Merge tag 'v3.10.13' into lsk/v3.10/topic/kvm

[firefly-linux-kernel-4.4.55.git] / drivers / acpi / glue.c

diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index 40a84cc6740c6c6522afc6bac6d5d5d2178a86bd..238412077c8394ee42ce66af4609697c670d6405 100644 (file)
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -78,32 +78,99 @@ 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;
-       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;
                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;
 
-       if (!parent)
-               return NULL;
+       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;
 
-       acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1, NULL,
-                           do_acpi_find_child, &address, &ret);
-       return (acpi_handle)ret;
+       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_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;
+}
+
+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(acpi_get_child);
+EXPORT_SYMBOL_GPL(acpi_find_child);
 
 static int acpi_bind_one(struct device *dev, acpi_handle handle)
 {