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Jeff Dike63ae2a92006-03-27 01:14:30 -08001/*
Jeff Dike4c9e1382007-10-16 01:26:54 -07002 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 * Licensed under the GPL
4 */
5
Al Viro37185b32012-10-08 03:27:32 +01006#include <linux/percpu.h>
7#include <asm/pgalloc.h>
8#include <asm/tlb.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07009
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#ifdef CONFIG_SMP
11
Al Viro37185b32012-10-08 03:27:32 +010012#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>
18#include <asm/smp.h>
19#include <asm/processor.h>
20#include <asm/spinlock.h>
21#include <kern.h>
22#include <irq_user.h>
23#include <os.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
Linus Torvalds1da177e2005-04-16 15:20:36 -070025/* 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.
28 */
29struct cpuinfo_um cpu_data[NR_CPUS];
30
31/* A statistic, can be a little off */
32int num_reschedules_sent = 0;
33
34/* Not changed after boot */
35struct task_struct *idle_threads[NR_CPUS];
36
37void smp_send_reschedule(int cpu)
38{
Jeff Dikea6ea4cc2007-05-06 14:51:43 -070039 os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 num_reschedules_sent++;
41}
42
43void smp_send_stop(void)
44{
45 int i;
46
47 printk(KERN_INFO "Stopping all CPUs...");
Jeff Dike4c9e1382007-10-16 01:26:54 -070048 for (i = 0; i < num_online_cpus(); i++) {
49 if (i == current_thread->cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 continue;
Jeff Dikea6ea4cc2007-05-06 14:51:43 -070051 os_write_file(cpu_data[i].ipi_pipe[1], "S", 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 }
Jeff Dikec5d4bb12008-02-04 22:31:14 -080053 printk(KERN_CONT "done\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -070054}
55
56static cpumask_t smp_commenced_mask = CPU_MASK_NONE;
57static cpumask_t cpu_callin_map = CPU_MASK_NONE;
58
59static int idle_proc(void *cpup)
60{
61 int cpu = (int) cpup, err;
62
63 err = os_pipe(cpu_data[cpu].ipi_pipe, 1, 1);
Jeff Dike4c9e1382007-10-16 01:26:54 -070064 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err);
66
Jeff Dikebf8fde72008-02-04 22:31:04 -080067 os_set_fd_async(cpu_data[cpu].ipi_pipe[0]);
Jeff Dike63ae2a92006-03-27 01:14:30 -080068
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 wmb();
70 if (cpu_test_and_set(cpu, cpu_callin_map)) {
Jeff Dike4c9e1382007-10-16 01:26:54 -070071 printk(KERN_ERR "huh, CPU#%d already present??\n", cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 BUG();
73 }
74
75 while (!cpu_isset(cpu, smp_commenced_mask))
76 cpu_relax();
77
Manfred Spraule545a612008-09-07 16:57:22 +020078 notify_cpu_starting(cpu);
Rusty Russell0b5f9c02012-03-29 15:38:30 +103079 set_cpu_online(cpu, true);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 default_idle();
Jeff Dikedc764e52007-05-06 14:51:41 -070081 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070082}
83
84static struct task_struct *idle_thread(int cpu)
85{
86 struct task_struct *new_task;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
Jeff Dikedc764e52007-05-06 14:51:41 -070088 current->thread.request.u.thread.proc = idle_proc;
89 current->thread.request.u.thread.arg = (void *) cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 new_task = fork_idle(cpu);
Jeff Dike4c9e1382007-10-16 01:26:54 -070091 if (IS_ERR(new_task))
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 panic("copy_process failed in idle_thread, error = %ld",
93 PTR_ERR(new_task));
94
Jeff Dike63ae2a92006-03-27 01:14:30 -080095 cpu_tasks[cpu] = ((struct cpu_task)
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 { .pid = new_task->thread.mode.tt.extern_pid,
97 .task = new_task } );
98 idle_threads[cpu] = new_task;
Jeff Dike42fda662007-10-16 01:26:50 -070099 panic("skas mode doesn't support SMP");
Jeff Dikedc764e52007-05-06 14:51:41 -0700100 return new_task;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101}
102
103void smp_prepare_cpus(unsigned int maxcpus)
104{
105 struct task_struct *idle;
106 unsigned long waittime;
107 int err, cpu, me = smp_processor_id();
108 int i;
109
110 for (i = 0; i < ncpus; ++i)
Rusty Russella6a01062009-09-24 09:34:48 -0600111 set_cpu_possible(i, true);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
Rusty Russell0b5f9c02012-03-29 15:38:30 +1030113 set_cpu_online(me, true);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 cpu_set(me, cpu_callin_map);
115
116 err = os_pipe(cpu_data[me].ipi_pipe, 1, 1);
Jeff Dike4c9e1382007-10-16 01:26:54 -0700117 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 panic("CPU#0 failed to create IPI pipe, errno = %d", -err);
119
Jeff Dikebf8fde72008-02-04 22:31:04 -0800120 os_set_fd_async(cpu_data[me].ipi_pipe[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
Jeff Dike4c9e1382007-10-16 01:26:54 -0700122 for (cpu = 1; cpu < ncpus; cpu++) {
123 printk(KERN_INFO "Booting processor %d...\n", cpu);
Jeff Dike63ae2a92006-03-27 01:14:30 -0800124
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 idle = idle_thread(cpu);
126
127 init_idle(idle, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128
129 waittime = 200000000;
130 while (waittime-- && !cpu_isset(cpu, cpu_callin_map))
131 cpu_relax();
132
Jeff Dikec5d4bb12008-02-04 22:31:14 -0800133 printk(KERN_INFO "%s\n",
134 cpu_isset(cpu, cpu_calling_map) ? "done" : "failed");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 }
136}
137
138void smp_prepare_boot_cpu(void)
139{
Rusty Russell0b5f9c02012-03-29 15:38:30 +1030140 set_cpu_online(smp_processor_id(), true);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141}
142
Thomas Gleixner8239c252012-04-20 13:05:42 +0000143int __cpu_up(unsigned int cpu, struct task_struct *tidle)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144{
145 cpu_set(cpu, smp_commenced_mask);
Rusty Russell0b5f9c02012-03-29 15:38:30 +1030146 while (!cpu_online(cpu))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 mb();
Jeff Dikedc764e52007-05-06 14:51:41 -0700148 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149}
150
151int setup_profiling_timer(unsigned int multiplier)
152{
153 printk(KERN_INFO "setup_profiling_timer\n");
Jeff Dikedc764e52007-05-06 14:51:41 -0700154 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155}
156
157void smp_call_function_slave(int cpu);
158
159void IPI_handler(int cpu)
160{
161 unsigned char c;
162 int fd;
163
164 fd = cpu_data[cpu].ipi_pipe[0];
Jeff Dikea6ea4cc2007-05-06 14:51:43 -0700165 while (os_read_file(fd, &c, 1) == 1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 switch (c) {
167 case 'C':
168 smp_call_function_slave(cpu);
169 break;
170
171 case 'R':
Peter Zijlstra184748c2011-04-05 17:23:39 +0200172 scheduler_ipi();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 break;
174
175 case 'S':
Jeff Dike4c9e1382007-10-16 01:26:54 -0700176 printk(KERN_INFO "CPU#%d stopping\n", cpu);
177 while (1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 pause();
179 break;
180
181 default:
Jeff Dike4c9e1382007-10-16 01:26:54 -0700182 printk(KERN_ERR "CPU#%d received unknown IPI [%c]!\n",
183 cpu, c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 break;
185 }
186 }
187}
188
189int hard_smp_processor_id(void)
190{
Jeff Dikedc764e52007-05-06 14:51:41 -0700191 return pid_to_processor_id(os_getpid());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192}
193
194static DEFINE_SPINLOCK(call_lock);
195static atomic_t scf_started;
196static atomic_t scf_finished;
197static void (*func)(void *info);
198static void *info;
199
200void smp_call_function_slave(int cpu)
201{
202 atomic_inc(&scf_started);
203 (*func)(info);
204 atomic_inc(&scf_finished);
205}
206
Jens Axboe8691e5a2008-06-06 11:18:06 +0200207int smp_call_function(void (*_func)(void *info), void *_info, int wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208{
209 int cpus = num_online_cpus() - 1;
210 int i;
211
212 if (!cpus)
213 return 0;
214
215 /* Can deadlock when called with interrupts disabled */
216 WARN_ON(irqs_disabled());
217
218 spin_lock_bh(&call_lock);
219 atomic_set(&scf_started, 0);
220 atomic_set(&scf_finished, 0);
221 func = _func;
222 info = _info;
223
224 for_each_online_cpu(i)
Jeff Dikea6ea4cc2007-05-06 14:51:43 -0700225 os_write_file(cpu_data[i].ipi_pipe[1], "C", 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
227 while (atomic_read(&scf_started) != cpus)
228 barrier();
229
230 if (wait)
231 while (atomic_read(&scf_finished) != cpus)
232 barrier();
233
234 spin_unlock_bh(&call_lock);
235 return 0;
236}
237
238#endif