drm/i915/selftests: Add compiler paranoia for checking HWSP values

Since we want to read the values from the HWSP as written to by the GPU,
warn the compiler that the values are volatile.

Signed-off-by: Chris Wilson <[email protected]>
Cc: Mika Kuoppala <[email protected]>
Reviewed-by: Mika Kuoppala <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Rodrigo Vivi <[email protected]>

1 files changed, 13 insertions, 11 deletions

diff --git a/drivers/gpu/drm/i915/gt/selftest_timeline.c b/drivers/gpu/drm/i915/gt/selftest_timeline.c
index fb5b7d3498a6..6564c989dbee 100644
--- a/drivers/gpu/drm/i915/gt/selftest_timeline.c
+++ b/drivers/gpu/drm/i915/gt/selftest_timeline.c
@@ -491,7 +491,7 @@ checked_intel_timeline_create(struct intel_gt *gt)
 	if (IS_ERR(tl))
 		return tl;
 
-	if (*tl->hwsp_seqno != tl->seqno) {
+	if (READ_ONCE(*tl->hwsp_seqno) != tl->seqno) {
 		pr_err("Timeline created with incorrect breadcrumb, found %x, expected %x\n",
 		       *tl->hwsp_seqno, tl->seqno);
 		intel_timeline_put(tl);
@@ -561,9 +561,9 @@ static int live_hwsp_engine(void *arg)
 	for (n = 0; n < count; n++) {
 		struct intel_timeline *tl = timelines[n];
 
-		if (!err && *tl->hwsp_seqno != n) {
-			pr_err("Invalid seqno stored in timeline %lu @ %x, found 0x%x\n",
-			       n, tl->hwsp_offset, *tl->hwsp_seqno);
+		if (!err && READ_ONCE(*tl->hwsp_seqno) != n) {
+			GEM_TRACE_ERR("Invalid seqno:%lu stored in timeline %llu @ %x, found 0x%x\n",
+				      n, tl->fence_context, tl->hwsp_offset, *tl->hwsp_seqno);
 			GEM_TRACE_DUMP();
 			err = -EINVAL;
 		}
@@ -633,9 +633,9 @@ out:
 	for (n = 0; n < count; n++) {
 		struct intel_timeline *tl = timelines[n];
 
-		if (!err && *tl->hwsp_seqno != n) {
-			pr_err("Invalid seqno stored in timeline %lu @ %x, found 0x%x\n",
-			       n, tl->hwsp_offset, *tl->hwsp_seqno);
+		if (!err && READ_ONCE(*tl->hwsp_seqno) != n) {
+			GEM_TRACE_ERR("Invalid seqno:%lu stored in timeline %llu @ %x, found 0x%x\n",
+				      n, tl->fence_context, tl->hwsp_offset, *tl->hwsp_seqno);
 			GEM_TRACE_DUMP();
 			err = -EINVAL;
 		}
@@ -733,7 +733,8 @@ static int live_hwsp_wrap(void *arg)
 			goto out;
 		}
 
-		if (*hwsp_seqno[0] != seqno[0] || *hwsp_seqno[1] != seqno[1]) {
+		if (READ_ONCE(*hwsp_seqno[0]) != seqno[0] ||
+		    READ_ONCE(*hwsp_seqno[1]) != seqno[1]) {
 			pr_err("Bad timeline values: found (%x, %x), expected (%x, %x)\n",
 			       *hwsp_seqno[0], *hwsp_seqno[1],
 			       seqno[0], seqno[1]);
@@ -966,9 +967,10 @@ static int live_hwsp_recycle(void *arg)
 				break;
 			}
 
-			if (*tl->hwsp_seqno != count) {
-				pr_err("Invalid seqno stored in timeline %lu @ tl->hwsp_offset, found 0x%x\n",
-				       count, *tl->hwsp_seqno);
+			if (READ_ONCE(*tl->hwsp_seqno) != count) {
+				GEM_TRACE_ERR("Invalid seqno:%lu stored in timeline %llu @ %x found 0x%x\n",
+					      count, tl->fence_context,
+					      tl->hwsp_offset, *tl->hwsp_seqno);
 				GEM_TRACE_DUMP();
 				err = -EINVAL;
 			}