[Mesa-dev] [PATCH 06/18] i965/cs: Add support for the SEND message that terminates a CS thread.

[Jordan Justen]

From: Paul Berry <stereotype441 at gmail.com>

This message must be sent to the "thread spawner" unit.

Reviewed-by: Jordan Justen <jordan.l.justen at intel.com>
---
 src/mesa/drivers/dri/i965/brw_eu.h      |  4 +++
 src/mesa/drivers/dri/i965/brw_eu_emit.c | 46 +++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/brw_eu.h b/src/mesa/drivers/dri/i965/brw_eu.h
index d9ad5bd..708c216 100644
--- a/src/mesa/drivers/dri/i965/brw_eu.h
+++ b/src/mesa/drivers/dri/i965/brw_eu.h
@@ -349,6 +349,10 @@ brw_jump_scale(const struct brw_context *brw)
    return 1;
 }
 
+void brw_cs_terminate(struct brw_compile *p,
+                      unsigned msg_reg_nr,
+                      struct brw_reg src0);
+
 /* If/else/endif.  Works by manipulating the execution flags on each
  * channel.
  */
diff --git a/src/mesa/drivers/dri/i965/brw_eu_emit.c b/src/mesa/drivers/dri/i965/brw_eu_emit.c
index 43e5783..9c166a3 100644
--- a/src/mesa/drivers/dri/i965/brw_eu_emit.c
+++ b/src/mesa/drivers/dri/i965/brw_eu_emit.c
@@ -2895,3 +2895,49 @@ void brw_shader_time_add(struct brw_compile *p,
                                      0 /* response length */,
                                      false /* header present */);
 }
+
+
+static void
+brw_set_cs_terminate_message(struct brw_context *brw,
+                             struct brw_compile *p,
+                             struct brw_inst *insn)
+{
+   /* Terminate a compute shader by sending a message to the thread spawner.
+    * Note that even though the thread has a URB resource associated with it,
+    * we set the "do not dereference URB" bit, because the URB resource is
+    * managed by the fixed-function unit, so it will free it automatically.
+    */
+   brw_set_message_descriptor(p, insn, BRW_SFID_THREAD_SPAWNER,
+                              1 /* msg_length */,
+                              0 /* response_length */,
+                              false /* header_present */,
+                              true /* end_of_thread */);
+   brw_inst_set_ts_opcode(brw, insn, 0); /* Dereference resource */
+   brw_inst_set_ts_request_type(brw, insn, 0); /* Root thread */
+   brw_inst_set_ts_resource_select(brw, insn, 1); /* Do not dereference URB */
+}
+
+
+/**
+ * Emit the SEND message to terminate a compute shader.
+ */
+void
+brw_cs_terminate(struct brw_compile *p,
+                 unsigned msg_reg_nr,
+                 struct brw_reg src0)
+{
+   struct brw_context *brw = p->brw;
+   struct brw_inst *insn;
+
+   gen6_resolve_implied_move(p, &src0, msg_reg_nr);
+   insn = next_insn(p, BRW_OPCODE_SEND);
+   brw_set_dest(p, insn, brw_null_reg());
+   brw_set_src0(p, insn, src0);
+   brw_set_src1(p, insn, brw_imm_d(0));
+
+   if (brw->gen < 6)
+      brw_inst_set_cond_modifier(brw, insn, msg_reg_nr);
+
+   brw_set_cs_terminate_message(brw, p, insn);
+   brw_inst_set_mask_control(brw, insn, BRW_MASK_DISABLE);
+}
-- 
2.1.4