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 __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_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         __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, struct task_struct *tsk)
 224 {
 225         unsigned long timeout;
 226
 227         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 228
 229         /* Fill in data in head.S for secondary cpus */
 230         stack_start.sp = tsk->thread.sp;
 231         stack_start.thread_info = tsk->stack;
 232         stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
 233         stack_start.start_kernel_fn = start_secondary;
 234
 235         flush_icache_range((unsigned long)&stack_start,
 236                            (unsigned long)&stack_start + sizeof(stack_start));
 237         wmb();
 238
 239         mp_ops->start_cpu(cpu, (unsigned long)_stext);
 240
 241         timeout = jiffies + HZ;
 242         while (time_before(jiffies, timeout)) {
 243                 if (cpu_online(cpu))
 244                         break;
 245
 246                 udelay(10);
 247                 barrier();
 248         }
 249
 250         if (cpu_online(cpu))
 251                 return 0;
 252
 253         return -ENOENT;
 254 }
 255
 256 void __init smp_cpus_done(unsigned int max_cpus)
 257 {
 258         unsigned long bogosum = 0;
 259         int cpu;
 260
 261         for_each_online_cpu(cpu)
 262                 bogosum += cpu_data[cpu].loops_per_jiffy;
 263
 264         printk(KERN_INFO "SMP: Total of %d processors activated "
 265                "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
 266                bogosum / (500000/HZ),
 267                (bogosum / (5000/HZ)) % 100);
 268 }
 269
 270 void smp_send_reschedule(int cpu)
 271 {
 272         mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
 273 }
 274
 275 void smp_send_stop(void)
 276 {
 277         smp_call_function(stop_this_cpu, 0, 0);
 278 }
 279
 280 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 281 {
 282         int cpu;
 283
 284         for_each_cpu(cpu, mask)
 285                 mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION);
 286 }
 287
 288 void arch_send_call_function_single_ipi(int cpu)
 289 {
 290         mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
 291 }
 292
 293 void smp_timer_broadcast(const struct cpumask *mask)
 294 {
 295         int cpu;
 296
 297         for_each_cpu(cpu, mask)
 298                 mp_ops->send_ipi(cpu, SMP_MSG_TIMER);
 299 }
 300
 301 static void ipi_timer(void)
 302 {
 303         irq_enter();
 304         local_timer_interrupt();
 305         irq_exit();
 306 }
 307
 308 void smp_message_recv(unsigned int msg)
 309 {
 310         switch (msg) {
 311         case SMP_MSG_FUNCTION:
 312                 generic_smp_call_function_interrupt();
 313                 break;
 314         case SMP_MSG_RESCHEDULE:
 315                 scheduler_ipi();
 316                 break;
 317         case SMP_MSG_FUNCTION_SINGLE:
 318                 generic_smp_call_function_single_interrupt();
 319                 break;
 320         case SMP_MSG_TIMER:
 321                 ipi_timer();
 322                 break;
 323         default:
 324                 printk(KERN_WARNING "SMP %d: %s(): unknown IPI %d\n",
 325                        smp_processor_id(), __func__, msg);
 326                 break;
 327         }
 328 }
 329
 330 /* Not really SMP stuff ... */
 331 int setup_profiling_timer(unsigned int multiplier)
 332 {
 333         return 0;
 334 }
 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 (i = 0; i < num_online_cpus(); 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 (i = 0; i < num_online_cpus(); 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 (i = 0; i < num_online_cpus(); 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 }