From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755335AbbGFPnC (ORCPT ); Mon, 6 Jul 2015 11:43:02 -0400 Received: from terminus.zytor.com ([198.137.202.10]:49358 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755302AbbGFPm6 (ORCPT ); Mon, 6 Jul 2015 11:42:58 -0400 Date: Mon, 6 Jul 2015 08:41:48 -0700 From: tip-bot for Andy Lutomirski Message-ID: Cc: hpa@zytor.com, ralf@linux-mips.org, luto@amacapital.net, mingo@kernel.org, brgerst@gmail.com, linux-kernel@vger.kernel.org, luto@kernel.org, tglx@linutronix.de, bp@suse.de, kvm@vger.kernel.org, ray.huang@amd.com, lenb@kernel.org, dvlasenk@redhat.com, torvalds@linux-foundation.org, peterz@infradead.org, bp@alien8.de, john.stultz@linaro.org Reply-To: ray.huang@amd.com, lenb@kernel.org, peterz@infradead.org, bp@alien8.de, dvlasenk@redhat.com, torvalds@linux-foundation.org, john.stultz@linaro.org, luto@amacapital.net, hpa@zytor.com, ralf@linux-mips.org, brgerst@gmail.com, mingo@kernel.org, linux-kernel@vger.kernel.org, bp@suse.de, kvm@vger.kernel.org, tglx@linutronix.de, luto@kernel.org In-Reply-To: References: To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/asm] x86/asm/tsc, x86/cpu/amd: Use the full 64-bit TSC to detect the 2.6.2 bug Git-Commit-ID: 3796366614598e48edf0561b86f18c230a7debc8 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: 3796366614598e48edf0561b86f18c230a7debc8 Gitweb: http://git.kernel.org/tip/3796366614598e48edf0561b86f18c230a7debc8 Author: Andy Lutomirski AuthorDate: Thu, 25 Jun 2015 18:44:01 +0200 Committer: Ingo Molnar CommitDate: Mon, 6 Jul 2015 15:23:27 +0200 x86/asm/tsc, x86/cpu/amd: Use the full 64-bit TSC to detect the 2.6.2 bug This code is timing 100k indirect calls, so the added overhead of counting the number of cycles elapsed as a 64-bit number should be insignificant. Drop the optimization of using a 32-bit count. Signed-off-by: Andy Lutomirski Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Huang Rui Cc: John Stultz Cc: Len Brown Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Ralf Baechle Cc: Thomas Gleixner Cc: kvm ML Link: http://lkml.kernel.org/r/d58f339a9c0dd8352b50d2f7a216f67ec2844f20.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/amd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index dd3a4ba..a69710d 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -114,7 +114,7 @@ static void init_amd_k6(struct cpuinfo_x86 *c) const int K6_BUG_LOOP = 1000000; int n; void (*f_vide)(void); - unsigned long d, d2; + u64 d, d2; printk(KERN_INFO "AMD K6 stepping B detected - "); @@ -125,10 +125,10 @@ static void init_amd_k6(struct cpuinfo_x86 *c) n = K6_BUG_LOOP; f_vide = vide; - rdtscl(d); + d = native_read_tsc(); while (n--) f_vide(); - rdtscl(d2); + d2 = native_read_tsc(); d = d2-d; if (d > 20*K6_BUG_LOOP)