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>
52 #include <asm/debug.h>
56 #define DBG(fmt...) udbg_printf(fmt)
61 #ifdef CONFIG_HOTPLUG_CPU
62 /* State of each CPU during hotplug phases */
63 static DEFINE_PER_CPU(int, cpu_state
) = { 0 };
66 struct thread_info
*secondary_ti
;
68 DEFINE_PER_CPU(cpumask_var_t
, cpu_sibling_map
);
69 DEFINE_PER_CPU(cpumask_var_t
, cpu_core_map
);
71 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map
);
72 EXPORT_PER_CPU_SYMBOL(cpu_core_map
);
74 /* SMP operations for this machine */
75 struct smp_ops_t
*smp_ops
;
77 /* Can't be static due to PowerMac hackery */
78 volatile unsigned int cpu_callin_map
[NR_CPUS
];
80 int smt_enabled_at_boot
= 1;
82 static void (*crash_ipi_function_ptr
)(struct pt_regs
*) = NULL
;
85 int smp_generic_kick_cpu(int nr
)
87 BUG_ON(nr
< 0 || nr
>= NR_CPUS
);
90 * The processor is currently spinning, waiting for the
91 * cpu_start field to become non-zero After we set cpu_start,
92 * the processor will continue on to secondary_start
94 if (!paca
[nr
].cpu_start
) {
95 paca
[nr
].cpu_start
= 1;
100 #ifdef CONFIG_HOTPLUG_CPU
102 * Ok it's not there, so it might be soft-unplugged, let's
103 * try to bring it back
105 generic_set_cpu_up(nr
);
107 smp_send_reschedule(nr
);
108 #endif /* CONFIG_HOTPLUG_CPU */
112 #endif /* CONFIG_PPC64 */
114 static irqreturn_t
call_function_action(int irq
, void *data
)
116 generic_smp_call_function_interrupt();
120 static irqreturn_t
reschedule_action(int irq
, void *data
)
126 static irqreturn_t
call_function_single_action(int irq
, void *data
)
128 generic_smp_call_function_single_interrupt();
132 static irqreturn_t
debug_ipi_action(int irq
, void *data
)
134 if (crash_ipi_function_ptr
) {
135 crash_ipi_function_ptr(get_irq_regs());
139 #ifdef CONFIG_DEBUGGER
140 debugger_ipi(get_irq_regs());
141 #endif /* CONFIG_DEBUGGER */
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
],
174 IRQF_PERCPU
| IRQF_NO_THREAD
| IRQF_NO_SUSPEND
,
175 smp_ipi_name
[msg
], 0);
176 WARN(err
< 0, "unable to request_irq %d for %s (rc %d)\n",
177 virq
, smp_ipi_name
[msg
], err
);
182 #ifdef CONFIG_PPC_SMP_MUXED_IPI
183 struct cpu_messages
{
184 int messages
; /* current messages */
185 unsigned long data
; /* data for cause ipi */
187 static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages
, ipi_message
);
189 void smp_muxed_ipi_set_data(int cpu
, unsigned long data
)
191 struct cpu_messages
*info
= &per_cpu(ipi_message
, cpu
);
196 void smp_muxed_ipi_message_pass(int cpu
, int msg
)
198 struct cpu_messages
*info
= &per_cpu(ipi_message
, cpu
);
199 char *message
= (char *)&info
->messages
;
202 * Order previous accesses before accesses in the IPI handler.
207 * cause_ipi functions are required to include a full barrier
208 * before doing whatever causes the IPI.
210 smp_ops
->cause_ipi(cpu
, info
->data
);
213 irqreturn_t
smp_ipi_demux(void)
215 struct cpu_messages
*info
= &__get_cpu_var(ipi_message
);
218 mb(); /* order any irq clear */
221 all
= xchg(&info
->messages
, 0);
224 if (all
& (1 << (24 - 8 * PPC_MSG_CALL_FUNCTION
)))
225 generic_smp_call_function_interrupt();
226 if (all
& (1 << (24 - 8 * PPC_MSG_RESCHEDULE
)))
228 if (all
& (1 << (24 - 8 * PPC_MSG_CALL_FUNC_SINGLE
)))
229 generic_smp_call_function_single_interrupt();
230 if (all
& (1 << (24 - 8 * PPC_MSG_DEBUGGER_BREAK
)))
231 debug_ipi_action(0, NULL
);
233 #error Unsupported ENDIAN
235 } while (info
->messages
);
239 #endif /* CONFIG_PPC_SMP_MUXED_IPI */
241 static inline void do_message_pass(int cpu
, int msg
)
243 if (smp_ops
->message_pass
)
244 smp_ops
->message_pass(cpu
, msg
);
245 #ifdef CONFIG_PPC_SMP_MUXED_IPI
247 smp_muxed_ipi_message_pass(cpu
, msg
);
251 void smp_send_reschedule(int cpu
)
254 do_message_pass(cpu
, PPC_MSG_RESCHEDULE
);
256 EXPORT_SYMBOL_GPL(smp_send_reschedule
);
258 void arch_send_call_function_single_ipi(int cpu
)
260 do_message_pass(cpu
, PPC_MSG_CALL_FUNC_SINGLE
);
263 void arch_send_call_function_ipi_mask(const struct cpumask
*mask
)
267 for_each_cpu(cpu
, mask
)
268 do_message_pass(cpu
, PPC_MSG_CALL_FUNCTION
);
271 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
272 void smp_send_debugger_break(void)
275 int me
= raw_smp_processor_id();
277 if (unlikely(!smp_ops
))
280 for_each_online_cpu(cpu
)
282 do_message_pass(cpu
, PPC_MSG_DEBUGGER_BREAK
);
287 void crash_send_ipi(void (*crash_ipi_callback
)(struct pt_regs
*))
289 crash_ipi_function_ptr
= crash_ipi_callback
;
290 if (crash_ipi_callback
) {
292 smp_send_debugger_break();
297 static void stop_this_cpu(void *dummy
)
299 /* Remove this CPU */
300 set_cpu_online(smp_processor_id(), false);
307 void smp_send_stop(void)
309 smp_call_function(stop_this_cpu
, NULL
, 0);
312 struct thread_info
*current_set
[NR_CPUS
];
314 static void smp_store_cpu_info(int id
)
316 per_cpu(cpu_pvr
, id
) = mfspr(SPRN_PVR
);
317 #ifdef CONFIG_PPC_FSL_BOOK3E
318 per_cpu(next_tlbcam_idx
, id
)
319 = (mfspr(SPRN_TLB1CFG
) & TLBnCFG_N_ENTRY
) - 1;
323 void __init
smp_prepare_cpus(unsigned int max_cpus
)
327 DBG("smp_prepare_cpus\n");
330 * setup_cpu may need to be called on the boot cpu. We havent
331 * spun any cpus up but lets be paranoid.
333 BUG_ON(boot_cpuid
!= smp_processor_id());
336 smp_store_cpu_info(boot_cpuid
);
337 cpu_callin_map
[boot_cpuid
] = 1;
339 for_each_possible_cpu(cpu
) {
340 zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map
, cpu
),
341 GFP_KERNEL
, cpu_to_node(cpu
));
342 zalloc_cpumask_var_node(&per_cpu(cpu_core_map
, cpu
),
343 GFP_KERNEL
, cpu_to_node(cpu
));
346 cpumask_set_cpu(boot_cpuid
, cpu_sibling_mask(boot_cpuid
));
347 cpumask_set_cpu(boot_cpuid
, cpu_core_mask(boot_cpuid
));
351 max_cpus
= smp_ops
->probe();
358 void smp_prepare_boot_cpu(void)
360 BUG_ON(smp_processor_id() != boot_cpuid
);
362 paca
[boot_cpuid
].__current
= current
;
364 current_set
[boot_cpuid
] = task_thread_info(current
);
367 #ifdef CONFIG_HOTPLUG_CPU
369 int generic_cpu_disable(void)
371 unsigned int cpu
= smp_processor_id();
373 if (cpu
== boot_cpuid
)
376 set_cpu_online(cpu
, false);
378 vdso_data
->processorCount
--;
384 void generic_cpu_die(unsigned int cpu
)
388 for (i
= 0; i
< 100; i
++) {
390 if (per_cpu(cpu_state
, cpu
) == CPU_DEAD
)
394 printk(KERN_ERR
"CPU%d didn't die...\n", cpu
);
397 void generic_mach_cpu_die(void)
403 cpu
= smp_processor_id();
404 printk(KERN_DEBUG
"CPU%d offline\n", cpu
);
405 __get_cpu_var(cpu_state
) = CPU_DEAD
;
407 while (__get_cpu_var(cpu_state
) != CPU_UP_PREPARE
)
411 void generic_set_cpu_dead(unsigned int cpu
)
413 per_cpu(cpu_state
, cpu
) = CPU_DEAD
;
417 * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
418 * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
419 * which makes the delay in generic_cpu_die() not happen.
421 void generic_set_cpu_up(unsigned int cpu
)
423 per_cpu(cpu_state
, cpu
) = CPU_UP_PREPARE
;
426 int generic_check_cpu_restart(unsigned int cpu
)
428 return per_cpu(cpu_state
, cpu
) == CPU_UP_PREPARE
;
431 static atomic_t secondary_inhibit_count
;
434 * Don't allow secondary CPU threads to come online
436 void inhibit_secondary_onlining(void)
439 * This makes secondary_inhibit_count stable during cpu
440 * online/offline operations.
444 atomic_inc(&secondary_inhibit_count
);
447 EXPORT_SYMBOL_GPL(inhibit_secondary_onlining
);
450 * Allow secondary CPU threads to come online again
452 void uninhibit_secondary_onlining(void)
455 atomic_dec(&secondary_inhibit_count
);
458 EXPORT_SYMBOL_GPL(uninhibit_secondary_onlining
);
460 static int secondaries_inhibited(void)
462 return atomic_read(&secondary_inhibit_count
);
465 #else /* HOTPLUG_CPU */
467 #define secondaries_inhibited() 0
471 static void cpu_idle_thread_init(unsigned int cpu
, struct task_struct
*idle
)
473 struct thread_info
*ti
= task_thread_info(idle
);
476 paca
[cpu
].__current
= idle
;
477 paca
[cpu
].kstack
= (unsigned long)ti
+ THREAD_SIZE
- STACK_FRAME_OVERHEAD
;
480 secondary_ti
= current_set
[cpu
] = ti
;
483 int __cpuinit
__cpu_up(unsigned int cpu
, struct task_struct
*tidle
)
488 * Don't allow secondary threads to come online if inhibited
490 if (threads_per_core
> 1 && secondaries_inhibited() &&
491 cpu
% threads_per_core
!= 0)
494 if (smp_ops
== NULL
||
495 (smp_ops
->cpu_bootable
&& !smp_ops
->cpu_bootable(cpu
)))
498 cpu_idle_thread_init(cpu
, tidle
);
500 /* Make sure callin-map entry is 0 (can be leftover a CPU
503 cpu_callin_map
[cpu
] = 0;
505 /* The information for processor bringup must
506 * be written out to main store before we release
512 DBG("smp: kicking cpu %d\n", cpu
);
513 rc
= smp_ops
->kick_cpu(cpu
);
515 pr_err("smp: failed starting cpu %d (rc %d)\n", cpu
, rc
);
520 * wait to see if the cpu made a callin (is actually up).
521 * use this value that I found through experimentation.
524 if (system_state
< SYSTEM_RUNNING
)
525 for (c
= 50000; c
&& !cpu_callin_map
[cpu
]; c
--)
527 #ifdef CONFIG_HOTPLUG_CPU
530 * CPUs can take much longer to come up in the
531 * hotplug case. Wait five seconds.
533 for (c
= 5000; c
&& !cpu_callin_map
[cpu
]; c
--)
537 if (!cpu_callin_map
[cpu
]) {
538 printk(KERN_ERR
"Processor %u is stuck.\n", cpu
);
542 DBG("Processor %u found.\n", cpu
);
544 if (smp_ops
->give_timebase
)
545 smp_ops
->give_timebase();
547 /* Wait until cpu puts itself in the online & active maps */
548 while (!cpu_online(cpu
) || !cpu_active(cpu
))
554 /* Return the value of the reg property corresponding to the given
557 int cpu_to_core_id(int cpu
)
559 struct device_node
*np
;
563 np
= of_get_cpu_node(cpu
, NULL
);
567 reg
= of_get_property(np
, "reg", NULL
);
577 /* Helper routines for cpu to core mapping */
578 int cpu_core_index_of_thread(int cpu
)
580 return cpu
>> threads_shift
;
582 EXPORT_SYMBOL_GPL(cpu_core_index_of_thread
);
584 int cpu_first_thread_of_core(int core
)
586 return core
<< threads_shift
;
588 EXPORT_SYMBOL_GPL(cpu_first_thread_of_core
);
590 /* Must be called when no change can occur to cpu_present_mask,
591 * i.e. during cpu online or offline.
593 static struct device_node
*cpu_to_l2cache(int cpu
)
595 struct device_node
*np
;
596 struct device_node
*cache
;
598 if (!cpu_present(cpu
))
601 np
= of_get_cpu_node(cpu
, NULL
);
605 cache
= of_find_next_cache_node(np
);
612 /* Activate a secondary processor. */
613 __cpuinit
void start_secondary(void *unused
)
615 unsigned int cpu
= smp_processor_id();
616 struct device_node
*l2_cache
;
619 atomic_inc(&init_mm
.mm_count
);
620 current
->active_mm
= &init_mm
;
622 smp_store_cpu_info(cpu
);
623 set_dec(tb_ticks_per_jiffy
);
625 cpu_callin_map
[cpu
] = 1;
627 if (smp_ops
->setup_cpu
)
628 smp_ops
->setup_cpu(cpu
);
629 if (smp_ops
->take_timebase
)
630 smp_ops
->take_timebase();
632 secondary_cpu_time_init();
635 if (system_state
== SYSTEM_RUNNING
)
636 vdso_data
->processorCount
++;
640 notify_cpu_starting(cpu
);
641 set_cpu_online(cpu
, true);
642 /* Update sibling maps */
643 base
= cpu_first_thread_sibling(cpu
);
644 for (i
= 0; i
< threads_per_core
; i
++) {
645 if (cpu_is_offline(base
+ i
))
647 cpumask_set_cpu(cpu
, cpu_sibling_mask(base
+ i
));
648 cpumask_set_cpu(base
+ i
, cpu_sibling_mask(cpu
));
650 /* cpu_core_map should be a superset of
651 * cpu_sibling_map even if we don't have cache
652 * information, so update the former here, too.
654 cpumask_set_cpu(cpu
, cpu_core_mask(base
+ i
));
655 cpumask_set_cpu(base
+ i
, cpu_core_mask(cpu
));
657 l2_cache
= cpu_to_l2cache(cpu
);
658 for_each_online_cpu(i
) {
659 struct device_node
*np
= cpu_to_l2cache(i
);
662 if (np
== l2_cache
) {
663 cpumask_set_cpu(cpu
, cpu_core_mask(i
));
664 cpumask_set_cpu(i
, cpu_core_mask(cpu
));
668 of_node_put(l2_cache
);
672 cpu_startup_entry(CPUHP_ONLINE
);
677 int setup_profiling_timer(unsigned int multiplier
)
682 void __init
smp_cpus_done(unsigned int max_cpus
)
684 cpumask_var_t old_mask
;
686 /* We want the setup_cpu() here to be called from CPU 0, but our
687 * init thread may have been "borrowed" by another CPU in the meantime
688 * se we pin us down to CPU 0 for a short while
690 alloc_cpumask_var(&old_mask
, GFP_NOWAIT
);
691 cpumask_copy(old_mask
, tsk_cpus_allowed(current
));
692 set_cpus_allowed_ptr(current
, cpumask_of(boot_cpuid
));
694 if (smp_ops
&& smp_ops
->setup_cpu
)
695 smp_ops
->setup_cpu(boot_cpuid
);
697 set_cpus_allowed_ptr(current
, old_mask
);
699 free_cpumask_var(old_mask
);
701 if (smp_ops
&& smp_ops
->bringup_done
)
702 smp_ops
->bringup_done();
704 dump_numa_cpu_topology();
708 int arch_sd_sibling_asym_packing(void)
710 if (cpu_has_feature(CPU_FTR_ASYM_SMT
)) {
711 printk_once(KERN_INFO
"Enabling Asymmetric SMT scheduling\n");
712 return SD_ASYM_PACKING
;
717 #ifdef CONFIG_HOTPLUG_CPU
718 int __cpu_disable(void)
720 struct device_node
*l2_cache
;
721 int cpu
= smp_processor_id();
725 if (!smp_ops
->cpu_disable
)
728 err
= smp_ops
->cpu_disable();
732 /* Update sibling maps */
733 base
= cpu_first_thread_sibling(cpu
);
734 for (i
= 0; i
< threads_per_core
; i
++) {
735 cpumask_clear_cpu(cpu
, cpu_sibling_mask(base
+ i
));
736 cpumask_clear_cpu(base
+ i
, cpu_sibling_mask(cpu
));
737 cpumask_clear_cpu(cpu
, cpu_core_mask(base
+ i
));
738 cpumask_clear_cpu(base
+ i
, cpu_core_mask(cpu
));
741 l2_cache
= cpu_to_l2cache(cpu
);
742 for_each_present_cpu(i
) {
743 struct device_node
*np
= cpu_to_l2cache(i
);
746 if (np
== l2_cache
) {
747 cpumask_clear_cpu(cpu
, cpu_core_mask(i
));
748 cpumask_clear_cpu(i
, cpu_core_mask(cpu
));
752 of_node_put(l2_cache
);
758 void __cpu_die(unsigned int cpu
)
760 if (smp_ops
->cpu_die
)
761 smp_ops
->cpu_die(cpu
);
764 static DEFINE_MUTEX(powerpc_cpu_hotplug_driver_mutex
);
766 void cpu_hotplug_driver_lock()
768 mutex_lock(&powerpc_cpu_hotplug_driver_mutex
);
771 void cpu_hotplug_driver_unlock()
773 mutex_unlock(&powerpc_cpu_hotplug_driver_mutex
);
781 /* If we return, we re-enter start_secondary */
782 start_secondary_resume();