Blackfin arch: fix bug - kgdb fails to continue after setting breakpoint on bf561...
[linux-3.10.git] / arch / blackfin / mach-common / smp.c
1 /*
2  * File:         arch/blackfin/kernel/smp.c
3  * Author:       Philippe Gerum <rpm@xenomai.org>
4  * IPI management based on arch/arm/kernel/smp.c.
5  *
6  *               Copyright 2007 Analog Devices Inc.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, see the file COPYING, or write
20  * to the Free Software Foundation, Inc.,
21  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
22  */
23
24 #include <linux/module.h>
25 #include <linux/delay.h>
26 #include <linux/init.h>
27 #include <linux/spinlock.h>
28 #include <linux/sched.h>
29 #include <linux/interrupt.h>
30 #include <linux/cache.h>
31 #include <linux/profile.h>
32 #include <linux/errno.h>
33 #include <linux/mm.h>
34 #include <linux/cpu.h>
35 #include <linux/smp.h>
36 #include <linux/seq_file.h>
37 #include <linux/irq.h>
38 #include <asm/atomic.h>
39 #include <asm/cacheflush.h>
40 #include <asm/mmu_context.h>
41 #include <asm/pgtable.h>
42 #include <asm/pgalloc.h>
43 #include <asm/processor.h>
44 #include <asm/ptrace.h>
45 #include <asm/cpu.h>
46 #include <linux/err.h>
47
48 struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));
49
50 void __cpuinitdata *init_retx_coreb, *init_saved_retx_coreb,
51         *init_saved_seqstat_coreb, *init_saved_icplb_fault_addr_coreb,
52         *init_saved_dcplb_fault_addr_coreb;
53
54 cpumask_t cpu_possible_map;
55 EXPORT_SYMBOL(cpu_possible_map);
56
57 cpumask_t cpu_online_map;
58 EXPORT_SYMBOL(cpu_online_map);
59
60 #define BFIN_IPI_RESCHEDULE   0
61 #define BFIN_IPI_CALL_FUNC    1
62 #define BFIN_IPI_CPU_STOP     2
63
64 struct blackfin_flush_data {
65         unsigned long start;
66         unsigned long end;
67 };
68
69 void *secondary_stack;
70
71
72 struct smp_call_struct {
73         void (*func)(void *info);
74         void *info;
75         int wait;
76         cpumask_t pending;
77         cpumask_t waitmask;
78 };
79
80 static struct blackfin_flush_data smp_flush_data;
81
82 static DEFINE_SPINLOCK(stop_lock);
83
84 struct ipi_message {
85         struct list_head list;
86         unsigned long type;
87         struct smp_call_struct call_struct;
88 };
89
90 struct ipi_message_queue {
91         struct list_head head;
92         spinlock_t lock;
93         unsigned long count;
94 };
95
96 static DEFINE_PER_CPU(struct ipi_message_queue, ipi_msg_queue);
97
98 static void ipi_cpu_stop(unsigned int cpu)
99 {
100         spin_lock(&stop_lock);
101         printk(KERN_CRIT "CPU%u: stopping\n", cpu);
102         dump_stack();
103         spin_unlock(&stop_lock);
104
105         cpu_clear(cpu, cpu_online_map);
106
107         local_irq_disable();
108
109         while (1)
110                 SSYNC();
111 }
112
113 static void ipi_flush_icache(void *info)
114 {
115         struct blackfin_flush_data *fdata = info;
116
117         /* Invalidate the memory holding the bounds of the flushed region. */
118         blackfin_dcache_invalidate_range((unsigned long)fdata,
119                                          (unsigned long)fdata + sizeof(*fdata));
120
121         blackfin_icache_flush_range(fdata->start, fdata->end);
122 }
123
124 static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
125 {
126         int wait;
127         void (*func)(void *info);
128         void *info;
129         func = msg->call_struct.func;
130         info = msg->call_struct.info;
131         wait = msg->call_struct.wait;
132         cpu_clear(cpu, msg->call_struct.pending);
133         func(info);
134         if (wait)
135                 cpu_clear(cpu, msg->call_struct.waitmask);
136         else
137                 kfree(msg);
138 }
139
140 static irqreturn_t ipi_handler(int irq, void *dev_instance)
141 {
142         struct ipi_message *msg, *mg;
143         struct ipi_message_queue *msg_queue;
144         unsigned int cpu = smp_processor_id();
145
146         platform_clear_ipi(cpu);
147
148         msg_queue = &__get_cpu_var(ipi_msg_queue);
149         msg_queue->count++;
150
151         spin_lock(&msg_queue->lock);
152         list_for_each_entry_safe(msg, mg, &msg_queue->head, list) {
153                 list_del(&msg->list);
154                 switch (msg->type) {
155                 case BFIN_IPI_RESCHEDULE:
156                         /* That's the easiest one; leave it to
157                          * return_from_int. */
158                         kfree(msg);
159                         break;
160                 case BFIN_IPI_CALL_FUNC:
161                         spin_unlock(&msg_queue->lock);
162                         ipi_call_function(cpu, msg);
163                         spin_lock(&msg_queue->lock);
164                         break;
165                 case BFIN_IPI_CPU_STOP:
166                         spin_unlock(&msg_queue->lock);
167                         ipi_cpu_stop(cpu);
168                         spin_lock(&msg_queue->lock);
169                         kfree(msg);
170                         break;
171                 default:
172                         printk(KERN_CRIT "CPU%u: Unknown IPI message \
173                         0x%lx\n", cpu, msg->type);
174                         kfree(msg);
175                         break;
176                 }
177         }
178         spin_unlock(&msg_queue->lock);
179         return IRQ_HANDLED;
180 }
181
182 static void ipi_queue_init(void)
183 {
184         unsigned int cpu;
185         struct ipi_message_queue *msg_queue;
186         for_each_possible_cpu(cpu) {
187                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
188                 INIT_LIST_HEAD(&msg_queue->head);
189                 spin_lock_init(&msg_queue->lock);
190                 msg_queue->count = 0;
191         }
192 }
193
194 int smp_call_function(void (*func)(void *info), void *info, int wait)
195 {
196         unsigned int cpu;
197         cpumask_t callmap;
198         unsigned long flags;
199         struct ipi_message_queue *msg_queue;
200         struct ipi_message *msg;
201
202         callmap = cpu_online_map;
203         cpu_clear(smp_processor_id(), callmap);
204         if (cpus_empty(callmap))
205                 return 0;
206
207         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
208         INIT_LIST_HEAD(&msg->list);
209         msg->call_struct.func = func;
210         msg->call_struct.info = info;
211         msg->call_struct.wait = wait;
212         msg->call_struct.pending = callmap;
213         msg->call_struct.waitmask = callmap;
214         msg->type = BFIN_IPI_CALL_FUNC;
215
216         for_each_cpu_mask(cpu, callmap) {
217                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
218                 spin_lock_irqsave(&msg_queue->lock, flags);
219                 list_add(&msg->list, &msg_queue->head);
220                 spin_unlock_irqrestore(&msg_queue->lock, flags);
221                 platform_send_ipi_cpu(cpu);
222         }
223         if (wait) {
224                 while (!cpus_empty(msg->call_struct.waitmask))
225                         blackfin_dcache_invalidate_range(
226                                 (unsigned long)(&msg->call_struct.waitmask),
227                                 (unsigned long)(&msg->call_struct.waitmask));
228                 kfree(msg);
229         }
230         return 0;
231 }
232 EXPORT_SYMBOL_GPL(smp_call_function);
233
234 int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
235                                 int wait)
236 {
237         unsigned int cpu = cpuid;
238         cpumask_t callmap;
239         unsigned long flags;
240         struct ipi_message_queue *msg_queue;
241         struct ipi_message *msg;
242
243         if (cpu_is_offline(cpu))
244                 return 0;
245         cpus_clear(callmap);
246         cpu_set(cpu, callmap);
247
248         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
249         INIT_LIST_HEAD(&msg->list);
250         msg->call_struct.func = func;
251         msg->call_struct.info = info;
252         msg->call_struct.wait = wait;
253         msg->call_struct.pending = callmap;
254         msg->call_struct.waitmask = callmap;
255         msg->type = BFIN_IPI_CALL_FUNC;
256
257         msg_queue = &per_cpu(ipi_msg_queue, cpu);
258         spin_lock_irqsave(&msg_queue->lock, flags);
259         list_add(&msg->list, &msg_queue->head);
260         spin_unlock_irqrestore(&msg_queue->lock, flags);
261         platform_send_ipi_cpu(cpu);
262
263         if (wait) {
264                 while (!cpus_empty(msg->call_struct.waitmask))
265                         blackfin_dcache_invalidate_range(
266                                 (unsigned long)(&msg->call_struct.waitmask),
267                                 (unsigned long)(&msg->call_struct.waitmask));
268                 kfree(msg);
269         }
270         return 0;
271 }
272 EXPORT_SYMBOL_GPL(smp_call_function_single);
273
274 void smp_send_reschedule(int cpu)
275 {
276         unsigned long flags;
277         struct ipi_message_queue *msg_queue;
278         struct ipi_message *msg;
279
280         if (cpu_is_offline(cpu))
281                 return;
282
283         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
284         memset(msg, 0, sizeof(msg));
285         INIT_LIST_HEAD(&msg->list);
286         msg->type = BFIN_IPI_RESCHEDULE;
287
288         msg_queue = &per_cpu(ipi_msg_queue, cpu);
289         spin_lock_irqsave(&msg_queue->lock, flags);
290         list_add(&msg->list, &msg_queue->head);
291         spin_unlock_irqrestore(&msg_queue->lock, flags);
292         platform_send_ipi_cpu(cpu);
293
294         return;
295 }
296
297 void smp_send_stop(void)
298 {
299         unsigned int cpu;
300         cpumask_t callmap;
301         unsigned long flags;
302         struct ipi_message_queue *msg_queue;
303         struct ipi_message *msg;
304
305         callmap = cpu_online_map;
306         cpu_clear(smp_processor_id(), callmap);
307         if (cpus_empty(callmap))
308                 return;
309
310         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
311         memset(msg, 0, sizeof(msg));
312         INIT_LIST_HEAD(&msg->list);
313         msg->type = BFIN_IPI_CPU_STOP;
314
315         for_each_cpu_mask(cpu, callmap) {
316                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
317                 spin_lock_irqsave(&msg_queue->lock, flags);
318                 list_add(&msg->list, &msg_queue->head);
319                 spin_unlock_irqrestore(&msg_queue->lock, flags);
320                 platform_send_ipi_cpu(cpu);
321         }
322         return;
323 }
324
325 int __cpuinit __cpu_up(unsigned int cpu)
326 {
327         struct task_struct *idle;
328         int ret;
329
330         idle = fork_idle(cpu);
331         if (IS_ERR(idle)) {
332                 printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
333                 return PTR_ERR(idle);
334         }
335
336         secondary_stack = task_stack_page(idle) + THREAD_SIZE;
337         smp_wmb();
338
339         ret = platform_boot_secondary(cpu, idle);
340
341         if (ret) {
342                 cpu_clear(cpu, cpu_present_map);
343                 printk(KERN_CRIT "CPU%u: processor failed to boot (%d)\n", cpu, ret);
344                 free_task(idle);
345         } else
346                 cpu_set(cpu, cpu_online_map);
347
348         secondary_stack = NULL;
349
350         return ret;
351 }
352
353 static void __cpuinit setup_secondary(unsigned int cpu)
354 {
355 #if !(defined(CONFIG_TICK_SOURCE_SYSTMR0) || defined(CONFIG_IPIPE))
356         struct irq_desc *timer_desc;
357 #endif
358         unsigned long ilat;
359
360         bfin_write_IMASK(0);
361         CSYNC();
362         ilat = bfin_read_ILAT();
363         CSYNC();
364         bfin_write_ILAT(ilat);
365         CSYNC();
366
367         /* Reserve the PDA space for the secondary CPU. */
368         reserve_pda();
369
370         /* Enable interrupt levels IVG7-15. IARs have been already
371          * programmed by the boot CPU.  */
372         bfin_irq_flags |= IMASK_IVG15 |
373             IMASK_IVG14 | IMASK_IVG13 | IMASK_IVG12 | IMASK_IVG11 |
374             IMASK_IVG10 | IMASK_IVG9 | IMASK_IVG8 | IMASK_IVG7 | IMASK_IVGHW;
375
376 #if defined(CONFIG_TICK_SOURCE_SYSTMR0) || defined(CONFIG_IPIPE)
377         /* Power down the core timer, just to play safe. */
378         bfin_write_TCNTL(0);
379
380         /* system timer0 has been setup by CoreA. */
381 #else
382         timer_desc = irq_desc + IRQ_CORETMR;
383         setup_core_timer();
384         timer_desc->chip->enable(IRQ_CORETMR);
385 #endif
386 }
387
388 void __cpuinit secondary_start_kernel(void)
389 {
390         unsigned int cpu = smp_processor_id();
391         struct mm_struct *mm = &init_mm;
392
393         if (_bfin_swrst & SWRST_DBL_FAULT_B) {
394                 printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n");
395 #ifdef CONFIG_DEBUG_DOUBLEFAULT
396                 printk(KERN_EMERG " While handling exception (EXCAUSE = 0x%x) at %pF\n",
397                         (int)init_saved_seqstat_coreb & SEQSTAT_EXCAUSE, init_saved_retx_coreb);
398                 printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr_coreb);
399                 printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr_coreb);
400 #endif
401                 printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
402                         init_retx_coreb);
403         }
404
405         /*
406          * We want the D-cache to be enabled early, in case the atomic
407          * support code emulates cache coherence (see
408          * __ARCH_SYNC_CORE_DCACHE).
409          */
410         init_exception_vectors();
411
412         bfin_setup_caches(cpu);
413
414         local_irq_disable();
415
416         /* Attach the new idle task to the global mm. */
417         atomic_inc(&mm->mm_users);
418         atomic_inc(&mm->mm_count);
419         current->active_mm = mm;
420         BUG_ON(current->mm);    /* Can't be, but better be safe than sorry. */
421
422         preempt_disable();
423
424         setup_secondary(cpu);
425
426         local_irq_enable();
427
428         platform_secondary_init(cpu);
429
430         cpu_idle();
431 }
432
433 void __init smp_prepare_boot_cpu(void)
434 {
435 }
436
437 void __init smp_prepare_cpus(unsigned int max_cpus)
438 {
439         platform_prepare_cpus(max_cpus);
440         ipi_queue_init();
441         platform_request_ipi(&ipi_handler);
442 }
443
444 void __init smp_cpus_done(unsigned int max_cpus)
445 {
446         unsigned long bogosum = 0;
447         unsigned int cpu;
448
449         for_each_online_cpu(cpu)
450                 bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy;
451
452         printk(KERN_INFO "SMP: Total of %d processors activated "
453                "(%lu.%02lu BogoMIPS).\n",
454                num_online_cpus(),
455                bogosum / (500000/HZ),
456                (bogosum / (5000/HZ)) % 100);
457 }
458
459 void smp_icache_flush_range_others(unsigned long start, unsigned long end)
460 {
461         smp_flush_data.start = start;
462         smp_flush_data.end = end;
463
464         if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 0))
465                 printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n");
466 }
467 EXPORT_SYMBOL_GPL(smp_icache_flush_range_others);
468
469 #ifdef __ARCH_SYNC_CORE_DCACHE
470 unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));
471
472 void resync_core_dcache(void)
473 {
474         unsigned int cpu = get_cpu();
475         blackfin_invalidate_entire_dcache();
476         ++per_cpu(cpu_data, cpu).dcache_invld_count;
477         put_cpu();
478 }
479 EXPORT_SYMBOL(resync_core_dcache);
480 #endif