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authorKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>2020-03-23 17:26:05 -0700
committerBjorn Helgaas <bhelgaas@google.com>2020-03-28 13:19:02 -0500
commit20e15e673b05a045fdbe534d40edf948e1b0b1af (patch)
treef400e1e8cffd7ad9e05efbcdba8eba051266c572 /drivers
parent27005618178ef9e9bf9c42fd91101771c92e9308 (diff)
downloadlinux-20e15e673b05a045fdbe534d40edf948e1b0b1af.tar.bz2
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/pci/pci.h2
-rw-r--r--drivers/pci/pcie/aer.c22
2 files changed, 20 insertions, 4 deletions
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;