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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm/kernel/smp.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/arm/kernel/smp.c')
-rw-r--r--arch/arm/kernel/smp.c396
1 files changed, 396 insertions, 0 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
new file mode 100644
index 000000000000..ecc8c3332408
--- /dev/null
+++ b/arch/arm/kernel/smp.c
@@ -0,0 +1,396 @@
1/*
2 * linux/arch/arm/kernel/smp.c
3 *
4 * Copyright (C) 2002 ARM Limited, All Rights Reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/config.h>
11#include <linux/delay.h>
12#include <linux/init.h>
13#include <linux/spinlock.h>
14#include <linux/sched.h>
15#include <linux/interrupt.h>
16#include <linux/cache.h>
17#include <linux/profile.h>
18#include <linux/errno.h>
19#include <linux/mm.h>
20#include <linux/cpu.h>
21#include <linux/smp.h>
22#include <linux/seq_file.h>
23
24#include <asm/atomic.h>
25#include <asm/cacheflush.h>
26#include <asm/cpu.h>
27#include <asm/processor.h>
28#include <asm/tlbflush.h>
29#include <asm/ptrace.h>
30
31/*
32 * bitmask of present and online CPUs.
33 * The present bitmask indicates that the CPU is physically present.
34 * The online bitmask indicates that the CPU is up and running.
35 */
36cpumask_t cpu_present_mask;
37cpumask_t cpu_online_map;
38
39/*
40 * structures for inter-processor calls
41 * - A collection of single bit ipi messages.
42 */
43struct ipi_data {
44 spinlock_t lock;
45 unsigned long ipi_count;
46 unsigned long bits;
47};
48
49static DEFINE_PER_CPU(struct ipi_data, ipi_data) = {
50 .lock = SPIN_LOCK_UNLOCKED,
51};
52
53enum ipi_msg_type {
54 IPI_TIMER,
55 IPI_RESCHEDULE,
56 IPI_CALL_FUNC,
57 IPI_CPU_STOP,
58};
59
60struct smp_call_struct {
61 void (*func)(void *info);
62 void *info;
63 int wait;
64 cpumask_t pending;
65 cpumask_t unfinished;
66};
67
68static struct smp_call_struct * volatile smp_call_function_data;
69static DEFINE_SPINLOCK(smp_call_function_lock);
70
71int __init __cpu_up(unsigned int cpu)
72{
73 struct task_struct *idle;
74 int ret;
75
76 /*
77 * Spawn a new process manually. Grab a pointer to
78 * its task struct so we can mess with it
79 */
80 idle = fork_idle(cpu);
81 if (IS_ERR(idle)) {
82 printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
83 return PTR_ERR(idle);
84 }
85
86 /*
87 * Now bring the CPU into our world.
88 */
89 ret = boot_secondary(cpu, idle);
90 if (ret) {
91 printk(KERN_CRIT "cpu_up: processor %d failed to boot\n", cpu);
92 /*
93 * FIXME: We need to clean up the new idle thread. --rmk
94 */
95 }
96
97 return ret;
98}
99
100/*
101 * Called by both boot and secondaries to move global data into
102 * per-processor storage.
103 */
104void __init smp_store_cpu_info(unsigned int cpuid)
105{
106 struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpuid);
107
108 cpu_info->loops_per_jiffy = loops_per_jiffy;
109}
110
111void __init smp_cpus_done(unsigned int max_cpus)
112{
113 int cpu;
114 unsigned long bogosum = 0;
115
116 for_each_online_cpu(cpu)
117 bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy;
118
119 printk(KERN_INFO "SMP: Total of %d processors activated "
120 "(%lu.%02lu BogoMIPS).\n",
121 num_online_cpus(),
122 bogosum / (500000/HZ),
123 (bogosum / (5000/HZ)) % 100);
124}
125
126void __init smp_prepare_boot_cpu(void)
127{
128 unsigned int cpu = smp_processor_id();
129
130 cpu_set(cpu, cpu_present_mask);
131 cpu_set(cpu, cpu_online_map);
132}
133
134static void send_ipi_message(cpumask_t callmap, enum ipi_msg_type msg)
135{
136 unsigned long flags;
137 unsigned int cpu;
138
139 local_irq_save(flags);
140
141 for_each_cpu_mask(cpu, callmap) {
142 struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
143
144 spin_lock(&ipi->lock);
145 ipi->bits |= 1 << msg;
146 spin_unlock(&ipi->lock);
147 }
148
149 /*
150 * Call the platform specific cross-CPU call function.
151 */
152 smp_cross_call(callmap);
153
154 local_irq_restore(flags);
155}
156
157/*
158 * You must not call this function with disabled interrupts, from a
159 * hardware interrupt handler, nor from a bottom half handler.
160 */
161int smp_call_function_on_cpu(void (*func)(void *info), void *info, int retry,
162 int wait, cpumask_t callmap)
163{
164 struct smp_call_struct data;
165 unsigned long timeout;
166 int ret = 0;
167
168 data.func = func;
169 data.info = info;
170 data.wait = wait;
171
172 cpu_clear(smp_processor_id(), callmap);
173 if (cpus_empty(callmap))
174 goto out;
175
176 data.pending = callmap;
177 if (wait)
178 data.unfinished = callmap;
179
180 /*
181 * try to get the mutex on smp_call_function_data
182 */
183 spin_lock(&smp_call_function_lock);
184 smp_call_function_data = &data;
185
186 send_ipi_message(callmap, IPI_CALL_FUNC);
187
188 timeout = jiffies + HZ;
189 while (!cpus_empty(data.pending) && time_before(jiffies, timeout))
190 barrier();
191
192 /*
193 * did we time out?
194 */
195 if (!cpus_empty(data.pending)) {
196 /*
197 * this may be causing our panic - report it
198 */
199 printk(KERN_CRIT
200 "CPU%u: smp_call_function timeout for %p(%p)\n"
201 " callmap %lx pending %lx, %swait\n",
202 smp_processor_id(), func, info, callmap, data.pending,
203 wait ? "" : "no ");
204
205 /*
206 * TRACE
207 */
208 timeout = jiffies + (5 * HZ);
209 while (!cpus_empty(data.pending) && time_before(jiffies, timeout))
210 barrier();
211
212 if (cpus_empty(data.pending))
213 printk(KERN_CRIT " RESOLVED\n");
214 else
215 printk(KERN_CRIT " STILL STUCK\n");
216 }
217
218 /*
219 * whatever happened, we're done with the data, so release it
220 */
221 smp_call_function_data = NULL;
222 spin_unlock(&smp_call_function_lock);
223
224 if (!cpus_empty(data.pending)) {
225 ret = -ETIMEDOUT;
226 goto out;
227 }
228
229 if (wait)
230 while (!cpus_empty(data.unfinished))
231 barrier();
232 out:
233
234 return 0;
235}
236
237int smp_call_function(void (*func)(void *info), void *info, int retry,
238 int wait)
239{
240 return smp_call_function_on_cpu(func, info, retry, wait,
241 cpu_online_map);
242}
243
244void show_ipi_list(struct seq_file *p)
245{
246 unsigned int cpu;
247
248 seq_puts(p, "IPI:");
249
250 for_each_online_cpu(cpu)
251 seq_printf(p, " %10lu", per_cpu(ipi_data, cpu).ipi_count);
252
253 seq_putc(p, '\n');
254}
255
256static void ipi_timer(struct pt_regs *regs)
257{
258 int user = user_mode(regs);
259
260 irq_enter();
261 profile_tick(CPU_PROFILING, regs);
262 update_process_times(user);
263 irq_exit();
264}
265
266/*
267 * ipi_call_function - handle IPI from smp_call_function()
268 *
269 * Note that we copy data out of the cross-call structure and then
270 * let the caller know that we're here and have done with their data
271 */
272static void ipi_call_function(unsigned int cpu)
273{
274 struct smp_call_struct *data = smp_call_function_data;
275 void (*func)(void *info) = data->func;
276 void *info = data->info;
277 int wait = data->wait;
278
279 cpu_clear(cpu, data->pending);
280
281 func(info);
282
283 if (wait)
284 cpu_clear(cpu, data->unfinished);
285}
286
287static DEFINE_SPINLOCK(stop_lock);
288
289/*
290 * ipi_cpu_stop - handle IPI from smp_send_stop()
291 */
292static void ipi_cpu_stop(unsigned int cpu)
293{
294 spin_lock(&stop_lock);
295 printk(KERN_CRIT "CPU%u: stopping\n", cpu);
296 dump_stack();
297 spin_unlock(&stop_lock);
298
299 cpu_clear(cpu, cpu_online_map);
300
301 local_fiq_disable();
302 local_irq_disable();
303
304 while (1)
305 cpu_relax();
306}
307
308/*
309 * Main handler for inter-processor interrupts
310 *
311 * For ARM, the ipimask now only identifies a single
312 * category of IPI (Bit 1 IPIs have been replaced by a
313 * different mechanism):
314 *
315 * Bit 0 - Inter-processor function call
316 */
317void do_IPI(struct pt_regs *regs)
318{
319 unsigned int cpu = smp_processor_id();
320 struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
321
322 ipi->ipi_count++;
323
324 for (;;) {
325 unsigned long msgs;
326
327 spin_lock(&ipi->lock);
328 msgs = ipi->bits;
329 ipi->bits = 0;
330 spin_unlock(&ipi->lock);
331
332 if (!msgs)
333 break;
334
335 do {
336 unsigned nextmsg;
337
338 nextmsg = msgs & -msgs;
339 msgs &= ~nextmsg;
340 nextmsg = ffz(~nextmsg);
341
342 switch (nextmsg) {
343 case IPI_TIMER:
344 ipi_timer(regs);
345 break;
346
347 case IPI_RESCHEDULE:
348 /*
349 * nothing more to do - eveything is
350 * done on the interrupt return path
351 */
352 break;
353
354 case IPI_CALL_FUNC:
355 ipi_call_function(cpu);
356 break;
357
358 case IPI_CPU_STOP:
359 ipi_cpu_stop(cpu);
360 break;
361
362 default:
363 printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n",
364 cpu, nextmsg);
365 break;
366 }
367 } while (msgs);
368 }
369}
370
371void smp_send_reschedule(int cpu)
372{
373 send_ipi_message(cpumask_of_cpu(cpu), IPI_RESCHEDULE);
374}
375
376void smp_send_timer(void)
377{
378 cpumask_t mask = cpu_online_map;
379 cpu_clear(smp_processor_id(), mask);
380 send_ipi_message(mask, IPI_TIMER);
381}
382
383void smp_send_stop(void)
384{
385 cpumask_t mask = cpu_online_map;
386 cpu_clear(smp_processor_id(), mask);
387 send_ipi_message(mask, IPI_CPU_STOP);
388}
389
390/*
391 * not supported here
392 */
393int __init setup_profiling_timer(unsigned int multiplier)
394{
395 return -EINVAL;
396}