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/r4k-timer.h>
  41 #include <asm/system.h>
  42 #include <asm/mmu_context.h>
  43 #include <asm/time.h>
  44
  45 #ifdef CONFIG_MIPS_MT_SMTC
  46 #include <asm/mipsmtregs.h>
  47 #endif /* CONFIG_MIPS_MT_SMTC */
  48
  49 volatile cpumask_t cpu_callin_map;      /* Bitmask of started secondaries */
  50
  51 int __cpu_number_map[NR_CPUS];          /* Map physical to logical */
  52 EXPORT_SYMBOL(__cpu_number_map);
  53
  54 int __cpu_logical_map[NR_CPUS];         /* Map logical to physical */
  55 EXPORT_SYMBOL(__cpu_logical_map);
  56
  57 /* Number of TCs (or siblings in Intel speak) per CPU core */
  58 int smp_num_siblings = 1;
  59 EXPORT_SYMBOL(smp_num_siblings);
  60
  61 /* representing the TCs (or siblings in Intel speak) of each logical CPU */
  62 cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
  63 EXPORT_SYMBOL(cpu_sibling_map);
  64
  65 /* representing cpus for which sibling maps can be computed */
  66 static cpumask_t cpu_sibling_setup_map;
  67
  68 static inline void set_cpu_sibling_map(int cpu)
  69 {
  70         int i;
  71
  72         cpu_set(cpu, cpu_sibling_setup_map);
  73
  74         if (smp_num_siblings > 1) {
  75                 for_each_cpu_mask(i, cpu_sibling_setup_map) {
  76                         if (cpu_data[cpu].core == cpu_data[i].core) {
  77                                 cpu_set(i, cpu_sibling_map[cpu]);
  78                                 cpu_set(cpu, cpu_sibling_map[i]);
  79                         }
  80                 }
  81         } else
  82                 cpu_set(cpu, cpu_sibling_map[cpu]);
  83 }
  84
  85 struct plat_smp_ops *mp_ops;
  86
  87 __cpuinit void register_smp_ops(struct plat_smp_ops *ops)
  88 {
  89         if (mp_ops)
  90                 printk(KERN_WARNING "Overriding previously set SMP ops\n");
  91
  92         mp_ops = ops;
  93 }
  94
  95 /*
  96  * First C code run on the secondary CPUs after being started up by
  97  * the master.
  98  */
  99 asmlinkage __cpuinit void start_secondary(void)
 100 {
 101         unsigned int cpu;
 102
 103 #ifdef CONFIG_MIPS_MT_SMTC
 104         /* Only do cpu_probe for first TC of CPU */
 105         if ((read_c0_tcbind() & TCBIND_CURTC) == 0)
 106 #endif /* CONFIG_MIPS_MT_SMTC */
 107         cpu_probe();
 108         cpu_report();
 109         per_cpu_trap_init();
 110         mips_clockevent_init();
 111         mp_ops->init_secondary();
 112
 113         /*
 114          * XXX parity protection should be folded in here when it's converted
 115          * to an option instead of something based on .cputype
 116          */
 117
 118         calibrate_delay();
 119         preempt_disable();
 120         cpu = smp_processor_id();
 121         cpu_data[cpu].udelay_val = loops_per_jiffy;
 122
 123         notify_cpu_starting(cpu);
 124
 125         mp_ops->smp_finish();
 126         set_cpu_sibling_map(cpu);
 127
 128         cpu_set(cpu, cpu_callin_map);
 129
 130         synchronise_count_slave();
 131
 132         cpu_idle();
 133 }
 134
 135 /*
 136  * Call into both interrupt handlers, as we share the IPI for them
 137  */
 138 void __irq_entry smp_call_function_interrupt(void)
 139 {
 140         irq_enter();
 141         generic_smp_call_function_single_interrupt();
 142         generic_smp_call_function_interrupt();
 143         irq_exit();
 144 }
 145
 146 static void stop_this_cpu(void *dummy)
 147 {
 148         /*
 149          * Remove this CPU:
 150          */
 151         cpu_clear(smp_processor_id(), cpu_online_map);
 152         for (;;) {
 153                 if (cpu_wait)
 154                         (*cpu_wait)();          /* Wait if available. */
 155         }
 156 }
 157
 158 void smp_send_stop(void)
 159 {
 160         smp_call_function(stop_this_cpu, NULL, 0);
 161 }
 162
 163 void __init smp_cpus_done(unsigned int max_cpus)
 164 {
 165         mp_ops->cpus_done();
 166         synchronise_count_master();
 167 }
 168
 169 /* called from main before smp_init() */
 170 void __init smp_prepare_cpus(unsigned int max_cpus)
 171 {
 172         init_new_context(current, &init_mm);
 173         current_thread_info()->cpu = 0;
 174         mp_ops->prepare_cpus(max_cpus);
 175         set_cpu_sibling_map(0);
 176 #ifndef CONFIG_HOTPLUG_CPU
 177         init_cpu_present(&cpu_possible_map);
 178 #endif
 179 }
 180
 181 /* preload SMP state for boot cpu */
 182 void __devinit smp_prepare_boot_cpu(void)
 183 {
 184         set_cpu_possible(0, true);
 185         set_cpu_online(0, true);
 186         cpu_set(0, cpu_callin_map);
 187 }
 188
 189 /*
 190  * Called once for each "cpu_possible(cpu)".  Needs to spin up the cpu
 191  * and keep control until "cpu_online(cpu)" is set.  Note: cpu is
 192  * physical, not logical.
 193  */
 194 static struct task_struct *cpu_idle_thread[NR_CPUS];
 195
 196 struct create_idle {
 197         struct work_struct work;
 198         struct task_struct *idle;
 199         struct completion done;
 200         int cpu;
 201 };
 202
 203 static void __cpuinit do_fork_idle(struct work_struct *work)
 204 {
 205         struct create_idle *c_idle =
 206                 container_of(work, struct create_idle, work);
 207
 208         c_idle->idle = fork_idle(c_idle->cpu);
 209         complete(&c_idle->done);
 210 }
 211
 212 int __cpuinit __cpu_up(unsigned int cpu)
 213 {
 214         struct task_struct *idle;
 215
 216         /*
 217          * Processor goes to start_secondary(), sets online flag
 218          * The following code is purely to make sure
 219          * Linux can schedule processes on this slave.
 220          */
 221         if (!cpu_idle_thread[cpu]) {
 222                 /*
 223                  * Schedule work item to avoid forking user task
 224                  * Ported from arch/x86/kernel/smpboot.c
 225                  */
 226                 struct create_idle c_idle = {
 227                         .cpu    = cpu,
 228                         .done   = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
 229                 };
 230
 231                 INIT_WORK_ONSTACK(&c_idle.work, do_fork_idle);
 232                 schedule_work(&c_idle.work);
 233                 wait_for_completion(&c_idle.done);
 234                 idle = cpu_idle_thread[cpu] = c_idle.idle;
 235
 236                 if (IS_ERR(idle))
 237                         panic(KERN_ERR "Fork failed for CPU %d", cpu);
 238         } else {
 239                 idle = cpu_idle_thread[cpu];
 240                 init_idle(idle, cpu);
 241         }
 242
 243         mp_ops->boot_secondary(cpu, idle);
 244
 245         /*
 246          * Trust is futile.  We should really have timeouts ...
 247          */
 248         while (!cpu_isset(cpu, cpu_callin_map))
 249                 udelay(100);
 250
 251         cpu_set(cpu, cpu_online_map);
 252
 253         return 0;
 254 }
 255
 256 /* Not really SMP stuff ... */
 257 int setup_profiling_timer(unsigned int multiplier)
 258 {
 259         return 0;
 260 }
 261
 262 static void flush_tlb_all_ipi(void *info)
 263 {
 264         local_flush_tlb_all();
 265 }
 266
 267 void flush_tlb_all(void)
 268 {
 269         on_each_cpu(flush_tlb_all_ipi, NULL, 1);
 270 }
 271
 272 static void flush_tlb_mm_ipi(void *mm)
 273 {
 274         local_flush_tlb_mm((struct mm_struct *)mm);
 275 }
 276
 277 /*
 278  * Special Variant of smp_call_function for use by TLB functions:
 279  *
 280  *  o No return value
 281  *  o collapses to normal function call on UP kernels
 282  *  o collapses to normal function call on systems with a single shared
 283  *    primary cache.
 284  *  o CONFIG_MIPS_MT_SMTC currently implies there is only one physical core.
 285  */
 286 static inline void smp_on_other_tlbs(void (*func) (void *info), void *info)
 287 {
 288 #ifndef CONFIG_MIPS_MT_SMTC
 289         smp_call_function(func, info, 1);
 290 #endif
 291 }
 292
 293 static inline void smp_on_each_tlb(void (*func) (void *info), void *info)
 294 {
 295         preempt_disable();
 296
 297         smp_on_other_tlbs(func, info);
 298         func(info);
 299
 300         preempt_enable();
 301 }
 302
 303 /*
 304  * The following tlb flush calls are invoked when old translations are
 305  * being torn down, or pte attributes are changing. For single threaded
 306  * address spaces, a new context is obtained on the current cpu, and tlb
 307  * context on other cpus are invalidated to force a new context allocation
 308  * at switch_mm time, should the mm ever be used on other cpus. For
 309  * multithreaded address spaces, intercpu interrupts have to be sent.
 310  * Another case where intercpu interrupts are required is when the target
 311  * mm might be active on another cpu (eg debuggers doing the flushes on
 312  * behalf of debugees, kswapd stealing pages from another process etc).
 313  * Kanoj 07/00.
 314  */
 315
 316 void flush_tlb_mm(struct mm_struct *mm)
 317 {
 318         preempt_disable();
 319
 320         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 321                 smp_on_other_tlbs(flush_tlb_mm_ipi, mm);
 322         } else {
 323                 cpumask_t mask = cpu_online_map;
 324                 unsigned int cpu;
 325
 326                 cpu_clear(smp_processor_id(), mask);
 327                 for_each_cpu_mask(cpu, mask)
 328                         if (cpu_context(cpu, mm))
 329                                 cpu_context(cpu, mm) = 0;
 330         }
 331         local_flush_tlb_mm(mm);
 332
 333         preempt_enable();
 334 }
 335
 336 struct flush_tlb_data {
 337         struct vm_area_struct *vma;
 338         unsigned long addr1;
 339         unsigned long addr2;
 340 };
 341
 342 static void flush_tlb_range_ipi(void *info)
 343 {
 344         struct flush_tlb_data *fd = info;
 345
 346         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 347 }
 348
 349 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
 350 {
 351         struct mm_struct *mm = vma->vm_mm;
 352
 353         preempt_disable();
 354         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 355                 struct flush_tlb_data fd = {
 356                         .vma = vma,
 357                         .addr1 = start,
 358                         .addr2 = end,
 359                 };
 360
 361                 smp_on_other_tlbs(flush_tlb_range_ipi, &fd);
 362         } else {
 363                 cpumask_t mask = cpu_online_map;
 364                 unsigned int cpu;
 365
 366                 cpu_clear(smp_processor_id(), mask);
 367                 for_each_cpu_mask(cpu, mask)
 368                         if (cpu_context(cpu, mm))
 369                                 cpu_context(cpu, mm) = 0;
 370         }
 371         local_flush_tlb_range(vma, start, end);
 372         preempt_enable();
 373 }
 374
 375 static void flush_tlb_kernel_range_ipi(void *info)
 376 {
 377         struct flush_tlb_data *fd = info;
 378
 379         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 380 }
 381
 382 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 383 {
 384         struct flush_tlb_data fd = {
 385                 .addr1 = start,
 386                 .addr2 = end,
 387         };
 388
 389         on_each_cpu(flush_tlb_kernel_range_ipi, &fd, 1);
 390 }
 391
 392 static void flush_tlb_page_ipi(void *info)
 393 {
 394         struct flush_tlb_data *fd = info;
 395
 396         local_flush_tlb_page(fd->vma, fd->addr1);
 397 }
 398
 399 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 400 {
 401         preempt_disable();
 402         if ((atomic_read(&vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) {
 403                 struct flush_tlb_data fd = {
 404                         .vma = vma,
 405                         .addr1 = page,
 406                 };
 407
 408                 smp_on_other_tlbs(flush_tlb_page_ipi, &fd);
 409         } else {
 410                 cpumask_t mask = cpu_online_map;
 411                 unsigned int cpu;
 412
 413                 cpu_clear(smp_processor_id(), mask);
 414                 for_each_cpu_mask(cpu, mask)
 415                         if (cpu_context(cpu, vma->vm_mm))
 416                                 cpu_context(cpu, vma->vm_mm) = 0;
 417         }
 418         local_flush_tlb_page(vma, page);
 419         preempt_enable();
 420 }
 421
 422 static void flush_tlb_one_ipi(void *info)
 423 {
 424         unsigned long vaddr = (unsigned long) info;
 425
 426         local_flush_tlb_one(vaddr);
 427 }
 428
 429 void flush_tlb_one(unsigned long vaddr)
 430 {
 431         smp_on_each_tlb(flush_tlb_one_ipi, (void *) vaddr);
 432 }
 433
 434 EXPORT_SYMBOL(flush_tlb_page);
 435 EXPORT_SYMBOL(flush_tlb_one);