[Mesa-dev] [PATCH v2 1/2] anv: Implement VK_KHR_draw_indirect_count for gen 7+

Danylo Piliaiev danylo.piliaiev at gmail.com
Tue Nov 6 16:18:33 UTC 2018


v2: by Jason Ekstrand
  - Move out of the draw loop population of registers
    which aren't changed in it
  - Remove dependency on ALU registers
  - Clarify usage of PIPE_CONTROL
  - Without usage of ALU registers patch works for gen7+

Signed-off-by: Danylo Piliaiev <danylo.piliaiev at globallogic.com>
---

I'm uncertain about usage of PIPE_CONTROL with PipeControlFlushEnable here
since before it cmd_buffer_flush_state is called which does a lot of related
things so PIPE_CONTROL may be unnecessary.

 src/intel/vulkan/anv_extensions.py |   1 +
 src/intel/vulkan/genX_cmd_buffer.c | 156 +++++++++++++++++++++++++++++
 2 files changed, 157 insertions(+)

diff --git a/src/intel/vulkan/anv_extensions.py b/src/intel/vulkan/anv_extensions.py
index e9afe06bb1..a6a381b1f3 100644
--- a/src/intel/vulkan/anv_extensions.py
+++ b/src/intel/vulkan/anv_extensions.py
@@ -113,6 +113,7 @@ EXTENSIONS = [
     Extension('VK_KHR_xlib_surface',                      6, 'VK_USE_PLATFORM_XLIB_KHR'),
     Extension('VK_KHR_multiview',                         1, True),
     Extension('VK_KHR_display',                          23, 'VK_USE_PLATFORM_DISPLAY_KHR'),
+    Extension('VK_KHR_draw_indirect_count',               1, True),
     Extension('VK_EXT_acquire_xlib_display',              1, 'VK_USE_PLATFORM_XLIB_XRANDR_EXT'),
     Extension('VK_EXT_debug_report',                      8, True),
     Extension('VK_EXT_direct_mode_display',               1, 'VK_USE_PLATFORM_DISPLAY_KHR'),
diff --git a/src/intel/vulkan/genX_cmd_buffer.c b/src/intel/vulkan/genX_cmd_buffer.c
index ed88157170..4c6bca48f3 100644
--- a/src/intel/vulkan/genX_cmd_buffer.c
+++ b/src/intel/vulkan/genX_cmd_buffer.c
@@ -2989,6 +2989,162 @@ void genX(CmdDrawIndexedIndirect)(
    }
 }
 
+static void
+prepare_for_draw_count_predicate(struct anv_cmd_buffer *cmd_buffer,
+                                 struct anv_address count_address)
+{
+   /* From the Sky Lake PRM Vol 7, MI_PREDICATE:
+    *
+    *    "MI_LOAD_REGISTER_MEM commands can be used to load the
+    *    MItemp0, MItemp1, and PredicateData registers prior
+    *    to MI_PREDICATE. To ensure the memory sources of the
+    *    MI_LOAD_REGISTER_MEM commands are coherent with previous
+    *    3D_PIPECONTROL store-DWord operations, software can use the
+    *    new Pipe Control Flush Enable bit in the PIPE_CONTROL command."
+    */
+   anv_batch_emit(&cmd_buffer->batch, GENX(PIPE_CONTROL), pc) {
+     pc.PipeControlFlushEnable = true;
+   }
+
+   /* Upload the current draw count from the draw parameters buffer to
+    * MI_PREDICATE_SRC0.
+    */
+   emit_lrm(&cmd_buffer->batch, MI_PREDICATE_SRC0, count_address);
+   emit_lri(&cmd_buffer->batch, MI_PREDICATE_SRC0 + 4, 0);
+
+   emit_lri(&cmd_buffer->batch, MI_PREDICATE_SRC1 + 4, 0);
+}
+
+static void
+emit_draw_count_predicate(struct anv_cmd_buffer *cmd_buffer,
+                          uint32_t draw_index)
+{
+   /* Upload the index of the current primitive to MI_PREDICATE_SRC1. */
+   emit_lri(&cmd_buffer->batch, MI_PREDICATE_SRC1, draw_index);
+
+   if (draw_index == 0) {
+       anv_batch_emit(&cmd_buffer->batch, GENX(MI_PREDICATE), mip) {
+          mip.LoadOperation    = LOAD_LOADINV;
+          mip.CombineOperation = COMBINE_SET;
+          mip.CompareOperation = COMPARE_SRCS_EQUAL;
+       }
+   } else {
+       /* While draw_index < draw_count the predicate's result will be
+        *  (draw_index == draw_count) ^ TRUE = TRUE
+        * When draw_index == draw_count the result is
+        *  (TRUE) ^ TRUE = FALSE
+        * After this all results will be:
+        *  (FALSE) ^ FALSE = FALSE
+        */
+       anv_batch_emit(&cmd_buffer->batch, GENX(MI_PREDICATE), mip) {
+          mip.LoadOperation    = LOAD_LOAD;
+          mip.CombineOperation = COMBINE_XOR;
+          mip.CompareOperation = COMPARE_SRCS_EQUAL;
+       }
+   }
+}
+
+void genX(CmdDrawIndirectCountKHR)(
+    VkCommandBuffer                             commandBuffer,
+    VkBuffer                                    _buffer,
+    VkDeviceSize                                offset,
+    VkBuffer                                    _countBuffer,
+    VkDeviceSize                                countBufferOffset,
+    uint32_t                                    maxDrawCount,
+    uint32_t                                    stride)
+{
+   ANV_FROM_HANDLE(anv_cmd_buffer, cmd_buffer, commandBuffer);
+   ANV_FROM_HANDLE(anv_buffer, buffer, _buffer);
+   ANV_FROM_HANDLE(anv_buffer, count_buffer, _countBuffer);
+   struct anv_cmd_state *cmd_state = &cmd_buffer->state;
+   struct anv_pipeline *pipeline = cmd_state->gfx.base.pipeline;
+   const struct brw_vs_prog_data *vs_prog_data = get_vs_prog_data(pipeline);
+
+   if (anv_batch_has_error(&cmd_buffer->batch))
+      return;
+
+   genX(cmd_buffer_flush_state)(cmd_buffer);
+
+   struct anv_address count_address =
+      anv_address_add(count_buffer->address, countBufferOffset);
+
+   prepare_for_draw_count_predicate(cmd_buffer, count_address);
+
+   for (uint32_t i = 0; i < maxDrawCount; i++) {
+      struct anv_address draw = anv_address_add(buffer->address, offset);
+
+      emit_draw_count_predicate(cmd_buffer, i);
+
+      if (vs_prog_data->uses_firstvertex ||
+          vs_prog_data->uses_baseinstance)
+         emit_base_vertex_instance_bo(cmd_buffer, anv_address_add(draw, 8));
+      if (vs_prog_data->uses_drawid)
+         emit_draw_index(cmd_buffer, i);
+
+      load_indirect_parameters(cmd_buffer, draw, false);
+
+      anv_batch_emit(&cmd_buffer->batch, GENX(3DPRIMITIVE), prim) {
+         prim.IndirectParameterEnable  = true;
+         prim.PredicateEnable          = true;
+         prim.VertexAccessType         = SEQUENTIAL;
+         prim.PrimitiveTopologyType    = pipeline->topology;
+      }
+
+      offset += stride;
+   }
+}
+
+void genX(CmdDrawIndexedIndirectCountKHR)(
+    VkCommandBuffer                             commandBuffer,
+    VkBuffer                                    _buffer,
+    VkDeviceSize                                offset,
+    VkBuffer                                    _countBuffer,
+    VkDeviceSize                                countBufferOffset,
+    uint32_t                                    maxDrawCount,
+    uint32_t                                    stride)
+{
+   ANV_FROM_HANDLE(anv_cmd_buffer, cmd_buffer, commandBuffer);
+   ANV_FROM_HANDLE(anv_buffer, buffer, _buffer);
+   ANV_FROM_HANDLE(anv_buffer, count_buffer, _countBuffer);
+   struct anv_cmd_state *cmd_state = &cmd_buffer->state;
+   struct anv_pipeline *pipeline = cmd_state->gfx.base.pipeline;
+   const struct brw_vs_prog_data *vs_prog_data = get_vs_prog_data(pipeline);
+
+   if (anv_batch_has_error(&cmd_buffer->batch))
+      return;
+
+   genX(cmd_buffer_flush_state)(cmd_buffer);
+
+   struct anv_address count_address =
+      anv_address_add(count_buffer->address, countBufferOffset);
+
+   prepare_for_draw_count_predicate(cmd_buffer, count_address);
+
+   for (uint32_t i = 0; i < maxDrawCount; i++) {
+      struct anv_address draw = anv_address_add(buffer->address, offset);
+
+      emit_draw_count_predicate(cmd_buffer, i);
+
+      /* TODO: We need to stomp base vertex to 0 somehow */
+      if (vs_prog_data->uses_firstvertex ||
+          vs_prog_data->uses_baseinstance)
+         emit_base_vertex_instance_bo(cmd_buffer, anv_address_add(draw, 12));
+      if (vs_prog_data->uses_drawid)
+         emit_draw_index(cmd_buffer, i);
+
+      load_indirect_parameters(cmd_buffer, draw, true);
+
+      anv_batch_emit(&cmd_buffer->batch, GENX(3DPRIMITIVE), prim) {
+         prim.IndirectParameterEnable  = true;
+         prim.PredicateEnable          = true;
+         prim.VertexAccessType         = RANDOM;
+         prim.PrimitiveTopologyType    = pipeline->topology;
+      }
+
+      offset += stride;
+   }
+}
+
 static VkResult
 flush_compute_descriptor_set(struct anv_cmd_buffer *cmd_buffer)
 {
-- 
2.18.0



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