kernel/drivers/pci/hotplug/pciehp_hpc.c, branch linux-6.5.y

PCI: pciehp: Use RMW accessors for changing LNKCTL

2023-09-13T07:53:30Z

[ Upstream commit 5f75f96c61039151c193775d776fde42477eace1 ] As hotplug is not the only driver touching LNKCTL, use the RMW capability accessor which handles concurrent changes correctly. Suggested-by: Lukas Wunner Fixes: 7f822999e12a ("PCI: pciehp: Add Disable/enable link functions") Link: https://lore.kernel.org/r/20230717120503.15276-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Acked-by: "Rafael J. Wysocki" Signed-off-by: Sasha Levin

Merge branch 'pci/hotplug'

2023-06-26T17:59:56Z

- Simplify Attention Button logging (Bjorn Helgaas) - Cancel bringup sequence if card is not present, to keep from blinking Power Indicator indefinitely (Rongguang Wei) - Reassign bridge resources if necessary for ACPI hotplug (Igor Mammedov) * pci/hotplug: PCI: acpiphp: Reassign resources on bridge if necessary PCI: pciehp: Cancel bringup sequence if card is not present PCI: pciehp: Simplify Attention Button logging

PCI: pciehp: Rely on dev->link_active_reporting

2023-06-14T22:58:12Z

Use dev->link_active_reporting to determine whether Data Link Layer Link Active Reporting is available rather than re-retrieving the capability. Link: https://lore.kernel.org/r/alpine.DEB.2.21.2305310028150.59226@angie.orcam.me.uk Signed-off-by: Maciej W. Rozycki Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner

PCI: pciehp: Simplify Attention Button logging

2023-05-24T16:49:50Z

Previously, pressing the Attention Button always logged two lines, the first from pciehp_ist() and the second from pciehp_handle_button_press(): Attention button pressed Powering on due to button press Since pciehp_handle_button_press() always logs the more detailed message, remove the generic "Attention button pressed" message. Reword the pciehp_handle_button_press() to be of the form: Button press: will power on in 5 sec Button press: will power off in 5 sec Button press: canceling request to power on Button press: canceling request to power off Button press: ignoring invalid state %#x Link: https://lore.kernel.org/r/20230522214051.619337-1-helgaas@kernel.org Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner

PCI: pciehp: Add Qualcomm quirk for Command Completed erratum

2023-02-14T17:47:49Z

The Qualcomm PCI bridge device (Device ID 0x010e) found in chipsets such as SC8280XP used in Lenovo Thinkpad X13s, does not set the Command Completed bit unless writes to the Slot Command register change "Control" bits. This results in timeouts like below during boot and resume from suspend: pcieport 0002:00:00.0: pciehp: Timeout on hotplug command 0x03c0 (issued 2020 msec ago) ... pcieport 0002:00:00.0: pciehp: Timeout on hotplug command 0x13f1 (issued 107724 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/20230213144922.89982-1-manivannan.sadhasivam@linaro.org Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas

PCI: pciehp: Enable Command Completed Interrupt only if supported

2022-12-07T14:27:20Z

The No Command Completed Support bit in the Slot Capabilities register indicates whether Command Completed Interrupt Enable is unsupported. We already check whether No Command Completed Support bit is set in pcie_wait_cmd(), and do not wait in this case. Don't enable this Command Completed Interrupt at all if NCCS is set, so that when users dump configuration space from userspace, the dump does not confuse them by saying that Command Completed Interrupt is not supported, but it is enabled. Link: https://lore.kernel.org/r/20220927141926.8895-2-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner

PCI: pciehp: Add Qualcomm quirk for Command Completed erratum

2022-02-10T22:43:45Z

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

PCI: pciehp: Clear cmd_busy bit in polling mode

2022-02-03T19:36:23Z

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+

Merge branch 'pci/errors'

2022-01-13T15:57:52Z

- Add PCI_ERROR_RESPONSE and related definitions for signaling and checking for transaction errors on PCI (Naveen Naidu) - Fabricate PCI_ERROR_RESPONSE data (~0) in config read wrappers, instead of in host controller drivers, when transactions fail on PCI (Naveen Naidu) - Use PCI_POSSIBLE_ERROR() to check for possible failure of config reads (Naveen Naidu) * pci/errors: PCI: xgene: Use PCI_ERROR_RESPONSE to identify config read errors PCI: hv: Use PCI_ERROR_RESPONSE to identify config read errors PCI: keystone: Use PCI_ERROR_RESPONSE to identify config read errors PCI: Use PCI_ERROR_RESPONSE to identify config read errors PCI: cpqphp: Use PCI_POSSIBLE_ERROR() to check config reads PCI/PME: Use PCI_POSSIBLE_ERROR() to check config reads PCI/DPC: Use PCI_POSSIBLE_ERROR() to check config reads PCI: pciehp: Use PCI_POSSIBLE_ERROR() to check config reads PCI: vmd: Use PCI_POSSIBLE_ERROR() to check config reads PCI/ERR: Use PCI_POSSIBLE_ERROR() to check config reads PCI: rockchip-host: Drop error data fabrication when config read fails PCI: rcar-host: Drop error data fabrication when config read fails PCI: altera: Drop error data fabrication when config read fails PCI: mvebu: Drop error data fabrication when config read fails PCI: aardvark: Drop error data fabrication when config read fails PCI: kirin: Drop error data fabrication when config read fails PCI: histb: Drop error data fabrication when config read fails PCI: exynos: Drop error data fabrication when config read fails PCI: mediatek: Drop error data fabrication when config read fails PCI: iproc: Drop error data fabrication when config read fails PCI: thunder: Drop error data fabrication when config read fails PCI: Drop error data fabrication when config read fails PCI: Use PCI_SET_ERROR_RESPONSE() for disconnected devices PCI: Set error response data when config read fails PCI: Add PCI_ERROR_RESPONSE and related definitions

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

2022-01-12T12:42:51Z

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