1 files changed, 100 insertions, 41 deletions

diff --git a/arch/s390/kernel/idle.c b/arch/s390/kernel/idle.c
index 39cb8d0ae348..dd12efb58201 100644
--- a/arch/s390/kernel/idle.c
+++ b/arch/s390/kernel/idle.c
@@ -9,46 +9,125 @@
 
 #include <linux/kernel.h>
 #include <linux/kernel_stat.h>
+#include <linux/sched/stat.h>
 #include <linux/notifier.h>
 #include <linux/init.h>
 #include <linux/cpu.h>
+#include <linux/export.h>
 #include <trace/events/power.h>
 #include <asm/cpu_mf.h>
 #include <asm/cputime.h>
+#include <asm/idle.h>
 #include <asm/nmi.h>
 #include <asm/smp.h>
-#include "entry.h"
 
-static DEFINE_PER_CPU(struct s390_idle_data, s390_idle);
+DEFINE_PER_CPU(struct s390_idle_data, s390_idle);
 
-void account_idle_time_irq(void)
+static __always_inline void __account_idle_time_irq(void)
 {
 	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
-	struct lowcore *lc = get_lowcore();
 	unsigned long idle_time;
-	u64 cycles_new[8];
-	int i;
 
-	if (smp_cpu_mtid) {
-		stcctm(MT_DIAG, smp_cpu_mtid, cycles_new);
-		for (i = 0; i < smp_cpu_mtid; i++)
-			this_cpu_add(mt_cycles[i], cycles_new[i] - idle->mt_cycles_enter[i]);
-	}
+	idle_time = idle->clock_idle_exit.tod - idle->clock_idle_enter.tod;
+	account_idle_time(cputime_to_nsecs(idle_time));
+}
+
+static __always_inline void __account_idle_time_setup(void)
+{
+	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
 
-	idle_time = lc->int_clock - idle->clock_idle_enter;
+	store_tod_clock_ext(&idle->clock_idle_enter);
+	idle->timer_idle_enter = get_cpu_timer();
+	idle->clock_idle_exit = idle->clock_idle_enter;
+}
 
-	lc->steal_timer += idle->clock_idle_enter - lc->last_update_clock;
-	lc->last_update_clock = lc->int_clock;
+#ifdef CONFIG_NO_HZ_COMMON
 
-	lc->system_timer += lc->last_update_timer - idle->timer_idle_enter;
-	lc->last_update_timer = lc->sys_enter_timer;
+static u64 arch_cpu_in_idle_time(int cpu)
+{
+	struct s390_idle_data *idle = &per_cpu(s390_idle, cpu);
+	union tod_clock now;
+	u64 idle_time;
+
+	if (!idle->in_idle)
+		return 0;
+	store_tod_clock_ext(&now);
+	if (tod_after(idle->clock_idle_exit.tod, idle->clock_idle_enter.tod))
+		idle_time = idle->clock_idle_exit.tod - idle->clock_idle_enter.tod;
+	else
+		idle_time = now.tod - idle->clock_idle_enter.tod;
+	return cputime_to_nsecs(idle_time);
+}
 
-	/* Account time spent with enabled wait psw loaded as idle time. */
-	WRITE_ONCE(idle->idle_time, READ_ONCE(idle->idle_time) + idle_time);
-	WRITE_ONCE(idle->idle_count, READ_ONCE(idle->idle_count) + 1);
-	account_idle_time(cputime_to_nsecs(idle_time));
+static u64 arch_cpu_idle_time(int cpu, enum cpu_usage_stat idx, bool compute_delta)
+{
+	struct kernel_cpustat *kc = &kcpustat_cpu(cpu);
+	u64 *cpustat = kc->cpustat;
+	unsigned int seq;
+	u64 idle_time;
+
+	/*
+	 * The open coded seqcount writer in entry.S relies on the
+	 * raw counting mechanism without any writer protection.
+	 */
+	typecheck(typeof(kc->idle_sleeptime_seq), seqcount_t);
+	do {
+		seq = read_seqcount_begin(&kc->idle_sleeptime_seq);
+		idle_time = cpustat[idx];
+		if (compute_delta)
+			idle_time += arch_cpu_in_idle_time(cpu);
+	} while (read_seqcount_retry(&kc->idle_sleeptime_seq, seq));
+	return idle_time;
+}
+
+u64 arch_kcpustat_field_idle(int cpu)
+{
+	return arch_cpu_idle_time(cpu, CPUTIME_IDLE, !nr_iowait_cpu(cpu));
+}
+EXPORT_SYMBOL_GPL(arch_kcpustat_field_idle);
+
+u64 arch_kcpustat_field_iowait(int cpu)
+{
+	return arch_cpu_idle_time(cpu, CPUTIME_IOWAIT, nr_iowait_cpu(cpu));
+}
+EXPORT_SYMBOL_GPL(arch_kcpustat_field_iowait);
+
+void account_idle_time_irq(void)
+{
+	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
+	struct kernel_cpustat *kc = kcpustat_this_cpu;
+
+	write_seqcount_begin(&kc->idle_sleeptime_seq);
+	idle->in_idle = false;
+	__account_idle_time_irq();
+	write_seqcount_end(&kc->idle_sleeptime_seq);
 }
 
+static __always_inline void account_idle_time_setup(void)
+{
+	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
+	struct kernel_cpustat *kc = kcpustat_this_cpu;
+
+	raw_write_seqcount_begin(&kc->idle_sleeptime_seq);
+	idle->in_idle = true;
+	__account_idle_time_setup();
+	raw_write_seqcount_end(&kc->idle_sleeptime_seq);
+}
+
+#else  /* CONFIG_NO_HZ_COMMON */
+
+void account_idle_time_irq(void)
+{
+	__account_idle_time_irq();
+}
+
+static __always_inline void account_idle_time_setup(void)
+{
+	__account_idle_time_setup();
+}
+
+#endif /* CONFIG_NO_HZ_COMMON */
+
 void noinstr arch_cpu_idle(void)
 {
 	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
@@ -57,34 +136,14 @@ void noinstr arch_cpu_idle(void)
 	/* Wait for external, I/O or machine check interrupt. */
 	psw_mask = PSW_KERNEL_BITS | PSW_MASK_WAIT |
 		   PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
-	clear_cpu_flag(CIF_NOHZ_DELAY);
 	set_cpu_flag(CIF_ENABLED_WAIT);
 	if (smp_cpu_mtid)
 		stcctm(MT_DIAG, smp_cpu_mtid, (u64 *)&idle->mt_cycles_enter);
-	idle->clock_idle_enter = get_tod_clock_fast();
-	idle->timer_idle_enter = get_cpu_timer();
+	account_idle_time_setup();
 	bpon();
 	__load_psw_mask(psw_mask);
 }
 
-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);
-
-	return sysfs_emit(buf, "%lu\n", READ_ONCE(idle->idle_count));
-}
-DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL);
-
-static ssize_t show_idle_time(struct device *dev,
-			      struct device_attribute *attr, char *buf)
-{
-	struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
-
-	return sysfs_emit(buf, "%lu\n", READ_ONCE(idle->idle_time) >> 12);
-}
-DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL);
-
 void arch_cpu_idle_enter(void)
 {
 }