--- zzzz-none-000/linux-2.6.19.2/arch/powerpc/kernel/time.c	2007-01-10 19:10:37.000000000 +0000
+++ davinci-8020-5504/linux-2.6.19.2/arch/powerpc/kernel/time.c	2007-01-11 07:38:19.000000000 +0000
@@ -220,8 +220,11 @@
  */
 struct cpu_purr_data {
 	int	initialized;			/* thread is running */
+	u64	tb0;			/* timebase at origin time */
+	u64	purr0;			/* PURR at origin time */
 	u64	tb;			/* last TB value read */
 	u64	purr;			/* last PURR value read */
+	u64	stolen;			/* stolen time so far */
 	spinlock_t lock;
 };
 
@@ -231,8 +234,10 @@
 {
 	struct cpu_purr_data *p = &__get_cpu_var(cpu_purr_data);
 
-	p->tb = mftb();
-	p->purr = mfspr(SPRN_PURR);
+	p->tb0 = mftb();
+	p->purr0 = mfspr(SPRN_PURR);
+	p->tb = p->tb0;
+	p->purr = 0;
 	wmb();
 	p->initialized = 1;
 }
@@ -253,24 +258,37 @@
 
 void calculate_steal_time(void)
 {
-	u64 tb, purr;
+	u64 tb, purr, t0;
 	s64 stolen;
-	struct cpu_purr_data *pme;
+	struct cpu_purr_data *p0, *pme, *phim;
+	int cpu;
 
 	if (!cpu_has_feature(CPU_FTR_PURR))
 		return;
-	pme = &per_cpu(cpu_purr_data, smp_processor_id());
+	cpu = smp_processor_id();
+	pme = &per_cpu(cpu_purr_data, cpu);
 	if (!pme->initialized)
 		return;		/* this can happen in early boot */
-	spin_lock(&pme->lock);
+	p0 = &per_cpu(cpu_purr_data, cpu & ~1);
+	phim = &per_cpu(cpu_purr_data, cpu ^ 1);
+	spin_lock(&p0->lock);
 	tb = mftb();
-	purr = mfspr(SPRN_PURR);
-	stolen = (tb - pme->tb) - (purr - pme->purr);
-	if (stolen > 0)
+	purr = mfspr(SPRN_PURR) - pme->purr0;
+	if (!phim->initialized || !cpu_online(cpu ^ 1)) {
+		stolen = (tb - pme->tb) - (purr - pme->purr);
+	} else {
+		t0 = pme->tb0;
+		if (phim->tb0 < t0)
+			t0 = phim->tb0;
+		stolen = phim->tb - t0 - phim->purr - purr - p0->stolen;
+	}
+	if (stolen > 0) {
 		account_steal_time(current, stolen);
+		p0->stolen += stolen;
+	}
 	pme->tb = tb;
 	pme->purr = purr;
-	spin_unlock(&pme->lock);
+	spin_unlock(&p0->lock);
 }
 
 /*
@@ -279,17 +297,30 @@
  */
 static void snapshot_purr(void)
 {
-	struct cpu_purr_data *pme;
+	int cpu;
+	u64 purr;
+	struct cpu_purr_data *p0, *pme, *phim;
 	unsigned long flags;
 
 	if (!cpu_has_feature(CPU_FTR_PURR))
 		return;
-	pme = &per_cpu(cpu_purr_data, smp_processor_id());
-	spin_lock_irqsave(&pme->lock, flags);
-	pme->tb = mftb();
-	pme->purr = mfspr(SPRN_PURR);
+	cpu = smp_processor_id();
+	pme = &per_cpu(cpu_purr_data, cpu);
+	p0 = &per_cpu(cpu_purr_data, cpu & ~1);
+	phim = &per_cpu(cpu_purr_data, cpu ^ 1);
+	spin_lock_irqsave(&p0->lock, flags);
+	pme->tb = pme->tb0 = mftb();
+	purr = mfspr(SPRN_PURR);
+	if (!phim->initialized) {
+		pme->purr = 0;
+		pme->purr0 = purr;
+	} else {
+		/* set p->purr and p->purr0 for no change in p0->stolen */
+		pme->purr = phim->tb - phim->tb0 - phim->purr - p0->stolen;
+		pme->purr0 = purr - pme->purr;
+	}
 	pme->initialized = 1;
-	spin_unlock_irqrestore(&pme->lock, flags);
+	spin_unlock_irqrestore(&p0->lock, flags);
 }
 
 #endif /* CONFIG_PPC_SPLPAR */
@@ -1014,6 +1045,48 @@
 	set_dec(tb_ticks_per_jiffy);
 }
 
+#ifdef CONFIG_RTC_CLASS
+static int set_rtc_class_time(struct rtc_time *tm)
+{
+	int err;
+	struct class_device *class_dev =
+		rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
+
+	if (class_dev == NULL)
+		return -ENODEV;
+
+	err = rtc_set_time(class_dev, tm);
+
+	rtc_class_close(class_dev);
+
+	return 0;
+}
+
+static void get_rtc_class_time(struct rtc_time *tm)
+{
+	int err;
+	struct class_device *class_dev =
+		rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
+
+	if (class_dev == NULL)
+		return;
+
+	err = rtc_read_time(class_dev, tm);
+
+	rtc_class_close(class_dev);
+
+	return;
+}
+
+int __init rtc_class_hookup(void)
+{
+	ppc_md.get_rtc_time = get_rtc_class_time;
+	ppc_md.set_rtc_time = set_rtc_class_time;
+
+	return 0;
+}
+#endif /* CONFIG_RTC_CLASS */
+
 
 #define FEBRUARY	2
 #define	STARTOFTIME	1970