arch/mips/kernel/smp.c

   1 /*
   2  * This program is free software; you can redistribute it and/or
   3  * modify it under the terms of the GNU General Public License
   4  * as published by the Free Software Foundation; either version 2
   5  * of the License, or (at your option) any later version.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU General Public License
  13  * along with this program; if not, write to the Free Software
  14  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  15  *
  16  * Copyright (C) 2000, 2001 Kanoj Sarcar
  17  * Copyright (C) 2000, 2001 Ralf Baechle
  18  * Copyright (C) 2000, 2001 Silicon Graphics, Inc.
  19  * Copyright (C) 2000, 2001, 2003 Broadcom Corporation
  20  */
  21 #include <linux/cache.h>
  22 #include <linux/delay.h>
  23 #include <linux/init.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/smp.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/threads.h>
  28 #include <linux/module.h>
  29 #include <linux/time.h>
  30 #include <linux/timex.h>
  31 #include <linux/sched.h>
  32 #include <linux/cpumask.h>
  33 #include <linux/cpu.h>
  34 #include <linux/err.h>
  35 #include <linux/ftrace.h>
  36
  37 #include <linux/atomic.h>
  38 #include <asm/cpu.h>
  39 #include <asm/processor.h>
  40 #include <asm/idle.h>
  41 #include <asm/r4k-timer.h>
  42 #include <asm/mmu_context.h>
  43 #include <asm/time.h>
  44 #include <asm/setup.h>
  45 #include <asm/maar.h>
  46
  47 cpumask_t cpu_callin_map;               /* Bitmask of started secondaries */
  48
  49 int __cpu_number_map[NR_CPUS];          /* Map physical to logical */
  50 EXPORT_SYMBOL(__cpu_number_map);
  51
  52 int __cpu_logical_map[NR_CPUS];         /* Map logical to physical */
  53 EXPORT_SYMBOL(__cpu_logical_map);
  54
  55 /* Number of TCs (or siblings in Intel speak) per CPU core */
  56 int smp_num_siblings = 1;
  57 EXPORT_SYMBOL(smp_num_siblings);
  58
  59 /* representing the TCs (or siblings in Intel speak) of each logical CPU */
  60 cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
  61 EXPORT_SYMBOL(cpu_sibling_map);
  62
  63 /* representing the core map of multi-core chips of each logical CPU */
  64 cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
  65 EXPORT_SYMBOL(cpu_core_map);
  66
  67 static DECLARE_COMPLETION(cpu_starting);
  68 static DECLARE_COMPLETION(cpu_running);
  69
  70 /*
  71  * A logcal cpu mask containing only one VPE per core to
  72  * reduce the number of IPIs on large MT systems.
  73  */
  74 cpumask_t cpu_foreign_map __read_mostly;
  75 EXPORT_SYMBOL(cpu_foreign_map);
  76
  77 /* representing cpus for which sibling maps can be computed */
  78 static cpumask_t cpu_sibling_setup_map;
  79
  80 /* representing cpus for which core maps can be computed */
  81 static cpumask_t cpu_core_setup_map;
  82
  83 cpumask_t cpu_coherent_mask;
  84
  85 static inline void set_cpu_sibling_map(int cpu)
  86 {
  87         int i;
  88
  89         cpumask_set_cpu(cpu, &cpu_sibling_setup_map);
  90
  91         if (smp_num_siblings > 1) {
  92                 for_each_cpu(i, &cpu_sibling_setup_map) {
  93                         if (cpu_data[cpu].package == cpu_data[i].package &&
  94                                     cpu_data[cpu].core == cpu_data[i].core) {
  95                                 cpumask_set_cpu(i, &cpu_sibling_map[cpu]);
  96                                 cpumask_set_cpu(cpu, &cpu_sibling_map[i]);
  97                         }
  98                 }
  99         } else
 100                 cpumask_set_cpu(cpu, &cpu_sibling_map[cpu]);
 101 }
 102
 103 static inline void set_cpu_core_map(int cpu)
 104 {
 105         int i;
 106
 107         cpumask_set_cpu(cpu, &cpu_core_setup_map);
 108
 109         for_each_cpu(i, &cpu_core_setup_map) {
 110                 if (cpu_data[cpu].package == cpu_data[i].package) {
 111                         cpumask_set_cpu(i, &cpu_core_map[cpu]);
 112                         cpumask_set_cpu(cpu, &cpu_core_map[i]);
 113                 }
 114         }
 115 }
 116
 117 /*
 118  * Calculate a new cpu_foreign_map mask whenever a
 119  * new cpu appears or disappears.
 120  */
 121 void calculate_cpu_foreign_map(void)
 122 {
 123         int i, k, core_present;
 124         cpumask_t temp_foreign_map;
 125
 126         /* Re-calculate the mask */
 127         cpumask_clear(&temp_foreign_map);
 128         for_each_online_cpu(i) {
 129                 core_present = 0;
 130                 for_each_cpu(k, &temp_foreign_map)
 131                         if (cpu_data[i].package == cpu_data[k].package &&
 132                             cpu_data[i].core == cpu_data[k].core)
 133                                 core_present = 1;
 134                 if (!core_present)
 135                         cpumask_set_cpu(i, &temp_foreign_map);
 136         }
 137
 138         cpumask_copy(&cpu_foreign_map, &temp_foreign_map);
 139 }
 140
 141 struct plat_smp_ops *mp_ops;
 142 EXPORT_SYMBOL(mp_ops);
 143
 144 void register_smp_ops(struct plat_smp_ops *ops)
 145 {
 146         if (mp_ops)
 147                 printk(KERN_WARNING "Overriding previously set SMP ops\n");
 148
 149         mp_ops = ops;
 150 }
 151
 152 /*
 153  * First C code run on the secondary CPUs after being started up by
 154  * the master.
 155  */
 156 asmlinkage void start_secondary(void)
 157 {
 158         unsigned int cpu;
 159
 160         cpu_probe();
 161         per_cpu_trap_init(false);
 162         mips_clockevent_init();
 163         mp_ops->init_secondary();
 164         cpu_report();
 165         maar_init();
 166
 167         /*
 168          * XXX parity protection should be folded in here when it's converted
 169          * to an option instead of something based on .cputype
 170          */
 171
 172         calibrate_delay();
 173         preempt_disable();
 174         cpu = smp_processor_id();
 175         cpu_data[cpu].udelay_val = loops_per_jiffy;
 176
 177         cpumask_set_cpu(cpu, &cpu_coherent_mask);
 178         notify_cpu_starting(cpu);
 179
 180         /* Notify boot CPU that we're starting & ready to sync counters */
 181         complete(&cpu_starting);
 182
 183         synchronise_count_slave(cpu);
 184
 185         /* The CPU is running and counters synchronised, now mark it online */
 186         set_cpu_online(cpu, true);
 187
 188         set_cpu_sibling_map(cpu);
 189         set_cpu_core_map(cpu);
 190
 191         calculate_cpu_foreign_map();
 192
 193         /*
 194          * Notify boot CPU that we're up & online and it can safely return
 195          * from __cpu_up
 196          */
 197         complete(&cpu_running);
 198
 199         /*
 200          * irq will be enabled in ->smp_finish(), enabling it too early
 201          * is dangerous.
 202          */
 203         WARN_ON_ONCE(!irqs_disabled());
 204         mp_ops->smp_finish();
 205
 206         cpu_startup_entry(CPUHP_ONLINE);
 207 }
 208
 209 static void stop_this_cpu(void *dummy)
 210 {
 211         /*
 212          * Remove this CPU. Be a bit slow here and
 213          * set the bits for every online CPU so we don't miss
 214          * any IPI whilst taking this VPE down.
 215          */
 216
 217         cpumask_copy(&cpu_foreign_map, cpu_online_mask);
 218
 219         /* Make it visible to every other CPU */
 220         smp_mb();
 221
 222         set_cpu_online(smp_processor_id(), false);
 223         calculate_cpu_foreign_map();
 224         local_irq_disable();
 225         while (1);
 226 }
 227
 228 void smp_send_stop(void)
 229 {
 230         smp_call_function(stop_this_cpu, NULL, 0);
 231 }
 232
 233 void __init smp_cpus_done(unsigned int max_cpus)
 234 {
 235 }
 236
 237 /* called from main before smp_init() */
 238 void __init smp_prepare_cpus(unsigned int max_cpus)
 239 {
 240         init_new_context(current, &init_mm);
 241         current_thread_info()->cpu = 0;
 242         mp_ops->prepare_cpus(max_cpus);
 243         set_cpu_sibling_map(0);
 244         set_cpu_core_map(0);
 245         calculate_cpu_foreign_map();
 246 #ifndef CONFIG_HOTPLUG_CPU
 247         init_cpu_present(cpu_possible_mask);
 248 #endif
 249         cpumask_copy(&cpu_coherent_mask, cpu_possible_mask);
 250 }
 251
 252 /* preload SMP state for boot cpu */
 253 void smp_prepare_boot_cpu(void)
 254 {
 255         set_cpu_possible(0, true);
 256         set_cpu_online(0, true);
 257 }
 258
 259 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 260 {
 261         mp_ops->boot_secondary(cpu, tidle);
 262
 263         /* Wait for CPU to start and be ready to sync counters */
 264         if (!wait_for_completion_timeout(&cpu_starting,
 265                                          msecs_to_jiffies(1000))) {
 266                 pr_crit("CPU%u: failed to start\n", cpu);
 267                 return -EIO;
 268         }
 269
 270         synchronise_count_master(cpu);
 271
 272         /* Wait for CPU to finish startup & mark itself online before return */
 273         wait_for_completion(&cpu_running);
 274         return 0;
 275 }
 276
 277 /* Not really SMP stuff ... */
 278 int setup_profiling_timer(unsigned int multiplier)
 279 {
 280         return 0;
 281 }
 282
 283 static void flush_tlb_all_ipi(void *info)
 284 {
 285         local_flush_tlb_all();
 286 }
 287
 288 void flush_tlb_all(void)
 289 {
 290         on_each_cpu(flush_tlb_all_ipi, NULL, 1);
 291 }
 292
 293 static void flush_tlb_mm_ipi(void *mm)
 294 {
 295         local_flush_tlb_mm((struct mm_struct *)mm);
 296 }
 297
 298 /*
 299  * Special Variant of smp_call_function for use by TLB functions:
 300  *
 301  *  o No return value
 302  *  o collapses to normal function call on UP kernels
 303  *  o collapses to normal function call on systems with a single shared
 304  *    primary cache.
 305  */
 306 static inline void smp_on_other_tlbs(void (*func) (void *info), void *info)
 307 {
 308         smp_call_function(func, info, 1);
 309 }
 310
 311 static inline void smp_on_each_tlb(void (*func) (void *info), void *info)
 312 {
 313         preempt_disable();
 314
 315         smp_on_other_tlbs(func, info);
 316         func(info);
 317
 318         preempt_enable();
 319 }
 320
 321 /*
 322  * The following tlb flush calls are invoked when old translations are
 323  * being torn down, or pte attributes are changing. For single threaded
 324  * address spaces, a new context is obtained on the current cpu, and tlb
 325  * context on other cpus are invalidated to force a new context allocation
 326  * at switch_mm time, should the mm ever be used on other cpus. For
 327  * multithreaded address spaces, intercpu interrupts have to be sent.
 328  * Another case where intercpu interrupts are required is when the target
 329  * mm might be active on another cpu (eg debuggers doing the flushes on
 330  * behalf of debugees, kswapd stealing pages from another process etc).
 331  * Kanoj 07/00.
 332  */
 333
 334 void flush_tlb_mm(struct mm_struct *mm)
 335 {
 336         preempt_disable();
 337
 338         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 339                 smp_on_other_tlbs(flush_tlb_mm_ipi, mm);
 340         } else {
 341                 unsigned int cpu;
 342
 343                 for_each_online_cpu(cpu) {
 344                         if (cpu != smp_processor_id() && cpu_context(cpu, mm))
 345                                 cpu_context(cpu, mm) = 0;
 346                 }
 347         }
 348         local_flush_tlb_mm(mm);
 349
 350         preempt_enable();
 351 }
 352
 353 struct flush_tlb_data {
 354         struct vm_area_struct *vma;
 355         unsigned long addr1;
 356         unsigned long addr2;
 357 };
 358
 359 static void flush_tlb_range_ipi(void *info)
 360 {
 361         struct flush_tlb_data *fd = info;
 362
 363         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 364 }
 365
 366 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
 367 {
 368         struct mm_struct *mm = vma->vm_mm;
 369
 370         preempt_disable();
 371         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 372                 struct flush_tlb_data fd = {
 373                         .vma = vma,
 374                         .addr1 = start,
 375                         .addr2 = end,
 376                 };
 377
 378                 smp_on_other_tlbs(flush_tlb_range_ipi, &fd);
 379         } else {
 380                 unsigned int cpu;
 381
 382                 for_each_online_cpu(cpu) {
 383                         if (cpu != smp_processor_id() && cpu_context(cpu, mm))
 384                                 cpu_context(cpu, mm) = 0;
 385                 }
 386         }
 387         local_flush_tlb_range(vma, start, end);
 388         preempt_enable();
 389 }
 390
 391 static void flush_tlb_kernel_range_ipi(void *info)
 392 {
 393         struct flush_tlb_data *fd = info;
 394
 395         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 396 }
 397
 398 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 399 {
 400         struct flush_tlb_data fd = {
 401                 .addr1 = start,
 402                 .addr2 = end,
 403         };
 404
 405         on_each_cpu(flush_tlb_kernel_range_ipi, &fd, 1);
 406 }
 407
 408 static void flush_tlb_page_ipi(void *info)
 409 {
 410         struct flush_tlb_data *fd = info;
 411
 412         local_flush_tlb_page(fd->vma, fd->addr1);
 413 }
 414
 415 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 416 {
 417         preempt_disable();
 418         if ((atomic_read(&vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) {
 419                 struct flush_tlb_data fd = {
 420                         .vma = vma,
 421                         .addr1 = page,
 422                 };
 423
 424                 smp_on_other_tlbs(flush_tlb_page_ipi, &fd);
 425         } else {
 426                 unsigned int cpu;
 427
 428                 for_each_online_cpu(cpu) {
 429                         if (cpu != smp_processor_id() && cpu_context(cpu, vma->vm_mm))
 430                                 cpu_context(cpu, vma->vm_mm) = 0;
 431                 }
 432         }
 433         local_flush_tlb_page(vma, page);
 434         preempt_enable();
 435 }
 436
 437 static void flush_tlb_one_ipi(void *info)
 438 {
 439         unsigned long vaddr = (unsigned long) info;
 440
 441         local_flush_tlb_one(vaddr);
 442 }
 443
 444 void flush_tlb_one(unsigned long vaddr)
 445 {
 446         smp_on_each_tlb(flush_tlb_one_ipi, (void *) vaddr);
 447 }
 448
 449 EXPORT_SYMBOL(flush_tlb_page);
 450 EXPORT_SYMBOL(flush_tlb_one);
 451
 452 #if defined(CONFIG_KEXEC)
 453 void (*dump_ipi_function_ptr)(void *) = NULL;
 454 void dump_send_ipi(void (*dump_ipi_callback)(void *))
 455 {
 456         int i;
 457         int cpu = smp_processor_id();
 458
 459         dump_ipi_function_ptr = dump_ipi_callback;
 460         smp_mb();
 461         for_each_online_cpu(i)
 462                 if (i != cpu)
 463                         mp_ops->send_ipi_single(i, SMP_DUMP);
 464
 465 }
 466 EXPORT_SYMBOL(dump_send_ipi);
 467 #endif
 468
 469 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 470
 471 static DEFINE_PER_CPU(atomic_t, tick_broadcast_count);
 472 static DEFINE_PER_CPU(struct call_single_data, tick_broadcast_csd);
 473
 474 void tick_broadcast(const struct cpumask *mask)
 475 {
 476         atomic_t *count;
 477         struct call_single_data *csd;
 478         int cpu;
 479
 480         for_each_cpu(cpu, mask) {
 481                 count = &per_cpu(tick_broadcast_count, cpu);
 482                 csd = &per_cpu(tick_broadcast_csd, cpu);
 483
 484                 if (atomic_inc_return(count) == 1)
 485                         smp_call_function_single_async(cpu, csd);
 486         }
 487 }
 488
 489 static void tick_broadcast_callee(void *info)
 490 {
 491         int cpu = smp_processor_id();
 492         tick_receive_broadcast();
 493         atomic_set(&per_cpu(tick_broadcast_count, cpu), 0);
 494 }
 495
 496 static int __init tick_broadcast_init(void)
 497 {
 498         struct call_single_data *csd;
 499         int cpu;
 500
 501         for (cpu = 0; cpu < NR_CPUS; cpu++) {
 502                 csd = &per_cpu(tick_broadcast_csd, cpu);
 503                 csd->func = tick_broadcast_callee;
 504         }
 505
 506         return 0;
 507 }
 508 early_initcall(tick_broadcast_init);
 509
 510 #endif /* CONFIG_GENERIC_CLOCKEVENTS_BROADCAST */