Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
  gameport: use this_cpu_read instead of lookup
  x86: udelay: Use this_cpu_read to avoid address calculation
  x86: Use this_cpu_inc_return for nmi counter
  x86: Replace uses of current_cpu_data with this_cpu ops
  x86: Use this_cpu_ops to optimize code
  vmstat: User per cpu atomics to avoid interrupt disable / enable
  irq_work: Use per cpu atomics instead of regular atomics
  cpuops: Use cmpxchg for xchg to avoid lock semantics
  x86: this_cpu_cmpxchg and this_cpu_xchg operations
  percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
  percpu,x86: relocate this_cpu_add_return() and friends
  connector: Use this_cpu operations
  xen: Use this_cpu_inc_return
  taskstats: Use this_cpu_ops
  random: Use this_cpu_inc_return
  fs: Use this_cpu_inc_return in buffer.c
  highmem: Use this_cpu_xx_return() operations
  vmstat: Use this_cpu_inc_return for vm statistics
  x86: Support for this_cpu_add, sub, dec, inc_return
  percpu: Generic support for this_cpu_add, sub, dec, inc_return
  ...

Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.

kernel/exit.c

@@ -69,7 +69,7 @@ static void __unhash_process(struct task_struct *p, bool group_dead)
 
 		list_del_rcu(&p->tasks);
 		list_del_init(&p->sibling);
-		__get_cpu_var(process_counts)--;
+		__this_cpu_dec(process_counts);
 	}
 	list_del_rcu(&p->thread_group);
 }

kernel/fork.c

@@ -1285,7 +1285,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 			attach_pid(p, PIDTYPE_SID, task_session(current));
 			list_add_tail(&p->sibling, &p->real_parent->children);
 			list_add_tail_rcu(&p->tasks, &init_task.tasks);
-			__get_cpu_var(process_counts)++;
+			__this_cpu_inc(process_counts);
 		}
 		attach_pid(p, PIDTYPE_PID, pid);
 		nr_threads++;

kernel/hrtimer.c

@@ -497,7 +497,7 @@ static inline int hrtimer_is_hres_enabled(void)
  */
 static inline int hrtimer_hres_active(void)
 {
-	return __get_cpu_var(hrtimer_bases).hres_active;
+	return __this_cpu_read(hrtimer_bases.hres_active);
 }
 
 /*

kernel/irq_work.c

@@ -77,21 +77,21 @@ void __weak arch_irq_work_raise(void)
  */
 static void __irq_work_queue(struct irq_work *entry)
 {
-	struct irq_work **head, *next;
+	struct irq_work *next;
 
-	head = &get_cpu_var(irq_work_list);
+	preempt_disable();
 
 	do {
-		next = *head;
+		next = __this_cpu_read(irq_work_list);
 		/* Can assign non-atomic because we keep the flags set. */
 		entry->next = next_flags(next, IRQ_WORK_FLAGS);
-	} while (cmpxchg(head, next, entry) != next);
+	} while (this_cpu_cmpxchg(irq_work_list, next, entry) != next);
 
 	/* The list was empty, raise self-interrupt to start processing. */
 	if (!irq_work_next(entry))
 		arch_irq_work_raise();
 
-	put_cpu_var(irq_work_list);
+	preempt_enable();
 }
 
 /*
@@ -120,16 +120,16 @@ EXPORT_SYMBOL_GPL(irq_work_queue);
  */
 void irq_work_run(void)
 {
-	struct irq_work *list, **head;
+	struct irq_work *list;
 
-	head = &__get_cpu_var(irq_work_list);
-	if (*head == NULL)
+	if (this_cpu_read(irq_work_list) == NULL)
 		return;
 
 	BUG_ON(!in_irq());
 	BUG_ON(!irqs_disabled());
 
-	list = xchg(head, NULL);
+	list = this_cpu_xchg(irq_work_list, NULL);
+
 	while (list != NULL) {
 		struct irq_work *entry = list;
 

kernel/kprobes.c

@@ -317,12 +317,12 @@ void __kprobes free_optinsn_slot(kprobe_opcode_t * slot, int dirty)
 /* We have preemption disabled.. so it is safe to use __ versions */
 static inline void set_kprobe_instance(struct kprobe *kp)
 {
-	__get_cpu_var(kprobe_instance) = kp;
+	__this_cpu_write(kprobe_instance, kp);
 }
 
 static inline void reset_kprobe_instance(void)
 {
-	__get_cpu_var(kprobe_instance) = NULL;
+	__this_cpu_write(kprobe_instance, NULL);
 }
 
 /*
@@ -965,7 +965,7 @@ static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs,
 static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs,
 					int trapnr)
 {
-	struct kprobe *cur = __get_cpu_var(kprobe_instance);
+	struct kprobe *cur = __this_cpu_read(kprobe_instance);
 
 	/*
 	 * if we faulted "during" the execution of a user specified
@@ -980,7 +980,7 @@ static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs,
 
 static int __kprobes aggr_break_handler(struct kprobe *p, struct pt_regs *regs)
 {
-	struct kprobe *cur = __get_cpu_var(kprobe_instance);
+	struct kprobe *cur = __this_cpu_read(kprobe_instance);
 	int ret = 0;
 
 	if (cur && cur->break_handler) {

kernel/rcutree.c

@@ -364,8 +364,8 @@ void rcu_irq_exit(void)
 	WARN_ON_ONCE(rdtp->dynticks & 0x1);
 
 	/* If the interrupt queued a callback, get out of dyntick mode. */
-	if (__get_cpu_var(rcu_sched_data).nxtlist ||
-	    __get_cpu_var(rcu_bh_data).nxtlist)
+	if (__this_cpu_read(rcu_sched_data.nxtlist) ||
+	    __this_cpu_read(rcu_bh_data.nxtlist))
 		set_need_resched();
 }
 

kernel/softirq.c

@@ -70,7 +70,7 @@ char *softirq_to_name[NR_SOFTIRQS] = {
 static void wakeup_softirqd(void)
 {
 	/* Interrupts are disabled: no need to stop preemption */
-	struct task_struct *tsk = __get_cpu_var(ksoftirqd);
+	struct task_struct *tsk = __this_cpu_read(ksoftirqd);
 
 	if (tsk && tsk->state != TASK_RUNNING)
 		wake_up_process(tsk);
@@ -388,8 +388,8 @@ void __tasklet_schedule(struct tasklet_struct *t)
 
 	local_irq_save(flags);
 	t->next = NULL;
-	*__get_cpu_var(tasklet_vec).tail = t;
-	__get_cpu_var(tasklet_vec).tail = &(t->next);
+	*__this_cpu_read(tasklet_vec.tail) = t;
+	__this_cpu_write(tasklet_vec.tail, &(t->next));
 	raise_softirq_irqoff(TASKLET_SOFTIRQ);
 	local_irq_restore(flags);
 }
@@ -402,8 +402,8 @@ void __tasklet_hi_schedule(struct tasklet_struct *t)
 
 	local_irq_save(flags);
 	t->next = NULL;
-	*__get_cpu_var(tasklet_hi_vec).tail = t;
-	__get_cpu_var(tasklet_hi_vec).tail = &(t->next);
+	*__this_cpu_read(tasklet_hi_vec.tail) = t;
+	__this_cpu_write(tasklet_hi_vec.tail,  &(t->next));
 	raise_softirq_irqoff(HI_SOFTIRQ);
 	local_irq_restore(flags);
 }
@@ -414,8 +414,8 @@ void __tasklet_hi_schedule_first(struct tasklet_struct *t)
 {
 	BUG_ON(!irqs_disabled());
 
-	t->next = __get_cpu_var(tasklet_hi_vec).head;
-	__get_cpu_var(tasklet_hi_vec).head = t;
+	t->next = __this_cpu_read(tasklet_hi_vec.head);
+	__this_cpu_write(tasklet_hi_vec.head, t);
 	__raise_softirq_irqoff(HI_SOFTIRQ);
 }
 
@@ -426,9 +426,9 @@ static void tasklet_action(struct softirq_action *a)
 	struct tasklet_struct *list;
 
 	local_irq_disable();
-	list = __get_cpu_var(tasklet_vec).head;
-	__get_cpu_var(tasklet_vec).head = NULL;
-	__get_cpu_var(tasklet_vec).tail = &__get_cpu_var(tasklet_vec).head;
+	list = __this_cpu_read(tasklet_vec.head);
+	__this_cpu_write(tasklet_vec.head, NULL);
+	__this_cpu_write(tasklet_vec.tail, &__get_cpu_var(tasklet_vec).head);
 	local_irq_enable();
 
 	while (list) {
@@ -449,8 +449,8 @@ static void tasklet_action(struct softirq_action *a)
 
 		local_irq_disable();
 		t->next = NULL;
-		*__get_cpu_var(tasklet_vec).tail = t;
-		__get_cpu_var(tasklet_vec).tail = &(t->next);
+		*__this_cpu_read(tasklet_vec.tail) = t;
+		__this_cpu_write(tasklet_vec.tail, &(t->next));
 		__raise_softirq_irqoff(TASKLET_SOFTIRQ);
 		local_irq_enable();
 	}
@@ -461,9 +461,9 @@ static void tasklet_hi_action(struct softirq_action *a)
 	struct tasklet_struct *list;
 
 	local_irq_disable();
-	list = __get_cpu_var(tasklet_hi_vec).head;
-	__get_cpu_var(tasklet_hi_vec).head = NULL;
-	__get_cpu_var(tasklet_hi_vec).tail = &__get_cpu_var(tasklet_hi_vec).head;
+	list = __this_cpu_read(tasklet_hi_vec.head);
+	__this_cpu_write(tasklet_hi_vec.head, NULL);
+	__this_cpu_write(tasklet_hi_vec.tail, &__get_cpu_var(tasklet_hi_vec).head);
 	local_irq_enable();
 
 	while (list) {
@@ -484,8 +484,8 @@ static void tasklet_hi_action(struct softirq_action *a)
 
 		local_irq_disable();
 		t->next = NULL;
-		*__get_cpu_var(tasklet_hi_vec).tail = t;
-		__get_cpu_var(tasklet_hi_vec).tail = &(t->next);
+		*__this_cpu_read(tasklet_hi_vec.tail) = t;
+		__this_cpu_write(tasklet_hi_vec.tail, &(t->next));
 		__raise_softirq_irqoff(HI_SOFTIRQ);
 		local_irq_enable();
 	}
@@ -802,16 +802,16 @@ static void takeover_tasklets(unsigned int cpu)
 
 	/* Find end, append list for that CPU. */
 	if (&per_cpu(tasklet_vec, cpu).head != per_cpu(tasklet_vec, cpu).tail) {
-		*(__get_cpu_var(tasklet_vec).tail) = per_cpu(tasklet_vec, cpu).head;
-		__get_cpu_var(tasklet_vec).tail = per_cpu(tasklet_vec, cpu).tail;
+		*__this_cpu_read(tasklet_vec.tail) = per_cpu(tasklet_vec, cpu).head;
+		this_cpu_write(tasklet_vec.tail, per_cpu(tasklet_vec, cpu).tail);
 		per_cpu(tasklet_vec, cpu).head = NULL;
 		per_cpu(tasklet_vec, cpu).tail = &per_cpu(tasklet_vec, cpu).head;
 	}
 	raise_softirq_irqoff(TASKLET_SOFTIRQ);
 
 	if (&per_cpu(tasklet_hi_vec, cpu).head != per_cpu(tasklet_hi_vec, cpu).tail) {
-		*__get_cpu_var(tasklet_hi_vec).tail = per_cpu(tasklet_hi_vec, cpu).head;
-		__get_cpu_var(tasklet_hi_vec).tail = per_cpu(tasklet_hi_vec, cpu).tail;
+		*__this_cpu_read(tasklet_hi_vec.tail) = per_cpu(tasklet_hi_vec, cpu).head;
+		__this_cpu_write(tasklet_hi_vec.tail, per_cpu(tasklet_hi_vec, cpu).tail);
 		per_cpu(tasklet_hi_vec, cpu).head = NULL;
 		per_cpu(tasklet_hi_vec, cpu).tail = &per_cpu(tasklet_hi_vec, cpu).head;
 	}

kernel/taskstats.c

@@ -89,8 +89,7 @@ static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp,
 		return -ENOMEM;
 
 	if (!info) {
-		int seq = get_cpu_var(taskstats_seqnum)++;
-		put_cpu_var(taskstats_seqnum);
+		int seq = this_cpu_inc_return(taskstats_seqnum) - 1;
 
 		reply = genlmsg_put(skb, 0, seq, &family, 0, cmd);
 	} else
@@ -612,7 +611,7 @@ void taskstats_exit(struct task_struct *tsk, int group_dead)
 		fill_tgid_exit(tsk);
 	}
 
-	listeners = &__raw_get_cpu_var(listener_array);
+	listeners = __this_cpu_ptr(&listener_array);
 	if (list_empty(&listeners->list))
 		return;
 

kernel/time/tick-common.c

@@ -49,7 +49,7 @@ struct tick_device *tick_get_device(int cpu)
  */
 int tick_is_oneshot_available(void)
 {
-	struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
+	struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
 
 	return dev && (dev->features & CLOCK_EVT_FEAT_ONESHOT);
 }

kernel/time/tick-oneshot.c

@@ -95,7 +95,7 @@ int tick_dev_program_event(struct clock_event_device *dev, ktime_t expires,
  */
 int tick_program_event(ktime_t expires, int force)
 {
-	struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
+	struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
 
 	return tick_dev_program_event(dev, expires, force);
 }
@@ -167,7 +167,7 @@ int tick_oneshot_mode_active(void)
 	int ret;
 
 	local_irq_save(flags);
-	ret = __get_cpu_var(tick_cpu_device).mode == TICKDEV_MODE_ONESHOT;
+	ret = __this_cpu_read(tick_cpu_device.mode) == TICKDEV_MODE_ONESHOT;
 	local_irq_restore(flags);
 
 	return ret;

kernel/watchdog.c

@@ -118,12 +118,12 @@ static void __touch_watchdog(void)
 {
 	int this_cpu = smp_processor_id();
 
-	__get_cpu_var(watchdog_touch_ts) = get_timestamp(this_cpu);
+	__this_cpu_write(watchdog_touch_ts, get_timestamp(this_cpu));
 }
 
 void touch_softlockup_watchdog(void)
 {
-	__raw_get_cpu_var(watchdog_touch_ts) = 0;
+	__this_cpu_write(watchdog_touch_ts, 0);
 }
 EXPORT_SYMBOL(touch_softlockup_watchdog);
 
@@ -167,12 +167,12 @@ void touch_softlockup_watchdog_sync(void)
 /* watchdog detector functions */
 static int is_hardlockup(void)
 {
-	unsigned long hrint = __get_cpu_var(hrtimer_interrupts);
+	unsigned long hrint = __this_cpu_read(hrtimer_interrupts);
 
-	if (__get_cpu_var(hrtimer_interrupts_saved) == hrint)
+	if (__this_cpu_read(hrtimer_interrupts_saved) == hrint)
 		return 1;
 
-	__get_cpu_var(hrtimer_interrupts_saved) = hrint;
+	__this_cpu_write(hrtimer_interrupts_saved, hrint);
 	return 0;
 }
 #endif
@@ -205,8 +205,8 @@ static void watchdog_overflow_callback(struct perf_event *event, int nmi,
 	/* Ensure the watchdog never gets throttled */
 	event->hw.interrupts = 0;
 
-	if (__get_cpu_var(watchdog_nmi_touch) == true) {
-		__get_cpu_var(watchdog_nmi_touch) = false;
+	if (__this_cpu_read(watchdog_nmi_touch) == true) {
+		__this_cpu_write(watchdog_nmi_touch, false);
 		return;
 	}
 
@@ -220,7 +220,7 @@ static void watchdog_overflow_callback(struct perf_event *event, int nmi,
 		int this_cpu = smp_processor_id();
 
 		/* only print hardlockups once */
-		if (__get_cpu_var(hard_watchdog_warn) == true)
+		if (__this_cpu_read(hard_watchdog_warn) == true)
 			return;
 
 		if (hardlockup_panic)
@@ -228,16 +228,16 @@ static void watchdog_overflow_callback(struct perf_event *event, int nmi,
 		else
 			WARN(1, "Watchdog detected hard LOCKUP on cpu %d", this_cpu);
 
-		__get_cpu_var(hard_watchdog_warn) = true;
+		__this_cpu_write(hard_watchdog_warn, true);
 		return;
 	}
 
-	__get_cpu_var(hard_watchdog_warn) = false;
+	__this_cpu_write(hard_watchdog_warn, false);
 	return;
 }
 static void watchdog_interrupt_count(void)
 {
-	__get_cpu_var(hrtimer_interrupts)++;
+	__this_cpu_inc(hrtimer_interrupts);
 }
 #else
 static inline void watchdog_interrupt_count(void) { return; }
@@ -246,7 +246,7 @@ static inline void watchdog_interrupt_count(void) { return; }
 /* watchdog kicker functions */
 static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
 {
-	unsigned long touch_ts = __get_cpu_var(watchdog_touch_ts);
+	unsigned long touch_ts = __this_cpu_read(watchdog_touch_ts);
 	struct pt_regs *regs = get_irq_regs();
 	int duration;
 
@@ -254,18 +254,18 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
 	watchdog_interrupt_count();
 
 	/* kick the softlockup detector */
-	wake_up_process(__get_cpu_var(softlockup_watchdog));
+	wake_up_process(__this_cpu_read(softlockup_watchdog));
 
 	/* .. and repeat */
 	hrtimer_forward_now(hrtimer, ns_to_ktime(get_sample_period()));
 
 	if (touch_ts == 0) {
-		if (unlikely(__get_cpu_var(softlockup_touch_sync))) {
+		if (unlikely(__this_cpu_read(softlockup_touch_sync))) {
 			/*
 			 * If the time stamp was touched atomically
 			 * make sure the scheduler tick is up to date.
 			 */
-			__get_cpu_var(softlockup_touch_sync) = false;
+			__this_cpu_write(softlockup_touch_sync, false);
 			sched_clock_tick();
 		}
 		__touch_watchdog();
@@ -281,7 +281,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
 	duration = is_softlockup(touch_ts);
 	if (unlikely(duration)) {
 		/* only warn once */
-		if (__get_cpu_var(soft_watchdog_warn) == true)
+		if (__this_cpu_read(soft_watchdog_warn) == true)
 			return HRTIMER_RESTART;
 
 		printk(KERN_ERR "BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n",
@@ -296,9 +296,9 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
 
 		if (softlockup_panic)
 			panic("softlockup: hung tasks");
-		__get_cpu_var(soft_watchdog_warn) = true;
+		__this_cpu_write(soft_watchdog_warn, true);
 	} else
-		__get_cpu_var(soft_watchdog_warn) = false;
+		__this_cpu_write(soft_watchdog_warn, false);
 
 	return HRTIMER_RESTART;
 }