1 From 6b7250b2393653e5d08deed591b78b41a2ee8d43 Mon Sep 17 00:00:00 2001
2 From: Eric Anholt <eric@anholt.net>
3 Date: Wed, 8 Feb 2017 15:00:54 -0800
4 Subject: [PATCH] drm/vc4: Fulfill user BO creation requests from the kernel BO
7 The from_cache flag was actually "the BO is invisible to userspace",
8 so we can repurpose to just zero out a cached BO and return it to
11 Improves wall time for a loop of 5 glsl-algebraic-add-add-1 by
12 -1.44989% +/- 0.862891% (n=28, 1 outlier removed from each that
13 appeared to be other system noise)
15 Note that there's an intel-gpu-tools test to check for the proper
16 zeroing behavior here, which we continue to pass.
18 Signed-off-by: Eric Anholt <eric@anholt.net>
20 drivers/gpu/drm/vc4/vc4_bo.c | 13 +++++++------
21 1 file changed, 7 insertions(+), 6 deletions(-)
23 diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c
24 index 56b779c..ce8a5fd 100644
25 --- a/drivers/gpu/drm/vc4/vc4_bo.c
26 +++ b/drivers/gpu/drm/vc4/vc4_bo.c
27 @@ -208,22 +208,23 @@ struct drm_gem_object *vc4_create_object(struct drm_device *dev, size_t size)
30 struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t unaligned_size,
32 + bool allow_unzeroed)
34 size_t size = roundup(unaligned_size, PAGE_SIZE);
35 struct vc4_dev *vc4 = to_vc4_dev(dev);
36 struct drm_gem_cma_object *cma_obj;
41 return ERR_PTR(-EINVAL);
43 /* First, try to get a vc4_bo from the kernel BO cache. */
45 - struct vc4_bo *bo = vc4_bo_get_from_cache(dev, size);
49 + bo = vc4_bo_get_from_cache(dev, size);
51 + if (!allow_unzeroed)
52 + memset(bo->base.vaddr, 0, bo->base.base.size);
56 /* Otherwise, make a new BO. */