diff options
Diffstat (limited to 'drivers/gpu/drm/drm_mm.c')
| -rw-r--r-- | drivers/gpu/drm/drm_mm.c | 41 |
1 files changed, 22 insertions, 19 deletions
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c index e54aa3fa538f..229b3f525dee 100644 --- a/drivers/gpu/drm/drm_mm.c +++ b/drivers/gpu/drm/drm_mm.c @@ -59,8 +59,8 @@ * * The main data struct is &drm_mm, allocations are tracked in &drm_mm_node. * Drivers are free to embed either of them into their own suitable - * datastructures. drm_mm itself will not do any allocations of its own, so if - * drivers choose not to embed nodes they need to still allocate them + * datastructures. drm_mm itself will not do any memory allocations of its own, + * so if drivers choose not to embed nodes they need to still allocate them * themselves. * * The range allocator also supports reservation of preallocated blocks. This is @@ -78,7 +78,7 @@ * steep cliff not a real concern. Removing a node again is O(1). * * drm_mm supports a few features: Alignment and range restrictions can be - * supplied. Further more every &drm_mm_node has a color value (which is just an + * supplied. Furthermore every &drm_mm_node has a color value (which is just an * opaque unsigned long) which in conjunction with a driver callback can be used * to implement sophisticated placement restrictions. The i915 DRM driver uses * this to implement guard pages between incompatible caching domains in the @@ -296,11 +296,11 @@ static void drm_mm_insert_helper(struct drm_mm_node *hole_node, * @mm: drm_mm allocator to insert @node into * @node: drm_mm_node to insert * - * This functions inserts an already set-up drm_mm_node into the allocator, - * meaning that start, size and color must be set by the caller. This is useful - * to initialize the allocator with preallocated objects which must be set-up - * before the range allocator can be set-up, e.g. when taking over a firmware - * framebuffer. + * This functions inserts an already set-up &drm_mm_node into the allocator, + * meaning that start, size and color must be set by the caller. All other + * fields must be cleared to 0. This is useful to initialize the allocator with + * preallocated objects which must be set-up before the range allocator can be + * set-up, e.g. when taking over a firmware framebuffer. * * Returns: * 0 on success, -ENOSPC if there's no hole where @node is. @@ -375,7 +375,7 @@ EXPORT_SYMBOL(drm_mm_reserve_node); * @sflags: flags to fine-tune the allocation search * @aflags: flags to fine-tune the allocation behavior * - * The preallocated node must be cleared to 0. + * The preallocated @node must be cleared to 0. * * Returns: * 0 on success, -ENOSPC if there's no suitable hole. @@ -537,7 +537,7 @@ void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new) EXPORT_SYMBOL(drm_mm_replace_node); /** - * DOC: lru scan roaster + * DOC: lru scan roster * * Very often GPUs need to have continuous allocations for a given object. When * evicting objects to make space for a new one it is therefore not most @@ -549,9 +549,11 @@ EXPORT_SYMBOL(drm_mm_replace_node); * The DRM range allocator supports this use-case through the scanning * interfaces. First a scan operation needs to be initialized with * drm_mm_scan_init() or drm_mm_scan_init_with_range(). The driver adds - * objects to the roster (probably by walking an LRU list, but this can be - * freely implemented) (using drm_mm_scan_add_block()) until a suitable hole - * is found or there are no further evictable objects. + * objects to the roster, probably by walking an LRU list, but this can be + * freely implemented. Eviction candiates are added using + * drm_mm_scan_add_block() until a suitable hole is found or there are no + * further evictable objects. Eviction roster metadata is tracked in struct + * &drm_mm_scan. * * The driver must walk through all objects again in exactly the reverse * order to restore the allocator state. Note that while the allocator is used @@ -559,7 +561,7 @@ EXPORT_SYMBOL(drm_mm_replace_node); * * Finally the driver evicts all objects selected (drm_mm_scan_remove_block() * reported true) in the scan, and any overlapping nodes after color adjustment - * (drm_mm_scan_evict_color()). Adding and removing an object is O(1), and + * (drm_mm_scan_color_evict()). Adding and removing an object is O(1), and * since freeing a node is also O(1) the overall complexity is * O(scanned_objects). So like the free stack which needs to be walked before a * scan operation even begins this is linear in the number of objects. It @@ -705,14 +707,15 @@ EXPORT_SYMBOL(drm_mm_scan_add_block); * @scan: the active drm_mm scanner * @node: drm_mm_node to remove * - * Nodes _must_ be removed in exactly the reverse order from the scan list as - * they have been added (e.g. using list_add as they are added and then - * list_for_each over that eviction list to remove), otherwise the internal + * Nodes **must** be removed in exactly the reverse order from the scan list as + * they have been added (e.g. using list_add() as they are added and then + * list_for_each() over that eviction list to remove), otherwise the internal * state of the memory manager will be corrupted. * * When the scan list is empty, the selected memory nodes can be freed. An - * immediately following drm_mm_search_free with !DRM_MM_SEARCH_BEST will then - * return the just freed block (because its at the top of the free_stack list). + * immediately following drm_mm_insert_node_in_range_generic() or one of the + * simpler versions of that function with !DRM_MM_SEARCH_BEST will then return + * the just freed block (because its at the top of the free_stack list). * * Returns: * True if this block should be evicted, false otherwise. Will always |