arch/sh/kernel/smp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * arch/sh/kernel/smp.c
   4  *
   5  * SMP support for the SuperH processors.
   6  *
   7  * Copyright (C) 2002 - 2010 Paul Mundt
   8  * Copyright (C) 2006 - 2007 Akio Idehara
   9  */
  10 #include <linux/err.h>
  11 #include <linux/cache.h>
  12 #include <linux/cpumask.h>
  13 #include <linux/delay.h>
  14 #include <linux/init.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/mm.h>
  17 #include <linux/module.h>
  18 #include <linux/cpu.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/sched/mm.h>
  21 #include <linux/sched/hotplug.h>
  22 #include <linux/atomic.h>
  23 #include <linux/clockchips.h>
  24 #include <asm/processor.h>
  25 #include <asm/mmu_context.h>
  26 #include <asm/smp.h>
  27 #include <asm/cacheflush.h>
  28 #include <asm/sections.h>
  29 #include <asm/setup.h>
  30
  31 int __cpu_number_map[NR_CPUS];          /* Map physical to logical */
  32 int __cpu_logical_map[NR_CPUS];         /* Map logical to physical */
  33
  34 struct plat_smp_ops *mp_ops = NULL;
  35
  36 /* State of each CPU */
  37 DEFINE_PER_CPU(int, cpu_state) = { 0 };
  38
  39 void register_smp_ops(struct plat_smp_ops *ops)
  40 {
  41         if (mp_ops)
  42                 printk(KERN_WARNING "Overriding previously set SMP ops\n");
  43
  44         mp_ops = ops;
  45 }
  46
  47 static inline void smp_store_cpu_info(unsigned int cpu)
  48 {
  49         struct sh_cpuinfo *c = cpu_data + cpu;
  50
  51         memcpy(c, &boot_cpu_data, sizeof(struct sh_cpuinfo));
  52
  53         c->loops_per_jiffy = loops_per_jiffy;
  54 }
  55
  56 void __init smp_prepare_cpus(unsigned int max_cpus)
  57 {
  58         unsigned int cpu = smp_processor_id();
  59
  60         init_new_context(current, &init_mm);
  61         current_thread_info()->cpu = cpu;
  62         mp_ops->prepare_cpus(max_cpus);
  63
  64 #ifndef CONFIG_HOTPLUG_CPU
  65         init_cpu_present(cpu_possible_mask);
  66 #endif
  67 }
  68
  69 void __init smp_prepare_boot_cpu(void)
  70 {
  71         unsigned int cpu = smp_processor_id();
  72
  73         __cpu_number_map[0] = cpu;
  74         __cpu_logical_map[0] = cpu;
  75
  76         set_cpu_online(cpu, true);
  77         set_cpu_possible(cpu, true);
  78
  79         per_cpu(cpu_state, cpu) = CPU_ONLINE;
  80 }
  81
  82 #ifdef CONFIG_HOTPLUG_CPU
  83 void native_cpu_die(unsigned int cpu)
  84 {
  85         unsigned int i;
  86
  87         for (i = 0; i < 10; i++) {
  88                 smp_rmb();
  89                 if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
  90                         if (system_state == SYSTEM_RUNNING)
  91                                 pr_info("CPU %u is now offline\n", cpu);
  92
  93                         return;
  94                 }
  95
  96                 msleep(100);
  97         }
  98
  99         pr_err("CPU %u didn't die...\n", cpu);
 100 }
 101
 102 int native_cpu_disable(unsigned int cpu)
 103 {
 104         return cpu == 0 ? -EPERM : 0;
 105 }
 106
 107 void play_dead_common(void)
 108 {
 109         idle_task_exit();
 110         irq_ctx_exit(raw_smp_processor_id());
 111         mb();
 112
 113         __this_cpu_write(cpu_state, CPU_DEAD);
 114         local_irq_disable();
 115 }
 116
 117 void native_play_dead(void)
 118 {
 119         play_dead_common();
 120 }
 121
 122 int __cpu_disable(void)
 123 {
 124         unsigned int cpu = smp_processor_id();
 125         int ret;
 126
 127         ret = mp_ops->cpu_disable(cpu);
 128         if (ret)
 129                 return ret;
 130
 131         /*
 132          * Take this CPU offline.  Once we clear this, we can't return,
 133          * and we must not schedule until we're ready to give up the cpu.
 134          */
 135         set_cpu_online(cpu, false);
 136
 137         /*
 138          * OK - migrate IRQs away from this CPU
 139          */
 140         migrate_irqs();
 141
 142         /*
 143          * Flush user cache and TLB mappings, and then remove this CPU
 144          * from the vm mask set of all processes.
 145          */
 146         flush_cache_all();
 147 #ifdef CONFIG_MMU
 148         local_flush_tlb_all();
 149 #endif
 150
 151         clear_tasks_mm_cpumask(cpu);
 152
 153         return 0;
 154 }
 155 #else /* ... !CONFIG_HOTPLUG_CPU */
 156 int native_cpu_disable(unsigned int cpu)
 157 {
 158         return -ENOSYS;
 159 }
 160
 161 void native_cpu_die(unsigned int cpu)
 162 {
 163         /* We said "no" in __cpu_disable */
 164         BUG();
 165 }
 166
 167 void native_play_dead(void)
 168 {
 169         BUG();
 170 }
 171 #endif
 172
 173 asmlinkage void start_secondary(void)
 174 {
 175         unsigned int cpu = smp_processor_id();
 176         struct mm_struct *mm = &init_mm;
 177
 178         enable_mmu();
 179         mmgrab(mm);
 180         mmget(mm);
 181         current->active_mm = mm;
 182 #ifdef CONFIG_MMU
 183         enter_lazy_tlb(mm, current);
 184         local_flush_tlb_all();
 185 #endif
 186
 187         per_cpu_trap_init();
 188
 189         preempt_disable();
 190
 191         notify_cpu_starting(cpu);
 192
 193         local_irq_enable();
 194
 195         calibrate_delay();
 196
 197         smp_store_cpu_info(cpu);
 198
 199         set_cpu_online(cpu, true);
 200         per_cpu(cpu_state, cpu) = CPU_ONLINE;
 201
 202         cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 203 }
 204
 205 extern struct {
 206         unsigned long sp;
 207         unsigned long bss_start;
 208         unsigned long bss_end;
 209         void *start_kernel_fn;
 210         void *cpu_init_fn;
 211         void *thread_info;
 212 } stack_start;
 213
 214 int __cpu_up(unsigned int cpu, struct task_struct *tsk)
 215 {
 216         unsigned long timeout;
 217
 218         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 219
 220         /* Fill in data in head.S for secondary cpus */
 221         stack_start.sp = tsk->thread.sp;
 222         stack_start.thread_info = tsk->stack;
 223         stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
 224         stack_start.start_kernel_fn = start_secondary;
 225
 226         flush_icache_range((unsigned long)&stack_start,
 227                            (unsigned long)&stack_start + sizeof(stack_start));
 228         wmb();
 229
 230         mp_ops->start_cpu(cpu, (unsigned long)_stext);
 231
 232         timeout = jiffies + HZ;
 233         while (time_before(jiffies, timeout)) {
 234                 if (cpu_online(cpu))
 235                         break;
 236
 237                 udelay(10);
 238                 barrier();
 239         }
 240
 241         if (cpu_online(cpu))
 242                 return 0;
 243
 244         return -ENOENT;
 245 }
 246
 247 void __init smp_cpus_done(unsigned int max_cpus)
 248 {
 249         unsigned long bogosum = 0;
 250         int cpu;
 251
 252         for_each_online_cpu(cpu)
 253                 bogosum += cpu_data[cpu].loops_per_jiffy;
 254
 255         printk(KERN_INFO "SMP: Total of %d processors activated "
 256                "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
 257                bogosum / (500000/HZ),
 258                (bogosum / (5000/HZ)) % 100);
 259 }
 260
 261 void smp_send_reschedule(int cpu)
 262 {
 263         mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
 264 }
 265
 266 void smp_send_stop(void)
 267 {
 268         smp_call_function(stop_this_cpu, 0, 0);
 269 }
 270
 271 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 272 {
 273         int cpu;
 274
 275         for_each_cpu(cpu, mask)
 276                 mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION);
 277 }
 278
 279 void arch_send_call_function_single_ipi(int cpu)
 280 {
 281         mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
 282 }
 283
 284 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 285 void tick_broadcast(const struct cpumask *mask)
 286 {
 287         int cpu;
 288
 289         for_each_cpu(cpu, mask)
 290                 mp_ops->send_ipi(cpu, SMP_MSG_TIMER);
 291 }
 292
 293 static void ipi_timer(void)
 294 {
 295         irq_enter();
 296         tick_receive_broadcast();
 297         irq_exit();
 298 }
 299 #endif
 300
 301 void smp_message_recv(unsigned int msg)
 302 {
 303         switch (msg) {
 304         case SMP_MSG_FUNCTION:
 305                 generic_smp_call_function_interrupt();
 306                 break;
 307         case SMP_MSG_RESCHEDULE:
 308                 scheduler_ipi();
 309                 break;
 310         case SMP_MSG_FUNCTION_SINGLE:
 311                 generic_smp_call_function_single_interrupt();
 312                 break;
 313 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 314         case SMP_MSG_TIMER:
 315                 ipi_timer();
 316                 break;
 317 #endif
 318         default:
 319                 printk(KERN_WARNING "SMP %d: %s(): unknown IPI %d\n",
 320                        smp_processor_id(), __func__, msg);
 321                 break;
 322         }
 323 }
 324
 325 /* Not really SMP stuff ... */
 326 int setup_profiling_timer(unsigned int multiplier)
 327 {
 328         return 0;
 329 }
 330
 331 #ifdef CONFIG_MMU
 332
 333 static void flush_tlb_all_ipi(void *info)
 334 {
 335         local_flush_tlb_all();
 336 }
 337
 338 void flush_tlb_all(void)
 339 {
 340         on_each_cpu(flush_tlb_all_ipi, 0, 1);
 341 }
 342
 343 static void flush_tlb_mm_ipi(void *mm)
 344 {
 345         local_flush_tlb_mm((struct mm_struct *)mm);
 346 }
 347
 348 /*
 349  * The following tlb flush calls are invoked when old translations are
 350  * being torn down, or pte attributes are changing. For single threaded
 351  * address spaces, a new context is obtained on the current cpu, and tlb
 352  * context on other cpus are invalidated to force a new context allocation
 353  * at switch_mm time, should the mm ever be used on other cpus. For
 354  * multithreaded address spaces, intercpu interrupts have to be sent.
 355  * Another case where intercpu interrupts are required is when the target
 356  * mm might be active on another cpu (eg debuggers doing the flushes on
 357  * behalf of debugees, kswapd stealing pages from another process etc).
 358  * Kanoj 07/00.
 359  */
 360 void flush_tlb_mm(struct mm_struct *mm)
 361 {
 362         preempt_disable();
 363
 364         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 365                 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
 366         } else {
 367                 int i;
 368                 for_each_online_cpu(i)
 369                         if (smp_processor_id() != i)
 370                                 cpu_context(i, mm) = 0;
 371         }
 372         local_flush_tlb_mm(mm);
 373
 374         preempt_enable();
 375 }
 376
 377 struct flush_tlb_data {
 378         struct vm_area_struct *vma;
 379         unsigned long addr1;
 380         unsigned long addr2;
 381 };
 382
 383 static void flush_tlb_range_ipi(void *info)
 384 {
 385         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 386
 387         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 388 }
 389
 390 void flush_tlb_range(struct vm_area_struct *vma,
 391                      unsigned long start, unsigned long end)
 392 {
 393         struct mm_struct *mm = vma->vm_mm;
 394
 395         preempt_disable();
 396         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 397                 struct flush_tlb_data fd;
 398
 399                 fd.vma = vma;
 400                 fd.addr1 = start;
 401                 fd.addr2 = end;
 402                 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
 403         } else {
 404                 int i;
 405                 for_each_online_cpu(i)
 406                         if (smp_processor_id() != i)
 407                                 cpu_context(i, mm) = 0;
 408         }
 409         local_flush_tlb_range(vma, start, end);
 410         preempt_enable();
 411 }
 412
 413 static void flush_tlb_kernel_range_ipi(void *info)
 414 {
 415         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 416
 417         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 418 }
 419
 420 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 421 {
 422         struct flush_tlb_data fd;
 423
 424         fd.addr1 = start;
 425         fd.addr2 = end;
 426         on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1);
 427 }
 428
 429 static void flush_tlb_page_ipi(void *info)
 430 {
 431         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 432
 433         local_flush_tlb_page(fd->vma, fd->addr1);
 434 }
 435
 436 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 437 {
 438         preempt_disable();
 439         if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
 440             (current->mm != vma->vm_mm)) {
 441                 struct flush_tlb_data fd;
 442
 443                 fd.vma = vma;
 444                 fd.addr1 = page;
 445                 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
 446         } else {
 447                 int i;
 448                 for_each_online_cpu(i)
 449                         if (smp_processor_id() != i)
 450                                 cpu_context(i, vma->vm_mm) = 0;
 451         }
 452         local_flush_tlb_page(vma, page);
 453         preempt_enable();
 454 }
 455
 456 static void flush_tlb_one_ipi(void *info)
 457 {
 458         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 459         local_flush_tlb_one(fd->addr1, fd->addr2);
 460 }
 461
 462 void flush_tlb_one(unsigned long asid, unsigned long vaddr)
 463 {
 464         struct flush_tlb_data fd;
 465
 466         fd.addr1 = asid;
 467         fd.addr2 = vaddr;
 468
 469         smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1);
 470         local_flush_tlb_one(asid, vaddr);
 471 }
 472
 473 #endif