From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4455C43387 for ; Mon, 17 Dec 2018 18:25:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D2D421849 for ; Mon, 17 Dec 2018 18:25:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388922AbeLQSZs (ORCPT ); Mon, 17 Dec 2018 13:25:48 -0500 Received: from terminus.zytor.com ([198.137.202.136]:57467 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727760AbeLQSZs (ORCPT ); Mon, 17 Dec 2018 13:25:48 -0500 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id wBHIPPAB2563375 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 17 Dec 2018 10:25:25 -0800 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id wBHIPOC72563372; Mon, 17 Dec 2018 10:25:24 -0800 Date: Mon, 17 Dec 2018 10:25:24 -0800 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Peter Zijlstra Message-ID: Cc: torvalds@linux-foundation.org, luto@kernel.org, dave.hansen@linux.intel.com, mingo@kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, tglx@linutronix.de, peterz@infradead.org, riel@surriel.com, bp@alien8.de Reply-To: torvalds@linux-foundation.org, dave.hansen@linux.intel.com, mingo@kernel.org, luto@kernel.org, tglx@linutronix.de, hpa@zytor.com, linux-kernel@vger.kernel.org, peterz@infradead.org, riel@surriel.com, bp@alien8.de In-Reply-To: <20181203171043.626999883@infradead.org> References: <20181203171043.626999883@infradead.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/mm] x86/mm/cpa: Better use CLFLUSHOPT Git-Commit-ID: c38116bb940ae37f51fccd315b420ee5961dcb76 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c38116bb940ae37f51fccd315b420ee5961dcb76 Gitweb: https://git.kernel.org/tip/c38116bb940ae37f51fccd315b420ee5961dcb76 Author: Peter Zijlstra AuthorDate: Mon, 3 Dec 2018 18:03:52 +0100 Committer: Ingo Molnar CommitDate: Mon, 17 Dec 2018 18:54:29 +0100 x86/mm/cpa: Better use CLFLUSHOPT Currently we issue an MFENCE before and after flushing a range. This means that if we flush a bunch of single page ranges -- like with the cpa array, we issue a whole bunch of superfluous MFENCEs. Reorgainze the code a little to avoid this. [ mingo: capitalize instructions, tweak changelog and comments. ] Signed-off-by: Peter Zijlstra (Intel) Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: Tom.StDenis@amd.com Cc: dave.hansen@intel.com Link: http://lkml.kernel.org/r/20181203171043.626999883@infradead.org Signed-off-by: Ingo Molnar --- arch/x86/mm/pageattr.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 85ef53b86fa0..7d05149995dc 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -251,15 +251,7 @@ static unsigned long __cpa_addr(struct cpa_data *cpa, unsigned long idx) * Flushing functions */ -/** - * clflush_cache_range - flush a cache range with clflush - * @vaddr: virtual start address - * @size: number of bytes to flush - * - * clflushopt is an unordered instruction which needs fencing with mfence or - * sfence to avoid ordering issues. - */ -void clflush_cache_range(void *vaddr, unsigned int size) +static void clflush_cache_range_opt(void *vaddr, unsigned int size) { const unsigned long clflush_size = boot_cpu_data.x86_clflush_size; void *p = (void *)((unsigned long)vaddr & ~(clflush_size - 1)); @@ -268,11 +260,22 @@ void clflush_cache_range(void *vaddr, unsigned int size) if (p >= vend) return; - mb(); - for (; p < vend; p += clflush_size) clflushopt(p); +} +/** + * clflush_cache_range - flush a cache range with clflush + * @vaddr: virtual start address + * @size: number of bytes to flush + * + * CLFLUSHOPT is an unordered instruction which needs fencing with MFENCE or + * SFENCE to avoid ordering issues. + */ +void clflush_cache_range(void *vaddr, unsigned int size) +{ + mb(); + clflush_cache_range_opt(vaddr, size); mb(); } EXPORT_SYMBOL_GPL(clflush_cache_range); @@ -333,6 +336,7 @@ static void cpa_flush(struct cpa_data *data, int cache) if (!cache) return; + mb(); for (i = 0; i < cpa->numpages; i++) { unsigned long addr = __cpa_addr(cpa, i); unsigned int level; @@ -343,8 +347,9 @@ static void cpa_flush(struct cpa_data *data, int cache) * Only flush present addresses: */ if (pte && (pte_val(*pte) & _PAGE_PRESENT)) - clflush_cache_range((void *)addr, PAGE_SIZE); + clflush_cache_range_opt((void *)addr, PAGE_SIZE); } + mb(); } static bool overlaps(unsigned long r1_start, unsigned long r1_end,