drm/i915/adlp: Add support for remapping CCS FBs

Add support for remapping CCS FBs on ADL-P to remove the restriction
of the power-of-two sized stride and the 2MB surface offset alignment
for these FBs.

We can only remap the tiles on the main surface, not the tiles on the
CCS surface, so userspace has to generate the CCS surface aligning to
the POT size padded main surface stride (by programming the AUX
pagetable accordingly). For the required AUX pagetable setup, this
requires that either the main surface stride is 8 tiles or that the
stride is 16 tiles aligned (= 64 kbytes, the area mapped by one AUX
PTE).

v2:
- Init intel_remapped_info::plane_alignment only for remapped views and
  do this from intel_fb_view_init().

Cc: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210906182715.3915100-6-imre.deak@intel.com

1 files changed, 27 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
index de3ac58fceec..cbd0e1010a46 100644
--- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
@@ -1373,13 +1373,28 @@ err_st_alloc:
 }
 
 static struct scatterlist *
-remap_pages(struct drm_i915_gem_object *obj, unsigned int offset,
+remap_pages(struct drm_i915_gem_object *obj,
+	    unsigned int offset, unsigned int alignment_pad,
 	    unsigned int width, unsigned int height,
 	    unsigned int src_stride, unsigned int dst_stride,
 	    struct sg_table *st, struct scatterlist *sg)
 {
 	unsigned int row;
 
+	if (alignment_pad) {
+		st->nents++;
+
+		/*
+		 * The DE ignores the PTEs for the padding tiles, the sg entry
+		 * here is just a convenience to indicate how many padding PTEs
+		 * to insert at this spot.
+		 */
+		sg_set_page(sg, NULL, alignment_pad * 4096, 0);
+		sg_dma_address(sg) = 0;
+		sg_dma_len(sg) = alignment_pad * 4096;
+		sg = sg_next(sg);
+	}
+
 	for (row = 0; row < height; row++) {
 		unsigned int left = width * I915_GTT_PAGE_SIZE;
 
@@ -1439,6 +1454,7 @@ intel_remap_pages(struct intel_remapped_info *rem_info,
 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
 	struct sg_table *st;
 	struct scatterlist *sg;
+	unsigned int gtt_offset = 0;
 	int ret = -ENOMEM;
 	int i;
 
@@ -1455,10 +1471,19 @@ intel_remap_pages(struct intel_remapped_info *rem_info,
 	sg = st->sgl;
 
 	for (i = 0 ; i < ARRAY_SIZE(rem_info->plane); i++) {
-		sg = remap_pages(obj, rem_info->plane[i].offset,
+		unsigned int alignment_pad = 0;
+
+		if (rem_info->plane_alignment)
+			alignment_pad = ALIGN(gtt_offset, rem_info->plane_alignment) - gtt_offset;
+
+		sg = remap_pages(obj,
+				 rem_info->plane[i].offset, alignment_pad,
 				 rem_info->plane[i].width, rem_info->plane[i].height,
 				 rem_info->plane[i].src_stride, rem_info->plane[i].dst_stride,
 				 st, sg);
+
+		gtt_offset += alignment_pad +
+			      rem_info->plane[i].dst_stride * rem_info->plane[i].height;
 	}
 
 	i915_sg_trim(st);