1 files changed, 3 insertions, 61 deletions

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 1e06436f07c..b6110bdf8dc 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -46,7 +46,6 @@
 #include <asm/processor.h>
 #include <asm/irq.h>
 #include <asm/timer.h>
-#include <asm/cpu.h>
 #include "entry.h"
 
 asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
@@ -76,35 +75,12 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
 	return sf->gprs[8];
 }
 
-DEFINE_PER_CPU(struct s390_idle_data, s390_idle) = {
-	.lock = __SPIN_LOCK_UNLOCKED(s390_idle.lock)
-};
-
-void s390_idle_leave(void)
-{
-	struct s390_idle_data *idle;
-	unsigned long long idle_time;
-
-	idle = &__get_cpu_var(s390_idle);
-	idle_time = S390_lowcore.int_clock - idle->idle_enter;
-	spin_lock(&idle->lock);
-	idle->idle_time += idle_time;
-	idle->idle_enter = 0ULL;
-	idle->idle_count++;
-	spin_unlock(&idle->lock);
-	vtime_start_cpu_timer();
-}
-
 extern void s390_handle_mcck(void);
 /*
  * The idle loop on a S390...
  */
 static void default_idle(void)
 {
-	struct s390_idle_data *idle = &__get_cpu_var(s390_idle);
-	unsigned long addr;
-	psw_t psw;
-
 	/* CPU is going idle. */
 	local_irq_disable();
 	if (need_resched()) {
@@ -120,7 +96,6 @@ static void default_idle(void)
 	local_mcck_disable();
 	if (test_thread_flag(TIF_MCCK_PENDING)) {
 		local_mcck_enable();
-		s390_idle_leave();
 		local_irq_enable();
 		s390_handle_mcck();
 		return;
@@ -128,42 +103,9 @@ static void default_idle(void)
 	trace_hardirqs_on();
 	/* Don't trace preempt off for idle. */
 	stop_critical_timings();
-	vtime_stop_cpu_timer();
-
-	/*
-	 * The inline assembly is equivalent to
-	 *	idle->idle_enter = get_clock();
-	 *	__load_psw_mask(psw_kernel_bits | PSW_MASK_WAIT |
-	 *			   PSW_MASK_IO | PSW_MASK_EXT);
-	 * The difference is that the inline assembly makes sure that
-	 * the stck instruction is right before the lpsw instruction.
-	 * This is done to increase the precision.
-	 */
-
-	/* Wait for external, I/O or machine check interrupt. */
-	psw.mask = psw_kernel_bits|PSW_MASK_WAIT|PSW_MASK_IO|PSW_MASK_EXT;
-#ifndef __s390x__
-	asm volatile(
-		"	basr	%0,0\n"
-		"0:	ahi	%0,1f-0b\n"
-		"	st	%0,4(%2)\n"
-		"	stck	0(%3)\n"
-		"	lpsw	0(%2)\n"
-		"1:"
-		: "=&d" (addr), "=m" (idle->idle_enter)
-		: "a" (&psw), "a" (&idle->idle_enter), "m" (psw)
-		: "memory", "cc");
-#else /* __s390x__ */
-	asm volatile(
-		"	larl	%0,1f\n"
-		"	stg	%0,8(%2)\n"
-		"	stck	0(%3)\n"
-		"	lpswe	0(%2)\n"
-		"1:"
-		: "=&d" (addr), "=m" (idle->idle_enter)
-		: "a" (&psw), "a" (&idle->idle_enter), "m" (psw)
-		: "memory", "cc");
-#endif /* __s390x__ */
+	/* Stop virtual timer and halt the cpu. */
+	vtime_stop_cpu();
+	/* Reenable preemption tracer. */
 	start_critical_timings();
 }