diff mbox series

[11/13] drm/client: Pin vmap'ed GEM buffers

Message ID 20240227113853.8464-12-tzimmermann@suse.de
State Accepted
Commit 1709474ba04179bee919f920c4da877aa1552b41
Headers show
Series drm: Fix reservation locking for pin/unpin and console | expand

Commit Message

Thomas Zimmermann Feb. 27, 2024, 10:14 a.m. UTC 
The function drm_client_buffer_vmap() establishes a long-term mapping
of the client's buffer object into the kernel address space. Make sure
that buffer does not move by pinning it to its current location. Same
for vunmap with unpin.

The only caller of drm_client_buffer_vmap() is fbdev-dma, which uses
gem-dma. As DMA-backed GEM buffers do not move, this change is for
correctness with little impact in practice.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/drm_client.c | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index 2cc81831236b5..77fe217aeaf36 100644
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -388,16 +388,30 @@  int
 drm_client_buffer_vmap(struct drm_client_buffer *buffer,
 		       struct iosys_map *map_copy)
 {
+	struct drm_gem_object *gem = buffer->gem;
 	struct iosys_map *map = &buffer->map;
 	int ret;
 
-	ret = drm_gem_vmap_unlocked(buffer->gem, map);
+	drm_gem_lock(gem);
+
+	ret = drm_gem_pin_locked(gem);
 	if (ret)
-		return ret;
+		goto err_drm_gem_pin_locked;
+	ret = drm_gem_vmap(gem, map);
+	if (ret)
+		goto err_drm_gem_vmap;
+
+	drm_gem_unlock(gem);
 
 	*map_copy = *map;
 
 	return 0;
+
+err_drm_gem_vmap:
+	drm_gem_unpin_locked(buffer->gem);
+err_drm_gem_pin_locked:
+	drm_gem_unlock(gem);
+	return ret;
 }
 EXPORT_SYMBOL(drm_client_buffer_vmap);
 
@@ -411,9 +425,13 @@  EXPORT_SYMBOL(drm_client_buffer_vmap);
  */
 void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
 {
+	struct drm_gem_object *gem = buffer->gem;
 	struct iosys_map *map = &buffer->map;
 
-	drm_gem_vunmap_unlocked(buffer->gem, map);
+	drm_gem_lock(gem);
+	drm_gem_vunmap(gem, map);
+	drm_gem_unpin_locked(gem);
+	drm_gem_unlock(gem);
 }
 EXPORT_SYMBOL(drm_client_buffer_vunmap);