#include <linux/init.h>
#include <linux/smp.h>
#include <linux/profile.h>
+#include <linux/clocksource.h>
#include <asm/uaccess.h>
#include <asm/io.h>
static unsigned long clocktick __read_mostly; /* timer cycles per tick */
-#ifdef CONFIG_SMP
-extern void smp_do_timer(struct pt_regs *regs);
-#endif
-
/*
* We keep time on PA-RISC Linux by using the Interval Timer which is
* a pair of registers; one is read-only and one is write-only; both
* held off for an arbitrarily long period of time by interrupts being
* disabled, so we may miss one or more ticks.
*/
-irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+irqreturn_t timer_interrupt(int irq, void *dev_id)
{
unsigned long now;
unsigned long next_tick;
unsigned long cycles_elapsed, ticks_elapsed;
unsigned long cycles_remainder;
unsigned int cpu = smp_processor_id();
+ struct cpuinfo_parisc *cpuinfo = &cpu_data[cpu];
/* gcc can optimize for "read-only" case with a local clocktick */
unsigned long cpt = clocktick;
- profile_tick(CPU_PROFILING, regs);
+ profile_tick(CPU_PROFILING);
/* Initialize next_tick to the expected tick time. */
- next_tick = cpu_data[cpu].it_value;
+ next_tick = cpuinfo->it_value;
/* Get current interval timer.
* CR16 reads as 64 bits in CPU wide mode.
* cycles after the IT fires. But it's arbitrary how much time passes
* before we call it "late". I've picked one second.
*/
- if (ticks_elapsed > HZ) {
+ if (unlikely(ticks_elapsed > HZ)) {
/* Scenario 3: very long delay? bad in any case */
printk (KERN_CRIT "timer_interrupt(CPU %d): delayed!"
" cycles %lX rem %lX "
*/
next_tick = now + cycles_remainder;
- cpu_data[cpu].it_value = next_tick;
+ cpuinfo->it_value = next_tick;
/* Skip one clocktick on purpose if we are likely to miss next_tick.
* We want to avoid the new next_tick being less than CR16.
next_tick += cpt;
/* Program the IT when to deliver the next interrupt. */
- /* Only bottom 32-bits of next_tick are written to cr16. */
+ /* Only bottom 32-bits of next_tick are written to cr16. */
mtctl(next_tick, 16);
/* Done mucking with unreliable delivery of interrupts.
* Go do system house keeping.
*/
-#ifdef CONFIG_SMP
- smp_do_timer(regs);
-#else
- update_process_times(user_mode(regs));
-#endif
+
+ if (!--cpuinfo->prof_counter) {
+ cpuinfo->prof_counter = cpuinfo->prof_multiplier;
+ update_process_times(user_mode(get_irq_regs()));
+ }
+
if (cpu == 0) {
write_seqlock(&xtime_lock);
do_timer(ticks_elapsed);
write_sequnlock(&xtime_lock);
}
- /* check soft power switch status */
- if (cpu == 0 && !atomic_read(&power_tasklet.count))
- tasklet_schedule(&power_tasklet);
-
return IRQ_HANDLED;
}
EXPORT_SYMBOL(profile_pc);
-/*
- * Return the number of micro-seconds that elapsed since the last
- * update to wall time (aka xtime). The xtime_lock
- * must be at least read-locked when calling this routine.
- */
-static inline unsigned long gettimeoffset (void)
-{
-#ifndef CONFIG_SMP
- /*
- * FIXME: This won't work on smp because jiffies are updated by cpu 0.
- * Once parisc-linux learns the cr16 difference between processors,
- * this could be made to work.
- */
- unsigned long now;
- unsigned long prev_tick;
- unsigned long next_tick;
- unsigned long elapsed_cycles;
- unsigned long usec;
- unsigned long cpuid = smp_processor_id();
- unsigned long cpt = clocktick;
-
- next_tick = cpu_data[cpuid].it_value;
- now = mfctl(16); /* Read the hardware interval timer. */
-
- prev_tick = next_tick - cpt;
-
- /* Assume Scenario 1: "now" is later than prev_tick. */
- elapsed_cycles = now - prev_tick;
-
-/* aproximate HZ with shifts. Intended math is "(elapsed/clocktick) > HZ" */
-#if HZ == 1000
- if (elapsed_cycles > (cpt << 10) )
-#elif HZ == 250
- if (elapsed_cycles > (cpt << 8) )
-#elif HZ == 100
- if (elapsed_cycles > (cpt << 7) )
-#else
-#warn WTF is HZ set to anyway?
- if (elapsed_cycles > (HZ * cpt) )
-#endif
- {
- /* Scenario 3: clock ticks are missing. */
- printk (KERN_CRIT "gettimeoffset(CPU %ld): missing %ld ticks!"
- " cycles %lX prev/now/next %lX/%lX/%lX clock %lX\n",
- cpuid, elapsed_cycles / cpt,
- elapsed_cycles, prev_tick, now, next_tick, cpt);
- }
-
- /* FIXME: Can we improve the precision? Not with PAGE0. */
- usec = (elapsed_cycles * 10000) / PAGE0->mem_10msec;
- return usec;
-#else
- return 0;
-#endif
-}
+/* clock source code */
-void
-do_gettimeofday (struct timeval *tv)
+static cycle_t read_cr16(void)
{
- unsigned long flags, seq, usec, sec;
-
- /* Hold xtime_lock and adjust timeval. */
- do {
- seq = read_seqbegin_irqsave(&xtime_lock, flags);
- usec = gettimeoffset();
- sec = xtime.tv_sec;
- usec += (xtime.tv_nsec / 1000);
- } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-
- /* Move adjusted usec's into sec's. */
- while (usec >= USEC_PER_SEC) {
- usec -= USEC_PER_SEC;
- ++sec;
- }
-
- /* Return adjusted result. */
- tv->tv_sec = sec;
- tv->tv_usec = usec;
+ return get_cycles();
}
-EXPORT_SYMBOL(do_gettimeofday);
+static struct clocksource clocksource_cr16 = {
+ .name = "cr16",
+ .rating = 300,
+ .read = read_cr16,
+ .mask = CLOCKSOURCE_MASK(BITS_PER_LONG),
+ .mult = 0, /* to be set */
+ .shift = 22,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
-int
-do_settimeofday (struct timespec *tv)
+#ifdef CONFIG_SMP
+int update_cr16_clocksource(void)
{
- 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 -= gettimeoffset() * 1000;
-
- 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);
-
- ntp_clear();
+ /* since the cr16 cycle counters are not synchronized across CPUs,
+ we'll check if we should switch to a safe clocksource: */
+ if (clocksource_cr16.rating != 0 && num_online_cpus() > 1) {
+ clocksource_change_rating(&clocksource_cr16, 0);
+ return 1;
}
- write_sequnlock_irq(&xtime_lock);
- clock_was_set();
+
return 0;
}
-EXPORT_SYMBOL(do_settimeofday);
-
-/*
- * XXX: We can do better than this.
- * Returns nanoseconds
- */
-
-unsigned long long sched_clock(void)
+#else
+int update_cr16_clocksource(void)
{
- return (unsigned long long)jiffies * (1000000000 / HZ);
+ return 0; /* no change */
}
-
+#endif /*CONFIG_SMP*/
void __init start_cpu_itimer(void)
{
void __init time_init(void)
{
static struct pdc_tod tod_data;
+ unsigned long current_cr16_khz;
clocktick = (100 * PAGE0->mem_10msec) / HZ;
start_cpu_itimer(); /* get CPU 0 started */
- if(pdc_tod_read(&tod_data) == 0) {
- write_seqlock_irq(&xtime_lock);
+ /* register at clocksource framework */
+ current_cr16_khz = PAGE0->mem_10msec/10; /* kHz */
+ clocksource_cr16.mult = clocksource_khz2mult(current_cr16_khz,
+ clocksource_cr16.shift);
+ clocksource_register(&clocksource_cr16);
+
+ if (pdc_tod_read(&tod_data) == 0) {
+ unsigned long flags;
+
+ write_seqlock_irqsave(&xtime_lock, flags);
xtime.tv_sec = tod_data.tod_sec;
xtime.tv_nsec = tod_data.tod_usec * 1000;
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
- write_sequnlock_irq(&xtime_lock);
+ write_sequnlock_irqrestore(&xtime_lock, flags);
} else {
printk(KERN_ERR "Error reading tod clock\n");
xtime.tv_sec = 0;