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 cpumask_t cpu_sibling_map[NR_CPUS] = { [0 ... NR_CPUS-1] = CPU_MASK_NONE };
66 EXPORT_SYMBOL(cpu_online_map);
67 EXPORT_SYMBOL(cpu_possible_map);
69 /* SMP operations for this machine */
70 struct smp_ops_t *smp_ops;
72 static volatile unsigned int cpu_callin_map[NR_CPUS];
74 void smp_call_function_interrupt(void);
76 int smt_enabled_at_boot = 1;
78 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
81 int __init smp_mpic_probe(void)
85 DBG("smp_mpic_probe()...\n");
87 nr_cpus = cpus_weight(cpu_possible_map);
89 DBG("nr_cpus: %d\n", nr_cpus);
97 void __devinit smp_mpic_setup_cpu(int cpu)
99 mpic_setup_this_cpu();
101 #endif /* CONFIG_MPIC */
104 void __devinit smp_generic_kick_cpu(int nr)
106 BUG_ON(nr < 0 || nr >= NR_CPUS);
109 * The processor is currently spinning, waiting for the
110 * cpu_start field to become non-zero After we set cpu_start,
111 * the processor will continue on to secondary_start
113 paca[nr].cpu_start = 1;
118 void smp_message_recv(int msg, struct pt_regs *regs)
121 case PPC_MSG_CALL_FUNCTION:
122 smp_call_function_interrupt();
124 case PPC_MSG_RESCHEDULE:
125 /* XXX Do we have to do this? */
128 case PPC_MSG_DEBUGGER_BREAK:
129 if (crash_ipi_function_ptr) {
130 crash_ipi_function_ptr(regs);
133 #ifdef CONFIG_DEBUGGER
136 #endif /* CONFIG_DEBUGGER */
139 printk("SMP %d: smp_message_recv(): unknown msg %d\n",
140 smp_processor_id(), msg);
145 void smp_send_reschedule(int cpu)
147 smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE);
150 #ifdef CONFIG_DEBUGGER
151 void smp_send_debugger_break(int cpu)
153 smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
158 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
160 crash_ipi_function_ptr = crash_ipi_callback;
161 if (crash_ipi_callback) {
163 smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_DEBUGGER_BREAK);
168 static void stop_this_cpu(void *dummy)
175 void smp_send_stop(void)
177 smp_call_function(stop_this_cpu, NULL, 1, 0);
181 * Structure and data for smp_call_function(). This is designed to minimise
182 * static memory requirements. It also looks cleaner.
183 * Stolen from the i386 version.
185 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(call_lock);
187 static struct call_data_struct {
188 void (*func) (void *info);
195 /* delay of at least 8 seconds */
196 #define SMP_CALL_TIMEOUT 8
199 * This function sends a 'generic call function' IPI to all other CPUs
202 * [SUMMARY] Run a function on all other CPUs.
203 * <func> The function to run. This must be fast and non-blocking.
204 * <info> An arbitrary pointer to pass to the function.
205 * <nonatomic> currently unused.
206 * <wait> If true, wait (atomically) until function has completed on other CPUs.
207 * [RETURNS] 0 on success, else a negative status code. Does not return until
208 * remote CPUs are nearly ready to execute <<func>> or are or have executed.
210 * You must not call this function with disabled interrupts or from a
211 * hardware interrupt handler or from a bottom half handler.
213 int smp_call_function (void (*func) (void *info), void *info, int nonatomic,
216 struct call_data_struct data;
220 /* Can deadlock when called with interrupts disabled */
221 WARN_ON(irqs_disabled());
225 atomic_set(&data.started, 0);
228 atomic_set(&data.finished, 0);
230 spin_lock(&call_lock);
231 /* Must grab online cpu count with preempt disabled, otherwise
233 cpus = num_online_cpus() - 1;
241 /* Send a message to all other CPUs and wait for them to respond */
242 smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_CALL_FUNCTION);
244 timeout = get_tb() + (u64) SMP_CALL_TIMEOUT * tb_ticks_per_sec;
246 /* Wait for response */
247 while (atomic_read(&data.started) != cpus) {
249 if (get_tb() >= timeout) {
250 printk("smp_call_function on cpu %d: other cpus not "
251 "responding (%d)\n", smp_processor_id(),
252 atomic_read(&data.started));
259 while (atomic_read(&data.finished) != cpus) {
261 if (get_tb() >= timeout) {
262 printk("smp_call_function on cpu %d: other "
263 "cpus not finishing (%d/%d)\n",
265 atomic_read(&data.finished),
266 atomic_read(&data.started));
278 spin_unlock(&call_lock);
282 EXPORT_SYMBOL(smp_call_function);
284 void smp_call_function_interrupt(void)
286 void (*func) (void *info);
290 /* call_data will be NULL if the sender timed out while
291 * waiting on us to receive the call.
296 func = call_data->func;
297 info = call_data->info;
298 wait = call_data->wait;
301 smp_mb__before_atomic_inc();
304 * Notify initiating CPU that I've grabbed the data and am
305 * about to execute the function
307 atomic_inc(&call_data->started);
309 * At this point the info structure may be out of scope unless wait==1
313 smp_mb__before_atomic_inc();
314 atomic_inc(&call_data->finished);
318 extern struct gettimeofday_struct do_gtod;
320 struct thread_info *current_set[NR_CPUS];
322 DECLARE_PER_CPU(unsigned int, pvr);
324 static void __devinit smp_store_cpu_info(int id)
326 per_cpu(pvr, id) = mfspr(SPRN_PVR);
329 static void __init smp_create_idle(unsigned int cpu)
331 struct task_struct *p;
333 /* create a process for the processor */
336 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
338 paca[cpu].__current = p;
340 current_set[cpu] = task_thread_info(p);
341 task_thread_info(p)->cpu = cpu;
344 void __init smp_prepare_cpus(unsigned int max_cpus)
348 DBG("smp_prepare_cpus\n");
351 * setup_cpu may need to be called on the boot cpu. We havent
352 * spun any cpus up but lets be paranoid.
354 BUG_ON(boot_cpuid != smp_processor_id());
357 smp_store_cpu_info(boot_cpuid);
358 cpu_callin_map[boot_cpuid] = 1;
360 max_cpus = smp_ops->probe();
362 smp_space_timers(max_cpus);
364 for_each_possible_cpu(cpu)
365 if (cpu != boot_cpuid)
366 smp_create_idle(cpu);
369 void __devinit smp_prepare_boot_cpu(void)
371 BUG_ON(smp_processor_id() != boot_cpuid);
373 cpu_set(boot_cpuid, cpu_online_map);
375 paca[boot_cpuid].__current = current;
377 current_set[boot_cpuid] = task_thread_info(current);
380 #ifdef CONFIG_HOTPLUG_CPU
381 /* State of each CPU during hotplug phases */
382 DEFINE_PER_CPU(int, cpu_state) = { 0 };
384 int generic_cpu_disable(void)
386 unsigned int cpu = smp_processor_id();
388 if (cpu == boot_cpuid)
391 cpu_clear(cpu, cpu_online_map);
393 vdso_data->processorCount--;
394 fixup_irqs(cpu_online_map);
399 int generic_cpu_enable(unsigned int cpu)
401 /* Do the normal bootup if we haven't
402 * already bootstrapped. */
403 if (system_state != SYSTEM_RUNNING)
406 /* get the target out of it's holding state */
407 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
410 while (!cpu_online(cpu))
414 fixup_irqs(cpu_online_map);
415 /* counter the irq disable in fixup_irqs */
421 void generic_cpu_die(unsigned int cpu)
425 for (i = 0; i < 100; i++) {
427 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
431 printk(KERN_ERR "CPU%d didn't die...\n", cpu);
434 void generic_mach_cpu_die(void)
439 cpu = smp_processor_id();
440 printk(KERN_DEBUG "CPU%d offline\n", cpu);
441 __get_cpu_var(cpu_state) = CPU_DEAD;
443 while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
449 cpu_set(cpu, cpu_online_map);
454 static int __devinit cpu_enable(unsigned int cpu)
456 if (smp_ops->cpu_enable)
457 return smp_ops->cpu_enable(cpu);
462 int __devinit __cpu_up(unsigned int cpu)
466 secondary_ti = current_set[cpu];
467 if (!cpu_enable(cpu))
470 if (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu))
473 /* Make sure callin-map entry is 0 (can be leftover a CPU
476 cpu_callin_map[cpu] = 0;
478 /* The information for processor bringup must
479 * be written out to main store before we release
485 DBG("smp: kicking cpu %d\n", cpu);
486 smp_ops->kick_cpu(cpu);
489 * wait to see if the cpu made a callin (is actually up).
490 * use this value that I found through experimentation.
493 if (system_state < SYSTEM_RUNNING)
494 for (c = 50000; c && !cpu_callin_map[cpu]; c--)
496 #ifdef CONFIG_HOTPLUG_CPU
499 * CPUs can take much longer to come up in the
500 * hotplug case. Wait five seconds.
502 for (c = 25; c && !cpu_callin_map[cpu]; c--) {
507 if (!cpu_callin_map[cpu]) {
508 printk("Processor %u is stuck.\n", cpu);
512 printk("Processor %u found.\n", cpu);
514 if (smp_ops->give_timebase)
515 smp_ops->give_timebase();
517 /* Wait until cpu puts itself in the online map */
518 while (!cpu_online(cpu))
525 /* Activate a secondary processor. */
526 int __devinit start_secondary(void *unused)
528 unsigned int cpu = smp_processor_id();
530 atomic_inc(&init_mm.mm_count);
531 current->active_mm = &init_mm;
533 smp_store_cpu_info(cpu);
534 set_dec(tb_ticks_per_jiffy);
536 cpu_callin_map[cpu] = 1;
538 smp_ops->setup_cpu(cpu);
539 if (smp_ops->take_timebase)
540 smp_ops->take_timebase();
542 if (system_state > SYSTEM_BOOTING)
545 spin_lock(&call_lock);
546 cpu_set(cpu, cpu_online_map);
547 spin_unlock(&call_lock);
555 int setup_profiling_timer(unsigned int multiplier)
560 void __init smp_cpus_done(unsigned int max_cpus)
564 /* We want the setup_cpu() here to be called from CPU 0, but our
565 * init thread may have been "borrowed" by another CPU in the meantime
566 * se we pin us down to CPU 0 for a short while
568 old_mask = current->cpus_allowed;
569 set_cpus_allowed(current, cpumask_of_cpu(boot_cpuid));
571 smp_ops->setup_cpu(boot_cpuid);
573 set_cpus_allowed(current, old_mask);
575 snapshot_timebases();
577 dump_numa_cpu_topology();
580 #ifdef CONFIG_HOTPLUG_CPU
581 int __cpu_disable(void)
583 if (smp_ops->cpu_disable)
584 return smp_ops->cpu_disable();
589 void __cpu_die(unsigned int cpu)
591 if (smp_ops->cpu_die)
592 smp_ops->cpu_die(cpu);