4 * Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great
5 * deal of code from the sparc and intel versions.
7 * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
9 * PowerPC-64 Support added by Dave Engebretsen, Peter Bergner, and
10 * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
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.
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/sched.h>
23 #include <linux/smp.h>
24 #include <linux/interrupt.h>
25 #include <linux/delay.h>
26 #include <linux/init.h>
27 #include <linux/spinlock.h>
28 #include <linux/cache.h>
29 #include <linux/err.h>
30 #include <linux/sysdev.h>
31 #include <linux/cpu.h>
32 #include <linux/notifier.h>
33 #include <linux/topology.h>
35 #include <asm/ptrace.h>
36 #include <asm/atomic.h>
39 #include <asm/pgtable.h>
43 #include <asm/machdep.h>
44 #include <asm/cputhreads.h>
45 #include <asm/cputable.h>
46 #include <asm/system.h>
48 #include <asm/vdso_datapage.h>
55 #define DBG(fmt...) udbg_printf(fmt)
60 struct thread_info *secondary_ti;
62 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
63 DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
65 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
66 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
68 /* SMP operations for this machine */
69 struct smp_ops_t *smp_ops;
71 /* Can't be static due to PowerMac hackery */
72 volatile unsigned int cpu_callin_map[NR_CPUS];
74 int smt_enabled_at_boot = 1;
76 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
79 void __devinit smp_generic_kick_cpu(int nr)
81 BUG_ON(nr < 0 || nr >= NR_CPUS);
84 * The processor is currently spinning, waiting for the
85 * cpu_start field to become non-zero After we set cpu_start,
86 * the processor will continue on to secondary_start
88 paca[nr].cpu_start = 1;
93 void smp_message_recv(int msg)
96 case PPC_MSG_CALL_FUNCTION:
97 generic_smp_call_function_interrupt();
99 case PPC_MSG_RESCHEDULE:
100 /* we notice need_resched on exit */
102 case PPC_MSG_CALL_FUNC_SINGLE:
103 generic_smp_call_function_single_interrupt();
105 case PPC_MSG_DEBUGGER_BREAK:
106 if (crash_ipi_function_ptr) {
107 crash_ipi_function_ptr(get_irq_regs());
110 #ifdef CONFIG_DEBUGGER
111 debugger_ipi(get_irq_regs());
113 #endif /* CONFIG_DEBUGGER */
116 printk("SMP %d: smp_message_recv(): unknown msg %d\n",
117 smp_processor_id(), msg);
122 static irqreturn_t call_function_action(int irq, void *data)
124 generic_smp_call_function_interrupt();
128 static irqreturn_t reschedule_action(int irq, void *data)
130 /* we just need the return path side effect of checking need_resched */
134 static irqreturn_t call_function_single_action(int irq, void *data)
136 generic_smp_call_function_single_interrupt();
140 static irqreturn_t debug_ipi_action(int irq, void *data)
142 smp_message_recv(PPC_MSG_DEBUGGER_BREAK);
146 static irq_handler_t smp_ipi_action[] = {
147 [PPC_MSG_CALL_FUNCTION] = call_function_action,
148 [PPC_MSG_RESCHEDULE] = reschedule_action,
149 [PPC_MSG_CALL_FUNC_SINGLE] = call_function_single_action,
150 [PPC_MSG_DEBUGGER_BREAK] = debug_ipi_action,
153 const char *smp_ipi_name[] = {
154 [PPC_MSG_CALL_FUNCTION] = "ipi call function",
155 [PPC_MSG_RESCHEDULE] = "ipi reschedule",
156 [PPC_MSG_CALL_FUNC_SINGLE] = "ipi call function single",
157 [PPC_MSG_DEBUGGER_BREAK] = "ipi debugger",
160 /* optional function to request ipi, for controllers with >= 4 ipis */
161 int smp_request_message_ipi(int virq, int msg)
165 if (msg < 0 || msg > PPC_MSG_DEBUGGER_BREAK) {
168 #if !defined(CONFIG_DEBUGGER) && !defined(CONFIG_KEXEC)
169 if (msg == PPC_MSG_DEBUGGER_BREAK) {
173 err = request_irq(virq, smp_ipi_action[msg], IRQF_DISABLED|IRQF_PERCPU,
174 smp_ipi_name[msg], 0);
175 WARN(err < 0, "unable to request_irq %d for %s (rc %d)\n",
176 virq, smp_ipi_name[msg], err);
181 void smp_send_reschedule(int cpu)
184 smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE);
187 void arch_send_call_function_single_ipi(int cpu)
189 smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNC_SINGLE);
192 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
196 for_each_cpu(cpu, mask)
197 smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNCTION);
200 #ifdef CONFIG_DEBUGGER
201 void smp_send_debugger_break(int cpu)
204 smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
209 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
211 crash_ipi_function_ptr = crash_ipi_callback;
212 if (crash_ipi_callback && smp_ops) {
214 smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_DEBUGGER_BREAK);
219 static void stop_this_cpu(void *dummy)
221 /* Remove this CPU */
222 set_cpu_online(smp_processor_id(), false);
229 void smp_send_stop(void)
231 smp_call_function(stop_this_cpu, NULL, 0);
234 struct thread_info *current_set[NR_CPUS];
236 static void __devinit smp_store_cpu_info(int id)
238 per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
241 static void __init smp_create_idle(unsigned int cpu)
243 struct task_struct *p;
245 /* create a process for the processor */
248 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
250 paca[cpu].__current = p;
251 paca[cpu].kstack = (unsigned long) task_thread_info(p)
252 + THREAD_SIZE - STACK_FRAME_OVERHEAD;
254 current_set[cpu] = task_thread_info(p);
255 task_thread_info(p)->cpu = cpu;
258 void __init smp_prepare_cpus(unsigned int max_cpus)
262 DBG("smp_prepare_cpus\n");
265 * setup_cpu may need to be called on the boot cpu. We havent
266 * spun any cpus up but lets be paranoid.
268 BUG_ON(boot_cpuid != smp_processor_id());
271 smp_store_cpu_info(boot_cpuid);
272 cpu_callin_map[boot_cpuid] = 1;
274 for_each_possible_cpu(cpu) {
275 zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu),
276 GFP_KERNEL, cpu_to_node(cpu));
277 zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
278 GFP_KERNEL, cpu_to_node(cpu));
281 cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
282 cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
286 max_cpus = smp_ops->probe();
292 smp_space_timers(max_cpus);
294 for_each_possible_cpu(cpu)
295 if (cpu != boot_cpuid)
296 smp_create_idle(cpu);
299 void __devinit smp_prepare_boot_cpu(void)
301 BUG_ON(smp_processor_id() != boot_cpuid);
303 paca[boot_cpuid].__current = current;
305 current_set[boot_cpuid] = task_thread_info(current);
308 #ifdef CONFIG_HOTPLUG_CPU
309 /* State of each CPU during hotplug phases */
310 DEFINE_PER_CPU(int, cpu_state) = { 0 };
312 int generic_cpu_disable(void)
314 unsigned int cpu = smp_processor_id();
316 if (cpu == boot_cpuid)
319 set_cpu_online(cpu, false);
321 vdso_data->processorCount--;
322 fixup_irqs(cpu_online_mask);
327 int generic_cpu_enable(unsigned int cpu)
329 /* Do the normal bootup if we haven't
330 * already bootstrapped. */
331 if (system_state != SYSTEM_RUNNING)
334 /* get the target out of it's holding state */
335 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
338 while (!cpu_online(cpu))
342 fixup_irqs(cpu_online_mask);
343 /* counter the irq disable in fixup_irqs */
349 void generic_cpu_die(unsigned int cpu)
353 for (i = 0; i < 100; i++) {
355 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
359 printk(KERN_ERR "CPU%d didn't die...\n", cpu);
362 void generic_mach_cpu_die(void)
367 cpu = smp_processor_id();
368 printk(KERN_DEBUG "CPU%d offline\n", cpu);
369 __get_cpu_var(cpu_state) = CPU_DEAD;
371 while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
373 set_cpu_online(cpu, true);
378 static int __devinit cpu_enable(unsigned int cpu)
380 if (smp_ops && smp_ops->cpu_enable)
381 return smp_ops->cpu_enable(cpu);
386 int __cpuinit __cpu_up(unsigned int cpu)
390 secondary_ti = current_set[cpu];
391 if (!cpu_enable(cpu))
394 if (smp_ops == NULL ||
395 (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
398 /* Make sure callin-map entry is 0 (can be leftover a CPU
401 cpu_callin_map[cpu] = 0;
403 /* The information for processor bringup must
404 * be written out to main store before we release
410 DBG("smp: kicking cpu %d\n", cpu);
411 smp_ops->kick_cpu(cpu);
414 * wait to see if the cpu made a callin (is actually up).
415 * use this value that I found through experimentation.
418 if (system_state < SYSTEM_RUNNING)
419 for (c = 50000; c && !cpu_callin_map[cpu]; c--)
421 #ifdef CONFIG_HOTPLUG_CPU
424 * CPUs can take much longer to come up in the
425 * hotplug case. Wait five seconds.
427 for (c = 5000; c && !cpu_callin_map[cpu]; c--)
431 if (!cpu_callin_map[cpu]) {
432 printk("Processor %u is stuck.\n", cpu);
436 printk("Processor %u found.\n", cpu);
438 if (smp_ops->give_timebase)
439 smp_ops->give_timebase();
441 /* Wait until cpu puts itself in the online map */
442 while (!cpu_online(cpu))
448 /* Return the value of the reg property corresponding to the given
451 int cpu_to_core_id(int cpu)
453 struct device_node *np;
457 np = of_get_cpu_node(cpu, NULL);
461 reg = of_get_property(np, "reg", NULL);
471 /* Must be called when no change can occur to cpu_present_mask,
472 * i.e. during cpu online or offline.
474 static struct device_node *cpu_to_l2cache(int cpu)
476 struct device_node *np;
477 struct device_node *cache;
479 if (!cpu_present(cpu))
482 np = of_get_cpu_node(cpu, NULL);
486 cache = of_find_next_cache_node(np);
493 /* Activate a secondary processor. */
494 int __devinit start_secondary(void *unused)
496 unsigned int cpu = smp_processor_id();
497 struct device_node *l2_cache;
500 atomic_inc(&init_mm.mm_count);
501 current->active_mm = &init_mm;
503 smp_store_cpu_info(cpu);
505 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
506 /* Clear any pending timer interrupts */
507 mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS);
509 /* Enable decrementer interrupt */
510 mtspr(SPRN_TCR, TCR_DIE);
512 set_dec(tb_ticks_per_jiffy);
514 cpu_callin_map[cpu] = 1;
516 if (smp_ops->setup_cpu)
517 smp_ops->setup_cpu(cpu);
518 if (smp_ops->take_timebase)
519 smp_ops->take_timebase();
521 if (system_state > SYSTEM_BOOTING)
524 secondary_cpu_time_init();
527 notify_cpu_starting(cpu);
528 set_cpu_online(cpu, true);
529 /* Update sibling maps */
530 base = cpu_first_thread_in_core(cpu);
531 for (i = 0; i < threads_per_core; i++) {
532 if (cpu_is_offline(base + i))
534 cpumask_set_cpu(cpu, cpu_sibling_mask(base + i));
535 cpumask_set_cpu(base + i, cpu_sibling_mask(cpu));
537 /* cpu_core_map should be a superset of
538 * cpu_sibling_map even if we don't have cache
539 * information, so update the former here, too.
541 cpumask_set_cpu(cpu, cpu_core_mask(base + i));
542 cpumask_set_cpu(base + i, cpu_core_mask(cpu));
544 l2_cache = cpu_to_l2cache(cpu);
545 for_each_online_cpu(i) {
546 struct device_node *np = cpu_to_l2cache(i);
549 if (np == l2_cache) {
550 cpumask_set_cpu(cpu, cpu_core_mask(i));
551 cpumask_set_cpu(i, cpu_core_mask(cpu));
555 of_node_put(l2_cache);
564 int setup_profiling_timer(unsigned int multiplier)
569 void __init smp_cpus_done(unsigned int max_cpus)
571 cpumask_var_t old_mask;
573 /* We want the setup_cpu() here to be called from CPU 0, but our
574 * init thread may have been "borrowed" by another CPU in the meantime
575 * se we pin us down to CPU 0 for a short while
577 alloc_cpumask_var(&old_mask, GFP_NOWAIT);
578 cpumask_copy(old_mask, ¤t->cpus_allowed);
579 set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid));
581 if (smp_ops && smp_ops->setup_cpu)
582 smp_ops->setup_cpu(boot_cpuid);
584 set_cpus_allowed_ptr(current, old_mask);
586 free_cpumask_var(old_mask);
588 snapshot_timebases();
590 dump_numa_cpu_topology();
593 #ifdef CONFIG_HOTPLUG_CPU
594 int __cpu_disable(void)
596 struct device_node *l2_cache;
597 int cpu = smp_processor_id();
601 if (!smp_ops->cpu_disable)
604 err = smp_ops->cpu_disable();
608 /* Update sibling maps */
609 base = cpu_first_thread_in_core(cpu);
610 for (i = 0; i < threads_per_core; i++) {
611 cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
612 cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
613 cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
614 cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
617 l2_cache = cpu_to_l2cache(cpu);
618 for_each_present_cpu(i) {
619 struct device_node *np = cpu_to_l2cache(i);
622 if (np == l2_cache) {
623 cpumask_clear_cpu(cpu, cpu_core_mask(i));
624 cpumask_clear_cpu(i, cpu_core_mask(cpu));
628 of_node_put(l2_cache);
634 void __cpu_die(unsigned int cpu)
636 if (smp_ops->cpu_die)
637 smp_ops->cpu_die(cpu);
640 static DEFINE_MUTEX(powerpc_cpu_hotplug_driver_mutex);
642 void cpu_hotplug_driver_lock()
644 mutex_lock(&powerpc_cpu_hotplug_driver_mutex);
647 void cpu_hotplug_driver_unlock()
649 mutex_unlock(&powerpc_cpu_hotplug_driver_mutex);