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/export.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/device.h>
31 #include <linux/cpu.h>
32 #include <linux/notifier.h>
33 #include <linux/topology.h>
35 #include <asm/ptrace.h>
36 #include <linux/atomic.h>
39 #include <asm/pgtable.h>
43 #include <asm/machdep.h>
44 #include <asm/cputhreads.h>
45 #include <asm/cputable.h>
47 #include <asm/vdso_datapage.h>
51 #include <asm/debug.h>
55 #define DBG(fmt...) udbg_printf(fmt)
60 #ifdef CONFIG_HOTPLUG_CPU
61 /* State of each CPU during hotplug phases */
62 static DEFINE_PER_CPU(int, cpu_state) = { 0 };
65 struct thread_info *secondary_ti;
67 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
68 DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
70 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
71 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
73 /* SMP operations for this machine */
74 struct smp_ops_t *smp_ops;
76 /* Can't be static due to PowerMac hackery */
77 volatile unsigned int cpu_callin_map[NR_CPUS];
79 int smt_enabled_at_boot = 1;
81 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
84 int __devinit smp_generic_kick_cpu(int nr)
86 BUG_ON(nr < 0 || nr >= NR_CPUS);
89 * The processor is currently spinning, waiting for the
90 * cpu_start field to become non-zero After we set cpu_start,
91 * the processor will continue on to secondary_start
93 if (!paca[nr].cpu_start) {
94 paca[nr].cpu_start = 1;
99 #ifdef CONFIG_HOTPLUG_CPU
101 * Ok it's not there, so it might be soft-unplugged, let's
102 * try to bring it back
104 per_cpu(cpu_state, nr) = CPU_UP_PREPARE;
106 smp_send_reschedule(nr);
107 #endif /* CONFIG_HOTPLUG_CPU */
111 #endif /* CONFIG_PPC64 */
113 static irqreturn_t call_function_action(int irq, void *data)
115 generic_smp_call_function_interrupt();
119 static irqreturn_t reschedule_action(int irq, void *data)
125 static irqreturn_t call_function_single_action(int irq, void *data)
127 generic_smp_call_function_single_interrupt();
131 static irqreturn_t debug_ipi_action(int irq, void *data)
133 if (crash_ipi_function_ptr) {
134 crash_ipi_function_ptr(get_irq_regs());
138 #ifdef CONFIG_DEBUGGER
139 debugger_ipi(get_irq_regs());
140 #endif /* CONFIG_DEBUGGER */
145 static irq_handler_t smp_ipi_action[] = {
146 [PPC_MSG_CALL_FUNCTION] = call_function_action,
147 [PPC_MSG_RESCHEDULE] = reschedule_action,
148 [PPC_MSG_CALL_FUNC_SINGLE] = call_function_single_action,
149 [PPC_MSG_DEBUGGER_BREAK] = debug_ipi_action,
152 const char *smp_ipi_name[] = {
153 [PPC_MSG_CALL_FUNCTION] = "ipi call function",
154 [PPC_MSG_RESCHEDULE] = "ipi reschedule",
155 [PPC_MSG_CALL_FUNC_SINGLE] = "ipi call function single",
156 [PPC_MSG_DEBUGGER_BREAK] = "ipi debugger",
159 /* optional function to request ipi, for controllers with >= 4 ipis */
160 int smp_request_message_ipi(int virq, int msg)
164 if (msg < 0 || msg > PPC_MSG_DEBUGGER_BREAK) {
167 #if !defined(CONFIG_DEBUGGER) && !defined(CONFIG_KEXEC)
168 if (msg == PPC_MSG_DEBUGGER_BREAK) {
172 err = request_irq(virq, smp_ipi_action[msg],
173 IRQF_PERCPU | IRQF_NO_THREAD,
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 #ifdef CONFIG_PPC_SMP_MUXED_IPI
182 struct cpu_messages {
183 int messages; /* current messages */
184 unsigned long data; /* data for cause ipi */
186 static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages, ipi_message);
188 void smp_muxed_ipi_set_data(int cpu, unsigned long data)
190 struct cpu_messages *info = &per_cpu(ipi_message, cpu);
195 void smp_muxed_ipi_message_pass(int cpu, int msg)
197 struct cpu_messages *info = &per_cpu(ipi_message, cpu);
198 char *message = (char *)&info->messages;
202 smp_ops->cause_ipi(cpu, info->data);
205 irqreturn_t smp_ipi_demux(void)
207 struct cpu_messages *info = &__get_cpu_var(ipi_message);
210 mb(); /* order any irq clear */
213 all = xchg_local(&info->messages, 0);
216 if (all & (1 << (24 - 8 * PPC_MSG_CALL_FUNCTION)))
217 generic_smp_call_function_interrupt();
218 if (all & (1 << (24 - 8 * PPC_MSG_RESCHEDULE)))
220 if (all & (1 << (24 - 8 * PPC_MSG_CALL_FUNC_SINGLE)))
221 generic_smp_call_function_single_interrupt();
222 if (all & (1 << (24 - 8 * PPC_MSG_DEBUGGER_BREAK)))
223 debug_ipi_action(0, NULL);
225 #error Unsupported ENDIAN
227 } while (info->messages);
231 #endif /* CONFIG_PPC_SMP_MUXED_IPI */
233 static inline void do_message_pass(int cpu, int msg)
235 if (smp_ops->message_pass)
236 smp_ops->message_pass(cpu, msg);
237 #ifdef CONFIG_PPC_SMP_MUXED_IPI
239 smp_muxed_ipi_message_pass(cpu, msg);
243 void smp_send_reschedule(int cpu)
246 do_message_pass(cpu, PPC_MSG_RESCHEDULE);
248 EXPORT_SYMBOL_GPL(smp_send_reschedule);
250 void arch_send_call_function_single_ipi(int cpu)
252 do_message_pass(cpu, PPC_MSG_CALL_FUNC_SINGLE);
255 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
259 for_each_cpu(cpu, mask)
260 do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
263 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
264 void smp_send_debugger_break(void)
267 int me = raw_smp_processor_id();
269 if (unlikely(!smp_ops))
272 for_each_online_cpu(cpu)
274 do_message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
279 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
281 crash_ipi_function_ptr = crash_ipi_callback;
282 if (crash_ipi_callback) {
284 smp_send_debugger_break();
289 static void stop_this_cpu(void *dummy)
291 /* Remove this CPU */
292 set_cpu_online(smp_processor_id(), false);
299 void smp_send_stop(void)
301 smp_call_function(stop_this_cpu, NULL, 0);
304 struct thread_info *current_set[NR_CPUS];
306 static void __devinit smp_store_cpu_info(int id)
308 per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
309 #ifdef CONFIG_PPC_FSL_BOOK3E
310 per_cpu(next_tlbcam_idx, id)
311 = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
315 void __init smp_prepare_cpus(unsigned int max_cpus)
319 DBG("smp_prepare_cpus\n");
322 * setup_cpu may need to be called on the boot cpu. We havent
323 * spun any cpus up but lets be paranoid.
325 BUG_ON(boot_cpuid != smp_processor_id());
328 smp_store_cpu_info(boot_cpuid);
329 cpu_callin_map[boot_cpuid] = 1;
331 for_each_possible_cpu(cpu) {
332 zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu),
333 GFP_KERNEL, cpu_to_node(cpu));
334 zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
335 GFP_KERNEL, cpu_to_node(cpu));
338 cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
339 cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
343 max_cpus = smp_ops->probe();
350 void __devinit smp_prepare_boot_cpu(void)
352 BUG_ON(smp_processor_id() != boot_cpuid);
354 paca[boot_cpuid].__current = current;
356 current_set[boot_cpuid] = task_thread_info(current);
359 #ifdef CONFIG_HOTPLUG_CPU
361 int generic_cpu_disable(void)
363 unsigned int cpu = smp_processor_id();
365 if (cpu == boot_cpuid)
368 set_cpu_online(cpu, false);
370 vdso_data->processorCount--;
376 void generic_cpu_die(unsigned int cpu)
380 for (i = 0; i < 100; i++) {
382 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
386 printk(KERN_ERR "CPU%d didn't die...\n", cpu);
389 void generic_mach_cpu_die(void)
395 cpu = smp_processor_id();
396 printk(KERN_DEBUG "CPU%d offline\n", cpu);
397 __get_cpu_var(cpu_state) = CPU_DEAD;
399 while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
403 void generic_set_cpu_dead(unsigned int cpu)
405 per_cpu(cpu_state, cpu) = CPU_DEAD;
408 int generic_check_cpu_restart(unsigned int cpu)
410 return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
414 static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
416 struct thread_info *ti = task_thread_info(idle);
419 paca[cpu].__current = idle;
420 paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
423 secondary_ti = current_set[cpu] = ti;
426 int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
430 if (smp_ops == NULL ||
431 (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
434 cpu_idle_thread_init(cpu, tidle);
436 /* Make sure callin-map entry is 0 (can be leftover a CPU
439 cpu_callin_map[cpu] = 0;
441 /* The information for processor bringup must
442 * be written out to main store before we release
448 DBG("smp: kicking cpu %d\n", cpu);
449 rc = smp_ops->kick_cpu(cpu);
451 pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc);
456 * wait to see if the cpu made a callin (is actually up).
457 * use this value that I found through experimentation.
460 if (system_state < SYSTEM_RUNNING)
461 for (c = 50000; c && !cpu_callin_map[cpu]; c--)
463 #ifdef CONFIG_HOTPLUG_CPU
466 * CPUs can take much longer to come up in the
467 * hotplug case. Wait five seconds.
469 for (c = 5000; c && !cpu_callin_map[cpu]; c--)
473 if (!cpu_callin_map[cpu]) {
474 printk(KERN_ERR "Processor %u is stuck.\n", cpu);
478 DBG("Processor %u found.\n", cpu);
480 if (smp_ops->give_timebase)
481 smp_ops->give_timebase();
483 /* Wait until cpu puts itself in the online map */
484 while (!cpu_online(cpu))
490 /* Return the value of the reg property corresponding to the given
493 int cpu_to_core_id(int cpu)
495 struct device_node *np;
499 np = of_get_cpu_node(cpu, NULL);
503 reg = of_get_property(np, "reg", NULL);
513 /* Helper routines for cpu to core mapping */
514 int cpu_core_index_of_thread(int cpu)
516 return cpu >> threads_shift;
518 EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);
520 int cpu_first_thread_of_core(int core)
522 return core << threads_shift;
524 EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
526 /* Must be called when no change can occur to cpu_present_mask,
527 * i.e. during cpu online or offline.
529 static struct device_node *cpu_to_l2cache(int cpu)
531 struct device_node *np;
532 struct device_node *cache;
534 if (!cpu_present(cpu))
537 np = of_get_cpu_node(cpu, NULL);
541 cache = of_find_next_cache_node(np);
548 /* Activate a secondary processor. */
549 void __devinit start_secondary(void *unused)
551 unsigned int cpu = smp_processor_id();
552 struct device_node *l2_cache;
555 atomic_inc(&init_mm.mm_count);
556 current->active_mm = &init_mm;
558 smp_store_cpu_info(cpu);
559 set_dec(tb_ticks_per_jiffy);
561 cpu_callin_map[cpu] = 1;
563 if (smp_ops->setup_cpu)
564 smp_ops->setup_cpu(cpu);
565 if (smp_ops->take_timebase)
566 smp_ops->take_timebase();
568 secondary_cpu_time_init();
571 if (system_state == SYSTEM_RUNNING)
572 vdso_data->processorCount++;
574 notify_cpu_starting(cpu);
575 set_cpu_online(cpu, true);
576 /* Update sibling maps */
577 base = cpu_first_thread_sibling(cpu);
578 for (i = 0; i < threads_per_core; i++) {
579 if (cpu_is_offline(base + i))
581 cpumask_set_cpu(cpu, cpu_sibling_mask(base + i));
582 cpumask_set_cpu(base + i, cpu_sibling_mask(cpu));
584 /* cpu_core_map should be a superset of
585 * cpu_sibling_map even if we don't have cache
586 * information, so update the former here, too.
588 cpumask_set_cpu(cpu, cpu_core_mask(base + i));
589 cpumask_set_cpu(base + i, cpu_core_mask(cpu));
591 l2_cache = cpu_to_l2cache(cpu);
592 for_each_online_cpu(i) {
593 struct device_node *np = cpu_to_l2cache(i);
596 if (np == l2_cache) {
597 cpumask_set_cpu(cpu, cpu_core_mask(i));
598 cpumask_set_cpu(i, cpu_core_mask(cpu));
602 of_node_put(l2_cache);
611 int setup_profiling_timer(unsigned int multiplier)
616 void __init smp_cpus_done(unsigned int max_cpus)
618 cpumask_var_t old_mask;
620 /* We want the setup_cpu() here to be called from CPU 0, but our
621 * init thread may have been "borrowed" by another CPU in the meantime
622 * se we pin us down to CPU 0 for a short while
624 alloc_cpumask_var(&old_mask, GFP_NOWAIT);
625 cpumask_copy(old_mask, tsk_cpus_allowed(current));
626 set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid));
628 if (smp_ops && smp_ops->setup_cpu)
629 smp_ops->setup_cpu(boot_cpuid);
631 set_cpus_allowed_ptr(current, old_mask);
633 free_cpumask_var(old_mask);
635 if (smp_ops && smp_ops->bringup_done)
636 smp_ops->bringup_done();
638 dump_numa_cpu_topology();
642 int arch_sd_sibling_asym_packing(void)
644 if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
645 printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
646 return SD_ASYM_PACKING;
651 #ifdef CONFIG_HOTPLUG_CPU
652 int __cpu_disable(void)
654 struct device_node *l2_cache;
655 int cpu = smp_processor_id();
659 if (!smp_ops->cpu_disable)
662 err = smp_ops->cpu_disable();
666 /* Update sibling maps */
667 base = cpu_first_thread_sibling(cpu);
668 for (i = 0; i < threads_per_core; i++) {
669 cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
670 cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
671 cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
672 cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
675 l2_cache = cpu_to_l2cache(cpu);
676 for_each_present_cpu(i) {
677 struct device_node *np = cpu_to_l2cache(i);
680 if (np == l2_cache) {
681 cpumask_clear_cpu(cpu, cpu_core_mask(i));
682 cpumask_clear_cpu(i, cpu_core_mask(cpu));
686 of_node_put(l2_cache);
692 void __cpu_die(unsigned int cpu)
694 if (smp_ops->cpu_die)
695 smp_ops->cpu_die(cpu);
698 static DEFINE_MUTEX(powerpc_cpu_hotplug_driver_mutex);
700 void cpu_hotplug_driver_lock()
702 mutex_lock(&powerpc_cpu_hotplug_driver_mutex);
705 void cpu_hotplug_driver_unlock()
707 mutex_unlock(&powerpc_cpu_hotplug_driver_mutex);
715 /* If we return, we re-enter start_secondary */
716 start_secondary_resume();