kernel/linux.git/drivers/pci/pcie/err.c, branch linux-5.9.y

PCI/ERR: Clear PCIe Device Status errors only if OS owns AER

2020-07-22T20:41:03+00:00

pcie_clear_device_status() resets the error bits in the PCIe Device Status Register (PCI_EXP_DEVSTA). Previously we did this unconditionally, but on ACPI systems, the _OSC AER bit negotiates control of the AER capability. Per sec 4.5.1 of the System Firmware Intermediary _OSC and DPC Updates ECN [1], this bit also covers other error enable/status bits including the following: Correctable Error Reporting Enable Non-Fatal Error Reporting Enable Fatal Error Reporting Enable Unsupported Request Reporting Enable These bits are all in the PCIe Device Control register (the ECN omitted "Reporting", but I think that's a typo), so by implication the _OSC AER bit also applies to the error status bits in the PCIe Device Status register: Correctable Error Detected Non-Fatal Error Detected Fatal Error Detected Unsupported Request Detected Clear the PCIe Device Status error bits only when the OS controls the AER capability and related error enable/status bits. If platform firmware controls the AER capability, firmware is responsible for clearing these bits. One call path leading here is: ghes_do_proc ghes_handle_aer aer_recover_queue schedule_work(&aer_recover_work) ... aer_recover_work_func pcie_do_recovery pcie_clear_device_status [1] System Firmware Intermediary (SFI) _OSC and DPC Updates ECN, Feb 24, 2020, affecting PCI Firmware Specification, Rev. 3.2 https://members.pcisig.com/wg/PCI-SIG/document/14076 [bhelgaas: commit log, move test from pcie_clear_device_status() to callers] Link: https://lore.kernel.org/r/20200622113523.891666-1-Jonathan.Cameron@huawei.com Signed-off-by: Jonathan Cameron Signed-off-by: Bjorn Helgaas

PCI/ERR: Rename pci_aer_clear_device_status() to pcie_clear_device_status()

2020-07-22T20:38:35+00:00

pci_aer_clear_device_status() clears the error bits in the PCIe Device Status Register (PCI_EXP_DEVSTA). Every PCIe device has this register, regardless of whether it supports AER. Rename pci_aer_clear_device_status() to pcie_clear_device_status() to make clear that it is PCIe-specific but not AER-specific. Move it to drivers/pci/pci.c, again since it's not AER-specific. No functional change intended. Link: https://lore.kernel.org/r/20200717195619.766662-1-helgaas@kernel.org Signed-off-by: Bjorn Helgaas

PCI: Use 'pci_channel_state_t' instead of 'enum pci_channel_state'

2020-07-07T22:11:52+00:00

The method struct pci_error_handlers.error_detected() is defined and documented as taking an 'enum pci_channel_state' for the second argument, but most drivers use 'pci_channel_state_t' instead. This 'pci_channel_state_t' is not a typedef for the enum but a typedef for a bitwise type in order to have better/stricter typechecking. Consolidate everything by using 'pci_channel_state_t' in the method's definition, in the related helpers and in the drivers. Enforce use of 'pci_channel_state_t' by replacing 'enum pci_channel_state' with an anonymous 'enum'. Note: Currently, from a typechecking point of view this patch changes nothing because only the constants defined by the enum are bitwise, not the enum itself (sparse doesn't have the notion of 'bitwise enum'). This may change in some not too far future, hence the patch. [bhelgaas: squash in https://lore.kernel.org/r/20200702162651.49526-3-luc.vanoostenryck@gmail.com https://lore.kernel.org/r/20200702162651.49526-4-luc.vanoostenryck@gmail.com] Link: https://lore.kernel.org/r/20200702162651.49526-2-luc.vanoostenryck@gmail.com Signed-off-by: Luc Van Oostenryck Signed-off-by: Bjorn Helgaas

PCI/AER: Rationalize error status register clearing

2020-03-28T18:19:05+00:00

The AER interfaces to clear error status registers were a confusing mess: - pci_cleanup_aer_uncorrect_error_status() cleared non-fatal errors from the Uncorrectable Error Status register. - pci_aer_clear_fatal_status() cleared fatal errors from the Uncorrectable Error Status register. - pci_cleanup_aer_error_status_regs() cleared the Root Error Status register (for Root Ports), the Uncorrectable Error Status register, and the Correctable Error Status register. Rename them to make them consistent: From To ---------------------------------------- ------------------------------- pci_cleanup_aer_uncorrect_error_status() pci_aer_clear_nonfatal_status() pci_aer_clear_fatal_status() pci_aer_clear_fatal_status() pci_cleanup_aer_error_status_regs() pci_aer_clear_status() Since pci_cleanup_aer_error_status_regs() (renamed to pci_aer_clear_status()) is only used within drivers/pci/, move the declaration from to drivers/pci/pci.h. [bhelgaas: commit log, add renames] Link: https://lore.kernel.org/r/d1310a75dc3d28f7e8da4e99c45fbd3e60fe238e.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Bjorn Helgaas

PCI/ERR: Return status of pcie_do_recovery()

2020-03-28T18:19:01+00:00

As per the DPC Enhancements ECN [1], sec 4.5.1, table 4-4, if the OS supports Error Disconnect Recover (EDR), it must invalidate the software state associated with child devices of the port without attempting to access the child device hardware. In addition, if the OS supports DPC, it must attempt to recover the child devices if the port implements the DPC Capability. If the OS continues operation, the OS must inform the firmware of the status of the recovery operation via the _OST method. Return the result of pcie_do_recovery() so we can report it to firmware via _OST. [1] Downstream Port Containment Related Enhancements ECN, Jan 28, 2019, affecting PCI Firmware Specification, Rev. 3.2 https://members.pcisig.com/wg/PCI-SIG/document/12888 Link: https://lore.kernel.org/r/eb60ec89448769349c6722954ffbf2de163155b5.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Bjorn Helgaas

PCI/ERR: Remove service dependency in pcie_do_recovery()

2020-03-28T18:18:54+00:00

Previously we passed the PCIe service type parameter to pcie_do_recovery(), where reset_link() looked up the underlying pci_port_service_driver and its .reset_link() function pointer. Instead of using this roundabout way, we can just pass the driver-specific .reset_link() callback function when calling pcie_do_recovery() function. This allows us to call pcie_do_recovery() from code that is not a PCIe port service driver, e.g., Error Disconnect Recover (EDR) support. Remove pcie_port_find_service() and pcie_port_service_driver.reset_link since they are now unused. Link: https://lore.kernel.org/r/60e02b87b526cdf2930400059d98704bf0a147d1.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Bjorn Helgaas

PCI/ERR: Update error status after reset_link()

2020-03-28T16:52:22+00:00

Commit bdb5ac85777d ("PCI/ERR: Handle fatal error recovery") uses reset_link() to recover from fatal errors. But during fatal error recovery, if the initial value of error status is PCI_ERS_RESULT_DISCONNECT or PCI_ERS_RESULT_NO_AER_DRIVER then even after successful recovery (using reset_link()) pcie_do_recovery() will report the recovery result as failure. Update the status of error after reset_link(). You can reproduce this issue by triggering a SW DPC using "DPC Software Trigger" bit in "DPC Control Register". You should see recovery failed dmesg log as below: pcieport 0000:00:16.0: DPC: containment event, status:0x1f27 source:0x0000 pcieport 0000:00:16.0: DPC: software trigger detected pci 0000:04:00.0: AER: can't recover (no error_detected callback) pcieport 0000:00:16.0: AER: device recovery failed Fixes: bdb5ac85777d ("PCI/ERR: Handle fatal error recovery") Link: https://lore.kernel.org/r/a255fcb3a3fdebcd90f84e08b555f1786eb8eba2.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com [bhelgaas: split pci_channel_io_frozen simplification to separate patch] Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Bjorn Helgaas Acked-by: Keith Busch Cc: Ashok Raj

PCI/ERR: Combine pci_channel_io_frozen cases

2020-03-28T16:50:56+00:00

pcie_do_recovery() had two "if (state == pci_channel_io_frozen)" cases right after each other. Combine them to make this easier to read. No functional change intended. Link: https://lore.kernel.org/r/20200317170654.GA23125@infradead.org [bhelgaas: split from https://lore.kernel.org/r/a255fcb3a3fdebcd90f84e08b555f1786eb8eba2.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com] Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Bjorn Helgaas

PCI/AER: Factor message prefixes with dev_fmt()

2020-01-23T22:39:53+00:00

Define dev_fmt() with the common prefix of log messages so we don't have to repeat it in every printk. No functional change intended. Link: https://lore.kernel.org/r/20191213225709.GA213811@google.com Signed-off-by: Bjorn Helgaas

PCI/AER: Log which device prevents error recovery

2020-01-23T22:39:02+00:00

PCI error recovery will fail if any device under the Root Port doesn't have an error_detected callback. Currently only the failure result is printed, which is not enough to identify the driver that lacks the callback. Log a message to identify the device with no error_detected callback. [bhelgaas: tweak log message] Link: https://lore.kernel.org/r/1576237474-32021-1-git-send-email-yangyicong@hisilicon.com Signed-off-by: Yicong Yang Signed-off-by: Bjorn Helgaas