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/system.h>
  27 #include <asm/mmu_context.h>
  28 #include <asm/smp.h>
  29 #include <asm/cacheflush.h>
  30 #include <asm/sections.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 __cpuinit 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 __cpuinit 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_map);
  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         __get_cpu_var(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         struct task_struct *p;
 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          * Stop the local timer for this CPU.
 146          */
 147         local_timer_stop(cpu);
 148
 149         /*
 150          * Flush user cache and TLB mappings, and then remove this CPU
 151          * from the vm mask set of all processes.
 152          */
 153         flush_cache_all();
 154         local_flush_tlb_all();
 155
 156         read_lock(&tasklist_lock);
 157         for_each_process(p)
 158                 if (p->mm)
 159                         cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
 160         read_unlock(&tasklist_lock);
 161
 162         return 0;
 163 }
 164 #else /* ... !CONFIG_HOTPLUG_CPU */
 165 int native_cpu_disable(unsigned int cpu)
 166 {
 167         return -ENOSYS;
 168 }
 169
 170 void native_cpu_die(unsigned int cpu)
 171 {
 172         /* We said "no" in __cpu_disable */
 173         BUG();
 174 }
 175
 176 void native_play_dead(void)
 177 {
 178         BUG();
 179 }
 180 #endif
 181
 182 asmlinkage void __cpuinit start_secondary(void)
 183 {
 184         unsigned int cpu = smp_processor_id();
 185         struct mm_struct *mm = &init_mm;
 186
 187         enable_mmu();
 188         atomic_inc(&mm->mm_count);
 189         atomic_inc(&mm->mm_users);
 190         current->active_mm = mm;
 191         enter_lazy_tlb(mm, current);
 192         local_flush_tlb_all();
 193
 194         per_cpu_trap_init();
 195
 196         preempt_disable();
 197
 198         notify_cpu_starting(cpu);
 199
 200         local_irq_enable();
 201
 202         /* Enable local timers */
 203         local_timer_setup(cpu);
 204         calibrate_delay();
 205
 206         smp_store_cpu_info(cpu);
 207
 208         set_cpu_online(cpu, true);
 209         per_cpu(cpu_state, cpu) = CPU_ONLINE;
 210
 211         cpu_idle();
 212 }
 213
 214 extern struct {
 215         unsigned long sp;
 216         unsigned long bss_start;
 217         unsigned long bss_end;
 218         void *start_kernel_fn;
 219         void *cpu_init_fn;
 220         void *thread_info;
 221 } stack_start;
 222
 223 int __cpuinit __cpu_up(unsigned int cpu)
 224 {
 225         struct task_struct *tsk;
 226         unsigned long timeout;
 227
 228         tsk = cpu_data[cpu].idle;
 229         if (!tsk) {
 230                 tsk = fork_idle(cpu);
 231                 if (IS_ERR(tsk)) {
 232                         pr_err("Failed forking idle task for cpu %d\n", cpu);
 233                         return PTR_ERR(tsk);
 234                 }
 235
 236                 cpu_data[cpu].idle = tsk;
 237         }
 238
 239         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 240
 241         /* Fill in data in head.S for secondary cpus */
 242         stack_start.sp = tsk->thread.sp;
 243         stack_start.thread_info = tsk->stack;
 244         stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
 245         stack_start.start_kernel_fn = start_secondary;
 246
 247         flush_icache_range((unsigned long)&stack_start,
 248                            (unsigned long)&stack_start + sizeof(stack_start));
 249         wmb();
 250
 251         mp_ops->start_cpu(cpu, (unsigned long)_stext);
 252
 253         timeout = jiffies + HZ;
 254         while (time_before(jiffies, timeout)) {
 255                 if (cpu_online(cpu))
 256                         break;
 257
 258                 udelay(10);
 259                 barrier();
 260         }
 261
 262         if (cpu_online(cpu))
 263                 return 0;
 264
 265         return -ENOENT;
 266 }
 267
 268 void __init smp_cpus_done(unsigned int max_cpus)
 269 {
 270         unsigned long bogosum = 0;
 271         int cpu;
 272
 273         for_each_online_cpu(cpu)
 274                 bogosum += cpu_data[cpu].loops_per_jiffy;
 275
 276         printk(KERN_INFO "SMP: Total of %d processors activated "
 277                "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
 278                bogosum / (500000/HZ),
 279                (bogosum / (5000/HZ)) % 100);
 280 }
 281
 282 void smp_send_reschedule(int cpu)
 283 {
 284         mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
 285 }
 286
 287 void smp_send_stop(void)
 288 {
 289         smp_call_function(stop_this_cpu, 0, 0);
 290 }
 291
 292 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 293 {
 294         int cpu;
 295
 296         for_each_cpu(cpu, mask)
 297                 mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION);
 298 }
 299
 300 void arch_send_call_function_single_ipi(int cpu)
 301 {
 302         mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
 303 }
 304
 305 void smp_timer_broadcast(const struct cpumask *mask)
 306 {
 307         int cpu;
 308
 309         for_each_cpu(cpu, mask)
 310                 mp_ops->send_ipi(cpu, SMP_MSG_TIMER);
 311 }
 312
 313 static void ipi_timer(void)
 314 {
 315         irq_enter();
 316         local_timer_interrupt();
 317         irq_exit();
 318 }
 319
 320 void smp_message_recv(unsigned int msg)
 321 {
 322         switch (msg) {
 323         case SMP_MSG_FUNCTION:
 324                 generic_smp_call_function_interrupt();
 325                 break;
 326         case SMP_MSG_RESCHEDULE:
 327                 scheduler_ipi();
 328                 break;
 329         case SMP_MSG_FUNCTION_SINGLE:
 330                 generic_smp_call_function_single_interrupt();
 331                 break;
 332         case SMP_MSG_TIMER:
 333                 ipi_timer();
 334                 break;
 335         default:
 336                 printk(KERN_WARNING "SMP %d: %s(): unknown IPI %d\n",
 337                        smp_processor_id(), __func__, msg);
 338                 break;
 339         }
 340 }
 341
 342 /* Not really SMP stuff ... */
 343 int setup_profiling_timer(unsigned int multiplier)
 344 {
 345         return 0;
 346 }
 347
 348 static void flush_tlb_all_ipi(void *info)
 349 {
 350         local_flush_tlb_all();
 351 }
 352
 353 void flush_tlb_all(void)
 354 {
 355         on_each_cpu(flush_tlb_all_ipi, 0, 1);
 356 }
 357
 358 static void flush_tlb_mm_ipi(void *mm)
 359 {
 360         local_flush_tlb_mm((struct mm_struct *)mm);
 361 }
 362
 363 /*
 364  * The following tlb flush calls are invoked when old translations are
 365  * being torn down, or pte attributes are changing. For single threaded
 366  * address spaces, a new context is obtained on the current cpu, and tlb
 367  * context on other cpus are invalidated to force a new context allocation
 368  * at switch_mm time, should the mm ever be used on other cpus. For
 369  * multithreaded address spaces, intercpu interrupts have to be sent.
 370  * Another case where intercpu interrupts are required is when the target
 371  * mm might be active on another cpu (eg debuggers doing the flushes on
 372  * behalf of debugees, kswapd stealing pages from another process etc).
 373  * Kanoj 07/00.
 374  */
 375 void flush_tlb_mm(struct mm_struct *mm)
 376 {
 377         preempt_disable();
 378
 379         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 380                 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
 381         } else {
 382                 int i;
 383                 for (i = 0; i < num_online_cpus(); i++)
 384                         if (smp_processor_id() != i)
 385                                 cpu_context(i, mm) = 0;
 386         }
 387         local_flush_tlb_mm(mm);
 388
 389         preempt_enable();
 390 }
 391
 392 struct flush_tlb_data {
 393         struct vm_area_struct *vma;
 394         unsigned long addr1;
 395         unsigned long addr2;
 396 };
 397
 398 static void flush_tlb_range_ipi(void *info)
 399 {
 400         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 401
 402         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 403 }
 404
 405 void flush_tlb_range(struct vm_area_struct *vma,
 406                      unsigned long start, unsigned long end)
 407 {
 408         struct mm_struct *mm = vma->vm_mm;
 409
 410         preempt_disable();
 411         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 412                 struct flush_tlb_data fd;
 413
 414                 fd.vma = vma;
 415                 fd.addr1 = start;
 416                 fd.addr2 = end;
 417                 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
 418         } else {
 419                 int i;
 420                 for (i = 0; i < num_online_cpus(); i++)
 421                         if (smp_processor_id() != i)
 422                                 cpu_context(i, mm) = 0;
 423         }
 424         local_flush_tlb_range(vma, start, end);
 425         preempt_enable();
 426 }
 427
 428 static void flush_tlb_kernel_range_ipi(void *info)
 429 {
 430         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 431
 432         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 433 }
 434
 435 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 436 {
 437         struct flush_tlb_data fd;
 438
 439         fd.addr1 = start;
 440         fd.addr2 = end;
 441         on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1);
 442 }
 443
 444 static void flush_tlb_page_ipi(void *info)
 445 {
 446         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 447
 448         local_flush_tlb_page(fd->vma, fd->addr1);
 449 }
 450
 451 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 452 {
 453         preempt_disable();
 454         if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
 455             (current->mm != vma->vm_mm)) {
 456                 struct flush_tlb_data fd;
 457
 458                 fd.vma = vma;
 459                 fd.addr1 = page;
 460                 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
 461         } else {
 462                 int i;
 463                 for (i = 0; i < num_online_cpus(); i++)
 464                         if (smp_processor_id() != i)
 465                                 cpu_context(i, vma->vm_mm) = 0;
 466         }
 467         local_flush_tlb_page(vma, page);
 468         preempt_enable();
 469 }
 470
 471 static void flush_tlb_one_ipi(void *info)
 472 {
 473         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 474         local_flush_tlb_one(fd->addr1, fd->addr2);
 475 }
 476
 477 void flush_tlb_one(unsigned long asid, unsigned long vaddr)
 478 {
 479         struct flush_tlb_data fd;
 480
 481         fd.addr1 = asid;
 482         fd.addr2 = vaddr;
 483
 484         smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1);
 485         local_flush_tlb_one(asid, vaddr);
 486 }