forked from Minki/linux
[PARISC] GENERIC_TIME patchset for parisc
Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
This commit is contained in:
Helge Deller
Kyle McMartin
parent
df47b4386a
commit
12df29b64c
@ -50,6 +50,10 @@ config GENERIC_CALIBRATE_DELAY
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bool
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default y
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config GENERIC_TIME
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bool
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default y
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config TIME_LOW_RES
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bool
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depends on SMP
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@ -22,6 +22,7 @@
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#include <linux/init.h>
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#include <linux/smp.h>
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#include <linux/profile.h>
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#include <linux/clocksource.h>
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#include <asm/uaccess.h>
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#include <asm/io.h>
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@ -172,121 +173,23 @@ unsigned long profile_pc(struct pt_regs *regs)
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EXPORT_SYMBOL(profile_pc);
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/*
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* Return the number of micro-seconds that elapsed since the last
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* update to wall time (aka xtime). The xtime_lock
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* must be at least read-locked when calling this routine.
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*/
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static inline unsigned long gettimeoffset (void)
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/* clock source code */
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static cycle_t read_cr16(void)
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{
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#ifndef CONFIG_SMP
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/*
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* FIXME: This won't work on smp because jiffies are updated by cpu 0.
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* Once parisc-linux learns the cr16 difference between processors,
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* this could be made to work.
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*/
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unsigned long now;
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unsigned long prev_tick;
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unsigned long next_tick;
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unsigned long elapsed_cycles;
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unsigned long usec;
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unsigned long cpuid = smp_processor_id();
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unsigned long cpt = clocktick;
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next_tick = cpu_data[cpuid].it_value;
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now = mfctl(16); /* Read the hardware interval timer. */
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prev_tick = next_tick - cpt;
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/* Assume Scenario 1: "now" is later than prev_tick. */
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elapsed_cycles = now - prev_tick;
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/* aproximate HZ with shifts. Intended math is "(elapsed/clocktick) > HZ" */
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#if HZ == 1000
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if (elapsed_cycles > (cpt << 10) )
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#elif HZ == 250
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if (elapsed_cycles > (cpt << 8) )
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#elif HZ == 100
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if (elapsed_cycles > (cpt << 7) )
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#else
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#warn WTF is HZ set to anyway?
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if (elapsed_cycles > (HZ * cpt) )
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#endif
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{
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/* Scenario 3: clock ticks are missing. */
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printk (KERN_CRIT "gettimeoffset(CPU %ld): missing %ld ticks!"
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" cycles %lX prev/now/next %lX/%lX/%lX clock %lX\n",
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cpuid, elapsed_cycles / cpt,
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elapsed_cycles, prev_tick, now, next_tick, cpt);
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}
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/* FIXME: Can we improve the precision? Not with PAGE0. */
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usec = (elapsed_cycles * 10000) / PAGE0->mem_10msec;
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return usec;
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#else
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return 0;
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#endif
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return get_cycles();
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}
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void
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do_gettimeofday (struct timeval *tv)
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{
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unsigned long flags, seq, usec, sec;
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static struct clocksource clocksource_cr16 = {
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.name = "cr16",
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.rating = 300,
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.read = read_cr16,
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.mask = CLOCKSOURCE_MASK(BITS_PER_LONG),
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.mult = 0, /* to be set */
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.shift = 22,
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.is_continuous = 1,
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};
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/* Hold xtime_lock and adjust timeval. */
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do {
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seq = read_seqbegin_irqsave(&xtime_lock, flags);
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usec = gettimeoffset();
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sec = xtime.tv_sec;
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usec += (xtime.tv_nsec / 1000);
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} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
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/* Move adjusted usec's into sec's. */
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while (usec >= USEC_PER_SEC) {
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usec -= USEC_PER_SEC;
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++sec;
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}
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/* Return adjusted result. */
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tv->tv_sec = sec;
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tv->tv_usec = usec;
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}
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EXPORT_SYMBOL(do_gettimeofday);
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int
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do_settimeofday (struct timespec *tv)
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{
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time_t wtm_sec, sec = tv->tv_sec;
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long wtm_nsec, nsec = tv->tv_nsec;
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if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
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return -EINVAL;
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write_seqlock_irq(&xtime_lock);
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{
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/*
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* This is revolting. We need to set "xtime"
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* correctly. However, the value in this location is
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* the value at the most recent update of wall time.
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* Discover what correction gettimeofday would have
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* done, and then undo it!
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*/
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nsec -= gettimeoffset() * 1000;
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wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
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wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
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set_normalized_timespec(&xtime, sec, nsec);
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set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
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ntp_clear();
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}
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write_sequnlock_irq(&xtime_lock);
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clock_was_set();
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return 0;
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}
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EXPORT_SYMBOL(do_settimeofday);
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/*
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* XXX: We can do better than this.
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@ -312,11 +215,22 @@ void __init start_cpu_itimer(void)
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void __init time_init(void)
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{
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static struct pdc_tod tod_data;
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unsigned long current_cr16_khz;
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clocktick = (100 * PAGE0->mem_10msec) / HZ;
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start_cpu_itimer(); /* get CPU 0 started */
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/* register at clocksource framework */
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current_cr16_khz = PAGE0->mem_10msec/10; /* kHz */
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clocksource_cr16.mult = clocksource_khz2mult(current_cr16_khz,
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clocksource_cr16.shift);
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/* lower the rating if we already know its unstable: */
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if (num_online_cpus()>1)
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clocksource_cr16.rating = 200;
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clocksource_register(&clocksource_cr16);
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if (pdc_tod_read(&tod_data) == 0) {
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unsigned long flags;
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