From: Don Zickus Date: Tue, 26 Sep 2006 08:52:26 +0000 (+0200) Subject: [PATCH] i386: Add SMP support on i386 to reservation framework X-Git-Tag: v2.6.19-rc1~1077^2~217 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b7471c6da94d30d3deadc55986cc38d1ff57f9ca;p=linux-2.6 [PATCH] i386: Add SMP support on i386 to reservation framework This patch includes the changes to make the nmi watchdog on i386 SMP aware. A bunch of code was moved around to make it simpler to read. In addition, it is now possible to determine if a particular NMI was the result of the watchdog or not. This feature allows the kernel to filter out unknown NMIs easier. Signed-off-by: Don Zickus Signed-off-by: Andi Kleen --- diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c index 8c844d0786..1a34fc5780 100644 --- a/arch/i386/kernel/apic.c +++ b/arch/i386/kernel/apic.c @@ -586,8 +586,7 @@ void __devinit setup_local_APIC(void) printk("No ESR for 82489DX.\n"); } - if (nmi_watchdog == NMI_LOCAL_APIC) - setup_apic_nmi_watchdog(); + setup_apic_nmi_watchdog(NULL); apic_pm_activate(); } diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c index 5d58dfeacd..d880043430 100644 --- a/arch/i386/kernel/nmi.c +++ b/arch/i386/kernel/nmi.c @@ -24,16 +24,10 @@ #include #include +#include #include "mach_traps.h" -unsigned int nmi_watchdog = NMI_NONE; -extern int unknown_nmi_panic; -static unsigned int nmi_hz = HZ; -static unsigned int nmi_perfctr_msr; /* the MSR to reset in NMI handler */ -static unsigned int nmi_p4_cccr_val; -extern void show_registers(struct pt_regs *regs); - /* perfctr_nmi_owner tracks the ownership of the perfctr registers: * evtsel_nmi_owner tracks the ownership of the event selection * - different performance counters/ event selection may be reserved for @@ -63,51 +57,31 @@ static unsigned int lapic_nmi_owner; #define LAPIC_NMI_RESERVED (1<<1) /* nmi_active: - * +1: the lapic NMI watchdog is active, but can be disabled - * 0: the lapic NMI watchdog has not been set up, and cannot + * >0: the lapic NMI watchdog is active, but can be disabled + * <0: the lapic NMI watchdog has not been set up, and cannot * be enabled - * -1: the lapic NMI watchdog is disabled, but can be enabled + * 0: the lapic NMI watchdog is disabled, but can be enabled */ -int nmi_active; +atomic_t nmi_active = ATOMIC_INIT(0); /* oprofile uses this */ -#define K7_EVNTSEL_ENABLE (1 << 22) -#define K7_EVNTSEL_INT (1 << 20) -#define K7_EVNTSEL_OS (1 << 17) -#define K7_EVNTSEL_USR (1 << 16) -#define K7_EVENT_CYCLES_PROCESSOR_IS_RUNNING 0x76 -#define K7_NMI_EVENT K7_EVENT_CYCLES_PROCESSOR_IS_RUNNING +unsigned int nmi_watchdog = NMI_DEFAULT; +static unsigned int nmi_hz = HZ; -#define P6_EVNTSEL0_ENABLE (1 << 22) -#define P6_EVNTSEL_INT (1 << 20) -#define P6_EVNTSEL_OS (1 << 17) -#define P6_EVNTSEL_USR (1 << 16) -#define P6_EVENT_CPU_CLOCKS_NOT_HALTED 0x79 -#define P6_NMI_EVENT P6_EVENT_CPU_CLOCKS_NOT_HALTED +struct nmi_watchdog_ctlblk { + int enabled; + u64 check_bit; + unsigned int cccr_msr; + unsigned int perfctr_msr; /* the MSR to reset in NMI handler */ + unsigned int evntsel_msr; /* the MSR to select the events to handle */ +}; +static DEFINE_PER_CPU(struct nmi_watchdog_ctlblk, nmi_watchdog_ctlblk); -#define MSR_P4_MISC_ENABLE 0x1A0 -#define MSR_P4_MISC_ENABLE_PERF_AVAIL (1<<7) -#define MSR_P4_MISC_ENABLE_PEBS_UNAVAIL (1<<12) -#define MSR_P4_PERFCTR0 0x300 -#define MSR_P4_CCCR0 0x360 -#define P4_ESCR_EVENT_SELECT(N) ((N)<<25) -#define P4_ESCR_OS (1<<3) -#define P4_ESCR_USR (1<<2) -#define P4_CCCR_OVF_PMI0 (1<<26) -#define P4_CCCR_OVF_PMI1 (1<<27) -#define P4_CCCR_THRESHOLD(N) ((N)<<20) -#define P4_CCCR_COMPLEMENT (1<<19) -#define P4_CCCR_COMPARE (1<<18) -#define P4_CCCR_REQUIRED (3<<16) -#define P4_CCCR_ESCR_SELECT(N) ((N)<<13) -#define P4_CCCR_ENABLE (1<<12) -/* Set up IQ_COUNTER0 to behave like a clock, by having IQ_CCCR0 filter - CRU_ESCR0 (with any non-null event selector) through a complemented - max threshold. [IA32-Vol3, Section 14.9.9] */ -#define MSR_P4_IQ_COUNTER0 0x30C -#define P4_NMI_CRU_ESCR0 (P4_ESCR_EVENT_SELECT(0x3F)|P4_ESCR_OS|P4_ESCR_USR) -#define P4_NMI_IQ_CCCR0 \ - (P4_CCCR_OVF_PMI0|P4_CCCR_THRESHOLD(15)|P4_CCCR_COMPLEMENT| \ - P4_CCCR_COMPARE|P4_CCCR_REQUIRED|P4_CCCR_ESCR_SELECT(4)|P4_CCCR_ENABLE) +/* local prototypes */ +static void stop_apic_nmi_watchdog(void *unused); +static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu); + +extern void show_registers(struct pt_regs *regs); +extern int unknown_nmi_panic; /* converts an msr to an appropriate reservation bit */ static inline unsigned int nmi_perfctr_msr_to_bit(unsigned int msr) @@ -208,6 +182,17 @@ void release_evntsel_nmi(unsigned int msr) clear_bit(counter, &__get_cpu_var(evntsel_nmi_owner)[0]); } +static __cpuinit inline int nmi_known_cpu(void) +{ + switch (boot_cpu_data.x86_vendor) { + case X86_VENDOR_AMD: + return ((boot_cpu_data.x86 == 15) || (boot_cpu_data.x86 == 6)); + case X86_VENDOR_INTEL: + return ((boot_cpu_data.x86 == 15) || (boot_cpu_data.x86 == 6)); + } + return 0; +} + #ifdef CONFIG_SMP /* The performance counters used by NMI_LOCAL_APIC don't trigger when * the CPU is idle. To make sure the NMI watchdog really ticks on all @@ -234,7 +219,10 @@ static int __init check_nmi_watchdog(void) unsigned int *prev_nmi_count; int cpu; - if (nmi_watchdog == NMI_NONE) + if ((nmi_watchdog == NMI_NONE) || (nmi_watchdog == NMI_DEFAULT)) + return 0; + + if (!atomic_read(&nmi_active)) return 0; prev_nmi_count = kmalloc(NR_CPUS * sizeof(int), GFP_KERNEL); @@ -258,18 +246,22 @@ static int __init check_nmi_watchdog(void) if (!cpu_isset(cpu, cpu_callin_map)) continue; #endif + if (!per_cpu(nmi_watchdog_ctlblk, cpu).enabled) + continue; if (nmi_count(cpu) - prev_nmi_count[cpu] <= 5) { - endflag = 1; printk("CPU#%d: NMI appears to be stuck (%d->%d)!\n", cpu, prev_nmi_count[cpu], nmi_count(cpu)); - nmi_active = 0; - lapic_nmi_owner &= ~LAPIC_NMI_WATCHDOG; - kfree(prev_nmi_count); - return -1; + per_cpu(nmi_watchdog_ctlblk, cpu).enabled = 0; + atomic_dec(&nmi_active); } } + if (!atomic_read(&nmi_active)) { + kfree(prev_nmi_count); + atomic_set(&nmi_active, -1); + return -1; + } endflag = 1; printk("OK.\n"); @@ -290,31 +282,16 @@ static int __init setup_nmi_watchdog(char *str) get_option(&str, &nmi); - if (nmi >= NMI_INVALID) + if ((nmi >= NMI_INVALID) || (nmi < NMI_NONE)) return 0; - if (nmi == NMI_NONE) - nmi_watchdog = nmi; /* * If any other x86 CPU has a local APIC, then * please test the NMI stuff there and send me the * missing bits. Right now Intel P6/P4 and AMD K7 only. */ - if ((nmi == NMI_LOCAL_APIC) && - (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && - (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15)) - nmi_watchdog = nmi; - if ((nmi == NMI_LOCAL_APIC) && - (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && - (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15)) - nmi_watchdog = nmi; - /* - * We can enable the IO-APIC watchdog - * unconditionally. - */ - if (nmi == NMI_IO_APIC) { - nmi_active = 1; - nmi_watchdog = nmi; - } + if ((nmi == NMI_LOCAL_APIC) && (nmi_known_cpu() == 0)) + return 0; /* no lapic support */ + nmi_watchdog = nmi; return 1; } @@ -322,41 +299,30 @@ __setup("nmi_watchdog=", setup_nmi_watchdog); static void disable_lapic_nmi_watchdog(void) { - if (nmi_active <= 0) + BUG_ON(nmi_watchdog != NMI_LOCAL_APIC); + + if (atomic_read(&nmi_active) <= 0) return; - switch (boot_cpu_data.x86_vendor) { - case X86_VENDOR_AMD: - wrmsr(MSR_K7_EVNTSEL0, 0, 0); - break; - case X86_VENDOR_INTEL: - switch (boot_cpu_data.x86) { - case 6: - if (boot_cpu_data.x86_model > 0xd) - break; - wrmsr(MSR_P6_EVNTSEL0, 0, 0); - break; - case 15: - if (boot_cpu_data.x86_model > 0x4) - break; + on_each_cpu(stop_apic_nmi_watchdog, NULL, 0, 1); - wrmsr(MSR_P4_IQ_CCCR0, 0, 0); - wrmsr(MSR_P4_CRU_ESCR0, 0, 0); - break; - } - break; - } - nmi_active = -1; - /* tell do_nmi() and others that we're not active any more */ - nmi_watchdog = 0; + BUG_ON(atomic_read(&nmi_active) != 0); } static void enable_lapic_nmi_watchdog(void) { - if (nmi_active < 0) { - nmi_watchdog = NMI_LOCAL_APIC; - setup_apic_nmi_watchdog(); - } + BUG_ON(nmi_watchdog != NMI_LOCAL_APIC); + + /* are we already enabled */ + if (atomic_read(&nmi_active) != 0) + return; + + /* are we lapic aware */ + if (nmi_known_cpu() <= 0) + return; + + on_each_cpu(setup_apic_nmi_watchdog, NULL, 0, 1); + touch_nmi_watchdog(); } int reserve_lapic_nmi(void) @@ -388,20 +354,25 @@ void release_lapic_nmi(void) void disable_timer_nmi_watchdog(void) { - if ((nmi_watchdog != NMI_IO_APIC) || (nmi_active <= 0)) + BUG_ON(nmi_watchdog != NMI_IO_APIC); + + if (atomic_read(&nmi_active) <= 0) return; - unset_nmi_callback(); - nmi_active = -1; - nmi_watchdog = NMI_NONE; + disable_irq(0); + on_each_cpu(stop_apic_nmi_watchdog, NULL, 0, 1); + + BUG_ON(atomic_read(&nmi_active) != 0); } void enable_timer_nmi_watchdog(void) { - if (nmi_active < 0) { - nmi_watchdog = NMI_IO_APIC; + BUG_ON(nmi_watchdog != NMI_IO_APIC); + + if (atomic_read(&nmi_active) == 0) { touch_nmi_watchdog(); - nmi_active = 1; + on_each_cpu(setup_apic_nmi_watchdog, NULL, 0, 1); + enable_irq(0); } } @@ -411,7 +382,7 @@ static int nmi_pm_active; /* nmi_active before suspend */ static int lapic_nmi_suspend(struct sys_device *dev, pm_message_t state) { - nmi_pm_active = nmi_active; + nmi_pm_active = atomic_read(&nmi_active); disable_lapic_nmi_watchdog(); return 0; } @@ -439,7 +410,13 @@ static int __init init_lapic_nmi_sysfs(void) { int error; - if (nmi_active == 0 || nmi_watchdog != NMI_LOCAL_APIC) + /* should really be a BUG_ON but b/c this is an + * init call, it just doesn't work. -dcz + */ + if (nmi_watchdog != NMI_LOCAL_APIC) + return 0; + + if ( atomic_read(&nmi_active) < 0 ) return 0; error = sysdev_class_register(&nmi_sysclass); @@ -457,143 +434,312 @@ late_initcall(init_lapic_nmi_sysfs); * Original code written by Keith Owens. */ -static void write_watchdog_counter(const char *descr) +static void write_watchdog_counter(unsigned int perfctr_msr, const char *descr) { u64 count = (u64)cpu_khz * 1000; do_div(count, nmi_hz); if(descr) Dprintk("setting %s to -0x%08Lx\n", descr, count); - wrmsrl(nmi_perfctr_msr, 0 - count); + wrmsrl(perfctr_msr, 0 - count); } +/* Note that these events don't tick when the CPU idles. This means + the frequency varies with CPU load. */ + +#define K7_EVNTSEL_ENABLE (1 << 22) +#define K7_EVNTSEL_INT (1 << 20) +#define K7_EVNTSEL_OS (1 << 17) +#define K7_EVNTSEL_USR (1 << 16) +#define K7_EVENT_CYCLES_PROCESSOR_IS_RUNNING 0x76 +#define K7_NMI_EVENT K7_EVENT_CYCLES_PROCESSOR_IS_RUNNING + static int setup_k7_watchdog(void) { + unsigned int perfctr_msr, evntsel_msr; unsigned int evntsel; + struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); - nmi_perfctr_msr = MSR_K7_PERFCTR0; - - if (!reserve_perfctr_nmi(nmi_perfctr_msr)) + perfctr_msr = MSR_K7_PERFCTR0; + evntsel_msr = MSR_K7_EVNTSEL0; + if (!reserve_perfctr_nmi(perfctr_msr)) goto fail; - if (!reserve_evntsel_nmi(MSR_K7_EVNTSEL0)) + if (!reserve_evntsel_nmi(evntsel_msr)) goto fail1; - wrmsrl(MSR_K7_PERFCTR0, 0UL); + wrmsrl(perfctr_msr, 0UL); evntsel = K7_EVNTSEL_INT | K7_EVNTSEL_OS | K7_EVNTSEL_USR | K7_NMI_EVENT; - wrmsr(MSR_K7_EVNTSEL0, evntsel, 0); - write_watchdog_counter("K7_PERFCTR0"); + /* setup the timer */ + wrmsr(evntsel_msr, evntsel, 0); + write_watchdog_counter(perfctr_msr, "K7_PERFCTR0"); apic_write(APIC_LVTPC, APIC_DM_NMI); evntsel |= K7_EVNTSEL_ENABLE; - wrmsr(MSR_K7_EVNTSEL0, evntsel, 0); + wrmsr(evntsel_msr, evntsel, 0); + + wd->perfctr_msr = perfctr_msr; + wd->evntsel_msr = evntsel_msr; + wd->cccr_msr = 0; //unused + wd->check_bit = 1ULL<<63; return 1; fail1: - release_perfctr_nmi(nmi_perfctr_msr); + release_perfctr_nmi(perfctr_msr); fail: return 0; } +static void stop_k7_watchdog(void) +{ + struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); + + wrmsr(wd->evntsel_msr, 0, 0); + + release_evntsel_nmi(wd->evntsel_msr); + release_perfctr_nmi(wd->perfctr_msr); +} + +#define P6_EVNTSEL0_ENABLE (1 << 22) +#define P6_EVNTSEL_INT (1 << 20) +#define P6_EVNTSEL_OS (1 << 17) +#define P6_EVNTSEL_USR (1 << 16) +#define P6_EVENT_CPU_CLOCKS_NOT_HALTED 0x79 +#define P6_NMI_EVENT P6_EVENT_CPU_CLOCKS_NOT_HALTED + static int setup_p6_watchdog(void) { + unsigned int perfctr_msr, evntsel_msr; unsigned int evntsel; + struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); - nmi_perfctr_msr = MSR_P6_PERFCTR0; - - if (!reserve_perfctr_nmi(nmi_perfctr_msr)) + perfctr_msr = MSR_P6_PERFCTR0; + evntsel_msr = MSR_P6_EVNTSEL0; + if (!reserve_perfctr_nmi(perfctr_msr)) goto fail; - if (!reserve_evntsel_nmi(MSR_P6_EVNTSEL0)) + if (!reserve_evntsel_nmi(evntsel_msr)) goto fail1; + wrmsrl(perfctr_msr, 0UL); + evntsel = P6_EVNTSEL_INT | P6_EVNTSEL_OS | P6_EVNTSEL_USR | P6_NMI_EVENT; - wrmsr(MSR_P6_EVNTSEL0, evntsel, 0); - write_watchdog_counter("P6_PERFCTR0"); + /* setup the timer */ + wrmsr(evntsel_msr, evntsel, 0); + write_watchdog_counter(perfctr_msr, "P6_PERFCTR0"); apic_write(APIC_LVTPC, APIC_DM_NMI); evntsel |= P6_EVNTSEL0_ENABLE; - wrmsr(MSR_P6_EVNTSEL0, evntsel, 0); + wrmsr(evntsel_msr, evntsel, 0); + + wd->perfctr_msr = perfctr_msr; + wd->evntsel_msr = evntsel_msr; + wd->cccr_msr = 0; //unused + wd->check_bit = 1ULL<<39; return 1; fail1: - release_perfctr_nmi(nmi_perfctr_msr); + release_perfctr_nmi(perfctr_msr); fail: return 0; } +static void stop_p6_watchdog(void) +{ + struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); + + wrmsr(wd->evntsel_msr, 0, 0); + + release_evntsel_nmi(wd->evntsel_msr); + release_perfctr_nmi(wd->perfctr_msr); +} + +/* Note that these events don't tick when the CPU idles. This means + the frequency varies with CPU load. */ + +#define MSR_P4_MISC_ENABLE_PERF_AVAIL (1<<7) +#define P4_ESCR_EVENT_SELECT(N) ((N)<<25) +#define P4_ESCR_OS (1<<3) +#define P4_ESCR_USR (1<<2) +#define P4_CCCR_OVF_PMI0 (1<<26) +#define P4_CCCR_OVF_PMI1 (1<<27) +#define P4_CCCR_THRESHOLD(N) ((N)<<20) +#define P4_CCCR_COMPLEMENT (1<<19) +#define P4_CCCR_COMPARE (1<<18) +#define P4_CCCR_REQUIRED (3<<16) +#define P4_CCCR_ESCR_SELECT(N) ((N)<<13) +#define P4_CCCR_ENABLE (1<<12) +#define P4_CCCR_OVF (1<<31) +/* Set up IQ_COUNTER0 to behave like a clock, by having IQ_CCCR0 filter + CRU_ESCR0 (with any non-null event selector) through a complemented + max threshold. [IA32-Vol3, Section 14.9.9] */ + static int setup_p4_watchdog(void) { + unsigned int perfctr_msr, evntsel_msr, cccr_msr; + unsigned int evntsel, cccr_val; unsigned int misc_enable, dummy; + unsigned int ht_num; + struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); - rdmsr(MSR_P4_MISC_ENABLE, misc_enable, dummy); + rdmsr(MSR_IA32_MISC_ENABLE, misc_enable, dummy); if (!(misc_enable & MSR_P4_MISC_ENABLE_PERF_AVAIL)) return 0; - nmi_perfctr_msr = MSR_P4_IQ_COUNTER0; - nmi_p4_cccr_val = P4_NMI_IQ_CCCR0; #ifdef CONFIG_SMP - if (smp_num_siblings == 2) - nmi_p4_cccr_val |= P4_CCCR_OVF_PMI1; + /* detect which hyperthread we are on */ + if (smp_num_siblings == 2) { + unsigned int ebx, apicid; + + ebx = cpuid_ebx(1); + apicid = (ebx >> 24) & 0xff; + ht_num = apicid & 1; + } else #endif + ht_num = 0; + + /* performance counters are shared resources + * assign each hyperthread its own set + * (re-use the ESCR0 register, seems safe + * and keeps the cccr_val the same) + */ + if (!ht_num) { + /* logical cpu 0 */ + perfctr_msr = MSR_P4_IQ_PERFCTR0; + evntsel_msr = MSR_P4_CRU_ESCR0; + cccr_msr = MSR_P4_IQ_CCCR0; + cccr_val = P4_CCCR_OVF_PMI0 | P4_CCCR_ESCR_SELECT(4); + } else { + /* logical cpu 1 */ + perfctr_msr = MSR_P4_IQ_PERFCTR1; + evntsel_msr = MSR_P4_CRU_ESCR0; + cccr_msr = MSR_P4_IQ_CCCR1; + cccr_val = P4_CCCR_OVF_PMI1 | P4_CCCR_ESCR_SELECT(4); + } - if (!reserve_perfctr_nmi(nmi_perfctr_msr)) + if (!reserve_perfctr_nmi(perfctr_msr)) goto fail; - if (!reserve_evntsel_nmi(MSR_P4_CRU_ESCR0)) + if (!reserve_evntsel_nmi(evntsel_msr)) goto fail1; - wrmsr(MSR_P4_CRU_ESCR0, P4_NMI_CRU_ESCR0, 0); - wrmsr(MSR_P4_IQ_CCCR0, P4_NMI_IQ_CCCR0 & ~P4_CCCR_ENABLE, 0); - write_watchdog_counter("P4_IQ_COUNTER0"); + evntsel = P4_ESCR_EVENT_SELECT(0x3F) + | P4_ESCR_OS + | P4_ESCR_USR; + + cccr_val |= P4_CCCR_THRESHOLD(15) + | P4_CCCR_COMPLEMENT + | P4_CCCR_COMPARE + | P4_CCCR_REQUIRED; + + wrmsr(evntsel_msr, evntsel, 0); + wrmsr(cccr_msr, cccr_val, 0); + write_watchdog_counter(perfctr_msr, "P4_IQ_COUNTER0"); apic_write(APIC_LVTPC, APIC_DM_NMI); - wrmsr(MSR_P4_IQ_CCCR0, nmi_p4_cccr_val, 0); + cccr_val |= P4_CCCR_ENABLE; + wrmsr(cccr_msr, cccr_val, 0); + wd->perfctr_msr = perfctr_msr; + wd->evntsel_msr = evntsel_msr; + wd->cccr_msr = cccr_msr; + wd->check_bit = 1ULL<<39; return 1; fail1: - release_perfctr_nmi(nmi_perfctr_msr); + release_perfctr_nmi(perfctr_msr); fail: return 0; } -void setup_apic_nmi_watchdog (void) +static void stop_p4_watchdog(void) { - switch (boot_cpu_data.x86_vendor) { - case X86_VENDOR_AMD: - if (boot_cpu_data.x86 != 6 && boot_cpu_data.x86 != 15) - return; - if (!setup_k7_watchdog()) - return; - break; - case X86_VENDOR_INTEL: - switch (boot_cpu_data.x86) { - case 6: - if (boot_cpu_data.x86_model > 0xd) - return; + struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); + + wrmsr(wd->cccr_msr, 0, 0); + wrmsr(wd->evntsel_msr, 0, 0); - if(!setup_p6_watchdog()) + release_evntsel_nmi(wd->evntsel_msr); + release_perfctr_nmi(wd->perfctr_msr); +} + +void setup_apic_nmi_watchdog (void *unused) +{ + /* only support LOCAL and IO APICs for now */ + if ((nmi_watchdog != NMI_LOCAL_APIC) && + (nmi_watchdog != NMI_IO_APIC)) + return; + + if (nmi_watchdog == NMI_LOCAL_APIC) { + switch (boot_cpu_data.x86_vendor) { + case X86_VENDOR_AMD: + if (boot_cpu_data.x86 != 6 && boot_cpu_data.x86 != 15) return; - break; - case 15: - if (boot_cpu_data.x86_model > 0x4) + if (!setup_k7_watchdog()) return; + break; + case X86_VENDOR_INTEL: + switch (boot_cpu_data.x86) { + case 6: + if (boot_cpu_data.x86_model > 0xd) + return; + + if (!setup_p6_watchdog()) + return; + break; + case 15: + if (boot_cpu_data.x86_model > 0x4) + return; - if (!setup_p4_watchdog()) + if (!setup_p4_watchdog()) + return; + break; + default: return; + } + break; + default: + return; + } + } + __get_cpu_var(nmi_watchdog_ctlblk.enabled) = 1; + atomic_inc(&nmi_active); +} + +static void stop_apic_nmi_watchdog(void *unused) +{ + /* only support LOCAL and IO APICs for now */ + if ((nmi_watchdog != NMI_LOCAL_APIC) && + (nmi_watchdog != NMI_IO_APIC)) + return; + + if (nmi_watchdog == NMI_LOCAL_APIC) { + switch (boot_cpu_data.x86_vendor) { + case X86_VENDOR_AMD: + stop_k7_watchdog(); + break; + case X86_VENDOR_INTEL: + switch (boot_cpu_data.x86) { + case 6: + if (boot_cpu_data.x86_model > 0xd) + break; + stop_p6_watchdog(); + break; + case 15: + if (boot_cpu_data.x86_model > 0x4) + break; + stop_p4_watchdog(); + break; + } break; default: return; } - break; - default: - return; } - lapic_nmi_owner = LAPIC_NMI_WATCHDOG; - nmi_active = 1; + __get_cpu_var(nmi_watchdog_ctlblk.enabled) = 0; + atomic_dec(&nmi_active); } /* @@ -635,7 +781,7 @@ EXPORT_SYMBOL(touch_nmi_watchdog); extern void die_nmi(struct pt_regs *, const char *msg); -void nmi_watchdog_tick (struct pt_regs * regs) +void nmi_watchdog_tick (struct pt_regs * regs, unsigned reason) { /* @@ -644,11 +790,21 @@ void nmi_watchdog_tick (struct pt_regs * regs) * smp_processor_id(). */ unsigned int sum; + int touched = 0; int cpu = smp_processor_id(); + struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); + u64 dummy; + + /* check for other users first */ + if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) + == NOTIFY_STOP) { + touched = 1; + } sum = per_cpu(irq_stat, cpu).apic_timer_irqs; - if (last_irq_sums[cpu] == sum) { + /* if the apic timer isn't firing, this cpu isn't doing much */ + if (!touched && last_irq_sums[cpu] == sum) { /* * Ayiee, looks like this CPU is stuck ... * wait a few IRQs (5 seconds) before doing the oops ... @@ -663,26 +819,41 @@ void nmi_watchdog_tick (struct pt_regs * regs) last_irq_sums[cpu] = sum; alert_counter[cpu] = 0; } - if (nmi_perfctr_msr) { - if (nmi_perfctr_msr == MSR_P4_IQ_COUNTER0) { - /* - * P4 quirks: - * - An overflown perfctr will assert its interrupt - * until the OVF flag in its CCCR is cleared. - * - LVTPC is masked on interrupt and must be - * unmasked by the LVTPC handler. - */ - wrmsr(MSR_P4_IQ_CCCR0, nmi_p4_cccr_val, 0); - apic_write(APIC_LVTPC, APIC_DM_NMI); - } - else if (nmi_perfctr_msr == MSR_P6_PERFCTR0) { - /* Only P6 based Pentium M need to re-unmask - * the apic vector but it doesn't hurt - * other P6 variant */ - apic_write(APIC_LVTPC, APIC_DM_NMI); + /* see if the nmi watchdog went off */ + if (wd->enabled) { + if (nmi_watchdog == NMI_LOCAL_APIC) { + rdmsrl(wd->perfctr_msr, dummy); + if (dummy & wd->check_bit){ + /* this wasn't a watchdog timer interrupt */ + goto done; + } + + /* only Intel P4 uses the cccr msr */ + if (wd->cccr_msr != 0) { + /* + * P4 quirks: + * - An overflown perfctr will assert its interrupt + * until the OVF flag in its CCCR is cleared. + * - LVTPC is masked on interrupt and must be + * unmasked by the LVTPC handler. + */ + rdmsrl(wd->cccr_msr, dummy); + dummy &= ~P4_CCCR_OVF; + wrmsrl(wd->cccr_msr, dummy); + apic_write(APIC_LVTPC, APIC_DM_NMI); + } + else if (wd->perfctr_msr == MSR_P6_PERFCTR0) { + /* Only P6 based Pentium M need to re-unmask + * the apic vector but it doesn't hurt + * other P6 variant */ + apic_write(APIC_LVTPC, APIC_DM_NMI); + } + /* start the cycle over again */ + write_watchdog_counter(wd->perfctr_msr, NULL); } - write_watchdog_counter(NULL); } +done: + return; } #ifdef CONFIG_SYSCTL diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index 7e9edafffd..3a07b2677e 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c @@ -724,7 +724,7 @@ static void default_do_nmi(struct pt_regs * regs) * so it must be the NMI watchdog. */ if (nmi_watchdog) { - nmi_watchdog_tick(regs); + nmi_watchdog_tick(regs, reason); return; } #endif diff --git a/arch/i386/oprofile/nmi_timer_int.c b/arch/i386/oprofile/nmi_timer_int.c index 930a1127bb..a33a73bb50 100644 --- a/arch/i386/oprofile/nmi_timer_int.c +++ b/arch/i386/oprofile/nmi_timer_int.c @@ -42,9 +42,7 @@ static void timer_stop(void) int __init op_nmi_timer_init(struct oprofile_operations * ops) { - extern int nmi_active; - - if (nmi_active <= 0) + if (atomic_read(&nmi_active) <= 0) return -ENODEV; ops->start = timer_start; diff --git a/include/asm-i386/nmi.h b/include/asm-i386/nmi.h index 27fc9e6f63..4cda6801ec 100644 --- a/include/asm-i386/nmi.h +++ b/include/asm-i386/nmi.h @@ -32,13 +32,14 @@ extern void release_perfctr_nmi(unsigned int); extern int reserve_evntsel_nmi(unsigned int); extern void release_evntsel_nmi(unsigned int); -extern void setup_apic_nmi_watchdog (void); +extern void setup_apic_nmi_watchdog (void *); extern int reserve_lapic_nmi(void); extern void release_lapic_nmi(void); extern void disable_timer_nmi_watchdog(void); extern void enable_timer_nmi_watchdog(void); -extern void nmi_watchdog_tick (struct pt_regs * regs); +extern void nmi_watchdog_tick (struct pt_regs * regs, unsigned reason); +extern atomic_t nmi_active; extern unsigned int nmi_watchdog; #define NMI_DEFAULT -1 #define NMI_NONE 0