[Mesa-dev] [PATCH 01/14] radeonsi: Add buffer for offchip storage between TCS and TES.

[Bas Nieuwenhuizen]

The buffer is quite large, but should only be allocated if the
application uses tessellation. Most non-games don't.

Signed-off-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
---
 src/gallium/drivers/radeonsi/si_pipe.c          |  1 +
 src/gallium/drivers/radeonsi/si_pipe.h          |  1 +
 src/gallium/drivers/radeonsi/si_state.h         |  1 +
 src/gallium/drivers/radeonsi/si_state_shaders.c | 17 +++++++++++++++++
 4 files changed, 20 insertions(+)

diff --git a/src/gallium/drivers/radeonsi/si_pipe.c b/src/gallium/drivers/radeonsi/si_pipe.c
index 61d5578..10123d4 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.c
+++ b/src/gallium/drivers/radeonsi/si_pipe.c
@@ -48,6 +48,7 @@ static void si_destroy_context(struct pipe_context *context)
 	pipe_resource_reference(&sctx->esgs_ring, NULL);
 	pipe_resource_reference(&sctx->gsvs_ring, NULL);
 	pipe_resource_reference(&sctx->tf_ring, NULL);
+	pipe_resource_reference(&sctx->tess_offchip_ring, NULL);
 	pipe_resource_reference(&sctx->null_const_buf.buffer, NULL);
 	r600_resource_reference(&sctx->border_color_buffer, NULL);
 	free(sctx->border_color_table);
diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h
index d31e9a9..b219dd4 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.h
+++ b/src/gallium/drivers/radeonsi/si_pipe.h
@@ -256,6 +256,7 @@ struct si_context {
 	struct pipe_resource		*esgs_ring;
 	struct pipe_resource		*gsvs_ring;
 	struct pipe_resource		*tf_ring;
+	struct pipe_resource		*tess_offchip_ring;
 	union pipe_color_union		*border_color_table; /* in CPU memory, any endian */
 	struct r600_resource		*border_color_buffer;
 	union pipe_color_union		*border_color_map; /* in VRAM (slow access), little endian */
diff --git a/src/gallium/drivers/radeonsi/si_state.h b/src/gallium/drivers/radeonsi/si_state.h
index f2a3b03..6d4346b 100644
--- a/src/gallium/drivers/radeonsi/si_state.h
+++ b/src/gallium/drivers/radeonsi/si_state.h
@@ -155,6 +155,7 @@ struct si_shader_data {
 /* Private read-write buffer slots. */
 enum {
 	SI_HS_RING_TESS_FACTOR,
+	SI_HS_RING_TESS_OFFCHIP,
 
 	SI_ES_RING_ESGS,
 	SI_GS_RING_ESGS,
diff --git a/src/gallium/drivers/radeonsi/si_state_shaders.c b/src/gallium/drivers/radeonsi/si_state_shaders.c
index 0bfd7e8..0fa32c8 100644
--- a/src/gallium/drivers/radeonsi/si_state_shaders.c
+++ b/src/gallium/drivers/radeonsi/si_state_shaders.c
@@ -1772,6 +1772,15 @@ static void si_init_tess_factor_ring(struct si_context *sctx)
 
 	assert(((sctx->tf_ring->width0 / 4) & C_030938_SIZE) == 0);
 
+	/* The size is derived from 256 blocks of 8192 dwords each, as set in
+	 * R_03093C_VGT_HS_OFFCHIP_PARAM. */
+	sctx->tess_offchip_ring = pipe_buffer_create(sctx->b.b.screen,
+	                                             PIPE_BIND_CUSTOM,
+	                                             PIPE_USAGE_DEFAULT,
+	                                             8 * 1024 * 1024);
+	if (!sctx->tess_offchip_ring)
+		return;
+
 	si_init_config_add_vgt_flush(sctx);
 
 	/* Append these registers to the init config state. */
@@ -1787,6 +1796,10 @@ static void si_init_tess_factor_ring(struct si_context *sctx)
 			       r600_resource(sctx->tf_ring)->gpu_address >> 8);
 	}
 
+	si_pm4_set_reg(sctx->init_config, R_03093C_VGT_HS_OFFCHIP_PARAM,
+	               S_03093C_OFFCHIP_BUFFERING(0xFF) |
+	               S_03093C_OFFCHIP_GRANULARITY(V_03093C_X_8K_DWORDS));
+
 	/* Flush the context to re-emit the init_config state.
 	 * This is done only once in a lifetime of a context.
 	 */
@@ -1796,6 +1809,10 @@ static void si_init_tess_factor_ring(struct si_context *sctx)
 
 	si_set_ring_buffer(&sctx->b.b, SI_HS_RING_TESS_FACTOR, sctx->tf_ring,
 			   0, sctx->tf_ring->width0, false, false, 0, 0, 0);
+
+	si_set_ring_buffer(&sctx->b.b, SI_HS_RING_TESS_OFFCHIP,
+	                   sctx->tess_offchip_ring, 0,
+	                   sctx->tess_offchip_ring->width0, false, false, 0, 0, 0);
 }
 
 /**
-- 
2.8.2