8 files changed, 123 insertions, 115 deletions

diff --git a/arch/s390/include/asm/cputime.h b/arch/s390/include/asm/cputime.h
index 258ba88b7b50..8b1a52a137c5 100644
--- a/arch/s390/include/asm/cputime.h
+++ b/arch/s390/include/asm/cputime.h
@@ -188,15 +188,16 @@ struct s390_idle_data {
 
 DECLARE_PER_CPU(struct s390_idle_data, s390_idle);
 
-void vtime_start_cpu(void);
+void vtime_start_cpu(__u64 int_clock, __u64 enter_timer);
 cputime64_t s390_get_idle_time(int cpu);
 
 #define arch_idle_time(cpu) s390_get_idle_time(cpu)
 
-static inline void s390_idle_check(void)
+static inline void s390_idle_check(struct pt_regs *regs, __u64 int_clock,
+                                   __u64 enter_timer)
 {
-        if ((&__get_cpu_var(s390_idle))->idle_enter != 0ULL)
-                vtime_start_cpu();
+        if (regs->psw.mask & PSW_MASK_WAIT)
+                vtime_start_cpu(int_clock, enter_timer);
 }
 
 static inline int s390_nohz_delay(int cpu)
diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index f7e78c79b8b1..2c02d46c3588 100644
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -104,37 +104,39 @@ struct _lowcore {
         /* CPU time accounting values */
         __u64   sync_enter_timer;               /* 0x0250 */
         __u64   async_enter_timer;              /* 0x0258 */
-        __u64   exit_timer;                     /* 0x0260 */
-        __u64   user_timer;                     /* 0x0268 */
-        __u64   system_timer;                   /* 0x0270 */
-        __u64   steal_timer;                    /* 0x0278 */
-        __u64   last_update_timer;              /* 0x0280 */
-        __u64   last_update_clock;              /* 0x0288 */
+        __u64   mcck_enter_timer;               /* 0x0260 */
+        __u64   exit_timer;                     /* 0x0268 */
+        __u64   user_timer;                     /* 0x0270 */
+        __u64   system_timer;                   /* 0x0278 */
+        __u64   steal_timer;                    /* 0x0280 */
+        __u64   last_update_timer;              /* 0x0288 */
+        __u64   last_update_clock;              /* 0x0290 */
 
         /* Current process. */
-        __u32   current_task;                   /* 0x0290 */
-        __u32   thread_info;                    /* 0x0294 */
-        __u32   kernel_stack;                   /* 0x0298 */
+        __u32   current_task;                   /* 0x0298 */
+        __u32   thread_info;                    /* 0x029c */
+        __u32   kernel_stack;                   /* 0x02a0 */
 
         /* Interrupt and panic stack. */
-        __u32   async_stack;                    /* 0x029c */
-        __u32   panic_stack;                    /* 0x02a0 */
+        __u32   async_stack;                    /* 0x02a4 */
+        __u32   panic_stack;                    /* 0x02a8 */
 
         /* Address space pointer. */
-        __u32   kernel_asce;                    /* 0x02a4 */
-        __u32   user_asce;                      /* 0x02a8 */
-        __u32   user_exec_asce;                 /* 0x02ac */
+        __u32   kernel_asce;                    /* 0x02ac */
+        __u32   user_asce;                      /* 0x02b0 */
+        __u32   user_exec_asce;                 /* 0x02b4 */
 
         /* SMP info area */
-        __u32   cpu_nr;                         /* 0x02b0 */
-        __u32   softirq_pending;                /* 0x02b4 */
-        __u32   percpu_offset;                  /* 0x02b8 */
-        __u32   ext_call_fast;                  /* 0x02bc */
-        __u64   int_clock;                      /* 0x02c0 */
-        __u64   clock_comparator;               /* 0x02c8 */
-        __u32   machine_flags;                  /* 0x02d0 */
-        __u32   ftrace_func;                    /* 0x02d4 */
-        __u8    pad_0x02d8[0x0300-0x02d8];      /* 0x02d8 */
+        __u32   cpu_nr;                         /* 0x02b8 */
+        __u32   softirq_pending;                /* 0x02bc */
+        __u32   percpu_offset;                  /* 0x02c0 */
+        __u32   ext_call_fast;                  /* 0x02c4 */
+        __u64   int_clock;                      /* 0x02c8 */
+        __u64   mcck_clock;                     /* 0x02d0 */
+        __u64   clock_comparator;               /* 0x02d8 */
+        __u32   machine_flags;                  /* 0x02e0 */
+        __u32   ftrace_func;                    /* 0x02e4 */
+        __u8    pad_0x02e8[0x0300-0x02e8];      /* 0x02e8 */
 
         /* Interrupt response block */
         __u8    irb[64];                        /* 0x0300 */
@@ -232,38 +234,40 @@ struct _lowcore {
         /* CPU accounting and timing values. */
         __u64   sync_enter_timer;               /* 0x02a0 */
         __u64   async_enter_timer;              /* 0x02a8 */
-        __u64   exit_timer;                     /* 0x02b0 */
-        __u64   user_timer;                     /* 0x02b8 */
-        __u64   system_timer;                   /* 0x02c0 */
-        __u64   steal_timer;                    /* 0x02c8 */
-        __u64   last_update_timer;              /* 0x02d0 */
-        __u64   last_update_clock;              /* 0x02d8 */
+        __u64   mcck_enter_timer;               /* 0x02b0 */
+        __u64   exit_timer;                     /* 0x02b8 */
+        __u64   user_timer;                     /* 0x02c0 */
+        __u64   system_timer;                   /* 0x02c8 */
+        __u64   steal_timer;                    /* 0x02d0 */
+        __u64   last_update_timer;              /* 0x02d8 */
+        __u64   last_update_clock;              /* 0x02e0 */
 
         /* Current process. */
-        __u64   current_task;                   /* 0x02e0 */
-        __u64   thread_info;                    /* 0x02e8 */
-        __u64   kernel_stack;                   /* 0x02f0 */
+        __u64   current_task;                   /* 0x02e8 */
+        __u64   thread_info;                    /* 0x02f0 */
+        __u64   kernel_stack;                   /* 0x02f8 */
 
         /* Interrupt and panic stack. */
-        __u64   async_stack;                    /* 0x02f8 */
-        __u64   panic_stack;                    /* 0x0300 */
+        __u64   async_stack;                    /* 0x0300 */
+        __u64   panic_stack;                    /* 0x0308 */
 
         /* Address space pointer. */
-        __u64   kernel_asce;                    /* 0x0308 */
-        __u64   user_asce;                      /* 0x0310 */
-        __u64   user_exec_asce;                 /* 0x0318 */
+        __u64   kernel_asce;                    /* 0x0310 */
+        __u64   user_asce;                      /* 0x0318 */
+        __u64   user_exec_asce;                 /* 0x0320 */
 
         /* SMP info area */
-        __u32   cpu_nr;                         /* 0x0320 */
-        __u32   softirq_pending;                /* 0x0324 */
-        __u64   percpu_offset;                  /* 0x0328 */
-        __u64   ext_call_fast;                  /* 0x0330 */
-        __u64   int_clock;                      /* 0x0338 */
-        __u64   clock_comparator;               /* 0x0340 */
-        __u64   vdso_per_cpu_data;              /* 0x0348 */
-        __u64   machine_flags;                  /* 0x0350 */
-        __u64   ftrace_func;                    /* 0x0358 */
-        __u8    pad_0x0368[0x0380-0x0360];      /* 0x0360 */
+        __u32   cpu_nr;                         /* 0x0328 */
+        __u32   softirq_pending;                /* 0x032c */
+        __u64   percpu_offset;                  /* 0x0330 */
+        __u64   ext_call_fast;                  /* 0x0338 */
+        __u64   int_clock;                      /* 0x0340 */
+        __u64   mcck_clock;                     /* 0x0348 */
+        __u64   clock_comparator;               /* 0x0350 */
+        __u64   vdso_per_cpu_data;              /* 0x0358 */
+        __u64   machine_flags;                  /* 0x0360 */
+        __u64   ftrace_func;                    /* 0x0368 */
+        __u8    pad_0x0370[0x0380-0x0370];      /* 0x0370 */
 
         /* Interrupt response block. */
         __u8    irb[64];                        /* 0x0380 */
diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index 32b1ede69858..816d81f479c0 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -112,6 +112,7 @@ int main(void)
         DEFINE(__LC_RETURN_MCCK_PSW, offsetof(struct _lowcore, return_mcck_psw));
         DEFINE(__LC_SYNC_ENTER_TIMER, offsetof(struct _lowcore, sync_enter_timer));
         DEFINE(__LC_ASYNC_ENTER_TIMER, offsetof(struct _lowcore, async_enter_timer));
+        DEFINE(__LC_MCCK_ENTER_TIMER, offsetof(struct _lowcore, mcck_enter_timer));
         DEFINE(__LC_EXIT_TIMER, offsetof(struct _lowcore, exit_timer));
         DEFINE(__LC_USER_TIMER, offsetof(struct _lowcore, user_timer));
         DEFINE(__LC_SYSTEM_TIMER, offsetof(struct _lowcore, system_timer));
@@ -127,6 +128,7 @@ int main(void)
         DEFINE(__LC_USER_ASCE, offsetof(struct _lowcore, user_asce));
         DEFINE(__LC_USER_EXEC_ASCE, offsetof(struct _lowcore, user_exec_asce));
         DEFINE(__LC_INT_CLOCK, offsetof(struct _lowcore, int_clock));
+        DEFINE(__LC_MCCK_CLOCK, offsetof(struct _lowcore, mcck_clock));
         DEFINE(__LC_MACHINE_FLAGS, offsetof(struct _lowcore, machine_flags));
         DEFINE(__LC_FTRACE_FUNC, offsetof(struct _lowcore, ftrace_func));
         DEFINE(__LC_IRB, offsetof(struct _lowcore, irb));
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 07d849995dac..0e2b16241dfa 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -742,15 +742,14 @@ __critical_end:
 
         .globl mcck_int_handler
 mcck_int_handler:
-        stck    __LC_INT_CLOCK
+        stck    __LC_MCCK_CLOCK
         spt     __LC_CPU_TIMER_SAVE_AREA        # revalidate cpu timer
         lm      %r0,%r15,__LC_GPREGS_SAVE_AREA  # revalidate gprs
         SAVE_ALL_BASE __LC_SAVE_AREA+32
         la      %r12,__LC_MCK_OLD_PSW
         tm      __LC_MCCK_CODE,0x80     # system damage?
         bo      BASED(mcck_int_main)    # yes -> rest of mcck code invalid
-        mvc     __LC_SAVE_AREA+52(8),__LC_ASYNC_ENTER_TIMER
-        mvc     __LC_ASYNC_ENTER_TIMER(8),__LC_CPU_TIMER_SAVE_AREA
+        mvc     __LC_MCCK_ENTER_TIMER(8),__LC_CPU_TIMER_SAVE_AREA
         tm      __LC_MCCK_CODE+5,0x02   # stored cpu timer value valid?
         bo      BASED(1f)
         la      %r14,__LC_SYNC_ENTER_TIMER
@@ -764,7 +763,7 @@ mcck_int_handler:
         bl      BASED(0f)
         la      %r14,__LC_LAST_UPDATE_TIMER
 0:      spt     0(%r14)
-        mvc     __LC_ASYNC_ENTER_TIMER(8),0(%r14)
+        mvc     __LC_MCCK_ENTER_TIMER(8),0(%r14)
 1:      tm      __LC_MCCK_CODE+2,0x09   # mwp + ia of old psw valid?
         bno     BASED(mcck_int_main)    # no -> skip cleanup critical
         tm      __LC_MCK_OLD_PSW+1,0x01 # test problem state bit
@@ -786,9 +785,9 @@ mcck_int_main:
         bno     BASED(mcck_no_vtime)    # no -> skip cleanup critical
         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
         bz      BASED(mcck_no_vtime)
-        UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
+        UPDATE_VTIME __LC_EXIT_TIMER,__LC_MCCK_ENTER_TIMER,__LC_USER_TIMER
         UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
-        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
+        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_MCCK_ENTER_TIMER
 mcck_no_vtime:
         l       %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
         la      %r2,SP_PTREGS(%r15)     # load pt_regs
@@ -811,7 +810,6 @@ mcck_no_vtime:
 mcck_return:
         mvc     __LC_RETURN_MCCK_PSW(8),SP_PSW(%r15) # move return PSW
         ni      __LC_RETURN_MCCK_PSW+1,0xfd # clear wait state bit
-        mvc     __LC_ASYNC_ENTER_TIMER(8),__LC_SAVE_AREA+52
         tm      __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
         bno     BASED(0f)
         lm      %r0,%r15,SP_R0(%r15)    # load gprs 0-15
@@ -934,15 +932,16 @@ cleanup_critical:
 
 cleanup_system_call:
         mvc     __LC_RETURN_PSW(8),0(%r12)
-        c       %r12,BASED(.Lmck_old_psw)
-        be      BASED(0f)
-        la      %r12,__LC_SAVE_AREA+16
-        b       BASED(1f)
-0:      la      %r12,__LC_SAVE_AREA+32
-1:
         clc     __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+4)
         bh      BASED(0f)
+        mvc     __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
+        c       %r12,BASED(.Lmck_old_psw)
+        be      BASED(0f)
         mvc     __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
+0:      c       %r12,BASED(.Lmck_old_psw)
+        la      %r12,__LC_SAVE_AREA+32
+        be      BASED(0f)
+        la      %r12,__LC_SAVE_AREA+16
 0:      clc     __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+8)
         bhe     BASED(cleanup_vtime)
         clc     __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn)
@@ -984,16 +983,19 @@ cleanup_sysc_tif:
 cleanup_sysc_restore:
         clc     4(4,%r12),BASED(cleanup_sysc_restore_insn)
         be      BASED(2f)
+        mvc     __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
+        c       %r12,BASED(.Lmck_old_psw)
+        be      BASED(0f)
         mvc     __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
-        clc     4(4,%r12),BASED(cleanup_sysc_restore_insn+4)
+0:      clc     4(4,%r12),BASED(cleanup_sysc_restore_insn+4)
         be      BASED(2f)
         mvc     __LC_RETURN_PSW(8),SP_PSW(%r15)
         c       %r12,BASED(.Lmck_old_psw)
-        bne     BASED(0f)
-        mvc     __LC_SAVE_AREA+32(16),SP_R12(%r15)
-        b       BASED(1f)
-0:      mvc     __LC_SAVE_AREA+16(16),SP_R12(%r15)
-1:      lm      %r0,%r11,SP_R0(%r15)
+        la      %r12,__LC_SAVE_AREA+32
+        be      BASED(1f)
+        la      %r12,__LC_SAVE_AREA+16
+1:      mvc     0(16,%r12),SP_R12(%r15)
+        lm      %r0,%r11,SP_R0(%r15)
         l       %r15,SP_R15(%r15)
 2:      la      %r12,__LC_RETURN_PSW
         br      %r14
@@ -1009,19 +1011,15 @@ cleanup_io_tif:
 
 cleanup_io_restore:
         clc     4(4,%r12),BASED(cleanup_io_restore_insn)
-        be      BASED(2f)
-        mvc     __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
+        be      BASED(1f)
+        mvc     __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
         clc     4(4,%r12),BASED(cleanup_io_restore_insn+4)
-        be      BASED(2f)
+        be      BASED(1f)
         mvc     __LC_RETURN_PSW(8),SP_PSW(%r15)
-        c       %r12,BASED(.Lmck_old_psw)
-        bne     BASED(0f)
         mvc     __LC_SAVE_AREA+32(16),SP_R12(%r15)
-        b       BASED(1f)
-0:      mvc     __LC_SAVE_AREA+16(16),SP_R12(%r15)
-1:      lm      %r0,%r11,SP_R0(%r15)
+        lm      %r0,%r11,SP_R0(%r15)
         l       %r15,SP_R15(%r15)
-2:      la      %r12,__LC_RETURN_PSW
+1:      la      %r12,__LC_RETURN_PSW
         br      %r14
 cleanup_io_restore_insn:
         .long   io_done - 4 + 0x80000000
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 860cea1d1c8a..6536f5ca46f5 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -725,7 +725,7 @@ __critical_end:
  */
         .globl mcck_int_handler
 mcck_int_handler:
-        stck    __LC_INT_CLOCK
+        stck    __LC_MCCK_CLOCK
         la      %r1,4095                # revalidate r1
         spt     __LC_CPU_TIMER_SAVE_AREA-4095(%r1)      # revalidate cpu timer
         lmg     %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs
@@ -734,8 +734,7 @@ mcck_int_handler:
         tm      __LC_MCCK_CODE,0x80     # system damage?
         jo      mcck_int_main           # yes -> rest of mcck code invalid
         la      %r14,4095
-        mvc     __LC_SAVE_AREA+104(8),__LC_ASYNC_ENTER_TIMER
-        mvc     __LC_ASYNC_ENTER_TIMER(8),__LC_CPU_TIMER_SAVE_AREA-4095(%r14)
+        mvc     __LC_MCCK_ENTER_TIMER(8),__LC_CPU_TIMER_SAVE_AREA-4095(%r14)
         tm      __LC_MCCK_CODE+5,0x02   # stored cpu timer value valid?
         jo      1f
         la      %r14,__LC_SYNC_ENTER_TIMER
@@ -749,7 +748,7 @@ mcck_int_handler:
         jl      0f
         la      %r14,__LC_LAST_UPDATE_TIMER
 0:      spt     0(%r14)
-        mvc     __LC_ASYNC_ENTER_TIMER(8),0(%r14)
+        mvc     __LC_MCCK_ENTER_TIMER(8),0(%r14)
 1:      tm      __LC_MCCK_CODE+2,0x09   # mwp + ia of old psw valid?
         jno     mcck_int_main           # no -> skip cleanup critical
         tm      __LC_MCK_OLD_PSW+1,0x01 # test problem state bit
@@ -770,9 +769,9 @@ mcck_int_main:
         jno     mcck_no_vtime           # no -> no timer update
         tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
         jz      mcck_no_vtime
-        UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
+        UPDATE_VTIME __LC_EXIT_TIMER,__LC_MCCK_ENTER_TIMER,__LC_USER_TIMER
         UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
-        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
+        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_MCCK_ENTER_TIMER
 mcck_no_vtime:
         lg      %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
         la      %r2,SP_PTREGS(%r15)     # load pt_regs
@@ -794,7 +793,6 @@ mcck_return:
         mvc     __LC_RETURN_MCCK_PSW(16),SP_PSW(%r15) # move return PSW
         ni      __LC_RETURN_MCCK_PSW+1,0xfd # clear wait state bit
         lmg     %r0,%r15,SP_R0(%r15)    # load gprs 0-15
-        mvc     __LC_ASYNC_ENTER_TIMER(8),__LC_SAVE_AREA+104
         tm      __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
         jno     0f
         stpt    __LC_EXIT_TIMER
@@ -909,15 +907,16 @@ cleanup_critical:
 
 cleanup_system_call:
         mvc     __LC_RETURN_PSW(16),0(%r12)
-        cghi    %r12,__LC_MCK_OLD_PSW
-        je      0f
-        la      %r12,__LC_SAVE_AREA+32
-        j       1f
-0:      la      %r12,__LC_SAVE_AREA+64
-1:
         clc     __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+8)
         jh      0f
+        mvc     __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
+        cghi    %r12,__LC_MCK_OLD_PSW
+        je      0f
         mvc     __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
+0:      cghi    %r12,__LC_MCK_OLD_PSW
+        la      %r12,__LC_SAVE_AREA+64
+        je      0f
+        la      %r12,__LC_SAVE_AREA+32
 0:      clc     __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+16)
         jhe     cleanup_vtime
         clc     __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn)
@@ -958,19 +957,22 @@ cleanup_sysc_tif:
 
 cleanup_sysc_restore:
         clc     8(8,%r12),BASED(cleanup_sysc_restore_insn)
-        je      3f
+        je      2f
         clc     8(8,%r12),BASED(cleanup_sysc_restore_insn+8)
         jhe     0f
+        mvc     __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
+        cghi    %r12,__LC_MCK_OLD_PSW
+        je      0f
         mvc     __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
 0:      mvc     __LC_RETURN_PSW(16),SP_PSW(%r15)
         cghi    %r12,__LC_MCK_OLD_PSW
-        jne     1f
-        mvc     __LC_SAVE_AREA+64(32),SP_R12(%r15)
-        j       2f
-1:      mvc     __LC_SAVE_AREA+32(32),SP_R12(%r15)
-2:      lmg     %r0,%r11,SP_R0(%r15)
+        la      %r12,__LC_SAVE_AREA+64
+        je      1f
+        la      %r12,__LC_SAVE_AREA+32
+1:      mvc     0(32,%r12),SP_R12(%r15)
+        lmg     %r0,%r11,SP_R0(%r15)
         lg      %r15,SP_R15(%r15)
-3:      la      %r12,__LC_RETURN_PSW
+2:      la      %r12,__LC_RETURN_PSW
         br      %r14
 cleanup_sysc_restore_insn:
         .quad   sysc_done - 4
@@ -984,19 +986,15 @@ cleanup_io_tif:
 
 cleanup_io_restore:
         clc     8(8,%r12),BASED(cleanup_io_restore_insn)
-        je      3f
+        je      1f
         clc     8(8,%r12),BASED(cleanup_io_restore_insn+8)
         jhe     0f
-        mvc     __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
+        mvc     __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
 0:      mvc     __LC_RETURN_PSW(16),SP_PSW(%r15)
-        cghi    %r12,__LC_MCK_OLD_PSW
-        jne     1f
         mvc     __LC_SAVE_AREA+64(32),SP_R12(%r15)
-        j       2f
-1:      mvc     __LC_SAVE_AREA+32(32),SP_R12(%r15)
-2:      lmg     %r0,%r11,SP_R0(%r15)
+        lmg     %r0,%r11,SP_R0(%r15)
         lg      %r15,SP_R15(%r15)
-3:      la      %r12,__LC_RETURN_PSW
+1:      la      %r12,__LC_RETURN_PSW
         br      %r14
 cleanup_io_restore_insn:
         .quad   io_done - 4
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
index 015e27da40eb..ac151399ef34 100644
--- a/arch/s390/kernel/nmi.c
+++ b/arch/s390/kernel/nmi.c
@@ -255,7 +255,8 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
         int umode;
 
         nmi_enter();
-        s390_idle_check();
+        s390_idle_check(regs, S390_lowcore.mcck_clock,
+                        S390_lowcore.mcck_enter_timer);
 
         mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
         mcck = &__get_cpu_var(cpu_mcck);
diff --git a/arch/s390/kernel/s390_ext.c b/arch/s390/kernel/s390_ext.c
index 59618bcd99b7..9ce641b5291f 100644
--- a/arch/s390/kernel/s390_ext.c
+++ b/arch/s390/kernel/s390_ext.c
@@ -120,7 +120,8 @@ void __irq_entry do_extint(struct pt_regs *regs, unsigned short code)
         struct pt_regs *old_regs;
 
         old_regs = set_irq_regs(regs);
-        s390_idle_check();
+        s390_idle_check(regs, S390_lowcore.int_clock,
+                        S390_lowcore.async_enter_timer);
         irq_enter();
         if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
                 /* Serve timer interrupts first. */
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index b59a812a010e..3479f1b0d4e0 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -121,32 +121,35 @@ void account_system_vtime(struct task_struct *tsk)
 }
 EXPORT_SYMBOL_GPL(account_system_vtime);
 
-void vtime_start_cpu(void)
+void vtime_start_cpu(__u64 int_clock, __u64 enter_timer)
 {
         struct s390_idle_data *idle = &__get_cpu_var(s390_idle);
         struct vtimer_queue *vq = &__get_cpu_var(virt_cpu_timer);
         __u64 idle_time, expires;
 
+        if (idle->idle_enter == 0ULL)
+                return;
+
         /* Account time spent with enabled wait psw loaded as idle time. */
-        idle_time = S390_lowcore.int_clock - idle->idle_enter;
+        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 = S390_lowcore.int_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 = S390_lowcore.async_enter_timer;
+        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 - S390_lowcore.async_enter_timer;
+                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 - S390_lowcore.async_enter_timer;
+                vq->elapsed -= vq->idle - enter_timer;
         }
 
         idle->sequence++;