From 1709474ba04179bee919f920c4da877aa1552b41 Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: Tue, 27 Feb 2024 11:14:58 +0100
Subject: [PATCH] drm/client: Pin vmap'ed GEM buffers
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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>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> # virtio-gpu
Acked-by: Zack Rusin <zack.rusin@broadcom.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240227113853.8464-12-tzimmermann@suse.de
---
drivers/gpu/drm/drm_client.c | 24 +++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)
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);
--
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