[PATCH v9 1/6] drm: Add arch arm64 for drm_clflush_virt_range

[Michael Cheng]

Add arm64 support for drm_clflush_virt_range. dcache_clean_inval_poc
performs a flush by first performing a clean, follow by an invalidation
operation.

v2 (Michael Cheng): Use correct macro for cleaning and invalidation the
		    dcache.

v3 (Michael Cheng): Remove ifdef for asm/cacheflush.h

v4 (Michael Cheng): Rebase

Signed-off-by: Michael Cheng <michael.cheng at intel.com>
---
 drivers/gpu/drm/drm_cache.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
index 66597e411764..ec8d91b088ff 100644
--- a/drivers/gpu/drm/drm_cache.c
+++ b/drivers/gpu/drm/drm_cache.c
@@ -28,6 +28,7 @@
  * Authors: Thomas Hellström <thomas-at-tungstengraphics-dot-com>
  */
 
+#include <asm/cacheflush.h>
 #include <linux/cc_platform.h>
 #include <linux/export.h>
 #include <linux/highmem.h>
@@ -174,6 +175,10 @@ drm_clflush_virt_range(void *addr, unsigned long length)
 
 	if (wbinvd_on_all_cpus())
 		pr_err("Timed out waiting for cache flush\n");
+
+#elif defined(CONFIG_ARM64)
+	void *end = addr + length;
+	dcache_clean_inval_poc((unsigned long)addr, (unsigned long)end);
 #else
 	WARN_ONCE(1, "Architecture has no drm_cache.c support\n");
 #endif
-- 
2.25.1