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>

3 files changed, 22 insertions, 20 deletions

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index ae5c6c147c4b..f1525ad06cb3 100644
--- a/kernel/posix-cpu-timers.c
+++ b/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,
diff --git a/kernel/time.c b/kernel/time.c
index 343e2515375a..cbe0d5a222ff 100644
--- a/kernel/time.c
+++ b/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);
 
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index a4492f3d64db..dbd6f8905614 100644
--- a/kernel/time/ntp.c
+++ b/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 */