linux_dsm_epyc7002/arch/mips/kernel/i8253.c
Thomas Bogendoerfer a07e332453
MIPS: kernel: only use i8253 clocksource with periodic clockevent
i8253 clocksource needs a free running timer. This could only
be used, if i8253 clockevent is set up as periodic.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
2019-07-18 14:41:04 -07:00

42 lines
824 B
C

// SPDX-License-Identifier: GPL-2.0
/*
* i8253.c 8253/PIT functions
*
*/
#include <linux/clockchips.h>
#include <linux/i8253.h>
#include <linux/export.h>
#include <linux/smp.h>
#include <linux/irq.h>
#include <asm/time.h>
static irqreturn_t timer_interrupt(int irq, void *dev_id)
{
i8253_clockevent.event_handler(&i8253_clockevent);
return IRQ_HANDLED;
}
static struct irqaction irq0 = {
.handler = timer_interrupt,
.flags = IRQF_NOBALANCING | IRQF_TIMER,
.name = "timer"
};
void __init setup_pit_timer(void)
{
clockevent_i8253_init(true);
setup_irq(0, &irq0);
}
static int __init init_pit_clocksource(void)
{
if (num_possible_cpus() > 1 || /* PIT does not scale! */
!clockevent_state_periodic(&i8253_clockevent))
return 0;
return clocksource_i8253_init();
}
arch_initcall(init_pit_clocksource);