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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
Linus Torvalds1da177e2005-04-16 15:20:36 -07006#include "linux/percpu.h"
7#include "asm/pgalloc.h"
8#include "asm/tlb.h"
9
10/* For some reason, mmu_gathers are referenced when CONFIG_SMP is off. */
11DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
12
13#ifdef CONFIG_SMP
14
15#include "linux/sched.h"
16#include "linux/module.h"
17#include "linux/threads.h"
18#include "linux/interrupt.h"
19#include "linux/err.h"
20#include "linux/hardirq.h"
21#include "asm/smp.h"
22#include "asm/processor.h"
23#include "asm/spinlock.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include "kern.h"
25#include "irq_user.h"
26#include "os.h"
27
Linus Torvalds1da177e2005-04-16 15:20:36 -070028/* Per CPU bogomips and other parameters
29 * The only piece used here is the ipi pipe, which is set before SMP is
30 * started and never changed.
31 */
32struct cpuinfo_um cpu_data[NR_CPUS];
33
34/* A statistic, can be a little off */
35int num_reschedules_sent = 0;
36
37/* Not changed after boot */
38struct task_struct *idle_threads[NR_CPUS];
39
40void smp_send_reschedule(int cpu)
41{
Jeff Dikea6ea4cc2007-05-06 14:51:43 -070042 os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 num_reschedules_sent++;
44}
45
46void smp_send_stop(void)
47{
48 int i;
49
50 printk(KERN_INFO "Stopping all CPUs...");
Jeff Dike4c9e1382007-10-16 01:26:54 -070051 for (i = 0; i < num_online_cpus(); i++) {
52 if (i == current_thread->cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 continue;
Jeff Dikea6ea4cc2007-05-06 14:51:43 -070054 os_write_file(cpu_data[i].ipi_pipe[1], "S", 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 }
Jeff Dikec5d4bb12008-02-04 22:31:14 -080056 printk(KERN_CONT "done\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -070057}
58
59static cpumask_t smp_commenced_mask = CPU_MASK_NONE;
60static cpumask_t cpu_callin_map = CPU_MASK_NONE;
61
62static int idle_proc(void *cpup)
63{
64 int cpu = (int) cpup, err;
65
66 err = os_pipe(cpu_data[cpu].ipi_pipe, 1, 1);
Jeff Dike4c9e1382007-10-16 01:26:54 -070067 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err);
69
Jeff Dikebf8fde72008-02-04 22:31:04 -080070 os_set_fd_async(cpu_data[cpu].ipi_pipe[0]);
Jeff Dike63ae2a92006-03-27 01:14:30 -080071
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 wmb();
73 if (cpu_test_and_set(cpu, cpu_callin_map)) {
Jeff Dike4c9e1382007-10-16 01:26:54 -070074 printk(KERN_ERR "huh, CPU#%d already present??\n", cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 BUG();
76 }
77
78 while (!cpu_isset(cpu, smp_commenced_mask))
79 cpu_relax();
80
Manfred Spraule545a612008-09-07 16:57:22 +020081 notify_cpu_starting(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 cpu_set(cpu, cpu_online_map);
83 default_idle();
Jeff Dikedc764e52007-05-06 14:51:41 -070084 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070085}
86
87static struct task_struct *idle_thread(int cpu)
88{
89 struct task_struct *new_task;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
Jeff Dikedc764e52007-05-06 14:51:41 -070091 current->thread.request.u.thread.proc = idle_proc;
92 current->thread.request.u.thread.arg = (void *) cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 new_task = fork_idle(cpu);
Jeff Dike4c9e1382007-10-16 01:26:54 -070094 if (IS_ERR(new_task))
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 panic("copy_process failed in idle_thread, error = %ld",
96 PTR_ERR(new_task));
97
Jeff Dike63ae2a92006-03-27 01:14:30 -080098 cpu_tasks[cpu] = ((struct cpu_task)
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 { .pid = new_task->thread.mode.tt.extern_pid,
100 .task = new_task } );
101 idle_threads[cpu] = new_task;
Jeff Dike42fda662007-10-16 01:26:50 -0700102 panic("skas mode doesn't support SMP");
Jeff Dikedc764e52007-05-06 14:51:41 -0700103 return new_task;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104}
105
106void smp_prepare_cpus(unsigned int maxcpus)
107{
108 struct task_struct *idle;
109 unsigned long waittime;
110 int err, cpu, me = smp_processor_id();
111 int i;
112
113 for (i = 0; i < ncpus; ++i)
Rusty Russella6a01062009-09-24 09:34:48 -0600114 set_cpu_possible(i, true);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115
116 cpu_clear(me, cpu_online_map);
117 cpu_set(me, cpu_online_map);
118 cpu_set(me, cpu_callin_map);
119
120 err = os_pipe(cpu_data[me].ipi_pipe, 1, 1);
Jeff Dike4c9e1382007-10-16 01:26:54 -0700121 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 panic("CPU#0 failed to create IPI pipe, errno = %d", -err);
123
Jeff Dikebf8fde72008-02-04 22:31:04 -0800124 os_set_fd_async(cpu_data[me].ipi_pipe[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
Jeff Dike4c9e1382007-10-16 01:26:54 -0700126 for (cpu = 1; cpu < ncpus; cpu++) {
127 printk(KERN_INFO "Booting processor %d...\n", cpu);
Jeff Dike63ae2a92006-03-27 01:14:30 -0800128
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 idle = idle_thread(cpu);
130
131 init_idle(idle, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
133 waittime = 200000000;
134 while (waittime-- && !cpu_isset(cpu, cpu_callin_map))
135 cpu_relax();
136
Jeff Dikec5d4bb12008-02-04 22:31:14 -0800137 printk(KERN_INFO "%s\n",
138 cpu_isset(cpu, cpu_calling_map) ? "done" : "failed");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 }
140}
141
142void smp_prepare_boot_cpu(void)
143{
144 cpu_set(smp_processor_id(), cpu_online_map);
145}
146
147int __cpu_up(unsigned int cpu)
148{
149 cpu_set(cpu, smp_commenced_mask);
150 while (!cpu_isset(cpu, cpu_online_map))
151 mb();
Jeff Dikedc764e52007-05-06 14:51:41 -0700152 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153}
154
155int setup_profiling_timer(unsigned int multiplier)
156{
157 printk(KERN_INFO "setup_profiling_timer\n");
Jeff Dikedc764e52007-05-06 14:51:41 -0700158 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159}
160
161void smp_call_function_slave(int cpu);
162
163void IPI_handler(int cpu)
164{
165 unsigned char c;
166 int fd;
167
168 fd = cpu_data[cpu].ipi_pipe[0];
Jeff Dikea6ea4cc2007-05-06 14:51:43 -0700169 while (os_read_file(fd, &c, 1) == 1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 switch (c) {
171 case 'C':
172 smp_call_function_slave(cpu);
173 break;
174
175 case 'R':
176 set_tsk_need_resched(current);
177 break;
178
179 case 'S':
Jeff Dike4c9e1382007-10-16 01:26:54 -0700180 printk(KERN_INFO "CPU#%d stopping\n", cpu);
181 while (1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 pause();
183 break;
184
185 default:
Jeff Dike4c9e1382007-10-16 01:26:54 -0700186 printk(KERN_ERR "CPU#%d received unknown IPI [%c]!\n",
187 cpu, c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 break;
189 }
190 }
191}
192
193int hard_smp_processor_id(void)
194{
Jeff Dikedc764e52007-05-06 14:51:41 -0700195 return pid_to_processor_id(os_getpid());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196}
197
198static DEFINE_SPINLOCK(call_lock);
199static atomic_t scf_started;
200static atomic_t scf_finished;
201static void (*func)(void *info);
202static void *info;
203
204void smp_call_function_slave(int cpu)
205{
206 atomic_inc(&scf_started);
207 (*func)(info);
208 atomic_inc(&scf_finished);
209}
210
Jens Axboe8691e5a2008-06-06 11:18:06 +0200211int smp_call_function(void (*_func)(void *info), void *_info, int wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212{
213 int cpus = num_online_cpus() - 1;
214 int i;
215
216 if (!cpus)
217 return 0;
218
219 /* Can deadlock when called with interrupts disabled */
220 WARN_ON(irqs_disabled());
221
222 spin_lock_bh(&call_lock);
223 atomic_set(&scf_started, 0);
224 atomic_set(&scf_finished, 0);
225 func = _func;
226 info = _info;
227
228 for_each_online_cpu(i)
Jeff Dikea6ea4cc2007-05-06 14:51:43 -0700229 os_write_file(cpu_data[i].ipi_pipe[1], "C", 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230
231 while (atomic_read(&scf_started) != cpus)
232 barrier();
233
234 if (wait)
235 while (atomic_read(&scf_finished) != cpus)
236 barrier();
237
238 spin_unlock_bh(&call_lock);
239 return 0;
240}
241
242#endif