2 * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
3 * Licensed under the GPL
6 #include "linux/config.h"
7 #include "linux/percpu.h"
8 #include "asm/pgalloc.h"
11 /* For some reason, mmu_gathers are referenced when CONFIG_SMP is off. */
12 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
16 #include "linux/sched.h"
17 #include "linux/module.h"
18 #include "linux/threads.h"
19 #include "linux/interrupt.h"
20 #include "linux/err.h"
22 #include "asm/processor.h"
23 #include "asm/spinlock.h"
24 #include "asm/hardirq.h"
25 #include "user_util.h"
26 #include "kern_util.h"
31 /* CPU online map, set by smp_boot_cpus */
32 unsigned long cpu_online_map = CPU_MASK_NONE;
34 EXPORT_SYMBOL(cpu_online_map);
36 /* Per CPU bogomips and other parameters
37 * The only piece used here is the ipi pipe, which is set before SMP is
38 * started and never changed.
40 struct cpuinfo_um cpu_data[NR_CPUS];
42 /* Set when the idlers are all forked */
43 int smp_threads_ready = 0;
45 /* A statistic, can be a little off */
46 int num_reschedules_sent = 0;
48 /* Small, random number, never changed */
49 unsigned long cache_decay_ticks = 5;
51 /* Not changed after boot */
52 struct task_struct *idle_threads[NR_CPUS];
54 void smp_send_reschedule(int cpu)
56 os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1);
57 num_reschedules_sent++;
60 void smp_send_stop(void)
64 printk(KERN_INFO "Stopping all CPUs...");
65 for(i = 0; i < num_online_cpus(); i++){
66 if(i == current_thread->cpu)
68 os_write_file(cpu_data[i].ipi_pipe[1], "S", 1);
73 static cpumask_t smp_commenced_mask = CPU_MASK_NONE;
74 static cpumask_t cpu_callin_map = CPU_MASK_NONE;
76 static int idle_proc(void *cpup)
78 int cpu = (int) cpup, err;
80 err = os_pipe(cpu_data[cpu].ipi_pipe, 1, 1);
82 panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err);
84 activate_ipi(cpu_data[cpu].ipi_pipe[0],
85 current->thread.mode.tt.extern_pid);
88 if (cpu_test_and_set(cpu, cpu_callin_map)) {
89 printk("huh, CPU#%d already present??\n", cpu);
93 while (!cpu_isset(cpu, smp_commenced_mask))
96 cpu_set(cpu, cpu_online_map);
101 static struct task_struct *idle_thread(int cpu)
103 struct task_struct *new_task;
106 current->thread.request.u.thread.proc = idle_proc;
107 current->thread.request.u.thread.arg = (void *) cpu;
108 new_task = copy_process(CLONE_VM | CLONE_IDLETASK, 0, NULL, 0, NULL,
111 panic("copy_process failed in idle_thread, error = %ld",
114 cpu_tasks[cpu] = ((struct cpu_task)
115 { .pid = new_task->thread.mode.tt.extern_pid,
116 .task = new_task } );
117 idle_threads[cpu] = new_task;
118 CHOOSE_MODE(os_write_file(new_task->thread.mode.tt.switch_pipe[1], &c,
120 wake_up_forked_process(new_task);
124 void smp_prepare_cpus(unsigned int maxcpus)
126 struct task_struct *idle;
127 unsigned long waittime;
128 int err, cpu, me = smp_processor_id();
130 cpu_clear(me, cpu_online_map);
131 cpu_set(me, cpu_online_map);
132 cpu_set(me, cpu_callin_map);
134 err = os_pipe(cpu_data[me].ipi_pipe, 1, 1);
136 panic("CPU#0 failed to create IPI pipe, errno = %d", -err);
138 activate_ipi(cpu_data[me].ipi_pipe[0],
139 current->thread.mode.tt.extern_pid);
141 for(cpu = 1; cpu < ncpus; cpu++){
142 printk("Booting processor %d...\n", cpu);
144 idle = idle_thread(cpu);
146 init_idle(idle, cpu);
147 unhash_process(idle);
149 waittime = 200000000;
150 while (waittime-- && !cpu_isset(cpu, cpu_callin_map))
153 if (cpu_isset(cpu, cpu_callin_map))
155 else printk("failed\n");
159 void smp_prepare_boot_cpu(void)
161 cpu_set(smp_processor_id(), cpu_online_map);
164 int __cpu_up(unsigned int cpu)
166 cpu_set(cpu, smp_commenced_mask);
167 while (!cpu_isset(cpu, cpu_online_map))
172 int setup_profiling_timer(unsigned int multiplier)
174 printk(KERN_INFO "setup_profiling_timer\n");
178 void smp_call_function_slave(int cpu);
180 void IPI_handler(int cpu)
185 fd = cpu_data[cpu].ipi_pipe[0];
186 while (os_read_file(fd, &c, 1) == 1) {
189 smp_call_function_slave(cpu);
193 set_tsk_need_resched(current);
197 printk("CPU#%d stopping\n", cpu);
203 printk("CPU#%d received unknown IPI [%c]!\n", cpu, c);
209 int hard_smp_processor_id(void)
211 return(pid_to_processor_id(os_getpid()));
214 static spinlock_t call_lock = SPIN_LOCK_UNLOCKED;
215 static atomic_t scf_started;
216 static atomic_t scf_finished;
217 static void (*func)(void *info);
220 void smp_call_function_slave(int cpu)
222 atomic_inc(&scf_started);
224 atomic_inc(&scf_finished);
227 int smp_call_function(void (*_func)(void *info), void *_info, int nonatomic,
230 int cpus = num_online_cpus() - 1;
236 /* Can deadlock when called with interrupts disabled */
237 WARN_ON(irqs_disabled());
239 spin_lock_bh(&call_lock);
240 atomic_set(&scf_started, 0);
241 atomic_set(&scf_finished, 0);
245 for (i=0;i<NR_CPUS;i++)
246 if((i != current_thread->cpu) &&
247 cpu_isset(i, cpu_online_map))
248 os_write_file(cpu_data[i].ipi_pipe[1], "C", 1);
250 while (atomic_read(&scf_started) != cpus)
254 while (atomic_read(&scf_finished) != cpus)
257 spin_unlock_bh(&call_lock);
264 * Overrides for Emacs so that we follow Linus's tabbing style.
265 * Emacs will notice this stuff at the end of the file and automatically
266 * adjust the settings for this buffer only. This must remain at the end
268 * ---------------------------------------------------------------------------
270 * c-file-style: "linux"