+static const char nouveau_op_dsm_muid[] = {
+ 0xF8, 0xD8, 0x86, 0xA4, 0xDA, 0x0B, 0x1B, 0x47,
+ 0xA7, 0x2B, 0x60, 0x42, 0xA6, 0xB5, 0xBE, 0xE0,
+};
+
+static int nouveau_optimus_dsm(acpi_handle handle, int func, int arg, uint32_t *result)
+{
+ struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct acpi_object_list input;
+ union acpi_object params[4];
+ union acpi_object *obj;
+ int err;
+
+ input.count = 4;
+ input.pointer = params;
+ params[0].type = ACPI_TYPE_BUFFER;
+ params[0].buffer.length = sizeof(nouveau_op_dsm_muid);
+ params[0].buffer.pointer = (char *)nouveau_op_dsm_muid;
+ params[1].type = ACPI_TYPE_INTEGER;
+ params[1].integer.value = 0x00000100;
+ params[2].type = ACPI_TYPE_INTEGER;
+ params[2].integer.value = func;
+ params[3].type = ACPI_TYPE_BUFFER;
+ params[3].buffer.length = 0;
+
+ err = acpi_evaluate_object(handle, "_DSM", &input, &output);
+ if (err) {
+ printk(KERN_INFO "failed to evaluate _DSM: %d\n", err);
+ return err;
+ }
+
+ obj = (union acpi_object *)output.pointer;
+
+ if (obj->type == ACPI_TYPE_INTEGER)
+ if (obj->integer.value == 0x80000002) {
+ return -ENODEV;
+ }
+
+ if (obj->type == ACPI_TYPE_BUFFER) {
+ if (obj->buffer.length == 4 && result) {
+ *result = 0;
+ *result |= obj->buffer.pointer[0];
+ *result |= (obj->buffer.pointer[1] << 8);
+ *result |= (obj->buffer.pointer[2] << 16);
+ *result |= (obj->buffer.pointer[3] << 24);
+ }
+ }
+
+ kfree(output.pointer);
+ return 0;
+}
+