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