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> | |
1da177e4 LT |
42 | #include <asm/time.h> |
43 | #include <asm/machdep.h> | |
44 | #include <asm/cputable.h> | |
45 | #include <asm/system.h> | |
bbeb3f4c | 46 | #include <asm/mpic.h> |
a7f290da | 47 | #include <asm/vdso_datapage.h> |
5ad57078 PM |
48 | #ifdef CONFIG_PPC64 |
49 | #include <asm/paca.h> | |
50 | #endif | |
51 | ||
1da177e4 | 52 | #ifdef DEBUG |
f9e4ec57 | 53 | #include <asm/udbg.h> |
1da177e4 LT |
54 | #define DBG(fmt...) udbg_printf(fmt) |
55 | #else | |
56 | #define DBG(fmt...) | |
57 | #endif | |
58 | ||
f9e4ec57 ME |
59 | int smp_hw_index[NR_CPUS]; |
60 | struct thread_info *secondary_ti; | |
61 | ||
1da177e4 LT |
62 | cpumask_t cpu_possible_map = CPU_MASK_NONE; |
63 | cpumask_t cpu_online_map = CPU_MASK_NONE; | |
64 | cpumask_t cpu_sibling_map[NR_CPUS] = { [0 ... NR_CPUS-1] = CPU_MASK_NONE }; | |
65 | ||
66 | EXPORT_SYMBOL(cpu_online_map); | |
67 | EXPORT_SYMBOL(cpu_possible_map); | |
68 | ||
5ad57078 | 69 | /* SMP operations for this machine */ |
1da177e4 LT |
70 | struct smp_ops_t *smp_ops; |
71 | ||
72 | static volatile unsigned int cpu_callin_map[NR_CPUS]; | |
73 | ||
1da177e4 LT |
74 | void smp_call_function_interrupt(void); |
75 | ||
76 | int smt_enabled_at_boot = 1; | |
77 | ||
cebf589c | 78 | #ifdef CONFIG_MPIC |
1da177e4 LT |
79 | int __init smp_mpic_probe(void) |
80 | { | |
81 | int nr_cpus; | |
82 | ||
83 | DBG("smp_mpic_probe()...\n"); | |
84 | ||
85 | nr_cpus = cpus_weight(cpu_possible_map); | |
86 | ||
87 | DBG("nr_cpus: %d\n", nr_cpus); | |
88 | ||
89 | if (nr_cpus > 1) | |
90 | mpic_request_ipis(); | |
91 | ||
92 | return nr_cpus; | |
93 | } | |
94 | ||
95 | void __devinit smp_mpic_setup_cpu(int cpu) | |
96 | { | |
97 | mpic_setup_this_cpu(); | |
98 | } | |
5ad57078 | 99 | #endif /* CONFIG_MPIC */ |
1da177e4 | 100 | |
5ad57078 | 101 | #ifdef CONFIG_PPC64 |
1da177e4 LT |
102 | void __devinit smp_generic_kick_cpu(int nr) |
103 | { | |
104 | BUG_ON(nr < 0 || nr >= NR_CPUS); | |
105 | ||
106 | /* | |
107 | * The processor is currently spinning, waiting for the | |
108 | * cpu_start field to become non-zero After we set cpu_start, | |
109 | * the processor will continue on to secondary_start | |
110 | */ | |
111 | paca[nr].cpu_start = 1; | |
0d8d4d42 | 112 | smp_mb(); |
1da177e4 | 113 | } |
5ad57078 | 114 | #endif |
1da177e4 | 115 | |
1da177e4 LT |
116 | void smp_message_recv(int msg, struct pt_regs *regs) |
117 | { | |
118 | switch(msg) { | |
119 | case PPC_MSG_CALL_FUNCTION: | |
120 | smp_call_function_interrupt(); | |
121 | break; | |
5ad57078 | 122 | case PPC_MSG_RESCHEDULE: |
1da177e4 LT |
123 | /* XXX Do we have to do this? */ |
124 | set_need_resched(); | |
125 | break; | |
1da177e4 LT |
126 | #ifdef CONFIG_DEBUGGER |
127 | case PPC_MSG_DEBUGGER_BREAK: | |
128 | debugger_ipi(regs); | |
129 | break; | |
130 | #endif | |
131 | default: | |
132 | printk("SMP %d: smp_message_recv(): unknown msg %d\n", | |
133 | smp_processor_id(), msg); | |
134 | break; | |
135 | } | |
136 | } | |
137 | ||
138 | void smp_send_reschedule(int cpu) | |
139 | { | |
140 | smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE); | |
141 | } | |
142 | ||
143 | #ifdef CONFIG_DEBUGGER | |
144 | void smp_send_debugger_break(int cpu) | |
145 | { | |
146 | smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK); | |
147 | } | |
148 | #endif | |
149 | ||
150 | static void stop_this_cpu(void *dummy) | |
151 | { | |
152 | local_irq_disable(); | |
153 | while (1) | |
154 | ; | |
155 | } | |
156 | ||
157 | void smp_send_stop(void) | |
158 | { | |
159 | smp_call_function(stop_this_cpu, NULL, 1, 0); | |
160 | } | |
161 | ||
162 | /* | |
163 | * Structure and data for smp_call_function(). This is designed to minimise | |
164 | * static memory requirements. It also looks cleaner. | |
165 | * Stolen from the i386 version. | |
166 | */ | |
167 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(call_lock); | |
168 | ||
169 | static struct call_data_struct { | |
170 | void (*func) (void *info); | |
171 | void *info; | |
172 | atomic_t started; | |
173 | atomic_t finished; | |
174 | int wait; | |
175 | } *call_data; | |
176 | ||
5ad57078 PM |
177 | /* delay of at least 8 seconds */ |
178 | #define SMP_CALL_TIMEOUT 8 | |
1da177e4 LT |
179 | |
180 | /* | |
181 | * This function sends a 'generic call function' IPI to all other CPUs | |
182 | * in the system. | |
183 | * | |
184 | * [SUMMARY] Run a function on all other CPUs. | |
185 | * <func> The function to run. This must be fast and non-blocking. | |
186 | * <info> An arbitrary pointer to pass to the function. | |
187 | * <nonatomic> currently unused. | |
188 | * <wait> If true, wait (atomically) until function has completed on other CPUs. | |
189 | * [RETURNS] 0 on success, else a negative status code. Does not return until | |
190 | * remote CPUs are nearly ready to execute <<func>> or are or have executed. | |
191 | * | |
192 | * You must not call this function with disabled interrupts or from a | |
193 | * hardware interrupt handler or from a bottom half handler. | |
194 | */ | |
195 | int smp_call_function (void (*func) (void *info), void *info, int nonatomic, | |
196 | int wait) | |
197 | { | |
198 | struct call_data_struct data; | |
199 | int ret = -1, cpus; | |
5ad57078 | 200 | u64 timeout; |
1da177e4 LT |
201 | |
202 | /* Can deadlock when called with interrupts disabled */ | |
203 | WARN_ON(irqs_disabled()); | |
204 | ||
205 | data.func = func; | |
206 | data.info = info; | |
207 | atomic_set(&data.started, 0); | |
208 | data.wait = wait; | |
209 | if (wait) | |
210 | atomic_set(&data.finished, 0); | |
211 | ||
212 | spin_lock(&call_lock); | |
213 | /* Must grab online cpu count with preempt disabled, otherwise | |
214 | * it can change. */ | |
215 | cpus = num_online_cpus() - 1; | |
216 | if (!cpus) { | |
217 | ret = 0; | |
218 | goto out; | |
219 | } | |
220 | ||
221 | call_data = &data; | |
0d8d4d42 | 222 | smp_wmb(); |
1da177e4 LT |
223 | /* Send a message to all other CPUs and wait for them to respond */ |
224 | smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_CALL_FUNCTION); | |
225 | ||
5ad57078 PM |
226 | timeout = get_tb() + (u64) SMP_CALL_TIMEOUT * tb_ticks_per_sec; |
227 | ||
1da177e4 | 228 | /* Wait for response */ |
1da177e4 LT |
229 | while (atomic_read(&data.started) != cpus) { |
230 | HMT_low(); | |
5ad57078 | 231 | if (get_tb() >= timeout) { |
1da177e4 LT |
232 | printk("smp_call_function on cpu %d: other cpus not " |
233 | "responding (%d)\n", smp_processor_id(), | |
234 | atomic_read(&data.started)); | |
235 | debugger(NULL); | |
236 | goto out; | |
237 | } | |
238 | } | |
239 | ||
240 | if (wait) { | |
1da177e4 LT |
241 | while (atomic_read(&data.finished) != cpus) { |
242 | HMT_low(); | |
5ad57078 | 243 | if (get_tb() >= timeout) { |
1da177e4 LT |
244 | printk("smp_call_function on cpu %d: other " |
245 | "cpus not finishing (%d/%d)\n", | |
246 | smp_processor_id(), | |
247 | atomic_read(&data.finished), | |
248 | atomic_read(&data.started)); | |
249 | debugger(NULL); | |
250 | goto out; | |
251 | } | |
252 | } | |
253 | } | |
254 | ||
255 | ret = 0; | |
256 | ||
5ad57078 | 257 | out: |
1da177e4 LT |
258 | call_data = NULL; |
259 | HMT_medium(); | |
260 | spin_unlock(&call_lock); | |
261 | return ret; | |
262 | } | |
263 | ||
264 | EXPORT_SYMBOL(smp_call_function); | |
265 | ||
266 | void smp_call_function_interrupt(void) | |
267 | { | |
268 | void (*func) (void *info); | |
269 | void *info; | |
270 | int wait; | |
271 | ||
272 | /* call_data will be NULL if the sender timed out while | |
273 | * waiting on us to receive the call. | |
274 | */ | |
275 | if (!call_data) | |
276 | return; | |
277 | ||
278 | func = call_data->func; | |
279 | info = call_data->info; | |
280 | wait = call_data->wait; | |
281 | ||
282 | if (!wait) | |
283 | smp_mb__before_atomic_inc(); | |
284 | ||
285 | /* | |
286 | * Notify initiating CPU that I've grabbed the data and am | |
287 | * about to execute the function | |
288 | */ | |
289 | atomic_inc(&call_data->started); | |
290 | /* | |
291 | * At this point the info structure may be out of scope unless wait==1 | |
292 | */ | |
293 | (*func)(info); | |
294 | if (wait) { | |
295 | smp_mb__before_atomic_inc(); | |
296 | atomic_inc(&call_data->finished); | |
297 | } | |
298 | } | |
299 | ||
1da177e4 LT |
300 | extern struct gettimeofday_struct do_gtod; |
301 | ||
302 | struct thread_info *current_set[NR_CPUS]; | |
303 | ||
304 | DECLARE_PER_CPU(unsigned int, pvr); | |
305 | ||
306 | static void __devinit smp_store_cpu_info(int id) | |
307 | { | |
308 | per_cpu(pvr, id) = mfspr(SPRN_PVR); | |
309 | } | |
310 | ||
311 | static void __init smp_create_idle(unsigned int cpu) | |
312 | { | |
313 | struct task_struct *p; | |
314 | ||
315 | /* create a process for the processor */ | |
316 | p = fork_idle(cpu); | |
317 | if (IS_ERR(p)) | |
318 | panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p)); | |
5ad57078 | 319 | #ifdef CONFIG_PPC64 |
1da177e4 | 320 | paca[cpu].__current = p; |
5ad57078 | 321 | #endif |
1da177e4 | 322 | current_set[cpu] = p->thread_info; |
5ad57078 | 323 | p->thread_info->cpu = cpu; |
1da177e4 LT |
324 | } |
325 | ||
326 | void __init smp_prepare_cpus(unsigned int max_cpus) | |
327 | { | |
328 | unsigned int cpu; | |
329 | ||
330 | DBG("smp_prepare_cpus\n"); | |
331 | ||
332 | /* | |
333 | * setup_cpu may need to be called on the boot cpu. We havent | |
334 | * spun any cpus up but lets be paranoid. | |
335 | */ | |
336 | BUG_ON(boot_cpuid != smp_processor_id()); | |
337 | ||
338 | /* Fixup boot cpu */ | |
339 | smp_store_cpu_info(boot_cpuid); | |
340 | cpu_callin_map[boot_cpuid] = 1; | |
341 | ||
1da177e4 LT |
342 | max_cpus = smp_ops->probe(); |
343 | ||
344 | smp_space_timers(max_cpus); | |
345 | ||
346 | for_each_cpu(cpu) | |
347 | if (cpu != boot_cpuid) | |
348 | smp_create_idle(cpu); | |
349 | } | |
350 | ||
351 | void __devinit smp_prepare_boot_cpu(void) | |
352 | { | |
353 | BUG_ON(smp_processor_id() != boot_cpuid); | |
354 | ||
355 | cpu_set(boot_cpuid, cpu_online_map); | |
5ad57078 | 356 | #ifdef CONFIG_PPC64 |
1da177e4 | 357 | paca[boot_cpuid].__current = current; |
5ad57078 | 358 | #endif |
1da177e4 LT |
359 | current_set[boot_cpuid] = current->thread_info; |
360 | } | |
361 | ||
362 | #ifdef CONFIG_HOTPLUG_CPU | |
363 | /* State of each CPU during hotplug phases */ | |
364 | DEFINE_PER_CPU(int, cpu_state) = { 0 }; | |
365 | ||
366 | int generic_cpu_disable(void) | |
367 | { | |
368 | unsigned int cpu = smp_processor_id(); | |
369 | ||
370 | if (cpu == boot_cpuid) | |
371 | return -EBUSY; | |
372 | ||
1da177e4 | 373 | cpu_clear(cpu, cpu_online_map); |
799d6046 | 374 | #ifdef CONFIG_PPC64 |
a7f290da | 375 | vdso_data->processorCount--; |
1da177e4 | 376 | fixup_irqs(cpu_online_map); |
094fe2e7 | 377 | #endif |
1da177e4 LT |
378 | return 0; |
379 | } | |
380 | ||
381 | int generic_cpu_enable(unsigned int cpu) | |
382 | { | |
383 | /* Do the normal bootup if we haven't | |
384 | * already bootstrapped. */ | |
385 | if (system_state != SYSTEM_RUNNING) | |
386 | return -ENOSYS; | |
387 | ||
388 | /* get the target out of it's holding state */ | |
389 | per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; | |
0d8d4d42 | 390 | smp_wmb(); |
1da177e4 LT |
391 | |
392 | while (!cpu_online(cpu)) | |
393 | cpu_relax(); | |
394 | ||
094fe2e7 | 395 | #ifdef CONFIG_PPC64 |
1da177e4 LT |
396 | fixup_irqs(cpu_online_map); |
397 | /* counter the irq disable in fixup_irqs */ | |
398 | local_irq_enable(); | |
094fe2e7 | 399 | #endif |
1da177e4 LT |
400 | return 0; |
401 | } | |
402 | ||
403 | void generic_cpu_die(unsigned int cpu) | |
404 | { | |
405 | int i; | |
406 | ||
407 | for (i = 0; i < 100; i++) { | |
0d8d4d42 | 408 | smp_rmb(); |
1da177e4 LT |
409 | if (per_cpu(cpu_state, cpu) == CPU_DEAD) |
410 | return; | |
411 | msleep(100); | |
412 | } | |
413 | printk(KERN_ERR "CPU%d didn't die...\n", cpu); | |
414 | } | |
415 | ||
416 | void generic_mach_cpu_die(void) | |
417 | { | |
418 | unsigned int cpu; | |
419 | ||
420 | local_irq_disable(); | |
421 | cpu = smp_processor_id(); | |
422 | printk(KERN_DEBUG "CPU%d offline\n", cpu); | |
423 | __get_cpu_var(cpu_state) = CPU_DEAD; | |
0d8d4d42 | 424 | smp_wmb(); |
1da177e4 LT |
425 | while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE) |
426 | cpu_relax(); | |
427 | ||
094fe2e7 | 428 | #ifdef CONFIG_PPC64 |
1da177e4 | 429 | flush_tlb_pending(); |
094fe2e7 | 430 | #endif |
1da177e4 LT |
431 | cpu_set(cpu, cpu_online_map); |
432 | local_irq_enable(); | |
433 | } | |
434 | #endif | |
435 | ||
436 | static int __devinit cpu_enable(unsigned int cpu) | |
437 | { | |
438 | if (smp_ops->cpu_enable) | |
439 | return smp_ops->cpu_enable(cpu); | |
440 | ||
441 | return -ENOSYS; | |
442 | } | |
443 | ||
444 | int __devinit __cpu_up(unsigned int cpu) | |
445 | { | |
446 | int c; | |
447 | ||
5ad57078 | 448 | secondary_ti = current_set[cpu]; |
1da177e4 LT |
449 | if (!cpu_enable(cpu)) |
450 | return 0; | |
451 | ||
452 | if (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)) | |
453 | return -EINVAL; | |
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); | |
5ad57078 | 516 | set_dec(tb_ticks_per_jiffy); |
e4d76e1c | 517 | preempt_disable(); |
1da177e4 LT |
518 | cpu_callin_map[cpu] = 1; |
519 | ||
520 | smp_ops->setup_cpu(cpu); | |
521 | if (smp_ops->take_timebase) | |
522 | smp_ops->take_timebase(); | |
523 | ||
524 | spin_lock(&call_lock); | |
525 | cpu_set(cpu, cpu_online_map); | |
526 | spin_unlock(&call_lock); | |
527 | ||
528 | local_irq_enable(); | |
529 | ||
530 | cpu_idle(); | |
531 | return 0; | |
532 | } | |
533 | ||
534 | int setup_profiling_timer(unsigned int multiplier) | |
535 | { | |
536 | return 0; | |
537 | } | |
538 | ||
539 | void __init smp_cpus_done(unsigned int max_cpus) | |
540 | { | |
541 | cpumask_t old_mask; | |
542 | ||
543 | /* We want the setup_cpu() here to be called from CPU 0, but our | |
544 | * init thread may have been "borrowed" by another CPU in the meantime | |
545 | * se we pin us down to CPU 0 for a short while | |
546 | */ | |
547 | old_mask = current->cpus_allowed; | |
548 | set_cpus_allowed(current, cpumask_of_cpu(boot_cpuid)); | |
549 | ||
550 | smp_ops->setup_cpu(boot_cpuid); | |
551 | ||
552 | set_cpus_allowed(current, old_mask); | |
553 | } | |
554 | ||
555 | #ifdef CONFIG_HOTPLUG_CPU | |
556 | int __cpu_disable(void) | |
557 | { | |
558 | if (smp_ops->cpu_disable) | |
559 | return smp_ops->cpu_disable(); | |
560 | ||
561 | return -ENOSYS; | |
562 | } | |
563 | ||
564 | void __cpu_die(unsigned int cpu) | |
565 | { | |
566 | if (smp_ops->cpu_die) | |
567 | smp_ops->cpu_die(cpu); | |
568 | } | |
569 | #endif |