Merge branch 'tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic...
[linux-2.6-block.git] / arch / powerpc / kernel / smp.c
CommitLineData
1da177e4
LT
1/*
2 * SMP support for ppc.
3 *
4 * Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great
5 * deal of code from the sparc and intel versions.
6 *
7 * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
8 *
9 * PowerPC-64 Support added by Dave Engebretsen, Peter Bergner, and
10 * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17
18#undef DEBUG
19
1da177e4
LT
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/sched.h>
23#include <linux/smp.h>
24#include <linux/interrupt.h>
25#include <linux/delay.h>
26#include <linux/init.h>
27#include <linux/spinlock.h>
28#include <linux/cache.h>
29#include <linux/err.h>
30#include <linux/sysdev.h>
31#include <linux/cpu.h>
32#include <linux/notifier.h>
4b703a23 33#include <linux/topology.h>
1da177e4
LT
34
35#include <asm/ptrace.h>
36#include <asm/atomic.h>
37#include <asm/irq.h>
38#include <asm/page.h>
39#include <asm/pgtable.h>
40#include <asm/prom.h>
41#include <asm/smp.h>
1da177e4
LT
42#include <asm/time.h>
43#include <asm/machdep.h>
e2075f79 44#include <asm/cputhreads.h>
1da177e4
LT
45#include <asm/cputable.h>
46#include <asm/system.h>
bbeb3f4c 47#include <asm/mpic.h>
a7f290da 48#include <asm/vdso_datapage.h>
5ad57078
PM
49#ifdef CONFIG_PPC64
50#include <asm/paca.h>
51#endif
52
1da177e4 53#ifdef DEBUG
f9e4ec57 54#include <asm/udbg.h>
1da177e4
LT
55#define DBG(fmt...) udbg_printf(fmt)
56#else
57#define DBG(fmt...)
58#endif
59
f9e4ec57
ME
60struct thread_info *secondary_ti;
61
d5a7430d 62DEFINE_PER_CPU(cpumask_t, cpu_sibling_map) = CPU_MASK_NONE;
440a0857 63DEFINE_PER_CPU(cpumask_t, cpu_core_map) = CPU_MASK_NONE;
1da177e4 64
d5a7430d 65EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
440a0857 66EXPORT_PER_CPU_SYMBOL(cpu_core_map);
1da177e4 67
5ad57078 68/* SMP operations for this machine */
1da177e4
LT
69struct smp_ops_t *smp_ops;
70
7ccbe504
BH
71/* Can't be static due to PowerMac hackery */
72volatile unsigned int cpu_callin_map[NR_CPUS];
1da177e4 73
1da177e4
LT
74int smt_enabled_at_boot = 1;
75
cc532915
ME
76static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
77
5ad57078 78#ifdef CONFIG_PPC64
1da177e4
LT
79void __devinit smp_generic_kick_cpu(int nr)
80{
81 BUG_ON(nr < 0 || nr >= NR_CPUS);
82
83 /*
84 * The processor is currently spinning, waiting for the
85 * cpu_start field to become non-zero After we set cpu_start,
86 * the processor will continue on to secondary_start
87 */
88 paca[nr].cpu_start = 1;
0d8d4d42 89 smp_mb();
1da177e4 90}
5ad57078 91#endif
1da177e4 92
7d12e780 93void smp_message_recv(int msg)
1da177e4
LT
94{
95 switch(msg) {
96 case PPC_MSG_CALL_FUNCTION:
b7d7a240 97 generic_smp_call_function_interrupt();
1da177e4 98 break;
5ad57078 99 case PPC_MSG_RESCHEDULE:
22d660ff 100 /* we notice need_resched on exit */
1da177e4 101 break;
b7d7a240
JA
102 case PPC_MSG_CALL_FUNC_SINGLE:
103 generic_smp_call_function_single_interrupt();
104 break;
1da177e4 105 case PPC_MSG_DEBUGGER_BREAK:
cc532915 106 if (crash_ipi_function_ptr) {
7d12e780 107 crash_ipi_function_ptr(get_irq_regs());
cc532915
ME
108 break;
109 }
110#ifdef CONFIG_DEBUGGER
7d12e780 111 debugger_ipi(get_irq_regs());
1da177e4 112 break;
cc532915
ME
113#endif /* CONFIG_DEBUGGER */
114 /* FALLTHROUGH */
1da177e4
LT
115 default:
116 printk("SMP %d: smp_message_recv(): unknown msg %d\n",
117 smp_processor_id(), msg);
118 break;
119 }
120}
121
25ddd738
MM
122static irqreturn_t call_function_action(int irq, void *data)
123{
124 generic_smp_call_function_interrupt();
125 return IRQ_HANDLED;
126}
127
128static irqreturn_t reschedule_action(int irq, void *data)
129{
130 /* we just need the return path side effect of checking need_resched */
131 return IRQ_HANDLED;
132}
133
134static irqreturn_t call_function_single_action(int irq, void *data)
135{
136 generic_smp_call_function_single_interrupt();
137 return IRQ_HANDLED;
138}
139
140static irqreturn_t debug_ipi_action(int irq, void *data)
141{
142 smp_message_recv(PPC_MSG_DEBUGGER_BREAK);
143 return IRQ_HANDLED;
144}
145
146static irq_handler_t smp_ipi_action[] = {
147 [PPC_MSG_CALL_FUNCTION] = call_function_action,
148 [PPC_MSG_RESCHEDULE] = reschedule_action,
149 [PPC_MSG_CALL_FUNC_SINGLE] = call_function_single_action,
150 [PPC_MSG_DEBUGGER_BREAK] = debug_ipi_action,
151};
152
153const char *smp_ipi_name[] = {
154 [PPC_MSG_CALL_FUNCTION] = "ipi call function",
155 [PPC_MSG_RESCHEDULE] = "ipi reschedule",
156 [PPC_MSG_CALL_FUNC_SINGLE] = "ipi call function single",
157 [PPC_MSG_DEBUGGER_BREAK] = "ipi debugger",
158};
159
160/* optional function to request ipi, for controllers with >= 4 ipis */
161int smp_request_message_ipi(int virq, int msg)
162{
163 int err;
164
165 if (msg < 0 || msg > PPC_MSG_DEBUGGER_BREAK) {
166 return -EINVAL;
167 }
168#if !defined(CONFIG_DEBUGGER) && !defined(CONFIG_KEXEC)
169 if (msg == PPC_MSG_DEBUGGER_BREAK) {
170 return 1;
171 }
172#endif
173 err = request_irq(virq, smp_ipi_action[msg], IRQF_DISABLED|IRQF_PERCPU,
174 smp_ipi_name[msg], 0);
175 WARN(err < 0, "unable to request_irq %d for %s (rc %d)\n",
176 virq, smp_ipi_name[msg], err);
177
178 return err;
179}
180
1da177e4
LT
181void smp_send_reschedule(int cpu)
182{
8cffc6ac
BH
183 if (likely(smp_ops))
184 smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE);
1da177e4
LT
185}
186
b7d7a240
JA
187void arch_send_call_function_single_ipi(int cpu)
188{
189 smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNC_SINGLE);
190}
191
f063ea02 192void arch_send_call_function_ipi_mask(const struct cpumask *mask)
b7d7a240
JA
193{
194 unsigned int cpu;
195
f063ea02 196 for_each_cpu(cpu, mask)
b7d7a240
JA
197 smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNCTION);
198}
199
1da177e4
LT
200#ifdef CONFIG_DEBUGGER
201void smp_send_debugger_break(int cpu)
202{
8cffc6ac
BH
203 if (likely(smp_ops))
204 smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
1da177e4
LT
205}
206#endif
207
cc532915
ME
208#ifdef CONFIG_KEXEC
209void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
210{
211 crash_ipi_function_ptr = crash_ipi_callback;
8cffc6ac 212 if (crash_ipi_callback && smp_ops) {
cc532915
ME
213 mb();
214 smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_DEBUGGER_BREAK);
215 }
216}
217#endif
218
1da177e4
LT
219static void stop_this_cpu(void *dummy)
220{
8389b37d
VB
221 /* Remove this CPU */
222 set_cpu_online(smp_processor_id(), false);
223
1da177e4
LT
224 local_irq_disable();
225 while (1)
226 ;
227}
228
8fd7675c
SS
229void smp_send_stop(void)
230{
8691e5a8 231 smp_call_function(stop_this_cpu, NULL, 0);
1da177e4
LT
232}
233
1da177e4
LT
234struct thread_info *current_set[NR_CPUS];
235
1da177e4
LT
236static void __devinit smp_store_cpu_info(int id)
237{
6b7487fc 238 per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
1da177e4
LT
239}
240
241static void __init smp_create_idle(unsigned int cpu)
242{
243 struct task_struct *p;
244
245 /* create a process for the processor */
246 p = fork_idle(cpu);
247 if (IS_ERR(p))
248 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
5ad57078 249#ifdef CONFIG_PPC64
1da177e4 250 paca[cpu].__current = p;
3b575064
PM
251 paca[cpu].kstack = (unsigned long) task_thread_info(p)
252 + THREAD_SIZE - STACK_FRAME_OVERHEAD;
5ad57078 253#endif
b5e2fc1c
AV
254 current_set[cpu] = task_thread_info(p);
255 task_thread_info(p)->cpu = cpu;
1da177e4
LT
256}
257
258void __init smp_prepare_cpus(unsigned int max_cpus)
259{
260 unsigned int cpu;
261
262 DBG("smp_prepare_cpus\n");
263
264 /*
265 * setup_cpu may need to be called on the boot cpu. We havent
266 * spun any cpus up but lets be paranoid.
267 */
268 BUG_ON(boot_cpuid != smp_processor_id());
269
270 /* Fixup boot cpu */
271 smp_store_cpu_info(boot_cpuid);
272 cpu_callin_map[boot_cpuid] = 1;
273
8cffc6ac 274 if (smp_ops)
757cbd46
KG
275 if (smp_ops->probe)
276 max_cpus = smp_ops->probe();
277 else
278 max_cpus = NR_CPUS;
8cffc6ac
BH
279 else
280 max_cpus = 1;
1da177e4
LT
281
282 smp_space_timers(max_cpus);
283
0e551954 284 for_each_possible_cpu(cpu)
1da177e4
LT
285 if (cpu != boot_cpuid)
286 smp_create_idle(cpu);
287}
288
289void __devinit smp_prepare_boot_cpu(void)
290{
291 BUG_ON(smp_processor_id() != boot_cpuid);
292
ea0f1cab 293 set_cpu_online(boot_cpuid, true);
e2075f79 294 cpu_set(boot_cpuid, per_cpu(cpu_sibling_map, boot_cpuid));
440a0857 295 cpu_set(boot_cpuid, per_cpu(cpu_core_map, boot_cpuid));
5ad57078 296#ifdef CONFIG_PPC64
1da177e4 297 paca[boot_cpuid].__current = current;
5ad57078 298#endif
b5e2fc1c 299 current_set[boot_cpuid] = task_thread_info(current);
1da177e4
LT
300}
301
302#ifdef CONFIG_HOTPLUG_CPU
303/* State of each CPU during hotplug phases */
304DEFINE_PER_CPU(int, cpu_state) = { 0 };
305
306int generic_cpu_disable(void)
307{
308 unsigned int cpu = smp_processor_id();
309
310 if (cpu == boot_cpuid)
311 return -EBUSY;
312
ea0f1cab 313 set_cpu_online(cpu, false);
799d6046 314#ifdef CONFIG_PPC64
a7f290da 315 vdso_data->processorCount--;
1da177e4 316 fixup_irqs(cpu_online_map);
094fe2e7 317#endif
1da177e4
LT
318 return 0;
319}
320
321int generic_cpu_enable(unsigned int cpu)
322{
323 /* Do the normal bootup if we haven't
324 * already bootstrapped. */
325 if (system_state != SYSTEM_RUNNING)
326 return -ENOSYS;
327
328 /* get the target out of it's holding state */
329 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
0d8d4d42 330 smp_wmb();
1da177e4
LT
331
332 while (!cpu_online(cpu))
333 cpu_relax();
334
094fe2e7 335#ifdef CONFIG_PPC64
1da177e4
LT
336 fixup_irqs(cpu_online_map);
337 /* counter the irq disable in fixup_irqs */
338 local_irq_enable();
094fe2e7 339#endif
1da177e4
LT
340 return 0;
341}
342
343void generic_cpu_die(unsigned int cpu)
344{
345 int i;
346
347 for (i = 0; i < 100; i++) {
0d8d4d42 348 smp_rmb();
1da177e4
LT
349 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
350 return;
351 msleep(100);
352 }
353 printk(KERN_ERR "CPU%d didn't die...\n", cpu);
354}
355
356void generic_mach_cpu_die(void)
357{
358 unsigned int cpu;
359
360 local_irq_disable();
361 cpu = smp_processor_id();
362 printk(KERN_DEBUG "CPU%d offline\n", cpu);
363 __get_cpu_var(cpu_state) = CPU_DEAD;
0d8d4d42 364 smp_wmb();
1da177e4
LT
365 while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
366 cpu_relax();
ea0f1cab 367 set_cpu_online(cpu, true);
1da177e4
LT
368 local_irq_enable();
369}
370#endif
371
372static int __devinit cpu_enable(unsigned int cpu)
373{
8cffc6ac 374 if (smp_ops && smp_ops->cpu_enable)
1da177e4
LT
375 return smp_ops->cpu_enable(cpu);
376
377 return -ENOSYS;
378}
379
b282b6f8 380int __cpuinit __cpu_up(unsigned int cpu)
1da177e4
LT
381{
382 int c;
383
5ad57078 384 secondary_ti = current_set[cpu];
1da177e4
LT
385 if (!cpu_enable(cpu))
386 return 0;
387
8cffc6ac
BH
388 if (smp_ops == NULL ||
389 (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
1da177e4
LT
390 return -EINVAL;
391
1da177e4
LT
392 /* Make sure callin-map entry is 0 (can be leftover a CPU
393 * hotplug
394 */
395 cpu_callin_map[cpu] = 0;
396
397 /* The information for processor bringup must
398 * be written out to main store before we release
399 * the processor.
400 */
0d8d4d42 401 smp_mb();
1da177e4
LT
402
403 /* wake up cpus */
404 DBG("smp: kicking cpu %d\n", cpu);
405 smp_ops->kick_cpu(cpu);
406
407 /*
408 * wait to see if the cpu made a callin (is actually up).
409 * use this value that I found through experimentation.
410 * -- Cort
411 */
412 if (system_state < SYSTEM_RUNNING)
ee0339f2 413 for (c = 50000; c && !cpu_callin_map[cpu]; c--)
1da177e4
LT
414 udelay(100);
415#ifdef CONFIG_HOTPLUG_CPU
416 else
417 /*
418 * CPUs can take much longer to come up in the
419 * hotplug case. Wait five seconds.
420 */
67764263
GS
421 for (c = 5000; c && !cpu_callin_map[cpu]; c--)
422 msleep(1);
1da177e4
LT
423#endif
424
425 if (!cpu_callin_map[cpu]) {
426 printk("Processor %u is stuck.\n", cpu);
427 return -ENOENT;
428 }
429
430 printk("Processor %u found.\n", cpu);
431
432 if (smp_ops->give_timebase)
433 smp_ops->give_timebase();
434
435 /* Wait until cpu puts itself in the online map */
436 while (!cpu_online(cpu))
437 cpu_relax();
438
439 return 0;
440}
441
e9efed3b
NL
442/* Return the value of the reg property corresponding to the given
443 * logical cpu.
444 */
445int cpu_to_core_id(int cpu)
446{
447 struct device_node *np;
448 const int *reg;
449 int id = -1;
450
451 np = of_get_cpu_node(cpu, NULL);
452 if (!np)
453 goto out;
454
455 reg = of_get_property(np, "reg", NULL);
456 if (!reg)
457 goto out;
458
459 id = *reg;
460out:
461 of_node_put(np);
462 return id;
463}
464
440a0857
NL
465/* Must be called when no change can occur to cpu_present_map,
466 * i.e. during cpu online or offline.
467 */
468static struct device_node *cpu_to_l2cache(int cpu)
469{
470 struct device_node *np;
b2ea25b9 471 struct device_node *cache;
440a0857
NL
472
473 if (!cpu_present(cpu))
474 return NULL;
475
476 np = of_get_cpu_node(cpu, NULL);
477 if (np == NULL)
478 return NULL;
479
b2ea25b9
NL
480 cache = of_find_next_cache_node(np);
481
440a0857
NL
482 of_node_put(np);
483
b2ea25b9 484 return cache;
440a0857 485}
1da177e4
LT
486
487/* Activate a secondary processor. */
488int __devinit start_secondary(void *unused)
489{
490 unsigned int cpu = smp_processor_id();
440a0857 491 struct device_node *l2_cache;
e2075f79 492 int i, base;
1da177e4
LT
493
494 atomic_inc(&init_mm.mm_count);
495 current->active_mm = &init_mm;
496
497 smp_store_cpu_info(cpu);
5ad57078 498 set_dec(tb_ticks_per_jiffy);
e4d76e1c 499 preempt_disable();
1da177e4
LT
500 cpu_callin_map[cpu] = 1;
501
757cbd46
KG
502 if (smp_ops->setup_cpu)
503 smp_ops->setup_cpu(cpu);
1da177e4
LT
504 if (smp_ops->take_timebase)
505 smp_ops->take_timebase();
506
7d4d6154 507 if (system_state > SYSTEM_BOOTING)
c6622f63 508 snapshot_timebase();
7d4d6154 509
d831d0b8
TB
510 secondary_cpu_time_init();
511
b7d7a240 512 ipi_call_lock();
e545a614 513 notify_cpu_starting(cpu);
ea0f1cab 514 set_cpu_online(cpu, true);
e2075f79
NL
515 /* Update sibling maps */
516 base = cpu_first_thread_in_core(cpu);
517 for (i = 0; i < threads_per_core; i++) {
518 if (cpu_is_offline(base + i))
519 continue;
520 cpu_set(cpu, per_cpu(cpu_sibling_map, base + i));
521 cpu_set(base + i, per_cpu(cpu_sibling_map, cpu));
440a0857
NL
522
523 /* cpu_core_map should be a superset of
524 * cpu_sibling_map even if we don't have cache
525 * information, so update the former here, too.
526 */
527 cpu_set(cpu, per_cpu(cpu_core_map, base +i));
528 cpu_set(base + i, per_cpu(cpu_core_map, cpu));
e2075f79 529 }
440a0857
NL
530 l2_cache = cpu_to_l2cache(cpu);
531 for_each_online_cpu(i) {
532 struct device_node *np = cpu_to_l2cache(i);
533 if (!np)
534 continue;
535 if (np == l2_cache) {
536 cpu_set(cpu, per_cpu(cpu_core_map, i));
537 cpu_set(i, per_cpu(cpu_core_map, cpu));
538 }
539 of_node_put(np);
540 }
541 of_node_put(l2_cache);
b7d7a240 542 ipi_call_unlock();
1da177e4
LT
543
544 local_irq_enable();
545
546 cpu_idle();
547 return 0;
548}
549
550int setup_profiling_timer(unsigned int multiplier)
551{
552 return 0;
553}
554
555void __init smp_cpus_done(unsigned int max_cpus)
556{
557 cpumask_t old_mask;
558
559 /* We want the setup_cpu() here to be called from CPU 0, but our
560 * init thread may have been "borrowed" by another CPU in the meantime
561 * se we pin us down to CPU 0 for a short while
562 */
563 old_mask = current->cpus_allowed;
564 set_cpus_allowed(current, cpumask_of_cpu(boot_cpuid));
565
757cbd46 566 if (smp_ops && smp_ops->setup_cpu)
8cffc6ac 567 smp_ops->setup_cpu(boot_cpuid);
1da177e4
LT
568
569 set_cpus_allowed(current, old_mask);
4b703a23 570
c6622f63
PM
571 snapshot_timebases();
572
4b703a23 573 dump_numa_cpu_topology();
1da177e4
LT
574}
575
576#ifdef CONFIG_HOTPLUG_CPU
577int __cpu_disable(void)
578{
440a0857 579 struct device_node *l2_cache;
e2075f79
NL
580 int cpu = smp_processor_id();
581 int base, i;
582 int err;
1da177e4 583
e2075f79
NL
584 if (!smp_ops->cpu_disable)
585 return -ENOSYS;
586
587 err = smp_ops->cpu_disable();
588 if (err)
589 return err;
590
591 /* Update sibling maps */
592 base = cpu_first_thread_in_core(cpu);
593 for (i = 0; i < threads_per_core; i++) {
594 cpu_clear(cpu, per_cpu(cpu_sibling_map, base + i));
595 cpu_clear(base + i, per_cpu(cpu_sibling_map, cpu));
440a0857
NL
596 cpu_clear(cpu, per_cpu(cpu_core_map, base +i));
597 cpu_clear(base + i, per_cpu(cpu_core_map, cpu));
598 }
599
600 l2_cache = cpu_to_l2cache(cpu);
601 for_each_present_cpu(i) {
602 struct device_node *np = cpu_to_l2cache(i);
603 if (!np)
604 continue;
605 if (np == l2_cache) {
606 cpu_clear(cpu, per_cpu(cpu_core_map, i));
607 cpu_clear(i, per_cpu(cpu_core_map, cpu));
608 }
609 of_node_put(np);
e2075f79 610 }
440a0857
NL
611 of_node_put(l2_cache);
612
e2075f79
NL
613
614 return 0;
1da177e4
LT
615}
616
617void __cpu_die(unsigned int cpu)
618{
619 if (smp_ops->cpu_die)
620 smp_ops->cpu_die(cpu);
621}
d0174c72
NF
622
623static DEFINE_MUTEX(powerpc_cpu_hotplug_driver_mutex);
624
625void cpu_hotplug_driver_lock()
626{
627 mutex_lock(&powerpc_cpu_hotplug_driver_mutex);
628}
629
630void cpu_hotplug_driver_unlock()
631{
632 mutex_unlock(&powerpc_cpu_hotplug_driver_mutex);
633}
1da177e4 634#endif