linux/linux-5.18.11/arch/mips/sgi-ip27/ip27-timer.c

161 lines
4.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org)
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
*/
#include <linux/bcd.h>
#include <linux/clockchips.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/sched_clock.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/param.h>
#include <linux/smp.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/mm.h>
#include <linux/platform_device.h>
#include <asm/time.h>
#include <asm/sgialib.h>
#include <asm/sn/klconfig.h>
#include <asm/sn/arch.h>
#include <asm/sn/addrs.h>
#include <asm/sn/agent.h>
#include "ip27-common.h"
static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
{
unsigned int cpu = smp_processor_id();
int slice = cputoslice(cpu);
unsigned long cnt;
cnt = LOCAL_HUB_L(PI_RT_COUNT);
cnt += delta;
LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt);
return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
}
static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
static DEFINE_PER_CPU(char [11], hub_rt_name);
static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
{
unsigned int cpu = smp_processor_id();
struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
int slice = cputoslice(cpu);
/*
* Ack
*/
LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0);
cd->event_handler(cd);
return IRQ_HANDLED;
}
struct irqaction hub_rt_irqaction = {
.handler = hub_rt_counter_handler,
.percpu_dev_id = &hub_rt_clockevent,
.flags = IRQF_PERCPU | IRQF_TIMER,
.name = "hub-rt",
};
/*
* This is a hack; we really need to figure these values out dynamically
*
* Since 800 ns works very well with various HUB frequencies, such as
* 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
*
* Ralf: which clock rate is used to feed the counter?
*/
#define NSEC_PER_CYCLE 800
#define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE)
void hub_rt_clock_event_init(void)
{
unsigned int cpu = smp_processor_id();
struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
unsigned char *name = per_cpu(hub_rt_name, cpu);
sprintf(name, "hub-rt %d", cpu);
cd->name = name;
cd->features = CLOCK_EVT_FEAT_ONESHOT;
clockevent_set_clock(cd, CYCLES_PER_SEC);
cd->max_delta_ns = clockevent_delta2ns(0xfffffffffffff, cd);
cd->max_delta_ticks = 0xfffffffffffff;
cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
cd->min_delta_ticks = 0x300;
cd->rating = 200;
cd->irq = IP27_RT_TIMER_IRQ;
cd->cpumask = cpumask_of(cpu);
cd->set_next_event = rt_next_event;
clockevents_register_device(cd);
enable_percpu_irq(IP27_RT_TIMER_IRQ, IRQ_TYPE_NONE);
}
static void __init hub_rt_clock_event_global_init(void)
{
irq_set_handler(IP27_RT_TIMER_IRQ, handle_percpu_devid_irq);
irq_set_percpu_devid(IP27_RT_TIMER_IRQ);
setup_percpu_irq(IP27_RT_TIMER_IRQ, &hub_rt_irqaction);
}
static u64 hub_rt_read(struct clocksource *cs)
{
return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
}
struct clocksource hub_rt_clocksource = {
.name = "HUB-RT",
.rating = 200,
.read = hub_rt_read,
.mask = CLOCKSOURCE_MASK(52),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static u64 notrace hub_rt_read_sched_clock(void)
{
return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
}
static void __init hub_rt_clocksource_init(void)
{
struct clocksource *cs = &hub_rt_clocksource;
clocksource_register_hz(cs, CYCLES_PER_SEC);
sched_clock_register(hub_rt_read_sched_clock, 52, CYCLES_PER_SEC);
}
void __init plat_time_init(void)
{
hub_rt_clocksource_init();
hub_rt_clock_event_global_init();
hub_rt_clock_event_init();
}
void hub_rtc_init(nasid_t nasid)
{
/*
* We only need to initialize the current node.
* If this is not the current node then it is a cpuless
* node and timeouts will not happen there.
*/
if (get_nasid() == nasid) {
LOCAL_HUB_S(PI_RT_EN_A, 1);
LOCAL_HUB_S(PI_RT_EN_B, 1);
LOCAL_HUB_S(PI_PROF_EN_A, 0);
LOCAL_HUB_S(PI_PROF_EN_B, 0);
LOCAL_HUB_S(PI_RT_COUNT, 0);
LOCAL_HUB_S(PI_RT_PEND_A, 0);
LOCAL_HUB_S(PI_RT_PEND_B, 0);
}
}