xref: /linux/kernel/time/tick-legacy.c (revision 56cc7b8a)
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  */
legacy_timer_tick(unsigned long ticks)25 void 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