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 | |
Thomas Gleixner | fe599f9 | 2008-01-30 13:30:26 +0100 | [diff] [blame] | 31 | #include <linux/init.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <linux/interrupt.h> |
| 33 | #include <linux/time.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | #include <linux/mca.h> |
| 35 | |
Thomas Gleixner | fe599f9 | 2008-01-30 13:30:26 +0100 | [diff] [blame] | 36 | #include <asm/arch_hooks.h> |
| 37 | #include <asm/hpet.h> |
Rusty Russell | d3561b7 | 2006-12-07 02:14:07 +0100 | [diff] [blame] | 38 | #include <asm/time.h> |
Jaswinder Singh | cc03849 | 2008-07-21 21:52:51 +0530 | [diff] [blame] | 39 | #include <asm/timer.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | #include "do_timer.h" |
| 42 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | int timer_ack; |
| 44 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | unsigned long profile_pc(struct pt_regs *regs) |
| 46 | { |
| 47 | unsigned long pc = instruction_pointer(regs); |
| 48 | |
Andi Kleen | 0cb91a2 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 49 | #ifdef CONFIG_SMP |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 50 | if (!v8086_mode(regs) && SEGMENT_IS_KERNEL_CODE(regs->cs) && |
Zachary Amsden | 7b35520 | 2007-02-13 13:26:21 +0100 | [diff] [blame] | 51 | in_lock_functions(pc)) { |
Andi Kleen | 0cb91a2 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 52 | #ifdef CONFIG_FRAME_POINTER |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 53 | return *(unsigned long *)(regs->bp + 4); |
Andi Kleen | 0cb91a2 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 54 | #else |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 55 | unsigned long *sp = (unsigned long *)®s->sp; |
Zachary Amsden | 7b35520 | 2007-02-13 13:26:21 +0100 | [diff] [blame] | 56 | |
Andi Kleen | 0cb91a2 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 57 | /* Return address is either directly at stack pointer |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 58 | or above a saved flags. Eflags has bits 22-31 zero, |
Andi Kleen | 0cb91a2 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 59 | kernel addresses don't. */ |
Thomas Gleixner | fe599f9 | 2008-01-30 13:30:26 +0100 | [diff] [blame] | 60 | if (sp[0] >> 22) |
Andi Kleen | 0cb91a2 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 61 | return sp[0]; |
| 62 | if (sp[1] >> 22) |
| 63 | return sp[1]; |
| 64 | #endif |
| 65 | } |
| 66 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | return pc; |
| 68 | } |
| 69 | EXPORT_SYMBOL(profile_pc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | |
| 71 | /* |
john stultz | 6f84fa2 | 2006-06-26 00:25:11 -0700 | [diff] [blame] | 72 | * This is the same as the above, except we _also_ save the current |
| 73 | * Time Stamp Counter value at the time of the timer interrupt, so that |
| 74 | * we later on can estimate the time of day more exactly. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | */ |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 76 | irqreturn_t timer_interrupt(int irq, void *dev_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | { |
Thomas Gleixner | 3c9aea4 | 2007-10-12 23:04:06 +0200 | [diff] [blame] | 78 | /* Keep nmi watchdog up to date */ |
| 79 | per_cpu(irq_stat, smp_processor_id()).irq0_irqs++; |
| 80 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | #ifdef CONFIG_X86_IO_APIC |
| 82 | if (timer_ack) { |
| 83 | /* |
| 84 | * Subtle, when I/O APICs are used we have to ack timer IRQ |
Maciej W. Rozycki | d11d579 | 2008-05-21 22:09:11 +0100 | [diff] [blame] | 85 | * manually to deassert NMI lines for the watchdog if run |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | * on an 82489DX-based system. |
| 87 | */ |
| 88 | spin_lock(&i8259A_lock); |
| 89 | outb(0x0c, PIC_MASTER_OCW3); |
| 90 | /* Ack the IRQ; AEOI will end it automatically. */ |
| 91 | inb(PIC_MASTER_POLL); |
| 92 | spin_unlock(&i8259A_lock); |
| 93 | } |
| 94 | #endif |
| 95 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 96 | do_timer_interrupt_hook(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | if (MCA_bus) { |
| 99 | /* The PS/2 uses level-triggered interrupts. You can't |
| 100 | turn them off, nor would you want to (any attempt to |
| 101 | enable edge-triggered interrupts usually gets intercepted by a |
| 102 | special hardware circuit). Hence we have to acknowledge |
| 103 | the timer interrupt. Through some incredibly stupid |
| 104 | design idea, the reset for IRQ 0 is done by setting the |
| 105 | high bit of the PPI port B (0x61). Note that some PS/2s, |
| 106 | notably the 55SX, work fine if this is removed. */ |
| 107 | |
Jeff Garzik | 86d91ba | 2006-10-06 13:32:44 -0400 | [diff] [blame] | 108 | u8 irq_v = inb_p( 0x61 ); /* read the current state */ |
| 109 | outb_p( irq_v|0x80, 0x61 ); /* reset the IRQ */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | return IRQ_HANDLED; |
| 113 | } |
| 114 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | /* Duplicate of time_init() below, with hpet_enable part added */ |
Zachary Amsden | e30fab3 | 2007-03-05 00:30:39 -0800 | [diff] [blame] | 116 | void __init hpet_time_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | { |
Thomas Gleixner | e9e2cdb | 2007-02-16 01:28:04 -0800 | [diff] [blame] | 118 | if (!hpet_enable()) |
| 119 | setup_pit_timer(); |
Zachary Amsden | e30fab3 | 2007-03-05 00:30:39 -0800 | [diff] [blame] | 120 | time_init_hook(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | |
Zachary Amsden | e30fab3 | 2007-03-05 00:30:39 -0800 | [diff] [blame] | 123 | /* |
| 124 | * This is called directly from init code; we must delay timer setup in the |
| 125 | * HPET case as we can't make the decision to turn on HPET this early in the |
| 126 | * boot process. |
| 127 | * |
| 128 | * The chosen time_init function will usually be hpet_time_init, above, but |
| 129 | * in the case of virtual hardware, an alternative function may be substituted. |
| 130 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | void __init time_init(void) |
| 132 | { |
Yinghai Lu | 63b5d7a | 2008-07-19 18:02:26 -0700 | [diff] [blame] | 133 | pre_time_init_hook(); |
john stultz | 6bb74df | 2007-03-05 00:30:50 -0800 | [diff] [blame] | 134 | tsc_init(); |
Zachary Amsden | e30fab3 | 2007-03-05 00:30:39 -0800 | [diff] [blame] | 135 | late_time_init = choose_time_init(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | } |