Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes...
[linux-2.6] / 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                         ipi_call_function(cpu, msg);
162                         break;
163                 case BFIN_IPI_CPU_STOP:
164                         ipi_cpu_stop(cpu);
165                         kfree(msg);
166                         break;
167                 default:
168                         printk(KERN_CRIT "CPU%u: Unknown IPI message \
169                         0x%lx\n", cpu, msg->type);
170                         kfree(msg);
171                         break;
172                 }
173         }
174         spin_unlock(&msg_queue->lock);
175         return IRQ_HANDLED;
176 }
177
178 static void ipi_queue_init(void)
179 {
180         unsigned int cpu;
181         struct ipi_message_queue *msg_queue;
182         for_each_possible_cpu(cpu) {
183                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
184                 INIT_LIST_HEAD(&msg_queue->head);
185                 spin_lock_init(&msg_queue->lock);
186                 msg_queue->count = 0;
187         }
188 }
189
190 int smp_call_function(void (*func)(void *info), void *info, int wait)
191 {
192         unsigned int cpu;
193         cpumask_t callmap;
194         unsigned long flags;
195         struct ipi_message_queue *msg_queue;
196         struct ipi_message *msg;
197
198         callmap = cpu_online_map;
199         cpu_clear(smp_processor_id(), callmap);
200         if (cpus_empty(callmap))
201                 return 0;
202
203         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
204         INIT_LIST_HEAD(&msg->list);
205         msg->call_struct.func = func;
206         msg->call_struct.info = info;
207         msg->call_struct.wait = wait;
208         msg->call_struct.pending = callmap;
209         msg->call_struct.waitmask = callmap;
210         msg->type = BFIN_IPI_CALL_FUNC;
211
212         for_each_cpu_mask(cpu, callmap) {
213                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
214                 spin_lock_irqsave(&msg_queue->lock, flags);
215                 list_add(&msg->list, &msg_queue->head);
216                 spin_unlock_irqrestore(&msg_queue->lock, flags);
217                 platform_send_ipi_cpu(cpu);
218         }
219         if (wait) {
220                 while (!cpus_empty(msg->call_struct.waitmask))
221                         blackfin_dcache_invalidate_range(
222                                 (unsigned long)(&msg->call_struct.waitmask),
223                                 (unsigned long)(&msg->call_struct.waitmask));
224                 kfree(msg);
225         }
226         return 0;
227 }
228 EXPORT_SYMBOL_GPL(smp_call_function);
229
230 int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
231                                 int wait)
232 {
233         unsigned int cpu = cpuid;
234         cpumask_t callmap;
235         unsigned long flags;
236         struct ipi_message_queue *msg_queue;
237         struct ipi_message *msg;
238
239         if (cpu_is_offline(cpu))
240                 return 0;
241         cpus_clear(callmap);
242         cpu_set(cpu, callmap);
243
244         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
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(&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 = kmalloc(sizeof(*msg), GFP_ATOMIC);
280         memset(msg, 0, sizeof(msg));
281         INIT_LIST_HEAD(&msg->list);
282         msg->type = BFIN_IPI_RESCHEDULE;
283
284         msg_queue = &per_cpu(ipi_msg_queue, cpu);
285         spin_lock_irqsave(&msg_queue->lock, flags);
286         list_add(&msg->list, &msg_queue->head);
287         spin_unlock_irqrestore(&msg_queue->lock, flags);
288         platform_send_ipi_cpu(cpu);
289
290         return;
291 }
292
293 void smp_send_stop(void)
294 {
295         unsigned int cpu;
296         cpumask_t callmap;
297         unsigned long flags;
298         struct ipi_message_queue *msg_queue;
299         struct ipi_message *msg;
300
301         callmap = cpu_online_map;
302         cpu_clear(smp_processor_id(), callmap);
303         if (cpus_empty(callmap))
304                 return;
305
306         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
307         memset(msg, 0, sizeof(msg));
308         INIT_LIST_HEAD(&msg->list);
309         msg->type = BFIN_IPI_CPU_STOP;
310
311         for_each_cpu_mask(cpu, callmap) {
312                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
313                 spin_lock_irqsave(&msg_queue->lock, flags);
314                 list_add(&msg->list, &msg_queue->head);
315                 spin_unlock_irqrestore(&msg_queue->lock, flags);
316                 platform_send_ipi_cpu(cpu);
317         }
318         return;
319 }
320
321 int __cpuinit __cpu_up(unsigned int cpu)
322 {
323         struct task_struct *idle;
324         int ret;
325
326         idle = fork_idle(cpu);
327         if (IS_ERR(idle)) {
328                 printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
329                 return PTR_ERR(idle);
330         }
331
332         secondary_stack = task_stack_page(idle) + THREAD_SIZE;
333         smp_wmb();
334
335         ret = platform_boot_secondary(cpu, idle);
336
337         if (ret) {
338                 cpu_clear(cpu, cpu_present_map);
339                 printk(KERN_CRIT "CPU%u: processor failed to boot (%d)\n", cpu, ret);
340                 free_task(idle);
341         } else
342                 cpu_set(cpu, cpu_online_map);
343
344         secondary_stack = NULL;
345
346         return ret;
347 }
348
349 static void __cpuinit setup_secondary(unsigned int cpu)
350 {
351 #if !(defined(CONFIG_TICK_SOURCE_SYSTMR0) || defined(CONFIG_IPIPE))
352         struct irq_desc *timer_desc;
353 #endif
354         unsigned long ilat;
355
356         bfin_write_IMASK(0);
357         CSYNC();
358         ilat = bfin_read_ILAT();
359         CSYNC();
360         bfin_write_ILAT(ilat);
361         CSYNC();
362
363         /* Reserve the PDA space for the secondary CPU. */
364         reserve_pda();
365
366         /* Enable interrupt levels IVG7-15. IARs have been already
367          * programmed by the boot CPU.  */
368         bfin_irq_flags |= IMASK_IVG15 |
369             IMASK_IVG14 | IMASK_IVG13 | IMASK_IVG12 | IMASK_IVG11 |
370             IMASK_IVG10 | IMASK_IVG9 | IMASK_IVG8 | IMASK_IVG7 | IMASK_IVGHW;
371
372 #if defined(CONFIG_TICK_SOURCE_SYSTMR0) || defined(CONFIG_IPIPE)
373         /* Power down the core timer, just to play safe. */
374         bfin_write_TCNTL(0);
375
376         /* system timer0 has been setup by CoreA. */
377 #else
378         timer_desc = irq_desc + IRQ_CORETMR;
379         setup_core_timer();
380         timer_desc->chip->enable(IRQ_CORETMR);
381 #endif
382 }
383
384 void __cpuinit secondary_start_kernel(void)
385 {
386         unsigned int cpu = smp_processor_id();
387         struct mm_struct *mm = &init_mm;
388
389         if (_bfin_swrst & SWRST_DBL_FAULT_B) {
390                 printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n");
391 #ifdef CONFIG_DEBUG_DOUBLEFAULT
392                 printk(KERN_EMERG " While handling exception (EXCAUSE = 0x%x) at %pF\n",
393                         (int)init_saved_seqstat_coreb & SEQSTAT_EXCAUSE, init_saved_retx_coreb);
394                 printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr_coreb);
395                 printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr_coreb);
396 #endif
397                 printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
398                         init_retx_coreb);
399         }
400
401         /*
402          * We want the D-cache to be enabled early, in case the atomic
403          * support code emulates cache coherence (see
404          * __ARCH_SYNC_CORE_DCACHE).
405          */
406         init_exception_vectors();
407
408         bfin_setup_caches(cpu);
409
410         local_irq_disable();
411
412         /* Attach the new idle task to the global mm. */
413         atomic_inc(&mm->mm_users);
414         atomic_inc(&mm->mm_count);
415         current->active_mm = mm;
416         BUG_ON(current->mm);    /* Can't be, but better be safe than sorry. */
417
418         preempt_disable();
419
420         setup_secondary(cpu);
421
422         local_irq_enable();
423
424         platform_secondary_init(cpu);
425
426         cpu_idle();
427 }
428
429 void __init smp_prepare_boot_cpu(void)
430 {
431 }
432
433 void __init smp_prepare_cpus(unsigned int max_cpus)
434 {
435         platform_prepare_cpus(max_cpus);
436         ipi_queue_init();
437         platform_request_ipi(&ipi_handler);
438 }
439
440 void __init smp_cpus_done(unsigned int max_cpus)
441 {
442         unsigned long bogosum = 0;
443         unsigned int cpu;
444
445         for_each_online_cpu(cpu)
446                 bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy;
447
448         printk(KERN_INFO "SMP: Total of %d processors activated "
449                "(%lu.%02lu BogoMIPS).\n",
450                num_online_cpus(),
451                bogosum / (500000/HZ),
452                (bogosum / (5000/HZ)) % 100);
453 }
454
455 void smp_icache_flush_range_others(unsigned long start, unsigned long end)
456 {
457         smp_flush_data.start = start;
458         smp_flush_data.end = end;
459
460         if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 1))
461                 printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n");
462 }
463 EXPORT_SYMBOL_GPL(smp_icache_flush_range_others);
464
465 #ifdef __ARCH_SYNC_CORE_DCACHE
466 unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));
467
468 void resync_core_dcache(void)
469 {
470         unsigned int cpu = get_cpu();
471         blackfin_invalidate_entire_dcache();
472         ++per_cpu(cpu_data, cpu).dcache_invld_count;
473         put_cpu();
474 }
475 EXPORT_SYMBOL(resync_core_dcache);
476 #endif