drm/gem: Take reservation lock for vmap/vunmap operations

The new common dma-buf locking convention will require buffer importers
to hold the reservation lock around mapping operations. Make DRM GEM core
to take the lock around the vmapping operations and update DRM drivers to
use the locked functions for the case where DRM core now holds the lock.
This patch prepares DRM core and drivers to the common dynamic dma-buf
locking convention.

Acked-by: Christian König <[e-mail]>
Signed-off-by: Dmitry Osipenko <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/drm_client.c

···
 	 * fd_install step out of the driver backend hooks, to make that
 	 * final step optional for internal users.
 	 */
-	ret = drm_gem_vmap(buffer->gem, map);
+	ret = drm_gem_vmap_unlocked(buffer->gem, map);
 	if (ret)
 		return ret;
 
···
 {
 	struct iosys_map *map = &buffer->map;
 
-	drm_gem_vunmap(buffer->gem, map);
+	drm_gem_vunmap_unlocked(buffer->gem, map);
 }
 EXPORT_SYMBOL(drm_client_buffer_vunmap);
 

drivers/gpu/drm/drm_gem.c

···
 {
 	int ret;
 
+	dma_resv_assert_held(obj->resv);
+
 	if (!obj->funcs->vmap)
 		return -EOPNOTSUPP;
 
···
 
 void drm_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map)
 {
+	dma_resv_assert_held(obj->resv);
+
 	if (iosys_map_is_null(map))
 		return;
 
···
 	iosys_map_clear(map);
 }
 EXPORT_SYMBOL(drm_gem_vunmap);
+
+int drm_gem_vmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map)
+{
+	int ret;
+
+	dma_resv_lock(obj->resv, NULL);
+	ret = drm_gem_vmap(obj, map);
+	dma_resv_unlock(obj->resv);
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_gem_vmap_unlocked);
+
+void drm_gem_vunmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map)
+{
+	dma_resv_lock(obj->resv, NULL);
+	drm_gem_vunmap(obj, map);
+	dma_resv_unlock(obj->resv);
+}
+EXPORT_SYMBOL(drm_gem_vunmap_unlocked);
 
 /**
  * drm_gem_lock_reservations - Sets up the ww context and acquires

drivers/gpu/drm/drm_gem_dma_helper.c

···
 
 	if (gem_obj->import_attach) {
 		if (dma_obj->vaddr)
-			dma_buf_vunmap(gem_obj->import_attach->dmabuf, &map);
+			dma_buf_vunmap_unlocked(gem_obj->import_attach->dmabuf, &map);
 		drm_prime_gem_destroy(gem_obj, dma_obj->sgt);
 	} else if (dma_obj->vaddr) {
 		if (dma_obj->map_noncoherent)
···
 	struct iosys_map map;
 	int ret;
 
-	ret = dma_buf_vmap(attach->dmabuf, &map);
+	ret = dma_buf_vmap_unlocked(attach->dmabuf, &map);
 	if (ret) {
 		DRM_ERROR("Failed to vmap PRIME buffer\n");
 		return ERR_PTR(ret);
···
 
 	obj = drm_gem_dma_prime_import_sg_table(dev, attach, sgt);
 	if (IS_ERR(obj)) {
-		dma_buf_vunmap(attach->dmabuf, &map);
+		dma_buf_vunmap_unlocked(attach->dmabuf, &map);
 		return obj;
 	}
 

drivers/gpu/drm/drm_gem_framebuffer_helper.c

···
 			ret = -EINVAL;
 			goto err_drm_gem_vunmap;
 		}
-		ret = drm_gem_vmap(obj, &map[i]);
+		ret = drm_gem_vmap_unlocked(obj, &map[i]);
 		if (ret)
 			goto err_drm_gem_vunmap;
 	}
···
 		obj = drm_gem_fb_get_obj(fb, i);
 		if (!obj)
 			continue;
-		drm_gem_vunmap(obj, &map[i]);
+		drm_gem_vunmap_unlocked(obj, &map[i]);
 	}
 	return ret;
 }
···
 			continue;
 		if (iosys_map_is_null(&map[i]))
 			continue;
-		drm_gem_vunmap(obj, &map[i]);
+		drm_gem_vunmap_unlocked(obj, &map[i]);
 	}
 }
 EXPORT_SYMBOL(drm_gem_fb_vunmap);

drivers/gpu/drm/drm_gem_ttm_helper.c

···
 		     struct iosys_map *map)
 {
 	struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
-	int ret;
 
-	dma_resv_lock(gem->resv, NULL);
-	ret = ttm_bo_vmap(bo, map);
-	dma_resv_unlock(gem->resv);
-
-	return ret;
+	return ttm_bo_vmap(bo, map);
 }
 EXPORT_SYMBOL(drm_gem_ttm_vmap);
 
···
 {
 	struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
 
-	dma_resv_lock(gem->resv, NULL);
 	ttm_bo_vunmap(bo, map);
-	dma_resv_unlock(gem->resv);
 }
 EXPORT_SYMBOL(drm_gem_ttm_vunmap);
 

drivers/gpu/drm/lima/lima_sched.c

···
 		} else {
 			buffer_chunk->size = lima_bo_size(bo);
 
-			ret = drm_gem_shmem_vmap(&bo->base, &map);
+			ret = drm_gem_vmap_unlocked(&bo->base.base, &map);
 			if (ret) {
 				kvfree(et);
 				goto out;
···
 
 			memcpy(buffer_chunk + 1, map.vaddr, buffer_chunk->size);
 
-			drm_gem_shmem_vunmap(&bo->base, &map);
+			drm_gem_vunmap_unlocked(&bo->base.base, &map);
 		}
 
 		buffer_chunk = (void *)(buffer_chunk + 1) + buffer_chunk->size;

drivers/gpu/drm/panfrost/panfrost_dump.c

···
 			goto dump_header;
 		}
 
-		ret = drm_gem_shmem_vmap(&bo->base, &map);
+		ret = drm_gem_vmap_unlocked(&bo->base.base, &map);
 		if (ret) {
 			dev_err(pfdev->dev, "Panfrost Dump: couldn't map Buffer Object\n");
 			iter.hdr->bomap.valid = 0;
···
 		vaddr = map.vaddr;
 		memcpy(iter.data, vaddr, bo->base.base.size);
 
-		drm_gem_shmem_vunmap(&bo->base, &map);
+		drm_gem_vunmap_unlocked(&bo->base.base, &map);
 
 		iter.hdr->bomap.valid = cpu_to_le32(1);
 

drivers/gpu/drm/panfrost/panfrost_perfcnt.c

···
 		goto err_close_bo;
 	}
 
-	ret = drm_gem_shmem_vmap(bo, &map);
+	ret = drm_gem_vmap_unlocked(&bo->base, &map);
 	if (ret)
 		goto err_put_mapping;
 	perfcnt->buf = map.vaddr;
···
 	return 0;
 
 err_vunmap:
-	drm_gem_shmem_vunmap(bo, &map);
+	drm_gem_vunmap_unlocked(&bo->base, &map);
 err_put_mapping:
 	panfrost_gem_mapping_put(perfcnt->mapping);
 err_close_bo:
···
 		  GPU_PERFCNT_CFG_MODE(GPU_PERFCNT_CFG_MODE_OFF));
 
 	perfcnt->user = NULL;
-	drm_gem_shmem_vunmap(&perfcnt->mapping->obj->base, &map);
+	drm_gem_vunmap_unlocked(&perfcnt->mapping->obj->base.base, &map);
 	perfcnt->buf = NULL;
 	panfrost_gem_close(&perfcnt->mapping->obj->base.base, file_priv);
 	panfrost_mmu_as_put(pfdev, perfcnt->mapping->mmu);

drivers/gpu/drm/qxl/qxl_object.c

···
 		bo->map_count++;
 		goto out;
 	}
-	r = ttm_bo_vmap(&bo->tbo, &bo->map);
+
+	r = __qxl_bo_pin(bo);
 	if (r)
 		return r;
+
+	r = ttm_bo_vmap(&bo->tbo, &bo->map);
+	if (r) {
+		__qxl_bo_unpin(bo);
+		return r;
+	}
 	bo->map_count = 1;
 
 	/* TODO: Remove kptr in favor of map everywhere. */
···
 	r = qxl_bo_reserve(bo);
 	if (r)
 		return r;
-
-	r = __qxl_bo_pin(bo);
-	if (r) {
-		qxl_bo_unreserve(bo);
-		return r;
-	}
 
 	r = qxl_bo_vmap_locked(bo, map);
 	qxl_bo_unreserve(bo);
···
 		return;
 	bo->kptr = NULL;
 	ttm_bo_vunmap(&bo->tbo, &bo->map);
+	__qxl_bo_unpin(bo);
 }
 
 int qxl_bo_vunmap(struct qxl_bo *bo)
···
 		return r;
 
 	qxl_bo_vunmap_locked(bo);
-	__qxl_bo_unpin(bo);
 	qxl_bo_unreserve(bo);
 	return 0;
 }

drivers/gpu/drm/qxl/qxl_prime.c

···
 	struct qxl_bo *bo = gem_to_qxl_bo(obj);
 	int ret;
 
-	ret = qxl_bo_vmap(bo, map);
+	ret = qxl_bo_vmap_locked(bo, map);
 	if (ret < 0)
 		return ret;
 
···
 {
 	struct qxl_bo *bo = gem_to_qxl_bo(obj);
 
-	qxl_bo_vunmap(bo);
+	qxl_bo_vunmap_locked(bo);
 }

include/drm/drm_gem.h

···
 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
 		bool dirty, bool accessed);
 
+int drm_gem_vmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map);
+void drm_gem_vunmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map);
+
 int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles,
 			   int count, struct drm_gem_object ***objs_out);
 struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle);