From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ross Zwisler Subject: [PATCH 5/6] x86: Use clwb in drm_clflush_page Date: Tue, 11 Nov 2014 11:43:15 -0700 Message-ID: <1415731396-19364-6-git-send-email-ross.zwisler@linux.intel.com> References: <1415731396-19364-1-git-send-email-ross.zwisler@linux.intel.com> Return-path: In-Reply-To: <1415731396-19364-1-git-send-email-ross.zwisler@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: Ross Zwisler , H Peter Anvin , Ingo Molnar , Thomas Gleixner , David Airlie , dri-devel@lists.freedesktop.org, x86@kernel.org List-Id: dri-devel@lists.freedesktop.org If clwb is available on the system, use it in drm_clflush_page. If clwb is not available, fall back to clflushopt if you can. If clflushopt is not supported, fall all the way back to clflush. Signed-off-by: Ross Zwisler Cc: H Peter Anvin Cc: Ingo Molnar Cc: Thomas Gleixner Cc: David Airlie Cc: dri-devel@lists.freedesktop.org Cc: x86@kernel.org --- drivers/gpu/drm/drm_cache.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c index a6b6906..aad9d82 100644 --- a/drivers/gpu/drm/drm_cache.c +++ b/drivers/gpu/drm/drm_cache.c @@ -34,9 +34,9 @@ #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. + * clwb and clflushopt are unordered instructions which need 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) @@ -50,7 +50,7 @@ drm_clflush_page(struct page *page) page_virtual = kmap_atomic(page); for (i = 0; i < PAGE_SIZE; i += size) - clflushopt(page_virtual + i); + clwb(page_virtual + i); kunmap_atomic(page_virtual); } -- 1.9.3