BMC/Intel-BMC/linux.git/drivers/pci/hotplug, branch dev-5.15-intel

PCI: pciehp: Add Qualcomm quirk for Command Completed erratum

2022-04-13T18:59:04+00:00

[ Upstream commit 9f72d4757cbe4d1ed669192f6d23817c9e437c4b ] The Qualcomm PCI bridge device (Device ID 0x0110) found in chipsets such as SM8450 does not set the Command Completed bit unless writes to the Slot Command register change "Control" bits. This results in timeouts like below: pcieport 0001:00:00.0: pciehp: Timeout on hotplug command 0x03c0 (issued 2020 msec ago) Add the device to the Command Completed quirk to mark commands "completed" immediately unless they change the "Control" bits. Link: https://lore.kernel.org/r/20220210145003.135907-1-manivannan.sadhasivam@linaro.org Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin

PCI: pciehp: Clear cmd_busy bit in polling mode

2022-04-08T12:23:04+00:00

commit 92912b175178c7e895f5e5e9f1e30ac30319162b upstream. Writes to a Downstream Port's Slot Control register are PCIe hotplug "commands." If the Port supports Command Completed events, software must wait for a command to complete before writing to Slot Control again. pcie_do_write_cmd() sets ctrl->cmd_busy when it writes to Slot Control. If software notification is enabled, i.e., PCI_EXP_SLTCTL_HPIE and PCI_EXP_SLTCTL_CCIE are set, ctrl->cmd_busy is cleared by pciehp_isr(). But when software notification is disabled, as it is when pcie_init() powers off an empty slot, pcie_wait_cmd() uses pcie_poll_cmd() to poll for command completion, and it neglects to clear ctrl->cmd_busy, which leads to spurious timeouts: pcieport 0000:00:03.0: pciehp: Timeout on hotplug command 0x01c0 (issued 2264 msec ago) pcieport 0000:00:03.0: pciehp: Timeout on hotplug command 0x05c0 (issued 2288 msec ago) Clear ctrl->cmd_busy in pcie_poll_cmd() when it detects a Command Completed event (PCI_EXP_SLTSTA_CC). [bhelgaas: commit log] Fixes: a5dd4b4b0570 ("PCI: pciehp: Wait for hotplug command completion where necessary") Link: https://lore.kernel.org/r/20211111054258.7309-1-zhangliguang@linux.alibaba.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=215143 Link: https://lore.kernel.org/r/20211126173309.GA12255@wunner.de Signed-off-by: Liguang Zhang Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Greg Kroah-Hartman

PCI: pciehp: Fix infinite loop in IRQ handler upon power fault

2022-02-05T11:38:56+00:00

commit 23584c1ed3e15a6f4bfab8dc5a88d94ab929ee12 upstream. The Power Fault Detected bit in the Slot Status register differs from all other hotplug events in that it is sticky: It can only be cleared after turning off slot power. Per PCIe r5.0, sec. 6.7.1.8: If a power controller detects a main power fault on the hot-plug slot, it must automatically set its internal main power fault latch [...]. The main power fault latch is cleared when software turns off power to the hot-plug slot. The stickiness used to cause interrupt storms and infinite loops which were fixed in 2009 by commits 5651c48cfafe ("PCI pciehp: fix power fault interrupt storm problem") and 99f0169c17f3 ("PCI: pciehp: enable software notification on empty slots"). Unfortunately in 2020 the infinite loop issue was inadvertently reintroduced by commit 8edf5332c393 ("PCI: pciehp: Fix MSI interrupt race"): The hardirq handler pciehp_isr() clears the PFD bit until pciehp's power_fault_detected flag is set. That happens in the IRQ thread pciehp_ist(), which never learns of the event because the hardirq handler is stuck in an infinite loop. Fix by setting the power_fault_detected flag already in the hardirq handler. Link: https://bugzilla.kernel.org/show_bug.cgi?id=214989 Link: https://lore.kernel.org/linux-pci/DM8PR11MB5702255A6A92F735D90A4446868B9@DM8PR11MB5702.namprd11.prod.outlook.com Fixes: 8edf5332c393 ("PCI: pciehp: Fix MSI interrupt race") Link: https://lore.kernel.org/r/66eaeef31d4997ceea357ad93259f290ededecfd.1637187226.git.lukas@wunner.de Reported-by: Joseph Bao Tested-by: Joseph Bao Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Cc: stable@vger.kernel.org # v4.19+ Cc: Stuart Hayes Signed-off-by: Greg Kroah-Hartman

PCI: pciehp: Use down_read/write_nested(reset_lock) to fix lockdep errors

2022-01-27T10:05:13+00:00

commit 085a9f43433f30cbe8a1ade62d9d7827c3217f4d upstream. Use down_read_nested() and down_write_nested() when taking the ctrl->reset_lock rw-sem, passing the number of PCIe hotplug controllers in the path to the PCI root bus as lock subclass parameter. This fixes the following false-positive lockdep report when unplugging a Lenovo X1C8 from a Lenovo 2nd gen TB3 dock: pcieport 0000:06:01.0: pciehp: Slot(1): Link Down pcieport 0000:06:01.0: pciehp: Slot(1): Card not present ============================================ WARNING: possible recursive locking detected 5.16.0-rc2+ #621 Not tainted -------------------------------------------- irq/124-pciehp/86 is trying to acquire lock: ffff8e5ac4299ef8 (&ctrl->reset_lock){.+.+}-{3:3}, at: pciehp_check_presence+0x23/0x80 but task is already holding lock: ffff8e5ac4298af8 (&ctrl->reset_lock){.+.+}-{3:3}, at: pciehp_ist+0xf3/0x180 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&ctrl->reset_lock); lock(&ctrl->reset_lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by irq/124-pciehp/86: #0: ffff8e5ac4298af8 (&ctrl->reset_lock){.+.+}-{3:3}, at: pciehp_ist+0xf3/0x180 #1: ffffffffa3b024e8 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pciehp_unconfigure_device+0x31/0x110 #2: ffff8e5ac1ee2248 (&dev->mutex){....}-{3:3}, at: device_release_driver+0x1c/0x40 stack backtrace: CPU: 4 PID: 86 Comm: irq/124-pciehp Not tainted 5.16.0-rc2+ #621 Hardware name: LENOVO 20U90SIT19/20U90SIT19, BIOS N2WET30W (1.20 ) 08/26/2021 Call Trace: dump_stack_lvl+0x59/0x73 __lock_acquire.cold+0xc5/0x2c6 lock_acquire+0xb5/0x2b0 down_read+0x3e/0x50 pciehp_check_presence+0x23/0x80 pciehp_runtime_resume+0x5c/0xa0 device_for_each_child+0x45/0x70 pcie_port_device_runtime_resume+0x20/0x30 pci_pm_runtime_resume+0xa7/0xc0 __rpm_callback+0x41/0x110 rpm_callback+0x59/0x70 rpm_resume+0x512/0x7b0 __pm_runtime_resume+0x4a/0x90 __device_release_driver+0x28/0x240 device_release_driver+0x26/0x40 pci_stop_bus_device+0x68/0x90 pci_stop_bus_device+0x2c/0x90 pci_stop_and_remove_bus_device+0xe/0x20 pciehp_unconfigure_device+0x6c/0x110 pciehp_disable_slot+0x5b/0xe0 pciehp_handle_presence_or_link_change+0xc3/0x2f0 pciehp_ist+0x179/0x180 This lockdep warning is triggered because with Thunderbolt, hotplug ports are nested. When removing multiple devices in a daisy-chain, each hotplug port's reset_lock may be acquired recursively. It's never the same lock, so the lockdep splat is a false positive. Because locks at the same hierarchy level are never acquired recursively, a per-level lockdep class is sufficient to fix the lockdep warning. The choice to use one lockdep subclass per pcie-hotplug controller in the path to the root-bus was made to conserve class keys because their number is limited and the complexity grows quadratically with number of keys according to Documentation/locking/lockdep-design.rst. Link: https://lore.kernel.org/linux-pci/20190402021933.GA2966@mit.edu/ Link: https://lore.kernel.org/linux-pci/de684a28-9038-8fc6-27ca-3f6f2f6400d7@redhat.com/ Link: https://lore.kernel.org/r/20211217141709.379663-1-hdegoede@redhat.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=208855 Reported-by: "Theodore Ts'o" Signed-off-by: Hans de Goede Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

s390/pci: fix zpci_zdev_put() on reserve

2021-10-04T07:49:10+00:00

Since commit 2a671f77ee49 ("s390/pci: fix use after free of zpci_dev") the reference count of a zpci_dev is incremented between pcibios_add_device() and pcibios_release_device() which was supposed to prevent the zpci_dev from being freed while the common PCI code has access to it. It was missed however that the handling of zPCI availability events assumed that once zpci_zdev_put() was called no later availability event would still see the device. With the previously mentioned commit however this assumption no longer holds and we must make sure that we only drop the initial long-lived reference the zPCI subsystem holds exactly once. Do so by introducing a zpci_device_reserved() function that handles when a device is reserved. Here we make sure the zpci_dev will not be considered for further events by removing it from the zpci_list. This also means that the device actually stays in the ZPCI_FN_STATE_RESERVED state between the time we know it has been reserved and the final reference going away. We thus need to consider it a real state instead of just a conceptual state after the removal. The final cleanup of PCI resources, removal from zbus, and destruction of the IOMMU stays in zpci_release_device() to make sure holders of the reference do see valid data until the release. Fixes: 2a671f77ee49 ("s390/pci: fix use after free of zpci_dev") Cc: stable@vger.kernel.org Signed-off-by: Niklas Schnelle Signed-off-by: Vasily Gorbik

Merge branch 'pci/reset'

2021-09-02T19:56:42+00:00

- Cache PCIe Device Capabilities register (Amey Narkhede) - Add pcie_reset_flr() with 'probe' argument (Amey Narkhede) - Add pdev->reset_methods[] array to track reset method ordering (Amey Narkhede) - Remove reset_fn field from pci_dev (Amey Narkhede) - Add sysfs interface to query and set device reset mechanism (Amey Narkhede) - Add pci_set_acpi_fwnode() to set ACPI_COMPANION (Shanker Donthineni) - Use acpi_pci_power_manageable() instead of duplicating logic (Shanker Donthineni) - Set ACPI fwnode early and at the same time with OF (Shanker Donthineni) - Add support for ACPI _RST reset method (Shanker Donthineni) - Change reset function 'probe' argument to bool (Amey Narkhede) * pci/reset: PCI: Change the type of probe argument in reset functions PCI: Add support for ACPI _RST reset method PCI: Setup ACPI fwnode early and at the same time with OF PCI: Use acpi_pci_power_manageable() PCI: Add pci_set_acpi_fwnode() to set ACPI_COMPANION PCI: Allow userspace to query and set device reset mechanism PCI: Remove reset_fn field from pci_dev PCI: Add array to track reset method ordering PCI: Add pcie_reset_flr() with 'probe' argument PCI: Cache PCIe Device Capabilities register

PCI: ibmphp: Fix double unmap of io_mem

2021-09-02T17:02:50+00:00

ebda_rsrc_controller() calls iounmap(io_mem) on the error path. Its caller, ibmphp_access_ebda(), also calls iounmap(io_mem) on good and error paths. Remove the iounmap(io_mem) invocation from ebda_rsrc_controller(). [bhelgaas: remove item from TODO] Link: https://lore.kernel.org/r/20210818165751.591185-1-os.vaslot@gmail.com Signed-off-by: Vishal Aslot Signed-off-by: Bjorn Helgaas

PCI: Change the type of probe argument in reset functions

2021-08-18T22:32:42+00:00

Change the type of probe argument in functions which implement reset methods from int to bool to make the context and intent clear. Suggested-by: Alex Williamson Link: https://lore.kernel.org/r/20210817180500.1253-10-ameynarkhede03@gmail.com Signed-off-by: Amey Narkhede Signed-off-by: Bjorn Helgaas

Merge branch 'pci/kernel-doc'

2021-07-06T15:56:29+00:00

- Fix kernel-doc formatting errors (Krzysztof Wilczyński) * pci/kernel-doc: PCI: Fix kernel-doc formatting

Merge branch 'pci/sysfs'

2021-07-06T15:56:25+00:00

- Fix dsm_label_utf16s_to_utf8s() buffer overrun (Krzysztof Wilczyński) - Use sysfs_emit() and sysfs_emit_at() in "show" functions (Krzysztof Wilczyński) - Fix 'resource_alignment' newline issues (Krzysztof Wilczyński) - Add newline to 'devspec' sysfs file (Krzysztof Wilczyński) * pci/sysfs: PCI/sysfs: Add 'devspec' newline PCI/sysfs: Fix 'resource_alignment' newline issues PCI/sysfs: Use sysfs_emit() and sysfs_emit_at() in "show" functions PCI/sysfs: Rely on lengths from scnprintf(), dsm_label_utf16s_to_utf8s() PCI/sysfs: Fix dsm_label_utf16s_to_utf8s() buffer overrun # Conflicts: # drivers/pci/p2pdma.c