diff options
Diffstat (limited to 'arch/i386/kernel/nmi.c')
| -rw-r--r-- | arch/i386/kernel/nmi.c | 940 |
1 files changed, 651 insertions, 289 deletions
diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c index acb3514..dbda706 100644 --- a/arch/i386/kernel/nmi.c +++ b/arch/i386/kernel/nmi.c @@ -21,83 +21,174 @@ #include <linux/sysdev.h> #include <linux/sysctl.h> #include <linux/percpu.h> +#include <linux/dmi.h> +#include <linux/kprobes.h> #include <asm/smp.h> #include <asm/nmi.h> +#include <asm/kdebug.h> #include <asm/intel_arch_perfmon.h> #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 + * different subsystems this reservation system just tries to coordinate + * things a little + */ +static DEFINE_PER_CPU(unsigned long, perfctr_nmi_owner); +static DEFINE_PER_CPU(unsigned long, evntsel_nmi_owner[3]); -/* - * lapic_nmi_owner tracks the ownership of the lapic NMI hardware: - * - it may be reserved by some other driver, or not - * - when not reserved by some other driver, it may be used for - * the NMI watchdog, or not - * - * This is maintained separately from nmi_active because the NMI - * watchdog may also be driven from the I/O APIC timer. +/* this number is calculated from Intel's MSR_P4_CRU_ESCR5 register and it's + * offset from MSR_P4_BSU_ESCR0. It will be the max for all platforms (for now) */ -static DEFINE_SPINLOCK(lapic_nmi_owner_lock); -static unsigned int lapic_nmi_owner; -#define LAPIC_NMI_WATCHDOG (1<<0) -#define LAPIC_NMI_RESERVED (1<<1) +#define NMI_MAX_COUNTER_BITS 66 /* 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 int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu); -#define ARCH_PERFMON_NMI_EVENT_SEL ARCH_PERFMON_UNHALTED_CORE_CYCLES_SEL -#define ARCH_PERFMON_NMI_EVENT_UMASK ARCH_PERFMON_UNHALTED_CORE_CYCLES_UMASK +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) +{ + /* returns the bit offset of the performance counter register */ + switch (boot_cpu_data.x86_vendor) { + case X86_VENDOR_AMD: + return (msr - MSR_K7_PERFCTR0); + case X86_VENDOR_INTEL: + if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) + return (msr - MSR_ARCH_PERFMON_PERFCTR0); + + switch (boot_cpu_data.x86) { + case 6: + return (msr - MSR_P6_PERFCTR0); + case 15: + return (msr - MSR_P4_BPU_PERFCTR0); + } + } + return 0; +} + +/* converts an msr to an appropriate reservation bit */ +static inline unsigned int nmi_evntsel_msr_to_bit(unsigned int msr) +{ + /* returns the bit offset of the event selection register */ + switch (boot_cpu_data.x86_vendor) { + case X86_VENDOR_AMD: + return (msr - MSR_K7_EVNTSEL0); + case X86_VENDOR_INTEL: + if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) + return (msr - MSR_ARCH_PERFMON_EVENTSEL0); + + switch (boot_cpu_data.x86) { + case 6: + return (msr - MSR_P6_EVNTSEL0); + case 15: + return (msr - MSR_P4_BSU_ESCR0); + } + } + return 0; +} + +/* checks for a bit availability (hack for oprofile) */ +int avail_to_resrv_perfctr_nmi_bit(unsigned int counter) +{ + BUG_ON(counter > NMI_MAX_COUNTER_BITS); + + return (!test_bit(counter, &__get_cpu_var(perfctr_nmi_owner))); +} + +/* checks the an msr for availability */ +int avail_to_resrv_perfctr_nmi(unsigned int msr) +{ + unsigned int counter; + + counter = nmi_perfctr_msr_to_bit(msr); + BUG_ON(counter > NMI_MAX_COUNTER_BITS); + + return (!test_bit(counter, &__get_cpu_var(perfctr_nmi_owner))); +} + +int reserve_perfctr_nmi(unsigned int msr) +{ + unsigned int counter; + + counter = nmi_perfctr_msr_to_bit(msr); + BUG_ON(counter > NMI_MAX_COUNTER_BITS); + + if (!test_and_set_bit(counter, &__get_cpu_var(perfctr_nmi_owner))) + return 1; + return 0; +} + +void release_perfctr_nmi(unsigned int msr) +{ + unsigned int counter; + + counter = nmi_perfctr_msr_to_bit(msr); + BUG_ON(counter > NMI_MAX_COUNTER_BITS); + + clear_bit(counter, &__get_cpu_var(perfctr_nmi_owner)); +} + +int reserve_evntsel_nmi(unsigned int msr) +{ + unsigned int counter; + + counter = nmi_evntsel_msr_to_bit(msr); + BUG_ON(counter > NMI_MAX_COUNTER_BITS); + + if (!test_and_set_bit(counter, &__get_cpu_var(evntsel_nmi_owner)[0])) + return 1; + return 0; +} + +void release_evntsel_nmi(unsigned int msr) +{ + unsigned int counter; + + counter = nmi_evntsel_msr_to_bit(msr); + BUG_ON(counter > NMI_MAX_COUNTER_BITS); + + 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: + if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) + return 1; + else + 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 @@ -125,7 +216,18 @@ static int __init check_nmi_watchdog(void) unsigned int *prev_nmi_count; int cpu; - if (nmi_watchdog == NMI_NONE) + /* Enable NMI watchdog for newer systems. + Actually it should be safe for most systems before 2004 too except + for some IBM systems that corrupt registers when NMI happens + during SMM. Unfortunately we don't have more exact information + on these and use this coarse check. */ + if (nmi_watchdog == NMI_DEFAULT && dmi_get_year(DMI_BIOS_DATE) >= 2004) + nmi_watchdog = NMI_LOCAL_APIC; + + 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); @@ -149,25 +251,45 @@ 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"); /* now that we know it works we can reduce NMI frequency to something more reasonable; makes a difference in some configs */ - if (nmi_watchdog == NMI_LOCAL_APIC) + if (nmi_watchdog == NMI_LOCAL_APIC) { + struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); + nmi_hz = 1; + /* + * On Intel CPUs with ARCH_PERFMON only 32 bits in the counter + * are writable, with higher bits sign extending from bit 31. + * So, we can only program the counter with 31 bit values and + * 32nd bit should be 1, for 33.. to be 1. + * Find the appropriate nmi_hz + */ + if (wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR0 && + ((u64)cpu_khz * 1000) > 0x7fffffffULL) { + u64 count = (u64)cpu_khz * 1000; + do_div(count, 0x7fffffffUL); + nmi_hz = count + 1; + } + } kfree(prev_nmi_count); return 0; @@ -181,124 +303,70 @@ 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; } __setup("nmi_watchdog=", setup_nmi_watchdog); -static void disable_intel_arch_watchdog(void); - 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: - if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) { - disable_intel_arch_watchdog(); - break; - } - 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); -int reserve_lapic_nmi(void) -{ - unsigned int old_owner; - - spin_lock(&lapic_nmi_owner_lock); - old_owner = lapic_nmi_owner; - lapic_nmi_owner |= LAPIC_NMI_RESERVED; - spin_unlock(&lapic_nmi_owner_lock); - if (old_owner & LAPIC_NMI_RESERVED) - return -EBUSY; - if (old_owner & LAPIC_NMI_WATCHDOG) - disable_lapic_nmi_watchdog(); - return 0; -} + /* are we already enabled */ + if (atomic_read(&nmi_active) != 0) + return; -void release_lapic_nmi(void) -{ - unsigned int new_owner; + /* are we lapic aware */ + if (nmi_known_cpu() <= 0) + return; - spin_lock(&lapic_nmi_owner_lock); - new_owner = lapic_nmi_owner & ~LAPIC_NMI_RESERVED; - lapic_nmi_owner = new_owner; - spin_unlock(&lapic_nmi_owner_lock); - if (new_owner & LAPIC_NMI_WATCHDOG) - enable_lapic_nmi_watchdog(); + on_each_cpu(setup_apic_nmi_watchdog, NULL, 0, 1); + touch_nmi_watchdog(); } 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); } } @@ -308,15 +376,20 @@ 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; - disable_lapic_nmi_watchdog(); + /* only CPU0 goes here, other CPUs should be offline */ + nmi_pm_active = atomic_read(&nmi_active); + stop_apic_nmi_watchdog(NULL); + BUG_ON(atomic_read(&nmi_active) != 0); return 0; } static int lapic_nmi_resume(struct sys_device *dev) { - if (nmi_pm_active > 0) - enable_lapic_nmi_watchdog(); + /* only CPU0 goes here, other CPUs should be offline */ + if (nmi_pm_active > 0) { + setup_apic_nmi_watchdog(NULL); + touch_nmi_watchdog(); + } return 0; } @@ -336,7 +409,13 @@ 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); @@ -354,138 +433,269 @@ late_initcall(init_lapic_nmi_sysfs); * Original code written by Keith Owens. */ -static void clear_msr_range(unsigned int base, unsigned int n) -{ - unsigned int i; - - for(i = 0; i < n; ++i) - wrmsr(base+i, 0, 0); -} - -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); } -static void setup_k7_watchdog(void) +/* 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); + + perfctr_msr = MSR_K7_PERFCTR0; + evntsel_msr = MSR_K7_EVNTSEL0; + if (!reserve_perfctr_nmi(perfctr_msr)) + goto fail; - nmi_perfctr_msr = MSR_K7_PERFCTR0; + if (!reserve_evntsel_nmi(evntsel_msr)) + goto fail1; - clear_msr_range(MSR_K7_EVNTSEL0, 4); - clear_msr_range(MSR_K7_PERFCTR0, 4); + 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(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); } -static void setup_p6_watchdog(void) +#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); + + perfctr_msr = MSR_P6_PERFCTR0; + evntsel_msr = MSR_P6_EVNTSEL0; + if (!reserve_perfctr_nmi(perfctr_msr)) + goto fail; - nmi_perfctr_msr = MSR_P6_PERFCTR0; + if (!reserve_evntsel_nmi(evntsel_msr)) + goto fail1; - clear_msr_range(MSR_P6_EVNTSEL0, 2); - clear_msr_range(MSR_P6_PERFCTR0, 2); + 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(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; - if (!(misc_enable & MSR_P4_MISC_ENABLE_PEBS_UNAVAIL)) - clear_msr_range(0x3F1, 2); - /* MSR 0x3F0 seems to have a default value of 0xFC00, but current - docs doesn't fully define it, so leave it alone for now. */ - if (boot_cpu_data.x86_model >= 0x3) { - /* MSR_P4_IQ_ESCR0/1 (0x3ba/0x3bb) removed */ - clear_msr_range(0x3A0, 26); - clear_msr_range(0x3BC, 3); + /* 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 { - clear_msr_range(0x3A0, 31); + /* 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); } - clear_msr_range(0x3C0, 6); - clear_msr_range(0x3C8, 6); - clear_msr_range(0x3E0, 2); - clear_msr_range(MSR_P4_CCCR0, 18); - clear_msr_range(MSR_P4_PERFCTR0, 18); - - 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"); + + if (!reserve_perfctr_nmi(perfctr_msr)) + goto fail; + + if (!reserve_evntsel_nmi(evntsel_msr)) + goto fail1; + + 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(perfctr_msr); +fail: + return 0; } -static void disable_intel_arch_watchdog(void) +static void stop_p4_watchdog(void) { - unsigned ebx; + struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); - /* - * Check whether the Architectural PerfMon supports - * Unhalted Core Cycles Event or not. - * NOTE: Corresponding bit = 0 in ebp indicates event present. - */ - ebx = cpuid_ebx(10); - if (!(ebx & ARCH_PERFMON_UNHALTED_CORE_CYCLES_PRESENT)) - wrmsr(MSR_ARCH_PERFMON_EVENTSEL0, 0, 0); + wrmsr(wd->cccr_msr, 0, 0); + wrmsr(wd->evntsel_msr, 0, 0); + + release_evntsel_nmi(wd->evntsel_msr); + release_perfctr_nmi(wd->perfctr_msr); } +#define ARCH_PERFMON_NMI_EVENT_SEL ARCH_PERFMON_UNHALTED_CORE_CYCLES_SEL +#define ARCH_PERFMON_NMI_EVENT_UMASK ARCH_PERFMON_UNHALTED_CORE_CYCLES_UMASK + static int setup_intel_arch_watchdog(void) { + unsigned int ebx; + union cpuid10_eax eax; + unsigned int unused; + unsigned int perfctr_msr, evntsel_msr; unsigned int evntsel; - unsigned ebx; + struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); /* * Check whether the Architectural PerfMon supports * Unhalted Core Cycles Event or not. - * NOTE: Corresponding bit = 0 in ebp indicates event present. + * NOTE: Corresponding bit = 0 in ebx indicates event present. */ - ebx = cpuid_ebx(10); - if ((ebx & ARCH_PERFMON_UNHALTED_CORE_CYCLES_PRESENT)) - return 0; + cpuid(10, &(eax.full), &ebx, &unused, &unused); + if ((eax.split.mask_length < (ARCH_PERFMON_UNHALTED_CORE_CYCLES_INDEX+1)) || + (ebx & ARCH_PERFMON_UNHALTED_CORE_CYCLES_PRESENT)) + goto fail; + + perfctr_msr = MSR_ARCH_PERFMON_PERFCTR0; + evntsel_msr = MSR_ARCH_PERFMON_EVENTSEL0; - nmi_perfctr_msr = MSR_ARCH_PERFMON_PERFCTR0; + if (!reserve_perfctr_nmi(perfctr_msr)) + goto fail; - clear_msr_range(MSR_ARCH_PERFMON_EVENTSEL0, 2); - clear_msr_range(MSR_ARCH_PERFMON_PERFCTR0, 2); + if (!reserve_evntsel_nmi(evntsel_msr)) + goto fail1; + + wrmsrl(perfctr_msr, 0UL); evntsel = ARCH_PERFMON_EVENTSEL_INT | ARCH_PERFMON_EVENTSEL_OS @@ -493,51 +703,145 @@ static int setup_intel_arch_watchdog(void) | ARCH_PERFMON_NMI_EVENT_SEL | ARCH_PERFMON_NMI_EVENT_UMASK; - wrmsr(MSR_ARCH_PERFMON_EVENTSEL0, evntsel, 0); - write_watchdog_counter("INTEL_ARCH_PERFCTR0"); + /* setup the timer */ + wrmsr(evntsel_msr, evntsel, 0); + write_watchdog_counter(perfctr_msr, "INTEL_ARCH_PERFCTR0"); apic_write(APIC_LVTPC, APIC_DM_NMI); evntsel |= ARCH_PERFMON_EVENTSEL0_ENABLE; - wrmsr(MSR_ARCH_PERFMON_EVENTSEL0, 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 << (eax.split.bit_width - 1); return 1; +fail1: + release_perfctr_nmi(perfctr_msr); +fail: + return 0; } -void setup_apic_nmi_watchdog (void) +static void stop_intel_arch_watchdog(void) { - switch (boot_cpu_data.x86_vendor) { - case X86_VENDOR_AMD: - if (boot_cpu_data.x86 != 6 && boot_cpu_data.x86 != 15) - return; - setup_k7_watchdog(); - break; - case X86_VENDOR_INTEL: - if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) { - if (!setup_intel_arch_watchdog()) + unsigned int ebx; + union cpuid10_eax eax; + unsigned int unused; + struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); + + /* + * Check whether the Architectural PerfMon supports + * Unhalted Core Cycles Event or not. + * NOTE: Corresponding bit = 0 in ebx indicates event present. + */ + cpuid(10, &(eax.full), &ebx, &unused, &unused); + if ((eax.split.mask_length < (ARCH_PERFMON_UNHALTED_CORE_CYCLES_INDEX+1)) || + (ebx & ARCH_PERFMON_UNHALTED_CORE_CYCLES_PRESENT)) + return; + + wrmsr(wd->evntsel_msr, 0, 0); + release_evntsel_nmi(wd->evntsel_msr); + release_perfctr_nmi(wd->perfctr_msr); +} + +void setup_apic_nmi_watchdog (void *unused) +{ + struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); + + /* only support LOCAL and IO APICs for now */ + if ((nmi_watchdog != NMI_LOCAL_APIC) && + (nmi_watchdog != NMI_IO_APIC)) + return; + + if (wd->enabled == 1) + return; + + /* cheap hack to support suspend/resume */ + /* if cpu0 is not active neither should the other cpus */ + if ((smp_processor_id() != 0) && (atomic_read(&nmi_active) <= 0)) + 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; - } - switch (boot_cpu_data.x86) { - case 6: - if (boot_cpu_data.x86_model > 0xd) + if (!setup_k7_watchdog()) return; - - setup_p6_watchdog(); break; - case 15: - if (boot_cpu_data.x86_model > 0x4) - return; + case X86_VENDOR_INTEL: + if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) { + if (!setup_intel_arch_watchdog()) + return; + break; + } + 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; } - break; - default: + } + wd->enabled = 1; + atomic_inc(&nmi_active); +} + +void stop_apic_nmi_watchdog(void *unused) +{ + struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); + + /* only support LOCAL and IO APICs for now */ + if ((nmi_watchdog != NMI_LOCAL_APIC) && + (nmi_watchdog != NMI_IO_APIC)) + return; + + if (wd->enabled == 0) 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: + if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) { + stop_intel_arch_watchdog(); + break; + } + 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; + } } - lapic_nmi_owner = LAPIC_NMI_WATCHDOG; - nmi_active = 1; + wd->enabled = 0; + atomic_dec(&nmi_active); } /* @@ -579,7 +883,7 @@ EXPORT_SYMBOL(touch_nmi_watchdog); extern void die_nmi(struct pt_regs *, const char *msg); -void nmi_watchdog_tick (struct pt_regs * regs) +__kprobes int nmi_watchdog_tick(struct pt_regs * regs, unsigned reason) { /* @@ -588,11 +892,23 @@ 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; + int rc=0; + + /* check for other users first */ + if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) + == NOTIFY_STOP) { + rc = 1; + 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 ... @@ -607,27 +923,59 @@ 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. + /* 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 || + wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR0) { + /* P6 based Pentium M need to re-unmask + * the apic vector but it doesn't hurt + * other P6 variant. + * ArchPerfom/Core Duo also needs this */ + apic_write(APIC_LVTPC, APIC_DM_NMI); + } + /* start the cycle over again */ + write_watchdog_counter(wd->perfctr_msr, NULL); + rc = 1; + } else if (nmi_watchdog == NMI_IO_APIC) { + /* don't know how to accurately check for this. + * just assume it was a watchdog timer interrupt + * This matches the old behaviour. */ - wrmsr(MSR_P4_IQ_CCCR0, nmi_p4_cccr_val, 0); - apic_write(APIC_LVTPC, APIC_DM_NMI); + rc = 1; } - else if (nmi_perfctr_msr == MSR_P6_PERFCTR0 || - nmi_perfctr_msr == MSR_ARCH_PERFMON_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); - } - write_watchdog_counter(NULL); } +done: + return rc; +} + +int do_nmi_callback(struct pt_regs * regs, int cpu) +{ +#ifdef CONFIG_SYSCTL + if (unknown_nmi_panic) + return unknown_nmi_panic_callback(regs, cpu); +#endif + return 0; } #ifdef CONFIG_SYSCTL @@ -637,36 +985,46 @@ static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu) unsigned char reason = get_nmi_reason(); char buf[64]; - if (!(reason & 0xc0)) { - sprintf(buf, "NMI received for unknown reason %02x\n", reason); - die_nmi(regs, buf); - } + sprintf(buf, "NMI received for unknown reason %02x\n", reason); + die_nmi(regs, buf); return 0; } /* - * proc handler for /proc/sys/kernel/unknown_nmi_panic + * proc handler for /proc/sys/kernel/nmi */ -int proc_unknown_nmi_panic(ctl_table *table, int write, struct file *file, +int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file, void __user *buffer, size_t *length, loff_t *ppos) { int old_state; - old_state = unknown_nmi_panic; + nmi_watchdog_enabled = (atomic_read(&nmi_active) > 0) ? 1 : 0; + old_state = nmi_watchdog_enabled; proc_dointvec(table, write, file, buffer, length, ppos); - if (!!old_state == !!unknown_nmi_panic) + if (!!old_state == !!nmi_watchdog_enabled) return 0; - if (unknown_nmi_panic) { - if (reserve_lapic_nmi() < 0) { - unknown_nmi_panic = 0; - return -EBUSY; - } else { - set_nmi_callback(unknown_nmi_panic_callback); - } + if (atomic_read(&nmi_active) < 0) { + printk( KERN_WARNING "NMI watchdog is permanently disabled\n"); + return -EIO; + } + + if (nmi_watchdog == NMI_DEFAULT) { + if (nmi_known_cpu() > 0) + nmi_watchdog = NMI_LOCAL_APIC; + else + nmi_watchdog = NMI_IO_APIC; + } + + if (nmi_watchdog == NMI_LOCAL_APIC) { + if (nmi_watchdog_enabled) + enable_lapic_nmi_watchdog(); + else + disable_lapic_nmi_watchdog(); } else { - release_lapic_nmi(); - unset_nmi_callback(); + printk( KERN_WARNING + "NMI watchdog doesn't know what hardware to touch\n"); + return -EIO; } return 0; } @@ -675,7 +1033,11 @@ int proc_unknown_nmi_panic(ctl_table *table, int write, struct file *file, EXPORT_SYMBOL(nmi_active); EXPORT_SYMBOL(nmi_watchdog); -EXPORT_SYMBOL(reserve_lapic_nmi); -EXPORT_SYMBOL(release_lapic_nmi); +EXPORT_SYMBOL(avail_to_resrv_perfctr_nmi); +EXPORT_SYMBOL(avail_to_resrv_perfctr_nmi_bit); +EXPORT_SYMBOL(reserve_perfctr_nmi); +EXPORT_SYMBOL(release_perfctr_nmi); +EXPORT_SYMBOL(reserve_evntsel_nmi); +EXPORT_SYMBOL(release_evntsel_nmi); EXPORT_SYMBOL(disable_timer_nmi_watchdog); EXPORT_SYMBOL(enable_timer_nmi_watchdog); |