Briefly describe what this is all about.
Signed-off-by: Christian König <christian.koenig@xxxxxxx>
---
Documentation/gpu/drm-mm.rst | 3 +++
include/drm/ttm/ttm_caching.h | 17 +++++++++++++++++
2 files changed, 20 insertions(+)
diff --git a/Documentation/gpu/drm-mm.rst b/Documentation/gpu/drm-mm.rst
index 6b7717af4f88..f22c9f9a2c0e 100644
--- a/Documentation/gpu/drm-mm.rst
+++ b/Documentation/gpu/drm-mm.rst
@@ -31,6 +31,9 @@ The Translation Table Manager (TTM)
.. kernel-doc:: drivers/gpu/drm/ttm/ttm_module.c
:doc: TTM
+.. kernel-doc:: include/drm/ttm/ttm_caching.h
+ :internal:
+
The Graphics Execution Manager (GEM)
====================================
diff --git a/include/drm/ttm/ttm_caching.h b/include/drm/ttm/ttm_caching.h
index 3c9dd65f5aaf..235a743d90e1 100644
--- a/include/drm/ttm/ttm_caching.h
+++ b/include/drm/ttm/ttm_caching.h
@@ -27,9 +27,26 @@
#define TTM_NUM_CACHING_TYPES 3
+/**
+ * enum ttm_caching - CPU caching and BUS snooping behavior.
+ */
enum ttm_caching {
+ /**
+ * @ttm_uncached: Most defensive option for device mappings,
+ * don't even allow write combining.
+ */
ttm_uncached,
+
+ /**
+ * @ttm_write_combined: Don't cache read accesses, but allow at least
+ * writes to be combined.
+ */
ttm_write_combined,
+
+ /**
+ * @ttm_cached: Fully cached like normal system memory, requires that
+ * devices snoop the CPU cache on accesses.
+ */
ttm_cached
};
--
2.25.1
