remove div_long_long_rem

x86 is the only arch right now, which provides an optimized for
div_long_long_rem and it has the downside that one has to be very careful that
the divide doesn't overflow.

The API is a little akward, as the arguments for the unsigned divide are
signed.  The signed version also doesn't handle a negative divisor and
produces worse code on 64bit archs.

There is little incentive to keep this API alive, so this converts the few
users to the new API.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/posix-cpu-timers.c

@@ -4,8 +4,9 @@
 
 #include <linux/sched.h>
 #include <linux/posix-timers.h>
-#include <asm/uaccess.h>
 #include <linux/errno.h>
+#include <linux/math64.h>
+#include <asm/uaccess.h>
 
 static int check_clock(const clockid_t which_clock)
 {
@@ -47,12 +48,10 @@ static void sample_to_timespec(const clockid_t which_clock,
 			       union cpu_time_count cpu,
 			       struct timespec *tp)
 {
-	if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
-		tp->tv_sec = div_long_long_rem(cpu.sched,
-					       NSEC_PER_SEC, &tp->tv_nsec);
-	} else {
+	if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED)
+		*tp = ns_to_timespec(cpu.sched);
+	else
 		cputime_to_timespec(cpu.cpu, tp);
-	}
 }
 
 static inline int cpu_time_before(const clockid_t which_clock,

kernel/time.c

@@ -392,13 +392,17 @@ EXPORT_SYMBOL(set_normalized_timespec);
 struct timespec ns_to_timespec(const s64 nsec)
 {
 	struct timespec ts;
+	s32 rem;
 
 	if (!nsec)
 		return (struct timespec) {0, 0};
 
-	ts.tv_sec = div_long_long_rem_signed(nsec, NSEC_PER_SEC, &ts.tv_nsec);
-	if (unlikely(nsec < 0))
-		set_normalized_timespec(&ts, ts.tv_sec, ts.tv_nsec);
+	ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem);
+	if (unlikely(rem < 0)) {
+		ts.tv_sec--;
+		rem += NSEC_PER_SEC;
+	}
+	ts.tv_nsec = rem;
 
 	return ts;
 }
@@ -528,8 +532,10 @@ jiffies_to_timespec(const unsigned long jiffies, struct timespec *value)
 	 * Convert jiffies to nanoseconds and separate with
 	 * one divide.
 	 */
-	u64 nsec = (u64)jiffies * TICK_NSEC;
-	value->tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &value->tv_nsec);
+	u32 rem;
+	value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC,
+				    NSEC_PER_SEC, &rem);
+	value->tv_nsec = rem;
 }
 EXPORT_SYMBOL(jiffies_to_timespec);
 
@@ -567,12 +573,11 @@ void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value)
 	 * Convert jiffies to nanoseconds and separate with
 	 * one divide.
 	 */
-	u64 nsec = (u64)jiffies * TICK_NSEC;
-	long tv_usec;
+	u32 rem;
 
-	value->tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &tv_usec);
-	tv_usec /= NSEC_PER_USEC;
-	value->tv_usec = tv_usec;
+	value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC,
+				    NSEC_PER_SEC, &rem);
+	value->tv_usec = rem / NSEC_PER_USEC;
 }
 EXPORT_SYMBOL(jiffies_to_timeval);
 

kernel/time/ntp.c

@@ -234,7 +234,7 @@ static inline void notify_cmos_timer(void) { }
  */
 int do_adjtimex(struct timex *txc)
 {
-	long mtemp, save_adjust, rem;
+	long mtemp, save_adjust;
 	s64 freq_adj;
 	int result;
 
@@ -345,9 +345,7 @@ int do_adjtimex(struct timex *txc)
 		    freq_adj += time_freq;
 		    freq_adj = min(freq_adj, (s64)MAXFREQ_NSEC);
 		    time_freq = max(freq_adj, (s64)-MAXFREQ_NSEC);
-		    time_offset = div_long_long_rem_signed(time_offset,
-							   NTP_INTERVAL_FREQ,
-							   &rem);
+		    time_offset = div_s64(time_offset, NTP_INTERVAL_FREQ);
 		    time_offset <<= SHIFT_UPDATE;
 		} /* STA_PLL */
 	    } /* txc->modes & ADJ_OFFSET */