Re: [Linaro-mm-sig] [PATCH v3 4/8] drm/gem: Create infrastructure for GEM vmap_local

On Wed, Dec 09, 2020 at 03:25:23PM +0100, Thomas Zimmermann wrote:

This patch adds vmap_local and vunmap_local to struct drm_gem_object_funcs; including the PRIME helpers to connect with dma-buf's related interfaces.

Besides the generic DRM core, this will become relevant for fbdev emulation with virtio, so we update it as well.

Signed-off-by: Thomas Zimmermann tzimmermann@suse.de

drivers/gpu/drm/drm_gem.c | 28 ++++++++++++++++++ drivers/gpu/drm/drm_internal.h | 2 ++ drivers/gpu/drm/drm_prime.c | 39 ++++++++++++++++++++++++++ drivers/gpu/drm/virtio/virtgpu_prime.c | 2 ++ include/drm/drm_gem.h | 20 +++++++++++++ include/drm/drm_prime.h | 2 ++ 6 files changed, 93 insertions(+)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 92f89cee213e..6e131d9bb7bd 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -1234,6 +1234,34 @@ void drm_gem_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map) dma_buf_map_clear(map); } +int drm_gem_vmap_local(struct drm_gem_object *obj, struct dma_buf_map *map) +{

• int ret;
• if (!obj->funcs->vmap_local)

• return -EOPNOTSUPP;
  

• ret = obj->funcs->vmap_local(obj, map);
• if (ret)

• return ret;
  

• else if (dma_buf_map_is_null(map))

• return -ENOMEM;
  

• return 0;

+}

+void drm_gem_vunmap_local(struct drm_gem_object *obj, struct dma_buf_map *map) +{

• if (dma_buf_map_is_null(map))

• return;
  

• if (obj->funcs->vunmap_local)

• obj->funcs->vunmap_local(obj, map);
  

• /* Always set the mapping to NULL. Callers may rely on this. */
• dma_buf_map_clear(map);

+}

/**

• drm_gem_lock_reservations - Sets up the ww context and acquires
• the lock on an array of GEM objects.

diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h index 81d386b5b92a..b0bf6aba763a 100644 --- a/drivers/gpu/drm/drm_internal.h +++ b/drivers/gpu/drm/drm_internal.h @@ -190,6 +190,8 @@ int drm_gem_pin(struct drm_gem_object *obj); void drm_gem_unpin(struct drm_gem_object *obj); int drm_gem_vmap(struct drm_gem_object *obj, struct dma_buf_map *map); void drm_gem_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map); +int drm_gem_vmap_local(struct drm_gem_object *obj, struct dma_buf_map *map); +void drm_gem_vunmap_local(struct drm_gem_object *obj, struct dma_buf_map *map); /* drm_debugfs.c drm_debugfs_crc.c */ #if defined(CONFIG_DEBUG_FS) diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 683aa29ecd3b..633edea76985 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -695,6 +695,43 @@ void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, struct dma_buf_map *map) } EXPORT_SYMBOL(drm_gem_dmabuf_vunmap); +/**

• • drm_gem_dmabuf_vmap_local - dma_buf vmap_local implementation for GEM
• • @dma_buf: buffer to be mapped
• • @map: the virtual address of the buffer
• • Sets up a kernel virtual mapping. This can be used as the &dma_buf_ops.vmap_local
• • callback. Calls into &drm_gem_object_funcs.vmap_local for device specific handling.
• • The kernel virtual address is returned in map.
• • Returns:
• • 0 on success or a negative errno code otherwise.
• */

+int drm_gem_dmabuf_vmap_local(struct dma_buf *dma_buf, struct dma_buf_map *map) +{

• struct drm_gem_object *obj = dma_buf->priv;
• return drm_gem_vmap_local(obj, map);

+} +EXPORT_SYMBOL(drm_gem_dmabuf_vmap_local);

+/**

• • drm_gem_dmabuf_vunmap_local - dma_buf vunmap_local implementation for GEM
• • @dma_buf: buffer to be unmapped
• • @map: the virtual address of the buffer
• • Releases a kernel virtual mapping. This can be used as the
• • &dma_buf_ops.vunmap_local callback. Calls into &drm_gem_object_funcs.vunmap_local
• • for device specific handling.
• */

+void drm_gem_dmabuf_vunmap_local(struct dma_buf *dma_buf, struct dma_buf_map *map) +{

• struct drm_gem_object *obj = dma_buf->priv;
• drm_gem_vunmap_local(obj, map);

+} +EXPORT_SYMBOL(drm_gem_dmabuf_vunmap_local);

/**

• drm_gem_prime_mmap - PRIME mmap function for GEM drivers
• @obj: GEM object

@@ -787,6 +824,8 @@ static const struct dma_buf_ops drm_gem_prime_dmabuf_ops = { .mmap = drm_gem_dmabuf_mmap, .vmap = drm_gem_dmabuf_vmap, .vunmap = drm_gem_dmabuf_vunmap,

• .vmap_local = drm_gem_dmabuf_vmap_local,
• .vunmap_local = drm_gem_dmabuf_vunmap_local,

}; /** diff --git a/drivers/gpu/drm/virtio/virtgpu_prime.c b/drivers/gpu/drm/virtio/virtgpu_prime.c index 807a27a16365..fea11a53d8fc 100644 --- a/drivers/gpu/drm/virtio/virtgpu_prime.c +++ b/drivers/gpu/drm/virtio/virtgpu_prime.c @@ -54,6 +54,8 @@ static const struct virtio_dma_buf_ops virtgpu_dmabuf_ops = { .mmap = drm_gem_dmabuf_mmap, .vmap = drm_gem_dmabuf_vmap, .vunmap = drm_gem_dmabuf_vunmap,

• .vmap = drm_gem_dmabuf_vmap_local,
  

• .vunmap = drm_gem_dmabuf_vunmap_local,
  

  }, .device_attach = drm_gem_map_attach, .get_uuid = virtgpu_virtio_get_uuid,

diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h index 5e6daa1c982f..1281f26de494 100644 --- a/include/drm/drm_gem.h +++ b/include/drm/drm_gem.h @@ -151,6 +151,26 @@ struct drm_gem_object_funcs { */ void (*vunmap)(struct drm_gem_object *obj, struct dma_buf_map *map);

• /**

• * @vmap_local:
  

• *
  

• * Returns a virtual address for the buffer. Used by the
  

• * drm_gem_dmabuf_vmap_local() helper.
  

I'd add "Callers will hold &drm_gem_object.resv already and only release it after @vunmap is called" (and pls check I typed this correctly for the linking).

Either way: Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch

• *
  

• * This callback is optional.
  

• */
  

• int (*vmap_local)(struct drm_gem_object *obj, struct dma_buf_map *map);
• /**

• * @vunmap_local:
  

• *
  

• * Releases the address previously returned by @vmap. Used by the
  

• * drm_gem_dmabuf_vunmap_local() helper.
  

• *
  

• * This callback is optional.
  

• */
  

• void (*vunmap_local)(struct drm_gem_object *obj, struct dma_buf_map *map);
• /**
  • @mmap:

diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h index 54f2c58305d2..fd2aef6966ef 100644 --- a/include/drm/drm_prime.h +++ b/include/drm/drm_prime.h @@ -85,6 +85,8 @@ void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach, enum dma_data_direction dir); int drm_gem_dmabuf_vmap(struct dma_buf *dma_buf, struct dma_buf_map *map); void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, struct dma_buf_map *map); +int drm_gem_dmabuf_vmap_local(struct dma_buf *dma_buf, struct dma_buf_map *map); +void drm_gem_dmabuf_vunmap_local(struct dma_buf *dma_buf, struct dma_buf_map *map); int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma); int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma); -- 2.29.2