[PATCH 3.19.y-ckt 037/196] drm: add helper to check for wc memory support

[Kamal Mostafa]

3.19.8-ckt16 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Dave Airlie <airlied at redhat.com>

commit 4b0e4e4af6c6dc8354dcb72182d52c1bc55f12fc upstream.

Reviewed-by: Christian König <christian.koenig at amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer at amd.com>
Signed-off-by: Dave Airlie <airlied at redhat.com>
Signed-off-by: Oded Gabbay <oded.gabbay at gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 include/drm/drm_cache.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/drm/drm_cache.h b/include/drm/drm_cache.h
index 7bfb063..461a055 100644
--- a/include/drm/drm_cache.h
+++ b/include/drm/drm_cache.h
@@ -35,4 +35,13 @@
 
 void drm_clflush_pages(struct page *pages[], unsigned long num_pages);
 
+static inline bool drm_arch_can_wc_memory(void)
+{
+#if defined(CONFIG_PPC) && !defined(CONFIG_NOT_COHERENT_CACHE)
+	return false;
+#else
+	return true;
+#endif
+}
+
 #endif
-- 
2.7.0