m68k: convert to use arch_gettimeoffset()

Convert m68k to use GENERIC_TIME via the arch_getoffset() infrastructure,
reducing the amount of arch specific code we need to maintain.

I've taken my best swing at converting this, but I'm not 100% confident
I got it right. My cross-compiler is now out of date (gcc4.2) so I
wasn't able to  check if it compiled. Any assistance from arch
maintainers or testers to get this merged would be great.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 8 insertions, 68 deletions

diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index fb87c08c6b5..29dd8489ffe 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -58,6 +58,12 @@ config HZ
         int
         default 100
 
+config GENERIC_TIME
+        def_bool y
+
+config ARCH_USES_GETTIMEOFFSET
+        def_bool y
+
 mainmenu "Linux/68k Kernel Configuration"
 
 source "init/Kconfig"
diff --git a/arch/m68k/kernel/time.c b/arch/m68k/kernel/time.c
index 54d980795fc..17dc2a31a7c 100644
--- a/arch/m68k/kernel/time.c
+++ b/arch/m68k/kernel/time.c
@@ -91,77 +91,11 @@ void __init time_init(void)
         mach_sched_init(timer_interrupt);
 }
 
-/*
- * This version of gettimeofday has near microsecond resolution.
- */
-void do_gettimeofday(struct timeval *tv)
+u32 arch_gettimeoffset(void)
 {
-        unsigned long flags;
-        unsigned long seq;
-        unsigned long usec, sec;
-        unsigned long max_ntp_tick = tick_usec - tickadj;
-
-        do {
-                seq = read_seqbegin_irqsave(&xtime_lock, flags);
-
-                usec = mach_gettimeoffset();
-
-                /*
-                 * If time_adjust is negative then NTP is slowing the clock
-                 * so make sure not to go into next possible interval.
-                 * Better to lose some accuracy than have time go backwards..
-                 */
-                if (unlikely(time_adjust < 0))
-                        usec = min(usec, max_ntp_tick);
-
-                sec = xtime.tv_sec;
-                usec += xtime.tv_nsec/1000;
-        } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-
-
-        while (usec >= 1000000) {
-                usec -= 1000000;
-                sec++;
-        }
-
-        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;
-
-        if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
-                return -EINVAL;
-
-        write_seqlock_irq(&xtime_lock);
-        /* This is revolting. We need to set the xtime.tv_nsec
-         * correctly. However, the value in this location is
-         * is value at the last tick.
-         * Discover what correction gettimeofday
-         * would have done, and then undo it!
-         */
-        nsec -= 1000 * mach_gettimeoffset();
-
-        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;
+        return mach_gettimeoffset() * 1000;
 }
 
-EXPORT_SYMBOL(do_settimeofday);
-
-
 static int __init rtc_init(void)
 {
         struct platform_device *pdev;