Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933196Ab1EZSNe (ORCPT ); Thu, 26 May 2011 14:13:34 -0400 Received: from hera.kernel.org ([140.211.167.34]:44431 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757810Ab1EZSNd (ORCPT ); Thu, 26 May 2011 14:13:33 -0400 Date: Thu, 26 May 2011 18:13:16 GMT From: tip-bot for Boris Ostrovsky Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, Andreas.Herrmann3@amd.com, cebbert@redhat.com, tglx@linutronix.de, hpa@linux.intel.com, ostr@amd64.org, borislav.petkov@amd.com, Hans.Rosenfeld@amd.com Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, Andreas.Herrmann3@amd.com, cebbert@redhat.com, tglx@linutronix.de, hpa@linux.intel.com, ostr@amd64.org, Hans.Rosenfeld@amd.com, borislav.petkov@amd.com In-Reply-To: <1306423192-19774-1-git-send-email-ostr@amd64.org> References: <1306423192-19774-1-git-send-email-ostr@amd64.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86, amd: Do not enable ARAT feature on AMD processors below family 0x12 Git-Commit-ID: e9cdd343a5e42c43bcda01e609fa23089e026470 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 26 May 2011 18:13:17 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2268 Lines: 56 Commit-ID: e9cdd343a5e42c43bcda01e609fa23089e026470 Gitweb: http://git.kernel.org/tip/e9cdd343a5e42c43bcda01e609fa23089e026470 Author: Boris Ostrovsky AuthorDate: Thu, 26 May 2011 11:19:52 -0400 Committer: H. Peter Anvin CommitDate: Thu, 26 May 2011 10:38:30 -0700 x86, amd: Do not enable ARAT feature on AMD processors below family 0x12 Commit b87cf80af3ba4b4c008b4face3c68d604e1715c6 added support for ARAT (Always Running APIC timer) on AMD processors that are not affected by erratum 400. This erratum is present on certain processor families and prevents APIC timer from waking up the CPU when it is in a deep C state, including C1E state. Determining whether a processor is affected by this erratum may have some corner cases and handling these cases is somewhat complicated. In the interest of simplicity we won't claim ARAT support on processor families below 0x12 and will go back to broadcasting timer when going idle. Signed-off-by: Boris Ostrovsky Link: http://lkml.kernel.org/r/1306423192-19774-1-git-send-email-ostr@amd64.org Tested-by: Boris Petkov Cc: Hans Rosenfeld Cc: Andreas Herrmann Cc: Chuck Ebbert Cc: stable@kernel.org # 32.x, 38.x, 39.x Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/amd.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 8f5cabb..b13ed39 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -612,8 +612,11 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) } #endif - /* As a rule processors have APIC timer running in deep C states */ - if (c->x86 > 0xf && !cpu_has_amd_erratum(amd_erratum_400)) + /* + * Family 0x12 and above processors have APIC timer + * running in deep C states. + */ + if (c->x86 > 0x11) set_cpu_cap(c, X86_FEATURE_ARAT); /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/