From 6a7068b4ef17dfb9de3191321f1adc91fa1659ca Mon Sep 17 00:00:00 2001
From: Dave Airlie <airlied@redhat.com>
Date: Tue, 3 Apr 2012 16:23:41 +0100
Subject: drm/radeon/kms: attempt to avoid copying data twice on coherent
 cards. (v3)

On coherent systems (not-AGP) the IB should be in cached memory so should
be just as fast, so we can avoid copying to temporary pages and just use it
directly.

provides minor speedups on rv530: gears ~1820->1860, ipers: 29.9->30.6,
but always good to use less CPU if we can.

v3: cleanup unneeded bits.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index 5cac832..e7b0b5d 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -278,11 +278,16 @@ int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data)
 				  p->chunks[p->chunk_ib_idx].length_dw);
 			return -EINVAL;
 		}
-		p->chunks[p->chunk_ib_idx].kpage[0] = kmalloc(PAGE_SIZE, GFP_KERNEL);
-		p->chunks[p->chunk_ib_idx].kpage[1] = kmalloc(PAGE_SIZE, GFP_KERNEL);
-		if (p->chunks[p->chunk_ib_idx].kpage[0] == NULL ||
-		    p->chunks[p->chunk_ib_idx].kpage[1] == NULL)
-			return -ENOMEM;
+		if ((p->rdev->flags & RADEON_IS_AGP)) {
+			p->chunks[p->chunk_ib_idx].kpage[0] = kmalloc(PAGE_SIZE, GFP_KERNEL);
+			p->chunks[p->chunk_ib_idx].kpage[1] = kmalloc(PAGE_SIZE, GFP_KERNEL);
+			if (p->chunks[p->chunk_ib_idx].kpage[0] == NULL ||
+			    p->chunks[p->chunk_ib_idx].kpage[1] == NULL) {
+				kfree(p->chunks[i].kpage[0]);
+				kfree(p->chunks[i].kpage[1]);
+				return -ENOMEM;
+			}
+		}
 		p->chunks[p->chunk_ib_idx].kpage_idx[0] = -1;
 		p->chunks[p->chunk_ib_idx].kpage_idx[1] = -1;
 		p->chunks[p->chunk_ib_idx].last_copied_page = -1;
@@ -323,8 +328,10 @@ static void radeon_cs_parser_fini(struct radeon_cs_parser *parser, int error)
 	kfree(parser->relocs_ptr);
 	for (i = 0; i < parser->nchunks; i++) {
 		kfree(parser->chunks[i].kdata);
-		kfree(parser->chunks[i].kpage[0]);
-		kfree(parser->chunks[i].kpage[1]);
+		if ((parser->rdev->flags & RADEON_IS_AGP)) {
+			kfree(parser->chunks[i].kpage[0]);
+			kfree(parser->chunks[i].kpage[1]);
+		}
 	}
 	kfree(parser->chunks);
 	kfree(parser->chunks_array);
@@ -573,6 +580,7 @@ int radeon_cs_update_pages(struct radeon_cs_parser *p, int pg_idx)
 	struct radeon_cs_chunk *ibc = &p->chunks[p->chunk_ib_idx];
 	int i;
 	int size = PAGE_SIZE;
+	bool copy1 = (p->rdev->flags & RADEON_IS_AGP) ? false : true;
 
 	for (i = ibc->last_copied_page + 1; i < pg_idx; i++) {
 		if (DRM_COPY_FROM_USER(p->ib->ptr + (i * (PAGE_SIZE/4)),
@@ -583,14 +591,16 @@ int radeon_cs_update_pages(struct radeon_cs_parser *p, int pg_idx)
 		}
 	}
 
-	new_page = ibc->kpage_idx[0] < ibc->kpage_idx[1] ? 0 : 1;
-
 	if (pg_idx == ibc->last_page_index) {
 		size = (ibc->length_dw * 4) % PAGE_SIZE;
-			if (size == 0)
-				size = PAGE_SIZE;
+		if (size == 0)
+			size = PAGE_SIZE;
 	}
 
+	new_page = ibc->kpage_idx[0] < ibc->kpage_idx[1] ? 0 : 1;
+	if (copy1)
+		ibc->kpage[new_page] = p->ib->ptr + (pg_idx * (PAGE_SIZE / 4));
+
 	if (DRM_COPY_FROM_USER(ibc->kpage[new_page],
 			       ibc->user_ptr + (pg_idx * PAGE_SIZE),
 			       size)) {
@@ -598,8 +608,9 @@ int radeon_cs_update_pages(struct radeon_cs_parser *p, int pg_idx)
 		return 0;
 	}
 
-	/* copy to IB here */
-	memcpy((void *)(p->ib->ptr+(pg_idx*(PAGE_SIZE/4))), ibc->kpage[new_page], size);
+	/* copy to IB for non single case */
+	if (!copy1)
+		memcpy((void *)(p->ib->ptr+(pg_idx*(PAGE_SIZE/4))), ibc->kpage[new_page], size);
 
 	ibc->last_copied_page = pg_idx;
 	ibc->kpage_idx[new_page] = pg_idx;
-- 
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