drm: Remove obsolete GEM and PRIME callbacks from struct drm_driver

Several GEM and PRIME callbacks have been deprecated in favor of
per-instance GEM object functions. Remove the callbacks as they are
now unused. The only exception is .gem_prime_mmap, which is still
in use by several drivers.

What is also gone is gem_vm_ops in struct drm_driver. All drivers now
use struct drm_gem_object_funcs.vm_ops instead.

While at it, the patch also improves error handling around calls
to .free and .get_sg_table callbacks.

v3:
	* restore default call to drm_gem_prime_export() in
	  drm_gem_prime_handle_to_fd()
	* return -ENOSYS if get_sg_table is not set
	* drop all checks for obj->funcs
	* clean up TODO list and documentation
v2:
	* update related TODO item (Sam)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200923102159.24084-23-tzimmermann@suse.de

3 files changed, 28 insertions, 47 deletions

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 19d73868490e..1da67d34e55d 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -247,12 +247,9 @@ drm_gem_object_release_handle(int id, void *ptr, void *data)
 {
 	struct drm_file *file_priv = data;
 	struct drm_gem_object *obj = ptr;
-	struct drm_device *dev = obj->dev;
 
-	if (obj->funcs && obj->funcs->close)
+	if (obj->funcs->close)
 		obj->funcs->close(obj, file_priv);
-	else if (dev->driver->gem_close_object)
-		dev->driver->gem_close_object(obj, file_priv);
 
 	drm_gem_remove_prime_handles(obj, file_priv);
 	drm_vma_node_revoke(&obj->vma_node, file_priv);
@@ -403,14 +400,10 @@ drm_gem_handle_create_tail(struct drm_file *file_priv,
 	if (ret)
 		goto err_remove;
 
-	if (obj->funcs && obj->funcs->open) {
+	if (obj->funcs->open) {
 		ret = obj->funcs->open(obj, file_priv);
 		if (ret)
 			goto err_revoke;
-	} else if (dev->driver->gem_open_object) {
-		ret = dev->driver->gem_open_object(obj, file_priv);
-		if (ret)
-			goto err_revoke;
 	}
 
 	*handlep = handle;
@@ -982,12 +975,11 @@ drm_gem_object_free(struct kref *kref)
 {
 	struct drm_gem_object *obj =
 		container_of(kref, struct drm_gem_object, refcount);
-	struct drm_device *dev = obj->dev;
 
-	if (obj->funcs)
-		obj->funcs->free(obj);
-	else if (dev->driver->gem_free_object_unlocked)
-		dev->driver->gem_free_object_unlocked(obj);
+	if (WARN_ON(!obj->funcs->free))
+		return;
+
+	obj->funcs->free(obj);
 }
 EXPORT_SYMBOL(drm_gem_object_free);
 
@@ -1049,9 +1041,9 @@ EXPORT_SYMBOL(drm_gem_vm_close);
  * @obj_size: the object size to be mapped, in bytes
  * @vma: VMA for the area to be mapped
  *
- * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops
- * provided by the driver. Depending on their requirements, drivers can either
- * provide a fault handler in their gem_vm_ops (in which case any accesses to
+ * Set up the VMA to prepare mapping of the GEM object using the GEM object's
+ * vm_ops. Depending on their requirements, GEM objects can either
+ * provide a fault handler in their vm_ops (in which case any accesses to
  * the object will be trapped, to perform migration, GTT binding, surface
  * register allocation, or performance monitoring), or mmap the buffer memory
  * synchronously after calling drm_gem_mmap_obj.
@@ -1065,12 +1057,11 @@ EXPORT_SYMBOL(drm_gem_vm_close);
  * callers must verify access restrictions before calling this helper.
  *
  * Return 0 or success or -EINVAL if the object size is smaller than the VMA
- * size, or if no gem_vm_ops are provided.
+ * size, or if no vm_ops are provided.
  */
 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
 		     struct vm_area_struct *vma)
 {
-	struct drm_device *dev = obj->dev;
 	int ret;
 
 	/* Check for valid size. */
@@ -1085,7 +1076,7 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
 	 */
 	drm_gem_object_get(obj);
 
-	if (obj->funcs && obj->funcs->mmap) {
+	if (obj->funcs->mmap) {
 		ret = obj->funcs->mmap(obj, vma);
 		if (ret) {
 			drm_gem_object_put(obj);
@@ -1093,10 +1084,8 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
 		}
 		WARN_ON(!(vma->vm_flags & VM_DONTEXPAND));
 	} else {
-		if (obj->funcs && obj->funcs->vm_ops)
+		if (obj->funcs->vm_ops)
 			vma->vm_ops = obj->funcs->vm_ops;
-		else if (dev->driver->gem_vm_ops)
-			vma->vm_ops = dev->driver->gem_vm_ops;
 		else {
 			drm_gem_object_put(obj);
 			return -EINVAL;
@@ -1198,36 +1187,30 @@ void drm_gem_print_info(struct drm_printer *p, unsigned int indent,
 	drm_printf_indent(p, indent, "imported=%s\n",
 			  obj->import_attach ? "yes" : "no");
 
-	if (obj->funcs && obj->funcs->print_info)
+	if (obj->funcs->print_info)
 		obj->funcs->print_info(p, indent, obj);
 }
 
 int drm_gem_pin(struct drm_gem_object *obj)
 {
-	if (obj->funcs && obj->funcs->pin)
+	if (obj->funcs->pin)
 		return obj->funcs->pin(obj);
-	else if (obj->dev->driver->gem_prime_pin)
-		return obj->dev->driver->gem_prime_pin(obj);
 	else
 		return 0;
 }
 
 void drm_gem_unpin(struct drm_gem_object *obj)
 {
-	if (obj->funcs && obj->funcs->unpin)
+	if (obj->funcs->unpin)
 		obj->funcs->unpin(obj);
-	else if (obj->dev->driver->gem_prime_unpin)
-		obj->dev->driver->gem_prime_unpin(obj);
 }
 
 void *drm_gem_vmap(struct drm_gem_object *obj)
 {
 	void *vaddr;
 
-	if (obj->funcs && obj->funcs->vmap)
+	if (obj->funcs->vmap)
 		vaddr = obj->funcs->vmap(obj);
-	else if (obj->dev->driver->gem_prime_vmap)
-		vaddr = obj->dev->driver->gem_prime_vmap(obj);
 	else
 		vaddr = ERR_PTR(-EOPNOTSUPP);
 
@@ -1242,10 +1225,8 @@ void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr)
 	if (!vaddr)
 		return;
 
-	if (obj->funcs && obj->funcs->vunmap)
+	if (obj->funcs->vunmap)
 		obj->funcs->vunmap(obj, vaddr);
-	else if (obj->dev->driver->gem_prime_vunmap)
-		obj->dev->driver->gem_prime_vunmap(obj, vaddr);
 }
 
 /**
diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
index 822edeadbab3..1e5b389c435c 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -171,7 +171,7 @@ drm_gem_cma_create_with_handle(struct drm_file *file_priv,
  * GEM object state and frees the memory used to store the object itself.
  * If the buffer is imported and the virtual address is set, it is released.
  * Drivers using the CMA helpers should set this as their
- * &drm_driver.gem_free_object_unlocked callback.
+ * &drm_gem_object_funcs.free callback.
  */
 void drm_gem_cma_free_object(struct drm_gem_object *gem_obj)
 {
@@ -419,7 +419,7 @@ EXPORT_SYMBOL(drm_gem_cma_print_info);
  *
  * This function exports a scatter/gather table suitable for PRIME usage by
  * calling the standard DMA mapping API. Drivers using the CMA helpers should
- * set this as their &drm_driver.gem_prime_get_sg_table callback.
+ * set this as their &drm_gem_object_funcs.get_sg_table callback.
  *
  * Returns:
  * A pointer to the scatter/gather table of pinned pages or NULL on failure.
@@ -542,7 +542,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap);
  * virtual address space. Since the CMA buffers are already mapped into the
  * kernel virtual address space this simply returns the cached virtual
  * address. Drivers using the CMA helpers should set this as their DRM
- * driver's &drm_driver.gem_prime_vmap callback.
+ * driver's &drm_gem_object_funcs.vmap callback.
  *
  * Returns:
  * The kernel virtual address of the CMA GEM object's backing store.
@@ -564,7 +564,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap);
  * This function removes a buffer exported via DRM PRIME from the kernel's
  * virtual address space. This is a no-op because CMA buffers cannot be
  * unmapped from kernel space. Drivers using the CMA helpers should set this
- * as their &drm_driver.gem_prime_vunmap callback.
+ * as their &drm_gem_object_funcs.vunmap callback.
  */
 void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
 {
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 8a6a3c99b7d8..194784a5b344 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -386,8 +386,6 @@ static struct dma_buf *export_and_register_object(struct drm_device *dev,
 
 	if (obj->funcs && obj->funcs->export)
 		dmabuf = obj->funcs->export(obj, flags);
-	else if (dev->driver->gem_prime_export)
-		dmabuf = dev->driver->gem_prime_export(obj, flags);
 	else
 		dmabuf = drm_gem_prime_export(obj, flags);
 	if (IS_ERR(dmabuf)) {
@@ -419,7 +417,7 @@ static struct dma_buf *export_and_register_object(struct drm_device *dev,
  * This is the PRIME export function which must be used mandatorily by GEM
  * drivers to ensure correct lifetime management of the underlying GEM object.
  * The actual exporting from GEM object to a dma-buf is done through the
- * &drm_driver.gem_prime_export driver callback.
+ * &drm_gem_object_funcs.export callback.
  */
 int drm_gem_prime_handle_to_fd(struct drm_device *dev,
 			       struct drm_file *file_priv, uint32_t handle,
@@ -621,10 +619,12 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 	if (WARN_ON(dir == DMA_NONE))
 		return ERR_PTR(-EINVAL);
 
-	if (obj->funcs)
-		sgt = obj->funcs->get_sg_table(obj);
-	else
-		sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
+	if (WARN_ON(!obj->funcs->get_sg_table))
+		return ERR_PTR(-ENOSYS);
+
+	sgt = obj->funcs->get_sg_table(obj);
+	if (IS_ERR(sgt))
+		return sgt;
 
 	if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
 			      DMA_ATTR_SKIP_CPU_SYNC)) {