Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934042Ab0HFARj (ORCPT ); Thu, 5 Aug 2010 20:17:39 -0400 Received: from hera.kernel.org ([140.211.167.34]:50114 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751662Ab0HFARe (ORCPT ); Thu, 5 Aug 2010 20:17:34 -0400 Date: Fri, 6 Aug 2010 00:15:57 GMT From: "tip-bot for Eric W. Biederman" Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, hilld@binarystorm.net, tglx@linutronix.de, hpa@linux.intel.com, tvrtko.ursulin@sophos.com, ebiederm@xmission.com Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, ebiederm@xmission.com, tvrtko.ursulin@sophos.com, hilld@binarystorm.net, tglx@linutronix.de, hpa@linux.intel.com In-Reply-To: References: To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86, apic: Map the local apic when parsing the MP table. Message-ID: Git-Commit-ID: 5989cd6a1cbf86587edcc856791f960978087311 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-4.2.3 (hera.kernel.org [127.0.0.1]); Fri, 06 Aug 2010 00:16:04 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3950 Lines: 109 Commit-ID: 5989cd6a1cbf86587edcc856791f960978087311 Gitweb: http://git.kernel.org/tip/5989cd6a1cbf86587edcc856791f960978087311 Author: Eric W. Biederman AuthorDate: Wed, 4 Aug 2010 13:30:27 -0700 Committer: H. Peter Anvin CommitDate: Thu, 5 Aug 2010 16:26:42 -0700 x86, apic: Map the local apic when parsing the MP table. This fixes a regression in 2.6.35 from 2.6.34, that is present for select models of Intel cpus when people are using an MP table. The commit cf7500c0ea133d66f8449d86392d83f840102632 "x86, ioapic: In mpparse use mp_register_ioapic" started calling mp_register_ioapic from MP_ioapic_info. An extremely simple change that was obviously correct. Unfortunately mp_register_ioapic did just a little more than the previous hand crafted code and so we gained this call path. The problem call path is: MP_ioapic_info() mp_register_ioapic() io_apic_unique_id() io_apic_get_unique_id() get_physical_broadcast() modern_apic() lapic_get_version() apic_read(APIC_LVR) Which turned out to be a problem because the local apic was not mapped, at that point, unlike the similar point in the ACPI parsing code. This problem is fixed by mapping the local apic when parsing the mptable as soon as we reasonably can. Looking at the number of places we setup the fixmap for the local apic, I see some serious simplification opportunities. For the moment except for not duplicating the setting up of the fixmap in init_apic_mappings, I have not acted on them. The regression from 2.6.34 is tracked in bug https://bugzilla.kernel.org/show_bug.cgi?id=16173 Cc: 2.6.35 Reported-by: David Hill Reported-by: Tvrtko Ursulin Tested-by: Tvrtko Ursulin Signed-off-by: Eric W. Biederman LKML-Reference: Signed-off-by: H. Peter Anvin --- arch/x86/kernel/apic/apic.c | 2 +- arch/x86/kernel/mpparse.c | 16 ++++++++++++++++ 2 files changed, 17 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index a96489e..c07e513 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1606,7 +1606,7 @@ void __init init_apic_mappings(void) * acpi lapic path already maps that address in * acpi_register_lapic_address() */ - if (!acpi_lapic) + if (!acpi_lapic && !smp_found_config) set_fixmap_nocache(FIX_APIC_BASE, apic_phys); apic_printk(APIC_VERBOSE, "mapped APIC to %08lx (%08lx)\n", diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c index d86dbf7..d7b6f7f 100644 --- a/arch/x86/kernel/mpparse.c +++ b/arch/x86/kernel/mpparse.c @@ -274,6 +274,18 @@ static void __init smp_dump_mptable(struct mpc_table *mpc, unsigned char *mpt) void __init default_smp_read_mpc_oem(struct mpc_table *mpc) { } +static void __init smp_register_lapic_address(unsigned long address) +{ + mp_lapic_addr = address; + + set_fixmap_nocache(FIX_APIC_BASE, address); + if (boot_cpu_physical_apicid == -1U) { + boot_cpu_physical_apicid = read_apic_id(); + apic_version[boot_cpu_physical_apicid] = + GET_APIC_VERSION(apic_read(APIC_LVR)); + } +} + static int __init smp_read_mpc(struct mpc_table *mpc, unsigned early) { char str[16]; @@ -295,6 +307,10 @@ static int __init smp_read_mpc(struct mpc_table *mpc, unsigned early) if (early) return 1; + /* Initialize the lapic mapping */ + if (!acpi_lapic) + smp_register_lapic_address(mpc->lapic); + if (mpc->oemptr) x86_init.mpparse.smp_read_mpc_oem(mpc); -- 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/