drm: Introduce drm_gem_object_{get,put}()

For consistency with other reference counting APIs in the kernel, add drm_gem_object_get() and drm_gem_object_put(), as well as an unlocked variant of the latter, to reference count GEM buffer objects. Compatibility aliases are added to keep existing code working. To help speed up the transition, all the instances of the old functions in the DRM core are already replaced in this commit. The existing semantic patch for the DRM subsystem-wide conversion is extended to account for these new helpers. Reviewed-by: Sean Paul <[email protected]> Acked-by: Christian König <[email protected]> Signed-off-by: Thierry Reding <[email protected]> Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]
josf · Feb 28, 2017 · e6b6271 · e6b6271
1 parent a4a69da
commit e6b6271
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Showing 7 changed files with 130 additions and 64 deletions.
diff --git a/Documentation/gpu/drm-mm.rst b/Documentation/gpu/drm-mm.rst
@@ -183,14 +183,12 @@ GEM Objects Lifetime
 --------------------
 
 All GEM objects are reference-counted by the GEM core. References can be
-acquired and release by :c:func:`calling
-drm_gem_object_reference()` and
-:c:func:`drm_gem_object_unreference()` respectively. The caller
-must hold the :c:type:`struct drm_device <drm_device>`
-struct_mutex lock when calling
-:c:func:`drm_gem_object_reference()`. As a convenience, GEM
-provides :c:func:`drm_gem_object_unreference_unlocked()`
-functions that can be called without holding the lock.
+acquired and release by :c:func:`calling drm_gem_object_get()` and
+:c:func:`drm_gem_object_put()` respectively. The caller must hold the
+:c:type:`struct drm_device <drm_device>` struct_mutex lock when calling
+:c:func:`drm_gem_object_get()`. As a convenience, GEM provides
+:c:func:`drm_gem_object_put_unlocked()` functions that can be called without
+holding the lock.
 
 When the last reference to a GEM object is released the GEM core calls
 the :c:type:`struct drm_driver <drm_driver>` gem_free_object

diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
@@ -102,7 +102,7 @@ void drm_fb_cma_destroy(struct drm_framebuffer *fb)
 
 	for (i = 0; i < 4; i++) {
 		if (fb_cma->obj[i])
-			drm_gem_object_unreference_unlocked(&fb_cma->obj[i]->base);
+			drm_gem_object_put_unlocked(&fb_cma->obj[i]->base);
 	}
 
 	drm_framebuffer_cleanup(fb);
@@ -190,32 +190,32 @@ struct drm_framebuffer *drm_fb_cma_create_with_funcs(struct drm_device *dev,
 		if (!obj) {
 			dev_err(dev->dev, "Failed to lookup GEM object\n");
 			ret = -ENXIO;
-			goto err_gem_object_unreference;
+			goto err_gem_object_put;
 		}
 
 		min_size = (height - 1) * mode_cmd->pitches[i]
 			 + width * info->cpp[i]
 			 + mode_cmd->offsets[i];
 
 		if (obj->size < min_size) {
-			drm_gem_object_unreference_unlocked(obj);
+			drm_gem_object_put_unlocked(obj);
 			ret = -EINVAL;
-			goto err_gem_object_unreference;
+			goto err_gem_object_put;
 		}
 		objs[i] = to_drm_gem_cma_obj(obj);
 	}
 
 	fb_cma = drm_fb_cma_alloc(dev, mode_cmd, objs, i, funcs);
 	if (IS_ERR(fb_cma)) {
 		ret = PTR_ERR(fb_cma);
-		goto err_gem_object_unreference;
+		goto err_gem_object_put;
 	}
 
 	return &fb_cma->fb;
 
-err_gem_object_unreference:
+err_gem_object_put:
 	for (i--; i >= 0; i--)
-		drm_gem_object_unreference_unlocked(&objs[i]->base);
+		drm_gem_object_put_unlocked(&objs[i]->base);
 	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(drm_fb_cma_create_with_funcs);
@@ -477,7 +477,7 @@ drm_fbdev_cma_create(struct drm_fb_helper *helper,
 err_fb_info_destroy:
 	drm_fb_helper_fini(helper);
 err_gem_free_object:
-	drm_gem_object_unreference_unlocked(&obj->base);
+	drm_gem_object_put_unlocked(&obj->base);
 	return ret;
 }
 

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
@@ -218,7 +218,7 @@ static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj)
 }
 
 static void
-drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj)
+drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj)
 {
 	struct drm_device *dev = obj->dev;
 	bool final = false;
@@ -241,7 +241,7 @@ drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj)
 	mutex_unlock(&dev->object_name_lock);
 
 	if (final)
-		drm_gem_object_unreference_unlocked(obj);
+		drm_gem_object_put_unlocked(obj);
 }
 
 /*
@@ -262,7 +262,7 @@ drm_gem_object_release_handle(int id, void *ptr, void *data)
 	if (dev->driver->gem_close_object)
 		dev->driver->gem_close_object(obj, file_priv);
 
-	drm_gem_object_handle_unreference_unlocked(obj);
+	drm_gem_object_handle_put_unlocked(obj);
 
 	return 0;
 }
@@ -352,7 +352,7 @@ drm_gem_handle_create_tail(struct drm_file *file_priv,
 
 	WARN_ON(!mutex_is_locked(&dev->object_name_lock));
 	if (obj->handle_count++ == 0)
-		drm_gem_object_reference(obj);
+		drm_gem_object_get(obj);
 
 	/*
 	 * Get the user-visible handle using idr.  Preload and perform
@@ -392,7 +392,7 @@ drm_gem_handle_create_tail(struct drm_file *file_priv,
 	idr_remove(&file_priv->object_idr, handle);
 	spin_unlock(&file_priv->table_lock);
 err_unref:
-	drm_gem_object_handle_unreference_unlocked(obj);
+	drm_gem_object_handle_put_unlocked(obj);
 	return ret;
 }
 
@@ -606,7 +606,7 @@ drm_gem_object_lookup(struct drm_file *filp, u32 handle)
 	/* Check if we currently have a reference on the object */
 	obj = idr_find(&filp->object_idr, handle);
 	if (obj)
-		drm_gem_object_reference(obj);
+		drm_gem_object_get(obj);
 
 	spin_unlock(&filp->table_lock);
 
@@ -683,7 +683,7 @@ drm_gem_flink_ioctl(struct drm_device *dev, void *data,
 
 err:
 	mutex_unlock(&dev->object_name_lock);
-	drm_gem_object_unreference_unlocked(obj);
+	drm_gem_object_put_unlocked(obj);
 	return ret;
 }
 
@@ -713,15 +713,15 @@ drm_gem_open_ioctl(struct drm_device *dev, void *data,
 	mutex_lock(&dev->object_name_lock);
 	obj = idr_find(&dev->object_name_idr, (int) args->name);
 	if (obj) {
-		drm_gem_object_reference(obj);
+		drm_gem_object_get(obj);
 	} else {
 		mutex_unlock(&dev->object_name_lock);
 		return -ENOENT;
 	}
 
 	/* drm_gem_handle_create_tail unlocks dev->object_name_lock. */
 	ret = drm_gem_handle_create_tail(file_priv, obj, &handle);
-	drm_gem_object_unreference_unlocked(obj);
+	drm_gem_object_put_unlocked(obj);
 	if (ret)
 		return ret;
 
@@ -809,16 +809,16 @@ drm_gem_object_free(struct kref *kref)
 EXPORT_SYMBOL(drm_gem_object_free);
 
 /**
- * drm_gem_object_unreference_unlocked - release a GEM BO reference
+ * drm_gem_object_put_unlocked - drop a GEM buffer object reference
  * @obj: GEM buffer object
  *
  * This releases a reference to @obj. Callers must not hold the
  * &drm_device.struct_mutex lock when calling this function.
  *
- * See also __drm_gem_object_unreference().
+ * See also __drm_gem_object_put().
  */
 void
-drm_gem_object_unreference_unlocked(struct drm_gem_object *obj)
+drm_gem_object_put_unlocked(struct drm_gem_object *obj)
 {
 	struct drm_device *dev;
 
@@ -834,29 +834,29 @@ drm_gem_object_unreference_unlocked(struct drm_gem_object *obj)
 				&dev->struct_mutex))
 		mutex_unlock(&dev->struct_mutex);
 }
-EXPORT_SYMBOL(drm_gem_object_unreference_unlocked);
+EXPORT_SYMBOL(drm_gem_object_put_unlocked);
 
 /**
- * drm_gem_object_unreference - release a GEM BO reference
+ * drm_gem_object_put - release a GEM buffer object reference
  * @obj: GEM buffer object
  *
  * This releases a reference to @obj. Callers must hold the
  * &drm_device.struct_mutex lock when calling this function, even when the
  * driver doesn't use &drm_device.struct_mutex for anything.
  *
  * For drivers not encumbered with legacy locking use
- * drm_gem_object_unreference_unlocked() instead.
+ * drm_gem_object_put_unlocked() instead.
  */
 void
-drm_gem_object_unreference(struct drm_gem_object *obj)
+drm_gem_object_put(struct drm_gem_object *obj)
 {
 	if (obj) {
 		WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
 
 		kref_put(&obj->refcount, drm_gem_object_free);
 	}
 }
-EXPORT_SYMBOL(drm_gem_object_unreference);
+EXPORT_SYMBOL(drm_gem_object_put);
 
 /**
  * drm_gem_vm_open - vma->ops->open implementation for GEM
@@ -869,7 +869,7 @@ void drm_gem_vm_open(struct vm_area_struct *vma)
 {
 	struct drm_gem_object *obj = vma->vm_private_data;
 
-	drm_gem_object_reference(obj);
+	drm_gem_object_get(obj);
 }
 EXPORT_SYMBOL(drm_gem_vm_open);
 
@@ -884,7 +884,7 @@ void drm_gem_vm_close(struct vm_area_struct *vma)
 {
 	struct drm_gem_object *obj = vma->vm_private_data;
 
-	drm_gem_object_unreference_unlocked(obj);
+	drm_gem_object_put_unlocked(obj);
 }
 EXPORT_SYMBOL(drm_gem_vm_close);
 
@@ -935,7 +935,7 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
 	 * (which should happen whether the vma was created by this call, or
 	 * by a vm_open due to mremap or partial unmap or whatever).
 	 */
-	drm_gem_object_reference(obj);
+	drm_gem_object_get(obj);
 
 	return 0;
 }
@@ -992,14 +992,14 @@ int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 		return -EINVAL;
 
 	if (!drm_vma_node_is_allowed(node, priv)) {
-		drm_gem_object_unreference_unlocked(obj);
+		drm_gem_object_put_unlocked(obj);
 		return -EACCES;
 	}
 
 	ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT,
 			       vma);
 
-	drm_gem_object_unreference_unlocked(obj);
+	drm_gem_object_put_unlocked(obj);
 
 	return ret;
 }

diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -121,7 +121,7 @@ struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
 	return cma_obj;
 
 error:
-	drm_gem_object_unreference_unlocked(&cma_obj->base);
+	drm_gem_object_put_unlocked(&cma_obj->base);
 	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(drm_gem_cma_create);
@@ -163,7 +163,7 @@ drm_gem_cma_create_with_handle(struct drm_file *file_priv,
 	 */
 	ret = drm_gem_handle_create(file_priv, gem_obj, handle);
 	/* drop reference from allocate - handle holds it now. */
-	drm_gem_object_unreference_unlocked(gem_obj);
+	drm_gem_object_put_unlocked(gem_obj);
 	if (ret)
 		return ERR_PTR(ret);
 
@@ -293,7 +293,7 @@ int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv,
 
 	*offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
 
-	drm_gem_object_unreference_unlocked(gem_obj);
+	drm_gem_object_put_unlocked(gem_obj);
 
 	return 0;
 }
@@ -416,13 +416,13 @@ unsigned long drm_gem_cma_get_unmapped_area(struct file *filp,
 		return -EINVAL;
 
 	if (!drm_vma_node_is_allowed(node, priv)) {
-		drm_gem_object_unreference_unlocked(obj);
+		drm_gem_object_put_unlocked(obj);
 		return -EACCES;
 	}
 
 	cma_obj = to_drm_gem_cma_obj(obj);
 
-	drm_gem_object_unreference_unlocked(obj);
+	drm_gem_object_put_unlocked(obj);
 
 	return cma_obj->vaddr ? (unsigned long)cma_obj->vaddr : -EINVAL;
 }

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
@@ -318,7 +318,7 @@ struct dma_buf *drm_gem_dmabuf_export(struct drm_device *dev,
 		return dma_buf;
 
 	drm_dev_ref(dev);
-	drm_gem_object_reference(exp_info->priv);
+	drm_gem_object_get(exp_info->priv);
 
 	return dma_buf;
 }
@@ -339,7 +339,7 @@ void drm_gem_dmabuf_release(struct dma_buf *dma_buf)
 	struct drm_device *dev = obj->dev;
 
 	/* drop the reference on the export fd holds */
-	drm_gem_object_unreference_unlocked(obj);
+	drm_gem_object_put_unlocked(obj);
 
 	drm_dev_unref(dev);
 }
@@ -585,7 +585,7 @@ int drm_gem_prime_handle_to_fd(struct drm_device *dev,
 fail_put_dmabuf:
 	dma_buf_put(dmabuf);
 out:
-	drm_gem_object_unreference_unlocked(obj);
+	drm_gem_object_put_unlocked(obj);
 out_unlock:
 	mutex_unlock(&file_priv->prime.lock);
 
@@ -616,7 +616,7 @@ struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
 			 * Importing dmabuf exported from out own gem increases
 			 * refcount on gem itself instead of f_count of dmabuf.
 			 */
-			drm_gem_object_reference(obj);
+			drm_gem_object_get(obj);
 			return obj;
 		}
 	}
@@ -704,7 +704,7 @@ int drm_gem_prime_fd_to_handle(struct drm_device *dev,
 
 	/* _handle_create_tail unconditionally unlocks dev->object_name_lock. */
 	ret = drm_gem_handle_create_tail(file_priv, obj, handle);
-	drm_gem_object_unreference_unlocked(obj);
+	drm_gem_object_put_unlocked(obj);
 	if (ret)
 		goto out_put;