Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 35 insertions, 133 deletions

diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index bb48977f5469..39ebff506946 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -26,6 +26,7 @@
 #include <asm/irq_regs.h>
 #include <asm/cputime.h>
 #include <asm/irq.h>
+#include "entry.h"
 
 static DEFINE_PER_CPU(struct vtimer_queue, virt_cpu_timer);
 
@@ -123,153 +124,53 @@ void account_system_vtime(struct task_struct *tsk)
 }
 EXPORT_SYMBOL_GPL(account_system_vtime);
 
-void __kprobes vtime_start_cpu(__u64 int_clock, __u64 enter_timer)
+void __kprobes vtime_stop_cpu(void)
 {
 	struct s390_idle_data *idle = &__get_cpu_var(s390_idle);
 	struct vtimer_queue *vq = &__get_cpu_var(virt_cpu_timer);
-	__u64 idle_time, expires;
+	unsigned long long idle_time;
+	unsigned long psw_mask;
 
-	if (idle->idle_enter == 0ULL)
-		return;
+	trace_hardirqs_on();
+	/* Don't trace preempt off for idle. */
+	stop_critical_timings();
 
-	/* Account time spent with enabled wait psw loaded as idle time. */
-	idle_time = int_clock - idle->idle_enter;
-	account_idle_time(idle_time);
-	S390_lowcore.steal_timer +=
-		idle->idle_enter - S390_lowcore.last_update_clock;
-	S390_lowcore.last_update_clock = int_clock;
-
-	/* Account system time spent going idle. */
-	S390_lowcore.system_timer += S390_lowcore.last_update_timer - vq->idle;
-	S390_lowcore.last_update_timer = enter_timer;
-
-	/* Restart vtime CPU timer */
-	if (vq->do_spt) {
-		/* Program old expire value but first save progress. */
-		expires = vq->idle - enter_timer;
-		expires += get_vtimer();
-		set_vtimer(expires);
-	} else {
-		/* Don't account the CPU timer delta while the cpu was idle. */
-		vq->elapsed -= vq->idle - enter_timer;
-	}
+	/* Wait for external, I/O or machine check interrupt. */
+	psw_mask = psw_kernel_bits | PSW_MASK_WAIT | PSW_MASK_DAT |
+		PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
+	idle->nohz_delay = 0;
 
+	/* Call the assembler magic in entry.S */
+	psw_idle(idle, vq, psw_mask, !list_empty(&vq->list));
+
+	/* Reenable preemption tracer. */
+	start_critical_timings();
+
+	/* Account time spent with enabled wait psw loaded as idle time. */
 	idle->sequence++;
 	smp_wmb();
+	idle_time = idle->idle_exit - idle->idle_enter;
 	idle->idle_time += idle_time;
-	idle->idle_enter = 0ULL;
+	idle->idle_enter = idle->idle_exit = 0ULL;
 	idle->idle_count++;
+	account_idle_time(idle_time);
 	smp_wmb();
 	idle->sequence++;
 }
 
-void __kprobes vtime_stop_cpu(void)
-{
-	struct s390_idle_data *idle = &__get_cpu_var(s390_idle);
-	struct vtimer_queue *vq = &__get_cpu_var(virt_cpu_timer);
-	psw_t psw;
-
-	/* Wait for external, I/O or machine check interrupt. */
-	psw.mask = psw_kernel_bits | PSW_MASK_WAIT |
-		PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
-
-	idle->nohz_delay = 0;
-
-	/* Check if the CPU timer needs to be reprogrammed. */
-	if (vq->do_spt) {
-		__u64 vmax = VTIMER_MAX_SLICE;
-		/*
-		 * The inline assembly is equivalent to
-		 *	vq->idle = get_cpu_timer();
-		 *	set_cpu_timer(VTIMER_MAX_SLICE);
-		 *	idle->idle_enter = get_clock();
-		 *	__load_psw_mask(psw_kernel_bits | PSW_MASK_WAIT |
-		 *			   PSW_MASK_DAT | PSW_MASK_IO |
-		 *			   PSW_MASK_EXT | PSW_MASK_MCHECK);
-		 * The difference is that the inline assembly makes sure that
-		 * the last three instruction are stpt, stck and lpsw in that
-		 * order. This is done to increase the precision.
-		 */
-		asm volatile(
-#ifndef CONFIG_64BIT
-			"	basr	1,0\n"
-			"0:	ahi	1,1f-0b\n"
-			"	st	1,4(%2)\n"
-#else /* CONFIG_64BIT */
-			"	larl	1,1f\n"
-			"	stg	1,8(%2)\n"
-#endif /* CONFIG_64BIT */
-			"	stpt	0(%4)\n"
-			"	spt	0(%5)\n"
-			"	stck	0(%3)\n"
-#ifndef CONFIG_64BIT
-			"	lpsw	0(%2)\n"
-#else /* CONFIG_64BIT */
-			"	lpswe	0(%2)\n"
-#endif /* CONFIG_64BIT */
-			"1:"
-			: "=m" (idle->idle_enter), "=m" (vq->idle)
-			: "a" (&psw), "a" (&idle->idle_enter),
-			  "a" (&vq->idle), "a" (&vmax), "m" (vmax), "m" (psw)
-			: "memory", "cc", "1");
-	} else {
-		/*
-		 * The inline assembly is equivalent to
-		 *	vq->idle = get_cpu_timer();
-		 *	idle->idle_enter = get_clock();
-		 *	__load_psw_mask(psw_kernel_bits | PSW_MASK_WAIT |
-		 *			   PSW_MASK_DAT | PSW_MASK_IO |
-		 *			   PSW_MASK_EXT | PSW_MASK_MCHECK);
-		 * The difference is that the inline assembly makes sure that
-		 * the last three instruction are stpt, stck and lpsw in that
-		 * order. This is done to increase the precision.
-		 */
-		asm volatile(
-#ifndef CONFIG_64BIT
-			"	basr	1,0\n"
-			"0:	ahi	1,1f-0b\n"
-			"	st	1,4(%2)\n"
-#else /* CONFIG_64BIT */
-			"	larl	1,1f\n"
-			"	stg	1,8(%2)\n"
-#endif /* CONFIG_64BIT */
-			"	stpt	0(%4)\n"
-			"	stck	0(%3)\n"
-#ifndef CONFIG_64BIT
-			"	lpsw	0(%2)\n"
-#else /* CONFIG_64BIT */
-			"	lpswe	0(%2)\n"
-#endif /* CONFIG_64BIT */
-			"1:"
-			: "=m" (idle->idle_enter), "=m" (vq->idle)
-			: "a" (&psw), "a" (&idle->idle_enter),
-			  "a" (&vq->idle), "m" (psw)
-			: "memory", "cc", "1");
-	}
-}
-
 cputime64_t s390_get_idle_time(int cpu)
 {
-	struct s390_idle_data *idle;
-	unsigned long long now, idle_time, idle_enter;
+	struct s390_idle_data *idle = &per_cpu(s390_idle, cpu);
+	unsigned long long now, idle_enter, idle_exit;
 	unsigned int sequence;
 
-	idle = &per_cpu(s390_idle, cpu);
-
-	now = get_clock();
-repeat:
-	sequence = idle->sequence;
-	smp_rmb();
-	if (sequence & 1)
-		goto repeat;
-	idle_time = 0;
-	idle_enter = idle->idle_enter;
-	if (idle_enter != 0ULL && idle_enter < now)
-		idle_time = now - idle_enter;
-	smp_rmb();
-	if (idle->sequence != sequence)
-		goto repeat;
-	return idle_time;
+	do {
+		now = get_clock();
+		sequence = ACCESS_ONCE(idle->sequence);
+		idle_enter = ACCESS_ONCE(idle->idle_enter);
+		idle_exit = ACCESS_ONCE(idle->idle_exit);
+	} while ((sequence & 1) || (idle->sequence != sequence));
+	return idle_enter ? ((idle_exit ? : now) - idle_enter) : 0;
 }
 
 /*
@@ -319,7 +220,7 @@ static void do_callbacks(struct list_head *cb_list)
 /*
  * Handler for the virtual CPU timer.
  */
-static void do_cpu_timer_interrupt(unsigned int ext_int_code,
+static void do_cpu_timer_interrupt(struct ext_code ext_code,
 				   unsigned int param32, unsigned long param64)
 {
 	struct vtimer_queue *vq;
@@ -346,7 +247,6 @@ static void do_cpu_timer_interrupt(unsigned int ext_int_code,
 	}
 	spin_unlock(&vq->lock);
 
-	vq->do_spt = list_empty(&cb_list);
 	do_callbacks(&cb_list);
 
 	/* next event is first in list */
@@ -355,8 +255,7 @@ static void do_cpu_timer_interrupt(unsigned int ext_int_code,
 	if (!list_empty(&vq->list)) {
 		event = list_first_entry(&vq->list, struct vtimer_list, entry);
 		next = event->expires;
-	} else
-		vq->do_spt = 0;
+	}
 	spin_unlock(&vq->lock);
 	/*
 	 * To improve precision add the time spent by the
@@ -570,6 +469,9 @@ void init_cpu_vtimer(void)
 
 	/* enable cpu timer interrupts */
 	__ctl_set_bit(0,10);
+
+	/* set initial cpu timer */
+	set_vtimer(0x7fffffffffffffffULL);
 }
 
 static int __cpuinit s390_nohz_notify(struct notifier_block *self,