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 void enable_rt_irq(struct irq_data *d) 42 { 43 } 44 45 static void disable_rt_irq(struct irq_data *d) 46 { 47 } 48 49 static struct irq_chip rt_irq_type = { 50 .name = "SN HUB RT timer", 51 .irq_mask = disable_rt_irq, 52 .irq_unmask = enable_rt_irq, 53 }; 54 55 static int rt_next_event(unsigned long delta, struct clock_event_device *evt) 56 { 57 unsigned int cpu = smp_processor_id(); 58 int slice = cputoslice(cpu); 59 unsigned long cnt; 60 61 cnt = LOCAL_HUB_L(PI_RT_COUNT); 62 cnt += delta; 63 LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt); 64 65 return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0; 66 } 67 68 unsigned int rt_timer_irq; 69 70 static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent); 71 static DEFINE_PER_CPU(char [11], hub_rt_name); 72 73 static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id) 74 { 75 unsigned int cpu = smp_processor_id(); 76 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); 77 int slice = cputoslice(cpu); 78 79 /* 80 * Ack 81 */ 82 LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0); 83 cd->event_handler(cd); 84 85 return IRQ_HANDLED; 86 } 87 88 struct irqaction hub_rt_irqaction = { 89 .handler = hub_rt_counter_handler, 90 .flags = IRQF_PERCPU | IRQF_TIMER, 91 .name = "hub-rt", 92 }; 93 94 /* 95 * This is a hack; we really need to figure these values out dynamically 96 * 97 * Since 800 ns works very well with various HUB frequencies, such as 98 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time. 99 * 100 * Ralf: which clock rate is used to feed the counter? 101 */ 102 #define NSEC_PER_CYCLE 800 103 #define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE) 104 105 void hub_rt_clock_event_init(void) 106 { 107 unsigned int cpu = smp_processor_id(); 108 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); 109 unsigned char *name = per_cpu(hub_rt_name, cpu); 110 int irq = rt_timer_irq; 111 112 sprintf(name, "hub-rt %d", cpu); 113 cd->name = name; 114 cd->features = CLOCK_EVT_FEAT_ONESHOT; 115 clockevent_set_clock(cd, CYCLES_PER_SEC); 116 cd->max_delta_ns = clockevent_delta2ns(0xfffffffffffff, cd); 117 cd->max_delta_ticks = 0xfffffffffffff; 118 cd->min_delta_ns = clockevent_delta2ns(0x300, cd); 119 cd->min_delta_ticks = 0x300; 120 cd->rating = 200; 121 cd->irq = irq; 122 cd->cpumask = cpumask_of(cpu); 123 cd->set_next_event = rt_next_event; 124 clockevents_register_device(cd); 125 } 126 127 static void __init hub_rt_clock_event_global_init(void) 128 { 129 int irq; 130 131 do { 132 smp_wmb(); 133 irq = rt_timer_irq; 134 if (irq) 135 break; 136 137 irq = allocate_irqno(); 138 if (irq < 0) 139 panic("Allocation of irq number for timer failed"); 140 } while (xchg(&rt_timer_irq, irq)); 141 142 irq_set_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq); 143 setup_irq(irq, &hub_rt_irqaction); 144 } 145 146 static u64 hub_rt_read(struct clocksource *cs) 147 { 148 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); 149 } 150 151 struct clocksource hub_rt_clocksource = { 152 .name = "HUB-RT", 153 .rating = 200, 154 .read = hub_rt_read, 155 .mask = CLOCKSOURCE_MASK(52), 156 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 157 }; 158 159 static u64 notrace hub_rt_read_sched_clock(void) 160 { 161 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); 162 } 163 164 static void __init hub_rt_clocksource_init(void) 165 { 166 struct clocksource *cs = &hub_rt_clocksource; 167 168 clocksource_register_hz(cs, CYCLES_PER_SEC); 169 170 sched_clock_register(hub_rt_read_sched_clock, 52, CYCLES_PER_SEC); 171 } 172 173 void __init plat_time_init(void) 174 { 175 hub_rt_clocksource_init(); 176 hub_rt_clock_event_global_init(); 177 hub_rt_clock_event_init(); 178 } 179 180 void cpu_time_init(void) 181 { 182 lboard_t *board; 183 klcpu_t *cpu; 184 int cpuid; 185 186 /* Don't use ARCS. ARCS is fragile. Klconfig is simple and sane. */ 187 board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27); 188 if (!board) 189 panic("Can't find board info for myself."); 190 191 cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX; 192 cpu = (klcpu_t *) KLCF_COMP(board, cpuid); 193 if (!cpu) 194 panic("No information about myself?"); 195 196 printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed); 197 198 set_c0_status(SRB_TIMOCLK); 199 } 200 201 void hub_rtc_init(cnodeid_t cnode) 202 { 203 204 /* 205 * We only need to initialize the current node. 206 * If this is not the current node then it is a cpuless 207 * node and timeouts will not happen there. 208 */ 209 if (get_compact_nodeid() == cnode) { 210 LOCAL_HUB_S(PI_RT_EN_A, 1); 211 LOCAL_HUB_S(PI_RT_EN_B, 1); 212 LOCAL_HUB_S(PI_PROF_EN_A, 0); 213 LOCAL_HUB_S(PI_PROF_EN_B, 0); 214 LOCAL_HUB_S(PI_RT_COUNT, 0); 215 LOCAL_HUB_S(PI_RT_PEND_A, 0); 216 LOCAL_HUB_S(PI_RT_PEND_B, 0); 217 } 218 } 219 220 static int __init sgi_ip27_rtc_devinit(void) 221 { 222 struct resource res; 223 224 memset(&res, 0, sizeof(res)); 225 res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base + 226 IOC3_BYTEBUS_DEV0); 227 res.end = res.start + 32767; 228 res.flags = IORESOURCE_MEM; 229 230 return IS_ERR(platform_device_register_simple("rtc-m48t35", -1, 231 &res, 1)); 232 } 233 234 /* 235 * kludge make this a device_initcall after ioc3 resource conflicts 236 * are resolved 237 */ 238 late_initcall(sgi_ip27_rtc_devinit); 239