Commit | Line | Data |
---|---|---|
63ae2a94 | 1 | /* |
4c9e1385 | 2 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
3 | * Licensed under the GPL |
4 | */ | |
5 | ||
1da177e4 LT |
6 | #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. */ | |
11 | DEFINE_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" | |
1da177e4 LT |
24 | #include "kern.h" |
25 | #include "irq_user.h" | |
26 | #include "os.h" | |
27 | ||
1da177e4 LT |
28 | /* 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 | */ | |
32 | struct cpuinfo_um cpu_data[NR_CPUS]; | |
33 | ||
34 | /* A statistic, can be a little off */ | |
35 | int num_reschedules_sent = 0; | |
36 | ||
37 | /* Not changed after boot */ | |
38 | struct task_struct *idle_threads[NR_CPUS]; | |
39 | ||
40 | void smp_send_reschedule(int cpu) | |
41 | { | |
a6ea4cce | 42 | os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1); |
1da177e4 LT |
43 | num_reschedules_sent++; |
44 | } | |
45 | ||
46 | void smp_send_stop(void) | |
47 | { | |
48 | int i; | |
49 | ||
50 | printk(KERN_INFO "Stopping all CPUs..."); | |
4c9e1385 JD |
51 | for (i = 0; i < num_online_cpus(); i++) { |
52 | if (i == current_thread->cpu) | |
1da177e4 | 53 | continue; |
a6ea4cce | 54 | os_write_file(cpu_data[i].ipi_pipe[1], "S", 1); |
1da177e4 | 55 | } |
c5d4bb17 | 56 | printk(KERN_CONT "done\n"); |
1da177e4 LT |
57 | } |
58 | ||
59 | static cpumask_t smp_commenced_mask = CPU_MASK_NONE; | |
60 | static cpumask_t cpu_callin_map = CPU_MASK_NONE; | |
61 | ||
62 | static int idle_proc(void *cpup) | |
63 | { | |
64 | int cpu = (int) cpup, err; | |
65 | ||
66 | err = os_pipe(cpu_data[cpu].ipi_pipe, 1, 1); | |
4c9e1385 | 67 | if (err < 0) |
1da177e4 LT |
68 | panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err); |
69 | ||
bf8fde78 | 70 | os_set_fd_async(cpu_data[cpu].ipi_pipe[0]); |
63ae2a94 | 71 | |
1da177e4 LT |
72 | wmb(); |
73 | if (cpu_test_and_set(cpu, cpu_callin_map)) { | |
4c9e1385 | 74 | printk(KERN_ERR "huh, CPU#%d already present??\n", cpu); |
1da177e4 LT |
75 | BUG(); |
76 | } | |
77 | ||
78 | while (!cpu_isset(cpu, smp_commenced_mask)) | |
79 | cpu_relax(); | |
80 | ||
e545a614 | 81 | notify_cpu_starting(cpu); |
1da177e4 LT |
82 | cpu_set(cpu, cpu_online_map); |
83 | default_idle(); | |
dc764e50 | 84 | return 0; |
1da177e4 LT |
85 | } |
86 | ||
87 | static struct task_struct *idle_thread(int cpu) | |
88 | { | |
89 | struct task_struct *new_task; | |
1da177e4 | 90 | |
dc764e50 JD |
91 | current->thread.request.u.thread.proc = idle_proc; |
92 | current->thread.request.u.thread.arg = (void *) cpu; | |
1da177e4 | 93 | new_task = fork_idle(cpu); |
4c9e1385 | 94 | if (IS_ERR(new_task)) |
1da177e4 LT |
95 | panic("copy_process failed in idle_thread, error = %ld", |
96 | PTR_ERR(new_task)); | |
97 | ||
63ae2a94 | 98 | cpu_tasks[cpu] = ((struct cpu_task) |
1da177e4 LT |
99 | { .pid = new_task->thread.mode.tt.extern_pid, |
100 | .task = new_task } ); | |
101 | idle_threads[cpu] = new_task; | |
42fda663 | 102 | panic("skas mode doesn't support SMP"); |
dc764e50 | 103 | return new_task; |
1da177e4 LT |
104 | } |
105 | ||
106 | void 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) | |
a6a01063 | 114 | set_cpu_possible(i, true); |
1da177e4 LT |
115 | |
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); | |
4c9e1385 | 121 | if (err < 0) |
1da177e4 LT |
122 | panic("CPU#0 failed to create IPI pipe, errno = %d", -err); |
123 | ||
bf8fde78 | 124 | os_set_fd_async(cpu_data[me].ipi_pipe[0]); |
1da177e4 | 125 | |
4c9e1385 JD |
126 | for (cpu = 1; cpu < ncpus; cpu++) { |
127 | printk(KERN_INFO "Booting processor %d...\n", cpu); | |
63ae2a94 | 128 | |
1da177e4 LT |
129 | idle = idle_thread(cpu); |
130 | ||
131 | init_idle(idle, cpu); | |
1da177e4 LT |
132 | |
133 | waittime = 200000000; | |
134 | while (waittime-- && !cpu_isset(cpu, cpu_callin_map)) | |
135 | cpu_relax(); | |
136 | ||
c5d4bb17 JD |
137 | printk(KERN_INFO "%s\n", |
138 | cpu_isset(cpu, cpu_calling_map) ? "done" : "failed"); | |
1da177e4 LT |
139 | } |
140 | } | |
141 | ||
142 | void smp_prepare_boot_cpu(void) | |
143 | { | |
144 | cpu_set(smp_processor_id(), cpu_online_map); | |
145 | } | |
146 | ||
147 | int __cpu_up(unsigned int cpu) | |
148 | { | |
149 | cpu_set(cpu, smp_commenced_mask); | |
150 | while (!cpu_isset(cpu, cpu_online_map)) | |
151 | mb(); | |
dc764e50 | 152 | return 0; |
1da177e4 LT |
153 | } |
154 | ||
155 | int setup_profiling_timer(unsigned int multiplier) | |
156 | { | |
157 | printk(KERN_INFO "setup_profiling_timer\n"); | |
dc764e50 | 158 | return 0; |
1da177e4 LT |
159 | } |
160 | ||
161 | void smp_call_function_slave(int cpu); | |
162 | ||
163 | void IPI_handler(int cpu) | |
164 | { | |
165 | unsigned char c; | |
166 | int fd; | |
167 | ||
168 | fd = cpu_data[cpu].ipi_pipe[0]; | |
a6ea4cce | 169 | while (os_read_file(fd, &c, 1) == 1) { |
1da177e4 LT |
170 | switch (c) { |
171 | case 'C': | |
172 | smp_call_function_slave(cpu); | |
173 | break; | |
174 | ||
175 | case 'R': | |
184748cc | 176 | scheduler_ipi(); |
1da177e4 LT |
177 | break; |
178 | ||
179 | case 'S': | |
4c9e1385 JD |
180 | printk(KERN_INFO "CPU#%d stopping\n", cpu); |
181 | while (1) | |
1da177e4 LT |
182 | pause(); |
183 | break; | |
184 | ||
185 | default: | |
4c9e1385 JD |
186 | printk(KERN_ERR "CPU#%d received unknown IPI [%c]!\n", |
187 | cpu, c); | |
1da177e4 LT |
188 | break; |
189 | } | |
190 | } | |
191 | } | |
192 | ||
193 | int hard_smp_processor_id(void) | |
194 | { | |
dc764e50 | 195 | return pid_to_processor_id(os_getpid()); |
1da177e4 LT |
196 | } |
197 | ||
198 | static DEFINE_SPINLOCK(call_lock); | |
199 | static atomic_t scf_started; | |
200 | static atomic_t scf_finished; | |
201 | static void (*func)(void *info); | |
202 | static void *info; | |
203 | ||
204 | void smp_call_function_slave(int cpu) | |
205 | { | |
206 | atomic_inc(&scf_started); | |
207 | (*func)(info); | |
208 | atomic_inc(&scf_finished); | |
209 | } | |
210 | ||
8691e5a8 | 211 | int smp_call_function(void (*_func)(void *info), void *_info, int wait) |
1da177e4 LT |
212 | { |
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) | |
a6ea4cce | 229 | os_write_file(cpu_data[i].ipi_pipe[1], "C", 1); |
1da177e4 LT |
230 | |
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 |