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>
34 #include <linux/topology.h>
36 #include <asm/ptrace.h>
37 #include <asm/atomic.h>
40 #include <asm/pgtable.h>
44 #include <asm/machdep.h>
45 #include <asm/cputable.h>
46 #include <asm/system.h>
48 #include <asm/vdso_datapage.h>
55 #define DBG(fmt...) udbg_printf(fmt)
60 int smp_hw_index
[NR_CPUS
];
61 struct thread_info
*secondary_ti
;
63 cpumask_t cpu_possible_map
= CPU_MASK_NONE
;
64 cpumask_t cpu_online_map
= CPU_MASK_NONE
;
65 cpumask_t cpu_sibling_map
[NR_CPUS
] = { [0 ... NR_CPUS
-1] = CPU_MASK_NONE
};
67 EXPORT_SYMBOL(cpu_online_map
);
68 EXPORT_SYMBOL(cpu_possible_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
, struct pt_regs
*regs
)
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(regs
);
134 #ifdef CONFIG_DEBUGGER
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
)
148 smp_ops
->message_pass(cpu
, PPC_MSG_RESCHEDULE
);
151 #ifdef CONFIG_DEBUGGER
152 void smp_send_debugger_break(int cpu
)
154 smp_ops
->message_pass(cpu
, PPC_MSG_DEBUGGER_BREAK
);
159 void crash_send_ipi(void (*crash_ipi_callback
)(struct pt_regs
*))
161 crash_ipi_function_ptr
= crash_ipi_callback
;
162 if (crash_ipi_callback
) {
164 smp_ops
->message_pass(MSG_ALL_BUT_SELF
, PPC_MSG_DEBUGGER_BREAK
);
169 static void stop_this_cpu(void *dummy
)
176 void smp_send_stop(void)
178 smp_call_function(stop_this_cpu
, NULL
, 1, 0);
182 * Structure and data for smp_call_function(). This is designed to minimise
183 * static memory requirements. It also looks cleaner.
184 * Stolen from the i386 version.
186 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(call_lock
);
188 static struct call_data_struct
{
189 void (*func
) (void *info
);
196 /* delay of at least 8 seconds */
197 #define SMP_CALL_TIMEOUT 8
200 * This function sends a 'generic call function' IPI to all other CPUs
203 * [SUMMARY] Run a function on all other CPUs.
204 * <func> The function to run. This must be fast and non-blocking.
205 * <info> An arbitrary pointer to pass to the function.
206 * <nonatomic> currently unused.
207 * <wait> If true, wait (atomically) until function has completed on other CPUs.
208 * [RETURNS] 0 on success, else a negative status code. Does not return until
209 * remote CPUs are nearly ready to execute <<func>> or are or have executed.
211 * You must not call this function with disabled interrupts or from a
212 * hardware interrupt handler or from a bottom half handler.
214 int smp_call_function (void (*func
) (void *info
), void *info
, int nonatomic
,
217 struct call_data_struct data
;
221 /* Can deadlock when called with interrupts disabled */
222 WARN_ON(irqs_disabled());
226 atomic_set(&data
.started
, 0);
229 atomic_set(&data
.finished
, 0);
231 spin_lock(&call_lock
);
232 /* Must grab online cpu count with preempt disabled, otherwise
234 cpus
= num_online_cpus() - 1;
242 /* Send a message to all other CPUs and wait for them to respond */
243 smp_ops
->message_pass(MSG_ALL_BUT_SELF
, PPC_MSG_CALL_FUNCTION
);
245 timeout
= get_tb() + (u64
) SMP_CALL_TIMEOUT
* tb_ticks_per_sec
;
247 /* Wait for response */
248 while (atomic_read(&data
.started
) != cpus
) {
250 if (get_tb() >= timeout
) {
251 printk("smp_call_function on cpu %d: other cpus not "
252 "responding (%d)\n", smp_processor_id(),
253 atomic_read(&data
.started
));
260 while (atomic_read(&data
.finished
) != cpus
) {
262 if (get_tb() >= timeout
) {
263 printk("smp_call_function on cpu %d: other "
264 "cpus not finishing (%d/%d)\n",
266 atomic_read(&data
.finished
),
267 atomic_read(&data
.started
));
279 spin_unlock(&call_lock
);
283 EXPORT_SYMBOL(smp_call_function
);
285 void smp_call_function_interrupt(void)
287 void (*func
) (void *info
);
291 /* call_data will be NULL if the sender timed out while
292 * waiting on us to receive the call.
297 func
= call_data
->func
;
298 info
= call_data
->info
;
299 wait
= call_data
->wait
;
302 smp_mb__before_atomic_inc();
305 * Notify initiating CPU that I've grabbed the data and am
306 * about to execute the function
308 atomic_inc(&call_data
->started
);
310 * At this point the info structure may be out of scope unless wait==1
314 smp_mb__before_atomic_inc();
315 atomic_inc(&call_data
->finished
);
319 extern struct gettimeofday_struct do_gtod
;
321 struct thread_info
*current_set
[NR_CPUS
];
323 DECLARE_PER_CPU(unsigned int, pvr
);
325 static void __devinit
smp_store_cpu_info(int id
)
327 per_cpu(pvr
, id
) = mfspr(SPRN_PVR
);
330 static void __init
smp_create_idle(unsigned int cpu
)
332 struct task_struct
*p
;
334 /* create a process for the processor */
337 panic("failed fork for CPU %u: %li", cpu
, PTR_ERR(p
));
339 paca
[cpu
].__current
= p
;
341 current_set
[cpu
] = task_thread_info(p
);
342 task_thread_info(p
)->cpu
= cpu
;
345 void __init
smp_prepare_cpus(unsigned int max_cpus
)
349 DBG("smp_prepare_cpus\n");
352 * setup_cpu may need to be called on the boot cpu. We havent
353 * spun any cpus up but lets be paranoid.
355 BUG_ON(boot_cpuid
!= smp_processor_id());
358 smp_store_cpu_info(boot_cpuid
);
359 cpu_callin_map
[boot_cpuid
] = 1;
361 max_cpus
= smp_ops
->probe();
363 smp_space_timers(max_cpus
);
366 if (cpu
!= boot_cpuid
)
367 smp_create_idle(cpu
);
370 void __devinit
smp_prepare_boot_cpu(void)
372 BUG_ON(smp_processor_id() != boot_cpuid
);
374 cpu_set(boot_cpuid
, cpu_online_map
);
376 paca
[boot_cpuid
].__current
= current
;
378 current_set
[boot_cpuid
] = task_thread_info(current
);
381 #ifdef CONFIG_HOTPLUG_CPU
382 /* State of each CPU during hotplug phases */
383 DEFINE_PER_CPU(int, cpu_state
) = { 0 };
385 int generic_cpu_disable(void)
387 unsigned int cpu
= smp_processor_id();
389 if (cpu
== boot_cpuid
)
392 cpu_clear(cpu
, cpu_online_map
);
394 vdso_data
->processorCount
--;
395 fixup_irqs(cpu_online_map
);
400 int generic_cpu_enable(unsigned int cpu
)
402 /* Do the normal bootup if we haven't
403 * already bootstrapped. */
404 if (system_state
!= SYSTEM_RUNNING
)
407 /* get the target out of it's holding state */
408 per_cpu(cpu_state
, cpu
) = CPU_UP_PREPARE
;
411 while (!cpu_online(cpu
))
415 fixup_irqs(cpu_online_map
);
416 /* counter the irq disable in fixup_irqs */
422 void generic_cpu_die(unsigned int cpu
)
426 for (i
= 0; i
< 100; i
++) {
428 if (per_cpu(cpu_state
, cpu
) == CPU_DEAD
)
432 printk(KERN_ERR
"CPU%d didn't die...\n", cpu
);
435 void generic_mach_cpu_die(void)
440 cpu
= smp_processor_id();
441 printk(KERN_DEBUG
"CPU%d offline\n", cpu
);
442 __get_cpu_var(cpu_state
) = CPU_DEAD
;
444 while (__get_cpu_var(cpu_state
) != CPU_UP_PREPARE
)
450 cpu_set(cpu
, cpu_online_map
);
455 static int __devinit
cpu_enable(unsigned int cpu
)
457 if (smp_ops
->cpu_enable
)
458 return smp_ops
->cpu_enable(cpu
);
463 int __devinit
__cpu_up(unsigned int cpu
)
467 secondary_ti
= current_set
[cpu
];
468 if (!cpu_enable(cpu
))
471 if (smp_ops
->cpu_bootable
&& !smp_ops
->cpu_bootable(cpu
))
474 /* Make sure callin-map entry is 0 (can be leftover a CPU
477 cpu_callin_map
[cpu
] = 0;
479 /* The information for processor bringup must
480 * be written out to main store before we release
486 DBG("smp: kicking cpu %d\n", cpu
);
487 smp_ops
->kick_cpu(cpu
);
490 * wait to see if the cpu made a callin (is actually up).
491 * use this value that I found through experimentation.
494 if (system_state
< SYSTEM_RUNNING
)
495 for (c
= 5000; c
&& !cpu_callin_map
[cpu
]; c
--)
497 #ifdef CONFIG_HOTPLUG_CPU
500 * CPUs can take much longer to come up in the
501 * hotplug case. Wait five seconds.
503 for (c
= 25; c
&& !cpu_callin_map
[cpu
]; c
--) {
508 if (!cpu_callin_map
[cpu
]) {
509 printk("Processor %u is stuck.\n", cpu
);
513 printk("Processor %u found.\n", cpu
);
515 if (smp_ops
->give_timebase
)
516 smp_ops
->give_timebase();
518 /* Wait until cpu puts itself in the online map */
519 while (!cpu_online(cpu
))
526 /* Activate a secondary processor. */
527 int __devinit
start_secondary(void *unused
)
529 unsigned int cpu
= smp_processor_id();
531 atomic_inc(&init_mm
.mm_count
);
532 current
->active_mm
= &init_mm
;
534 smp_store_cpu_info(cpu
);
535 set_dec(tb_ticks_per_jiffy
);
537 cpu_callin_map
[cpu
] = 1;
539 smp_ops
->setup_cpu(cpu
);
540 if (smp_ops
->take_timebase
)
541 smp_ops
->take_timebase();
543 if (system_state
> SYSTEM_BOOTING
)
544 per_cpu(last_jiffy
, cpu
) = get_tb();
546 spin_lock(&call_lock
);
547 cpu_set(cpu
, cpu_online_map
);
548 spin_unlock(&call_lock
);
556 int setup_profiling_timer(unsigned int multiplier
)
561 void __init
smp_cpus_done(unsigned int max_cpus
)
565 /* We want the setup_cpu() here to be called from CPU 0, but our
566 * init thread may have been "borrowed" by another CPU in the meantime
567 * se we pin us down to CPU 0 for a short while
569 old_mask
= current
->cpus_allowed
;
570 set_cpus_allowed(current
, cpumask_of_cpu(boot_cpuid
));
572 smp_ops
->setup_cpu(boot_cpuid
);
574 set_cpus_allowed(current
, old_mask
);
576 dump_numa_cpu_topology();
579 #ifdef CONFIG_HOTPLUG_CPU
580 int __cpu_disable(void)
582 if (smp_ops
->cpu_disable
)
583 return smp_ops
->cpu_disable();
588 void __cpu_die(unsigned int cpu
)
590 if (smp_ops
->cpu_die
)
591 smp_ops
->cpu_die(cpu
);