ACPI / bind: Simplify child device lookups
[deliverable/linux.git] / drivers / acpi / glue.c
index 10f0f40587bb73309eee9e959fc1049cbaf6dc05..ea77512ad70c58e9d660628929cad52c76ab863f 100644 (file)
@@ -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);
 
@@ -197,30 +170,28 @@ static void acpi_physnode_link_name(char *buf, unsigned int node_id)
 
 int acpi_bind_one(struct device *dev, acpi_handle handle)
 {
-       struct acpi_device *acpi_dev;
-       acpi_status status;
+       struct acpi_device *acpi_dev = NULL;
        struct acpi_device_physical_node *physical_node, *pn;
        char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
        struct list_head *physnode_list;
        unsigned int node_id;
        int retval = -EINVAL;
 
-       if (ACPI_HANDLE(dev)) {
+       if (ACPI_COMPANION(dev)) {
                if (handle) {
-                       dev_warn(dev, "ACPI handle is already set\n");
+                       dev_warn(dev, "ACPI companion already set\n");
                        return -EINVAL;
                } else {
-                       handle = ACPI_HANDLE(dev);
+                       acpi_dev = ACPI_COMPANION(dev);
                }
+       } else {
+               acpi_bus_get_device(handle, &acpi_dev);
        }
-       if (!handle)
+       if (!acpi_dev)
                return -EINVAL;
 
+       get_device(&acpi_dev->dev);
        get_device(dev);
-       status = acpi_bus_get_device(handle, &acpi_dev);
-       if (ACPI_FAILURE(status))
-               goto err;
-
        physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
        if (!physical_node) {
                retval = -ENOMEM;
@@ -242,10 +213,11 @@ int acpi_bind_one(struct device *dev, acpi_handle handle)
 
                        dev_warn(dev, "Already associated with ACPI node\n");
                        kfree(physical_node);
-                       if (ACPI_HANDLE(dev) != handle)
+                       if (ACPI_COMPANION(dev) != acpi_dev)
                                goto err;
 
                        put_device(dev);
+                       put_device(&acpi_dev->dev);
                        return 0;
                }
                if (pn->node_id == node_id) {
@@ -259,8 +231,8 @@ int acpi_bind_one(struct device *dev, acpi_handle handle)
        list_add(&physical_node->node, physnode_list);
        acpi_dev->physical_node_count++;
 
-       if (!ACPI_HANDLE(dev))
-               ACPI_HANDLE_SET(dev, acpi_dev->handle);
+       if (!ACPI_COMPANION(dev))
+               ACPI_COMPANION_SET(dev, acpi_dev);
 
        acpi_physnode_link_name(physical_node_name, node_id);
        retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
@@ -283,27 +255,21 @@ int acpi_bind_one(struct device *dev, acpi_handle handle)
        return 0;
 
  err:
-       ACPI_HANDLE_SET(dev, NULL);
+       ACPI_COMPANION_SET(dev, NULL);
        put_device(dev);
+       put_device(&acpi_dev->dev);
        return retval;
 }
 EXPORT_SYMBOL_GPL(acpi_bind_one);
 
 int acpi_unbind_one(struct device *dev)
 {
+       struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
        struct acpi_device_physical_node *entry;
-       struct acpi_device *acpi_dev;
-       acpi_status status;
 
-       if (!ACPI_HANDLE(dev))
+       if (!acpi_dev)
                return 0;
 
-       status = acpi_bus_get_device(ACPI_HANDLE(dev), &acpi_dev);
-       if (ACPI_FAILURE(status)) {
-               dev_err(dev, "Oops, ACPI handle corrupt in %s()\n", __func__);
-               return -EINVAL;
-       }
-
        mutex_lock(&acpi_dev->physical_node_lock);
 
        list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
@@ -316,9 +282,10 @@ int acpi_unbind_one(struct device *dev)
                        acpi_physnode_link_name(physnode_name, entry->node_id);
                        sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
                        sysfs_remove_link(&dev->kobj, "firmware_node");
-                       ACPI_HANDLE_SET(dev, NULL);
-                       /* acpi_bind_one() increase refcnt by one. */
+                       ACPI_COMPANION_SET(dev, NULL);
+                       /* Drop references taken by acpi_bind_one(). */
                        put_device(dev);
+                       put_device(&acpi_dev->dev);
                        kfree(entry);
                        break;
                }
@@ -328,6 +295,15 @@ int acpi_unbind_one(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(acpi_unbind_one);
 
+void acpi_preset_companion(struct device *dev, acpi_handle parent, u64 addr)
+{
+       struct acpi_device *adev;
+
+       if (!acpi_bus_get_device(acpi_get_child(parent, addr), &adev))
+               ACPI_COMPANION_SET(dev, adev);
+}
+EXPORT_SYMBOL_GPL(acpi_preset_companion);
+
 static int acpi_platform_notify(struct device *dev)
 {
        struct acpi_bus_type *type = acpi_get_bus_type(dev);
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