mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-08-23 01:10:04 +00:00
Code Issues Releases Wiki Activity

drm/gem_shmem: Use a writecombine mapping for ->vaddr

Browse source 
Right now, the BO is mapped as a cached region when ->vmap() is called
and the underlying object is not a dmabuf.
Doing that makes cache management a bit more complicated (you'd need
to call dma_map/unmap_sg() on the ->sgt field everytime the BO is about
to be passed to the GPU/CPU), so let's map the BO with writecombine
attributes instead (as done in most drivers).

Fixes: 2194a63a81 ("drm: Add library for shmem backed GEM objects")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190529065121.13485-1-boris.brezillon@collabora.com
This commit is contained in:
Boris Brezillon 2019-05-29 08:51:21 +02:00 committed by Rob Herring
parent 652b8b0865
commit be7d9f05c5
1 changed files with 2 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
drivers/gpu/drm/drm_gem_shmem_helper.c
View file

@ -255,7 +255,8 @@ static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem)
if (obj->import_attach)
shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf);
else
shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT, VM_MAP, PAGE_KERNEL);
shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT,
VM_MAP, pgprot_writecombine(PAGE_KERNEL));
if (!shmem->vaddr) {
DRM_DEBUG_KMS("Failed to vmap pages\n");