X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=arch%2Fx86%2Fkernel%2Ftsc.c;h=bb64beb301d982a7653af75b45c4195d0daecd91;hb=b0f969009f647cd473c5e559aeec9c4229d12f87;hp=648fb269e5d1e800e1cdb9dffc466d167122c985;hpb=d3b8f889a220aed825accc28eb64ce283a0d51ac;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 648fb26..bb64beb 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -17,6 +17,8 @@ #include #include #include +#include +#include unsigned int __read_mostly cpu_khz; /* TSC clocks / usec, not used here */ EXPORT_SYMBOL(cpu_khz); @@ -48,7 +50,7 @@ u64 native_sched_clock(void) * unstable. We do this because unlike Time Of Day, * the scheduler clock tolerates small errors and it's * very important for it to be as fast as the platform - * can achive it. ) + * can achieve it. ) */ if (unlikely(tsc_disabled)) { /* No locking but a rare wrong value is not a big deal: */ @@ -102,10 +104,14 @@ int __init notsc_setup(char *str) __setup("notsc", notsc_setup); +static int no_sched_irq_time; + static int __init tsc_setup(char *str) { if (!strcmp(str, "reliable")) tsc_clocksource_reliable = 1; + if (!strncmp(str, "noirqtime", 9)) + no_sched_irq_time = 1; return 1; } @@ -400,15 +406,9 @@ unsigned long native_calibrate_tsc(void) { u64 tsc1, tsc2, delta, ref1, ref2; unsigned long tsc_pit_min = ULONG_MAX, tsc_ref_min = ULONG_MAX; - unsigned long flags, latch, ms, fast_calibrate, hv_tsc_khz; + unsigned long flags, latch, ms, fast_calibrate; int hpet = is_hpet_enabled(), i, loopmin; - hv_tsc_khz = get_hypervisor_tsc_freq(); - if (hv_tsc_khz) { - printk(KERN_INFO "TSC: Frequency read from the hypervisor\n"); - return hv_tsc_khz; - } - local_irq_save(flags); fast_calibrate = quick_pit_calibrate(); local_irq_restore(flags); @@ -566,7 +566,7 @@ int recalibrate_cpu_khz(void) unsigned long cpu_khz_old = cpu_khz; if (cpu_has_tsc) { - tsc_khz = calibrate_tsc(); + tsc_khz = x86_platform.calibrate_tsc(); cpu_khz = tsc_khz; cpu_data(0).loops_per_jiffy = cpufreq_scale(cpu_data(0).loops_per_jiffy, @@ -630,6 +630,44 @@ static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu) local_irq_restore(flags); } +static unsigned long long cyc2ns_suspend; + +void save_sched_clock_state(void) +{ + if (!sched_clock_stable) + return; + + cyc2ns_suspend = sched_clock(); +} + +/* + * Even on processors with invariant TSC, TSC gets reset in some the + * ACPI system sleep states. And in some systems BIOS seem to reinit TSC to + * arbitrary value (still sync'd across cpu's) during resume from such sleep + * states. To cope up with this, recompute the cyc2ns_offset for each cpu so + * that sched_clock() continues from the point where it was left off during + * suspend. + */ +void restore_sched_clock_state(void) +{ + unsigned long long offset; + unsigned long flags; + int cpu; + + if (!sched_clock_stable) + return; + + local_irq_save(flags); + + __get_cpu_var(cyc2ns_offset) = 0; + offset = cyc2ns_suspend - sched_clock(); + + for_each_possible_cpu(cpu) + per_cpu(cyc2ns_offset, cpu) = offset; + + local_irq_restore(flags); +} + #ifdef CONFIG_CPU_FREQ /* Frequency scaling support. Adjust the TSC based timer when the cpu frequency @@ -670,7 +708,7 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, if ((val == CPUFREQ_PRECHANGE && freq->old < freq->new) || (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) || (val == CPUFREQ_RESUMECHANGE)) { - *lpj = cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new); + *lpj = cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new); tsc_khz = cpufreq_scale(tsc_khz_ref, ref_freq, freq->new); if (!(freq->flags & CPUFREQ_CONST_LOOPS)) @@ -744,12 +782,17 @@ static cycle_t __vsyscall_fn vread_tsc(void) } #endif +static void resume_tsc(struct clocksource *cs) +{ + clocksource_tsc.cycle_last = 0; +} + static struct clocksource clocksource_tsc = { .name = "tsc", .rating = 300, .read = read_tsc, + .resume = resume_tsc, .mask = CLOCKSOURCE_MASK(64), - .shift = 22, .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_MUST_VERIFY, #ifdef CONFIG_X86_64 @@ -761,12 +804,16 @@ void mark_tsc_unstable(char *reason) { if (!tsc_unstable) { tsc_unstable = 1; - printk("Marking TSC unstable due to %s\n", reason); + sched_clock_stable = 0; + disable_sched_clock_irqtime(); + printk(KERN_INFO "Marking TSC unstable due to %s\n", reason); /* Change only the rating, when not registered */ if (clocksource_tsc.mult) - clocksource_change_rating(&clocksource_tsc, 0); - else + clocksource_mark_unstable(&clocksource_tsc); + else { + clocksource_tsc.flags |= CLOCK_SOURCE_UNSTABLE; clocksource_tsc.rating = 0; + } } } @@ -801,7 +848,7 @@ static void __init check_system_tsc_reliable(void) unsigned long res_low, res_high; rdmsr_safe(MSR_GEODE_BUSCONT_CONF0, &res_low, &res_high); - /* Geode_LX - the OLPC CPU has a possibly a very reliable TSC */ + /* Geode_LX - the OLPC CPU has a very reliable TSC */ if (res_low & RTSC_SUSP) tsc_clocksource_reliable = 1; #endif @@ -843,8 +890,6 @@ __cpuinit int unsynchronized_tsc(void) static void __init init_tsc_clocksource(void) { - clocksource_tsc.mult = clocksource_khz2mult(tsc_khz, - clocksource_tsc.shift); if (tsc_clocksource_reliable) clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY; /* lower the rating if we already know its unstable: */ @@ -852,7 +897,7 @@ static void __init init_tsc_clocksource(void) clocksource_tsc.rating = 0; clocksource_tsc.flags &= ~CLOCK_SOURCE_IS_CONTINUOUS; } - clocksource_register(&clocksource_tsc); + clocksource_register_khz(&clocksource_tsc, tsc_khz); } void __init tsc_init(void) @@ -860,10 +905,12 @@ void __init tsc_init(void) u64 lpj; int cpu; + x86_init.timers.tsc_pre_init(); + if (!cpu_has_tsc) return; - tsc_khz = calibrate_tsc(); + tsc_khz = x86_platform.calibrate_tsc(); cpu_khz = tsc_khz; if (!tsc_khz) { @@ -871,12 +918,6 @@ 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, (unsigned long)cpu_khz % 1000); @@ -896,6 +937,9 @@ void __init tsc_init(void) /* now allow native_sched_clock() to use rdtsc */ tsc_disabled = 0; + if (!no_sched_irq_time) + enable_sched_clock_irqtime(); + lpj = ((u64)tsc_khz * 1000); do_div(lpj, HZ); lpj_fine = lpj;