drm/nouveau/nvif: simplify and tidy library interfaces

A variety of tweaks to the NVIF library interfaces, mostly ripping out
things that turned out to be not so useful.

- Removed refcounting from nvif_object, callers are expected to not be
  stupid instead.
- nvif_client is directly reachable from anything derived from nvif_object,
  removing the need for heuristics to locate it
- _new() versions of interfaces, that allocate memory for the object
  they construct, have been removed.  The vast majority of callers used
  the embedded _init() interfaces.
- No longer storing constructor arguments (and the data returned from
  nvkm) inside nvif_object, it's more or less unused and just wastes
  memory.

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

drivers/gpu/drm/nouveau/nouveau_dma.c

@@ -52,9 +52,9 @@ READ_GET(struct nouveau_channel *chan, uint64_t *prev_get, int *timeout)
 {
 	uint64_t val;
 
-	val = nvif_rd32(chan, chan->user_get);
+	val = nvif_rd32(&chan->user, chan->user_get);
         if (chan->user_get_hi)
-                val |= (uint64_t)nvif_rd32(chan, chan->user_get_hi) << 32;
+                val |= (uint64_t)nvif_rd32(&chan->user, chan->user_get_hi) << 32;
 
 	/* reset counter as long as GET is still advancing, this is
 	 * to avoid misdetecting a GPU lockup if the GPU happens to
@@ -82,7 +82,7 @@ void
 nv50_dma_push(struct nouveau_channel *chan, struct nouveau_bo *bo,
 	      int delta, int length)
 {
-	struct nouveau_cli *cli = (void *)nvif_client(&chan->device->base);
+	struct nouveau_cli *cli = (void *)chan->user.client;
 	struct nouveau_bo *pb = chan->push.buffer;
 	struct nvkm_vma *vma;
 	int ip = (chan->dma.ib_put * 2) + chan->dma.ib_base;
@@ -103,7 +103,7 @@ nv50_dma_push(struct nouveau_channel *chan, struct nouveau_bo *bo,
 	/* Flush writes. */
 	nouveau_bo_rd32(pb, 0);
 
-	nvif_wr32(chan, 0x8c, chan->dma.ib_put);
+	nvif_wr32(&chan->user, 0x8c, chan->dma.ib_put);
 	chan->dma.ib_free--;
 }
 
@@ -113,7 +113,7 @@ nv50_dma_push_wait(struct nouveau_channel *chan, int count)
 	uint32_t cnt = 0, prev_get = 0;
 
 	while (chan->dma.ib_free < count) {
-		uint32_t get = nvif_rd32(chan, 0x88);
+		uint32_t get = nvif_rd32(&chan->user, 0x88);
 		if (get != prev_get) {
 			prev_get = get;
 			cnt = 0;