diff options
Diffstat (limited to 'arch/x86_64/kernel/nmi.c')
| -rw-r--r-- | arch/x86_64/kernel/nmi.c | 130 |
1 files changed, 125 insertions, 5 deletions
diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c index 1b76d157452..4d6fb047952 100644 --- a/arch/x86_64/kernel/nmi.c +++ b/arch/x86_64/kernel/nmi.c @@ -26,6 +26,7 @@ #include <asm/proto.h> #include <asm/kdebug.h> #include <asm/mce.h> +#include <asm/intel_arch_perfmon.h> /* perfctr_nmi_owner tracks the ownership of the perfctr registers: * evtsel_nmi_owner tracks the ownership of the event selection @@ -73,7 +74,10 @@ static inline unsigned int nmi_perfctr_msr_to_bit(unsigned int msr) case X86_VENDOR_AMD: return (msr - MSR_K7_PERFCTR0); case X86_VENDOR_INTEL: - return (msr - MSR_P4_BPU_PERFCTR0); + if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) + return (msr - MSR_ARCH_PERFMON_PERFCTR0); + else + return (msr - MSR_P4_BPU_PERFCTR0); } return 0; } @@ -86,7 +90,10 @@ static inline unsigned int nmi_evntsel_msr_to_bit(unsigned int msr) case X86_VENDOR_AMD: return (msr - MSR_K7_EVNTSEL0); case X86_VENDOR_INTEL: - return (msr - MSR_P4_BSU_ESCR0); + if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) + return (msr - MSR_ARCH_PERFMON_EVENTSEL0); + else + return (msr - MSR_P4_BSU_ESCR0); } return 0; } @@ -160,7 +167,10 @@ static __cpuinit inline int nmi_known_cpu(void) case X86_VENDOR_AMD: return boot_cpu_data.x86 == 15; case X86_VENDOR_INTEL: - return boot_cpu_data.x86 == 15; + if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) + return 1; + else + return (boot_cpu_data.x86 == 15); } return 0; } @@ -246,8 +256,22 @@ int __init check_nmi_watchdog (void) /* 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) { + nmi_hz = ((u64)cpu_khz * 1000) / 0x7fffffffUL + 1; + } + } kfree(counts); return 0; @@ -563,6 +587,87 @@ static void stop_p4_watchdog(void) 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; + 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)) + goto fail; + + perfctr_msr = MSR_ARCH_PERFMON_PERFCTR0; + evntsel_msr = MSR_ARCH_PERFMON_EVENTSEL0; + + if (!reserve_perfctr_nmi(perfctr_msr)) + goto fail; + + if (!reserve_evntsel_nmi(evntsel_msr)) + goto fail1; + + wrmsrl(perfctr_msr, 0UL); + + evntsel = ARCH_PERFMON_EVENTSEL_INT + | ARCH_PERFMON_EVENTSEL_OS + | ARCH_PERFMON_EVENTSEL_USR + | ARCH_PERFMON_NMI_EVENT_SEL + | ARCH_PERFMON_NMI_EVENT_UMASK; + + /* setup the timer */ + wrmsr(evntsel_msr, evntsel, 0); + wrmsrl(perfctr_msr, -((u64)cpu_khz * 1000 / nmi_hz)); + + apic_write(APIC_LVTPC, APIC_DM_NMI); + evntsel |= ARCH_PERFMON_EVENTSEL0_ENABLE; + 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; +} + +static void stop_intel_arch_watchdog(void) +{ + 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); @@ -589,6 +694,11 @@ void setup_apic_nmi_watchdog(void *unused) return; break; case X86_VENDOR_INTEL: + if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) { + if (!setup_intel_arch_watchdog()) + return; + break; + } if (!setup_p4_watchdog()) return; break; @@ -620,6 +730,10 @@ void stop_apic_nmi_watchdog(void *unused) stop_k7_watchdog(); break; case X86_VENDOR_INTEL: + if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) { + stop_intel_arch_watchdog(); + break; + } stop_p4_watchdog(); break; default: @@ -724,7 +838,13 @@ int __kprobes nmi_watchdog_tick(struct pt_regs * regs, unsigned reason) dummy &= ~P4_CCCR_OVF; wrmsrl(wd->cccr_msr, dummy); apic_write(APIC_LVTPC, APIC_DM_NMI); - } + } else if (wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR0) { + /* + * ArchPerfom/Core Duo needs to re-unmask + * the apic vector + */ + apic_write(APIC_LVTPC, APIC_DM_NMI); + } /* start the cycle over again */ wrmsrl(wd->perfctr_msr, -((u64)cpu_khz * 1000 / nmi_hz)); rc = 1; |