1 files changed, 227 insertions, 276 deletions

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index c627cf86d1e3..9368da371f36 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -65,24 +65,68 @@
 #include <asm/div64.h>
 #include <asm/smp.h>
 #include <asm/vdso_datapage.h>
-#ifdef CONFIG_PPC64
 #include <asm/firmware.h>
-#endif
 #ifdef CONFIG_PPC_ISERIES
 #include <asm/iseries/it_lp_queue.h>
 #include <asm/iseries/hv_call_xm.h>
 #endif
-#include <asm/smp.h>
 
-/* keep track of when we need to update the rtc */
-time_t last_rtc_update;
+/* powerpc clocksource/clockevent code */
+
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+
+static cycle_t rtc_read(void);
+static struct clocksource clocksource_rtc = {
+	.name         = "rtc",
+	.rating       = 400,
+	.flags        = CLOCK_SOURCE_IS_CONTINUOUS,
+	.mask         = CLOCKSOURCE_MASK(64),
+	.shift        = 22,
+	.mult         = 0,	/* To be filled in */
+	.read         = rtc_read,
+};
+
+static cycle_t timebase_read(void);
+static struct clocksource clocksource_timebase = {
+	.name         = "timebase",
+	.rating       = 400,
+	.flags        = CLOCK_SOURCE_IS_CONTINUOUS,
+	.mask         = CLOCKSOURCE_MASK(64),
+	.shift        = 22,
+	.mult         = 0,	/* To be filled in */
+	.read         = timebase_read,
+};
+
+#define DECREMENTER_MAX	0x7fffffff
+
+static int decrementer_set_next_event(unsigned long evt,
+				      struct clock_event_device *dev);
+static void decrementer_set_mode(enum clock_event_mode mode,
+				 struct clock_event_device *dev);
+
+static struct clock_event_device decrementer_clockevent = {
+       .name           = "decrementer",
+       .rating         = 200,
+       .shift          = 16,
+       .mult           = 0,	/* To be filled in */
+       .irq            = 0,
+       .set_next_event = decrementer_set_next_event,
+       .set_mode       = decrementer_set_mode,
+       .features       = CLOCK_EVT_FEAT_ONESHOT,
+};
+
+static DEFINE_PER_CPU(struct clock_event_device, decrementers);
+void init_decrementer_clockevent(void);
+static DEFINE_PER_CPU(u64, decrementer_next_tb);
+
 #ifdef CONFIG_PPC_ISERIES
 static unsigned long __initdata iSeries_recal_titan;
 static signed long __initdata iSeries_recal_tb;
-#endif
 
-/* The decrementer counts down by 128 every 128ns on a 601. */
-#define DECREMENTER_COUNT_601	(1000000000 / HZ)
+/* Forward declaration is only needed for iSereis compiles */
+void __init clocksource_init(void);
+#endif
 
 #define XSEC_PER_SEC (1024*1024)
 
@@ -349,98 +393,6 @@ void udelay(unsigned long usecs)
 }
 EXPORT_SYMBOL(udelay);
 
-static __inline__ void timer_check_rtc(void)
-{
-        /*
-         * update the rtc when needed, this should be performed on the
-         * right fraction of a second. Half or full second ?
-         * Full second works on mk48t59 clocks, others need testing.
-         * Note that this update is basically only used through 
-         * the adjtimex system calls. Setting the HW clock in
-         * any other way is a /dev/rtc and userland business.
-         * This is still wrong by -0.5/+1.5 jiffies because of the
-         * timer interrupt resolution and possible delay, but here we 
-         * hit a quantization limit which can only be solved by higher
-         * resolution timers and decoupling time management from timer
-         * interrupts. This is also wrong on the clocks
-         * which require being written at the half second boundary.
-         * We should have an rtc call that only sets the minutes and
-         * seconds like on Intel to avoid problems with non UTC clocks.
-         */
-        if (ppc_md.set_rtc_time && ntp_synced() &&
-	    xtime.tv_sec - last_rtc_update >= 659 &&
-	    abs((xtime.tv_nsec/1000) - (1000000-1000000/HZ)) < 500000/HZ) {
-		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 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)
-	 * if done in units of 1/2^20 rather than microseconds.
-	 * The conversion to microseconds at the end is done
-	 * without a divide (and in fact, without a multiply)
-	 */
-	temp_varp = do_gtod.varp;
-
-	/* 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);
-	sec = xsec / XSEC_PER_SEC;
-	usec = (unsigned long)xsec & (XSEC_PER_SEC - 1);
-	usec = SCALE_XSEC(usec, 1000000);
-
-	tv->tv_sec = sec;
-	tv->tv_usec = usec;
-}
-
-void do_gettimeofday(struct timeval *tv)
-{
-	if (__USE_RTC()) {
-		/* do this the old way */
-		unsigned long flags, seq;
-		unsigned int sec, nsec, usec;
-
-		do {
-			seq = read_seqbegin_irqsave(&xtime_lock, flags);
-			sec = xtime.tv_sec;
-			nsec = xtime.tv_nsec + tb_ticks_since(tb_last_jiffy);
-		} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-		usec = nsec / 1000;
-		while (usec >= 1000000) {
-			usec -= 1000000;
-			++sec;
-		}
-		tv->tv_sec = sec;
-		tv->tv_usec = usec;
-		return;
-	}
-	__do_gettimeofday(tv);
-}
-
-EXPORT_SYMBOL(do_gettimeofday);
 
 /*
  * There are two copies of tb_to_xs and stamp_xsec so that no
@@ -486,56 +438,6 @@ static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec,
 	++(vdso_data->tb_update_count);
 }
 
-/*
- * 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;
-	u64 tlen, t2x;
-	u64 tb, xsec_old, xsec_new;
-	struct gettimeofday_vars *varp;
-
-	if (__USE_RTC())
-		return;
-	tlen = current_tick_length();
-	offset = cur_tb - do_gtod.varp->tb_orig_stamp;
-	if (tlen == last_tick_len && offset < 0x80000000u)
-		return;
-	if (tlen != last_tick_len) {
-		t2x = mulhdu(tlen << TICKLEN_SHIFT, ticklen_to_xs);
-		last_tick_len = tlen;
-	} else
-		t2x = do_gtod.varp->tb_to_xs;
-	new_stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC;
-	do_div(new_stamp_xsec, 1000000000);
-	new_stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC;
-
-	++vdso_data->tb_update_count;
-	smp_mb();
-
-	/*
-	 * Make sure time doesn't go backwards for userspace gettimeofday.
-	 */
-	tb = get_tb();
-	varp = do_gtod.varp;
-	xsec_old = mulhdu(tb - varp->tb_orig_stamp, varp->tb_to_xs)
-		+ varp->stamp_xsec;
-	xsec_new = mulhdu(tb - cur_tb, t2x) + new_stamp_xsec;
-	if (xsec_new < xsec_old)
-		new_stamp_xsec += xsec_old - xsec_new;
-
-	update_gtod(cur_tb, new_stamp_xsec, t2x);
-}
-
 #ifdef CONFIG_SMP
 unsigned long profile_pc(struct pt_regs *regs)
 {
@@ -607,6 +509,8 @@ static int __init iSeries_tb_recal(void)
 	iSeries_recal_titan = titan;
 	iSeries_recal_tb = tb;
 
+	/* Called here as now we know accurate values for the timebase */
+	clocksource_init();
 	return 0;
 }
 late_initcall(iSeries_tb_recal);
@@ -636,20 +540,30 @@ void __init iSeries_time_init_early(void)
 void timer_interrupt(struct pt_regs * regs)
 {
 	struct pt_regs *old_regs;
-	int next_dec;
 	int cpu = smp_processor_id();
-	unsigned long ticks;
-	u64 tb_next_jiffy;
+	struct clock_event_device *evt = &per_cpu(decrementers, cpu);
+	u64 now;
+
+	/* Ensure a positive value is written to the decrementer, or else
+	 * some CPUs will continuue to take decrementer exceptions */
+	set_dec(DECREMENTER_MAX);
 
 #ifdef CONFIG_PPC32
 	if (atomic_read(&ppc_n_lost_interrupts) != 0)
 		do_IRQ(regs);
 #endif
 
+	now = get_tb_or_rtc();
+	if (now < per_cpu(decrementer_next_tb, cpu)) {
+		/* not time for this event yet */
+		now = per_cpu(decrementer_next_tb, cpu) - now;
+		if (now <= DECREMENTER_MAX)
+			set_dec((unsigned int)now - 1);
+		return;
+	}
 	old_regs = set_irq_regs(regs);
 	irq_enter();
 
-	profile_tick(CPU_PROFILING);
 	calculate_steal_time();
 
 #ifdef CONFIG_PPC_ISERIES
@@ -657,46 +571,20 @@ void timer_interrupt(struct pt_regs * regs)
 		get_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;
-
-		/*
-		 * We cannot disable the decrementer, so in the period
-		 * between this cpu's being marked offline in cpu_online_map
-		 * and calling stop-self, it is taking timer interrupts.
-		 * Avoid calling into the scheduler rebalancing code if this
-		 * is the case.
-		 */
-		if (!cpu_is_offline(cpu))
-			account_process_time(regs);
-
-		/*
-		 * No need to check whether cpu is offline here; boot_cpuid
-		 * should have been fixed up by now.
-		 */
-		if (cpu != boot_cpuid)
-			continue;
+	/*
+	 * We cannot disable the decrementer, so in the period
+	 * between this cpu's being marked offline in cpu_online_map
+	 * and calling stop-self, it is taking timer interrupts.
+	 * Avoid calling into the scheduler rebalancing code if this
+	 * is the case.
+	 */
+	if (!cpu_is_offline(cpu))
+		account_process_time(regs);
 
-		write_seqlock(&xtime_lock);
-		tb_next_jiffy = tb_last_jiffy + tb_ticks_per_jiffy;
-		if (__USE_RTC() && tb_next_jiffy >= 1000000000)
-			tb_next_jiffy -= 1000000000;
-		if (per_cpu(last_jiffy, cpu) >= tb_next_jiffy) {
-			tb_last_jiffy = tb_next_jiffy;
-			do_timer(1);
-			timer_recalc_offset(tb_last_jiffy);
-			timer_check_rtc();
-		}
-		write_sequnlock(&xtime_lock);
-	}
-	
-	next_dec = tb_ticks_per_jiffy - ticks;
-	set_dec(next_dec);
+	if (evt->event_handler)
+		evt->event_handler(evt);
+	else
+		evt->set_next_event(DECREMENTER_MAX, evt);
 
 #ifdef CONFIG_PPC_ISERIES
 	if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending())
@@ -762,71 +650,6 @@ unsigned long long sched_clock(void)
 	return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
 }
 
-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;
-	u64 new_xsec;
-	unsigned long tb_delta;
-
-	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 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.
-	 */
-
-	/* Make userspace gettimeofday spin until we're done. */
-	++vdso_data->tb_update_count;
-	smp_mb();
-
-	/*
-	 * Subtract off the number of nanoseconds since the
-	 * beginning of the last tick.
-	 */
-	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);
-
-	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - new_sec);
-	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - new_nsec);
-
- 	set_normalized_timespec(&xtime, new_sec, new_nsec);
-	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
-
-	/* In case of a large backwards jump in time with NTP, we want the 
-	 * clock to be updated as soon as the PLL is again in lock.
-	 */
-	last_rtc_update = new_sec - 658;
-
-	ntp_clear();
-
-	new_xsec = xtime.tv_nsec;
-	if (new_xsec != 0) {
-		new_xsec *= XSEC_PER_SEC;
-		do_div(new_xsec, NSEC_PER_SEC);
-	}
-	new_xsec += (u64)xtime.tv_sec * XSEC_PER_SEC;
-	update_gtod(tb_last_jiffy, new_xsec, do_gtod.varp->tb_to_xs);
-
-	vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
-	vdso_data->tz_dsttime = sys_tz.tz_dsttime;
-
-	write_sequnlock_irqrestore(&xtime_lock, flags);
-	clock_was_set();
-	return 0;
-}
-
-EXPORT_SYMBOL(do_settimeofday);
-
 static int __init get_freq(char *name, int cells, unsigned long *val)
 {
 	struct device_node *cpu;
@@ -869,7 +692,7 @@ void __init generic_calibrate_decr(void)
 				"(not found)\n");
 	}
 
-#ifdef CONFIG_BOOKE
+#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 	/* Set the time base to zero */
 	mtspr(SPRN_TBWL, 0);
 	mtspr(SPRN_TBWU, 0);
@@ -882,12 +705,35 @@ void __init generic_calibrate_decr(void)
 #endif
 }
 
-unsigned long get_boot_time(void)
+int update_persistent_clock(struct timespec now)
 {
 	struct rtc_time tm;
 
-	if (ppc_md.get_boot_time)
-		return ppc_md.get_boot_time();
+	if (!ppc_md.set_rtc_time)
+		return 0;
+
+	to_tm(now.tv_sec + 1 + timezone_offset, &tm);
+	tm.tm_year -= 1900;
+	tm.tm_mon -= 1;
+
+	return ppc_md.set_rtc_time(&tm);
+}
+
+unsigned long read_persistent_clock(void)
+{
+	struct rtc_time tm;
+	static int first = 1;
+
+	/* XXX this is a litle fragile but will work okay in the short term */
+	if (first) {
+		first = 0;
+		if (ppc_md.time_init)
+			timezone_offset = ppc_md.time_init();
+
+		/* get_boot_time() isn't guaranteed to be safe to call late */
+		if (ppc_md.get_boot_time)
+			return ppc_md.get_boot_time() -timezone_offset;
+	}
 	if (!ppc_md.get_rtc_time)
 		return 0;
 	ppc_md.get_rtc_time(&tm);
@@ -895,18 +741,128 @@ unsigned long get_boot_time(void)
 		      tm.tm_hour, tm.tm_min, tm.tm_sec);
 }
 
+/* clocksource code */
+static cycle_t rtc_read(void)
+{
+	return (cycle_t)get_rtc();
+}
+
+static cycle_t timebase_read(void)
+{
+	return (cycle_t)get_tb();
+}
+
+void update_vsyscall(struct timespec *wall_time, struct clocksource *clock)
+{
+	u64 t2x, stamp_xsec;
+
+	if (clock != &clocksource_timebase)
+		return;
+
+	/* Make userspace gettimeofday spin until we're done. */
+	++vdso_data->tb_update_count;
+	smp_mb();
+
+	/* XXX this assumes clock->shift == 22 */
+	/* 4611686018 ~= 2^(20+64-22) / 1e9 */
+	t2x = (u64) clock->mult * 4611686018ULL;
+	stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC;
+	do_div(stamp_xsec, 1000000000);
+	stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC;
+	update_gtod(clock->cycle_last, stamp_xsec, t2x);
+}
+
+void update_vsyscall_tz(void)
+{
+	/* Make userspace gettimeofday spin until we're done. */
+	++vdso_data->tb_update_count;
+	smp_mb();
+	vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
+	vdso_data->tz_dsttime = sys_tz.tz_dsttime;
+	smp_mb();
+	++vdso_data->tb_update_count;
+}
+
+void __init clocksource_init(void)
+{
+	struct clocksource *clock;
+
+	if (__USE_RTC())
+		clock = &clocksource_rtc;
+	else
+		clock = &clocksource_timebase;
+
+	clock->mult = clocksource_hz2mult(tb_ticks_per_sec, clock->shift);
+
+	if (clocksource_register(clock)) {
+		printk(KERN_ERR "clocksource: %s is already registered\n",
+		       clock->name);
+		return;
+	}
+
+	printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
+	       clock->name, clock->mult, clock->shift);
+}
+
+static int decrementer_set_next_event(unsigned long evt,
+				      struct clock_event_device *dev)
+{
+	__get_cpu_var(decrementer_next_tb) = get_tb_or_rtc() + evt;
+	/* The decrementer interrupts on the 0 -> -1 transition */
+	if (evt)
+		--evt;
+	set_dec(evt);
+	return 0;
+}
+
+static void decrementer_set_mode(enum clock_event_mode mode,
+				 struct clock_event_device *dev)
+{
+	if (mode != CLOCK_EVT_MODE_ONESHOT)
+		decrementer_set_next_event(DECREMENTER_MAX, dev);
+}
+
+static void register_decrementer_clockevent(int cpu)
+{
+	struct clock_event_device *dec = &per_cpu(decrementers, cpu);
+
+	*dec = decrementer_clockevent;
+	dec->cpumask = cpumask_of_cpu(cpu);
+
+	printk(KERN_ERR "clockevent: %s mult[%lx] shift[%d] cpu[%d]\n",
+	       dec->name, dec->mult, dec->shift, cpu);
+
+	clockevents_register_device(dec);
+}
+
+void init_decrementer_clockevent(void)
+{
+	int cpu = smp_processor_id();
+
+	decrementer_clockevent.mult = div_sc(ppc_tb_freq, NSEC_PER_SEC,
+					     decrementer_clockevent.shift);
+	decrementer_clockevent.max_delta_ns =
+		clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent);
+	decrementer_clockevent.min_delta_ns = 1000;
+
+	register_decrementer_clockevent(cpu);
+}
+
+void secondary_cpu_time_init(void)
+{
+	/* FIME: Should make unrelatred change to move snapshot_timebase
+	 * call here ! */
+	register_decrementer_clockevent(smp_processor_id());
+}
+
 /* This function is only called on the boot processor */
 void __init time_init(void)
 {
 	unsigned long flags;
-	unsigned long tm = 0;
 	struct div_result res;
 	u64 scale, x;
 	unsigned shift;
 
-        if (ppc_md.time_init != NULL)
-                timezone_offset = ppc_md.time_init();
-
 	if (__USE_RTC()) {
 		/* 601 processor: dec counts down by 128 every 128ns */
 		ppc_tb_freq = 1000000000;
@@ -981,19 +937,14 @@ void __init time_init(void)
 	/* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
 	boot_tb = get_tb_or_rtc();
 
-	tm = get_boot_time();
-
 	write_seqlock_irqsave(&xtime_lock, flags);
 
 	/* 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;
-		tm -= timezone_offset;
         }
 
-	xtime.tv_sec = tm;
-	xtime.tv_nsec = 0;
 	do_gtod.varp = &do_gtod.vars[0];
 	do_gtod.var_idx = 0;
 	do_gtod.varp->tb_orig_stamp = tb_last_jiffy;
@@ -1011,13 +962,13 @@ void __init time_init(void)
 
 	time_freq = 0;
 
-	last_rtc_update = xtime.tv_sec;
-	set_normalized_timespec(&wall_to_monotonic,
-	                        -xtime.tv_sec, -xtime.tv_nsec);
 	write_sequnlock_irqrestore(&xtime_lock, flags);
 
-	/* Not exact, but the timer interrupt takes care of this */
-	set_dec(tb_ticks_per_jiffy);
+	/* Register the clocksource, if we're not running on iSeries */
+	if (!firmware_has_feature(FW_FEATURE_ISERIES))
+		clocksource_init();
+
+	init_decrementer_clockevent();
 }