powerpc/perf_event: Fix oops due to perf_event_do_pending call
[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 #define CREATE_TRACE_POINTS
73 #include <asm/trace.h>
74
75 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
76 EXPORT_PER_CPU_SYMBOL(irq_stat);
77
78 int __irq_offset_value;
79
80 #ifdef CONFIG_PPC32
81 EXPORT_SYMBOL(__irq_offset_value);
82 atomic_t ppc_n_lost_interrupts;
83
84 #ifdef CONFIG_TAU_INT
85 extern int tau_initialized;
86 extern int tau_interrupts(int);
87 #endif
88 #endif /* CONFIG_PPC32 */
89
90 #ifdef CONFIG_PPC64
91
92 #ifndef CONFIG_SPARSE_IRQ
93 EXPORT_SYMBOL(irq_desc);
94 #endif
95
96 int distribute_irqs = 1;
97
98 static inline notrace unsigned long get_hard_enabled(void)
99 {
100         unsigned long enabled;
101
102         __asm__ __volatile__("lbz %0,%1(13)"
103         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
104
105         return enabled;
106 }
107
108 static inline notrace void set_soft_enabled(unsigned long enable)
109 {
110         __asm__ __volatile__("stb %0,%1(13)"
111         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
112 }
113
114 notrace void raw_local_irq_restore(unsigned long en)
115 {
116         /*
117          * get_paca()->soft_enabled = en;
118          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
119          * That was allowed before, and in such a case we do need to take care
120          * that gcc will set soft_enabled directly via r13, not choose to use
121          * an intermediate register, lest we're preempted to a different cpu.
122          */
123         set_soft_enabled(en);
124         if (!en)
125                 return;
126
127 #ifdef CONFIG_PPC_STD_MMU_64
128         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
129                 /*
130                  * Do we need to disable preemption here?  Not really: in the
131                  * unlikely event that we're preempted to a different cpu in
132                  * between getting r13, loading its lppaca_ptr, and loading
133                  * its any_int, we might call iseries_handle_interrupts without
134                  * an interrupt pending on the new cpu, but that's no disaster,
135                  * is it?  And the business of preempting us off the old cpu
136                  * would itself involve a local_irq_restore which handles the
137                  * interrupt to that cpu.
138                  *
139                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
140                  * to avoid any preemption checking added into get_paca().
141                  */
142                 if (local_paca->lppaca_ptr->int_dword.any_int)
143                         iseries_handle_interrupts();
144         }
145 #endif /* CONFIG_PPC_STD_MMU_64 */
146
147         /*
148          * if (get_paca()->hard_enabled) return;
149          * But again we need to take care that gcc gets hard_enabled directly
150          * via r13, not choose to use an intermediate register, lest we're
151          * preempted to a different cpu in between the two instructions.
152          */
153         if (get_hard_enabled())
154                 return;
155
156         /*
157          * Need to hard-enable interrupts here.  Since currently disabled,
158          * no need to take further asm precautions against preemption; but
159          * use local_paca instead of get_paca() to avoid preemption checking.
160          */
161         local_paca->hard_enabled = en;
162         if ((int)mfspr(SPRN_DEC) < 0)
163                 mtspr(SPRN_DEC, 1);
164
165         /*
166          * Force the delivery of pending soft-disabled interrupts on PS3.
167          * Any HV call will have this side effect.
168          */
169         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
170                 u64 tmp;
171                 lv1_get_version_info(&tmp);
172         }
173
174         __hard_irq_enable();
175 }
176 EXPORT_SYMBOL(raw_local_irq_restore);
177 #endif /* CONFIG_PPC64 */
178
179 static int show_other_interrupts(struct seq_file *p, int prec)
180 {
181         int j;
182
183 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
184         if (tau_initialized) {
185                 seq_printf(p, "%*s: ", prec, "TAU");
186                 for_each_online_cpu(j)
187                         seq_printf(p, "%10u ", tau_interrupts(j));
188                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
189         }
190 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
191
192         seq_printf(p, "%*s: ", prec, "LOC");
193         for_each_online_cpu(j)
194                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
195         seq_printf(p, "  Local timer interrupts\n");
196
197         seq_printf(p, "%*s: ", prec, "SPU");
198         for_each_online_cpu(j)
199                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
200         seq_printf(p, "  Spurious interrupts\n");
201
202         seq_printf(p, "%*s: ", prec, "CNT");
203         for_each_online_cpu(j)
204                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
205         seq_printf(p, "  Performance monitoring interrupts\n");
206
207         seq_printf(p, "%*s: ", prec, "MCE");
208         for_each_online_cpu(j)
209                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
210         seq_printf(p, "  Machine check exceptions\n");
211
212         return 0;
213 }
214
215 int show_interrupts(struct seq_file *p, void *v)
216 {
217         unsigned long flags, any_count = 0;
218         int i = *(loff_t *) v, j, prec;
219         struct irqaction *action;
220         struct irq_desc *desc;
221
222         if (i > nr_irqs)
223                 return 0;
224
225         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
226                 j *= 10;
227
228         if (i == nr_irqs)
229                 return show_other_interrupts(p, prec);
230
231         /* print header */
232         if (i == 0) {
233                 seq_printf(p, "%*s", prec + 8, "");
234                 for_each_online_cpu(j)
235                         seq_printf(p, "CPU%-8d", j);
236                 seq_putc(p, '\n');
237         }
238
239         desc = irq_to_desc(i);
240         if (!desc)
241                 return 0;
242
243         raw_spin_lock_irqsave(&desc->lock, flags);
244         for_each_online_cpu(j)
245                 any_count |= kstat_irqs_cpu(i, j);
246         action = desc->action;
247         if (!action && !any_count)
248                 goto out;
249
250         seq_printf(p, "%*d: ", prec, i);
251         for_each_online_cpu(j)
252                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
253
254         if (desc->chip)
255                 seq_printf(p, "  %-16s", desc->chip->name);
256         else
257                 seq_printf(p, "  %-16s", "None");
258         seq_printf(p, " %-8s", (desc->status & IRQ_LEVEL) ? "Level" : "Edge");
259
260         if (action) {
261                 seq_printf(p, "     %s", action->name);
262                 while ((action = action->next) != NULL)
263                         seq_printf(p, ", %s", action->name);
264         }
265
266         seq_putc(p, '\n');
267 out:
268         raw_spin_unlock_irqrestore(&desc->lock, flags);
269         return 0;
270 }
271
272 /*
273  * /proc/stat helpers
274  */
275 u64 arch_irq_stat_cpu(unsigned int cpu)
276 {
277         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
278
279         sum += per_cpu(irq_stat, cpu).pmu_irqs;
280         sum += per_cpu(irq_stat, cpu).mce_exceptions;
281         sum += per_cpu(irq_stat, cpu).spurious_irqs;
282
283         return sum;
284 }
285
286 #ifdef CONFIG_HOTPLUG_CPU
287 void fixup_irqs(cpumask_t map)
288 {
289         struct irq_desc *desc;
290         unsigned int irq;
291         static int warned;
292
293         for_each_irq(irq) {
294                 cpumask_t mask;
295
296                 desc = irq_to_desc(irq);
297                 if (desc && desc->status & IRQ_PER_CPU)
298                         continue;
299
300                 cpumask_and(&mask, desc->affinity, &map);
301                 if (any_online_cpu(mask) == NR_CPUS) {
302                         printk("Breaking affinity for irq %i\n", irq);
303                         mask = map;
304                 }
305                 if (desc->chip->set_affinity)
306                         desc->chip->set_affinity(irq, &mask);
307                 else if (desc->action && !(warned++))
308                         printk("Cannot set affinity for irq %i\n", irq);
309         }
310
311         local_irq_enable();
312         mdelay(1);
313         local_irq_disable();
314 }
315 #endif
316
317 #ifdef CONFIG_IRQSTACKS
318 static inline void handle_one_irq(unsigned int irq)
319 {
320         struct thread_info *curtp, *irqtp;
321         unsigned long saved_sp_limit;
322         struct irq_desc *desc;
323
324         /* Switch to the irq stack to handle this */
325         curtp = current_thread_info();
326         irqtp = hardirq_ctx[smp_processor_id()];
327
328         if (curtp == irqtp) {
329                 /* We're already on the irq stack, just handle it */
330                 generic_handle_irq(irq);
331                 return;
332         }
333
334         desc = irq_to_desc(irq);
335         saved_sp_limit = current->thread.ksp_limit;
336
337         irqtp->task = curtp->task;
338         irqtp->flags = 0;
339
340         /* Copy the softirq bits in preempt_count so that the
341          * softirq checks work in the hardirq context. */
342         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
343                                (curtp->preempt_count & SOFTIRQ_MASK);
344
345         current->thread.ksp_limit = (unsigned long)irqtp +
346                 _ALIGN_UP(sizeof(struct thread_info), 16);
347
348         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
349         current->thread.ksp_limit = saved_sp_limit;
350         irqtp->task = NULL;
351
352         /* Set any flag that may have been set on the
353          * alternate stack
354          */
355         if (irqtp->flags)
356                 set_bits(irqtp->flags, &curtp->flags);
357 }
358 #else
359 static inline void handle_one_irq(unsigned int irq)
360 {
361         generic_handle_irq(irq);
362 }
363 #endif
364
365 static inline void check_stack_overflow(void)
366 {
367 #ifdef CONFIG_DEBUG_STACKOVERFLOW
368         long sp;
369
370         sp = __get_SP() & (THREAD_SIZE-1);
371
372         /* check for stack overflow: is there less than 2KB free? */
373         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
374                 printk("do_IRQ: stack overflow: %ld\n",
375                         sp - sizeof(struct thread_info));
376                 dump_stack();
377         }
378 #endif
379 }
380
381 void do_IRQ(struct pt_regs *regs)
382 {
383         struct pt_regs *old_regs = set_irq_regs(regs);
384         unsigned int irq;
385
386         trace_irq_entry(regs);
387
388         irq_enter();
389
390         check_stack_overflow();
391
392         irq = ppc_md.get_irq();
393
394         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
395                 handle_one_irq(irq);
396         else if (irq != NO_IRQ_IGNORE)
397                 __get_cpu_var(irq_stat).spurious_irqs++;
398
399         irq_exit();
400         set_irq_regs(old_regs);
401
402 #ifdef CONFIG_PPC_ISERIES
403         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
404                         get_lppaca()->int_dword.fields.decr_int) {
405                 get_lppaca()->int_dword.fields.decr_int = 0;
406                 /* Signal a fake decrementer interrupt */
407                 timer_interrupt(regs);
408         }
409 #endif
410
411         trace_irq_exit(regs);
412 }
413
414 void __init init_IRQ(void)
415 {
416         if (ppc_md.init_IRQ)
417                 ppc_md.init_IRQ();
418
419         exc_lvl_ctx_init();
420
421         irq_ctx_init();
422 }
423
424 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
425 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
426 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
427 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
428
429 void exc_lvl_ctx_init(void)
430 {
431         struct thread_info *tp;
432         int i;
433
434         for_each_possible_cpu(i) {
435                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
436                 tp = critirq_ctx[i];
437                 tp->cpu = i;
438                 tp->preempt_count = 0;
439
440 #ifdef CONFIG_BOOKE
441                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
442                 tp = dbgirq_ctx[i];
443                 tp->cpu = i;
444                 tp->preempt_count = 0;
445
446                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
447                 tp = mcheckirq_ctx[i];
448                 tp->cpu = i;
449                 tp->preempt_count = HARDIRQ_OFFSET;
450 #endif
451         }
452 }
453 #endif
454
455 #ifdef CONFIG_IRQSTACKS
456 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
457 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
458
459 void irq_ctx_init(void)
460 {
461         struct thread_info *tp;
462         int i;
463
464         for_each_possible_cpu(i) {
465                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
466                 tp = softirq_ctx[i];
467                 tp->cpu = i;
468                 tp->preempt_count = 0;
469
470                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
471                 tp = hardirq_ctx[i];
472                 tp->cpu = i;
473                 tp->preempt_count = HARDIRQ_OFFSET;
474         }
475 }
476
477 static inline void do_softirq_onstack(void)
478 {
479         struct thread_info *curtp, *irqtp;
480         unsigned long saved_sp_limit = current->thread.ksp_limit;
481
482         curtp = current_thread_info();
483         irqtp = softirq_ctx[smp_processor_id()];
484         irqtp->task = curtp->task;
485         current->thread.ksp_limit = (unsigned long)irqtp +
486                                     _ALIGN_UP(sizeof(struct thread_info), 16);
487         call_do_softirq(irqtp);
488         current->thread.ksp_limit = saved_sp_limit;
489         irqtp->task = NULL;
490 }
491
492 #else
493 #define do_softirq_onstack()    __do_softirq()
494 #endif /* CONFIG_IRQSTACKS */
495
496 void do_softirq(void)
497 {
498         unsigned long flags;
499
500         if (in_interrupt())
501                 return;
502
503         local_irq_save(flags);
504
505         if (local_softirq_pending())
506                 do_softirq_onstack();
507
508         local_irq_restore(flags);
509 }
510
511
512 /*
513  * IRQ controller and virtual interrupts
514  */
515
516 static LIST_HEAD(irq_hosts);
517 static DEFINE_RAW_SPINLOCK(irq_big_lock);
518 static unsigned int revmap_trees_allocated;
519 static DEFINE_MUTEX(revmap_trees_mutex);
520 struct irq_map_entry irq_map[NR_IRQS];
521 static unsigned int irq_virq_count = NR_IRQS;
522 static struct irq_host *irq_default_host;
523
524 irq_hw_number_t virq_to_hw(unsigned int virq)
525 {
526         return irq_map[virq].hwirq;
527 }
528 EXPORT_SYMBOL_GPL(virq_to_hw);
529
530 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
531 {
532         return h->of_node != NULL && h->of_node == np;
533 }
534
535 struct irq_host *irq_alloc_host(struct device_node *of_node,
536                                 unsigned int revmap_type,
537                                 unsigned int revmap_arg,
538                                 struct irq_host_ops *ops,
539                                 irq_hw_number_t inval_irq)
540 {
541         struct irq_host *host;
542         unsigned int size = sizeof(struct irq_host);
543         unsigned int i;
544         unsigned int *rmap;
545         unsigned long flags;
546
547         /* Allocate structure and revmap table if using linear mapping */
548         if (revmap_type == IRQ_HOST_MAP_LINEAR)
549                 size += revmap_arg * sizeof(unsigned int);
550         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
551         if (host == NULL)
552                 return NULL;
553
554         /* Fill structure */
555         host->revmap_type = revmap_type;
556         host->inval_irq = inval_irq;
557         host->ops = ops;
558         host->of_node = of_node_get(of_node);
559
560         if (host->ops->match == NULL)
561                 host->ops->match = default_irq_host_match;
562
563         raw_spin_lock_irqsave(&irq_big_lock, flags);
564
565         /* If it's a legacy controller, check for duplicates and
566          * mark it as allocated (we use irq 0 host pointer for that
567          */
568         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
569                 if (irq_map[0].host != NULL) {
570                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
571                         /* If we are early boot, we can't free the structure,
572                          * too bad...
573                          * this will be fixed once slab is made available early
574                          * instead of the current cruft
575                          */
576                         if (mem_init_done)
577                                 kfree(host);
578                         return NULL;
579                 }
580                 irq_map[0].host = host;
581         }
582
583         list_add(&host->link, &irq_hosts);
584         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
585
586         /* Additional setups per revmap type */
587         switch(revmap_type) {
588         case IRQ_HOST_MAP_LEGACY:
589                 /* 0 is always the invalid number for legacy */
590                 host->inval_irq = 0;
591                 /* setup us as the host for all legacy interrupts */
592                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
593                         irq_map[i].hwirq = i;
594                         smp_wmb();
595                         irq_map[i].host = host;
596                         smp_wmb();
597
598                         /* Clear norequest flags */
599                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
600
601                         /* Legacy flags are left to default at this point,
602                          * one can then use irq_create_mapping() to
603                          * explicitly change them
604                          */
605                         ops->map(host, i, i);
606                 }
607                 break;
608         case IRQ_HOST_MAP_LINEAR:
609                 rmap = (unsigned int *)(host + 1);
610                 for (i = 0; i < revmap_arg; i++)
611                         rmap[i] = NO_IRQ;
612                 host->revmap_data.linear.size = revmap_arg;
613                 smp_wmb();
614                 host->revmap_data.linear.revmap = rmap;
615                 break;
616         default:
617                 break;
618         }
619
620         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
621
622         return host;
623 }
624
625 struct irq_host *irq_find_host(struct device_node *node)
626 {
627         struct irq_host *h, *found = NULL;
628         unsigned long flags;
629
630         /* We might want to match the legacy controller last since
631          * it might potentially be set to match all interrupts in
632          * the absence of a device node. This isn't a problem so far
633          * yet though...
634          */
635         raw_spin_lock_irqsave(&irq_big_lock, flags);
636         list_for_each_entry(h, &irq_hosts, link)
637                 if (h->ops->match(h, node)) {
638                         found = h;
639                         break;
640                 }
641         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
642         return found;
643 }
644 EXPORT_SYMBOL_GPL(irq_find_host);
645
646 void irq_set_default_host(struct irq_host *host)
647 {
648         pr_debug("irq: Default host set to @0x%p\n", host);
649
650         irq_default_host = host;
651 }
652
653 void irq_set_virq_count(unsigned int count)
654 {
655         pr_debug("irq: Trying to set virq count to %d\n", count);
656
657         BUG_ON(count < NUM_ISA_INTERRUPTS);
658         if (count < NR_IRQS)
659                 irq_virq_count = count;
660 }
661
662 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
663                             irq_hw_number_t hwirq)
664 {
665         struct irq_desc *desc;
666
667         desc = irq_to_desc_alloc_node(virq, 0);
668         if (!desc) {
669                 pr_debug("irq: -> allocating desc failed\n");
670                 goto error;
671         }
672
673         /* Clear IRQ_NOREQUEST flag */
674         desc->status &= ~IRQ_NOREQUEST;
675
676         /* map it */
677         smp_wmb();
678         irq_map[virq].hwirq = hwirq;
679         smp_mb();
680
681         if (host->ops->map(host, virq, hwirq)) {
682                 pr_debug("irq: -> mapping failed, freeing\n");
683                 goto error;
684         }
685
686         return 0;
687
688 error:
689         irq_free_virt(virq, 1);
690         return -1;
691 }
692
693 unsigned int irq_create_direct_mapping(struct irq_host *host)
694 {
695         unsigned int virq;
696
697         if (host == NULL)
698                 host = irq_default_host;
699
700         BUG_ON(host == NULL);
701         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
702
703         virq = irq_alloc_virt(host, 1, 0);
704         if (virq == NO_IRQ) {
705                 pr_debug("irq: create_direct virq allocation failed\n");
706                 return NO_IRQ;
707         }
708
709         pr_debug("irq: create_direct obtained virq %d\n", virq);
710
711         if (irq_setup_virq(host, virq, virq))
712                 return NO_IRQ;
713
714         return virq;
715 }
716
717 unsigned int irq_create_mapping(struct irq_host *host,
718                                 irq_hw_number_t hwirq)
719 {
720         unsigned int virq, hint;
721
722         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
723
724         /* Look for default host if nececssary */
725         if (host == NULL)
726                 host = irq_default_host;
727         if (host == NULL) {
728                 printk(KERN_WARNING "irq_create_mapping called for"
729                        " NULL host, hwirq=%lx\n", hwirq);
730                 WARN_ON(1);
731                 return NO_IRQ;
732         }
733         pr_debug("irq: -> using host @%p\n", host);
734
735         /* Check if mapping already exist, if it does, call
736          * host->ops->map() to update the flags
737          */
738         virq = irq_find_mapping(host, hwirq);
739         if (virq != NO_IRQ) {
740                 if (host->ops->remap)
741                         host->ops->remap(host, virq, hwirq);
742                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
743                 return virq;
744         }
745
746         /* Get a virtual interrupt number */
747         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
748                 /* Handle legacy */
749                 virq = (unsigned int)hwirq;
750                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
751                         return NO_IRQ;
752                 return virq;
753         } else {
754                 /* Allocate a virtual interrupt number */
755                 hint = hwirq % irq_virq_count;
756                 virq = irq_alloc_virt(host, 1, hint);
757                 if (virq == NO_IRQ) {
758                         pr_debug("irq: -> virq allocation failed\n");
759                         return NO_IRQ;
760                 }
761         }
762
763         if (irq_setup_virq(host, virq, hwirq))
764                 return NO_IRQ;
765
766         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
767                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
768
769         return virq;
770 }
771 EXPORT_SYMBOL_GPL(irq_create_mapping);
772
773 unsigned int irq_create_of_mapping(struct device_node *controller,
774                                    const u32 *intspec, unsigned int intsize)
775 {
776         struct irq_host *host;
777         irq_hw_number_t hwirq;
778         unsigned int type = IRQ_TYPE_NONE;
779         unsigned int virq;
780
781         if (controller == NULL)
782                 host = irq_default_host;
783         else
784                 host = irq_find_host(controller);
785         if (host == NULL) {
786                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
787                        controller->full_name);
788                 return NO_IRQ;
789         }
790
791         /* If host has no translation, then we assume interrupt line */
792         if (host->ops->xlate == NULL)
793                 hwirq = intspec[0];
794         else {
795                 if (host->ops->xlate(host, controller, intspec, intsize,
796                                      &hwirq, &type))
797                         return NO_IRQ;
798         }
799
800         /* Create mapping */
801         virq = irq_create_mapping(host, hwirq);
802         if (virq == NO_IRQ)
803                 return virq;
804
805         /* Set type if specified and different than the current one */
806         if (type != IRQ_TYPE_NONE &&
807             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
808                 set_irq_type(virq, type);
809         return virq;
810 }
811 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
812
813 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
814 {
815         struct of_irq oirq;
816
817         if (of_irq_map_one(dev, index, &oirq))
818                 return NO_IRQ;
819
820         return irq_create_of_mapping(oirq.controller, oirq.specifier,
821                                      oirq.size);
822 }
823 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
824
825 void irq_dispose_mapping(unsigned int virq)
826 {
827         struct irq_host *host;
828         irq_hw_number_t hwirq;
829
830         if (virq == NO_IRQ)
831                 return;
832
833         host = irq_map[virq].host;
834         WARN_ON (host == NULL);
835         if (host == NULL)
836                 return;
837
838         /* Never unmap legacy interrupts */
839         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
840                 return;
841
842         /* remove chip and handler */
843         set_irq_chip_and_handler(virq, NULL, NULL);
844
845         /* Make sure it's completed */
846         synchronize_irq(virq);
847
848         /* Tell the PIC about it */
849         if (host->ops->unmap)
850                 host->ops->unmap(host, virq);
851         smp_mb();
852
853         /* Clear reverse map */
854         hwirq = irq_map[virq].hwirq;
855         switch(host->revmap_type) {
856         case IRQ_HOST_MAP_LINEAR:
857                 if (hwirq < host->revmap_data.linear.size)
858                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
859                 break;
860         case IRQ_HOST_MAP_TREE:
861                 /*
862                  * Check if radix tree allocated yet, if not then nothing to
863                  * remove.
864                  */
865                 smp_rmb();
866                 if (revmap_trees_allocated < 1)
867                         break;
868                 mutex_lock(&revmap_trees_mutex);
869                 radix_tree_delete(&host->revmap_data.tree, hwirq);
870                 mutex_unlock(&revmap_trees_mutex);
871                 break;
872         }
873
874         /* Destroy map */
875         smp_mb();
876         irq_map[virq].hwirq = host->inval_irq;
877
878         /* Set some flags */
879         irq_to_desc(virq)->status |= IRQ_NOREQUEST;
880
881         /* Free it */
882         irq_free_virt(virq, 1);
883 }
884 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
885
886 unsigned int irq_find_mapping(struct irq_host *host,
887                               irq_hw_number_t hwirq)
888 {
889         unsigned int i;
890         unsigned int hint = hwirq % irq_virq_count;
891
892         /* Look for default host if nececssary */
893         if (host == NULL)
894                 host = irq_default_host;
895         if (host == NULL)
896                 return NO_IRQ;
897
898         /* legacy -> bail early */
899         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
900                 return hwirq;
901
902         /* Slow path does a linear search of the map */
903         if (hint < NUM_ISA_INTERRUPTS)
904                 hint = NUM_ISA_INTERRUPTS;
905         i = hint;
906         do  {
907                 if (irq_map[i].host == host &&
908                     irq_map[i].hwirq == hwirq)
909                         return i;
910                 i++;
911                 if (i >= irq_virq_count)
912                         i = NUM_ISA_INTERRUPTS;
913         } while(i != hint);
914         return NO_IRQ;
915 }
916 EXPORT_SYMBOL_GPL(irq_find_mapping);
917
918
919 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
920                                      irq_hw_number_t hwirq)
921 {
922         struct irq_map_entry *ptr;
923         unsigned int virq;
924
925         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
926
927         /*
928          * Check if the radix tree exists and has bee initialized.
929          * If not, we fallback to slow mode
930          */
931         if (revmap_trees_allocated < 2)
932                 return irq_find_mapping(host, hwirq);
933
934         /* Now try to resolve */
935         /*
936          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
937          * as it's referencing an entry in the static irq_map table.
938          */
939         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
940
941         /*
942          * If found in radix tree, then fine.
943          * Else fallback to linear lookup - this should not happen in practice
944          * as it means that we failed to insert the node in the radix tree.
945          */
946         if (ptr)
947                 virq = ptr - irq_map;
948         else
949                 virq = irq_find_mapping(host, hwirq);
950
951         return virq;
952 }
953
954 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
955                              irq_hw_number_t hwirq)
956 {
957
958         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
959
960         /*
961          * Check if the radix tree exists yet.
962          * If not, then the irq will be inserted into the tree when it gets
963          * initialized.
964          */
965         smp_rmb();
966         if (revmap_trees_allocated < 1)
967                 return;
968
969         if (virq != NO_IRQ) {
970                 mutex_lock(&revmap_trees_mutex);
971                 radix_tree_insert(&host->revmap_data.tree, hwirq,
972                                   &irq_map[virq]);
973                 mutex_unlock(&revmap_trees_mutex);
974         }
975 }
976
977 unsigned int irq_linear_revmap(struct irq_host *host,
978                                irq_hw_number_t hwirq)
979 {
980         unsigned int *revmap;
981
982         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
983
984         /* Check revmap bounds */
985         if (unlikely(hwirq >= host->revmap_data.linear.size))
986                 return irq_find_mapping(host, hwirq);
987
988         /* Check if revmap was allocated */
989         revmap = host->revmap_data.linear.revmap;
990         if (unlikely(revmap == NULL))
991                 return irq_find_mapping(host, hwirq);
992
993         /* Fill up revmap with slow path if no mapping found */
994         if (unlikely(revmap[hwirq] == NO_IRQ))
995                 revmap[hwirq] = irq_find_mapping(host, hwirq);
996
997         return revmap[hwirq];
998 }
999
1000 unsigned int irq_alloc_virt(struct irq_host *host,
1001                             unsigned int count,
1002                             unsigned int hint)
1003 {
1004         unsigned long flags;
1005         unsigned int i, j, found = NO_IRQ;
1006
1007         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
1008                 return NO_IRQ;
1009
1010         raw_spin_lock_irqsave(&irq_big_lock, flags);
1011
1012         /* Use hint for 1 interrupt if any */
1013         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
1014             hint < irq_virq_count && irq_map[hint].host == NULL) {
1015                 found = hint;
1016                 goto hint_found;
1017         }
1018
1019         /* Look for count consecutive numbers in the allocatable
1020          * (non-legacy) space
1021          */
1022         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1023                 if (irq_map[i].host != NULL)
1024                         j = 0;
1025                 else
1026                         j++;
1027
1028                 if (j == count) {
1029                         found = i - count + 1;
1030                         break;
1031                 }
1032         }
1033         if (found == NO_IRQ) {
1034                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1035                 return NO_IRQ;
1036         }
1037  hint_found:
1038         for (i = found; i < (found + count); i++) {
1039                 irq_map[i].hwirq = host->inval_irq;
1040                 smp_wmb();
1041                 irq_map[i].host = host;
1042         }
1043         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1044         return found;
1045 }
1046
1047 void irq_free_virt(unsigned int virq, unsigned int count)
1048 {
1049         unsigned long flags;
1050         unsigned int i;
1051
1052         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1053         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1054
1055         raw_spin_lock_irqsave(&irq_big_lock, flags);
1056         for (i = virq; i < (virq + count); i++) {
1057                 struct irq_host *host;
1058
1059                 if (i < NUM_ISA_INTERRUPTS ||
1060                     (virq + count) > irq_virq_count)
1061                         continue;
1062
1063                 host = irq_map[i].host;
1064                 irq_map[i].hwirq = host->inval_irq;
1065                 smp_wmb();
1066                 irq_map[i].host = NULL;
1067         }
1068         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1069 }
1070
1071 int arch_early_irq_init(void)
1072 {
1073         struct irq_desc *desc;
1074         int i;
1075
1076         for (i = 0; i < NR_IRQS; i++) {
1077                 desc = irq_to_desc(i);
1078                 if (desc)
1079                         desc->status |= IRQ_NOREQUEST;
1080         }
1081
1082         return 0;
1083 }
1084
1085 int arch_init_chip_data(struct irq_desc *desc, int node)
1086 {
1087         desc->status |= IRQ_NOREQUEST;
1088         return 0;
1089 }
1090
1091 /* We need to create the radix trees late */
1092 static int irq_late_init(void)
1093 {
1094         struct irq_host *h;
1095         unsigned int i;
1096
1097         /*
1098          * No mutual exclusion with respect to accessors of the tree is needed
1099          * here as the synchronization is done via the state variable
1100          * revmap_trees_allocated.
1101          */
1102         list_for_each_entry(h, &irq_hosts, link) {
1103                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1104                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1105         }
1106
1107         /*
1108          * Make sure the radix trees inits are visible before setting
1109          * the flag
1110          */
1111         smp_wmb();
1112         revmap_trees_allocated = 1;
1113
1114         /*
1115          * Insert the reverse mapping for those interrupts already present
1116          * in irq_map[].
1117          */
1118         mutex_lock(&revmap_trees_mutex);
1119         for (i = 0; i < irq_virq_count; i++) {
1120                 if (irq_map[i].host &&
1121                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1122                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1123                                           irq_map[i].hwirq, &irq_map[i]);
1124         }
1125         mutex_unlock(&revmap_trees_mutex);
1126
1127         /*
1128          * Make sure the radix trees insertions are visible before setting
1129          * the flag
1130          */
1131         smp_wmb();
1132         revmap_trees_allocated = 2;
1133
1134         return 0;
1135 }
1136 arch_initcall(irq_late_init);
1137
1138 #ifdef CONFIG_VIRQ_DEBUG
1139 static int virq_debug_show(struct seq_file *m, void *private)
1140 {
1141         unsigned long flags;
1142         struct irq_desc *desc;
1143         const char *p;
1144         char none[] = "none";
1145         int i;
1146
1147         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1148                       "chip name", "host name");
1149
1150         for (i = 1; i < nr_irqs; i++) {
1151                 desc = irq_to_desc(i);
1152                 if (!desc)
1153                         continue;
1154
1155                 raw_spin_lock_irqsave(&desc->lock, flags);
1156
1157                 if (desc->action && desc->action->handler) {
1158                         seq_printf(m, "%5d  ", i);
1159                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1160
1161                         if (desc->chip && desc->chip->name)
1162                                 p = desc->chip->name;
1163                         else
1164                                 p = none;
1165                         seq_printf(m, "%-15s  ", p);
1166
1167                         if (irq_map[i].host && irq_map[i].host->of_node)
1168                                 p = irq_map[i].host->of_node->full_name;
1169                         else
1170                                 p = none;
1171                         seq_printf(m, "%s\n", p);
1172                 }
1173
1174                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1175         }
1176
1177         return 0;
1178 }
1179
1180 static int virq_debug_open(struct inode *inode, struct file *file)
1181 {
1182         return single_open(file, virq_debug_show, inode->i_private);
1183 }
1184
1185 static const struct file_operations virq_debug_fops = {
1186         .open = virq_debug_open,
1187         .read = seq_read,
1188         .llseek = seq_lseek,
1189         .release = single_release,
1190 };
1191
1192 static int __init irq_debugfs_init(void)
1193 {
1194         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1195                                  NULL, &virq_debug_fops) == NULL)
1196                 return -ENOMEM;
1197
1198         return 0;
1199 }
1200 __initcall(irq_debugfs_init);
1201 #endif /* CONFIG_VIRQ_DEBUG */
1202
1203 #ifdef CONFIG_PPC64
1204 static int __init setup_noirqdistrib(char *str)
1205 {
1206         distribute_irqs = 0;
1207         return 1;
1208 }
1209
1210 __setup("noirqdistrib", setup_noirqdistrib);
1211 #endif /* CONFIG_PPC64 */