Mesa (master): intel: Map write-only buffer objects through the GTT when possible.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: aa422b262509bc0763a50f63a51a1730139ea52f
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=aa422b262509bc0763a50f63a51a1730139ea52f

Author: Eric Anholt <eric at anholt.net>
Date:   Sun May 10 09:45:43 2009 -0700

intel: Map write-only buffer objects through the GTT when possible.

This looks to be a win of a few percent in cairogears with new vbo code,
thanks to not polluting caches.

---

 src/mesa/drivers/dri/intel/intel_buffer_objects.c |   16 ++++++++++++++--
 src/mesa/drivers/dri/intel/intel_buffer_objects.h |    1 +
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/mesa/drivers/dri/intel/intel_buffer_objects.c b/src/mesa/drivers/dri/intel/intel_buffer_objects.c
index f6b0d76..0db1f39 100644
--- a/src/mesa/drivers/dri/intel/intel_buffer_objects.c
+++ b/src/mesa/drivers/dri/intel/intel_buffer_objects.c
@@ -214,6 +214,7 @@ intel_bufferobj_map(GLcontext * ctx,
    struct intel_context *intel = intel_context(ctx);
    struct intel_buffer_object *intel_obj = intel_buffer_object(obj);
    GLboolean read_only = (access == GL_READ_ONLY_ARB);
+   GLboolean write_only = (access == GL_WRITE_ONLY_ARB);
 
    assert(intel_obj);
 
@@ -225,7 +226,14 @@ intel_bufferobj_map(GLcontext * ctx,
       return NULL;
    }
 
-   dri_bo_map(intel_obj->buffer, !read_only);
+   if (write_only && intel->intelScreen->kernel_exec_fencing) {
+      drm_intel_gem_bo_map_gtt(intel_obj->buffer);
+      intel_obj->mapped_gtt = GL_TRUE;
+   } else {
+      drm_intel_bo_map(intel_obj->buffer, !read_only);
+      intel_obj->mapped_gtt = GL_FALSE;
+   }
+
    obj->Pointer = intel_obj->buffer->virtual;
    return obj->Pointer;
 }
@@ -243,7 +251,11 @@ intel_bufferobj_unmap(GLcontext * ctx,
    assert(intel_obj);
    if (intel_obj->buffer != NULL) {
       assert(obj->Pointer);
-      dri_bo_unmap(intel_obj->buffer);
+      if (intel_obj->mapped_gtt) {
+	 drm_intel_gem_bo_unmap_gtt(intel_obj->buffer);
+      } else {
+	 drm_intel_bo_unmap(intel_obj->buffer);
+      }
       obj->Pointer = NULL;
    }
    return GL_TRUE;
diff --git a/src/mesa/drivers/dri/intel/intel_buffer_objects.h b/src/mesa/drivers/dri/intel/intel_buffer_objects.h
index bf6dbd5..7ef7238 100644
--- a/src/mesa/drivers/dri/intel/intel_buffer_objects.h
+++ b/src/mesa/drivers/dri/intel/intel_buffer_objects.h
@@ -46,6 +46,7 @@ struct intel_buffer_object
    struct intel_region *region; /* Is there a zero-copy texture
                                    associated with this (pixel)
                                    buffer object? */
+   GLboolean mapped_gtt;
 };