1 files changed, 15 insertions, 14 deletions

diff --git a/arch/s390/kernel/idle.c b/arch/s390/kernel/idle.c
index 7559f1beab29..7a55c29b0b33 100644
--- a/arch/s390/kernel/idle.c
+++ b/arch/s390/kernel/idle.c
@@ -19,7 +19,7 @@
 
 static DEFINE_PER_CPU(struct s390_idle_data, s390_idle);
 
-void __kprobes enabled_wait(void)
+void enabled_wait(void)
 {
         struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
         unsigned long long idle_time;
@@ -35,31 +35,32 @@ void __kprobes enabled_wait(void)
         /* Call the assembler magic in entry.S */
         psw_idle(idle, psw_mask);
 
+        trace_hardirqs_off();
+
         /* Account time spent with enabled wait psw loaded as idle time. */
-        idle->sequence++;
-        smp_wmb();
+        write_seqcount_begin(&idle->seqcount);
         idle_time = idle->clock_idle_exit - idle->clock_idle_enter;
         idle->clock_idle_enter = idle->clock_idle_exit = 0ULL;
         idle->idle_time += idle_time;
         idle->idle_count++;
         account_idle_time(idle_time);
-        smp_wmb();
-        idle->sequence++;
+        write_seqcount_end(&idle->seqcount);
 }
+NOKPROBE_SYMBOL(enabled_wait);
 
 static ssize_t show_idle_count(struct device *dev,
                                 struct device_attribute *attr, char *buf)
 {
         struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
         unsigned long long idle_count;
-        unsigned int sequence;
+        unsigned int seq;
 
         do {
-                sequence = ACCESS_ONCE(idle->sequence);
+                seq = read_seqcount_begin(&idle->seqcount);
                 idle_count = ACCESS_ONCE(idle->idle_count);
                 if (ACCESS_ONCE(idle->clock_idle_enter))
                         idle_count++;
-        } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence));
+        } while (read_seqcount_retry(&idle->seqcount, seq));
         return sprintf(buf, "%llu\n", idle_count);
 }
 DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL);
@@ -69,15 +70,15 @@ static ssize_t show_idle_time(struct device *dev,
 {
         struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
         unsigned long long now, idle_time, idle_enter, idle_exit;
-        unsigned int sequence;
+        unsigned int seq;
 
         do {
                 now = get_tod_clock();
-                sequence = ACCESS_ONCE(idle->sequence);
+                seq = read_seqcount_begin(&idle->seqcount);
                 idle_time = ACCESS_ONCE(idle->idle_time);
                 idle_enter = ACCESS_ONCE(idle->clock_idle_enter);
                 idle_exit = ACCESS_ONCE(idle->clock_idle_exit);
-        } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence));
+        } while (read_seqcount_retry(&idle->seqcount, seq));
         idle_time += idle_enter ? ((idle_exit ? : now) - idle_enter) : 0;
         return sprintf(buf, "%llu\n", idle_time >> 12);
 }
@@ -87,14 +88,14 @@ cputime64_t arch_cpu_idle_time(int cpu)
 {
         struct s390_idle_data *idle = &per_cpu(s390_idle, cpu);
         unsigned long long now, idle_enter, idle_exit;
-        unsigned int sequence;
+        unsigned int seq;
 
         do {
                 now = get_tod_clock();
-                sequence = ACCESS_ONCE(idle->sequence);
+                seq = read_seqcount_begin(&idle->seqcount);
                 idle_enter = ACCESS_ONCE(idle->clock_idle_enter);
                 idle_exit = ACCESS_ONCE(idle->clock_idle_exit);
-        } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence));
+        } while (read_seqcount_retry(&idle->seqcount, seq));
         return idle_enter ? ((idle_exit ?: now) - idle_enter) : 0;
 }