powerpc: Merge time.c and asm/time.h.

We now use the merged time.c for both 32-bit and 64-bit compilation
with ARCH=powerpc, and for ARCH=ppc64, but not for ARCH=ppc32.
This removes setup_default_decr (folds its function into time_init)
and moves wakeup_decrementer into time.c.  This also makes an
asm-powerpc/rtc.h.

Signed-off-by: Paul Mackerras <paulus@samba.org>

12 files changed, 356 insertions, 243 deletions

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 5c5d2b5f3ca2..b347ac320252 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -29,7 +29,7 @@ extra-$(CONFIG_PPC64)		+= entry_64.o
 extra-$(CONFIG_PPC_FPU)         += fpu.o
 extra-y                         += vmlinux.lds
 
-obj-y                           += process.o init_task.o \
+obj-y                           += process.o init_task.o time.o \
                                    prom.o systbl.o traps.o
 obj-$(CONFIG_PPC32)             += entry_32.o idle_6xx.o setup_32.o misc_32.o
 obj-$(CONFIG_PPC64)             += setup_64.o misc_64.o
@@ -44,7 +44,7 @@ endif
 
 else
 # stuff used from here for ARCH=ppc or ARCH=ppc64
-obj-$(CONFIG_PPC64)             += traps.o process.o init_task.o
+obj-$(CONFIG_PPC64)             += traps.o process.o init_task.o time.o
 
 fpux-$(CONFIG_PPC32)            += fpu.o
 extra-$(CONFIG_PPC_FPU)         += $(fpux-y)
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 0b0e908b5065..303229b090b8 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -36,6 +36,33 @@ _GLOBAL(__delay)
         blr
 
 /*
+ * This returns the high 64 bits of the product of two 64-bit numbers.
+ */
+_GLOBAL(mulhdu)
+        cmpwi   r6,0
+        cmpwi   cr1,r3,0
+        mr      r10,r4
+        mulhwu  r4,r4,r5
+        beq     1f
+        mulhwu  r0,r10,r6
+        mullw   r7,r10,r5
+        addc    r7,r0,r7
+        addze   r4,r4
+1:      beqlr   cr1             /* all done if high part of A is 0 */
+        mr      r10,r3
+        mullw   r9,r3,r5
+        mulhwu  r3,r3,r5
+        beq     2f
+        mullw   r0,r10,r6
+        mulhwu  r8,r10,r6
+        addc    r7,r0,r7
+        adde    r4,r4,r8
+        addze   r3,r3
+2:      addc    r4,r4,r9
+        addze   r3,r3
+        blr
+
+/*
  * Returns (address we're running at) - (address we were linked at)
  * for use before the text and data are mapped to KERNELBASE.
  */
diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c
index 010554e5fe48..40c9e67e1b28 100644
--- a/arch/powerpc/kernel/ppc_ksyms.c
+++ b/arch/powerpc/kernel/ppc_ksyms.c
@@ -260,7 +260,6 @@ EXPORT_SYMBOL(__res);
 #ifdef CONFIG_PPC32
 EXPORT_SYMBOL(next_mmu_context);
 EXPORT_SYMBOL(set_context);
-EXPORT_SYMBOL(disarm_decr);
 #endif
 
 #ifdef CONFIG_PPC_STD_MMU_32
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 4fcf67575cbb..6f29614c3581 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -1083,15 +1083,6 @@ void ppc64_terminate_msg(unsigned int src, const char *msg)
         printk("[terminate]%04x %s\n", src, msg);
 }
 
-/* This should only be called on processor 0 during calibrate decr */
-void __init setup_default_decr(void)
-{
-        struct paca_struct *lpaca = get_paca();
-
-        lpaca->default_decr = tb_ticks_per_jiffy;
-        lpaca->next_jiffy_update_tb = get_tb() + tb_ticks_per_jiffy;
-}
-
 #ifndef CONFIG_PPC_ISERIES
 /*
  * This function can be used by platforms to "find" legacy serial ports.
diff --git a/arch/ppc64/kernel/time.c b/arch/powerpc/kernel/time.c
index 7f63755eddfd..d1608473075f 100644
--- a/arch/ppc64/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -1,5 +1,4 @@
 /*
- * 
  * Common time routines among all ppc machines.
  *
  * Written by Cort Dougan (cort@cs.nmt.edu) to merge
@@ -44,29 +43,32 @@
 #include <linux/interrupt.h>
 #include <linux/timex.h>
 #include <linux/kernel_stat.h>
-#include <linux/mc146818rtc.h>
 #include <linux/time.h>
 #include <linux/init.h>
 #include <linux/profile.h>
 #include <linux/cpu.h>
 #include <linux/security.h>
+#include <linux/percpu.h>
+#include <linux/rtc.h>
 
 #include <asm/io.h>
 #include <asm/processor.h>
 #include <asm/nvram.h>
 #include <asm/cache.h>
 #include <asm/machdep.h>
-#ifdef CONFIG_PPC_ISERIES
-#include <asm/iSeries/ItLpQueue.h>
-#include <asm/iSeries/HvCallXm.h>
-#endif
 #include <asm/uaccess.h>
 #include <asm/time.h>
-#include <asm/ppcdebug.h>
 #include <asm/prom.h>
-#include <asm/sections.h>
+#include <asm/irq.h>
+#include <asm/div64.h>
+#ifdef CONFIG_PPC64
 #include <asm/systemcfg.h>
 #include <asm/firmware.h>
+#endif
+#ifdef CONFIG_PPC_ISERIES
+#include <asm/iSeries/ItLpQueue.h>
+#include <asm/iSeries/HvCallXm.h>
+#endif
 
 u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;
 
@@ -81,27 +83,37 @@ unsigned long iSeries_recal_tb = 0;
 static unsigned long first_settimeofday = 1;
 #endif
 
+/* The decrementer counts down by 128 every 128ns on a 601. */
+#define DECREMENTER_COUNT_601   (1000000000 / HZ)
+
 #define XSEC_PER_SEC (1024*1024)
 
+#ifdef CONFIG_PPC64
+#define SCALE_XSEC(xsec, max)   (((xsec) * max) / XSEC_PER_SEC)
+#else
+/* compute ((xsec << 12) * max) >> 32 */
+#define SCALE_XSEC(xsec, max)   mulhwu((xsec) << 12, max)
+#endif
+
 unsigned long tb_ticks_per_jiffy;
 unsigned long tb_ticks_per_usec = 100; /* sane default */
 EXPORT_SYMBOL(tb_ticks_per_usec);
 unsigned long tb_ticks_per_sec;
-unsigned long tb_to_xs;
-unsigned      tb_to_us;
+u64 tb_to_xs;
+unsigned tb_to_us;
 unsigned long processor_freq;
 DEFINE_SPINLOCK(rtc_lock);
 EXPORT_SYMBOL_GPL(rtc_lock);
 
-unsigned long tb_to_ns_scale;
-unsigned long tb_to_ns_shift;
+u64 tb_to_ns_scale;
+unsigned tb_to_ns_shift;
 
 struct gettimeofday_struct do_gtod;
 
 extern unsigned long wall_jiffies;
-extern int smp_tb_synchronized;
 
 extern struct timezone sys_tz;
+static long timezone_offset;
 
 void ppc_adjtimex(void);
 
@@ -110,6 +122,10 @@ static unsigned adjusting_time = 0;
 unsigned long ppc_proc_freq;
 unsigned long ppc_tb_freq;
 
+#ifdef CONFIG_PPC32     /* XXX for now */
+#define boot_cpuid      0
+#endif
+
 static __inline__ void timer_check_rtc(void)
 {
         /*
@@ -129,30 +145,30 @@ static __inline__ void timer_check_rtc(void)
          * seconds like on Intel to avoid problems with non UTC clocks.
          */
         if (ntp_synced() &&
-             xtime.tv_sec - last_rtc_update >= 659 &&
-             abs((xtime.tv_nsec/1000) - (1000000-1000000/HZ)) < 500000/HZ &&
-             jiffies - wall_jiffies == 1) {
-            struct rtc_time tm;
-            to_tm(xtime.tv_sec+1, &tm);
-            tm.tm_year -= 1900;
-            tm.tm_mon -= 1;
-            if (ppc_md.set_rtc_time(&tm) == 0)
-                last_rtc_update = xtime.tv_sec+1;
-            else
-                /* Try again one minute later */
-                last_rtc_update += 60;
+            xtime.tv_sec - last_rtc_update >= 659 &&
+            abs((xtime.tv_nsec/1000) - (1000000-1000000/HZ)) < 500000/HZ &&
+            jiffies - wall_jiffies == 1) {
+                struct rtc_time tm;
+                to_tm(xtime.tv_sec + 1 + timezone_offset, &tm);
+                tm.tm_year -= 1900;
+                tm.tm_mon -= 1;
+                if (ppc_md.set_rtc_time(&tm) == 0)
+                        last_rtc_update = xtime.tv_sec + 1;
+                else
+                        /* Try again one minute later */
+                        last_rtc_update += 60;
         }
 }
 
 /*
  * This version of gettimeofday has microsecond resolution.
  */
-static inline void __do_gettimeofday(struct timeval *tv, unsigned long tb_val)
+static inline void __do_gettimeofday(struct timeval *tv, u64 tb_val)
 {
-        unsigned long sec, usec, tb_ticks;
-        unsigned long xsec, tb_xsec;
-        struct gettimeofday_vars * temp_varp;
-        unsigned long temp_tb_to_xs, temp_stamp_xsec;
+        unsigned long sec, usec;
+        u64 tb_ticks, xsec;
+        struct gettimeofday_vars *temp_varp;
+        u64 temp_tb_to_xs, temp_stamp_xsec;
 
         /*
          * These calculations are faster (gets rid of divides)
@@ -164,11 +180,10 @@ static inline void __do_gettimeofday(struct timeval *tv, unsigned long tb_val)
         tb_ticks = tb_val - temp_varp->tb_orig_stamp;
         temp_tb_to_xs = temp_varp->tb_to_xs;
         temp_stamp_xsec = temp_varp->stamp_xsec;
-        tb_xsec = mulhdu( tb_ticks, temp_tb_to_xs );
-        xsec = temp_stamp_xsec + tb_xsec;
+        xsec = temp_stamp_xsec + mulhdu(tb_ticks, temp_tb_to_xs);
         sec = xsec / XSEC_PER_SEC;
-        xsec -= sec * XSEC_PER_SEC;
-        usec = (xsec * USEC_PER_SEC)/XSEC_PER_SEC;
+        usec = (unsigned long)xsec & (XSEC_PER_SEC - 1);
+        usec = SCALE_XSEC(usec, 1000000);
 
         tv->tv_sec = sec;
         tv->tv_usec = usec;
@@ -185,6 +200,8 @@ EXPORT_SYMBOL(do_gettimeofday);
 
 static inline void timer_sync_xtime(unsigned long cur_tb)
 {
+#ifdef CONFIG_PPC64
+        /* why do we do this? */
         struct timeval my_tv;
 
         __do_gettimeofday(&my_tv, cur_tb);
@@ -193,47 +210,74 @@ static inline void timer_sync_xtime(unsigned long cur_tb)
                 xtime.tv_sec = my_tv.tv_sec;
                 xtime.tv_nsec = my_tv.tv_usec * 1000;
         }
+#endif
 }
 
 /*
- * When the timebase - tb_orig_stamp gets too big, we do a manipulation
- * between tb_orig_stamp and stamp_xsec. The goal here is to keep the
- * difference tb - tb_orig_stamp small enough to always fit inside a
- * 32 bits number. This is a requirement of our fast 32 bits userland
- * implementation in the vdso. If we "miss" a call to this function
- * (interrupt latency, CPU locked in a spinlock, ...) and we end up
- * with a too big difference, then the vdso will fallback to calling
- * the syscall
+ * There are two copies of tb_to_xs and stamp_xsec so that no
+ * lock is needed to access and use these values in
+ * do_gettimeofday.  We alternate the copies and as long as a
+ * reasonable time elapses between changes, there will never
+ * be inconsistent values.  ntpd has a minimum of one minute
+ * between updates.
  */
-static __inline__ void timer_recalc_offset(unsigned long cur_tb)
+static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec,
+                               unsigned int new_tb_to_xs)
 {
-        struct gettimeofday_vars * temp_varp;
         unsigned temp_idx;
-        unsigned long offset, new_stamp_xsec, new_tb_orig_stamp;
-
-        if (((cur_tb - do_gtod.varp->tb_orig_stamp) & 0x80000000u) == 0)
-                return;
+        struct gettimeofday_vars *temp_varp;
 
         temp_idx = (do_gtod.var_idx == 0);
         temp_varp = &do_gtod.vars[temp_idx];
 
-        new_tb_orig_stamp = cur_tb;
-        offset = new_tb_orig_stamp - do_gtod.varp->tb_orig_stamp;
-        new_stamp_xsec = do_gtod.varp->stamp_xsec + mulhdu(offset, do_gtod.varp->tb_to_xs);
-
-        temp_varp->tb_to_xs = do_gtod.varp->tb_to_xs;
-        temp_varp->tb_orig_stamp = new_tb_orig_stamp;
+        temp_varp->tb_to_xs = new_tb_to_xs;
+        temp_varp->tb_orig_stamp = new_tb_stamp;
         temp_varp->stamp_xsec = new_stamp_xsec;
         smp_mb();
         do_gtod.varp = temp_varp;
         do_gtod.var_idx = temp_idx;
 
+#ifdef CONFIG_PPC64
+        /*
+         * tb_update_count is used to allow the userspace gettimeofday code
+         * to assure itself that it sees a consistent view of the tb_to_xs and
+         * stamp_xsec variables.  It reads the tb_update_count, then reads
+         * tb_to_xs and stamp_xsec and then reads tb_update_count again.  If
+         * the two values of tb_update_count match and are even then the
+         * tb_to_xs and stamp_xsec values are consistent.  If not, then it
+         * loops back and reads them again until this criteria is met.
+         */
         ++(systemcfg->tb_update_count);
         smp_wmb();
-        systemcfg->tb_orig_stamp = new_tb_orig_stamp;
+        systemcfg->tb_orig_stamp = new_tb_stamp;
         systemcfg->stamp_xsec = new_stamp_xsec;
+        systemcfg->tb_to_xs = new_tb_to_xs;
         smp_wmb();
         ++(systemcfg->tb_update_count);
+#endif
+}
+
+/*
+ * When the timebase - tb_orig_stamp gets too big, we do a manipulation
+ * between tb_orig_stamp and stamp_xsec. The goal here is to keep the
+ * difference tb - tb_orig_stamp small enough to always fit inside a
+ * 32 bits number. This is a requirement of our fast 32 bits userland
+ * implementation in the vdso. If we "miss" a call to this function
+ * (interrupt latency, CPU locked in a spinlock, ...) and we end up
+ * with a too big difference, then the vdso will fallback to calling
+ * the syscall
+ */
+static __inline__ void timer_recalc_offset(u64 cur_tb)
+{
+        unsigned long offset;
+        u64 new_stamp_xsec;
+
+        offset = cur_tb - do_gtod.varp->tb_orig_stamp;
+        if ((offset & 0x80000000u) == 0)
+                return;
+        new_stamp_xsec = do_gtod.varp->stamp_xsec
+                + mulhdu(offset, do_gtod.varp->tb_to_xs);
+        update_gtod(cur_tb, new_stamp_xsec, do_gtod.varp->tb_to_xs);
 }
 
 #ifdef CONFIG_SMP
@@ -313,7 +357,14 @@ static void iSeries_tb_recal(void)
  * call will not be needed)
  */
 
-unsigned long tb_last_stamp __cacheline_aligned_in_smp;
+u64 tb_last_stamp __cacheline_aligned_in_smp;
+
+/*
+ * 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);
 
 /*
  * timer_interrupt - gets called when the decrementer overflows,
@@ -322,17 +373,30 @@ unsigned long tb_last_stamp __cacheline_aligned_in_smp;
 void timer_interrupt(struct pt_regs * regs)
 {
         int next_dec;
-        unsigned long cur_tb;
-        struct paca_struct *lpaca = get_paca();
-        unsigned long cpu = smp_processor_id();
+        int cpu = smp_processor_id();
+        unsigned long ticks;
+
+#ifdef CONFIG_PPC32
+        if (atomic_read(&ppc_n_lost_interrupts) != 0)
+                do_IRQ(regs);
+#endif
 
         irq_enter();
 
         profile_tick(CPU_PROFILING, regs);
 
-        lpaca->lppaca.int_dword.fields.decr_int = 0;
+#ifdef CONFIG_PPC_ISERIES
+        get_paca()->lppaca.int_dword.fields.decr_int = 0;
+#endif
+
+        while ((ticks = tb_ticks_since(per_cpu(last_jiffy, cpu)))
+               >= tb_ticks_per_jiffy) {
+                /* Update last_jiffy */
+                per_cpu(last_jiffy, cpu) += tb_ticks_per_jiffy;
+                /* Handle RTCL overflow on 601 */
+                if (__USE_RTC() && per_cpu(last_jiffy, cpu) >= 1000000000)
+                        per_cpu(last_jiffy, cpu) -= 1000000000;
 
-        while (lpaca->next_jiffy_update_tb <= (cur_tb = get_tb())) {
                 /*
                  * We cannot disable the decrementer, so in the period
                  * between this cpu's being marked offline in cpu_online_map
@@ -342,27 +406,26 @@ void timer_interrupt(struct pt_regs * regs)
                  */
                 if (!cpu_is_offline(cpu))
                         update_process_times(user_mode(regs));
+
                 /*
                  * No need to check whether cpu is offline here; boot_cpuid
                  * should have been fixed up by now.
                  */
-                if (cpu == boot_cpuid) {
-                        write_seqlock(&xtime_lock);
-                        tb_last_stamp = lpaca->next_jiffy_update_tb;
-                        timer_recalc_offset(lpaca->next_jiffy_update_tb);
-                        do_timer(regs);
-                        timer_sync_xtime(lpaca->next_jiffy_update_tb);
-                        timer_check_rtc();
-                        write_sequnlock(&xtime_lock);
-                        if ( adjusting_time && (time_adjust == 0) )
-                                ppc_adjtimex();
-                }
-                lpaca->next_jiffy_update_tb += tb_ticks_per_jiffy;
+                if (cpu != boot_cpuid)
+                        continue;
+
+                write_seqlock(&xtime_lock);
+                tb_last_stamp += tb_ticks_per_jiffy;
+                timer_recalc_offset(tb_last_stamp);
+                do_timer(regs);
+                timer_sync_xtime(tb_last_stamp);
+                timer_check_rtc();
+                write_sequnlock(&xtime_lock);
+                if (adjusting_time && (time_adjust == 0))
+                        ppc_adjtimex();
         }
         
-        next_dec = lpaca->next_jiffy_update_tb - cur_tb;
-        if (next_dec > lpaca->default_decr)
-                next_dec = lpaca->default_decr;
+        next_dec = tb_ticks_per_jiffy - ticks;
         set_dec(next_dec);
 
 #ifdef CONFIG_PPC_ISERIES
@@ -370,15 +433,47 @@ void timer_interrupt(struct pt_regs * regs)
                 process_hvlpevents(regs);
 #endif
 
+#ifdef CONFIG_PPC64
         /* collect purr register values often, for accurate calculations */
         if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
                 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
                 cu->current_tb = mfspr(SPRN_PURR);
         }
+#endif
 
         irq_exit();
 }
 
+void wakeup_decrementer(void)
+{
+        int i;
+
+        set_dec(tb_ticks_per_jiffy);
+        /*
+         * We don't expect this to be called on a machine with a 601,
+         * so using get_tbl is fine.
+         */
+        tb_last_stamp = get_tb();
+        for_each_cpu(i)
+                per_cpu(last_jiffy, i) = tb_last_stamp;
+}
+
+#ifdef CONFIG_SMPxxx
+void __init smp_space_timers(unsigned int max_cpus)
+{
+        int i;
+        unsigned long offset = tb_ticks_per_jiffy / max_cpus;
+        unsigned long previous_tb = per_cpu(last_jiffy, boot_cpuid);
+
+        for_each_cpu(i) {
+                if (i != boot_cpuid) {
+                        previous_tb += offset;
+                        per_cpu(last_jiffy, i) = previous_tb;
+                }
+        }
+}
+#endif
+
 /*
  * Scheduler clock - returns current time in nanosec units.
  *
@@ -396,23 +491,24 @@ int do_settimeofday(struct timespec *tv)
         time_t wtm_sec, new_sec = tv->tv_sec;
         long wtm_nsec, new_nsec = tv->tv_nsec;
         unsigned long flags;
-        unsigned long delta_xsec;
         long int tb_delta;
-        unsigned long new_xsec;
+        u64 new_xsec;
 
         if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
                 return -EINVAL;
 
         write_seqlock_irqsave(&xtime_lock, flags);
-        /* Updating the RTC is not the job of this code. If the time is
-         * stepped under NTP, the RTC will be update after STA_UNSYNC
-         * is cleared. Tool like clock/hwclock either copy the RTC
+
+        /*
+         * Updating the RTC is not the job of this code. If the time is
+         * stepped under NTP, the RTC will be updated after STA_UNSYNC
+         * is cleared.  Tools like clock/hwclock either copy the RTC
          * to the system time, in which case there is no point in writing
          * to the RTC again, or write to the RTC but then they don't call
          * settimeofday to perform this operation.
          */
 #ifdef CONFIG_PPC_ISERIES
-        if ( first_settimeofday ) {
+        if (first_settimeofday) {
                 iSeries_tb_recal();
                 first_settimeofday = 0;
         }
@@ -420,7 +516,7 @@ int do_settimeofday(struct timespec *tv)
         tb_delta = tb_ticks_since(tb_last_stamp);
         tb_delta += (jiffies - wall_jiffies) * tb_ticks_per_jiffy;
 
-        new_nsec -= tb_delta / tb_ticks_per_usec / 1000;
+        new_nsec -= 1000 * mulhwu(tb_to_us, tb_delta);
 
         wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - new_sec);
         wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - new_nsec);
@@ -435,28 +531,15 @@ int do_settimeofday(struct timespec *tv)
 
         ntp_clear();
 
-        delta_xsec = mulhdu( (tb_last_stamp-do_gtod.varp->tb_orig_stamp),
-                             do_gtod.varp->tb_to_xs );
-
-        new_xsec = (new_nsec * XSEC_PER_SEC) / NSEC_PER_SEC;
-        new_xsec += new_sec * XSEC_PER_SEC;
-        if ( new_xsec > delta_xsec ) {
-                do_gtod.varp->stamp_xsec = new_xsec - delta_xsec;
-                systemcfg->stamp_xsec = new_xsec - delta_xsec;
-        }
-        else {
-                /* This is only for the case where the user is setting the time
-                 * way back to a time such that the boot time would have been
-                 * before 1970 ... eg. we booted ten days ago, and we are setting
-                 * the time to Jan 5, 1970 */
-                do_gtod.varp->stamp_xsec = new_xsec;
-                do_gtod.varp->tb_orig_stamp = tb_last_stamp;
-                systemcfg->stamp_xsec = new_xsec;
-                systemcfg->tb_orig_stamp = tb_last_stamp;
-        }
+        new_xsec = (u64)new_nsec * XSEC_PER_SEC;
+        do_div(new_xsec, NSEC_PER_SEC);
+        new_xsec += (u64)new_sec * XSEC_PER_SEC;
+        update_gtod(tb_last_stamp, new_xsec, do_gtod.varp->tb_to_xs);
 
+#ifdef CONFIG_PPC64
         systemcfg->tz_minuteswest = sys_tz.tz_minuteswest;
         systemcfg->tz_dsttime = sys_tz.tz_dsttime;
+#endif
 
         write_sequnlock_irqrestore(&xtime_lock, flags);
         clock_was_set();
@@ -520,21 +603,40 @@ void __init generic_calibrate_decr(void)
         tb_to_us = mulhwu_scale_factor(ppc_tb_freq, 1000000);
         div128_by_32(1024*1024, 0, tb_ticks_per_sec, &divres);
         tb_to_xs = divres.result_low;
-
-        setup_default_decr();
 }
 #endif
 
+unsigned long get_boot_time(void)
+{
+        struct rtc_time tm;
+
+        if (ppc_md.get_boot_time)
+                return ppc_md.get_boot_time();
+        if (!ppc_md.get_rtc_time)
+                return 0;
+        ppc_md.get_rtc_time(&tm);
+        return mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
+                      tm.tm_hour, tm.tm_min, tm.tm_sec);
+}
+
+/* This function is only called on the boot processor */
 void __init time_init(void)
 {
-        /* This function is only called on the boot processor */
         unsigned long flags;
-        struct rtc_time tm;
+        unsigned long tm = 0;
         struct div_result res;
-        unsigned long scale, shift;
+        u64 scale;
+        unsigned shift;
+
+        if (ppc_md.time_init != NULL)
+                timezone_offset = ppc_md.time_init();
 
         ppc_md.calibrate_decr();
 
+#ifdef CONFIG_PPC64
+        get_paca()->default_decr = tb_ticks_per_jiffy;
+#endif
+
         /*
          * Compute scale factor for sched_clock.
          * The calibrate_decr() function has set tb_ticks_per_sec,
@@ -557,29 +659,37 @@ void __init time_init(void)
 #ifdef CONFIG_PPC_ISERIES
         if (!piranha_simulator)
 #endif
-                ppc_md.get_boot_time(&tm);
+                tm = get_boot_time();
 
         write_seqlock_irqsave(&xtime_lock, flags);
-        xtime.tv_sec = mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
-                              tm.tm_hour, tm.tm_min, tm.tm_sec);
+        xtime.tv_sec = tm;
+        xtime.tv_nsec = 0;
         tb_last_stamp = get_tb();
         do_gtod.varp = &do_gtod.vars[0];
         do_gtod.var_idx = 0;
         do_gtod.varp->tb_orig_stamp = tb_last_stamp;
-        get_paca()->next_jiffy_update_tb = tb_last_stamp + tb_ticks_per_jiffy;
-        do_gtod.varp->stamp_xsec = xtime.tv_sec * XSEC_PER_SEC;
+        __get_cpu_var(last_jiffy) = tb_last_stamp;
+        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;
         do_gtod.tb_to_us = tb_to_us;
+#ifdef CONFIG_PPC64
         systemcfg->tb_orig_stamp = tb_last_stamp;
         systemcfg->tb_update_count = 0;
         systemcfg->tb_ticks_per_sec = tb_ticks_per_sec;
         systemcfg->stamp_xsec = xtime.tv_sec * XSEC_PER_SEC;
         systemcfg->tb_to_xs = tb_to_xs;
+#endif
 
         time_freq = 0;
 
-        xtime.tv_nsec = 0;
+        /* If platform provided a timezone (pmac), we correct the time */
+        if (timezone_offset) {
+                sys_tz.tz_minuteswest = -timezone_offset / 60;
+                sys_tz.tz_dsttime = 0;
+                xtime.tv_sec -= timezone_offset;
+        }
+
         last_rtc_update = xtime.tv_sec;
         set_normalized_timespec(&wall_to_monotonic,
                                 -xtime.tv_sec, -xtime.tv_nsec);
@@ -602,25 +712,28 @@ void __init time_init(void)
 
 void ppc_adjtimex(void)
 {
-        unsigned long den, new_tb_ticks_per_sec, tb_ticks, old_xsec, new_tb_to_xs, new_xsec, new_stamp_xsec;
+#ifdef CONFIG_PPC64
+        unsigned long den, new_tb_ticks_per_sec, tb_ticks, old_xsec,
+                new_tb_to_xs, new_xsec, new_stamp_xsec;
         unsigned long tb_ticks_per_sec_delta;
         long delta_freq, ltemp;
         struct div_result divres; 
         unsigned long flags;
-        struct gettimeofday_vars * temp_varp;
-        unsigned temp_idx;
         long singleshot_ppm = 0;
 
-        /* Compute parts per million frequency adjustment to accomplish the time adjustment
-           implied by time_offset to be applied over the elapsed time indicated by time_constant.
-           Use SHIFT_USEC to get it into the same units as time_freq. */
+        /*
+         * Compute parts per million frequency adjustment to
+         * accomplish the time adjustment implied by time_offset to be
+         * applied over the elapsed time indicated by time_constant.
+         * Use SHIFT_USEC to get it into the same units as
+         * time_freq.
+         */
         if ( time_offset < 0 ) {
                 ltemp = -time_offset;
                 ltemp <<= SHIFT_USEC - SHIFT_UPDATE;
                 ltemp >>= SHIFT_KG + time_constant;
                 ltemp = -ltemp;
-        }
-        else {
+        } else {
                 ltemp = time_offset;
                 ltemp <<= SHIFT_USEC - SHIFT_UPDATE;
                 ltemp >>= SHIFT_KG + time_constant;
@@ -637,7 +750,10 @@ void ppc_adjtimex(void)
         
                 adjusting_time = 1;
                 
-                /* Compute parts per million frequency adjustment to match time_adjust */
+                /*
+                 * Compute parts per million frequency adjustment
+                 * to match time_adjust
+                 */
                 singleshot_ppm = tickadj * HZ;  
                 /*
                  * The adjustment should be tickadj*HZ to match the code in
@@ -645,7 +761,7 @@ void ppc_adjtimex(void)
                  * large. 3/4 of tickadj*HZ seems about right
                  */
                 singleshot_ppm -= singleshot_ppm / 4;
-                /* Use SHIFT_USEC to get it into the same units as time_freq */ 
+                /* Use SHIFT_USEC to get it into the same units as time_freq */
                 singleshot_ppm <<= SHIFT_USEC;
                 if ( time_adjust < 0 )
                         singleshot_ppm = -singleshot_ppm;
@@ -661,7 +777,10 @@ void ppc_adjtimex(void)
         /* Add up all of the frequency adjustments */
         delta_freq = time_freq + ltemp + singleshot_ppm;
         
-        /* Compute a new value for tb_ticks_per_sec based on the frequency adjustment */
+        /*
+         * Compute a new value for tb_ticks_per_sec based on
+         * the frequency adjustment
+         */
         den = 1000000 * (1 << (SHIFT_USEC - 8));
         if ( delta_freq < 0 ) {
                 tb_ticks_per_sec_delta = ( tb_ticks_per_sec * ( (-delta_freq) >> (SHIFT_USEC - 8))) / den;
@@ -676,61 +795,37 @@ void ppc_adjtimex(void)
         printk("ppc_adjtimex: ltemp = %ld, time_freq = %ld, singleshot_ppm = %ld\n", ltemp, time_freq, singleshot_ppm);
         printk("ppc_adjtimex: tb_ticks_per_sec - base = %ld  new = %ld\n", tb_ticks_per_sec, new_tb_ticks_per_sec);
 #endif
-                                
-        /* Compute a new value of tb_to_xs (used to convert tb to microseconds and a new value of 
-           stamp_xsec which is the time (in 1/2^20 second units) corresponding to tb_orig_stamp.  This 
-           new value of stamp_xsec compensates for the change in frequency (implied by the new tb_to_xs)
-           which guarantees that the current time remains the same */ 
+
+        /*
+         * Compute a new value of tb_to_xs (used to convert tb to
+         * microseconds) and a new value of stamp_xsec which is the
+         * time (in 1/2^20 second units) corresponding to
+         * tb_orig_stamp.  This new value of stamp_xsec compensates
+         * for the change in frequency (implied by the new tb_to_xs)
+         * which guarantees that the current time remains the same.
+         */
         write_seqlock_irqsave( &xtime_lock, flags );
         tb_ticks = get_tb() - do_gtod.varp->tb_orig_stamp;
-        div128_by_32( 1024*1024, 0, new_tb_ticks_per_sec, &divres );
+        div128_by_32(1024*1024, 0, new_tb_ticks_per_sec, &divres);
         new_tb_to_xs = divres.result_low;
-        new_xsec = mulhdu( tb_ticks, new_tb_to_xs );
+        new_xsec = mulhdu(tb_ticks, new_tb_to_xs);
 
-        old_xsec = mulhdu( tb_ticks, do_gtod.varp->tb_to_xs );
+        old_xsec = mulhdu(tb_ticks, do_gtod.varp->tb_to_xs);
         new_stamp_xsec = do_gtod.varp->stamp_xsec + old_xsec - new_xsec;
 
-        /* There are two copies of tb_to_xs and stamp_xsec so that no lock is needed to access and use these
-           values in do_gettimeofday.  We alternate the copies and as long as a reasonable time elapses between
-           changes, there will never be inconsistent values.  ntpd has a minimum of one minute between updates */
-
-        temp_idx = (do_gtod.var_idx == 0);
-        temp_varp = &do_gtod.vars[temp_idx];
-
-        temp_varp->tb_to_xs = new_tb_to_xs;
-        temp_varp->stamp_xsec = new_stamp_xsec;
-        temp_varp->tb_orig_stamp = do_gtod.varp->tb_orig_stamp;
-        smp_mb();
-        do_gtod.varp = temp_varp;
-        do_gtod.var_idx = temp_idx;
-
-        /*
-         * tb_update_count is used to allow the problem state gettimeofday code
-         * to assure itself that it sees a consistent view of the tb_to_xs and
-         * stamp_xsec variables.  It reads the tb_update_count, then reads
-         * tb_to_xs and stamp_xsec and then reads tb_update_count again.  If
-         * the two values of tb_update_count match and are even then the
-         * tb_to_xs and stamp_xsec values are consistent.  If not, then it
-         * loops back and reads them again until this criteria is met.
-         */
-        ++(systemcfg->tb_update_count);
-        smp_wmb();
-        systemcfg->tb_to_xs = new_tb_to_xs;
-        systemcfg->stamp_xsec = new_stamp_xsec;
-        smp_wmb();
-        ++(systemcfg->tb_update_count);
+        update_gtod(do_gtod.varp->tb_orig_stamp, new_stamp_xsec, new_tb_to_xs);
 
         write_sequnlock_irqrestore( &xtime_lock, flags );
-
+#endif /* CONFIG_PPC64 */
 }
 
 
-#define TICK_SIZE tick
 #define FEBRUARY        2
 #define STARTOFTIME     1970
 #define SECDAY          86400L
 #define SECYR           (SECDAY * 365)
-#define leapyear(year)          ((year) % 4 == 0)
+#define leapyear(year)          ((year) % 4 == 0 && \
+                                 ((year) % 100 != 0 || (year) % 400 == 0))
 #define days_in_year(a)         (leapyear(a) ? 366 : 365)
 #define days_in_month(a)        (month_days[(a) - 1])
 
@@ -748,37 +843,25 @@ void GregorianDay(struct rtc_time * tm)
         int day;
         int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
 
-        lastYear=tm->tm_year-1;
+        lastYear = tm->tm_year - 1;
 
         /*
          * Number of leap corrections to apply up to end of last year
          */
-        leapsToDate = lastYear/4 - lastYear/100 + lastYear/400;
+        leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400;
 
         /*
          * This year is a leap year if it is divisible by 4 except when it is
          * divisible by 100 unless it is divisible by 400
          *
-         * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 will be
+         * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was
          */
-        if((tm->tm_year%4==0) &&
-           ((tm->tm_year%100!=0) || (tm->tm_year%400==0)) &&
-           (tm->tm_mon>2))
-        {
-                /*
-                 * We are past Feb. 29 in a leap year
-                 */
-                day=1;
-        }
-        else
-        {
-                day=0;
-        }
+        day = tm->tm_mon > 2 && leapyear(tm->tm_year);
 
         day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] +
                    tm->tm_mday;
 
-        tm->tm_wday=day%7;
+        tm->tm_wday = day % 7;
 }
 
 void to_tm(int tim, struct rtc_time * tm)
@@ -824,14 +907,16 @@ void to_tm(int tim, struct rtc_time * tm)
  * oscillators and the precision with which the timebase frequency
  * is measured but does not harm.
  */
-unsigned mulhwu_scale_factor(unsigned inscale, unsigned outscale) {
+unsigned mulhwu_scale_factor(unsigned inscale, unsigned outscale)
+{
         unsigned mlt=0, tmp, err;
         /* No concern for performance, it's done once: use a stupid
          * but safe and compact method to find the multiplier.
          */
   
         for (tmp = 1U<<31; tmp != 0; tmp >>= 1) {
-                if (mulhwu(inscale, mlt|tmp) < outscale) mlt|=tmp;
+                if (mulhwu(inscale, mlt|tmp) < outscale)
+                        mlt |= tmp;
         }
   
         /* We might still be off by 1 for the best approximation.
@@ -841,39 +926,53 @@ unsigned mulhwu_scale_factor(unsigned inscale, unsigned outscale) {
          * some might have been forgotten in the test however.
          */
   
-        err = inscale*(mlt+1);
-        if (err <= inscale/2) mlt++;
+        err = inscale * (mlt+1);
+        if (err <= inscale/2)
+                mlt++;
         return mlt;
-  }
+}
 
 /*
  * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
  * result.
  */
-
-void div128_by_32( unsigned long dividend_high, unsigned long dividend_low,
-                   unsigned divisor, struct div_result *dr )
+void div128_by_32(u64 dividend_high, u64 dividend_low,
+                  unsigned divisor, struct div_result *dr)
 {
-        unsigned long a,b,c,d, w,x,y,z, ra,rb,rc;
+        unsigned long a, b, c, d;
+        unsigned long w, x, y, z;
+        u64 ra, rb, rc;
 
         a = dividend_high >> 32;
         b = dividend_high & 0xffffffff;
         c = dividend_low >> 32;
         d = dividend_low & 0xffffffff;
 
-        w = a/divisor;
-        ra = (a - (w * divisor)) << 32;
+        w = a / divisor;
+        ra = ((u64)(a - (w * divisor)) << 32) + b;
+
+#ifdef CONFIG_PPC64
+        x = ra / divisor;
+        rb = ((ra - (x * divisor)) << 32) + c;
 
-        x = (ra + b)/divisor;
-        rb = ((ra + b) - (x * divisor)) << 32;
+        y = rb / divisor;
+        rc = ((rb - (y * divisor)) << 32) + d;
 
-        y = (rb + c)/divisor;
-        rc = ((rb + b) - (y * divisor)) << 32;
+        z = rc / divisor;
+#else
+        /* for 32-bit, use do_div from div64.h */
+        rb = ((u64) do_div(ra, divisor) << 32) + c;
+        x = ra;
 
-        z = (rc + d)/divisor;
+        rc = ((u64) do_div(rb, divisor) << 32) + d;
+        y = rb;
+
+        do_div(rc, divisor);
+        z = rc;
+#endif
 
-        dr->result_high = (w << 32) + x;
-        dr->result_low  = (y << 32) + z;
+        dr->result_high = ((u64)w << 32) + x;
+        dr->result_low  = ((u64)y << 32) + z;
 
 }
 
diff --git a/arch/powerpc/platforms/powermac/cpufreq.c b/arch/powerpc/platforms/powermac/cpufreq.c
index bcd9224f3f90..c47f8b69725c 100644
--- a/arch/powerpc/platforms/powermac/cpufreq.c
+++ b/arch/powerpc/platforms/powermac/cpufreq.c
@@ -110,15 +110,6 @@ static inline void local_delay(unsigned long ms)
                 msleep(ms);
 }
 
-static inline void wakeup_decrementer(void)
-{
-        set_dec(tb_ticks_per_jiffy);
-        /* No currently-supported powerbook has a 601,
-         * so use get_tbl, not native
-         */
-        last_jiffy_stamp(0) = tb_last_stamp = get_tbl();
-}
-
 #ifdef DEBUG_FREQ
 static inline void debug_calc_bogomips(void)
 {
diff --git a/arch/powerpc/platforms/powermac/time.c b/arch/powerpc/platforms/powermac/time.c
index 3ee6d8aa14c4..eb9969b52f96 100644
--- a/arch/powerpc/platforms/powermac/time.c
+++ b/arch/powerpc/platforms/powermac/time.c
@@ -6,6 +6,8 @@
  *
  * Paul Mackerras       August 1996.
  * Copyright (C) 1996 Paul Mackerras.
+ * Copyright (C) 2003-2005 Benjamin Herrenschmidt.
+ *
  */
 #include <linux/config.h>
 #include <linux/errno.h>
@@ -19,7 +21,9 @@
 #include <linux/adb.h>
 #include <linux/cuda.h>
 #include <linux/pmu.h>
+#include <linux/interrupt.h>
 #include <linux/hardirq.h>
+#include <linux/rtc.h>
 
 #include <asm/sections.h>
 #include <asm/prom.h>
@@ -30,6 +34,14 @@
 #include <asm/time.h>
 #include <asm/nvram.h>
 
+#undef DEBUG
+
+#ifdef DEBUG
+#define DBG(x...) printk(x)
+#else
+#define DBG(x...)
+#endif
+
 /* Apparently the RTC stores seconds since 1 Jan 1904 */
 #define RTC_OFFSET      2082844800
 
@@ -54,10 +66,7 @@
 /* Bits in IFR and IER */
 #define T1_INT          0x40            /* Timer 1 interrupt */
 
-extern struct timezone sys_tz;
-
-long __init
-pmac_time_init(void)
+long __init pmac_time_init(void)
 {
 #ifdef CONFIG_NVRAM
         s32 delta = 0;
@@ -210,7 +219,7 @@ via_calibrate_decr(void)
         tb_ticks_per_jiffy = (dstart - dend) / ((6 * HZ)/100);
         tb_to_us = mulhwu_scale_factor(dstart - dend, 60000);
 
-        printk(KERN_INFO "via_calibrate_decr: ticks per jiffy = %u (%u ticks)\n",
+        printk(KERN_INFO "via_calibrate_decr: ticks per jiffy = %lu (%u ticks)\n",
                tb_ticks_per_jiffy, dstart - dend);
 
         iounmap(via);
@@ -228,6 +237,7 @@ time_sleep_notify(struct pmu_sleep_notifier *self, int when)
         static unsigned long time_diff;
         unsigned long flags;
         unsigned long seq;
+        struct timespec tv;
 
         switch (when) {
         case PBOOK_SLEEP_NOW:
@@ -237,11 +247,9 @@ time_sleep_notify(struct pmu_sleep_notifier *self, int when)
                 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
                 break;
         case PBOOK_WAKE:
-                write_seqlock_irqsave(&xtime_lock, flags);
-                xtime.tv_sec = pmac_get_rtc_time() + time_diff;
-                xtime.tv_nsec = 0;
-                last_rtc_update = xtime.tv_sec;
-                write_sequnlock_irqrestore(&xtime_lock, flags);
+                tv.tv_sec = pmac_get_boot_time() + time_diff;
+                tv.tv_nsec = 0;
+                do_settimeofday(&tv);
                 break;
         }
         return PBOOK_SLEEP_OK;
diff --git a/arch/ppc/kernel/Makefile b/arch/ppc/kernel/Makefile
index 5a742c7b0509..ccbc442c9ed3 100644
--- a/arch/ppc/kernel/Makefile
+++ b/arch/ppc/kernel/Makefile
@@ -37,7 +37,7 @@ endif
 # These are here while we do the architecture merge
 
 else
-obj-y                           := irq.o idle.o time.o \
+obj-y                           := irq.o idle.o \
                                         align.o perfmon.o
 obj-$(CONFIG_6xx)               += l2cr.o cpu_setup_6xx.o
 obj-$(CONFIG_SOFTWARE_SUSPEND)  += swsusp.o
diff --git a/arch/ppc/kernel/time.c b/arch/ppc/kernel/time.c
index 22d7fd1e0aea..76f44ce4772e 100644
--- a/arch/ppc/kernel/time.c
+++ b/arch/ppc/kernel/time.c
@@ -121,6 +121,15 @@ unsigned long profile_pc(struct pt_regs *regs)
 EXPORT_SYMBOL(profile_pc);
 #endif
 
+void wakeup_decrementer(void)
+{
+        set_dec(tb_ticks_per_jiffy);
+        /* No currently-supported powerbook has a 601,
+         * so use get_tbl, not native
+         */
+        last_jiffy_stamp(0) = tb_last_stamp = get_tbl();
+}
+
 /*
  * timer_interrupt - gets called when the decrementer overflows,
  * with interrupts disabled.
diff --git a/arch/ppc64/kernel/Makefile b/arch/ppc64/kernel/Makefile
index 8c9012f0ce6a..18f477fa1df2 100644
--- a/arch/ppc64/kernel/Makefile
+++ b/arch/ppc64/kernel/Makefile
@@ -12,7 +12,7 @@ obj-y               :=	setup.o entry.o misc.o prom.o
 endif
 
 obj-y               +=  irq.o idle.o dma.o \
-                        time.o signal.o \
+                        signal.o \
                         align.o bitops.o pacaData.o \
                         udbg.o ioctl32.o \
                         rtc.o \
diff --git a/arch/ppc64/kernel/pmac_time.c b/arch/ppc64/kernel/pmac_time.c
index c89bfefbbecd..56f335115916 100644
--- a/arch/ppc64/kernel/pmac_time.c
+++ b/arch/ppc64/kernel/pmac_time.c
@@ -180,7 +180,5 @@ void __init pmac_calibrate_decr(void)
         if (fp == 0)
                 panic("can't get cpu processor frequency");
         ppc_proc_freq = *fp;
-
-        setup_default_decr();
 }
 
diff --git a/arch/ppc64/kernel/setup.c b/arch/ppc64/kernel/setup.c
index 776b55b45e1b..3e6c1547b718 100644
--- a/arch/ppc64/kernel/setup.c
+++ b/arch/ppc64/kernel/setup.c
@@ -1083,15 +1083,6 @@ void ppc64_terminate_msg(unsigned int src, const char *msg)
         printk("[terminate]%04x %s\n", src, msg);
 }
 
-/* This should only be called on processor 0 during calibrate decr */
-void __init setup_default_decr(void)
-{
-        struct paca_struct *lpaca = get_paca();
-
-        lpaca->default_decr = tb_ticks_per_jiffy;
-        lpaca->next_jiffy_update_tb = get_tb() + tb_ticks_per_jiffy;
-}
-
 #ifndef CONFIG_PPC_ISERIES
 /*
  * This function can be used by platforms to "find" legacy serial ports.