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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 | // SPDX-License-Identifier: GPL-2.0 /* * Idle functions for s390. * * Copyright IBM Corp. 2014 * * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> */ #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 <asm/nmi.h> #include <asm/smp.h> #include "entry.h" static DEFINE_PER_CPU(struct s390_idle_data, s390_idle); void enabled_wait(void) { struct s390_idle_data *idle = this_cpu_ptr(&s390_idle); unsigned long long idle_time; unsigned long psw_mask; trace_hardirqs_on(); /* 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); /* 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. */ 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(cputime_to_nsecs(idle_time)); 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 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); } DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL); static ssize_t show_idle_time(struct device *dev, 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); } 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) { cpu_die(); } |