drm/ttm: optimize bo_kmap_type values
A micro-optimization on the function ttm_kmap_obj_virtual().
By defining the values of enum ttm_bo_kmap_obj::bo_kmap_type to have a
bit indicating iomem, size of the function ttm_kmap_obj_virtual() will be
reduced by 16 bytes on x86_64 (gcc 4.1.2).
ttm_kmap_obj_virtual() may be heavily used, when buffer objects are
accessed via wrappers, that work for both kinds of memory addresses:
iomem cookies and kernel virtual.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index cd22ab4..99dc521 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -245,14 +245,15 @@
* premapped region.
*/
+#define TTM_BO_MAP_IOMEM_MASK 0x80
struct ttm_bo_kmap_obj {
void *virtual;
struct page *page;
enum {
- ttm_bo_map_iomap,
- ttm_bo_map_vmap,
- ttm_bo_map_kmap,
- ttm_bo_map_premapped,
+ ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
+ ttm_bo_map_vmap = 2,
+ ttm_bo_map_kmap = 3,
+ ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
} bo_kmap_type;
};
@@ -522,8 +523,7 @@
static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
bool *is_iomem)
{
- *is_iomem = (map->bo_kmap_type == ttm_bo_map_iomap ||
- map->bo_kmap_type == ttm_bo_map_premapped);
+ *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
return map->virtual;
}
