Start coding up memory domains

1 files changed, 38 insertions, 0 deletions

diff --git a/linux-core/drm_gem.c b/linux-core/drm_gem.c
index 80d5a350..929c008f 100644
--- a/linux-core/drm_gem.c
+++ b/linux-core/drm_gem.c
@@ -539,3 +539,41 @@ drm_gem_object_handle_free (struct kref *kref)
 	
 }
 EXPORT_SYMBOL(drm_gem_object_handle_free);
+
+/*
+ * Set the next domain for the specified object. This
+ * may not actually perform the necessary flushing/invaliding though,
+ * as that may want to be batched with other set_domain operations
+ */
+int drm_gem_object_set_domain (struct drm_gem_object *obj,
+			       uint32_t read_domains,
+			       uint32_t write_domain)
+{
+	struct drm_device	*dev = obj->dev;
+	uint32_t		invalidate_domains = 0;
+	uint32_t		flush_domains = 0;
+	
+	/*
+	 * Flush the current write domain if
+	 * the new read domains don't match. Invalidate
+	 * any read domains which differ from the old
+	 * write domain
+	 */
+	if (obj->write_domain && obj->write_domain != read_domains)
+	{
+		flush_domains |= obj->write_domain;
+		invalidate_domains |= read_domains & ~obj->write_domain;
+	}
+	/*
+	 * Invalidate any read caches which may have
+	 * stale data. That is, any new read domains.
+	 */
+	invalidate_domains |= read_domains & ~obj->read_domains;
+	obj->write_domain = write_domain;
+	obj->read_domain = read_domains;
+	if ((flush_domains | invalidate_domains) & DRM_GEM_DOMAIN_CPU)
+		drm_gem_object_clflush (obj);
+	dev->invalidate_domains |= invalidate_domains & ~DRM_GEM_DOMAIN_CPU;
+	dev->flush_domains |= flush_domains & ~DRM_GEM_DOMAIN_CPU;
+}
+EXPORT_SYMBOL(drm_gem_object_set_domain);