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@xxxxxxx>
> ---
> 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@xxxxxxxx>
> + *
> + * 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
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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