[Intel-xe] [PATCH 12/15] drm/xe/migrate: retain CCS aux state for vram -> vram

[Matthew Auld]

On small-bar we likely need to be able to deal with vram -> vram
transfers. During eviction, as an optimisation,  we don't always
want/need to kick stuff into smem. Plus for some types of CCS surfaces,
where the clear color needs to be accessed from the CPU, we might need
to migrate it.

v2: (Lucas):
  - s/lmem/vram/ in the commit message
  - Tidy up the code a bit; use one emit_copy_ccs()

Signed-off-by: Matthew Auld <matthew.auld at intel.com>
---
 drivers/gpu/drm/xe/xe_migrate.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c
index cbcc355cd391..418d4f900cdb 100644
--- a/drivers/gpu/drm/xe/xe_migrate.c
+++ b/drivers/gpu/drm/xe/xe_migrate.c
@@ -544,11 +544,19 @@ static u32 xe_migrate_ccs_copy(struct xe_migrate *m,
 
 	if (xe_device_has_flat_ccs(gt_to_xe(gt)) && !copy_ccs && dst_is_vram) {
 		/*
-		 * If the bo doesn't have any CCS metadata attached, we still
-		 * need to clear it for security reasons.
+		 * If the src is already in vram, then it should already
+		 * have been cleared by us, or has been populated by the
+		 * user. Make sure we copy the CCS aux state as-is.
+		 *
+		 * Otherwise if the bo doesn't have any CCS metadata attached,
+		 * we still need to clear it for security reasons.
 		 */
-		emit_copy_ccs(gt, bb, dst_ofs, true, m->cleared_vram_ofs, false,
-			      dst_size);
+		u64 ccs_src_ofs =  src_is_vram ? src_ofs : m->cleared_vram_ofs;
+
+		emit_copy_ccs(gt, bb,
+			      dst_ofs, true,
+			      ccs_src_ofs, src_is_vram, dst_size);
+
 		flush_flags = MI_FLUSH_DW_CCS;
 	} else if (copy_ccs) {
 		if (!src_is_vram)
-- 
2.39.1