From b22c3d82757109fa107ce17ba9484d45273eed05 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 20 Sep 2010 18:50:00 +0200 Subject: [PATCH] PCI/PCIe/AER: Disable native AER service if BIOS has precedence There is a design issue related to PCIe AER and _OSC that the BIOS may be asked to grant control of the AER service even if some Hardware Error Source Table (HEST) entries contain information meaning that the BIOS really should control it. Namely, pcie_port_acpi_setup() calls pcie_aer_get_firmware_first() that determines whether or not the AER service should be controlled by the BIOS on the basis of the HEST information for the given PCIe port. The BIOS is asked to grant control of the AER service for a PCIe Root Complex if pcie_aer_get_firmware_first() returns 'false' for at least one root port in that complex, even if all of the other root ports' HEST entries have the FIRMWARE_FIRST flag set (and none of them has the GLOBAL flag set). However, if the AER service is controlled by the kernel, that may interfere with the BIOS' handling of the error sources having the FIRMWARE_FIRST flag. Moreover, there may be PCIe endpoints that have the FIRMWARE_FIRST flag set in HEST and are attached to the root ports in question, in which case it also may be unsafe to ask the BIOS for control of the AER service. For this reason, introduce a function checking if there's at least one PCIe-related HEST entry with the FIRMWARE_FIRST flag set and disable the native AER service altogether if this function returns 'true'. Signed-off-by: Rafael J. Wysocki Signed-off-by: Jesse Barnes --- drivers/pci/pcie/aer/aerdrv.c | 2 +- drivers/pci/pcie/aer/aerdrv.h | 3 +++ drivers/pci/pcie/aer/aerdrv_acpi.c | 34 ++++++++++++++++++++++++++++++ drivers/pci/pcie/portdrv_acpi.c | 2 +- 4 files changed, 39 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pcie/aer/aerdrv.c b/drivers/pci/pcie/aer/aerdrv.c index f409948e1a9b..2b2b6508efde 100644 --- a/drivers/pci/pcie/aer/aerdrv.c +++ b/drivers/pci/pcie/aer/aerdrv.c @@ -416,7 +416,7 @@ static void aer_error_resume(struct pci_dev *dev) */ static int __init aer_service_init(void) { - if (!pci_aer_available()) + if (!pci_aer_available() || aer_acpi_firmware_first()) return -ENXIO; return pcie_port_service_register(&aerdriver); } diff --git a/drivers/pci/pcie/aer/aerdrv.h b/drivers/pci/pcie/aer/aerdrv.h index 80c11d131499..9656e3060412 100644 --- a/drivers/pci/pcie/aer/aerdrv.h +++ b/drivers/pci/pcie/aer/aerdrv.h @@ -132,6 +132,7 @@ static inline int aer_osc_setup(struct pcie_device *pciedev) #ifdef CONFIG_ACPI_APEI extern int pcie_aer_get_firmware_first(struct pci_dev *pci_dev); +extern bool aer_acpi_firmware_first(void); #else static inline int pcie_aer_get_firmware_first(struct pci_dev *pci_dev) { @@ -139,6 +140,8 @@ static inline int pcie_aer_get_firmware_first(struct pci_dev *pci_dev) return pci_dev->__aer_firmware_first; return 0; } + +static inline bool aer_acpi_firmware_first(void) { return false; } #endif static inline void pcie_aer_force_firmware_first(struct pci_dev *pci_dev, diff --git a/drivers/pci/pcie/aer/aerdrv_acpi.c b/drivers/pci/pcie/aer/aerdrv_acpi.c index 2bb9b8972211..275bf158ffa7 100644 --- a/drivers/pci/pcie/aer/aerdrv_acpi.c +++ b/drivers/pci/pcie/aer/aerdrv_acpi.c @@ -93,4 +93,38 @@ int pcie_aer_get_firmware_first(struct pci_dev *dev) aer_set_firmware_first(dev); return dev->__aer_firmware_first; } + +static bool aer_firmware_first; + +static int aer_hest_parse_aff(struct acpi_hest_header *hest_hdr, void *data) +{ + struct acpi_hest_aer_common *p; + + if (aer_firmware_first) + return 0; + + switch (hest_hdr->type) { + case ACPI_HEST_TYPE_AER_ROOT_PORT: + case ACPI_HEST_TYPE_AER_ENDPOINT: + case ACPI_HEST_TYPE_AER_BRIDGE: + p = (struct acpi_hest_aer_common *)(hest_hdr + 1); + aer_firmware_first = !!(p->flags & ACPI_HEST_FIRMWARE_FIRST); + default: + return 0; + } +} + +/** + * aer_acpi_firmware_first - Check if APEI should control AER. + */ +bool aer_acpi_firmware_first(void) +{ + static bool parsed = false; + + if (!parsed) { + apei_hest_parse(aer_hest_parse_aff, NULL); + parsed = true; + } + return aer_firmware_first; +} #endif diff --git a/drivers/pci/pcie/portdrv_acpi.c b/drivers/pci/pcie/portdrv_acpi.c index b7c4cb1ccb23..5982b6a63b89 100644 --- a/drivers/pci/pcie/portdrv_acpi.c +++ b/drivers/pci/pcie/portdrv_acpi.c @@ -49,7 +49,7 @@ int pcie_port_acpi_setup(struct pci_dev *port, int *srv_mask) | OSC_PCI_EXPRESS_PME_CONTROL; if (pci_aer_available()) { - if (pcie_aer_get_firmware_first(port)) + if (aer_acpi_firmware_first()) dev_dbg(&port->dev, "PCIe errors handled by BIOS.\n"); else flags |= OSC_PCI_EXPRESS_AER_CONTROL; -- 2.34.1