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	Assign the output from get_lowcore() to a local variable, so the code is easier to read. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
		
			
				
	
	
		
			99 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			99 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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/*
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 * Idle functions for s390.
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 *
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 * Copyright IBM Corp. 2014
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 *
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 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
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 */
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#include <linux/kernel.h>
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#include <linux/kernel_stat.h>
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#include <linux/notifier.h>
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#include <linux/init.h>
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#include <linux/cpu.h>
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#include <trace/events/power.h>
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#include <asm/cpu_mf.h>
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#include <asm/cputime.h>
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#include <asm/nmi.h>
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#include <asm/smp.h>
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#include "entry.h"
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static DEFINE_PER_CPU(struct s390_idle_data, s390_idle);
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void account_idle_time_irq(void)
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{
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	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
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	struct lowcore *lc = get_lowcore();
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	unsigned long idle_time;
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	u64 cycles_new[8];
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	int i;
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	if (smp_cpu_mtid) {
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		stcctm(MT_DIAG, smp_cpu_mtid, cycles_new);
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		for (i = 0; i < smp_cpu_mtid; i++)
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			this_cpu_add(mt_cycles[i], cycles_new[i] - idle->mt_cycles_enter[i]);
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	}
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	idle_time = lc->int_clock - idle->clock_idle_enter;
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	lc->steal_timer += idle->clock_idle_enter - lc->last_update_clock;
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	lc->last_update_clock = lc->int_clock;
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	lc->system_timer += lc->last_update_timer - idle->timer_idle_enter;
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	lc->last_update_timer = lc->sys_enter_timer;
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	/* Account time spent with enabled wait psw loaded as idle time. */
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	WRITE_ONCE(idle->idle_time, READ_ONCE(idle->idle_time) + idle_time);
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	WRITE_ONCE(idle->idle_count, READ_ONCE(idle->idle_count) + 1);
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	account_idle_time(cputime_to_nsecs(idle_time));
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}
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void noinstr arch_cpu_idle(void)
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{
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	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
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	unsigned long psw_mask;
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	/* Wait for external, I/O or machine check interrupt. */
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	psw_mask = PSW_KERNEL_BITS | PSW_MASK_WAIT |
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		   PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
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	clear_cpu_flag(CIF_NOHZ_DELAY);
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	set_cpu_flag(CIF_ENABLED_WAIT);
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	if (smp_cpu_mtid)
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		stcctm(MT_DIAG, smp_cpu_mtid, (u64 *)&idle->mt_cycles_enter);
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	idle->clock_idle_enter = get_tod_clock_fast();
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	idle->timer_idle_enter = get_cpu_timer();
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	bpon();
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	__load_psw_mask(psw_mask);
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}
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static ssize_t show_idle_count(struct device *dev,
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			       struct device_attribute *attr, char *buf)
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{
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	struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
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	return sysfs_emit(buf, "%lu\n", READ_ONCE(idle->idle_count));
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}
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DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL);
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static ssize_t show_idle_time(struct device *dev,
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			      struct device_attribute *attr, char *buf)
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{
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	struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
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	return sysfs_emit(buf, "%lu\n", READ_ONCE(idle->idle_time) >> 12);
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}
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DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL);
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void arch_cpu_idle_enter(void)
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{
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}
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void arch_cpu_idle_exit(void)
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{
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}
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void __noreturn arch_cpu_idle_dead(void)
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{
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	cpu_die();
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}
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