iommu/vt-d: Search for ACPI _DSM method for DMAR hotplug

According to Intel VT-d specification, _DSM method to support DMAR
hotplug should exist directly under corresponding ACPI object
representing PCI host bridge. But some BIOSes doesn't conform to
this, so search for _DSM method in the subtree starting from the
ACPI object representing the PCI host bridge.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Reviewed-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Jiang Liu 2014-11-09 22:47:59 +08:00 committed by Joerg Roedel
parent 6b1972493a
commit d35165a955

View file

@ -1942,21 +1942,48 @@ static int dmar_hotplug_remove(acpi_handle handle)
return ret;
}
static acpi_status dmar_get_dsm_handle(acpi_handle handle, u32 lvl,
void *context, void **retval)
{
acpi_handle *phdl = retval;
if (dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD)) {
*phdl = handle;
return AE_CTRL_TERMINATE;
}
return AE_OK;
}
static int dmar_device_hotplug(acpi_handle handle, bool insert)
{
int ret;
acpi_handle tmp = NULL;
acpi_status status;
if (!dmar_in_use())
return 0;
if (!dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD))
if (dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD)) {
tmp = handle;
} else {
status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
ACPI_UINT32_MAX,
dmar_get_dsm_handle,
NULL, NULL, &tmp);
if (ACPI_FAILURE(status)) {
pr_warn("Failed to locate _DSM method.\n");
return -ENXIO;
}
}
if (tmp == NULL)
return 0;
down_write(&dmar_global_lock);
if (insert)
ret = dmar_hotplug_insert(handle);
ret = dmar_hotplug_insert(tmp);
else
ret = dmar_hotplug_remove(handle);
ret = dmar_hotplug_remove(tmp);
up_write(&dmar_global_lock);
return ret;