* Copyright (c) 2002 Vojtech Pavlik
* Copyright (c) 2003 Andi Kleen
* RTC support code taken from arch/i386/kernel/timers/time_hpet.c
- *
*/
#include <linux/kernel.h>
#include <asm/timex.h>
#include <asm/proto.h>
#include <asm/hpet.h>
+#include <asm/sections.h>
#include <linux/cpufreq.h>
#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/apic.h>
EXPORT_SYMBOL(jiffies_64);
+#ifdef CONFIG_CPU_FREQ
+static void cpufreq_delayed_get(void);
+#endif
+
extern int using_apic_timer;
spinlock_t rtc_lock = SPIN_LOCK_UNLOCKED;
* timer interrupt has happened already, but vxtime.trigger wasn't updated yet.
* This is not a problem, because jiffies hasn't updated either. They are bound
* together by xtime_lock.
- */
+ */
static inline unsigned int do_gettimeoffset_tsc(void)
{
usec = xtime.tv_nsec / 1000;
/* i386 does some correction here to keep the clock
- monotonus even when ntpd is fixing drift.
+ monotonous even when ntpd is fixing drift.
But they didn't work for me, there is a non monotonic
clock anyways with ntp.
I dropped all corrections now until a real solution can
EXPORT_SYMBOL(do_settimeofday);
+unsigned long profile_pc(struct pt_regs *regs)
+{
+ unsigned long pc = instruction_pointer(regs);
+
+ /* Assume the lock function has either no stack frame or only a single word.
+ This checks if the address on the stack looks like a kernel text address.
+ There is a small window for false hits, but in that case the tick
+ is just accounted to the spinlock function.
+ Better would be to write these functions in assembler again
+ and check exactly. */
+ if (in_lock_functions(pc)) {
+ char *v = *(char **)regs->rsp;
+ if ((v >= _stext && v <= _etext) ||
+ (v >= _sinittext && v <= _einittext) ||
+ (v >= (char *)MODULES_VADDR && v <= (char *)MODULES_END))
+ return (unsigned long)v;
+ return ((unsigned long *)regs->rsp)[1];
+ }
+ return pc;
+}
+EXPORT_SYMBOL(profile_pc);
+
/*
* In order to set the CMOS clock precisely, set_rtc_mmss has to be called 500
* ms after the second nowtime has started, because when nowtime is written
* overflow. This avoids messing with unknown time zones but requires your RTC
* not to be off by more than 15 minutes. Since we're calling it only when
* our clock is externally synchronized using NTP, this shouldn't be a problem.
- */
+ */
real_seconds = nowtime % 60;
real_minutes = nowtime / 60;
}
EXPORT_SYMBOL(monotonic_clock);
+static noinline void handle_lost_ticks(int lost, struct pt_regs *regs)
+{
+ static long lost_count;
+ static int warned;
+
+ if (report_lost_ticks) {
+ printk(KERN_WARNING "time.c: Lost %d timer "
+ "tick(s)! ", lost);
+ print_symbol("rip %s)\n", regs->rip);
+ }
+
+ if (lost_count == 100 && !warned) {
+ printk(KERN_WARNING
+ "warning: many lost ticks.\n"
+ KERN_WARNING "Your time source seems to be instable or "
+ "some driver is hogging interupts\n");
+ print_symbol("rip %s\n", regs->rip);
+ if (vxtime.mode == VXTIME_TSC && vxtime.hpet_address) {
+ printk(KERN_WARNING "Falling back to HPET\n");
+ vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
+ vxtime.mode = VXTIME_HPET;
+ do_gettimeoffset = do_gettimeoffset_hpet;
+ }
+ /* else should fall back to PIT, but code missing. */
+ warned = 1;
+ } else
+ lost_count++;
+
+#ifdef CONFIG_CPU_FREQ
+ /* In some cases the CPU can change frequency without us noticing
+ (like going into thermal throttle)
+ Give cpufreq a change to catch up. */
+ if ((lost_count+1) % 25 == 0) {
+ cpufreq_delayed_get();
+ }
+#endif
+}
static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
static unsigned long rtc_update = 0;
- unsigned long tsc, lost = 0;
- int delay, offset = 0;
+ unsigned long tsc;
+ int delay, offset = 0, lost = 0;
/*
* Here we are in the timer irq handler. We have irqs locally disabled (so we
* don't need spin_lock_irqsave()) but we don't know if the timer_bh is running
* on the other CPU, so we need a lock. We also need to lock the vsyscall
* variables, because both do_timer() and us change them -arca+vojtech
- */
+ */
write_seqlock(&xtime_lock);
(((long) offset << 32) / vxtime.tsc_quot) - 1;
}
- if (lost) {
- if (report_lost_ticks) {
- printk(KERN_WARNING "time.c: Lost %ld timer "
- "tick(s)! ", lost);
- print_symbol("rip %s)\n", regs->rip);
- }
+ if (lost > 0) {
+ handle_lost_ticks(lost, regs);
jiffies += lost;
}
*/
#ifndef CONFIG_X86_LOCAL_APIC
- x86_do_profile(regs);
+ profile_tick(CPU_PROFILING, regs);
#else
if (!using_apic_timer)
smp_local_timer_interrupt(regs);
Should fix up last_tsc too. Currently gettimeofday in the
first tick after the change will be slightly wrong. */
+#include <linux/workqueue.h>
+
+static unsigned int cpufreq_delayed_issched = 0;
+static unsigned int cpufreq_init = 0;
+static struct work_struct cpufreq_delayed_get_work;
+
+static void handle_cpufreq_delayed_get(void *v)
+{
+ unsigned int cpu;
+ for_each_online_cpu(cpu) {
+ cpufreq_get(cpu);
+ }
+ cpufreq_delayed_issched = 0;
+}
+
+/* if we notice lost ticks, schedule a call to cpufreq_get() as it tries
+ * to verify the CPU frequency the timing core thinks the CPU is running
+ * at is still correct.
+ */
+static void cpufreq_delayed_get(void)
+{
+ static int warned;
+ if (cpufreq_init && !cpufreq_delayed_issched) {
+ cpufreq_delayed_issched = 1;
+ if (!warned) {
+ warned = 1;
+ printk(KERN_DEBUG "Losing some ticks... checking if CPU frequency changed.\n");
+ }
+ schedule_work(&cpufreq_delayed_get_work);
+ }
+}
+
static unsigned int ref_freq = 0;
static unsigned long loops_per_jiffy_ref = 0;
void *data)
{
struct cpufreq_freqs *freq = data;
- unsigned long *lpj;
+ unsigned long *lpj, dummy;
+ lpj = &dummy;
+ if (!(freq->flags & CPUFREQ_CONST_LOOPS))
#ifdef CONFIG_SMP
lpj = &cpu_data[freq->cpu].loops_per_jiffy;
#else
lpj = &boot_cpu_data.loops_per_jiffy;
#endif
+
+
if (!ref_freq) {
ref_freq = freq->old;
loops_per_jiffy_ref = *lpj;
cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new);
cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new);
- vxtime.tsc_quot = (1000L << 32) / cpu_khz;
+ if (!(freq->flags & CPUFREQ_CONST_LOOPS))
+ vxtime.tsc_quot = (1000L << 32) / cpu_khz;
}
set_cyc2ns_scale(cpu_khz_ref / 1000);
static struct notifier_block time_cpufreq_notifier_block = {
.notifier_call = time_cpufreq_notifier
};
+
+static int __init cpufreq_tsc(void)
+{
+ INIT_WORK(&cpufreq_delayed_get_work, handle_cpufreq_delayed_get, NULL);
+ if (!cpufreq_register_notifier(&time_cpufreq_notifier_block,
+ CPUFREQ_TRANSITION_NOTIFIER))
+ cpufreq_init = 1;
+ return 0;
+}
+
+core_initcall(cpufreq_tsc);
+
#endif
/*
outl(0x800038a0, 0xcf8);
outl(0xff000001, 0xcfc);
outl(0x800038a0, 0xcf8);
- hpet_address = inl(0xcfc) & 0xfffffffe;
+ vxtime.hpet_address = inl(0xcfc) & 0xfffffffe;
printk(KERN_WARNING "time.c: WARNING: Enabled HPET "
- "at %#lx.\n", hpet_address);
+ "at %#lx.\n", vxtime.hpet_address);
}
#endif
if (nohpet)
cpu_khz = hpet_calibrate_tsc();
timename = "HPET";
} else {
- pit_init();
- cpu_khz = pit_calibrate_tsc();
+ pit_init();
+ cpu_khz = pit_calibrate_tsc();
timename = "PIT";
}
setup_irq(0, &irq0);
set_cyc2ns_scale(cpu_khz / 1000);
-
-#ifdef CONFIG_CPU_FREQ
- cpufreq_register_notifier(&time_cpufreq_notifier_block,
- CPUFREQ_TRANSITION_NOTIFIER);
-#endif
}
void __init time_init_smp(void)
static int time_resume(struct sys_device *dev)
{
+ unsigned long flags;
unsigned long sec = get_cmos_time() + clock_cmos_diff;
- write_seqlock_irq(&xtime_lock);
+ write_seqlock_irqsave(&xtime_lock,flags);
xtime.tv_sec = sec;
xtime.tv_nsec = 0;
- write_sequnlock_irq(&xtime_lock);
+ write_sequnlock_irqrestore(&xtime_lock,flags);
return 0;
}
}
#endif
+
+
static int __init nohpet_setup(char *s)
{
nohpet = 1;
git://git.onelab.eu / linux-2.6.git / blobdiff