arch/sh/kernel/smp.c

   1 /*
   2  * arch/sh/kernel/smp.c
   3  *
   4  * SMP support for the SuperH processors.
   5  *
   6  * Copyright (C) 2002 - 2010 Paul Mundt
   7  * Copyright (C) 2006 - 2007 Akio Idehara
   8  *
   9  * This file is subject to the terms and conditions of the GNU General Public
  10  * License.  See the file "COPYING" in the main directory of this archive
  11  * for more details.
  12  */
  13 #include <linux/err.h>
  14 #include <linux/cache.h>
  15 #include <linux/cpumask.h>
  16 #include <linux/delay.h>
  17 #include <linux/init.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/mm.h>
  20 #include <linux/module.h>
  21 #include <linux/cpu.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/sched/mm.h>
  24 #include <linux/sched/hotplug.h>
  25 #include <linux/atomic.h>
  26 #include <linux/clockchips.h>
  27 #include <asm/processor.h>
  28 #include <asm/mmu_context.h>
  29 #include <asm/smp.h>
  30 #include <asm/cacheflush.h>
  31 #include <asm/sections.h>
  32 #include <asm/setup.h>
  33
  34 int __cpu_number_map[NR_CPUS];          /* Map physical to logical */
  35 int __cpu_logical_map[NR_CPUS];         /* Map logical to physical */
  36
  37 struct plat_smp_ops *mp_ops = NULL;
  38
  39 /* State of each CPU */
  40 DEFINE_PER_CPU(int, cpu_state) = { 0 };
  41
  42 void register_smp_ops(struct plat_smp_ops *ops)
  43 {
  44         if (mp_ops)
  45                 printk(KERN_WARNING "Overriding previously set SMP ops\n");
  46
  47         mp_ops = ops;
  48 }
  49
  50 static inline void smp_store_cpu_info(unsigned int cpu)
  51 {
  52         struct sh_cpuinfo *c = cpu_data + cpu;
  53
  54         memcpy(c, &boot_cpu_data, sizeof(struct sh_cpuinfo));
  55
  56         c->loops_per_jiffy = loops_per_jiffy;
  57 }
  58
  59 void __init smp_prepare_cpus(unsigned int max_cpus)
  60 {
  61         unsigned int cpu = smp_processor_id();
  62
  63         init_new_context(current, &init_mm);
  64         current_thread_info()->cpu = cpu;
  65         mp_ops->prepare_cpus(max_cpus);
  66
  67 #ifndef CONFIG_HOTPLUG_CPU
  68         init_cpu_present(cpu_possible_mask);
  69 #endif
  70 }
  71
  72 void __init smp_prepare_boot_cpu(void)
  73 {
  74         unsigned int cpu = smp_processor_id();
  75
  76         __cpu_number_map[0] = cpu;
  77         __cpu_logical_map[0] = cpu;
  78
  79         set_cpu_online(cpu, true);
  80         set_cpu_possible(cpu, true);
  81
  82         per_cpu(cpu_state, cpu) = CPU_ONLINE;
  83 }
  84
  85 #ifdef CONFIG_HOTPLUG_CPU
  86 void native_cpu_die(unsigned int cpu)
  87 {
  88         unsigned int i;
  89
  90         for (i = 0; i < 10; i++) {
  91                 smp_rmb();
  92                 if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
  93                         if (system_state == SYSTEM_RUNNING)
  94                                 pr_info("CPU %u is now offline\n", cpu);
  95
  96                         return;
  97                 }
  98
  99                 msleep(100);
 100         }
 101
 102         pr_err("CPU %u didn't die...\n", cpu);
 103 }
 104
 105 int native_cpu_disable(unsigned int cpu)
 106 {
 107         return cpu == 0 ? -EPERM : 0;
 108 }
 109
 110 void play_dead_common(void)
 111 {
 112         idle_task_exit();
 113         irq_ctx_exit(raw_smp_processor_id());
 114         mb();
 115
 116         __this_cpu_write(cpu_state, CPU_DEAD);
 117         local_irq_disable();
 118 }
 119
 120 void native_play_dead(void)
 121 {
 122         play_dead_common();
 123 }
 124
 125 int __cpu_disable(void)
 126 {
 127         unsigned int cpu = smp_processor_id();
 128         int ret;
 129
 130         ret = mp_ops->cpu_disable(cpu);
 131         if (ret)
 132                 return ret;
 133
 134         /*
 135          * Take this CPU offline.  Once we clear this, we can't return,
 136          * and we must not schedule until we're ready to give up the cpu.
 137          */
 138         set_cpu_online(cpu, false);
 139
 140         /*
 141          * OK - migrate IRQs away from this CPU
 142          */
 143         migrate_irqs();
 144
 145         /*
 146          * Flush user cache and TLB mappings, and then remove this CPU
 147          * from the vm mask set of all processes.
 148          */
 149         flush_cache_all();
 150 #ifdef CONFIG_MMU
 151         local_flush_tlb_all();
 152 #endif
 153
 154         clear_tasks_mm_cpumask(cpu);
 155
 156         return 0;
 157 }
 158 #else /* ... !CONFIG_HOTPLUG_CPU */
 159 int native_cpu_disable(unsigned int cpu)
 160 {
 161         return -ENOSYS;
 162 }
 163
 164 void native_cpu_die(unsigned int cpu)
 165 {
 166         /* We said "no" in __cpu_disable */
 167         BUG();
 168 }
 169
 170 void native_play_dead(void)
 171 {
 172         BUG();
 173 }
 174 #endif
 175
 176 asmlinkage void start_secondary(void)
 177 {
 178         unsigned int cpu = smp_processor_id();
 179         struct mm_struct *mm = &init_mm;
 180
 181         enable_mmu();
 182         mmgrab(mm);
 183         mmget(mm);
 184         current->active_mm = mm;
 185 #ifdef CONFIG_MMU
 186         enter_lazy_tlb(mm, current);
 187         local_flush_tlb_all();
 188 #endif
 189
 190         per_cpu_trap_init();
 191
 192         preempt_disable();
 193
 194         notify_cpu_starting(cpu);
 195
 196         local_irq_enable();
 197
 198         calibrate_delay();
 199
 200         smp_store_cpu_info(cpu);
 201
 202         set_cpu_online(cpu, true);
 203         per_cpu(cpu_state, cpu) = CPU_ONLINE;
 204
 205         cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 206 }
 207
 208 extern struct {
 209         unsigned long sp;
 210         unsigned long bss_start;
 211         unsigned long bss_end;
 212         void *start_kernel_fn;
 213         void *cpu_init_fn;
 214         void *thread_info;
 215 } stack_start;
 216
 217 int __cpu_up(unsigned int cpu, struct task_struct *tsk)
 218 {
 219         unsigned long timeout;
 220
 221         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 222
 223         /* Fill in data in head.S for secondary cpus */
 224         stack_start.sp = tsk->thread.sp;
 225         stack_start.thread_info = tsk->stack;
 226         stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
 227         stack_start.start_kernel_fn = start_secondary;
 228
 229         flush_icache_range((unsigned long)&stack_start,
 230                            (unsigned long)&stack_start + sizeof(stack_start));
 231         wmb();
 232
 233         mp_ops->start_cpu(cpu, (unsigned long)_stext);
 234
 235         timeout = jiffies + HZ;
 236         while (time_before(jiffies, timeout)) {
 237                 if (cpu_online(cpu))
 238                         break;
 239
 240                 udelay(10);
 241                 barrier();
 242         }
 243
 244         if (cpu_online(cpu))
 245                 return 0;
 246
 247         return -ENOENT;
 248 }
 249
 250 void __init smp_cpus_done(unsigned int max_cpus)
 251 {
 252         unsigned long bogosum = 0;
 253         int cpu;
 254
 255         for_each_online_cpu(cpu)
 256                 bogosum += cpu_data[cpu].loops_per_jiffy;
 257
 258         printk(KERN_INFO "SMP: Total of %d processors activated "
 259                "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
 260                bogosum / (500000/HZ),
 261                (bogosum / (5000/HZ)) % 100);
 262 }
 263
 264 void smp_send_reschedule(int cpu)
 265 {
 266         mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
 267 }
 268
 269 void smp_send_stop(void)
 270 {
 271         smp_call_function(stop_this_cpu, 0, 0);
 272 }
 273
 274 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 275 {
 276         int cpu;
 277
 278         for_each_cpu(cpu, mask)
 279                 mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION);
 280 }
 281
 282 void arch_send_call_function_single_ipi(int cpu)
 283 {
 284         mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
 285 }
 286
 287 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 288 void tick_broadcast(const struct cpumask *mask)
 289 {
 290         int cpu;
 291
 292         for_each_cpu(cpu, mask)
 293                 mp_ops->send_ipi(cpu, SMP_MSG_TIMER);
 294 }
 295
 296 static void ipi_timer(void)
 297 {
 298         irq_enter();
 299         tick_receive_broadcast();
 300         irq_exit();
 301 }
 302 #endif
 303
 304 void smp_message_recv(unsigned int msg)
 305 {
 306         switch (msg) {
 307         case SMP_MSG_FUNCTION:
 308                 generic_smp_call_function_interrupt();
 309                 break;
 310         case SMP_MSG_RESCHEDULE:
 311                 scheduler_ipi();
 312                 break;
 313         case SMP_MSG_FUNCTION_SINGLE:
 314                 generic_smp_call_function_single_interrupt();
 315                 break;
 316 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 317         case SMP_MSG_TIMER:
 318                 ipi_timer();
 319                 break;
 320 #endif
 321         default:
 322                 printk(KERN_WARNING "SMP %d: %s(): unknown IPI %d\n",
 323                        smp_processor_id(), __func__, msg);
 324                 break;
 325         }
 326 }
 327
 328 /* Not really SMP stuff ... */
 329 int setup_profiling_timer(unsigned int multiplier)
 330 {
 331         return 0;
 332 }
 333
 334 #ifdef CONFIG_MMU
 335
 336 static void flush_tlb_all_ipi(void *info)
 337 {
 338         local_flush_tlb_all();
 339 }
 340
 341 void flush_tlb_all(void)
 342 {
 343         on_each_cpu(flush_tlb_all_ipi, 0, 1);
 344 }
 345
 346 static void flush_tlb_mm_ipi(void *mm)
 347 {
 348         local_flush_tlb_mm((struct mm_struct *)mm);
 349 }
 350
 351 /*
 352  * The following tlb flush calls are invoked when old translations are
 353  * being torn down, or pte attributes are changing. For single threaded
 354  * address spaces, a new context is obtained on the current cpu, and tlb
 355  * context on other cpus are invalidated to force a new context allocation
 356  * at switch_mm time, should the mm ever be used on other cpus. For
 357  * multithreaded address spaces, intercpu interrupts have to be sent.
 358  * Another case where intercpu interrupts are required is when the target
 359  * mm might be active on another cpu (eg debuggers doing the flushes on
 360  * behalf of debugees, kswapd stealing pages from another process etc).
 361  * Kanoj 07/00.
 362  */
 363 void flush_tlb_mm(struct mm_struct *mm)
 364 {
 365         preempt_disable();
 366
 367         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 368                 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
 369         } else {
 370                 int i;
 371                 for_each_online_cpu(i)
 372                         if (smp_processor_id() != i)
 373                                 cpu_context(i, mm) = 0;
 374         }
 375         local_flush_tlb_mm(mm);
 376
 377         preempt_enable();
 378 }
 379
 380 struct flush_tlb_data {
 381         struct vm_area_struct *vma;
 382         unsigned long addr1;
 383         unsigned long addr2;
 384 };
 385
 386 static void flush_tlb_range_ipi(void *info)
 387 {
 388         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 389
 390         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 391 }
 392
 393 void flush_tlb_range(struct vm_area_struct *vma,
 394                      unsigned long start, unsigned long end)
 395 {
 396         struct mm_struct *mm = vma->vm_mm;
 397
 398         preempt_disable();
 399         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 400                 struct flush_tlb_data fd;
 401
 402                 fd.vma = vma;
 403                 fd.addr1 = start;
 404                 fd.addr2 = end;
 405                 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
 406         } else {
 407                 int i;
 408                 for_each_online_cpu(i)
 409                         if (smp_processor_id() != i)
 410                                 cpu_context(i, mm) = 0;
 411         }
 412         local_flush_tlb_range(vma, start, end);
 413         preempt_enable();
 414 }
 415
 416 static void flush_tlb_kernel_range_ipi(void *info)
 417 {
 418         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 419
 420         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 421 }
 422
 423 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 424 {
 425         struct flush_tlb_data fd;
 426
 427         fd.addr1 = start;
 428         fd.addr2 = end;
 429         on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1);
 430 }
 431
 432 static void flush_tlb_page_ipi(void *info)
 433 {
 434         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 435
 436         local_flush_tlb_page(fd->vma, fd->addr1);
 437 }
 438
 439 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 440 {
 441         preempt_disable();
 442         if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
 443             (current->mm != vma->vm_mm)) {
 444                 struct flush_tlb_data fd;
 445
 446                 fd.vma = vma;
 447                 fd.addr1 = page;
 448                 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
 449         } else {
 450                 int i;
 451                 for_each_online_cpu(i)
 452                         if (smp_processor_id() != i)
 453                                 cpu_context(i, vma->vm_mm) = 0;
 454         }
 455         local_flush_tlb_page(vma, page);
 456         preempt_enable();
 457 }
 458
 459 static void flush_tlb_one_ipi(void *info)
 460 {
 461         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 462         local_flush_tlb_one(fd->addr1, fd->addr2);
 463 }
 464
 465 void flush_tlb_one(unsigned long asid, unsigned long vaddr)
 466 {
 467         struct flush_tlb_data fd;
 468
 469         fd.addr1 = asid;
 470         fd.addr2 = vaddr;
 471
 472         smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1);
 473         local_flush_tlb_one(asid, vaddr);
 474 }
 475
 476 #endif