From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Replace the kvmalloc_array() with i915_gem_object_get_dma_address() when
populating rotated vmas. One random access mechanism ought to be enough
for everyone?
To calculate the size of the radix tree I think we can do
something like this (assuming 64bit pointers):
num_pages = obj_size / 4096
tree_height = ceil(log64(num_pages))
num_nodes = sum(64^n, n, 0, tree_height-1)
tree_size = num_nodes * 576
If we compare that with the object size we should get a relative
overhead of around .2% to 1% for reasonable sized objects,
which framebuffers tend to be.
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
Suggested-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_gem_gtt.c | 31 ++++++-----------------------
1 file changed, 6 insertions(+), 25 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 29ca9007a704..98d9a1eb1ed2 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -3637,7 +3637,7 @@ void i915_gem_restore_gtt_mappings(struct drm_i915_private *dev_priv)
}
static struct scatterlist *
-rotate_pages(const dma_addr_t *in, unsigned int offset,
+rotate_pages(struct drm_i915_gem_object *obj, unsigned int offset,
unsigned int width, unsigned int height,
unsigned int stride,
struct sg_table *st, struct scatterlist *sg)
@@ -3646,7 +3646,7 @@ rotate_pages(const dma_addr_t *in, unsigned int offset,
unsigned int src_idx;
for (column = 0; column < width; column++) {
- src_idx = stride * (height - 1) + column;
+ src_idx = stride * (height - 1) + column + offset;
for (row = 0; row < height; row++) {
st->nents++;
/* We don't need the pages, but need to initialize
@@ -3654,7 +3654,8 @@ rotate_pages(const dma_addr_t *in, unsigned int offset,
* The only thing we need are DMA addresses.
*/
sg_set_page(sg, NULL, I915_GTT_PAGE_SIZE, 0);
- sg_dma_address(sg) = in[offset + src_idx];
+ sg_dma_address(sg) =
+ i915_gem_object_get_dma_address(obj, src_idx);
sg_dma_len(sg) = I915_GTT_PAGE_SIZE;
sg = sg_next(sg);
src_idx -= stride;
@@ -3668,22 +3669,11 @@ static noinline struct sg_table *
intel_rotate_pages(struct intel_rotation_info *rot_info,
struct drm_i915_gem_object *obj)
{
- const unsigned long n_pages = obj->base.size / I915_GTT_PAGE_SIZE;
unsigned int size = intel_rotation_info_size(rot_info);
- struct sgt_iter sgt_iter;
- dma_addr_t dma_addr;
- unsigned long i;
- dma_addr_t *page_addr_list;
struct sg_table *st;
struct scatterlist *sg;
int ret = -ENOMEM;
-
- /* Allocate a temporary list of source pages for random access. */
- page_addr_list = kvmalloc_array(n_pages,
- sizeof(dma_addr_t),
- GFP_KERNEL);
- if (!page_addr_list)
- return ERR_PTR(ret);
+ int i;
/* Allocate target SG list. */
st = kmalloc(sizeof(*st), GFP_KERNEL);
@@ -3694,29 +3684,20 @@ intel_rotate_pages(struct intel_rotation_info *rot_info,
if (ret)
goto err_sg_alloc;
- /* Populate source page list from the object. */
- i = 0;
- for_each_sgt_dma(dma_addr, sgt_iter, obj->mm.pages)
- page_addr_list[i++] = dma_addr;
-
- GEM_BUG_ON(i != n_pages);
st->nents = 0;
sg = st->sgl;
for (i = 0 ; i < ARRAY_SIZE(rot_info->plane); i++) {
- sg = rotate_pages(page_addr_list, rot_info->plane[i].offset,
+ sg = rotate_pages(obj, rot_info->plane[i].offset,
rot_info->plane[i].width, rot_info->plane[i].height,
rot_info->plane[i].stride, st, sg);
}
- kvfree(page_addr_list);
-
return st;
err_sg_alloc:
kfree(st);
err_st_alloc:
- kvfree(page_addr_list);
DRM_DEBUG_DRIVER("Failed to create rotated mapping for object size %zu! (%ux%u tiles, %u pages)\n",
obj->base.size, rot_info->plane[0].width, rot_info->plane[0].height, size);
--
2.18.1
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