i965: Implement DispatchCompute() back-end

brw_emit_gpgpu_walker will be implemented in a subsequent patch.

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/mesa/drivers/dri/i965/Makefile.sources

@@ -17,6 +17,7 @@ i965_FILES = \
 	brw_clip_tri.c \
 	brw_clip_unfilled.c \
 	brw_clip_util.c \
+	brw_compute.c \
 	brw_context.c \
 	brw_context.h \
 	brw_cs.cpp \

src/mesa/drivers/dri/i965/brw_compute.c

@@ -0,0 +1,121 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <sys/errno.h>
+
+#include "main/condrender.h"
+#include "main/glheader.h"
+#include "main/mtypes.h"
+#include "main/state.h"
+#include "brw_context.h"
+#include "brw_draw.h"
+#include "brw_state.h"
+#include "intel_batchbuffer.h"
+
+
+static void
+brw_emit_gpgpu_walker(struct brw_context *brw, const GLuint *num_groups)
+{
+   _mesa_problem(&brw->ctx, "TODO: implement brw_emit_gpgpu_walker");
+}
+
+
+static void
+brw_dispatch_compute(struct gl_context *ctx, const GLuint *num_groups)
+{
+   struct brw_context *brw = brw_context(ctx);
+   int estimated_buffer_space_needed;
+   bool fail_next = false;
+
+   if (!_mesa_check_conditional_render(ctx))
+      return;
+
+   if (ctx->NewState)
+      _mesa_update_state(ctx);
+
+   brw_validate_textures(brw);
+
+   const int sampler_state_size = 16; /* 16 bytes */
+   estimated_buffer_space_needed = 512; /* batchbuffer commands */
+   estimated_buffer_space_needed += (BRW_MAX_TEX_UNIT *
+                                     (sampler_state_size +
+                                      sizeof(struct gen5_sampler_default_color)));
+   estimated_buffer_space_needed += 1024; /* push constants */
+   estimated_buffer_space_needed += 512; /* misc. pad */
+
+   /* Flush the batch if it's approaching full, so that we don't wrap while
+    * we've got validated state that needs to be in the same batch as the
+    * primitives.
+    */
+   intel_batchbuffer_require_space(brw, estimated_buffer_space_needed,
+                                   RENDER_RING);
+   intel_batchbuffer_save_state(brw);
+
+ retry:
+   brw->no_batch_wrap = true;
+   brw_upload_compute_state(brw);
+
+   brw_emit_gpgpu_walker(brw, num_groups);
+
+   brw->no_batch_wrap = false;
+
+   if (dri_bufmgr_check_aperture_space(&brw->batch.bo, 1)) {
+      if (!fail_next) {
+         intel_batchbuffer_reset_to_saved(brw);
+         intel_batchbuffer_flush(brw);
+         fail_next = true;
+         goto retry;
+      } else {
+         if (intel_batchbuffer_flush(brw) == -ENOSPC) {
+            static bool warned = false;
+
+            if (!warned) {
+               fprintf(stderr, "i965: Single compute shader dispatch "
+                       "exceeded available aperture space\n");
+               warned = true;
+            }
+         }
+      }
+   }
+
+   /* Now that we know we haven't run out of aperture space, we can safely
+    * reset the dirty bits.
+    */
+   brw_compute_state_finished(brw);
+
+   if (brw->always_flush_batch)
+      intel_batchbuffer_flush(brw);
+
+   brw_state_cache_check_size(brw);
+
+   /* Note: since compute shaders can't write to framebuffers, there's no need
+    * to call brw_postdraw_set_buffers_need_resolve().
+    */
+}
+
+
+void
+brw_init_compute_functions(struct dd_function_table *functions)
+{
+   functions->DispatchCompute = brw_dispatch_compute;
+}

src/mesa/drivers/dri/i965/brw_context.c

@@ -288,6 +288,7 @@ brw_init_driver_functions(struct brw_context *brw,
       gen6_init_queryobj_functions(functions);
    else
       gen4_init_queryobj_functions(functions);
+   brw_init_compute_functions(functions);
 
    functions->QuerySamplesForFormat = brw_query_samples_for_format;
 

src/mesa/drivers/dri/i965/brw_context.h

@@ -1829,6 +1829,10 @@ gen7_emit_urb_state(struct brw_context *brw,
 extern GLenum
 brw_get_graphics_reset_status(struct gl_context *ctx);
 
+/* brw_compute.c */
+extern void
+brw_init_compute_functions(struct dd_function_table *functions);
+
 /*======================================================================
  * Inline conversion functions.  These are better-typed than the
  * macros used previously: