@@ -1927,21 +1927,48 @@ static int dmar_hotplug_remove(acpi_handle handle)
return ret;
}
-static int dmar_device_hotplug(acpi_handle handle, bool insert)
+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;
+}
+
+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;
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> --- drivers/iommu/dmar.c | 35 +++++++++++++++++++++++++++++++---- 1 file changed, 31 insertions(+), 4 deletions(-)