Merge tag 'sh-for-linus' of git://github.com/pmundt/linux-sh
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / parisc / kernel / smp.c
1 /*
2 ** SMP Support
3 **
4 ** Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
5 ** Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
6 ** Copyright (C) 2001,2004 Grant Grundler <grundler@parisc-linux.org>
7 **
8 ** Lots of stuff stolen from arch/alpha/kernel/smp.c
9 ** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^)
10 **
11 ** Thanks to John Curry and Ullas Ponnadi. I learned a lot from their work.
12 ** -grant (1/12/2001)
13 **
14 ** This program is free software; you can redistribute it and/or modify
15 ** it under the terms of the GNU General Public License as published by
16 ** the Free Software Foundation; either version 2 of the License, or
17 ** (at your option) any later version.
18 */
19 #include <linux/types.h>
20 #include <linux/spinlock.h>
21
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/sched.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/smp.h>
28 #include <linux/kernel_stat.h>
29 #include <linux/mm.h>
30 #include <linux/err.h>
31 #include <linux/delay.h>
32 #include <linux/bitops.h>
33 #include <linux/ftrace.h>
34
35 #include <linux/atomic.h>
36 #include <asm/current.h>
37 #include <asm/delay.h>
38 #include <asm/tlbflush.h>
39
40 #include <asm/io.h>
41 #include <asm/irq.h> /* for CPU_IRQ_REGION and friends */
42 #include <asm/mmu_context.h>
43 #include <asm/page.h>
44 #include <asm/pgtable.h>
45 #include <asm/pgalloc.h>
46 #include <asm/processor.h>
47 #include <asm/ptrace.h>
48 #include <asm/unistd.h>
49 #include <asm/cacheflush.h>
50
51 #undef DEBUG_SMP
52 #ifdef DEBUG_SMP
53 static int smp_debug_lvl = 0;
54 #define smp_debug(lvl, printargs...) \
55 if (lvl >= smp_debug_lvl) \
56 printk(printargs);
57 #else
58 #define smp_debug(lvl, ...) do { } while(0)
59 #endif /* DEBUG_SMP */
60
61 volatile struct task_struct *smp_init_current_idle_task;
62
63 /* track which CPU is booting */
64 static volatile int cpu_now_booting __cpuinitdata;
65
66 static int parisc_max_cpus __cpuinitdata = 1;
67
68 static DEFINE_PER_CPU(spinlock_t, ipi_lock);
69
70 enum ipi_message_type {
71 IPI_NOP=0,
72 IPI_RESCHEDULE=1,
73 IPI_CALL_FUNC,
74 IPI_CALL_FUNC_SINGLE,
75 IPI_CPU_START,
76 IPI_CPU_STOP,
77 IPI_CPU_TEST
78 };
79
80
81 /********** SMP inter processor interrupt and communication routines */
82
83 #undef PER_CPU_IRQ_REGION
84 #ifdef PER_CPU_IRQ_REGION
85 /* XXX REVISIT Ignore for now.
86 ** *May* need this "hook" to register IPI handler
87 ** once we have perCPU ExtIntr switch tables.
88 */
89 static void
90 ipi_init(int cpuid)
91 {
92 #error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region
93
94 if(cpu_online(cpuid) )
95 {
96 switch_to_idle_task(current);
97 }
98
99 return;
100 }
101 #endif
102
103
104 /*
105 ** Yoink this CPU from the runnable list...
106 **
107 */
108 static void
109 halt_processor(void)
110 {
111 /* REVISIT : redirect I/O Interrupts to another CPU? */
112 /* REVISIT : does PM *know* this CPU isn't available? */
113 set_cpu_online(smp_processor_id(), false);
114 local_irq_disable();
115 for (;;)
116 ;
117 }
118
119
120 irqreturn_t __irq_entry
121 ipi_interrupt(int irq, void *dev_id)
122 {
123 int this_cpu = smp_processor_id();
124 struct cpuinfo_parisc *p = &per_cpu(cpu_data, this_cpu);
125 unsigned long ops;
126 unsigned long flags;
127
128 /* Count this now; we may make a call that never returns. */
129 p->ipi_count++;
130
131 mb(); /* Order interrupt and bit testing. */
132
133 for (;;) {
134 spinlock_t *lock = &per_cpu(ipi_lock, this_cpu);
135 spin_lock_irqsave(lock, flags);
136 ops = p->pending_ipi;
137 p->pending_ipi = 0;
138 spin_unlock_irqrestore(lock, flags);
139
140 mb(); /* Order bit clearing and data access. */
141
142 if (!ops)
143 break;
144
145 while (ops) {
146 unsigned long which = ffz(~ops);
147
148 ops &= ~(1 << which);
149
150 switch (which) {
151 case IPI_NOP:
152 smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu);
153 break;
154
155 case IPI_RESCHEDULE:
156 smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
157 scheduler_ipi();
158 break;
159
160 case IPI_CALL_FUNC:
161 smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu);
162 generic_smp_call_function_interrupt();
163 break;
164
165 case IPI_CALL_FUNC_SINGLE:
166 smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC_SINGLE\n", this_cpu);
167 generic_smp_call_function_single_interrupt();
168 break;
169
170 case IPI_CPU_START:
171 smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu);
172 break;
173
174 case IPI_CPU_STOP:
175 smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu);
176 halt_processor();
177 break;
178
179 case IPI_CPU_TEST:
180 smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu);
181 break;
182
183 default:
184 printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
185 this_cpu, which);
186 return IRQ_NONE;
187 } /* Switch */
188 /* let in any pending interrupts */
189 local_irq_enable();
190 local_irq_disable();
191 } /* while (ops) */
192 }
193 return IRQ_HANDLED;
194 }
195
196
197 static inline void
198 ipi_send(int cpu, enum ipi_message_type op)
199 {
200 struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpu);
201 spinlock_t *lock = &per_cpu(ipi_lock, cpu);
202 unsigned long flags;
203
204 spin_lock_irqsave(lock, flags);
205 p->pending_ipi |= 1 << op;
206 gsc_writel(IPI_IRQ - CPU_IRQ_BASE, p->hpa);
207 spin_unlock_irqrestore(lock, flags);
208 }
209
210 static void
211 send_IPI_mask(const struct cpumask *mask, enum ipi_message_type op)
212 {
213 int cpu;
214
215 for_each_cpu(cpu, mask)
216 ipi_send(cpu, op);
217 }
218
219 static inline void
220 send_IPI_single(int dest_cpu, enum ipi_message_type op)
221 {
222 BUG_ON(dest_cpu == NO_PROC_ID);
223
224 ipi_send(dest_cpu, op);
225 }
226
227 static inline void
228 send_IPI_allbutself(enum ipi_message_type op)
229 {
230 int i;
231
232 for_each_online_cpu(i) {
233 if (i != smp_processor_id())
234 send_IPI_single(i, op);
235 }
236 }
237
238
239 inline void
240 smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }
241
242 static inline void
243 smp_send_start(void) { send_IPI_allbutself(IPI_CPU_START); }
244
245 void
246 smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
247
248 void
249 smp_send_all_nop(void)
250 {
251 send_IPI_allbutself(IPI_NOP);
252 }
253
254 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
255 {
256 send_IPI_mask(mask, IPI_CALL_FUNC);
257 }
258
259 void arch_send_call_function_single_ipi(int cpu)
260 {
261 send_IPI_single(cpu, IPI_CALL_FUNC_SINGLE);
262 }
263
264 /*
265 * Flush all other CPU's tlb and then mine. Do this with on_each_cpu()
266 * as we want to ensure all TLB's flushed before proceeding.
267 */
268
269 void
270 smp_flush_tlb_all(void)
271 {
272 on_each_cpu(flush_tlb_all_local, NULL, 1);
273 }
274
275 /*
276 * Called by secondaries to update state and initialize CPU registers.
277 */
278 static void __init
279 smp_cpu_init(int cpunum)
280 {
281 extern int init_per_cpu(int); /* arch/parisc/kernel/processor.c */
282 extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
283 extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
284
285 /* Set modes and Enable floating point coprocessor */
286 (void) init_per_cpu(cpunum);
287
288 disable_sr_hashing();
289
290 mb();
291
292 /* Well, support 2.4 linux scheme as well. */
293 if (cpu_isset(cpunum, cpu_online_map))
294 {
295 extern void machine_halt(void); /* arch/parisc.../process.c */
296
297 printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
298 machine_halt();
299 }
300 set_cpu_online(cpunum, true);
301
302 /* Initialise the idle task for this CPU */
303 atomic_inc(&init_mm.mm_count);
304 current->active_mm = &init_mm;
305 BUG_ON(current->mm);
306 enter_lazy_tlb(&init_mm, current);
307
308 init_IRQ(); /* make sure no IRQs are enabled or pending */
309 start_cpu_itimer();
310 }
311
312
313 /*
314 * Slaves start using C here. Indirectly called from smp_slave_stext.
315 * Do what start_kernel() and main() do for boot strap processor (aka monarch)
316 */
317 void __init smp_callin(void)
318 {
319 int slave_id = cpu_now_booting;
320
321 smp_cpu_init(slave_id);
322 preempt_disable();
323
324 flush_cache_all_local(); /* start with known state */
325 flush_tlb_all_local(NULL);
326
327 local_irq_enable(); /* Interrupts have been off until now */
328
329 cpu_idle(); /* Wait for timer to schedule some work */
330
331 /* NOTREACHED */
332 panic("smp_callin() AAAAaaaaahhhh....\n");
333 }
334
335 /*
336 * Bring one cpu online.
337 */
338 int __cpuinit smp_boot_one_cpu(int cpuid)
339 {
340 const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
341 struct task_struct *idle;
342 long timeout;
343
344 /*
345 * Create an idle task for this CPU. Note the address wed* give
346 * to kernel_thread is irrelevant -- it's going to start
347 * where OS_BOOT_RENDEVZ vector in SAL says to start. But
348 * this gets all the other task-y sort of data structures set
349 * up like we wish. We need to pull the just created idle task
350 * off the run queue and stuff it into the init_tasks[] array.
351 * Sheesh . . .
352 */
353
354 idle = fork_idle(cpuid);
355 if (IS_ERR(idle))
356 panic("SMP: fork failed for CPU:%d", cpuid);
357
358 task_thread_info(idle)->cpu = cpuid;
359
360 /* Let _start know what logical CPU we're booting
361 ** (offset into init_tasks[],cpu_data[])
362 */
363 cpu_now_booting = cpuid;
364
365 /*
366 ** boot strap code needs to know the task address since
367 ** it also contains the process stack.
368 */
369 smp_init_current_idle_task = idle ;
370 mb();
371
372 printk(KERN_INFO "Releasing cpu %d now, hpa=%lx\n", cpuid, p->hpa);
373
374 /*
375 ** This gets PDC to release the CPU from a very tight loop.
376 **
377 ** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
378 ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
379 ** is executed after receiving the rendezvous signal (an interrupt to
380 ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
381 ** contents of memory are valid."
382 */
383 gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, p->hpa);
384 mb();
385
386 /*
387 * OK, wait a bit for that CPU to finish staggering about.
388 * Slave will set a bit when it reaches smp_cpu_init().
389 * Once the "monarch CPU" sees the bit change, it can move on.
390 */
391 for (timeout = 0; timeout < 10000; timeout++) {
392 if(cpu_online(cpuid)) {
393 /* Which implies Slave has started up */
394 cpu_now_booting = 0;
395 smp_init_current_idle_task = NULL;
396 goto alive ;
397 }
398 udelay(100);
399 barrier();
400 }
401
402 put_task_struct(idle);
403 idle = NULL;
404
405 printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
406 return -1;
407
408 alive:
409 /* Remember the Slave data */
410 smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
411 cpuid, timeout * 100);
412 return 0;
413 }
414
415 void __init smp_prepare_boot_cpu(void)
416 {
417 int bootstrap_processor = per_cpu(cpu_data, 0).cpuid;
418
419 /* Setup BSP mappings */
420 printk(KERN_INFO "SMP: bootstrap CPU ID is %d\n", bootstrap_processor);
421
422 set_cpu_online(bootstrap_processor, true);
423 set_cpu_present(bootstrap_processor, true);
424 }
425
426
427
428 /*
429 ** inventory.c:do_inventory() hasn't yet been run and thus we
430 ** don't 'discover' the additional CPUs until later.
431 */
432 void __init smp_prepare_cpus(unsigned int max_cpus)
433 {
434 int cpu;
435
436 for_each_possible_cpu(cpu)
437 spin_lock_init(&per_cpu(ipi_lock, cpu));
438
439 init_cpu_present(cpumask_of(0));
440
441 parisc_max_cpus = max_cpus;
442 if (!max_cpus)
443 printk(KERN_INFO "SMP mode deactivated.\n");
444 }
445
446
447 void smp_cpus_done(unsigned int cpu_max)
448 {
449 return;
450 }
451
452
453 int __cpuinit __cpu_up(unsigned int cpu)
454 {
455 if (cpu != 0 && cpu < parisc_max_cpus)
456 smp_boot_one_cpu(cpu);
457
458 return cpu_online(cpu) ? 0 : -ENOSYS;
459 }
460
461 #ifdef CONFIG_PROC_FS
462 int __init
463 setup_profiling_timer(unsigned int multiplier)
464 {
465 return -EINVAL;
466 }
467 #endif