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
  46 cpumask_t cpu_callin_map;               /* Bitmask of started secondaries */
  47
  48 int __cpu_number_map[NR_CPUS];          /* Map physical to logical */
  49 EXPORT_SYMBOL(__cpu_number_map);
  50
  51 int __cpu_logical_map[NR_CPUS];         /* Map logical to physical */
  52 EXPORT_SYMBOL(__cpu_logical_map);
  53
  54 /* Number of TCs (or siblings in Intel speak) per CPU core */
  55 int smp_num_siblings = 1;
  56 EXPORT_SYMBOL(smp_num_siblings);
  57
  58 /* representing the TCs (or siblings in Intel speak) of each logical CPU */
  59 cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
  60 EXPORT_SYMBOL(cpu_sibling_map);
  61
  62 /* representing the core map of multi-core chips of each logical CPU */
  63 cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
  64 EXPORT_SYMBOL(cpu_core_map);
  65
  66 /* representing cpus for which sibling maps can be computed */
  67 static cpumask_t cpu_sibling_setup_map;
  68
  69 /* representing cpus for which core maps can be computed */
  70 static cpumask_t cpu_core_setup_map;
  71
  72 cpumask_t cpu_coherent_mask;
  73
  74 static inline void set_cpu_sibling_map(int cpu)
  75 {
  76         int i;
  77
  78         cpumask_set_cpu(cpu, &cpu_sibling_setup_map);
  79
  80         if (smp_num_siblings > 1) {
  81                 for_each_cpu(i, &cpu_sibling_setup_map) {
  82                         if (cpu_data[cpu].package == cpu_data[i].package &&
  83                                     cpu_data[cpu].core == cpu_data[i].core) {
  84                                 cpumask_set_cpu(i, &cpu_sibling_map[cpu]);
  85                                 cpumask_set_cpu(cpu, &cpu_sibling_map[i]);
  86                         }
  87                 }
  88         } else
  89                 cpumask_set_cpu(cpu, &cpu_sibling_map[cpu]);
  90 }
  91
  92 static inline void set_cpu_core_map(int cpu)
  93 {
  94         int i;
  95
  96         cpumask_set_cpu(cpu, &cpu_core_setup_map);
  97
  98         for_each_cpu(i, &cpu_core_setup_map) {
  99                 if (cpu_data[cpu].package == cpu_data[i].package) {
 100                         cpumask_set_cpu(i, &cpu_core_map[cpu]);
 101                         cpumask_set_cpu(cpu, &cpu_core_map[i]);
 102                 }
 103         }
 104 }
 105
 106 struct plat_smp_ops *mp_ops;
 107 EXPORT_SYMBOL(mp_ops);
 108
 109 void register_smp_ops(struct plat_smp_ops *ops)
 110 {
 111         if (mp_ops)
 112                 printk(KERN_WARNING "Overriding previously set SMP ops\n");
 113
 114         mp_ops = ops;
 115 }
 116
 117 /*
 118  * First C code run on the secondary CPUs after being started up by
 119  * the master.
 120  */
 121 asmlinkage void start_secondary(void)
 122 {
 123         unsigned int cpu;
 124
 125         cpu_probe();
 126         per_cpu_trap_init(false);
 127         mips_clockevent_init();
 128         mp_ops->init_secondary();
 129         cpu_report();
 130
 131         /*
 132          * XXX parity protection should be folded in here when it's converted
 133          * to an option instead of something based on .cputype
 134          */
 135
 136         calibrate_delay();
 137         preempt_disable();
 138         cpu = smp_processor_id();
 139         cpu_data[cpu].udelay_val = loops_per_jiffy;
 140
 141         cpumask_set_cpu(cpu, &cpu_coherent_mask);
 142         notify_cpu_starting(cpu);
 143
 144         set_cpu_online(cpu, true);
 145
 146         set_cpu_sibling_map(cpu);
 147         set_cpu_core_map(cpu);
 148
 149         cpumask_set_cpu(cpu, &cpu_callin_map);
 150
 151         synchronise_count_slave(cpu);
 152
 153         /*
 154          * irq will be enabled in ->smp_finish(), enabling it too early
 155          * is dangerous.
 156          */
 157         WARN_ON_ONCE(!irqs_disabled());
 158         mp_ops->smp_finish();
 159
 160         cpu_startup_entry(CPUHP_ONLINE);
 161 }
 162
 163 /*
 164  * Call into both interrupt handlers, as we share the IPI for them
 165  */
 166 void __irq_entry smp_call_function_interrupt(void)
 167 {
 168         irq_enter();
 169         generic_smp_call_function_interrupt();
 170         irq_exit();
 171 }
 172
 173 static void stop_this_cpu(void *dummy)
 174 {
 175         /*
 176          * Remove this CPU:
 177          */
 178         set_cpu_online(smp_processor_id(), false);
 179         local_irq_disable();
 180         while (1);
 181 }
 182
 183 void smp_send_stop(void)
 184 {
 185         smp_call_function(stop_this_cpu, NULL, 0);
 186 }
 187
 188 void __init smp_cpus_done(unsigned int max_cpus)
 189 {
 190 }
 191
 192 /* called from main before smp_init() */
 193 void __init smp_prepare_cpus(unsigned int max_cpus)
 194 {
 195         init_new_context(current, &init_mm);
 196         current_thread_info()->cpu = 0;
 197         mp_ops->prepare_cpus(max_cpus);
 198         set_cpu_sibling_map(0);
 199         set_cpu_core_map(0);
 200 #ifndef CONFIG_HOTPLUG_CPU
 201         init_cpu_present(cpu_possible_mask);
 202 #endif
 203         cpumask_copy(&cpu_coherent_mask, cpu_possible_mask);
 204 }
 205
 206 /* preload SMP state for boot cpu */
 207 void smp_prepare_boot_cpu(void)
 208 {
 209         set_cpu_possible(0, true);
 210         set_cpu_online(0, true);
 211         cpumask_set_cpu(0, &cpu_callin_map);
 212 }
 213
 214 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 215 {
 216         mp_ops->boot_secondary(cpu, tidle);
 217
 218         /*
 219          * Trust is futile.  We should really have timeouts ...
 220          */
 221         while (!cpumask_test_cpu(cpu, &cpu_callin_map)) {
 222                 udelay(100);
 223                 schedule();
 224         }
 225
 226         synchronise_count_master(cpu);
 227         return 0;
 228 }
 229
 230 /* Not really SMP stuff ... */
 231 int setup_profiling_timer(unsigned int multiplier)
 232 {
 233         return 0;
 234 }
 235
 236 static void flush_tlb_all_ipi(void *info)
 237 {
 238         local_flush_tlb_all();
 239 }
 240
 241 void flush_tlb_all(void)
 242 {
 243         on_each_cpu(flush_tlb_all_ipi, NULL, 1);
 244 }
 245
 246 static void flush_tlb_mm_ipi(void *mm)
 247 {
 248         local_flush_tlb_mm((struct mm_struct *)mm);
 249 }
 250
 251 /*
 252  * Special Variant of smp_call_function for use by TLB functions:
 253  *
 254  *  o No return value
 255  *  o collapses to normal function call on UP kernels
 256  *  o collapses to normal function call on systems with a single shared
 257  *    primary cache.
 258  */
 259 static inline void smp_on_other_tlbs(void (*func) (void *info), void *info)
 260 {
 261         smp_call_function(func, info, 1);
 262 }
 263
 264 static inline void smp_on_each_tlb(void (*func) (void *info), void *info)
 265 {
 266         preempt_disable();
 267
 268         smp_on_other_tlbs(func, info);
 269         func(info);
 270
 271         preempt_enable();
 272 }
 273
 274 /*
 275  * The following tlb flush calls are invoked when old translations are
 276  * being torn down, or pte attributes are changing. For single threaded
 277  * address spaces, a new context is obtained on the current cpu, and tlb
 278  * context on other cpus are invalidated to force a new context allocation
 279  * at switch_mm time, should the mm ever be used on other cpus. For
 280  * multithreaded address spaces, intercpu interrupts have to be sent.
 281  * Another case where intercpu interrupts are required is when the target
 282  * mm might be active on another cpu (eg debuggers doing the flushes on
 283  * behalf of debugees, kswapd stealing pages from another process etc).
 284  * Kanoj 07/00.
 285  */
 286
 287 void flush_tlb_mm(struct mm_struct *mm)
 288 {
 289         preempt_disable();
 290
 291         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 292                 smp_on_other_tlbs(flush_tlb_mm_ipi, mm);
 293         } else {
 294                 unsigned int cpu;
 295
 296                 for_each_online_cpu(cpu) {
 297                         if (cpu != smp_processor_id() && cpu_context(cpu, mm))
 298                                 cpu_context(cpu, mm) = 0;
 299                 }
 300         }
 301         local_flush_tlb_mm(mm);
 302
 303         preempt_enable();
 304 }
 305
 306 struct flush_tlb_data {
 307         struct vm_area_struct *vma;
 308         unsigned long addr1;
 309         unsigned long addr2;
 310 };
 311
 312 static void flush_tlb_range_ipi(void *info)
 313 {
 314         struct flush_tlb_data *fd = info;
 315
 316         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 317 }
 318
 319 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
 320 {
 321         struct mm_struct *mm = vma->vm_mm;
 322
 323         preempt_disable();
 324         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 325                 struct flush_tlb_data fd = {
 326                         .vma = vma,
 327                         .addr1 = start,
 328                         .addr2 = end,
 329                 };
 330
 331                 smp_on_other_tlbs(flush_tlb_range_ipi, &fd);
 332         } else {
 333                 unsigned int cpu;
 334
 335                 for_each_online_cpu(cpu) {
 336                         if (cpu != smp_processor_id() && cpu_context(cpu, mm))
 337                                 cpu_context(cpu, mm) = 0;
 338                 }
 339         }
 340         local_flush_tlb_range(vma, start, end);
 341         preempt_enable();
 342 }
 343
 344 static void flush_tlb_kernel_range_ipi(void *info)
 345 {
 346         struct flush_tlb_data *fd = info;
 347
 348         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 349 }
 350
 351 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 352 {
 353         struct flush_tlb_data fd = {
 354                 .addr1 = start,
 355                 .addr2 = end,
 356         };
 357
 358         on_each_cpu(flush_tlb_kernel_range_ipi, &fd, 1);
 359 }
 360
 361 static void flush_tlb_page_ipi(void *info)
 362 {
 363         struct flush_tlb_data *fd = info;
 364
 365         local_flush_tlb_page(fd->vma, fd->addr1);
 366 }
 367
 368 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 369 {
 370         preempt_disable();
 371         if ((atomic_read(&vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) {
 372                 struct flush_tlb_data fd = {
 373                         .vma = vma,
 374                         .addr1 = page,
 375                 };
 376
 377                 smp_on_other_tlbs(flush_tlb_page_ipi, &fd);
 378         } else {
 379                 unsigned int cpu;
 380
 381                 for_each_online_cpu(cpu) {
 382                         if (cpu != smp_processor_id() && cpu_context(cpu, vma->vm_mm))
 383                                 cpu_context(cpu, vma->vm_mm) = 0;
 384                 }
 385         }
 386         local_flush_tlb_page(vma, page);
 387         preempt_enable();
 388 }
 389
 390 static void flush_tlb_one_ipi(void *info)
 391 {
 392         unsigned long vaddr = (unsigned long) info;
 393
 394         local_flush_tlb_one(vaddr);
 395 }
 396
 397 void flush_tlb_one(unsigned long vaddr)
 398 {
 399         smp_on_each_tlb(flush_tlb_one_ipi, (void *) vaddr);
 400 }
 401
 402 EXPORT_SYMBOL(flush_tlb_page);
 403 EXPORT_SYMBOL(flush_tlb_one);
 404
 405 #if defined(CONFIG_KEXEC)
 406 void (*dump_ipi_function_ptr)(void *) = NULL;
 407 void dump_send_ipi(void (*dump_ipi_callback)(void *))
 408 {
 409         int i;
 410         int cpu = smp_processor_id();
 411
 412         dump_ipi_function_ptr = dump_ipi_callback;
 413         smp_mb();
 414         for_each_online_cpu(i)
 415                 if (i != cpu)
 416                         mp_ops->send_ipi_single(i, SMP_DUMP);
 417
 418 }
 419 EXPORT_SYMBOL(dump_send_ipi);
 420 #endif
 421
 422 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 423
 424 static DEFINE_PER_CPU(atomic_t, tick_broadcast_count);
 425 static DEFINE_PER_CPU(struct call_single_data, tick_broadcast_csd);
 426
 427 void tick_broadcast(const struct cpumask *mask)
 428 {
 429         atomic_t *count;
 430         struct call_single_data *csd;
 431         int cpu;
 432
 433         for_each_cpu(cpu, mask) {
 434                 count = &per_cpu(tick_broadcast_count, cpu);
 435                 csd = &per_cpu(tick_broadcast_csd, cpu);
 436
 437                 if (atomic_inc_return(count) == 1)
 438                         smp_call_function_single_async(cpu, csd);
 439         }
 440 }
 441
 442 static void tick_broadcast_callee(void *info)
 443 {
 444         int cpu = smp_processor_id();
 445         tick_receive_broadcast();
 446         atomic_set(&per_cpu(tick_broadcast_count, cpu), 0);
 447 }
 448
 449 static int __init tick_broadcast_init(void)
 450 {
 451         struct call_single_data *csd;
 452         int cpu;
 453
 454         for (cpu = 0; cpu < NR_CPUS; cpu++) {
 455                 csd = &per_cpu(tick_broadcast_csd, cpu);
 456                 csd->func = tick_broadcast_callee;
 457         }
 458
 459         return 0;
 460 }
 461 early_initcall(tick_broadcast_init);
 462
 463 #endif /* CONFIG_GENERIC_CLOCKEVENTS_BROADCAST */