5 files changed, 55 insertions, 0 deletions
diff --git a/src/gbm/backends/dri/gbm_dri.c b/src/gbm/backends/dri/gbm_dri.c
index 5a98b6aba68..7106dc12292 100644
--- a/src/gbm/backends/dri/gbm_dri.c
+++ b/src/gbm/backends/dri/gbm_dri.c
@@ -701,6 +701,40 @@ gbm_dri_bo_get_stride(struct gbm_bo *_bo, int plane)
    return (uint32_t)stride;
 }
 
+static int64_t
+gbm_dri_bo_get_offset(struct gbm_bo *_bo, int plane)
+{
+   struct gbm_dri_device *dri = gbm_dri_device(_bo->gbm);
+   struct gbm_dri_bo *bo = gbm_dri_bo(_bo);
+   int offset = 0;
+
+   if (!dri->image || dri->image->base.version < 13 || !dri->image->fromPlanar) {
+      errno = ENOSYS;
+      return -1;
+   }
+
+   if (plane >= get_number_planes(dri, bo->image)) {
+      errno = EINVAL;
+      return -2;
+   }
+
+    /* Dumb images have no offset */
+   if (bo->image == NULL) {
+      assert(plane == 0);
+      return 0;
+   }
+
+   __DRIimage *image = dri->image->fromPlanar(bo->image, plane, NULL);
+   if (image) {
+      dri->image->queryImage(image, __DRI_IMAGE_ATTRIB_OFFSET, &offset);
+      dri->image->destroyImage(image);
+   } else {
+      dri->image->queryImage(bo->image, __DRI_IMAGE_ATTRIB_OFFSET, &offset);
+   }
+
+   return (uint32_t)offset;
+}
+
 static void
 gbm_dri_bo_destroy(struct gbm_bo *_bo)
 {
@@ -1196,6 +1230,7 @@ dri_device_create(int fd)
    dri->base.base.bo_get_planes = gbm_dri_bo_get_planes;
    dri->base.base.bo_get_handle = gbm_dri_bo_get_handle_for_plane;
    dri->base.base.bo_get_stride = gbm_dri_bo_get_stride;
+   dri->base.base.bo_get_offset = gbm_dri_bo_get_offset;
    dri->base.base.bo_destroy = gbm_dri_bo_destroy;
    dri->base.base.destroy = dri_destroy;
    dri->base.base.surface_create = gbm_dri_surface_create;
diff --git a/src/gbm/gbm-symbols-check b/src/gbm/gbm-symbols-check
index 459006a63fe..7ff78ab4004 100755
--- a/src/gbm/gbm-symbols-check
+++ b/src/gbm/gbm-symbols-check
@@ -16,6 +16,7 @@ gbm_bo_get_height
 gbm_bo_get_stride
 gbm_bo_get_stride_for_plane
 gbm_bo_get_format
+gbm_bo_get_offset
 gbm_bo_get_device
 gbm_bo_get_handle
 gbm_bo_get_fd
diff --git a/src/gbm/main/gbm.c b/src/gbm/main/gbm.c
index 0a9f0bef7ee..afcca63da3a 100644
--- a/src/gbm/main/gbm.c
+++ b/src/gbm/main/gbm.c
@@ -194,6 +194,21 @@ gbm_bo_get_format(struct gbm_bo *bo)
    return bo->format;
 }
 
+/** Get the offset for the data of the specified plane
+ *
+ * Extra planes, and even the first plane, may have an offset from the start of
+ * the buffer object. This function will provide the offset for the given plane
+ * to be used in various KMS APIs.
+ *
+ * \param bo The buffer object
+ * \return The offset
+ */
+GBM_EXPORT int64_t
+gbm_bo_get_offset(struct gbm_bo *bo, int plane)
+{
+   return bo->gbm->bo_get_offset(bo, plane);
+}
+
 /** Get the gbm device used to create the buffer object
  *
  * \param bo The buffer object
diff --git a/src/gbm/main/gbm.h b/src/gbm/main/gbm.h
index 1719c5312a5..e3e5d34d976 100644
--- a/src/gbm/main/gbm.h
+++ b/src/gbm/main/gbm.h
@@ -309,6 +309,9 @@ gbm_bo_get_stride_for_plane(struct gbm_bo *bo, int plane);
 uint32_t
 gbm_bo_get_format(struct gbm_bo *bo);
 
+int64_t
+gbm_bo_get_offset(struct gbm_bo *bo, int plane);
+
 struct gbm_device *
 gbm_bo_get_device(struct gbm_bo *bo);
 
diff --git a/src/gbm/main/gbmint.h b/src/gbm/main/gbmint.h
index 26d18bab6bf..a6541d91c55 100644
--- a/src/gbm/main/gbmint.h
+++ b/src/gbm/main/gbmint.h
@@ -79,6 +79,7 @@ struct gbm_device {
    int (*bo_get_planes)(struct gbm_bo *bo);
    union gbm_bo_handle (*bo_get_handle)(struct gbm_bo *bo, int plane);
    uint32_t (*bo_get_stride)(struct gbm_bo *bo, int plane);
+   int64_t (*bo_get_offset)(struct gbm_bo *bo, int plane);
    void (*bo_destroy)(struct gbm_bo *bo);
 
    struct gbm_surface *(*surface_create)(struct gbm_device *gbm,