PCIe controller driver: - Fix interrupt bit definitions so the SEC and DED interrupt handlers work correctly - Make driver buildable as a module - Read FPGA MSI configuration parameters from hardware instead of hard-coding them Microsoft Hyper-V host bridge driver: - To avoid a NULL pointer dereference, skip MSI restore after hibernate if MSI/MSI-X hasn't been enabled NVIDIA Tegra194 PCIe controller driver: - Revert 'PCI: tegra194: Enable support for 256 Byte payload' because Linux doesn't know how to reduce MPS from to 256 to 128 bytes for endpoints below a switch (because other devices below the switch might already be operating), which leads to 'Malformed TLP' errors Qualcomm PCIe controller driver: - Add DT and driver support for interconnect bandwidth voting for 'pcie-mem' and 'cpu-pcie' interconnects - Fix broken SDX65 'compatible' DT property - Configure controller so MHI bus master clock will be switched off while in ASPM L1.x states - Use alignment restriction from EPF core in EPF MHI driver - Add Endpoint eDMA support - Add MHI eDMA support - Add Snapdragon SM8450 support to the EPF MHI driversupport - Add MHI eDMA support - Add Snapdragon SM8450 support to the EPF MHI driversupport - Add MHI eDMA support - Add Snapdragon SM8450 support to the EPF MHI driversupport - Add MHI eDMA support - Add Snapdragon SM8450 support to the EPF MHI driver - Use iATU for EPF MHI transfers smaller than 4K to avoid eDMA setup latency - Add sa8775p DT binding and driver support Rockchip PCIe controller driver: - Use 64-bit mask on MSI 64-bit PCI address to avoid zeroing out the upper 32 bits SiFive FU740 PCIe controller driver: - Set the supported number of MSI vectors so we can use all available MSI interrupts Synopsys DesignWare PCIe controller driver: - Add generic dwc suspend/resume APIs (dw_pcie_suspend_noirq() and dw_pcie_resume_noirq()) to be called by controller driver suspend/resume ops, and a controller callback to send PME_Turn_Off MicroSemi Switchtec management driver: - Add support for PCIe Gen5 devices Miscellaneous: - Reorder and compress to reduce size of struct pci_dev - Fix race in DOE destroy_work_on_stack() - Add stubs to avoid casts between incompatible function types - Explicitly include correct DT includes to untangle headers" * tag 'pci-v6.6-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (96 commits) PCI: qcom-ep: Add ICC bandwidth voting support dt-bindings: PCI: qcom: ep: Add interconnects path PCI: qcom-ep: Treat unknown IRQ events as an error dt-bindings: PCI: qcom: Fix SDX65 compatible PCI: endpoint: Add kernel-doc for pci_epc_mem_init() API PCI: epf-mhi: Use iATU for small transfers PCI: epf-mhi: Add support for SM8450 PCI: epf-mhi: Add eDMA support PCI: qcom-ep: Add eDMA support PCI: epf-mhi: Make use of the alignment restriction from EPF core PCI/PM: Only read PCI_PM_CTRL register when available PCI: qcom: Add support for sa8775p SoC dt-bindings: PCI: qcom: Add sa8775p compatible PCI: qcom-ep: Pass alignment restriction to the EPF core PCI: Simplify pcie_capability_clear_and_set_word() control flow PCI: Tidy config space save/restore messages PCI: Fix code formatting inconsistencies PCI: Fix typos in docs and comments PCI: Fix pci_bus_resetable(), pci_slot_resetable() name typos PCI: Simplify pci_dev_driver() ...