diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2016-12-22 08:36:34 +0000 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2016-12-28 11:51:52 +0100 |
| commit | 9a956b1548794033d5b893d6d6fcc00b197cfc9b (patch) | |
| tree | 8b8cfbe1b61e48ac2a8a7aca0620a16bc29fcd15 /drivers/gpu/drm/drm_mm.c | |
| parent | 0b04d474a611e2831d142e246422a03a10998ae1 (diff) | |
drm: Optimise power-of-two alignments in drm_mm_scan_add_block()
For power-of-two alignments, we can avoid the 64bit divide and do a
simple bitwise add instead.
v2: s/alignment_mask/remainder_mask/
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161222083641.2691-32-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/drm_mm.c')
| -rw-r--r-- | drivers/gpu/drm/drm_mm.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c index 189ab84c5a59..0441d84fba74 100644 --- a/drivers/gpu/drm/drm_mm.c +++ b/drivers/gpu/drm/drm_mm.c @@ -742,8 +742,12 @@ void drm_mm_scan_init_with_range(struct drm_mm_scan *scan, scan->mm = mm; + if (alignment <= 1) + alignment = 0; + scan->color = color; scan->alignment = alignment; + scan->remainder_mask = is_power_of_2(alignment) ? alignment - 1 : 0; scan->size = size; scan->flags = flags; @@ -811,7 +815,10 @@ bool drm_mm_scan_add_block(struct drm_mm_scan *scan, if (scan->alignment) { u64 rem; - div64_u64_rem(adj_start, scan->alignment, &rem); + if (likely(scan->remainder_mask)) + rem = adj_start & scan->remainder_mask; + else + div64_u64_rem(adj_start, scan->alignment, &rem); if (rem) { adj_start -= rem; if (scan->flags != DRM_MM_CREATE_TOP) |