1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copytight (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org) 4 * Copytight (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 struct irqaction hub_rt_irqaction = { 62 .handler = hub_rt_counter_handler, 63 .percpu_dev_id = &hub_rt_clockevent, 64 .flags = IRQF_PERCPU | IRQF_TIMER, 65 .name = "hub-rt", 66 }; 67 68 /* 69 * This is a hack; we really need to figure these values out dynamically 70 * 71 * Since 800 ns works very well with various HUB frequencies, such as 72 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time. 73 * 74 * Ralf: which clock rate is used to feed the counter? 75 */ 76 #define NSEC_PER_CYCLE 800 77 #define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE) 78 79 void hub_rt_clock_event_init(void) 80 { 81 unsigned int cpu = smp_processor_id(); 82 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); 83 unsigned char *name = per_cpu(hub_rt_name, cpu); 84 85 sprintf(name, "hub-rt %d", cpu); 86 cd->name = name; 87 cd->features = CLOCK_EVT_FEAT_ONESHOT; 88 clockevent_set_clock(cd, CYCLES_PER_SEC); 89 cd->max_delta_ns = clockevent_delta2ns(0xfffffffffffff, cd); 90 cd->max_delta_ticks = 0xfffffffffffff; 91 cd->min_delta_ns = clockevent_delta2ns(0x300, cd); 92 cd->min_delta_ticks = 0x300; 93 cd->rating = 200; 94 cd->irq = IP27_RT_TIMER_IRQ; 95 cd->cpumask = cpumask_of(cpu); 96 cd->set_next_event = rt_next_event; 97 clockevents_register_device(cd); 98 99 enable_percpu_irq(IP27_RT_TIMER_IRQ, IRQ_TYPE_NONE); 100 } 101 102 static void __init hub_rt_clock_event_global_init(void) 103 { 104 irq_set_handler(IP27_RT_TIMER_IRQ, handle_percpu_devid_irq); 105 irq_set_percpu_devid(IP27_RT_TIMER_IRQ); 106 setup_percpu_irq(IP27_RT_TIMER_IRQ, &hub_rt_irqaction); 107 } 108 109 static u64 hub_rt_read(struct clocksource *cs) 110 { 111 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); 112 } 113 114 struct clocksource hub_rt_clocksource = { 115 .name = "HUB-RT", 116 .rating = 200, 117 .read = hub_rt_read, 118 .mask = CLOCKSOURCE_MASK(52), 119 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 120 }; 121 122 static u64 notrace hub_rt_read_sched_clock(void) 123 { 124 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); 125 } 126 127 static void __init hub_rt_clocksource_init(void) 128 { 129 struct clocksource *cs = &hub_rt_clocksource; 130 131 clocksource_register_hz(cs, CYCLES_PER_SEC); 132 133 sched_clock_register(hub_rt_read_sched_clock, 52, CYCLES_PER_SEC); 134 } 135 136 void __init plat_time_init(void) 137 { 138 hub_rt_clocksource_init(); 139 hub_rt_clock_event_global_init(); 140 hub_rt_clock_event_init(); 141 } 142 143 void hub_rtc_init(nasid_t nasid) 144 { 145 146 /* 147 * We only need to initialize the current node. 148 * If this is not the current node then it is a cpuless 149 * node and timeouts will not happen there. 150 */ 151 if (get_nasid() == nasid) { 152 LOCAL_HUB_S(PI_RT_EN_A, 1); 153 LOCAL_HUB_S(PI_RT_EN_B, 1); 154 LOCAL_HUB_S(PI_PROF_EN_A, 0); 155 LOCAL_HUB_S(PI_PROF_EN_B, 0); 156 LOCAL_HUB_S(PI_RT_COUNT, 0); 157 LOCAL_HUB_S(PI_RT_PEND_A, 0); 158 LOCAL_HUB_S(PI_RT_PEND_B, 0); 159 } 160 } 161