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
);
68 EXPORT_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
)
155 void smp_send_stop(void)
157 smp_call_function(stop_this_cpu
, NULL
, 1, 0);
161 * Structure and data for smp_call_function(). This is designed to minimise
162 * static memory requirements. It also looks cleaner.
163 * Stolen from the i386 version.
165 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(call_lock
);
167 static struct call_data_struct
{
168 void (*func
) (void *info
);
175 /* delay of at least 8 seconds */
176 #define SMP_CALL_TIMEOUT 8
179 * These functions send a 'generic call function' IPI to other online
180 * CPUS in the system.
182 * [SUMMARY] Run a function on other CPUs.
183 * <func> The function to run. This must be fast and non-blocking.
184 * <info> An arbitrary pointer to pass to the function.
185 * <nonatomic> currently unused.
186 * <wait> If true, wait (atomically) until function has completed on other CPUs.
187 * [RETURNS] 0 on success, else a negative status code. Does not return until
188 * remote CPUs are nearly ready to execute <<func>> or are or have executed.
190 * You must not call this function with disabled interrupts or from a
191 * hardware interrupt handler or from a bottom half handler.
193 int smp_call_function_map(void (*func
) (void *info
), void *info
, int nonatomic
,
194 int wait
, cpumask_t map
)
196 struct call_data_struct data
;
197 int ret
= -1, num_cpus
;
201 /* Can deadlock when called with interrupts disabled */
202 WARN_ON(irqs_disabled());
204 if (unlikely(smp_ops
== NULL
))
209 atomic_set(&data
.started
, 0);
212 atomic_set(&data
.finished
, 0);
214 spin_lock(&call_lock
);
215 /* Must grab online cpu count with preempt disabled, otherwise
217 num_cpus
= num_online_cpus() - 1;
221 /* remove 'self' from the map */
222 if (cpu_isset(smp_processor_id(), map
))
223 cpu_clear(smp_processor_id(), map
);
225 /* sanity check the map, remove any non-online processors. */
226 cpus_and(map
, map
, cpu_online_map
);
232 /* Send a message to all CPUs in the map */
233 for_each_cpu_mask(cpu
, map
)
234 smp_ops
->message_pass(cpu
, PPC_MSG_CALL_FUNCTION
);
236 timeout
= get_tb() + (u64
) SMP_CALL_TIMEOUT
* tb_ticks_per_sec
;
238 /* Wait for indication that they have received the message */
239 while (atomic_read(&data
.started
) != num_cpus
) {
241 if (get_tb() >= timeout
) {
242 printk("smp_call_function on cpu %d: other cpus not "
243 "responding (%d)\n", smp_processor_id(),
244 atomic_read(&data
.started
));
250 /* optionally wait for the CPUs to complete */
252 while (atomic_read(&data
.finished
) != num_cpus
) {
254 if (get_tb() >= timeout
) {
255 printk("smp_call_function on cpu %d: other "
256 "cpus not finishing (%d/%d)\n",
258 atomic_read(&data
.finished
),
259 atomic_read(&data
.started
));
272 spin_unlock(&call_lock
);
276 int smp_call_function(void (*func
) (void *info
), void *info
, int nonatomic
,
279 return smp_call_function_map(func
,info
,nonatomic
,wait
,cpu_online_map
);
281 EXPORT_SYMBOL(smp_call_function
);
283 int smp_call_function_single(int cpu
, void (*func
) (void *info
), void *info
, int nonatomic
,
286 cpumask_t map
= CPU_MASK_NONE
;
289 if (!cpu_online(cpu
))
293 if (cpu
!= get_cpu())
294 ret
= smp_call_function_map(func
,info
,nonatomic
,wait
,map
);
298 EXPORT_SYMBOL(smp_call_function_single
);
300 void smp_call_function_interrupt(void)
302 void (*func
) (void *info
);
306 /* call_data will be NULL if the sender timed out while
307 * waiting on us to receive the call.
312 func
= call_data
->func
;
313 info
= call_data
->info
;
314 wait
= call_data
->wait
;
317 smp_mb__before_atomic_inc();
320 * Notify initiating CPU that I've grabbed the data and am
321 * about to execute the function
323 atomic_inc(&call_data
->started
);
325 * At this point the info structure may be out of scope unless wait==1
329 smp_mb__before_atomic_inc();
330 atomic_inc(&call_data
->finished
);
334 extern struct gettimeofday_struct do_gtod
;
336 struct thread_info
*current_set
[NR_CPUS
];
338 DECLARE_PER_CPU(unsigned int, pvr
);
340 static void __devinit
smp_store_cpu_info(int id
)
342 per_cpu(pvr
, id
) = mfspr(SPRN_PVR
);
345 static void __init
smp_create_idle(unsigned int cpu
)
347 struct task_struct
*p
;
349 /* create a process for the processor */
352 panic("failed fork for CPU %u: %li", cpu
, PTR_ERR(p
));
354 paca
[cpu
].__current
= p
;
356 current_set
[cpu
] = task_thread_info(p
);
357 task_thread_info(p
)->cpu
= cpu
;
360 void __init
smp_prepare_cpus(unsigned int max_cpus
)
364 DBG("smp_prepare_cpus\n");
367 * setup_cpu may need to be called on the boot cpu. We havent
368 * spun any cpus up but lets be paranoid.
370 BUG_ON(boot_cpuid
!= smp_processor_id());
373 smp_store_cpu_info(boot_cpuid
);
374 cpu_callin_map
[boot_cpuid
] = 1;
377 max_cpus
= smp_ops
->probe();
381 smp_space_timers(max_cpus
);
383 for_each_possible_cpu(cpu
)
384 if (cpu
!= boot_cpuid
)
385 smp_create_idle(cpu
);
388 void __devinit
smp_prepare_boot_cpu(void)
390 BUG_ON(smp_processor_id() != boot_cpuid
);
392 cpu_set(boot_cpuid
, cpu_online_map
);
394 paca
[boot_cpuid
].__current
= current
;
396 current_set
[boot_cpuid
] = task_thread_info(current
);
399 #ifdef CONFIG_HOTPLUG_CPU
400 /* State of each CPU during hotplug phases */
401 DEFINE_PER_CPU(int, cpu_state
) = { 0 };
403 int generic_cpu_disable(void)
405 unsigned int cpu
= smp_processor_id();
407 if (cpu
== boot_cpuid
)
410 cpu_clear(cpu
, cpu_online_map
);
412 vdso_data
->processorCount
--;
413 fixup_irqs(cpu_online_map
);
418 int generic_cpu_enable(unsigned int cpu
)
420 /* Do the normal bootup if we haven't
421 * already bootstrapped. */
422 if (system_state
!= SYSTEM_RUNNING
)
425 /* get the target out of it's holding state */
426 per_cpu(cpu_state
, cpu
) = CPU_UP_PREPARE
;
429 while (!cpu_online(cpu
))
433 fixup_irqs(cpu_online_map
);
434 /* counter the irq disable in fixup_irqs */
440 void generic_cpu_die(unsigned int cpu
)
444 for (i
= 0; i
< 100; i
++) {
446 if (per_cpu(cpu_state
, cpu
) == CPU_DEAD
)
450 printk(KERN_ERR
"CPU%d didn't die...\n", cpu
);
453 void generic_mach_cpu_die(void)
458 cpu
= smp_processor_id();
459 printk(KERN_DEBUG
"CPU%d offline\n", cpu
);
460 __get_cpu_var(cpu_state
) = CPU_DEAD
;
462 while (__get_cpu_var(cpu_state
) != CPU_UP_PREPARE
)
464 cpu_set(cpu
, cpu_online_map
);
469 static int __devinit
cpu_enable(unsigned int cpu
)
471 if (smp_ops
&& smp_ops
->cpu_enable
)
472 return smp_ops
->cpu_enable(cpu
);
477 int __cpuinit
__cpu_up(unsigned int cpu
)
481 secondary_ti
= current_set
[cpu
];
482 if (!cpu_enable(cpu
))
485 if (smp_ops
== NULL
||
486 (smp_ops
->cpu_bootable
&& !smp_ops
->cpu_bootable(cpu
)))
489 /* Make sure callin-map entry is 0 (can be leftover a CPU
492 cpu_callin_map
[cpu
] = 0;
494 /* The information for processor bringup must
495 * be written out to main store before we release
501 DBG("smp: kicking cpu %d\n", cpu
);
502 smp_ops
->kick_cpu(cpu
);
505 * wait to see if the cpu made a callin (is actually up).
506 * use this value that I found through experimentation.
509 if (system_state
< SYSTEM_RUNNING
)
510 for (c
= 50000; c
&& !cpu_callin_map
[cpu
]; c
--)
512 #ifdef CONFIG_HOTPLUG_CPU
515 * CPUs can take much longer to come up in the
516 * hotplug case. Wait five seconds.
518 for (c
= 25; c
&& !cpu_callin_map
[cpu
]; c
--) {
523 if (!cpu_callin_map
[cpu
]) {
524 printk("Processor %u is stuck.\n", cpu
);
528 printk("Processor %u found.\n", cpu
);
530 if (smp_ops
->give_timebase
)
531 smp_ops
->give_timebase();
533 /* Wait until cpu puts itself in the online map */
534 while (!cpu_online(cpu
))
541 /* Activate a secondary processor. */
542 int __devinit
start_secondary(void *unused
)
544 unsigned int cpu
= smp_processor_id();
546 atomic_inc(&init_mm
.mm_count
);
547 current
->active_mm
= &init_mm
;
549 smp_store_cpu_info(cpu
);
550 set_dec(tb_ticks_per_jiffy
);
552 cpu_callin_map
[cpu
] = 1;
554 smp_ops
->setup_cpu(cpu
);
555 if (smp_ops
->take_timebase
)
556 smp_ops
->take_timebase();
558 if (system_state
> SYSTEM_BOOTING
)
561 spin_lock(&call_lock
);
562 cpu_set(cpu
, cpu_online_map
);
563 spin_unlock(&call_lock
);
571 int setup_profiling_timer(unsigned int multiplier
)
576 void __init
smp_cpus_done(unsigned int max_cpus
)
580 /* We want the setup_cpu() here to be called from CPU 0, but our
581 * init thread may have been "borrowed" by another CPU in the meantime
582 * se we pin us down to CPU 0 for a short while
584 old_mask
= current
->cpus_allowed
;
585 set_cpus_allowed(current
, cpumask_of_cpu(boot_cpuid
));
588 smp_ops
->setup_cpu(boot_cpuid
);
590 set_cpus_allowed(current
, old_mask
);
592 snapshot_timebases();
594 dump_numa_cpu_topology();
597 #ifdef CONFIG_HOTPLUG_CPU
598 int __cpu_disable(void)
600 if (smp_ops
->cpu_disable
)
601 return smp_ops
->cpu_disable();
606 void __cpu_die(unsigned int cpu
)
608 if (smp_ops
->cpu_die
)
609 smp_ops
->cpu_die(cpu
);