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author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2020-05-14 22:22:56 +0200 |
---|---|---|
committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2020-06-03 15:06:38 +0200 |
commit | 0cc5fb4e87216320e5bc42603f735d666e101e43 (patch) | |
tree | 3bc79bb0e06bbded5ff3b0fb1e8e8e126bd58062 /drivers/gpu/drm/drm_gem_shmem_helper.c | |
parent | 3a5a5971bc1fe34a9a24b59118db0b3a1f9c2902 (diff) | |
download | linux-0cc5fb4e87216320e5bc42603f735d666e101e43.tar.gz linux-0cc5fb4e87216320e5bc42603f735d666e101e43.tar.bz2 linux-0cc5fb4e87216320e5bc42603f735d666e101e43.zip |
drm/shmem-helpers: Don't call get/put_pages on imported dma-buf in vmap
There's no direct harm, because for the shmem helpers these are noops
on imported buffers. The trouble is in the locks these take - I want
to change dma_buf_vmap locking, and so need to make sure that we only
ever take certain locks on one side of the dma-buf interface: Either
for exporters, or for importers.
v2: Change the control flow less compared to what's there (Thomas)
Tested-by: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200514202256.490926-1-daniel.vetter@ffwll.ch
Diffstat (limited to 'drivers/gpu/drm/drm_gem_shmem_helper.c')
-rw-r--r-- | drivers/gpu/drm/drm_gem_shmem_helper.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 3885854e85a9..0aac83ed9f5d 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -252,15 +252,15 @@ static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem) if (shmem->vmap_use_count++ > 0) return shmem->vaddr; - ret = drm_gem_shmem_get_pages(shmem); - if (ret) - goto err_zero_use; - if (obj->import_attach) { shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf); } else { pgprot_t prot = PAGE_KERNEL; + ret = drm_gem_shmem_get_pages(shmem); + if (ret) + goto err_zero_use; + if (!shmem->map_cached) prot = pgprot_writecombine(prot); shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT, @@ -276,7 +276,8 @@ static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem) return shmem->vaddr; err_put_pages: - drm_gem_shmem_put_pages(shmem); + if (!obj->import_attach) + drm_gem_shmem_put_pages(shmem); err_zero_use: shmem->vmap_use_count = 0; |