[Mesa-dev] [PATCH 13/25] i965: Add memory fence opcode.

Francisco Jerez currojerez at riseup.net
Mon Dec 2 11:39:21 PST 2013


---
 src/mesa/drivers/dri/i965/brw_defines.h          |  2 +
 src/mesa/drivers/dri/i965/brw_eu.h               |  4 ++
 src/mesa/drivers/dri/i965/brw_eu_emit.c          | 69 ++++++++++++++++++++++++
 src/mesa/drivers/dri/i965/brw_fs.cpp             |  2 +
 src/mesa/drivers/dri/i965/brw_fs_generator.cpp   |  4 ++
 src/mesa/drivers/dri/i965/brw_shader.cpp         |  1 +
 src/mesa/drivers/dri/i965/brw_vec4.cpp           |  2 +
 src/mesa/drivers/dri/i965/brw_vec4_generator.cpp |  4 ++
 8 files changed, 88 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h
index 631473a..9e51e2c 100644
--- a/src/mesa/drivers/dri/i965/brw_defines.h
+++ b/src/mesa/drivers/dri/i965/brw_defines.h
@@ -784,6 +784,8 @@ enum opcode {
    SHADER_OPCODE_TYPED_SURFACE_READ,
    SHADER_OPCODE_TYPED_SURFACE_WRITE,
 
+   SHADER_OPCODE_MEMORY_FENCE,
+
    SHADER_OPCODE_GEN4_SCRATCH_READ,
    SHADER_OPCODE_GEN4_SCRATCH_WRITE,
    SHADER_OPCODE_GEN7_SCRATCH_READ,
diff --git a/src/mesa/drivers/dri/i965/brw_eu.h b/src/mesa/drivers/dri/i965/brw_eu.h
index 17822ce..a47c730 100644
--- a/src/mesa/drivers/dri/i965/brw_eu.h
+++ b/src/mesa/drivers/dri/i965/brw_eu.h
@@ -408,6 +408,10 @@ brw_typed_surface_write(struct brw_compile *p,
                         unsigned msg_length,
                         unsigned num_channels);
 
+void
+brw_memory_fence(struct brw_compile *p,
+                 struct brw_reg mrf);
+
 /*********************************************************************** 
  * brw_eu_util.c:
  */
diff --git a/src/mesa/drivers/dri/i965/brw_eu_emit.c b/src/mesa/drivers/dri/i965/brw_eu_emit.c
index 772be7a..3ee86c6 100644
--- a/src/mesa/drivers/dri/i965/brw_eu_emit.c
+++ b/src/mesa/drivers/dri/i965/brw_eu_emit.c
@@ -2919,6 +2919,75 @@ brw_typed_surface_write(struct brw_compile *p,
    brw_send_indirect_message(p, sfid, dst, mrf, desc);
 }
 
+static void
+brw_set_memory_fence_message(struct brw_compile *p,
+                             struct brw_instruction *insn,
+                             enum brw_message_target sfid,
+                             bool commit_enable)
+{
+   brw_set_message_descriptor(p, insn, sfid,
+                              1 /* message length */,
+                              (commit_enable ? 1 : 0) /* response length */,
+                              true /* header present */,
+                              false);
+
+   switch (sfid) {
+   case GEN6_SFID_DATAPORT_RENDER_CACHE:
+      insn->bits3.gen7_dp.msg_type = GEN7_DATAPORT_RC_MEMORY_FENCE;
+      break;
+   case GEN7_SFID_DATAPORT_DATA_CACHE:
+      insn->bits3.gen7_dp.msg_type = GEN7_DATAPORT_DC_MEMORY_FENCE;
+      break;
+   default:
+      unreachable();
+   }
+
+   if (commit_enable)
+      insn->bits3.ud |= 1 << 13;
+}
+
+void
+brw_memory_fence(struct brw_compile *p,
+                 struct brw_reg mrf)
+{
+   const bool commit_enable = !p->brw->is_haswell;
+   struct brw_instruction *insn;
+
+   /* Set mrf as destination for dependency tracking, the MEMORY_FENCE
+    * message doesn't write anything back.
+    */
+   insn = next_insn(p, BRW_OPCODE_SEND);
+   mrf = retype(mrf, BRW_REGISTER_TYPE_UD);
+   brw_set_dest(p, insn, mrf);
+   brw_set_src0(p, insn, mrf);
+   brw_set_memory_fence_message(p, insn, GEN7_SFID_DATAPORT_DATA_CACHE,
+                                commit_enable);
+
+   if (!p->brw->is_haswell) {
+      /* IVB does typed surface access through the render cache, so we
+       * need to flush that too.  Use a different register so both
+       * flushes can be pipelined by the hardware.
+       */
+      insn = next_insn(p, BRW_OPCODE_SEND);
+      brw_set_dest(p, insn, offset(mrf, 1));
+      brw_set_src0(p, insn, offset(mrf, 1));
+      brw_set_memory_fence_message(p, insn, GEN6_SFID_DATAPORT_RENDER_CACHE,
+                                   commit_enable);
+
+      /* Now write the response of the second message into the
+       * response of the first to trigger a pipeline stall -- This way
+       * future render and data cache messages will be properly
+       * ordered with respect to past data and render cache messages
+       * respectively.
+       */
+      brw_push_insn_state(p);
+      brw_set_compression_control(p, BRW_COMPRESSION_NONE);
+      brw_set_mask_control(p, BRW_MASK_DISABLE);
+      brw_MOV(p, mrf, offset(mrf, 1));
+      brw_pop_insn_state(p);
+   }
+}
+
 /**
  * This instruction is generated as a single-channel align1 instruction by
  * both the VS and FS stages when using INTEL_DEBUG=shader_time.
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 20cb4b9..cce6ed0 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -786,6 +786,8 @@ fs_visitor::implied_mrf_writes(fs_inst *inst)
    case SHADER_OPCODE_TYPED_SURFACE_READ:
    case SHADER_OPCODE_TYPED_SURFACE_WRITE:
       return 0;
+   case SHADER_OPCODE_MEMORY_FENCE:
+      return 1;
    default:
       assert(!"not reached");
       return inst->mlen;
diff --git a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
index 9601183..5ead435 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
@@ -1714,6 +1714,10 @@ fs_generator::generate_code(exec_list *instructions)
                                  src[0], inst->mlen, src[1].dw1.ud);
          break;
 
+      case SHADER_OPCODE_MEMORY_FENCE:
+         brw_memory_fence(p, brw_message_reg(inst->base_mrf));
+         break;
+
       case FS_OPCODE_SET_SIMD4X2_OFFSET:
          generate_set_simd4x2_offset(inst, dst, src[0]);
          break;
diff --git a/src/mesa/drivers/dri/i965/brw_shader.cpp b/src/mesa/drivers/dri/i965/brw_shader.cpp
index fc8d0ff..26300a6 100644
--- a/src/mesa/drivers/dri/i965/brw_shader.cpp
+++ b/src/mesa/drivers/dri/i965/brw_shader.cpp
@@ -663,6 +663,7 @@ backend_instruction::has_side_effects() const
    case SHADER_OPCODE_UNTYPED_ATOMIC:
    case SHADER_OPCODE_TYPED_ATOMIC:
    case SHADER_OPCODE_TYPED_SURFACE_WRITE:
+   case SHADER_OPCODE_MEMORY_FENCE:
       return true;
    default:
       return false;
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp
index 04054d5..e98fff5 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp
@@ -298,6 +298,8 @@ vec4_visitor::implied_mrf_writes(vec4_instruction *inst)
    case SHADER_OPCODE_TYPED_SURFACE_READ:
    case SHADER_OPCODE_TYPED_SURFACE_WRITE:
       return 0;
+   case SHADER_OPCODE_MEMORY_FENCE:
+      return 1;
    default:
       assert(!"not reached");
       return inst->mlen;
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
index 1d7e5e8..8637f75 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
@@ -1196,6 +1196,10 @@ vec4_generator::generate_vec4_instruction(vec4_instruction *instruction,
                               src[0], inst->mlen, src[1].dw1.ud);
       break;
 
+   case SHADER_OPCODE_MEMORY_FENCE:
+      brw_memory_fence(p, brw_message_reg(inst->base_mrf));
+      break;
+
    case VS_OPCODE_UNPACK_FLAGS_SIMD4X2:
       generate_unpack_flags(inst, dst);
       break;
-- 
1.8.3.4



More information about the mesa-dev mailing list