kernel/git/stable/linux.git/drivers/pci/hotplug, branch linux-5.16.y

PCI: pciehp: Add Qualcomm quirk for Command Completed erratum

2022-04-13T18:03:01+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

2022-04-08T12:05:36+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

2022-02-05T11:39:54+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

2022-01-27T11:02:46+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: implement reset_slot for hotplug slot

2021-11-08T13:17:49+00:00

This is done by adding a zpci_hot_reset_device() call which does a low level reset of the PCI function without changing its higher level function state. This way it can be used while the zPCI function is bound to a driver and with DMA tables being controlled either through the IOMMU or DMA APIs which is prohibited when using zpci_disable_device() as that drop existing DMA translations. As this reset, unlike a normal FLR, also calls zpci_clear_irq() we need to implement arch_restore_msi_irqs() and make sure we re-enable IRQs for the PCI function if they were previously disabled. Reviewed-by: Pierre Morel Reviewed-by: Matthew Rosato Signed-off-by: Niklas Schnelle Signed-off-by: Vasily Gorbik

Merge tag 'pci-v5.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2021-11-06T21:36:12+00:00

Pull pci updates from Bjorn Helgaas: "Enumeration: - Conserve IRQs by setting up portdrv IRQs only when there are users (Jan Kiszka) - Rework and simplify _OSC negotiation for control of PCIe features (Joerg Roedel) - Remove struct pci_dev.driver pointer since it's redundant with the struct device.driver pointer (Uwe Kleine-König) Resource management: - Coalesce contiguous host bridge apertures from _CRS to accommodate BARs that cover more than one aperture (Kai-Heng Feng) Sysfs: - Check CAP_SYS_ADMIN before parsing user input (Krzysztof Wilczyński) - Return -EINVAL consistently from "store" functions (Krzysztof Wilczyński) - Use sysfs_emit() in endpoint "show" functions to avoid buffer overruns (Kunihiko Hayashi) PCIe native device hotplug: - Ignore Link Down/Up caused by resets during error recovery so endpoint drivers can remain bound to the device (Lukas Wunner) Virtualization: - Avoid bus resets on Atheros QCA6174, where they hang the device (Ingmar Klein) - Work around Pericom PI7C9X2G switch packet drop erratum by using store and forward mode instead of cut-through (Nathan Rossi) - Avoid trying to enable AtomicOps on VFs; the PF setting applies to all VFs (Selvin Xavier) MSI: - Document that /sys/bus/pci/devices/.../irq contains the legacy INTx interrupt or the IRQ of the first MSI (not MSI-X) vector (Barry Song) VPD: - Add pci_read_vpd_any() and pci_write_vpd_any() to access anywhere in the possible VPD space; use these to simplify the cxgb3 driver (Heiner Kallweit) Peer-to-peer DMA: - Add (not subtract) the bus offset when calculating DMA address (Wang Lu) ASPM: - Re-enable LTR at Downstream Ports so they don't report Unsupported Requests when reset or hot-added devices send LTR messages (Mingchuang Qiao) Apple PCIe controller driver: - Add driver for Apple M1 PCIe controller (Alyssa Rosenzweig, Marc Zyngier) Cadence PCIe controller driver: - Return success when probe succeeds instead of falling into error path (Li Chen) HiSilicon Kirin PCIe controller driver: - Reorganize PHY logic and add support for external PHY drivers (Mauro Carvalho Chehab) - Support PERST# GPIOs for HiKey970 external PEX 8606 bridge (Mauro Carvalho Chehab) - Add Kirin 970 support (Mauro Carvalho Chehab) - Make driver removable (Mauro Carvalho Chehab) Intel VMD host bridge driver: - If IOMMU supports interrupt remapping, leave VMD MSI-X remapping enabled (Adrian Huang) - Number each controller so we can tell them apart in /proc/interrupts (Chunguang Xu) - Avoid building on UML because VMD depends on x86 bare metal APIs (Johannes Berg) Marvell Aardvark PCIe controller driver: - Define macros for PCI_EXP_DEVCTL_PAYLOAD_* (Pali Rohár) - Set Max Payload Size to 512 bytes per Marvell spec (Pali Rohár) - Downgrade PIO Response Status messages to debug level (Marek Behún) - Preserve CRS SV (Config Request Retry Software Visibility) bit in emulated Root Control register (Pali Rohár) - Fix issue in configuring reference clock (Pali Rohár) - Don't clear status bits for masked interrupts (Pali Rohár) - Don't mask unused interrupts (Pali Rohár) - Avoid code repetition in advk_pcie_rd_conf() (Marek Behún) - Retry config accesses on CRS response (Pali Rohár) - Simplify emulated Root Capabilities initialization (Pali Rohár) - Fix several link training issues (Pali Rohár) - Fix link-up checking via LTSSM (Pali Rohár) - Fix reporting of Data Link Layer Link Active (Pali Rohár) - Fix emulation of W1C bits (Marek Behún) - Fix MSI domain .alloc() method to return zero on success (Marek Behún) - Read entire 16-bit MSI vector in MSI handler, not just low 8 bits (Marek Behún) - Clear Root Port I/O Space, Memory Space, and Bus Master Enable bits at startup; PCI core will set those as necessary (Pali Rohár) - When operating as a Root Port, set class code to "PCI Bridge" instead of the default "Mass Storage Controller" (Pali Rohár) - Add emulation for PCI_BRIDGE_CTL_BUS_RESET since aardvark doesn't implement this per spec (Pali Rohár) - Add emulation of option ROM BAR since aardvark doesn't implement this per spec (Pali Rohár) MediaTek MT7621 PCIe controller driver: - Add MediaTek MT7621 PCIe host controller driver and DT binding (Sergio Paracuellos) Qualcomm PCIe controller driver: - Add SC8180x compatible string (Bjorn Andersson) - Add endpoint controller driver and DT binding (Manivannan Sadhasivam) - Restructure to use of_device_get_match_data() (Prasad Malisetty) - Add SC7280-specific pcie_1_pipe_clk_src handling (Prasad Malisetty) Renesas R-Car PCIe controller driver: - Remove unnecessary includes (Geert Uytterhoeven) Rockchip DesignWare PCIe controller driver: - Add DT binding (Simon Xue) Socionext UniPhier Pro5 controller driver: - Serialize INTx masking/unmasking (Kunihiko Hayashi) Synopsys DesignWare PCIe controller driver: - Run dwc .host_init() method before registering MSI interrupt handler so we can deal with pending interrupts left by bootloader (Bjorn Andersson) - Clean up Kconfig dependencies (Andy Shevchenko) - Export symbols to allow more modular drivers (Luca Ceresoli) TI DRA7xx PCIe controller driver: - Allow host and endpoint drivers to be modules (Luca Ceresoli) - Enable external clock if present (Luca Ceresoli) TI J721E PCIe driver: - Disable PHY when probe fails after initializing it (Christophe JAILLET) MicroSemi Switchtec management driver: - Return error to application when command execution fails because an out-of-band reset has cleared the device BARs, Memory Space Enable, etc (Kelvin Cao) - Fix MRPC error status handling issue (Kelvin Cao) - Mask out other bits when reading of management VEP instance ID (Kelvin Cao) - Return EOPNOTSUPP instead of ENOTSUPP from sysfs show functions (Kelvin Cao) - Add check of event support (Logan Gunthorpe) Miscellaneous: - Remove unused pci_pool wrappers, which have been replaced by dma_pool (Cai Huoqing) - Use 'unsigned int' instead of bare 'unsigned' (Krzysztof Wilczyński) - Use kstrtobool() directly, sans strtobool() wrapper (Krzysztof Wilczyński) - Fix some sscanf(), sprintf() format mismatches (Krzysztof Wilczyński) - Update PCI subsystem information in MAINTAINERS (Krzysztof Wilczyński) - Correct some misspellings (Krzysztof Wilczyński)" * tag 'pci-v5.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (137 commits) PCI: Add ACS quirk for Pericom PI7C9X2G switches PCI: apple: Configure RID to SID mapper on device addition iommu/dart: Exclude MSI doorbell from PCIe device IOVA range PCI: apple: Implement MSI support PCI: apple: Add INTx and per-port interrupt support PCI: kirin: Allow removing the driver PCI: kirin: De-init the dwc driver PCI: kirin: Disable clkreq during poweroff sequence PCI: kirin: Move the power-off code to a common routine PCI: kirin: Add power_off support for Kirin 960 PHY PCI: kirin: Allow building it as a module PCI: kirin: Add MODULE_* macros PCI: kirin: Add Kirin 970 compatible PCI: kirin: Support PERST# GPIOs for HiKey970 external PEX 8606 bridge PCI: apple: Set up reference clocks when probing PCI: apple: Add initial hardware bring-up PCI: of: Allow matching of an interrupt-map local to a PCI device of/irq: Allow matching of an interrupt-map local to an interrupt controller irqdomain: Make of_phandle_args_to_fwspec() generally available PCI: Do not enable AtomicOps on VFs ...

Merge branch 'pci/misc'

2021-11-05T16:28:47+00:00

- Tidy setup-irq.c comments (Pranay Sanghai) - Fix misspellings (Krzysztof Wilczyński) - Fix sprintf(), sscanf() format mismatches (Krzysztof Wilczyński) - Tidy cpqphp code formatting (Krzysztof Wilczyński) - Remove unused pci_pool wrappers, which have been replaced by dma_pool (Cai Huoqing) - Remove a redundant initialization in __pci_reset_function_locked() (Colin Ian King) - Use 'unsigned int' instead of 'unsigned' (Krzysztof Wilczyński) - Update PCI subsystem information in MAINTAINERS (Krzysztof Wilczyński) - Include generic headers instead of for cpqphp and vmd (Krzysztof Wilczyński) * pci/misc: PCI: vmd: Drop redundant includes of , PCI: cpqphp: Use instead of MAINTAINERS: Update PCI subsystem information PCI: Prefer 'unsigned int' over bare 'unsigned' PCI: Remove redundant 'rc' initialization PCI: Remove unused pci_pool wrappers PCI: cpqphp: Format if-statement code block correctly PCI: Use unsigned to match sscanf("%x") in pci_dev_str_match_path() PCI: hv: Remove unnecessary use of %hx PCI: Correct misspelled and remove duplicated words PCI: Tidy comments

PCI: cpqphp: Use instead of

2021-11-02T19:41:58+00:00

Use the preferred generic header file linux/io.h that already includes the corresponding asm/io.h file. Link: https://lore.kernel.org/r/20211013003145.1107148-2-kw@linux.com Signed-off-by: Krzysztof Wilczyński Signed-off-by: Bjorn Helgaas Reviewed-by: Jonathan Derrick

PCI: pciehp: Ignore Link Down/Up caused by error-induced Hot Reset

2021-10-15T19:23:46+00:00

Stuart Hayes reports that an error handled by DPC at a Root Port results in pciehp gratuitously bringing down a subordinate hotplug port: RP -- UP -- DP -- UP -- DP (hotplug) -- EP pciehp brings the slot down because the Link to the Endpoint goes down. That is caused by a Hot Reset being propagated as a result of DPC. Per PCIe Base Spec 5.0, section 6.6.1 "Conventional Reset": For a Switch, the following must cause a hot reset to be sent on all Downstream Ports: [...] * The Data Link Layer of the Upstream Port reporting DL_Down status. In Switches that support Link speeds greater than 5.0 GT/s, the Upstream Port must direct the LTSSM of each Downstream Port to the Hot Reset state, but not hold the LTSSMs in that state. This permits each Downstream Port to begin Link training immediately after its hot reset completes. This behavior is recommended for all Switches. * Receiving a hot reset on the Upstream Port. Once DPC recovers, pcie_do_recovery() walks down the hierarchy and invokes pcie_portdrv_slot_reset() to restore each port's config space. At that point, a hotplug interrupt is signaled per PCIe Base Spec r5.0, section 6.7.3.4 "Software Notification of Hot-Plug Events": If the Port is enabled for edge-triggered interrupt signaling using MSI or MSI-X, an interrupt message must be sent every time the logical AND of the following conditions transitions from FALSE to TRUE: [...] * The Hot-Plug Interrupt Enable bit in the Slot Control register is set to 1b. * At least one hot-plug event status bit in the Slot Status register and its associated enable bit in the Slot Control register are both set to 1b. Prevent pciehp from gratuitously bringing down the slot by clearing the error-induced Data Link Layer State Changed event before restoring config space. Afterwards, check whether the link has unexpectedly failed to retrain and synthesize a DLLSC event if so. Allow each pcie_port_service_driver (one of them being pciehp) to define a slot_reset callback and re-use the existing pm_iter() function to iterate over the callbacks. Thereby, the Endpoint driver remains bound throughout error recovery and may restore the device to working state. Surprise removal during error recovery is detected through a Presence Detect Changed event. The hotplug port is expected to not signal that event as a result of a Hot Reset. The issue isn't DPC-specific, it also occurs when an error is handled by AER through aer_root_reset(). So while the issue was noticed only now, it's been around since 2006 when AER support was first introduced. [bhelgaas: drop PCI_ERROR_RECOVERY Kconfig, split pm_iter() rename to preparatory patch] Link: https://lore.kernel.org/linux-pci/08c046b0-c9f2-3489-eeef-7e7aca435bb9@gmail.com/ Fixes: 6c2b374d7485 ("PCI-Express AER implemetation: AER core and aerdriver") Link: https://lore.kernel.org/r/251f4edcc04c14f873ff1c967bc686169cd07d2d.1627638184.git.lukas@wunner.de Reported-by: Stuart Hayes Tested-by: Stuart Hayes Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Cc: stable@vger.kernel.org # v2.6.19+: ba952824e6c1: PCI/portdrv: Report reset for frozen channel Cc: Keith Busch

PCI: cpqphp: Format if-statement code block correctly

2021-10-13T01:48:44+00:00

The code block related to the if-statement in cpqhp_set_irq() is somewhat awkwardly formatted making the code hard to read. Make it readable. No change to functionality intended. Link: https://lore.kernel.org/r/20211013011412.1110829-1-kw@linux.com Signed-off-by: Krzysztof Wilczyński Signed-off-by: Bjorn Helgaas