From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754490AbaBZTMw (ORCPT ); Wed, 26 Feb 2014 14:12:52 -0500 Received: from mga02.intel.com ([134.134.136.20]:20204 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753695AbaBZTJC (ORCPT ); Wed, 26 Feb 2014 14:09:02 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,549,1389772800"; d="scan'208";a="490301633" From: Ross Zwisler To: linux-kernel@vger.kernel.org Cc: Ross Zwisler , H Peter Anvin , Ingo Molnar , Thomas Gleixner Subject: [PATCH 3/4] x86: Use clflushopt in drm_clflush_page Date: Wed, 26 Feb 2014 12:06:51 -0700 Message-Id: <1393441612-19729-4-git-send-email-ross.zwisler@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1393441612-19729-1-git-send-email-ross.zwisler@linux.intel.com> References: <1393441612-19729-1-git-send-email-ross.zwisler@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If clflushopt is available on the system, use it instead of clflush in drm_clflush_page. Signed-off-by: Ross Zwisler Cc: H Peter Anvin Cc: Ingo Molnar Cc: Thomas Gleixner --- 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 #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