drm/i915: Prepare to dynamic dma-buf locking specification

Prepare i915 driver to the common dynamic dma-buf locking convention
by starting to use the unlocked versions of dma-buf API functions
and handling cases where importer now holds the reservation lock.
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221017172229.42269-7-dmitry.osipenko@collabora.com

drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c

@@ -72,7 +72,7 @@ static int i915_gem_dmabuf_vmap(struct dma_buf *dma_buf,
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 	void *vaddr;
 
-	vaddr = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WB);
+	vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
 	if (IS_ERR(vaddr))
 		return PTR_ERR(vaddr);
 

drivers/gpu/drm/i915/gem/i915_gem_object.c

@@ -290,7 +290,21 @@ void __i915_gem_object_pages_fini(struct drm_i915_gem_object *obj)
 	__i915_gem_object_free_mmaps(obj);
 
 	atomic_set(&obj->mm.pages_pin_count, 0);
+
+	/*
+	 * dma_buf_unmap_attachment() requires reservation to be
+	 * locked. The imported GEM shouldn't share reservation lock
+	 * and ttm_bo_cleanup_memtype_use() shouldn't be invoked for
+	 * dma-buf, so it's safe to take the lock.
+	 */
+	if (obj->base.import_attach)
+		i915_gem_object_lock(obj, NULL);
+
 	__i915_gem_object_put_pages(obj);
+
+	if (obj->base.import_attach)
+		i915_gem_object_unlock(obj);
+
 	GEM_BUG_ON(i915_gem_object_has_pages(obj));
 }
 

drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c

@@ -213,7 +213,7 @@ static int igt_dmabuf_import_same_driver(struct drm_i915_private *i915,
 		goto out_import;
 	}
 
-	st = dma_buf_map_attachment(import_attach, DMA_BIDIRECTIONAL);
+	st = dma_buf_map_attachment_unlocked(import_attach, DMA_BIDIRECTIONAL);
 	if (IS_ERR(st)) {
 		err = PTR_ERR(st);
 		goto out_detach;
@@ -226,7 +226,7 @@ static int igt_dmabuf_import_same_driver(struct drm_i915_private *i915,
 		timeout = -ETIME;
 	}
 	err = timeout > 0 ? 0 : timeout;
-	dma_buf_unmap_attachment(import_attach, st, DMA_BIDIRECTIONAL);
+	dma_buf_unmap_attachment_unlocked(import_attach, st, DMA_BIDIRECTIONAL);
 out_detach:
 	dma_buf_detach(dmabuf, import_attach);
 out_import:
@@ -296,7 +296,7 @@ static int igt_dmabuf_import(void *arg)
 		goto out_obj;
 	}
 
-	err = dma_buf_vmap(dmabuf, &map);
+	err = dma_buf_vmap_unlocked(dmabuf, &map);
 	dma_map = err ? NULL : map.vaddr;
 	if (!dma_map) {
 		pr_err("dma_buf_vmap failed\n");
@@ -337,7 +337,7 @@ static int igt_dmabuf_import(void *arg)
 
 	err = 0;
 out_dma_map:
-	dma_buf_vunmap(dmabuf, &map);
+	dma_buf_vunmap_unlocked(dmabuf, &map);
 out_obj:
 	i915_gem_object_put(obj);
 out_dmabuf:
@@ -358,7 +358,7 @@ static int igt_dmabuf_import_ownership(void *arg)
 	if (IS_ERR(dmabuf))
 		return PTR_ERR(dmabuf);
 
-	err = dma_buf_vmap(dmabuf, &map);
+	err = dma_buf_vmap_unlocked(dmabuf, &map);
 	ptr = err ? NULL : map.vaddr;
 	if (!ptr) {
 		pr_err("dma_buf_vmap failed\n");
@@ -367,7 +367,7 @@ static int igt_dmabuf_import_ownership(void *arg)
 	}
 
 	memset(ptr, 0xc5, PAGE_SIZE);
-	dma_buf_vunmap(dmabuf, &map);
+	dma_buf_vunmap_unlocked(dmabuf, &map);
 
 	obj = to_intel_bo(i915_gem_prime_import(&i915->drm, dmabuf));
 	if (IS_ERR(obj)) {
@@ -418,7 +418,7 @@ static int igt_dmabuf_export_vmap(void *arg)
 	}
 	i915_gem_object_put(obj);
 
-	err = dma_buf_vmap(dmabuf, &map);
+	err = dma_buf_vmap_unlocked(dmabuf, &map);
 	ptr = err ? NULL : map.vaddr;
 	if (!ptr) {
 		pr_err("dma_buf_vmap failed\n");
@@ -435,7 +435,7 @@ static int igt_dmabuf_export_vmap(void *arg)
 	memset(ptr, 0xc5, dmabuf->size);
 
 	err = 0;
-	dma_buf_vunmap(dmabuf, &map);
+	dma_buf_vunmap_unlocked(dmabuf, &map);
 out:
 	dma_buf_put(dmabuf);
 	return err;