LXR linux/kernel/time/tick-legacy.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Timer tick function for architectures that lack generic clockevents,
   4 * consolidated here from m68k/ia64/parisc/arm.
   5 */
   6
   7#include <linux/irq.h>
   8#include <linux/profile.h>
   9#include <linux/timekeeper_internal.h>
  10
  11#include "tick-internal.h"
  12
  13/**
  14 * legacy_timer_tick() - advances the timekeeping infrastructure
  15 * @ticks:      number of ticks, that have elapsed since the last call.
  16 *
  17 * This is used by platforms that have not been converted to
  18 * generic clockevents.
  19 *
  20 * If 'ticks' is zero, the CPU is not handling timekeeping, so
  21 * only perform process accounting and profiling.
  22 *
  23 * Must be called with interrupts disabled.
  24 */
  25void legacy_timer_tick(unsigned long ticks)
  26{
  27        if (ticks) {
  28                raw_spin_lock(&jiffies_lock);
  29                write_seqcount_begin(&jiffies_seq);
  30                do_timer(ticks);
  31                write_seqcount_end(&jiffies_seq);
  32                raw_spin_unlock(&jiffies_lock);
  33                update_wall_time();
  34        }
  35        update_process_times(user_mode(get_irq_regs()));
  36        profile_tick(CPU_PROFILING);
  37}
  38