i965: Specialize SURFACE_STATE creation for shader time.

This is basically a copy and paste of gen7_create_constant_surface, but
with the parameters filled in to offer a simpler interface.

It will diverge shortly.

I didn't bother adding it to the vtable for now since shader time is only
exposed on Gen7+.

v2: Replace tabs in the new code (by anholt)
    Add back dropped memset() and add a comment about HSW channel selects.

NOTE: This is a candidate for the 9.1 branch.
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>

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

                                bool is_render_target);
 void gen7_check_surface_setup(uint32_t *surf, bool is_render_target);
 void gen7_init_vtable_surface_functions(struct brw_context *brw);
+void gen7_create_shader_time_surface(struct brw_context *brw,
+                                     uint32_t *out_offset);
 
 /* brw_wm_sampler_state.c */
 uint32_t translate_wrap_mode(GLenum wrap, bool using_nearest);

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

 static void
 brw_vs_upload_binding_table(struct brw_context *brw)
 {
-   struct intel_context *intel = &brw->intel;
    uint32_t *bind;
    int i;
 
    if (INTEL_DEBUG & DEBUG_SHADER_TIME) {
-      intel->vtbl.create_constant_surface(brw, brw->shader_time.bo, 0,
-                                          brw->shader_time.bo->size,
-                                          &brw->vs.surf_offset[SURF_INDEX_VS_SHADER_TIME]);
+      gen7_create_shader_time_surface(brw, &brw->vs.surf_offset[SURF_INDEX_VS_SHADER_TIME]);
 
       assert(brw->vs.prog_data->num_surfaces <= SURF_INDEX_VS_SHADER_TIME);
       brw->vs.prog_data->num_surfaces = SURF_INDEX_VS_SHADER_TIME;

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

 static void
 brw_upload_wm_binding_table(struct brw_context *brw)
 {
-   struct intel_context *intel = &brw->intel;
    uint32_t *bind;
    int i;
 
    if (INTEL_DEBUG & DEBUG_SHADER_TIME) {
-      intel->vtbl.create_constant_surface(brw, brw->shader_time.bo, 0,
-                                          brw->shader_time.bo->size,
-                                          &brw->wm.surf_offset[SURF_INDEX_WM_SHADER_TIME]);
+      gen7_create_shader_time_surface(brw, &brw->wm.surf_offset[SURF_INDEX_WM_SHADER_TIME]);
    }
 
    /* Might want to calculate nr_surfaces first, to avoid taking up so much

src/mesa/drivers/dri/i965/gen7_wm_surface_state.c

    gen7_check_surface_setup(surf, false /* is_render_target */);
 }
 
+/**
+ * Create a surface for shader time.
+ */
+void
+gen7_create_shader_time_surface(struct brw_context *brw, uint32_t *out_offset)
+{
+   struct intel_context *intel = &brw->intel;
+   const int w = brw->shader_time.bo->size - 1;
+
+   uint32_t *surf = brw_state_batch(brw, AUB_TRACE_SURFACE_STATE,
+                                    8 * 4, 32, out_offset);
+   memset(surf, 0, 8 * 4);
+
+   surf[0] = BRW_SURFACE_BUFFER << BRW_SURFACE_TYPE_SHIFT |
+             BRW_SURFACEFORMAT_R32G32B32A32_FLOAT << BRW_SURFACE_FORMAT_SHIFT |
+             BRW_SURFACE_RC_READ_WRITE;
+
+   surf[1] = brw->shader_time.bo->offset; /* reloc */
+
+   surf[2] = SET_FIELD(w & 0x7f, GEN7_SURFACE_WIDTH) |
+             SET_FIELD((w >> 7) & 0x1fff, GEN7_SURFACE_HEIGHT);
+   surf[3] = SET_FIELD((w >> 20) & 0x7f, BRW_SURFACE_DEPTH) |
+             (16 - 1); /* stride between samples */
+
+   /* Unlike texture or renderbuffer surfaces, we only do untyped operations
+    * on the shader_time surface, so there's no need to set HSW channel
+    * overrides.
+    */
+
+   /* Emit relocation to surface contents.  Section 5.1.1 of the gen4
+    * bspec ("Data Cache") says that the data cache does not exist as
+    * a separate cache and is just the sampler cache.
+    */
+   drm_intel_bo_emit_reloc(intel->batch.bo,
+                           *out_offset + 4,
+                           brw->shader_time.bo, 0,
+                           I915_GEM_DOMAIN_SAMPLER, 0);
+
+   gen7_check_surface_setup(surf, false /* is_render_target */);
+}
+
 static void
 gen7_update_null_renderbuffer_surface(struct brw_context *brw, unsigned unit)
 {