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 int __init
smp_mpic_probe(void)
86 DBG("smp_mpic_probe()...\n");
88 nr_cpus
= cpus_weight(cpu_possible_map
);
90 DBG("nr_cpus: %d\n", nr_cpus
);
98 void __devinit
smp_mpic_setup_cpu(int cpu
)
100 mpic_setup_this_cpu();
102 #endif /* CONFIG_MPIC */
105 void __devinit
smp_generic_kick_cpu(int nr
)
107 BUG_ON(nr
< 0 || nr
>= NR_CPUS
);
110 * The processor is currently spinning, waiting for the
111 * cpu_start field to become non-zero After we set cpu_start,
112 * the processor will continue on to secondary_start
114 paca
[nr
].cpu_start
= 1;
119 void smp_message_recv(int msg
)
122 case PPC_MSG_CALL_FUNCTION
:
123 smp_call_function_interrupt();
125 case PPC_MSG_RESCHEDULE
:
126 /* XXX Do we have to do this? */
129 case PPC_MSG_DEBUGGER_BREAK
:
130 if (crash_ipi_function_ptr
) {
131 crash_ipi_function_ptr(get_irq_regs());
134 #ifdef CONFIG_DEBUGGER
135 debugger_ipi(get_irq_regs());
137 #endif /* CONFIG_DEBUGGER */
140 printk("SMP %d: smp_message_recv(): unknown msg %d\n",
141 smp_processor_id(), msg
);
146 void smp_send_reschedule(int cpu
)
149 smp_ops
->message_pass(cpu
, PPC_MSG_RESCHEDULE
);
152 #ifdef CONFIG_DEBUGGER
153 void smp_send_debugger_break(int cpu
)
156 smp_ops
->message_pass(cpu
, PPC_MSG_DEBUGGER_BREAK
);
161 void crash_send_ipi(void (*crash_ipi_callback
)(struct pt_regs
*))
163 crash_ipi_function_ptr
= crash_ipi_callback
;
164 if (crash_ipi_callback
&& smp_ops
) {
166 smp_ops
->message_pass(MSG_ALL_BUT_SELF
, PPC_MSG_DEBUGGER_BREAK
);
171 static void stop_this_cpu(void *dummy
)
178 void smp_send_stop(void)
180 smp_call_function(stop_this_cpu
, NULL
, 1, 0);
184 * Structure and data for smp_call_function(). This is designed to minimise
185 * static memory requirements. It also looks cleaner.
186 * Stolen from the i386 version.
188 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(call_lock
);
190 static struct call_data_struct
{
191 void (*func
) (void *info
);
198 /* delay of at least 8 seconds */
199 #define SMP_CALL_TIMEOUT 8
202 * This function sends a 'generic call function' IPI to all other CPUs
205 * [SUMMARY] Run a function on all other CPUs.
206 * <func> The function to run. This must be fast and non-blocking.
207 * <info> An arbitrary pointer to pass to the function.
208 * <nonatomic> currently unused.
209 * <wait> If true, wait (atomically) until function has completed on other CPUs.
210 * [RETURNS] 0 on success, else a negative status code. Does not return until
211 * remote CPUs are nearly ready to execute <<func>> or are or have executed.
213 * You must not call this function with disabled interrupts or from a
214 * hardware interrupt handler or from a bottom half handler.
216 int smp_call_function (void (*func
) (void *info
), void *info
, int nonatomic
,
219 struct call_data_struct data
;
223 /* Can deadlock when called with interrupts disabled */
224 WARN_ON(irqs_disabled());
226 if (unlikely(smp_ops
== NULL
))
231 atomic_set(&data
.started
, 0);
234 atomic_set(&data
.finished
, 0);
236 spin_lock(&call_lock
);
237 /* Must grab online cpu count with preempt disabled, otherwise
239 cpus
= num_online_cpus() - 1;
247 /* Send a message to all other CPUs and wait for them to respond */
248 smp_ops
->message_pass(MSG_ALL_BUT_SELF
, PPC_MSG_CALL_FUNCTION
);
250 timeout
= get_tb() + (u64
) SMP_CALL_TIMEOUT
* tb_ticks_per_sec
;
252 /* Wait for response */
253 while (atomic_read(&data
.started
) != cpus
) {
255 if (get_tb() >= timeout
) {
256 printk("smp_call_function on cpu %d: other cpus not "
257 "responding (%d)\n", smp_processor_id(),
258 atomic_read(&data
.started
));
265 while (atomic_read(&data
.finished
) != cpus
) {
267 if (get_tb() >= timeout
) {
268 printk("smp_call_function on cpu %d: other "
269 "cpus not finishing (%d/%d)\n",
271 atomic_read(&data
.finished
),
272 atomic_read(&data
.started
));
284 spin_unlock(&call_lock
);
288 EXPORT_SYMBOL(smp_call_function
);
290 void smp_call_function_interrupt(void)
292 void (*func
) (void *info
);
296 /* call_data will be NULL if the sender timed out while
297 * waiting on us to receive the call.
302 func
= call_data
->func
;
303 info
= call_data
->info
;
304 wait
= call_data
->wait
;
307 smp_mb__before_atomic_inc();
310 * Notify initiating CPU that I've grabbed the data and am
311 * about to execute the function
313 atomic_inc(&call_data
->started
);
315 * At this point the info structure may be out of scope unless wait==1
319 smp_mb__before_atomic_inc();
320 atomic_inc(&call_data
->finished
);
324 extern struct gettimeofday_struct do_gtod
;
326 struct thread_info
*current_set
[NR_CPUS
];
328 DECLARE_PER_CPU(unsigned int, pvr
);
330 static void __devinit
smp_store_cpu_info(int id
)
332 per_cpu(pvr
, id
) = mfspr(SPRN_PVR
);
335 static void __init
smp_create_idle(unsigned int cpu
)
337 struct task_struct
*p
;
339 /* create a process for the processor */
342 panic("failed fork for CPU %u: %li", cpu
, PTR_ERR(p
));
344 paca
[cpu
].__current
= p
;
346 current_set
[cpu
] = task_thread_info(p
);
347 task_thread_info(p
)->cpu
= cpu
;
350 void __init
smp_prepare_cpus(unsigned int max_cpus
)
354 DBG("smp_prepare_cpus\n");
357 * setup_cpu may need to be called on the boot cpu. We havent
358 * spun any cpus up but lets be paranoid.
360 BUG_ON(boot_cpuid
!= smp_processor_id());
363 smp_store_cpu_info(boot_cpuid
);
364 cpu_callin_map
[boot_cpuid
] = 1;
367 max_cpus
= smp_ops
->probe();
371 smp_space_timers(max_cpus
);
373 for_each_possible_cpu(cpu
)
374 if (cpu
!= boot_cpuid
)
375 smp_create_idle(cpu
);
378 void __devinit
smp_prepare_boot_cpu(void)
380 BUG_ON(smp_processor_id() != boot_cpuid
);
382 cpu_set(boot_cpuid
, cpu_online_map
);
384 paca
[boot_cpuid
].__current
= current
;
386 current_set
[boot_cpuid
] = task_thread_info(current
);
389 #ifdef CONFIG_HOTPLUG_CPU
390 /* State of each CPU during hotplug phases */
391 DEFINE_PER_CPU(int, cpu_state
) = { 0 };
393 int generic_cpu_disable(void)
395 unsigned int cpu
= smp_processor_id();
397 if (cpu
== boot_cpuid
)
400 cpu_clear(cpu
, cpu_online_map
);
402 vdso_data
->processorCount
--;
403 fixup_irqs(cpu_online_map
);
408 int generic_cpu_enable(unsigned int cpu
)
410 /* Do the normal bootup if we haven't
411 * already bootstrapped. */
412 if (system_state
!= SYSTEM_RUNNING
)
415 /* get the target out of it's holding state */
416 per_cpu(cpu_state
, cpu
) = CPU_UP_PREPARE
;
419 while (!cpu_online(cpu
))
423 fixup_irqs(cpu_online_map
);
424 /* counter the irq disable in fixup_irqs */
430 void generic_cpu_die(unsigned int cpu
)
434 for (i
= 0; i
< 100; i
++) {
436 if (per_cpu(cpu_state
, cpu
) == CPU_DEAD
)
440 printk(KERN_ERR
"CPU%d didn't die...\n", cpu
);
443 void generic_mach_cpu_die(void)
448 cpu
= smp_processor_id();
449 printk(KERN_DEBUG
"CPU%d offline\n", cpu
);
450 __get_cpu_var(cpu_state
) = CPU_DEAD
;
452 while (__get_cpu_var(cpu_state
) != CPU_UP_PREPARE
)
458 cpu_set(cpu
, cpu_online_map
);
463 static int __devinit
cpu_enable(unsigned int cpu
)
465 if (smp_ops
&& smp_ops
->cpu_enable
)
466 return smp_ops
->cpu_enable(cpu
);
471 int __cpuinit
__cpu_up(unsigned int cpu
)
475 secondary_ti
= current_set
[cpu
];
476 if (!cpu_enable(cpu
))
479 if (smp_ops
== NULL
||
480 (smp_ops
->cpu_bootable
&& !smp_ops
->cpu_bootable(cpu
)))
483 /* Make sure callin-map entry is 0 (can be leftover a CPU
486 cpu_callin_map
[cpu
] = 0;
488 /* The information for processor bringup must
489 * be written out to main store before we release
495 DBG("smp: kicking cpu %d\n", cpu
);
496 smp_ops
->kick_cpu(cpu
);
499 * wait to see if the cpu made a callin (is actually up).
500 * use this value that I found through experimentation.
503 if (system_state
< SYSTEM_RUNNING
)
504 for (c
= 50000; c
&& !cpu_callin_map
[cpu
]; c
--)
506 #ifdef CONFIG_HOTPLUG_CPU
509 * CPUs can take much longer to come up in the
510 * hotplug case. Wait five seconds.
512 for (c
= 25; c
&& !cpu_callin_map
[cpu
]; c
--) {
517 if (!cpu_callin_map
[cpu
]) {
518 printk("Processor %u is stuck.\n", cpu
);
522 printk("Processor %u found.\n", cpu
);
524 if (smp_ops
->give_timebase
)
525 smp_ops
->give_timebase();
527 /* Wait until cpu puts itself in the online map */
528 while (!cpu_online(cpu
))
535 /* Activate a secondary processor. */
536 int __devinit
start_secondary(void *unused
)
538 unsigned int cpu
= smp_processor_id();
540 atomic_inc(&init_mm
.mm_count
);
541 current
->active_mm
= &init_mm
;
543 smp_store_cpu_info(cpu
);
544 set_dec(tb_ticks_per_jiffy
);
546 cpu_callin_map
[cpu
] = 1;
548 smp_ops
->setup_cpu(cpu
);
549 if (smp_ops
->take_timebase
)
550 smp_ops
->take_timebase();
552 if (system_state
> SYSTEM_BOOTING
)
555 spin_lock(&call_lock
);
556 cpu_set(cpu
, cpu_online_map
);
557 spin_unlock(&call_lock
);
565 int setup_profiling_timer(unsigned int multiplier
)
570 void __init
smp_cpus_done(unsigned int max_cpus
)
574 /* We want the setup_cpu() here to be called from CPU 0, but our
575 * init thread may have been "borrowed" by another CPU in the meantime
576 * se we pin us down to CPU 0 for a short while
578 old_mask
= current
->cpus_allowed
;
579 set_cpus_allowed(current
, cpumask_of_cpu(boot_cpuid
));
582 smp_ops
->setup_cpu(boot_cpuid
);
584 set_cpus_allowed(current
, old_mask
);
586 snapshot_timebases();
588 dump_numa_cpu_topology();
591 #ifdef CONFIG_HOTPLUG_CPU
592 int __cpu_disable(void)
594 if (smp_ops
->cpu_disable
)
595 return smp_ops
->cpu_disable();
600 void __cpu_die(unsigned int cpu
)
602 if (smp_ops
->cpu_die
)
603 smp_ops
->cpu_die(cpu
);