1 // SPDX-License-Identifier: GPL-2.0 2 /* smp.c: Sparc SMP support. 3 * 4 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) 5 * Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz) 6 * Copyright (C) 2004 Keith M Wesolowski (wesolows@foobazco.org) 7 */ 8 9 #include <asm/head.h> 10 11 #include <linux/kernel.h> 12 #include <linux/sched.h> 13 #include <linux/threads.h> 14 #include <linux/smp.h> 15 #include <linux/interrupt.h> 16 #include <linux/kernel_stat.h> 17 #include <linux/init.h> 18 #include <linux/spinlock.h> 19 #include <linux/mm.h> 20 #include <linux/fs.h> 21 #include <linux/seq_file.h> 22 #include <linux/cache.h> 23 #include <linux/delay.h> 24 #include <linux/profile.h> 25 #include <linux/cpu.h> 26 27 #include <asm/ptrace.h> 28 #include <linux/atomic.h> 29 30 #include <asm/irq.h> 31 #include <asm/page.h> 32 #include <asm/oplib.h> 33 #include <asm/cacheflush.h> 34 #include <asm/tlbflush.h> 35 #include <asm/cpudata.h> 36 #include <asm/timer.h> 37 #include <asm/leon.h> 38 39 #include "kernel.h" 40 #include "irq.h" 41 42 volatile unsigned long cpu_callin_map[NR_CPUS] = {0,}; 43 44 cpumask_t smp_commenced_mask = CPU_MASK_NONE; 45 46 const struct sparc32_ipi_ops *sparc32_ipi_ops; 47 48 /* The only guaranteed locking primitive available on all Sparc 49 * processors is 'ldstub [%reg + immediate], %dest_reg' which atomically 50 * places the current byte at the effective address into dest_reg and 51 * places 0xff there afterwards. Pretty lame locking primitive 52 * compared to the Alpha and the Intel no? Most Sparcs have 'swap' 53 * instruction which is much better... 54 */ 55 smp_store_cpu_info(int id)56 void smp_store_cpu_info(int id) 57 { 58 int cpu_node; 59 int mid; 60 61 cpu_data(id).udelay_val = loops_per_jiffy; 62 63 cpu_find_by_mid(id, &cpu_node); 64 cpu_data(id).clock_tick = prom_getintdefault(cpu_node, 65 "clock-frequency", 0); 66 cpu_data(id).prom_node = cpu_node; 67 mid = cpu_get_hwmid(cpu_node); 68 69 if (mid < 0) { 70 printk(KERN_NOTICE "No MID found for CPU%d at node 0x%08x", id, cpu_node); 71 mid = 0; 72 } 73 cpu_data(id).mid = mid; 74 } 75 smp_cpus_done(unsigned int max_cpus)76 void __init smp_cpus_done(unsigned int max_cpus) 77 { 78 unsigned long bogosum = 0; 79 int cpu, num = 0; 80 81 for_each_online_cpu(cpu) { 82 num++; 83 bogosum += cpu_data(cpu).udelay_val; 84 } 85 86 printk("Total of %d processors activated (%lu.%02lu BogoMIPS).\n", 87 num, bogosum/(500000/HZ), 88 (bogosum/(5000/HZ))%100); 89 90 switch(sparc_cpu_model) { 91 case sun4m: 92 smp4m_smp_done(); 93 break; 94 case sun4d: 95 smp4d_smp_done(); 96 break; 97 case sparc_leon: 98 leon_smp_done(); 99 break; 100 case sun4e: 101 printk("SUN4E\n"); 102 BUG(); 103 break; 104 case sun4u: 105 printk("SUN4U\n"); 106 BUG(); 107 break; 108 default: 109 printk("UNKNOWN!\n"); 110 BUG(); 111 break; 112 } 113 } 114 cpu_panic(void)115 void cpu_panic(void) 116 { 117 printk("CPU[%d]: Returns from cpu_idle!\n", smp_processor_id()); 118 panic("SMP bolixed\n"); 119 } 120 121 struct linux_prom_registers smp_penguin_ctable = { 0 }; 122 arch_smp_send_reschedule(int cpu)123 void arch_smp_send_reschedule(int cpu) 124 { 125 /* 126 * CPU model dependent way of implementing IPI generation targeting 127 * a single CPU. The trap handler needs only to do trap entry/return 128 * to call schedule. 129 */ 130 sparc32_ipi_ops->resched(cpu); 131 } 132 smp_send_stop(void)133 void smp_send_stop(void) 134 { 135 } 136 arch_send_call_function_single_ipi(int cpu)137 void arch_send_call_function_single_ipi(int cpu) 138 { 139 /* trigger one IPI single call on one CPU */ 140 sparc32_ipi_ops->single(cpu); 141 } 142 arch_send_call_function_ipi_mask(const struct cpumask * mask)143 void arch_send_call_function_ipi_mask(const struct cpumask *mask) 144 { 145 int cpu; 146 147 /* trigger IPI mask call on each CPU */ 148 for_each_cpu(cpu, mask) 149 sparc32_ipi_ops->mask_one(cpu); 150 } 151 smp_resched_interrupt(void)152 void smp_resched_interrupt(void) 153 { 154 irq_enter(); 155 scheduler_ipi(); 156 local_cpu_data().irq_resched_count++; 157 irq_exit(); 158 /* re-schedule routine called by interrupt return code. */ 159 } 160 smp_call_function_single_interrupt(void)161 void smp_call_function_single_interrupt(void) 162 { 163 irq_enter(); 164 generic_smp_call_function_single_interrupt(); 165 local_cpu_data().irq_call_count++; 166 irq_exit(); 167 } 168 smp_call_function_interrupt(void)169 void smp_call_function_interrupt(void) 170 { 171 irq_enter(); 172 generic_smp_call_function_interrupt(); 173 local_cpu_data().irq_call_count++; 174 irq_exit(); 175 } 176 smp_prepare_cpus(unsigned int max_cpus)177 void __init smp_prepare_cpus(unsigned int max_cpus) 178 { 179 int i, cpuid, extra; 180 181 printk("Entering SMP Mode...\n"); 182 183 extra = 0; 184 for (i = 0; !cpu_find_by_instance(i, NULL, &cpuid); i++) { 185 if (cpuid >= NR_CPUS) 186 extra++; 187 } 188 /* i = number of cpus */ 189 if (extra && max_cpus > i - extra) 190 printk("Warning: NR_CPUS is too low to start all cpus\n"); 191 192 smp_store_cpu_info(boot_cpu_id); 193 194 switch(sparc_cpu_model) { 195 case sun4m: 196 smp4m_boot_cpus(); 197 break; 198 case sun4d: 199 smp4d_boot_cpus(); 200 break; 201 case sparc_leon: 202 leon_boot_cpus(); 203 break; 204 case sun4e: 205 printk("SUN4E\n"); 206 BUG(); 207 break; 208 case sun4u: 209 printk("SUN4U\n"); 210 BUG(); 211 break; 212 default: 213 printk("UNKNOWN!\n"); 214 BUG(); 215 break; 216 } 217 } 218 219 /* Set this up early so that things like the scheduler can init 220 * properly. We use the same cpu mask for both the present and 221 * possible cpu map. 222 */ smp_setup_cpu_possible_map(void)223 void __init smp_setup_cpu_possible_map(void) 224 { 225 int instance, mid; 226 227 instance = 0; 228 while (!cpu_find_by_instance(instance, NULL, &mid)) { 229 if (mid < NR_CPUS) { 230 set_cpu_possible(mid, true); 231 set_cpu_present(mid, true); 232 } 233 instance++; 234 } 235 } 236 smp_prepare_boot_cpu(void)237 void __init smp_prepare_boot_cpu(void) 238 { 239 int cpuid = hard_smp_processor_id(); 240 241 if (cpuid >= NR_CPUS) { 242 prom_printf("Serious problem, boot cpu id >= NR_CPUS\n"); 243 prom_halt(); 244 } 245 if (cpuid != 0) 246 printk("boot cpu id != 0, this could work but is untested\n"); 247 248 current_thread_info()->cpu = cpuid; 249 set_cpu_online(cpuid, true); 250 set_cpu_possible(cpuid, true); 251 } 252 __cpu_up(unsigned int cpu,struct task_struct * tidle)253 int __cpu_up(unsigned int cpu, struct task_struct *tidle) 254 { 255 int ret=0; 256 257 switch(sparc_cpu_model) { 258 case sun4m: 259 ret = smp4m_boot_one_cpu(cpu, tidle); 260 break; 261 case sun4d: 262 ret = smp4d_boot_one_cpu(cpu, tidle); 263 break; 264 case sparc_leon: 265 ret = leon_boot_one_cpu(cpu, tidle); 266 break; 267 case sun4e: 268 printk("SUN4E\n"); 269 BUG(); 270 break; 271 case sun4u: 272 printk("SUN4U\n"); 273 BUG(); 274 break; 275 default: 276 printk("UNKNOWN!\n"); 277 BUG(); 278 break; 279 } 280 281 if (!ret) { 282 cpumask_set_cpu(cpu, &smp_commenced_mask); 283 while (!cpu_online(cpu)) 284 mb(); 285 } 286 return ret; 287 } 288 arch_cpu_pre_starting(void * arg)289 static void arch_cpu_pre_starting(void *arg) 290 { 291 local_ops->cache_all(); 292 local_ops->tlb_all(); 293 294 switch(sparc_cpu_model) { 295 case sun4m: 296 sun4m_cpu_pre_starting(arg); 297 break; 298 case sun4d: 299 sun4d_cpu_pre_starting(arg); 300 break; 301 case sparc_leon: 302 leon_cpu_pre_starting(arg); 303 break; 304 default: 305 BUG(); 306 } 307 } 308 arch_cpu_pre_online(void * arg)309 static void arch_cpu_pre_online(void *arg) 310 { 311 unsigned int cpuid = hard_smp_processor_id(); 312 313 register_percpu_ce(cpuid); 314 315 calibrate_delay(); 316 smp_store_cpu_info(cpuid); 317 318 local_ops->cache_all(); 319 local_ops->tlb_all(); 320 321 switch(sparc_cpu_model) { 322 case sun4m: 323 sun4m_cpu_pre_online(arg); 324 break; 325 case sun4d: 326 sun4d_cpu_pre_online(arg); 327 break; 328 case sparc_leon: 329 leon_cpu_pre_online(arg); 330 break; 331 default: 332 BUG(); 333 } 334 } 335 sparc_start_secondary(void * arg)336 static void sparc_start_secondary(void *arg) 337 { 338 unsigned int cpu; 339 340 /* 341 * SMP booting is extremely fragile in some architectures. So run 342 * the cpu initialization code first before anything else. 343 */ 344 arch_cpu_pre_starting(arg); 345 346 cpu = smp_processor_id(); 347 348 notify_cpu_starting(cpu); 349 arch_cpu_pre_online(arg); 350 351 /* Set the CPU in the cpu_online_mask */ 352 set_cpu_online(cpu, true); 353 354 /* Enable local interrupts now */ 355 local_irq_enable(); 356 357 wmb(); 358 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); 359 360 /* We should never reach here! */ 361 BUG(); 362 } 363 smp_callin(void)364 void smp_callin(void) 365 { 366 sparc_start_secondary(NULL); 367 } 368 smp_bogo(struct seq_file * m)369 void smp_bogo(struct seq_file *m) 370 { 371 int i; 372 373 for_each_online_cpu(i) { 374 seq_printf(m, 375 "Cpu%dBogo\t: %lu.%02lu\n", 376 i, 377 cpu_data(i).udelay_val/(500000/HZ), 378 (cpu_data(i).udelay_val/(5000/HZ))%100); 379 } 380 } 381 smp_info(struct seq_file * m)382 void smp_info(struct seq_file *m) 383 { 384 int i; 385 386 seq_printf(m, "State:\n"); 387 for_each_online_cpu(i) 388 seq_printf(m, "CPU%d\t\t: online\n", i); 389 } 390