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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/kernel/smp.c | |
3 | * | |
4 | * Copyright (C) 2002 ARM Limited, All Rights Reserved. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | #include <linux/config.h> | |
11 | #include <linux/delay.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/spinlock.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/interrupt.h> | |
16 | #include <linux/cache.h> | |
17 | #include <linux/profile.h> | |
18 | #include <linux/errno.h> | |
19 | #include <linux/mm.h> | |
20 | #include <linux/cpu.h> | |
21 | #include <linux/smp.h> | |
22 | #include <linux/seq_file.h> | |
23 | ||
24 | #include <asm/atomic.h> | |
25 | #include <asm/cacheflush.h> | |
26 | #include <asm/cpu.h> | |
e65f38ed RK |
27 | #include <asm/mmu_context.h> |
28 | #include <asm/pgtable.h> | |
29 | #include <asm/pgalloc.h> | |
1da177e4 LT |
30 | #include <asm/processor.h> |
31 | #include <asm/tlbflush.h> | |
32 | #include <asm/ptrace.h> | |
33 | ||
34 | /* | |
35 | * bitmask of present and online CPUs. | |
36 | * The present bitmask indicates that the CPU is physically present. | |
37 | * The online bitmask indicates that the CPU is up and running. | |
38 | */ | |
39 | cpumask_t cpu_present_mask; | |
40 | cpumask_t cpu_online_map; | |
41 | ||
e65f38ed RK |
42 | /* |
43 | * as from 2.5, kernels no longer have an init_tasks structure | |
44 | * so we need some other way of telling a new secondary core | |
45 | * where to place its SVC stack | |
46 | */ | |
47 | struct secondary_data secondary_data; | |
48 | ||
1da177e4 LT |
49 | /* |
50 | * structures for inter-processor calls | |
51 | * - A collection of single bit ipi messages. | |
52 | */ | |
53 | struct ipi_data { | |
54 | spinlock_t lock; | |
55 | unsigned long ipi_count; | |
56 | unsigned long bits; | |
57 | }; | |
58 | ||
59 | static DEFINE_PER_CPU(struct ipi_data, ipi_data) = { | |
60 | .lock = SPIN_LOCK_UNLOCKED, | |
61 | }; | |
62 | ||
63 | enum ipi_msg_type { | |
64 | IPI_TIMER, | |
65 | IPI_RESCHEDULE, | |
66 | IPI_CALL_FUNC, | |
67 | IPI_CPU_STOP, | |
68 | }; | |
69 | ||
70 | struct smp_call_struct { | |
71 | void (*func)(void *info); | |
72 | void *info; | |
73 | int wait; | |
74 | cpumask_t pending; | |
75 | cpumask_t unfinished; | |
76 | }; | |
77 | ||
78 | static struct smp_call_struct * volatile smp_call_function_data; | |
79 | static DEFINE_SPINLOCK(smp_call_function_lock); | |
80 | ||
81 | int __init __cpu_up(unsigned int cpu) | |
82 | { | |
83 | struct task_struct *idle; | |
e65f38ed RK |
84 | pgd_t *pgd; |
85 | pmd_t *pmd; | |
1da177e4 LT |
86 | int ret; |
87 | ||
88 | /* | |
89 | * Spawn a new process manually. Grab a pointer to | |
90 | * its task struct so we can mess with it | |
91 | */ | |
92 | idle = fork_idle(cpu); | |
93 | if (IS_ERR(idle)) { | |
94 | printk(KERN_ERR "CPU%u: fork() failed\n", cpu); | |
95 | return PTR_ERR(idle); | |
96 | } | |
97 | ||
e65f38ed RK |
98 | /* |
99 | * Allocate initial page tables to allow the new CPU to | |
100 | * enable the MMU safely. This essentially means a set | |
101 | * of our "standard" page tables, with the addition of | |
102 | * a 1:1 mapping for the physical address of the kernel. | |
103 | */ | |
104 | pgd = pgd_alloc(&init_mm); | |
105 | pmd = pmd_offset(pgd, PHYS_OFFSET); | |
106 | *pmd = __pmd((PHYS_OFFSET & PGDIR_MASK) | | |
107 | PMD_TYPE_SECT | PMD_SECT_AP_WRITE); | |
108 | ||
109 | /* | |
110 | * We need to tell the secondary core where to find | |
111 | * its stack and the page tables. | |
112 | */ | |
113 | secondary_data.stack = (void *)idle->thread_info + THREAD_SIZE - 8; | |
114 | secondary_data.pgdir = virt_to_phys(pgd); | |
115 | wmb(); | |
116 | ||
1da177e4 LT |
117 | /* |
118 | * Now bring the CPU into our world. | |
119 | */ | |
120 | ret = boot_secondary(cpu, idle); | |
e65f38ed RK |
121 | if (ret == 0) { |
122 | unsigned long timeout; | |
123 | ||
124 | /* | |
125 | * CPU was successfully started, wait for it | |
126 | * to come online or time out. | |
127 | */ | |
128 | timeout = jiffies + HZ; | |
129 | while (time_before(jiffies, timeout)) { | |
130 | if (cpu_online(cpu)) | |
131 | break; | |
132 | ||
133 | udelay(10); | |
134 | barrier(); | |
135 | } | |
136 | ||
137 | if (!cpu_online(cpu)) | |
138 | ret = -EIO; | |
139 | } | |
140 | ||
141 | secondary_data.stack = 0; | |
142 | secondary_data.pgdir = 0; | |
143 | ||
144 | *pmd_offset(pgd, PHYS_OFFSET) = __pmd(0); | |
145 | pgd_free(pgd); | |
146 | ||
1da177e4 LT |
147 | if (ret) { |
148 | printk(KERN_CRIT "cpu_up: processor %d failed to boot\n", cpu); | |
149 | /* | |
150 | * FIXME: We need to clean up the new idle thread. --rmk | |
151 | */ | |
152 | } | |
153 | ||
154 | return ret; | |
155 | } | |
156 | ||
e65f38ed RK |
157 | /* |
158 | * This is the secondary CPU boot entry. We're using this CPUs | |
159 | * idle thread stack, but a set of temporary page tables. | |
160 | */ | |
161 | asmlinkage void __init secondary_start_kernel(void) | |
162 | { | |
163 | struct mm_struct *mm = &init_mm; | |
164 | unsigned int cpu = smp_processor_id(); | |
165 | ||
166 | printk("CPU%u: Booted secondary processor\n", cpu); | |
167 | ||
168 | /* | |
169 | * All kernel threads share the same mm context; grab a | |
170 | * reference and switch to it. | |
171 | */ | |
172 | atomic_inc(&mm->mm_users); | |
173 | atomic_inc(&mm->mm_count); | |
174 | current->active_mm = mm; | |
175 | cpu_set(cpu, mm->cpu_vm_mask); | |
176 | cpu_switch_mm(mm->pgd, mm); | |
177 | enter_lazy_tlb(mm, current); | |
178 | ||
179 | cpu_init(); | |
180 | ||
181 | /* | |
182 | * Give the platform a chance to do its own initialisation. | |
183 | */ | |
184 | platform_secondary_init(cpu); | |
185 | ||
186 | /* | |
187 | * Enable local interrupts. | |
188 | */ | |
189 | local_irq_enable(); | |
190 | local_fiq_enable(); | |
191 | ||
192 | calibrate_delay(); | |
193 | ||
194 | smp_store_cpu_info(cpu); | |
195 | ||
196 | /* | |
197 | * OK, now it's safe to let the boot CPU continue | |
198 | */ | |
199 | cpu_set(cpu, cpu_online_map); | |
200 | ||
201 | /* | |
202 | * OK, it's off to the idle thread for us | |
203 | */ | |
204 | cpu_idle(); | |
205 | } | |
206 | ||
1da177e4 LT |
207 | /* |
208 | * Called by both boot and secondaries to move global data into | |
209 | * per-processor storage. | |
210 | */ | |
211 | void __init smp_store_cpu_info(unsigned int cpuid) | |
212 | { | |
213 | struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpuid); | |
214 | ||
215 | cpu_info->loops_per_jiffy = loops_per_jiffy; | |
216 | } | |
217 | ||
218 | void __init smp_cpus_done(unsigned int max_cpus) | |
219 | { | |
220 | int cpu; | |
221 | unsigned long bogosum = 0; | |
222 | ||
223 | for_each_online_cpu(cpu) | |
224 | bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy; | |
225 | ||
226 | printk(KERN_INFO "SMP: Total of %d processors activated " | |
227 | "(%lu.%02lu BogoMIPS).\n", | |
228 | num_online_cpus(), | |
229 | bogosum / (500000/HZ), | |
230 | (bogosum / (5000/HZ)) % 100); | |
231 | } | |
232 | ||
233 | void __init smp_prepare_boot_cpu(void) | |
234 | { | |
235 | unsigned int cpu = smp_processor_id(); | |
236 | ||
237 | cpu_set(cpu, cpu_present_mask); | |
238 | cpu_set(cpu, cpu_online_map); | |
239 | } | |
240 | ||
241 | static void send_ipi_message(cpumask_t callmap, enum ipi_msg_type msg) | |
242 | { | |
243 | unsigned long flags; | |
244 | unsigned int cpu; | |
245 | ||
246 | local_irq_save(flags); | |
247 | ||
248 | for_each_cpu_mask(cpu, callmap) { | |
249 | struct ipi_data *ipi = &per_cpu(ipi_data, cpu); | |
250 | ||
251 | spin_lock(&ipi->lock); | |
252 | ipi->bits |= 1 << msg; | |
253 | spin_unlock(&ipi->lock); | |
254 | } | |
255 | ||
256 | /* | |
257 | * Call the platform specific cross-CPU call function. | |
258 | */ | |
259 | smp_cross_call(callmap); | |
260 | ||
261 | local_irq_restore(flags); | |
262 | } | |
263 | ||
264 | /* | |
265 | * You must not call this function with disabled interrupts, from a | |
266 | * hardware interrupt handler, nor from a bottom half handler. | |
267 | */ | |
268 | int smp_call_function_on_cpu(void (*func)(void *info), void *info, int retry, | |
269 | int wait, cpumask_t callmap) | |
270 | { | |
271 | struct smp_call_struct data; | |
272 | unsigned long timeout; | |
273 | int ret = 0; | |
274 | ||
275 | data.func = func; | |
276 | data.info = info; | |
277 | data.wait = wait; | |
278 | ||
279 | cpu_clear(smp_processor_id(), callmap); | |
280 | if (cpus_empty(callmap)) | |
281 | goto out; | |
282 | ||
283 | data.pending = callmap; | |
284 | if (wait) | |
285 | data.unfinished = callmap; | |
286 | ||
287 | /* | |
288 | * try to get the mutex on smp_call_function_data | |
289 | */ | |
290 | spin_lock(&smp_call_function_lock); | |
291 | smp_call_function_data = &data; | |
292 | ||
293 | send_ipi_message(callmap, IPI_CALL_FUNC); | |
294 | ||
295 | timeout = jiffies + HZ; | |
296 | while (!cpus_empty(data.pending) && time_before(jiffies, timeout)) | |
297 | barrier(); | |
298 | ||
299 | /* | |
300 | * did we time out? | |
301 | */ | |
302 | if (!cpus_empty(data.pending)) { | |
303 | /* | |
304 | * this may be causing our panic - report it | |
305 | */ | |
306 | printk(KERN_CRIT | |
307 | "CPU%u: smp_call_function timeout for %p(%p)\n" | |
308 | " callmap %lx pending %lx, %swait\n", | |
309 | smp_processor_id(), func, info, callmap, data.pending, | |
310 | wait ? "" : "no "); | |
311 | ||
312 | /* | |
313 | * TRACE | |
314 | */ | |
315 | timeout = jiffies + (5 * HZ); | |
316 | while (!cpus_empty(data.pending) && time_before(jiffies, timeout)) | |
317 | barrier(); | |
318 | ||
319 | if (cpus_empty(data.pending)) | |
320 | printk(KERN_CRIT " RESOLVED\n"); | |
321 | else | |
322 | printk(KERN_CRIT " STILL STUCK\n"); | |
323 | } | |
324 | ||
325 | /* | |
326 | * whatever happened, we're done with the data, so release it | |
327 | */ | |
328 | smp_call_function_data = NULL; | |
329 | spin_unlock(&smp_call_function_lock); | |
330 | ||
331 | if (!cpus_empty(data.pending)) { | |
332 | ret = -ETIMEDOUT; | |
333 | goto out; | |
334 | } | |
335 | ||
336 | if (wait) | |
337 | while (!cpus_empty(data.unfinished)) | |
338 | barrier(); | |
339 | out: | |
340 | ||
341 | return 0; | |
342 | } | |
343 | ||
344 | int smp_call_function(void (*func)(void *info), void *info, int retry, | |
345 | int wait) | |
346 | { | |
347 | return smp_call_function_on_cpu(func, info, retry, wait, | |
348 | cpu_online_map); | |
349 | } | |
350 | ||
351 | void show_ipi_list(struct seq_file *p) | |
352 | { | |
353 | unsigned int cpu; | |
354 | ||
355 | seq_puts(p, "IPI:"); | |
356 | ||
357 | for_each_online_cpu(cpu) | |
358 | seq_printf(p, " %10lu", per_cpu(ipi_data, cpu).ipi_count); | |
359 | ||
360 | seq_putc(p, '\n'); | |
361 | } | |
362 | ||
363 | static void ipi_timer(struct pt_regs *regs) | |
364 | { | |
365 | int user = user_mode(regs); | |
366 | ||
367 | irq_enter(); | |
368 | profile_tick(CPU_PROFILING, regs); | |
369 | update_process_times(user); | |
370 | irq_exit(); | |
371 | } | |
372 | ||
373 | /* | |
374 | * ipi_call_function - handle IPI from smp_call_function() | |
375 | * | |
376 | * Note that we copy data out of the cross-call structure and then | |
377 | * let the caller know that we're here and have done with their data | |
378 | */ | |
379 | static void ipi_call_function(unsigned int cpu) | |
380 | { | |
381 | struct smp_call_struct *data = smp_call_function_data; | |
382 | void (*func)(void *info) = data->func; | |
383 | void *info = data->info; | |
384 | int wait = data->wait; | |
385 | ||
386 | cpu_clear(cpu, data->pending); | |
387 | ||
388 | func(info); | |
389 | ||
390 | if (wait) | |
391 | cpu_clear(cpu, data->unfinished); | |
392 | } | |
393 | ||
394 | static DEFINE_SPINLOCK(stop_lock); | |
395 | ||
396 | /* | |
397 | * ipi_cpu_stop - handle IPI from smp_send_stop() | |
398 | */ | |
399 | static void ipi_cpu_stop(unsigned int cpu) | |
400 | { | |
401 | spin_lock(&stop_lock); | |
402 | printk(KERN_CRIT "CPU%u: stopping\n", cpu); | |
403 | dump_stack(); | |
404 | spin_unlock(&stop_lock); | |
405 | ||
406 | cpu_clear(cpu, cpu_online_map); | |
407 | ||
408 | local_fiq_disable(); | |
409 | local_irq_disable(); | |
410 | ||
411 | while (1) | |
412 | cpu_relax(); | |
413 | } | |
414 | ||
415 | /* | |
416 | * Main handler for inter-processor interrupts | |
417 | * | |
418 | * For ARM, the ipimask now only identifies a single | |
419 | * category of IPI (Bit 1 IPIs have been replaced by a | |
420 | * different mechanism): | |
421 | * | |
422 | * Bit 0 - Inter-processor function call | |
423 | */ | |
424 | void do_IPI(struct pt_regs *regs) | |
425 | { | |
426 | unsigned int cpu = smp_processor_id(); | |
427 | struct ipi_data *ipi = &per_cpu(ipi_data, cpu); | |
428 | ||
429 | ipi->ipi_count++; | |
430 | ||
431 | for (;;) { | |
432 | unsigned long msgs; | |
433 | ||
434 | spin_lock(&ipi->lock); | |
435 | msgs = ipi->bits; | |
436 | ipi->bits = 0; | |
437 | spin_unlock(&ipi->lock); | |
438 | ||
439 | if (!msgs) | |
440 | break; | |
441 | ||
442 | do { | |
443 | unsigned nextmsg; | |
444 | ||
445 | nextmsg = msgs & -msgs; | |
446 | msgs &= ~nextmsg; | |
447 | nextmsg = ffz(~nextmsg); | |
448 | ||
449 | switch (nextmsg) { | |
450 | case IPI_TIMER: | |
451 | ipi_timer(regs); | |
452 | break; | |
453 | ||
454 | case IPI_RESCHEDULE: | |
455 | /* | |
456 | * nothing more to do - eveything is | |
457 | * done on the interrupt return path | |
458 | */ | |
459 | break; | |
460 | ||
461 | case IPI_CALL_FUNC: | |
462 | ipi_call_function(cpu); | |
463 | break; | |
464 | ||
465 | case IPI_CPU_STOP: | |
466 | ipi_cpu_stop(cpu); | |
467 | break; | |
468 | ||
469 | default: | |
470 | printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n", | |
471 | cpu, nextmsg); | |
472 | break; | |
473 | } | |
474 | } while (msgs); | |
475 | } | |
476 | } | |
477 | ||
478 | void smp_send_reschedule(int cpu) | |
479 | { | |
480 | send_ipi_message(cpumask_of_cpu(cpu), IPI_RESCHEDULE); | |
481 | } | |
482 | ||
483 | void smp_send_timer(void) | |
484 | { | |
485 | cpumask_t mask = cpu_online_map; | |
486 | cpu_clear(smp_processor_id(), mask); | |
487 | send_ipi_message(mask, IPI_TIMER); | |
488 | } | |
489 | ||
490 | void smp_send_stop(void) | |
491 | { | |
492 | cpumask_t mask = cpu_online_map; | |
493 | cpu_clear(smp_processor_id(), mask); | |
494 | send_ipi_message(mask, IPI_CPU_STOP); | |
495 | } | |
496 | ||
497 | /* | |
498 | * not supported here | |
499 | */ | |
500 | int __init setup_profiling_timer(unsigned int multiplier) | |
501 | { | |
502 | return -EINVAL; | |
503 | } |