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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/frv/kernel/time.c
downloadlinux-stericsson-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
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!
Diffstat (limited to 'arch/frv/kernel/time.c')
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diff --git a/arch/frv/kernel/time.c b/arch/frv/kernel/time.c
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+/* time.c: FRV arch-specific time handling
+ *
+ * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ * - Derived from arch/m68k/kernel/time.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.h> /* CONFIG_HEARTBEAT */
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/string.h>
+#include <linux/interrupt.h>
+#include <linux/profile.h>
+#include <linux/irq.h>
+#include <linux/mm.h>
+
+#include <asm/io.h>
+#include <asm/timer-regs.h>
+#include <asm/mb-regs.h>
+#include <asm/mb86943a.h>
+#include <asm/irq-routing.h>
+
+#include <linux/timex.h>
+
+#define TICK_SIZE (tick_nsec / 1000)
+
+extern unsigned long wall_jiffies;
+
+u64 jiffies_64 = INITIAL_JIFFIES;
+EXPORT_SYMBOL(jiffies_64);
+
+unsigned long __nongprelbss __clkin_clock_speed_HZ;
+unsigned long __nongprelbss __ext_bus_clock_speed_HZ;
+unsigned long __nongprelbss __res_bus_clock_speed_HZ;
+unsigned long __nongprelbss __sdram_clock_speed_HZ;
+unsigned long __nongprelbss __core_bus_clock_speed_HZ;
+unsigned long __nongprelbss __core_clock_speed_HZ;
+unsigned long __nongprelbss __dsu_clock_speed_HZ;
+unsigned long __nongprelbss __serial_clock_speed_HZ;
+unsigned long __delay_loops_MHz;
+
+static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs *regs);
+
+static struct irqaction timer_irq = {
+ timer_interrupt, SA_INTERRUPT, CPU_MASK_NONE, "timer", NULL, NULL
+};
+
+static inline int set_rtc_mmss(unsigned long nowtime)
+{
+ return -1;
+}
+
+/*
+ * timer_interrupt() needs to keep up the real-time clock,
+ * as well as call the "do_timer()" routine every clocktick
+ */
+static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
+{
+ /* last time the cmos clock got updated */
+ static long last_rtc_update = 0;
+
+ /*
+ * 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);
+
+ do_timer(regs);
+ update_process_times(user_mode(regs));
+ profile_tick(CPU_PROFILING, regs);
+
+ /*
+ * 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.
+ */
+ if ((time_status & STA_UNSYNC) == 0 &&
+ xtime.tv_sec > last_rtc_update + 660 &&
+ (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
+ (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2
+ ) {
+ if (set_rtc_mmss(xtime.tv_sec) == 0)
+ last_rtc_update = xtime.tv_sec;
+ else
+ last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
+ }
+
+#ifdef CONFIG_HEARTBEAT
+ static unsigned short n;
+ n++;
+ __set_LEDS(n);
+#endif /* CONFIG_HEARTBEAT */
+
+ write_sequnlock(&xtime_lock);
+ return IRQ_HANDLED;
+}
+
+void time_divisor_init(void)
+{
+ unsigned short base, pre, prediv;
+
+ /* set the scheduling timer going */
+ pre = 1;
+ prediv = 4;
+ base = __res_bus_clock_speed_HZ / pre / HZ / (1 << prediv);
+
+ __set_TPRV(pre);
+ __set_TxCKSL_DATA(0, prediv);
+ __set_TCTR(TCTR_SC_CTR0 | TCTR_RL_RW_LH8 | TCTR_MODE_2);
+ __set_TCSR_DATA(0, base & 0xff);
+ __set_TCSR_DATA(0, base >> 8);
+}
+
+void time_init(void)
+{
+ unsigned int year, mon, day, hour, min, sec;
+
+ extern void arch_gettod(int *year, int *mon, int *day, int *hour, int *min, int *sec);
+
+ /* FIX by dqg : Set to zero for platforms that don't have tod */
+ /* without this time is undefined and can overflow time_t, causing */
+ /* very stange errors */
+ year = 1980;
+ mon = day = 1;
+ hour = min = sec = 0;
+ arch_gettod (&year, &mon, &day, &hour, &min, &sec);
+
+ if ((year += 1900) < 1970)
+ year += 100;
+ xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
+ xtime.tv_nsec = 0;
+
+ /* install scheduling interrupt handler */
+ setup_irq(IRQ_CPU_TIMER0, &timer_irq);
+
+ time_divisor_init();
+}
+
+/*
+ * This version of gettimeofday has near microsecond resolution.
+ */
+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 = 0;
+ 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;
+}
+
+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 -= 0 * 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;
+}
+
+/*
+ * Scheduler clock - returns current time in nanosec units.
+ */
+unsigned long long sched_clock(void)
+{
+ return jiffies_64 * (1000000000 / HZ);
+}