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 | ||
28 | /* CPU online map, set by smp_boot_cpus */ | |
29 | cpumask_t cpu_online_map = CPU_MASK_NONE; | |
30 | cpumask_t cpu_possible_map = CPU_MASK_NONE; | |
31 | ||
32 | EXPORT_SYMBOL(cpu_online_map); | |
33 | EXPORT_SYMBOL(cpu_possible_map); | |
34 | ||
35 | /* Per CPU bogomips and other parameters | |
36 | * The only piece used here is the ipi pipe, which is set before SMP is | |
37 | * started and never changed. | |
38 | */ | |
39 | struct cpuinfo_um cpu_data[NR_CPUS]; | |
40 | ||
41 | /* A statistic, can be a little off */ | |
42 | int num_reschedules_sent = 0; | |
43 | ||
44 | /* Not changed after boot */ | |
45 | struct task_struct *idle_threads[NR_CPUS]; | |
46 | ||
47 | void smp_send_reschedule(int cpu) | |
48 | { | |
a6ea4cce | 49 | os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1); |
1da177e4 LT |
50 | num_reschedules_sent++; |
51 | } | |
52 | ||
53 | void smp_send_stop(void) | |
54 | { | |
55 | int i; | |
56 | ||
57 | printk(KERN_INFO "Stopping all CPUs..."); | |
4c9e1385 JD |
58 | for (i = 0; i < num_online_cpus(); i++) { |
59 | if (i == current_thread->cpu) | |
1da177e4 | 60 | continue; |
a6ea4cce | 61 | os_write_file(cpu_data[i].ipi_pipe[1], "S", 1); |
1da177e4 | 62 | } |
c5d4bb17 | 63 | printk(KERN_CONT "done\n"); |
1da177e4 LT |
64 | } |
65 | ||
66 | static cpumask_t smp_commenced_mask = CPU_MASK_NONE; | |
67 | static cpumask_t cpu_callin_map = CPU_MASK_NONE; | |
68 | ||
69 | static int idle_proc(void *cpup) | |
70 | { | |
71 | int cpu = (int) cpup, err; | |
72 | ||
73 | err = os_pipe(cpu_data[cpu].ipi_pipe, 1, 1); | |
4c9e1385 | 74 | if (err < 0) |
1da177e4 LT |
75 | panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err); |
76 | ||
bf8fde78 | 77 | os_set_fd_async(cpu_data[cpu].ipi_pipe[0]); |
63ae2a94 | 78 | |
1da177e4 LT |
79 | wmb(); |
80 | if (cpu_test_and_set(cpu, cpu_callin_map)) { | |
4c9e1385 | 81 | printk(KERN_ERR "huh, CPU#%d already present??\n", cpu); |
1da177e4 LT |
82 | BUG(); |
83 | } | |
84 | ||
85 | while (!cpu_isset(cpu, smp_commenced_mask)) | |
86 | cpu_relax(); | |
87 | ||
88 | cpu_set(cpu, cpu_online_map); | |
89 | default_idle(); | |
dc764e50 | 90 | return 0; |
1da177e4 LT |
91 | } |
92 | ||
93 | static struct task_struct *idle_thread(int cpu) | |
94 | { | |
95 | struct task_struct *new_task; | |
1da177e4 | 96 | |
dc764e50 JD |
97 | current->thread.request.u.thread.proc = idle_proc; |
98 | current->thread.request.u.thread.arg = (void *) cpu; | |
1da177e4 | 99 | new_task = fork_idle(cpu); |
4c9e1385 | 100 | if (IS_ERR(new_task)) |
1da177e4 LT |
101 | panic("copy_process failed in idle_thread, error = %ld", |
102 | PTR_ERR(new_task)); | |
103 | ||
63ae2a94 | 104 | cpu_tasks[cpu] = ((struct cpu_task) |
1da177e4 LT |
105 | { .pid = new_task->thread.mode.tt.extern_pid, |
106 | .task = new_task } ); | |
107 | idle_threads[cpu] = new_task; | |
42fda663 | 108 | panic("skas mode doesn't support SMP"); |
dc764e50 | 109 | return new_task; |
1da177e4 LT |
110 | } |
111 | ||
112 | void smp_prepare_cpus(unsigned int maxcpus) | |
113 | { | |
114 | struct task_struct *idle; | |
115 | unsigned long waittime; | |
116 | int err, cpu, me = smp_processor_id(); | |
117 | int i; | |
118 | ||
119 | for (i = 0; i < ncpus; ++i) | |
120 | cpu_set(i, cpu_possible_map); | |
121 | ||
122 | cpu_clear(me, cpu_online_map); | |
123 | cpu_set(me, cpu_online_map); | |
124 | cpu_set(me, cpu_callin_map); | |
125 | ||
126 | err = os_pipe(cpu_data[me].ipi_pipe, 1, 1); | |
4c9e1385 | 127 | if (err < 0) |
1da177e4 LT |
128 | panic("CPU#0 failed to create IPI pipe, errno = %d", -err); |
129 | ||
bf8fde78 | 130 | os_set_fd_async(cpu_data[me].ipi_pipe[0]); |
1da177e4 | 131 | |
4c9e1385 JD |
132 | for (cpu = 1; cpu < ncpus; cpu++) { |
133 | printk(KERN_INFO "Booting processor %d...\n", cpu); | |
63ae2a94 | 134 | |
1da177e4 LT |
135 | idle = idle_thread(cpu); |
136 | ||
137 | init_idle(idle, cpu); | |
1da177e4 LT |
138 | |
139 | waittime = 200000000; | |
140 | while (waittime-- && !cpu_isset(cpu, cpu_callin_map)) | |
141 | cpu_relax(); | |
142 | ||
c5d4bb17 JD |
143 | printk(KERN_INFO "%s\n", |
144 | cpu_isset(cpu, cpu_calling_map) ? "done" : "failed"); | |
1da177e4 LT |
145 | } |
146 | } | |
147 | ||
148 | void smp_prepare_boot_cpu(void) | |
149 | { | |
150 | cpu_set(smp_processor_id(), cpu_online_map); | |
151 | } | |
152 | ||
153 | int __cpu_up(unsigned int cpu) | |
154 | { | |
155 | cpu_set(cpu, smp_commenced_mask); | |
156 | while (!cpu_isset(cpu, cpu_online_map)) | |
157 | mb(); | |
dc764e50 | 158 | return 0; |
1da177e4 LT |
159 | } |
160 | ||
161 | int setup_profiling_timer(unsigned int multiplier) | |
162 | { | |
163 | printk(KERN_INFO "setup_profiling_timer\n"); | |
dc764e50 | 164 | return 0; |
1da177e4 LT |
165 | } |
166 | ||
167 | void smp_call_function_slave(int cpu); | |
168 | ||
169 | void IPI_handler(int cpu) | |
170 | { | |
171 | unsigned char c; | |
172 | int fd; | |
173 | ||
174 | fd = cpu_data[cpu].ipi_pipe[0]; | |
a6ea4cce | 175 | while (os_read_file(fd, &c, 1) == 1) { |
1da177e4 LT |
176 | switch (c) { |
177 | case 'C': | |
178 | smp_call_function_slave(cpu); | |
179 | break; | |
180 | ||
181 | case 'R': | |
182 | set_tsk_need_resched(current); | |
183 | break; | |
184 | ||
185 | case 'S': | |
4c9e1385 JD |
186 | printk(KERN_INFO "CPU#%d stopping\n", cpu); |
187 | while (1) | |
1da177e4 LT |
188 | pause(); |
189 | break; | |
190 | ||
191 | default: | |
4c9e1385 JD |
192 | printk(KERN_ERR "CPU#%d received unknown IPI [%c]!\n", |
193 | cpu, c); | |
1da177e4 LT |
194 | break; |
195 | } | |
196 | } | |
197 | } | |
198 | ||
199 | int hard_smp_processor_id(void) | |
200 | { | |
dc764e50 | 201 | return pid_to_processor_id(os_getpid()); |
1da177e4 LT |
202 | } |
203 | ||
204 | static DEFINE_SPINLOCK(call_lock); | |
205 | static atomic_t scf_started; | |
206 | static atomic_t scf_finished; | |
207 | static void (*func)(void *info); | |
208 | static void *info; | |
209 | ||
210 | void smp_call_function_slave(int cpu) | |
211 | { | |
212 | atomic_inc(&scf_started); | |
213 | (*func)(info); | |
214 | atomic_inc(&scf_finished); | |
215 | } | |
216 | ||
8691e5a8 | 217 | int smp_call_function(void (*_func)(void *info), void *_info, int wait) |
1da177e4 LT |
218 | { |
219 | int cpus = num_online_cpus() - 1; | |
220 | int i; | |
221 | ||
222 | if (!cpus) | |
223 | return 0; | |
224 | ||
225 | /* Can deadlock when called with interrupts disabled */ | |
226 | WARN_ON(irqs_disabled()); | |
227 | ||
228 | spin_lock_bh(&call_lock); | |
229 | atomic_set(&scf_started, 0); | |
230 | atomic_set(&scf_finished, 0); | |
231 | func = _func; | |
232 | info = _info; | |
233 | ||
234 | for_each_online_cpu(i) | |
a6ea4cce | 235 | os_write_file(cpu_data[i].ipi_pipe[1], "C", 1); |
1da177e4 LT |
236 | |
237 | while (atomic_read(&scf_started) != cpus) | |
238 | barrier(); | |
239 | ||
240 | if (wait) | |
241 | while (atomic_read(&scf_finished) != cpus) | |
242 | barrier(); | |
243 | ||
244 | spin_unlock_bh(&call_lock); | |
245 | return 0; | |
246 | } | |
247 | ||
248 | #endif |