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