~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/mips/kernel/smp.c

Version: ~ [ linux-5.2-rc1 ] ~ [ linux-5.1.2 ] ~ [ linux-5.0.16 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.43 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.119 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.176 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.179 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.139 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.67 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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/export.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 #include <linux/irqdomain.h>
 37 #include <linux/of.h>
 38 #include <linux/of_irq.h>
 39 
 40 #include <linux/atomic.h>
 41 #include <asm/cpu.h>
 42 #include <asm/processor.h>
 43 #include <asm/idle.h>
 44 #include <asm/r4k-timer.h>
 45 #include <asm/mips-cpc.h>
 46 #include <asm/mmu_context.h>
 47 #include <asm/time.h>
 48 #include <asm/setup.h>
 49 #include <asm/maar.h>
 50 
 51 cpumask_t cpu_callin_map;               /* Bitmask of started secondaries */
 52 
 53 int __cpu_number_map[NR_CPUS];          /* Map physical to logical */
 54 EXPORT_SYMBOL(__cpu_number_map);
 55 
 56 int __cpu_logical_map[NR_CPUS];         /* Map logical to physical */
 57 EXPORT_SYMBOL(__cpu_logical_map);
 58 
 59 /* Number of TCs (or siblings in Intel speak) per CPU core */
 60 int smp_num_siblings = 1;
 61 EXPORT_SYMBOL(smp_num_siblings);
 62 
 63 /* representing the TCs (or siblings in Intel speak) of each logical CPU */
 64 cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
 65 EXPORT_SYMBOL(cpu_sibling_map);
 66 
 67 /* representing the core map of multi-core chips of each logical CPU */
 68 cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
 69 EXPORT_SYMBOL(cpu_core_map);
 70 
 71 /*
 72  * A logcal cpu mask containing only one VPE per core to
 73  * reduce the number of IPIs on large MT systems.
 74  */
 75 cpumask_t cpu_foreign_map[NR_CPUS] __read_mostly;
 76 EXPORT_SYMBOL(cpu_foreign_map);
 77 
 78 /* representing cpus for which sibling maps can be computed */
 79 static cpumask_t cpu_sibling_setup_map;
 80 
 81 /* representing cpus for which core maps can be computed */
 82 static cpumask_t cpu_core_setup_map;
 83 
 84 cpumask_t cpu_coherent_mask;
 85 
 86 #ifdef CONFIG_GENERIC_IRQ_IPI
 87 static struct irq_desc *call_desc;
 88 static struct irq_desc *sched_desc;
 89 #endif
 90 
 91 static inline void set_cpu_sibling_map(int cpu)
 92 {
 93         int i;
 94 
 95         cpumask_set_cpu(cpu, &cpu_sibling_setup_map);
 96 
 97         if (smp_num_siblings > 1) {
 98                 for_each_cpu(i, &cpu_sibling_setup_map) {
 99                         if (cpu_data[cpu].package == cpu_data[i].package &&
100                                     cpu_data[cpu].core == cpu_data[i].core) {
101                                 cpumask_set_cpu(i, &cpu_sibling_map[cpu]);
102                                 cpumask_set_cpu(cpu, &cpu_sibling_map[i]);
103                         }
104                 }
105         } else
106                 cpumask_set_cpu(cpu, &cpu_sibling_map[cpu]);
107 }
108 
109 static inline void set_cpu_core_map(int cpu)
110 {
111         int i;
112 
113         cpumask_set_cpu(cpu, &cpu_core_setup_map);
114 
115         for_each_cpu(i, &cpu_core_setup_map) {
116                 if (cpu_data[cpu].package == cpu_data[i].package) {
117                         cpumask_set_cpu(i, &cpu_core_map[cpu]);
118                         cpumask_set_cpu(cpu, &cpu_core_map[i]);
119                 }
120         }
121 }
122 
123 /*
124  * Calculate a new cpu_foreign_map mask whenever a
125  * new cpu appears or disappears.
126  */
127 void calculate_cpu_foreign_map(void)
128 {
129         int i, k, core_present;
130         cpumask_t temp_foreign_map;
131 
132         /* Re-calculate the mask */
133         cpumask_clear(&temp_foreign_map);
134         for_each_online_cpu(i) {
135                 core_present = 0;
136                 for_each_cpu(k, &temp_foreign_map)
137                         if (cpu_data[i].package == cpu_data[k].package &&
138                             cpu_data[i].core == cpu_data[k].core)
139                                 core_present = 1;
140                 if (!core_present)
141                         cpumask_set_cpu(i, &temp_foreign_map);
142         }
143 
144         for_each_online_cpu(i)
145                 cpumask_andnot(&cpu_foreign_map[i],
146                                &temp_foreign_map, &cpu_sibling_map[i]);
147 }
148 
149 struct plat_smp_ops *mp_ops;
150 EXPORT_SYMBOL(mp_ops);
151 
152 void register_smp_ops(struct plat_smp_ops *ops)
153 {
154         if (mp_ops)
155                 printk(KERN_WARNING "Overriding previously set SMP ops\n");
156 
157         mp_ops = ops;
158 }
159 
160 #ifdef CONFIG_GENERIC_IRQ_IPI
161 void mips_smp_send_ipi_single(int cpu, unsigned int action)
162 {
163         mips_smp_send_ipi_mask(cpumask_of(cpu), action);
164 }
165 
166 void mips_smp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
167 {
168         unsigned long flags;
169         unsigned int core;
170         int cpu;
171 
172         local_irq_save(flags);
173 
174         switch (action) {
175         case SMP_CALL_FUNCTION:
176                 __ipi_send_mask(call_desc, mask);
177                 break;
178 
179         case SMP_RESCHEDULE_YOURSELF:
180                 __ipi_send_mask(sched_desc, mask);
181                 break;
182 
183         default:
184                 BUG();
185         }
186 
187         if (mips_cpc_present()) {
188                 for_each_cpu(cpu, mask) {
189                         core = cpu_data[cpu].core;
190 
191                         if (core == current_cpu_data.core)
192                                 continue;
193 
194                         while (!cpumask_test_cpu(cpu, &cpu_coherent_mask)) {
195                                 mips_cm_lock_other(core, 0);
196                                 mips_cpc_lock_other(core);
197                                 write_cpc_co_cmd(CPC_Cx_CMD_PWRUP);
198                                 mips_cpc_unlock_other();
199                                 mips_cm_unlock_other();
200                         }
201                 }
202         }
203 
204         local_irq_restore(flags);
205 }
206 
207 
208 static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
209 {
210         scheduler_ipi();
211 
212         return IRQ_HANDLED;
213 }
214 
215 static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
216 {
217         generic_smp_call_function_interrupt();
218 
219         return IRQ_HANDLED;
220 }
221 
222 static struct irqaction irq_resched = {
223         .handler        = ipi_resched_interrupt,
224         .flags          = IRQF_PERCPU,
225         .name           = "IPI resched"
226 };
227 
228 static struct irqaction irq_call = {
229         .handler        = ipi_call_interrupt,
230         .flags          = IRQF_PERCPU,
231         .name           = "IPI call"
232 };
233 
234 static void smp_ipi_init_one(unsigned int virq,
235                                     struct irqaction *action)
236 {
237         int ret;
238 
239         irq_set_handler(virq, handle_percpu_irq);
240         ret = setup_irq(virq, action);
241         BUG_ON(ret);
242 }
243 
244 static unsigned int call_virq, sched_virq;
245 
246 int mips_smp_ipi_allocate(const struct cpumask *mask)
247 {
248         int virq;
249         struct irq_domain *ipidomain;
250         struct device_node *node;
251 
252         node = of_irq_find_parent(of_root);
253         ipidomain = irq_find_matching_host(node, DOMAIN_BUS_IPI);
254 
255         /*
256          * Some platforms have half DT setup. So if we found irq node but
257          * didn't find an ipidomain, try to search for one that is not in the
258          * DT.
259          */
260         if (node && !ipidomain)
261                 ipidomain = irq_find_matching_host(NULL, DOMAIN_BUS_IPI);
262 
263         /*
264          * There are systems which only use IPI domains some of the time,
265          * depending upon configuration we don't know until runtime. An
266          * example is Malta where we may compile in support for GIC & the
267          * MT ASE, but run on a system which has multiple VPEs in a single
268          * core and doesn't include a GIC. Until all IPI implementations
269          * have been converted to use IPI domains the best we can do here
270          * is to return & hope some other code sets up the IPIs.
271          */
272         if (!ipidomain)
273                 return 0;
274 
275         virq = irq_reserve_ipi(ipidomain, mask);
276         BUG_ON(!virq);
277         if (!call_virq)
278                 call_virq = virq;
279 
280         virq = irq_reserve_ipi(ipidomain, mask);
281         BUG_ON(!virq);
282         if (!sched_virq)
283                 sched_virq = virq;
284 
285         if (irq_domain_is_ipi_per_cpu(ipidomain)) {
286                 int cpu;
287 
288                 for_each_cpu(cpu, mask) {
289                         smp_ipi_init_one(call_virq + cpu, &irq_call);
290                         smp_ipi_init_one(sched_virq + cpu, &irq_resched);
291                 }
292         } else {
293                 smp_ipi_init_one(call_virq, &irq_call);
294                 smp_ipi_init_one(sched_virq, &irq_resched);
295         }
296 
297         return 0;
298 }
299 
300 int mips_smp_ipi_free(const struct cpumask *mask)
301 {
302         struct irq_domain *ipidomain;
303         struct device_node *node;
304 
305         node = of_irq_find_parent(of_root);
306         ipidomain = irq_find_matching_host(node, DOMAIN_BUS_IPI);
307 
308         /*
309          * Some platforms have half DT setup. So if we found irq node but
310          * didn't find an ipidomain, try to search for one that is not in the
311          * DT.
312          */
313         if (node && !ipidomain)
314                 ipidomain = irq_find_matching_host(NULL, DOMAIN_BUS_IPI);
315 
316         BUG_ON(!ipidomain);
317 
318         if (irq_domain_is_ipi_per_cpu(ipidomain)) {
319                 int cpu;
320 
321                 for_each_cpu(cpu, mask) {
322                         remove_irq(call_virq + cpu, &irq_call);
323                         remove_irq(sched_virq + cpu, &irq_resched);
324                 }
325         }
326         irq_destroy_ipi(call_virq, mask);
327         irq_destroy_ipi(sched_virq, mask);
328         return 0;
329 }
330 
331 
332 static int __init mips_smp_ipi_init(void)
333 {
334         mips_smp_ipi_allocate(cpu_possible_mask);
335 
336         call_desc = irq_to_desc(call_virq);
337         sched_desc = irq_to_desc(sched_virq);
338 
339         return 0;
340 }
341 early_initcall(mips_smp_ipi_init);
342 #endif
343 
344 /*
345  * First C code run on the secondary CPUs after being started up by
346  * the master.
347  */
348 asmlinkage void start_secondary(void)
349 {
350         unsigned int cpu;
351 
352         cpu_probe();
353         per_cpu_trap_init(false);
354         mips_clockevent_init();
355         mp_ops->init_secondary();
356         cpu_report();
357         maar_init();
358 
359         /*
360          * XXX parity protection should be folded in here when it's converted
361          * to an option instead of something based on .cputype
362          */
363 
364         calibrate_delay();
365         preempt_disable();
366         cpu = smp_processor_id();
367         cpu_data[cpu].udelay_val = loops_per_jiffy;
368 
369         cpumask_set_cpu(cpu, &cpu_coherent_mask);
370         notify_cpu_starting(cpu);
371 
372         cpumask_set_cpu(cpu, &cpu_callin_map);
373         synchronise_count_slave(cpu);
374 
375         set_cpu_online(cpu, true);
376 
377         set_cpu_sibling_map(cpu);
378         set_cpu_core_map(cpu);
379 
380         calculate_cpu_foreign_map();
381 
382         /*
383          * irq will be enabled in ->smp_finish(), enabling it too early
384          * is dangerous.
385          */
386         WARN_ON_ONCE(!irqs_disabled());
387         mp_ops->smp_finish();
388 
389         cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
390 }
391 
392 static void stop_this_cpu(void *dummy)
393 {
394         /*
395          * Remove this CPU:
396          */
397 
398         set_cpu_online(smp_processor_id(), false);
399         calculate_cpu_foreign_map();
400         local_irq_disable();
401         while (1);
402 }
403 
404 void smp_send_stop(void)
405 {
406         smp_call_function(stop_this_cpu, NULL, 0);
407 }
408 
409 void __init smp_cpus_done(unsigned int max_cpus)
410 {
411 }
412 
413 /* called from main before smp_init() */
414 void __init smp_prepare_cpus(unsigned int max_cpus)
415 {
416         init_new_context(current, &init_mm);
417         current_thread_info()->cpu = 0;
418         mp_ops->prepare_cpus(max_cpus);
419         set_cpu_sibling_map(0);
420         set_cpu_core_map(0);
421         calculate_cpu_foreign_map();
422 #ifndef CONFIG_HOTPLUG_CPU
423         init_cpu_present(cpu_possible_mask);
424 #endif
425         cpumask_copy(&cpu_coherent_mask, cpu_possible_mask);
426 }
427 
428 /* preload SMP state for boot cpu */
429 void smp_prepare_boot_cpu(void)
430 {
431         set_cpu_possible(0, true);
432         set_cpu_online(0, true);
433         cpumask_set_cpu(0, &cpu_callin_map);
434 }
435 
436 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
437 {
438         mp_ops->boot_secondary(cpu, tidle);
439 
440         /*
441          * Trust is futile.  We should really have timeouts ...
442          */
443         while (!cpumask_test_cpu(cpu, &cpu_callin_map)) {
444                 udelay(100);
445                 schedule();
446         }
447 
448         synchronise_count_master(cpu);
449         return 0;
450 }
451 
452 /* Not really SMP stuff ... */
453 int setup_profiling_timer(unsigned int multiplier)
454 {
455         return 0;
456 }
457 
458 static void flush_tlb_all_ipi(void *info)
459 {
460         local_flush_tlb_all();
461 }
462 
463 void flush_tlb_all(void)
464 {
465         on_each_cpu(flush_tlb_all_ipi, NULL, 1);
466 }
467 
468 static void flush_tlb_mm_ipi(void *mm)
469 {
470         local_flush_tlb_mm((struct mm_struct *)mm);
471 }
472 
473 /*
474  * Special Variant of smp_call_function for use by TLB functions:
475  *
476  *  o No return value
477  *  o collapses to normal function call on UP kernels
478  *  o collapses to normal function call on systems with a single shared
479  *    primary cache.
480  */
481 static inline void smp_on_other_tlbs(void (*func) (void *info), void *info)
482 {
483         smp_call_function(func, info, 1);
484 }
485 
486 static inline void smp_on_each_tlb(void (*func) (void *info), void *info)
487 {
488         preempt_disable();
489 
490         smp_on_other_tlbs(func, info);
491         func(info);
492 
493         preempt_enable();
494 }
495 
496 /*
497  * The following tlb flush calls are invoked when old translations are
498  * being torn down, or pte attributes are changing. For single threaded
499  * address spaces, a new context is obtained on the current cpu, and tlb
500  * context on other cpus are invalidated to force a new context allocation
501  * at switch_mm time, should the mm ever be used on other cpus. For
502  * multithreaded address spaces, intercpu interrupts have to be sent.
503  * Another case where intercpu interrupts are required is when the target
504  * mm might be active on another cpu (eg debuggers doing the flushes on
505  * behalf of debugees, kswapd stealing pages from another process etc).
506  * Kanoj 07/00.
507  */
508 
509 void flush_tlb_mm(struct mm_struct *mm)
510 {
511         preempt_disable();
512 
513         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
514                 smp_on_other_tlbs(flush_tlb_mm_ipi, mm);
515         } else {
516                 unsigned int cpu;
517 
518                 for_each_online_cpu(cpu) {
519                         if (cpu != smp_processor_id() && cpu_context(cpu, mm))
520                                 cpu_context(cpu, mm) = 0;
521                 }
522         }
523         local_flush_tlb_mm(mm);
524 
525         preempt_enable();
526 }
527 
528 struct flush_tlb_data {
529         struct vm_area_struct *vma;
530         unsigned long addr1;
531         unsigned long addr2;
532 };
533 
534 static void flush_tlb_range_ipi(void *info)
535 {
536         struct flush_tlb_data *fd = info;
537 
538         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
539 }
540 
541 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
542 {
543         struct mm_struct *mm = vma->vm_mm;
544 
545         preempt_disable();
546         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
547                 struct flush_tlb_data fd = {
548                         .vma = vma,
549                         .addr1 = start,
550                         .addr2 = end,
551                 };
552 
553                 smp_on_other_tlbs(flush_tlb_range_ipi, &fd);
554         } else {
555                 unsigned int cpu;
556                 int exec = vma->vm_flags & VM_EXEC;
557 
558                 for_each_online_cpu(cpu) {
559                         /*
560                          * flush_cache_range() will only fully flush icache if
561                          * the VMA is executable, otherwise we must invalidate
562                          * ASID without it appearing to has_valid_asid() as if
563                          * mm has been completely unused by that CPU.
564                          */
565                         if (cpu != smp_processor_id() && cpu_context(cpu, mm))
566                                 cpu_context(cpu, mm) = !exec;
567                 }
568         }
569         local_flush_tlb_range(vma, start, end);
570         preempt_enable();
571 }
572 
573 static void flush_tlb_kernel_range_ipi(void *info)
574 {
575         struct flush_tlb_data *fd = info;
576 
577         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
578 }
579 
580 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
581 {
582         struct flush_tlb_data fd = {
583                 .addr1 = start,
584                 .addr2 = end,
585         };
586 
587         on_each_cpu(flush_tlb_kernel_range_ipi, &fd, 1);
588 }
589 
590 static void flush_tlb_page_ipi(void *info)
591 {
592         struct flush_tlb_data *fd = info;
593 
594         local_flush_tlb_page(fd->vma, fd->addr1);
595 }
596 
597 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
598 {
599         preempt_disable();
600         if ((atomic_read(&vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) {
601                 struct flush_tlb_data fd = {
602                         .vma = vma,
603                         .addr1 = page,
604                 };
605 
606                 smp_on_other_tlbs(flush_tlb_page_ipi, &fd);
607         } else {
608                 unsigned int cpu;
609 
610                 for_each_online_cpu(cpu) {
611                         /*
612                          * flush_cache_page() only does partial flushes, so
613                          * invalidate ASID without it appearing to
614                          * has_valid_asid() as if mm has been completely unused
615                          * by that CPU.
616                          */
617                         if (cpu != smp_processor_id() && cpu_context(cpu, vma->vm_mm))
618                                 cpu_context(cpu, vma->vm_mm) = 1;
619                 }
620         }
621         local_flush_tlb_page(vma, page);
622         preempt_enable();
623 }
624 
625 static void flush_tlb_one_ipi(void *info)
626 {
627         unsigned long vaddr = (unsigned long) info;
628 
629         local_flush_tlb_one(vaddr);
630 }
631 
632 void flush_tlb_one(unsigned long vaddr)
633 {
634         smp_on_each_tlb(flush_tlb_one_ipi, (void *) vaddr);
635 }
636 
637 EXPORT_SYMBOL(flush_tlb_page);
638 EXPORT_SYMBOL(flush_tlb_one);
639 
640 #if defined(CONFIG_KEXEC)
641 void (*dump_ipi_function_ptr)(void *) = NULL;
642 void dump_send_ipi(void (*dump_ipi_callback)(void *))
643 {
644         int i;
645         int cpu = smp_processor_id();
646 
647         dump_ipi_function_ptr = dump_ipi_callback;
648         smp_mb();
649         for_each_online_cpu(i)
650                 if (i != cpu)
651                         mp_ops->send_ipi_single(i, SMP_DUMP);
652 
653 }
654 EXPORT_SYMBOL(dump_send_ipi);
655 #endif
656 
657 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
658 
659 static DEFINE_PER_CPU(atomic_t, tick_broadcast_count);
660 static DEFINE_PER_CPU(struct call_single_data, tick_broadcast_csd);
661 
662 void tick_broadcast(const struct cpumask *mask)
663 {
664         atomic_t *count;
665         struct call_single_data *csd;
666         int cpu;
667 
668         for_each_cpu(cpu, mask) {
669                 count = &per_cpu(tick_broadcast_count, cpu);
670                 csd = &per_cpu(tick_broadcast_csd, cpu);
671 
672                 if (atomic_inc_return(count) == 1)
673                         smp_call_function_single_async(cpu, csd);
674         }
675 }
676 
677 static void tick_broadcast_callee(void *info)
678 {
679         int cpu = smp_processor_id();
680         tick_receive_broadcast();
681         atomic_set(&per_cpu(tick_broadcast_count, cpu), 0);
682 }
683 
684 static int __init tick_broadcast_init(void)
685 {
686         struct call_single_data *csd;
687         int cpu;
688 
689         for (cpu = 0; cpu < NR_CPUS; cpu++) {
690                 csd = &per_cpu(tick_broadcast_csd, cpu);
691                 csd->func = tick_broadcast_callee;
692         }
693 
694         return 0;
695 }
696 early_initcall(tick_broadcast_init);
697 
698 #endif /* CONFIG_GENERIC_CLOCKEVENTS_BROADCAST */
699 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp