diff --git a/drivers/gpu/drm/nouveau/include/nvif/device.h b/drivers/gpu/drm/nouveau/include/nvif/device.h
index 1973e65f21a6..68b431b24ae6 100644
--- a/drivers/gpu/drm/nouveau/include/nvif/device.h
+++ b/drivers/gpu/drm/nouveau/include/nvif/device.h
@@ -9,7 +9,7 @@ struct nvif_device {
 	struct nv_device_info_v0 info;
 };
 
-int  nvif_device_init(struct nvif_object *, u32 handle, u32 oclass, void *, u32,
+int  nvif_device_init(struct nvif_object *, u32 handle, s32 oclass, void *, u32,
 		      struct nvif_device *);
 void nvif_device_fini(struct nvif_device *);
 u64  nvif_device_time(struct nvif_device *);
diff --git a/drivers/gpu/drm/nouveau/include/nvif/ioctl.h b/drivers/gpu/drm/nouveau/include/nvif/ioctl.h
index 772db0de044a..193437c4a1f0 100644
--- a/drivers/gpu/drm/nouveau/include/nvif/ioctl.h
+++ b/drivers/gpu/drm/nouveau/include/nvif/ioctl.h
@@ -40,7 +40,7 @@ struct nvif_ioctl_sclass_v0 {
 	__u8  version;
 	__u8  count;
 	__u8  pad02[6];
-	__u32 oclass[];
+	__s32 oclass[];
 };
 
 struct nvif_ioctl_new_v0 {
@@ -52,10 +52,10 @@ struct nvif_ioctl_new_v0 {
 	__u64 object;
 	__u32 handle;
 /* these class numbers are made up by us, and not nvidia-assigned */
-#define NVIF_IOCTL_NEW_V0_PERFMON                                    0x0000ffff
-#define NVIF_IOCTL_NEW_V0_PERFDOM                                    0x0000fffe
-#define NVIF_IOCTL_NEW_V0_CONTROL                                    0x0000fffd
-	__u32 oclass;
+#define NVIF_IOCTL_NEW_V0_CONTROL                                            -1
+#define NVIF_IOCTL_NEW_V0_PERFMON                                            -2
+#define NVIF_IOCTL_NEW_V0_PERFDOM                                            -3
+	__s32 oclass;
 	__u8  data[];		/* class data (class.h) */
 };
 
diff --git a/drivers/gpu/drm/nouveau/include/nvif/object.h b/drivers/gpu/drm/nouveau/include/nvif/object.h
index b46c2f4aa0db..66d3425e4764 100644
--- a/drivers/gpu/drm/nouveau/include/nvif/object.h
+++ b/drivers/gpu/drm/nouveau/include/nvif/object.h
@@ -6,7 +6,7 @@
 struct nvif_object {
 	struct nvif_client *client;
 	u32 handle;
-	u32 oclass;
+	s32 oclass;
 	void *priv; /*XXX: hack */
 	struct {
 		void __iomem *ptr;
@@ -14,11 +14,11 @@ struct nvif_object {
 	} map;
 };
 
-int  nvif_object_init(struct nvif_object *, u32 handle, u32 oclass, void *, u32,
+int  nvif_object_init(struct nvif_object *, u32 handle, s32 oclass, void *, u32,
 		      struct nvif_object *);
 void nvif_object_fini(struct nvif_object *);
 int  nvif_object_ioctl(struct nvif_object *, void *, u32, void **);
-int  nvif_object_sclass(struct nvif_object *, u32 *, int);
+int  nvif_object_sclass(struct nvif_object *, s32 *, int);
 u32  nvif_object_rd(struct nvif_object *, int, u64);
 void nvif_object_wr(struct nvif_object *, int, u64, u32);
 int  nvif_object_mthd(struct nvif_object *, u32, void *, u32);
diff --git a/drivers/gpu/drm/nouveau/include/nvkm/core/client.h b/drivers/gpu/drm/nouveau/include/nvkm/core/client.h
index d70d28f90285..977c8a85e119 100644
--- a/drivers/gpu/drm/nouveau/include/nvkm/core/client.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/core/client.h
@@ -22,20 +22,11 @@ bool nvkm_client_insert(struct nvkm_client *, struct nvkm_handle *);
 void nvkm_client_remove(struct nvkm_client *, struct nvkm_handle *);
 struct nvkm_handle *nvkm_client_search(struct nvkm_client *, u64 handle);
 
-static inline struct nvkm_client *
-nv_client(void *obj)
-{
-#if CONFIG_NOUVEAU_DEBUG >= NV_DBG_PARANOIA
-	BUG_ON(!nv_iclass(obj, NV_CLIENT_CLASS));
-#endif
-	return obj;
-}
-
 static inline struct nvkm_client *
 nvkm_client(void *obj)
 {
 	struct nvkm_object *client = nv_object(obj);
-	while (client && !(nv_iclass(client, NV_CLIENT_CLASS)))
+	while (client && client->parent)
 		client = client->parent;
 	return (void *)client;
 }
diff --git a/drivers/gpu/drm/nouveau/include/nvkm/core/object.h b/drivers/gpu/drm/nouveau/include/nvkm/core/object.h
index ef0ff9e1a948..005cd4a86849 100644
--- a/drivers/gpu/drm/nouveau/include/nvkm/core/object.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/core/object.h
@@ -62,7 +62,7 @@ extern struct nvkm_ofuncs nvkm_object_ofuncs;
 /* Don't allocate dynamically, because lockdep needs lock_class_keys to be in
  * ".data". */
 struct nvkm_oclass {
-	u32 handle;
+	s32 handle;
 	struct nvkm_ofuncs * const ofuncs;
 	struct nvkm_omthds * const omthds;
 	struct lock_class_key lock_class_key;
diff --git a/drivers/gpu/drm/nouveau/include/nvkm/core/parent.h b/drivers/gpu/drm/nouveau/include/nvkm/core/parent.h
index 2e5266fa7584..bc4dc1f2403f 100644
--- a/drivers/gpu/drm/nouveau/include/nvkm/core/parent.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/core/parent.h
@@ -44,8 +44,8 @@ void _nvkm_parent_dtor(struct nvkm_object *);
 #define _nvkm_parent_init nvkm_object_init
 #define _nvkm_parent_fini nvkm_object_fini
 
-int nvkm_parent_sclass(struct nvkm_object *, u16 handle,
+int nvkm_parent_sclass(struct nvkm_object *, s32 handle,
 		       struct nvkm_object **pengine,
 		       struct nvkm_oclass **poclass);
-int nvkm_parent_lclass(struct nvkm_object *, u32 *, int);
+int nvkm_parent_lclass(struct nvkm_object *, s32 *, int);
 #endif
diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 5529fc479d8a..496c00d585cd 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1104,7 +1104,7 @@ nouveau_bo_move_init(struct nouveau_drm *drm)
 	static const struct {
 		const char *name;
 		int engine;
-		u32 oclass;
+		s32 oclass;
 		int (*exec)(struct nouveau_channel *,
 			    struct ttm_buffer_object *,
 			    struct ttm_mem_reg *, struct ttm_mem_reg *);
diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
index 11cf52a7ff75..65ceb6fa4209 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -153,7 +153,7 @@ nouveau_accel_init(struct nouveau_drm *drm)
 {
 	struct nvif_device *device = &drm->device;
 	u32 arg0, arg1;
-	u32 sclass[16];
+	s32 sclass[16];
 	int ret, i;
 
 	if (nouveau_noaccel)
diff --git a/drivers/gpu/drm/nouveau/nv50_display.c b/drivers/gpu/drm/nouveau/nv50_display.c
index c8e797404353..65e70f085325 100644
--- a/drivers/gpu/drm/nouveau/nv50_display.c
+++ b/drivers/gpu/drm/nouveau/nv50_display.c
@@ -65,11 +65,11 @@ struct nv50_chan {
 
 static int
 nv50_chan_create(struct nvif_device *device, struct nvif_object *disp,
-		 const u32 *oclass, u8 head, void *data, u32 size,
+		 const s32 *oclass, u8 head, void *data, u32 size,
 		 struct nv50_chan *chan)
 {
 	const u32 handle = (oclass[0] << 16) | head;
-	u32 sclass[8];
+	s32 sclass[8];
 	int ret, i;
 
 	chan->device = device;
@@ -117,7 +117,7 @@ nv50_pioc_destroy(struct nv50_pioc *pioc)
 
 static int
 nv50_pioc_create(struct nvif_device *device, struct nvif_object *disp,
-		 const u32 *oclass, u8 head, void *data, u32 size,
+		 const s32 *oclass, u8 head, void *data, u32 size,
 		 struct nv50_pioc *pioc)
 {
 	return nv50_chan_create(device, disp, oclass, head, data, size,
@@ -139,7 +139,7 @@ nv50_curs_create(struct nvif_device *device, struct nvif_object *disp,
 	struct nv50_disp_cursor_v0 args = {
 		.head = head,
 	};
-	static const u32 oclass[] = {
+	static const s32 oclass[] = {
 		GK104_DISP_CURSOR,
 		GF110_DISP_CURSOR,
 		GT214_DISP_CURSOR,
@@ -167,7 +167,7 @@ nv50_oimm_create(struct nvif_device *device, struct nvif_object *disp,
 	struct nv50_disp_cursor_v0 args = {
 		.head = head,
 	};
-	static const u32 oclass[] = {
+	static const s32 oclass[] = {
 		GK104_DISP_OVERLAY,
 		GF110_DISP_OVERLAY,
 		GT214_DISP_OVERLAY,
@@ -216,7 +216,7 @@ nv50_dmac_destroy(struct nv50_dmac *dmac, struct nvif_object *disp)
 
 static int
 nv50_dmac_create(struct nvif_device *device, struct nvif_object *disp,
-		 const u32 *oclass, u8 head, void *data, u32 size, u64 syncbuf,
+		 const s32 *oclass, u8 head, void *data, u32 size, u64 syncbuf,
 		 struct nv50_dmac *dmac)
 {
 	struct nv50_disp_core_channel_dma_v0 *args = data;
@@ -288,7 +288,7 @@ nv50_core_create(struct nvif_device *device, struct nvif_object *disp,
 	struct nv50_disp_core_channel_dma_v0 args = {
 		.pushbuf = 0xb0007d00,
 	};
-	static const u32 oclass[] = {
+	static const s32 oclass[] = {
 		GM204_DISP_CORE_CHANNEL_DMA,
 		GM107_DISP_CORE_CHANNEL_DMA,
 		GK110_DISP_CORE_CHANNEL_DMA,
@@ -324,7 +324,7 @@ nv50_base_create(struct nvif_device *device, struct nvif_object *disp,
 		.pushbuf = 0xb0007c00 | head,
 		.head = head,
 	};
-	static const u32 oclass[] = {
+	static const s32 oclass[] = {
 		GK110_DISP_BASE_CHANNEL_DMA,
 		GK104_DISP_BASE_CHANNEL_DMA,
 		GF110_DISP_BASE_CHANNEL_DMA,
@@ -355,7 +355,7 @@ nv50_ovly_create(struct nvif_device *device, struct nvif_object *disp,
 		.pushbuf = 0xb0007e00 | head,
 		.head = head,
 	};
-	static const u32 oclass[] = {
+	static const s32 oclass[] = {
 		GK104_DISP_OVERLAY_CONTROL_DMA,
 		GF110_DISP_OVERLAY_CONTROL_DMA,
 		GT214_DISP_OVERLAY_CHANNEL_DMA,
diff --git a/drivers/gpu/drm/nouveau/nvif/device.c b/drivers/gpu/drm/nouveau/nvif/device.c
index f15d51a69df2..561fb9d7b155 100644
--- a/drivers/gpu/drm/nouveau/nvif/device.c
+++ b/drivers/gpu/drm/nouveau/nvif/device.c
@@ -37,7 +37,7 @@ nvif_device_fini(struct nvif_device *device)
 }
 
 int
-nvif_device_init(struct nvif_object *parent, u32 handle, u32 oclass,
+nvif_device_init(struct nvif_object *parent, u32 handle, s32 oclass,
 		 void *data, u32 size, struct nvif_device *device)
 {
 	int ret = nvif_object_init(parent, handle, oclass, data, size,
diff --git a/drivers/gpu/drm/nouveau/nvif/object.c b/drivers/gpu/drm/nouveau/nvif/object.c
index b914e34a43c3..0c09e6433fbb 100644
--- a/drivers/gpu/drm/nouveau/nvif/object.c
+++ b/drivers/gpu/drm/nouveau/nvif/object.c
@@ -49,7 +49,7 @@ nvif_object_ioctl(struct nvif_object *object, void *data, u32 size, void **hack)
 }
 
 int
-nvif_object_sclass(struct nvif_object *object, u32 *oclass, int count)
+nvif_object_sclass(struct nvif_object *object, s32 *oclass, int count)
 {
 	struct {
 		struct nvif_ioctl_v0 ioctl;
@@ -65,7 +65,6 @@ nvif_object_sclass(struct nvif_object *object, u32 *oclass, int count)
 	args->sclass.version = 0;
 	args->sclass.count = count;
 
-	memcpy(args->sclass.oclass, oclass, size);
 	ret = nvif_object_ioctl(object, args, sizeof(*args) + size, NULL);
 	ret = ret ? ret : args->sclass.count;
 	memcpy(oclass, args->sclass.oclass, size);
@@ -203,7 +202,7 @@ nvif_object_fini(struct nvif_object *object)
 }
 
 int
-nvif_object_init(struct nvif_object *parent, u32 handle, u32 oclass,
+nvif_object_init(struct nvif_object *parent, u32 handle, s32 oclass,
 		 void *data, u32 size, struct nvif_object *object)
 {
 	struct {
diff --git a/drivers/gpu/drm/nouveau/nvkm/core/parent.c b/drivers/gpu/drm/nouveau/nvkm/core/parent.c
index 5c75c64f2270..43abd208b486 100644
--- a/drivers/gpu/drm/nouveau/nvkm/core/parent.c
+++ b/drivers/gpu/drm/nouveau/nvkm/core/parent.c
@@ -26,7 +26,7 @@
 #include <core/engine.h>
 
 int
-nvkm_parent_sclass(struct nvkm_object *parent, u16 handle,
+nvkm_parent_sclass(struct nvkm_object *parent, s32 handle,
 		   struct nvkm_object **pengine,
 		   struct nvkm_oclass **poclass)
 {
@@ -66,7 +66,7 @@ nvkm_parent_sclass(struct nvkm_object *parent, u16 handle,
 }
 
 int
-nvkm_parent_lclass(struct nvkm_object *parent, u32 *lclass, int size)
+nvkm_parent_lclass(struct nvkm_object *parent, s32 *lclass, int size)
 {
 	struct nvkm_oclass *sclass, *oclass;
 	struct nvkm_engine *engine;