1 files changed, 46 insertions, 89 deletions

diff --git a/arch/s390/kernel/idle.c b/arch/s390/kernel/idle.c
index 8f8456816d83..39cb8d0ae348 100644
--- a/arch/s390/kernel/idle.c
+++ b/arch/s390/kernel/idle.c
@@ -9,134 +9,91 @@
 
 #include <linux/kernel.h>
 #include <linux/kernel_stat.h>
-#include <linux/kprobes.h>
 #include <linux/notifier.h>
 #include <linux/init.h>
 #include <linux/cpu.h>
-#include <linux/sched/cputime.h>
+#include <trace/events/power.h>
+#include <asm/cpu_mf.h>
+#include <asm/cputime.h>
 #include <asm/nmi.h>
 #include <asm/smp.h>
 #include "entry.h"
 
 static DEFINE_PER_CPU(struct s390_idle_data, s390_idle);
 
-void enabled_wait(void)
+void account_idle_time_irq(void)
 {
 	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
-	unsigned long long idle_time;
-	unsigned long psw_mask;
-
-	trace_hardirqs_on();
+	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]);
+	}
 
-	/* Wait for external, I/O or machine check interrupt. */
-	psw_mask = PSW_KERNEL_BITS | PSW_MASK_WAIT | PSW_MASK_DAT |
-		PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
-	clear_cpu_flag(CIF_NOHZ_DELAY);
+	idle_time = lc->int_clock - idle->clock_idle_enter;
 
-	/* Call the assembler magic in entry.S */
-	psw_idle(idle, psw_mask);
+	lc->steal_timer += idle->clock_idle_enter - lc->last_update_clock;
+	lc->last_update_clock = lc->int_clock;
 
-	trace_hardirqs_off();
+	lc->system_timer += lc->last_update_timer - idle->timer_idle_enter;
+	lc->last_update_timer = lc->sys_enter_timer;
 
 	/* Account time spent with enabled wait psw loaded as idle time. */
-	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++;
+	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));
-	write_seqcount_end(&idle->seqcount);
 }
-NOKPROBE_SYMBOL(enabled_wait);
+
+void noinstr arch_cpu_idle(void)
+{
+	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
+	unsigned long psw_mask;
+
+	/* 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();
+	bpon();
+	__load_psw_mask(psw_mask);
+}
 
 static ssize_t show_idle_count(struct device *dev,
-				struct device_attribute *attr, char *buf)
+			       struct device_attribute *attr, char *buf)
 {
 	struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
-	unsigned long long idle_count;
-	unsigned int seq;
-
-	do {
-		seq = read_seqcount_begin(&idle->seqcount);
-		idle_count = READ_ONCE(idle->idle_count);
-		if (READ_ONCE(idle->clock_idle_enter))
-			idle_count++;
-	} while (read_seqcount_retry(&idle->seqcount, seq));
-	return sprintf(buf, "%llu\n", idle_count);
+
+	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 device_attribute *attr, char *buf)
 {
-	unsigned long long now, idle_time, idle_enter, idle_exit, in_idle;
 	struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
-	unsigned int seq;
-
-	do {
-		seq = read_seqcount_begin(&idle->seqcount);
-		idle_time = READ_ONCE(idle->idle_time);
-		idle_enter = READ_ONCE(idle->clock_idle_enter);
-		idle_exit = READ_ONCE(idle->clock_idle_exit);
-	} while (read_seqcount_retry(&idle->seqcount, seq));
-	in_idle = 0;
-	now = get_tod_clock();
-	if (idle_enter) {
-		if (idle_exit) {
-			in_idle = idle_exit - idle_enter;
-		} else if (now > idle_enter) {
-			in_idle = now - idle_enter;
-		}
-	}
-	idle_time += in_idle;
-	return sprintf(buf, "%llu\n", idle_time >> 12);
-}
-DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL);
 
-u64 arch_cpu_idle_time(int cpu)
-{
-	struct s390_idle_data *idle = &per_cpu(s390_idle, cpu);
-	unsigned long long now, idle_enter, idle_exit, in_idle;
-	unsigned int seq;
-
-	do {
-		seq = read_seqcount_begin(&idle->seqcount);
-		idle_enter = READ_ONCE(idle->clock_idle_enter);
-		idle_exit = READ_ONCE(idle->clock_idle_exit);
-	} while (read_seqcount_retry(&idle->seqcount, seq));
-	in_idle = 0;
-	now = get_tod_clock();
-	if (idle_enter) {
-		if (idle_exit) {
-			in_idle = idle_exit - idle_enter;
-		} else if (now > idle_enter) {
-			in_idle = now - idle_enter;
-		}
-	}
-	return cputime_to_nsecs(in_idle);
+	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)
 {
-	local_mcck_disable();
-}
-
-void arch_cpu_idle(void)
-{
-	if (!test_cpu_flag(CIF_MCCK_PENDING))
-		/* Halt the cpu and keep track of cpu time accounting. */
-		enabled_wait();
-	local_irq_enable();
 }
 
 void arch_cpu_idle_exit(void)
 {
-	local_mcck_enable();
-	if (test_cpu_flag(CIF_MCCK_PENDING))
-		s390_handle_mcck();
 }
 
-void arch_cpu_idle_dead(void)
+void __noreturn arch_cpu_idle_dead(void)
 {
 	cpu_die();
 }