From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754001AbbEKMqp (ORCPT ); Mon, 11 May 2015 08:46:45 -0400 Received: from terminus.zytor.com ([198.137.202.10]:60742 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753511AbbEKMqj (ORCPT ); Mon, 11 May 2015 08:46:39 -0400 Date: Mon, 11 May 2015 05:45:39 -0700 From: tip-bot for Ross Zwisler Message-ID: Cc: luto@amacapital.net, linux-kernel@vger.kernel.org, brgerst@gmail.com, bp@alien8.de, mcgrof@suse.com, bp@suse.de, toshi.kani@hp.com, hpa@zytor.com, akpm@linux-foundation.org, ross.zwisler@linux.intel.com, tglx@linutronix.de, peterz@infradead.org, dvlasenk@redhat.com, mingo@kernel.org, torvalds@linux-foundation.org Reply-To: hpa@zytor.com, akpm@linux-foundation.org, mingo@kernel.org, torvalds@linux-foundation.org, ross.zwisler@linux.intel.com, dvlasenk@redhat.com, tglx@linutronix.de, peterz@infradead.org, brgerst@gmail.com, luto@amacapital.net, linux-kernel@vger.kernel.org, mcgrof@suse.com, bp@suse.de, toshi.kani@hp.com, bp@alien8.de In-Reply-To: <1431332153-18566-5-git-send-email-bp@alien8.de> References: <1430259192-18802-1-git-send-email-ross.zwisler@linux.intel.com> <1431332153-18566-5-git-send-email-bp@alien8.de> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/mm] x86/mm: Do not flush last cacheline twice in clflush_cache_range() Git-Commit-ID: 6c434d6176c0cb42847c33245189667d645db7bf 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 6c434d6176c0cb42847c33245189667d645db7bf Gitweb: http://git.kernel.org/tip/6c434d6176c0cb42847c33245189667d645db7bf Author: Ross Zwisler AuthorDate: Mon, 11 May 2015 10:15:49 +0200 Committer: Ingo Molnar CommitDate: Mon, 11 May 2015 10:38:44 +0200 x86/mm: Do not flush last cacheline twice in clflush_cache_range() The current algorithm used in clflush_cache_range() can cause the last cache line of the buffer to be flushed twice. Fix that algorithm so that each cache line will only be flushed once. Reported-by: H. Peter Anvin Signed-off-by: Ross Zwisler Signed-off-by: Borislav Petkov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Linus Torvalds Cc: Luis R. Rodriguez Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Toshi Kani Link: http://lkml.kernel.org/r/1430259192-18802-1-git-send-email-ross.zwisler@linux.intel.com Link: http://lkml.kernel.org/r/1431332153-18566-5-git-send-email-bp@alien8.de [ Changed it to 'void *' to simplify the type conversions. ] Signed-off-by: Ingo Molnar --- arch/x86/mm/pageattr.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 89af288..5ddd900 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -129,16 +129,15 @@ within(unsigned long addr, unsigned long start, unsigned long end) */ void clflush_cache_range(void *vaddr, unsigned int size) { - void *vend = vaddr + size - 1; + unsigned long clflush_mask = boot_cpu_data.x86_clflush_size - 1; + void *vend = vaddr + size; + void *p; mb(); - for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size) - clflushopt(vaddr); - /* - * Flush any possible final partial cacheline: - */ - clflushopt(vend); + for (p = (void *)((unsigned long)vaddr & ~clflush_mask); + p < vend; p += boot_cpu_data.x86_clflush_size) + clflushopt(p); mb(); }