4 * SMP support for the SuperH processors.
6 * Copyright (C) 2002, 2003 Paul Mundt
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
13 #include <linux/config.h>
14 #include <linux/cache.h>
15 #include <linux/cpumask.h>
16 #include <linux/delay.h>
17 #include <linux/init.h>
18 #include <linux/interrupt.h>
19 #include <linux/spinlock.h>
20 #include <linux/threads.h>
21 #include <linux/module.h>
22 #include <linux/time.h>
23 #include <linux/timex.h>
24 #include <linux/sched.h>
26 #include <asm/atomic.h>
27 #include <asm/processor.h>
28 #include <asm/system.h>
29 #include <asm/hardirq.h>
30 #include <asm/mmu_context.h>
34 * This was written with the Sega Saturn (SMP SH-2 7604) in mind,
35 * but is designed to be usable regardless if there's an MMU
38 int smp_threads_ready = 0;
39 struct sh_cpuinfo cpu_data[NR_CPUS];
41 extern int cpu_idle(void *unused);
42 extern void per_cpu_trap_init(void);
44 cpumask_t cpu_possible_map;
45 cpumask_t cpu_online_map;
46 unsigned long cache_decay_ticks = HZ / 100;
47 static atomic_t cpus_booted = ATOMIC_INIT(0);
49 /* These are defined by the board-specific code. */
52 * Cause the function described by call_data to be executed on the passed
53 * cpu. When the function has finished, increment the finished field of
56 void __smp_send_ipi(unsigned int cpu, unsigned int action);
59 * Find the number of available processors
61 unsigned int __smp_probe_cpus(void);
64 * Start a particular processor
66 void __smp_slave_init(unsigned int cpu);
69 * Run specified function on a particular processor.
71 void __smp_call_function(unsigned int cpu);
73 static inline void __init smp_store_cpu_info(unsigned int cpu)
75 cpu_data[cpu].loops_per_jiffy = loops_per_jiffy;
78 void __init smp_prepare_cpus(unsigned int max_cpus)
80 unsigned int cpu = smp_processor_id();
83 atomic_set(&cpus_booted, 1);
84 smp_store_cpu_info(cpu);
86 for (i = 0; i < __smp_probe_cpus(); i++)
87 cpu_set(i, cpu_possible_map);
90 void __devinit smp_prepare_boot_cpu(void)
92 unsigned int cpu = smp_processor_id();
94 cpu_set(cpu, cpu_online_map);
95 cpu_set(cpu, cpu_possible_map);
98 int __cpu_up(unsigned int cpu)
100 struct task_struct *tsk;
103 memset(®s, 0, sizeof(struct pt_regs));
104 tsk = copy_process(CLONE_VM | CLONE_IDLETASK, 0, ®s, 0, 0, 0);
107 panic("Failed forking idle task for cpu %d\n", cpu);
109 wake_up_forked_process(tsk);
114 tsk->thread_info->cpu = cpu;
116 cpu_set(cpu, cpu_online_map);
121 int start_secondary(void *unused)
123 unsigned int cpu = smp_processor_id();
125 atomic_inc(&init_mm.mm_count);
126 current->active_mm = &init_mm;
128 smp_store_cpu_info(cpu);
130 __smp_slave_init(cpu);
133 atomic_inc(&cpus_booted);
138 void __init smp_cpus_done(unsigned int max_cpus)
140 smp_threads_ready = 1;
144 void smp_send_reschedule(int cpu)
146 __smp_send_ipi(cpu, SMP_MSG_RESCHEDULE);
149 static void stop_this_cpu(void *unused)
151 cpu_clear(smp_processor_id(), cpu_online_map);
158 void smp_send_stop(void)
160 smp_call_function(stop_this_cpu, 0, 1, 0);
164 struct smp_fn_call_struct smp_fn_call = {
165 .lock = SPIN_LOCK_UNLOCKED,
166 .finished = ATOMIC_INIT(0),
170 * The caller of this wants the passed function to run on every cpu. If wait
171 * is set, wait until all cpus have finished the function before returning.
172 * The lock is here to protect the call structure.
173 * You must not call this function with disabled interrupts or from a
174 * hardware interrupt handler or from a bottom half handler.
176 int smp_call_function(void (*func)(void *info), void *info, int retry, int wait)
178 unsigned int nr_cpus = atomic_read(&cpus_booted);
184 spin_lock(&smp_fn_call.lock);
186 atomic_set(&smp_fn_call.finished, 0);
187 smp_fn_call.fn = func;
188 smp_fn_call.data = info;
190 for (i = 0; i < nr_cpus; i++)
191 if (i != smp_processor_id())
192 __smp_call_function(i);
195 while (atomic_read(&smp_fn_call.finished) != (nr_cpus - 1));
197 spin_unlock(&smp_fn_call.lock);
202 /* Not really SMP stuff ... */
203 int setup_profiling_timer(unsigned int multiplier)