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/config.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/sched.h>
24 #include <linux/smp.h>
25 #include <linux/interrupt.h>
26 #include <linux/delay.h>
27 #include <linux/init.h>
28 #include <linux/spinlock.h>
29 #include <linux/cache.h>
30 #include <linux/err.h>
31 #include <linux/sysdev.h>
32 #include <linux/cpu.h>
33 #include <linux/notifier.h>
35 #include <asm/ptrace.h>
36 #include <asm/atomic.h>
39 #include <asm/pgtable.h>
44 #include <asm/machdep.h>
45 #include <asm/cputable.h>
46 #include <asm/system.h>
47 #include <asm/abs_addr.h>
52 #define DBG(fmt...) udbg_printf(fmt)
57 cpumask_t cpu_possible_map = CPU_MASK_NONE;
58 cpumask_t cpu_online_map = CPU_MASK_NONE;
59 cpumask_t cpu_sibling_map[NR_CPUS] = { [0 ... NR_CPUS-1] = CPU_MASK_NONE };
61 EXPORT_SYMBOL(cpu_online_map);
62 EXPORT_SYMBOL(cpu_possible_map);
64 struct smp_ops_t *smp_ops;
66 static volatile unsigned int cpu_callin_map[NR_CPUS];
68 extern unsigned char stab_array[];
70 void smp_call_function_interrupt(void);
72 int smt_enabled_at_boot = 1;
74 #ifdef CONFIG_PPC_MULTIPLATFORM
75 void smp_mpic_message_pass(int target, int msg)
77 /* make sure we're sending something that translates to an IPI */
79 printk("SMP %d: smp_message_pass: unknown msg %d\n",
80 smp_processor_id(), msg);
86 mpic_send_ipi(msg, 0xffffffff);
88 case MSG_ALL_BUT_SELF:
89 mpic_send_ipi(msg, 0xffffffff & ~(1 << smp_processor_id()));
92 mpic_send_ipi(msg, 1 << target);
97 int __init smp_mpic_probe(void)
101 DBG("smp_mpic_probe()...\n");
103 nr_cpus = cpus_weight(cpu_possible_map);
105 DBG("nr_cpus: %d\n", nr_cpus);
113 void __devinit smp_mpic_setup_cpu(int cpu)
115 mpic_setup_this_cpu();
118 void __devinit smp_generic_kick_cpu(int nr)
120 BUG_ON(nr < 0 || nr >= NR_CPUS);
123 * The processor is currently spinning, waiting for the
124 * cpu_start field to become non-zero After we set cpu_start,
125 * the processor will continue on to secondary_start
127 paca[nr].cpu_start = 1;
131 #endif /* CONFIG_PPC_MULTIPLATFORM */
133 static void __init smp_space_timers(unsigned int max_cpus)
136 unsigned long offset = tb_ticks_per_jiffy / max_cpus;
137 unsigned long previous_tb = paca[boot_cpuid].next_jiffy_update_tb;
140 if (i != boot_cpuid) {
141 paca[i].next_jiffy_update_tb =
142 previous_tb + offset;
143 previous_tb = paca[i].next_jiffy_update_tb;
148 void smp_message_recv(int msg, struct pt_regs *regs)
151 case PPC_MSG_CALL_FUNCTION:
152 smp_call_function_interrupt();
154 case PPC_MSG_RESCHEDULE:
155 /* XXX Do we have to do this? */
159 case PPC_MSG_MIGRATE_TASK:
163 #ifdef CONFIG_DEBUGGER
164 case PPC_MSG_DEBUGGER_BREAK:
169 printk("SMP %d: smp_message_recv(): unknown msg %d\n",
170 smp_processor_id(), msg);
175 void smp_send_reschedule(int cpu)
177 smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE);
180 #ifdef CONFIG_DEBUGGER
181 void smp_send_debugger_break(int cpu)
183 smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
187 static void stop_this_cpu(void *dummy)
194 void smp_send_stop(void)
196 smp_call_function(stop_this_cpu, NULL, 1, 0);
200 * Structure and data for smp_call_function(). This is designed to minimise
201 * static memory requirements. It also looks cleaner.
202 * Stolen from the i386 version.
204 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(call_lock);
206 static struct call_data_struct {
207 void (*func) (void *info);
214 /* delay of at least 8 seconds on 1GHz cpu */
215 #define SMP_CALL_TIMEOUT (1UL << (30 + 3))
218 * This function sends a 'generic call function' IPI to all other CPUs
221 * [SUMMARY] Run a function on all other CPUs.
222 * <func> The function to run. This must be fast and non-blocking.
223 * <info> An arbitrary pointer to pass to the function.
224 * <nonatomic> currently unused.
225 * <wait> If 1, wait (atomically) until function has completed on other CPUs.
226 * If 0, wait for the IPI to be received by other CPUs, but do not
227 * wait for the function completion on each CPU.
228 * If -1, do not wait for other CPUs to receive IPI.
229 * [RETURNS] 0 on success, else a negative status code. Does not return until
230 * remote CPUs are nearly ready to execute <<func>> or are or have executed.
232 * You must not call this function with disabled interrupts or from a
233 * hardware interrupt handler or from a bottom half handler.
235 int smp_call_function (void (*func) (void *info), void *info, int nonatomic,
238 static struct call_data_struct dumpdata;
239 struct call_data_struct normaldata;
240 struct call_data_struct *data;
242 unsigned long timeout;
244 /* Can deadlock when called with interrupts disabled */
245 WARN_ON(irqs_disabled() && wait >= 0);
247 spin_lock(&call_lock);
259 atomic_set(&data->started, 0);
260 data->wait = wait > 0 ? wait : 0;
262 atomic_set(&data->finished, 0);
264 /* Must grab online cpu count with preempt disabled, otherwise
266 cpus = num_online_cpus() - 1;
274 /* Send a message to all other CPUs and wait for them to respond */
275 smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_CALL_FUNCTION);
277 /* Wait for response */
278 timeout = SMP_CALL_TIMEOUT;
279 while (atomic_read(&data->started) != cpus) {
281 if (--timeout == 0) {
282 printk("smp_call_function on cpu %d: other cpus not "
283 "responding (%d)\n", smp_processor_id(),
284 atomic_read(&data->started));
292 timeout = SMP_CALL_TIMEOUT;
293 while (atomic_read(&data->finished) != cpus) {
295 if (--timeout == 0) {
296 printk("smp_call_function on cpu %d: other "
297 "cpus not finishing (%d/%d)\n",
299 atomic_read(&data->finished),
300 atomic_read(&data->started));
312 spin_unlock(&call_lock);
316 EXPORT_SYMBOL(smp_call_function);
318 void smp_call_function_interrupt(void)
320 void (*func) (void *info);
324 /* call_data will be NULL if the sender timed out while
325 * waiting on us to receive the call.
330 func = call_data->func;
331 info = call_data->info;
332 wait = call_data->wait;
335 smp_mb__before_atomic_inc();
338 * Notify initiating CPU that I've grabbed the data and am
339 * about to execute the function
341 atomic_inc(&call_data->started);
343 * At this point the info structure may be out of scope unless wait==1
347 smp_mb__before_atomic_inc();
348 atomic_inc(&call_data->finished);
352 extern struct gettimeofday_struct do_gtod;
354 struct thread_info *current_set[NR_CPUS];
356 DECLARE_PER_CPU(unsigned int, pvr);
358 static void __devinit smp_store_cpu_info(int id)
360 per_cpu(pvr, id) = mfspr(SPRN_PVR);
363 static void __init smp_create_idle(unsigned int cpu)
365 struct task_struct *p;
367 /* create a process for the processor */
370 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
371 paca[cpu].__current = p;
372 current_set[cpu] = p->thread_info;
375 void __init smp_prepare_cpus(unsigned int max_cpus)
379 DBG("smp_prepare_cpus\n");
382 * setup_cpu may need to be called on the boot cpu. We havent
383 * spun any cpus up but lets be paranoid.
385 BUG_ON(boot_cpuid != smp_processor_id());
388 smp_store_cpu_info(boot_cpuid);
389 cpu_callin_map[boot_cpuid] = 1;
391 #ifndef CONFIG_PPC_ISERIES
392 paca[boot_cpuid].next_jiffy_update_tb = tb_last_stamp = get_tb();
395 * Should update do_gtod.stamp_xsec.
396 * For now we leave it which means the time can be some
397 * number of msecs off until someone does a settimeofday()
399 do_gtod.varp->tb_orig_stamp = tb_last_stamp;
400 systemcfg->tb_orig_stamp = tb_last_stamp;
403 max_cpus = smp_ops->probe();
405 smp_space_timers(max_cpus);
408 if (cpu != boot_cpuid)
409 smp_create_idle(cpu);
412 void __devinit smp_prepare_boot_cpu(void)
414 BUG_ON(smp_processor_id() != boot_cpuid);
416 cpu_set(boot_cpuid, cpu_online_map);
418 paca[boot_cpuid].__current = current;
419 current_set[boot_cpuid] = current->thread_info;
422 #ifdef CONFIG_HOTPLUG_CPU
423 /* State of each CPU during hotplug phases */
424 DEFINE_PER_CPU(int, cpu_state) = { 0 };
426 int generic_cpu_disable(void)
428 unsigned int cpu = smp_processor_id();
430 if (cpu == boot_cpuid)
433 systemcfg->processorCount--;
434 cpu_clear(cpu, cpu_online_map);
435 fixup_irqs(cpu_online_map);
439 int generic_cpu_enable(unsigned int cpu)
441 /* Do the normal bootup if we haven't
442 * already bootstrapped. */
443 if (system_state != SYSTEM_RUNNING)
446 /* get the target out of it's holding state */
447 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
450 while (!cpu_online(cpu))
453 fixup_irqs(cpu_online_map);
454 /* counter the irq disable in fixup_irqs */
459 void generic_cpu_die(unsigned int cpu)
463 for (i = 0; i < 100; i++) {
465 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
469 printk(KERN_ERR "CPU%d didn't die...\n", cpu);
472 void generic_mach_cpu_die(void)
477 cpu = smp_processor_id();
478 printk(KERN_DEBUG "CPU%d offline\n", cpu);
479 __get_cpu_var(cpu_state) = CPU_DEAD;
481 while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
485 cpu_set(cpu, cpu_online_map);
490 static int __devinit cpu_enable(unsigned int cpu)
492 if (smp_ops->cpu_enable)
493 return smp_ops->cpu_enable(cpu);
498 int __devinit __cpu_up(unsigned int cpu)
502 if (!cpu_enable(cpu))
505 if (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu))
508 paca[cpu].default_decr = tb_ticks_per_jiffy;
510 if (!cpu_has_feature(CPU_FTR_SLB)) {
513 /* maximum of 48 CPUs on machines with a segment table */
517 tmp = &stab_array[PAGE_SIZE * cpu];
518 memset(tmp, 0, PAGE_SIZE);
519 paca[cpu].stab_addr = (unsigned long)tmp;
520 paca[cpu].stab_real = virt_to_abs(tmp);
523 /* Make sure callin-map entry is 0 (can be leftover a CPU
526 cpu_callin_map[cpu] = 0;
528 /* The information for processor bringup must
529 * be written out to main store before we release
535 DBG("smp: kicking cpu %d\n", cpu);
536 smp_ops->kick_cpu(cpu);
539 * wait to see if the cpu made a callin (is actually up).
540 * use this value that I found through experimentation.
543 if (system_state < SYSTEM_RUNNING)
544 for (c = 5000; c && !cpu_callin_map[cpu]; c--)
546 #ifdef CONFIG_HOTPLUG_CPU
549 * CPUs can take much longer to come up in the
550 * hotplug case. Wait five seconds.
552 for (c = 25; c && !cpu_callin_map[cpu]; c--) {
557 if (!cpu_callin_map[cpu]) {
558 printk("Processor %u is stuck.\n", cpu);
562 printk("Processor %u found.\n", cpu);
564 if (smp_ops->give_timebase)
565 smp_ops->give_timebase();
567 /* Wait until cpu puts itself in the online map */
568 while (!cpu_online(cpu))
575 /* Activate a secondary processor. */
576 int __devinit start_secondary(void *unused)
578 unsigned int cpu = smp_processor_id();
580 atomic_inc(&init_mm.mm_count);
581 current->active_mm = &init_mm;
583 smp_store_cpu_info(cpu);
584 set_dec(paca[cpu].default_decr);
585 cpu_callin_map[cpu] = 1;
587 smp_ops->setup_cpu(cpu);
588 if (smp_ops->take_timebase)
589 smp_ops->take_timebase();
591 spin_lock(&call_lock);
592 cpu_set(cpu, cpu_online_map);
593 spin_unlock(&call_lock);
601 int setup_profiling_timer(unsigned int multiplier)
606 void __init smp_cpus_done(unsigned int max_cpus)
610 /* We want the setup_cpu() here to be called from CPU 0, but our
611 * init thread may have been "borrowed" by another CPU in the meantime
612 * se we pin us down to CPU 0 for a short while
614 old_mask = current->cpus_allowed;
615 set_cpus_allowed(current, cpumask_of_cpu(boot_cpuid));
617 smp_ops->setup_cpu(boot_cpuid);
619 set_cpus_allowed(current, old_mask);
622 #ifdef CONFIG_HOTPLUG_CPU
623 int __cpu_disable(void)
625 if (smp_ops->cpu_disable)
626 return smp_ops->cpu_disable();
631 void __cpu_die(unsigned int cpu)
633 if (smp_ops->cpu_die)
634 smp_ops->cpu_die(cpu);