drm/nouveau/nvif: extend nop ioctl to return nvif version identifier

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/include/nvif/client.h

@@ -6,6 +6,7 @@
 struct nvif_client {
 	struct nvif_object object;
 	const struct nvif_driver *driver;
+	u64 version;
 	u8 route;
 	bool super;
 };

drivers/gpu/drm/nouveau/include/nvif/ioctl.h

@@ -1,6 +1,8 @@
 #ifndef __NVIF_IOCTL_H__
 #define __NVIF_IOCTL_H__
 
+#define NVIF_VERSION_LATEST                               0x0000000000000000ULL
+
 struct nvif_ioctl_v0 {
 	__u8  version;
 #define NVIF_IOCTL_V0_NOP                                                  0x00
@@ -29,7 +31,8 @@ struct nvif_ioctl_v0 {
 	__u8  data[];		/* ioctl data (below) */
 };
 
-struct nvif_ioctl_nop {
+struct nvif_ioctl_nop_v0 {
+	__u64 version;
 };
 
 struct nvif_ioctl_sclass_v0 {

drivers/gpu/drm/nouveau/nvif/client.c

@@ -71,6 +71,10 @@ int
 nvif_client_init(const char *driver, const char *name, u64 device,
 		 const char *cfg, const char *dbg, struct nvif_client *client)
 {
+	struct {
+		struct nvif_ioctl_v0 ioctl;
+		struct nvif_ioctl_nop_v0 nop;
+	} args = {};
 	int ret, i;
 
 	ret = nvif_object_init(NULL, 0, 0, NULL, 0, &client->object);
@@ -91,6 +95,11 @@ nvif_client_init(const char *driver, const char *name, u64 device,
 		}
 	}
 
+	if (ret == 0) {
+		ret = nvif_client_ioctl(client, &args, sizeof(args));
+		client->version = args.nop.version;
+	}
+
 	if (ret)
 		nvif_client_fini(client);
 	return ret;

drivers/gpu/drm/nouveau/nvkm/core/ioctl.c

@@ -35,13 +35,14 @@ nvkm_ioctl_nop(struct nvkm_handle *handle, void *data, u32 size)
 {
 	struct nvkm_object *object = handle->object;
 	union {
-		struct nvif_ioctl_nop none;
+		struct nvif_ioctl_nop_v0 v0;
 	} *args = data;
 	int ret;
 
 	nvif_ioctl(object, "nop size %d\n", size);
-	if (nvif_unvers(args->none)) {
-		nvif_ioctl(object, "nop\n");
+	if (nvif_unpack(args->v0, 0, 0, false)) {
+		nvif_ioctl(object, "nop vers %lld\n", args->v0.version);
+		args->v0.version = NVIF_VERSION_LATEST;
 	}
 
 	return ret;