ACPI / property: Hierarchical properties support update

The definition document of the Hierarchical Properties Extension UUID
for _DSD has been changed recently to allow local references to be
used as sub-node link targets (previously, it only allowed strings to
be used for that purpose).

Update the code in drivers/acpi/property.c to reflect that change.

Link: http://www.uefi.org/sites/default/files/resources/_DSD-hierarchical-data-extension-UUID-v1.1.pdf
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c
index 7b2c48fde4e2b19f7134c1900931ff0695469ad9..24418932612eeabc62d72185df50980ed55ee5bd 100644 (file)
--- a/drivers/acpi/device_sysfs.c
+++ b/drivers/acpi/device_sysfs.c
@@ -52,7 +52,7 @@ struct acpi_data_node_attr {
 
 static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
 {
-       return acpi_object_path(dn->handle, buf);
+       return dn->handle ? acpi_object_path(dn->handle, buf) : 0;
 }
 
 DATA_NODE_ATTR(path);
@@ -105,10 +105,10 @@ static void acpi_expose_nondev_subnodes(struct kobject *kobj,
                init_completion(&dn->kobj_done);
                ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
                                           kobj, "%s", dn->name);
-               if (ret)
-                       acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
-               else
+               if (!ret)
                        acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
+               else if (dn->handle)
+                       acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
        }
 }
 

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 03f5ec11ab3197de66ced4e7f09d39dbab6b8232..3afddcd834efdb407f8b5dec1bebf42ce704c0c5 100644 (file)
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -41,14 +41,13 @@ static bool acpi_enumerate_nondev_subnodes(acpi_handle scope,
 static bool acpi_extract_properties(const union acpi_object *desc,
                                    struct acpi_device_data *data);
 
-static bool acpi_nondev_subnode_ok(acpi_handle scope,
-                                  const union acpi_object *link,
-                                  struct list_head *list)
+static bool acpi_nondev_subnode_extract(const union acpi_object *desc,
+                                       acpi_handle handle,
+                                       const union acpi_object *link,
+                                       struct list_head *list)
 {
-       struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
        struct acpi_data_node *dn;
-       acpi_handle handle;
-       acpi_status status;
+       bool result;
 
        dn = kzalloc(sizeof(*dn), GFP_KERNEL);
        if (!dn)
@@ -58,43 +57,75 @@ static bool acpi_nondev_subnode_ok(acpi_handle scope,
        dn->fwnode.type = FWNODE_ACPI_DATA;
        INIT_LIST_HEAD(&dn->data.subnodes);
 
-       status = acpi_get_handle(scope, link->package.elements[1].string.pointer,
-                                &handle);
-       if (ACPI_FAILURE(status))
-               goto fail;
+       result = acpi_extract_properties(desc, &dn->data);
 
-       status = acpi_evaluate_object_typed(handle, NULL, NULL, &buf,
-                                           ACPI_TYPE_PACKAGE);
-       if (ACPI_FAILURE(status))
-               goto fail;
+       if (handle) {
+               acpi_handle scope;
+               acpi_status status;
 
-       if (acpi_extract_properties(buf.pointer, &dn->data))
-               dn->handle = handle;
+               /*
+                * The scope for the subnode object lookup is the one of the
+                * namespace node (device) containing the object that has
+                * returned the package.  That is, it's the scope of that
+                * object's parent.
+                */
+               status = acpi_get_parent(handle, &scope);
+               if (ACPI_SUCCESS(status)
+                   && acpi_enumerate_nondev_subnodes(scope, desc, &dn->data))
+                       result = true;
+       } else if (acpi_enumerate_nondev_subnodes(NULL, desc, &dn->data)) {
+               result = true;
+       }
 
-       /*
-        * The scope for the subnode object lookup is the one of the namespace
-        * node (device) containing the object that has returned the package.
-        * That is, it's the scope of that object's parent.
-        */
-       status = acpi_get_parent(handle, &scope);
-       if (ACPI_SUCCESS(status)
-           && acpi_enumerate_nondev_subnodes(scope, buf.pointer, &dn->data))
+       if (result) {
                dn->handle = handle;
-
-       if (dn->handle) {
-               dn->data.pointer = buf.pointer;
+               dn->data.pointer = desc;
                list_add_tail(&dn->sibling, list);
                return true;
        }
 
+       kfree(dn);
        acpi_handle_debug(handle, "Invalid properties/subnodes data, skipping\n");
+       return false;
+}
+
+static bool acpi_nondev_subnode_data_ok(acpi_handle handle,
+                                       const union acpi_object *link,
+                                       struct list_head *list)
+{
+       struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
+       acpi_status status;
+
+       status = acpi_evaluate_object_typed(handle, NULL, NULL, &buf,
+                                           ACPI_TYPE_PACKAGE);
+       if (ACPI_FAILURE(status))
+               return false;
+
+       if (acpi_nondev_subnode_extract(buf.pointer, handle, link, list))
+               return true;
 
- fail:
        ACPI_FREE(buf.pointer);
-       kfree(dn);
        return false;
 }
 
+static bool acpi_nondev_subnode_ok(acpi_handle scope,
+                                  const union acpi_object *link,
+                                  struct list_head *list)
+{
+       acpi_handle handle;
+       acpi_status status;
+
+       if (!scope)
+               return false;
+
+       status = acpi_get_handle(scope, link->package.elements[1].string.pointer,
+                                &handle);
+       if (ACPI_FAILURE(status))
+               return false;
+
+       return acpi_nondev_subnode_data_ok(handle, link, list);
+}
+
 static int acpi_add_nondev_subnodes(acpi_handle scope,
                                    const union acpi_object *links,
                                    struct list_head *list)
@@ -103,15 +134,37 @@ static int acpi_add_nondev_subnodes(acpi_handle scope,
        int i;
 
        for (i = 0; i < links->package.count; i++) {
-               const union acpi_object *link;
+               const union acpi_object *link, *desc;
+               acpi_handle handle;
+               bool result;
 
                link = &links->package.elements[i];
-               /* Only two elements allowed, both must be strings. */
-               if (link->package.count == 2
-                   && link->package.elements[0].type == ACPI_TYPE_STRING
-                   && link->package.elements[1].type == ACPI_TYPE_STRING
-                   && acpi_nondev_subnode_ok(scope, link, list))
-                       ret = true;
+               /* Only two elements allowed. */
+               if (link->package.count != 2)
+                       continue;
+
+               /* The first one must be a string. */
+               if (link->package.elements[0].type != ACPI_TYPE_STRING)
+                       continue;
+
+               /* The second one may be a string, a reference or a package. */
+               switch (link->package.elements[1].type) {
+               case ACPI_TYPE_STRING:
+                       result = acpi_nondev_subnode_ok(scope, link, list);
+                       break;
+               case ACPI_TYPE_LOCAL_REFERENCE:
+                       handle = link->package.elements[1].reference.handle;
+                       result = acpi_nondev_subnode_data_ok(handle, link, list);
+                       break;
+               case ACPI_TYPE_PACKAGE:
+                       desc = &link->package.elements[1];
+                       result = acpi_nondev_subnode_extract(desc, NULL, link, list);
+                       break;
+               default:
+                       result = false;
+                       break;
+               }
+               ret = ret || result;
        }
 
        return ret;