alpha: convert to use arch_gettimeoffset()

Converts alpha to use GENERIC_TIME via the arch_getoffset()
infrastructure, reducing the amount of arch specific code we need to
maintain.

I suspect the alpha arch could even be further improved to provide and
rpcc() based clocksource, but not having the hardware, I don't feel
comfortable attempting the more complicated conversion (but I'd be glad to
help if anyone else is interested).

[akpm@linux-foundation.org: fix build]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 15 insertions, 72 deletions

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 9fb8aae5c391..443448154f32 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -45,6 +45,14 @@ config GENERIC_CALIBRATE_DELAY
         bool
         default y
 
+config GENERIC_TIME
+        bool
+        default y
+
+config ARCH_USES_GETTIMEOFFSET
+        bool
+        default y
+
 config ZONE_DMA
         bool
         default y
diff --git a/arch/alpha/kernel/time.c b/arch/alpha/kernel/time.c
index b04e2cbf23a4..5d0826654c61 100644
--- a/arch/alpha/kernel/time.c
+++ b/arch/alpha/kernel/time.c
@@ -408,28 +408,17 @@ time_init(void)
  * part.  So we can't do the "find absolute time in terms of cycles" thing
  * that the other ports do.
  */
-void
-do_gettimeofday(struct timeval *tv)
+u32 arch_gettimeoffset(void)
 {
-        unsigned long flags;
-        unsigned long sec, usec, seq;
-        unsigned long delta_cycles, delta_usec, partial_tick;
-
-        do {
-                seq = read_seqbegin_irqsave(&xtime_lock, flags);
-
-                delta_cycles = rpcc() - state.last_time;
-                sec = xtime.tv_sec;
-                usec = (xtime.tv_nsec / 1000);
-                partial_tick = state.partial_tick;
-
-        } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-
 #ifdef CONFIG_SMP
         /* Until and unless we figure out how to get cpu cycle counters
            in sync and keep them there, we can't use the rpcc tricks.  */
-        delta_usec = 0;
+        return 0;
 #else
+        unsigned long delta_cycles, delta_usec, partial_tick;
+
+        delta_cycles = rpcc() - state.last_time;
+        partial_tick = state.partial_tick;
         /*
          * usec = cycles * ticks_per_cycle * 2**48 * 1e6 / (2**48 * ticks)
          *      = cycles * (s_t_p_c) * 1e6 / (2**48 * ticks)
@@ -446,64 +435,10 @@ do_gettimeofday(struct timeval *tv)
         delta_usec = (delta_cycles * state.scaled_ticks_per_cycle 
                       + partial_tick) * 15625;
         delta_usec = ((delta_usec / ((1UL << (FIX_SHIFT-6-1)) * HZ)) + 1) / 2;
+        return delta_usec * 1000;
 #endif
-
-        usec += delta_usec;
-        if (usec >= 1000000) {
-                sec += 1;
-                usec -= 1000000;
-        }
-
-        tv->tv_sec = sec;
-        tv->tv_usec = usec;
 }
 
-EXPORT_SYMBOL(do_gettimeofday);
-
-int
-do_settimeofday(struct timespec *tv)
-{
-        time_t wtm_sec, sec = tv->tv_sec;
-        long wtm_nsec, nsec = tv->tv_nsec;
-        unsigned long delta_nsec;
-
-        if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
-                return -EINVAL;
-
-        write_seqlock_irq(&xtime_lock);
-
-        /* The offset that is added into time in do_gettimeofday above
-           must be subtracted out here to keep a coherent view of the
-           time.  Without this, a full-tick error is possible.  */
-
-#ifdef CONFIG_SMP
-        delta_nsec = 0;
-#else
-        delta_nsec = rpcc() - state.last_time;
-        delta_nsec = (delta_nsec * state.scaled_ticks_per_cycle 
-                      + state.partial_tick) * 15625;
-        delta_nsec = ((delta_nsec / ((1UL << (FIX_SHIFT-6-1)) * HZ)) + 1) / 2;
-        delta_nsec *= 1000;
-#endif
-
-        nsec -= delta_nsec;
-
-        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();
-
-        write_sequnlock_irq(&xtime_lock);
-        clock_was_set();
-        return 0;
-}
-
-EXPORT_SYMBOL(do_settimeofday);
-
-
 /*
  * In order to set the CMOS clock precisely, set_rtc_mmss has to be
  * called 500 ms after the second nowtime has started, because when