Blackfin: fix memset in smp_send_reschedule() and -stop()
[linux-3.10.git] / arch / blackfin / mach-common / smp.c
1 /*
2  * IPI management based on arch/arm/kernel/smp.c (Copyright 2002 ARM Limited)
3  *
4  * Copyright 2007-2009 Analog Devices Inc.
5  *                         Philippe Gerum <rpm@xenomai.org>
6  *
7  * Licensed under the GPL-2.
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>
22 #include <linux/seq_file.h>
23 #include <linux/irq.h>
24 #include <asm/atomic.h>
25 #include <asm/cacheflush.h>
26 #include <asm/mmu_context.h>
27 #include <asm/pgtable.h>
28 #include <asm/pgalloc.h>
29 #include <asm/processor.h>
30 #include <asm/ptrace.h>
31 #include <asm/cpu.h>
32 #include <asm/time.h>
33 #include <linux/err.h>
34
35 /*
36  * Anomaly notes:
37  * 05000120 - we always define corelock as 32-bit integer in L2
38  */
39 struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));
40
41 void __cpuinitdata *init_retx_coreb, *init_saved_retx_coreb,
42         *init_saved_seqstat_coreb, *init_saved_icplb_fault_addr_coreb,
43         *init_saved_dcplb_fault_addr_coreb;
44
45 cpumask_t cpu_possible_map;
46 EXPORT_SYMBOL(cpu_possible_map);
47
48 cpumask_t cpu_online_map;
49 EXPORT_SYMBOL(cpu_online_map);
50
51 #define BFIN_IPI_RESCHEDULE   0
52 #define BFIN_IPI_CALL_FUNC    1
53 #define BFIN_IPI_CPU_STOP     2
54
55 struct blackfin_flush_data {
56         unsigned long start;
57         unsigned long end;
58 };
59
60 void *secondary_stack;
61
62
63 struct smp_call_struct {
64         void (*func)(void *info);
65         void *info;
66         int wait;
67         cpumask_t pending;
68         cpumask_t waitmask;
69 };
70
71 static struct blackfin_flush_data smp_flush_data;
72
73 static DEFINE_SPINLOCK(stop_lock);
74
75 struct ipi_message {
76         struct list_head list;
77         unsigned long type;
78         struct smp_call_struct call_struct;
79 };
80
81 struct ipi_message_queue {
82         struct list_head head;
83         spinlock_t lock;
84         unsigned long count;
85 };
86
87 static DEFINE_PER_CPU(struct ipi_message_queue, ipi_msg_queue);
88
89 static void ipi_cpu_stop(unsigned int cpu)
90 {
91         spin_lock(&stop_lock);
92         printk(KERN_CRIT "CPU%u: stopping\n", cpu);
93         dump_stack();
94         spin_unlock(&stop_lock);
95
96         cpu_clear(cpu, cpu_online_map);
97
98         local_irq_disable();
99
100         while (1)
101                 SSYNC();
102 }
103
104 static void ipi_flush_icache(void *info)
105 {
106         struct blackfin_flush_data *fdata = info;
107
108         /* Invalidate the memory holding the bounds of the flushed region. */
109         blackfin_dcache_invalidate_range((unsigned long)fdata,
110                                          (unsigned long)fdata + sizeof(*fdata));
111
112         blackfin_icache_flush_range(fdata->start, fdata->end);
113 }
114
115 static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
116 {
117         int wait;
118         void (*func)(void *info);
119         void *info;
120         func = msg->call_struct.func;
121         info = msg->call_struct.info;
122         wait = msg->call_struct.wait;
123         cpu_clear(cpu, msg->call_struct.pending);
124         func(info);
125         if (wait)
126                 cpu_clear(cpu, msg->call_struct.waitmask);
127         else
128                 kfree(msg);
129 }
130
131 static irqreturn_t ipi_handler(int irq, void *dev_instance)
132 {
133         struct ipi_message *msg;
134         struct ipi_message_queue *msg_queue;
135         unsigned int cpu = smp_processor_id();
136
137         platform_clear_ipi(cpu);
138
139         msg_queue = &__get_cpu_var(ipi_msg_queue);
140         msg_queue->count++;
141
142         spin_lock(&msg_queue->lock);
143         while (!list_empty(&msg_queue->head)) {
144                 msg = list_entry(msg_queue->head.next, typeof(*msg), list);
145                 list_del(&msg->list);
146                 switch (msg->type) {
147                 case BFIN_IPI_RESCHEDULE:
148                         /* That's the easiest one; leave it to
149                          * return_from_int. */
150                         kfree(msg);
151                         break;
152                 case BFIN_IPI_CALL_FUNC:
153                         spin_unlock(&msg_queue->lock);
154                         ipi_call_function(cpu, msg);
155                         spin_lock(&msg_queue->lock);
156                         break;
157                 case BFIN_IPI_CPU_STOP:
158                         spin_unlock(&msg_queue->lock);
159                         ipi_cpu_stop(cpu);
160                         spin_lock(&msg_queue->lock);
161                         kfree(msg);
162                         break;
163                 default:
164                         printk(KERN_CRIT "CPU%u: Unknown IPI message \
165                         0x%lx\n", cpu, msg->type);
166                         kfree(msg);
167                         break;
168                 }
169         }
170         spin_unlock(&msg_queue->lock);
171         return IRQ_HANDLED;
172 }
173
174 static void ipi_queue_init(void)
175 {
176         unsigned int cpu;
177         struct ipi_message_queue *msg_queue;
178         for_each_possible_cpu(cpu) {
179                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
180                 INIT_LIST_HEAD(&msg_queue->head);
181                 spin_lock_init(&msg_queue->lock);
182                 msg_queue->count = 0;
183         }
184 }
185
186 int smp_call_function(void (*func)(void *info), void *info, int wait)
187 {
188         unsigned int cpu;
189         cpumask_t callmap;
190         unsigned long flags;
191         struct ipi_message_queue *msg_queue;
192         struct ipi_message *msg;
193
194         callmap = cpu_online_map;
195         cpu_clear(smp_processor_id(), callmap);
196         if (cpus_empty(callmap))
197                 return 0;
198
199         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
200         if (!msg)
201                 return -ENOMEM;
202         INIT_LIST_HEAD(&msg->list);
203         msg->call_struct.func = func;
204         msg->call_struct.info = info;
205         msg->call_struct.wait = wait;
206         msg->call_struct.pending = callmap;
207         msg->call_struct.waitmask = callmap;
208         msg->type = BFIN_IPI_CALL_FUNC;
209
210         for_each_cpu_mask(cpu, callmap) {
211                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
212                 spin_lock_irqsave(&msg_queue->lock, flags);
213                 list_add_tail(&msg->list, &msg_queue->head);
214                 spin_unlock_irqrestore(&msg_queue->lock, flags);
215                 platform_send_ipi_cpu(cpu);
216         }
217         if (wait) {
218                 while (!cpus_empty(msg->call_struct.waitmask))
219                         blackfin_dcache_invalidate_range(
220                                 (unsigned long)(&msg->call_struct.waitmask),
221                                 (unsigned long)(&msg->call_struct.waitmask));
222                 kfree(msg);
223         }
224         return 0;
225 }
226 EXPORT_SYMBOL_GPL(smp_call_function);
227
228 int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
229                                 int wait)
230 {
231         unsigned int cpu = cpuid;
232         cpumask_t callmap;
233         unsigned long flags;
234         struct ipi_message_queue *msg_queue;
235         struct ipi_message *msg;
236
237         if (cpu_is_offline(cpu))
238                 return 0;
239         cpus_clear(callmap);
240         cpu_set(cpu, callmap);
241
242         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
243         if (!msg)
244                 return -ENOMEM;
245         INIT_LIST_HEAD(&msg->list);
246         msg->call_struct.func = func;
247         msg->call_struct.info = info;
248         msg->call_struct.wait = wait;
249         msg->call_struct.pending = callmap;
250         msg->call_struct.waitmask = callmap;
251         msg->type = BFIN_IPI_CALL_FUNC;
252
253         msg_queue = &per_cpu(ipi_msg_queue, cpu);
254         spin_lock_irqsave(&msg_queue->lock, flags);
255         list_add_tail(&msg->list, &msg_queue->head);
256         spin_unlock_irqrestore(&msg_queue->lock, flags);
257         platform_send_ipi_cpu(cpu);
258
259         if (wait) {
260                 while (!cpus_empty(msg->call_struct.waitmask))
261                         blackfin_dcache_invalidate_range(
262                                 (unsigned long)(&msg->call_struct.waitmask),
263                                 (unsigned long)(&msg->call_struct.waitmask));
264                 kfree(msg);
265         }
266         return 0;
267 }
268 EXPORT_SYMBOL_GPL(smp_call_function_single);
269
270 void smp_send_reschedule(int cpu)
271 {
272         unsigned long flags;
273         struct ipi_message_queue *msg_queue;
274         struct ipi_message *msg;
275
276         if (cpu_is_offline(cpu))
277                 return;
278
279         msg = kzalloc(sizeof(*msg), GFP_ATOMIC);
280         if (!msg)
281                 return;
282         INIT_LIST_HEAD(&msg->list);
283         msg->type = BFIN_IPI_RESCHEDULE;
284
285         msg_queue = &per_cpu(ipi_msg_queue, cpu);
286         spin_lock_irqsave(&msg_queue->lock, flags);
287         list_add_tail(&msg->list, &msg_queue->head);
288         spin_unlock_irqrestore(&msg_queue->lock, flags);
289         platform_send_ipi_cpu(cpu);
290
291         return;
292 }
293
294 void smp_send_stop(void)
295 {
296         unsigned int cpu;
297         cpumask_t callmap;
298         unsigned long flags;
299         struct ipi_message_queue *msg_queue;
300         struct ipi_message *msg;
301
302         callmap = cpu_online_map;
303         cpu_clear(smp_processor_id(), callmap);
304         if (cpus_empty(callmap))
305                 return;
306
307         msg = kzalloc(sizeof(*msg), GFP_ATOMIC);
308         if (!msg)
309                 return;
310         INIT_LIST_HEAD(&msg->list);
311         msg->type = BFIN_IPI_CPU_STOP;
312
313         for_each_cpu_mask(cpu, callmap) {
314                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
315                 spin_lock_irqsave(&msg_queue->lock, flags);
316                 list_add_tail(&msg->list, &msg_queue->head);
317                 spin_unlock_irqrestore(&msg_queue->lock, flags);
318                 platform_send_ipi_cpu(cpu);
319         }
320         return;
321 }
322
323 int __cpuinit __cpu_up(unsigned int cpu)
324 {
325         struct task_struct *idle;
326         int ret;
327
328         idle = fork_idle(cpu);
329         if (IS_ERR(idle)) {
330                 printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
331                 return PTR_ERR(idle);
332         }
333
334         secondary_stack = task_stack_page(idle) + THREAD_SIZE;
335         smp_wmb();
336
337         ret = platform_boot_secondary(cpu, idle);
338
339         if (ret) {
340                 cpu_clear(cpu, cpu_present_map);
341                 printk(KERN_CRIT "CPU%u: processor failed to boot (%d)\n", cpu, ret);
342                 free_task(idle);
343         } else
344                 cpu_set(cpu, cpu_online_map);
345
346         secondary_stack = NULL;
347
348         return ret;
349 }
350
351 static void __cpuinit setup_secondary(unsigned int cpu)
352 {
353 #if !defined(CONFIG_TICKSOURCE_GPTMR0)
354         struct irq_desc *timer_desc;
355 #endif
356         unsigned long ilat;
357
358         bfin_write_IMASK(0);
359         CSYNC();
360         ilat = bfin_read_ILAT();
361         CSYNC();
362         bfin_write_ILAT(ilat);
363         CSYNC();
364
365         /* Enable interrupt levels IVG7-15. IARs have been already
366          * programmed by the boot CPU.  */
367         bfin_irq_flags |= IMASK_IVG15 |
368             IMASK_IVG14 | IMASK_IVG13 | IMASK_IVG12 | IMASK_IVG11 |
369             IMASK_IVG10 | IMASK_IVG9 | IMASK_IVG8 | IMASK_IVG7 | IMASK_IVGHW;
370
371 #if defined(CONFIG_TICKSOURCE_GPTMR0)
372         /* Power down the core timer, just to play safe. */
373         bfin_write_TCNTL(0);
374
375         /* system timer0 has been setup by CoreA. */
376 #else
377         timer_desc = irq_desc + IRQ_CORETMR;
378         setup_core_timer();
379         timer_desc->chip->enable(IRQ_CORETMR);
380 #endif
381 }
382
383 void __cpuinit secondary_start_kernel(void)
384 {
385         unsigned int cpu = smp_processor_id();
386         struct mm_struct *mm = &init_mm;
387
388         if (_bfin_swrst & SWRST_DBL_FAULT_B) {
389                 printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n");
390 #ifdef CONFIG_DEBUG_DOUBLEFAULT
391                 printk(KERN_EMERG " While handling exception (EXCAUSE = 0x%x) at %pF\n",
392                         (int)init_saved_seqstat_coreb & SEQSTAT_EXCAUSE, init_saved_retx_coreb);
393                 printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr_coreb);
394                 printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr_coreb);
395 #endif
396                 printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
397                         init_retx_coreb);
398         }
399
400         /*
401          * We want the D-cache to be enabled early, in case the atomic
402          * support code emulates cache coherence (see
403          * __ARCH_SYNC_CORE_DCACHE).
404          */
405         init_exception_vectors();
406
407         bfin_setup_caches(cpu);
408
409         local_irq_disable();
410
411         /* Attach the new idle task to the global mm. */
412         atomic_inc(&mm->mm_users);
413         atomic_inc(&mm->mm_count);
414         current->active_mm = mm;
415         BUG_ON(current->mm);    /* Can't be, but better be safe than sorry. */
416
417         preempt_disable();
418
419         setup_secondary(cpu);
420
421         local_irq_enable();
422
423         platform_secondary_init(cpu);
424
425         cpu_idle();
426 }
427
428 void __init smp_prepare_boot_cpu(void)
429 {
430 }
431
432 void __init smp_prepare_cpus(unsigned int max_cpus)
433 {
434         platform_prepare_cpus(max_cpus);
435         ipi_queue_init();
436         platform_request_ipi(&ipi_handler);
437 }
438
439 void __init smp_cpus_done(unsigned int max_cpus)
440 {
441         unsigned long bogosum = 0;
442         unsigned int cpu;
443
444         for_each_online_cpu(cpu)
445                 bogosum += loops_per_jiffy;
446
447         printk(KERN_INFO "SMP: Total of %d processors activated "
448                "(%lu.%02lu BogoMIPS).\n",
449                num_online_cpus(),
450                bogosum / (500000/HZ),
451                (bogosum / (5000/HZ)) % 100);
452 }
453
454 void smp_icache_flush_range_others(unsigned long start, unsigned long end)
455 {
456         smp_flush_data.start = start;
457         smp_flush_data.end = end;
458
459         if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 0))
460                 printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n");
461 }
462 EXPORT_SYMBOL_GPL(smp_icache_flush_range_others);
463
464 #ifdef __ARCH_SYNC_CORE_ICACHE
465 void resync_core_icache(void)
466 {
467         unsigned int cpu = get_cpu();
468         blackfin_invalidate_entire_icache();
469         ++per_cpu(cpu_data, cpu).icache_invld_count;
470         put_cpu();
471 }
472 EXPORT_SYMBOL(resync_core_icache);
473 #endif
474
475 #ifdef __ARCH_SYNC_CORE_DCACHE
476 unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));
477
478 void resync_core_dcache(void)
479 {
480         unsigned int cpu = get_cpu();
481         blackfin_invalidate_entire_dcache();
482         ++per_cpu(cpu_data, cpu).dcache_invld_count;
483         put_cpu();
484 }
485 EXPORT_SYMBOL(resync_core_dcache);
486 #endif