Prepare things for standardizing synchronization around CPU accesses
of GEM buffers. This will be used to provide default
drm_gem_dmabuf_{begin,end}_cpu_access() implementations, and provide
a way for drivers to add their own ioctls to synchronize CPU
writes/reads when they can't do it directly from userland.v2: - New commit Signed-off-by: Boris Brezillon <[email protected]> --- drivers/gpu/drm/drm_gem.c | 10 +++++++++ include/drm/drm_gem.h | 45 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 55 insertions(+) diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index cbeb76b2124f..ec92ea81d9db 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -1333,6 +1333,16 @@ void drm_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map) } EXPORT_SYMBOL(drm_gem_vunmap); +int drm_gem_sync(struct drm_gem_object *obj, size_t offset, size_t size, + enum drm_gem_object_access_flags access) +{ + if (obj->funcs->sync) + return obj->funcs->sync(obj, offset, size, access); + + return 0; +} +EXPORT_SYMBOL(drm_gem_sync); + /** * drm_gem_lock_reservations - Sets up the ww context and acquires * the lock on an array of GEM objects. diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h index 8d48d2af2649..1c33e59ab305 100644 --- a/include/drm/drm_gem.h +++ b/include/drm/drm_gem.h @@ -66,6 +66,33 @@ enum drm_gem_object_status { DRM_GEM_OBJECT_ACTIVE = BIT(2), }; +/** + * enum drm_gem_object_status - bitmask describing GEM access types to prepare for + */ +enum drm_gem_object_access_flags { + /** @DRM_GEM_OBJECT_CPU_ACCESS: Prepare for a CPU access. */ + DRM_GEM_OBJECT_CPU_ACCESS = 0, + + /** @DRM_GEM_OBJECT_DEV_ACCESS: Prepare for a device access. */ + DRM_GEM_OBJECT_DEV_ACCESS = BIT(0), + + /** @DRM_GEM_OBJECT_ACCESSOR_MASK: Mask used to check the entity doing the access. */ + DRM_GEM_OBJECT_ACCESSOR_MASK = BIT(0), + + /** @DRM_GEM_OBJECT_READ_ACCESS: Prepare for read-only accesses. */ + DRM_GEM_OBJECT_READ_ACCESS = BIT(1), + + /** @DRM_GEM_OBJECT_WRITE_ACCESS: Prepare for write-only accesses. */ + DRM_GEM_OBJECT_WRITE_ACCESS = BIT(2), + + /** @DRM_GEM_OBJECT_RW_ACCESS: Prepare for a read/write accesses. */ + DRM_GEM_OBJECT_RW_ACCESS = DRM_GEM_OBJECT_READ_ACCESS | + DRM_GEM_OBJECT_WRITE_ACCESS, + + /** @DRM_GEM_OBJECT_ACCESS_TYPE_MASK: Mask used to check the access type. */ + DRM_GEM_OBJECT_ACCESS_TYPE_MASK = DRM_GEM_OBJECT_RW_ACCESS, +}; + /** * struct drm_gem_object_funcs - GEM object functions */ @@ -191,6 +218,21 @@ struct drm_gem_object_funcs { */ int (*mmap)(struct drm_gem_object *obj, struct vm_area_struct *vma); + /** + * @sync: + * + * Prepare for CPU/device access. This can involve migration of + * a buffer to the system-RAM/VRAM, or for UMA, flushing/invalidating + * the CPU caches. The range can be used to optimize the synchronization + * when possible. + * + * Returns 0 on success, -errno otherwise. + * + * This callback is optional. + */ + int (*sync)(struct drm_gem_object *obj, size_t offset, size_t size, + enum drm_gem_object_access_flags access); + /** * @evict: * @@ -559,6 +601,9 @@ void drm_gem_unlock(struct drm_gem_object *obj); int drm_gem_vmap(struct drm_gem_object *obj, struct iosys_map *map); void drm_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map); +int drm_gem_sync(struct drm_gem_object *obj, size_t offset, size_t size, + enum drm_gem_object_access_flags access); + int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles, int count, struct drm_gem_object ***objs_out); struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle); -- 2.51.0
