diff options
author | john stultz <johnstul@us.ibm.com> | 2007-02-16 04:28:19 -0500 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-16 11:14:00 -0500 |
commit | c37e7bb5d2ce36ef377caabfced0b132bb1bf6a7 (patch) | |
tree | 3cc175f6922e7921bad5e588dd3046db1a67f996 /arch/x86_64/kernel/time.c | |
parent | 2d0c87c3bc49c60ab5bbac401fb1ef37ff10bbe2 (diff) |
[PATCH] time: x86_64: split x86_64/kernel/time.c up
In preparation for the x86_64 generic time conversion, this patch splits out
TSC and HPET related code from arch/x86_64/kernel/time.c into respective
hpet.c and tsc.c files.
[akpm@osdl.org: fix printk timestamps]
[akpm@osdl.org: cleanup]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@muc.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86_64/kernel/time.c')
-rw-r--r-- | arch/x86_64/kernel/time.c | 664 |
1 files changed, 4 insertions, 660 deletions
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index 76857add2f51..216fc9d74247 100644 --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c | |||
@@ -42,9 +42,10 @@ | |||
42 | #include <linux/cpufreq.h> | 42 | #include <linux/cpufreq.h> |
43 | #include <linux/hpet.h> | 43 | #include <linux/hpet.h> |
44 | #include <asm/apic.h> | 44 | #include <asm/apic.h> |
45 | #include <asm/hpet.h> | ||
45 | 46 | ||
46 | #ifdef CONFIG_CPU_FREQ | 47 | #ifdef CONFIG_CPU_FREQ |
47 | static void cpufreq_delayed_get(void); | 48 | extern void cpufreq_delayed_get(void); |
48 | #endif | 49 | #endif |
49 | extern void i8254_timer_resume(void); | 50 | extern void i8254_timer_resume(void); |
50 | extern int using_apic_timer; | 51 | extern int using_apic_timer; |
@@ -55,22 +56,6 @@ DEFINE_SPINLOCK(rtc_lock); | |||
55 | EXPORT_SYMBOL(rtc_lock); | 56 | EXPORT_SYMBOL(rtc_lock); |
56 | DEFINE_SPINLOCK(i8253_lock); | 57 | DEFINE_SPINLOCK(i8253_lock); |
57 | 58 | ||
58 | int nohpet __initdata = 0; | ||
59 | static int notsc __initdata = 0; | ||
60 | |||
61 | #define USEC_PER_TICK (USEC_PER_SEC / HZ) | ||
62 | #define NSEC_PER_TICK (NSEC_PER_SEC / HZ) | ||
63 | #define FSEC_PER_TICK (FSEC_PER_SEC / HZ) | ||
64 | |||
65 | #define NS_SCALE 10 /* 2^10, carefully chosen */ | ||
66 | #define US_SCALE 32 /* 2^32, arbitralrily chosen */ | ||
67 | |||
68 | unsigned int cpu_khz; /* TSC clocks / usec, not used here */ | ||
69 | EXPORT_SYMBOL(cpu_khz); | ||
70 | unsigned long hpet_address; | ||
71 | static unsigned long hpet_period; /* fsecs / HPET clock */ | ||
72 | unsigned long hpet_tick; /* HPET clocks / interrupt */ | ||
73 | int hpet_use_timer; /* Use counter of hpet for time keeping, otherwise PIT */ | ||
74 | unsigned long vxtime_hz = PIT_TICK_RATE; | 59 | unsigned long vxtime_hz = PIT_TICK_RATE; |
75 | int report_lost_ticks; /* command line option */ | 60 | int report_lost_ticks; /* command line option */ |
76 | unsigned long long monotonic_base; | 61 | unsigned long long monotonic_base; |
@@ -81,34 +66,6 @@ volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES; | |||
81 | struct timespec __xtime __section_xtime; | 66 | struct timespec __xtime __section_xtime; |
82 | struct timezone __sys_tz __section_sys_tz; | 67 | struct timezone __sys_tz __section_sys_tz; |
83 | 68 | ||
84 | /* | ||
85 | * do_gettimeoffset() returns microseconds since last timer interrupt was | ||
86 | * triggered by hardware. A memory read of HPET is slower than a register read | ||
87 | * of TSC, but much more reliable. It's also synchronized to the timer | ||
88 | * interrupt. Note that do_gettimeoffset() may return more than hpet_tick, if a | ||
89 | * timer interrupt has happened already, but vxtime.trigger wasn't updated yet. | ||
90 | * This is not a problem, because jiffies hasn't updated either. They are bound | ||
91 | * together by xtime_lock. | ||
92 | */ | ||
93 | |||
94 | static inline unsigned int do_gettimeoffset_tsc(void) | ||
95 | { | ||
96 | unsigned long t; | ||
97 | unsigned long x; | ||
98 | t = get_cycles_sync(); | ||
99 | if (t < vxtime.last_tsc) | ||
100 | t = vxtime.last_tsc; /* hack */ | ||
101 | x = ((t - vxtime.last_tsc) * vxtime.tsc_quot) >> US_SCALE; | ||
102 | return x; | ||
103 | } | ||
104 | |||
105 | static inline unsigned int do_gettimeoffset_hpet(void) | ||
106 | { | ||
107 | /* cap counter read to one tick to avoid inconsistencies */ | ||
108 | unsigned long counter = hpet_readl(HPET_COUNTER) - vxtime.last; | ||
109 | return (min(counter,hpet_tick) * vxtime.quot) >> US_SCALE; | ||
110 | } | ||
111 | |||
112 | unsigned int (*do_gettimeoffset)(void) = do_gettimeoffset_tsc; | 69 | unsigned int (*do_gettimeoffset)(void) = do_gettimeoffset_tsc; |
113 | 70 | ||
114 | /* | 71 | /* |
@@ -272,7 +229,7 @@ static void set_rtc_mmss(unsigned long nowtime) | |||
272 | * Note: This function is required to return accurate | 229 | * Note: This function is required to return accurate |
273 | * time even in the absence of multiple timer ticks. | 230 | * time even in the absence of multiple timer ticks. |
274 | */ | 231 | */ |
275 | static inline unsigned long long cycles_2_ns(unsigned long long cyc); | 232 | extern unsigned long long cycles_2_ns(unsigned long long cyc); |
276 | unsigned long long monotonic_clock(void) | 233 | unsigned long long monotonic_clock(void) |
277 | { | 234 | { |
278 | unsigned long seq; | 235 | unsigned long seq; |
@@ -462,40 +419,6 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id) | |||
462 | return IRQ_HANDLED; | 419 | return IRQ_HANDLED; |
463 | } | 420 | } |
464 | 421 | ||
465 | static unsigned int cyc2ns_scale __read_mostly; | ||
466 | |||
467 | static inline void set_cyc2ns_scale(unsigned long cpu_khz) | ||
468 | { | ||
469 | cyc2ns_scale = (NSEC_PER_MSEC << NS_SCALE) / cpu_khz; | ||
470 | } | ||
471 | |||
472 | static inline unsigned long long cycles_2_ns(unsigned long long cyc) | ||
473 | { | ||
474 | return (cyc * cyc2ns_scale) >> NS_SCALE; | ||
475 | } | ||
476 | |||
477 | unsigned long long sched_clock(void) | ||
478 | { | ||
479 | unsigned long a = 0; | ||
480 | |||
481 | #if 0 | ||
482 | /* Don't do a HPET read here. Using TSC always is much faster | ||
483 | and HPET may not be mapped yet when the scheduler first runs. | ||
484 | Disadvantage is a small drift between CPUs in some configurations, | ||
485 | but that should be tolerable. */ | ||
486 | if (__vxtime.mode == VXTIME_HPET) | ||
487 | return (hpet_readl(HPET_COUNTER) * vxtime.quot) >> US_SCALE; | ||
488 | #endif | ||
489 | |||
490 | /* Could do CPU core sync here. Opteron can execute rdtsc speculatively, | ||
491 | which means it is not completely exact and may not be monotonous between | ||
492 | CPUs. But the errors should be too small to matter for scheduling | ||
493 | purposes. */ | ||
494 | |||
495 | rdtscll(a); | ||
496 | return cycles_2_ns(a); | ||
497 | } | ||
498 | |||
499 | static unsigned long get_cmos_time(void) | 422 | static unsigned long get_cmos_time(void) |
500 | { | 423 | { |
501 | unsigned int year, mon, day, hour, min, sec; | 424 | unsigned int year, mon, day, hour, min, sec; |
@@ -547,164 +470,6 @@ static unsigned long get_cmos_time(void) | |||
547 | return mktime(year, mon, day, hour, min, sec); | 470 | return mktime(year, mon, day, hour, min, sec); |
548 | } | 471 | } |
549 | 472 | ||
550 | #ifdef CONFIG_CPU_FREQ | ||
551 | |||
552 | /* Frequency scaling support. Adjust the TSC based timer when the cpu frequency | ||
553 | changes. | ||
554 | |||
555 | RED-PEN: On SMP we assume all CPUs run with the same frequency. It's | ||
556 | not that important because current Opteron setups do not support | ||
557 | scaling on SMP anyroads. | ||
558 | |||
559 | Should fix up last_tsc too. Currently gettimeofday in the | ||
560 | first tick after the change will be slightly wrong. */ | ||
561 | |||
562 | #include <linux/workqueue.h> | ||
563 | |||
564 | static unsigned int cpufreq_delayed_issched = 0; | ||
565 | static unsigned int cpufreq_init = 0; | ||
566 | static struct work_struct cpufreq_delayed_get_work; | ||
567 | |||
568 | static void handle_cpufreq_delayed_get(struct work_struct *v) | ||
569 | { | ||
570 | unsigned int cpu; | ||
571 | for_each_online_cpu(cpu) { | ||
572 | cpufreq_get(cpu); | ||
573 | } | ||
574 | cpufreq_delayed_issched = 0; | ||
575 | } | ||
576 | |||
577 | /* if we notice lost ticks, schedule a call to cpufreq_get() as it tries | ||
578 | * to verify the CPU frequency the timing core thinks the CPU is running | ||
579 | * at is still correct. | ||
580 | */ | ||
581 | static void cpufreq_delayed_get(void) | ||
582 | { | ||
583 | static int warned; | ||
584 | if (cpufreq_init && !cpufreq_delayed_issched) { | ||
585 | cpufreq_delayed_issched = 1; | ||
586 | if (!warned) { | ||
587 | warned = 1; | ||
588 | printk(KERN_DEBUG | ||
589 | "Losing some ticks... checking if CPU frequency changed.\n"); | ||
590 | } | ||
591 | schedule_work(&cpufreq_delayed_get_work); | ||
592 | } | ||
593 | } | ||
594 | |||
595 | static unsigned int ref_freq = 0; | ||
596 | static unsigned long loops_per_jiffy_ref = 0; | ||
597 | |||
598 | static unsigned long cpu_khz_ref = 0; | ||
599 | |||
600 | static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, | ||
601 | void *data) | ||
602 | { | ||
603 | struct cpufreq_freqs *freq = data; | ||
604 | unsigned long *lpj, dummy; | ||
605 | |||
606 | if (cpu_has(&cpu_data[freq->cpu], X86_FEATURE_CONSTANT_TSC)) | ||
607 | return 0; | ||
608 | |||
609 | lpj = &dummy; | ||
610 | if (!(freq->flags & CPUFREQ_CONST_LOOPS)) | ||
611 | #ifdef CONFIG_SMP | ||
612 | lpj = &cpu_data[freq->cpu].loops_per_jiffy; | ||
613 | #else | ||
614 | lpj = &boot_cpu_data.loops_per_jiffy; | ||
615 | #endif | ||
616 | |||
617 | if (!ref_freq) { | ||
618 | ref_freq = freq->old; | ||
619 | loops_per_jiffy_ref = *lpj; | ||
620 | cpu_khz_ref = cpu_khz; | ||
621 | } | ||
622 | if ((val == CPUFREQ_PRECHANGE && freq->old < freq->new) || | ||
623 | (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) || | ||
624 | (val == CPUFREQ_RESUMECHANGE)) { | ||
625 | *lpj = | ||
626 | cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new); | ||
627 | |||
628 | cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new); | ||
629 | if (!(freq->flags & CPUFREQ_CONST_LOOPS)) | ||
630 | vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz; | ||
631 | } | ||
632 | |||
633 | set_cyc2ns_scale(cpu_khz_ref); | ||
634 | |||
635 | return 0; | ||
636 | } | ||
637 | |||
638 | static struct notifier_block time_cpufreq_notifier_block = { | ||
639 | .notifier_call = time_cpufreq_notifier | ||
640 | }; | ||
641 | |||
642 | static int __init cpufreq_tsc(void) | ||
643 | { | ||
644 | INIT_WORK(&cpufreq_delayed_get_work, handle_cpufreq_delayed_get); | ||
645 | if (!cpufreq_register_notifier(&time_cpufreq_notifier_block, | ||
646 | CPUFREQ_TRANSITION_NOTIFIER)) | ||
647 | cpufreq_init = 1; | ||
648 | return 0; | ||
649 | } | ||
650 | |||
651 | core_initcall(cpufreq_tsc); | ||
652 | |||
653 | #endif | ||
654 | |||
655 | /* | ||
656 | * calibrate_tsc() calibrates the processor TSC in a very simple way, comparing | ||
657 | * it to the HPET timer of known frequency. | ||
658 | */ | ||
659 | |||
660 | #define TICK_COUNT 100000000 | ||
661 | #define TICK_MIN 5000 | ||
662 | #define MAX_READ_RETRIES 5 | ||
663 | |||
664 | /* | ||
665 | * Some platforms take periodic SMI interrupts with 5ms duration. Make sure none | ||
666 | * occurs between the reads of the hpet & TSC. | ||
667 | */ | ||
668 | static void __init read_hpet_tsc(int *hpet, int *tsc) | ||
669 | { | ||
670 | int tsc1, tsc2, hpet1, retries = 0; | ||
671 | static int msg; | ||
672 | |||
673 | do { | ||
674 | tsc1 = get_cycles_sync(); | ||
675 | hpet1 = hpet_readl(HPET_COUNTER); | ||
676 | tsc2 = get_cycles_sync(); | ||
677 | } while (tsc2 - tsc1 > TICK_MIN && retries++ < MAX_READ_RETRIES); | ||
678 | if (retries >= MAX_READ_RETRIES && !msg++) | ||
679 | printk(KERN_WARNING | ||
680 | "hpet.c: exceeded max retries to read HPET & TSC\n"); | ||
681 | *hpet = hpet1; | ||
682 | *tsc = tsc2; | ||
683 | } | ||
684 | |||
685 | |||
686 | static unsigned int __init hpet_calibrate_tsc(void) | ||
687 | { | ||
688 | int tsc_start, hpet_start; | ||
689 | int tsc_now, hpet_now; | ||
690 | unsigned long flags; | ||
691 | |||
692 | local_irq_save(flags); | ||
693 | local_irq_disable(); | ||
694 | |||
695 | read_hpet_tsc(&hpet_start, &tsc_start); | ||
696 | |||
697 | do { | ||
698 | local_irq_disable(); | ||
699 | read_hpet_tsc(&hpet_now, &tsc_now); | ||
700 | local_irq_restore(flags); | ||
701 | } while ((tsc_now - tsc_start) < TICK_COUNT && | ||
702 | (hpet_now - hpet_start) < TICK_COUNT); | ||
703 | |||
704 | return (tsc_now - tsc_start) * 1000000000L | ||
705 | / ((hpet_now - hpet_start) * hpet_period / 1000); | ||
706 | } | ||
707 | |||
708 | 473 | ||
709 | /* | 474 | /* |
710 | * pit_calibrate_tsc() uses the speaker output (channel 2) of | 475 | * pit_calibrate_tsc() uses the speaker output (channel 2) of |
@@ -735,124 +500,6 @@ static unsigned int __init pit_calibrate_tsc(void) | |||
735 | return (end - start) / 50; | 500 | return (end - start) / 50; |
736 | } | 501 | } |
737 | 502 | ||
738 | #ifdef CONFIG_HPET | ||
739 | static __init int late_hpet_init(void) | ||
740 | { | ||
741 | struct hpet_data hd; | ||
742 | unsigned int ntimer; | ||
743 | |||
744 | if (!hpet_address) | ||
745 | return 0; | ||
746 | |||
747 | memset(&hd, 0, sizeof (hd)); | ||
748 | |||
749 | ntimer = hpet_readl(HPET_ID); | ||
750 | ntimer = (ntimer & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT; | ||
751 | ntimer++; | ||
752 | |||
753 | /* | ||
754 | * Register with driver. | ||
755 | * Timer0 and Timer1 is used by platform. | ||
756 | */ | ||
757 | hd.hd_phys_address = hpet_address; | ||
758 | hd.hd_address = (void __iomem *)fix_to_virt(FIX_HPET_BASE); | ||
759 | hd.hd_nirqs = ntimer; | ||
760 | hd.hd_flags = HPET_DATA_PLATFORM; | ||
761 | hpet_reserve_timer(&hd, 0); | ||
762 | #ifdef CONFIG_HPET_EMULATE_RTC | ||
763 | hpet_reserve_timer(&hd, 1); | ||
764 | #endif | ||
765 | hd.hd_irq[0] = HPET_LEGACY_8254; | ||
766 | hd.hd_irq[1] = HPET_LEGACY_RTC; | ||
767 | if (ntimer > 2) { | ||
768 | struct hpet *hpet; | ||
769 | struct hpet_timer *timer; | ||
770 | int i; | ||
771 | |||
772 | hpet = (struct hpet *) fix_to_virt(FIX_HPET_BASE); | ||
773 | timer = &hpet->hpet_timers[2]; | ||
774 | for (i = 2; i < ntimer; timer++, i++) | ||
775 | hd.hd_irq[i] = (timer->hpet_config & | ||
776 | Tn_INT_ROUTE_CNF_MASK) >> | ||
777 | Tn_INT_ROUTE_CNF_SHIFT; | ||
778 | |||
779 | } | ||
780 | |||
781 | hpet_alloc(&hd); | ||
782 | return 0; | ||
783 | } | ||
784 | fs_initcall(late_hpet_init); | ||
785 | #endif | ||
786 | |||
787 | static int hpet_timer_stop_set_go(unsigned long tick) | ||
788 | { | ||
789 | unsigned int cfg; | ||
790 | |||
791 | /* | ||
792 | * Stop the timers and reset the main counter. | ||
793 | */ | ||
794 | |||
795 | cfg = hpet_readl(HPET_CFG); | ||
796 | cfg &= ~(HPET_CFG_ENABLE | HPET_CFG_LEGACY); | ||
797 | hpet_writel(cfg, HPET_CFG); | ||
798 | hpet_writel(0, HPET_COUNTER); | ||
799 | hpet_writel(0, HPET_COUNTER + 4); | ||
800 | |||
801 | /* | ||
802 | * Set up timer 0, as periodic with first interrupt to happen at hpet_tick, | ||
803 | * and period also hpet_tick. | ||
804 | */ | ||
805 | if (hpet_use_timer) { | ||
806 | hpet_writel(HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL | | ||
807 | HPET_TN_32BIT, HPET_T0_CFG); | ||
808 | hpet_writel(hpet_tick, HPET_T0_CMP); /* next interrupt */ | ||
809 | hpet_writel(hpet_tick, HPET_T0_CMP); /* period */ | ||
810 | cfg |= HPET_CFG_LEGACY; | ||
811 | } | ||
812 | /* | ||
813 | * Go! | ||
814 | */ | ||
815 | |||
816 | cfg |= HPET_CFG_ENABLE; | ||
817 | hpet_writel(cfg, HPET_CFG); | ||
818 | |||
819 | return 0; | ||
820 | } | ||
821 | |||
822 | static int hpet_init(void) | ||
823 | { | ||
824 | unsigned int id; | ||
825 | |||
826 | if (!hpet_address) | ||
827 | return -1; | ||
828 | set_fixmap_nocache(FIX_HPET_BASE, hpet_address); | ||
829 | __set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE); | ||
830 | |||
831 | /* | ||
832 | * Read the period, compute tick and quotient. | ||
833 | */ | ||
834 | |||
835 | id = hpet_readl(HPET_ID); | ||
836 | |||
837 | if (!(id & HPET_ID_VENDOR) || !(id & HPET_ID_NUMBER)) | ||
838 | return -1; | ||
839 | |||
840 | hpet_period = hpet_readl(HPET_PERIOD); | ||
841 | if (hpet_period < 100000 || hpet_period > 100000000) | ||
842 | return -1; | ||
843 | |||
844 | hpet_tick = (FSEC_PER_TICK + hpet_period / 2) / hpet_period; | ||
845 | |||
846 | hpet_use_timer = (id & HPET_ID_LEGSUP); | ||
847 | |||
848 | return hpet_timer_stop_set_go(hpet_tick); | ||
849 | } | ||
850 | |||
851 | static int hpet_reenable(void) | ||
852 | { | ||
853 | return hpet_timer_stop_set_go(hpet_tick); | ||
854 | } | ||
855 | |||
856 | #define PIT_MODE 0x43 | 503 | #define PIT_MODE 0x43 |
857 | #define PIT_CH0 0x40 | 504 | #define PIT_CH0 0x40 |
858 | 505 | ||
@@ -910,7 +557,7 @@ void __init time_init(void) | |||
910 | set_normalized_timespec(&wall_to_monotonic, | 557 | set_normalized_timespec(&wall_to_monotonic, |
911 | -xtime.tv_sec, -xtime.tv_nsec); | 558 | -xtime.tv_sec, -xtime.tv_nsec); |
912 | 559 | ||
913 | if (!hpet_init()) | 560 | if (!hpet_arch_init()) |
914 | vxtime_hz = (FSEC_PER_SEC + hpet_period / 2) / hpet_period; | 561 | vxtime_hz = (FSEC_PER_SEC + hpet_period / 2) / hpet_period; |
915 | else | 562 | else |
916 | hpet_address = 0; | 563 | hpet_address = 0; |
@@ -945,42 +592,6 @@ void __init time_init(void) | |||
945 | #endif | 592 | #endif |
946 | } | 593 | } |
947 | 594 | ||
948 | static int tsc_unstable = 0; | ||
949 | |||
950 | void mark_tsc_unstable(void) | ||
951 | { | ||
952 | tsc_unstable = 1; | ||
953 | } | ||
954 | EXPORT_SYMBOL_GPL(mark_tsc_unstable); | ||
955 | |||
956 | /* | ||
957 | * Make an educated guess if the TSC is trustworthy and synchronized | ||
958 | * over all CPUs. | ||
959 | */ | ||
960 | __cpuinit int unsynchronized_tsc(void) | ||
961 | { | ||
962 | if (tsc_unstable) | ||
963 | return 1; | ||
964 | |||
965 | #ifdef CONFIG_SMP | ||
966 | if (apic_is_clustered_box()) | ||
967 | return 1; | ||
968 | #endif | ||
969 | /* Most intel systems have synchronized TSCs except for | ||
970 | multi node systems */ | ||
971 | if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) { | ||
972 | #ifdef CONFIG_ACPI | ||
973 | /* But TSC doesn't tick in C3 so don't use it there */ | ||
974 | if (acpi_gbl_FADT.header.length > 0 && acpi_gbl_FADT.C3latency < 1000) | ||
975 | return 1; | ||
976 | #endif | ||
977 | return 0; | ||
978 | } | ||
979 | |||
980 | /* Assume multi socket systems are not synchronized */ | ||
981 | return num_present_cpus() > 1; | ||
982 | } | ||
983 | |||
984 | /* | 595 | /* |
985 | * Decide what mode gettimeofday should use. | 596 | * Decide what mode gettimeofday should use. |
986 | */ | 597 | */ |
@@ -1116,270 +727,3 @@ static int time_init_device(void) | |||
1116 | } | 727 | } |
1117 | 728 | ||
1118 | device_initcall(time_init_device); | 729 | device_initcall(time_init_device); |
1119 | |||
1120 | #ifdef CONFIG_HPET_EMULATE_RTC | ||
1121 | /* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET | ||
1122 | * is enabled, we support RTC interrupt functionality in software. | ||
1123 | * RTC has 3 kinds of interrupts: | ||
1124 | * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock | ||
1125 | * is updated | ||
1126 | * 2) Alarm Interrupt - generate an interrupt at a specific time of day | ||
1127 | * 3) Periodic Interrupt - generate periodic interrupt, with frequencies | ||
1128 | * 2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2) | ||
1129 | * (1) and (2) above are implemented using polling at a frequency of | ||
1130 | * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt | ||
1131 | * overhead. (DEFAULT_RTC_INT_FREQ) | ||
1132 | * For (3), we use interrupts at 64Hz or user specified periodic | ||
1133 | * frequency, whichever is higher. | ||
1134 | */ | ||
1135 | #include <linux/rtc.h> | ||
1136 | |||
1137 | #define DEFAULT_RTC_INT_FREQ 64 | ||
1138 | #define RTC_NUM_INTS 1 | ||
1139 | |||
1140 | static unsigned long UIE_on; | ||
1141 | static unsigned long prev_update_sec; | ||
1142 | |||
1143 | static unsigned long AIE_on; | ||
1144 | static struct rtc_time alarm_time; | ||
1145 | |||
1146 | static unsigned long PIE_on; | ||
1147 | static unsigned long PIE_freq = DEFAULT_RTC_INT_FREQ; | ||
1148 | static unsigned long PIE_count; | ||
1149 | |||
1150 | static unsigned long hpet_rtc_int_freq; /* RTC interrupt frequency */ | ||
1151 | static unsigned int hpet_t1_cmp; /* cached comparator register */ | ||
1152 | |||
1153 | int is_hpet_enabled(void) | ||
1154 | { | ||
1155 | return hpet_address != 0; | ||
1156 | } | ||
1157 | |||
1158 | /* | ||
1159 | * Timer 1 for RTC, we do not use periodic interrupt feature, | ||
1160 | * even if HPET supports periodic interrupts on Timer 1. | ||
1161 | * The reason being, to set up a periodic interrupt in HPET, we need to | ||
1162 | * stop the main counter. And if we do that everytime someone diables/enables | ||
1163 | * RTC, we will have adverse effect on main kernel timer running on Timer 0. | ||
1164 | * So, for the time being, simulate the periodic interrupt in software. | ||
1165 | * | ||
1166 | * hpet_rtc_timer_init() is called for the first time and during subsequent | ||
1167 | * interuppts reinit happens through hpet_rtc_timer_reinit(). | ||
1168 | */ | ||
1169 | int hpet_rtc_timer_init(void) | ||
1170 | { | ||
1171 | unsigned int cfg, cnt; | ||
1172 | unsigned long flags; | ||
1173 | |||
1174 | if (!is_hpet_enabled()) | ||
1175 | return 0; | ||
1176 | /* | ||
1177 | * Set the counter 1 and enable the interrupts. | ||
1178 | */ | ||
1179 | if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ)) | ||
1180 | hpet_rtc_int_freq = PIE_freq; | ||
1181 | else | ||
1182 | hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ; | ||
1183 | |||
1184 | local_irq_save(flags); | ||
1185 | |||
1186 | cnt = hpet_readl(HPET_COUNTER); | ||
1187 | cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq); | ||
1188 | hpet_writel(cnt, HPET_T1_CMP); | ||
1189 | hpet_t1_cmp = cnt; | ||
1190 | |||
1191 | cfg = hpet_readl(HPET_T1_CFG); | ||
1192 | cfg &= ~HPET_TN_PERIODIC; | ||
1193 | cfg |= HPET_TN_ENABLE | HPET_TN_32BIT; | ||
1194 | hpet_writel(cfg, HPET_T1_CFG); | ||
1195 | |||
1196 | local_irq_restore(flags); | ||
1197 | |||
1198 | return 1; | ||
1199 | } | ||
1200 | |||
1201 | static void hpet_rtc_timer_reinit(void) | ||
1202 | { | ||
1203 | unsigned int cfg, cnt, ticks_per_int, lost_ints; | ||
1204 | |||
1205 | if (unlikely(!(PIE_on | AIE_on | UIE_on))) { | ||
1206 | cfg = hpet_readl(HPET_T1_CFG); | ||
1207 | cfg &= ~HPET_TN_ENABLE; | ||
1208 | hpet_writel(cfg, HPET_T1_CFG); | ||
1209 | return; | ||
1210 | } | ||
1211 | |||
1212 | if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ)) | ||
1213 | hpet_rtc_int_freq = PIE_freq; | ||
1214 | else | ||
1215 | hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ; | ||
1216 | |||
1217 | /* It is more accurate to use the comparator value than current count.*/ | ||
1218 | ticks_per_int = hpet_tick * HZ / hpet_rtc_int_freq; | ||
1219 | hpet_t1_cmp += ticks_per_int; | ||
1220 | hpet_writel(hpet_t1_cmp, HPET_T1_CMP); | ||
1221 | |||
1222 | /* | ||
1223 | * If the interrupt handler was delayed too long, the write above tries | ||
1224 | * to schedule the next interrupt in the past and the hardware would | ||
1225 | * not interrupt until the counter had wrapped around. | ||
1226 | * So we have to check that the comparator wasn't set to a past time. | ||
1227 | */ | ||
1228 | cnt = hpet_readl(HPET_COUNTER); | ||
1229 | if (unlikely((int)(cnt - hpet_t1_cmp) > 0)) { | ||
1230 | lost_ints = (cnt - hpet_t1_cmp) / ticks_per_int + 1; | ||
1231 | /* Make sure that, even with the time needed to execute | ||
1232 | * this code, the next scheduled interrupt has been moved | ||
1233 | * back to the future: */ | ||
1234 | lost_ints++; | ||
1235 | |||
1236 | hpet_t1_cmp += lost_ints * ticks_per_int; | ||
1237 | hpet_writel(hpet_t1_cmp, HPET_T1_CMP); | ||
1238 | |||
1239 | if (PIE_on) | ||
1240 | PIE_count += lost_ints; | ||
1241 | |||
1242 | if (printk_ratelimit()) | ||
1243 | printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n", | ||
1244 | hpet_rtc_int_freq); | ||
1245 | } | ||
1246 | } | ||
1247 | |||
1248 | /* | ||
1249 | * The functions below are called from rtc driver. | ||
1250 | * Return 0 if HPET is not being used. | ||
1251 | * Otherwise do the necessary changes and return 1. | ||
1252 | */ | ||
1253 | int hpet_mask_rtc_irq_bit(unsigned long bit_mask) | ||
1254 | { | ||
1255 | if (!is_hpet_enabled()) | ||
1256 | return 0; | ||
1257 | |||
1258 | if (bit_mask & RTC_UIE) | ||
1259 | UIE_on = 0; | ||
1260 | if (bit_mask & RTC_PIE) | ||
1261 | PIE_on = 0; | ||
1262 | if (bit_mask & RTC_AIE) | ||
1263 | AIE_on = 0; | ||
1264 | |||
1265 | return 1; | ||
1266 | } | ||
1267 | |||
1268 | int hpet_set_rtc_irq_bit(unsigned long bit_mask) | ||
1269 | { | ||
1270 | int timer_init_reqd = 0; | ||
1271 | |||
1272 | if (!is_hpet_enabled()) | ||
1273 | return 0; | ||
1274 | |||
1275 | if (!(PIE_on | AIE_on | UIE_on)) | ||
1276 | timer_init_reqd = 1; | ||
1277 | |||
1278 | if (bit_mask & RTC_UIE) { | ||
1279 | UIE_on = 1; | ||
1280 | } | ||
1281 | if (bit_mask & RTC_PIE) { | ||
1282 | PIE_on = 1; | ||
1283 | PIE_count = 0; | ||
1284 | } | ||
1285 | if (bit_mask & RTC_AIE) { | ||
1286 | AIE_on = 1; | ||
1287 | } | ||
1288 | |||
1289 | if (timer_init_reqd) | ||
1290 | hpet_rtc_timer_init(); | ||
1291 | |||
1292 | return 1; | ||
1293 | } | ||
1294 | |||
1295 | int hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec) | ||
1296 | { | ||
1297 | if (!is_hpet_enabled()) | ||
1298 | return 0; | ||
1299 | |||
1300 | alarm_time.tm_hour = hrs; | ||
1301 | alarm_time.tm_min = min; | ||
1302 | alarm_time.tm_sec = sec; | ||
1303 | |||
1304 | return 1; | ||
1305 | } | ||
1306 | |||
1307 | int hpet_set_periodic_freq(unsigned long freq) | ||
1308 | { | ||
1309 | if (!is_hpet_enabled()) | ||
1310 | return 0; | ||
1311 | |||
1312 | PIE_freq = freq; | ||
1313 | PIE_count = 0; | ||
1314 | |||
1315 | return 1; | ||
1316 | } | ||
1317 | |||
1318 | int hpet_rtc_dropped_irq(void) | ||
1319 | { | ||
1320 | if (!is_hpet_enabled()) | ||
1321 | return 0; | ||
1322 | |||
1323 | return 1; | ||
1324 | } | ||
1325 | |||
1326 | irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs) | ||
1327 | { | ||
1328 | struct rtc_time curr_time; | ||
1329 | unsigned long rtc_int_flag = 0; | ||
1330 | int call_rtc_interrupt = 0; | ||
1331 | |||
1332 | hpet_rtc_timer_reinit(); | ||
1333 | |||
1334 | if (UIE_on | AIE_on) { | ||
1335 | rtc_get_rtc_time(&curr_time); | ||
1336 | } | ||
1337 | if (UIE_on) { | ||
1338 | if (curr_time.tm_sec != prev_update_sec) { | ||
1339 | /* Set update int info, call real rtc int routine */ | ||
1340 | call_rtc_interrupt = 1; | ||
1341 | rtc_int_flag = RTC_UF; | ||
1342 | prev_update_sec = curr_time.tm_sec; | ||
1343 | } | ||
1344 | } | ||
1345 | if (PIE_on) { | ||
1346 | PIE_count++; | ||
1347 | if (PIE_count >= hpet_rtc_int_freq/PIE_freq) { | ||
1348 | /* Set periodic int info, call real rtc int routine */ | ||
1349 | call_rtc_interrupt = 1; | ||
1350 | rtc_int_flag |= RTC_PF; | ||
1351 | PIE_count = 0; | ||
1352 | } | ||
1353 | } | ||
1354 | if (AIE_on) { | ||
1355 | if ((curr_time.tm_sec == alarm_time.tm_sec) && | ||
1356 | (curr_time.tm_min == alarm_time.tm_min) && | ||
1357 | (curr_time.tm_hour == alarm_time.tm_hour)) { | ||
1358 | /* Set alarm int info, call real rtc int routine */ | ||
1359 | call_rtc_interrupt = 1; | ||
1360 | rtc_int_flag |= RTC_AF; | ||
1361 | } | ||
1362 | } | ||
1363 | if (call_rtc_interrupt) { | ||
1364 | rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8)); | ||
1365 | rtc_interrupt(rtc_int_flag, dev_id); | ||
1366 | } | ||
1367 | return IRQ_HANDLED; | ||
1368 | } | ||
1369 | #endif | ||
1370 | |||
1371 | static int __init nohpet_setup(char *s) | ||
1372 | { | ||
1373 | nohpet = 1; | ||
1374 | return 1; | ||
1375 | } | ||
1376 | |||
1377 | __setup("nohpet", nohpet_setup); | ||
1378 | |||
1379 | int __init notsc_setup(char *s) | ||
1380 | { | ||
1381 | notsc = 1; | ||
1382 | return 1; | ||
1383 | } | ||
1384 | |||
1385 | __setup("notsc", notsc_setup); | ||