Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * Copyright (C) 1991, 1992, 1995 Linus Torvalds |
| 3 | * |
| 4 | * This file contains the PC-specific time handling details: |
| 5 | * reading the RTC at bootup, etc.. |
| 6 | * 1994-07-02 Alan Modra |
| 7 | * fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime |
| 8 | * 1995-03-26 Markus Kuhn |
| 9 | * fixed 500 ms bug at call to set_rtc_mmss, fixed DS12887 |
| 10 | * precision CMOS clock update |
| 11 | * 1996-05-03 Ingo Molnar |
| 12 | * fixed time warps in do_[slow|fast]_gettimeoffset() |
| 13 | * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 |
| 14 | * "A Kernel Model for Precision Timekeeping" by Dave Mills |
| 15 | * 1998-09-05 (Various) |
| 16 | * More robust do_fast_gettimeoffset() algorithm implemented |
| 17 | * (works with APM, Cyrix 6x86MX and Centaur C6), |
| 18 | * monotonic gettimeofday() with fast_get_timeoffset(), |
| 19 | * drift-proof precision TSC calibration on boot |
| 20 | * (C. Scott Ananian <cananian@alumni.princeton.edu>, Andrew D. |
| 21 | * Balsa <andrebalsa@altern.org>, Philip Gladstone <philip@raptor.com>; |
| 22 | * ported from 2.0.35 Jumbo-9 by Michael Krause <m.krause@tu-harburg.de>). |
| 23 | * 1998-12-16 Andrea Arcangeli |
| 24 | * Fixed Jumbo-9 code in 2.1.131: do_gettimeofday was missing 1 jiffy |
| 25 | * because was not accounting lost_ticks. |
| 26 | * 1998-12-24 Copyright (C) 1998 Andrea Arcangeli |
| 27 | * Fixed a xtime SMP race (we need the xtime_lock rw spinlock to |
| 28 | * serialize accesses to xtime/lost_ticks). |
| 29 | */ |
| 30 | |
| 31 | #include <linux/errno.h> |
| 32 | #include <linux/sched.h> |
| 33 | #include <linux/kernel.h> |
| 34 | #include <linux/param.h> |
| 35 | #include <linux/string.h> |
| 36 | #include <linux/mm.h> |
| 37 | #include <linux/interrupt.h> |
| 38 | #include <linux/time.h> |
| 39 | #include <linux/delay.h> |
| 40 | #include <linux/init.h> |
| 41 | #include <linux/smp.h> |
| 42 | #include <linux/module.h> |
| 43 | #include <linux/sysdev.h> |
| 44 | #include <linux/bcd.h> |
| 45 | #include <linux/efi.h> |
| 46 | #include <linux/mca.h> |
| 47 | |
| 48 | #include <asm/io.h> |
| 49 | #include <asm/smp.h> |
| 50 | #include <asm/irq.h> |
| 51 | #include <asm/msr.h> |
| 52 | #include <asm/delay.h> |
| 53 | #include <asm/mpspec.h> |
| 54 | #include <asm/uaccess.h> |
| 55 | #include <asm/processor.h> |
| 56 | #include <asm/timer.h> |
Rusty Russell | d3561b7 | 2006-12-07 02:14:07 +0100 | [diff] [blame] | 57 | #include <asm/time.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | |
| 59 | #include "mach_time.h" |
| 60 | |
| 61 | #include <linux/timex.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | |
| 63 | #include <asm/hpet.h> |
| 64 | |
| 65 | #include <asm/arch_hooks.h> |
| 66 | |
| 67 | #include "io_ports.h" |
| 68 | |
Ingo Molnar | 306e440 | 2005-06-30 02:58:55 -0700 | [diff] [blame] | 69 | #include <asm/i8259.h> |
| 70 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | #include "do_timer.h" |
| 72 | |
Andrew Morton | a3a255e | 2005-06-23 00:08:34 -0700 | [diff] [blame] | 73 | unsigned int cpu_khz; /* Detected as we calibrate the TSC */ |
Alexey Dobriyan | 129f694 | 2005-06-23 00:08:33 -0700 | [diff] [blame] | 74 | EXPORT_SYMBOL(cpu_khz); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | DEFINE_SPINLOCK(rtc_lock); |
Alexey Dobriyan | 129f694 | 2005-06-23 00:08:33 -0700 | [diff] [blame] | 77 | EXPORT_SYMBOL(rtc_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | /* |
| 80 | * This is a special lock that is owned by the CPU and holds the index |
| 81 | * register we are working with. It is required for NMI access to the |
| 82 | * CMOS/RTC registers. See include/asm-i386/mc146818rtc.h for details. |
| 83 | */ |
| 84 | volatile unsigned long cmos_lock = 0; |
| 85 | EXPORT_SYMBOL(cmos_lock); |
| 86 | |
| 87 | /* Routines for accessing the CMOS RAM/RTC. */ |
| 88 | unsigned char rtc_cmos_read(unsigned char addr) |
| 89 | { |
| 90 | unsigned char val; |
| 91 | lock_cmos_prefix(addr); |
| 92 | outb_p(addr, RTC_PORT(0)); |
| 93 | val = inb_p(RTC_PORT(1)); |
| 94 | lock_cmos_suffix(addr); |
| 95 | return val; |
| 96 | } |
| 97 | EXPORT_SYMBOL(rtc_cmos_read); |
| 98 | |
| 99 | void rtc_cmos_write(unsigned char val, unsigned char addr) |
| 100 | { |
| 101 | lock_cmos_prefix(addr); |
| 102 | outb_p(addr, RTC_PORT(0)); |
| 103 | outb_p(val, RTC_PORT(1)); |
| 104 | lock_cmos_suffix(addr); |
| 105 | } |
| 106 | EXPORT_SYMBOL(rtc_cmos_write); |
| 107 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | static int set_rtc_mmss(unsigned long nowtime) |
| 109 | { |
| 110 | int retval; |
john stultz | 6f84fa2 | 2006-06-26 00:25:11 -0700 | [diff] [blame] | 111 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | |
| 113 | /* gets recalled with irq locally disabled */ |
john stultz | 6f84fa2 | 2006-06-26 00:25:11 -0700 | [diff] [blame] | 114 | /* XXX - does irqsave resolve this? -johnstul */ |
| 115 | spin_lock_irqsave(&rtc_lock, flags); |
Rusty Russell | d3561b7 | 2006-12-07 02:14:07 +0100 | [diff] [blame] | 116 | retval = set_wallclock(nowtime); |
john stultz | 6f84fa2 | 2006-06-26 00:25:11 -0700 | [diff] [blame] | 117 | spin_unlock_irqrestore(&rtc_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | |
| 119 | return retval; |
| 120 | } |
| 121 | |
| 122 | |
| 123 | int timer_ack; |
| 124 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | unsigned long profile_pc(struct pt_regs *regs) |
| 126 | { |
| 127 | unsigned long pc = instruction_pointer(regs); |
| 128 | |
Andi Kleen | 0cb91a2 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 129 | #ifdef CONFIG_SMP |
Zachary Amsden | 7b35520 | 2007-02-13 13:26:21 +0100 | [diff] [blame] | 130 | if (!v8086_mode(regs) && SEGMENT_IS_KERNEL_CODE(regs->xcs) && |
| 131 | in_lock_functions(pc)) { |
Andi Kleen | 0cb91a2 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 132 | #ifdef CONFIG_FRAME_POINTER |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | return *(unsigned long *)(regs->ebp + 4); |
Andi Kleen | 0cb91a2 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 134 | #else |
Zachary Amsden | 7b35520 | 2007-02-13 13:26:21 +0100 | [diff] [blame] | 135 | unsigned long *sp = (unsigned long *)®s->esp; |
| 136 | |
Andi Kleen | 0cb91a2 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 137 | /* Return address is either directly at stack pointer |
| 138 | or above a saved eflags. Eflags has bits 22-31 zero, |
| 139 | kernel addresses don't. */ |
| 140 | if (sp[0] >> 22) |
| 141 | return sp[0]; |
| 142 | if (sp[1] >> 22) |
| 143 | return sp[1]; |
| 144 | #endif |
| 145 | } |
| 146 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | return pc; |
| 148 | } |
| 149 | EXPORT_SYMBOL(profile_pc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | |
| 151 | /* |
john stultz | 6f84fa2 | 2006-06-26 00:25:11 -0700 | [diff] [blame] | 152 | * This is the same as the above, except we _also_ save the current |
| 153 | * Time Stamp Counter value at the time of the timer interrupt, so that |
| 154 | * we later on can estimate the time of day more exactly. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | */ |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 156 | irqreturn_t timer_interrupt(int irq, void *dev_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | { |
Thomas Gleixner | 3c9aea4 | 2007-10-12 23:04:06 +0200 | [diff] [blame] | 158 | /* Keep nmi watchdog up to date */ |
| 159 | per_cpu(irq_stat, smp_processor_id()).irq0_irqs++; |
| 160 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | #ifdef CONFIG_X86_IO_APIC |
| 162 | if (timer_ack) { |
| 163 | /* |
| 164 | * Subtle, when I/O APICs are used we have to ack timer IRQ |
| 165 | * manually to reset the IRR bit for do_slow_gettimeoffset(). |
| 166 | * This will also deassert NMI lines for the watchdog if run |
| 167 | * on an 82489DX-based system. |
| 168 | */ |
| 169 | spin_lock(&i8259A_lock); |
| 170 | outb(0x0c, PIC_MASTER_OCW3); |
| 171 | /* Ack the IRQ; AEOI will end it automatically. */ |
| 172 | inb(PIC_MASTER_POLL); |
| 173 | spin_unlock(&i8259A_lock); |
| 174 | } |
| 175 | #endif |
| 176 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 177 | do_timer_interrupt_hook(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | if (MCA_bus) { |
| 180 | /* The PS/2 uses level-triggered interrupts. You can't |
| 181 | turn them off, nor would you want to (any attempt to |
| 182 | enable edge-triggered interrupts usually gets intercepted by a |
| 183 | special hardware circuit). Hence we have to acknowledge |
| 184 | the timer interrupt. Through some incredibly stupid |
| 185 | design idea, the reset for IRQ 0 is done by setting the |
| 186 | high bit of the PPI port B (0x61). Note that some PS/2s, |
| 187 | notably the 55SX, work fine if this is removed. */ |
| 188 | |
Jeff Garzik | 86d91ba | 2006-10-06 13:32:44 -0400 | [diff] [blame] | 189 | u8 irq_v = inb_p( 0x61 ); /* read the current state */ |
| 190 | outb_p( irq_v|0x80, 0x61 ); /* reset the IRQ */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | return IRQ_HANDLED; |
| 194 | } |
| 195 | |
| 196 | /* not static: needed by APM */ |
John Stultz | c1d370e | 2007-02-16 01:27:31 -0800 | [diff] [blame] | 197 | unsigned long read_persistent_clock(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | { |
| 199 | unsigned long retval; |
Andrew Morton | 7ba1c6c | 2006-07-10 04:44:59 -0700 | [diff] [blame] | 200 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | |
Andrew Morton | 7ba1c6c | 2006-07-10 04:44:59 -0700 | [diff] [blame] | 202 | spin_lock_irqsave(&rtc_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | |
Rusty Russell | d3561b7 | 2006-12-07 02:14:07 +0100 | [diff] [blame] | 204 | retval = get_wallclock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | |
Andrew Morton | 7ba1c6c | 2006-07-10 04:44:59 -0700 | [diff] [blame] | 206 | spin_unlock_irqrestore(&rtc_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | |
| 208 | return retval; |
| 209 | } |
Alexey Dobriyan | 129f694 | 2005-06-23 00:08:33 -0700 | [diff] [blame] | 210 | |
Thomas Gleixner | 8264445 | 2007-07-21 04:37:37 -0700 | [diff] [blame] | 211 | int update_persistent_clock(struct timespec now) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | { |
Thomas Gleixner | 8264445 | 2007-07-21 04:37:37 -0700 | [diff] [blame] | 213 | return set_rtc_mmss(now.tv_sec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | } |
| 215 | |
Linus Torvalds | 1e4c85f | 2005-10-31 19:16:17 -0800 | [diff] [blame] | 216 | extern void (*late_time_init)(void); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | /* Duplicate of time_init() below, with hpet_enable part added */ |
Zachary Amsden | e30fab3 | 2007-03-05 00:30:39 -0800 | [diff] [blame] | 218 | void __init hpet_time_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | { |
Thomas Gleixner | e9e2cdb | 2007-02-16 01:28:04 -0800 | [diff] [blame] | 220 | if (!hpet_enable()) |
| 221 | setup_pit_timer(); |
Zachary Amsden | e30fab3 | 2007-03-05 00:30:39 -0800 | [diff] [blame] | 222 | time_init_hook(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | |
Zachary Amsden | e30fab3 | 2007-03-05 00:30:39 -0800 | [diff] [blame] | 225 | /* |
| 226 | * This is called directly from init code; we must delay timer setup in the |
| 227 | * HPET case as we can't make the decision to turn on HPET this early in the |
| 228 | * boot process. |
| 229 | * |
| 230 | * The chosen time_init function will usually be hpet_time_init, above, but |
| 231 | * in the case of virtual hardware, an alternative function may be substituted. |
| 232 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | void __init time_init(void) |
| 234 | { |
john stultz | 6bb74df | 2007-03-05 00:30:50 -0800 | [diff] [blame] | 235 | tsc_init(); |
Zachary Amsden | e30fab3 | 2007-03-05 00:30:39 -0800 | [diff] [blame] | 236 | late_time_init = choose_time_init(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | } |