3 files changed, 94 insertions, 8 deletions

diff --git a/src/gbm/main/gbm.c b/src/gbm/main/gbm.c
index 79ba65051f2..3994f86aafc 100644
--- a/src/gbm/main/gbm.c
+++ b/src/gbm/main/gbm.c
@@ -231,6 +231,65 @@ gbm_bo_get_handle(struct gbm_bo *bo)
    return bo->handle;
 }
 
+/** Write data into the buffer object
+ *
+ * If the buffer object was created with the GBM_BO_USE_WRITE flag,
+ * this function can used to write data into the buffer object.  The
+ * data is copied directly into the object and it's the responsiblity
+ * of the caller to make sure the data represents valid pixel data,
+ * according to the width, height, stride and format of the buffer object.
+ *
+ * \param bo The buffer object
+ * \param buf The data to write
+ * \param count The number of bytes to write
+ * \return Returns -1 on error, 0 otherwise
+ */
+GBM_EXPORT int
+gbm_bo_write(struct gbm_bo *bo, const void *buf, size_t count)
+{
+   return bo->gbm->bo_write(bo, buf, count);
+}
+
+/** Get the gbm device used to create the buffer object
+ *
+ * \param bo The buffer object
+ * \return Returns the gbm device with which the buffer object was created
+ */
+GBM_EXPORT struct gbm_device *
+gbm_bo_get_device(struct gbm_bo *bo)
+{
+	return bo->gbm;
+}
+
+/** Set the user data associated with a buffer object
+ *
+ * \param bo The buffer object
+ * \param data The data to associate to the buffer object
+ * \param destroy_user_data A callback (which may be %NULL) that will be
+ * called prior to the buffer destruction
+ */
+GBM_EXPORT void
+gbm_bo_set_user_data(struct gbm_bo *bo, void *data,
+		     void (*destroy_user_data)(struct gbm_bo *, void *))
+{
+   bo->user_data = data;
+   bo->destroy_user_data = destroy_user_data;
+}
+
+/** Get the user data associated with a buffer object
+ *
+ * \param bo The buffer object
+ * \return Returns the user data associated with the buffer object or %NULL
+ * if no data was associated with it
+ *
+ * \sa gbm_bo_set_user_data()
+ */
+GBM_EXPORT void *
+gbm_bo_get_user_data(struct gbm_bo *bo)
+{
+   return bo->user_data;
+}
+
 /**
  * Destroys the given buffer object and frees all resources associated with
  * it.
@@ -240,6 +299,9 @@ gbm_bo_get_handle(struct gbm_bo *bo)
 GBM_EXPORT void
 gbm_bo_destroy(struct gbm_bo *bo)
 {
+   if (bo->destroy_user_data)
+      bo->destroy_user_data(bo, bo->user_data);
+
    bo->gbm->bo_destroy(bo);
 }
 
@@ -357,10 +419,11 @@ gbm_surface_destroy(struct gbm_surface *surf)
  *
  * \param surf The surface
  *
- * \return A newly allocated buffer object that should be released
- * with gbm_surface_release_buffer() when no longer needed.  This bo
- * should not be destroyed using gbm_bo_destroy().  If an error occurs
- * this function returns %NULL.
+ * \return A buffer object that should be released with
+ * gbm_surface_release_buffer() when no longer needed.  The implementation
+ * is free to reuse buffers released with gbm_surface_release_buffer() so
+ * this bo should not be destroyed using gbm_bo_destroy().  If an error
+ * occurs this function returns %NULL.
  */
 GBM_EXPORT struct gbm_bo *
 gbm_surface_lock_front_buffer(struct gbm_surface *surf)
@@ -371,10 +434,11 @@ gbm_surface_lock_front_buffer(struct gbm_surface *surf)
 /**
  * Release a locked buffer obtained with gbm_surface_lock_front_buffer()
  *
- * The bo is destroyed after a call to this function and returns the
- * underlying buffer to the gbm surface.  Releasing a bo will
- * typically make gbm_surface_has_free_buffer() return 1 and thus
- * allow rendering the next frame, but not always.
+ * Returns the underlying buffer to the gbm surface.  Releasing a bo
+ * will typically make gbm_surface_has_free_buffer() return 1 and thus
+ * allow rendering the next frame, but not always. The implementation
+ * may choose to destroy the bo immediately or reuse it, in which case
+ * the user data associated with it is unchanged.
  *
  * \param surf The surface
  * \param bo The buffer object
diff --git a/src/gbm/main/gbm.h b/src/gbm/main/gbm.h
index 6748752d8f1..af5dc5aee8c 100644
--- a/src/gbm/main/gbm.h
+++ b/src/gbm/main/gbm.h
@@ -201,6 +201,12 @@ enum gbm_bo_flags {
     * as the storage for a color buffer
     */
    GBM_BO_USE_RENDERING    = (1 << 2),
+   /**
+    * Buffer can be used for gbm_bo_write.  This is guaranteed to work
+    * with GBM_BO_USE_CURSOR_64X64. but may not work for other
+    * combinations.
+    */
+   GBM_BO_USE_WRITE    = (1 << 3),
 };
 
 int
@@ -242,9 +248,22 @@ gbm_bo_get_pitch(struct gbm_bo *bo);
 uint32_t
 gbm_bo_get_format(struct gbm_bo *bo);
 
+struct gbm_device *
+gbm_bo_get_device(struct gbm_bo *bo);
+
 union gbm_bo_handle
 gbm_bo_get_handle(struct gbm_bo *bo);
 
+int
+gbm_bo_write(struct gbm_bo *bo, const void *buf, size_t count);
+
+void
+gbm_bo_set_user_data(struct gbm_bo *bo, void *data,
+		     void (*destroy_user_data)(struct gbm_bo *, void *));
+
+void *
+gbm_bo_get_user_data(struct gbm_bo *bo);
+
 void
 gbm_bo_destroy(struct gbm_bo *bo);
 
diff --git a/src/gbm/main/gbmint.h b/src/gbm/main/gbmint.h
index 53d73f40df6..8eb8671aeb2 100644
--- a/src/gbm/main/gbmint.h
+++ b/src/gbm/main/gbmint.h
@@ -70,6 +70,7 @@ struct gbm_device {
                                               void *egl_dpy, void *egl_img,
                                               uint32_t width, uint32_t height,
                                               uint32_t usage);
+   int (*bo_write)(struct gbm_bo *bo, const void *buf, size_t data);
    void (*bo_destroy)(struct gbm_bo *bo);
 
    struct gbm_surface *(*surface_create)(struct gbm_device *gbm,
@@ -94,6 +95,8 @@ struct gbm_bo {
    uint32_t pitch;
    uint32_t format;
    union gbm_bo_handle  handle;
+   void *user_data;
+   void (*destroy_user_data)(struct gbm_bo *, void *);
 };
 
 struct gbm_surface {