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authorLinus Torvalds <torvalds@linux-foundation.org>2009-09-18 17:05:47 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-18 17:05:47 -0400
commit78f28b7c555359c67c2a0d23f7436e915329421e (patch)
tree7f8197f82f83c0c19fd9bc85b5d10b5a755d0656 /arch/x86/kernel/tsc.c
parent3240a77b515f4a15e24d8a3a2135bc87b02cf1d6 (diff)
parent7bd867dfb4e0357e06a3211ab2bd0e714110def3 (diff)
Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (38 commits) x86: Move get/set_wallclock to x86_platform_ops x86: platform: Fix section annotations x86: apic namespace cleanup x86: Distangle ioapic and i8259 x86: Add Moorestown early detection x86: Add hardware_subarch ID for Moorestown x86: Add early platform detection x86: Move tsc_init to late_time_init x86: Move tsc_calibration to x86_init_ops x86: Replace the now identical time_32/64.c by time.c x86: time_32/64.c unify profile_pc x86: Move calibrate_cpu to tsc.c x86: Make timer setup and global variables the same in time_32/64.c x86: Remove mca bus ifdef from timer interrupt x86: Simplify timer_ack magic in time_32.c x86: Prepare unification of time_32/64.c x86: Remove do_timer hook x86: Add timer_init to x86_init_ops x86: Move percpu clockevents setup to x86_init_ops x86: Move xen_post_allocator_init into xen_pagetable_setup_done ... Fix up conflicts in arch/x86/include/asm/io_apic.h
Diffstat (limited to 'arch/x86/kernel/tsc.c')
-rw-r--r--arch/x86/kernel/tsc.c72
1 files changed, 61 insertions, 11 deletions
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index fc3672a303d6..17409e8d1097 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -17,6 +17,8 @@
17#include <asm/time.h> 17#include <asm/time.h>
18#include <asm/delay.h> 18#include <asm/delay.h>
19#include <asm/hypervisor.h> 19#include <asm/hypervisor.h>
20#include <asm/nmi.h>
21#include <asm/x86_init.h>
20 22
21unsigned int __read_mostly cpu_khz; /* TSC clocks / usec, not used here */ 23unsigned int __read_mostly cpu_khz; /* TSC clocks / usec, not used here */
22EXPORT_SYMBOL(cpu_khz); 24EXPORT_SYMBOL(cpu_khz);
@@ -400,15 +402,9 @@ unsigned long native_calibrate_tsc(void)
400{ 402{
401 u64 tsc1, tsc2, delta, ref1, ref2; 403 u64 tsc1, tsc2, delta, ref1, ref2;
402 unsigned long tsc_pit_min = ULONG_MAX, tsc_ref_min = ULONG_MAX; 404 unsigned long tsc_pit_min = ULONG_MAX, tsc_ref_min = ULONG_MAX;
403 unsigned long flags, latch, ms, fast_calibrate, hv_tsc_khz; 405 unsigned long flags, latch, ms, fast_calibrate;
404 int hpet = is_hpet_enabled(), i, loopmin; 406 int hpet = is_hpet_enabled(), i, loopmin;
405 407
406 hv_tsc_khz = get_hypervisor_tsc_freq();
407 if (hv_tsc_khz) {
408 printk(KERN_INFO "TSC: Frequency read from the hypervisor\n");
409 return hv_tsc_khz;
410 }
411
412 local_irq_save(flags); 408 local_irq_save(flags);
413 fast_calibrate = quick_pit_calibrate(); 409 fast_calibrate = quick_pit_calibrate();
414 local_irq_restore(flags); 410 local_irq_restore(flags);
@@ -566,7 +562,7 @@ int recalibrate_cpu_khz(void)
566 unsigned long cpu_khz_old = cpu_khz; 562 unsigned long cpu_khz_old = cpu_khz;
567 563
568 if (cpu_has_tsc) { 564 if (cpu_has_tsc) {
569 tsc_khz = calibrate_tsc(); 565 tsc_khz = x86_platform.calibrate_tsc();
570 cpu_khz = tsc_khz; 566 cpu_khz = tsc_khz;
571 cpu_data(0).loops_per_jiffy = 567 cpu_data(0).loops_per_jiffy =
572 cpufreq_scale(cpu_data(0).loops_per_jiffy, 568 cpufreq_scale(cpu_data(0).loops_per_jiffy,
@@ -860,15 +856,71 @@ static void __init init_tsc_clocksource(void)
860 clocksource_register(&clocksource_tsc); 856 clocksource_register(&clocksource_tsc);
861} 857}
862 858
859#ifdef CONFIG_X86_64
860/*
861 * calibrate_cpu is used on systems with fixed rate TSCs to determine
862 * processor frequency
863 */
864#define TICK_COUNT 100000000
865static unsigned long __init calibrate_cpu(void)
866{
867 int tsc_start, tsc_now;
868 int i, no_ctr_free;
869 unsigned long evntsel3 = 0, pmc3 = 0, pmc_now = 0;
870 unsigned long flags;
871
872 for (i = 0; i < 4; i++)
873 if (avail_to_resrv_perfctr_nmi_bit(i))
874 break;
875 no_ctr_free = (i == 4);
876 if (no_ctr_free) {
877 WARN(1, KERN_WARNING "Warning: AMD perfctrs busy ... "
878 "cpu_khz value may be incorrect.\n");
879 i = 3;
880 rdmsrl(MSR_K7_EVNTSEL3, evntsel3);
881 wrmsrl(MSR_K7_EVNTSEL3, 0);
882 rdmsrl(MSR_K7_PERFCTR3, pmc3);
883 } else {
884 reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i);
885 reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + i);
886 }
887 local_irq_save(flags);
888 /* start measuring cycles, incrementing from 0 */
889 wrmsrl(MSR_K7_PERFCTR0 + i, 0);
890 wrmsrl(MSR_K7_EVNTSEL0 + i, 1 << 22 | 3 << 16 | 0x76);
891 rdtscl(tsc_start);
892 do {
893 rdmsrl(MSR_K7_PERFCTR0 + i, pmc_now);
894 tsc_now = get_cycles();
895 } while ((tsc_now - tsc_start) < TICK_COUNT);
896
897 local_irq_restore(flags);
898 if (no_ctr_free) {
899 wrmsrl(MSR_K7_EVNTSEL3, 0);
900 wrmsrl(MSR_K7_PERFCTR3, pmc3);
901 wrmsrl(MSR_K7_EVNTSEL3, evntsel3);
902 } else {
903 release_perfctr_nmi(MSR_K7_PERFCTR0 + i);
904 release_evntsel_nmi(MSR_K7_EVNTSEL0 + i);
905 }
906
907 return pmc_now * tsc_khz / (tsc_now - tsc_start);
908}
909#else
910static inline unsigned long calibrate_cpu(void) { return cpu_khz; }
911#endif
912
863void __init tsc_init(void) 913void __init tsc_init(void)
864{ 914{
865 u64 lpj; 915 u64 lpj;
866 int cpu; 916 int cpu;
867 917
918 x86_init.timers.tsc_pre_init();
919
868 if (!cpu_has_tsc) 920 if (!cpu_has_tsc)
869 return; 921 return;
870 922
871 tsc_khz = calibrate_tsc(); 923 tsc_khz = x86_platform.calibrate_tsc();
872 cpu_khz = tsc_khz; 924 cpu_khz = tsc_khz;
873 925
874 if (!tsc_khz) { 926 if (!tsc_khz) {
@@ -876,11 +928,9 @@ void __init tsc_init(void)
876 return; 928 return;
877 } 929 }
878 930
879#ifdef CONFIG_X86_64
880 if (cpu_has(&boot_cpu_data, X86_FEATURE_CONSTANT_TSC) && 931 if (cpu_has(&boot_cpu_data, X86_FEATURE_CONSTANT_TSC) &&
881 (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)) 932 (boot_cpu_data.x86_vendor == X86_VENDOR_AMD))
882 cpu_khz = calibrate_cpu(); 933 cpu_khz = calibrate_cpu();
883#endif
884 934
885 printk("Detected %lu.%03lu MHz processor.\n", 935 printk("Detected %lu.%03lu MHz processor.\n",
886 (unsigned long)cpu_khz / 1000, 936 (unsigned long)cpu_khz / 1000,