Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c
new file mode 100644
index 0000000..9b55e30e
--- /dev/null
+++ b/arch/i386/kernel/time.c
@@ -0,0 +1,476 @@
+/*
+ * linux/arch/i386/kernel/time.c
+ *
+ * Copyright (C) 1991, 1992, 1995 Linus Torvalds
+ *
+ * This file contains the PC-specific time handling details:
+ * reading the RTC at bootup, etc..
+ * 1994-07-02 Alan Modra
+ * fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime
+ * 1995-03-26 Markus Kuhn
+ * fixed 500 ms bug at call to set_rtc_mmss, fixed DS12887
+ * precision CMOS clock update
+ * 1996-05-03 Ingo Molnar
+ * fixed time warps in do_[slow|fast]_gettimeoffset()
+ * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
+ * "A Kernel Model for Precision Timekeeping" by Dave Mills
+ * 1998-09-05 (Various)
+ * More robust do_fast_gettimeoffset() algorithm implemented
+ * (works with APM, Cyrix 6x86MX and Centaur C6),
+ * monotonic gettimeofday() with fast_get_timeoffset(),
+ * drift-proof precision TSC calibration on boot
+ * (C. Scott Ananian <cananian@alumni.princeton.edu>, Andrew D.
+ * Balsa <andrebalsa@altern.org>, Philip Gladstone <philip@raptor.com>;
+ * ported from 2.0.35 Jumbo-9 by Michael Krause <m.krause@tu-harburg.de>).
+ * 1998-12-16 Andrea Arcangeli
+ * Fixed Jumbo-9 code in 2.1.131: do_gettimeofday was missing 1 jiffy
+ * because was not accounting lost_ticks.
+ * 1998-12-24 Copyright (C) 1998 Andrea Arcangeli
+ * Fixed a xtime SMP race (we need the xtime_lock rw spinlock to
+ * serialize accesses to xtime/lost_ticks).
+ */
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/module.h>
+#include <linux/sysdev.h>
+#include <linux/bcd.h>
+#include <linux/efi.h>
+#include <linux/mca.h>
+
+#include <asm/io.h>
+#include <asm/smp.h>
+#include <asm/irq.h>
+#include <asm/msr.h>
+#include <asm/delay.h>
+#include <asm/mpspec.h>
+#include <asm/uaccess.h>
+#include <asm/processor.h>
+#include <asm/timer.h>
+
+#include "mach_time.h"
+
+#include <linux/timex.h>
+#include <linux/config.h>
+
+#include <asm/hpet.h>
+
+#include <asm/arch_hooks.h>
+
+#include "io_ports.h"
+
+extern spinlock_t i8259A_lock;
+int pit_latch_buggy; /* extern */
+
+#include "do_timer.h"
+
+u64 jiffies_64 = INITIAL_JIFFIES;
+
+EXPORT_SYMBOL(jiffies_64);
+
+unsigned long cpu_khz; /* Detected as we calibrate the TSC */
+
+extern unsigned long wall_jiffies;
+
+DEFINE_SPINLOCK(rtc_lock);
+
+DEFINE_SPINLOCK(i8253_lock);
+EXPORT_SYMBOL(i8253_lock);
+
+struct timer_opts *cur_timer = &timer_none;
+
+/*
+ * This is a special lock that is owned by the CPU and holds the index
+ * register we are working with. It is required for NMI access to the
+ * CMOS/RTC registers. See include/asm-i386/mc146818rtc.h for details.
+ */
+volatile unsigned long cmos_lock = 0;
+EXPORT_SYMBOL(cmos_lock);
+
+/* Routines for accessing the CMOS RAM/RTC. */
+unsigned char rtc_cmos_read(unsigned char addr)
+{
+ unsigned char val;
+ lock_cmos_prefix(addr);
+ outb_p(addr, RTC_PORT(0));
+ val = inb_p(RTC_PORT(1));
+ lock_cmos_suffix(addr);
+ return val;
+}
+EXPORT_SYMBOL(rtc_cmos_read);
+
+void rtc_cmos_write(unsigned char val, unsigned char addr)
+{
+ lock_cmos_prefix(addr);
+ outb_p(addr, RTC_PORT(0));
+ outb_p(val, RTC_PORT(1));
+ lock_cmos_suffix(addr);
+}
+EXPORT_SYMBOL(rtc_cmos_write);
+
+/*
+ * This version of gettimeofday has microsecond resolution
+ * and better than microsecond precision on fast x86 machines with TSC.
+ */
+void do_gettimeofday(struct timeval *tv)
+{
+ unsigned long seq;
+ unsigned long usec, sec;
+ unsigned long max_ntp_tick;
+
+ do {
+ unsigned long lost;
+
+ seq = read_seqbegin(&xtime_lock);
+
+ usec = cur_timer->get_offset();
+ lost = jiffies - wall_jiffies;
+
+ /*
+ * If time_adjust is negative then NTP is slowing the clock
+ * so make sure not to go into next possible interval.
+ * Better to lose some accuracy than have time go backwards..
+ */
+ if (unlikely(time_adjust < 0)) {
+ max_ntp_tick = (USEC_PER_SEC / HZ) - tickadj;
+ usec = min(usec, max_ntp_tick);
+
+ if (lost)
+ usec += lost * max_ntp_tick;
+ }
+ else if (unlikely(lost))
+ usec += lost * (USEC_PER_SEC / HZ);
+
+ sec = xtime.tv_sec;
+ usec += (xtime.tv_nsec / 1000);
+ } while (read_seqretry(&xtime_lock, seq));
+
+ while (usec >= 1000000) {
+ usec -= 1000000;
+ sec++;
+ }
+
+ tv->tv_sec = sec;
+ tv->tv_usec = usec;
+}
+
+EXPORT_SYMBOL(do_gettimeofday);
+
+int do_settimeofday(struct timespec *tv)
+{
+ time_t wtm_sec, sec = tv->tv_sec;
+ long wtm_nsec, nsec = tv->tv_nsec;
+
+ if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
+ return -EINVAL;
+
+ write_seqlock_irq(&xtime_lock);
+ /*
+ * This is revolting. We need to set "xtime" correctly. However, the
+ * value in this location is the value at the most recent update of
+ * wall time. Discover what correction gettimeofday() would have
+ * made, and then undo it!
+ */
+ nsec -= cur_timer->get_offset() * NSEC_PER_USEC;
+ nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
+
+ wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+ wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+ set_normalized_timespec(&xtime, sec, nsec);
+ set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
+
+ time_adjust = 0; /* stop active adjtime() */
+ time_status |= STA_UNSYNC;
+ time_maxerror = NTP_PHASE_LIMIT;
+ time_esterror = NTP_PHASE_LIMIT;
+ write_sequnlock_irq(&xtime_lock);
+ clock_was_set();
+ return 0;
+}
+
+EXPORT_SYMBOL(do_settimeofday);
+
+static int set_rtc_mmss(unsigned long nowtime)
+{
+ int retval;
+
+ WARN_ON(irqs_disabled());
+
+ /* gets recalled with irq locally disabled */
+ spin_lock_irq(&rtc_lock);
+ if (efi_enabled)
+ retval = efi_set_rtc_mmss(nowtime);
+ else
+ retval = mach_set_rtc_mmss(nowtime);
+ spin_unlock_irq(&rtc_lock);
+
+ return retval;
+}
+
+
+int timer_ack;
+
+/* monotonic_clock(): returns # of nanoseconds passed since time_init()
+ * Note: This function is required to return accurate
+ * time even in the absence of multiple timer ticks.
+ */
+unsigned long long monotonic_clock(void)
+{
+ return cur_timer->monotonic_clock();
+}
+EXPORT_SYMBOL(monotonic_clock);
+
+#if defined(CONFIG_SMP) && defined(CONFIG_FRAME_POINTER)
+unsigned long profile_pc(struct pt_regs *regs)
+{
+ unsigned long pc = instruction_pointer(regs);
+
+ if (in_lock_functions(pc))
+ return *(unsigned long *)(regs->ebp + 4);
+
+ return pc;
+}
+EXPORT_SYMBOL(profile_pc);
+#endif
+
+/*
+ * timer_interrupt() needs to keep up the real-time clock,
+ * as well as call the "do_timer()" routine every clocktick
+ */
+static inline void do_timer_interrupt(int irq, void *dev_id,
+ struct pt_regs *regs)
+{
+#ifdef CONFIG_X86_IO_APIC
+ if (timer_ack) {
+ /*
+ * Subtle, when I/O APICs are used we have to ack timer IRQ
+ * manually to reset the IRR bit for do_slow_gettimeoffset().
+ * This will also deassert NMI lines for the watchdog if run
+ * on an 82489DX-based system.
+ */
+ spin_lock(&i8259A_lock);
+ outb(0x0c, PIC_MASTER_OCW3);
+ /* Ack the IRQ; AEOI will end it automatically. */
+ inb(PIC_MASTER_POLL);
+ spin_unlock(&i8259A_lock);
+ }
+#endif
+
+ do_timer_interrupt_hook(regs);
+
+
+ if (MCA_bus) {
+ /* The PS/2 uses level-triggered interrupts. You can't
+ turn them off, nor would you want to (any attempt to
+ enable edge-triggered interrupts usually gets intercepted by a
+ special hardware circuit). Hence we have to acknowledge
+ the timer interrupt. Through some incredibly stupid
+ design idea, the reset for IRQ 0 is done by setting the
+ high bit of the PPI port B (0x61). Note that some PS/2s,
+ notably the 55SX, work fine if this is removed. */
+
+ irq = inb_p( 0x61 ); /* read the current state */
+ outb_p( irq|0x80, 0x61 ); /* reset the IRQ */
+ }
+}
+
+/*
+ * This is the same as the above, except we _also_ save the current
+ * Time Stamp Counter value at the time of the timer interrupt, so that
+ * we later on can estimate the time of day more exactly.
+ */
+irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+ /*
+ * Here we are in the timer irq handler. We just have irqs locally
+ * disabled but we don't know if the timer_bh is running on the other
+ * CPU. We need to avoid to SMP race with it. NOTE: we don' t need
+ * the irq version of write_lock because as just said we have irq
+ * locally disabled. -arca
+ */
+ write_seqlock(&xtime_lock);
+
+ cur_timer->mark_offset();
+
+ do_timer_interrupt(irq, NULL, regs);
+
+ write_sequnlock(&xtime_lock);
+ return IRQ_HANDLED;
+}
+
+/* not static: needed by APM */
+unsigned long get_cmos_time(void)
+{
+ unsigned long retval;
+
+ spin_lock(&rtc_lock);
+
+ if (efi_enabled)
+ retval = efi_get_time();
+ else
+ retval = mach_get_cmos_time();
+
+ spin_unlock(&rtc_lock);
+
+ return retval;
+}
+static void sync_cmos_clock(unsigned long dummy);
+
+static struct timer_list sync_cmos_timer =
+ TIMER_INITIALIZER(sync_cmos_clock, 0, 0);
+
+static void sync_cmos_clock(unsigned long dummy)
+{
+ struct timeval now, next;
+ int fail = 1;
+
+ /*
+ * If we have an externally synchronized Linux clock, then update
+ * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
+ * called as close as possible to 500 ms before the new second starts.
+ * This code is run on a timer. If the clock is set, that timer
+ * may not expire at the correct time. Thus, we adjust...
+ */
+ if ((time_status & STA_UNSYNC) != 0)
+ /*
+ * Not synced, exit, do not restart a timer (if one is
+ * running, let it run out).
+ */
+ return;
+
+ do_gettimeofday(&now);
+ if (now.tv_usec >= USEC_AFTER - ((unsigned) TICK_SIZE) / 2 &&
+ now.tv_usec <= USEC_BEFORE + ((unsigned) TICK_SIZE) / 2)
+ fail = set_rtc_mmss(now.tv_sec);
+
+ next.tv_usec = USEC_AFTER - now.tv_usec;
+ if (next.tv_usec <= 0)
+ next.tv_usec += USEC_PER_SEC;
+
+ if (!fail)
+ next.tv_sec = 659;
+ else
+ next.tv_sec = 0;
+
+ if (next.tv_usec >= USEC_PER_SEC) {
+ next.tv_sec++;
+ next.tv_usec -= USEC_PER_SEC;
+ }
+ mod_timer(&sync_cmos_timer, jiffies + timeval_to_jiffies(&next));
+}
+
+void notify_arch_cmos_timer(void)
+{
+ mod_timer(&sync_cmos_timer, jiffies + 1);
+}
+
+static long clock_cmos_diff, sleep_start;
+
+static int timer_suspend(struct sys_device *dev, u32 state)
+{
+ /*
+ * Estimate time zone so that set_time can update the clock
+ */
+ clock_cmos_diff = -get_cmos_time();
+ clock_cmos_diff += get_seconds();
+ sleep_start = get_cmos_time();
+ return 0;
+}
+
+static int timer_resume(struct sys_device *dev)
+{
+ unsigned long flags;
+ unsigned long sec;
+ unsigned long sleep_length;
+
+#ifdef CONFIG_HPET_TIMER
+ if (is_hpet_enabled())
+ hpet_reenable();
+#endif
+ sec = get_cmos_time() + clock_cmos_diff;
+ sleep_length = (get_cmos_time() - sleep_start) * HZ;
+ write_seqlock_irqsave(&xtime_lock, flags);
+ xtime.tv_sec = sec;
+ xtime.tv_nsec = 0;
+ write_sequnlock_irqrestore(&xtime_lock, flags);
+ jiffies += sleep_length;
+ wall_jiffies += sleep_length;
+ return 0;
+}
+
+static struct sysdev_class timer_sysclass = {
+ .resume = timer_resume,
+ .suspend = timer_suspend,
+ set_kset_name("timer"),
+};
+
+
+/* XXX this driverfs 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);
+
+#ifdef CONFIG_HPET_TIMER
+extern void (*late_time_init)(void);
+/* Duplicate of time_init() below, with hpet_enable part added */
+static void __init hpet_time_init(void)
+{
+ xtime.tv_sec = get_cmos_time();
+ xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
+ set_normalized_timespec(&wall_to_monotonic,
+ -xtime.tv_sec, -xtime.tv_nsec);
+
+ if (hpet_enable() >= 0) {
+ printk("Using HPET for base-timer\n");
+ }
+
+ cur_timer = select_timer();
+ printk(KERN_INFO "Using %s for high-res timesource\n",cur_timer->name);
+
+ time_init_hook();
+}
+#endif
+
+void __init time_init(void)
+{
+#ifdef CONFIG_HPET_TIMER
+ if (is_hpet_capable()) {
+ /*
+ * HPET initialization needs to do memory-mapped io. So, let
+ * us do a late initialization after mem_init().
+ */
+ late_time_init = hpet_time_init;
+ return;
+ }
+#endif
+ xtime.tv_sec = get_cmos_time();
+ xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
+ set_normalized_timespec(&wall_to_monotonic,
+ -xtime.tv_sec, -xtime.tv_nsec);
+
+ cur_timer = select_timer();
+ printk(KERN_INFO "Using %s for high-res timesource\n",cur_timer->name);
+
+ time_init_hook();
+}