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         notify_cpu_starting(cpu);
 190
 191         local_irq_enable();
 192
 193         calibrate_delay();
 194
 195         smp_store_cpu_info(cpu);
 196
 197         set_cpu_online(cpu, true);
 198         per_cpu(cpu_state, cpu) = CPU_ONLINE;
 199
 200         cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 201 }
 202
 203 extern struct {
 204         unsigned long sp;
 205         unsigned long bss_start;
 206         unsigned long bss_end;
 207         void *start_kernel_fn;
 208         void *cpu_init_fn;
 209         void *thread_info;
 210 } stack_start;
 211
 212 int __cpu_up(unsigned int cpu, struct task_struct *tsk)
 213 {
 214         unsigned long timeout;
 215
 216         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 217
 218         /* Fill in data in head.S for secondary cpus */
 219         stack_start.sp = tsk->thread.sp;
 220         stack_start.thread_info = tsk->stack;
 221         stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
 222         stack_start.start_kernel_fn = start_secondary;
 223
 224         flush_icache_range((unsigned long)&stack_start,
 225                            (unsigned long)&stack_start + sizeof(stack_start));
 226         wmb();
 227
 228         mp_ops->start_cpu(cpu, (unsigned long)_stext);
 229
 230         timeout = jiffies + HZ;
 231         while (time_before(jiffies, timeout)) {
 232                 if (cpu_online(cpu))
 233                         break;
 234
 235                 udelay(10);
 236                 barrier();
 237         }
 238
 239         if (cpu_online(cpu))
 240                 return 0;
 241
 242         return -ENOENT;
 243 }
 244
 245 void __init smp_cpus_done(unsigned int max_cpus)
 246 {
 247         unsigned long bogosum = 0;
 248         int cpu;
 249
 250         for_each_online_cpu(cpu)
 251                 bogosum += cpu_data[cpu].loops_per_jiffy;
 252
 253         printk(KERN_INFO "SMP: Total of %d processors activated "
 254                "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
 255                bogosum / (500000/HZ),
 256                (bogosum / (5000/HZ)) % 100);
 257 }
 258
 259 void arch_smp_send_reschedule(int cpu)
 260 {
 261         mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
 262 }
 263
 264 void smp_send_stop(void)
 265 {
 266         smp_call_function(stop_this_cpu, 0, 0);
 267 }
 268
 269 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 270 {
 271         int cpu;
 272
 273         for_each_cpu(cpu, mask)
 274                 mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION);
 275 }
 276
 277 void arch_send_call_function_single_ipi(int cpu)
 278 {
 279         mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
 280 }
 281
 282 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 283 void tick_broadcast(const struct cpumask *mask)
 284 {
 285         int cpu;
 286
 287         for_each_cpu(cpu, mask)
 288                 mp_ops->send_ipi(cpu, SMP_MSG_TIMER);
 289 }
 290
 291 static void ipi_timer(void)
 292 {
 293         irq_enter();
 294         tick_receive_broadcast();
 295         irq_exit();
 296 }
 297 #endif
 298
 299 void smp_message_recv(unsigned int msg)
 300 {
 301         switch (msg) {
 302         case SMP_MSG_FUNCTION:
 303                 generic_smp_call_function_interrupt();
 304                 break;
 305         case SMP_MSG_RESCHEDULE:
 306                 scheduler_ipi();
 307                 break;
 308         case SMP_MSG_FUNCTION_SINGLE:
 309                 generic_smp_call_function_single_interrupt();
 310                 break;
 311 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 312         case SMP_MSG_TIMER:
 313                 ipi_timer();
 314                 break;
 315 #endif
 316         default:
 317                 printk(KERN_WARNING "SMP %d: %s(): unknown IPI %d\n",
 318                        smp_processor_id(), __func__, msg);
 319                 break;
 320         }
 321 }
 322
 323 /* Not really SMP stuff ... */
 324 int setup_profiling_timer(unsigned int multiplier)
 325 {
 326         return 0;
 327 }
 328
 329 #ifdef CONFIG_MMU
 330
 331 static void flush_tlb_all_ipi(void *info)
 332 {
 333         local_flush_tlb_all();
 334 }
 335
 336 void flush_tlb_all(void)
 337 {
 338         on_each_cpu(flush_tlb_all_ipi, 0, 1);
 339 }
 340
 341 static void flush_tlb_mm_ipi(void *mm)
 342 {
 343         local_flush_tlb_mm((struct mm_struct *)mm);
 344 }
 345
 346 /*
 347  * The following tlb flush calls are invoked when old translations are
 348  * being torn down, or pte attributes are changing. For single threaded
 349  * address spaces, a new context is obtained on the current cpu, and tlb
 350  * context on other cpus are invalidated to force a new context allocation
 351  * at switch_mm time, should the mm ever be used on other cpus. For
 352  * multithreaded address spaces, intercpu interrupts have to be sent.
 353  * Another case where intercpu interrupts are required is when the target
 354  * mm might be active on another cpu (eg debuggers doing the flushes on
 355  * behalf of debugees, kswapd stealing pages from another process etc).
 356  * Kanoj 07/00.
 357  */
 358 void flush_tlb_mm(struct mm_struct *mm)
 359 {
 360         preempt_disable();
 361
 362         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 363                 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
 364         } else {
 365                 int i;
 366                 for_each_online_cpu(i)
 367                         if (smp_processor_id() != i)
 368                                 cpu_context(i, mm) = 0;
 369         }
 370         local_flush_tlb_mm(mm);
 371
 372         preempt_enable();
 373 }
 374
 375 struct flush_tlb_data {
 376         struct vm_area_struct *vma;
 377         unsigned long addr1;
 378         unsigned long addr2;
 379 };
 380
 381 static void flush_tlb_range_ipi(void *info)
 382 {
 383         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 384
 385         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 386 }
 387
 388 void flush_tlb_range(struct vm_area_struct *vma,
 389                      unsigned long start, unsigned long end)
 390 {
 391         struct mm_struct *mm = vma->vm_mm;
 392
 393         preempt_disable();
 394         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 395                 struct flush_tlb_data fd;
 396
 397                 fd.vma = vma;
 398                 fd.addr1 = start;
 399                 fd.addr2 = end;
 400                 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
 401         } else {
 402                 int i;
 403                 for_each_online_cpu(i)
 404                         if (smp_processor_id() != i)
 405                                 cpu_context(i, mm) = 0;
 406         }
 407         local_flush_tlb_range(vma, start, end);
 408         preempt_enable();
 409 }
 410
 411 static void flush_tlb_kernel_range_ipi(void *info)
 412 {
 413         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 414
 415         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 416 }
 417
 418 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 419 {
 420         struct flush_tlb_data fd;
 421
 422         fd.addr1 = start;
 423         fd.addr2 = end;
 424         on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1);
 425 }
 426
 427 static void flush_tlb_page_ipi(void *info)
 428 {
 429         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 430
 431         local_flush_tlb_page(fd->vma, fd->addr1);
 432 }
 433
 434 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 435 {
 436         preempt_disable();
 437         if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
 438             (current->mm != vma->vm_mm)) {
 439                 struct flush_tlb_data fd;
 440
 441                 fd.vma = vma;
 442                 fd.addr1 = page;
 443                 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
 444         } else {
 445                 int i;
 446                 for_each_online_cpu(i)
 447                         if (smp_processor_id() != i)
 448                                 cpu_context(i, vma->vm_mm) = 0;
 449         }
 450         local_flush_tlb_page(vma, page);
 451         preempt_enable();
 452 }
 453
 454 static void flush_tlb_one_ipi(void *info)
 455 {
 456         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 457         local_flush_tlb_one(fd->addr1, fd->addr2);
 458 }
 459
 460 void flush_tlb_one(unsigned long asid, unsigned long vaddr)
 461 {
 462         struct flush_tlb_data fd;
 463
 464         fd.addr1 = asid;
 465         fd.addr2 = vaddr;
 466
 467         smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1);
 468         local_flush_tlb_one(asid, vaddr);
 469 }
 470
 471 #endif