sched: Provide scheduler_ipi() callback in response to smp_send_reschedule()
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / blackfin / mach-common / smp.c
CommitLineData
6b3087c6 1/*
96f1050d 2 * IPI management based on arch/arm/kernel/smp.c (Copyright 2002 ARM Limited)
6b3087c6 3 *
96f1050d
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4 * Copyright 2007-2009 Analog Devices Inc.
5 * Philippe Gerum <rpm@xenomai.org>
6b3087c6 6 *
96f1050d 7 * Licensed under the GPL-2.
6b3087c6
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8 */
9
10#include <linux/module.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>
9c199b59 22#include <linux/cpumask.h>
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23#include <linux/seq_file.h>
24#include <linux/irq.h>
5a0e3ad6 25#include <linux/slab.h>
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26#include <asm/atomic.h>
27#include <asm/cacheflush.h>
28#include <asm/mmu_context.h>
29#include <asm/pgtable.h>
30#include <asm/pgalloc.h>
31#include <asm/processor.h>
32#include <asm/ptrace.h>
33#include <asm/cpu.h>
1fa9be72 34#include <asm/time.h>
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35#include <linux/err.h>
36
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37/*
38 * Anomaly notes:
39 * 05000120 - we always define corelock as 32-bit integer in L2
40 */
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41struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));
42
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43#ifdef CONFIG_ICACHE_FLUSH_L1
44unsigned long blackfin_iflush_l1_entry[NR_CPUS];
45#endif
46
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47void __cpuinitdata *init_retx_coreb, *init_saved_retx_coreb,
48 *init_saved_seqstat_coreb, *init_saved_icplb_fault_addr_coreb,
49 *init_saved_dcplb_fault_addr_coreb;
50
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51#define BFIN_IPI_RESCHEDULE 0
52#define BFIN_IPI_CALL_FUNC 1
53#define BFIN_IPI_CPU_STOP 2
54
55struct blackfin_flush_data {
56 unsigned long start;
57 unsigned long end;
58};
59
60void *secondary_stack;
61
62
63struct smp_call_struct {
64 void (*func)(void *info);
65 void *info;
66 int wait;
73a40064 67 cpumask_t *waitmask;
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68};
69
70static struct blackfin_flush_data smp_flush_data;
71
72static DEFINE_SPINLOCK(stop_lock);
73
74struct ipi_message {
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75 unsigned long type;
76 struct smp_call_struct call_struct;
77};
78
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79/* A magic number - stress test shows this is safe for common cases */
80#define BFIN_IPI_MSGQ_LEN 5
81
82/* Simple FIFO buffer, overflow leads to panic */
6b3087c6 83struct ipi_message_queue {
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84 spinlock_t lock;
85 unsigned long count;
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86 unsigned long head; /* head of the queue */
87 struct ipi_message ipi_message[BFIN_IPI_MSGQ_LEN];
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88};
89
90static DEFINE_PER_CPU(struct ipi_message_queue, ipi_msg_queue);
91
92static void ipi_cpu_stop(unsigned int cpu)
93{
94 spin_lock(&stop_lock);
95 printk(KERN_CRIT "CPU%u: stopping\n", cpu);
96 dump_stack();
97 spin_unlock(&stop_lock);
98
99 cpu_clear(cpu, cpu_online_map);
100
101 local_irq_disable();
102
103 while (1)
104 SSYNC();
105}
106
107static void ipi_flush_icache(void *info)
108{
109 struct blackfin_flush_data *fdata = info;
110
111 /* Invalidate the memory holding the bounds of the flushed region. */
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112 invalidate_dcache_range((unsigned long)fdata,
113 (unsigned long)fdata + sizeof(*fdata));
6b3087c6 114
5f362c91 115 flush_icache_range(fdata->start, fdata->end);
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116}
117
118static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
119{
120 int wait;
121 void (*func)(void *info);
122 void *info;
123 func = msg->call_struct.func;
124 info = msg->call_struct.info;
125 wait = msg->call_struct.wait;
6b3087c6 126 func(info);
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127 if (wait) {
128#ifdef __ARCH_SYNC_CORE_DCACHE
129 /*
130 * 'wait' usually means synchronization between CPUs.
131 * Invalidate D cache in case shared data was changed
132 * by func() to ensure cache coherence.
133 */
134 resync_core_dcache();
135#endif
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136 cpu_clear(cpu, *msg->call_struct.waitmask);
137 }
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138}
139
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140/* Use IRQ_SUPPLE_0 to request reschedule.
141 * When returning from interrupt to user space,
142 * there is chance to reschedule */
143static irqreturn_t ipi_handler_int0(int irq, void *dev_instance)
144{
145 unsigned int cpu = smp_processor_id();
146
147 platform_clear_ipi(cpu, IRQ_SUPPLE_0);
148 return IRQ_HANDLED;
149}
150
151static irqreturn_t ipi_handler_int1(int irq, void *dev_instance)
6b3087c6 152{
86f2008b 153 struct ipi_message *msg;
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154 struct ipi_message_queue *msg_queue;
155 unsigned int cpu = smp_processor_id();
73a40064 156 unsigned long flags;
6b3087c6 157
73a40064 158 platform_clear_ipi(cpu, IRQ_SUPPLE_1);
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159
160 msg_queue = &__get_cpu_var(ipi_msg_queue);
6b3087c6 161
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162 spin_lock_irqsave(&msg_queue->lock, flags);
163
164 while (msg_queue->count) {
165 msg = &msg_queue->ipi_message[msg_queue->head];
6b3087c6 166 switch (msg->type) {
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167 case BFIN_IPI_RESCHEDULE:
168 scheduler_ipi();
169 break;
6b3087c6 170 case BFIN_IPI_CALL_FUNC:
73a40064 171 spin_unlock_irqrestore(&msg_queue->lock, flags);
6b3087c6 172 ipi_call_function(cpu, msg);
73a40064 173 spin_lock_irqsave(&msg_queue->lock, flags);
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174 break;
175 case BFIN_IPI_CPU_STOP:
73a40064 176 spin_unlock_irqrestore(&msg_queue->lock, flags);
6b3087c6 177 ipi_cpu_stop(cpu);
73a40064 178 spin_lock_irqsave(&msg_queue->lock, flags);
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179 break;
180 default:
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181 printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%lx\n",
182 cpu, msg->type);
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183 break;
184 }
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185 msg_queue->head++;
186 msg_queue->head %= BFIN_IPI_MSGQ_LEN;
187 msg_queue->count--;
6b3087c6 188 }
73a40064 189 spin_unlock_irqrestore(&msg_queue->lock, flags);
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190 return IRQ_HANDLED;
191}
192
193static void ipi_queue_init(void)
194{
195 unsigned int cpu;
196 struct ipi_message_queue *msg_queue;
197 for_each_possible_cpu(cpu) {
198 msg_queue = &per_cpu(ipi_msg_queue, cpu);
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199 spin_lock_init(&msg_queue->lock);
200 msg_queue->count = 0;
73a40064 201 msg_queue->head = 0;
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202 }
203}
204
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205static inline void smp_send_message(cpumask_t callmap, unsigned long type,
206 void (*func) (void *info), void *info, int wait)
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207{
208 unsigned int cpu;
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209 struct ipi_message_queue *msg_queue;
210 struct ipi_message *msg;
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211 unsigned long flags, next_msg;
212 cpumask_t waitmask = callmap; /* waitmask is shared by all cpus */
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213
214 for_each_cpu_mask(cpu, callmap) {
215 msg_queue = &per_cpu(ipi_msg_queue, cpu);
216 spin_lock_irqsave(&msg_queue->lock, flags);
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217 if (msg_queue->count < BFIN_IPI_MSGQ_LEN) {
218 next_msg = (msg_queue->head + msg_queue->count)
219 % BFIN_IPI_MSGQ_LEN;
220 msg = &msg_queue->ipi_message[next_msg];
221 msg->type = type;
222 if (type == BFIN_IPI_CALL_FUNC) {
223 msg->call_struct.func = func;
224 msg->call_struct.info = info;
225 msg->call_struct.wait = wait;
226 msg->call_struct.waitmask = &waitmask;
227 }
228 msg_queue->count++;
229 } else
230 panic("IPI message queue overflow\n");
6b3087c6 231 spin_unlock_irqrestore(&msg_queue->lock, flags);
73a40064 232 platform_send_ipi_cpu(cpu, IRQ_SUPPLE_1);
6b3087c6 233 }
73a40064 234
6b3087c6 235 if (wait) {
73a40064 236 while (!cpus_empty(waitmask))
6b3087c6 237 blackfin_dcache_invalidate_range(
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238 (unsigned long)(&waitmask),
239 (unsigned long)(&waitmask));
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240#ifdef __ARCH_SYNC_CORE_DCACHE
241 /*
242 * Invalidate D cache in case shared data was changed by
243 * other processors to ensure cache coherence.
244 */
245 resync_core_dcache();
246#endif
6b3087c6 247 }
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248}
249
250int smp_call_function(void (*func)(void *info), void *info, int wait)
251{
252 cpumask_t callmap;
253
567ebfc9 254 preempt_disable();
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255 callmap = cpu_online_map;
256 cpu_clear(smp_processor_id(), callmap);
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257 if (!cpus_empty(callmap))
258 smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);
73a40064 259
567ebfc9 260 preempt_enable();
73a40064 261
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262 return 0;
263}
264EXPORT_SYMBOL_GPL(smp_call_function);
265
266int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
267 int wait)
268{
269 unsigned int cpu = cpuid;
270 cpumask_t callmap;
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271
272 if (cpu_is_offline(cpu))
273 return 0;
274 cpus_clear(callmap);
275 cpu_set(cpu, callmap);
276
73a40064 277 smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);
6b3087c6 278
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279 return 0;
280}
281EXPORT_SYMBOL_GPL(smp_call_function_single);
282
283void smp_send_reschedule(int cpu)
284{
73a40064 285 /* simply trigger an ipi */
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286 if (cpu_is_offline(cpu))
287 return;
73a40064 288 platform_send_ipi_cpu(cpu, IRQ_SUPPLE_0);
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289
290 return;
291}
292
293void smp_send_stop(void)
294{
6b3087c6 295 cpumask_t callmap;
6b3087c6 296
567ebfc9 297 preempt_disable();
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298 callmap = cpu_online_map;
299 cpu_clear(smp_processor_id(), callmap);
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300 if (!cpus_empty(callmap))
301 smp_send_message(callmap, BFIN_IPI_CPU_STOP, NULL, NULL, 0);
6b3087c6 302
567ebfc9 303 preempt_enable();
6b3087c6 304
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305 return;
306}
307
308int __cpuinit __cpu_up(unsigned int cpu)
309{
6b3087c6 310 int ret;
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311 static struct task_struct *idle;
312
313 if (idle)
314 free_task(idle);
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315
316 idle = fork_idle(cpu);
317 if (IS_ERR(idle)) {
318 printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
319 return PTR_ERR(idle);
320 }
321
322 secondary_stack = task_stack_page(idle) + THREAD_SIZE;
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323
324 ret = platform_boot_secondary(cpu, idle);
325
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326 secondary_stack = NULL;
327
328 return ret;
329}
330
331static void __cpuinit setup_secondary(unsigned int cpu)
332{
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333 unsigned long ilat;
334
335 bfin_write_IMASK(0);
336 CSYNC();
337 ilat = bfin_read_ILAT();
338 CSYNC();
339 bfin_write_ILAT(ilat);
340 CSYNC();
341
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342 /* Enable interrupt levels IVG7-15. IARs have been already
343 * programmed by the boot CPU. */
40059784 344 bfin_irq_flags |= IMASK_IVG15 |
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345 IMASK_IVG14 | IMASK_IVG13 | IMASK_IVG12 | IMASK_IVG11 |
346 IMASK_IVG10 | IMASK_IVG9 | IMASK_IVG8 | IMASK_IVG7 | IMASK_IVGHW;
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347}
348
349void __cpuinit secondary_start_kernel(void)
350{
351 unsigned int cpu = smp_processor_id();
352 struct mm_struct *mm = &init_mm;
353
354 if (_bfin_swrst & SWRST_DBL_FAULT_B) {
355 printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n");
356#ifdef CONFIG_DEBUG_DOUBLEFAULT
357 printk(KERN_EMERG " While handling exception (EXCAUSE = 0x%x) at %pF\n",
358 (int)init_saved_seqstat_coreb & SEQSTAT_EXCAUSE, init_saved_retx_coreb);
359 printk(KERN_NOTICE " DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr_coreb);
360 printk(KERN_NOTICE " ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr_coreb);
361#endif
362 printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
363 init_retx_coreb);
364 }
365
366 /*
367 * We want the D-cache to be enabled early, in case the atomic
368 * support code emulates cache coherence (see
369 * __ARCH_SYNC_CORE_DCACHE).
370 */
371 init_exception_vectors();
372
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373 local_irq_disable();
374
375 /* Attach the new idle task to the global mm. */
376 atomic_inc(&mm->mm_users);
377 atomic_inc(&mm->mm_count);
378 current->active_mm = mm;
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379
380 preempt_disable();
381
382 setup_secondary(cpu);
383
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384 platform_secondary_init(cpu);
385
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386 /* setup local core timer */
387 bfin_local_timer_setup();
388
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389 local_irq_enable();
390
ab61d2ac 391 bfin_setup_caches(cpu);
392
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393 /*
394 * Calibrate loops per jiffy value.
395 * IRQs need to be enabled here - D-cache can be invalidated
396 * in timer irq handler, so core B can read correct jiffies.
397 */
398 calibrate_delay();
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399
400 cpu_idle();
401}
402
403void __init smp_prepare_boot_cpu(void)
404{
405}
406
407void __init smp_prepare_cpus(unsigned int max_cpus)
408{
409 platform_prepare_cpus(max_cpus);
410 ipi_queue_init();
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411 platform_request_ipi(IRQ_SUPPLE_0, ipi_handler_int0);
412 platform_request_ipi(IRQ_SUPPLE_1, ipi_handler_int1);
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413}
414
415void __init smp_cpus_done(unsigned int max_cpus)
416{
417 unsigned long bogosum = 0;
418 unsigned int cpu;
419
420 for_each_online_cpu(cpu)
c70c754f 421 bogosum += loops_per_jiffy;
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422
423 printk(KERN_INFO "SMP: Total of %d processors activated "
424 "(%lu.%02lu BogoMIPS).\n",
425 num_online_cpus(),
426 bogosum / (500000/HZ),
427 (bogosum / (5000/HZ)) % 100);
428}
429
430void smp_icache_flush_range_others(unsigned long start, unsigned long end)
431{
432 smp_flush_data.start = start;
433 smp_flush_data.end = end;
434
0bf3d933 435 if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 0))
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436 printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n");
437}
438EXPORT_SYMBOL_GPL(smp_icache_flush_range_others);
439
47e9dedb 440#ifdef __ARCH_SYNC_CORE_ICACHE
718340f6 441unsigned long icache_invld_count[NR_CPUS];
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442void resync_core_icache(void)
443{
444 unsigned int cpu = get_cpu();
445 blackfin_invalidate_entire_icache();
718340f6 446 icache_invld_count[cpu]++;
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447 put_cpu();
448}
449EXPORT_SYMBOL(resync_core_icache);
450#endif
451
6b3087c6 452#ifdef __ARCH_SYNC_CORE_DCACHE
718340f6 453unsigned long dcache_invld_count[NR_CPUS];
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454unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));
455
456void resync_core_dcache(void)
457{
458 unsigned int cpu = get_cpu();
459 blackfin_invalidate_entire_dcache();
718340f6 460 dcache_invld_count[cpu]++;
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461 put_cpu();
462}
463EXPORT_SYMBOL(resync_core_dcache);
464#endif
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465
466#ifdef CONFIG_HOTPLUG_CPU
467int __cpuexit __cpu_disable(void)
468{
469 unsigned int cpu = smp_processor_id();
470
471 if (cpu == 0)
472 return -EPERM;
473
474 set_cpu_online(cpu, false);
475 return 0;
476}
477
478static DECLARE_COMPLETION(cpu_killed);
479
480int __cpuexit __cpu_die(unsigned int cpu)
481{
482 return wait_for_completion_timeout(&cpu_killed, 5000);
483}
484
485void cpu_die(void)
486{
487 complete(&cpu_killed);
488
489 atomic_dec(&init_mm.mm_users);
490 atomic_dec(&init_mm.mm_count);
491
492 local_irq_disable();
493 platform_cpu_die();
494}
495#endif