For review and comment. Feedback from Hidetoshi Seto and Kenji
Kaneshige incorporated.
Today, the PCIe Advanced Error Reporting (AER) driver attaches itself
to every PCIe root port for which BIOS reports it should, via ACPI
_OSC.
However, _OSC alone is insufficient for newer BIOSes. Part of ACPI
4.0 is the new APEI (ACPI Platform Error Interfaces) which is a way
for OS and BIOS to handshake over which errors for which components
each will handle. One table in ACPI 4.0 is the Hardware Error Source
Table (HEST), where BIOS can define that errors for certain PCIe
devices (or all devices), should be handled by BIOS ("Firmware First
mode"), rather than be handled by the OS.
Dell PowerEdge 11G server BIOS defines Firmware First mode in HEST, so
that it may manage such errors, log them to the System Event Log, and
possibly take other actions. The aer driver should honor this, and
not attach itself to devices noted as such.
Furthermore, Kenji Kaneshige reminded us to disallow changing the AER
registers when respecting Firmware First mode. Platform firmware is
expected to manage these, and if changes to them are allowed, it could
break that firmware's behavior.
The HEST parsing code may be replaced in the future by a more
feature-rich implementation. This patch provides the minimum needed
to prevent breakage until that implementation is available.
Signed-off-by: Matt Domsch <Matt_Domsch@xxxxxxxx>
---
drivers/acpi/Makefile | 1 +
drivers/acpi/hest.c | 106 ++++++++++++++++++++++++++++++++++++
drivers/pci/pcie/aer/aerdrv_core.c | 26 ++++++++-
include/acpi/acpi_hest.h | 8 +++
include/linux/pci.h | 1 +
5 files changed, 140 insertions(+), 2 deletions(-)
create mode 100644 drivers/acpi/hest.c
create mode 100644 include/acpi/acpi_hest.h
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 7702118..9ab0d6d 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -19,6 +19,7 @@ obj-y += acpi.o \
# All the builtin files are in the "acpi." module_param namespace.
acpi-y += osl.o utils.o reboot.o
+obj-y += hest.o
# sleep related files
acpi-y += wakeup.o
diff --git a/drivers/acpi/hest.c b/drivers/acpi/hest.c
new file mode 100644
index 0000000..9684f50
--- /dev/null
+++ b/drivers/acpi/hest.c
@@ -0,0 +1,106 @@
+#include <linux/acpi.h>
+#include <linux/pci.h>
+
+static unsigned long parse_acpi_hest_ia_machine_check(struct acpi_hest_ia_machine_check *p)
+{
+ return sizeof(*p) +
+ (sizeof(struct acpi_hest_ia_error_bank) * p->num_hardware_banks);
+}
+
+static unsigned long parse_acpi_hest_ia_corrected(struct acpi_hest_ia_corrected *p)
+{
+ return sizeof(*p) +
+ (sizeof(struct acpi_hest_ia_error_bank) * p->num_hardware_banks);
+}
+
+static unsigned long parse_acpi_hest_ia_nmi(struct acpi_hest_ia_nmi *p)
+{
+ return sizeof(*p);
+}
+
+static unsigned long parse_acpi_hest_generic(struct acpi_hest_generic *p)
+{
+ return sizeof(*p);
+}
+
+static unsigned long parse_acpi_hest_aer(void *hdr, int type, struct pci_dev *pci, int *firmware_first)
+{
+ struct acpi_hest_aer_common *p = hdr + sizeof(struct acpi_hest_header);
+ unsigned long rc=0;
+ switch (type) {
+ case ACPI_HEST_TYPE_AER_ROOT_PORT:
+ rc = sizeof(struct acpi_hest_aer_root);
+ break;
+ case ACPI_HEST_TYPE_AER_ENDPOINT:
+ rc = sizeof(struct acpi_hest_aer);
+ break;
+ case ACPI_HEST_TYPE_AER_BRIDGE:
+ rc = sizeof(struct acpi_hest_aer_bridge);
+ break;
+ }
+
+ if (p->flags & ACPI_HEST_FIRMWARE_FIRST &&
+ (p->flags & ACPI_HEST_GLOBAL ||
+ (p->bus == pci->bus->number &&
+ p->device == PCI_SLOT(pci->devfn) &&
+ p->function == PCI_FUNC(pci->devfn))))
+ *firmware_first = 1;
+ return rc;
+}
+
+static int acpi_hest_firmware_first(struct acpi_table_header *stdheader, struct pci_dev *pci)
+{
+ struct acpi_table_hest *hest = (struct acpi_table_hest *)stdheader;
+ void *p = (void *)hest + sizeof(*hest); /* defined by the ACPI 4.0 spec */
+ struct acpi_hest_header *hdr = p;
+
+ int i;
+ int firmware_first = 0;
+
+ for (i=0, hdr=p; p < (((void *)hest) + hest->header.length) && i < hest->error_source_count; i++) {
+ switch (hdr->type) {
+ case ACPI_HEST_TYPE_IA32_CHECK:
+ p += parse_acpi_hest_ia_machine_check(p);
+ break;
+ case ACPI_HEST_TYPE_IA32_CORRECTED_CHECK:
+ p += parse_acpi_hest_ia_corrected(p);
+ break;
+ case ACPI_HEST_TYPE_IA32_NMI:
+ p += parse_acpi_hest_ia_nmi(p);
+ break;
+ /* These three should never appear */
+ case ACPI_HEST_TYPE_NOT_USED3:
+ case ACPI_HEST_TYPE_NOT_USED4:
+ case ACPI_HEST_TYPE_NOT_USED5:
+ break;
+ case ACPI_HEST_TYPE_AER_ROOT_PORT:
+ case ACPI_HEST_TYPE_AER_ENDPOINT:
+ case ACPI_HEST_TYPE_AER_BRIDGE:
+ p += parse_acpi_hest_aer(p, hdr->type, pci, &firmware_first);
+ break;
+ case ACPI_HEST_TYPE_GENERIC_ERROR:
+ p += parse_acpi_hest_generic(p);
+ break;
+ /* These should never appear either */
+ case ACPI_HEST_TYPE_RESERVED:
+ default:
+ break;
+ }
+ }
+ return firmware_first;
+}
+
+int acpi_hest_firmware_first_pci(struct pci_dev *pci)
+{
+ acpi_status status = AE_NOT_FOUND;
+ struct acpi_table_header *hest = NULL;
+ status = acpi_get_table(ACPI_SIG_HEST, 1, &hest);
+
+ if (ACPI_SUCCESS(status)) {
+ if (acpi_hest_firmware_first(hest, pci)) {
+ return 1;
+ }
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_hest_firmware_first_pci);
diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c
index 9f5ccbe..aef2db2 100644
--- a/drivers/pci/pcie/aer/aerdrv_core.c
+++ b/drivers/pci/pcie/aer/aerdrv_core.c
@@ -23,6 +23,7 @@
#include <linux/pm.h>
#include <linux/suspend.h>
#include <linux/delay.h>
+#include <acpi/acpi_hest.h>
#include "aerdrv.h"
static int forceload;
@@ -35,6 +36,9 @@ int pci_enable_pcie_error_reporting(struct pci_dev *dev)
u16 reg16 = 0;
int pos;
+ if (dev->aer_firmware_first)
+ return -EIO;
+
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
if (!pos)
return -EIO;
@@ -60,6 +64,9 @@ int pci_disable_pcie_error_reporting(struct pci_dev *dev)
u16 reg16 = 0;
int pos;
+ if (dev->aer_firmware_first)
+ return -EIO;
+
pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
if (!pos)
return -EIO;
@@ -874,8 +881,23 @@ void aer_delete_rootport(struct aer_rpc *rpc)
*/
int aer_init(struct pcie_device *dev)
{
- if (aer_osc_setup(dev) && !forceload)
- return -ENXIO;
+ if (acpi_hest_firmware_first_pci(dev->port)) {
+ dev_printk(KERN_DEBUG, &dev->device,
+ "PCIe device errors handled by platform firmware.\n");
+ dev->port->aer_firmware_first=1;
+ goto out;
+ }
+
+ if (aer_osc_setup(dev))
+ goto out;
return 0;
+out:
+ if (forceload) {
+ dev_printk(KERN_DEBUG, &dev->device,
+ "aerdrv forceload requested.\n");
+ dev->port->aer_firmware_first=0;
+ return 0;
+ }
+ return -ENXIO;
}
diff --git a/include/acpi/acpi_hest.h b/include/acpi/acpi_hest.h
new file mode 100644
index 0000000..0d41408
--- /dev/null
+++ b/include/acpi/acpi_hest.h
@@ -0,0 +1,8 @@
+#ifndef __ACPI_HEST_H
+#define __ACPI_HEST_H
+
+#include <linux/pci.h>
+
+extern int acpi_hest_firmware_first_pci(struct pci_dev *pci);
+
+#endif
diff --git a/include/linux/pci.h b/include/linux/pci.h
index da4128f..9d646e6 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -280,6 +280,7 @@ struct pci_dev {
unsigned int is_virtfn:1;
unsigned int reset_fn:1;
unsigned int is_hotplug_bridge:1;
+ unsigned int aer_firmware_first:1;
pci_dev_flags_t dev_flags;
atomic_t enable_cnt; /* pci_enable_device has been called */
--
1.6.2.5
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