From df2e0900a5965795c2607640e4e9c2667e16c669 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Thu, 22 Oct 2015 19:11:29 +0200 Subject: [PATCH] drm/gem: Update/Polish docs A bunch of things have been removed meanwhile and docs not fully brought up to speed. And a few gaps closed where I noticed missing kerneldoc while reading through the overview sections. Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1445533889-7661-3-git-send-email-daniel.vetter@ffwll.ch Reviewed-by: Alex Deucher Signed-off-by: Daniel Vetter --- Documentation/DocBook/gpu.tmpl | 33 ++++---------------------------- drivers/gpu/drm/drm_gem.c | 35 +++++++++++++++++++++++++++++++--- 2 files changed, 36 insertions(+), 32 deletions(-) diff --git a/Documentation/DocBook/gpu.tmpl b/Documentation/DocBook/gpu.tmpl index 47b06dfa454d..944e65a87033 100644 --- a/Documentation/DocBook/gpu.tmpl +++ b/Documentation/DocBook/gpu.tmpl @@ -615,18 +615,6 @@ char *date; drm_gem_object_init. Storage for private GEM objects must be managed by drivers. - - Drivers that do not need to extend GEM objects with private information - can call the drm_gem_object_alloc function to - allocate and initialize a struct drm_gem_object - instance. The GEM core will call the optional driver - gem_init_object operation after initializing - the GEM object with drm_gem_object_init. - int (*gem_init_object) (struct drm_gem_object *obj); - - - No alloc-and-init function exists for private GEM objects. - GEM Objects Lifetime @@ -649,15 +637,9 @@ char *date; void (*gem_free_object) (struct drm_gem_object *obj); - Drivers are responsible for freeing all GEM object resources, including - the resources created by the GEM core. If an mmap offset has been - created for the object (in which case - drm_gem_object::map_list::map - is not NULL) it must be freed by a call to - drm_gem_free_mmap_offset. The shmfs backing store - must be released by calling drm_gem_object_release - (that function can safely be called if no shmfs backing store has been - created). + Drivers are responsible for freeing all GEM object resources. This includes + the resources created by the GEM core, which need to be released with + drm_gem_object_release. @@ -740,17 +722,10 @@ char *date; DRM identifies the GEM object to be mapped by a fake offset passed through the mmap offset argument. Prior to being mapped, a GEM object must thus be associated with a fake offset. To do so, drivers must call - drm_gem_create_mmap_offset on the object. The - function allocates a fake offset range from a pool and stores the - offset divided by PAGE_SIZE in - obj->map_list.hash.key. Care must be taken not to - call drm_gem_create_mmap_offset if a fake offset - has already been allocated for the object. This can be tested by - obj->map_list.map being non-NULL. + drm_gem_create_mmap_offset on the object. Once allocated, the fake offset value - (obj->map_list.hash.key << PAGE_SHIFT) must be passed to the application in a driver-specific way and can then be used as the mmap offset argument. diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index c7de454e8e88..2e10bba4468b 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -244,8 +244,9 @@ drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj) * @filp: drm file-private structure to use for the handle look up * @handle: userspace handle to delete * - * Removes the GEM handle from the @filp lookup table and if this is the last - * handle also cleans up linked resources like GEM names. + * Removes the GEM handle from the @filp lookup table which has been added with + * drm_gem_handle_create(). If this is the last handle also cleans up linked + * resources like GEM names. */ int drm_gem_handle_delete(struct drm_file *filp, u32 handle) @@ -314,6 +315,10 @@ EXPORT_SYMBOL(drm_gem_dumb_destroy); * This expects the dev->object_name_lock to be held already and will drop it * before returning. Used to avoid races in establishing new handles when * importing an object from either an flink name or a dma-buf. + * + * Handles must be release again through drm_gem_handle_delete(). This is done + * when userspace closes @file_priv for all attached handles, or through the + * GEM_CLOSE ioctl for individual handles. */ int drm_gem_handle_create_tail(struct drm_file *file_priv, @@ -541,7 +546,17 @@ void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages, } EXPORT_SYMBOL(drm_gem_put_pages); -/** Returns a reference to the object named by the handle. */ +/** + * drm_gem_object_lookup - look up a GEM object from it's handle + * @dev: DRM device + * @filp: DRM file private date + * @handle: userspace handle + * + * Returns: + * + * A reference to the object named by the handle if such exists on @filp, NULL + * otherwise. + */ struct drm_gem_object * drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp, u32 handle) @@ -774,6 +789,13 @@ drm_gem_object_free(struct kref *kref) } EXPORT_SYMBOL(drm_gem_object_free); +/** + * drm_gem_vm_open - vma->ops->open implementation for GEM + * @vma: VM area structure + * + * This function implements the #vm_operations_struct open() callback for GEM + * drivers. This must be used together with drm_gem_vm_close(). + */ void drm_gem_vm_open(struct vm_area_struct *vma) { struct drm_gem_object *obj = vma->vm_private_data; @@ -782,6 +804,13 @@ void drm_gem_vm_open(struct vm_area_struct *vma) } EXPORT_SYMBOL(drm_gem_vm_open); +/** + * drm_gem_vm_close - vma->ops->close implementation for GEM + * @vma: VM area structure + * + * This function implements the #vm_operations_struct close() callback for GEM + * drivers. This must be used together with drm_gem_vm_open(). + */ void drm_gem_vm_close(struct vm_area_struct *vma) { struct drm_gem_object *obj = vma->vm_private_data; -- 2.20.1