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/pgtable.h> 23 #include <asm/sgialib.h> 24 #include <asm/sn/ioc3.h> 25 #include <asm/sn/klconfig.h> 26 #include <asm/sn/arch.h> 27 #include <asm/sn/addrs.h> 28 #include <asm/sn/sn_private.h> 29 #include <asm/sn/sn0/ip27.h> 30 #include <asm/sn/sn0/hub.h> 31 32 #define TICK_SIZE (tick_nsec / 1000) 33 34 /* Includes for ioc3_init(). */ 35 #include <asm/sn/types.h> 36 #include <asm/sn/sn0/addrs.h> 37 #include <asm/sn/sn0/hubni.h> 38 #include <asm/sn/sn0/hubio.h> 39 #include <asm/pci/bridge.h> 40 41 static int rt_next_event(unsigned long delta, struct clock_event_device *evt) 42 { 43 unsigned int cpu = smp_processor_id(); 44 int slice = cputoslice(cpu); 45 unsigned long cnt; 46 47 cnt = LOCAL_HUB_L(PI_RT_COUNT); 48 cnt += delta; 49 LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt); 50 51 return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0; 52 } 53 54 static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent); 55 static DEFINE_PER_CPU(char [11], hub_rt_name); 56 57 static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id) 58 { 59 unsigned int cpu = smp_processor_id(); 60 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); 61 int slice = cputoslice(cpu); 62 63 /* 64 * Ack 65 */ 66 LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0); 67 cd->event_handler(cd); 68 69 return IRQ_HANDLED; 70 } 71 72 struct irqaction hub_rt_irqaction = { 73 .handler = hub_rt_counter_handler, 74 .percpu_dev_id = &hub_rt_clockevent, 75 .flags = IRQF_PERCPU | IRQF_TIMER, 76 .name = "hub-rt", 77 }; 78 79 /* 80 * This is a hack; we really need to figure these values out dynamically 81 * 82 * Since 800 ns works very well with various HUB frequencies, such as 83 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time. 84 * 85 * Ralf: which clock rate is used to feed the counter? 86 */ 87 #define NSEC_PER_CYCLE 800 88 #define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE) 89 90 void hub_rt_clock_event_init(void) 91 { 92 unsigned int cpu = smp_processor_id(); 93 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); 94 unsigned char *name = per_cpu(hub_rt_name, cpu); 95 96 sprintf(name, "hub-rt %d", cpu); 97 cd->name = name; 98 cd->features = CLOCK_EVT_FEAT_ONESHOT; 99 clockevent_set_clock(cd, CYCLES_PER_SEC); 100 cd->max_delta_ns = clockevent_delta2ns(0xfffffffffffff, cd); 101 cd->max_delta_ticks = 0xfffffffffffff; 102 cd->min_delta_ns = clockevent_delta2ns(0x300, cd); 103 cd->min_delta_ticks = 0x300; 104 cd->rating = 200; 105 cd->irq = IP27_RT_TIMER_IRQ; 106 cd->cpumask = cpumask_of(cpu); 107 cd->set_next_event = rt_next_event; 108 clockevents_register_device(cd); 109 110 enable_percpu_irq(IP27_RT_TIMER_IRQ, IRQ_TYPE_NONE); 111 } 112 113 static void __init hub_rt_clock_event_global_init(void) 114 { 115 irq_set_handler(IP27_RT_TIMER_IRQ, handle_percpu_devid_irq); 116 irq_set_percpu_devid(IP27_RT_TIMER_IRQ); 117 setup_percpu_irq(IP27_RT_TIMER_IRQ, &hub_rt_irqaction); 118 } 119 120 static u64 hub_rt_read(struct clocksource *cs) 121 { 122 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); 123 } 124 125 struct clocksource hub_rt_clocksource = { 126 .name = "HUB-RT", 127 .rating = 200, 128 .read = hub_rt_read, 129 .mask = CLOCKSOURCE_MASK(52), 130 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 131 }; 132 133 static u64 notrace hub_rt_read_sched_clock(void) 134 { 135 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); 136 } 137 138 static void __init hub_rt_clocksource_init(void) 139 { 140 struct clocksource *cs = &hub_rt_clocksource; 141 142 clocksource_register_hz(cs, CYCLES_PER_SEC); 143 144 sched_clock_register(hub_rt_read_sched_clock, 52, CYCLES_PER_SEC); 145 } 146 147 void __init plat_time_init(void) 148 { 149 hub_rt_clocksource_init(); 150 hub_rt_clock_event_global_init(); 151 hub_rt_clock_event_init(); 152 } 153 154 void cpu_time_init(void) 155 { 156 lboard_t *board; 157 klcpu_t *cpu; 158 int cpuid; 159 160 /* Don't use ARCS. ARCS is fragile. Klconfig is simple and sane. */ 161 board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27); 162 if (!board) 163 panic("Can't find board info for myself."); 164 165 cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX; 166 cpu = (klcpu_t *) KLCF_COMP(board, cpuid); 167 if (!cpu) 168 panic("No information about myself?"); 169 170 printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed); 171 } 172 173 void hub_rtc_init(cnodeid_t cnode) 174 { 175 176 /* 177 * We only need to initialize the current node. 178 * If this is not the current node then it is a cpuless 179 * node and timeouts will not happen there. 180 */ 181 if (get_compact_nodeid() == cnode) { 182 LOCAL_HUB_S(PI_RT_EN_A, 1); 183 LOCAL_HUB_S(PI_RT_EN_B, 1); 184 LOCAL_HUB_S(PI_PROF_EN_A, 0); 185 LOCAL_HUB_S(PI_PROF_EN_B, 0); 186 LOCAL_HUB_S(PI_RT_COUNT, 0); 187 LOCAL_HUB_S(PI_RT_PEND_A, 0); 188 LOCAL_HUB_S(PI_RT_PEND_B, 0); 189 } 190 } 191 192 static int __init sgi_ip27_rtc_devinit(void) 193 { 194 struct resource res; 195 196 memset(&res, 0, sizeof(res)); 197 res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base + 198 IOC3_BYTEBUS_DEV0); 199 res.end = res.start + 32767; 200 res.flags = IORESOURCE_MEM; 201 202 return IS_ERR(platform_device_register_simple("rtc-m48t35", -1, 203 &res, 1)); 204 } 205 206 /* 207 * kludge make this a device_initcall after ioc3 resource conflicts 208 * are resolved 209 */ 210 late_initcall(sgi_ip27_rtc_devinit); 211