cpumask: Use accessors for cpu_*_mask: powerpc
[linux-2.6.git] / arch / powerpc / kernel / smp.c
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
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>
33 #include <linux/topology.h>
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>
42 #include <asm/time.h>
43 #include <asm/machdep.h>
44 #include <asm/cputhreads.h>
45 #include <asm/cputable.h>
46 #include <asm/system.h>
47 #include <asm/mpic.h>
48 #include <asm/vdso_datapage.h>
49 #ifdef CONFIG_PPC64
50 #include <asm/paca.h>
51 #endif
52
53 #ifdef DEBUG
54 #include <asm/udbg.h>
55 #define DBG(fmt...) udbg_printf(fmt)
56 #else
57 #define DBG(fmt...)
58 #endif
59
60 struct thread_info *secondary_ti;
61
62 DEFINE_PER_CPU(cpumask_t, cpu_sibling_map) = CPU_MASK_NONE;
63 DEFINE_PER_CPU(cpumask_t, cpu_core_map) = CPU_MASK_NONE;
64
65 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
66 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
67
68 /* SMP operations for this machine */
69 struct smp_ops_t *smp_ops;
70
71 /* Can't be static due to PowerMac hackery */
72 volatile unsigned int cpu_callin_map[NR_CPUS];
73
74 int smt_enabled_at_boot = 1;
75
76 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
77
78 #ifdef CONFIG_PPC64
79 void __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;
89         smp_mb();
90 }
91 #endif
92
93 void smp_message_recv(int msg)
94 {
95         switch(msg) {
96         case PPC_MSG_CALL_FUNCTION:
97                 generic_smp_call_function_interrupt();
98                 break;
99         case PPC_MSG_RESCHEDULE:
100                 /* we notice need_resched on exit */
101                 break;
102         case PPC_MSG_CALL_FUNC_SINGLE:
103                 generic_smp_call_function_single_interrupt();
104                 break;
105         case PPC_MSG_DEBUGGER_BREAK:
106                 if (crash_ipi_function_ptr) {
107                         crash_ipi_function_ptr(get_irq_regs());
108                         break;
109                 }
110 #ifdef CONFIG_DEBUGGER
111                 debugger_ipi(get_irq_regs());
112                 break;
113 #endif /* CONFIG_DEBUGGER */
114                 /* FALLTHROUGH */
115         default:
116                 printk("SMP %d: smp_message_recv(): unknown msg %d\n",
117                        smp_processor_id(), msg);
118                 break;
119         }
120 }
121
122 static irqreturn_t call_function_action(int irq, void *data)
123 {
124         generic_smp_call_function_interrupt();
125         return IRQ_HANDLED;
126 }
127
128 static 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
134 static irqreturn_t call_function_single_action(int irq, void *data)
135 {
136         generic_smp_call_function_single_interrupt();
137         return IRQ_HANDLED;
138 }
139
140 static irqreturn_t debug_ipi_action(int irq, void *data)
141 {
142         smp_message_recv(PPC_MSG_DEBUGGER_BREAK);
143         return IRQ_HANDLED;
144 }
145
146 static 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
153 const 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 */
161 int 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
181 void smp_send_reschedule(int cpu)
182 {
183         if (likely(smp_ops))
184                 smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE);
185 }
186
187 void arch_send_call_function_single_ipi(int cpu)
188 {
189         smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNC_SINGLE);
190 }
191
192 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
193 {
194         unsigned int cpu;
195
196         for_each_cpu(cpu, mask)
197                 smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNCTION);
198 }
199
200 #ifdef CONFIG_DEBUGGER
201 void smp_send_debugger_break(int cpu)
202 {
203         if (likely(smp_ops))
204                 smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
205 }
206 #endif
207
208 #ifdef CONFIG_KEXEC
209 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
210 {
211         crash_ipi_function_ptr = crash_ipi_callback;
212         if (crash_ipi_callback && smp_ops) {
213                 mb();
214                 smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_DEBUGGER_BREAK);
215         }
216 }
217 #endif
218
219 static void stop_this_cpu(void *dummy)
220 {
221         local_irq_disable();
222         while (1)
223                 ;
224 }
225
226 void smp_send_stop(void)
227 {
228         smp_call_function(stop_this_cpu, NULL, 0);
229 }
230
231 struct thread_info *current_set[NR_CPUS];
232
233 static void __devinit smp_store_cpu_info(int id)
234 {
235         per_cpu(pvr, id) = mfspr(SPRN_PVR);
236 }
237
238 static void __init smp_create_idle(unsigned int cpu)
239 {
240         struct task_struct *p;
241
242         /* create a process for the processor */
243         p = fork_idle(cpu);
244         if (IS_ERR(p))
245                 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
246 #ifdef CONFIG_PPC64
247         paca[cpu].__current = p;
248         paca[cpu].kstack = (unsigned long) task_thread_info(p)
249                 + THREAD_SIZE - STACK_FRAME_OVERHEAD;
250 #endif
251         current_set[cpu] = task_thread_info(p);
252         task_thread_info(p)->cpu = cpu;
253 }
254
255 void __init smp_prepare_cpus(unsigned int max_cpus)
256 {
257         unsigned int cpu;
258
259         DBG("smp_prepare_cpus\n");
260
261         /* 
262          * setup_cpu may need to be called on the boot cpu. We havent
263          * spun any cpus up but lets be paranoid.
264          */
265         BUG_ON(boot_cpuid != smp_processor_id());
266
267         /* Fixup boot cpu */
268         smp_store_cpu_info(boot_cpuid);
269         cpu_callin_map[boot_cpuid] = 1;
270
271         if (smp_ops)
272                 if (smp_ops->probe)
273                         max_cpus = smp_ops->probe();
274                 else
275                         max_cpus = NR_CPUS;
276         else
277                 max_cpus = 1;
278  
279         smp_space_timers(max_cpus);
280
281         for_each_possible_cpu(cpu)
282                 if (cpu != boot_cpuid)
283                         smp_create_idle(cpu);
284 }
285
286 void __devinit smp_prepare_boot_cpu(void)
287 {
288         BUG_ON(smp_processor_id() != boot_cpuid);
289
290         set_cpu_online(boot_cpuid, true);
291         cpu_set(boot_cpuid, per_cpu(cpu_sibling_map, boot_cpuid));
292         cpu_set(boot_cpuid, per_cpu(cpu_core_map, boot_cpuid));
293 #ifdef CONFIG_PPC64
294         paca[boot_cpuid].__current = current;
295 #endif
296         current_set[boot_cpuid] = task_thread_info(current);
297 }
298
299 #ifdef CONFIG_HOTPLUG_CPU
300 /* State of each CPU during hotplug phases */
301 DEFINE_PER_CPU(int, cpu_state) = { 0 };
302
303 int generic_cpu_disable(void)
304 {
305         unsigned int cpu = smp_processor_id();
306
307         if (cpu == boot_cpuid)
308                 return -EBUSY;
309
310         set_cpu_online(cpu, false);
311 #ifdef CONFIG_PPC64
312         vdso_data->processorCount--;
313         fixup_irqs(cpu_online_map);
314 #endif
315         return 0;
316 }
317
318 int generic_cpu_enable(unsigned int cpu)
319 {
320         /* Do the normal bootup if we haven't
321          * already bootstrapped. */
322         if (system_state != SYSTEM_RUNNING)
323                 return -ENOSYS;
324
325         /* get the target out of it's holding state */
326         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
327         smp_wmb();
328
329         while (!cpu_online(cpu))
330                 cpu_relax();
331
332 #ifdef CONFIG_PPC64
333         fixup_irqs(cpu_online_map);
334         /* counter the irq disable in fixup_irqs */
335         local_irq_enable();
336 #endif
337         return 0;
338 }
339
340 void generic_cpu_die(unsigned int cpu)
341 {
342         int i;
343
344         for (i = 0; i < 100; i++) {
345                 smp_rmb();
346                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
347                         return;
348                 msleep(100);
349         }
350         printk(KERN_ERR "CPU%d didn't die...\n", cpu);
351 }
352
353 void generic_mach_cpu_die(void)
354 {
355         unsigned int cpu;
356
357         local_irq_disable();
358         cpu = smp_processor_id();
359         printk(KERN_DEBUG "CPU%d offline\n", cpu);
360         __get_cpu_var(cpu_state) = CPU_DEAD;
361         smp_wmb();
362         while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
363                 cpu_relax();
364         set_cpu_online(cpu, true);
365         local_irq_enable();
366 }
367 #endif
368
369 static int __devinit cpu_enable(unsigned int cpu)
370 {
371         if (smp_ops && smp_ops->cpu_enable)
372                 return smp_ops->cpu_enable(cpu);
373
374         return -ENOSYS;
375 }
376
377 int __cpuinit __cpu_up(unsigned int cpu)
378 {
379         int c;
380
381         secondary_ti = current_set[cpu];
382         if (!cpu_enable(cpu))
383                 return 0;
384
385         if (smp_ops == NULL ||
386             (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
387                 return -EINVAL;
388
389         /* Make sure callin-map entry is 0 (can be leftover a CPU
390          * hotplug
391          */
392         cpu_callin_map[cpu] = 0;
393
394         /* The information for processor bringup must
395          * be written out to main store before we release
396          * the processor.
397          */
398         smp_mb();
399
400         /* wake up cpus */
401         DBG("smp: kicking cpu %d\n", cpu);
402         smp_ops->kick_cpu(cpu);
403
404         /*
405          * wait to see if the cpu made a callin (is actually up).
406          * use this value that I found through experimentation.
407          * -- Cort
408          */
409         if (system_state < SYSTEM_RUNNING)
410                 for (c = 50000; c && !cpu_callin_map[cpu]; c--)
411                         udelay(100);
412 #ifdef CONFIG_HOTPLUG_CPU
413         else
414                 /*
415                  * CPUs can take much longer to come up in the
416                  * hotplug case.  Wait five seconds.
417                  */
418                 for (c = 5000; c && !cpu_callin_map[cpu]; c--)
419                         msleep(1);
420 #endif
421
422         if (!cpu_callin_map[cpu]) {
423                 printk("Processor %u is stuck.\n", cpu);
424                 return -ENOENT;
425         }
426
427         printk("Processor %u found.\n", cpu);
428
429         if (smp_ops->give_timebase)
430                 smp_ops->give_timebase();
431
432         /* Wait until cpu puts itself in the online map */
433         while (!cpu_online(cpu))
434                 cpu_relax();
435
436         return 0;
437 }
438
439 /* Return the value of the reg property corresponding to the given
440  * logical cpu.
441  */
442 int cpu_to_core_id(int cpu)
443 {
444         struct device_node *np;
445         const int *reg;
446         int id = -1;
447
448         np = of_get_cpu_node(cpu, NULL);
449         if (!np)
450                 goto out;
451
452         reg = of_get_property(np, "reg", NULL);
453         if (!reg)
454                 goto out;
455
456         id = *reg;
457 out:
458         of_node_put(np);
459         return id;
460 }
461
462 /* Must be called when no change can occur to cpu_present_map,
463  * i.e. during cpu online or offline.
464  */
465 static struct device_node *cpu_to_l2cache(int cpu)
466 {
467         struct device_node *np;
468         struct device_node *cache;
469
470         if (!cpu_present(cpu))
471                 return NULL;
472
473         np = of_get_cpu_node(cpu, NULL);
474         if (np == NULL)
475                 return NULL;
476
477         cache = of_find_next_cache_node(np);
478
479         of_node_put(np);
480
481         return cache;
482 }
483
484 /* Activate a secondary processor. */
485 int __devinit start_secondary(void *unused)
486 {
487         unsigned int cpu = smp_processor_id();
488         struct device_node *l2_cache;
489         int i, base;
490
491         atomic_inc(&init_mm.mm_count);
492         current->active_mm = &init_mm;
493
494         smp_store_cpu_info(cpu);
495         set_dec(tb_ticks_per_jiffy);
496         preempt_disable();
497         cpu_callin_map[cpu] = 1;
498
499         if (smp_ops->setup_cpu)
500                 smp_ops->setup_cpu(cpu);
501         if (smp_ops->take_timebase)
502                 smp_ops->take_timebase();
503
504         if (system_state > SYSTEM_BOOTING)
505                 snapshot_timebase();
506
507         secondary_cpu_time_init();
508
509         ipi_call_lock();
510         notify_cpu_starting(cpu);
511         set_cpu_online(cpu, true);
512         /* Update sibling maps */
513         base = cpu_first_thread_in_core(cpu);
514         for (i = 0; i < threads_per_core; i++) {
515                 if (cpu_is_offline(base + i))
516                         continue;
517                 cpu_set(cpu, per_cpu(cpu_sibling_map, base + i));
518                 cpu_set(base + i, per_cpu(cpu_sibling_map, cpu));
519
520                 /* cpu_core_map should be a superset of
521                  * cpu_sibling_map even if we don't have cache
522                  * information, so update the former here, too.
523                  */
524                 cpu_set(cpu, per_cpu(cpu_core_map, base +i));
525                 cpu_set(base + i, per_cpu(cpu_core_map, cpu));
526         }
527         l2_cache = cpu_to_l2cache(cpu);
528         for_each_online_cpu(i) {
529                 struct device_node *np = cpu_to_l2cache(i);
530                 if (!np)
531                         continue;
532                 if (np == l2_cache) {
533                         cpu_set(cpu, per_cpu(cpu_core_map, i));
534                         cpu_set(i, per_cpu(cpu_core_map, cpu));
535                 }
536                 of_node_put(np);
537         }
538         of_node_put(l2_cache);
539         ipi_call_unlock();
540
541         local_irq_enable();
542
543         cpu_idle();
544         return 0;
545 }
546
547 int setup_profiling_timer(unsigned int multiplier)
548 {
549         return 0;
550 }
551
552 void __init smp_cpus_done(unsigned int max_cpus)
553 {
554         cpumask_t old_mask;
555
556         /* We want the setup_cpu() here to be called from CPU 0, but our
557          * init thread may have been "borrowed" by another CPU in the meantime
558          * se we pin us down to CPU 0 for a short while
559          */
560         old_mask = current->cpus_allowed;
561         set_cpus_allowed(current, cpumask_of_cpu(boot_cpuid));
562         
563         if (smp_ops && smp_ops->setup_cpu)
564                 smp_ops->setup_cpu(boot_cpuid);
565
566         set_cpus_allowed(current, old_mask);
567
568         snapshot_timebases();
569
570         dump_numa_cpu_topology();
571 }
572
573 #ifdef CONFIG_HOTPLUG_CPU
574 int __cpu_disable(void)
575 {
576         struct device_node *l2_cache;
577         int cpu = smp_processor_id();
578         int base, i;
579         int err;
580
581         if (!smp_ops->cpu_disable)
582                 return -ENOSYS;
583
584         err = smp_ops->cpu_disable();
585         if (err)
586                 return err;
587
588         /* Update sibling maps */
589         base = cpu_first_thread_in_core(cpu);
590         for (i = 0; i < threads_per_core; i++) {
591                 cpu_clear(cpu, per_cpu(cpu_sibling_map, base + i));
592                 cpu_clear(base + i, per_cpu(cpu_sibling_map, cpu));
593                 cpu_clear(cpu, per_cpu(cpu_core_map, base +i));
594                 cpu_clear(base + i, per_cpu(cpu_core_map, cpu));
595         }
596
597         l2_cache = cpu_to_l2cache(cpu);
598         for_each_present_cpu(i) {
599                 struct device_node *np = cpu_to_l2cache(i);
600                 if (!np)
601                         continue;
602                 if (np == l2_cache) {
603                         cpu_clear(cpu, per_cpu(cpu_core_map, i));
604                         cpu_clear(i, per_cpu(cpu_core_map, cpu));
605                 }
606                 of_node_put(np);
607         }
608         of_node_put(l2_cache);
609
610
611         return 0;
612 }
613
614 void __cpu_die(unsigned int cpu)
615 {
616         if (smp_ops->cpu_die)
617                 smp_ops->cpu_die(cpu);
618 }
619 #endif