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 <asm/atomic.h>
  24 #include <asm/processor.h>
  25 #include <asm/system.h>
  26 #include <asm/mmu_context.h>
  27 #include <asm/smp.h>
  28 #include <asm/cacheflush.h>
  29 #include <asm/sections.h>
  30
  31 int __cpu_number_map[NR_CPUS];          /* Map physical to logical */
  32 int __cpu_logical_map[NR_CPUS];         /* Map logical to physical */
  33
  34 struct plat_smp_ops *mp_ops = NULL;
  35
  36 /* State of each CPU */
  37 DEFINE_PER_CPU(int, cpu_state) = { 0 };
  38
  39 void __cpuinit register_smp_ops(struct plat_smp_ops *ops)
  40 {
  41         if (mp_ops)
  42                 printk(KERN_WARNING "Overriding previously set SMP ops\n");
  43
  44         mp_ops = ops;
  45 }
  46
  47 static inline void __cpuinit smp_store_cpu_info(unsigned int cpu)
  48 {
  49         struct sh_cpuinfo *c = cpu_data + cpu;
  50
  51         memcpy(c, &boot_cpu_data, sizeof(struct sh_cpuinfo));
  52
  53         c->loops_per_jiffy = loops_per_jiffy;
  54 }
  55
  56 void __init smp_prepare_cpus(unsigned int max_cpus)
  57 {
  58         unsigned int cpu = smp_processor_id();
  59
  60         init_new_context(current, &init_mm);
  61         current_thread_info()->cpu = cpu;
  62         mp_ops->prepare_cpus(max_cpus);
  63
  64 #ifndef CONFIG_HOTPLUG_CPU
  65         init_cpu_present(&cpu_possible_map);
  66 #endif
  67 }
  68
  69 void __init smp_prepare_boot_cpu(void)
  70 {
  71         unsigned int cpu = smp_processor_id();
  72
  73         __cpu_number_map[0] = cpu;
  74         __cpu_logical_map[0] = cpu;
  75
  76         set_cpu_online(cpu, true);
  77         set_cpu_possible(cpu, true);
  78
  79         per_cpu(cpu_state, cpu) = CPU_ONLINE;
  80 }
  81
  82 #ifdef CONFIG_HOTPLUG_CPU
  83 void native_cpu_die(unsigned int cpu)
  84 {
  85         unsigned int i;
  86
  87         for (i = 0; i < 10; i++) {
  88                 smp_rmb();
  89                 if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
  90                         if (system_state == SYSTEM_RUNNING)
  91                                 pr_info("CPU %u is now offline\n", cpu);
  92
  93                         return;
  94                 }
  95
  96                 msleep(100);
  97         }
  98
  99         pr_err("CPU %u didn't die...\n", cpu);
 100 }
 101
 102 int native_cpu_disable(unsigned int cpu)
 103 {
 104         return cpu == 0 ? -EPERM : 0;
 105 }
 106
 107 void play_dead_common(void)
 108 {
 109         idle_task_exit();
 110         irq_ctx_exit(raw_smp_processor_id());
 111         mb();
 112
 113         __get_cpu_var(cpu_state) = CPU_DEAD;
 114         local_irq_disable();
 115 }
 116
 117 void native_play_dead(void)
 118 {
 119         play_dead_common();
 120 }
 121
 122 int __cpu_disable(void)
 123 {
 124         unsigned int cpu = smp_processor_id();
 125         struct task_struct *p;
 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         read_lock(&tasklist_lock);
 156         for_each_process(p)
 157                 if (p->mm)
 158                         cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
 159         read_unlock(&tasklist_lock);
 160
 161         return 0;
 162 }
 163 #else /* ... !CONFIG_HOTPLUG_CPU */
 164 int native_cpu_disable(unsigned int cpu)
 165 {
 166         return -ENOSYS;
 167 }
 168
 169 void native_cpu_die(unsigned int cpu)
 170 {
 171         /* We said "no" in __cpu_disable */
 172         BUG();
 173 }
 174
 175 void native_play_dead(void)
 176 {
 177         BUG();
 178 }
 179 #endif
 180
 181 asmlinkage void __cpuinit start_secondary(void)
 182 {
 183         unsigned int cpu = smp_processor_id();
 184         struct mm_struct *mm = &init_mm;
 185
 186         enable_mmu();
 187         atomic_inc(&mm->mm_count);
 188         atomic_inc(&mm->mm_users);
 189         current->active_mm = mm;
 190         enter_lazy_tlb(mm, current);
 191         local_flush_tlb_all();
 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_idle();
 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 __cpuinit __cpu_up(unsigned int cpu)
 223 {
 224         struct task_struct *tsk;
 225         unsigned long timeout;
 226
 227         tsk = cpu_data[cpu].idle;
 228         if (!tsk) {
 229                 tsk = fork_idle(cpu);
 230                 if (IS_ERR(tsk)) {
 231                         pr_err("Failed forking idle task for cpu %d\n", cpu);
 232                         return PTR_ERR(tsk);
 233                 }
 234
 235                 cpu_data[cpu].idle = tsk;
 236         }
 237
 238         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 239
 240         /* Fill in data in head.S for secondary cpus */
 241         stack_start.sp = tsk->thread.sp;
 242         stack_start.thread_info = tsk->stack;
 243         stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
 244         stack_start.start_kernel_fn = start_secondary;
 245
 246         flush_icache_range((unsigned long)&stack_start,
 247                            (unsigned long)&stack_start + sizeof(stack_start));
 248         wmb();
 249
 250         mp_ops->start_cpu(cpu, (unsigned long)_stext);
 251
 252         timeout = jiffies + HZ;
 253         while (time_before(jiffies, timeout)) {
 254                 if (cpu_online(cpu))
 255                         break;
 256
 257                 udelay(10);
 258                 barrier();
 259         }
 260
 261         if (cpu_online(cpu))
 262                 return 0;
 263
 264         return -ENOENT;
 265 }
 266
 267 void __init smp_cpus_done(unsigned int max_cpus)
 268 {
 269         unsigned long bogosum = 0;
 270         int cpu;
 271
 272         for_each_online_cpu(cpu)
 273                 bogosum += cpu_data[cpu].loops_per_jiffy;
 274
 275         printk(KERN_INFO "SMP: Total of %d processors activated "
 276                "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
 277                bogosum / (500000/HZ),
 278                (bogosum / (5000/HZ)) % 100);
 279 }
 280
 281 void smp_send_reschedule(int cpu)
 282 {
 283         mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
 284 }
 285
 286 void smp_send_stop(void)
 287 {
 288         smp_call_function(stop_this_cpu, 0, 0);
 289 }
 290
 291 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 292 {
 293         int cpu;
 294
 295         for_each_cpu(cpu, mask)
 296                 mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION);
 297 }
 298
 299 void arch_send_call_function_single_ipi(int cpu)
 300 {
 301         mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
 302 }
 303
 304 void smp_timer_broadcast(const struct cpumask *mask)
 305 {
 306         int cpu;
 307
 308         for_each_cpu(cpu, mask)
 309                 mp_ops->send_ipi(cpu, SMP_MSG_TIMER);
 310 }
 311
 312 static void ipi_timer(void)
 313 {
 314         irq_enter();
 315         local_timer_interrupt();
 316         irq_exit();
 317 }
 318
 319 void smp_message_recv(unsigned int msg)
 320 {
 321         switch (msg) {
 322         case SMP_MSG_FUNCTION:
 323                 generic_smp_call_function_interrupt();
 324                 break;
 325         case SMP_MSG_RESCHEDULE:
 326                 break;
 327         case SMP_MSG_FUNCTION_SINGLE:
 328                 generic_smp_call_function_single_interrupt();
 329                 break;
 330         case SMP_MSG_TIMER:
 331                 ipi_timer();
 332                 break;
 333         default:
 334                 printk(KERN_WARNING "SMP %d: %s(): unknown IPI %d\n",
 335                        smp_processor_id(), __func__, msg);
 336                 break;
 337         }
 338 }
 339
 340 /* Not really SMP stuff ... */
 341 int setup_profiling_timer(unsigned int multiplier)
 342 {
 343         return 0;
 344 }
 345
 346 static void flush_tlb_all_ipi(void *info)
 347 {
 348         local_flush_tlb_all();
 349 }
 350
 351 void flush_tlb_all(void)
 352 {
 353         on_each_cpu(flush_tlb_all_ipi, 0, 1);
 354 }
 355
 356 static void flush_tlb_mm_ipi(void *mm)
 357 {
 358         local_flush_tlb_mm((struct mm_struct *)mm);
 359 }
 360
 361 /*
 362  * The following tlb flush calls are invoked when old translations are
 363  * being torn down, or pte attributes are changing. For single threaded
 364  * address spaces, a new context is obtained on the current cpu, and tlb
 365  * context on other cpus are invalidated to force a new context allocation
 366  * at switch_mm time, should the mm ever be used on other cpus. For
 367  * multithreaded address spaces, intercpu interrupts have to be sent.
 368  * Another case where intercpu interrupts are required is when the target
 369  * mm might be active on another cpu (eg debuggers doing the flushes on
 370  * behalf of debugees, kswapd stealing pages from another process etc).
 371  * Kanoj 07/00.
 372  */
 373 void flush_tlb_mm(struct mm_struct *mm)
 374 {
 375         preempt_disable();
 376
 377         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 378                 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
 379         } else {
 380                 int i;
 381                 for (i = 0; i < num_online_cpus(); i++)
 382                         if (smp_processor_id() != i)
 383                                 cpu_context(i, mm) = 0;
 384         }
 385         local_flush_tlb_mm(mm);
 386
 387         preempt_enable();
 388 }
 389
 390 struct flush_tlb_data {
 391         struct vm_area_struct *vma;
 392         unsigned long addr1;
 393         unsigned long addr2;
 394 };
 395
 396 static void flush_tlb_range_ipi(void *info)
 397 {
 398         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 399
 400         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 401 }
 402
 403 void flush_tlb_range(struct vm_area_struct *vma,
 404                      unsigned long start, unsigned long end)
 405 {
 406         struct mm_struct *mm = vma->vm_mm;
 407
 408         preempt_disable();
 409         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 410                 struct flush_tlb_data fd;
 411
 412                 fd.vma = vma;
 413                 fd.addr1 = start;
 414                 fd.addr2 = end;
 415                 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
 416         } else {
 417                 int i;
 418                 for (i = 0; i < num_online_cpus(); i++)
 419                         if (smp_processor_id() != i)
 420                                 cpu_context(i, mm) = 0;
 421         }
 422         local_flush_tlb_range(vma, start, end);
 423         preempt_enable();
 424 }
 425
 426 static void flush_tlb_kernel_range_ipi(void *info)
 427 {
 428         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 429
 430         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 431 }
 432
 433 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 434 {
 435         struct flush_tlb_data fd;
 436
 437         fd.addr1 = start;
 438         fd.addr2 = end;
 439         on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1);
 440 }
 441
 442 static void flush_tlb_page_ipi(void *info)
 443 {
 444         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 445
 446         local_flush_tlb_page(fd->vma, fd->addr1);
 447 }
 448
 449 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 450 {
 451         preempt_disable();
 452         if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
 453             (current->mm != vma->vm_mm)) {
 454                 struct flush_tlb_data fd;
 455
 456                 fd.vma = vma;
 457                 fd.addr1 = page;
 458                 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
 459         } else {
 460                 int i;
 461                 for (i = 0; i < num_online_cpus(); i++)
 462                         if (smp_processor_id() != i)
 463                                 cpu_context(i, vma->vm_mm) = 0;
 464         }
 465         local_flush_tlb_page(vma, page);
 466         preempt_enable();
 467 }
 468
 469 static void flush_tlb_one_ipi(void *info)
 470 {
 471         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 472         local_flush_tlb_one(fd->addr1, fd->addr2);
 473 }
 474
 475 void flush_tlb_one(unsigned long asid, unsigned long vaddr)
 476 {
 477         struct flush_tlb_data fd;
 478
 479         fd.addr1 = asid;
 480         fd.addr2 = vaddr;
 481
 482         smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1);
 483         local_flush_tlb_one(asid, vaddr);
 484 }