kernel/time/sched_clock.c

1 // SPDX-License-Identifier: GPL-2.0
4  * counters to full 64-bit ns values.
23  * struct clock_data - all data needed for sched_clock() (including
30  * @rate:		Tick rate of the registered clock.
34  * performance. In particular 'seq' and 'read_data[0]' (combined) should fit
35  * into a single 64-byte cache line.
47 static int irqtime = -1;
54 	 * We don't need to use get_jiffies_64 on 32-bit arches here  in jiffy_sched_clock_read()
57 	return (u64)(jiffies - INITIAL_JIFFIES);  in jiffy_sched_clock_read()
91 		cyc = (rd->read_sched_clock() - rd->epoch_cyc) &  in sched_clock()
92 		      rd->sched_clock_mask;  in sched_clock()
93 		res = rd->epoch_ns + cyc_to_ns(cyc, rd->mult, rd->shift);  in sched_clock()
102  * sched_clock() will never observe mis-matched data even if called from
105  * In order to preserve the data cache profile of sched_clock() as much
136 	ns = rd.epoch_ns + cyc_to_ns((cyc - rd.epoch_cyc) & rd.sched_clock_mask, rd.mult, rd.shift);  in update_sched_clock()
182 	ns = rd.epoch_ns + cyc_to_ns((cyc - rd.epoch_cyc) & rd.sched_clock_mask, rd.mult, rd.shift);  in sched_clock_register()
220 	if (irqtime > 0 || (irqtime == -1 && rate >= 1000000))  in sched_clock_register()
231 	 * If no sched_clock() function has been provided at that point,  in generic_sched_clock_init()
255  * section in sched_clock(). It relies on the read_seqcount_retry()
272 	rd->read_sched_clock = suspended_sched_clock_read;  in sched_clock_suspend()
281 	rd->epoch_cyc = cd.actual_read_sched_clock();  in sched_clock_resume()
283 	rd->read_sched_clock = cd.actual_read_sched_clock;  in sched_clock_resume()
287 	.suspend	= sched_clock_suspend,