Blackfin: convert to use arch_gettimeoffset()

Convert Blackfin 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  My cross-compiler is now out of date (gcc4.2) so I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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

2 files changed, 8 insertions, 65 deletions

diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 9a01d445eca..e51988237d3 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -229,7 +229,7 @@ endchoice
 
 config SMP
         depends on BF561
-        select GENERIC_TIME
+        select GENERIC_CLOCKEVENTS
         bool "Symmetric multi-processing support"
         ---help---
           This enables support for systems with more than one CPU,
@@ -613,12 +613,10 @@ comment "Kernel Timer/Scheduler"
 source kernel/Kconfig.hz
 
 config GENERIC_TIME
-        bool "Generic time"
-        default y
+        def_bool y
 
 config GENERIC_CLOCKEVENTS
         bool "Generic clock events"
-        depends on GENERIC_TIME
         default y
 
 choice
@@ -653,6 +651,10 @@ config GPTMR0_CLOCKSOURCE
         depends on GENERIC_CLOCKEVENTS
         depends on !TICKSOURCE_GPTMR0
 
+config ARCH_USES_GETTIMEOFFSET
+        depends on !GENERIC_CLOCKEVENTS
+        def_bool y
+
 source kernel/time/Kconfig
 
 comment "Misc"
diff --git a/arch/blackfin/kernel/time.c b/arch/blackfin/kernel/time.c
index adb54aa7d7c..e5069fe6861 100644
--- a/arch/blackfin/kernel/time.c
+++ b/arch/blackfin/kernel/time.c
@@ -81,11 +81,11 @@ time_sched_init(irqreturn_t(*timer_routine) (int, void *))
 #endif
 }
 
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 /*
  * Should return useconds since last timer tick
  */
-#ifndef CONFIG_GENERIC_TIME
-static unsigned long gettimeoffset(void)
+u32 arch_gettimeoffset(void)
 {
         unsigned long offset;
         unsigned long clocks_per_jiffy;
@@ -184,65 +184,6 @@ void __init time_init(void)
         time_sched_init(timer_interrupt);
 }
 
-#ifndef CONFIG_GENERIC_TIME
-void do_gettimeofday(struct timeval *tv)
-{
-        unsigned long flags;
-        unsigned long seq;
-        unsigned long usec, sec;
-
-        do {
-                seq = read_seqbegin_irqsave(&xtime_lock, flags);
-                usec = gettimeoffset();
-                sec = xtime.tv_sec;
-                usec += (xtime.tv_nsec / NSEC_PER_USEC);
-        }
-        while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-
-        while (usec >= USEC_PER_SEC) {
-                usec -= USEC_PER_SEC;
-                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_usec
-         * 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 -= (gettimeoffset() * NSEC_PER_USEC);
-
-        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);
-#endif /* !CONFIG_GENERIC_TIME */
-
 /*
  * Scheduler clock - returns current time in nanosec units.
  */