]> rtime.felk.cvut.cz Git - linux-imx.git/blobdiff - drivers/acpi/glue.c
ACPI: Try harder to resolve _ADR collisions for bridges
[linux-imx.git] / drivers / acpi / glue.c
index f68095756fb7465bc034ca5335f9345a806dd97d..408f6b2a5fa8ee5c6578cd9e555a8386e112e370 100644 (file)
@@ -31,6 +31,7 @@ static LIST_HEAD(bus_type_list);
 static DECLARE_RWSEM(bus_type_sem);
 
 #define PHYSICAL_NODE_STRING "physical_node"
+#define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10)
 
 int register_acpi_bus_type(struct acpi_bus_type *type)
 {
@@ -78,41 +79,108 @@ static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
        return ret;
 }
 
-static acpi_status do_acpi_find_child(acpi_handle handle, u32 lvl_not_used,
-                                     void *addr_p, void **ret_p)
+static acpi_status acpi_dev_present(acpi_handle handle, u32 lvl_not_used,
+                                 void *not_used, void **ret_p)
 {
-       unsigned long long addr, sta;
-       acpi_status status;
+       struct acpi_device *adev = NULL;
 
-       status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr);
-       if (ACPI_SUCCESS(status) && addr == *((u64 *)addr_p)) {
+       acpi_bus_get_device(handle, &adev);
+       if (adev) {
                *ret_p = handle;
-               status = acpi_bus_get_status_handle(handle, &sta);
-               if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_ENABLED))
-                       return AE_CTRL_TERMINATE;
+               return AE_CTRL_TERMINATE;
        }
        return AE_OK;
 }
 
-acpi_handle acpi_get_child(acpi_handle parent, u64 address)
+static bool acpi_extra_checks_passed(acpi_handle handle, bool is_bridge)
 {
-       void *ret = NULL;
+       unsigned long long sta;
+       acpi_status status;
+
+       status = acpi_bus_get_status_handle(handle, &sta);
+       if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
+               return false;
+
+       if (is_bridge) {
+               void *test = NULL;
+
+               /* Check if this object has at least one child device. */
+               acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
+                                   acpi_dev_present, NULL, NULL, &test);
+               return !!test;
+       }
+       return true;
+}
+
+struct find_child_context {
+       u64 addr;
+       bool is_bridge;
+       acpi_handle ret;
+       bool ret_checked;
+};
+
+static acpi_status do_find_child(acpi_handle handle, u32 lvl_not_used,
+                                void *data, void **not_used)
+{
+       struct find_child_context *context = data;
+       unsigned long long addr;
+       acpi_status status;
 
-       if (!parent)
-               return NULL;
+       status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr);
+       if (ACPI_FAILURE(status) || addr != context->addr)
+               return AE_OK;
 
-       acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1, NULL,
-                           do_acpi_find_child, &address, &ret);
-       return (acpi_handle)ret;
+       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_checked) {
+               if (acpi_extra_checks_passed(context->ret, context->is_bridge))
+                       return AE_CTRL_TERMINATE;
+               else
+                       context->ret_checked = true;
+       }
+       if (acpi_extra_checks_passed(handle, context->is_bridge)) {
+               context->ret = handle;
+               return AE_CTRL_TERMINATE;
+       }
+       return AE_OK;
 }
-EXPORT_SYMBOL(acpi_get_child);
+
+acpi_handle acpi_find_child(acpi_handle parent, 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;
+}
+EXPORT_SYMBOL_GPL(acpi_find_child);
 
 int acpi_bind_one(struct device *dev, acpi_handle handle)
 {
        struct acpi_device *acpi_dev;
        acpi_status status;
        struct acpi_device_physical_node *physical_node, *pn;
-       char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
+       char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
+       struct list_head *physnode_list;
+       unsigned int node_id;
        int retval = -EINVAL;
 
        if (ACPI_HANDLE(dev)) {
@@ -139,25 +207,27 @@ int acpi_bind_one(struct device *dev, acpi_handle handle)
 
        mutex_lock(&acpi_dev->physical_node_lock);
 
-       /* Sanity check. */
-       list_for_each_entry(pn, &acpi_dev->physical_node_list, node)
+       /*
+        * Keep the list sorted by node_id so that the IDs of removed nodes can
+        * be recycled easily.
+        */
+       physnode_list = &acpi_dev->physical_node_list;
+       node_id = 0;
+       list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
+               /* Sanity check. */
                if (pn->dev == dev) {
                        dev_warn(dev, "Already associated with ACPI node\n");
                        goto err_free;
                }
-
-       /* allocate physical node id according to physical_node_id_bitmap */
-       physical_node->node_id =
-               find_first_zero_bit(acpi_dev->physical_node_id_bitmap,
-               ACPI_MAX_PHYSICAL_NODE);
-       if (physical_node->node_id >= ACPI_MAX_PHYSICAL_NODE) {
-               retval = -ENOSPC;
-               goto err_free;
+               if (pn->node_id == node_id) {
+                       physnode_list = &pn->node;
+                       node_id++;
+               }
        }
 
-       set_bit(physical_node->node_id, acpi_dev->physical_node_id_bitmap);
+       physical_node->node_id = node_id;
        physical_node->dev = dev;
-       list_add_tail(&physical_node->node, &acpi_dev->physical_node_list);
+       list_add(&physical_node->node, physnode_list);
        acpi_dev->physical_node_count++;
 
        mutex_unlock(&acpi_dev->physical_node_lock);
@@ -208,7 +278,7 @@ int acpi_unbind_one(struct device *dev)
 
        mutex_lock(&acpi_dev->physical_node_lock);
        list_for_each_safe(node, next, &acpi_dev->physical_node_list) {
-               char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
+               char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
 
                entry = list_entry(node, struct acpi_device_physical_node,
                        node);
@@ -216,7 +286,6 @@ int acpi_unbind_one(struct device *dev)
                        continue;
 
                list_del(node);
-               clear_bit(entry->node_id, acpi_dev->physical_node_id_bitmap);
 
                acpi_dev->physical_node_count--;