ACPI / bind: Simplify child device lookups

[deliverable/linux.git] / drivers / acpi / glue.c

diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index a22a295edb692347f16066bff26d145973ab2523..ea77512ad70c58e9d660628929cad52c76ab863f 100644 (file)
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -82,107 +82,80 @@ static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
 #define FIND_CHILD_MIN_SCORE   1
 #define FIND_CHILD_MAX_SCORE   2
 
-static acpi_status acpi_dev_present(acpi_handle handle, u32 lvl_not_used,
-                                 void *not_used, void **ret_p)
-{
-       struct acpi_device *adev = NULL;
-
-       acpi_bus_get_device(handle, &adev);
-       if (adev) {
-               *ret_p = handle;
-               return AE_CTRL_TERMINATE;
-       }
-       return AE_OK;
-}
-
-static int do_find_child_checks(acpi_handle handle, bool is_bridge)
+static int find_child_checks(struct acpi_device *adev, bool check_children)
 {
        bool sta_present = true;
        unsigned long long sta;
        acpi_status status;
 
-       status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
+       status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
        if (status == AE_NOT_FOUND)
                sta_present = false;
        else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
                return -ENODEV;
 
-       if (is_bridge) {
-               void *test = NULL;
+       if (check_children && list_empty(&adev->children))
+               return -ENODEV;
 
-               /* Check if this object has at least one child device. */
-               acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
-                                   acpi_dev_present, NULL, NULL, &test);
-               if (!test)
-                       return -ENODEV;
-       }
        return sta_present ? FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
 }
 
-struct find_child_context {
-       u64 addr;
-       bool is_bridge;
-       acpi_handle ret;
-       int ret_score;
-};
-
-static acpi_status do_find_child(acpi_handle handle, u32 lvl_not_used,
-                                void *data, void **not_used)
+struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
+                                          u64 address, bool check_children)
 {
-       struct find_child_context *context = data;
-       unsigned long long addr;
-       acpi_status status;
-       int score;
-
-       status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr);
-       if (ACPI_FAILURE(status) || addr != context->addr)
-               return AE_OK;
-
-       if (!context->ret) {
-               /* This is the first matching object.  Save its handle. */
-               context->ret = handle;
-               return AE_OK;
-       }
-       /*
-        * There is more than one matching object with the same _ADR value.
-        * That really is unexpected, so we are kind of beyond the scope of the
-        * spec here.  We have to choose which one to return, though.
-        *
-        * First, check if the previously found object is good enough and return
-        * its handle if so.  Second, check the same for the object that we've
-        * just found.
-        */
-       if (!context->ret_score) {
-               score = do_find_child_checks(context->ret, context->is_bridge);
-               if (score == FIND_CHILD_MAX_SCORE)
-                       return AE_CTRL_TERMINATE;
-               else
-                       context->ret_score = score;
-       }
-       score = do_find_child_checks(handle, context->is_bridge);
-       if (score == FIND_CHILD_MAX_SCORE) {
-               context->ret = handle;
-               return AE_CTRL_TERMINATE;
-       } else if (score > context->ret_score) {
-               context->ret = handle;
-               context->ret_score = score;
+       struct acpi_device *adev, *ret = NULL;
+       int ret_score = 0;
+
+       list_for_each_entry(adev, &parent->children, node) {
+               unsigned long long addr;
+               acpi_status status;
+               int score;
+
+               status = acpi_evaluate_integer(adev->handle, METHOD_NAME__ADR,
+                                              NULL, &addr);
+               if (ACPI_FAILURE(status) || addr != address)
+                       continue;
+
+               if (!ret) {
+                       /* This is the first matching object.  Save it. */
+                       ret = adev;
+                       continue;
+               }
+               /*
+                * There is more than one matching device object with the same
+                * _ADR value.  That really is unexpected, so we are kind of
+                * beyond the scope of the spec here.  We have to choose which
+                * one to return, though.
+                *
+                * First, check if the previously found object is good enough
+                * and return it if so.  Second, do the same for the object that
+                * we've just found.
+                */
+               if (!ret_score) {
+                       ret_score = find_child_checks(ret, check_children);
+                       if (ret_score == FIND_CHILD_MAX_SCORE)
+                               return ret;
+               }
+               score = find_child_checks(adev, check_children);
+               if (score == FIND_CHILD_MAX_SCORE) {
+                       return adev;
+               } else if (score > ret_score) {
+                       ret = adev;
+                       ret_score = score;
+               }
        }
-       return AE_OK;
+       return ret;
 }
 
-acpi_handle acpi_find_child(acpi_handle parent, u64 addr, bool is_bridge)
+acpi_handle acpi_find_child(acpi_handle handle, u64 addr, bool is_bridge)
 {
-       if (parent) {
-               struct find_child_context context = {
-                       .addr = addr,
-                       .is_bridge = is_bridge,
-               };
-
-               acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1, do_find_child,
-                                   NULL, &context, NULL);
-               return context.ret;
-       }
-       return NULL;
+       struct acpi_device *adev;
+
+       if (!handle || acpi_bus_get_device(handle, &adev))
+               return NULL;
+
+       adev = acpi_find_child_device(adev, addr, is_bridge);
+       return adev ? adev->handle : NULL;
 }
 EXPORT_SYMBOL_GPL(acpi_find_child);