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/cputable.h>
45 #include <asm/system.h>
47 #include <asm/vdso_datapage.h>
54 #define DBG(fmt...) udbg_printf(fmt)
59 int smp_hw_index[NR_CPUS];
60 struct thread_info *secondary_ti;
62 cpumask_t cpu_possible_map = CPU_MASK_NONE;
63 cpumask_t cpu_online_map = CPU_MASK_NONE;
64 DEFINE_PER_CPU(cpumask_t, cpu_sibling_map) = CPU_MASK_NONE;
66 EXPORT_SYMBOL(cpu_online_map);
67 EXPORT_SYMBOL(cpu_possible_map);
68 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
70 /* SMP operations for this machine */
71 struct smp_ops_t *smp_ops;
73 static volatile unsigned int cpu_callin_map[NR_CPUS];
75 void smp_call_function_interrupt(void);
77 int smt_enabled_at_boot = 1;
79 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
82 void __devinit smp_generic_kick_cpu(int nr)
84 BUG_ON(nr < 0 || nr >= NR_CPUS);
87 * The processor is currently spinning, waiting for the
88 * cpu_start field to become non-zero After we set cpu_start,
89 * the processor will continue on to secondary_start
91 paca[nr].cpu_start = 1;
96 void smp_message_recv(int msg)
99 case PPC_MSG_CALL_FUNCTION:
100 smp_call_function_interrupt();
102 case PPC_MSG_RESCHEDULE:
103 /* XXX Do we have to do this? */
106 case PPC_MSG_DEBUGGER_BREAK:
107 if (crash_ipi_function_ptr) {
108 crash_ipi_function_ptr(get_irq_regs());
111 #ifdef CONFIG_DEBUGGER
112 debugger_ipi(get_irq_regs());
114 #endif /* CONFIG_DEBUGGER */
117 printk("SMP %d: smp_message_recv(): unknown msg %d\n",
118 smp_processor_id(), msg);
123 void smp_send_reschedule(int cpu)
126 smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE);
129 #ifdef CONFIG_DEBUGGER
130 void smp_send_debugger_break(int cpu)
133 smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
138 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
140 crash_ipi_function_ptr = crash_ipi_callback;
141 if (crash_ipi_callback && smp_ops) {
143 smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_DEBUGGER_BREAK);
148 static void stop_this_cpu(void *dummy)
156 * Structure and data for smp_call_function(). This is designed to minimise
157 * static memory requirements. It also looks cleaner.
158 * Stolen from the i386 version.
160 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(call_lock);
162 static struct call_data_struct {
163 void (*func) (void *info);
170 /* delay of at least 8 seconds */
171 #define SMP_CALL_TIMEOUT 8
174 * These functions send a 'generic call function' IPI to other online
175 * CPUS in the system.
177 * [SUMMARY] Run a function on other CPUs.
178 * <func> The function to run. This must be fast and non-blocking.
179 * <info> An arbitrary pointer to pass to the function.
180 * <nonatomic> currently unused.
181 * <wait> If true, wait (atomically) until function has completed on other CPUs.
182 * [RETURNS] 0 on success, else a negative status code. Does not return until
183 * remote CPUs are nearly ready to execute <<func>> or are or have executed.
184 * <map> is a cpu map of the cpus to send IPI to.
186 * You must not call this function with disabled interrupts or from a
187 * hardware interrupt handler or from a bottom half handler.
189 static int __smp_call_function_map(void (*func) (void *info), void *info,
190 int nonatomic, int wait, cpumask_t map)
192 struct call_data_struct data;
193 int ret = -1, num_cpus;
197 if (unlikely(smp_ops == NULL))
202 atomic_set(&data.started, 0);
205 atomic_set(&data.finished, 0);
207 spin_lock(&call_lock);
209 /* remove 'self' from the map */
210 if (cpu_isset(smp_processor_id(), map))
211 cpu_clear(smp_processor_id(), map);
213 /* sanity check the map, remove any non-online processors. */
214 cpus_and(map, map, cpu_online_map);
216 num_cpus = cpus_weight(map);
222 /* Send a message to all CPUs in the map */
223 for_each_cpu_mask(cpu, map)
224 smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNCTION);
226 timeout = get_tb() + (u64) SMP_CALL_TIMEOUT * tb_ticks_per_sec;
228 /* Wait for indication that they have received the message */
229 while (atomic_read(&data.started) != num_cpus) {
231 if (get_tb() >= timeout) {
232 printk("smp_call_function on cpu %d: other cpus not "
233 "responding (%d)\n", smp_processor_id(),
234 atomic_read(&data.started));
240 /* optionally wait for the CPUs to complete */
242 while (atomic_read(&data.finished) != num_cpus) {
244 if (get_tb() >= timeout) {
245 printk("smp_call_function on cpu %d: other "
246 "cpus not finishing (%d/%d)\n",
248 atomic_read(&data.finished),
249 atomic_read(&data.started));
262 spin_unlock(&call_lock);
266 static int __smp_call_function(void (*func)(void *info), void *info,
267 int nonatomic, int wait)
269 return __smp_call_function_map(func, info, nonatomic, wait,
273 int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
276 /* Can deadlock when called with interrupts disabled */
277 WARN_ON(irqs_disabled());
279 return __smp_call_function(func, info, nonatomic, wait);
281 EXPORT_SYMBOL(smp_call_function);
283 int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
284 int nonatomic, int wait)
286 cpumask_t map = CPU_MASK_NONE;
289 /* Can deadlock when called with interrupts disabled */
290 WARN_ON(irqs_disabled());
292 if (!cpu_online(cpu))
296 if (cpu != get_cpu())
297 ret = __smp_call_function_map(func, info, nonatomic, wait, map);
306 EXPORT_SYMBOL(smp_call_function_single);
308 void smp_send_stop(void)
310 __smp_call_function(stop_this_cpu, NULL, 1, 0);
313 void smp_call_function_interrupt(void)
315 void (*func) (void *info);
319 /* call_data will be NULL if the sender timed out while
320 * waiting on us to receive the call.
325 func = call_data->func;
326 info = call_data->info;
327 wait = call_data->wait;
330 smp_mb__before_atomic_inc();
333 * Notify initiating CPU that I've grabbed the data and am
334 * about to execute the function
336 atomic_inc(&call_data->started);
338 * At this point the info structure may be out of scope unless wait==1
342 smp_mb__before_atomic_inc();
343 atomic_inc(&call_data->finished);
347 extern struct gettimeofday_struct do_gtod;
349 struct thread_info *current_set[NR_CPUS];
351 DECLARE_PER_CPU(unsigned int, pvr);
353 static void __devinit smp_store_cpu_info(int id)
355 per_cpu(pvr, id) = mfspr(SPRN_PVR);
358 static void __init smp_create_idle(unsigned int cpu)
360 struct task_struct *p;
362 /* create a process for the processor */
365 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
367 paca[cpu].__current = p;
369 current_set[cpu] = task_thread_info(p);
370 task_thread_info(p)->cpu = cpu;
373 void __init smp_prepare_cpus(unsigned int max_cpus)
377 DBG("smp_prepare_cpus\n");
380 * setup_cpu may need to be called on the boot cpu. We havent
381 * spun any cpus up but lets be paranoid.
383 BUG_ON(boot_cpuid != smp_processor_id());
386 smp_store_cpu_info(boot_cpuid);
387 cpu_callin_map[boot_cpuid] = 1;
390 max_cpus = smp_ops->probe();
394 smp_space_timers(max_cpus);
396 for_each_possible_cpu(cpu)
397 if (cpu != boot_cpuid)
398 smp_create_idle(cpu);
401 void __devinit smp_prepare_boot_cpu(void)
403 BUG_ON(smp_processor_id() != boot_cpuid);
405 cpu_set(boot_cpuid, cpu_online_map);
407 paca[boot_cpuid].__current = current;
409 current_set[boot_cpuid] = task_thread_info(current);
412 #ifdef CONFIG_HOTPLUG_CPU
413 /* State of each CPU during hotplug phases */
414 DEFINE_PER_CPU(int, cpu_state) = { 0 };
416 int generic_cpu_disable(void)
418 unsigned int cpu = smp_processor_id();
420 if (cpu == boot_cpuid)
423 cpu_clear(cpu, cpu_online_map);
425 vdso_data->processorCount--;
426 fixup_irqs(cpu_online_map);
431 int generic_cpu_enable(unsigned int cpu)
433 /* Do the normal bootup if we haven't
434 * already bootstrapped. */
435 if (system_state != SYSTEM_RUNNING)
438 /* get the target out of it's holding state */
439 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
442 while (!cpu_online(cpu))
446 fixup_irqs(cpu_online_map);
447 /* counter the irq disable in fixup_irqs */
453 void generic_cpu_die(unsigned int cpu)
457 for (i = 0; i < 100; i++) {
459 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
463 printk(KERN_ERR "CPU%d didn't die...\n", cpu);
466 void generic_mach_cpu_die(void)
471 cpu = smp_processor_id();
472 printk(KERN_DEBUG "CPU%d offline\n", cpu);
473 __get_cpu_var(cpu_state) = CPU_DEAD;
475 while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
477 cpu_set(cpu, cpu_online_map);
482 static int __devinit cpu_enable(unsigned int cpu)
484 if (smp_ops && smp_ops->cpu_enable)
485 return smp_ops->cpu_enable(cpu);
490 int __cpuinit __cpu_up(unsigned int cpu)
494 secondary_ti = current_set[cpu];
495 if (!cpu_enable(cpu))
498 if (smp_ops == NULL ||
499 (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
502 /* Make sure callin-map entry is 0 (can be leftover a CPU
505 cpu_callin_map[cpu] = 0;
507 /* The information for processor bringup must
508 * be written out to main store before we release
514 DBG("smp: kicking cpu %d\n", cpu);
515 smp_ops->kick_cpu(cpu);
518 * wait to see if the cpu made a callin (is actually up).
519 * use this value that I found through experimentation.
522 if (system_state < SYSTEM_RUNNING)
523 for (c = 50000; c && !cpu_callin_map[cpu]; c--)
525 #ifdef CONFIG_HOTPLUG_CPU
528 * CPUs can take much longer to come up in the
529 * hotplug case. Wait five seconds.
531 for (c = 25; c && !cpu_callin_map[cpu]; c--) {
536 if (!cpu_callin_map[cpu]) {
537 printk("Processor %u is stuck.\n", cpu);
541 printk("Processor %u found.\n", cpu);
543 if (smp_ops->give_timebase)
544 smp_ops->give_timebase();
546 /* Wait until cpu puts itself in the online map */
547 while (!cpu_online(cpu))
554 /* Activate a secondary processor. */
555 int __devinit start_secondary(void *unused)
557 unsigned int cpu = smp_processor_id();
559 atomic_inc(&init_mm.mm_count);
560 current->active_mm = &init_mm;
562 smp_store_cpu_info(cpu);
563 set_dec(tb_ticks_per_jiffy);
565 cpu_callin_map[cpu] = 1;
567 smp_ops->setup_cpu(cpu);
568 if (smp_ops->take_timebase)
569 smp_ops->take_timebase();
571 if (system_state > SYSTEM_BOOTING)
574 secondary_cpu_time_init();
576 spin_lock(&call_lock);
577 cpu_set(cpu, cpu_online_map);
578 spin_unlock(&call_lock);
586 int setup_profiling_timer(unsigned int multiplier)
591 void __init smp_cpus_done(unsigned int max_cpus)
595 /* We want the setup_cpu() here to be called from CPU 0, but our
596 * init thread may have been "borrowed" by another CPU in the meantime
597 * se we pin us down to CPU 0 for a short while
599 old_mask = current->cpus_allowed;
600 set_cpus_allowed(current, cpumask_of_cpu(boot_cpuid));
603 smp_ops->setup_cpu(boot_cpuid);
605 set_cpus_allowed(current, old_mask);
607 snapshot_timebases();
609 dump_numa_cpu_topology();
612 #ifdef CONFIG_HOTPLUG_CPU
613 int __cpu_disable(void)
615 if (smp_ops->cpu_disable)
616 return smp_ops->cpu_disable();
621 void __cpu_die(unsigned int cpu)
623 if (smp_ops->cpu_die)
624 smp_ops->cpu_die(cpu);