From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753909AbaATNm1 (ORCPT ); Mon, 20 Jan 2014 08:42:27 -0500 Received: from mail-ea0-f176.google.com ([209.85.215.176]:38673 "EHLO mail-ea0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751643AbaATNmY (ORCPT ); Mon, 20 Jan 2014 08:42:24 -0500 Date: Mon, 20 Jan 2014 14:42:20 +0100 From: Ingo Molnar To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, "H. Peter Anvin" , Thomas Gleixner , Andrew Morton Subject: [GIT PULL] x86/apic changes for v3.14 Message-ID: <20140120134220.GA12050@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus, Please pull the latest x86-apic-for-linus git tree from: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-apic-for-linus # HEAD: 5b4d1dbc24bb6fd7179ada0f47be34e27e64decb x86, apic: Make disabled_cpu_apicid static read_mostly, fix typos Two main changes: - Improve local APIC Error Status Register reporting robustness. - Add the 'disable_cpu_apicid=x' boot parameter for kexec booting. Thanks, Ingo ------------------> H. Peter Anvin (1): x86, apic: Make disabled_cpu_apicid static read_mostly, fix typos HATAYAMA Daisuke (1): x86, apic, kexec: Add disable_cpu_apicid kernel parameter Richard Weinberger (1): x86/apic: Read Error Status Register correctly Documentation/kernel-parameters.txt | 9 +++++ arch/x86/kernel/apic/apic.c | 66 ++++++++++++++++++++++++++++++++----- 2 files changed, 66 insertions(+), 9 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index b9e9bd8..6fdbf8c 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -774,6 +774,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted. disable= [IPV6] See Documentation/networking/ipv6.txt. + disable_cpu_apicid= [X86,APIC,SMP] + Format: + The number of initial APIC ID for the + corresponding CPU to be disabled at boot, + mostly used for the kdump 2nd kernel to + disable BSP to wake up multiple CPUs without + causing system reset or hang due to sending + INIT from AP to BSP. + disable_ddw [PPC/PSERIES] Disable Dynamic DMA Window support. Use this if to workaround buggy firmware. diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index d278736..7f26c9a 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -75,6 +75,13 @@ unsigned int max_physical_apicid; physid_mask_t phys_cpu_present_map; /* + * Processor to be disabled specified by kernel parameter + * disable_cpu_apicid=, mostly used for the kdump 2nd kernel to + * avoid undefined behaviour caused by sending INIT from AP to BSP. + */ +static unsigned int disabled_cpu_apicid __read_mostly = BAD_APICID; + +/* * Map cpu index to physical APIC ID */ DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid, BAD_APICID); @@ -1968,7 +1975,7 @@ __visible void smp_trace_spurious_interrupt(struct pt_regs *regs) */ static inline void __smp_error_interrupt(struct pt_regs *regs) { - u32 v0, v1; + u32 v; u32 i = 0; static const char * const error_interrupt_reason[] = { "Send CS error", /* APIC Error Bit 0 */ @@ -1982,21 +1989,20 @@ static inline void __smp_error_interrupt(struct pt_regs *regs) }; /* First tickle the hardware, only then report what went on. -- REW */ - v0 = apic_read(APIC_ESR); apic_write(APIC_ESR, 0); - v1 = apic_read(APIC_ESR); + v = apic_read(APIC_ESR); ack_APIC_irq(); atomic_inc(&irq_err_count); - apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x(%02x)", - smp_processor_id(), v0 , v1); + apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x", + smp_processor_id(), v); - v1 = v1 & 0xff; - while (v1) { - if (v1 & 0x1) + v &= 0xff; + while (v) { + if (v & 0x1) apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]); i++; - v1 >>= 1; + v >>= 1; } apic_printk(APIC_DEBUG, KERN_CONT "\n"); @@ -2115,6 +2121,39 @@ int generic_processor_info(int apicid, int version) phys_cpu_present_map); /* + * boot_cpu_physical_apicid is designed to have the apicid + * returned by read_apic_id(), i.e, the apicid of the + * currently booting-up processor. However, on some platforms, + * it is temporarily modified by the apicid reported as BSP + * through MP table. Concretely: + * + * - arch/x86/kernel/mpparse.c: MP_processor_info() + * - arch/x86/mm/amdtopology.c: amd_numa_init() + * - arch/x86/platform/visws/visws_quirks.c: MP_processor_info() + * + * This function is executed with the modified + * boot_cpu_physical_apicid. So, disabled_cpu_apicid kernel + * parameter doesn't work to disable APs on kdump 2nd kernel. + * + * Since fixing handling of boot_cpu_physical_apicid requires + * another discussion and tests on each platform, we leave it + * for now and here we use read_apic_id() directly in this + * function, generic_processor_info(). + */ + if (disabled_cpu_apicid != BAD_APICID && + disabled_cpu_apicid != read_apic_id() && + disabled_cpu_apicid == apicid) { + int thiscpu = num_processors + disabled_cpus; + + pr_warning("APIC: Disabling requested cpu." + " Processor %d/0x%x ignored.\n", + thiscpu, apicid); + + disabled_cpus++; + return -ENODEV; + } + + /* * If boot cpu has not been detected yet, then only allow upto * nr_cpu_ids - 1 processors and keep one slot free for boot cpu */ @@ -2592,3 +2631,12 @@ static int __init lapic_insert_resource(void) * that is using request_resource */ late_initcall(lapic_insert_resource); + +static int __init apic_set_disabled_cpu_apicid(char *arg) +{ + if (!arg || !get_option(&arg, &disabled_cpu_apicid)) + return -EINVAL; + + return 0; +} +early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);