radeonsi: always prefetch later shaders after the draw packet

so that the draw is started as soon as possible.

v2: only prefetch the API VS and VBO descriptors

Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>

3 files changed, 75 insertions, 26 deletions

diff --git a/src/gallium/drivers/radeonsi/si_cp_dma.c b/src/gallium/drivers/radeonsi/si_cp_dma.c
index e2d261d7e09..358b33c4eb1 100644
--- a/src/gallium/drivers/radeonsi/si_cp_dma.c
+++ b/src/gallium/drivers/radeonsi/si_cp_dma.c
@@ -520,67 +520,110 @@ static void cik_prefetch_VBO_descriptors(struct si_context *sctx)
 				 sctx->vertex_elements->desc_list_byte_size);
 }
 
-void cik_emit_prefetch_L2(struct si_context *sctx)
+/**
+ * Prefetch shaders and VBO descriptors.
+ *
+ * \param vertex_stage_only  Whether only the the API VS and VBO descriptors
+ *                           should be prefetched.
+ */
+void cik_emit_prefetch_L2(struct si_context *sctx, bool vertex_stage_only)
 {
+	unsigned mask = sctx->prefetch_L2_mask;
+	assert(mask);
+
 	/* Prefetch shaders and VBO descriptors to TC L2. */
 	if (sctx->chip_class >= GFX9) {
 		/* Choose the right spot for the VBO prefetch. */
 		if (sctx->tes_shader.cso) {
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_HS)
+			if (mask & SI_PREFETCH_HS)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.hs);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_VBO_DESCRIPTORS)
+			if (mask & SI_PREFETCH_VBO_DESCRIPTORS)
 				cik_prefetch_VBO_descriptors(sctx);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_GS)
+			if (vertex_stage_only) {
+				sctx->prefetch_L2_mask &= ~(SI_PREFETCH_HS |
+							    SI_PREFETCH_VBO_DESCRIPTORS);
+				return;
+			}
+
+			if (mask & SI_PREFETCH_GS)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.gs);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_VS)
+			if (mask & SI_PREFETCH_VS)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.vs);
 		} else if (sctx->gs_shader.cso) {
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_GS)
+			if (mask & SI_PREFETCH_GS)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.gs);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_VBO_DESCRIPTORS)
+			if (mask & SI_PREFETCH_VBO_DESCRIPTORS)
 				cik_prefetch_VBO_descriptors(sctx);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_VS)
+			if (vertex_stage_only) {
+				sctx->prefetch_L2_mask &= ~(SI_PREFETCH_GS |
+							    SI_PREFETCH_VBO_DESCRIPTORS);
+				return;
+			}
+
+			if (mask & SI_PREFETCH_VS)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.vs);
 		} else {
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_VS)
+			if (mask & SI_PREFETCH_VS)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.vs);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_VBO_DESCRIPTORS)
+			if (mask & SI_PREFETCH_VBO_DESCRIPTORS)
 				cik_prefetch_VBO_descriptors(sctx);
+			if (vertex_stage_only) {
+				sctx->prefetch_L2_mask &= ~(SI_PREFETCH_VS |
+							    SI_PREFETCH_VBO_DESCRIPTORS);
+				return;
+			}
 		}
 	} else {
 		/* SI-CI-VI */
 		/* Choose the right spot for the VBO prefetch. */
 		if (sctx->tes_shader.cso) {
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_LS)
+			if (mask & SI_PREFETCH_LS)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.ls);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_VBO_DESCRIPTORS)
+			if (mask & SI_PREFETCH_VBO_DESCRIPTORS)
 				cik_prefetch_VBO_descriptors(sctx);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_HS)
+			if (vertex_stage_only) {
+				sctx->prefetch_L2_mask &= ~(SI_PREFETCH_LS |
+							    SI_PREFETCH_VBO_DESCRIPTORS);
+				return;
+			}
+
+			if (mask & SI_PREFETCH_HS)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.hs);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_ES)
+			if (mask & SI_PREFETCH_ES)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.es);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_GS)
+			if (mask & SI_PREFETCH_GS)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.gs);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_VS)
+			if (mask & SI_PREFETCH_VS)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.vs);
 		} else if (sctx->gs_shader.cso) {
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_ES)
+			if (mask & SI_PREFETCH_ES)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.es);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_VBO_DESCRIPTORS)
+			if (mask & SI_PREFETCH_VBO_DESCRIPTORS)
 				cik_prefetch_VBO_descriptors(sctx);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_GS)
+			if (vertex_stage_only) {
+				sctx->prefetch_L2_mask &= ~(SI_PREFETCH_ES |
+							    SI_PREFETCH_VBO_DESCRIPTORS);
+				return;
+			}
+
+			if (mask & SI_PREFETCH_GS)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.gs);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_VS)
+			if (mask & SI_PREFETCH_VS)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.vs);
 		} else {
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_VS)
+			if (mask & SI_PREFETCH_VS)
 				cik_prefetch_shader_async(sctx, sctx->queued.named.vs);
-			if (sctx->prefetch_L2_mask & SI_PREFETCH_VBO_DESCRIPTORS)
+			if (mask & SI_PREFETCH_VBO_DESCRIPTORS)
 				cik_prefetch_VBO_descriptors(sctx);
+			if (vertex_stage_only) {
+				sctx->prefetch_L2_mask &= ~(SI_PREFETCH_VS |
+							    SI_PREFETCH_VBO_DESCRIPTORS);
+				return;
+			}
 		}
 	}
 
-	if (sctx->prefetch_L2_mask & SI_PREFETCH_PS)
+	if (mask & SI_PREFETCH_PS)
 		cik_prefetch_shader_async(sctx, sctx->queued.named.ps);
 
 	sctx->prefetch_L2_mask = 0;
diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h
index e3e5d5ac91b..c7ad5366a68 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.h
+++ b/src/gallium/drivers/radeonsi/si_pipe.h
@@ -911,7 +911,7 @@ void si_copy_buffer(struct si_context *sctx,
 		    unsigned user_flags);
 void cik_prefetch_TC_L2_async(struct si_context *sctx, struct pipe_resource *buf,
 			      uint64_t offset, unsigned size);
-void cik_emit_prefetch_L2(struct si_context *sctx);
+void cik_emit_prefetch_L2(struct si_context *sctx, bool vertex_stage_only);
 void si_init_cp_dma_functions(struct si_context *sctx);
 
 /* si_debug.c */
diff --git a/src/gallium/drivers/radeonsi/si_state_draw.c b/src/gallium/drivers/radeonsi/si_state_draw.c
index f8d52cbc98f..96dfd93645d 100644
--- a/src/gallium/drivers/radeonsi/si_state_draw.c
+++ b/src/gallium/drivers/radeonsi/si_state_draw.c
@@ -1456,7 +1456,7 @@ void si_draw_vbo(struct pipe_context *ctx, const struct pipe_draw_info *info)
 		 * in parallel, but starting the draw first is more important.
 		 */
 		if (sctx->chip_class >= CIK && sctx->prefetch_L2_mask)
-			cik_emit_prefetch_L2(sctx);
+			cik_emit_prefetch_L2(sctx, false);
 	} else {
 		/* If we don't wait for idle, start prefetches first, then set
 		 * states, and draw at the end.
@@ -1464,14 +1464,20 @@ void si_draw_vbo(struct pipe_context *ctx, const struct pipe_draw_info *info)
 		if (sctx->flags)
 			si_emit_cache_flush(sctx);
 
+		/* Only prefetch the API VS and VBO descriptors. */
 		if (sctx->chip_class >= CIK && sctx->prefetch_L2_mask)
-			cik_emit_prefetch_L2(sctx);
+			cik_emit_prefetch_L2(sctx, true);
 
 		if (!si_upload_graphics_shader_descriptors(sctx))
 			return;
 
 		si_emit_all_states(sctx, info, 0);
 		si_emit_draw_packets(sctx, info, indexbuf, index_size, index_offset);
+
+		/* Prefetch the remaining shaders after the draw has been
+		 * started. */
+		if (sctx->chip_class >= CIK && sctx->prefetch_L2_mask)
+			cik_emit_prefetch_L2(sctx, false);
 	}
 
 	if (unlikely(sctx->current_saved_cs)) {