genirq: Convert irq_desc.lock to raw_spinlock
[linux-3.10.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 #include <linux/perf_event.h>
57
58 #include <asm/uaccess.h>
59 #include <asm/system.h>
60 #include <asm/io.h>
61 #include <asm/pgtable.h>
62 #include <asm/irq.h>
63 #include <asm/cache.h>
64 #include <asm/prom.h>
65 #include <asm/ptrace.h>
66 #include <asm/machdep.h>
67 #include <asm/udbg.h>
68 #ifdef CONFIG_PPC64
69 #include <asm/paca.h>
70 #include <asm/firmware.h>
71 #include <asm/lv1call.h>
72 #endif
73 #define CREATE_TRACE_POINTS
74 #include <asm/trace.h>
75
76 int __irq_offset_value;
77 static int ppc_spurious_interrupts;
78
79 #ifdef CONFIG_PPC32
80 EXPORT_SYMBOL(__irq_offset_value);
81 atomic_t ppc_n_lost_interrupts;
82
83 #ifdef CONFIG_TAU_INT
84 extern int tau_initialized;
85 extern int tau_interrupts(int);
86 #endif
87 #endif /* CONFIG_PPC32 */
88
89 #ifdef CONFIG_PPC64
90
91 #ifndef CONFIG_SPARSE_IRQ
92 EXPORT_SYMBOL(irq_desc);
93 #endif
94
95 int distribute_irqs = 1;
96
97 static inline notrace unsigned long get_hard_enabled(void)
98 {
99         unsigned long enabled;
100
101         __asm__ __volatile__("lbz %0,%1(13)"
102         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
103
104         return enabled;
105 }
106
107 static inline notrace void set_soft_enabled(unsigned long enable)
108 {
109         __asm__ __volatile__("stb %0,%1(13)"
110         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
111 }
112
113 notrace void raw_local_irq_restore(unsigned long en)
114 {
115         /*
116          * get_paca()->soft_enabled = en;
117          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
118          * That was allowed before, and in such a case we do need to take care
119          * that gcc will set soft_enabled directly via r13, not choose to use
120          * an intermediate register, lest we're preempted to a different cpu.
121          */
122         set_soft_enabled(en);
123         if (!en)
124                 return;
125
126 #ifdef CONFIG_PPC_STD_MMU_64
127         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
128                 /*
129                  * Do we need to disable preemption here?  Not really: in the
130                  * unlikely event that we're preempted to a different cpu in
131                  * between getting r13, loading its lppaca_ptr, and loading
132                  * its any_int, we might call iseries_handle_interrupts without
133                  * an interrupt pending on the new cpu, but that's no disaster,
134                  * is it?  And the business of preempting us off the old cpu
135                  * would itself involve a local_irq_restore which handles the
136                  * interrupt to that cpu.
137                  *
138                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
139                  * to avoid any preemption checking added into get_paca().
140                  */
141                 if (local_paca->lppaca_ptr->int_dword.any_int)
142                         iseries_handle_interrupts();
143         }
144 #endif /* CONFIG_PPC_STD_MMU_64 */
145
146         if (test_perf_event_pending()) {
147                 clear_perf_event_pending();
148                 perf_event_do_pending();
149         }
150
151         /*
152          * if (get_paca()->hard_enabled) return;
153          * But again we need to take care that gcc gets hard_enabled directly
154          * via r13, not choose to use an intermediate register, lest we're
155          * preempted to a different cpu in between the two instructions.
156          */
157         if (get_hard_enabled())
158                 return;
159
160         /*
161          * Need to hard-enable interrupts here.  Since currently disabled,
162          * no need to take further asm precautions against preemption; but
163          * use local_paca instead of get_paca() to avoid preemption checking.
164          */
165         local_paca->hard_enabled = en;
166         if ((int)mfspr(SPRN_DEC) < 0)
167                 mtspr(SPRN_DEC, 1);
168
169         /*
170          * Force the delivery of pending soft-disabled interrupts on PS3.
171          * Any HV call will have this side effect.
172          */
173         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
174                 u64 tmp;
175                 lv1_get_version_info(&tmp);
176         }
177
178         __hard_irq_enable();
179 }
180 EXPORT_SYMBOL(raw_local_irq_restore);
181 #endif /* CONFIG_PPC64 */
182
183 int show_interrupts(struct seq_file *p, void *v)
184 {
185         int i = *(loff_t *)v, j;
186         struct irqaction *action;
187         struct irq_desc *desc;
188         unsigned long flags;
189
190         if (i == 0) {
191                 seq_puts(p, "           ");
192                 for_each_online_cpu(j)
193                         seq_printf(p, "CPU%d       ", j);
194                 seq_putc(p, '\n');
195         } else if (i == nr_irqs) {
196 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
197                 if (tau_initialized){
198                         seq_puts(p, "TAU: ");
199                         for_each_online_cpu(j)
200                                 seq_printf(p, "%10u ", tau_interrupts(j));
201                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
202                 }
203 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT*/
204                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
205
206                 return 0;
207         }
208
209         desc = irq_to_desc(i);
210         if (!desc)
211                 return 0;
212
213         raw_spin_lock_irqsave(&desc->lock, flags);
214
215         action = desc->action;
216         if (!action || !action->handler)
217                 goto skip;
218
219         seq_printf(p, "%3d: ", i);
220 #ifdef CONFIG_SMP
221         for_each_online_cpu(j)
222                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
223 #else
224         seq_printf(p, "%10u ", kstat_irqs(i));
225 #endif /* CONFIG_SMP */
226
227         if (desc->chip)
228                 seq_printf(p, " %s ", desc->chip->name);
229         else
230                 seq_puts(p, "  None      ");
231
232         seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
233         seq_printf(p, "    %s", action->name);
234
235         for (action = action->next; action; action = action->next)
236                 seq_printf(p, ", %s", action->name);
237         seq_putc(p, '\n');
238
239 skip:
240         raw_spin_unlock_irqrestore(&desc->lock, flags);
241
242         return 0;
243 }
244
245 #ifdef CONFIG_HOTPLUG_CPU
246 void fixup_irqs(cpumask_t map)
247 {
248         struct irq_desc *desc;
249         unsigned int irq;
250         static int warned;
251
252         for_each_irq(irq) {
253                 cpumask_t mask;
254
255                 desc = irq_to_desc(irq);
256                 if (desc && desc->status & IRQ_PER_CPU)
257                         continue;
258
259                 cpumask_and(&mask, desc->affinity, &map);
260                 if (any_online_cpu(mask) == NR_CPUS) {
261                         printk("Breaking affinity for irq %i\n", irq);
262                         mask = map;
263                 }
264                 if (desc->chip->set_affinity)
265                         desc->chip->set_affinity(irq, &mask);
266                 else if (desc->action && !(warned++))
267                         printk("Cannot set affinity for irq %i\n", irq);
268         }
269
270         local_irq_enable();
271         mdelay(1);
272         local_irq_disable();
273 }
274 #endif
275
276 #ifdef CONFIG_IRQSTACKS
277 static inline void handle_one_irq(unsigned int irq)
278 {
279         struct thread_info *curtp, *irqtp;
280         unsigned long saved_sp_limit;
281         struct irq_desc *desc;
282
283         /* Switch to the irq stack to handle this */
284         curtp = current_thread_info();
285         irqtp = hardirq_ctx[smp_processor_id()];
286
287         if (curtp == irqtp) {
288                 /* We're already on the irq stack, just handle it */
289                 generic_handle_irq(irq);
290                 return;
291         }
292
293         desc = irq_to_desc(irq);
294         saved_sp_limit = current->thread.ksp_limit;
295
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         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
302                                (curtp->preempt_count & SOFTIRQ_MASK);
303
304         current->thread.ksp_limit = (unsigned long)irqtp +
305                 _ALIGN_UP(sizeof(struct thread_info), 16);
306
307         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
308         current->thread.ksp_limit = saved_sp_limit;
309         irqtp->task = NULL;
310
311         /* Set any flag that may have been set on the
312          * alternate stack
313          */
314         if (irqtp->flags)
315                 set_bits(irqtp->flags, &curtp->flags);
316 }
317 #else
318 static inline void handle_one_irq(unsigned int irq)
319 {
320         generic_handle_irq(irq);
321 }
322 #endif
323
324 static inline void check_stack_overflow(void)
325 {
326 #ifdef CONFIG_DEBUG_STACKOVERFLOW
327         long sp;
328
329         sp = __get_SP() & (THREAD_SIZE-1);
330
331         /* check for stack overflow: is there less than 2KB free? */
332         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
333                 printk("do_IRQ: stack overflow: %ld\n",
334                         sp - sizeof(struct thread_info));
335                 dump_stack();
336         }
337 #endif
338 }
339
340 void do_IRQ(struct pt_regs *regs)
341 {
342         struct pt_regs *old_regs = set_irq_regs(regs);
343         unsigned int irq;
344
345         trace_irq_entry(regs);
346
347         irq_enter();
348
349         check_stack_overflow();
350
351         irq = ppc_md.get_irq();
352
353         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
354                 handle_one_irq(irq);
355         else if (irq != NO_IRQ_IGNORE)
356                 /* That's not SMP safe ... but who cares ? */
357                 ppc_spurious_interrupts++;
358
359         irq_exit();
360         set_irq_regs(old_regs);
361
362 #ifdef CONFIG_PPC_ISERIES
363         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
364                         get_lppaca()->int_dword.fields.decr_int) {
365                 get_lppaca()->int_dword.fields.decr_int = 0;
366                 /* Signal a fake decrementer interrupt */
367                 timer_interrupt(regs);
368         }
369 #endif
370
371         trace_irq_exit(regs);
372 }
373
374 void __init init_IRQ(void)
375 {
376         if (ppc_md.init_IRQ)
377                 ppc_md.init_IRQ();
378
379         exc_lvl_ctx_init();
380
381         irq_ctx_init();
382 }
383
384 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
385 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
386 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
387 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
388
389 void exc_lvl_ctx_init(void)
390 {
391         struct thread_info *tp;
392         int i;
393
394         for_each_possible_cpu(i) {
395                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
396                 tp = critirq_ctx[i];
397                 tp->cpu = i;
398                 tp->preempt_count = 0;
399
400 #ifdef CONFIG_BOOKE
401                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
402                 tp = dbgirq_ctx[i];
403                 tp->cpu = i;
404                 tp->preempt_count = 0;
405
406                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
407                 tp = mcheckirq_ctx[i];
408                 tp->cpu = i;
409                 tp->preempt_count = HARDIRQ_OFFSET;
410 #endif
411         }
412 }
413 #endif
414
415 #ifdef CONFIG_IRQSTACKS
416 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
417 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
418
419 void irq_ctx_init(void)
420 {
421         struct thread_info *tp;
422         int i;
423
424         for_each_possible_cpu(i) {
425                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
426                 tp = softirq_ctx[i];
427                 tp->cpu = i;
428                 tp->preempt_count = 0;
429
430                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
431                 tp = hardirq_ctx[i];
432                 tp->cpu = i;
433                 tp->preempt_count = HARDIRQ_OFFSET;
434         }
435 }
436
437 static inline void do_softirq_onstack(void)
438 {
439         struct thread_info *curtp, *irqtp;
440         unsigned long saved_sp_limit = current->thread.ksp_limit;
441
442         curtp = current_thread_info();
443         irqtp = softirq_ctx[smp_processor_id()];
444         irqtp->task = curtp->task;
445         current->thread.ksp_limit = (unsigned long)irqtp +
446                                     _ALIGN_UP(sizeof(struct thread_info), 16);
447         call_do_softirq(irqtp);
448         current->thread.ksp_limit = saved_sp_limit;
449         irqtp->task = NULL;
450 }
451
452 #else
453 #define do_softirq_onstack()    __do_softirq()
454 #endif /* CONFIG_IRQSTACKS */
455
456 void do_softirq(void)
457 {
458         unsigned long flags;
459
460         if (in_interrupt())
461                 return;
462
463         local_irq_save(flags);
464
465         if (local_softirq_pending())
466                 do_softirq_onstack();
467
468         local_irq_restore(flags);
469 }
470
471
472 /*
473  * IRQ controller and virtual interrupts
474  */
475
476 static LIST_HEAD(irq_hosts);
477 static DEFINE_SPINLOCK(irq_big_lock);
478 static unsigned int revmap_trees_allocated;
479 static DEFINE_MUTEX(revmap_trees_mutex);
480 struct irq_map_entry irq_map[NR_IRQS];
481 static unsigned int irq_virq_count = NR_IRQS;
482 static struct irq_host *irq_default_host;
483
484 irq_hw_number_t virq_to_hw(unsigned int virq)
485 {
486         return irq_map[virq].hwirq;
487 }
488 EXPORT_SYMBOL_GPL(virq_to_hw);
489
490 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
491 {
492         return h->of_node != NULL && h->of_node == np;
493 }
494
495 struct irq_host *irq_alloc_host(struct device_node *of_node,
496                                 unsigned int revmap_type,
497                                 unsigned int revmap_arg,
498                                 struct irq_host_ops *ops,
499                                 irq_hw_number_t inval_irq)
500 {
501         struct irq_host *host;
502         unsigned int size = sizeof(struct irq_host);
503         unsigned int i;
504         unsigned int *rmap;
505         unsigned long flags;
506
507         /* Allocate structure and revmap table if using linear mapping */
508         if (revmap_type == IRQ_HOST_MAP_LINEAR)
509                 size += revmap_arg * sizeof(unsigned int);
510         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
511         if (host == NULL)
512                 return NULL;
513
514         /* Fill structure */
515         host->revmap_type = revmap_type;
516         host->inval_irq = inval_irq;
517         host->ops = ops;
518         host->of_node = of_node_get(of_node);
519
520         if (host->ops->match == NULL)
521                 host->ops->match = default_irq_host_match;
522
523         spin_lock_irqsave(&irq_big_lock, flags);
524
525         /* If it's a legacy controller, check for duplicates and
526          * mark it as allocated (we use irq 0 host pointer for that
527          */
528         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
529                 if (irq_map[0].host != NULL) {
530                         spin_unlock_irqrestore(&irq_big_lock, flags);
531                         /* If we are early boot, we can't free the structure,
532                          * too bad...
533                          * this will be fixed once slab is made available early
534                          * instead of the current cruft
535                          */
536                         if (mem_init_done)
537                                 kfree(host);
538                         return NULL;
539                 }
540                 irq_map[0].host = host;
541         }
542
543         list_add(&host->link, &irq_hosts);
544         spin_unlock_irqrestore(&irq_big_lock, flags);
545
546         /* Additional setups per revmap type */
547         switch(revmap_type) {
548         case IRQ_HOST_MAP_LEGACY:
549                 /* 0 is always the invalid number for legacy */
550                 host->inval_irq = 0;
551                 /* setup us as the host for all legacy interrupts */
552                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
553                         irq_map[i].hwirq = i;
554                         smp_wmb();
555                         irq_map[i].host = host;
556                         smp_wmb();
557
558                         /* Clear norequest flags */
559                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
560
561                         /* Legacy flags are left to default at this point,
562                          * one can then use irq_create_mapping() to
563                          * explicitly change them
564                          */
565                         ops->map(host, i, i);
566                 }
567                 break;
568         case IRQ_HOST_MAP_LINEAR:
569                 rmap = (unsigned int *)(host + 1);
570                 for (i = 0; i < revmap_arg; i++)
571                         rmap[i] = NO_IRQ;
572                 host->revmap_data.linear.size = revmap_arg;
573                 smp_wmb();
574                 host->revmap_data.linear.revmap = rmap;
575                 break;
576         default:
577                 break;
578         }
579
580         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
581
582         return host;
583 }
584
585 struct irq_host *irq_find_host(struct device_node *node)
586 {
587         struct irq_host *h, *found = NULL;
588         unsigned long flags;
589
590         /* We might want to match the legacy controller last since
591          * it might potentially be set to match all interrupts in
592          * the absence of a device node. This isn't a problem so far
593          * yet though...
594          */
595         spin_lock_irqsave(&irq_big_lock, flags);
596         list_for_each_entry(h, &irq_hosts, link)
597                 if (h->ops->match(h, node)) {
598                         found = h;
599                         break;
600                 }
601         spin_unlock_irqrestore(&irq_big_lock, flags);
602         return found;
603 }
604 EXPORT_SYMBOL_GPL(irq_find_host);
605
606 void irq_set_default_host(struct irq_host *host)
607 {
608         pr_debug("irq: Default host set to @0x%p\n", host);
609
610         irq_default_host = host;
611 }
612
613 void irq_set_virq_count(unsigned int count)
614 {
615         pr_debug("irq: Trying to set virq count to %d\n", count);
616
617         BUG_ON(count < NUM_ISA_INTERRUPTS);
618         if (count < NR_IRQS)
619                 irq_virq_count = count;
620 }
621
622 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
623                             irq_hw_number_t hwirq)
624 {
625         struct irq_desc *desc;
626
627         desc = irq_to_desc_alloc_node(virq, 0);
628         if (!desc) {
629                 pr_debug("irq: -> allocating desc failed\n");
630                 goto error;
631         }
632
633         /* Clear IRQ_NOREQUEST flag */
634         desc->status &= ~IRQ_NOREQUEST;
635
636         /* map it */
637         smp_wmb();
638         irq_map[virq].hwirq = hwirq;
639         smp_mb();
640
641         if (host->ops->map(host, virq, hwirq)) {
642                 pr_debug("irq: -> mapping failed, freeing\n");
643                 goto error;
644         }
645
646         return 0;
647
648 error:
649         irq_free_virt(virq, 1);
650         return -1;
651 }
652
653 unsigned int irq_create_direct_mapping(struct irq_host *host)
654 {
655         unsigned int virq;
656
657         if (host == NULL)
658                 host = irq_default_host;
659
660         BUG_ON(host == NULL);
661         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
662
663         virq = irq_alloc_virt(host, 1, 0);
664         if (virq == NO_IRQ) {
665                 pr_debug("irq: create_direct virq allocation failed\n");
666                 return NO_IRQ;
667         }
668
669         pr_debug("irq: create_direct obtained virq %d\n", virq);
670
671         if (irq_setup_virq(host, virq, virq))
672                 return NO_IRQ;
673
674         return virq;
675 }
676
677 unsigned int irq_create_mapping(struct irq_host *host,
678                                 irq_hw_number_t hwirq)
679 {
680         unsigned int virq, hint;
681
682         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
683
684         /* Look for default host if nececssary */
685         if (host == NULL)
686                 host = irq_default_host;
687         if (host == NULL) {
688                 printk(KERN_WARNING "irq_create_mapping called for"
689                        " NULL host, hwirq=%lx\n", hwirq);
690                 WARN_ON(1);
691                 return NO_IRQ;
692         }
693         pr_debug("irq: -> using host @%p\n", host);
694
695         /* Check if mapping already exist, if it does, call
696          * host->ops->map() to update the flags
697          */
698         virq = irq_find_mapping(host, hwirq);
699         if (virq != NO_IRQ) {
700                 if (host->ops->remap)
701                         host->ops->remap(host, virq, hwirq);
702                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
703                 return virq;
704         }
705
706         /* Get a virtual interrupt number */
707         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
708                 /* Handle legacy */
709                 virq = (unsigned int)hwirq;
710                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
711                         return NO_IRQ;
712                 return virq;
713         } else {
714                 /* Allocate a virtual interrupt number */
715                 hint = hwirq % irq_virq_count;
716                 virq = irq_alloc_virt(host, 1, hint);
717                 if (virq == NO_IRQ) {
718                         pr_debug("irq: -> virq allocation failed\n");
719                         return NO_IRQ;
720                 }
721         }
722
723         if (irq_setup_virq(host, virq, hwirq))
724                 return NO_IRQ;
725
726         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
727                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
728
729         return virq;
730 }
731 EXPORT_SYMBOL_GPL(irq_create_mapping);
732
733 unsigned int irq_create_of_mapping(struct device_node *controller,
734                                    const u32 *intspec, unsigned int intsize)
735 {
736         struct irq_host *host;
737         irq_hw_number_t hwirq;
738         unsigned int type = IRQ_TYPE_NONE;
739         unsigned int virq;
740
741         if (controller == NULL)
742                 host = irq_default_host;
743         else
744                 host = irq_find_host(controller);
745         if (host == NULL) {
746                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
747                        controller->full_name);
748                 return NO_IRQ;
749         }
750
751         /* If host has no translation, then we assume interrupt line */
752         if (host->ops->xlate == NULL)
753                 hwirq = intspec[0];
754         else {
755                 if (host->ops->xlate(host, controller, intspec, intsize,
756                                      &hwirq, &type))
757                         return NO_IRQ;
758         }
759
760         /* Create mapping */
761         virq = irq_create_mapping(host, hwirq);
762         if (virq == NO_IRQ)
763                 return virq;
764
765         /* Set type if specified and different than the current one */
766         if (type != IRQ_TYPE_NONE &&
767             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
768                 set_irq_type(virq, type);
769         return virq;
770 }
771 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
772
773 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
774 {
775         struct of_irq oirq;
776
777         if (of_irq_map_one(dev, index, &oirq))
778                 return NO_IRQ;
779
780         return irq_create_of_mapping(oirq.controller, oirq.specifier,
781                                      oirq.size);
782 }
783 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
784
785 void irq_dispose_mapping(unsigned int virq)
786 {
787         struct irq_host *host;
788         irq_hw_number_t hwirq;
789
790         if (virq == NO_IRQ)
791                 return;
792
793         host = irq_map[virq].host;
794         WARN_ON (host == NULL);
795         if (host == NULL)
796                 return;
797
798         /* Never unmap legacy interrupts */
799         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
800                 return;
801
802         /* remove chip and handler */
803         set_irq_chip_and_handler(virq, NULL, NULL);
804
805         /* Make sure it's completed */
806         synchronize_irq(virq);
807
808         /* Tell the PIC about it */
809         if (host->ops->unmap)
810                 host->ops->unmap(host, virq);
811         smp_mb();
812
813         /* Clear reverse map */
814         hwirq = irq_map[virq].hwirq;
815         switch(host->revmap_type) {
816         case IRQ_HOST_MAP_LINEAR:
817                 if (hwirq < host->revmap_data.linear.size)
818                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
819                 break;
820         case IRQ_HOST_MAP_TREE:
821                 /*
822                  * Check if radix tree allocated yet, if not then nothing to
823                  * remove.
824                  */
825                 smp_rmb();
826                 if (revmap_trees_allocated < 1)
827                         break;
828                 mutex_lock(&revmap_trees_mutex);
829                 radix_tree_delete(&host->revmap_data.tree, hwirq);
830                 mutex_unlock(&revmap_trees_mutex);
831                 break;
832         }
833
834         /* Destroy map */
835         smp_mb();
836         irq_map[virq].hwirq = host->inval_irq;
837
838         /* Set some flags */
839         irq_to_desc(virq)->status |= IRQ_NOREQUEST;
840
841         /* Free it */
842         irq_free_virt(virq, 1);
843 }
844 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
845
846 unsigned int irq_find_mapping(struct irq_host *host,
847                               irq_hw_number_t hwirq)
848 {
849         unsigned int i;
850         unsigned int hint = hwirq % irq_virq_count;
851
852         /* Look for default host if nececssary */
853         if (host == NULL)
854                 host = irq_default_host;
855         if (host == NULL)
856                 return NO_IRQ;
857
858         /* legacy -> bail early */
859         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
860                 return hwirq;
861
862         /* Slow path does a linear search of the map */
863         if (hint < NUM_ISA_INTERRUPTS)
864                 hint = NUM_ISA_INTERRUPTS;
865         i = hint;
866         do  {
867                 if (irq_map[i].host == host &&
868                     irq_map[i].hwirq == hwirq)
869                         return i;
870                 i++;
871                 if (i >= irq_virq_count)
872                         i = NUM_ISA_INTERRUPTS;
873         } while(i != hint);
874         return NO_IRQ;
875 }
876 EXPORT_SYMBOL_GPL(irq_find_mapping);
877
878
879 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
880                                      irq_hw_number_t hwirq)
881 {
882         struct irq_map_entry *ptr;
883         unsigned int virq;
884
885         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
886
887         /*
888          * Check if the radix tree exists and has bee initialized.
889          * If not, we fallback to slow mode
890          */
891         if (revmap_trees_allocated < 2)
892                 return irq_find_mapping(host, hwirq);
893
894         /* Now try to resolve */
895         /*
896          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
897          * as it's referencing an entry in the static irq_map table.
898          */
899         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
900
901         /*
902          * If found in radix tree, then fine.
903          * Else fallback to linear lookup - this should not happen in practice
904          * as it means that we failed to insert the node in the radix tree.
905          */
906         if (ptr)
907                 virq = ptr - irq_map;
908         else
909                 virq = irq_find_mapping(host, hwirq);
910
911         return virq;
912 }
913
914 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
915                              irq_hw_number_t hwirq)
916 {
917
918         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
919
920         /*
921          * Check if the radix tree exists yet.
922          * If not, then the irq will be inserted into the tree when it gets
923          * initialized.
924          */
925         smp_rmb();
926         if (revmap_trees_allocated < 1)
927                 return;
928
929         if (virq != NO_IRQ) {
930                 mutex_lock(&revmap_trees_mutex);
931                 radix_tree_insert(&host->revmap_data.tree, hwirq,
932                                   &irq_map[virq]);
933                 mutex_unlock(&revmap_trees_mutex);
934         }
935 }
936
937 unsigned int irq_linear_revmap(struct irq_host *host,
938                                irq_hw_number_t hwirq)
939 {
940         unsigned int *revmap;
941
942         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
943
944         /* Check revmap bounds */
945         if (unlikely(hwirq >= host->revmap_data.linear.size))
946                 return irq_find_mapping(host, hwirq);
947
948         /* Check if revmap was allocated */
949         revmap = host->revmap_data.linear.revmap;
950         if (unlikely(revmap == NULL))
951                 return irq_find_mapping(host, hwirq);
952
953         /* Fill up revmap with slow path if no mapping found */
954         if (unlikely(revmap[hwirq] == NO_IRQ))
955                 revmap[hwirq] = irq_find_mapping(host, hwirq);
956
957         return revmap[hwirq];
958 }
959
960 unsigned int irq_alloc_virt(struct irq_host *host,
961                             unsigned int count,
962                             unsigned int hint)
963 {
964         unsigned long flags;
965         unsigned int i, j, found = NO_IRQ;
966
967         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
968                 return NO_IRQ;
969
970         spin_lock_irqsave(&irq_big_lock, flags);
971
972         /* Use hint for 1 interrupt if any */
973         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
974             hint < irq_virq_count && irq_map[hint].host == NULL) {
975                 found = hint;
976                 goto hint_found;
977         }
978
979         /* Look for count consecutive numbers in the allocatable
980          * (non-legacy) space
981          */
982         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
983                 if (irq_map[i].host != NULL)
984                         j = 0;
985                 else
986                         j++;
987
988                 if (j == count) {
989                         found = i - count + 1;
990                         break;
991                 }
992         }
993         if (found == NO_IRQ) {
994                 spin_unlock_irqrestore(&irq_big_lock, flags);
995                 return NO_IRQ;
996         }
997  hint_found:
998         for (i = found; i < (found + count); i++) {
999                 irq_map[i].hwirq = host->inval_irq;
1000                 smp_wmb();
1001                 irq_map[i].host = host;
1002         }
1003         spin_unlock_irqrestore(&irq_big_lock, flags);
1004         return found;
1005 }
1006
1007 void irq_free_virt(unsigned int virq, unsigned int count)
1008 {
1009         unsigned long flags;
1010         unsigned int i;
1011
1012         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1013         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1014
1015         spin_lock_irqsave(&irq_big_lock, flags);
1016         for (i = virq; i < (virq + count); i++) {
1017                 struct irq_host *host;
1018
1019                 if (i < NUM_ISA_INTERRUPTS ||
1020                     (virq + count) > irq_virq_count)
1021                         continue;
1022
1023                 host = irq_map[i].host;
1024                 irq_map[i].hwirq = host->inval_irq;
1025                 smp_wmb();
1026                 irq_map[i].host = NULL;
1027         }
1028         spin_unlock_irqrestore(&irq_big_lock, flags);
1029 }
1030
1031 int arch_early_irq_init(void)
1032 {
1033         struct irq_desc *desc;
1034         int i;
1035
1036         for (i = 0; i < NR_IRQS; i++) {
1037                 desc = irq_to_desc(i);
1038                 if (desc)
1039                         desc->status |= IRQ_NOREQUEST;
1040         }
1041
1042         return 0;
1043 }
1044
1045 int arch_init_chip_data(struct irq_desc *desc, int node)
1046 {
1047         desc->status |= IRQ_NOREQUEST;
1048         return 0;
1049 }
1050
1051 /* We need to create the radix trees late */
1052 static int irq_late_init(void)
1053 {
1054         struct irq_host *h;
1055         unsigned int i;
1056
1057         /*
1058          * No mutual exclusion with respect to accessors of the tree is needed
1059          * here as the synchronization is done via the state variable
1060          * revmap_trees_allocated.
1061          */
1062         list_for_each_entry(h, &irq_hosts, link) {
1063                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1064                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1065         }
1066
1067         /*
1068          * Make sure the radix trees inits are visible before setting
1069          * the flag
1070          */
1071         smp_wmb();
1072         revmap_trees_allocated = 1;
1073
1074         /*
1075          * Insert the reverse mapping for those interrupts already present
1076          * in irq_map[].
1077          */
1078         mutex_lock(&revmap_trees_mutex);
1079         for (i = 0; i < irq_virq_count; i++) {
1080                 if (irq_map[i].host &&
1081                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1082                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1083                                           irq_map[i].hwirq, &irq_map[i]);
1084         }
1085         mutex_unlock(&revmap_trees_mutex);
1086
1087         /*
1088          * Make sure the radix trees insertions are visible before setting
1089          * the flag
1090          */
1091         smp_wmb();
1092         revmap_trees_allocated = 2;
1093
1094         return 0;
1095 }
1096 arch_initcall(irq_late_init);
1097
1098 #ifdef CONFIG_VIRQ_DEBUG
1099 static int virq_debug_show(struct seq_file *m, void *private)
1100 {
1101         unsigned long flags;
1102         struct irq_desc *desc;
1103         const char *p;
1104         char none[] = "none";
1105         int i;
1106
1107         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1108                       "chip name", "host name");
1109
1110         for (i = 1; i < nr_irqs; i++) {
1111                 desc = irq_to_desc(i);
1112                 if (!desc)
1113                         continue;
1114
1115                 raw_spin_lock_irqsave(&desc->lock, flags);
1116
1117                 if (desc->action && desc->action->handler) {
1118                         seq_printf(m, "%5d  ", i);
1119                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1120
1121                         if (desc->chip && desc->chip->name)
1122                                 p = desc->chip->name;
1123                         else
1124                                 p = none;
1125                         seq_printf(m, "%-15s  ", p);
1126
1127                         if (irq_map[i].host && irq_map[i].host->of_node)
1128                                 p = irq_map[i].host->of_node->full_name;
1129                         else
1130                                 p = none;
1131                         seq_printf(m, "%s\n", p);
1132                 }
1133
1134                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1135         }
1136
1137         return 0;
1138 }
1139
1140 static int virq_debug_open(struct inode *inode, struct file *file)
1141 {
1142         return single_open(file, virq_debug_show, inode->i_private);
1143 }
1144
1145 static const struct file_operations virq_debug_fops = {
1146         .open = virq_debug_open,
1147         .read = seq_read,
1148         .llseek = seq_lseek,
1149         .release = single_release,
1150 };
1151
1152 static int __init irq_debugfs_init(void)
1153 {
1154         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1155                                  NULL, &virq_debug_fops) == NULL)
1156                 return -ENOMEM;
1157
1158         return 0;
1159 }
1160 __initcall(irq_debugfs_init);
1161 #endif /* CONFIG_VIRQ_DEBUG */
1162
1163 #ifdef CONFIG_PPC64
1164 static int __init setup_noirqdistrib(char *str)
1165 {
1166         distribute_irqs = 0;
1167         return 1;
1168 }
1169
1170 __setup("noirqdistrib", setup_noirqdistrib);
1171 #endif /* CONFIG_PPC64 */