Linux-2.6.12-rc2v2.6.12-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!

1 files changed, 599 insertions, 0 deletions

diff --git a/kernel/time.c b/kernel/time.c
new file mode 100644
index 000000000000..96fd0f499631
--- /dev/null
+++ b/kernel/time.c
@@ -0,0 +1,599 @@
+/*
+ *  linux/kernel/time.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  This file contains the interface functions for the various
+ *  time related system calls: time, stime, gettimeofday, settimeofday,
+ *			       adjtime
+ */
+/*
+ * Modification history kernel/time.c
+ * 
+ * 1993-09-02    Philip Gladstone
+ *      Created file with time related functions from sched.c and adjtimex() 
+ * 1993-10-08    Torsten Duwe
+ *      adjtime interface update and CMOS clock write code
+ * 1995-08-13    Torsten Duwe
+ *      kernel PLL updated to 1994-12-13 specs (rfc-1589)
+ * 1999-01-16    Ulrich Windl
+ *	Introduced error checking for many cases in adjtimex().
+ *	Updated NTP code according to technical memorandum Jan '96
+ *	"A Kernel Model for Precision Timekeeping" by Dave Mills
+ *	Allow time_constant larger than MAXTC(6) for NTP v4 (MAXTC == 10)
+ *	(Even though the technical memorandum forbids it)
+ * 2004-07-14	 Christoph Lameter
+ *	Added getnstimeofday to allow the posix timer functions to return
+ *	with nanosecond accuracy
+ */
+
+#include <linux/module.h>
+#include <linux/timex.h>
+#include <linux/errno.h>
+#include <linux/smp_lock.h>
+#include <linux/syscalls.h>
+#include <linux/security.h>
+#include <linux/fs.h>
+#include <linux/module.h>
+
+#include <asm/uaccess.h>
+#include <asm/unistd.h>
+
+/* 
+ * The timezone where the local system is located.  Used as a default by some
+ * programs who obtain this value by using gettimeofday.
+ */
+struct timezone sys_tz;
+
+EXPORT_SYMBOL(sys_tz);
+
+#ifdef __ARCH_WANT_SYS_TIME
+
+/*
+ * sys_time() can be implemented in user-level using
+ * sys_gettimeofday().  Is this for backwards compatibility?  If so,
+ * why not move it into the appropriate arch directory (for those
+ * architectures that need it).
+ */
+asmlinkage long sys_time(time_t __user * tloc)
+{
+	time_t i;
+	struct timeval tv;
+
+	do_gettimeofday(&tv);
+	i = tv.tv_sec;
+
+	if (tloc) {
+		if (put_user(i,tloc))
+			i = -EFAULT;
+	}
+	return i;
+}
+
+/*
+ * sys_stime() can be implemented in user-level using
+ * sys_settimeofday().  Is this for backwards compatibility?  If so,
+ * why not move it into the appropriate arch directory (for those
+ * architectures that need it).
+ */
+ 
+asmlinkage long sys_stime(time_t __user *tptr)
+{
+	struct timespec tv;
+	int err;
+
+	if (get_user(tv.tv_sec, tptr))
+		return -EFAULT;
+
+	tv.tv_nsec = 0;
+
+	err = security_settime(&tv, NULL);
+	if (err)
+		return err;
+
+	do_settimeofday(&tv);
+	return 0;
+}
+
+#endif /* __ARCH_WANT_SYS_TIME */
+
+asmlinkage long sys_gettimeofday(struct timeval __user *tv, struct timezone __user *tz)
+{
+	if (likely(tv != NULL)) {
+		struct timeval ktv;
+		do_gettimeofday(&ktv);
+		if (copy_to_user(tv, &ktv, sizeof(ktv)))
+			return -EFAULT;
+	}
+	if (unlikely(tz != NULL)) {
+		if (copy_to_user(tz, &sys_tz, sizeof(sys_tz)))
+			return -EFAULT;
+	}
+	return 0;
+}
+
+/*
+ * Adjust the time obtained from the CMOS to be UTC time instead of
+ * local time.
+ * 
+ * This is ugly, but preferable to the alternatives.  Otherwise we
+ * would either need to write a program to do it in /etc/rc (and risk
+ * confusion if the program gets run more than once; it would also be 
+ * hard to make the program warp the clock precisely n hours)  or
+ * compile in the timezone information into the kernel.  Bad, bad....
+ *
+ *              				- TYT, 1992-01-01
+ *
+ * The best thing to do is to keep the CMOS clock in universal time (UTC)
+ * as real UNIX machines always do it. This avoids all headaches about
+ * daylight saving times and warping kernel clocks.
+ */
+inline static void warp_clock(void)
+{
+	write_seqlock_irq(&xtime_lock);
+	wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60;
+	xtime.tv_sec += sys_tz.tz_minuteswest * 60;
+	time_interpolator_reset();
+	write_sequnlock_irq(&xtime_lock);
+	clock_was_set();
+}
+
+/*
+ * In case for some reason the CMOS clock has not already been running
+ * in UTC, but in some local time: The first time we set the timezone,
+ * we will warp the clock so that it is ticking UTC time instead of
+ * local time. Presumably, if someone is setting the timezone then we
+ * are running in an environment where the programs understand about
+ * timezones. This should be done at boot time in the /etc/rc script,
+ * as soon as possible, so that the clock can be set right. Otherwise,
+ * various programs will get confused when the clock gets warped.
+ */
+
+int do_sys_settimeofday(struct timespec *tv, struct timezone *tz)
+{
+	static int firsttime = 1;
+	int error = 0;
+
+	error = security_settime(tv, tz);
+	if (error)
+		return error;
+
+	if (tz) {
+		/* SMP safe, global irq locking makes it work. */
+		sys_tz = *tz;
+		if (firsttime) {
+			firsttime = 0;
+			if (!tv)
+				warp_clock();
+		}
+	}
+	if (tv)
+	{
+		/* SMP safe, again the code in arch/foo/time.c should
+		 * globally block out interrupts when it runs.
+		 */
+		return do_settimeofday(tv);
+	}
+	return 0;
+}
+
+asmlinkage long sys_settimeofday(struct timeval __user *tv,
+				struct timezone __user *tz)
+{
+	struct timeval user_tv;
+	struct timespec	new_ts;
+	struct timezone new_tz;
+
+	if (tv) {
+		if (copy_from_user(&user_tv, tv, sizeof(*tv)))
+			return -EFAULT;
+		new_ts.tv_sec = user_tv.tv_sec;
+		new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;
+	}
+	if (tz) {
+		if (copy_from_user(&new_tz, tz, sizeof(*tz)))
+			return -EFAULT;
+	}
+
+	return do_sys_settimeofday(tv ? &new_ts : NULL, tz ? &new_tz : NULL);
+}
+
+long pps_offset;		/* pps time offset (us) */
+long pps_jitter = MAXTIME;	/* time dispersion (jitter) (us) */
+
+long pps_freq;			/* frequency offset (scaled ppm) */
+long pps_stabil = MAXFREQ;	/* frequency dispersion (scaled ppm) */
+
+long pps_valid = PPS_VALID;	/* pps signal watchdog counter */
+
+int pps_shift = PPS_SHIFT;	/* interval duration (s) (shift) */
+
+long pps_jitcnt;		/* jitter limit exceeded */
+long pps_calcnt;		/* calibration intervals */
+long pps_errcnt;		/* calibration errors */
+long pps_stbcnt;		/* stability limit exceeded */
+
+/* hook for a loadable hardpps kernel module */
+void (*hardpps_ptr)(struct timeval *);
+
+/* we call this to notify the arch when the clock is being
+ * controlled.  If no such arch routine, do nothing.
+ */
+void __attribute__ ((weak)) notify_arch_cmos_timer(void)
+{
+	return;
+}
+
+/* adjtimex mainly allows reading (and writing, if superuser) of
+ * kernel time-keeping variables. used by xntpd.
+ */
+int do_adjtimex(struct timex *txc)
+{
+        long ltemp, mtemp, save_adjust;
+	int result;
+
+	/* In order to modify anything, you gotta be super-user! */
+	if (txc->modes && !capable(CAP_SYS_TIME))
+		return -EPERM;
+		
+	/* Now we validate the data before disabling interrupts */
+
+	if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
+	  /* singleshot must not be used with any other mode bits */
+		if (txc->modes != ADJ_OFFSET_SINGLESHOT)
+			return -EINVAL;
+
+	if (txc->modes != ADJ_OFFSET_SINGLESHOT && (txc->modes & ADJ_OFFSET))
+	  /* adjustment Offset limited to +- .512 seconds */
+		if (txc->offset <= - MAXPHASE || txc->offset >= MAXPHASE )
+			return -EINVAL;	
+
+	/* if the quartz is off by more than 10% something is VERY wrong ! */
+	if (txc->modes & ADJ_TICK)
+		if (txc->tick <  900000/USER_HZ ||
+		    txc->tick > 1100000/USER_HZ)
+			return -EINVAL;
+
+	write_seqlock_irq(&xtime_lock);
+	result = time_state;	/* mostly `TIME_OK' */
+
+	/* Save for later - semantics of adjtime is to return old value */
+	save_adjust = time_next_adjust ? time_next_adjust : time_adjust;
+
+#if 0	/* STA_CLOCKERR is never set yet */
+	time_status &= ~STA_CLOCKERR;		/* reset STA_CLOCKERR */
+#endif
+	/* If there are input parameters, then process them */
+	if (txc->modes)
+	{
+	    if (txc->modes & ADJ_STATUS)	/* only set allowed bits */
+		time_status =  (txc->status & ~STA_RONLY) |
+			      (time_status & STA_RONLY);
+
+	    if (txc->modes & ADJ_FREQUENCY) {	/* p. 22 */
+		if (txc->freq > MAXFREQ || txc->freq < -MAXFREQ) {
+		    result = -EINVAL;
+		    goto leave;
+		}
+		time_freq = txc->freq - pps_freq;
+	    }
+
+	    if (txc->modes & ADJ_MAXERROR) {
+		if (txc->maxerror < 0 || txc->maxerror >= NTP_PHASE_LIMIT) {
+		    result = -EINVAL;
+		    goto leave;
+		}
+		time_maxerror = txc->maxerror;
+	    }
+
+	    if (txc->modes & ADJ_ESTERROR) {
+		if (txc->esterror < 0 || txc->esterror >= NTP_PHASE_LIMIT) {
+		    result = -EINVAL;
+		    goto leave;
+		}
+		time_esterror = txc->esterror;
+	    }
+
+	    if (txc->modes & ADJ_TIMECONST) {	/* p. 24 */
+		if (txc->constant < 0) {	/* NTP v4 uses values > 6 */
+		    result = -EINVAL;
+		    goto leave;
+		}
+		time_constant = txc->constant;
+	    }
+
+	    if (txc->modes & ADJ_OFFSET) {	/* values checked earlier */
+		if (txc->modes == ADJ_OFFSET_SINGLESHOT) {
+		    /* adjtime() is independent from ntp_adjtime() */
+		    if ((time_next_adjust = txc->offset) == 0)
+			 time_adjust = 0;
+		}
+		else if ( time_status & (STA_PLL | STA_PPSTIME) ) {
+		    ltemp = (time_status & (STA_PPSTIME | STA_PPSSIGNAL)) ==
+		            (STA_PPSTIME | STA_PPSSIGNAL) ?
+		            pps_offset : txc->offset;
+
+		    /*
+		     * Scale the phase adjustment and
+		     * clamp to the operating range.
+		     */
+		    if (ltemp > MAXPHASE)
+		        time_offset = MAXPHASE << SHIFT_UPDATE;
+		    else if (ltemp < -MAXPHASE)
+			time_offset = -(MAXPHASE << SHIFT_UPDATE);
+		    else
+		        time_offset = ltemp << SHIFT_UPDATE;
+
+		    /*
+		     * Select whether the frequency is to be controlled
+		     * and in which mode (PLL or FLL). Clamp to the operating
+		     * range. Ugly multiply/divide should be replaced someday.
+		     */
+
+		    if (time_status & STA_FREQHOLD || time_reftime == 0)
+		        time_reftime = xtime.tv_sec;
+		    mtemp = xtime.tv_sec - time_reftime;
+		    time_reftime = xtime.tv_sec;
+		    if (time_status & STA_FLL) {
+		        if (mtemp >= MINSEC) {
+			    ltemp = (time_offset / mtemp) << (SHIFT_USEC -
+							      SHIFT_UPDATE);
+			    if (ltemp < 0)
+			        time_freq -= -ltemp >> SHIFT_KH;
+			    else
+			        time_freq += ltemp >> SHIFT_KH;
+			} else /* calibration interval too short (p. 12) */
+				result = TIME_ERROR;
+		    } else {	/* PLL mode */
+		        if (mtemp < MAXSEC) {
+			    ltemp *= mtemp;
+			    if (ltemp < 0)
+			        time_freq -= -ltemp >> (time_constant +
+							time_constant +
+							SHIFT_KF - SHIFT_USEC);
+			    else
+			        time_freq += ltemp >> (time_constant +
+						       time_constant +
+						       SHIFT_KF - SHIFT_USEC);
+			} else /* calibration interval too long (p. 12) */
+				result = TIME_ERROR;
+		    }
+		    if (time_freq > time_tolerance)
+		        time_freq = time_tolerance;
+		    else if (time_freq < -time_tolerance)
+		        time_freq = -time_tolerance;
+		} /* STA_PLL || STA_PPSTIME */
+	    } /* txc->modes & ADJ_OFFSET */
+	    if (txc->modes & ADJ_TICK) {
+		tick_usec = txc->tick;
+		tick_nsec = TICK_USEC_TO_NSEC(tick_usec);
+	    }
+	} /* txc->modes */
+leave:	if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0
+	    || ((time_status & (STA_PPSFREQ|STA_PPSTIME)) != 0
+		&& (time_status & STA_PPSSIGNAL) == 0)
+	    /* p. 24, (b) */
+	    || ((time_status & (STA_PPSTIME|STA_PPSJITTER))
+		== (STA_PPSTIME|STA_PPSJITTER))
+	    /* p. 24, (c) */
+	    || ((time_status & STA_PPSFREQ) != 0
+		&& (time_status & (STA_PPSWANDER|STA_PPSERROR)) != 0))
+	    /* p. 24, (d) */
+		result = TIME_ERROR;
+	
+	if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
+	    txc->offset	   = save_adjust;
+	else {
+	    if (time_offset < 0)
+		txc->offset = -(-time_offset >> SHIFT_UPDATE);
+	    else
+		txc->offset = time_offset >> SHIFT_UPDATE;
+	}
+	txc->freq	   = time_freq + pps_freq;
+	txc->maxerror	   = time_maxerror;
+	txc->esterror	   = time_esterror;
+	txc->status	   = time_status;
+	txc->constant	   = time_constant;
+	txc->precision	   = time_precision;
+	txc->tolerance	   = time_tolerance;
+	txc->tick	   = tick_usec;
+	txc->ppsfreq	   = pps_freq;
+	txc->jitter	   = pps_jitter >> PPS_AVG;
+	txc->shift	   = pps_shift;
+	txc->stabil	   = pps_stabil;
+	txc->jitcnt	   = pps_jitcnt;
+	txc->calcnt	   = pps_calcnt;
+	txc->errcnt	   = pps_errcnt;
+	txc->stbcnt	   = pps_stbcnt;
+	write_sequnlock_irq(&xtime_lock);
+	do_gettimeofday(&txc->time);
+	notify_arch_cmos_timer();
+	return(result);
+}
+
+asmlinkage long sys_adjtimex(struct timex __user *txc_p)
+{
+	struct timex txc;		/* Local copy of parameter */
+	int ret;
+
+	/* Copy the user data space into the kernel copy
+	 * structure. But bear in mind that the structures
+	 * may change
+	 */
+	if(copy_from_user(&txc, txc_p, sizeof(struct timex)))
+		return -EFAULT;
+	ret = do_adjtimex(&txc);
+	return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret;
+}
+
+inline struct timespec current_kernel_time(void)
+{
+        struct timespec now;
+        unsigned long seq;
+
+	do {
+		seq = read_seqbegin(&xtime_lock);
+		
+		now = xtime;
+	} while (read_seqretry(&xtime_lock, seq));
+
+	return now; 
+}
+
+EXPORT_SYMBOL(current_kernel_time);
+
+/**
+ * current_fs_time - Return FS time
+ * @sb: Superblock.
+ *
+ * Return the current time truncated to the time granuality supported by
+ * the fs.
+ */
+struct timespec current_fs_time(struct super_block *sb)
+{
+	struct timespec now = current_kernel_time();
+	return timespec_trunc(now, sb->s_time_gran);
+}
+EXPORT_SYMBOL(current_fs_time);
+
+/**
+ * timespec_trunc - Truncate timespec to a granuality
+ * @t: Timespec
+ * @gran: Granuality in ns.
+ *
+ * Truncate a timespec to a granuality. gran must be smaller than a second.
+ * Always rounds down.
+ *
+ * This function should be only used for timestamps returned by
+ * current_kernel_time() or CURRENT_TIME, not with do_gettimeofday() because
+ * it doesn't handle the better resolution of the later.
+ */
+struct timespec timespec_trunc(struct timespec t, unsigned gran)
+{
+	/*
+	 * Division is pretty slow so avoid it for common cases.
+	 * Currently current_kernel_time() never returns better than
+	 * jiffies resolution. Exploit that.
+	 */
+	if (gran <= jiffies_to_usecs(1) * 1000) {
+		/* nothing */
+	} else if (gran == 1000000000) {
+		t.tv_nsec = 0;
+	} else {
+		t.tv_nsec -= t.tv_nsec % gran;
+	}
+	return t;
+}
+EXPORT_SYMBOL(timespec_trunc);
+
+#ifdef CONFIG_TIME_INTERPOLATION
+void getnstimeofday (struct timespec *tv)
+{
+	unsigned long seq,sec,nsec;
+
+	do {
+		seq = read_seqbegin(&xtime_lock);
+		sec = xtime.tv_sec;
+		nsec = xtime.tv_nsec+time_interpolator_get_offset();
+	} while (unlikely(read_seqretry(&xtime_lock, seq)));
+
+	while (unlikely(nsec >= NSEC_PER_SEC)) {
+		nsec -= NSEC_PER_SEC;
+		++sec;
+	}
+	tv->tv_sec = sec;
+	tv->tv_nsec = nsec;
+}
+EXPORT_SYMBOL_GPL(getnstimeofday);
+
+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 done, and then undo
+		 * it!
+		 */
+		nsec -= time_interpolator_get_offset();
+
+		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;
+		time_interpolator_reset();
+	}
+	write_sequnlock_irq(&xtime_lock);
+	clock_was_set();
+	return 0;
+}
+
+void do_gettimeofday (struct timeval *tv)
+{
+	unsigned long seq, nsec, usec, sec, offset;
+	do {
+		seq = read_seqbegin(&xtime_lock);
+		offset = time_interpolator_get_offset();
+		sec = xtime.tv_sec;
+		nsec = xtime.tv_nsec;
+	} while (unlikely(read_seqretry(&xtime_lock, seq)));
+
+	usec = (nsec + offset) / 1000;
+
+	while (unlikely(usec >= USEC_PER_SEC)) {
+		usec -= USEC_PER_SEC;
+		++sec;
+	}
+
+	tv->tv_sec = sec;
+	tv->tv_usec = usec;
+}
+
+EXPORT_SYMBOL(do_gettimeofday);
+
+
+#else
+/*
+ * Simulate gettimeofday using do_gettimeofday which only allows a timeval
+ * and therefore only yields usec accuracy
+ */
+void getnstimeofday(struct timespec *tv)
+{
+	struct timeval x;
+
+	do_gettimeofday(&x);
+	tv->tv_sec = x.tv_sec;
+	tv->tv_nsec = x.tv_usec * NSEC_PER_USEC;
+}
+#endif
+
+#if (BITS_PER_LONG < 64)
+u64 get_jiffies_64(void)
+{
+	unsigned long seq;
+	u64 ret;
+
+	do {
+		seq = read_seqbegin(&xtime_lock);
+		ret = jiffies_64;
+	} while (read_seqretry(&xtime_lock, seq));
+	return ret;
+}
+
+EXPORT_SYMBOL(get_jiffies_64);
+#endif
+
+EXPORT_SYMBOL(jiffies);