drm/nouveau: use GEM references instead of TTMs

TTM wants to get rid of the duplicate refcounting of the embedded GEM
object and its own reference count.

Hence, use of GEM object references where possible.

Also get rid of nouveau_bo_ref() and replace it with nouveau_bo_fini(),
which drops the initial reference we get from initializing a ttm_bo.
Reviewed-by: Ben Skeggs <bskeggs@nvidia.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240718165959.3983-4-dakr@kernel.org

drivers/gpu/drm/nouveau/dispnv04/crtc.c

@@ -617,9 +617,15 @@ nv_crtc_swap_fbs(struct drm_crtc *crtc, struct drm_framebuffer *old_fb)
 
 	ret = nouveau_bo_pin(nvbo, NOUVEAU_GEM_DOMAIN_VRAM, false);
 	if (ret == 0) {
-		if (disp->image[nv_crtc->index])
-			nouveau_bo_unpin(disp->image[nv_crtc->index]);
-		nouveau_bo_ref(nvbo, &disp->image[nv_crtc->index]);
+		if (disp->image[nv_crtc->index]) {
+			struct nouveau_bo *bo = disp->image[nv_crtc->index];
+
+			nouveau_bo_unpin(bo);
+			drm_gem_object_put(&bo->bo.base);
+		}
+
+		drm_gem_object_get(&nvbo->bo.base);
+		disp->image[nv_crtc->index] = nvbo;
 	}
 
 	return ret;
@@ -754,13 +760,17 @@ static void nv_crtc_destroy(struct drm_crtc *crtc)
 
 	drm_crtc_cleanup(crtc);
 
-	if (disp->image[nv_crtc->index])
-		nouveau_bo_unpin(disp->image[nv_crtc->index]);
-	nouveau_bo_ref(NULL, &disp->image[nv_crtc->index]);
+	if (disp->image[nv_crtc->index]) {
+		struct nouveau_bo *bo = disp->image[nv_crtc->index];
+
+		nouveau_bo_unpin(bo);
+		drm_gem_object_put(&bo->bo.base);
+		disp->image[nv_crtc->index] = NULL;
+	}
 
 	nouveau_bo_unmap(nv_crtc->cursor.nvbo);
 	nouveau_bo_unpin(nv_crtc->cursor.nvbo);
-	nouveau_bo_ref(NULL, &nv_crtc->cursor.nvbo);
+	nouveau_bo_fini(nv_crtc->cursor.nvbo);
 	nvif_event_dtor(&nv_crtc->vblank);
 	nvif_head_dtor(&nv_crtc->head);
 	kfree(nv_crtc);
@@ -794,9 +804,14 @@ nv_crtc_disable(struct drm_crtc *crtc)
 {
 	struct nv04_display *disp = nv04_display(crtc->dev);
 	struct nouveau_crtc *nv_crtc = nouveau_crtc(crtc);
-	if (disp->image[nv_crtc->index])
-		nouveau_bo_unpin(disp->image[nv_crtc->index]);
-	nouveau_bo_ref(NULL, &disp->image[nv_crtc->index]);
+
+	if (disp->image[nv_crtc->index]) {
+		struct nouveau_bo *bo = disp->image[nv_crtc->index];
+
+		nouveau_bo_unpin(bo);
+		drm_gem_object_put(&bo->bo.base);
+		disp->image[nv_crtc->index] = NULL;
+	}
 }
 
 static int
@@ -1210,7 +1225,11 @@ nv04_crtc_page_flip(struct drm_crtc *crtc, struct drm_framebuffer *fb,
 		PUSH_NVSQ(push, NV05F, 0x0130, 0);
 	}
 
-	nouveau_bo_ref(new_bo, &dispnv04->image[head]);
+	if (dispnv04->image[head])
+		drm_gem_object_put(&dispnv04->image[head]->bo.base);
+
+	drm_gem_object_get(&new_bo->bo.base);
+	dispnv04->image[head] = new_bo;
 
 	ret = nv04_page_flip_emit(chan, old_bo, new_bo, s, &fence);
 	if (ret)
@@ -1329,7 +1348,7 @@ nv04_crtc_create(struct drm_device *dev, int crtc_num)
 				nouveau_bo_unpin(nv_crtc->cursor.nvbo);
 		}
 		if (ret)
-			nouveau_bo_ref(NULL, &nv_crtc->cursor.nvbo);
+			nouveau_bo_fini(nv_crtc->cursor.nvbo);
 	}
 
 	nv04_cursor_init(nv_crtc);

drivers/gpu/drm/nouveau/dispnv50/disp.c

@@ -2819,7 +2819,7 @@ nv50_display_destroy(struct drm_device *dev)
 	nouveau_bo_unmap(disp->sync);
 	if (disp->sync)
 		nouveau_bo_unpin(disp->sync);
-	nouveau_bo_ref(NULL, &disp->sync);
+	nouveau_bo_fini(disp->sync);
 
 	nouveau_display(dev)->priv = NULL;
 	kfree(disp);
@@ -2862,7 +2862,7 @@ nv50_display_create(struct drm_device *dev)
 				nouveau_bo_unpin(disp->sync);
 		}
 		if (ret)
-			nouveau_bo_ref(NULL, &disp->sync);
+			nouveau_bo_fini(disp->sync);
 	}
 
 	if (ret)

drivers/gpu/drm/nouveau/nouveau_bo.h

@@ -53,25 +53,10 @@ nouveau_bo(struct ttm_buffer_object *bo)
 	return container_of(bo, struct nouveau_bo, bo);
 }
 
-static inline int
-nouveau_bo_ref(struct nouveau_bo *ref, struct nouveau_bo **pnvbo)
+static inline void
+nouveau_bo_fini(struct nouveau_bo *bo)
 {
-	struct nouveau_bo *prev;
-
-	if (!pnvbo)
-		return -EINVAL;
-	prev = *pnvbo;
-
-	if (ref) {
-		ttm_bo_get(&ref->bo);
-		*pnvbo = nouveau_bo(&ref->bo);
-	} else {
-		*pnvbo = NULL;
-	}
-	if (prev)
-		ttm_bo_put(&prev->bo);
-
-	return 0;
+	ttm_bo_put(&bo->bo);
 }
 
 extern struct ttm_device_funcs nouveau_bo_driver;

drivers/gpu/drm/nouveau/nouveau_chan.c

@@ -110,7 +110,7 @@ nouveau_channel_del(struct nouveau_channel **pchan)
 		nouveau_bo_unmap(chan->push.buffer);
 		if (chan->push.buffer && chan->push.buffer->bo.pin_count)
 			nouveau_bo_unpin(chan->push.buffer);
-		nouveau_bo_ref(NULL, &chan->push.buffer);
+		nouveau_bo_fini(chan->push.buffer);
 		kfree(chan);
 	}
 	*pchan = NULL;

drivers/gpu/drm/nouveau/nouveau_dmem.c

@@ -294,7 +294,7 @@ nouveau_dmem_chunk_alloc(struct nouveau_drm *drm, struct page **ppage)
 out_bo_unpin:
 	nouveau_bo_unpin(chunk->bo);
 out_bo_free:
-	nouveau_bo_ref(NULL, &chunk->bo);
+	nouveau_bo_fini(chunk->bo);
 out_release:
 	release_mem_region(chunk->pagemap.range.start, range_len(&chunk->pagemap.range));
 out_free:
@@ -426,7 +426,7 @@ nouveau_dmem_fini(struct nouveau_drm *drm)
 	list_for_each_entry_safe(chunk, tmp, &drm->dmem->chunks, list) {
 		nouveau_dmem_evict_chunk(chunk);
 		nouveau_bo_unpin(chunk->bo);
-		nouveau_bo_ref(NULL, &chunk->bo);
+		nouveau_bo_fini(chunk->bo);
 		WARN_ON(chunk->callocated);
 		list_del(&chunk->list);
 		memunmap_pages(&chunk->pagemap);

drivers/gpu/drm/nouveau/nv10_fence.c

@@ -88,7 +88,7 @@ nv10_fence_destroy(struct nouveau_drm *drm)
 	nouveau_bo_unmap(priv->bo);
 	if (priv->bo)
 		nouveau_bo_unpin(priv->bo);
-	nouveau_bo_ref(NULL, &priv->bo);
+	nouveau_bo_fini(priv->bo);
 	drm->fence = NULL;
 	kfree(priv);
 }

drivers/gpu/drm/nouveau/nv17_fence.c

@@ -141,7 +141,7 @@ nv17_fence_create(struct nouveau_drm *drm)
 				nouveau_bo_unpin(priv->bo);
 		}
 		if (ret)
-			nouveau_bo_ref(NULL, &priv->bo);
+			nouveau_bo_fini(priv->bo);
 	}
 
 	if (ret) {

drivers/gpu/drm/nouveau/nv50_fence.c

@@ -92,7 +92,7 @@ nv50_fence_create(struct nouveau_drm *drm)
 				nouveau_bo_unpin(priv->bo);
 		}
 		if (ret)
-			nouveau_bo_ref(NULL, &priv->bo);
+			nouveau_bo_fini(priv->bo);
 	}
 
 	if (ret) {

drivers/gpu/drm/nouveau/nv84_fence.c

@@ -188,7 +188,7 @@ nv84_fence_destroy(struct nouveau_drm *drm)
 	nouveau_bo_unmap(priv->bo);
 	if (priv->bo)
 		nouveau_bo_unpin(priv->bo);
-	nouveau_bo_ref(NULL, &priv->bo);
+	nouveau_bo_fini(priv->bo);
 	drm->fence = NULL;
 	kfree(priv);
 }
@@ -232,7 +232,7 @@ nv84_fence_create(struct nouveau_drm *drm)
 				nouveau_bo_unpin(priv->bo);
 		}
 		if (ret)
-			nouveau_bo_ref(NULL, &priv->bo);
+			nouveau_bo_fini(priv->bo);
 	}
 
 	if (ret)