intel: Add always_flush_cache driconf option for debugging cache flush failure.

I keep wanting to hack this knob in as a one-time thing, so it seemed useful
to have all the time.

src/mesa/drivers/dri/common/xmlpool/options.h

@@ -546,3 +546,13 @@ DRI_CONF_OPT_BEGIN(nv_vertex_program,bool,def) \
         DRI_CONF_DESC(fr,"Activer l'extension GL_NV_vertex_program") \
         DRI_CONF_DESC(sv,"Aktivera tillägget GL_NV_vertex_program") \
 DRI_CONF_OPT_END
+
+#define DRI_CONF_ALWAYS_FLUSH_CACHE(def) \
+DRI_CONF_OPT_BEGIN(always_flush_cache,bool,def) \
+        DRI_CONF_DESC(en,"Enable flushing GPU caches with each draw call") \
+        DRI_CONF_DESC(de,"Enable flushing GPU caches with each draw call") \
+        DRI_CONF_DESC(es,"Enable flushing GPU caches with each draw call") \
+        DRI_CONF_DESC(nl,"Enable flushing GPU caches with each draw call") \
+        DRI_CONF_DESC(fr,"Enable flushing GPU caches with each draw call") \
+        DRI_CONF_DESC(sv,"Enable flushing GPU caches with each draw call") \
+DRI_CONF_OPT_END

src/mesa/drivers/dri/common/xmlpool/t_options.h

@@ -237,3 +237,8 @@ DRI_CONF_OPT_END
 DRI_CONF_OPT_BEGIN(nv_vertex_program,bool,def) \
         DRI_CONF_DESC(en,gettext("Enable extension GL_NV_vertex_program")) \
 DRI_CONF_OPT_END
+
+#define DRI_CONF_ALWAYS_FLUSH_CACHE(def) \
+DRI_CONF_OPT_BEGIN(always_flush_cache,bool,def) \
+        DRI_CONF_DESC(en,gettext("Enable flushing GPU caches with each draw call")) \
+DRI_CONF_OPT_END

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

@@ -127,6 +127,7 @@ static void brw_emit_prim(struct brw_context *brw,
 			  uint32_t hw_prim)
 {
    struct brw_3d_primitive prim_packet;
+   struct intel_context *intel = &brw->intel;
 
    if (INTEL_DEBUG & DEBUG_PRIMS)
       _mesa_printf("PRIM: %s %d %d\n", _mesa_lookup_enum_by_nr(prim->mode), 
@@ -146,10 +147,27 @@ static void brw_emit_prim(struct brw_context *brw,
 
    /* Can't wrap here, since we rely on the validated state. */
    brw->no_batch_wrap = GL_TRUE;
+
+   /* If we're set to always flush, do it before and after the primitive emit.
+    * We want to catch both missed flushes that hurt instruction/state cache
+    * and missed flushes of the render cache as it heads to other parts of
+    * the besides the draw code.
+    */
+   if (intel->always_flush_cache) {
+      BEGIN_BATCH(1, IGNORE_CLIPRECTS);
+      OUT_BATCH(intel->vtbl.flush_cmd());
+      ADVANCE_BATCH();
+   }
    if (prim_packet.verts_per_instance) {
       intel_batchbuffer_data( brw->intel.batch, &prim_packet,
 			      sizeof(prim_packet), LOOP_CLIPRECTS);
    }
+   if (intel->always_flush_cache) {
+      BEGIN_BATCH(1, IGNORE_CLIPRECTS);
+      OUT_BATCH(intel->vtbl.flush_cmd());
+      ADVANCE_BATCH();
+   }
+
    brw->no_batch_wrap = GL_FALSE;
 }
 

src/mesa/drivers/dri/intel/intel_batchbuffer.c

@@ -207,7 +207,7 @@ _intel_batchbuffer_flush(struct intel_batchbuffer *batch, const char *file,
 	      used);
 
    /* Emit a flush if the bufmgr doesn't do it for us. */
-   if (!intel->ttm) {
+   if (intel->always_flush_cache || !intel->ttm) {
       *(GLuint *) (batch->ptr) = intel->vtbl.flush_cmd();
       batch->ptr += 4;
       used = batch->ptr - batch->map;

src/mesa/drivers/dri/intel/intel_context.c

@@ -618,6 +618,11 @@ intelInitContext(struct intel_context *intel,
       intel->no_rast = 1;
    }
 
+   if (driQueryOptionb(&intel->optionCache, "always_flush_cache")) {
+      fprintf(stderr, "flushing GPU caches before/after each draw call\n");
+      intel->always_flush_cache = 1;
+   }
+
    /* Disable all hardware rendering (skip emitting batches and fences/waits
     * to the kernel)
     */

src/mesa/drivers/dri/intel/intel_context.h

@@ -228,6 +228,7 @@ struct intel_context
    GLboolean hw_stipple;
    GLboolean depth_buffer_is_float;
    GLboolean no_rast;
+   GLboolean always_flush_cache;
 
    /* 0 - nonconformant, best performance;
     * 1 - fallback to sw for known conformance bugs

src/mesa/drivers/dri/intel/intel_screen.c

@@ -71,10 +71,11 @@ PUBLIC const char __driConfigOptions[] =
    DRI_CONF_SECTION_END
    DRI_CONF_SECTION_DEBUG
      DRI_CONF_NO_RAST(false)
+     DRI_CONF_ALWAYS_FLUSH_CACHE(false)
    DRI_CONF_SECTION_END
 DRI_CONF_END;
 
-const GLuint __driNConfigOptions = 6;
+const GLuint __driNConfigOptions = 7;
 
 #ifdef USE_NEW_INTERFACE
 static PFNGLXCREATECONTEXTMODES create_context_modes = NULL;