Commit | Line | Data |
---|---|---|
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 | ||
20 | #include <linux/config.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/sched.h> | |
24 | #include <linux/smp.h> | |
25 | #include <linux/interrupt.h> | |
26 | #include <linux/delay.h> | |
27 | #include <linux/init.h> | |
28 | #include <linux/spinlock.h> | |
29 | #include <linux/cache.h> | |
30 | #include <linux/err.h> | |
31 | #include <linux/sysdev.h> | |
32 | #include <linux/cpu.h> | |
33 | #include <linux/notifier.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/paca.h> | |
43 | #include <asm/time.h> | |
44 | #include <asm/machdep.h> | |
45 | #include <asm/cputable.h> | |
46 | #include <asm/system.h> | |
47 | #include <asm/abs_addr.h> | |
48 | ||
49 | #include "mpic.h" | |
50 | ||
51 | #ifdef DEBUG | |
52 | #define DBG(fmt...) udbg_printf(fmt) | |
53 | #else | |
54 | #define DBG(fmt...) | |
55 | #endif | |
56 | ||
57 | cpumask_t cpu_possible_map = CPU_MASK_NONE; | |
58 | cpumask_t cpu_online_map = CPU_MASK_NONE; | |
59 | cpumask_t cpu_sibling_map[NR_CPUS] = { [0 ... NR_CPUS-1] = CPU_MASK_NONE }; | |
60 | ||
61 | EXPORT_SYMBOL(cpu_online_map); | |
62 | EXPORT_SYMBOL(cpu_possible_map); | |
63 | ||
64 | struct smp_ops_t *smp_ops; | |
65 | ||
66 | static volatile unsigned int cpu_callin_map[NR_CPUS]; | |
67 | ||
68 | extern unsigned char stab_array[]; | |
69 | ||
70 | void smp_call_function_interrupt(void); | |
71 | ||
72 | int smt_enabled_at_boot = 1; | |
73 | ||
74 | #ifdef CONFIG_PPC_MULTIPLATFORM | |
75 | void smp_mpic_message_pass(int target, int msg) | |
76 | { | |
77 | /* make sure we're sending something that translates to an IPI */ | |
78 | if ( msg > 0x3 ){ | |
79 | printk("SMP %d: smp_message_pass: unknown msg %d\n", | |
80 | smp_processor_id(), msg); | |
81 | return; | |
82 | } | |
83 | switch ( target ) | |
84 | { | |
85 | case MSG_ALL: | |
86 | mpic_send_ipi(msg, 0xffffffff); | |
87 | break; | |
88 | case MSG_ALL_BUT_SELF: | |
89 | mpic_send_ipi(msg, 0xffffffff & ~(1 << smp_processor_id())); | |
90 | break; | |
91 | default: | |
92 | mpic_send_ipi(msg, 1 << target); | |
93 | break; | |
94 | } | |
95 | } | |
96 | ||
97 | int __init smp_mpic_probe(void) | |
98 | { | |
99 | int nr_cpus; | |
100 | ||
101 | DBG("smp_mpic_probe()...\n"); | |
102 | ||
103 | nr_cpus = cpus_weight(cpu_possible_map); | |
104 | ||
105 | DBG("nr_cpus: %d\n", nr_cpus); | |
106 | ||
107 | if (nr_cpus > 1) | |
108 | mpic_request_ipis(); | |
109 | ||
110 | return nr_cpus; | |
111 | } | |
112 | ||
113 | void __devinit smp_mpic_setup_cpu(int cpu) | |
114 | { | |
115 | mpic_setup_this_cpu(); | |
116 | } | |
117 | ||
118 | void __devinit smp_generic_kick_cpu(int nr) | |
119 | { | |
120 | BUG_ON(nr < 0 || nr >= NR_CPUS); | |
121 | ||
122 | /* | |
123 | * The processor is currently spinning, waiting for the | |
124 | * cpu_start field to become non-zero After we set cpu_start, | |
125 | * the processor will continue on to secondary_start | |
126 | */ | |
127 | paca[nr].cpu_start = 1; | |
128 | mb(); | |
129 | } | |
130 | ||
131 | #endif /* CONFIG_PPC_MULTIPLATFORM */ | |
132 | ||
133 | static void __init smp_space_timers(unsigned int max_cpus) | |
134 | { | |
135 | int i; | |
136 | unsigned long offset = tb_ticks_per_jiffy / max_cpus; | |
137 | unsigned long previous_tb = paca[boot_cpuid].next_jiffy_update_tb; | |
138 | ||
139 | for_each_cpu(i) { | |
140 | if (i != boot_cpuid) { | |
141 | paca[i].next_jiffy_update_tb = | |
142 | previous_tb + offset; | |
143 | previous_tb = paca[i].next_jiffy_update_tb; | |
144 | } | |
145 | } | |
146 | } | |
147 | ||
148 | void smp_message_recv(int msg, struct pt_regs *regs) | |
149 | { | |
150 | switch(msg) { | |
151 | case PPC_MSG_CALL_FUNCTION: | |
152 | smp_call_function_interrupt(); | |
153 | break; | |
154 | case PPC_MSG_RESCHEDULE: | |
155 | /* XXX Do we have to do this? */ | |
156 | set_need_resched(); | |
157 | break; | |
158 | #if 0 | |
159 | case PPC_MSG_MIGRATE_TASK: | |
160 | /* spare */ | |
161 | break; | |
162 | #endif | |
163 | #ifdef CONFIG_DEBUGGER | |
164 | case PPC_MSG_DEBUGGER_BREAK: | |
165 | debugger_ipi(regs); | |
166 | break; | |
167 | #endif | |
168 | default: | |
169 | printk("SMP %d: smp_message_recv(): unknown msg %d\n", | |
170 | smp_processor_id(), msg); | |
171 | break; | |
172 | } | |
173 | } | |
174 | ||
175 | void smp_send_reschedule(int cpu) | |
176 | { | |
177 | smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE); | |
178 | } | |
179 | ||
180 | #ifdef CONFIG_DEBUGGER | |
181 | void smp_send_debugger_break(int cpu) | |
182 | { | |
183 | smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK); | |
184 | } | |
185 | #endif | |
186 | ||
187 | static void stop_this_cpu(void *dummy) | |
188 | { | |
189 | local_irq_disable(); | |
190 | while (1) | |
191 | ; | |
192 | } | |
193 | ||
194 | void smp_send_stop(void) | |
195 | { | |
196 | smp_call_function(stop_this_cpu, NULL, 1, 0); | |
197 | } | |
198 | ||
199 | /* | |
200 | * Structure and data for smp_call_function(). This is designed to minimise | |
201 | * static memory requirements. It also looks cleaner. | |
202 | * Stolen from the i386 version. | |
203 | */ | |
204 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(call_lock); | |
205 | ||
206 | static struct call_data_struct { | |
207 | void (*func) (void *info); | |
208 | void *info; | |
209 | atomic_t started; | |
210 | atomic_t finished; | |
211 | int wait; | |
212 | } *call_data; | |
213 | ||
214 | /* delay of at least 8 seconds on 1GHz cpu */ | |
215 | #define SMP_CALL_TIMEOUT (1UL << (30 + 3)) | |
216 | ||
217 | /* | |
218 | * This function sends a 'generic call function' IPI to all other CPUs | |
219 | * in the system. | |
220 | * | |
221 | * [SUMMARY] Run a function on all other CPUs. | |
222 | * <func> The function to run. This must be fast and non-blocking. | |
223 | * <info> An arbitrary pointer to pass to the function. | |
224 | * <nonatomic> currently unused. | |
225 | * <wait> If true, wait (atomically) until function has completed on other CPUs. | |
226 | * [RETURNS] 0 on success, else a negative status code. Does not return until | |
227 | * remote CPUs are nearly ready to execute <<func>> or are or have executed. | |
228 | * | |
229 | * You must not call this function with disabled interrupts or from a | |
230 | * hardware interrupt handler or from a bottom half handler. | |
231 | */ | |
232 | int smp_call_function (void (*func) (void *info), void *info, int nonatomic, | |
233 | int wait) | |
234 | { | |
235 | struct call_data_struct data; | |
236 | int ret = -1, cpus; | |
237 | unsigned long timeout; | |
238 | ||
239 | /* Can deadlock when called with interrupts disabled */ | |
240 | WARN_ON(irqs_disabled()); | |
241 | ||
242 | data.func = func; | |
243 | data.info = info; | |
244 | atomic_set(&data.started, 0); | |
245 | data.wait = wait; | |
246 | if (wait) | |
247 | atomic_set(&data.finished, 0); | |
248 | ||
249 | spin_lock(&call_lock); | |
250 | /* Must grab online cpu count with preempt disabled, otherwise | |
251 | * it can change. */ | |
252 | cpus = num_online_cpus() - 1; | |
253 | if (!cpus) { | |
254 | ret = 0; | |
255 | goto out; | |
256 | } | |
257 | ||
258 | call_data = &data; | |
259 | wmb(); | |
260 | /* Send a message to all other CPUs and wait for them to respond */ | |
261 | smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_CALL_FUNCTION); | |
262 | ||
263 | /* Wait for response */ | |
264 | timeout = SMP_CALL_TIMEOUT; | |
265 | while (atomic_read(&data.started) != cpus) { | |
266 | HMT_low(); | |
267 | if (--timeout == 0) { | |
268 | printk("smp_call_function on cpu %d: other cpus not " | |
269 | "responding (%d)\n", smp_processor_id(), | |
270 | atomic_read(&data.started)); | |
271 | debugger(NULL); | |
272 | goto out; | |
273 | } | |
274 | } | |
275 | ||
276 | if (wait) { | |
277 | timeout = SMP_CALL_TIMEOUT; | |
278 | while (atomic_read(&data.finished) != cpus) { | |
279 | HMT_low(); | |
280 | if (--timeout == 0) { | |
281 | printk("smp_call_function on cpu %d: other " | |
282 | "cpus not finishing (%d/%d)\n", | |
283 | smp_processor_id(), | |
284 | atomic_read(&data.finished), | |
285 | atomic_read(&data.started)); | |
286 | debugger(NULL); | |
287 | goto out; | |
288 | } | |
289 | } | |
290 | } | |
291 | ||
292 | ret = 0; | |
293 | ||
294 | out: | |
295 | call_data = NULL; | |
296 | HMT_medium(); | |
297 | spin_unlock(&call_lock); | |
298 | return ret; | |
299 | } | |
300 | ||
301 | EXPORT_SYMBOL(smp_call_function); | |
302 | ||
303 | void smp_call_function_interrupt(void) | |
304 | { | |
305 | void (*func) (void *info); | |
306 | void *info; | |
307 | int wait; | |
308 | ||
309 | /* call_data will be NULL if the sender timed out while | |
310 | * waiting on us to receive the call. | |
311 | */ | |
312 | if (!call_data) | |
313 | return; | |
314 | ||
315 | func = call_data->func; | |
316 | info = call_data->info; | |
317 | wait = call_data->wait; | |
318 | ||
319 | if (!wait) | |
320 | smp_mb__before_atomic_inc(); | |
321 | ||
322 | /* | |
323 | * Notify initiating CPU that I've grabbed the data and am | |
324 | * about to execute the function | |
325 | */ | |
326 | atomic_inc(&call_data->started); | |
327 | /* | |
328 | * At this point the info structure may be out of scope unless wait==1 | |
329 | */ | |
330 | (*func)(info); | |
331 | if (wait) { | |
332 | smp_mb__before_atomic_inc(); | |
333 | atomic_inc(&call_data->finished); | |
334 | } | |
335 | } | |
336 | ||
337 | extern unsigned long decr_overclock; | |
338 | extern struct gettimeofday_struct do_gtod; | |
339 | ||
340 | struct thread_info *current_set[NR_CPUS]; | |
341 | ||
342 | DECLARE_PER_CPU(unsigned int, pvr); | |
343 | ||
344 | static void __devinit smp_store_cpu_info(int id) | |
345 | { | |
346 | per_cpu(pvr, id) = mfspr(SPRN_PVR); | |
347 | } | |
348 | ||
349 | static void __init smp_create_idle(unsigned int cpu) | |
350 | { | |
351 | struct task_struct *p; | |
352 | ||
353 | /* create a process for the processor */ | |
354 | p = fork_idle(cpu); | |
355 | if (IS_ERR(p)) | |
356 | panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p)); | |
357 | paca[cpu].__current = p; | |
358 | current_set[cpu] = p->thread_info; | |
359 | } | |
360 | ||
361 | void __init smp_prepare_cpus(unsigned int max_cpus) | |
362 | { | |
363 | unsigned int cpu; | |
364 | ||
365 | DBG("smp_prepare_cpus\n"); | |
366 | ||
367 | /* | |
368 | * setup_cpu may need to be called on the boot cpu. We havent | |
369 | * spun any cpus up but lets be paranoid. | |
370 | */ | |
371 | BUG_ON(boot_cpuid != smp_processor_id()); | |
372 | ||
373 | /* Fixup boot cpu */ | |
374 | smp_store_cpu_info(boot_cpuid); | |
375 | cpu_callin_map[boot_cpuid] = 1; | |
376 | ||
377 | #ifndef CONFIG_PPC_ISERIES | |
378 | paca[boot_cpuid].next_jiffy_update_tb = tb_last_stamp = get_tb(); | |
379 | ||
380 | /* | |
381 | * Should update do_gtod.stamp_xsec. | |
382 | * For now we leave it which means the time can be some | |
383 | * number of msecs off until someone does a settimeofday() | |
384 | */ | |
385 | do_gtod.varp->tb_orig_stamp = tb_last_stamp; | |
386 | systemcfg->tb_orig_stamp = tb_last_stamp; | |
387 | #endif | |
388 | ||
389 | max_cpus = smp_ops->probe(); | |
390 | ||
391 | smp_space_timers(max_cpus); | |
392 | ||
393 | for_each_cpu(cpu) | |
394 | if (cpu != boot_cpuid) | |
395 | smp_create_idle(cpu); | |
396 | } | |
397 | ||
398 | void __devinit smp_prepare_boot_cpu(void) | |
399 | { | |
400 | BUG_ON(smp_processor_id() != boot_cpuid); | |
401 | ||
402 | cpu_set(boot_cpuid, cpu_online_map); | |
403 | ||
404 | paca[boot_cpuid].__current = current; | |
405 | current_set[boot_cpuid] = current->thread_info; | |
406 | } | |
407 | ||
408 | #ifdef CONFIG_HOTPLUG_CPU | |
409 | /* State of each CPU during hotplug phases */ | |
410 | DEFINE_PER_CPU(int, cpu_state) = { 0 }; | |
411 | ||
412 | int generic_cpu_disable(void) | |
413 | { | |
414 | unsigned int cpu = smp_processor_id(); | |
415 | ||
416 | if (cpu == boot_cpuid) | |
417 | return -EBUSY; | |
418 | ||
419 | systemcfg->processorCount--; | |
420 | cpu_clear(cpu, cpu_online_map); | |
421 | fixup_irqs(cpu_online_map); | |
422 | return 0; | |
423 | } | |
424 | ||
425 | int generic_cpu_enable(unsigned int cpu) | |
426 | { | |
427 | /* Do the normal bootup if we haven't | |
428 | * already bootstrapped. */ | |
429 | if (system_state != SYSTEM_RUNNING) | |
430 | return -ENOSYS; | |
431 | ||
432 | /* get the target out of it's holding state */ | |
433 | per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; | |
434 | wmb(); | |
435 | ||
436 | while (!cpu_online(cpu)) | |
437 | cpu_relax(); | |
438 | ||
439 | fixup_irqs(cpu_online_map); | |
440 | /* counter the irq disable in fixup_irqs */ | |
441 | local_irq_enable(); | |
442 | return 0; | |
443 | } | |
444 | ||
445 | void generic_cpu_die(unsigned int cpu) | |
446 | { | |
447 | int i; | |
448 | ||
449 | for (i = 0; i < 100; i++) { | |
450 | rmb(); | |
451 | if (per_cpu(cpu_state, cpu) == CPU_DEAD) | |
452 | return; | |
453 | msleep(100); | |
454 | } | |
455 | printk(KERN_ERR "CPU%d didn't die...\n", cpu); | |
456 | } | |
457 | ||
458 | void generic_mach_cpu_die(void) | |
459 | { | |
460 | unsigned int cpu; | |
461 | ||
462 | local_irq_disable(); | |
463 | cpu = smp_processor_id(); | |
464 | printk(KERN_DEBUG "CPU%d offline\n", cpu); | |
465 | __get_cpu_var(cpu_state) = CPU_DEAD; | |
466 | wmb(); | |
467 | while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE) | |
468 | cpu_relax(); | |
469 | ||
470 | flush_tlb_pending(); | |
471 | cpu_set(cpu, cpu_online_map); | |
472 | local_irq_enable(); | |
473 | } | |
474 | #endif | |
475 | ||
476 | static int __devinit cpu_enable(unsigned int cpu) | |
477 | { | |
478 | if (smp_ops->cpu_enable) | |
479 | return smp_ops->cpu_enable(cpu); | |
480 | ||
481 | return -ENOSYS; | |
482 | } | |
483 | ||
484 | int __devinit __cpu_up(unsigned int cpu) | |
485 | { | |
486 | int c; | |
487 | ||
488 | if (!cpu_enable(cpu)) | |
489 | return 0; | |
490 | ||
491 | if (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)) | |
492 | return -EINVAL; | |
493 | ||
494 | paca[cpu].default_decr = tb_ticks_per_jiffy / decr_overclock; | |
495 | ||
496 | if (!cpu_has_feature(CPU_FTR_SLB)) { | |
497 | void *tmp; | |
498 | ||
499 | /* maximum of 48 CPUs on machines with a segment table */ | |
500 | if (cpu >= 48) | |
501 | BUG(); | |
502 | ||
503 | tmp = &stab_array[PAGE_SIZE * cpu]; | |
504 | memset(tmp, 0, PAGE_SIZE); | |
505 | paca[cpu].stab_addr = (unsigned long)tmp; | |
506 | paca[cpu].stab_real = virt_to_abs(tmp); | |
507 | } | |
508 | ||
509 | /* Make sure callin-map entry is 0 (can be leftover a CPU | |
510 | * hotplug | |
511 | */ | |
512 | cpu_callin_map[cpu] = 0; | |
513 | ||
514 | /* The information for processor bringup must | |
515 | * be written out to main store before we release | |
516 | * the processor. | |
517 | */ | |
518 | mb(); | |
519 | ||
520 | /* wake up cpus */ | |
521 | DBG("smp: kicking cpu %d\n", cpu); | |
522 | smp_ops->kick_cpu(cpu); | |
523 | ||
524 | /* | |
525 | * wait to see if the cpu made a callin (is actually up). | |
526 | * use this value that I found through experimentation. | |
527 | * -- Cort | |
528 | */ | |
529 | if (system_state < SYSTEM_RUNNING) | |
530 | for (c = 5000; c && !cpu_callin_map[cpu]; c--) | |
531 | udelay(100); | |
532 | #ifdef CONFIG_HOTPLUG_CPU | |
533 | else | |
534 | /* | |
535 | * CPUs can take much longer to come up in the | |
536 | * hotplug case. Wait five seconds. | |
537 | */ | |
538 | for (c = 25; c && !cpu_callin_map[cpu]; c--) { | |
539 | msleep(200); | |
540 | } | |
541 | #endif | |
542 | ||
543 | if (!cpu_callin_map[cpu]) { | |
544 | printk("Processor %u is stuck.\n", cpu); | |
545 | return -ENOENT; | |
546 | } | |
547 | ||
548 | printk("Processor %u found.\n", cpu); | |
549 | ||
550 | if (smp_ops->give_timebase) | |
551 | smp_ops->give_timebase(); | |
552 | ||
553 | /* Wait until cpu puts itself in the online map */ | |
554 | while (!cpu_online(cpu)) | |
555 | cpu_relax(); | |
556 | ||
557 | return 0; | |
558 | } | |
559 | ||
560 | ||
561 | /* Activate a secondary processor. */ | |
562 | int __devinit start_secondary(void *unused) | |
563 | { | |
564 | unsigned int cpu = smp_processor_id(); | |
565 | ||
566 | atomic_inc(&init_mm.mm_count); | |
567 | current->active_mm = &init_mm; | |
568 | ||
569 | smp_store_cpu_info(cpu); | |
570 | set_dec(paca[cpu].default_decr); | |
571 | cpu_callin_map[cpu] = 1; | |
572 | ||
573 | smp_ops->setup_cpu(cpu); | |
574 | if (smp_ops->take_timebase) | |
575 | smp_ops->take_timebase(); | |
576 | ||
577 | spin_lock(&call_lock); | |
578 | cpu_set(cpu, cpu_online_map); | |
579 | spin_unlock(&call_lock); | |
580 | ||
581 | local_irq_enable(); | |
582 | ||
583 | cpu_idle(); | |
584 | return 0; | |
585 | } | |
586 | ||
587 | int setup_profiling_timer(unsigned int multiplier) | |
588 | { | |
589 | return 0; | |
590 | } | |
591 | ||
592 | void __init smp_cpus_done(unsigned int max_cpus) | |
593 | { | |
594 | cpumask_t old_mask; | |
595 | ||
596 | /* We want the setup_cpu() here to be called from CPU 0, but our | |
597 | * init thread may have been "borrowed" by another CPU in the meantime | |
598 | * se we pin us down to CPU 0 for a short while | |
599 | */ | |
600 | old_mask = current->cpus_allowed; | |
601 | set_cpus_allowed(current, cpumask_of_cpu(boot_cpuid)); | |
602 | ||
603 | smp_ops->setup_cpu(boot_cpuid); | |
604 | ||
605 | set_cpus_allowed(current, old_mask); | |
606 | } | |
607 | ||
608 | #ifdef CONFIG_HOTPLUG_CPU | |
609 | int __cpu_disable(void) | |
610 | { | |
611 | if (smp_ops->cpu_disable) | |
612 | return smp_ops->cpu_disable(); | |
613 | ||
614 | return -ENOSYS; | |
615 | } | |
616 | ||
617 | void __cpu_die(unsigned int cpu) | |
618 | { | |
619 | if (smp_ops->cpu_die) | |
620 | smp_ops->cpu_die(cpu); | |
621 | } | |
622 | #endif |