From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756980Ab3BKMha (ORCPT ); Mon, 11 Feb 2013 07:37:30 -0500 Received: from terminus.zytor.com ([198.137.202.10]:60874 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756912Ab3BKMh1 (ORCPT ); Mon, 11 Feb 2013 07:37:27 -0500 Date: Mon, 11 Feb 2013 04:37:11 -0800 From: tip-bot for Stoney Wang Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, yinghai@kernel.org, song-bo.wang@hp.com, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, song-bo.wang@hp.com, yinghai@kernel.org, tglx@linutronix.de In-Reply-To: <1360263182-16226-1-git-send-email-yinghai@kernel.org> References: <1360263182-16226-1-git-send-email-yinghai@kernel.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/apic: Work around boot failure on HP ProLiant DL980 G7 Server systems Git-Commit-ID: cb214ede7657db458fd0b2a25ea0b28dbf900ebc 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 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (terminus.zytor.com [127.0.0.1]); Mon, 11 Feb 2013 04:37:16 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: cb214ede7657db458fd0b2a25ea0b28dbf900ebc Gitweb: http://git.kernel.org/tip/cb214ede7657db458fd0b2a25ea0b28dbf900ebc Author: Stoney Wang AuthorDate: Thu, 7 Feb 2013 10:53:02 -0800 Committer: Ingo Molnar CommitDate: Mon, 11 Feb 2013 11:13:00 +0100 x86/apic: Work around boot failure on HP ProLiant DL980 G7 Server systems When a HP ProLiant DL980 G7 Server boots a regular kernel, there will be intermittent lost interrupts which could result in a hang or (in extreme cases) data loss. The reason is that this system only supports x2apic physical mode, while the kernel boots with a logical-cluster default setting. This bug can be worked around by specifying the "x2apic_phys" or "nox2apic" boot option, but we want to handle this system without requiring manual workarounds. The BIOS sets ACPI_FADT_APIC_PHYSICAL in FADT table. As all apicids are smaller than 255, BIOS need to pass the control to the OS with xapic mode, according to x2apic-spec, chapter 2.9. Current code handle x2apic when BIOS pass with xapic mode enabled: When user specifies x2apic_phys, or FADT indicates PHYSICAL: 1. During madt oem check, apic driver is set with xapic logical or xapic phys driver at first. 2. enable_IR_x2apic() will enable x2apic_mode. 3. if user specifies x2apic_phys on the boot line, x2apic_phys_probe() will install the correct x2apic phys driver and use x2apic phys mode. Otherwise it will skip the driver will let x2apic_cluster_probe to take over to install x2apic cluster driver (wrong one) even though FADT indicates PHYSICAL, because x2apic_phys_probe does not check FADT PHYSICAL. Add checking x2apic_fadt_phys in x2apic_phys_probe() to fix the problem. Signed-off-by: Stoney Wang [ updated the changelog and simplified the code ] Signed-off-by: Yinghai Lu Cc: stable@kernel.org Link: http://lkml.kernel.org/r/1360263182-16226-1-git-send-email-yinghai@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/x2apic_phys.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c index e03a1e1..562a76d 100644 --- a/arch/x86/kernel/apic/x2apic_phys.c +++ b/arch/x86/kernel/apic/x2apic_phys.c @@ -20,18 +20,19 @@ static int set_x2apic_phys_mode(char *arg) } early_param("x2apic_phys", set_x2apic_phys_mode); -static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id) +static bool x2apic_fadt_phys(void) { - if (x2apic_phys) - return x2apic_enabled(); - else if ((acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) && - (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL) && - x2apic_enabled()) { + if ((acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) && + (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) { printk(KERN_DEBUG "System requires x2apic physical mode\n"); - return 1; + return true; } - else - return 0; + return false; +} + +static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id) +{ + return x2apic_enabled() && (x2apic_phys || x2apic_fadt_phys()); } static void @@ -82,7 +83,7 @@ static void init_x2apic_ldr(void) static int x2apic_phys_probe(void) { - if (x2apic_mode && x2apic_phys) + if (x2apic_mode && (x2apic_phys || x2apic_fadt_phys())) return 1; return apic == &apic_x2apic_phys;