From: Thomas Gleixner Date: Thu, 11 Oct 2007 09:14:54 +0000 (+0200) Subject: x86_64: prepare shared kernel/time.c X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=abb11834c6515161babea211a7be1fc6dcb893dc;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git x86_64: prepare shared kernel/time.c Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile index b0a29b51042..1c9ae60f0bf 100644 --- a/arch/x86_64/kernel/Makefile +++ b/arch/x86_64/kernel/Makefile @@ -5,7 +5,7 @@ extra-y := head.o head64.o init_task.o vmlinux.lds EXTRA_AFLAGS := -traditional obj-y := process.o signal_64.o entry.o traps_64.o irq.o \ - ptrace.o time.o ioport_64.o ldt.o setup_64.o i8259_64.o sys_x86_64.o \ + ptrace.o time_64.o ioport_64.o ldt.o setup_64.o i8259_64.o sys_x86_64.o \ x8664_ksyms.o i387_64.o syscall.o vsyscall_64.o \ setup64.o bootflag.o e820_64.o reboot.o quirks.o i8237.o \ pci-dma_64.o pci-nommu_64.o alternative.o hpet_64.o tsc.o bugs_64.o \ diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c deleted file mode 100644 index 6d48a4e826d..00000000000 --- a/arch/x86_64/kernel/time.c +++ /dev/null @@ -1,447 +0,0 @@ -/* - * linux/arch/x86-64/kernel/time.c - * - * "High Precision Event Timer" based timekeeping. - * - * Copyright (c) 1991,1992,1995 Linus Torvalds - * Copyright (c) 1994 Alan Modra - * Copyright (c) 1995 Markus Kuhn - * Copyright (c) 1996 Ingo Molnar - * Copyright (c) 1998 Andrea Arcangeli - * Copyright (c) 2002,2006 Vojtech Pavlik - * Copyright (c) 2003 Andi Kleen - * RTC support code taken from arch/i386/kernel/timers/time_hpet.c - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#ifdef CONFIG_ACPI -#include /* for PM timer frequency */ -#include -#endif -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -static char *timename = NULL; - -DEFINE_SPINLOCK(rtc_lock); -EXPORT_SYMBOL(rtc_lock); -DEFINE_SPINLOCK(i8253_lock); -EXPORT_SYMBOL(i8253_lock); - -volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES; - -unsigned long profile_pc(struct pt_regs *regs) -{ - unsigned long pc = instruction_pointer(regs); - - /* Assume the lock function has either no stack frame or a copy - of eflags from PUSHF - Eflags always has bits 22 and up cleared unlike kernel addresses. */ - if (!user_mode(regs) && in_lock_functions(pc)) { - unsigned long *sp = (unsigned long *)regs->rsp; - if (sp[0] >> 22) - return sp[0]; - if (sp[1] >> 22) - return sp[1]; - } - return pc; -} -EXPORT_SYMBOL(profile_pc); - -/* - * In order to set the CMOS clock precisely, set_rtc_mmss has to be called 500 - * ms after the second nowtime has started, because when nowtime is written - * into the registers of the CMOS clock, it will jump to the next second - * precisely 500 ms later. Check the Motorola MC146818A or Dallas DS12887 data - * sheet for details. - */ - -static int set_rtc_mmss(unsigned long nowtime) -{ - int retval = 0; - int real_seconds, real_minutes, cmos_minutes; - unsigned char control, freq_select; - -/* - * IRQs are disabled when we're called from the timer interrupt, - * no need for spin_lock_irqsave() - */ - - spin_lock(&rtc_lock); - -/* - * Tell the clock it's being set and stop it. - */ - - control = CMOS_READ(RTC_CONTROL); - CMOS_WRITE(control | RTC_SET, RTC_CONTROL); - - freq_select = CMOS_READ(RTC_FREQ_SELECT); - CMOS_WRITE(freq_select | RTC_DIV_RESET2, RTC_FREQ_SELECT); - - cmos_minutes = CMOS_READ(RTC_MINUTES); - BCD_TO_BIN(cmos_minutes); - -/* - * since we're only adjusting minutes and seconds, don't interfere with hour - * overflow. This avoids messing with unknown time zones but requires your RTC - * not to be off by more than 15 minutes. Since we're calling it only when - * our clock is externally synchronized using NTP, this shouldn't be a problem. - */ - - real_seconds = nowtime % 60; - real_minutes = nowtime / 60; - if (((abs(real_minutes - cmos_minutes) + 15) / 30) & 1) - real_minutes += 30; /* correct for half hour time zone */ - real_minutes %= 60; - - if (abs(real_minutes - cmos_minutes) >= 30) { - printk(KERN_WARNING "time.c: can't update CMOS clock " - "from %d to %d\n", cmos_minutes, real_minutes); - retval = -1; - } else { - BIN_TO_BCD(real_seconds); - BIN_TO_BCD(real_minutes); - CMOS_WRITE(real_seconds, RTC_SECONDS); - CMOS_WRITE(real_minutes, RTC_MINUTES); - } - -/* - * The following flags have to be released exactly in this order, otherwise the - * DS12887 (popular MC146818A clone with integrated battery and quartz) will - * not reset the oscillator and will not update precisely 500 ms later. You - * won't find this mentioned in the Dallas Semiconductor data sheets, but who - * believes data sheets anyway ... -- Markus Kuhn - */ - - CMOS_WRITE(control, RTC_CONTROL); - CMOS_WRITE(freq_select, RTC_FREQ_SELECT); - - spin_unlock(&rtc_lock); - - return retval; -} - -int update_persistent_clock(struct timespec now) -{ - return set_rtc_mmss(now.tv_sec); -} - -void main_timer_handler(void) -{ -/* - * Here we are in the timer irq handler. We have irqs locally disabled (so we - * don't need spin_lock_irqsave()) but we don't know if the timer_bh is running - * on the other CPU, so we need a lock. We also need to lock the vsyscall - * variables, because both do_timer() and us change them -arca+vojtech - */ - - write_seqlock(&xtime_lock); - -/* - * Do the timer stuff. - */ - - do_timer(1); -#ifndef CONFIG_SMP - update_process_times(user_mode(get_irq_regs())); -#endif - -/* - * In the SMP case we use the local APIC timer interrupt to do the profiling, - * except when we simulate SMP mode on a uniprocessor system, in that case we - * have to call the local interrupt handler. - */ - - if (!using_apic_timer) - smp_local_timer_interrupt(); - - write_sequnlock(&xtime_lock); -} - -static irqreturn_t timer_interrupt(int irq, void *dev_id) -{ - if (apic_runs_main_timer > 1) - return IRQ_HANDLED; - main_timer_handler(); - if (using_apic_timer) - smp_send_timer_broadcast_ipi(); - return IRQ_HANDLED; -} - -unsigned long read_persistent_clock(void) -{ - unsigned int year, mon, day, hour, min, sec; - unsigned long flags; - unsigned century = 0; - - spin_lock_irqsave(&rtc_lock, flags); - - do { - sec = CMOS_READ(RTC_SECONDS); - min = CMOS_READ(RTC_MINUTES); - hour = CMOS_READ(RTC_HOURS); - day = CMOS_READ(RTC_DAY_OF_MONTH); - mon = CMOS_READ(RTC_MONTH); - year = CMOS_READ(RTC_YEAR); -#ifdef CONFIG_ACPI - if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID && - acpi_gbl_FADT.century) - century = CMOS_READ(acpi_gbl_FADT.century); -#endif - } while (sec != CMOS_READ(RTC_SECONDS)); - - spin_unlock_irqrestore(&rtc_lock, flags); - - /* - * We know that x86-64 always uses BCD format, no need to check the - * config register. - */ - - BCD_TO_BIN(sec); - BCD_TO_BIN(min); - BCD_TO_BIN(hour); - BCD_TO_BIN(day); - BCD_TO_BIN(mon); - BCD_TO_BIN(year); - - if (century) { - BCD_TO_BIN(century); - year += century * 100; - printk(KERN_INFO "Extended CMOS year: %d\n", century * 100); - } else { - /* - * x86-64 systems only exists since 2002. - * This will work up to Dec 31, 2100 - */ - year += 2000; - } - - 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 - * the PIT. This is better than using the timer interrupt output, - * because we can read the value of the speaker with just one inb(), - * where we need three i/o operations for the interrupt channel. - * We count how many ticks the TSC does in 50 ms. - */ - -static unsigned int __init pit_calibrate_tsc(void) -{ - unsigned long start, end; - unsigned long flags; - - spin_lock_irqsave(&i8253_lock, flags); - - outb((inb(0x61) & ~0x02) | 0x01, 0x61); - - outb(0xb0, 0x43); - outb((PIT_TICK_RATE / (1000 / 50)) & 0xff, 0x42); - outb((PIT_TICK_RATE / (1000 / 50)) >> 8, 0x42); - start = get_cycles_sync(); - while ((inb(0x61) & 0x20) == 0); - end = get_cycles_sync(); - - spin_unlock_irqrestore(&i8253_lock, flags); - - return (end - start) / 50; -} - -#define PIT_MODE 0x43 -#define PIT_CH0 0x40 - -static void __pit_init(int val, u8 mode) -{ - unsigned long flags; - - spin_lock_irqsave(&i8253_lock, flags); - outb_p(mode, PIT_MODE); - outb_p(val & 0xff, PIT_CH0); /* LSB */ - outb_p(val >> 8, PIT_CH0); /* MSB */ - spin_unlock_irqrestore(&i8253_lock, flags); -} - -void __init pit_init(void) -{ - __pit_init(LATCH, 0x34); /* binary, mode 2, LSB/MSB, ch 0 */ -} - -void pit_stop_interrupt(void) -{ - __pit_init(0, 0x30); /* mode 0 */ -} - -void stop_timer_interrupt(void) -{ - char *name; - if (hpet_address) { - name = "HPET"; - hpet_timer_stop_set_go(0); - } else { - name = "PIT"; - pit_stop_interrupt(); - } - printk(KERN_INFO "timer: %s interrupt stopped.\n", name); -} - -static struct irqaction irq0 = { - .handler = timer_interrupt, - .flags = IRQF_DISABLED | IRQF_IRQPOLL, - .mask = CPU_MASK_NONE, - .name = "timer" -}; - -void __init time_init(void) -{ - if (nohpet) - hpet_address = 0; - - if (hpet_arch_init()) - hpet_address = 0; - - if (hpet_use_timer) { - /* set tick_nsec to use the proper rate for HPET */ - tick_nsec = TICK_NSEC_HPET; - tsc_khz = hpet_calibrate_tsc(); - timename = "HPET"; - } else { - pit_init(); - 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("TSCs unsynchronized"); - - if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP)) - vgetcpu_mode = VGETCPU_RDTSCP; - else - vgetcpu_mode = VGETCPU_LSL; - - 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(); - - setup_irq(0, &irq0); -} - -/* - * sysfs support for the timer. - */ - -static int timer_suspend(struct sys_device *dev, pm_message_t state) -{ - return 0; -} - -static int timer_resume(struct sys_device *dev) -{ - if (hpet_address) - hpet_reenable(); - else - i8254_timer_resume(); - return 0; -} - -static struct sysdev_class timer_sysclass = { - .resume = timer_resume, - .suspend = timer_suspend, - set_kset_name("timer"), -}; - -/* XXX this sysfs stuff should probably go elsewhere later -john */ -static struct sys_device device_timer = { - .id = 0, - .cls = &timer_sysclass, -}; - -static int time_init_device(void) -{ - int error = sysdev_class_register(&timer_sysclass); - if (!error) - error = sysdev_register(&device_timer); - return error; -} - -device_initcall(time_init_device); diff --git a/arch/x86_64/kernel/time_64.c b/arch/x86_64/kernel/time_64.c new file mode 100644 index 00000000000..6d48a4e826d --- /dev/null +++ b/arch/x86_64/kernel/time_64.c @@ -0,0 +1,447 @@ +/* + * linux/arch/x86-64/kernel/time.c + * + * "High Precision Event Timer" based timekeeping. + * + * Copyright (c) 1991,1992,1995 Linus Torvalds + * Copyright (c) 1994 Alan Modra + * Copyright (c) 1995 Markus Kuhn + * Copyright (c) 1996 Ingo Molnar + * Copyright (c) 1998 Andrea Arcangeli + * Copyright (c) 2002,2006 Vojtech Pavlik + * Copyright (c) 2003 Andi Kleen + * RTC support code taken from arch/i386/kernel/timers/time_hpet.c + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#ifdef CONFIG_ACPI +#include /* for PM timer frequency */ +#include +#endif +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static char *timename = NULL; + +DEFINE_SPINLOCK(rtc_lock); +EXPORT_SYMBOL(rtc_lock); +DEFINE_SPINLOCK(i8253_lock); +EXPORT_SYMBOL(i8253_lock); + +volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES; + +unsigned long profile_pc(struct pt_regs *regs) +{ + unsigned long pc = instruction_pointer(regs); + + /* Assume the lock function has either no stack frame or a copy + of eflags from PUSHF + Eflags always has bits 22 and up cleared unlike kernel addresses. */ + if (!user_mode(regs) && in_lock_functions(pc)) { + unsigned long *sp = (unsigned long *)regs->rsp; + if (sp[0] >> 22) + return sp[0]; + if (sp[1] >> 22) + return sp[1]; + } + return pc; +} +EXPORT_SYMBOL(profile_pc); + +/* + * In order to set the CMOS clock precisely, set_rtc_mmss has to be called 500 + * ms after the second nowtime has started, because when nowtime is written + * into the registers of the CMOS clock, it will jump to the next second + * precisely 500 ms later. Check the Motorola MC146818A or Dallas DS12887 data + * sheet for details. + */ + +static int set_rtc_mmss(unsigned long nowtime) +{ + int retval = 0; + int real_seconds, real_minutes, cmos_minutes; + unsigned char control, freq_select; + +/* + * IRQs are disabled when we're called from the timer interrupt, + * no need for spin_lock_irqsave() + */ + + spin_lock(&rtc_lock); + +/* + * Tell the clock it's being set and stop it. + */ + + control = CMOS_READ(RTC_CONTROL); + CMOS_WRITE(control | RTC_SET, RTC_CONTROL); + + freq_select = CMOS_READ(RTC_FREQ_SELECT); + CMOS_WRITE(freq_select | RTC_DIV_RESET2, RTC_FREQ_SELECT); + + cmos_minutes = CMOS_READ(RTC_MINUTES); + BCD_TO_BIN(cmos_minutes); + +/* + * since we're only adjusting minutes and seconds, don't interfere with hour + * overflow. This avoids messing with unknown time zones but requires your RTC + * not to be off by more than 15 minutes. Since we're calling it only when + * our clock is externally synchronized using NTP, this shouldn't be a problem. + */ + + real_seconds = nowtime % 60; + real_minutes = nowtime / 60; + if (((abs(real_minutes - cmos_minutes) + 15) / 30) & 1) + real_minutes += 30; /* correct for half hour time zone */ + real_minutes %= 60; + + if (abs(real_minutes - cmos_minutes) >= 30) { + printk(KERN_WARNING "time.c: can't update CMOS clock " + "from %d to %d\n", cmos_minutes, real_minutes); + retval = -1; + } else { + BIN_TO_BCD(real_seconds); + BIN_TO_BCD(real_minutes); + CMOS_WRITE(real_seconds, RTC_SECONDS); + CMOS_WRITE(real_minutes, RTC_MINUTES); + } + +/* + * The following flags have to be released exactly in this order, otherwise the + * DS12887 (popular MC146818A clone with integrated battery and quartz) will + * not reset the oscillator and will not update precisely 500 ms later. You + * won't find this mentioned in the Dallas Semiconductor data sheets, but who + * believes data sheets anyway ... -- Markus Kuhn + */ + + CMOS_WRITE(control, RTC_CONTROL); + CMOS_WRITE(freq_select, RTC_FREQ_SELECT); + + spin_unlock(&rtc_lock); + + return retval; +} + +int update_persistent_clock(struct timespec now) +{ + return set_rtc_mmss(now.tv_sec); +} + +void main_timer_handler(void) +{ +/* + * Here we are in the timer irq handler. We have irqs locally disabled (so we + * don't need spin_lock_irqsave()) but we don't know if the timer_bh is running + * on the other CPU, so we need a lock. We also need to lock the vsyscall + * variables, because both do_timer() and us change them -arca+vojtech + */ + + write_seqlock(&xtime_lock); + +/* + * Do the timer stuff. + */ + + do_timer(1); +#ifndef CONFIG_SMP + update_process_times(user_mode(get_irq_regs())); +#endif + +/* + * In the SMP case we use the local APIC timer interrupt to do the profiling, + * except when we simulate SMP mode on a uniprocessor system, in that case we + * have to call the local interrupt handler. + */ + + if (!using_apic_timer) + smp_local_timer_interrupt(); + + write_sequnlock(&xtime_lock); +} + +static irqreturn_t timer_interrupt(int irq, void *dev_id) +{ + if (apic_runs_main_timer > 1) + return IRQ_HANDLED; + main_timer_handler(); + if (using_apic_timer) + smp_send_timer_broadcast_ipi(); + return IRQ_HANDLED; +} + +unsigned long read_persistent_clock(void) +{ + unsigned int year, mon, day, hour, min, sec; + unsigned long flags; + unsigned century = 0; + + spin_lock_irqsave(&rtc_lock, flags); + + do { + sec = CMOS_READ(RTC_SECONDS); + min = CMOS_READ(RTC_MINUTES); + hour = CMOS_READ(RTC_HOURS); + day = CMOS_READ(RTC_DAY_OF_MONTH); + mon = CMOS_READ(RTC_MONTH); + year = CMOS_READ(RTC_YEAR); +#ifdef CONFIG_ACPI + if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID && + acpi_gbl_FADT.century) + century = CMOS_READ(acpi_gbl_FADT.century); +#endif + } while (sec != CMOS_READ(RTC_SECONDS)); + + spin_unlock_irqrestore(&rtc_lock, flags); + + /* + * We know that x86-64 always uses BCD format, no need to check the + * config register. + */ + + BCD_TO_BIN(sec); + BCD_TO_BIN(min); + BCD_TO_BIN(hour); + BCD_TO_BIN(day); + BCD_TO_BIN(mon); + BCD_TO_BIN(year); + + if (century) { + BCD_TO_BIN(century); + year += century * 100; + printk(KERN_INFO "Extended CMOS year: %d\n", century * 100); + } else { + /* + * x86-64 systems only exists since 2002. + * This will work up to Dec 31, 2100 + */ + year += 2000; + } + + 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 + * the PIT. This is better than using the timer interrupt output, + * because we can read the value of the speaker with just one inb(), + * where we need three i/o operations for the interrupt channel. + * We count how many ticks the TSC does in 50 ms. + */ + +static unsigned int __init pit_calibrate_tsc(void) +{ + unsigned long start, end; + unsigned long flags; + + spin_lock_irqsave(&i8253_lock, flags); + + outb((inb(0x61) & ~0x02) | 0x01, 0x61); + + outb(0xb0, 0x43); + outb((PIT_TICK_RATE / (1000 / 50)) & 0xff, 0x42); + outb((PIT_TICK_RATE / (1000 / 50)) >> 8, 0x42); + start = get_cycles_sync(); + while ((inb(0x61) & 0x20) == 0); + end = get_cycles_sync(); + + spin_unlock_irqrestore(&i8253_lock, flags); + + return (end - start) / 50; +} + +#define PIT_MODE 0x43 +#define PIT_CH0 0x40 + +static void __pit_init(int val, u8 mode) +{ + unsigned long flags; + + spin_lock_irqsave(&i8253_lock, flags); + outb_p(mode, PIT_MODE); + outb_p(val & 0xff, PIT_CH0); /* LSB */ + outb_p(val >> 8, PIT_CH0); /* MSB */ + spin_unlock_irqrestore(&i8253_lock, flags); +} + +void __init pit_init(void) +{ + __pit_init(LATCH, 0x34); /* binary, mode 2, LSB/MSB, ch 0 */ +} + +void pit_stop_interrupt(void) +{ + __pit_init(0, 0x30); /* mode 0 */ +} + +void stop_timer_interrupt(void) +{ + char *name; + if (hpet_address) { + name = "HPET"; + hpet_timer_stop_set_go(0); + } else { + name = "PIT"; + pit_stop_interrupt(); + } + printk(KERN_INFO "timer: %s interrupt stopped.\n", name); +} + +static struct irqaction irq0 = { + .handler = timer_interrupt, + .flags = IRQF_DISABLED | IRQF_IRQPOLL, + .mask = CPU_MASK_NONE, + .name = "timer" +}; + +void __init time_init(void) +{ + if (nohpet) + hpet_address = 0; + + if (hpet_arch_init()) + hpet_address = 0; + + if (hpet_use_timer) { + /* set tick_nsec to use the proper rate for HPET */ + tick_nsec = TICK_NSEC_HPET; + tsc_khz = hpet_calibrate_tsc(); + timename = "HPET"; + } else { + pit_init(); + 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("TSCs unsynchronized"); + + if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP)) + vgetcpu_mode = VGETCPU_RDTSCP; + else + vgetcpu_mode = VGETCPU_LSL; + + 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(); + + setup_irq(0, &irq0); +} + +/* + * sysfs support for the timer. + */ + +static int timer_suspend(struct sys_device *dev, pm_message_t state) +{ + return 0; +} + +static int timer_resume(struct sys_device *dev) +{ + if (hpet_address) + hpet_reenable(); + else + i8254_timer_resume(); + return 0; +} + +static struct sysdev_class timer_sysclass = { + .resume = timer_resume, + .suspend = timer_suspend, + set_kset_name("timer"), +}; + +/* XXX this sysfs stuff should probably go elsewhere later -john */ +static struct sys_device device_timer = { + .id = 0, + .cls = &timer_sysclass, +}; + +static int time_init_device(void) +{ + int error = sysdev_class_register(&timer_sysclass); + if (!error) + error = sysdev_register(&device_timer); + return error; +} + +device_initcall(time_init_device);