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[SPARC64]: More sensible udelay implementation.

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Take a page from the powerpc folks and just calculate the
delay factor directly.

Since frequency scaling chips use a system-tick register,
the value is going to be the same system-wide.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller
2007-07-14 02:23:37 -07:00
parent 27a2ef382c
commit 8b99cfb8cc
10 changed files with 31 additions and 125 deletions
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28
arch/sparc64/kernel/time.c
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@ -849,9 +849,6 @@ static unsigned long sparc64_init_timers(void)
{
struct device_node *dp;
unsigned long clock;
#ifdef CONFIG_SMP
extern void smp_tick_init(void);
#endif
dp = of_find_node_by_path("/");
if (tlb_type == spitfire) {
@ -874,10 +871,6 @@ static unsigned long sparc64_init_timers(void)
clock = of_getintprop_default(dp, "stick-frequency", 0);
}
#ifdef CONFIG_SMP
smp_tick_init();
#endif
return clock;
}
@ -1038,10 +1031,31 @@ static void __init setup_clockevent_multiplier(unsigned long hz)
sparc64_clockevent.mult = mult;
}
static unsigned long tb_ticks_per_usec __read_mostly;
void __delay(unsigned long loops)
{
unsigned long bclock, now;
bclock = tick_ops->get_tick();
do {
now = tick_ops->get_tick();
} while ((now-bclock) < loops);
}
EXPORT_SYMBOL(__delay);
void udelay(unsigned long usecs)
{
__delay(tb_ticks_per_usec * usecs);
}
EXPORT_SYMBOL(udelay);
void __init time_init(void)
{
unsigned long clock = sparc64_init_timers();
tb_ticks_per_usec = clock / USEC_PER_SEC;
timer_ticks_per_nsec_quotient =
clocksource_hz2mult(clock, SPARC64_NSEC_PER_CYC_SHIFT);