1 /* 2 * Copytight (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org) 3 * Copytight (C) 1999, 2000 Silicon Graphics, Inc. 4 */ 5 #include <linux/bcd.h> 6 #include <linux/clockchips.h> 7 #include <linux/init.h> 8 #include <linux/kernel.h> 9 #include <linux/sched.h> 10 #include <linux/sched_clock.h> 11 #include <linux/interrupt.h> 12 #include <linux/kernel_stat.h> 13 #include <linux/param.h> 14 #include <linux/smp.h> 15 #include <linux/time.h> 16 #include <linux/timex.h> 17 #include <linux/mm.h> 18 #include <linux/platform_device.h> 19 20 #include <asm/time.h> 21 #include <asm/pgtable.h> 22 #include <asm/sgialib.h> 23 #include <asm/sn/ioc3.h> 24 #include <asm/sn/klconfig.h> 25 #include <asm/sn/arch.h> 26 #include <asm/sn/addrs.h> 27 #include <asm/sn/sn_private.h> 28 #include <asm/sn/sn0/ip27.h> 29 #include <asm/sn/sn0/hub.h> 30 31 #define TICK_SIZE (tick_nsec / 1000) 32 33 /* Includes for ioc3_init(). */ 34 #include <asm/sn/types.h> 35 #include <asm/sn/sn0/addrs.h> 36 #include <asm/sn/sn0/hubni.h> 37 #include <asm/sn/sn0/hubio.h> 38 #include <asm/pci/bridge.h> 39 40 static void enable_rt_irq(struct irq_data *d) 41 { 42 } 43 44 static void disable_rt_irq(struct irq_data *d) 45 { 46 } 47 48 static struct irq_chip rt_irq_type = { 49 .name = "SN HUB RT timer", 50 .irq_mask = disable_rt_irq, 51 .irq_unmask = enable_rt_irq, 52 }; 53 54 static int rt_next_event(unsigned long delta, struct clock_event_device *evt) 55 { 56 unsigned int cpu = smp_processor_id(); 57 int slice = cputoslice(cpu); 58 unsigned long cnt; 59 60 cnt = LOCAL_HUB_L(PI_RT_COUNT); 61 cnt += delta; 62 LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt); 63 64 return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0; 65 } 66 67 unsigned int rt_timer_irq; 68 69 static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent); 70 static DEFINE_PER_CPU(char [11], hub_rt_name); 71 72 static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id) 73 { 74 unsigned int cpu = smp_processor_id(); 75 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); 76 int slice = cputoslice(cpu); 77 78 /* 79 * Ack 80 */ 81 LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0); 82 cd->event_handler(cd); 83 84 return IRQ_HANDLED; 85 } 86 87 struct irqaction hub_rt_irqaction = { 88 .handler = hub_rt_counter_handler, 89 .flags = IRQF_PERCPU | IRQF_TIMER, 90 .name = "hub-rt", 91 }; 92 93 /* 94 * This is a hack; we really need to figure these values out dynamically 95 * 96 * Since 800 ns works very well with various HUB frequencies, such as 97 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time. 98 * 99 * Ralf: which clock rate is used to feed the counter? 100 */ 101 #define NSEC_PER_CYCLE 800 102 #define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE) 103 104 void hub_rt_clock_event_init(void) 105 { 106 unsigned int cpu = smp_processor_id(); 107 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); 108 unsigned char *name = per_cpu(hub_rt_name, cpu); 109 int irq = rt_timer_irq; 110 111 sprintf(name, "hub-rt %d", cpu); 112 cd->name = name; 113 cd->features = CLOCK_EVT_FEAT_ONESHOT; 114 clockevent_set_clock(cd, CYCLES_PER_SEC); 115 cd->max_delta_ns = clockevent_delta2ns(0xfffffffffffff, cd); 116 cd->min_delta_ns = clockevent_delta2ns(0x300, cd); 117 cd->rating = 200; 118 cd->irq = irq; 119 cd->cpumask = cpumask_of(cpu); 120 cd->set_next_event = rt_next_event; 121 clockevents_register_device(cd); 122 } 123 124 static void __init hub_rt_clock_event_global_init(void) 125 { 126 int irq; 127 128 do { 129 smp_wmb(); 130 irq = rt_timer_irq; 131 if (irq) 132 break; 133 134 irq = allocate_irqno(); 135 if (irq < 0) 136 panic("Allocation of irq number for timer failed"); 137 } while (xchg(&rt_timer_irq, irq)); 138 139 irq_set_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq); 140 setup_irq(irq, &hub_rt_irqaction); 141 } 142 143 static cycle_t hub_rt_read(struct clocksource *cs) 144 { 145 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); 146 } 147 148 struct clocksource hub_rt_clocksource = { 149 .name = "HUB-RT", 150 .rating = 200, 151 .read = hub_rt_read, 152 .mask = CLOCKSOURCE_MASK(52), 153 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 154 }; 155 156 static u64 notrace hub_rt_read_sched_clock(void) 157 { 158 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); 159 } 160 161 static void __init hub_rt_clocksource_init(void) 162 { 163 struct clocksource *cs = &hub_rt_clocksource; 164 165 clocksource_register_hz(cs, CYCLES_PER_SEC); 166 167 sched_clock_register(hub_rt_read_sched_clock, 52, CYCLES_PER_SEC); 168 } 169 170 void __init plat_time_init(void) 171 { 172 hub_rt_clocksource_init(); 173 hub_rt_clock_event_global_init(); 174 hub_rt_clock_event_init(); 175 } 176 177 void cpu_time_init(void) 178 { 179 lboard_t *board; 180 klcpu_t *cpu; 181 int cpuid; 182 183 /* Don't use ARCS. ARCS is fragile. Klconfig is simple and sane. */ 184 board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27); 185 if (!board) 186 panic("Can't find board info for myself."); 187 188 cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX; 189 cpu = (klcpu_t *) KLCF_COMP(board, cpuid); 190 if (!cpu) 191 panic("No information about myself?"); 192 193 printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed); 194 195 set_c0_status(SRB_TIMOCLK); 196 } 197 198 void hub_rtc_init(cnodeid_t cnode) 199 { 200 201 /* 202 * We only need to initialize the current node. 203 * If this is not the current node then it is a cpuless 204 * node and timeouts will not happen there. 205 */ 206 if (get_compact_nodeid() == cnode) { 207 LOCAL_HUB_S(PI_RT_EN_A, 1); 208 LOCAL_HUB_S(PI_RT_EN_B, 1); 209 LOCAL_HUB_S(PI_PROF_EN_A, 0); 210 LOCAL_HUB_S(PI_PROF_EN_B, 0); 211 LOCAL_HUB_S(PI_RT_COUNT, 0); 212 LOCAL_HUB_S(PI_RT_PEND_A, 0); 213 LOCAL_HUB_S(PI_RT_PEND_B, 0); 214 } 215 } 216 217 static int __init sgi_ip27_rtc_devinit(void) 218 { 219 struct resource res; 220 221 memset(&res, 0, sizeof(res)); 222 res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base + 223 IOC3_BYTEBUS_DEV0); 224 res.end = res.start + 32767; 225 res.flags = IORESOURCE_MEM; 226 227 return IS_ERR(platform_device_register_simple("rtc-m48t35", -1, 228 &res, 1)); 229 } 230 231 /* 232 * kludge make this a device_initcall after ioc3 resource conflicts 233 * are resolved 234 */ 235 late_initcall(sgi_ip27_rtc_devinit); 236