If clflushopt is available on the system, use it instead of clflush in drm_clflush_page.
Signed-off-by: Ross Zwisler <[email protected]> Cc: H Peter Anvin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> --- drivers/gpu/drm/drm_cache.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c index bb8f580..c518fb6 100644 --- a/drivers/gpu/drm/drm_cache.c +++ b/drivers/gpu/drm/drm_cache.c @@ -32,6 +32,12 @@ #include <drm/drmP.h> #if defined(CONFIG_X86) + +/* + * clflushopt is an unordered instruction which needs fencing with mfence or + * sfence to avoid ordering issues. For drm_clflush_page this fencing happens + * in the caller. + */ static void drm_clflush_page(struct page *page) { @@ -44,7 +50,7 @@ drm_clflush_page(struct page *page) page_virtual = kmap_atomic(page); for (i = 0; i < PAGE_SIZE; i += size) - clflush(page_virtual + i); + clflushopt(page_virtual + i); kunmap_atomic(page_virtual); } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
