From 08047c4f1740c7cee75d58e2919d48c09f951649 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 20 Aug 2009 16:27:41 +0200 Subject: [PATCH] x86: Move calibrate_cpu to tsc.c Move the code where it's only user is. Also we need to look whether this hardwired hackery might interfere with perfcounters. Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/time.h | 2 -- arch/x86/kernel/time_32.c | 1 - arch/x86/kernel/time_64.c | 51 --------------------------------- arch/x86/kernel/tsc.c | 57 +++++++++++++++++++++++++++++++++++-- 4 files changed, 55 insertions(+), 56 deletions(-) diff --git a/arch/x86/include/asm/time.h b/arch/x86/include/asm/time.h index 91bb162b5a31..9c5608b21c27 100644 --- a/arch/x86/include/asm/time.h +++ b/arch/x86/include/asm/time.h @@ -57,6 +57,4 @@ extern void time_init(void); #endif /* CONFIG_PARAVIRT */ -extern unsigned long __init calibrate_cpu(void); - #endif /* _ASM_X86_TIME_H */ diff --git a/arch/x86/kernel/time_32.c b/arch/x86/kernel/time_32.c index 186abc577b2b..fd876cc77487 100644 --- a/arch/x86/kernel/time_32.c +++ b/arch/x86/kernel/time_32.c @@ -21,7 +21,6 @@ #include #include #include -#include #if defined(CONFIG_X86_32) && defined(CONFIG_X86_IO_APIC) int timer_ack; diff --git a/arch/x86/kernel/time_64.c b/arch/x86/kernel/time_64.c index 78cbdf5c006b..e59a40ebff14 100644 --- a/arch/x86/kernel/time_64.c +++ b/arch/x86/kernel/time_64.c @@ -21,7 +21,6 @@ #include #include #include -#include #if defined(CONFIG_X86_32) && defined(CONFIG_X86_IO_APIC) int timer_ack; @@ -84,56 +83,6 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } -/* - * calibrate_cpu is used on systems with fixed rate TSCs to determine - * processor frequency - */ -#define TICK_COUNT 100000000 -unsigned long __init calibrate_cpu(void) -{ - int tsc_start, tsc_now; - int i, no_ctr_free; - unsigned long evntsel3 = 0, pmc3 = 0, pmc_now = 0; - unsigned long flags; - - for (i = 0; i < 4; i++) - if (avail_to_resrv_perfctr_nmi_bit(i)) - break; - no_ctr_free = (i == 4); - if (no_ctr_free) { - WARN(1, KERN_WARNING "Warning: AMD perfctrs busy ... " - "cpu_khz value may be incorrect.\n"); - i = 3; - rdmsrl(MSR_K7_EVNTSEL3, evntsel3); - wrmsrl(MSR_K7_EVNTSEL3, 0); - rdmsrl(MSR_K7_PERFCTR3, pmc3); - } else { - reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i); - reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + i); - } - local_irq_save(flags); - /* start measuring cycles, incrementing from 0 */ - wrmsrl(MSR_K7_PERFCTR0 + i, 0); - wrmsrl(MSR_K7_EVNTSEL0 + i, 1 << 22 | 3 << 16 | 0x76); - rdtscl(tsc_start); - do { - rdmsrl(MSR_K7_PERFCTR0 + i, pmc_now); - tsc_now = get_cycles(); - } while ((tsc_now - tsc_start) < TICK_COUNT); - - local_irq_restore(flags); - if (no_ctr_free) { - wrmsrl(MSR_K7_EVNTSEL3, 0); - wrmsrl(MSR_K7_PERFCTR3, pmc3); - wrmsrl(MSR_K7_EVNTSEL3, evntsel3); - } else { - release_perfctr_nmi(MSR_K7_PERFCTR0 + i); - release_evntsel_nmi(MSR_K7_EVNTSEL0 + i); - } - - return pmc_now * tsc_khz / (tsc_now - tsc_start); -} - static struct irqaction irq0 = { .handler = timer_interrupt, .flags = IRQF_DISABLED | IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER, diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 652bc214eebf..97a0bcbad100 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -17,6 +17,7 @@ #include #include #include +#include unsigned int __read_mostly cpu_khz; /* TSC clocks / usec, not used here */ EXPORT_SYMBOL(cpu_khz); @@ -852,6 +853,60 @@ static void __init init_tsc_clocksource(void) clocksource_register(&clocksource_tsc); } +#ifdef CONFIG_X86_64 +/* + * calibrate_cpu is used on systems with fixed rate TSCs to determine + * processor frequency + */ +#define TICK_COUNT 100000000 +static unsigned long __init calibrate_cpu(void) +{ + int tsc_start, tsc_now; + int i, no_ctr_free; + unsigned long evntsel3 = 0, pmc3 = 0, pmc_now = 0; + unsigned long flags; + + for (i = 0; i < 4; i++) + if (avail_to_resrv_perfctr_nmi_bit(i)) + break; + no_ctr_free = (i == 4); + if (no_ctr_free) { + WARN(1, KERN_WARNING "Warning: AMD perfctrs busy ... " + "cpu_khz value may be incorrect.\n"); + i = 3; + rdmsrl(MSR_K7_EVNTSEL3, evntsel3); + wrmsrl(MSR_K7_EVNTSEL3, 0); + rdmsrl(MSR_K7_PERFCTR3, pmc3); + } else { + reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i); + reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + i); + } + local_irq_save(flags); + /* start measuring cycles, incrementing from 0 */ + wrmsrl(MSR_K7_PERFCTR0 + i, 0); + wrmsrl(MSR_K7_EVNTSEL0 + i, 1 << 22 | 3 << 16 | 0x76); + rdtscl(tsc_start); + do { + rdmsrl(MSR_K7_PERFCTR0 + i, pmc_now); + tsc_now = get_cycles(); + } while ((tsc_now - tsc_start) < TICK_COUNT); + + local_irq_restore(flags); + if (no_ctr_free) { + wrmsrl(MSR_K7_EVNTSEL3, 0); + wrmsrl(MSR_K7_PERFCTR3, pmc3); + wrmsrl(MSR_K7_EVNTSEL3, evntsel3); + } else { + release_perfctr_nmi(MSR_K7_PERFCTR0 + i); + release_evntsel_nmi(MSR_K7_EVNTSEL0 + i); + } + + return pmc_now * tsc_khz / (tsc_now - tsc_start); +} +#else +static inline unsigned long calibrate_cpu(void) { return cpu_khz; } +#endif + void __init tsc_init(void) { u64 lpj; @@ -870,11 +925,9 @@ void __init tsc_init(void) return; } -#ifdef CONFIG_X86_64 if (cpu_has(&boot_cpu_data, X86_FEATURE_CONSTANT_TSC) && (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)) cpu_khz = calibrate_cpu(); -#endif printk("Detected %lu.%03lu MHz processor.\n", (unsigned long)cpu_khz / 1000, -- GitLab