+ mutex_lock(&resource->resource_lock);
+ list_for_each_safe(node, next, &resource->reference) {
+ ref = container_of(node, struct acpi_power_reference, node);
+ if (dev->handle == ref->device->handle) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n",
+ dev->pnp.bus_id, resource->name));
+ found = 1;
+ break;
+ }
+ }
+
+ if (!found) {
+ ref = kmalloc(sizeof (struct acpi_power_reference),
+ irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
+ if (!ref) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n"));
+ mutex_unlock(&resource->resource_lock);
+ return -ENOMEM;
+ }
+ list_add_tail(&ref->node, &resource->reference);
+ ref->device = dev;
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n",
+ dev->pnp.bus_id, resource->name));
+ }
+ mutex_unlock(&resource->resource_lock);