[SPARC64]: More sensible udelay implementation.

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>

1 files changed, 21 insertions, 7 deletions

diff --git a/arch/sparc64/kernel/time.c b/arch/sparc64/kernel/time.c
index a31a0439244f..62e316ab1339 100644
--- a/arch/sparc64/kernel/time.c
+++ b/arch/sparc64/kernel/time.c
@@ -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);