[Mesa-dev] [PATCH 1/3] radeonsi: don't invalidate VMEM L1 for memory barriers for index buffers

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

---
 src/gallium/drivers/radeonsi/si_state.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/gallium/drivers/radeonsi/si_state.c b/src/gallium/drivers/radeonsi/si_state.c
index ddf6cfe..34f3ed7 100644
--- a/src/gallium/drivers/radeonsi/si_state.c
+++ b/src/gallium/drivers/radeonsi/si_state.c
@@ -3359,20 +3359,21 @@ static void si_set_tess_state(struct pipe_context *ctx,
 static void si_texture_barrier(struct pipe_context *ctx)
 {
 	struct si_context *sctx = (struct si_context *)ctx;
 
 	sctx->b.flags |= SI_CONTEXT_INV_VMEM_L1 |
 			 SI_CONTEXT_INV_GLOBAL_L2 |
 			 SI_CONTEXT_FLUSH_AND_INV_CB |
 			 SI_CONTEXT_CS_PARTIAL_FLUSH;
 }
 
+/* This only ensures coherency for shader image/buffer stores. */
 static void si_memory_barrier(struct pipe_context *ctx, unsigned flags)
 {
 	struct si_context *sctx = (struct si_context *)ctx;
 
 	/* Subsequent commands must wait for all shader invocations to
 	 * complete. */
 	sctx->b.flags |= SI_CONTEXT_PS_PARTIAL_FLUSH |
 	                 SI_CONTEXT_CS_PARTIAL_FLUSH;
 
 	if (flags & PIPE_BARRIER_CONSTANT_BUFFER)
@@ -3385,23 +3386,23 @@ static void si_memory_barrier(struct pipe_context *ctx, unsigned flags)
 		     PIPE_BARRIER_IMAGE |
 		     PIPE_BARRIER_STREAMOUT_BUFFER |
 		     PIPE_BARRIER_GLOBAL_BUFFER)) {
 		/* As far as I can tell, L1 contents are written back to L2
 		 * automatically at end of shader, but the contents of other
 		 * L1 caches might still be stale. */
 		sctx->b.flags |= SI_CONTEXT_INV_VMEM_L1;
 	}
 
 	if (flags & PIPE_BARRIER_INDEX_BUFFER) {
-		sctx->b.flags |= SI_CONTEXT_INV_VMEM_L1;
-
-		/* Indices are read through TC L2 since VI. */
+		/* Indices are read through TC L2 since VI.
+		 * L1 isn't used.
+		 */
 		if (sctx->screen->b.chip_class <= CIK)
 			sctx->b.flags |= SI_CONTEXT_INV_GLOBAL_L2;
 	}
 
 	if (flags & PIPE_BARRIER_FRAMEBUFFER)
 		sctx->b.flags |= SI_CONTEXT_FLUSH_AND_INV_FRAMEBUFFER;
 
 	if (flags & (PIPE_BARRIER_FRAMEBUFFER |
 		     PIPE_BARRIER_INDIRECT_BUFFER)) {
 		/* Not sure if INV_GLOBAL_L2 is the best thing here.
-- 
2.7.4