Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756164AbZFGOno (ORCPT ); Sun, 7 Jun 2009 10:43:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755888AbZFGOn0 (ORCPT ); Sun, 7 Jun 2009 10:43:26 -0400 Received: from hera.kernel.org ([140.211.167.34]:52879 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755858AbZFGOnX (ORCPT ); Sun, 7 Jun 2009 10:43:23 -0400 Date: Sun, 7 Jun 2009 14:42:56 GMT From: tip-bot for Andreas Herrmann To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, andreas.herrmann3@amd.com, stable@kernel.org, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, andreas.herrmann3@amd.com, stable@kernel.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <20090604104016.GT5736@alberich.amd.com> References: <20090604104016.GT5736@alberich.amd.com> Subject: [tip:x86/urgent] x86: Detect use of extended APIC ID for AMD CPUs Message-ID: Git-Commit-ID: 37f36c1017f0032fa7a1fb85a0cddfc0d526d17f X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Sun, 07 Jun 2009 14:42:57 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3878 Lines: 105 Commit-ID: 37f36c1017f0032fa7a1fb85a0cddfc0d526d17f Gitweb: http://git.kernel.org/tip/37f36c1017f0032fa7a1fb85a0cddfc0d526d17f Author: Andreas Herrmann AuthorDate: Thu, 4 Jun 2009 12:40:16 +0200 Committer: Ingo Molnar CommitDate: Sun, 7 Jun 2009 16:39:38 +0200 x86: Detect use of extended APIC ID for AMD CPUs Booting a 32-bit kernel on Magny-Cours results in the following panic ... Using APIC driver default ... Overriding APIC driver with bigsmp ... Getting VERSION: 80050010 Getting VERSION: 80050010 Getting ID: 10000000 Getting ID: ef000000 Getting LVT0: 700 Getting LVT1: 10000 Kernel panic - not syncing: Boot APIC ID in local APIC unexpected (16 vs 0) Pid: 1, comm: swapper Not tainted 2.6.30-rcX #2 Call Trace: [] ? panic+0x38/0xd3 [] ? native_smp_prepare_cpus+0x259/0x31f [] ? kernel_init+0x3e/0x141 [] ? kernel_init+0x0/0x141 [] ? kernel_thread_helper+0x7/0x10 The reason is that default_get_apic_id handled extension of local APIC ID field just in case of XAPIC. Thus for this AMD CPU, default_get_apic_id() returns 0 and bigsmp_get_apic_id() returns 16 which leads to the respective kernel panic. This patch introduces a Linux specific feature flag to indicate support for extended APIC id (8 bits instead of 4 bits width) and sets the flag on AMD CPUs if applicable. Signed-off-by: Andreas Herrmann Cc: LKML-Reference: <20090604104016.GT5736@alberich.amd.com> Signed-off-by: Ingo Molnar --- arch/x86/include/asm/apic.h | 2 +- arch/x86/include/asm/cpufeature.h | 1 + arch/x86/kernel/cpu/amd.c | 10 ++++++++++ 3 files changed, 12 insertions(+), 1 deletions(-) diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 42f2f83..9b2c049 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -410,7 +410,7 @@ static inline unsigned default_get_apic_id(unsigned long x) { unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR)); - if (APIC_XAPIC(ver)) + if (APIC_XAPIC(ver) || boot_cpu_has(X86_FEATURE_EXTD_APICID)) return (x >> 24) & 0xFF; else return (x >> 24) & 0x0F; diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index bb83b1c..78dee4f 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -94,6 +94,7 @@ #define X86_FEATURE_TSC_RELIABLE (3*32+23) /* TSC is known to be reliable */ #define X86_FEATURE_NONSTOP_TSC (3*32+24) /* TSC does not stop in C states */ #define X86_FEATURE_CLFLUSH_MONITOR (3*32+25) /* "" clflush reqd with monitor */ +#define X86_FEATURE_EXTD_APICID (3*32+26) /* has extended APICID (8 bits) */ /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */ #define X86_FEATURE_XMM3 (4*32+ 0) /* "pni" SSE-3 */ diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 7e4a459..fae8be8 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -351,6 +351,16 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c) (c->x86_model == 8 && c->x86_mask >= 8)) set_cpu_cap(c, X86_FEATURE_K6_MTRR); #endif +#ifdef CONFIG_X86_LOCAL_APIC + /* check CPU config space for extended APIC ID */ + if (c->x86 >= 0xf) { + unsigned int val; + + val = read_pci_config(0, 24, 0, 0x68); + if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18))) + set_cpu_cap(c, X86_FEATURE_EXTD_APICID); + } +#endif } static void __cpuinit init_amd(struct cpuinfo_x86 *c) -- 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/