Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
[linux-2.6] / arch / powerpc / kernel / irq.c
1 /*
2  *  Derived from arch/i386/kernel/irq.c
3  *    Copyright (C) 1992 Linus Torvalds
4  *  Adapted from arch/i386 by Gary Thomas
5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
6  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
7  *    Copyright (C) 1996-2001 Cort Dougan
8  *  Adapted for Power Macintosh by Paul Mackerras
9  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License
13  * as published by the Free Software Foundation; either version
14  * 2 of the License, or (at your option) any later version.
15  *
16  * This file contains the code used by various IRQ handling routines:
17  * asking for different IRQ's should be done through these routines
18  * instead of just grabbing them. Thus setups with different IRQ numbers
19  * shouldn't result in any weird surprises, and installing new handlers
20  * should be easier.
21  *
22  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
23  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
24  * mask register (of which only 16 are defined), hence the weird shifting
25  * and complement of the cached_irq_mask.  I want to be able to stuff
26  * this right into the SIU SMASK register.
27  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
28  * to reduce code space and undefined function references.
29  */
30
31 #undef DEBUG
32
33 #include <linux/module.h>
34 #include <linux/threads.h>
35 #include <linux/kernel_stat.h>
36 #include <linux/signal.h>
37 #include <linux/sched.h>
38 #include <linux/ptrace.h>
39 #include <linux/ioport.h>
40 #include <linux/interrupt.h>
41 #include <linux/timex.h>
42 #include <linux/init.h>
43 #include <linux/slab.h>
44 #include <linux/delay.h>
45 #include <linux/irq.h>
46 #include <linux/seq_file.h>
47 #include <linux/cpumask.h>
48 #include <linux/profile.h>
49 #include <linux/bitops.h>
50 #include <linux/list.h>
51 #include <linux/radix-tree.h>
52 #include <linux/mutex.h>
53 #include <linux/bootmem.h>
54 #include <linux/pci.h>
55 #include <linux/debugfs.h>
56
57 #include <asm/uaccess.h>
58 #include <asm/system.h>
59 #include <asm/io.h>
60 #include <asm/pgtable.h>
61 #include <asm/irq.h>
62 #include <asm/cache.h>
63 #include <asm/prom.h>
64 #include <asm/ptrace.h>
65 #include <asm/machdep.h>
66 #include <asm/udbg.h>
67 #ifdef CONFIG_PPC64
68 #include <asm/paca.h>
69 #include <asm/firmware.h>
70 #include <asm/lv1call.h>
71 #endif
72
73 int __irq_offset_value;
74 static int ppc_spurious_interrupts;
75
76 #ifdef CONFIG_PPC32
77 EXPORT_SYMBOL(__irq_offset_value);
78 atomic_t ppc_n_lost_interrupts;
79
80 #ifdef CONFIG_TAU_INT
81 extern int tau_initialized;
82 extern int tau_interrupts(int);
83 #endif
84 #endif /* CONFIG_PPC32 */
85
86 #ifdef CONFIG_PPC64
87 EXPORT_SYMBOL(irq_desc);
88
89 int distribute_irqs = 1;
90
91 static inline notrace unsigned long get_hard_enabled(void)
92 {
93         unsigned long enabled;
94
95         __asm__ __volatile__("lbz %0,%1(13)"
96         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
97
98         return enabled;
99 }
100
101 static inline notrace void set_soft_enabled(unsigned long enable)
102 {
103         __asm__ __volatile__("stb %0,%1(13)"
104         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
105 }
106
107 notrace void raw_local_irq_restore(unsigned long en)
108 {
109         /*
110          * get_paca()->soft_enabled = en;
111          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
112          * That was allowed before, and in such a case we do need to take care
113          * that gcc will set soft_enabled directly via r13, not choose to use
114          * an intermediate register, lest we're preempted to a different cpu.
115          */
116         set_soft_enabled(en);
117         if (!en)
118                 return;
119
120         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
121                 /*
122                  * Do we need to disable preemption here?  Not really: in the
123                  * unlikely event that we're preempted to a different cpu in
124                  * between getting r13, loading its lppaca_ptr, and loading
125                  * its any_int, we might call iseries_handle_interrupts without
126                  * an interrupt pending on the new cpu, but that's no disaster,
127                  * is it?  And the business of preempting us off the old cpu
128                  * would itself involve a local_irq_restore which handles the
129                  * interrupt to that cpu.
130                  *
131                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
132                  * to avoid any preemption checking added into get_paca().
133                  */
134                 if (local_paca->lppaca_ptr->int_dword.any_int)
135                         iseries_handle_interrupts();
136         }
137
138         /*
139          * if (get_paca()->hard_enabled) return;
140          * But again we need to take care that gcc gets hard_enabled directly
141          * via r13, not choose to use an intermediate register, lest we're
142          * preempted to a different cpu in between the two instructions.
143          */
144         if (get_hard_enabled())
145                 return;
146
147         /*
148          * Need to hard-enable interrupts here.  Since currently disabled,
149          * no need to take further asm precautions against preemption; but
150          * use local_paca instead of get_paca() to avoid preemption checking.
151          */
152         local_paca->hard_enabled = en;
153         if ((int)mfspr(SPRN_DEC) < 0)
154                 mtspr(SPRN_DEC, 1);
155
156         /*
157          * Force the delivery of pending soft-disabled interrupts on PS3.
158          * Any HV call will have this side effect.
159          */
160         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
161                 u64 tmp;
162                 lv1_get_version_info(&tmp);
163         }
164
165         __hard_irq_enable();
166 }
167 EXPORT_SYMBOL(raw_local_irq_restore);
168 #endif /* CONFIG_PPC64 */
169
170 int show_interrupts(struct seq_file *p, void *v)
171 {
172         int i = *(loff_t *)v, j;
173         struct irqaction *action;
174         struct irq_desc *desc;
175         unsigned long flags;
176
177         if (i == 0) {
178                 seq_puts(p, "           ");
179                 for_each_online_cpu(j)
180                         seq_printf(p, "CPU%d       ", j);
181                 seq_putc(p, '\n');
182         }
183
184         if (i < NR_IRQS) {
185                 desc = get_irq_desc(i);
186                 spin_lock_irqsave(&desc->lock, flags);
187                 action = desc->action;
188                 if (!action || !action->handler)
189                         goto skip;
190                 seq_printf(p, "%3d: ", i);
191 #ifdef CONFIG_SMP
192                 for_each_online_cpu(j)
193                         seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
194 #else
195                 seq_printf(p, "%10u ", kstat_irqs(i));
196 #endif /* CONFIG_SMP */
197                 if (desc->chip)
198                         seq_printf(p, " %s ", desc->chip->typename);
199                 else
200                         seq_puts(p, "  None      ");
201                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
202                 seq_printf(p, "    %s", action->name);
203                 for (action = action->next; action; action = action->next)
204                         seq_printf(p, ", %s", action->name);
205                 seq_putc(p, '\n');
206 skip:
207                 spin_unlock_irqrestore(&desc->lock, flags);
208         } else if (i == NR_IRQS) {
209 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
210                 if (tau_initialized){
211                         seq_puts(p, "TAU: ");
212                         for_each_online_cpu(j)
213                                 seq_printf(p, "%10u ", tau_interrupts(j));
214                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
215                 }
216 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT*/
217                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
218         }
219         return 0;
220 }
221
222 #ifdef CONFIG_HOTPLUG_CPU
223 void fixup_irqs(cpumask_t map)
224 {
225         unsigned int irq;
226         static int warned;
227
228         for_each_irq(irq) {
229                 cpumask_t mask;
230
231                 if (irq_desc[irq].status & IRQ_PER_CPU)
232                         continue;
233
234                 cpumask_and(&mask, irq_desc[irq].affinity, &map);
235                 if (any_online_cpu(mask) == NR_CPUS) {
236                         printk("Breaking affinity for irq %i\n", irq);
237                         mask = map;
238                 }
239                 if (irq_desc[irq].chip->set_affinity)
240                         irq_desc[irq].chip->set_affinity(irq, &mask);
241                 else if (irq_desc[irq].action && !(warned++))
242                         printk("Cannot set affinity for irq %i\n", irq);
243         }
244
245         local_irq_enable();
246         mdelay(1);
247         local_irq_disable();
248 }
249 #endif
250
251 void do_IRQ(struct pt_regs *regs)
252 {
253         struct pt_regs *old_regs = set_irq_regs(regs);
254         unsigned int irq;
255 #ifdef CONFIG_IRQSTACKS
256         struct thread_info *curtp, *irqtp;
257 #endif
258
259         irq_enter();
260
261 #ifdef CONFIG_DEBUG_STACKOVERFLOW
262         /* Debugging check for stack overflow: is there less than 2KB free? */
263         {
264                 long sp;
265
266                 sp = __get_SP() & (THREAD_SIZE-1);
267
268                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
269                         printk("do_IRQ: stack overflow: %ld\n",
270                                 sp - sizeof(struct thread_info));
271                         dump_stack();
272                 }
273         }
274 #endif
275
276         /*
277          * Every platform is required to implement ppc_md.get_irq.
278          * This function will either return an irq number or NO_IRQ to
279          * indicate there are no more pending.
280          * The value NO_IRQ_IGNORE is for buggy hardware and means that this
281          * IRQ has already been handled. -- Tom
282          */
283         irq = ppc_md.get_irq();
284
285         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
286 #ifdef CONFIG_IRQSTACKS
287                 /* Switch to the irq stack to handle this */
288                 curtp = current_thread_info();
289                 irqtp = hardirq_ctx[smp_processor_id()];
290                 if (curtp != irqtp) {
291                         struct irq_desc *desc = irq_desc + irq;
292                         void *handler = desc->handle_irq;
293                         unsigned long saved_sp_limit = current->thread.ksp_limit;
294                         if (handler == NULL)
295                                 handler = &__do_IRQ;
296                         irqtp->task = curtp->task;
297                         irqtp->flags = 0;
298
299                         /* Copy the softirq bits in preempt_count so that the
300                          * softirq checks work in the hardirq context.
301                          */
302                         irqtp->preempt_count =
303                                 (irqtp->preempt_count & ~SOFTIRQ_MASK) |
304                                 (curtp->preempt_count & SOFTIRQ_MASK);
305
306                         current->thread.ksp_limit = (unsigned long)irqtp +
307                                 _ALIGN_UP(sizeof(struct thread_info), 16);
308                         call_handle_irq(irq, desc, irqtp, handler);
309                         current->thread.ksp_limit = saved_sp_limit;
310                         irqtp->task = NULL;
311
312
313                         /* Set any flag that may have been set on the
314                          * alternate stack
315                          */
316                         if (irqtp->flags)
317                                 set_bits(irqtp->flags, &curtp->flags);
318                 } else
319 #endif
320                         generic_handle_irq(irq);
321         } else if (irq != NO_IRQ_IGNORE)
322                 /* That's not SMP safe ... but who cares ? */
323                 ppc_spurious_interrupts++;
324
325         irq_exit();
326         set_irq_regs(old_regs);
327
328 #ifdef CONFIG_PPC_ISERIES
329         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
330                         get_lppaca()->int_dword.fields.decr_int) {
331                 get_lppaca()->int_dword.fields.decr_int = 0;
332                 /* Signal a fake decrementer interrupt */
333                 timer_interrupt(regs);
334         }
335 #endif
336 }
337
338 void __init init_IRQ(void)
339 {
340         if (ppc_md.init_IRQ)
341                 ppc_md.init_IRQ();
342
343         exc_lvl_ctx_init();
344
345         irq_ctx_init();
346 }
347
348 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
349 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
350 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
351 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
352
353 void exc_lvl_ctx_init(void)
354 {
355         struct thread_info *tp;
356         int i;
357
358         for_each_possible_cpu(i) {
359                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
360                 tp = critirq_ctx[i];
361                 tp->cpu = i;
362                 tp->preempt_count = 0;
363
364 #ifdef CONFIG_BOOKE
365                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
366                 tp = dbgirq_ctx[i];
367                 tp->cpu = i;
368                 tp->preempt_count = 0;
369
370                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
371                 tp = mcheckirq_ctx[i];
372                 tp->cpu = i;
373                 tp->preempt_count = HARDIRQ_OFFSET;
374 #endif
375         }
376 }
377 #endif
378
379 #ifdef CONFIG_IRQSTACKS
380 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
381 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
382
383 void irq_ctx_init(void)
384 {
385         struct thread_info *tp;
386         int i;
387
388         for_each_possible_cpu(i) {
389                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
390                 tp = softirq_ctx[i];
391                 tp->cpu = i;
392                 tp->preempt_count = 0;
393
394                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
395                 tp = hardirq_ctx[i];
396                 tp->cpu = i;
397                 tp->preempt_count = HARDIRQ_OFFSET;
398         }
399 }
400
401 static inline void do_softirq_onstack(void)
402 {
403         struct thread_info *curtp, *irqtp;
404         unsigned long saved_sp_limit = current->thread.ksp_limit;
405
406         curtp = current_thread_info();
407         irqtp = softirq_ctx[smp_processor_id()];
408         irqtp->task = curtp->task;
409         current->thread.ksp_limit = (unsigned long)irqtp +
410                                     _ALIGN_UP(sizeof(struct thread_info), 16);
411         call_do_softirq(irqtp);
412         current->thread.ksp_limit = saved_sp_limit;
413         irqtp->task = NULL;
414 }
415
416 #else
417 #define do_softirq_onstack()    __do_softirq()
418 #endif /* CONFIG_IRQSTACKS */
419
420 void do_softirq(void)
421 {
422         unsigned long flags;
423
424         if (in_interrupt())
425                 return;
426
427         local_irq_save(flags);
428
429         if (local_softirq_pending())
430                 do_softirq_onstack();
431
432         local_irq_restore(flags);
433 }
434
435
436 /*
437  * IRQ controller and virtual interrupts
438  */
439
440 static LIST_HEAD(irq_hosts);
441 static DEFINE_SPINLOCK(irq_big_lock);
442 static unsigned int revmap_trees_allocated;
443 static DEFINE_MUTEX(revmap_trees_mutex);
444 struct irq_map_entry irq_map[NR_IRQS];
445 static unsigned int irq_virq_count = NR_IRQS;
446 static struct irq_host *irq_default_host;
447
448 irq_hw_number_t virq_to_hw(unsigned int virq)
449 {
450         return irq_map[virq].hwirq;
451 }
452 EXPORT_SYMBOL_GPL(virq_to_hw);
453
454 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
455 {
456         return h->of_node != NULL && h->of_node == np;
457 }
458
459 struct irq_host *irq_alloc_host(struct device_node *of_node,
460                                 unsigned int revmap_type,
461                                 unsigned int revmap_arg,
462                                 struct irq_host_ops *ops,
463                                 irq_hw_number_t inval_irq)
464 {
465         struct irq_host *host;
466         unsigned int size = sizeof(struct irq_host);
467         unsigned int i;
468         unsigned int *rmap;
469         unsigned long flags;
470
471         /* Allocate structure and revmap table if using linear mapping */
472         if (revmap_type == IRQ_HOST_MAP_LINEAR)
473                 size += revmap_arg * sizeof(unsigned int);
474         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
475         if (host == NULL)
476                 return NULL;
477
478         /* Fill structure */
479         host->revmap_type = revmap_type;
480         host->inval_irq = inval_irq;
481         host->ops = ops;
482         host->of_node = of_node_get(of_node);
483
484         if (host->ops->match == NULL)
485                 host->ops->match = default_irq_host_match;
486
487         spin_lock_irqsave(&irq_big_lock, flags);
488
489         /* If it's a legacy controller, check for duplicates and
490          * mark it as allocated (we use irq 0 host pointer for that
491          */
492         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
493                 if (irq_map[0].host != NULL) {
494                         spin_unlock_irqrestore(&irq_big_lock, flags);
495                         /* If we are early boot, we can't free the structure,
496                          * too bad...
497                          * this will be fixed once slab is made available early
498                          * instead of the current cruft
499                          */
500                         if (mem_init_done)
501                                 kfree(host);
502                         return NULL;
503                 }
504                 irq_map[0].host = host;
505         }
506
507         list_add(&host->link, &irq_hosts);
508         spin_unlock_irqrestore(&irq_big_lock, flags);
509
510         /* Additional setups per revmap type */
511         switch(revmap_type) {
512         case IRQ_HOST_MAP_LEGACY:
513                 /* 0 is always the invalid number for legacy */
514                 host->inval_irq = 0;
515                 /* setup us as the host for all legacy interrupts */
516                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
517                         irq_map[i].hwirq = i;
518                         smp_wmb();
519                         irq_map[i].host = host;
520                         smp_wmb();
521
522                         /* Clear norequest flags */
523                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
524
525                         /* Legacy flags are left to default at this point,
526                          * one can then use irq_create_mapping() to
527                          * explicitly change them
528                          */
529                         ops->map(host, i, i);
530                 }
531                 break;
532         case IRQ_HOST_MAP_LINEAR:
533                 rmap = (unsigned int *)(host + 1);
534                 for (i = 0; i < revmap_arg; i++)
535                         rmap[i] = NO_IRQ;
536                 host->revmap_data.linear.size = revmap_arg;
537                 smp_wmb();
538                 host->revmap_data.linear.revmap = rmap;
539                 break;
540         default:
541                 break;
542         }
543
544         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
545
546         return host;
547 }
548
549 struct irq_host *irq_find_host(struct device_node *node)
550 {
551         struct irq_host *h, *found = NULL;
552         unsigned long flags;
553
554         /* We might want to match the legacy controller last since
555          * it might potentially be set to match all interrupts in
556          * the absence of a device node. This isn't a problem so far
557          * yet though...
558          */
559         spin_lock_irqsave(&irq_big_lock, flags);
560         list_for_each_entry(h, &irq_hosts, link)
561                 if (h->ops->match(h, node)) {
562                         found = h;
563                         break;
564                 }
565         spin_unlock_irqrestore(&irq_big_lock, flags);
566         return found;
567 }
568 EXPORT_SYMBOL_GPL(irq_find_host);
569
570 void irq_set_default_host(struct irq_host *host)
571 {
572         pr_debug("irq: Default host set to @0x%p\n", host);
573
574         irq_default_host = host;
575 }
576
577 void irq_set_virq_count(unsigned int count)
578 {
579         pr_debug("irq: Trying to set virq count to %d\n", count);
580
581         BUG_ON(count < NUM_ISA_INTERRUPTS);
582         if (count < NR_IRQS)
583                 irq_virq_count = count;
584 }
585
586 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
587                             irq_hw_number_t hwirq)
588 {
589         /* Clear IRQ_NOREQUEST flag */
590         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
591
592         /* map it */
593         smp_wmb();
594         irq_map[virq].hwirq = hwirq;
595         smp_mb();
596
597         if (host->ops->map(host, virq, hwirq)) {
598                 pr_debug("irq: -> mapping failed, freeing\n");
599                 irq_free_virt(virq, 1);
600                 return -1;
601         }
602
603         return 0;
604 }
605
606 unsigned int irq_create_direct_mapping(struct irq_host *host)
607 {
608         unsigned int virq;
609
610         if (host == NULL)
611                 host = irq_default_host;
612
613         BUG_ON(host == NULL);
614         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
615
616         virq = irq_alloc_virt(host, 1, 0);
617         if (virq == NO_IRQ) {
618                 pr_debug("irq: create_direct virq allocation failed\n");
619                 return NO_IRQ;
620         }
621
622         pr_debug("irq: create_direct obtained virq %d\n", virq);
623
624         if (irq_setup_virq(host, virq, virq))
625                 return NO_IRQ;
626
627         return virq;
628 }
629
630 unsigned int irq_create_mapping(struct irq_host *host,
631                                 irq_hw_number_t hwirq)
632 {
633         unsigned int virq, hint;
634
635         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
636
637         /* Look for default host if nececssary */
638         if (host == NULL)
639                 host = irq_default_host;
640         if (host == NULL) {
641                 printk(KERN_WARNING "irq_create_mapping called for"
642                        " NULL host, hwirq=%lx\n", hwirq);
643                 WARN_ON(1);
644                 return NO_IRQ;
645         }
646         pr_debug("irq: -> using host @%p\n", host);
647
648         /* Check if mapping already exist, if it does, call
649          * host->ops->map() to update the flags
650          */
651         virq = irq_find_mapping(host, hwirq);
652         if (virq != NO_IRQ) {
653                 if (host->ops->remap)
654                         host->ops->remap(host, virq, hwirq);
655                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
656                 return virq;
657         }
658
659         /* Get a virtual interrupt number */
660         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
661                 /* Handle legacy */
662                 virq = (unsigned int)hwirq;
663                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
664                         return NO_IRQ;
665                 return virq;
666         } else {
667                 /* Allocate a virtual interrupt number */
668                 hint = hwirq % irq_virq_count;
669                 virq = irq_alloc_virt(host, 1, hint);
670                 if (virq == NO_IRQ) {
671                         pr_debug("irq: -> virq allocation failed\n");
672                         return NO_IRQ;
673                 }
674         }
675
676         if (irq_setup_virq(host, virq, hwirq))
677                 return NO_IRQ;
678
679         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
680                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
681
682         return virq;
683 }
684 EXPORT_SYMBOL_GPL(irq_create_mapping);
685
686 unsigned int irq_create_of_mapping(struct device_node *controller,
687                                    u32 *intspec, unsigned int intsize)
688 {
689         struct irq_host *host;
690         irq_hw_number_t hwirq;
691         unsigned int type = IRQ_TYPE_NONE;
692         unsigned int virq;
693
694         if (controller == NULL)
695                 host = irq_default_host;
696         else
697                 host = irq_find_host(controller);
698         if (host == NULL) {
699                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
700                        controller->full_name);
701                 return NO_IRQ;
702         }
703
704         /* If host has no translation, then we assume interrupt line */
705         if (host->ops->xlate == NULL)
706                 hwirq = intspec[0];
707         else {
708                 if (host->ops->xlate(host, controller, intspec, intsize,
709                                      &hwirq, &type))
710                         return NO_IRQ;
711         }
712
713         /* Create mapping */
714         virq = irq_create_mapping(host, hwirq);
715         if (virq == NO_IRQ)
716                 return virq;
717
718         /* Set type if specified and different than the current one */
719         if (type != IRQ_TYPE_NONE &&
720             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
721                 set_irq_type(virq, type);
722         return virq;
723 }
724 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
725
726 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
727 {
728         struct of_irq oirq;
729
730         if (of_irq_map_one(dev, index, &oirq))
731                 return NO_IRQ;
732
733         return irq_create_of_mapping(oirq.controller, oirq.specifier,
734                                      oirq.size);
735 }
736 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
737
738 void irq_dispose_mapping(unsigned int virq)
739 {
740         struct irq_host *host;
741         irq_hw_number_t hwirq;
742
743         if (virq == NO_IRQ)
744                 return;
745
746         host = irq_map[virq].host;
747         WARN_ON (host == NULL);
748         if (host == NULL)
749                 return;
750
751         /* Never unmap legacy interrupts */
752         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
753                 return;
754
755         /* remove chip and handler */
756         set_irq_chip_and_handler(virq, NULL, NULL);
757
758         /* Make sure it's completed */
759         synchronize_irq(virq);
760
761         /* Tell the PIC about it */
762         if (host->ops->unmap)
763                 host->ops->unmap(host, virq);
764         smp_mb();
765
766         /* Clear reverse map */
767         hwirq = irq_map[virq].hwirq;
768         switch(host->revmap_type) {
769         case IRQ_HOST_MAP_LINEAR:
770                 if (hwirq < host->revmap_data.linear.size)
771                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
772                 break;
773         case IRQ_HOST_MAP_TREE:
774                 /*
775                  * Check if radix tree allocated yet, if not then nothing to
776                  * remove.
777                  */
778                 smp_rmb();
779                 if (revmap_trees_allocated < 1)
780                         break;
781                 mutex_lock(&revmap_trees_mutex);
782                 radix_tree_delete(&host->revmap_data.tree, hwirq);
783                 mutex_unlock(&revmap_trees_mutex);
784                 break;
785         }
786
787         /* Destroy map */
788         smp_mb();
789         irq_map[virq].hwirq = host->inval_irq;
790
791         /* Set some flags */
792         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
793
794         /* Free it */
795         irq_free_virt(virq, 1);
796 }
797 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
798
799 unsigned int irq_find_mapping(struct irq_host *host,
800                               irq_hw_number_t hwirq)
801 {
802         unsigned int i;
803         unsigned int hint = hwirq % irq_virq_count;
804
805         /* Look for default host if nececssary */
806         if (host == NULL)
807                 host = irq_default_host;
808         if (host == NULL)
809                 return NO_IRQ;
810
811         /* legacy -> bail early */
812         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
813                 return hwirq;
814
815         /* Slow path does a linear search of the map */
816         if (hint < NUM_ISA_INTERRUPTS)
817                 hint = NUM_ISA_INTERRUPTS;
818         i = hint;
819         do  {
820                 if (irq_map[i].host == host &&
821                     irq_map[i].hwirq == hwirq)
822                         return i;
823                 i++;
824                 if (i >= irq_virq_count)
825                         i = NUM_ISA_INTERRUPTS;
826         } while(i != hint);
827         return NO_IRQ;
828 }
829 EXPORT_SYMBOL_GPL(irq_find_mapping);
830
831
832 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
833                                      irq_hw_number_t hwirq)
834 {
835         struct irq_map_entry *ptr;
836         unsigned int virq;
837
838         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
839
840         /*
841          * Check if the radix tree exists and has bee initialized.
842          * If not, we fallback to slow mode
843          */
844         if (revmap_trees_allocated < 2)
845                 return irq_find_mapping(host, hwirq);
846
847         /* Now try to resolve */
848         /*
849          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
850          * as it's referencing an entry in the static irq_map table.
851          */
852         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
853
854         /*
855          * If found in radix tree, then fine.
856          * Else fallback to linear lookup - this should not happen in practice
857          * as it means that we failed to insert the node in the radix tree.
858          */
859         if (ptr)
860                 virq = ptr - irq_map;
861         else
862                 virq = irq_find_mapping(host, hwirq);
863
864         return virq;
865 }
866
867 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
868                              irq_hw_number_t hwirq)
869 {
870
871         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
872
873         /*
874          * Check if the radix tree exists yet.
875          * If not, then the irq will be inserted into the tree when it gets
876          * initialized.
877          */
878         smp_rmb();
879         if (revmap_trees_allocated < 1)
880                 return;
881
882         if (virq != NO_IRQ) {
883                 mutex_lock(&revmap_trees_mutex);
884                 radix_tree_insert(&host->revmap_data.tree, hwirq,
885                                   &irq_map[virq]);
886                 mutex_unlock(&revmap_trees_mutex);
887         }
888 }
889
890 unsigned int irq_linear_revmap(struct irq_host *host,
891                                irq_hw_number_t hwirq)
892 {
893         unsigned int *revmap;
894
895         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
896
897         /* Check revmap bounds */
898         if (unlikely(hwirq >= host->revmap_data.linear.size))
899                 return irq_find_mapping(host, hwirq);
900
901         /* Check if revmap was allocated */
902         revmap = host->revmap_data.linear.revmap;
903         if (unlikely(revmap == NULL))
904                 return irq_find_mapping(host, hwirq);
905
906         /* Fill up revmap with slow path if no mapping found */
907         if (unlikely(revmap[hwirq] == NO_IRQ))
908                 revmap[hwirq] = irq_find_mapping(host, hwirq);
909
910         return revmap[hwirq];
911 }
912
913 unsigned int irq_alloc_virt(struct irq_host *host,
914                             unsigned int count,
915                             unsigned int hint)
916 {
917         unsigned long flags;
918         unsigned int i, j, found = NO_IRQ;
919
920         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
921                 return NO_IRQ;
922
923         spin_lock_irqsave(&irq_big_lock, flags);
924
925         /* Use hint for 1 interrupt if any */
926         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
927             hint < irq_virq_count && irq_map[hint].host == NULL) {
928                 found = hint;
929                 goto hint_found;
930         }
931
932         /* Look for count consecutive numbers in the allocatable
933          * (non-legacy) space
934          */
935         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
936                 if (irq_map[i].host != NULL)
937                         j = 0;
938                 else
939                         j++;
940
941                 if (j == count) {
942                         found = i - count + 1;
943                         break;
944                 }
945         }
946         if (found == NO_IRQ) {
947                 spin_unlock_irqrestore(&irq_big_lock, flags);
948                 return NO_IRQ;
949         }
950  hint_found:
951         for (i = found; i < (found + count); i++) {
952                 irq_map[i].hwirq = host->inval_irq;
953                 smp_wmb();
954                 irq_map[i].host = host;
955         }
956         spin_unlock_irqrestore(&irq_big_lock, flags);
957         return found;
958 }
959
960 void irq_free_virt(unsigned int virq, unsigned int count)
961 {
962         unsigned long flags;
963         unsigned int i;
964
965         WARN_ON (virq < NUM_ISA_INTERRUPTS);
966         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
967
968         spin_lock_irqsave(&irq_big_lock, flags);
969         for (i = virq; i < (virq + count); i++) {
970                 struct irq_host *host;
971
972                 if (i < NUM_ISA_INTERRUPTS ||
973                     (virq + count) > irq_virq_count)
974                         continue;
975
976                 host = irq_map[i].host;
977                 irq_map[i].hwirq = host->inval_irq;
978                 smp_wmb();
979                 irq_map[i].host = NULL;
980         }
981         spin_unlock_irqrestore(&irq_big_lock, flags);
982 }
983
984 void irq_early_init(void)
985 {
986         unsigned int i;
987
988         for (i = 0; i < NR_IRQS; i++)
989                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
990 }
991
992 /* We need to create the radix trees late */
993 static int irq_late_init(void)
994 {
995         struct irq_host *h;
996         unsigned int i;
997
998         /*
999          * No mutual exclusion with respect to accessors of the tree is needed
1000          * here as the synchronization is done via the state variable
1001          * revmap_trees_allocated.
1002          */
1003         list_for_each_entry(h, &irq_hosts, link) {
1004                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1005                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1006         }
1007
1008         /*
1009          * Make sure the radix trees inits are visible before setting
1010          * the flag
1011          */
1012         smp_wmb();
1013         revmap_trees_allocated = 1;
1014
1015         /*
1016          * Insert the reverse mapping for those interrupts already present
1017          * in irq_map[].
1018          */
1019         mutex_lock(&revmap_trees_mutex);
1020         for (i = 0; i < irq_virq_count; i++) {
1021                 if (irq_map[i].host &&
1022                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1023                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1024                                           irq_map[i].hwirq, &irq_map[i]);
1025         }
1026         mutex_unlock(&revmap_trees_mutex);
1027
1028         /*
1029          * Make sure the radix trees insertions are visible before setting
1030          * the flag
1031          */
1032         smp_wmb();
1033         revmap_trees_allocated = 2;
1034
1035         return 0;
1036 }
1037 arch_initcall(irq_late_init);
1038
1039 #ifdef CONFIG_VIRQ_DEBUG
1040 static int virq_debug_show(struct seq_file *m, void *private)
1041 {
1042         unsigned long flags;
1043         struct irq_desc *desc;
1044         const char *p;
1045         char none[] = "none";
1046         int i;
1047
1048         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1049                       "chip name", "host name");
1050
1051         for (i = 1; i < NR_IRQS; i++) {
1052                 desc = get_irq_desc(i);
1053                 spin_lock_irqsave(&desc->lock, flags);
1054
1055                 if (desc->action && desc->action->handler) {
1056                         seq_printf(m, "%5d  ", i);
1057                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1058
1059                         if (desc->chip && desc->chip->typename)
1060                                 p = desc->chip->typename;
1061                         else
1062                                 p = none;
1063                         seq_printf(m, "%-15s  ", p);
1064
1065                         if (irq_map[i].host && irq_map[i].host->of_node)
1066                                 p = irq_map[i].host->of_node->full_name;
1067                         else
1068                                 p = none;
1069                         seq_printf(m, "%s\n", p);
1070                 }
1071
1072                 spin_unlock_irqrestore(&desc->lock, flags);
1073         }
1074
1075         return 0;
1076 }
1077
1078 static int virq_debug_open(struct inode *inode, struct file *file)
1079 {
1080         return single_open(file, virq_debug_show, inode->i_private);
1081 }
1082
1083 static const struct file_operations virq_debug_fops = {
1084         .open = virq_debug_open,
1085         .read = seq_read,
1086         .llseek = seq_lseek,
1087         .release = single_release,
1088 };
1089
1090 static int __init irq_debugfs_init(void)
1091 {
1092         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1093                                  NULL, &virq_debug_fops) == NULL)
1094                 return -ENOMEM;
1095
1096         return 0;
1097 }
1098 __initcall(irq_debugfs_init);
1099 #endif /* CONFIG_VIRQ_DEBUG */
1100
1101 #ifdef CONFIG_PPC64
1102 static int __init setup_noirqdistrib(char *str)
1103 {
1104         distribute_irqs = 0;
1105         return 1;
1106 }
1107
1108 __setup("noirqdistrib", setup_noirqdistrib);
1109 #endif /* CONFIG_PPC64 */