gbm: Add map/unmap functions

This adds map and unmap functions to GBM utilizing the DRIimage extension
mapImage/unmapImage functions or existing internal mapping for dumb
buffers. Unlike prior attempts, this version provides a region to map and
usage flags for the mapping. The operation follows the same semantics as
the gallium transfer_map() function.

This was tested with GBM based gralloc on Android.

Signed-off-by: Rob Herring <[email protected]>
[Emil Velikov: drop no longer relevant hunk from commit message.]
Reviewed-by: Emil Velikov <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>

1 files changed, 35 insertions, 0 deletions

diff --git a/src/gbm/main/gbm.h b/src/gbm/main/gbm.h
index 63d9a9edfd6..8a2f2a6a8cc 100644
--- a/src/gbm/main/gbm.h
+++ b/src/gbm/main/gbm.h
@@ -253,6 +253,41 @@ struct gbm_bo *
 gbm_bo_import(struct gbm_device *gbm, uint32_t type,
               void *buffer, uint32_t usage);
 
+/**
+ * Flags to indicate the type of mapping for the buffer - these are
+ * passed into gbm_bo_map(). The caller must set the union of all the
+ * flags that are appropriate.
+ *
+ * These flags are independent of the GBM_BO_USE_* creation flags. However,
+ * mapping the buffer may require copying to/from a staging buffer.
+ *
+ * See also: pipe_transfer_usage
+ */
+enum gbm_bo_transfer_flags {
+   /**
+    * Buffer contents read back (or accessed directly) at transfer
+    * create time.
+    */
+   GBM_BO_TRANSFER_READ       = (1 << 0),
+   /**
+    * Buffer contents will be written back at unmap time
+    * (or modified as a result of being accessed directly).
+    */
+   GBM_BO_TRANSFER_WRITE      = (1 << 1),
+   /**
+    * Read/modify/write
+    */
+   GBM_BO_TRANSFER_READ_WRITE = (GBM_BO_TRANSFER_READ | GBM_BO_TRANSFER_WRITE),
+};
+
+void *
+gbm_bo_map(struct gbm_bo *bo,
+           uint32_t x, uint32_t y, uint32_t width, uint32_t height,
+           uint32_t flags, uint32_t *stride, void **map_data);
+
+void
+gbm_bo_unmap(struct gbm_bo *bo, void *map_data);
+
 uint32_t
 gbm_bo_get_width(struct gbm_bo *bo);