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Commit | Line | Data |
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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 | */ | |
c97d4869 | 10 | #include <linux/module.h> |
1da177e4 LT |
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> | |
61b5cb1c | 19 | #include <linux/ftrace.h> |
1da177e4 | 20 | #include <linux/mm.h> |
4e950f6f | 21 | #include <linux/err.h> |
1da177e4 LT |
22 | #include <linux/cpu.h> |
23 | #include <linux/smp.h> | |
24 | #include <linux/seq_file.h> | |
c97d4869 | 25 | #include <linux/irq.h> |
bc28248e RK |
26 | #include <linux/percpu.h> |
27 | #include <linux/clockchips.h> | |
3c030bea | 28 | #include <linux/completion.h> |
1da177e4 | 29 | |
60063497 | 30 | #include <linux/atomic.h> |
1da177e4 LT |
31 | #include <asm/cacheflush.h> |
32 | #include <asm/cpu.h> | |
42578c82 | 33 | #include <asm/cputype.h> |
e65f38ed RK |
34 | #include <asm/mmu_context.h> |
35 | #include <asm/pgtable.h> | |
36 | #include <asm/pgalloc.h> | |
1da177e4 | 37 | #include <asm/processor.h> |
37b05b63 | 38 | #include <asm/sections.h> |
1da177e4 LT |
39 | #include <asm/tlbflush.h> |
40 | #include <asm/ptrace.h> | |
bc28248e | 41 | #include <asm/localtimer.h> |
1da177e4 | 42 | |
e65f38ed RK |
43 | /* |
44 | * as from 2.5, kernels no longer have an init_tasks structure | |
45 | * so we need some other way of telling a new secondary core | |
46 | * where to place its SVC stack | |
47 | */ | |
48 | struct secondary_data secondary_data; | |
49 | ||
1da177e4 | 50 | enum ipi_msg_type { |
24480d98 | 51 | IPI_TIMER = 2, |
1da177e4 LT |
52 | IPI_RESCHEDULE, |
53 | IPI_CALL_FUNC, | |
f6dd9fa5 | 54 | IPI_CALL_FUNC_SINGLE, |
1da177e4 LT |
55 | IPI_CPU_STOP, |
56 | }; | |
57 | ||
bd6f68af | 58 | int __cpuinit __cpu_up(unsigned int cpu) |
1da177e4 | 59 | { |
71f512e8 RK |
60 | struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu); |
61 | struct task_struct *idle = ci->idle; | |
e65f38ed | 62 | pgd_t *pgd; |
1da177e4 LT |
63 | int ret; |
64 | ||
65 | /* | |
71f512e8 RK |
66 | * Spawn a new process manually, if not already done. |
67 | * Grab a pointer to its task struct so we can mess with it | |
1da177e4 | 68 | */ |
71f512e8 RK |
69 | if (!idle) { |
70 | idle = fork_idle(cpu); | |
71 | if (IS_ERR(idle)) { | |
72 | printk(KERN_ERR "CPU%u: fork() failed\n", cpu); | |
73 | return PTR_ERR(idle); | |
74 | } | |
75 | ci->idle = idle; | |
13ea9cc8 SS |
76 | } else { |
77 | /* | |
78 | * Since this idle thread is being re-used, call | |
79 | * init_idle() to reinitialize the thread structure. | |
80 | */ | |
81 | init_idle(idle, cpu); | |
1da177e4 LT |
82 | } |
83 | ||
e65f38ed RK |
84 | /* |
85 | * Allocate initial page tables to allow the new CPU to | |
86 | * enable the MMU safely. This essentially means a set | |
87 | * of our "standard" page tables, with the addition of | |
88 | * a 1:1 mapping for the physical address of the kernel. | |
89 | */ | |
90 | pgd = pgd_alloc(&init_mm); | |
37b05b63 RK |
91 | if (!pgd) |
92 | return -ENOMEM; | |
93 | ||
94 | if (PHYS_OFFSET != PAGE_OFFSET) { | |
95 | #ifndef CONFIG_HOTPLUG_CPU | |
96 | identity_mapping_add(pgd, __pa(__init_begin), __pa(__init_end)); | |
97 | #endif | |
98 | identity_mapping_add(pgd, __pa(_stext), __pa(_etext)); | |
99 | identity_mapping_add(pgd, __pa(_sdata), __pa(_edata)); | |
100 | } | |
e65f38ed RK |
101 | |
102 | /* | |
103 | * We need to tell the secondary core where to find | |
104 | * its stack and the page tables. | |
105 | */ | |
32d39a93 | 106 | secondary_data.stack = task_stack_page(idle) + THREAD_START_SP; |
e65f38ed | 107 | secondary_data.pgdir = virt_to_phys(pgd); |
d427958a | 108 | secondary_data.swapper_pg_dir = virt_to_phys(swapper_pg_dir); |
1027247f RK |
109 | __cpuc_flush_dcache_area(&secondary_data, sizeof(secondary_data)); |
110 | outer_clean_range(__pa(&secondary_data), __pa(&secondary_data + 1)); | |
e65f38ed | 111 | |
1da177e4 LT |
112 | /* |
113 | * Now bring the CPU into our world. | |
114 | */ | |
115 | ret = boot_secondary(cpu, idle); | |
e65f38ed RK |
116 | if (ret == 0) { |
117 | unsigned long timeout; | |
118 | ||
119 | /* | |
120 | * CPU was successfully started, wait for it | |
121 | * to come online or time out. | |
122 | */ | |
123 | timeout = jiffies + HZ; | |
124 | while (time_before(jiffies, timeout)) { | |
125 | if (cpu_online(cpu)) | |
126 | break; | |
127 | ||
128 | udelay(10); | |
129 | barrier(); | |
130 | } | |
131 | ||
58613cd1 RK |
132 | if (!cpu_online(cpu)) { |
133 | pr_crit("CPU%u: failed to come online\n", cpu); | |
e65f38ed | 134 | ret = -EIO; |
58613cd1 RK |
135 | } |
136 | } else { | |
137 | pr_err("CPU%u: failed to boot: %d\n", cpu, ret); | |
e65f38ed RK |
138 | } |
139 | ||
5d43045b | 140 | secondary_data.stack = NULL; |
e65f38ed RK |
141 | secondary_data.pgdir = 0; |
142 | ||
37b05b63 RK |
143 | if (PHYS_OFFSET != PAGE_OFFSET) { |
144 | #ifndef CONFIG_HOTPLUG_CPU | |
145 | identity_mapping_del(pgd, __pa(__init_begin), __pa(__init_end)); | |
146 | #endif | |
147 | identity_mapping_del(pgd, __pa(_stext), __pa(_etext)); | |
148 | identity_mapping_del(pgd, __pa(_sdata), __pa(_edata)); | |
149 | } | |
150 | ||
5e541973 | 151 | pgd_free(&init_mm, pgd); |
e65f38ed | 152 | |
1da177e4 LT |
153 | return ret; |
154 | } | |
155 | ||
a054a811 | 156 | #ifdef CONFIG_HOTPLUG_CPU |
10034aab RK |
157 | static void percpu_timer_stop(void); |
158 | ||
a054a811 RK |
159 | /* |
160 | * __cpu_disable runs on the processor to be shutdown. | |
161 | */ | |
90140c30 | 162 | int __cpu_disable(void) |
a054a811 RK |
163 | { |
164 | unsigned int cpu = smp_processor_id(); | |
165 | struct task_struct *p; | |
166 | int ret; | |
167 | ||
8e2a43f5 | 168 | ret = platform_cpu_disable(cpu); |
a054a811 RK |
169 | if (ret) |
170 | return ret; | |
171 | ||
172 | /* | |
173 | * Take this CPU offline. Once we clear this, we can't return, | |
174 | * and we must not schedule until we're ready to give up the cpu. | |
175 | */ | |
e03cdade | 176 | set_cpu_online(cpu, false); |
a054a811 RK |
177 | |
178 | /* | |
179 | * OK - migrate IRQs away from this CPU | |
180 | */ | |
181 | migrate_irqs(); | |
182 | ||
37ee16ae RK |
183 | /* |
184 | * Stop the local timer for this CPU. | |
185 | */ | |
10034aab | 186 | percpu_timer_stop(); |
37ee16ae | 187 | |
a054a811 RK |
188 | /* |
189 | * Flush user cache and TLB mappings, and then remove this CPU | |
190 | * from the vm mask set of all processes. | |
191 | */ | |
192 | flush_cache_all(); | |
193 | local_flush_tlb_all(); | |
194 | ||
195 | read_lock(&tasklist_lock); | |
196 | for_each_process(p) { | |
197 | if (p->mm) | |
56f8ba83 | 198 | cpumask_clear_cpu(cpu, mm_cpumask(p->mm)); |
a054a811 RK |
199 | } |
200 | read_unlock(&tasklist_lock); | |
201 | ||
202 | return 0; | |
203 | } | |
204 | ||
3c030bea RK |
205 | static DECLARE_COMPLETION(cpu_died); |
206 | ||
a054a811 RK |
207 | /* |
208 | * called on the thread which is asking for a CPU to be shutdown - | |
209 | * waits until shutdown has completed, or it is timed out. | |
210 | */ | |
90140c30 | 211 | void __cpu_die(unsigned int cpu) |
a054a811 | 212 | { |
3c030bea RK |
213 | if (!wait_for_completion_timeout(&cpu_died, msecs_to_jiffies(5000))) { |
214 | pr_err("CPU%u: cpu didn't die\n", cpu); | |
215 | return; | |
216 | } | |
217 | printk(KERN_NOTICE "CPU%u: shutdown\n", cpu); | |
218 | ||
a054a811 RK |
219 | if (!platform_cpu_kill(cpu)) |
220 | printk("CPU%u: unable to kill\n", cpu); | |
221 | } | |
222 | ||
223 | /* | |
224 | * Called from the idle thread for the CPU which has been shutdown. | |
225 | * | |
226 | * Note that we disable IRQs here, but do not re-enable them | |
227 | * before returning to the caller. This is also the behaviour | |
228 | * of the other hotplug-cpu capable cores, so presumably coming | |
229 | * out of idle fixes this. | |
230 | */ | |
90140c30 | 231 | void __ref cpu_die(void) |
a054a811 RK |
232 | { |
233 | unsigned int cpu = smp_processor_id(); | |
234 | ||
a054a811 RK |
235 | idle_task_exit(); |
236 | ||
f36d3401 RK |
237 | local_irq_disable(); |
238 | mb(); | |
239 | ||
3c030bea RK |
240 | /* Tell __cpu_die() that this CPU is now safe to dispose of */ |
241 | complete(&cpu_died); | |
242 | ||
a054a811 RK |
243 | /* |
244 | * actual CPU shutdown procedure is at least platform (if not | |
3c030bea | 245 | * CPU) specific. |
a054a811 RK |
246 | */ |
247 | platform_cpu_die(cpu); | |
248 | ||
249 | /* | |
250 | * Do not return to the idle loop - jump back to the secondary | |
251 | * cpu initialisation. There's some initialisation which needs | |
252 | * to be repeated to undo the effects of taking the CPU offline. | |
253 | */ | |
254 | __asm__("mov sp, %0\n" | |
faabfa08 | 255 | " mov fp, #0\n" |
a054a811 RK |
256 | " b secondary_start_kernel" |
257 | : | |
32d39a93 | 258 | : "r" (task_stack_page(current) + THREAD_SIZE - 8)); |
a054a811 RK |
259 | } |
260 | #endif /* CONFIG_HOTPLUG_CPU */ | |
261 | ||
05c74a6c RK |
262 | /* |
263 | * Called by both boot and secondaries to move global data into | |
264 | * per-processor storage. | |
265 | */ | |
266 | static void __cpuinit smp_store_cpu_info(unsigned int cpuid) | |
267 | { | |
268 | struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpuid); | |
269 | ||
270 | cpu_info->loops_per_jiffy = loops_per_jiffy; | |
271 | } | |
272 | ||
e65f38ed RK |
273 | /* |
274 | * This is the secondary CPU boot entry. We're using this CPUs | |
275 | * idle thread stack, but a set of temporary page tables. | |
276 | */ | |
bd6f68af | 277 | asmlinkage void __cpuinit secondary_start_kernel(void) |
e65f38ed RK |
278 | { |
279 | struct mm_struct *mm = &init_mm; | |
da2660d2 | 280 | unsigned int cpu = smp_processor_id(); |
e65f38ed RK |
281 | |
282 | printk("CPU%u: Booted secondary processor\n", cpu); | |
283 | ||
284 | /* | |
285 | * All kernel threads share the same mm context; grab a | |
286 | * reference and switch to it. | |
287 | */ | |
e65f38ed RK |
288 | atomic_inc(&mm->mm_count); |
289 | current->active_mm = mm; | |
56f8ba83 | 290 | cpumask_set_cpu(cpu, mm_cpumask(mm)); |
e65f38ed RK |
291 | cpu_switch_mm(mm->pgd, mm); |
292 | enter_lazy_tlb(mm, current); | |
505d7b19 | 293 | local_flush_tlb_all(); |
e65f38ed RK |
294 | |
295 | cpu_init(); | |
5bfb5d69 | 296 | preempt_disable(); |
2c0136db | 297 | trace_hardirqs_off(); |
e65f38ed RK |
298 | |
299 | /* | |
300 | * Give the platform a chance to do its own initialisation. | |
301 | */ | |
302 | platform_secondary_init(cpu); | |
303 | ||
304 | /* | |
305 | * Enable local interrupts. | |
306 | */ | |
e545a614 | 307 | notify_cpu_starting(cpu); |
e65f38ed RK |
308 | local_irq_enable(); |
309 | local_fiq_enable(); | |
310 | ||
a8655e83 | 311 | /* |
bc28248e | 312 | * Setup the percpu timer for this CPU. |
a8655e83 | 313 | */ |
bc28248e | 314 | percpu_timer_setup(); |
a8655e83 | 315 | |
e65f38ed RK |
316 | calibrate_delay(); |
317 | ||
318 | smp_store_cpu_info(cpu); | |
319 | ||
320 | /* | |
573619d1 RK |
321 | * OK, now it's safe to let the boot CPU continue. Wait for |
322 | * the CPU migration code to notice that the CPU is online | |
323 | * before we continue. | |
e65f38ed | 324 | */ |
e03cdade | 325 | set_cpu_online(cpu, true); |
573619d1 RK |
326 | while (!cpu_active(cpu)) |
327 | cpu_relax(); | |
e65f38ed RK |
328 | |
329 | /* | |
330 | * OK, it's off to the idle thread for us | |
331 | */ | |
332 | cpu_idle(); | |
333 | } | |
334 | ||
1da177e4 LT |
335 | void __init smp_cpus_done(unsigned int max_cpus) |
336 | { | |
337 | int cpu; | |
338 | unsigned long bogosum = 0; | |
339 | ||
340 | for_each_online_cpu(cpu) | |
341 | bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy; | |
342 | ||
343 | printk(KERN_INFO "SMP: Total of %d processors activated " | |
344 | "(%lu.%02lu BogoMIPS).\n", | |
345 | num_online_cpus(), | |
346 | bogosum / (500000/HZ), | |
347 | (bogosum / (5000/HZ)) % 100); | |
348 | } | |
349 | ||
350 | void __init smp_prepare_boot_cpu(void) | |
351 | { | |
352 | unsigned int cpu = smp_processor_id(); | |
353 | ||
71f512e8 | 354 | per_cpu(cpu_data, cpu).idle = current; |
1da177e4 LT |
355 | } |
356 | ||
05c74a6c | 357 | void __init smp_prepare_cpus(unsigned int max_cpus) |
1da177e4 | 358 | { |
05c74a6c | 359 | unsigned int ncores = num_possible_cpus(); |
1da177e4 | 360 | |
05c74a6c | 361 | smp_store_cpu_info(smp_processor_id()); |
1da177e4 LT |
362 | |
363 | /* | |
05c74a6c | 364 | * are we trying to boot more cores than exist? |
1da177e4 | 365 | */ |
05c74a6c RK |
366 | if (max_cpus > ncores) |
367 | max_cpus = ncores; | |
7fa22bd5 | 368 | if (ncores > 1 && max_cpus) { |
05c74a6c RK |
369 | /* |
370 | * Enable the local timer or broadcast device for the | |
371 | * boot CPU, but only if we have more than one CPU. | |
372 | */ | |
373 | percpu_timer_setup(); | |
1da177e4 | 374 | |
7fa22bd5 SB |
375 | /* |
376 | * Initialise the present map, which describes the set of CPUs | |
377 | * actually populated at the present time. A platform should | |
378 | * re-initialize the map in platform_smp_prepare_cpus() if | |
379 | * present != possible (e.g. physical hotplug). | |
380 | */ | |
381 | init_cpu_present(&cpu_possible_map); | |
382 | ||
05c74a6c RK |
383 | /* |
384 | * Initialise the SCU if there are more than one CPU | |
385 | * and let them know where to start. | |
386 | */ | |
387 | platform_smp_prepare_cpus(max_cpus); | |
388 | } | |
1da177e4 LT |
389 | } |
390 | ||
0f7b332f RK |
391 | static void (*smp_cross_call)(const struct cpumask *, unsigned int); |
392 | ||
393 | void __init set_smp_cross_call(void (*fn)(const struct cpumask *, unsigned int)) | |
394 | { | |
395 | smp_cross_call = fn; | |
396 | } | |
397 | ||
82668104 | 398 | void arch_send_call_function_ipi_mask(const struct cpumask *mask) |
1da177e4 | 399 | { |
e3fbb087 | 400 | smp_cross_call(mask, IPI_CALL_FUNC); |
1da177e4 LT |
401 | } |
402 | ||
f6dd9fa5 | 403 | void arch_send_call_function_single_ipi(int cpu) |
3e459990 | 404 | { |
e3fbb087 | 405 | smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE); |
3e459990 | 406 | } |
3e459990 | 407 | |
4a88abd7 RK |
408 | static const char *ipi_types[NR_IPI] = { |
409 | #define S(x,s) [x - IPI_TIMER] = s | |
410 | S(IPI_TIMER, "Timer broadcast interrupts"), | |
411 | S(IPI_RESCHEDULE, "Rescheduling interrupts"), | |
412 | S(IPI_CALL_FUNC, "Function call interrupts"), | |
413 | S(IPI_CALL_FUNC_SINGLE, "Single function call interrupts"), | |
414 | S(IPI_CPU_STOP, "CPU stop interrupts"), | |
415 | }; | |
416 | ||
f13cd417 | 417 | void show_ipi_list(struct seq_file *p, int prec) |
1da177e4 | 418 | { |
4a88abd7 | 419 | unsigned int cpu, i; |
1da177e4 | 420 | |
4a88abd7 RK |
421 | for (i = 0; i < NR_IPI; i++) { |
422 | seq_printf(p, "%*s%u: ", prec - 1, "IPI", i); | |
1da177e4 | 423 | |
4a88abd7 RK |
424 | for_each_present_cpu(cpu) |
425 | seq_printf(p, "%10u ", | |
426 | __get_irq_stat(cpu, ipi_irqs[i])); | |
1da177e4 | 427 | |
4a88abd7 RK |
428 | seq_printf(p, " %s\n", ipi_types[i]); |
429 | } | |
1da177e4 LT |
430 | } |
431 | ||
b54992fe | 432 | u64 smp_irq_stat_cpu(unsigned int cpu) |
37ee16ae | 433 | { |
b54992fe RK |
434 | u64 sum = 0; |
435 | int i; | |
37ee16ae | 436 | |
b54992fe RK |
437 | for (i = 0; i < NR_IPI; i++) |
438 | sum += __get_irq_stat(cpu, ipi_irqs[i]); | |
37ee16ae | 439 | |
b54992fe RK |
440 | #ifdef CONFIG_LOCAL_TIMERS |
441 | sum += __get_irq_stat(cpu, local_timer_irqs); | |
442 | #endif | |
37ee16ae | 443 | |
b54992fe | 444 | return sum; |
37ee16ae RK |
445 | } |
446 | ||
bc28248e RK |
447 | /* |
448 | * Timer (local or broadcast) support | |
449 | */ | |
450 | static DEFINE_PER_CPU(struct clock_event_device, percpu_clockevent); | |
451 | ||
c97d4869 | 452 | static void ipi_timer(void) |
1da177e4 | 453 | { |
bc28248e | 454 | struct clock_event_device *evt = &__get_cpu_var(percpu_clockevent); |
1da177e4 | 455 | irq_enter(); |
bc28248e | 456 | evt->event_handler(evt); |
1da177e4 LT |
457 | irq_exit(); |
458 | } | |
459 | ||
37ee16ae | 460 | #ifdef CONFIG_LOCAL_TIMERS |
61b5cb1c | 461 | asmlinkage void __exception_irq_entry do_local_timer(struct pt_regs *regs) |
37ee16ae | 462 | { |
c97d4869 | 463 | struct pt_regs *old_regs = set_irq_regs(regs); |
37ee16ae RK |
464 | int cpu = smp_processor_id(); |
465 | ||
466 | if (local_timer_ack()) { | |
46c48f22 | 467 | __inc_irq_stat(cpu, local_timer_irqs); |
c97d4869 | 468 | ipi_timer(); |
37ee16ae | 469 | } |
c97d4869 RK |
470 | |
471 | set_irq_regs(old_regs); | |
37ee16ae | 472 | } |
ec405ea9 | 473 | |
f13cd417 | 474 | void show_local_irqs(struct seq_file *p, int prec) |
ec405ea9 RK |
475 | { |
476 | unsigned int cpu; | |
477 | ||
f13cd417 | 478 | seq_printf(p, "%*s: ", prec, "LOC"); |
ec405ea9 RK |
479 | |
480 | for_each_present_cpu(cpu) | |
46c48f22 | 481 | seq_printf(p, "%10u ", __get_irq_stat(cpu, local_timer_irqs)); |
ec405ea9 | 482 | |
f13cd417 | 483 | seq_printf(p, " Local timer interrupts\n"); |
ec405ea9 | 484 | } |
37ee16ae RK |
485 | #endif |
486 | ||
bc28248e RK |
487 | #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST |
488 | static void smp_timer_broadcast(const struct cpumask *mask) | |
489 | { | |
e3fbb087 | 490 | smp_cross_call(mask, IPI_TIMER); |
bc28248e | 491 | } |
5388a6b2 RK |
492 | #else |
493 | #define smp_timer_broadcast NULL | |
494 | #endif | |
bc28248e RK |
495 | |
496 | static void broadcast_timer_set_mode(enum clock_event_mode mode, | |
497 | struct clock_event_device *evt) | |
498 | { | |
499 | } | |
500 | ||
a8d2518c | 501 | static void __cpuinit broadcast_timer_setup(struct clock_event_device *evt) |
bc28248e RK |
502 | { |
503 | evt->name = "dummy_timer"; | |
504 | evt->features = CLOCK_EVT_FEAT_ONESHOT | | |
505 | CLOCK_EVT_FEAT_PERIODIC | | |
506 | CLOCK_EVT_FEAT_DUMMY; | |
507 | evt->rating = 400; | |
508 | evt->mult = 1; | |
509 | evt->set_mode = broadcast_timer_set_mode; | |
bc28248e RK |
510 | |
511 | clockevents_register_device(evt); | |
512 | } | |
bc28248e RK |
513 | |
514 | void __cpuinit percpu_timer_setup(void) | |
515 | { | |
516 | unsigned int cpu = smp_processor_id(); | |
517 | struct clock_event_device *evt = &per_cpu(percpu_clockevent, cpu); | |
518 | ||
519 | evt->cpumask = cpumask_of(cpu); | |
5388a6b2 | 520 | evt->broadcast = smp_timer_broadcast; |
bc28248e | 521 | |
af90f10d SS |
522 | if (local_timer_setup(evt)) |
523 | broadcast_timer_setup(evt); | |
bc28248e RK |
524 | } |
525 | ||
10034aab RK |
526 | #ifdef CONFIG_HOTPLUG_CPU |
527 | /* | |
528 | * The generic clock events code purposely does not stop the local timer | |
529 | * on CPU_DEAD/CPU_DEAD_FROZEN hotplug events, so we have to do it | |
530 | * manually here. | |
531 | */ | |
532 | static void percpu_timer_stop(void) | |
533 | { | |
534 | unsigned int cpu = smp_processor_id(); | |
535 | struct clock_event_device *evt = &per_cpu(percpu_clockevent, cpu); | |
536 | ||
537 | evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt); | |
538 | } | |
539 | #endif | |
540 | ||
1da177e4 LT |
541 | static DEFINE_SPINLOCK(stop_lock); |
542 | ||
543 | /* | |
544 | * ipi_cpu_stop - handle IPI from smp_send_stop() | |
545 | */ | |
546 | static void ipi_cpu_stop(unsigned int cpu) | |
547 | { | |
3d3f78d7 RK |
548 | if (system_state == SYSTEM_BOOTING || |
549 | system_state == SYSTEM_RUNNING) { | |
550 | spin_lock(&stop_lock); | |
551 | printk(KERN_CRIT "CPU%u: stopping\n", cpu); | |
552 | dump_stack(); | |
553 | spin_unlock(&stop_lock); | |
554 | } | |
1da177e4 | 555 | |
e03cdade | 556 | set_cpu_online(cpu, false); |
1da177e4 LT |
557 | |
558 | local_fiq_disable(); | |
559 | local_irq_disable(); | |
560 | ||
561 | while (1) | |
562 | cpu_relax(); | |
563 | } | |
564 | ||
565 | /* | |
566 | * Main handler for inter-processor interrupts | |
1da177e4 | 567 | */ |
4073723a | 568 | asmlinkage void __exception_irq_entry do_IPI(int ipinr, struct pt_regs *regs) |
1da177e4 LT |
569 | { |
570 | unsigned int cpu = smp_processor_id(); | |
c97d4869 | 571 | struct pt_regs *old_regs = set_irq_regs(regs); |
1da177e4 | 572 | |
4a88abd7 RK |
573 | if (ipinr >= IPI_TIMER && ipinr < IPI_TIMER + NR_IPI) |
574 | __inc_irq_stat(cpu, ipi_irqs[ipinr - IPI_TIMER]); | |
1da177e4 | 575 | |
24480d98 RK |
576 | switch (ipinr) { |
577 | case IPI_TIMER: | |
578 | ipi_timer(); | |
579 | break; | |
1da177e4 | 580 | |
24480d98 | 581 | case IPI_RESCHEDULE: |
184748cc | 582 | scheduler_ipi(); |
24480d98 | 583 | break; |
1da177e4 | 584 | |
24480d98 RK |
585 | case IPI_CALL_FUNC: |
586 | generic_smp_call_function_interrupt(); | |
587 | break; | |
f6dd9fa5 | 588 | |
24480d98 RK |
589 | case IPI_CALL_FUNC_SINGLE: |
590 | generic_smp_call_function_single_interrupt(); | |
591 | break; | |
1da177e4 | 592 | |
24480d98 RK |
593 | case IPI_CPU_STOP: |
594 | ipi_cpu_stop(cpu); | |
595 | break; | |
1da177e4 | 596 | |
24480d98 RK |
597 | default: |
598 | printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n", | |
599 | cpu, ipinr); | |
600 | break; | |
1da177e4 | 601 | } |
c97d4869 | 602 | set_irq_regs(old_regs); |
1da177e4 LT |
603 | } |
604 | ||
605 | void smp_send_reschedule(int cpu) | |
606 | { | |
e3fbb087 | 607 | smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE); |
1da177e4 LT |
608 | } |
609 | ||
1da177e4 LT |
610 | void smp_send_stop(void) |
611 | { | |
28e18293 | 612 | unsigned long timeout; |
1da177e4 | 613 | |
28e18293 RK |
614 | if (num_online_cpus() > 1) { |
615 | cpumask_t mask = cpu_online_map; | |
616 | cpu_clear(smp_processor_id(), mask); | |
4b0ef3b1 | 617 | |
e3fbb087 | 618 | smp_cross_call(&mask, IPI_CPU_STOP); |
28e18293 | 619 | } |
4b0ef3b1 | 620 | |
28e18293 RK |
621 | /* Wait up to one second for other CPUs to stop */ |
622 | timeout = USEC_PER_SEC; | |
623 | while (num_online_cpus() > 1 && timeout--) | |
624 | udelay(1); | |
4b0ef3b1 | 625 | |
28e18293 RK |
626 | if (num_online_cpus() > 1) |
627 | pr_warning("SMP: failed to stop secondary CPUs\n"); | |
4b0ef3b1 RK |
628 | } |
629 | ||
4b0ef3b1 | 630 | /* |
1da177e4 | 631 | * not supported here |
4b0ef3b1 | 632 | */ |
5048bcba | 633 | int setup_profiling_timer(unsigned int multiplier) |
4b0ef3b1 | 634 | { |
1da177e4 | 635 | return -EINVAL; |
4b0ef3b1 | 636 | } |