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| 1 | +// SPDX-License-Identifier: GPL-2.0 |
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| 1 | 2 | /* |
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| 2 | | - * linux/kernel/time/tick-common.c |
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| 3 | | - * |
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| 4 | 3 | * This file contains the base functions to manage periodic tick |
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| 5 | 4 | * related events. |
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| 6 | 5 | * |
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| 7 | 6 | * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de> |
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| 8 | 7 | * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar |
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| 9 | 8 | * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner |
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| 10 | | - * |
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| 11 | | - * This code is licenced under the GPL version 2. For details see |
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| 12 | | - * kernel-base/COPYING. |
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| 13 | 9 | */ |
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| 14 | 10 | #include <linux/cpu.h> |
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| 15 | 11 | #include <linux/err.h> |
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| .. | .. |
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| 21 | 17 | #include <linux/sched.h> |
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| 22 | 18 | #include <linux/module.h> |
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| 23 | 19 | #include <trace/events/power.h> |
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| 20 | +#include <trace/hooks/sched.h> |
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| 24 | 21 | |
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| 25 | 22 | #include <asm/irq_regs.h> |
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| 26 | 23 | |
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| .. | .. |
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| 51 | 48 | * procedure also covers cpu hotplug. |
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| 52 | 49 | */ |
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| 53 | 50 | int tick_do_timer_cpu __read_mostly = TICK_DO_TIMER_BOOT; |
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| 51 | +#ifdef CONFIG_NO_HZ_FULL |
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| 52 | +/* |
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| 53 | + * tick_do_timer_boot_cpu indicates the boot CPU temporarily owns |
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| 54 | + * tick_do_timer_cpu and it should be taken over by an eligible secondary |
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| 55 | + * when one comes online. |
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| 56 | + */ |
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| 57 | +static int tick_do_timer_boot_cpu __read_mostly = -1; |
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| 58 | +#endif |
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| 54 | 59 | |
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| 55 | 60 | /* |
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| 56 | 61 | * Debugging: see timer_list.c |
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| .. | .. |
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| 80 | 85 | static void tick_periodic(int cpu) |
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| 81 | 86 | { |
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| 82 | 87 | if (tick_do_timer_cpu == cpu) { |
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| 83 | | - write_seqlock(&jiffies_lock); |
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| 88 | + raw_spin_lock(&jiffies_lock); |
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| 89 | + write_seqcount_begin(&jiffies_seq); |
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| 84 | 90 | |
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| 85 | 91 | /* Keep track of the next tick event */ |
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| 86 | 92 | tick_next_period = ktime_add(tick_next_period, tick_period); |
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| 87 | 93 | |
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| 88 | 94 | do_timer(1); |
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| 89 | | - write_sequnlock(&jiffies_lock); |
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| 95 | + write_seqcount_end(&jiffies_seq); |
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| 96 | + raw_spin_unlock(&jiffies_lock); |
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| 90 | 97 | update_wall_time(); |
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| 98 | + trace_android_vh_jiffies_update(NULL); |
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| 91 | 99 | } |
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| 92 | 100 | |
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| 93 | 101 | update_process_times(user_mode(get_irq_regs())); |
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| .. | .. |
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| 154 | 162 | !tick_broadcast_oneshot_active()) { |
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| 155 | 163 | clockevents_switch_state(dev, CLOCK_EVT_STATE_PERIODIC); |
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| 156 | 164 | } else { |
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| 157 | | - unsigned long seq; |
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| 165 | + unsigned int seq; |
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| 158 | 166 | ktime_t next; |
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| 159 | 167 | |
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| 160 | 168 | do { |
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| 161 | | - seq = read_seqbegin(&jiffies_lock); |
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| 169 | + seq = read_seqcount_begin(&jiffies_seq); |
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| 162 | 170 | next = tick_next_period; |
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| 163 | | - } while (read_seqretry(&jiffies_lock, seq)); |
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| 171 | + } while (read_seqcount_retry(&jiffies_seq, seq)); |
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| 164 | 172 | |
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| 165 | 173 | clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT); |
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| 166 | 174 | |
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| .. | .. |
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| 171 | 179 | } |
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| 172 | 180 | } |
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| 173 | 181 | } |
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| 182 | + |
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| 183 | +#ifdef CONFIG_NO_HZ_FULL |
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| 184 | +static void giveup_do_timer(void *info) |
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| 185 | +{ |
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| 186 | + int cpu = *(unsigned int *)info; |
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| 187 | + |
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| 188 | + WARN_ON(tick_do_timer_cpu != smp_processor_id()); |
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| 189 | + |
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| 190 | + tick_do_timer_cpu = cpu; |
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| 191 | +} |
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| 192 | + |
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| 193 | +static void tick_take_do_timer_from_boot(void) |
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| 194 | +{ |
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| 195 | + int cpu = smp_processor_id(); |
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| 196 | + int from = tick_do_timer_boot_cpu; |
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| 197 | + |
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| 198 | + if (from >= 0 && from != cpu) |
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| 199 | + smp_call_function_single(from, giveup_do_timer, &cpu, 1); |
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| 200 | +} |
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| 201 | +#endif |
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| 174 | 202 | |
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| 175 | 203 | /* |
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| 176 | 204 | * Setup the tick device |
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| .. | .. |
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| 191 | 219 | * this cpu: |
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| 192 | 220 | */ |
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| 193 | 221 | if (tick_do_timer_cpu == TICK_DO_TIMER_BOOT) { |
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| 194 | | - if (!tick_nohz_full_cpu(cpu)) |
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| 195 | | - tick_do_timer_cpu = cpu; |
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| 196 | | - else |
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| 197 | | - tick_do_timer_cpu = TICK_DO_TIMER_NONE; |
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| 222 | + tick_do_timer_cpu = cpu; |
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| 223 | + |
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| 198 | 224 | tick_next_period = ktime_get(); |
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| 199 | 225 | tick_period = NSEC_PER_SEC / HZ; |
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| 226 | +#ifdef CONFIG_NO_HZ_FULL |
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| 227 | + /* |
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| 228 | + * The boot CPU may be nohz_full, in which case set |
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| 229 | + * tick_do_timer_boot_cpu so the first housekeeping |
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| 230 | + * secondary that comes up will take do_timer from |
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| 231 | + * us. |
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| 232 | + */ |
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| 233 | + if (tick_nohz_full_cpu(cpu)) |
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| 234 | + tick_do_timer_boot_cpu = cpu; |
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| 235 | + |
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| 236 | + } else if (tick_do_timer_boot_cpu != -1 && |
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| 237 | + !tick_nohz_full_cpu(cpu)) { |
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| 238 | + tick_take_do_timer_from_boot(); |
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| 239 | + tick_do_timer_boot_cpu = -1; |
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| 240 | + WARN_ON(tick_do_timer_cpu != cpu); |
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| 241 | +#endif |
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| 200 | 242 | } |
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| 201 | 243 | |
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| 202 | 244 | /* |
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| .. | .. |
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| 338 | 380 | /* |
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| 339 | 381 | * Can the new device be used as a broadcast device ? |
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| 340 | 382 | */ |
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| 341 | | - tick_install_broadcast_device(newdev); |
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| 383 | + tick_install_broadcast_device(newdev, cpu); |
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| 342 | 384 | } |
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| 343 | 385 | |
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| 344 | 386 | /** |
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