X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fia64%2Fsn%2Fkernel%2Fsn2%2Ftimer.c;h=56a88b6df4b41fbca0df635ab5fc23988b0298b4;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=57844feea36113ac92fea0319799ec3d147ebc8c;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git

diff --git a/arch/ia64/sn/kernel/sn2/timer.c b/arch/ia64/sn/kernel/sn2/timer.c
index 57844feea..56a88b6df 100644
--- a/arch/ia64/sn/kernel/sn2/timer.c
+++ b/arch/ia64/sn/kernel/sn2/timer.c
@@ -14,63 +14,42 @@
 
 #include <asm/hw_irq.h>
 #include <asm/system.h>
+#include <asm/timex.h>
 
 #include <asm/sn/leds.h>
+#include <asm/sn/shub_mmr.h>
 #include <asm/sn/clksupport.h>
 
-
 extern unsigned long sn_rtc_cycles_per_second;
-static volatile unsigned long last_wall_rtc;
-
-static unsigned long rtc_offset;	/* updated only when xtime write-lock is held! */
-static long rtc_nsecs_per_cycle;
-static long rtc_per_timer_tick;
-
-static unsigned long
-getoffset(void)
-{
-	return rtc_offset + (GET_RTC_COUNTER() - last_wall_rtc)*rtc_nsecs_per_cycle;
-}
 
+static struct time_interpolator sn2_interpolator = {
+	.drift = -1,
+	.shift = 10,
+	.mask = (1LL << 55) - 1,
+	.source = TIME_SOURCE_MMIO64
+};
 
+/*
+ * sn udelay uses the RTC instead of the ITC because the ITC is not
+ * synchronized across all CPUs, and the thread may migrate to another CPU
+ * if preemption is enabled.
+ */
 static void
-update(long delta_nsec)
+ia64_sn_udelay (unsigned long usecs)
 {
-	unsigned long rtc_counter = GET_RTC_COUNTER();
-	unsigned long offset = rtc_offset + (rtc_counter - last_wall_rtc)*rtc_nsecs_per_cycle;
+	unsigned long start = rtc_time();
+	unsigned long end = start +
+			usecs * sn_rtc_cycles_per_second / 1000000;
 
-	/* Be careful about signed/unsigned comparisons here: */
-	if (delta_nsec < 0 || (unsigned long) delta_nsec < offset)
-		rtc_offset = offset - delta_nsec;
-	else
-		rtc_offset = 0;
-	last_wall_rtc = rtc_counter;
+	while (time_before((unsigned long)rtc_time(), end))
+		cpu_relax();
 }
 
-
-static void
-reset(void)
-{
-	rtc_offset = 0;
-	last_wall_rtc = GET_RTC_COUNTER();
-}
-
-
-static struct time_interpolator sn2_interpolator = {
-	.get_offset =	getoffset,
-	.update =	update,
-	.reset =	reset
-};
-
-void __init
-sn_timer_init(void)
+void __init sn_timer_init(void)
 {
 	sn2_interpolator.frequency = sn_rtc_cycles_per_second;
-	sn2_interpolator.drift = -1;	/* unknown */
+	sn2_interpolator.addr = RTC_COUNTER_ADDR;
 	register_time_interpolator(&sn2_interpolator);
 
-	rtc_per_timer_tick = sn_rtc_cycles_per_second / HZ;
-	rtc_nsecs_per_cycle = 1000000000 / sn_rtc_cycles_per_second;
-
-	last_wall_rtc = GET_RTC_COUNTER();
+	ia64_udelay = &ia64_sn_udelay;
 }