Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / arch / s390 / kernel / time.c

diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 8f27942..2a6c6ef 100644 (file)
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -49,10 +49,6 @@
 
 #define TICK_SIZE tick
 
-u64 jiffies_64 = INITIAL_JIFFIES;
-
-EXPORT_SYMBOL(jiffies_64);
-
 static ext_int_info_t ext_int_info_cc;
 static u64 init_timer_cc;
 static u64 jiffies_timer_cc;
@@ -65,8 +61,17 @@ extern unsigned long wall_jiffies;
  */
 unsigned long long sched_clock(void)
 {
-       return ((get_clock() - jiffies_timer_cc) * 1000) >> 12;
+       return ((get_clock() - jiffies_timer_cc) * 125) >> 9;
+}
+
+/*
+ * Monotonic_clock - returns # of nanoseconds passed since time_init()
+ */
+unsigned long long monotonic_clock(void)
+{
+       return sched_clock();
 }
+EXPORT_SYMBOL(monotonic_clock);
 
 void tod_to_timeval(__u64 todval, struct timespec *xtime)
 {
@@ -139,10 +144,7 @@ int do_settimeofday(struct timespec *tv)
        set_normalized_timespec(&xtime, sec, nsec);
        set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
-       time_adjust = 0;                /* stop active adjtime() */
-       time_status |= STA_UNSYNC;
-       time_maxerror = NTP_PHASE_LIMIT;
-       time_esterror = NTP_PHASE_LIMIT;
+       ntp_clear();
        write_sequnlock_irq(&xtime_lock);
        clock_was_set();
        return 0;
@@ -150,28 +152,6 @@ int do_settimeofday(struct timespec *tv)
 
 EXPORT_SYMBOL(do_settimeofday);
 
-#ifndef CONFIG_ARCH_S390X
-
-static inline __u32
-__calculate_ticks(__u64 elapsed)
-{
-       register_pair rp;
-
-       rp.pair = elapsed >> 1;
-       asm ("dr %0,%1" : "+d" (rp) : "d" (CLK_TICKS_PER_JIFFY >> 1));
-       return rp.subreg.odd;
-}
-
-#else /* CONFIG_ARCH_S390X */
-
-static inline __u32
-__calculate_ticks(__u64 elapsed)
-{
-       return elapsed / CLK_TICKS_PER_JIFFY;
-}
-
-#endif /* CONFIG_ARCH_S390X */
-
 
 #ifdef CONFIG_PROFILING
 #define s390_do_profile(regs)  profile_tick(CPU_PROFILING, regs)
@@ -187,14 +167,23 @@ __calculate_ticks(__u64 elapsed)
 void account_ticks(struct pt_regs *regs)
 {
        __u64 tmp;
-       __u32 ticks;
+       __u32 ticks, xticks;
 
        /* Calculate how many ticks have passed. */
-       if (S390_lowcore.int_clock < S390_lowcore.jiffy_timer)
+       if (S390_lowcore.int_clock < S390_lowcore.jiffy_timer) {
+               /*
+                * We have to program the clock comparator even if
+                * no tick has passed. That happens if e.g. an i/o
+                * interrupt wakes up an idle processor that has
+                * switched off its hz timer.
+                */
+               tmp = S390_lowcore.jiffy_timer + CPU_DEVIATION;
+               asm volatile ("SCKC %0" : : "m" (tmp));
                return;
+       }
        tmp = S390_lowcore.int_clock - S390_lowcore.jiffy_timer;
        if (tmp >= 2*CLK_TICKS_PER_JIFFY) {  /* more than two ticks ? */
-               ticks = __calculate_ticks(tmp) + 1;
+               ticks = __div(tmp, CLK_TICKS_PER_JIFFY) + 1;
                S390_lowcore.jiffy_timer +=
                        CLK_TICKS_PER_JIFFY * (__u64) ticks;
        } else if (tmp >= CLK_TICKS_PER_JIFFY) {
@@ -216,11 +205,9 @@ void account_ticks(struct pt_regs *regs)
         */
        write_seqlock(&xtime_lock);
        if (S390_lowcore.jiffy_timer > xtime_cc) {
-               __u32 xticks;
-
                tmp = S390_lowcore.jiffy_timer - xtime_cc;
                if (tmp >= 2*CLK_TICKS_PER_JIFFY) {
-                       xticks = __calculate_ticks(tmp);
+                       xticks = __div(tmp, CLK_TICKS_PER_JIFFY);
                        xtime_cc += (__u64) xticks * CLK_TICKS_PER_JIFFY;
                } else {
                        xticks = 1;
@@ -230,12 +217,18 @@ void account_ticks(struct pt_regs *regs)
                        do_timer(regs);
        }
        write_sequnlock(&xtime_lock);
-       while (ticks--)
-               update_process_times(user_mode(regs));
 #else
-       while (ticks--)
+       for (xticks = ticks; xticks > 0; xticks--)
                do_timer(regs);
 #endif
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+       account_tick_vtime(current);
+#else
+       while (ticks--)
+               update_process_times(user_mode(regs));
+#endif
+
        s390_do_profile(regs);
 }
 
@@ -253,26 +246,42 @@ int sysctl_hz_timer = 1;
  */
 static inline void stop_hz_timer(void)
 {
-       __u64 timer;
+       unsigned long flags;
+       unsigned long seq, next;
+       __u64 timer, todval;
+       int cpu = smp_processor_id();
 
        if (sysctl_hz_timer != 0)
                return;
 
+       cpu_set(cpu, nohz_cpu_mask);
+
        /*
         * Leave the clock comparator set up for the next timer
         * tick if either rcu or a softirq is pending.
         */
-       if (rcu_pending(smp_processor_id()) || local_softirq_pending())
+       if (rcu_needs_cpu(cpu) || local_softirq_pending()) {
+               cpu_clear(cpu, nohz_cpu_mask);
                return;
+       }
 
        /*
         * This cpu is going really idle. Set up the clock comparator
         * for the next event.
         */
-       cpu_set(smp_processor_id(), nohz_cpu_mask);
-       timer = (__u64) (next_timer_interrupt() - jiffies) + jiffies_64;
-       timer = jiffies_timer_cc + timer * CLK_TICKS_PER_JIFFY;
-       asm volatile ("SCKC %0" : : "m" (timer));
+       next = next_timer_interrupt();
+       do {
+               seq = read_seqbegin_irqsave(&xtime_lock, flags);
+               timer = ((__u64) next) - ((__u64) jiffies) + jiffies_64;
+       } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
+       todval = -1ULL;
+       /* Be careful about overflows. */
+       if (timer < (-1ULL / CLK_TICKS_PER_JIFFY)) {
+               timer = jiffies_timer_cc + timer * CLK_TICKS_PER_JIFFY;
+               if (timer >= jiffies_timer_cc)
+                       todval = timer;
+       }
+       asm volatile ("SCKC %0" : : "m" (todval));
 }
 
 /*
@@ -283,7 +292,7 @@ static inline void start_hz_timer(void)
 {
        if (!cpu_isset(smp_processor_id(), nohz_cpu_mask))
                return;
-       account_ticks(__KSTK_PTREGS(current));
+       account_ticks(task_pt_regs(current));
        cpu_clear(smp_processor_id(), nohz_cpu_mask);
 }