1 files changed, 40 insertions, 53 deletions

diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index 4a4a34caec55..1254a4d0d762 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -31,11 +31,10 @@ static DEFINE_PER_CPU(struct vtimer_queue, virt_cpu_timer);
  * Update process times based on virtual cpu times stored by entry.S
  * to the lowcore fields user_timer, system_timer & steal_clock.
  */
-void account_process_tick(struct task_struct *tsk, int user_tick)
+static void do_account_vtime(struct task_struct *tsk, int hardirq_offset)
 {
-        cputime_t cputime;
-        __u64 timer, clock;
-        int rcu_user_flag;
+        struct thread_info *ti = task_thread_info(tsk);
+        __u64 timer, clock, user, system, steal;
 
         timer = S390_lowcore.last_update_timer;
         clock = S390_lowcore.last_update_clock;
@@ -44,59 +43,47 @@ void account_process_tick(struct task_struct *tsk, int user_tick)
                       : "=m" (S390_lowcore.last_update_timer),
                         "=m" (S390_lowcore.last_update_clock) );
         S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer;
-        S390_lowcore.steal_clock += S390_lowcore.last_update_clock - clock;
+        S390_lowcore.steal_timer += S390_lowcore.last_update_clock - clock;
 
-        cputime = S390_lowcore.user_timer >> 12;
-        rcu_user_flag = cputime != 0;
-        S390_lowcore.user_timer -= cputime << 12;
-        S390_lowcore.steal_clock -= cputime << 12;
-        account_user_time(tsk, cputime, cputime);
+        user = S390_lowcore.user_timer - ti->user_timer;
+        S390_lowcore.steal_timer -= user;
+        ti->user_timer = S390_lowcore.user_timer;
+        account_user_time(tsk, user, user);
 
-        cputime =  S390_lowcore.system_timer >> 12;
-        S390_lowcore.system_timer -= cputime << 12;
-        S390_lowcore.steal_clock -= cputime << 12;
+        system = S390_lowcore.system_timer - ti->system_timer;
+        S390_lowcore.steal_timer -= system;
+        ti->system_timer = S390_lowcore.system_timer;
         if (idle_task(smp_processor_id()) != current)
-                account_system_time(tsk, HARDIRQ_OFFSET, cputime, cputime);
+                account_system_time(tsk, hardirq_offset, system, system);
         else
-                account_idle_time(cputime);
+                account_idle_time(system);
 
-        cputime = S390_lowcore.steal_clock;
-        if ((__s64) cputime > 0) {
-                cputime >>= 12;
-                S390_lowcore.steal_clock -= cputime << 12;
+        steal = S390_lowcore.steal_timer;
+        if ((s64) steal > 0) {
+                S390_lowcore.steal_timer = 0;
                 if (idle_task(smp_processor_id()) != current)
-                        account_steal_time(cputime);
+                        account_steal_time(steal);
                 else
-                        account_idle_time(cputime);
+                        account_idle_time(steal);
         }
 }
 
-/*
- * Update process times based on virtual cpu times stored by entry.S
- * to the lowcore fields user_timer, system_timer & steal_clock.
- */
-void account_vtime(struct task_struct *tsk)
+void account_vtime(struct task_struct *prev, struct task_struct *next)
 {
-        cputime_t cputime;
-        __u64 timer;
-
-        timer = S390_lowcore.last_update_timer;
-        asm volatile ("  STPT %0"    /* Store current cpu timer value */
-                      : "=m" (S390_lowcore.last_update_timer) );
-        S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer;
-
-        cputime = S390_lowcore.user_timer >> 12;
-        S390_lowcore.user_timer -= cputime << 12;
-        S390_lowcore.steal_clock -= cputime << 12;
-        account_user_time(tsk, cputime, cputime);
+        struct thread_info *ti;
+
+        do_account_vtime(prev, 0);
+        ti = task_thread_info(prev);
+        ti->user_timer = S390_lowcore.user_timer;
+        ti->system_timer = S390_lowcore.system_timer;
+        ti = task_thread_info(next);
+        S390_lowcore.user_timer = ti->user_timer;
+        S390_lowcore.system_timer = ti->system_timer;
+}
 
-        cputime =  S390_lowcore.system_timer >> 12;
-        S390_lowcore.system_timer -= cputime << 12;
-        S390_lowcore.steal_clock -= cputime << 12;
-        if (idle_task(smp_processor_id()) != current)
-                account_system_time(tsk, 0, cputime, cputime);
-        else
-                account_idle_time(cputime);
+void account_process_tick(struct task_struct *tsk, int user_tick)
+{
+        do_account_vtime(tsk, HARDIRQ_OFFSET);
 }
 
 /*
@@ -105,21 +92,21 @@ void account_vtime(struct task_struct *tsk)
  */
 void account_system_vtime(struct task_struct *tsk)
 {
-        cputime_t cputime;
-        __u64 timer;
+        struct thread_info *ti = task_thread_info(tsk);
+        __u64 timer, system;
 
         timer = S390_lowcore.last_update_timer;
         asm volatile ("  STPT %0"    /* Store current cpu timer value */
                       : "=m" (S390_lowcore.last_update_timer) );
         S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer;
 
-        cputime =  S390_lowcore.system_timer >> 12;
-        S390_lowcore.system_timer -= cputime << 12;
-        S390_lowcore.steal_clock -= cputime << 12;
+        system = S390_lowcore.system_timer - ti->system_timer;
+        S390_lowcore.steal_timer -= system;
+        ti->system_timer = S390_lowcore.system_timer;
         if (in_irq() || idle_task(smp_processor_id()) != current)
-                account_system_time(tsk, 0, cputime, cputime);
+                account_system_time(tsk, 0, system, system);
         else
-                account_idle_time(cputime);
+                account_idle_time(system);
 }
 EXPORT_SYMBOL_GPL(account_system_vtime);
 
@@ -490,8 +477,8 @@ void init_cpu_vtimer(void)
         /* kick the virtual timer */
         S390_lowcore.exit_timer = VTIMER_MAX_SLICE;
         S390_lowcore.last_update_timer = VTIMER_MAX_SLICE;
-        asm volatile ("SPT %0" : : "m" (S390_lowcore.last_update_timer));
         asm volatile ("STCK %0" : "=m" (S390_lowcore.last_update_clock));
+        asm volatile ("SPT %0" : : "m" (S390_lowcore.last_update_timer));
 
         /* enable cpu timer interrupts */
         __ctl_set_bit(0,10);