From 20e15e673b05a045fdbe534d40edf948e1b0b1af Mon Sep 17 00:00:00 2001 From: Kuppuswamy Sathyanarayanan Date: Mon, 23 Mar 2020 17:26:05 -0700 Subject: PCI/AER: Add pci_aer_raw_clear_status() to unconditionally clear Error Status Per the SFI _OSC and DPC Updates ECN [1] implementation note flowchart, the OS seems to be expected to clear AER status even if it doesn't have ownership of the AER capability. Unlike the DPC capability, where a DPC ECN [2] specifies a window when the OS is allowed to access DPC registers even if it doesn't have ownership, there is no clear model for AER. Add pci_aer_raw_clear_status() to clear the AER error status registers unconditionally. This is intended for use only by the EDR path (see [2]). [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 [2] 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 [bhelgaas: changelog] Link: https://lore.kernel.org/r/c19ad28f3633cce67448609e89a75635da0da07d.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.h | 2 ++ drivers/pci/pcie/aer.c | 22 ++++++++++++++++++---- 2 files changed, 20 insertions(+), 4 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index e48677a0ba42..6d09bb22b73d 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -654,12 +654,14 @@ void pci_aer_exit(struct pci_dev *dev); extern const struct attribute_group aer_stats_attr_group; void pci_aer_clear_fatal_status(struct pci_dev *dev); void pci_aer_clear_device_status(struct pci_dev *dev); +int pci_aer_raw_clear_status(struct pci_dev *dev); #else static inline void pci_no_aer(void) { } static inline void pci_aer_init(struct pci_dev *d) { } static inline void pci_aer_exit(struct pci_dev *d) { } static inline void pci_aer_clear_fatal_status(struct pci_dev *dev) { } static inline void pci_aer_clear_device_status(struct pci_dev *dev) { } +static inline int pci_aer_raw_clear_status(struct pci_dev *dev) { return -EINVAL; } #endif #ifdef CONFIG_ACPI diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c index c0540c3761dc..bd9f122165e0 100644 --- a/drivers/pci/pcie/aer.c +++ b/drivers/pci/pcie/aer.c @@ -420,7 +420,16 @@ void pci_aer_clear_fatal_status(struct pci_dev *dev) pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status); } -int pci_cleanup_aer_error_status_regs(struct pci_dev *dev) +/** + * pci_aer_raw_clear_status - Clear AER error registers. + * @dev: the PCI device + * + * Clearing AER error status registers unconditionally, regardless of + * whether they're owned by firmware or the OS. + * + * Returns 0 on success, or negative on failure. + */ +int pci_aer_raw_clear_status(struct pci_dev *dev) { int pos; u32 status; @@ -433,9 +442,6 @@ int pci_cleanup_aer_error_status_regs(struct pci_dev *dev) if (!pos) return -EIO; - if (pcie_aer_get_firmware_first(dev)) - return -EIO; - port_type = pci_pcie_type(dev); if (port_type == PCI_EXP_TYPE_ROOT_PORT) { pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &status); @@ -451,6 +457,14 @@ int pci_cleanup_aer_error_status_regs(struct pci_dev *dev) return 0; } +int pci_cleanup_aer_error_status_regs(struct pci_dev *dev) +{ + if (pcie_aer_get_firmware_first(dev)) + return -EIO; + + return pci_aer_raw_clear_status(dev); +} + void pci_save_aer_state(struct pci_dev *dev) { struct pci_cap_saved_state *save_state; -- cgit v1.2.3