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