From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266085AbUHQM3Q (ORCPT ); Tue, 17 Aug 2004 08:29:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266126AbUHQM3Q (ORCPT ); Tue, 17 Aug 2004 08:29:16 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.104]:59637 "EHLO e4.ny.us.ibm.com") by vger.kernel.org with ESMTP id S266085AbUHQM2o (ORCPT ); Tue, 17 Aug 2004 08:28:44 -0400 Date: Tue, 17 Aug 2004 17:39:11 +0530 From: Hariprasad Nellitheertha To: linux-kernel@vger.kernel.org, fastboot@osdl.org Cc: akpm@osdl.org, Suparna Bhattacharya , mbligh@aracnet.com, litke@us.ibm.com, ebiederm@xmission.com Subject: Re: [PATCH][4/6]Register snapshotting before kexec-boot Message-ID: <20040817120911.GE3916@in.ibm.com> Reply-To: hari@in.ibm.com References: <20040817120239.GA3916@in.ibm.com> <20040817120531.GB3916@in.ibm.com> <20040817120717.GC3916@in.ibm.com> <20040817120809.GD3916@in.ibm.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="M38YqGLZlgb6RLPS" Content-Disposition: inline In-Reply-To: <20040817120809.GD3916@in.ibm.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --M38YqGLZlgb6RLPS Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Regards, Hari -- Hariprasad Nellitheertha Linux Technology Center India Software Labs IBM India, Bangalore --M38YqGLZlgb6RLPS Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="kd-reg-268.patch" This patch contains the code for stopping the other cpus and snapshotting their register values before doing the kexec reboot. Signed off by Hariprasad Nellitheertha --- linux-2.6.8.1-hari/arch/i386/kernel/Makefile | 1 linux-2.6.8.1-hari/arch/i386/kernel/crash_dump.c | 98 ++++++++++ linux-2.6.8.1-hari/arch/i386/kernel/machine_kexec.c | 14 + linux-2.6.8.1-hari/arch/i386/kernel/smp.c | 13 + linux-2.6.8.1-hari/include/asm-i386/crash_dump.h | 32 +++ linux-2.6.8.1-hari/include/asm-i386/mach-default/irq_vectors.h | 1 linux-2.6.8.1-hari/include/asm-i386/smp.h | 1 7 files changed, 156 insertions(+), 4 deletions(-) diff -puN arch/i386/kernel/Makefile~kd-reg-268 arch/i386/kernel/Makefile --- linux-2.6.8.1/arch/i386/kernel/Makefile~kd-reg-268 2004-08-17 17:08:08.000000000 +0530 +++ linux-2.6.8.1-hari/arch/i386/kernel/Makefile 2004-08-17 17:08:18.000000000 +0530 @@ -24,6 +24,7 @@ obj-$(CONFIG_X86_MPPARSE) += mpparse.o obj-$(CONFIG_X86_LOCAL_APIC) += apic.o nmi.o obj-$(CONFIG_X86_IO_APIC) += io_apic.o obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o +obj-$(CONFIG_CRASH_DUMP) += crash_dump.o obj-$(CONFIG_X86_NUMAQ) += numaq.o obj-$(CONFIG_X86_SUMMIT_NUMA) += summit.o obj-$(CONFIG_MODULES) += module.o diff -puN /dev/null arch/i386/kernel/crash_dump.c --- /dev/null 2003-01-30 15:54:37.000000000 +0530 +++ linux-2.6.8.1-hari/arch/i386/kernel/crash_dump.c 2004-08-17 17:08:34.000000000 +0530 @@ -0,0 +1,98 @@ +/* + * Architecture specific (i386) functions for kexec based crash dumps. + * + * Created by: Hariprasad Nellitheertha (hari@in.ibm.com) + * + * Copyright (C) IBM Corporation, 2004. All rights reserved. + * + */ + +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#ifdef CONFIG_SMP +static atomic_t waiting_for_dump_ipi; +static int crash_dump_expect_ipi[NR_CPUS]; +extern void crash_dump_send_ipi(void); +extern void stop_this_cpu(void *); + +static int crash_dump_nmi_callback(struct pt_regs *regs, int cpu) +{ + if (!crash_dump_expect_ipi[cpu]) + return 0; + + crash_dump_expect_ipi[cpu] = 0; + crash_dump_save_this_cpu(regs, cpu); + atomic_dec(&waiting_for_dump_ipi); + + stop_this_cpu(NULL); + + return 1; +} + +void __crash_dump_stop_cpus(void) +{ + int i, cpu = smp_processor_id(); + int other_cpus = num_online_cpus()-1; + + if (other_cpus > 0) { + atomic_set(&waiting_for_dump_ipi, other_cpus); + + for (i = 0; i < NR_CPUS; i++) + crash_dump_expect_ipi[i] = (i != cpu && cpu_online(i)); + + set_nmi_callback(crash_dump_nmi_callback); + /* Ensure the new callback function is set before sending + * out the IPI + */ + wmb(); + + crash_dump_send_ipi(); + while (atomic_read(&waiting_for_dump_ipi) > 0) + cpu_relax(); + + unset_nmi_callback(); + } else { + local_irq_disable(); + disable_local_APIC(); + local_irq_enable(); + } +} +#else +void __crash_dump_stop_cpus(void) {} +#endif + +void crash_get_current_regs(struct pt_regs *regs) +{ + __asm__ __volatile__("movl %%ebx,%0" : "=m"(regs->ebx)); + __asm__ __volatile__("movl %%ecx,%0" : "=m"(regs->ecx)); + __asm__ __volatile__("movl %%edx,%0" : "=m"(regs->edx)); + __asm__ __volatile__("movl %%esi,%0" : "=m"(regs->esi)); + __asm__ __volatile__("movl %%edi,%0" : "=m"(regs->edi)); + __asm__ __volatile__("movl %%ebp,%0" : "=m"(regs->ebp)); + __asm__ __volatile__("movl %%eax,%0" : "=m"(regs->eax)); + __asm__ __volatile__("movl %%esp,%0" : "=m"(regs->esp)); + __asm__ __volatile__("movw %%ss, %%ax;" :"=a"(regs->xss)); + __asm__ __volatile__("movw %%cs, %%ax;" :"=a"(regs->xcs)); + __asm__ __volatile__("movw %%ds, %%ax;" :"=a"(regs->xds)); + __asm__ __volatile__("movw %%es, %%ax;" :"=a"(regs->xes)); + __asm__ __volatile__("pushfl; popl %0" :"=m"(regs->eflags)); + + regs->eip = (unsigned long)current_text_addr(); +} + +void crash_dump_save_this_cpu(struct pt_regs *regs, int cpu) +{ + crash_smp_current_task[cpu] = (int)current; + crash_smp_regs[cpu] = *regs; +} + diff -puN arch/i386/kernel/machine_kexec.c~kd-reg-268 arch/i386/kernel/machine_kexec.c --- linux-2.6.8.1/arch/i386/kernel/machine_kexec.c~kd-reg-268 2004-08-17 17:08:08.000000000 +0530 +++ linux-2.6.8.1-hari/arch/i386/kernel/machine_kexec.c 2004-08-17 17:08:18.000000000 +0530 @@ -17,8 +17,9 @@ #include #include #include -#include +struct pt_regs crash_smp_regs[NR_CPUS]; +u32 crash_smp_current_task[NR_CPUS]; static void set_idt(void *newidt, __u16 limit) { @@ -97,6 +98,14 @@ void __relocate_base_mem(unsigned long b if (PageReserved(page)) copy_page(dest_addr, src_addr); } + + /* Now copy over the saved task pointers and the registers + * to the end of the reserved area + */ + dest_addr = (void *)(__va(CRASH_BACKUP_BASE + CRASH_BACKUP_SIZE)); + memcpy(dest_addr, crash_smp_regs, (sizeof(struct pt_regs)*NR_CPUS)); + dest_addr += sizeof(struct pt_regs)*NR_CPUS; + memcpy(dest_addr, crash_smp_current_task, (sizeof(u32)*NR_CPUS)); } /* @@ -111,7 +120,8 @@ void machine_kexec(struct kimage *image) /* switch to an mm where the reboot_code_buffer is identity mapped */ use_mm(&init_mm); - stop_apics(); + + crash_dump_stop_cpus(); /* Interrupts aren't acceptable while we reboot */ local_irq_disable(); diff -puN arch/i386/kernel/smp.c~kd-reg-268 arch/i386/kernel/smp.c --- linux-2.6.8.1/arch/i386/kernel/smp.c~kd-reg-268 2004-08-17 17:08:08.000000000 +0530 +++ linux-2.6.8.1-hari/arch/i386/kernel/smp.c 2004-08-17 17:08:18.000000000 +0530 @@ -143,6 +143,9 @@ inline void __send_IPI_shortcut(unsigned */ cfg = __prepare_ICR(shortcut, vector); + if (vector == CRASH_DUMP_VECTOR) + cfg = (cfg&~APIC_VECTOR_MASK)|APIC_DM_NMI; + /* * Send the IPI. The write to APIC_ICR fires this off. */ @@ -221,6 +224,9 @@ inline void send_IPI_mask_sequence(cpuma */ cfg = __prepare_ICR(0, vector); + if (vector == CRASH_DUMP_VECTOR) + cfg = (cfg&~APIC_VECTOR_MASK)|APIC_DM_NMI; + /* * Send the IPI. The write to APIC_ICR fires this off. */ @@ -467,6 +473,11 @@ void flush_tlb_all(void) on_each_cpu(do_flush_tlb_all, NULL, 1, 1); } +void crash_dump_send_ipi(void) +{ + send_IPI_allbutself(CRASH_DUMP_VECTOR); +} + /* * this function sends a 'reschedule' IPI to another CPU. * it goes straight through and wastes no time serializing @@ -548,7 +559,7 @@ int smp_call_function (void (*func) (voi return 0; } -static void stop_this_cpu (void * dummy) +void stop_this_cpu (void * dummy) { /* * Remove this CPU: diff -puN include/asm-i386/crash_dump.h~kd-reg-268 include/asm-i386/crash_dump.h --- linux-2.6.8.1/include/asm-i386/crash_dump.h~kd-reg-268 2004-08-17 17:08:09.000000000 +0530 +++ linux-2.6.8.1-hari/include/asm-i386/crash_dump.h 2004-08-17 17:08:18.000000000 +0530 @@ -1,5 +1,7 @@ /* asm-i386/crash_dump.h */ #include +#include +#include extern unsigned int dump_enabled; @@ -8,6 +10,11 @@ void __init find_max_pfn(void); void __relocate_base_mem(unsigned long, unsigned long); extern unsigned int crashed; +extern struct pt_regs crash_smp_regs[NR_CPUS]; +extern u32 crash_smp_current_task[NR_CPUS]; +extern void crash_dump_save_this_cpu(struct pt_regs *, int); +extern void __crash_dump_stop_cpus(void); +extern void crash_get_current_regs(struct pt_regs *regs); #ifdef CONFIG_CRASH_DUMP #define CRASH_BACKUP_BASE ((unsigned long)CONFIG_BACKUP_BASE * 0x100000) @@ -28,7 +35,26 @@ static inline void set_saved_max_pfn(voi static inline void crash_reserve_bootmem(void) { if (!dump_enabled) - reserve_bootmem(CRASH_BACKUP_BASE, CRASH_BACKUP_SIZE); + reserve_bootmem(CRASH_BACKUP_BASE, CRASH_BACKUP_SIZE + PAGE_SIZE); +} + +static inline void crash_dump_stop_cpus(void) +{ + if (!crashed) + stop_apics(); + else { + int cpu = smp_processor_id(); + + crash_smp_current_task[cpu] = (int)current; + crash_get_current_regs(&crash_smp_regs[cpu]); + + /* This also captures the register states of the other cpus */ + __crash_dump_stop_cpus(); +#if defined(CONFIG_X86_IO_APIC) + disable_IO_APIC(); +#endif + disconnect_bsp_APIC(); + } } #else #define CRASH_BACKUP_BASE 0x08000000 @@ -36,4 +62,8 @@ static inline void crash_reserve_bootmem static inline void relocate_base_mem(void) {} static inline void set_saved_max_pfn(void) {} static inline void crash_reserve_bootmem(void) {} +static inline void crash_dump_stop_cpus(void) +{ + stop_apics(); +} #endif diff -puN include/asm-i386/mach-default/irq_vectors.h~kd-reg-268 include/asm-i386/mach-default/irq_vectors.h --- linux-2.6.8.1/include/asm-i386/mach-default/irq_vectors.h~kd-reg-268 2004-08-17 17:08:09.000000000 +0530 +++ linux-2.6.8.1-hari/include/asm-i386/mach-default/irq_vectors.h 2004-08-17 17:08:18.000000000 +0530 @@ -48,6 +48,7 @@ #define INVALIDATE_TLB_VECTOR 0xfd #define RESCHEDULE_VECTOR 0xfc #define CALL_FUNCTION_VECTOR 0xfb +#define CRASH_DUMP_VECTOR 0xfa #define THERMAL_APIC_VECTOR 0xf0 /* diff -puN include/asm-i386/smp.h~kd-reg-268 include/asm-i386/smp.h --- linux-2.6.8.1/include/asm-i386/smp.h~kd-reg-268 2004-08-17 17:08:09.000000000 +0530 +++ linux-2.6.8.1-hari/include/asm-i386/smp.h 2004-08-17 17:08:18.000000000 +0530 @@ -41,6 +41,7 @@ extern void smp_message_irq(int cpl, voi extern void smp_invalidate_rcv(void); /* Process an NMI */ extern void (*mtrr_hook) (void); extern void zap_low_mappings (void); +extern void stop_this_cpu(void *); #define MAX_APICID 256 _ --M38YqGLZlgb6RLPS--