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1/*
2 * linux/arch/arm/kernel/smp.c
3 *
4 * Copyright (C) 2002 ARM Limited, All Rights Reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/module.h>
11#include <linux/delay.h>
12#include <linux/init.h>
13#include <linux/spinlock.h>
14#include <linux/sched.h>
15#include <linux/interrupt.h>
16#include <linux/cache.h>
17#include <linux/profile.h>
18#include <linux/errno.h>
19#include <linux/mm.h>
20#include <linux/err.h>
21#include <linux/cpu.h>
22#include <linux/seq_file.h>
23#include <linux/irq.h>
24#include <linux/percpu.h>
25#include <linux/clockchips.h>
26#include <linux/completion.h>
27#include <linux/cpufreq.h>
28#include <linux/irq_work.h>
29
30#include <linux/atomic.h>
31#include <asm/smp.h>
32#include <asm/cacheflush.h>
33#include <asm/cpu.h>
34#include <asm/cputype.h>
35#include <asm/exception.h>
36#include <asm/idmap.h>
37#include <asm/topology.h>
38#include <asm/mmu_context.h>
39#include <asm/pgtable.h>
40#include <asm/pgalloc.h>
41#include <asm/processor.h>
42#include <asm/sections.h>
43#include <asm/tlbflush.h>
44#include <asm/ptrace.h>
45#include <asm/smp_plat.h>
46#include <asm/virt.h>
47#include <asm/mach/arch.h>
48#include <asm/mpu.h>
49
50/*
51 * as from 2.5, kernels no longer have an init_tasks structure
52 * so we need some other way of telling a new secondary core
53 * where to place its SVC stack
54 */
55struct secondary_data secondary_data;
56
57/*
58 * control for which core is the next to come out of the secondary
59 * boot "holding pen"
60 */
61volatile int pen_release = -1;
62
63enum ipi_msg_type {
64 IPI_WAKEUP,
65 IPI_TIMER,
66 IPI_RESCHEDULE,
67 IPI_CALL_FUNC,
68 IPI_CALL_FUNC_SINGLE,
69 IPI_CPU_STOP,
70 IPI_IRQ_WORK,
71 IPI_COMPLETION,
72};
73
74static DECLARE_COMPLETION(cpu_running);
75
76static struct smp_operations smp_ops;
77
78void __init smp_set_ops(struct smp_operations *ops)
79{
80 if (ops)
81 smp_ops = *ops;
82};
83
84static unsigned long get_arch_pgd(pgd_t *pgd)
85{
86 phys_addr_t pgdir = virt_to_idmap(pgd);
87 BUG_ON(pgdir & ARCH_PGD_MASK);
88 return pgdir >> ARCH_PGD_SHIFT;
89}
90
91int __cpu_up(unsigned int cpu, struct task_struct *idle)
92{
93 int ret;
94
95 /*
96 * We need to tell the secondary core where to find
97 * its stack and the page tables.
98 */
99 secondary_data.stack = task_stack_page(idle) + THREAD_START_SP;
100#ifdef CONFIG_ARM_MPU
101 secondary_data.mpu_rgn_szr = mpu_rgn_info.rgns[MPU_RAM_REGION].drsr;
102#endif
103
104#ifdef CONFIG_MMU
105 secondary_data.pgdir = get_arch_pgd(idmap_pgd);
106 secondary_data.swapper_pg_dir = get_arch_pgd(swapper_pg_dir);
107#endif
108 sync_cache_w(&secondary_data);
109
110 /*
111 * Now bring the CPU into our world.
112 */
113 ret = boot_secondary(cpu, idle);
114 if (ret == 0) {
115 /*
116 * CPU was successfully started, wait for it
117 * to come online or time out.
118 */
119 wait_for_completion_timeout(&cpu_running,
120 msecs_to_jiffies(1000));
121
122 if (!cpu_online(cpu)) {
123 pr_crit("CPU%u: failed to come online\n", cpu);
124 ret = -EIO;
125 }
126 } else {
127 pr_err("CPU%u: failed to boot: %d\n", cpu, ret);
128 }
129
130
131 memset(&secondary_data, 0, sizeof(secondary_data));
132 return ret;
133}
134
135/* platform specific SMP operations */
136void __init smp_init_cpus(void)
137{
138 if (smp_ops.smp_init_cpus)
139 smp_ops.smp_init_cpus();
140}
141
142int boot_secondary(unsigned int cpu, struct task_struct *idle)
143{
144 if (smp_ops.smp_boot_secondary)
145 return smp_ops.smp_boot_secondary(cpu, idle);
146 return -ENOSYS;
147}
148
149int platform_can_cpu_hotplug(void)
150{
151#ifdef CONFIG_HOTPLUG_CPU
152 if (smp_ops.cpu_kill)
153 return 1;
154#endif
155
156 return 0;
157}
158
159#ifdef CONFIG_HOTPLUG_CPU
160static int platform_cpu_kill(unsigned int cpu)
161{
162 if (smp_ops.cpu_kill)
163 return smp_ops.cpu_kill(cpu);
164 return 1;
165}
166
167static int platform_cpu_disable(unsigned int cpu)
168{
169 if (smp_ops.cpu_disable)
170 return smp_ops.cpu_disable(cpu);
171
172 /*
173 * By default, allow disabling all CPUs except the first one,
174 * since this is special on a lot of platforms, e.g. because
175 * of clock tick interrupts.
176 */
177 return cpu == 0 ? -EPERM : 0;
178}
179/*
180 * __cpu_disable runs on the processor to be shutdown.
181 */
182int __cpu_disable(void)
183{
184 unsigned int cpu = smp_processor_id();
185 int ret;
186
187 ret = platform_cpu_disable(cpu);
188 if (ret)
189 return ret;
190
191 /*
192 * Take this CPU offline. Once we clear this, we can't return,
193 * and we must not schedule until we're ready to give up the cpu.
194 */
195 set_cpu_online(cpu, false);
196
197 /*
198 * OK - migrate IRQs away from this CPU
199 */
200 migrate_irqs();
201
202 /*
203 * Flush user cache and TLB mappings, and then remove this CPU
204 * from the vm mask set of all processes.
205 *
206 * Caches are flushed to the Level of Unification Inner Shareable
207 * to write-back dirty lines to unified caches shared by all CPUs.
208 */
209 flush_cache_louis();
210 local_flush_tlb_all();
211
212 clear_tasks_mm_cpumask(cpu);
213
214 return 0;
215}
216
217static DECLARE_COMPLETION(cpu_died);
218
219/*
220 * called on the thread which is asking for a CPU to be shutdown -
221 * waits until shutdown has completed, or it is timed out.
222 */
223void __cpu_die(unsigned int cpu)
224{
225 if (!wait_for_completion_timeout(&cpu_died, msecs_to_jiffies(5000))) {
226 pr_err("CPU%u: cpu didn't die\n", cpu);
227 return;
228 }
229 printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
230
231 /*
232 * platform_cpu_kill() is generally expected to do the powering off
233 * and/or cutting of clocks to the dying CPU. Optionally, this may
234 * be done by the CPU which is dying in preference to supporting
235 * this call, but that means there is _no_ synchronisation between
236 * the requesting CPU and the dying CPU actually losing power.
237 */
238 if (!platform_cpu_kill(cpu))
239 printk("CPU%u: unable to kill\n", cpu);
240}
241
242/*
243 * Called from the idle thread for the CPU which has been shutdown.
244 *
245 * Note that we disable IRQs here, but do not re-enable them
246 * before returning to the caller. This is also the behaviour
247 * of the other hotplug-cpu capable cores, so presumably coming
248 * out of idle fixes this.
249 */
250void __ref cpu_die(void)
251{
252 unsigned int cpu = smp_processor_id();
253
254 idle_task_exit();
255
256 local_irq_disable();
257
258 /*
259 * Flush the data out of the L1 cache for this CPU. This must be
260 * before the completion to ensure that data is safely written out
261 * before platform_cpu_kill() gets called - which may disable
262 * *this* CPU and power down its cache.
263 */
264 flush_cache_louis();
265
266 /*
267 * Tell __cpu_die() that this CPU is now safe to dispose of. Once
268 * this returns, power and/or clocks can be removed at any point
269 * from this CPU and its cache by platform_cpu_kill().
270 */
271 complete(&cpu_died);
272
273 /*
274 * Ensure that the cache lines associated with that completion are
275 * written out. This covers the case where _this_ CPU is doing the
276 * powering down, to ensure that the completion is visible to the
277 * CPU waiting for this one.
278 */
279 flush_cache_louis();
280
281 /*
282 * The actual CPU shutdown procedure is at least platform (if not
283 * CPU) specific. This may remove power, or it may simply spin.
284 *
285 * Platforms are generally expected *NOT* to return from this call,
286 * although there are some which do because they have no way to
287 * power down the CPU. These platforms are the _only_ reason we
288 * have a return path which uses the fragment of assembly below.
289 *
290 * The return path should not be used for platforms which can
291 * power off the CPU.
292 */
293 if (smp_ops.cpu_die)
294 smp_ops.cpu_die(cpu);
295
296 pr_warn("CPU%u: smp_ops.cpu_die() returned, trying to resuscitate\n",
297 cpu);
298
299 /*
300 * Do not return to the idle loop - jump back to the secondary
301 * cpu initialisation. There's some initialisation which needs
302 * to be repeated to undo the effects of taking the CPU offline.
303 */
304 __asm__("mov sp, %0\n"
305 " mov fp, #0\n"
306 " b secondary_start_kernel"
307 :
308 : "r" (task_stack_page(current) + THREAD_SIZE - 8));
309}
310#endif /* CONFIG_HOTPLUG_CPU */
311
312/*
313 * Called by both boot and secondaries to move global data into
314 * per-processor storage.
315 */
316static void smp_store_cpu_info(unsigned int cpuid)
317{
318 struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpuid);
319
320 cpu_info->loops_per_jiffy = loops_per_jiffy;
321 cpu_info->cpuid = read_cpuid_id();
322
323 store_cpu_topology(cpuid);
324}
325
326/*
327 * This is the secondary CPU boot entry. We're using this CPUs
328 * idle thread stack, but a set of temporary page tables.
329 */
330asmlinkage void secondary_start_kernel(void)
331{
332 struct mm_struct *mm = &init_mm;
333 unsigned int cpu;
334
335 /*
336 * The identity mapping is uncached (strongly ordered), so
337 * switch away from it before attempting any exclusive accesses.
338 */
339 cpu_switch_mm(mm->pgd, mm);
340 local_flush_bp_all();
341 enter_lazy_tlb(mm, current);
342 local_flush_tlb_all();
343
344 /*
345 * All kernel threads share the same mm context; grab a
346 * reference and switch to it.
347 */
348 cpu = smp_processor_id();
349 atomic_inc(&mm->mm_count);
350 current->active_mm = mm;
351 cpumask_set_cpu(cpu, mm_cpumask(mm));
352
353 cpu_init();
354
355 printk("CPU%u: Booted secondary processor\n", cpu);
356
357 preempt_disable();
358 trace_hardirqs_off();
359
360 /*
361 * Give the platform a chance to do its own initialisation.
362 */
363 if (smp_ops.smp_secondary_init)
364 smp_ops.smp_secondary_init(cpu);
365
366 notify_cpu_starting(cpu);
367
368 calibrate_delay();
369
370 smp_store_cpu_info(cpu);
371
372 /*
373 * OK, now it's safe to let the boot CPU continue. Wait for
374 * the CPU migration code to notice that the CPU is online
375 * before we continue - which happens after __cpu_up returns.
376 */
377 set_cpu_online(cpu, true);
378 complete(&cpu_running);
379
380 local_irq_enable();
381 local_fiq_enable();
382
383 /*
384 * OK, it's off to the idle thread for us
385 */
386 cpu_startup_entry(CPUHP_ONLINE);
387}
388
389void __init smp_cpus_done(unsigned int max_cpus)
390{
391 printk(KERN_INFO "SMP: Total of %d processors activated.\n",
392 num_online_cpus());
393
394 hyp_mode_check();
395}
396
397void __init smp_prepare_boot_cpu(void)
398{
399 set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
400}
401
402void __init smp_prepare_cpus(unsigned int max_cpus)
403{
404 unsigned int ncores = num_possible_cpus();
405
406 init_cpu_topology();
407
408 smp_store_cpu_info(smp_processor_id());
409
410 /*
411 * are we trying to boot more cores than exist?
412 */
413 if (max_cpus > ncores)
414 max_cpus = ncores;
415 if (ncores > 1 && max_cpus) {
416 /*
417 * Initialise the present map, which describes the set of CPUs
418 * actually populated at the present time. A platform should
419 * re-initialize the map in the platforms smp_prepare_cpus()
420 * if present != possible (e.g. physical hotplug).
421 */
422 init_cpu_present(cpu_possible_mask);
423
424 /*
425 * Initialise the SCU if there are more than one CPU
426 * and let them know where to start.
427 */
428 if (smp_ops.smp_prepare_cpus)
429 smp_ops.smp_prepare_cpus(max_cpus);
430 }
431}
432
433static void (*smp_cross_call)(const struct cpumask *, unsigned int);
434
435void __init set_smp_cross_call(void (*fn)(const struct cpumask *, unsigned int))
436{
437 if (!smp_cross_call)
438 smp_cross_call = fn;
439}
440
441void arch_send_call_function_ipi_mask(const struct cpumask *mask)
442{
443 smp_cross_call(mask, IPI_CALL_FUNC);
444}
445
446void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
447{
448 smp_cross_call(mask, IPI_WAKEUP);
449}
450
451void arch_send_call_function_single_ipi(int cpu)
452{
453 smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
454}
455
456#ifdef CONFIG_IRQ_WORK
457void arch_irq_work_raise(void)
458{
459 if (is_smp())
460 smp_cross_call(cpumask_of(smp_processor_id()), IPI_IRQ_WORK);
461}
462#endif
463
464static const char *ipi_types[NR_IPI] = {
465#define S(x,s) [x] = s
466 S(IPI_WAKEUP, "CPU wakeup interrupts"),
467 S(IPI_TIMER, "Timer broadcast interrupts"),
468 S(IPI_RESCHEDULE, "Rescheduling interrupts"),
469 S(IPI_CALL_FUNC, "Function call interrupts"),
470 S(IPI_CALL_FUNC_SINGLE, "Single function call interrupts"),
471 S(IPI_CPU_STOP, "CPU stop interrupts"),
472 S(IPI_IRQ_WORK, "IRQ work interrupts"),
473 S(IPI_COMPLETION, "completion interrupts"),
474};
475
476void show_ipi_list(struct seq_file *p, int prec)
477{
478 unsigned int cpu, i;
479
480 for (i = 0; i < NR_IPI; i++) {
481 seq_printf(p, "%*s%u: ", prec - 1, "IPI", i);
482
483 for_each_online_cpu(cpu)
484 seq_printf(p, "%10u ",
485 __get_irq_stat(cpu, ipi_irqs[i]));
486
487 seq_printf(p, " %s\n", ipi_types[i]);
488 }
489}
490
491u64 smp_irq_stat_cpu(unsigned int cpu)
492{
493 u64 sum = 0;
494 int i;
495
496 for (i = 0; i < NR_IPI; i++)
497 sum += __get_irq_stat(cpu, ipi_irqs[i]);
498
499 return sum;
500}
501
502#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
503void tick_broadcast(const struct cpumask *mask)
504{
505 smp_cross_call(mask, IPI_TIMER);
506}
507#endif
508
509static DEFINE_RAW_SPINLOCK(stop_lock);
510
511/*
512 * ipi_cpu_stop - handle IPI from smp_send_stop()
513 */
514static void ipi_cpu_stop(unsigned int cpu)
515{
516 if (system_state == SYSTEM_BOOTING ||
517 system_state == SYSTEM_RUNNING) {
518 raw_spin_lock(&stop_lock);
519 printk(KERN_CRIT "CPU%u: stopping\n", cpu);
520 dump_stack();
521 raw_spin_unlock(&stop_lock);
522 }
523
524 set_cpu_online(cpu, false);
525
526 local_fiq_disable();
527 local_irq_disable();
528
529 while (1)
530 cpu_relax();
531}
532
533static DEFINE_PER_CPU(struct completion *, cpu_completion);
534
535int register_ipi_completion(struct completion *completion, int cpu)
536{
537 per_cpu(cpu_completion, cpu) = completion;
538 return IPI_COMPLETION;
539}
540
541static void ipi_complete(unsigned int cpu)
542{
543 complete(per_cpu(cpu_completion, cpu));
544}
545
546/*
547 * Main handler for inter-processor interrupts
548 */
549asmlinkage void __exception_irq_entry do_IPI(int ipinr, struct pt_regs *regs)
550{
551 handle_IPI(ipinr, regs);
552}
553
554void handle_IPI(int ipinr, struct pt_regs *regs)
555{
556 unsigned int cpu = smp_processor_id();
557 struct pt_regs *old_regs = set_irq_regs(regs);
558
559 if (ipinr < NR_IPI)
560 __inc_irq_stat(cpu, ipi_irqs[ipinr]);
561
562 switch (ipinr) {
563 case IPI_WAKEUP:
564 break;
565
566#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
567 case IPI_TIMER:
568 irq_enter();
569 tick_receive_broadcast();
570 irq_exit();
571 break;
572#endif
573
574 case IPI_RESCHEDULE:
575 scheduler_ipi();
576 break;
577
578 case IPI_CALL_FUNC:
579 irq_enter();
580 generic_smp_call_function_interrupt();
581 irq_exit();
582 break;
583
584 case IPI_CALL_FUNC_SINGLE:
585 irq_enter();
586 generic_smp_call_function_single_interrupt();
587 irq_exit();
588 break;
589
590 case IPI_CPU_STOP:
591 irq_enter();
592 ipi_cpu_stop(cpu);
593 irq_exit();
594 break;
595
596#ifdef CONFIG_IRQ_WORK
597 case IPI_IRQ_WORK:
598 irq_enter();
599 irq_work_run();
600 irq_exit();
601 break;
602#endif
603
604 case IPI_COMPLETION:
605 irq_enter();
606 ipi_complete(cpu);
607 irq_exit();
608 break;
609
610 default:
611 printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n",
612 cpu, ipinr);
613 break;
614 }
615 set_irq_regs(old_regs);
616}
617
618void smp_send_reschedule(int cpu)
619{
620 smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
621}
622
623void smp_send_stop(void)
624{
625 unsigned long timeout;
626 struct cpumask mask;
627
628 cpumask_copy(&mask, cpu_online_mask);
629 cpumask_clear_cpu(smp_processor_id(), &mask);
630 if (!cpumask_empty(&mask))
631 smp_cross_call(&mask, IPI_CPU_STOP);
632
633 /* Wait up to one second for other CPUs to stop */
634 timeout = USEC_PER_SEC;
635 while (num_online_cpus() > 1 && timeout--)
636 udelay(1);
637
638 if (num_online_cpus() > 1)
639 pr_warning("SMP: failed to stop secondary CPUs\n");
640}
641
642/*
643 * not supported here
644 */
645int setup_profiling_timer(unsigned int multiplier)
646{
647 return -EINVAL;
648}
649
650#ifdef CONFIG_CPU_FREQ
651
652static DEFINE_PER_CPU(unsigned long, l_p_j_ref);
653static DEFINE_PER_CPU(unsigned long, l_p_j_ref_freq);
654static unsigned long global_l_p_j_ref;
655static unsigned long global_l_p_j_ref_freq;
656
657static int cpufreq_callback(struct notifier_block *nb,
658 unsigned long val, void *data)
659{
660 struct cpufreq_freqs *freq = data;
661 int cpu = freq->cpu;
662
663 if (freq->flags & CPUFREQ_CONST_LOOPS)
664 return NOTIFY_OK;
665
666 if (!per_cpu(l_p_j_ref, cpu)) {
667 per_cpu(l_p_j_ref, cpu) =
668 per_cpu(cpu_data, cpu).loops_per_jiffy;
669 per_cpu(l_p_j_ref_freq, cpu) = freq->old;
670 if (!global_l_p_j_ref) {
671 global_l_p_j_ref = loops_per_jiffy;
672 global_l_p_j_ref_freq = freq->old;
673 }
674 }
675
676 if ((val == CPUFREQ_PRECHANGE && freq->old < freq->new) ||
677 (val == CPUFREQ_POSTCHANGE && freq->old > freq->new)) {
678 loops_per_jiffy = cpufreq_scale(global_l_p_j_ref,
679 global_l_p_j_ref_freq,
680 freq->new);
681 per_cpu(cpu_data, cpu).loops_per_jiffy =
682 cpufreq_scale(per_cpu(l_p_j_ref, cpu),
683 per_cpu(l_p_j_ref_freq, cpu),
684 freq->new);
685 }
686 return NOTIFY_OK;
687}
688
689static struct notifier_block cpufreq_notifier = {
690 .notifier_call = cpufreq_callback,
691};
692
693static int __init register_cpufreq_notifier(void)
694{
695 return cpufreq_register_notifier(&cpufreq_notifier,
696 CPUFREQ_TRANSITION_NOTIFIER);
697}
698core_initcall(register_cpufreq_notifier);
699
700#endif
1/*
2 * linux/arch/arm/kernel/smp.c
3 *
4 * Copyright (C) 2002 ARM Limited, All Rights Reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/module.h>
11#include <linux/delay.h>
12#include <linux/init.h>
13#include <linux/spinlock.h>
14#include <linux/sched.h>
15#include <linux/interrupt.h>
16#include <linux/cache.h>
17#include <linux/profile.h>
18#include <linux/errno.h>
19#include <linux/mm.h>
20#include <linux/err.h>
21#include <linux/cpu.h>
22#include <linux/seq_file.h>
23#include <linux/irq.h>
24#include <linux/nmi.h>
25#include <linux/percpu.h>
26#include <linux/clockchips.h>
27#include <linux/completion.h>
28#include <linux/cpufreq.h>
29#include <linux/irq_work.h>
30
31#include <linux/atomic.h>
32#include <asm/smp.h>
33#include <asm/cacheflush.h>
34#include <asm/cpu.h>
35#include <asm/cputype.h>
36#include <asm/exception.h>
37#include <asm/idmap.h>
38#include <asm/topology.h>
39#include <asm/mmu_context.h>
40#include <asm/pgtable.h>
41#include <asm/pgalloc.h>
42#include <asm/processor.h>
43#include <asm/sections.h>
44#include <asm/tlbflush.h>
45#include <asm/ptrace.h>
46#include <asm/smp_plat.h>
47#include <asm/virt.h>
48#include <asm/mach/arch.h>
49#include <asm/mpu.h>
50
51#define CREATE_TRACE_POINTS
52#include <trace/events/ipi.h>
53
54/*
55 * as from 2.5, kernels no longer have an init_tasks structure
56 * so we need some other way of telling a new secondary core
57 * where to place its SVC stack
58 */
59struct secondary_data secondary_data;
60
61/*
62 * control for which core is the next to come out of the secondary
63 * boot "holding pen"
64 */
65volatile int pen_release = -1;
66
67enum ipi_msg_type {
68 IPI_WAKEUP,
69 IPI_TIMER,
70 IPI_RESCHEDULE,
71 IPI_CALL_FUNC,
72 IPI_CPU_STOP,
73 IPI_IRQ_WORK,
74 IPI_COMPLETION,
75 IPI_CPU_BACKTRACE,
76 /*
77 * SGI8-15 can be reserved by secure firmware, and thus may
78 * not be usable by the kernel. Please keep the above limited
79 * to at most 8 entries.
80 */
81};
82
83static DECLARE_COMPLETION(cpu_running);
84
85static struct smp_operations smp_ops;
86
87void __init smp_set_ops(const struct smp_operations *ops)
88{
89 if (ops)
90 smp_ops = *ops;
91};
92
93static unsigned long get_arch_pgd(pgd_t *pgd)
94{
95#ifdef CONFIG_ARM_LPAE
96 return __phys_to_pfn(virt_to_phys(pgd));
97#else
98 return virt_to_phys(pgd);
99#endif
100}
101
102int __cpu_up(unsigned int cpu, struct task_struct *idle)
103{
104 int ret;
105
106 if (!smp_ops.smp_boot_secondary)
107 return -ENOSYS;
108
109 /*
110 * We need to tell the secondary core where to find
111 * its stack and the page tables.
112 */
113 secondary_data.stack = task_stack_page(idle) + THREAD_START_SP;
114#ifdef CONFIG_ARM_MPU
115 secondary_data.mpu_rgn_szr = mpu_rgn_info.rgns[MPU_RAM_REGION].drsr;
116#endif
117
118#ifdef CONFIG_MMU
119 secondary_data.pgdir = virt_to_phys(idmap_pgd);
120 secondary_data.swapper_pg_dir = get_arch_pgd(swapper_pg_dir);
121#endif
122 sync_cache_w(&secondary_data);
123
124 /*
125 * Now bring the CPU into our world.
126 */
127 ret = smp_ops.smp_boot_secondary(cpu, idle);
128 if (ret == 0) {
129 /*
130 * CPU was successfully started, wait for it
131 * to come online or time out.
132 */
133 wait_for_completion_timeout(&cpu_running,
134 msecs_to_jiffies(1000));
135
136 if (!cpu_online(cpu)) {
137 pr_crit("CPU%u: failed to come online\n", cpu);
138 ret = -EIO;
139 }
140 } else {
141 pr_err("CPU%u: failed to boot: %d\n", cpu, ret);
142 }
143
144
145 memset(&secondary_data, 0, sizeof(secondary_data));
146 return ret;
147}
148
149/* platform specific SMP operations */
150void __init smp_init_cpus(void)
151{
152 if (smp_ops.smp_init_cpus)
153 smp_ops.smp_init_cpus();
154}
155
156int platform_can_secondary_boot(void)
157{
158 return !!smp_ops.smp_boot_secondary;
159}
160
161int platform_can_cpu_hotplug(void)
162{
163#ifdef CONFIG_HOTPLUG_CPU
164 if (smp_ops.cpu_kill)
165 return 1;
166#endif
167
168 return 0;
169}
170
171#ifdef CONFIG_HOTPLUG_CPU
172static int platform_cpu_kill(unsigned int cpu)
173{
174 if (smp_ops.cpu_kill)
175 return smp_ops.cpu_kill(cpu);
176 return 1;
177}
178
179static int platform_cpu_disable(unsigned int cpu)
180{
181 if (smp_ops.cpu_disable)
182 return smp_ops.cpu_disable(cpu);
183
184 return 0;
185}
186
187int platform_can_hotplug_cpu(unsigned int cpu)
188{
189 /* cpu_die must be specified to support hotplug */
190 if (!smp_ops.cpu_die)
191 return 0;
192
193 if (smp_ops.cpu_can_disable)
194 return smp_ops.cpu_can_disable(cpu);
195
196 /*
197 * By default, allow disabling all CPUs except the first one,
198 * since this is special on a lot of platforms, e.g. because
199 * of clock tick interrupts.
200 */
201 return cpu != 0;
202}
203
204/*
205 * __cpu_disable runs on the processor to be shutdown.
206 */
207int __cpu_disable(void)
208{
209 unsigned int cpu = smp_processor_id();
210 int ret;
211
212 ret = platform_cpu_disable(cpu);
213 if (ret)
214 return ret;
215
216 /*
217 * Take this CPU offline. Once we clear this, we can't return,
218 * and we must not schedule until we're ready to give up the cpu.
219 */
220 set_cpu_online(cpu, false);
221
222 /*
223 * OK - migrate IRQs away from this CPU
224 */
225 migrate_irqs();
226
227 /*
228 * Flush user cache and TLB mappings, and then remove this CPU
229 * from the vm mask set of all processes.
230 *
231 * Caches are flushed to the Level of Unification Inner Shareable
232 * to write-back dirty lines to unified caches shared by all CPUs.
233 */
234 flush_cache_louis();
235 local_flush_tlb_all();
236
237 clear_tasks_mm_cpumask(cpu);
238
239 return 0;
240}
241
242static DECLARE_COMPLETION(cpu_died);
243
244/*
245 * called on the thread which is asking for a CPU to be shutdown -
246 * waits until shutdown has completed, or it is timed out.
247 */
248void __cpu_die(unsigned int cpu)
249{
250 if (!wait_for_completion_timeout(&cpu_died, msecs_to_jiffies(5000))) {
251 pr_err("CPU%u: cpu didn't die\n", cpu);
252 return;
253 }
254 pr_notice("CPU%u: shutdown\n", cpu);
255
256 /*
257 * platform_cpu_kill() is generally expected to do the powering off
258 * and/or cutting of clocks to the dying CPU. Optionally, this may
259 * be done by the CPU which is dying in preference to supporting
260 * this call, but that means there is _no_ synchronisation between
261 * the requesting CPU and the dying CPU actually losing power.
262 */
263 if (!platform_cpu_kill(cpu))
264 pr_err("CPU%u: unable to kill\n", cpu);
265}
266
267/*
268 * Called from the idle thread for the CPU which has been shutdown.
269 *
270 * Note that we disable IRQs here, but do not re-enable them
271 * before returning to the caller. This is also the behaviour
272 * of the other hotplug-cpu capable cores, so presumably coming
273 * out of idle fixes this.
274 */
275void arch_cpu_idle_dead(void)
276{
277 unsigned int cpu = smp_processor_id();
278
279 idle_task_exit();
280
281 local_irq_disable();
282
283 /*
284 * Flush the data out of the L1 cache for this CPU. This must be
285 * before the completion to ensure that data is safely written out
286 * before platform_cpu_kill() gets called - which may disable
287 * *this* CPU and power down its cache.
288 */
289 flush_cache_louis();
290
291 /*
292 * Tell __cpu_die() that this CPU is now safe to dispose of. Once
293 * this returns, power and/or clocks can be removed at any point
294 * from this CPU and its cache by platform_cpu_kill().
295 */
296 complete(&cpu_died);
297
298 /*
299 * Ensure that the cache lines associated with that completion are
300 * written out. This covers the case where _this_ CPU is doing the
301 * powering down, to ensure that the completion is visible to the
302 * CPU waiting for this one.
303 */
304 flush_cache_louis();
305
306 /*
307 * The actual CPU shutdown procedure is at least platform (if not
308 * CPU) specific. This may remove power, or it may simply spin.
309 *
310 * Platforms are generally expected *NOT* to return from this call,
311 * although there are some which do because they have no way to
312 * power down the CPU. These platforms are the _only_ reason we
313 * have a return path which uses the fragment of assembly below.
314 *
315 * The return path should not be used for platforms which can
316 * power off the CPU.
317 */
318 if (smp_ops.cpu_die)
319 smp_ops.cpu_die(cpu);
320
321 pr_warn("CPU%u: smp_ops.cpu_die() returned, trying to resuscitate\n",
322 cpu);
323
324 /*
325 * Do not return to the idle loop - jump back to the secondary
326 * cpu initialisation. There's some initialisation which needs
327 * to be repeated to undo the effects of taking the CPU offline.
328 */
329 __asm__("mov sp, %0\n"
330 " mov fp, #0\n"
331 " b secondary_start_kernel"
332 :
333 : "r" (task_stack_page(current) + THREAD_SIZE - 8));
334}
335#endif /* CONFIG_HOTPLUG_CPU */
336
337/*
338 * Called by both boot and secondaries to move global data into
339 * per-processor storage.
340 */
341static void smp_store_cpu_info(unsigned int cpuid)
342{
343 struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpuid);
344
345 cpu_info->loops_per_jiffy = loops_per_jiffy;
346 cpu_info->cpuid = read_cpuid_id();
347
348 store_cpu_topology(cpuid);
349}
350
351/*
352 * This is the secondary CPU boot entry. We're using this CPUs
353 * idle thread stack, but a set of temporary page tables.
354 */
355asmlinkage void secondary_start_kernel(void)
356{
357 struct mm_struct *mm = &init_mm;
358 unsigned int cpu;
359
360 /*
361 * The identity mapping is uncached (strongly ordered), so
362 * switch away from it before attempting any exclusive accesses.
363 */
364 cpu_switch_mm(mm->pgd, mm);
365 local_flush_bp_all();
366 enter_lazy_tlb(mm, current);
367 local_flush_tlb_all();
368
369 /*
370 * All kernel threads share the same mm context; grab a
371 * reference and switch to it.
372 */
373 cpu = smp_processor_id();
374 atomic_inc(&mm->mm_count);
375 current->active_mm = mm;
376 cpumask_set_cpu(cpu, mm_cpumask(mm));
377
378 cpu_init();
379
380 pr_debug("CPU%u: Booted secondary processor\n", cpu);
381
382 preempt_disable();
383 trace_hardirqs_off();
384
385 /*
386 * Give the platform a chance to do its own initialisation.
387 */
388 if (smp_ops.smp_secondary_init)
389 smp_ops.smp_secondary_init(cpu);
390
391 notify_cpu_starting(cpu);
392
393 calibrate_delay();
394
395 smp_store_cpu_info(cpu);
396
397 /*
398 * OK, now it's safe to let the boot CPU continue. Wait for
399 * the CPU migration code to notice that the CPU is online
400 * before we continue - which happens after __cpu_up returns.
401 */
402 set_cpu_online(cpu, true);
403 complete(&cpu_running);
404
405 local_irq_enable();
406 local_fiq_enable();
407 local_abt_enable();
408
409 /*
410 * OK, it's off to the idle thread for us
411 */
412 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
413}
414
415void __init smp_cpus_done(unsigned int max_cpus)
416{
417 int cpu;
418 unsigned long bogosum = 0;
419
420 for_each_online_cpu(cpu)
421 bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy;
422
423 printk(KERN_INFO "SMP: Total of %d processors activated "
424 "(%lu.%02lu BogoMIPS).\n",
425 num_online_cpus(),
426 bogosum / (500000/HZ),
427 (bogosum / (5000/HZ)) % 100);
428
429 hyp_mode_check();
430}
431
432void __init smp_prepare_boot_cpu(void)
433{
434 set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
435}
436
437void __init smp_prepare_cpus(unsigned int max_cpus)
438{
439 unsigned int ncores = num_possible_cpus();
440
441 init_cpu_topology();
442
443 smp_store_cpu_info(smp_processor_id());
444
445 /*
446 * are we trying to boot more cores than exist?
447 */
448 if (max_cpus > ncores)
449 max_cpus = ncores;
450 if (ncores > 1 && max_cpus) {
451 /*
452 * Initialise the present map, which describes the set of CPUs
453 * actually populated at the present time. A platform should
454 * re-initialize the map in the platforms smp_prepare_cpus()
455 * if present != possible (e.g. physical hotplug).
456 */
457 init_cpu_present(cpu_possible_mask);
458
459 /*
460 * Initialise the SCU if there are more than one CPU
461 * and let them know where to start.
462 */
463 if (smp_ops.smp_prepare_cpus)
464 smp_ops.smp_prepare_cpus(max_cpus);
465 }
466}
467
468static void (*__smp_cross_call)(const struct cpumask *, unsigned int);
469
470void __init set_smp_cross_call(void (*fn)(const struct cpumask *, unsigned int))
471{
472 if (!__smp_cross_call)
473 __smp_cross_call = fn;
474}
475
476static const char *ipi_types[NR_IPI] __tracepoint_string = {
477#define S(x,s) [x] = s
478 S(IPI_WAKEUP, "CPU wakeup interrupts"),
479 S(IPI_TIMER, "Timer broadcast interrupts"),
480 S(IPI_RESCHEDULE, "Rescheduling interrupts"),
481 S(IPI_CALL_FUNC, "Function call interrupts"),
482 S(IPI_CPU_STOP, "CPU stop interrupts"),
483 S(IPI_IRQ_WORK, "IRQ work interrupts"),
484 S(IPI_COMPLETION, "completion interrupts"),
485};
486
487static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
488{
489 trace_ipi_raise(target, ipi_types[ipinr]);
490 __smp_cross_call(target, ipinr);
491}
492
493void show_ipi_list(struct seq_file *p, int prec)
494{
495 unsigned int cpu, i;
496
497 for (i = 0; i < NR_IPI; i++) {
498 seq_printf(p, "%*s%u: ", prec - 1, "IPI", i);
499
500 for_each_online_cpu(cpu)
501 seq_printf(p, "%10u ",
502 __get_irq_stat(cpu, ipi_irqs[i]));
503
504 seq_printf(p, " %s\n", ipi_types[i]);
505 }
506}
507
508u64 smp_irq_stat_cpu(unsigned int cpu)
509{
510 u64 sum = 0;
511 int i;
512
513 for (i = 0; i < NR_IPI; i++)
514 sum += __get_irq_stat(cpu, ipi_irqs[i]);
515
516 return sum;
517}
518
519void arch_send_call_function_ipi_mask(const struct cpumask *mask)
520{
521 smp_cross_call(mask, IPI_CALL_FUNC);
522}
523
524void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
525{
526 smp_cross_call(mask, IPI_WAKEUP);
527}
528
529void arch_send_call_function_single_ipi(int cpu)
530{
531 smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC);
532}
533
534#ifdef CONFIG_IRQ_WORK
535void arch_irq_work_raise(void)
536{
537 if (arch_irq_work_has_interrupt())
538 smp_cross_call(cpumask_of(smp_processor_id()), IPI_IRQ_WORK);
539}
540#endif
541
542#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
543void tick_broadcast(const struct cpumask *mask)
544{
545 smp_cross_call(mask, IPI_TIMER);
546}
547#endif
548
549static DEFINE_RAW_SPINLOCK(stop_lock);
550
551/*
552 * ipi_cpu_stop - handle IPI from smp_send_stop()
553 */
554static void ipi_cpu_stop(unsigned int cpu)
555{
556 if (system_state == SYSTEM_BOOTING ||
557 system_state == SYSTEM_RUNNING) {
558 raw_spin_lock(&stop_lock);
559 pr_crit("CPU%u: stopping\n", cpu);
560 dump_stack();
561 raw_spin_unlock(&stop_lock);
562 }
563
564 set_cpu_online(cpu, false);
565
566 local_fiq_disable();
567 local_irq_disable();
568
569 while (1)
570 cpu_relax();
571}
572
573static DEFINE_PER_CPU(struct completion *, cpu_completion);
574
575int register_ipi_completion(struct completion *completion, int cpu)
576{
577 per_cpu(cpu_completion, cpu) = completion;
578 return IPI_COMPLETION;
579}
580
581static void ipi_complete(unsigned int cpu)
582{
583 complete(per_cpu(cpu_completion, cpu));
584}
585
586/*
587 * Main handler for inter-processor interrupts
588 */
589asmlinkage void __exception_irq_entry do_IPI(int ipinr, struct pt_regs *regs)
590{
591 handle_IPI(ipinr, regs);
592}
593
594void handle_IPI(int ipinr, struct pt_regs *regs)
595{
596 unsigned int cpu = smp_processor_id();
597 struct pt_regs *old_regs = set_irq_regs(regs);
598
599 if ((unsigned)ipinr < NR_IPI) {
600 trace_ipi_entry_rcuidle(ipi_types[ipinr]);
601 __inc_irq_stat(cpu, ipi_irqs[ipinr]);
602 }
603
604 switch (ipinr) {
605 case IPI_WAKEUP:
606 break;
607
608#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
609 case IPI_TIMER:
610 irq_enter();
611 tick_receive_broadcast();
612 irq_exit();
613 break;
614#endif
615
616 case IPI_RESCHEDULE:
617 scheduler_ipi();
618 break;
619
620 case IPI_CALL_FUNC:
621 irq_enter();
622 generic_smp_call_function_interrupt();
623 irq_exit();
624 break;
625
626 case IPI_CPU_STOP:
627 irq_enter();
628 ipi_cpu_stop(cpu);
629 irq_exit();
630 break;
631
632#ifdef CONFIG_IRQ_WORK
633 case IPI_IRQ_WORK:
634 irq_enter();
635 irq_work_run();
636 irq_exit();
637 break;
638#endif
639
640 case IPI_COMPLETION:
641 irq_enter();
642 ipi_complete(cpu);
643 irq_exit();
644 break;
645
646 case IPI_CPU_BACKTRACE:
647 irq_enter();
648 nmi_cpu_backtrace(regs);
649 irq_exit();
650 break;
651
652 default:
653 pr_crit("CPU%u: Unknown IPI message 0x%x\n",
654 cpu, ipinr);
655 break;
656 }
657
658 if ((unsigned)ipinr < NR_IPI)
659 trace_ipi_exit_rcuidle(ipi_types[ipinr]);
660 set_irq_regs(old_regs);
661}
662
663void smp_send_reschedule(int cpu)
664{
665 smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
666}
667
668void smp_send_stop(void)
669{
670 unsigned long timeout;
671 struct cpumask mask;
672
673 cpumask_copy(&mask, cpu_online_mask);
674 cpumask_clear_cpu(smp_processor_id(), &mask);
675 if (!cpumask_empty(&mask))
676 smp_cross_call(&mask, IPI_CPU_STOP);
677
678 /* Wait up to one second for other CPUs to stop */
679 timeout = USEC_PER_SEC;
680 while (num_online_cpus() > 1 && timeout--)
681 udelay(1);
682
683 if (num_online_cpus() > 1)
684 pr_warn("SMP: failed to stop secondary CPUs\n");
685}
686
687/*
688 * not supported here
689 */
690int setup_profiling_timer(unsigned int multiplier)
691{
692 return -EINVAL;
693}
694
695#ifdef CONFIG_CPU_FREQ
696
697static DEFINE_PER_CPU(unsigned long, l_p_j_ref);
698static DEFINE_PER_CPU(unsigned long, l_p_j_ref_freq);
699static unsigned long global_l_p_j_ref;
700static unsigned long global_l_p_j_ref_freq;
701
702static int cpufreq_callback(struct notifier_block *nb,
703 unsigned long val, void *data)
704{
705 struct cpufreq_freqs *freq = data;
706 int cpu = freq->cpu;
707
708 if (freq->flags & CPUFREQ_CONST_LOOPS)
709 return NOTIFY_OK;
710
711 if (!per_cpu(l_p_j_ref, cpu)) {
712 per_cpu(l_p_j_ref, cpu) =
713 per_cpu(cpu_data, cpu).loops_per_jiffy;
714 per_cpu(l_p_j_ref_freq, cpu) = freq->old;
715 if (!global_l_p_j_ref) {
716 global_l_p_j_ref = loops_per_jiffy;
717 global_l_p_j_ref_freq = freq->old;
718 }
719 }
720
721 if ((val == CPUFREQ_PRECHANGE && freq->old < freq->new) ||
722 (val == CPUFREQ_POSTCHANGE && freq->old > freq->new)) {
723 loops_per_jiffy = cpufreq_scale(global_l_p_j_ref,
724 global_l_p_j_ref_freq,
725 freq->new);
726 per_cpu(cpu_data, cpu).loops_per_jiffy =
727 cpufreq_scale(per_cpu(l_p_j_ref, cpu),
728 per_cpu(l_p_j_ref_freq, cpu),
729 freq->new);
730 }
731 return NOTIFY_OK;
732}
733
734static struct notifier_block cpufreq_notifier = {
735 .notifier_call = cpufreq_callback,
736};
737
738static int __init register_cpufreq_notifier(void)
739{
740 return cpufreq_register_notifier(&cpufreq_notifier,
741 CPUFREQ_TRANSITION_NOTIFIER);
742}
743core_initcall(register_cpufreq_notifier);
744
745#endif
746
747static void raise_nmi(cpumask_t *mask)
748{
749 /*
750 * Generate the backtrace directly if we are running in a calling
751 * context that is not preemptible by the backtrace IPI. Note
752 * that nmi_cpu_backtrace() automatically removes the current cpu
753 * from mask.
754 */
755 if (cpumask_test_cpu(smp_processor_id(), mask) && irqs_disabled())
756 nmi_cpu_backtrace(NULL);
757
758 smp_cross_call(mask, IPI_CPU_BACKTRACE);
759}
760
761void arch_trigger_all_cpu_backtrace(bool include_self)
762{
763 nmi_trigger_all_cpu_backtrace(include_self, raise_nmi);
764}