[PATCH 2/4] drm/i915: Support appending to the rotated pages mapping

Tvrtko Ursulin
2015-09-21T09:45:42Z

From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

By providing a start offset into the source array of pages, and returning the
end position in the scatter-gather table, we will be able to append the UV
plane to the rotated mapping in later patches.

v2: Rebase.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
drivers/gpu/drm/i915/i915_gem_gtt.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 87862813cfde..59c934fb9230 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -3234,15 +3234,18 @@ i915_gem_obj_lookup_or_create_ggtt_vma(struct drm_i915_gem_object *obj,

}

-static void
-rotate_pages(dma_addr_t *in, unsigned int width, unsigned int height,
- struct sg_table *st)
+static struct scatterlist *
+rotate_pages(dma_addr_t *in, unsigned int offset,
+ unsigned int width, unsigned int height,
+ struct sg_table *st, struct scatterlist *sg)
{
unsigned int column, row;
unsigned int src_idx;
- struct scatterlist *sg = st->sgl;

- st->nents = 0;
+ if (!sg) {
+ st->nents = 0;
+ sg = st->sgl;
+ }

for (column = 0; column < width; column++) {
src_idx = width * (height - 1) + column;
@@ -3253,12 +3256,14 @@ rotate_pages(dma_addr_t *in, unsigned int width, unsigned int height,
* The only thing we need are DMA addresses.
*/
sg_set_page(sg, NULL, PAGE_SIZE, 0);
- sg_dma_address(sg) = in[src_idx];
+ sg_dma_address(sg) = in[offset + src_idx];
sg_dma_len(sg) = PAGE_SIZE;
sg = sg_next(sg);
src_idx -= width;
}
}
+
+ return sg;
}

static struct sg_table *
@@ -3296,9 +3301,9 @@ intel_rotate_fb_obj_pages(struct i915_ggtt_view *ggtt_view,
}

/* Rotate the pages. */
- rotate_pages(page_addr_list,
+ rotate_pages(page_addr_list, 0,
rot_info->width_pages, rot_info->height_pages,
- st);
+ st, NULL);

DRM_DEBUG_KMS(
"Created rotated page mapping for object size %zu (pitch=%u, height=%u, pixel_format=0x%x, %ux%u tiles, %u pages).\n",
--
2.5.1