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 <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Kuppuswamy Sathyanarayanan
2020-03-23 17:26:05 -07:00
committed by Bjorn Helgaas
parent 2700561817
commit 20e15e673b
2 changed files with 20 additions and 4 deletions

View File

@@ -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