1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org) 4 * Copyright (C) 1999, 2000 Silicon Graphics, Inc. 5 */ 6 #include <linux/bcd.h> 7 #include <linux/clockchips.h> 8 #include <linux/init.h> 9 #include <linux/kernel.h> 10 #include <linux/sched.h> 11 #include <linux/sched_clock.h> 12 #include <linux/interrupt.h> 13 #include <linux/kernel_stat.h> 14 #include <linux/param.h> 15 #include <linux/smp.h> 16 #include <linux/time.h> 17 #include <linux/timex.h> 18 #include <linux/mm.h> 19 #include <linux/platform_device.h> 20 21 #include <asm/time.h> 22 #include <asm/sgialib.h> 23 #include <asm/sn/klconfig.h> 24 #include <asm/sn/arch.h> 25 #include <asm/sn/addrs.h> 26 #include <asm/sn/agent.h> 27 28 #include "ip27-common.h" 29 30 static int rt_next_event(unsigned long delta, struct clock_event_device *evt) 31 { 32 unsigned int cpu = smp_processor_id(); 33 int slice = cputoslice(cpu); 34 unsigned long cnt; 35 36 cnt = LOCAL_HUB_L(PI_RT_COUNT); 37 cnt += delta; 38 LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt); 39 40 return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0; 41 } 42 43 static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent); 44 static DEFINE_PER_CPU(char [11], hub_rt_name); 45 46 static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id) 47 { 48 unsigned int cpu = smp_processor_id(); 49 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); 50 int slice = cputoslice(cpu); 51 52 /* 53 * Ack 54 */ 55 LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0); 56 cd->event_handler(cd); 57 58 return IRQ_HANDLED; 59 } 60 61 /* 62 * This is a hack; we really need to figure these values out dynamically 63 * 64 * Since 800 ns works very well with various HUB frequencies, such as 65 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time. 66 * 67 * Ralf: which clock rate is used to feed the counter? 68 */ 69 #define NSEC_PER_CYCLE 800 70 #define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE) 71 72 void hub_rt_clock_event_init(void) 73 { 74 unsigned int cpu = smp_processor_id(); 75 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); 76 unsigned char *name = per_cpu(hub_rt_name, cpu); 77 78 sprintf(name, "hub-rt %d", cpu); 79 cd->name = name; 80 cd->features = CLOCK_EVT_FEAT_ONESHOT; 81 clockevent_set_clock(cd, CYCLES_PER_SEC); 82 cd->max_delta_ns = clockevent_delta2ns(0xfffffffffffff, cd); 83 cd->max_delta_ticks = 0xfffffffffffff; 84 cd->min_delta_ns = clockevent_delta2ns(0x300, cd); 85 cd->min_delta_ticks = 0x300; 86 cd->rating = 200; 87 cd->irq = IP27_RT_TIMER_IRQ; 88 cd->cpumask = cpumask_of(cpu); 89 cd->set_next_event = rt_next_event; 90 clockevents_register_device(cd); 91 92 enable_percpu_irq(IP27_RT_TIMER_IRQ, IRQ_TYPE_NONE); 93 } 94 95 static void __init hub_rt_clock_event_global_init(void) 96 { 97 irq_set_handler(IP27_RT_TIMER_IRQ, handle_percpu_devid_irq); 98 irq_set_percpu_devid(IP27_RT_TIMER_IRQ); 99 WARN_ON(request_percpu_irq(IP27_RT_TIMER_IRQ, hub_rt_counter_handler, 100 "hub-rt", &hub_rt_clockevent)); 101 } 102 103 static u64 hub_rt_read(struct clocksource *cs) 104 { 105 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); 106 } 107 108 struct clocksource hub_rt_clocksource = { 109 .name = "HUB-RT", 110 .rating = 200, 111 .read = hub_rt_read, 112 .mask = CLOCKSOURCE_MASK(52), 113 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 114 }; 115 116 static u64 notrace hub_rt_read_sched_clock(void) 117 { 118 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); 119 } 120 121 static void __init hub_rt_clocksource_init(void) 122 { 123 struct clocksource *cs = &hub_rt_clocksource; 124 125 clocksource_register_hz(cs, CYCLES_PER_SEC); 126 127 sched_clock_register(hub_rt_read_sched_clock, 52, CYCLES_PER_SEC); 128 } 129 130 void __init plat_time_init(void) 131 { 132 hub_rt_clocksource_init(); 133 hub_rt_clock_event_global_init(); 134 hub_rt_clock_event_init(); 135 } 136 137 void hub_rtc_init(nasid_t nasid) 138 { 139 140 /* 141 * We only need to initialize the current node. 142 * If this is not the current node then it is a cpuless 143 * node and timeouts will not happen there. 144 */ 145 if (get_nasid() == nasid) { 146 LOCAL_HUB_S(PI_RT_EN_A, 1); 147 LOCAL_HUB_S(PI_RT_EN_B, 1); 148 LOCAL_HUB_S(PI_PROF_EN_A, 0); 149 LOCAL_HUB_S(PI_PROF_EN_B, 0); 150 LOCAL_HUB_S(PI_RT_COUNT, 0); 151 LOCAL_HUB_S(PI_RT_PEND_A, 0); 152 LOCAL_HUB_S(PI_RT_PEND_B, 0); 153 } 154 } 155