2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
6 #include "linux/percpu.h"
7 #include "asm/pgalloc.h"
12 #include "linux/sched.h"
13 #include "linux/module.h"
14 #include "linux/threads.h"
15 #include "linux/interrupt.h"
16 #include "linux/err.h"
17 #include "linux/hardirq.h"
19 #include "asm/processor.h"
20 #include "asm/spinlock.h"
25 /* Per CPU bogomips and other parameters
26 * The only piece used here is the ipi pipe, which is set before SMP is
27 * started and never changed.
29 struct cpuinfo_um cpu_data[NR_CPUS];
31 /* A statistic, can be a little off */
32 int num_reschedules_sent = 0;
34 /* Not changed after boot */
35 struct task_struct *idle_threads[NR_CPUS];
37 void smp_send_reschedule(int cpu)
39 os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1);
40 num_reschedules_sent++;
43 void smp_send_stop(void)
47 printk(KERN_INFO "Stopping all CPUs...");
48 for (i = 0; i < num_online_cpus(); i++) {
49 if (i == current_thread->cpu)
51 os_write_file(cpu_data[i].ipi_pipe[1], "S", 1);
53 printk(KERN_CONT "done\n");
56 static cpumask_t smp_commenced_mask = CPU_MASK_NONE;
57 static cpumask_t cpu_callin_map = CPU_MASK_NONE;
59 static int idle_proc(void *cpup)
61 int cpu = (int) cpup, err;
63 err = os_pipe(cpu_data[cpu].ipi_pipe, 1, 1);
65 panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err);
67 os_set_fd_async(cpu_data[cpu].ipi_pipe[0]);
70 if (cpu_test_and_set(cpu, cpu_callin_map)) {
71 printk(KERN_ERR "huh, CPU#%d already present??\n", cpu);
75 while (!cpu_isset(cpu, smp_commenced_mask))
78 notify_cpu_starting(cpu);
79 cpu_set(cpu, cpu_online_map);
84 static struct task_struct *idle_thread(int cpu)
86 struct task_struct *new_task;
88 current->thread.request.u.thread.proc = idle_proc;
89 current->thread.request.u.thread.arg = (void *) cpu;
90 new_task = fork_idle(cpu);
92 panic("copy_process failed in idle_thread, error = %ld",
95 cpu_tasks[cpu] = ((struct cpu_task)
96 { .pid = new_task->thread.mode.tt.extern_pid,
98 idle_threads[cpu] = new_task;
99 panic("skas mode doesn't support SMP");
103 void smp_prepare_cpus(unsigned int maxcpus)
105 struct task_struct *idle;
106 unsigned long waittime;
107 int err, cpu, me = smp_processor_id();
110 for (i = 0; i < ncpus; ++i)
111 set_cpu_possible(i, true);
113 cpu_clear(me, cpu_online_map);
114 cpu_set(me, cpu_online_map);
115 cpu_set(me, cpu_callin_map);
117 err = os_pipe(cpu_data[me].ipi_pipe, 1, 1);
119 panic("CPU#0 failed to create IPI pipe, errno = %d", -err);
121 os_set_fd_async(cpu_data[me].ipi_pipe[0]);
123 for (cpu = 1; cpu < ncpus; cpu++) {
124 printk(KERN_INFO "Booting processor %d...\n", cpu);
126 idle = idle_thread(cpu);
128 init_idle(idle, cpu);
130 waittime = 200000000;
131 while (waittime-- && !cpu_isset(cpu, cpu_callin_map))
134 printk(KERN_INFO "%s\n",
135 cpu_isset(cpu, cpu_calling_map) ? "done" : "failed");
139 void smp_prepare_boot_cpu(void)
141 cpu_set(smp_processor_id(), cpu_online_map);
144 int __cpu_up(unsigned int cpu)
146 cpu_set(cpu, smp_commenced_mask);
147 while (!cpu_isset(cpu, cpu_online_map))
152 int setup_profiling_timer(unsigned int multiplier)
154 printk(KERN_INFO "setup_profiling_timer\n");
158 void smp_call_function_slave(int cpu);
160 void IPI_handler(int cpu)
165 fd = cpu_data[cpu].ipi_pipe[0];
166 while (os_read_file(fd, &c, 1) == 1) {
169 smp_call_function_slave(cpu);
177 printk(KERN_INFO "CPU#%d stopping\n", cpu);
183 printk(KERN_ERR "CPU#%d received unknown IPI [%c]!\n",
190 int hard_smp_processor_id(void)
192 return pid_to_processor_id(os_getpid());
195 static DEFINE_SPINLOCK(call_lock);
196 static atomic_t scf_started;
197 static atomic_t scf_finished;
198 static void (*func)(void *info);
201 void smp_call_function_slave(int cpu)
203 atomic_inc(&scf_started);
205 atomic_inc(&scf_finished);
208 int smp_call_function(void (*_func)(void *info), void *_info, int wait)
210 int cpus = num_online_cpus() - 1;
216 /* Can deadlock when called with interrupts disabled */
217 WARN_ON(irqs_disabled());
219 spin_lock_bh(&call_lock);
220 atomic_set(&scf_started, 0);
221 atomic_set(&scf_finished, 0);
225 for_each_online_cpu(i)
226 os_write_file(cpu_data[i].ipi_pipe[1], "C", 1);
228 while (atomic_read(&scf_started) != cpus)
232 while (atomic_read(&scf_finished) != cpus)
235 spin_unlock_bh(&call_lock);