Merge branch 'merge'

[pandora-kernel.git] / arch / powerpc / kernel / time.c

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index d209075..b9a2061 100644 (file)
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -32,7 +32,6 @@
  *      2 of the License, or (at your option) any later version.
  */
 
-#include <linux/config.h>
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/sched.h>
@@ -102,7 +101,7 @@ EXPORT_SYMBOL(tb_ticks_per_sec);    /* for cputime_t conversions */
 u64 tb_to_xs;
 unsigned tb_to_us;
 
-#define TICKLEN_SCALE  (SHIFT_SCALE - 10)
+#define TICKLEN_SCALE  TICK_LENGTH_SHIFT
 u64 last_tick_len;     /* units are ns / 2^TICKLEN_SCALE */
 u64 ticklen_to_xs;     /* 0.64 fraction */
 
@@ -126,15 +125,8 @@ static long timezone_offset;
 unsigned long ppc_proc_freq;
 unsigned long ppc_tb_freq;
 
-u64 tb_last_jiffy __cacheline_aligned_in_smp;
-unsigned long tb_last_stamp;
-
-/*
- * Note that on ppc32 this only stores the bottom 32 bits of
- * the timebase value, but that's enough to tell when a jiffy
- * has passed.
- */
-DEFINE_PER_CPU(unsigned long, last_jiffy);
+static u64 tb_last_jiffy __cacheline_aligned_in_smp;
+static DEFINE_PER_CPU(u64, last_jiffy);
 
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 /*
@@ -418,7 +410,7 @@ static __inline__ void timer_check_rtc(void)
 /*
  * This version of gettimeofday has microsecond resolution.
  */
-static inline void __do_gettimeofday(struct timeval *tv, u64 tb_val)
+static inline void __do_gettimeofday(struct timeval *tv)
 {
        unsigned long sec, usec;
        u64 tb_ticks, xsec;
@@ -432,7 +424,12 @@ static inline void __do_gettimeofday(struct timeval *tv, u64 tb_val)
         * without a divide (and in fact, without a multiply)
         */
        temp_varp = do_gtod.varp;
-       tb_ticks = tb_val - temp_varp->tb_orig_stamp;
+
+       /* Sampling the time base must be done after loading
+        * do_gtod.varp in order to avoid racing with update_gtod.
+        */
+       data_barrier(temp_varp);
+       tb_ticks = get_tb() - temp_varp->tb_orig_stamp;
        temp_tb_to_xs = temp_varp->tb_to_xs;
        temp_stamp_xsec = temp_varp->stamp_xsec;
        xsec = temp_stamp_xsec + mulhdu(tb_ticks, temp_tb_to_xs);
@@ -454,7 +451,7 @@ void do_gettimeofday(struct timeval *tv)
                do {
                        seq = read_seqbegin_irqsave(&xtime_lock, flags);
                        sec = xtime.tv_sec;
-                       nsec = xtime.tv_nsec + tb_ticks_since(tb_last_stamp);
+                       nsec = xtime.tv_nsec + tb_ticks_since(tb_last_jiffy);
                } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
                usec = nsec / 1000;
                while (usec >= 1000000) {
@@ -465,7 +462,7 @@ void do_gettimeofday(struct timeval *tv)
                tv->tv_usec = usec;
                return;
        }
-       __do_gettimeofday(tv, get_tb());
+       __do_gettimeofday(tv);
 }
 
 EXPORT_SYMBOL(do_gettimeofday);
@@ -651,6 +648,7 @@ void timer_interrupt(struct pt_regs * regs)
        int next_dec;
        int cpu = smp_processor_id();
        unsigned long ticks;
+       u64 tb_next_jiffy;
 
 #ifdef CONFIG_PPC32
        if (atomic_read(&ppc_n_lost_interrupts) != 0)
@@ -692,11 +690,13 @@ void timer_interrupt(struct pt_regs * regs)
                        continue;
 
                write_seqlock(&xtime_lock);
-               tb_last_jiffy += tb_ticks_per_jiffy;
-               tb_last_stamp = per_cpu(last_jiffy, cpu);
-               do_timer(regs);
-               timer_recalc_offset(tb_last_jiffy);
-               timer_check_rtc();
+               tb_next_jiffy = tb_last_jiffy + tb_ticks_per_jiffy;
+               if (per_cpu(last_jiffy, cpu) >= tb_next_jiffy) {
+                       tb_last_jiffy = tb_next_jiffy;
+                       do_timer(regs);
+                       timer_recalc_offset(tb_last_jiffy);
+                       timer_check_rtc();
+               }
                write_sequnlock(&xtime_lock);
        }
        
@@ -741,7 +741,7 @@ void __init smp_space_timers(unsigned int max_cpus)
        int i;
        unsigned long half = tb_ticks_per_jiffy / 2;
        unsigned long offset = tb_ticks_per_jiffy / max_cpus;
-       unsigned long previous_tb = per_cpu(last_jiffy, boot_cpuid);
+       u64 previous_tb = per_cpu(last_jiffy, boot_cpuid);
 
        /* make sure tb > per_cpu(last_jiffy, cpu) for all cpus always */
        previous_tb -= tb_ticks_per_jiffy;
@@ -822,7 +822,7 @@ int do_settimeofday(struct timespec *tv)
         * and therefore the (jiffies - wall_jiffies) computation
         * has been removed.
         */
-       tb_delta = tb_ticks_since(tb_last_stamp);
+       tb_delta = tb_ticks_since(tb_last_jiffy);
        tb_delta = mulhdu(tb_delta, do_gtod.varp->tb_to_xs); /* in xsec */
        new_nsec -= SCALE_XSEC(tb_delta, 1000000000);
 
@@ -860,14 +860,14 @@ EXPORT_SYMBOL(do_settimeofday);
 static int __init get_freq(char *name, int cells, unsigned long *val)
 {
        struct device_node *cpu;
-       unsigned int *fp;
+       const unsigned int *fp;
        int found = 0;
 
        /* The cpu node should have timebase and clock frequency properties */
        cpu = of_find_node_by_type(NULL, "cpu");
 
        if (cpu) {
-               fp = (unsigned int *)get_property(cpu, name, NULL);
+               fp = get_property(cpu, name, NULL);
                if (fp) {
                        found = 1;
                        *val = 0;
@@ -942,8 +942,7 @@ void __init time_init(void)
        if (__USE_RTC()) {
                /* 601 processor: dec counts down by 128 every 128ns */
                ppc_tb_freq = 1000000000;
-               tb_last_stamp = get_rtcl();
-               tb_last_jiffy = tb_last_stamp;
+               tb_last_jiffy = get_rtcl();
        } else {
                /* Normal PowerPC with timebase register */
                ppc_md.calibrate_decr();
@@ -951,7 +950,7 @@ void __init time_init(void)
                       ppc_tb_freq / 1000000, ppc_tb_freq % 1000000);
                printk(KERN_DEBUG "time_init: processor frequency   = %lu.%.6lu MHz\n",
                       ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
-               tb_last_stamp = tb_last_jiffy = get_tb();
+               tb_last_jiffy = get_tb();
        }
 
        tb_ticks_per_jiffy = ppc_tb_freq / HZ;
@@ -1028,7 +1027,7 @@ void __init time_init(void)
        do_gtod.varp = &do_gtod.vars[0];
        do_gtod.var_idx = 0;
        do_gtod.varp->tb_orig_stamp = tb_last_jiffy;
-       __get_cpu_var(last_jiffy) = tb_last_stamp;
+       __get_cpu_var(last_jiffy) = tb_last_jiffy;
        do_gtod.varp->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC;
        do_gtod.tb_ticks_per_sec = tb_ticks_per_sec;
        do_gtod.varp->tb_to_xs = tb_to_xs;