Commit | Line | Data |
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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> | |
bbeb3f4c | 48 | #include <asm/mpic.h> |
1da177e4 LT |
49 | |
50 | #ifdef DEBUG | |
51 | #define DBG(fmt...) udbg_printf(fmt) | |
52 | #else | |
53 | #define DBG(fmt...) | |
54 | #endif | |
55 | ||
56 | cpumask_t cpu_possible_map = CPU_MASK_NONE; | |
57 | cpumask_t cpu_online_map = CPU_MASK_NONE; | |
58 | cpumask_t cpu_sibling_map[NR_CPUS] = { [0 ... NR_CPUS-1] = CPU_MASK_NONE }; | |
59 | ||
60 | EXPORT_SYMBOL(cpu_online_map); | |
61 | EXPORT_SYMBOL(cpu_possible_map); | |
62 | ||
63 | struct smp_ops_t *smp_ops; | |
64 | ||
65 | static volatile unsigned int cpu_callin_map[NR_CPUS]; | |
66 | ||
1da177e4 LT |
67 | void smp_call_function_interrupt(void); |
68 | ||
69 | int smt_enabled_at_boot = 1; | |
70 | ||
cebf589c | 71 | #ifdef CONFIG_MPIC |
1da177e4 LT |
72 | int __init smp_mpic_probe(void) |
73 | { | |
74 | int nr_cpus; | |
75 | ||
76 | DBG("smp_mpic_probe()...\n"); | |
77 | ||
78 | nr_cpus = cpus_weight(cpu_possible_map); | |
79 | ||
80 | DBG("nr_cpus: %d\n", nr_cpus); | |
81 | ||
82 | if (nr_cpus > 1) | |
83 | mpic_request_ipis(); | |
84 | ||
85 | return nr_cpus; | |
86 | } | |
87 | ||
88 | void __devinit smp_mpic_setup_cpu(int cpu) | |
89 | { | |
90 | mpic_setup_this_cpu(); | |
91 | } | |
92 | ||
93 | void __devinit smp_generic_kick_cpu(int nr) | |
94 | { | |
95 | BUG_ON(nr < 0 || nr >= NR_CPUS); | |
96 | ||
97 | /* | |
98 | * The processor is currently spinning, waiting for the | |
99 | * cpu_start field to become non-zero After we set cpu_start, | |
100 | * the processor will continue on to secondary_start | |
101 | */ | |
102 | paca[nr].cpu_start = 1; | |
0d8d4d42 | 103 | smp_mb(); |
1da177e4 LT |
104 | } |
105 | ||
cebf589c | 106 | #endif /* CONFIG_MPIC */ |
1da177e4 | 107 | |
1da177e4 LT |
108 | void smp_message_recv(int msg, struct pt_regs *regs) |
109 | { | |
110 | switch(msg) { | |
111 | case PPC_MSG_CALL_FUNCTION: | |
112 | smp_call_function_interrupt(); | |
113 | break; | |
114 | case PPC_MSG_RESCHEDULE: | |
115 | /* XXX Do we have to do this? */ | |
116 | set_need_resched(); | |
117 | break; | |
118 | #if 0 | |
119 | case PPC_MSG_MIGRATE_TASK: | |
120 | /* spare */ | |
121 | break; | |
122 | #endif | |
123 | #ifdef CONFIG_DEBUGGER | |
124 | case PPC_MSG_DEBUGGER_BREAK: | |
125 | debugger_ipi(regs); | |
126 | break; | |
127 | #endif | |
128 | default: | |
129 | printk("SMP %d: smp_message_recv(): unknown msg %d\n", | |
130 | smp_processor_id(), msg); | |
131 | break; | |
132 | } | |
133 | } | |
134 | ||
135 | void smp_send_reschedule(int cpu) | |
136 | { | |
137 | smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE); | |
138 | } | |
139 | ||
140 | #ifdef CONFIG_DEBUGGER | |
141 | void smp_send_debugger_break(int cpu) | |
142 | { | |
143 | smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK); | |
144 | } | |
145 | #endif | |
146 | ||
147 | static void stop_this_cpu(void *dummy) | |
148 | { | |
149 | local_irq_disable(); | |
150 | while (1) | |
151 | ; | |
152 | } | |
153 | ||
154 | void smp_send_stop(void) | |
155 | { | |
156 | smp_call_function(stop_this_cpu, NULL, 1, 0); | |
157 | } | |
158 | ||
159 | /* | |
160 | * Structure and data for smp_call_function(). This is designed to minimise | |
161 | * static memory requirements. It also looks cleaner. | |
162 | * Stolen from the i386 version. | |
163 | */ | |
164 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(call_lock); | |
165 | ||
166 | static struct call_data_struct { | |
167 | void (*func) (void *info); | |
168 | void *info; | |
169 | atomic_t started; | |
170 | atomic_t finished; | |
171 | int wait; | |
172 | } *call_data; | |
173 | ||
174 | /* delay of at least 8 seconds on 1GHz cpu */ | |
175 | #define SMP_CALL_TIMEOUT (1UL << (30 + 3)) | |
176 | ||
177 | /* | |
178 | * This function sends a 'generic call function' IPI to all other CPUs | |
179 | * in the system. | |
180 | * | |
181 | * [SUMMARY] Run a function on all other CPUs. | |
182 | * <func> The function to run. This must be fast and non-blocking. | |
183 | * <info> An arbitrary pointer to pass to the function. | |
184 | * <nonatomic> currently unused. | |
185 | * <wait> If true, wait (atomically) until function has completed on other CPUs. | |
186 | * [RETURNS] 0 on success, else a negative status code. Does not return until | |
187 | * remote CPUs are nearly ready to execute <<func>> or are or have executed. | |
188 | * | |
189 | * You must not call this function with disabled interrupts or from a | |
190 | * hardware interrupt handler or from a bottom half handler. | |
191 | */ | |
192 | int smp_call_function (void (*func) (void *info), void *info, int nonatomic, | |
193 | int wait) | |
194 | { | |
195 | struct call_data_struct data; | |
196 | int ret = -1, cpus; | |
197 | unsigned long timeout; | |
198 | ||
199 | /* Can deadlock when called with interrupts disabled */ | |
200 | WARN_ON(irqs_disabled()); | |
201 | ||
202 | data.func = func; | |
203 | data.info = info; | |
204 | atomic_set(&data.started, 0); | |
205 | data.wait = wait; | |
206 | if (wait) | |
207 | atomic_set(&data.finished, 0); | |
208 | ||
209 | spin_lock(&call_lock); | |
210 | /* Must grab online cpu count with preempt disabled, otherwise | |
211 | * it can change. */ | |
212 | cpus = num_online_cpus() - 1; | |
213 | if (!cpus) { | |
214 | ret = 0; | |
215 | goto out; | |
216 | } | |
217 | ||
218 | call_data = &data; | |
0d8d4d42 | 219 | smp_wmb(); |
1da177e4 LT |
220 | /* Send a message to all other CPUs and wait for them to respond */ |
221 | smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_CALL_FUNCTION); | |
222 | ||
223 | /* Wait for response */ | |
224 | timeout = SMP_CALL_TIMEOUT; | |
225 | while (atomic_read(&data.started) != cpus) { | |
226 | HMT_low(); | |
227 | if (--timeout == 0) { | |
228 | printk("smp_call_function on cpu %d: other cpus not " | |
229 | "responding (%d)\n", smp_processor_id(), | |
230 | atomic_read(&data.started)); | |
231 | debugger(NULL); | |
232 | goto out; | |
233 | } | |
234 | } | |
235 | ||
236 | if (wait) { | |
237 | timeout = SMP_CALL_TIMEOUT; | |
238 | while (atomic_read(&data.finished) != cpus) { | |
239 | HMT_low(); | |
240 | if (--timeout == 0) { | |
241 | printk("smp_call_function on cpu %d: other " | |
242 | "cpus not finishing (%d/%d)\n", | |
243 | smp_processor_id(), | |
244 | atomic_read(&data.finished), | |
245 | atomic_read(&data.started)); | |
246 | debugger(NULL); | |
247 | goto out; | |
248 | } | |
249 | } | |
250 | } | |
251 | ||
252 | ret = 0; | |
253 | ||
254 | out: | |
255 | call_data = NULL; | |
256 | HMT_medium(); | |
257 | spin_unlock(&call_lock); | |
258 | return ret; | |
259 | } | |
260 | ||
261 | EXPORT_SYMBOL(smp_call_function); | |
262 | ||
263 | void smp_call_function_interrupt(void) | |
264 | { | |
265 | void (*func) (void *info); | |
266 | void *info; | |
267 | int wait; | |
268 | ||
269 | /* call_data will be NULL if the sender timed out while | |
270 | * waiting on us to receive the call. | |
271 | */ | |
272 | if (!call_data) | |
273 | return; | |
274 | ||
275 | func = call_data->func; | |
276 | info = call_data->info; | |
277 | wait = call_data->wait; | |
278 | ||
279 | if (!wait) | |
280 | smp_mb__before_atomic_inc(); | |
281 | ||
282 | /* | |
283 | * Notify initiating CPU that I've grabbed the data and am | |
284 | * about to execute the function | |
285 | */ | |
286 | atomic_inc(&call_data->started); | |
287 | /* | |
288 | * At this point the info structure may be out of scope unless wait==1 | |
289 | */ | |
290 | (*func)(info); | |
291 | if (wait) { | |
292 | smp_mb__before_atomic_inc(); | |
293 | atomic_inc(&call_data->finished); | |
294 | } | |
295 | } | |
296 | ||
1da177e4 LT |
297 | extern struct gettimeofday_struct do_gtod; |
298 | ||
299 | struct thread_info *current_set[NR_CPUS]; | |
300 | ||
301 | DECLARE_PER_CPU(unsigned int, pvr); | |
302 | ||
303 | static void __devinit smp_store_cpu_info(int id) | |
304 | { | |
305 | per_cpu(pvr, id) = mfspr(SPRN_PVR); | |
306 | } | |
307 | ||
308 | static void __init smp_create_idle(unsigned int cpu) | |
309 | { | |
310 | struct task_struct *p; | |
311 | ||
312 | /* create a process for the processor */ | |
313 | p = fork_idle(cpu); | |
314 | if (IS_ERR(p)) | |
315 | panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p)); | |
316 | paca[cpu].__current = p; | |
317 | current_set[cpu] = p->thread_info; | |
318 | } | |
319 | ||
320 | void __init smp_prepare_cpus(unsigned int max_cpus) | |
321 | { | |
322 | unsigned int cpu; | |
323 | ||
324 | DBG("smp_prepare_cpus\n"); | |
325 | ||
326 | /* | |
327 | * setup_cpu may need to be called on the boot cpu. We havent | |
328 | * spun any cpus up but lets be paranoid. | |
329 | */ | |
330 | BUG_ON(boot_cpuid != smp_processor_id()); | |
331 | ||
332 | /* Fixup boot cpu */ | |
333 | smp_store_cpu_info(boot_cpuid); | |
334 | cpu_callin_map[boot_cpuid] = 1; | |
335 | ||
336 | #ifndef CONFIG_PPC_ISERIES | |
337 | paca[boot_cpuid].next_jiffy_update_tb = tb_last_stamp = get_tb(); | |
338 | ||
339 | /* | |
340 | * Should update do_gtod.stamp_xsec. | |
341 | * For now we leave it which means the time can be some | |
342 | * number of msecs off until someone does a settimeofday() | |
343 | */ | |
344 | do_gtod.varp->tb_orig_stamp = tb_last_stamp; | |
345 | systemcfg->tb_orig_stamp = tb_last_stamp; | |
346 | #endif | |
347 | ||
348 | max_cpus = smp_ops->probe(); | |
349 | ||
350 | smp_space_timers(max_cpus); | |
351 | ||
352 | for_each_cpu(cpu) | |
353 | if (cpu != boot_cpuid) | |
354 | smp_create_idle(cpu); | |
355 | } | |
356 | ||
357 | void __devinit smp_prepare_boot_cpu(void) | |
358 | { | |
359 | BUG_ON(smp_processor_id() != boot_cpuid); | |
360 | ||
361 | cpu_set(boot_cpuid, cpu_online_map); | |
362 | ||
363 | paca[boot_cpuid].__current = current; | |
364 | current_set[boot_cpuid] = current->thread_info; | |
365 | } | |
366 | ||
367 | #ifdef CONFIG_HOTPLUG_CPU | |
368 | /* State of each CPU during hotplug phases */ | |
369 | DEFINE_PER_CPU(int, cpu_state) = { 0 }; | |
370 | ||
371 | int generic_cpu_disable(void) | |
372 | { | |
373 | unsigned int cpu = smp_processor_id(); | |
374 | ||
375 | if (cpu == boot_cpuid) | |
376 | return -EBUSY; | |
377 | ||
378 | systemcfg->processorCount--; | |
379 | cpu_clear(cpu, cpu_online_map); | |
380 | fixup_irqs(cpu_online_map); | |
381 | return 0; | |
382 | } | |
383 | ||
384 | int generic_cpu_enable(unsigned int cpu) | |
385 | { | |
386 | /* Do the normal bootup if we haven't | |
387 | * already bootstrapped. */ | |
388 | if (system_state != SYSTEM_RUNNING) | |
389 | return -ENOSYS; | |
390 | ||
391 | /* get the target out of it's holding state */ | |
392 | per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; | |
0d8d4d42 | 393 | smp_wmb(); |
1da177e4 LT |
394 | |
395 | while (!cpu_online(cpu)) | |
396 | cpu_relax(); | |
397 | ||
398 | fixup_irqs(cpu_online_map); | |
399 | /* counter the irq disable in fixup_irqs */ | |
400 | local_irq_enable(); | |
401 | return 0; | |
402 | } | |
403 | ||
404 | void generic_cpu_die(unsigned int cpu) | |
405 | { | |
406 | int i; | |
407 | ||
408 | for (i = 0; i < 100; i++) { | |
0d8d4d42 | 409 | smp_rmb(); |
1da177e4 LT |
410 | if (per_cpu(cpu_state, cpu) == CPU_DEAD) |
411 | return; | |
412 | msleep(100); | |
413 | } | |
414 | printk(KERN_ERR "CPU%d didn't die...\n", cpu); | |
415 | } | |
416 | ||
417 | void generic_mach_cpu_die(void) | |
418 | { | |
419 | unsigned int cpu; | |
420 | ||
421 | local_irq_disable(); | |
422 | cpu = smp_processor_id(); | |
423 | printk(KERN_DEBUG "CPU%d offline\n", cpu); | |
424 | __get_cpu_var(cpu_state) = CPU_DEAD; | |
0d8d4d42 | 425 | smp_wmb(); |
1da177e4 LT |
426 | while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE) |
427 | cpu_relax(); | |
428 | ||
429 | flush_tlb_pending(); | |
430 | cpu_set(cpu, cpu_online_map); | |
431 | local_irq_enable(); | |
432 | } | |
433 | #endif | |
434 | ||
435 | static int __devinit cpu_enable(unsigned int cpu) | |
436 | { | |
437 | if (smp_ops->cpu_enable) | |
438 | return smp_ops->cpu_enable(cpu); | |
439 | ||
440 | return -ENOSYS; | |
441 | } | |
442 | ||
443 | int __devinit __cpu_up(unsigned int cpu) | |
444 | { | |
445 | int c; | |
446 | ||
447 | if (!cpu_enable(cpu)) | |
448 | return 0; | |
449 | ||
450 | if (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)) | |
451 | return -EINVAL; | |
452 | ||
c4eb2a93 | 453 | paca[cpu].default_decr = tb_ticks_per_jiffy; |
1da177e4 | 454 | |
1da177e4 LT |
455 | /* Make sure callin-map entry is 0 (can be leftover a CPU |
456 | * hotplug | |
457 | */ | |
458 | cpu_callin_map[cpu] = 0; | |
459 | ||
460 | /* The information for processor bringup must | |
461 | * be written out to main store before we release | |
462 | * the processor. | |
463 | */ | |
0d8d4d42 | 464 | smp_mb(); |
1da177e4 LT |
465 | |
466 | /* wake up cpus */ | |
467 | DBG("smp: kicking cpu %d\n", cpu); | |
468 | smp_ops->kick_cpu(cpu); | |
469 | ||
470 | /* | |
471 | * wait to see if the cpu made a callin (is actually up). | |
472 | * use this value that I found through experimentation. | |
473 | * -- Cort | |
474 | */ | |
475 | if (system_state < SYSTEM_RUNNING) | |
476 | for (c = 5000; c && !cpu_callin_map[cpu]; c--) | |
477 | udelay(100); | |
478 | #ifdef CONFIG_HOTPLUG_CPU | |
479 | else | |
480 | /* | |
481 | * CPUs can take much longer to come up in the | |
482 | * hotplug case. Wait five seconds. | |
483 | */ | |
484 | for (c = 25; c && !cpu_callin_map[cpu]; c--) { | |
485 | msleep(200); | |
486 | } | |
487 | #endif | |
488 | ||
489 | if (!cpu_callin_map[cpu]) { | |
490 | printk("Processor %u is stuck.\n", cpu); | |
491 | return -ENOENT; | |
492 | } | |
493 | ||
494 | printk("Processor %u found.\n", cpu); | |
495 | ||
496 | if (smp_ops->give_timebase) | |
497 | smp_ops->give_timebase(); | |
498 | ||
499 | /* Wait until cpu puts itself in the online map */ | |
500 | while (!cpu_online(cpu)) | |
501 | cpu_relax(); | |
502 | ||
503 | return 0; | |
504 | } | |
505 | ||
506 | ||
507 | /* Activate a secondary processor. */ | |
508 | int __devinit start_secondary(void *unused) | |
509 | { | |
510 | unsigned int cpu = smp_processor_id(); | |
511 | ||
512 | atomic_inc(&init_mm.mm_count); | |
513 | current->active_mm = &init_mm; | |
514 | ||
515 | smp_store_cpu_info(cpu); | |
516 | set_dec(paca[cpu].default_decr); | |
517 | cpu_callin_map[cpu] = 1; | |
518 | ||
519 | smp_ops->setup_cpu(cpu); | |
520 | if (smp_ops->take_timebase) | |
521 | smp_ops->take_timebase(); | |
522 | ||
523 | spin_lock(&call_lock); | |
524 | cpu_set(cpu, cpu_online_map); | |
525 | spin_unlock(&call_lock); | |
526 | ||
527 | local_irq_enable(); | |
528 | ||
529 | cpu_idle(); | |
530 | return 0; | |
531 | } | |
532 | ||
533 | int setup_profiling_timer(unsigned int multiplier) | |
534 | { | |
535 | return 0; | |
536 | } | |
537 | ||
538 | void __init smp_cpus_done(unsigned int max_cpus) | |
539 | { | |
540 | cpumask_t old_mask; | |
541 | ||
542 | /* We want the setup_cpu() here to be called from CPU 0, but our | |
543 | * init thread may have been "borrowed" by another CPU in the meantime | |
544 | * se we pin us down to CPU 0 for a short while | |
545 | */ | |
546 | old_mask = current->cpus_allowed; | |
547 | set_cpus_allowed(current, cpumask_of_cpu(boot_cpuid)); | |
548 | ||
549 | smp_ops->setup_cpu(boot_cpuid); | |
550 | ||
551 | set_cpus_allowed(current, old_mask); | |
552 | } | |
553 | ||
554 | #ifdef CONFIG_HOTPLUG_CPU | |
555 | int __cpu_disable(void) | |
556 | { | |
557 | if (smp_ops->cpu_disable) | |
558 | return smp_ops->cpu_disable(); | |
559 | ||
560 | return -ENOSYS; | |
561 | } | |
562 | ||
563 | void __cpu_die(unsigned int cpu) | |
564 | { | |
565 | if (smp_ops->cpu_die) | |
566 | smp_ops->cpu_die(cpu); | |
567 | } | |
568 | #endif |