1 /* 2 * sun4m SMP support. 3 * 4 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) 5 */ 6 7 #include <linux/clockchips.h> 8 #include <linux/interrupt.h> 9 #include <linux/profile.h> 10 #include <linux/delay.h> 11 #include <linux/sched/mm.h> 12 #include <linux/cpu.h> 13 14 #include <asm/cacheflush.h> 15 #include <asm/switch_to.h> 16 #include <asm/tlbflush.h> 17 #include <asm/timer.h> 18 #include <asm/oplib.h> 19 20 #include "irq.h" 21 #include "kernel.h" 22 23 #define IRQ_IPI_SINGLE 12 24 #define IRQ_IPI_MASK 13 25 #define IRQ_IPI_RESCHED 14 26 #define IRQ_CROSS_CALL 15 27 28 static inline unsigned long 29 swap_ulong(volatile unsigned long *ptr, unsigned long val) 30 { 31 __asm__ __volatile__("swap [%1], %0\n\t" : 32 "=&r" (val), "=&r" (ptr) : 33 "0" (val), "1" (ptr)); 34 return val; 35 } 36 37 void sun4m_cpu_pre_starting(void *arg) 38 { 39 } 40 41 void sun4m_cpu_pre_online(void *arg) 42 { 43 int cpuid = hard_smp_processor_id(); 44 45 /* Allow master to continue. The master will then give us the 46 * go-ahead by setting the smp_commenced_mask and will wait without 47 * timeouts until our setup is completed fully (signified by 48 * our bit being set in the cpu_online_mask). 49 */ 50 swap_ulong(&cpu_callin_map[cpuid], 1); 51 52 /* XXX: What's up with all the flushes? */ 53 local_ops->cache_all(); 54 local_ops->tlb_all(); 55 56 /* Fix idle thread fields. */ 57 __asm__ __volatile__("ld [%0], %%g6\n\t" 58 : : "r" (¤t_set[cpuid]) 59 : "memory" /* paranoid */); 60 61 /* Attach to the address space of init_task. */ 62 mmgrab(&init_mm); 63 current->active_mm = &init_mm; 64 65 while (!cpumask_test_cpu(cpuid, &smp_commenced_mask)) 66 mb(); 67 } 68 69 /* 70 * Cycle through the processors asking the PROM to start each one. 71 */ 72 void __init smp4m_boot_cpus(void) 73 { 74 sun4m_unmask_profile_irq(); 75 local_ops->cache_all(); 76 } 77 78 int smp4m_boot_one_cpu(int i, struct task_struct *idle) 79 { 80 unsigned long *entry = &sun4m_cpu_startup; 81 int timeout; 82 int cpu_node; 83 84 cpu_find_by_mid(i, &cpu_node); 85 current_set[i] = task_thread_info(idle); 86 87 /* See trampoline.S for details... */ 88 entry += ((i - 1) * 3); 89 90 /* 91 * Initialize the contexts table 92 * Since the call to prom_startcpu() trashes the structure, 93 * we need to re-initialize it for each cpu 94 */ 95 smp_penguin_ctable.which_io = 0; 96 smp_penguin_ctable.phys_addr = (unsigned int) srmmu_ctx_table_phys; 97 smp_penguin_ctable.reg_size = 0; 98 99 /* whirrr, whirrr, whirrrrrrrrr... */ 100 printk(KERN_INFO "Starting CPU %d at %p\n", i, entry); 101 local_ops->cache_all(); 102 prom_startcpu(cpu_node, &smp_penguin_ctable, 0, (char *)entry); 103 104 /* wheee... it's going... */ 105 for (timeout = 0; timeout < 10000; timeout++) { 106 if (cpu_callin_map[i]) 107 break; 108 udelay(200); 109 } 110 111 if (!(cpu_callin_map[i])) { 112 printk(KERN_ERR "Processor %d is stuck.\n", i); 113 return -ENODEV; 114 } 115 116 local_ops->cache_all(); 117 return 0; 118 } 119 120 void __init smp4m_smp_done(void) 121 { 122 int i, first; 123 int *prev; 124 125 /* setup cpu list for irq rotation */ 126 first = 0; 127 prev = &first; 128 for_each_online_cpu(i) { 129 *prev = i; 130 prev = &cpu_data(i).next; 131 } 132 *prev = first; 133 local_ops->cache_all(); 134 135 /* Ok, they are spinning and ready to go. */ 136 } 137 138 static void sun4m_send_ipi(int cpu, int level) 139 { 140 sbus_writel(SUN4M_SOFT_INT(level), &sun4m_irq_percpu[cpu]->set); 141 } 142 143 static void sun4m_ipi_resched(int cpu) 144 { 145 sun4m_send_ipi(cpu, IRQ_IPI_RESCHED); 146 } 147 148 static void sun4m_ipi_single(int cpu) 149 { 150 sun4m_send_ipi(cpu, IRQ_IPI_SINGLE); 151 } 152 153 static void sun4m_ipi_mask_one(int cpu) 154 { 155 sun4m_send_ipi(cpu, IRQ_IPI_MASK); 156 } 157 158 static struct smp_funcall { 159 smpfunc_t func; 160 unsigned long arg1; 161 unsigned long arg2; 162 unsigned long arg3; 163 unsigned long arg4; 164 unsigned long arg5; 165 unsigned long processors_in[SUN4M_NCPUS]; /* Set when ipi entered. */ 166 unsigned long processors_out[SUN4M_NCPUS]; /* Set when ipi exited. */ 167 } ccall_info; 168 169 static DEFINE_SPINLOCK(cross_call_lock); 170 171 /* Cross calls must be serialized, at least currently. */ 172 static void sun4m_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1, 173 unsigned long arg2, unsigned long arg3, 174 unsigned long arg4) 175 { 176 register int ncpus = SUN4M_NCPUS; 177 unsigned long flags; 178 179 spin_lock_irqsave(&cross_call_lock, flags); 180 181 /* Init function glue. */ 182 ccall_info.func = func; 183 ccall_info.arg1 = arg1; 184 ccall_info.arg2 = arg2; 185 ccall_info.arg3 = arg3; 186 ccall_info.arg4 = arg4; 187 ccall_info.arg5 = 0; 188 189 /* Init receive/complete mapping, plus fire the IPI's off. */ 190 { 191 register int i; 192 193 cpumask_clear_cpu(smp_processor_id(), &mask); 194 cpumask_and(&mask, cpu_online_mask, &mask); 195 for (i = 0; i < ncpus; i++) { 196 if (cpumask_test_cpu(i, &mask)) { 197 ccall_info.processors_in[i] = 0; 198 ccall_info.processors_out[i] = 0; 199 sun4m_send_ipi(i, IRQ_CROSS_CALL); 200 } else { 201 ccall_info.processors_in[i] = 1; 202 ccall_info.processors_out[i] = 1; 203 } 204 } 205 } 206 207 { 208 register int i; 209 210 i = 0; 211 do { 212 if (!cpumask_test_cpu(i, &mask)) 213 continue; 214 while (!ccall_info.processors_in[i]) 215 barrier(); 216 } while (++i < ncpus); 217 218 i = 0; 219 do { 220 if (!cpumask_test_cpu(i, &mask)) 221 continue; 222 while (!ccall_info.processors_out[i]) 223 barrier(); 224 } while (++i < ncpus); 225 } 226 spin_unlock_irqrestore(&cross_call_lock, flags); 227 } 228 229 /* Running cross calls. */ 230 void smp4m_cross_call_irq(void) 231 { 232 int i = smp_processor_id(); 233 234 ccall_info.processors_in[i] = 1; 235 ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3, 236 ccall_info.arg4, ccall_info.arg5); 237 ccall_info.processors_out[i] = 1; 238 } 239 240 void smp4m_percpu_timer_interrupt(struct pt_regs *regs) 241 { 242 struct pt_regs *old_regs; 243 struct clock_event_device *ce; 244 int cpu = smp_processor_id(); 245 246 old_regs = set_irq_regs(regs); 247 248 ce = &per_cpu(sparc32_clockevent, cpu); 249 250 if (clockevent_state_periodic(ce)) 251 sun4m_clear_profile_irq(cpu); 252 else 253 sparc_config.load_profile_irq(cpu, 0); /* Is this needless? */ 254 255 irq_enter(); 256 ce->event_handler(ce); 257 irq_exit(); 258 259 set_irq_regs(old_regs); 260 } 261 262 static const struct sparc32_ipi_ops sun4m_ipi_ops = { 263 .cross_call = sun4m_cross_call, 264 .resched = sun4m_ipi_resched, 265 .single = sun4m_ipi_single, 266 .mask_one = sun4m_ipi_mask_one, 267 }; 268 269 void __init sun4m_init_smp(void) 270 { 271 sparc32_ipi_ops = &sun4m_ipi_ops; 272 } 273