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