iris: Insert buffer-local memory barriers for indirect draw parameters.

This adds buffer-local barriers so any required synchronization
commands are emitted before a buffer object is used as source for
indirect draw parameters.  An unconditional PIPE_CONTROL meant to
flush the contents of the draw count buffer can now be removed, since
it's redundant with the more accurate buffer-local barrier introduced
here, which should avoid flushing in cases where the buffer wasn't
written by any incoherent cache since the last flush.

(Rebased by Kenneth Graunke.)

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12691>

diff --git a/src/gallium/drivers/iris/iris_draw.c b/src/gallium/drivers/iris/iris_draw.c
index 2f76be1..0616571 100644 (file)
--- a/src/gallium/drivers/iris/iris_draw.c
+++ b/src/gallium/drivers/iris/iris_draw.c
@@ -187,10 +187,19 @@ iris_indirect_draw_vbo(struct iris_context *ice,
    struct pipe_draw_info info = *dinfo;
    struct pipe_draw_indirect_info indirect = *dindirect;
 
-   if (indirect.indirect_draw_count &&
-       ice->state.predicate == IRIS_PREDICATE_STATE_USE_BIT) {
-      /* Upload MI_PREDICATE_RESULT to GPR15.*/
-      batch->screen->vtbl.load_register_reg64(batch, CS_GPR(15), MI_PREDICATE_RESULT);
+   iris_emit_buffer_barrier_for(batch, iris_resource_bo(indirect.buffer),
+                                IRIS_DOMAIN_VF_READ);
+
+   if (indirect.indirect_draw_count) {
+      struct iris_bo *draw_count_bo =
+         iris_resource_bo(indirect.indirect_draw_count);
+      iris_emit_buffer_barrier_for(batch, draw_count_bo,
+                                   IRIS_DOMAIN_OTHER_READ);
+
+      if (ice->state.predicate == IRIS_PREDICATE_STATE_USE_BIT) {
+         /* Upload MI_PREDICATE_RESULT to GPR15.*/
+         batch->screen->vtbl.load_register_reg64(batch, CS_GPR(15), MI_PREDICATE_RESULT);
+      }
    }
 
    const uint64_t orig_dirty = ice->state.dirty;

diff --git a/src/gallium/drivers/iris/iris_state.c b/src/gallium/drivers/iris/iris_state.c
index be87c60..a6d5668 100644 (file)
--- a/src/gallium/drivers/iris/iris_state.c
+++ b/src/gallium/drivers/iris/iris_state.c
@@ -6735,10 +6735,6 @@ iris_upload_render_state(struct iris_context *ice,
          unsigned draw_count_offset =
             indirect->indirect_draw_count_offset;
 
-         iris_emit_pipe_control_flush(batch,
-                                      "ensure indirect draw buffer is flushed",
-                                      PIPE_CONTROL_FLUSH_ENABLE);
-
          if (ice->state.predicate == IRIS_PREDICATE_STATE_USE_BIT) {
             struct mi_builder b;
             mi_builder_init(&b, &batch->screen->devinfo, batch);