diff options
Diffstat (limited to 'arch/mips/sgi-ip27/ip27-timer.c')
| -rw-r--r-- | arch/mips/sgi-ip27/ip27-timer.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/arch/mips/sgi-ip27/ip27-timer.c b/arch/mips/sgi-ip27/ip27-timer.c new file mode 100644 index 000000000..444b5e0e9 --- /dev/null +++ b/arch/mips/sgi-ip27/ip27-timer.c @@ -0,0 +1,160 @@ +// 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); + } +} |