From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751687AbWFXASn (ORCPT ); Fri, 23 Jun 2006 20:18:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752182AbWFXASm (ORCPT ); Fri, 23 Jun 2006 20:18:42 -0400 Received: from mail.suse.de ([195.135.220.2]:64654 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1751687AbWFXASm (ORCPT ); Fri, 23 Jun 2006 20:18:42 -0400 Date: Sat, 24 Jun 2006 02:18:40 +0200 From: "Andi Kleen" To: torvalds@osdl.org Cc: discuss@x86-64.org, akpm@osdl.org, linux-kernel@vger.kernel.org Subject: [PATCH] [4/82] i386/x86-64: Use new official CPUID to get APICID/core split on AMD platforms Message-ID: <449C84E0.mailCMY1N1S88@suse.de> User-Agent: nail 10.6 11/15/03 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Previously the apicid<->coreid split was computed based on the max number of cores. Now use a new CPUID AMD defined for that. On most systems right now it should be 0 and the old method will be used. Signed-off-by: Andi Kleen --- arch/i386/kernel/cpu/amd.c | 14 ++++++++------ arch/x86_64/kernel/setup.c | 20 +++++++++++++------- 2 files changed, 21 insertions(+), 13 deletions(-) Index: linux/arch/x86_64/kernel/setup.c =================================================================== --- linux.orig/arch/x86_64/kernel/setup.c +++ linux/arch/x86_64/kernel/setup.c @@ -968,10 +968,18 @@ static void __init amd_detect_cmp(struct int node = 0; unsigned apicid = hard_smp_processor_id(); #endif + unsigned ecx = cpuid_ecx(0x80000008); - bits = 0; - while ((1 << bits) < c->x86_max_cores) - bits++; + c->x86_max_cores = (ecx & 0xff) + 1; + + /* CPU telling us the core id bits shift? */ + bits = (ecx >> 12) & 0xF; + + /* Otherwise recompute */ + if (bits == 0) { + while ((1 << bits) < c->x86_max_cores) + bits++; + } /* Low order bits define the core id (index of core in socket) */ cpu_core_id[cpu] = phys_proc_id[cpu] & ((1 << bits)-1); @@ -1059,11 +1067,9 @@ static int __init init_amd(struct cpuinf if (c->x86_power & (1<<8)) set_bit(X86_FEATURE_CONSTANT_TSC, &c->x86_capability); - if (c->extended_cpuid_level >= 0x80000008) { - c->x86_max_cores = (cpuid_ecx(0x80000008) & 0xff) + 1; - + /* Multi core CPU? */ + if (c->extended_cpuid_level >= 0x80000008) amd_detect_cmp(c); - } return r; } Index: linux/arch/i386/kernel/cpu/amd.c =================================================================== --- linux.orig/arch/i386/kernel/cpu/amd.c +++ linux/arch/i386/kernel/cpu/amd.c @@ -224,15 +224,17 @@ static void __init init_amd(struct cpuin #ifdef CONFIG_X86_HT /* - * On a AMD dual core setup the lower bits of the APIC id - * distingush the cores. Assumes number of cores is a power - * of two. + * On a AMD multi core setup the lower bits of the APIC id + * distingush the cores. */ if (c->x86_max_cores > 1) { int cpu = smp_processor_id(); - unsigned bits = 0; - while ((1 << bits) < c->x86_max_cores) - bits++; + unsigned bits = (cpuid_ecx(0x80000008) >> 12) & 0xf; + + if (bits == 0) { + while ((1 << bits) < c->x86_max_cores) + bits++; + } cpu_core_id[cpu] = phys_proc_id[cpu] & ((1<>= bits; printk(KERN_INFO "CPU %d(%d) -> Core %d\n",