Merge commit 'v2.6.27-rc7' into x86/debug
[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         irq_desc_t *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_cpu(j).irqs[i]);
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                 cpus_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 DEFINE_PER_CPU(unsigned int, irq_radix_reader);
443 static unsigned int irq_radix_writer;
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 /* radix tree not lockless safe ! we use a brlock-type mecanism
587  * for now, until we can use a lockless radix tree
588  */
589 static void irq_radix_wrlock(unsigned long *flags)
590 {
591         unsigned int cpu, ok;
592
593         spin_lock_irqsave(&irq_big_lock, *flags);
594         irq_radix_writer = 1;
595         smp_mb();
596         do {
597                 barrier();
598                 ok = 1;
599                 for_each_possible_cpu(cpu) {
600                         if (per_cpu(irq_radix_reader, cpu)) {
601                                 ok = 0;
602                                 break;
603                         }
604                 }
605                 if (!ok)
606                         cpu_relax();
607         } while(!ok);
608 }
609
610 static void irq_radix_wrunlock(unsigned long flags)
611 {
612         smp_wmb();
613         irq_radix_writer = 0;
614         spin_unlock_irqrestore(&irq_big_lock, flags);
615 }
616
617 static void irq_radix_rdlock(unsigned long *flags)
618 {
619         local_irq_save(*flags);
620         __get_cpu_var(irq_radix_reader) = 1;
621         smp_mb();
622         if (likely(irq_radix_writer == 0))
623                 return;
624         __get_cpu_var(irq_radix_reader) = 0;
625         smp_wmb();
626         spin_lock(&irq_big_lock);
627         __get_cpu_var(irq_radix_reader) = 1;
628         spin_unlock(&irq_big_lock);
629 }
630
631 static void irq_radix_rdunlock(unsigned long flags)
632 {
633         __get_cpu_var(irq_radix_reader) = 0;
634         local_irq_restore(flags);
635 }
636
637 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
638                             irq_hw_number_t hwirq)
639 {
640         /* Clear IRQ_NOREQUEST flag */
641         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
642
643         /* map it */
644         smp_wmb();
645         irq_map[virq].hwirq = hwirq;
646         smp_mb();
647
648         if (host->ops->map(host, virq, hwirq)) {
649                 pr_debug("irq: -> mapping failed, freeing\n");
650                 irq_free_virt(virq, 1);
651                 return -1;
652         }
653
654         return 0;
655 }
656
657 unsigned int irq_create_direct_mapping(struct irq_host *host)
658 {
659         unsigned int virq;
660
661         if (host == NULL)
662                 host = irq_default_host;
663
664         BUG_ON(host == NULL);
665         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
666
667         virq = irq_alloc_virt(host, 1, 0);
668         if (virq == NO_IRQ) {
669                 pr_debug("irq: create_direct virq allocation failed\n");
670                 return NO_IRQ;
671         }
672
673         pr_debug("irq: create_direct obtained virq %d\n", virq);
674
675         if (irq_setup_virq(host, virq, virq))
676                 return NO_IRQ;
677
678         return virq;
679 }
680
681 unsigned int irq_create_mapping(struct irq_host *host,
682                                 irq_hw_number_t hwirq)
683 {
684         unsigned int virq, hint;
685
686         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
687
688         /* Look for default host if nececssary */
689         if (host == NULL)
690                 host = irq_default_host;
691         if (host == NULL) {
692                 printk(KERN_WARNING "irq_create_mapping called for"
693                        " NULL host, hwirq=%lx\n", hwirq);
694                 WARN_ON(1);
695                 return NO_IRQ;
696         }
697         pr_debug("irq: -> using host @%p\n", host);
698
699         /* Check if mapping already exist, if it does, call
700          * host->ops->map() to update the flags
701          */
702         virq = irq_find_mapping(host, hwirq);
703         if (virq != NO_IRQ) {
704                 if (host->ops->remap)
705                         host->ops->remap(host, virq, hwirq);
706                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
707                 return virq;
708         }
709
710         /* Get a virtual interrupt number */
711         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
712                 /* Handle legacy */
713                 virq = (unsigned int)hwirq;
714                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
715                         return NO_IRQ;
716                 return virq;
717         } else {
718                 /* Allocate a virtual interrupt number */
719                 hint = hwirq % irq_virq_count;
720                 virq = irq_alloc_virt(host, 1, hint);
721                 if (virq == NO_IRQ) {
722                         pr_debug("irq: -> virq allocation failed\n");
723                         return NO_IRQ;
724                 }
725         }
726         pr_debug("irq: -> obtained virq %d\n", virq);
727
728         if (irq_setup_virq(host, virq, hwirq))
729                 return NO_IRQ;
730
731         return virq;
732 }
733 EXPORT_SYMBOL_GPL(irq_create_mapping);
734
735 unsigned int irq_create_of_mapping(struct device_node *controller,
736                                    u32 *intspec, unsigned int intsize)
737 {
738         struct irq_host *host;
739         irq_hw_number_t hwirq;
740         unsigned int type = IRQ_TYPE_NONE;
741         unsigned int virq;
742
743         if (controller == NULL)
744                 host = irq_default_host;
745         else
746                 host = irq_find_host(controller);
747         if (host == NULL) {
748                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
749                        controller->full_name);
750                 return NO_IRQ;
751         }
752
753         /* If host has no translation, then we assume interrupt line */
754         if (host->ops->xlate == NULL)
755                 hwirq = intspec[0];
756         else {
757                 if (host->ops->xlate(host, controller, intspec, intsize,
758                                      &hwirq, &type))
759                         return NO_IRQ;
760         }
761
762         /* Create mapping */
763         virq = irq_create_mapping(host, hwirq);
764         if (virq == NO_IRQ)
765                 return virq;
766
767         /* Set type if specified and different than the current one */
768         if (type != IRQ_TYPE_NONE &&
769             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
770                 set_irq_type(virq, type);
771         return virq;
772 }
773 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
774
775 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
776 {
777         struct of_irq oirq;
778
779         if (of_irq_map_one(dev, index, &oirq))
780                 return NO_IRQ;
781
782         return irq_create_of_mapping(oirq.controller, oirq.specifier,
783                                      oirq.size);
784 }
785 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
786
787 void irq_dispose_mapping(unsigned int virq)
788 {
789         struct irq_host *host;
790         irq_hw_number_t hwirq;
791         unsigned long flags;
792
793         if (virq == NO_IRQ)
794                 return;
795
796         host = irq_map[virq].host;
797         WARN_ON (host == NULL);
798         if (host == NULL)
799                 return;
800
801         /* Never unmap legacy interrupts */
802         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
803                 return;
804
805         /* remove chip and handler */
806         set_irq_chip_and_handler(virq, NULL, NULL);
807
808         /* Make sure it's completed */
809         synchronize_irq(virq);
810
811         /* Tell the PIC about it */
812         if (host->ops->unmap)
813                 host->ops->unmap(host, virq);
814         smp_mb();
815
816         /* Clear reverse map */
817         hwirq = irq_map[virq].hwirq;
818         switch(host->revmap_type) {
819         case IRQ_HOST_MAP_LINEAR:
820                 if (hwirq < host->revmap_data.linear.size)
821                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
822                 break;
823         case IRQ_HOST_MAP_TREE:
824                 /* Check if radix tree allocated yet */
825                 if (host->revmap_data.tree.gfp_mask == 0)
826                         break;
827                 irq_radix_wrlock(&flags);
828                 radix_tree_delete(&host->revmap_data.tree, hwirq);
829                 irq_radix_wrunlock(flags);
830                 break;
831         }
832
833         /* Destroy map */
834         smp_mb();
835         irq_map[virq].hwirq = host->inval_irq;
836
837         /* Set some flags */
838         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
839
840         /* Free it */
841         irq_free_virt(virq, 1);
842 }
843 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
844
845 unsigned int irq_find_mapping(struct irq_host *host,
846                               irq_hw_number_t hwirq)
847 {
848         unsigned int i;
849         unsigned int hint = hwirq % irq_virq_count;
850
851         /* Look for default host if nececssary */
852         if (host == NULL)
853                 host = irq_default_host;
854         if (host == NULL)
855                 return NO_IRQ;
856
857         /* legacy -> bail early */
858         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
859                 return hwirq;
860
861         /* Slow path does a linear search of the map */
862         if (hint < NUM_ISA_INTERRUPTS)
863                 hint = NUM_ISA_INTERRUPTS;
864         i = hint;
865         do  {
866                 if (irq_map[i].host == host &&
867                     irq_map[i].hwirq == hwirq)
868                         return i;
869                 i++;
870                 if (i >= irq_virq_count)
871                         i = NUM_ISA_INTERRUPTS;
872         } while(i != hint);
873         return NO_IRQ;
874 }
875 EXPORT_SYMBOL_GPL(irq_find_mapping);
876
877
878 unsigned int irq_radix_revmap(struct irq_host *host,
879                               irq_hw_number_t hwirq)
880 {
881         struct radix_tree_root *tree;
882         struct irq_map_entry *ptr;
883         unsigned int virq;
884         unsigned long flags;
885
886         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
887
888         /* Check if the radix tree exist yet. We test the value of
889          * the gfp_mask for that. Sneaky but saves another int in the
890          * structure. If not, we fallback to slow mode
891          */
892         tree = &host->revmap_data.tree;
893         if (tree->gfp_mask == 0)
894                 return irq_find_mapping(host, hwirq);
895
896         /* Now try to resolve */
897         irq_radix_rdlock(&flags);
898         ptr = radix_tree_lookup(tree, hwirq);
899         irq_radix_rdunlock(flags);
900
901         /* Found it, return */
902         if (ptr) {
903                 virq = ptr - irq_map;
904                 return virq;
905         }
906
907         /* If not there, try to insert it */
908         virq = irq_find_mapping(host, hwirq);
909         if (virq != NO_IRQ) {
910                 irq_radix_wrlock(&flags);
911                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
912                 irq_radix_wrunlock(flags);
913         }
914         return virq;
915 }
916
917 unsigned int irq_linear_revmap(struct irq_host *host,
918                                irq_hw_number_t hwirq)
919 {
920         unsigned int *revmap;
921
922         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
923
924         /* Check revmap bounds */
925         if (unlikely(hwirq >= host->revmap_data.linear.size))
926                 return irq_find_mapping(host, hwirq);
927
928         /* Check if revmap was allocated */
929         revmap = host->revmap_data.linear.revmap;
930         if (unlikely(revmap == NULL))
931                 return irq_find_mapping(host, hwirq);
932
933         /* Fill up revmap with slow path if no mapping found */
934         if (unlikely(revmap[hwirq] == NO_IRQ))
935                 revmap[hwirq] = irq_find_mapping(host, hwirq);
936
937         return revmap[hwirq];
938 }
939
940 unsigned int irq_alloc_virt(struct irq_host *host,
941                             unsigned int count,
942                             unsigned int hint)
943 {
944         unsigned long flags;
945         unsigned int i, j, found = NO_IRQ;
946
947         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
948                 return NO_IRQ;
949
950         spin_lock_irqsave(&irq_big_lock, flags);
951
952         /* Use hint for 1 interrupt if any */
953         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
954             hint < irq_virq_count && irq_map[hint].host == NULL) {
955                 found = hint;
956                 goto hint_found;
957         }
958
959         /* Look for count consecutive numbers in the allocatable
960          * (non-legacy) space
961          */
962         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
963                 if (irq_map[i].host != NULL)
964                         j = 0;
965                 else
966                         j++;
967
968                 if (j == count) {
969                         found = i - count + 1;
970                         break;
971                 }
972         }
973         if (found == NO_IRQ) {
974                 spin_unlock_irqrestore(&irq_big_lock, flags);
975                 return NO_IRQ;
976         }
977  hint_found:
978         for (i = found; i < (found + count); i++) {
979                 irq_map[i].hwirq = host->inval_irq;
980                 smp_wmb();
981                 irq_map[i].host = host;
982         }
983         spin_unlock_irqrestore(&irq_big_lock, flags);
984         return found;
985 }
986
987 void irq_free_virt(unsigned int virq, unsigned int count)
988 {
989         unsigned long flags;
990         unsigned int i;
991
992         WARN_ON (virq < NUM_ISA_INTERRUPTS);
993         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
994
995         spin_lock_irqsave(&irq_big_lock, flags);
996         for (i = virq; i < (virq + count); i++) {
997                 struct irq_host *host;
998
999                 if (i < NUM_ISA_INTERRUPTS ||
1000                     (virq + count) > irq_virq_count)
1001                         continue;
1002
1003                 host = irq_map[i].host;
1004                 irq_map[i].hwirq = host->inval_irq;
1005                 smp_wmb();
1006                 irq_map[i].host = NULL;
1007         }
1008         spin_unlock_irqrestore(&irq_big_lock, flags);
1009 }
1010
1011 void irq_early_init(void)
1012 {
1013         unsigned int i;
1014
1015         for (i = 0; i < NR_IRQS; i++)
1016                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
1017 }
1018
1019 /* We need to create the radix trees late */
1020 static int irq_late_init(void)
1021 {
1022         struct irq_host *h;
1023         unsigned long flags;
1024
1025         irq_radix_wrlock(&flags);
1026         list_for_each_entry(h, &irq_hosts, link) {
1027                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1028                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
1029         }
1030         irq_radix_wrunlock(flags);
1031
1032         return 0;
1033 }
1034 arch_initcall(irq_late_init);
1035
1036 #ifdef CONFIG_VIRQ_DEBUG
1037 static int virq_debug_show(struct seq_file *m, void *private)
1038 {
1039         unsigned long flags;
1040         irq_desc_t *desc;
1041         const char *p;
1042         char none[] = "none";
1043         int i;
1044
1045         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1046                       "chip name", "host name");
1047
1048         for (i = 1; i < NR_IRQS; i++) {
1049                 desc = get_irq_desc(i);
1050                 spin_lock_irqsave(&desc->lock, flags);
1051
1052                 if (desc->action && desc->action->handler) {
1053                         seq_printf(m, "%5d  ", i);
1054                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1055
1056                         if (desc->chip && desc->chip->typename)
1057                                 p = desc->chip->typename;
1058                         else
1059                                 p = none;
1060                         seq_printf(m, "%-15s  ", p);
1061
1062                         if (irq_map[i].host && irq_map[i].host->of_node)
1063                                 p = irq_map[i].host->of_node->full_name;
1064                         else
1065                                 p = none;
1066                         seq_printf(m, "%s\n", p);
1067                 }
1068
1069                 spin_unlock_irqrestore(&desc->lock, flags);
1070         }
1071
1072         return 0;
1073 }
1074
1075 static int virq_debug_open(struct inode *inode, struct file *file)
1076 {
1077         return single_open(file, virq_debug_show, inode->i_private);
1078 }
1079
1080 static const struct file_operations virq_debug_fops = {
1081         .open = virq_debug_open,
1082         .read = seq_read,
1083         .llseek = seq_lseek,
1084         .release = single_release,
1085 };
1086
1087 static int __init irq_debugfs_init(void)
1088 {
1089         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1090                                  NULL, &virq_debug_fops) == NULL)
1091                 return -ENOMEM;
1092
1093         return 0;
1094 }
1095 __initcall(irq_debugfs_init);
1096 #endif /* CONFIG_VIRQ_DEBUG */
1097
1098 #ifdef CONFIG_PPC64
1099 static int __init setup_noirqdistrib(char *str)
1100 {
1101         distribute_irqs = 0;
1102         return 1;
1103 }
1104
1105 __setup("noirqdistrib", setup_noirqdistrib);
1106 #endif /* CONFIG_PPC64 */