95 lines
2.5 KiB
C
95 lines
2.5 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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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 = S390_lowcore.int_clock - idle->clock_idle_enter;
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S390_lowcore.steal_timer += idle->clock_idle_enter - S390_lowcore.last_update_clock;
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S390_lowcore.last_update_clock = S390_lowcore.int_clock;
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S390_lowcore.system_timer += S390_lowcore.last_update_timer - idle->timer_idle_enter;
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S390_lowcore.last_update_timer = S390_lowcore.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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/* psw_idle() returns with interrupts disabled. */
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psw_idle(idle, 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 arch_cpu_idle_dead(void)
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{
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cpu_die();
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}
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