[PATCH] x86-64: fix cpu MHz reporting on constant_tsc cpus (6b37f5a2) · Commits · 戴 / test

arch/x86_64/kernel/apic.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -843,7 +843,7 @@ static int __init calibrate_APIC_clock(void)
		} while ((tsc - tsc_start) < TICK_COUNT &&
		(apic - apic_start) < TICK_COUNT);

		result = (apic_start - apic) * 1000L * cpu_khz /
		result = (apic_start - apic) * 1000L * tsc_khz /
		(tsc - tsc_start);
		}
		printk("result %d\n", result);

arch/x86_64/kernel/time.c

+55 −3

Original line number	Diff line number	Diff line
		@@ -43,6 +43,7 @@
		#include <asm/apic.h>
		#include <asm/hpet.h>
		#include <asm/mpspec.h>
		#include <asm/nmi.h>

		static char *timename = NULL;

		@@ -249,6 +250,51 @@ static unsigned long get_cmos_time(void)
		return mktime(year, mon, day, hour, min, sec);
		}

		/* calibrate_cpu is used on systems with fixed rate TSCs to determine
		* processor frequency */
		#define TICK_COUNT 100000000
		static unsigned int __init tsc_calibrate_cpu_khz(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) {
		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 meauring 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_sync();
		} 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);
		}

		/*
		* pit_calibrate_tsc() uses the speaker output (channel 2) of
		@@ -336,14 +382,20 @@ void __init time_init(void)
		if (hpet_use_timer) {
		/* set tick_nsec to use the proper rate for HPET */
		tick_nsec = TICK_NSEC_HPET;
		cpu_khz = hpet_calibrate_tsc();
		tsc_khz = hpet_calibrate_tsc();
		timename = "HPET";
		} else {
		pit_init();
		cpu_khz = pit_calibrate_tsc();
		tsc_khz = pit_calibrate_tsc();
		timename = "PIT";
		}

		cpu_khz = tsc_khz;
		if (cpu_has(&boot_cpu_data, X86_FEATURE_CONSTANT_TSC) &&
		boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
		boot_cpu_data.x86 == 16)
		cpu_khz = tsc_calibrate_cpu_khz();

		if (unsynchronized_tsc())
		mark_tsc_unstable();

		@@ -352,7 +404,7 @@ void __init time_init(void)
		else
		vgetcpu_mode = VGETCPU_LSL;

		set_cyc2ns_scale(cpu_khz);
		set_cyc2ns_scale(tsc_khz);
		printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
		cpu_khz / 1000, cpu_khz % 1000);
		init_tsc_clocksource();

arch/x86_64/kernel/tsc.c

+7 −5

Original line number	Diff line number	Diff line
		@@ -13,6 +13,8 @@ static int notsc __initdata = 0;

		unsigned int cpu_khz; /* TSC clocks / usec, not used here */
		EXPORT_SYMBOL(cpu_khz);
		unsigned int tsc_khz;
		EXPORT_SYMBOL(tsc_khz);

		static unsigned int cyc2ns_scale __read_mostly;

		@@ -77,7 +79,7 @@ static void handle_cpufreq_delayed_get(struct work_struct *v)
		static unsigned int ref_freq = 0;
		static unsigned long loops_per_jiffy_ref = 0;

		static unsigned long cpu_khz_ref = 0;
		static unsigned long tsc_khz_ref = 0;

		static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
		void *data)
		@@ -99,7 +101,7 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
		if (!ref_freq) {
		ref_freq = freq->old;
		loops_per_jiffy_ref = *lpj;
		cpu_khz_ref = cpu_khz;
		tsc_khz_ref = tsc_khz;
		}
		if ((val == CPUFREQ_PRECHANGE && freq->old < freq->new) \|\|
		(val == CPUFREQ_POSTCHANGE && freq->old > freq->new) \|\|
		@@ -107,12 +109,12 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
		*lpj =
		cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new);

		cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new);
		tsc_khz = cpufreq_scale(tsc_khz_ref, ref_freq, freq->new);
		if (!(freq->flags & CPUFREQ_CONST_LOOPS))
		mark_tsc_unstable();
		}

		set_cyc2ns_scale(cpu_khz_ref);
		set_cyc2ns_scale(tsc_khz_ref);

		return 0;
		}
		@@ -213,7 +215,7 @@ EXPORT_SYMBOL_GPL(mark_tsc_unstable);
		void __init init_tsc_clocksource(void)
		{
		if (!notsc) {
		clocksource_tsc.mult = clocksource_khz2mult(cpu_khz,
		clocksource_tsc.mult = clocksource_khz2mult(tsc_khz,
		clocksource_tsc.shift);
		if (check_tsc_unstable())
		clocksource_tsc.rating = 0;

arch/x86_64/kernel/tsc_sync.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -50,7 +50,7 @@ static __cpuinit void check_tsc_warp(void)
		/*
		* The measurement runs for 20 msecs:
		*/
		end = start + cpu_khz * 20ULL;
		end = start + tsc_khz * 20ULL;
		now = start;

		for (i = 0; ; i++) {

include/asm-x86_64/proto.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -92,6 +92,7 @@ extern unsigned long table_start, table_end;

		extern int exception_trace;
		extern unsigned cpu_khz;
		extern unsigned tsc_khz;

		extern void no_iommu_init(void);
		extern int force_iommu, no_iommu;

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