linux/drivers/pci/pcie/aer/aerdrv_acpi.c
Rafael J. Wysocki 75fb60f26b ACPI/PCI: Negotiate _OSC control bits before requesting them
It is possible that the BIOS will not grant control of all _OSC
features requested via acpi_pci_osc_control_set(), so it is
recommended to negotiate the final set of _OSC features with the
query flag set before calling _OSC to request control of these
features.

To implement it, rework acpi_pci_osc_control_set() so that the caller
can specify the mask of _OSC control bits to negotiate and the mask
of _OSC control bits that are absolutely necessary to it.  Then,
acpi_pci_osc_control_set() will run _OSC queries in a loop until
the mask of _OSC control bits returned by the BIOS is equal to the
mask passed to it.  Also, before running the _OSC request
acpi_pci_osc_control_set() will check if the caller's required
control bits are present in the final mask.

Using this mechanism we will be able to avoid situations in which the
BIOS doesn't grant control of certain _OSC features, because they
depend on some other _OSC features that have not been requested.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-08-24 13:44:40 -07:00

133 lines
3.1 KiB
C

/*
* Access ACPI _OSC method
*
* Copyright (C) 2006 Intel Corp.
* Tom Long Nguyen (tom.l.nguyen@intel.com)
* Zhang Yanmin (yanmin.zhang@intel.com)
*
*/
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/pm.h>
#include <linux/suspend.h>
#include <linux/acpi.h>
#include <linux/pci-acpi.h>
#include <linux/delay.h>
#include <acpi/apei.h>
#include "aerdrv.h"
/**
* aer_osc_setup - run ACPI _OSC method
* @pciedev: pcie_device which AER is being enabled on
*
* @return: Zero on success. Nonzero otherwise.
*
* Invoked when PCIe bus loads AER service driver. To avoid conflict with
* BIOS AER support requires BIOS to yield AER control to OS native driver.
**/
int aer_osc_setup(struct pcie_device *pciedev)
{
acpi_status status = AE_NOT_FOUND;
struct pci_dev *pdev = pciedev->port;
acpi_handle handle = NULL;
if (acpi_pci_disabled)
return -1;
handle = acpi_find_root_bridge_handle(pdev);
if (handle) {
u32 flags = OSC_PCI_EXPRESS_AER_CONTROL |
OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL;
status = acpi_pci_osc_control_set(handle, &flags, flags);
}
if (ACPI_FAILURE(status)) {
dev_printk(KERN_DEBUG, &pciedev->device, "AER service couldn't "
"init device: %s\n",
(status == AE_SUPPORT || status == AE_NOT_FOUND) ?
"no _OSC support" : "_OSC failed");
return -1;
}
return 0;
}
#ifdef CONFIG_ACPI_APEI
static inline int hest_match_pci(struct acpi_hest_aer_common *p,
struct pci_dev *pci)
{
return (0 == pci_domain_nr(pci->bus) &&
p->bus == pci->bus->number &&
p->device == PCI_SLOT(pci->devfn) &&
p->function == PCI_FUNC(pci->devfn));
}
struct aer_hest_parse_info {
struct pci_dev *pci_dev;
int firmware_first;
};
static int aer_hest_parse(struct acpi_hest_header *hest_hdr, void *data)
{
struct aer_hest_parse_info *info = data;
struct acpi_hest_aer_common *p;
u8 pcie_type = 0;
u8 bridge = 0;
int ff = 0;
switch (hest_hdr->type) {
case ACPI_HEST_TYPE_AER_ROOT_PORT:
pcie_type = PCI_EXP_TYPE_ROOT_PORT;
break;
case ACPI_HEST_TYPE_AER_ENDPOINT:
pcie_type = PCI_EXP_TYPE_ENDPOINT;
break;
case ACPI_HEST_TYPE_AER_BRIDGE:
if ((info->pci_dev->class >> 16) == PCI_BASE_CLASS_BRIDGE)
bridge = 1;
break;
default:
return 0;
}
p = (struct acpi_hest_aer_common *)(hest_hdr + 1);
if (p->flags & ACPI_HEST_GLOBAL) {
if ((info->pci_dev->is_pcie &&
info->pci_dev->pcie_type == pcie_type) || bridge)
ff = !!(p->flags & ACPI_HEST_FIRMWARE_FIRST);
} else
if (hest_match_pci(p, info->pci_dev))
ff = !!(p->flags & ACPI_HEST_FIRMWARE_FIRST);
info->firmware_first = ff;
return 0;
}
static void aer_set_firmware_first(struct pci_dev *pci_dev)
{
int rc;
struct aer_hest_parse_info info = {
.pci_dev = pci_dev,
.firmware_first = 0,
};
rc = apei_hest_parse(aer_hest_parse, &info);
if (rc)
pci_dev->__aer_firmware_first = 0;
else
pci_dev->__aer_firmware_first = info.firmware_first;
pci_dev->__aer_firmware_first_valid = 1;
}
int pcie_aer_get_firmware_first(struct pci_dev *dev)
{
if (!dev->__aer_firmware_first_valid)
aer_set_firmware_first(dev);
return dev->__aer_firmware_first;
}
#endif