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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Smp support for ppc. | |
3 | * | |
4 | * Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great | |
5 | * deal of code from the sparc and intel versions. | |
6 | * | |
7 | * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu> | |
8 | * | |
9 | */ | |
10 | ||
11 | #include <linux/config.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/smp.h> | |
16 | #include <linux/smp_lock.h> | |
17 | #include <linux/interrupt.h> | |
18 | #include <linux/kernel_stat.h> | |
19 | #include <linux/delay.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/spinlock.h> | |
22 | #include <linux/cache.h> | |
23 | ||
24 | #include <asm/ptrace.h> | |
25 | #include <asm/atomic.h> | |
26 | #include <asm/irq.h> | |
27 | #include <asm/page.h> | |
28 | #include <asm/pgtable.h> | |
29 | #include <asm/io.h> | |
30 | #include <asm/prom.h> | |
31 | #include <asm/smp.h> | |
32 | #include <asm/residual.h> | |
33 | #include <asm/time.h> | |
34 | #include <asm/thread_info.h> | |
35 | #include <asm/tlbflush.h> | |
36 | #include <asm/xmon.h> | |
37 | ||
38 | volatile int smp_commenced; | |
39 | int smp_tb_synchronized; | |
40 | struct cpuinfo_PPC cpu_data[NR_CPUS]; | |
41 | struct klock_info_struct klock_info = { KLOCK_CLEAR, 0 }; | |
42 | atomic_t ipi_recv; | |
43 | atomic_t ipi_sent; | |
44 | cpumask_t cpu_online_map; | |
45 | cpumask_t cpu_possible_map; | |
46 | int smp_hw_index[NR_CPUS]; | |
47 | struct thread_info *secondary_ti; | |
48 | ||
49 | EXPORT_SYMBOL(cpu_online_map); | |
50 | EXPORT_SYMBOL(cpu_possible_map); | |
51 | ||
52 | /* SMP operations for this machine */ | |
53 | static struct smp_ops_t *smp_ops; | |
54 | ||
55 | /* all cpu mappings are 1-1 -- Cort */ | |
56 | volatile unsigned long cpu_callin_map[NR_CPUS]; | |
57 | ||
58 | int start_secondary(void *); | |
59 | void smp_call_function_interrupt(void); | |
60 | static int __smp_call_function(void (*func) (void *info), void *info, | |
61 | int wait, int target); | |
62 | ||
63 | /* Low level assembly function used to backup CPU 0 state */ | |
64 | extern void __save_cpu_setup(void); | |
65 | ||
66 | /* Since OpenPIC has only 4 IPIs, we use slightly different message numbers. | |
67 | * | |
68 | * Make sure this matches openpic_request_IPIs in open_pic.c, or what shows up | |
69 | * in /proc/interrupts will be wrong!!! --Troy */ | |
70 | #define PPC_MSG_CALL_FUNCTION 0 | |
71 | #define PPC_MSG_RESCHEDULE 1 | |
72 | #define PPC_MSG_INVALIDATE_TLB 2 | |
73 | #define PPC_MSG_XMON_BREAK 3 | |
74 | ||
75 | static inline void | |
76 | smp_message_pass(int target, int msg, unsigned long data, int wait) | |
77 | { | |
78 | if (smp_ops){ | |
79 | atomic_inc(&ipi_sent); | |
80 | smp_ops->message_pass(target,msg,data,wait); | |
81 | } | |
82 | } | |
83 | ||
84 | /* | |
85 | * Common functions | |
86 | */ | |
87 | void smp_message_recv(int msg, struct pt_regs *regs) | |
88 | { | |
89 | atomic_inc(&ipi_recv); | |
90 | ||
91 | switch( msg ) { | |
92 | case PPC_MSG_CALL_FUNCTION: | |
93 | smp_call_function_interrupt(); | |
94 | break; | |
95 | case PPC_MSG_RESCHEDULE: | |
96 | set_need_resched(); | |
97 | break; | |
98 | case PPC_MSG_INVALIDATE_TLB: | |
99 | _tlbia(); | |
100 | break; | |
101 | #ifdef CONFIG_XMON | |
102 | case PPC_MSG_XMON_BREAK: | |
103 | xmon(regs); | |
104 | break; | |
105 | #endif /* CONFIG_XMON */ | |
106 | default: | |
107 | printk("SMP %d: smp_message_recv(): unknown msg %d\n", | |
108 | smp_processor_id(), msg); | |
109 | break; | |
110 | } | |
111 | } | |
112 | ||
113 | /* | |
114 | * 750's don't broadcast tlb invalidates so | |
115 | * we have to emulate that behavior. | |
116 | * -- Cort | |
117 | */ | |
118 | void smp_send_tlb_invalidate(int cpu) | |
119 | { | |
120 | if ( PVR_VER(mfspr(SPRN_PVR)) == 8 ) | |
121 | smp_message_pass(MSG_ALL_BUT_SELF, PPC_MSG_INVALIDATE_TLB, 0, 0); | |
122 | } | |
123 | ||
124 | void smp_send_reschedule(int cpu) | |
125 | { | |
126 | /* | |
127 | * This is only used if `cpu' is running an idle task, | |
128 | * so it will reschedule itself anyway... | |
129 | * | |
130 | * This isn't the case anymore since the other CPU could be | |
131 | * sleeping and won't reschedule until the next interrupt (such | |
132 | * as the timer). | |
133 | * -- Cort | |
134 | */ | |
135 | /* This is only used if `cpu' is running an idle task, | |
136 | so it will reschedule itself anyway... */ | |
137 | smp_message_pass(cpu, PPC_MSG_RESCHEDULE, 0, 0); | |
138 | } | |
139 | ||
140 | #ifdef CONFIG_XMON | |
141 | void smp_send_xmon_break(int cpu) | |
142 | { | |
143 | smp_message_pass(cpu, PPC_MSG_XMON_BREAK, 0, 0); | |
144 | } | |
145 | #endif /* CONFIG_XMON */ | |
146 | ||
147 | static void stop_this_cpu(void *dummy) | |
148 | { | |
149 | local_irq_disable(); | |
150 | while (1) | |
151 | ; | |
152 | } | |
153 | ||
154 | void smp_send_stop(void) | |
155 | { | |
156 | smp_call_function(stop_this_cpu, NULL, 1, 0); | |
157 | } | |
158 | ||
159 | /* | |
160 | * Structure and data for smp_call_function(). This is designed to minimise | |
161 | * static memory requirements. It also looks cleaner. | |
162 | * Stolen from the i386 version. | |
163 | */ | |
164 | static DEFINE_SPINLOCK(call_lock); | |
165 | ||
166 | static struct call_data_struct { | |
167 | void (*func) (void *info); | |
168 | void *info; | |
169 | atomic_t started; | |
170 | atomic_t finished; | |
171 | int wait; | |
172 | } *call_data; | |
173 | ||
174 | /* | |
175 | * this function sends a 'generic call function' IPI to all other CPUs | |
176 | * in the system. | |
177 | */ | |
178 | ||
179 | int smp_call_function(void (*func) (void *info), void *info, int nonatomic, | |
180 | int wait) | |
181 | /* | |
182 | * [SUMMARY] Run a function on all other CPUs. | |
183 | * <func> The function to run. This must be fast and non-blocking. | |
184 | * <info> An arbitrary pointer to pass to the function. | |
185 | * <nonatomic> currently unused. | |
186 | * <wait> If true, wait (atomically) until function has completed on other CPUs. | |
187 | * [RETURNS] 0 on success, else a negative status code. Does not return until | |
188 | * remote CPUs are nearly ready to execute <<func>> or are or have executed. | |
189 | * | |
190 | * You must not call this function with disabled interrupts or from a | |
191 | * hardware interrupt handler or from a bottom half handler. | |
192 | */ | |
193 | { | |
194 | /* FIXME: get cpu lock with hotplug cpus, or change this to | |
195 | bitmask. --RR */ | |
196 | if (num_online_cpus() <= 1) | |
197 | return 0; | |
198 | /* Can deadlock when called with interrupts disabled */ | |
199 | WARN_ON(irqs_disabled()); | |
200 | return __smp_call_function(func, info, wait, MSG_ALL_BUT_SELF); | |
201 | } | |
202 | ||
203 | static int __smp_call_function(void (*func) (void *info), void *info, | |
204 | int wait, int target) | |
205 | { | |
206 | struct call_data_struct data; | |
207 | int ret = -1; | |
208 | int timeout; | |
209 | int ncpus = 1; | |
210 | ||
211 | if (target == MSG_ALL_BUT_SELF) | |
212 | ncpus = num_online_cpus() - 1; | |
213 | else if (target == MSG_ALL) | |
214 | ncpus = num_online_cpus(); | |
215 | ||
216 | data.func = func; | |
217 | data.info = info; | |
218 | atomic_set(&data.started, 0); | |
219 | data.wait = wait; | |
220 | if (wait) | |
221 | atomic_set(&data.finished, 0); | |
222 | ||
223 | spin_lock(&call_lock); | |
224 | call_data = &data; | |
225 | /* Send a message to all other CPUs and wait for them to respond */ | |
226 | smp_message_pass(target, PPC_MSG_CALL_FUNCTION, 0, 0); | |
227 | ||
228 | /* Wait for response */ | |
229 | timeout = 1000000; | |
230 | while (atomic_read(&data.started) != ncpus) { | |
231 | if (--timeout == 0) { | |
232 | printk("smp_call_function on cpu %d: other cpus not responding (%d)\n", | |
233 | smp_processor_id(), atomic_read(&data.started)); | |
234 | goto out; | |
235 | } | |
236 | barrier(); | |
237 | udelay(1); | |
238 | } | |
239 | ||
240 | if (wait) { | |
241 | timeout = 1000000; | |
242 | while (atomic_read(&data.finished) != ncpus) { | |
243 | if (--timeout == 0) { | |
244 | printk("smp_call_function on cpu %d: other cpus not finishing (%d/%d)\n", | |
245 | smp_processor_id(), atomic_read(&data.finished), atomic_read(&data.started)); | |
246 | goto out; | |
247 | } | |
248 | barrier(); | |
249 | udelay(1); | |
250 | } | |
251 | } | |
252 | ret = 0; | |
253 | ||
254 | out: | |
255 | spin_unlock(&call_lock); | |
256 | return ret; | |
257 | } | |
258 | ||
259 | void smp_call_function_interrupt(void) | |
260 | { | |
261 | void (*func) (void *info) = call_data->func; | |
262 | void *info = call_data->info; | |
263 | int wait = call_data->wait; | |
264 | ||
265 | /* | |
266 | * Notify initiating CPU that I've grabbed the data and am | |
267 | * about to execute the function | |
268 | */ | |
269 | atomic_inc(&call_data->started); | |
270 | /* | |
271 | * At this point the info structure may be out of scope unless wait==1 | |
272 | */ | |
273 | (*func)(info); | |
274 | if (wait) | |
275 | atomic_inc(&call_data->finished); | |
276 | } | |
277 | ||
278 | static void __devinit smp_store_cpu_info(int id) | |
279 | { | |
280 | struct cpuinfo_PPC *c = &cpu_data[id]; | |
281 | ||
282 | /* assume bogomips are same for everything */ | |
283 | c->loops_per_jiffy = loops_per_jiffy; | |
284 | c->pvr = mfspr(SPRN_PVR); | |
285 | } | |
286 | ||
287 | void __init smp_prepare_cpus(unsigned int max_cpus) | |
288 | { | |
289 | int num_cpus, i; | |
290 | ||
291 | /* Fixup boot cpu */ | |
292 | smp_store_cpu_info(smp_processor_id()); | |
293 | cpu_callin_map[smp_processor_id()] = 1; | |
294 | ||
295 | smp_ops = ppc_md.smp_ops; | |
296 | if (smp_ops == NULL) { | |
297 | printk("SMP not supported on this machine.\n"); | |
298 | return; | |
299 | } | |
300 | ||
301 | /* Probe platform for CPUs: always linear. */ | |
302 | num_cpus = smp_ops->probe(); | |
303 | for (i = 0; i < num_cpus; ++i) | |
304 | cpu_set(i, cpu_possible_map); | |
305 | ||
306 | /* Backup CPU 0 state */ | |
307 | __save_cpu_setup(); | |
308 | ||
309 | if (smp_ops->space_timers) | |
310 | smp_ops->space_timers(num_cpus); | |
311 | } | |
312 | ||
313 | void __devinit smp_prepare_boot_cpu(void) | |
314 | { | |
315 | cpu_set(smp_processor_id(), cpu_online_map); | |
316 | cpu_set(smp_processor_id(), cpu_possible_map); | |
317 | } | |
318 | ||
319 | int __init setup_profiling_timer(unsigned int multiplier) | |
320 | { | |
321 | return 0; | |
322 | } | |
323 | ||
324 | /* Processor coming up starts here */ | |
325 | int __devinit start_secondary(void *unused) | |
326 | { | |
327 | int cpu; | |
328 | ||
329 | atomic_inc(&init_mm.mm_count); | |
330 | current->active_mm = &init_mm; | |
331 | ||
332 | cpu = smp_processor_id(); | |
333 | smp_store_cpu_info(cpu); | |
334 | set_dec(tb_ticks_per_jiffy); | |
335 | cpu_callin_map[cpu] = 1; | |
336 | ||
337 | printk("CPU %i done callin...\n", cpu); | |
338 | smp_ops->setup_cpu(cpu); | |
339 | printk("CPU %i done setup...\n", cpu); | |
340 | local_irq_enable(); | |
341 | smp_ops->take_timebase(); | |
342 | printk("CPU %i done timebase take...\n", cpu); | |
343 | ||
344 | cpu_idle(); | |
345 | return 0; | |
346 | } | |
347 | ||
348 | int __cpu_up(unsigned int cpu) | |
349 | { | |
350 | struct task_struct *p; | |
351 | char buf[32]; | |
352 | int c; | |
353 | ||
354 | /* create a process for the processor */ | |
355 | /* only regs.msr is actually used, and 0 is OK for it */ | |
356 | p = fork_idle(cpu); | |
357 | if (IS_ERR(p)) | |
358 | panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p)); | |
359 | secondary_ti = p->thread_info; | |
360 | p->thread_info->cpu = cpu; | |
361 | ||
362 | /* | |
363 | * There was a cache flush loop here to flush the cache | |
364 | * to memory for the first 8MB of RAM. The cache flush | |
365 | * has been pushed into the kick_cpu function for those | |
366 | * platforms that need it. | |
367 | */ | |
368 | ||
369 | /* wake up cpu */ | |
370 | smp_ops->kick_cpu(cpu); | |
371 | ||
372 | /* | |
373 | * wait to see if the cpu made a callin (is actually up). | |
374 | * use this value that I found through experimentation. | |
375 | * -- Cort | |
376 | */ | |
377 | for (c = 1000; c && !cpu_callin_map[cpu]; c--) | |
378 | udelay(100); | |
379 | ||
380 | if (!cpu_callin_map[cpu]) { | |
381 | sprintf(buf, "didn't find cpu %u", cpu); | |
382 | if (ppc_md.progress) ppc_md.progress(buf, 0x360+cpu); | |
383 | printk("Processor %u is stuck.\n", cpu); | |
384 | return -ENOENT; | |
385 | } | |
386 | ||
387 | sprintf(buf, "found cpu %u", cpu); | |
388 | if (ppc_md.progress) ppc_md.progress(buf, 0x350+cpu); | |
389 | printk("Processor %d found.\n", cpu); | |
390 | ||
391 | smp_ops->give_timebase(); | |
392 | cpu_set(cpu, cpu_online_map); | |
393 | return 0; | |
394 | } | |
395 | ||
396 | void smp_cpus_done(unsigned int max_cpus) | |
397 | { | |
398 | smp_ops->setup_cpu(0); | |
399 | } |