Mesa (master): radeonsi: implement SDMA-based buffer clearing for CIK-VI

[Marek Olšák]

Module: Mesa
Branch: master
Commit: d4c0ad4de8c4eeec1cc0478b12ce542e9a7faa0f
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=d4c0ad4de8c4eeec1cc0478b12ce542e9a7faa0f

Author: Marek Olšák <marek.olsak at amd.com>
Date:   Sat Dec 24 22:52:45 2016 +0100

radeonsi: implement SDMA-based buffer clearing for CIK-VI

Reviewed-by: Nicolai Hähnle <nicolai.haehnle at amd.com>

---

 src/gallium/drivers/radeon/r600_pipe_common.c |  9 ++++++
 src/gallium/drivers/radeon/r600_pipe_common.h |  3 ++
 src/gallium/drivers/radeonsi/cik_sdma.c       | 42 +++++++++++++++++++++++++++
 3 files changed, 54 insertions(+)

diff --git a/src/gallium/drivers/radeon/r600_pipe_common.c b/src/gallium/drivers/radeon/r600_pipe_common.c
index e0b914c..a319845 100644
--- a/src/gallium/drivers/radeon/r600_pipe_common.c
+++ b/src/gallium/drivers/radeon/r600_pipe_common.c
@@ -533,6 +533,14 @@ bool r600_check_device_reset(struct r600_common_context *rctx)
 	return true;
 }
 
+static void r600_dma_clear_buffer_fallback(struct pipe_context *ctx,
+					   struct pipe_resource *dst,
+					   uint64_t offset, uint64_t size,
+					   unsigned value)
+{
+	ctx->clear_buffer(ctx, dst, offset, size, &value, 4);
+}
+
 bool r600_common_context_init(struct r600_common_context *rctx,
 			      struct r600_common_screen *rscreen,
 			      unsigned context_flags)
@@ -559,6 +567,7 @@ bool r600_common_context_init(struct r600_common_context *rctx,
 	rctx->b.memory_barrier = r600_memory_barrier;
 	rctx->b.flush = r600_flush_from_st;
 	rctx->b.set_debug_callback = r600_set_debug_callback;
+	rctx->dma_clear_buffer = r600_dma_clear_buffer_fallback;
 
 	/* evergreen_compute.c has a special codepath for global buffers.
 	 * Everything else can use the direct path.
diff --git a/src/gallium/drivers/radeon/r600_pipe_common.h b/src/gallium/drivers/radeon/r600_pipe_common.h
index 25d40da..da4b63c 100644
--- a/src/gallium/drivers/radeon/r600_pipe_common.h
+++ b/src/gallium/drivers/radeon/r600_pipe_common.h
@@ -626,6 +626,9 @@ struct r600_common_context {
 			 unsigned src_level,
 			 const struct pipe_box *src_box);
 
+	void (*dma_clear_buffer)(struct pipe_context *ctx, struct pipe_resource *dst,
+				 uint64_t offset, uint64_t size, unsigned value);
+
 	void (*clear_buffer)(struct pipe_context *ctx, struct pipe_resource *dst,
 			     uint64_t offset, uint64_t size, unsigned value,
 			     enum r600_coherency coher);
diff --git a/src/gallium/drivers/radeonsi/cik_sdma.c b/src/gallium/drivers/radeonsi/cik_sdma.c
index b3eaed5..698f8f6 100644
--- a/src/gallium/drivers/radeonsi/cik_sdma.c
+++ b/src/gallium/drivers/radeonsi/cik_sdma.c
@@ -82,6 +82,47 @@ static void cik_sdma_copy_buffer(struct si_context *ctx,
 	r600_dma_emit_wait_idle(&ctx->b);
 }
 
+static void cik_sdma_clear_buffer(struct pipe_context *ctx,
+				  struct pipe_resource *dst,
+				  uint64_t offset,
+				  uint64_t size,
+				  unsigned clear_value)
+{
+	struct si_context *sctx = (struct si_context *)ctx;
+	struct radeon_winsys_cs *cs = sctx->b.dma.cs;
+	unsigned i, ncopy, csize;
+	struct r600_resource *rdst = r600_resource(dst);
+
+	if (!cs || offset % 4 != 0 || size % 4 != 0) {
+		ctx->clear_buffer(ctx, dst, offset, size, &clear_value, 4);
+		return;
+	}
+
+	/* Mark the buffer range of destination as valid (initialized),
+	 * so that transfer_map knows it should wait for the GPU when mapping
+	 * that range. */
+	util_range_add(&rdst->valid_buffer_range, offset, offset + size);
+
+	offset += rdst->gpu_address;
+
+	/* the same maximum size as for copying */
+	ncopy = DIV_ROUND_UP(size, CIK_SDMA_COPY_MAX_SIZE);
+	r600_need_dma_space(&sctx->b, ncopy * 5, rdst, NULL);
+
+	for (i = 0; i < ncopy; i++) {
+		csize = MIN2(size, CIK_SDMA_COPY_MAX_SIZE);
+		radeon_emit(cs, CIK_SDMA_PACKET(CIK_SDMA_PACKET_CONSTANT_FILL, 0,
+						0x8000 /* dword copy */));
+		radeon_emit(cs, offset);
+		radeon_emit(cs, offset >> 32);
+		radeon_emit(cs, clear_value);
+		radeon_emit(cs, csize);
+		offset += csize;
+		size -= csize;
+	}
+	r600_dma_emit_wait_idle(&sctx->b);
+}
+
 static unsigned minify_as_blocks(unsigned width, unsigned level, unsigned blk_w)
 {
 	width = u_minify(width, level);
@@ -525,4 +566,5 @@ fallback:
 void cik_init_sdma_functions(struct si_context *sctx)
 {
 	sctx->b.dma_copy = cik_sdma_copy;
+	sctx->b.dma_clear_buffer = cik_sdma_clear_buffer;
 }