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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/of.h>
57 #include <linux/of_irq.h>
58
59 #include <asm/uaccess.h>
60 #include <asm/system.h>
61 #include <asm/io.h>
62 #include <asm/pgtable.h>
63 #include <asm/irq.h>
64 #include <asm/cache.h>
65 #include <asm/prom.h>
66 #include <asm/ptrace.h>
67 #include <asm/machdep.h>
68 #include <asm/udbg.h>
69 #include <asm/dbell.h>
70 #include <asm/smp.h>
71
72 #ifdef CONFIG_PPC64
73 #include <asm/paca.h>
74 #include <asm/firmware.h>
75 #include <asm/lv1call.h>
76 #endif
77 #define CREATE_TRACE_POINTS
78 #include <asm/trace.h>
79
80 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
81 EXPORT_PER_CPU_SYMBOL(irq_stat);
82
83 int __irq_offset_value;
84
85 #ifdef CONFIG_PPC32
86 EXPORT_SYMBOL(__irq_offset_value);
87 atomic_t ppc_n_lost_interrupts;
88
89 #ifdef CONFIG_TAU_INT
90 extern int tau_initialized;
91 extern int tau_interrupts(int);
92 #endif
93 #endif /* CONFIG_PPC32 */
94
95 #ifdef CONFIG_PPC64
96
97 #ifndef CONFIG_SPARSE_IRQ
98 EXPORT_SYMBOL(irq_desc);
99 #endif
100
101 int distribute_irqs = 1;
102
103 static inline notrace unsigned long get_hard_enabled(void)
104 {
105         unsigned long enabled;
106
107         __asm__ __volatile__("lbz %0,%1(13)"
108         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
109
110         return enabled;
111 }
112
113 static inline notrace void set_soft_enabled(unsigned long enable)
114 {
115         __asm__ __volatile__("stb %0,%1(13)"
116         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
117 }
118
119 notrace void raw_local_irq_restore(unsigned long en)
120 {
121         /*
122          * get_paca()->soft_enabled = en;
123          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
124          * That was allowed before, and in such a case we do need to take care
125          * that gcc will set soft_enabled directly via r13, not choose to use
126          * an intermediate register, lest we're preempted to a different cpu.
127          */
128         set_soft_enabled(en);
129         if (!en)
130                 return;
131
132 #ifdef CONFIG_PPC_STD_MMU_64
133         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
134                 /*
135                  * Do we need to disable preemption here?  Not really: in the
136                  * unlikely event that we're preempted to a different cpu in
137                  * between getting r13, loading its lppaca_ptr, and loading
138                  * its any_int, we might call iseries_handle_interrupts without
139                  * an interrupt pending on the new cpu, but that's no disaster,
140                  * is it?  And the business of preempting us off the old cpu
141                  * would itself involve a local_irq_restore which handles the
142                  * interrupt to that cpu.
143                  *
144                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
145                  * to avoid any preemption checking added into get_paca().
146                  */
147                 if (local_paca->lppaca_ptr->int_dword.any_int)
148                         iseries_handle_interrupts();
149         }
150 #endif /* CONFIG_PPC_STD_MMU_64 */
151
152         /*
153          * if (get_paca()->hard_enabled) return;
154          * But again we need to take care that gcc gets hard_enabled directly
155          * via r13, not choose to use an intermediate register, lest we're
156          * preempted to a different cpu in between the two instructions.
157          */
158         if (get_hard_enabled())
159                 return;
160
161 #if defined(CONFIG_BOOKE) && defined(CONFIG_SMP)
162         /* Check for pending doorbell interrupts and resend to ourself */
163         doorbell_check_self();
164 #endif
165
166         /*
167          * Need to hard-enable interrupts here.  Since currently disabled,
168          * no need to take further asm precautions against preemption; but
169          * use local_paca instead of get_paca() to avoid preemption checking.
170          */
171         local_paca->hard_enabled = en;
172
173 #ifndef CONFIG_BOOKE
174         /* On server, re-trigger the decrementer if it went negative since
175          * some processors only trigger on edge transitions of the sign bit.
176          *
177          * BookE has a level sensitive decrementer (latches in TSR) so we
178          * don't need that
179          */
180         if ((int)mfspr(SPRN_DEC) < 0)
181                 mtspr(SPRN_DEC, 1);
182 #endif /* CONFIG_BOOKE */
183
184         /*
185          * Force the delivery of pending soft-disabled interrupts on PS3.
186          * Any HV call will have this side effect.
187          */
188         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
189                 u64 tmp;
190                 lv1_get_version_info(&tmp);
191         }
192
193         __hard_irq_enable();
194 }
195 EXPORT_SYMBOL(raw_local_irq_restore);
196 #endif /* CONFIG_PPC64 */
197
198 static int show_other_interrupts(struct seq_file *p, int prec)
199 {
200         int j;
201
202 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
203         if (tau_initialized) {
204                 seq_printf(p, "%*s: ", prec, "TAU");
205                 for_each_online_cpu(j)
206                         seq_printf(p, "%10u ", tau_interrupts(j));
207                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
208         }
209 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
210
211         seq_printf(p, "%*s: ", prec, "LOC");
212         for_each_online_cpu(j)
213                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
214         seq_printf(p, "  Local timer interrupts\n");
215
216         seq_printf(p, "%*s: ", prec, "SPU");
217         for_each_online_cpu(j)
218                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
219         seq_printf(p, "  Spurious interrupts\n");
220
221         seq_printf(p, "%*s: ", prec, "CNT");
222         for_each_online_cpu(j)
223                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
224         seq_printf(p, "  Performance monitoring interrupts\n");
225
226         seq_printf(p, "%*s: ", prec, "MCE");
227         for_each_online_cpu(j)
228                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
229         seq_printf(p, "  Machine check exceptions\n");
230
231         return 0;
232 }
233
234 int show_interrupts(struct seq_file *p, void *v)
235 {
236         unsigned long flags, any_count = 0;
237         int i = *(loff_t *) v, j, prec;
238         struct irqaction *action;
239         struct irq_desc *desc;
240
241         if (i > nr_irqs)
242                 return 0;
243
244         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
245                 j *= 10;
246
247         if (i == nr_irqs)
248                 return show_other_interrupts(p, prec);
249
250         /* print header */
251         if (i == 0) {
252                 seq_printf(p, "%*s", prec + 8, "");
253                 for_each_online_cpu(j)
254                         seq_printf(p, "CPU%-8d", j);
255                 seq_putc(p, '\n');
256         }
257
258         desc = irq_to_desc(i);
259         if (!desc)
260                 return 0;
261
262         raw_spin_lock_irqsave(&desc->lock, flags);
263         for_each_online_cpu(j)
264                 any_count |= kstat_irqs_cpu(i, j);
265         action = desc->action;
266         if (!action && !any_count)
267                 goto out;
268
269         seq_printf(p, "%*d: ", prec, i);
270         for_each_online_cpu(j)
271                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
272
273         if (desc->chip)
274                 seq_printf(p, "  %-16s", desc->chip->name);
275         else
276                 seq_printf(p, "  %-16s", "None");
277         seq_printf(p, " %-8s", (desc->status & IRQ_LEVEL) ? "Level" : "Edge");
278
279         if (action) {
280                 seq_printf(p, "     %s", action->name);
281                 while ((action = action->next) != NULL)
282                         seq_printf(p, ", %s", action->name);
283         }
284
285         seq_putc(p, '\n');
286 out:
287         raw_spin_unlock_irqrestore(&desc->lock, flags);
288         return 0;
289 }
290
291 /*
292  * /proc/stat helpers
293  */
294 u64 arch_irq_stat_cpu(unsigned int cpu)
295 {
296         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
297
298         sum += per_cpu(irq_stat, cpu).pmu_irqs;
299         sum += per_cpu(irq_stat, cpu).mce_exceptions;
300         sum += per_cpu(irq_stat, cpu).spurious_irqs;
301
302         return sum;
303 }
304
305 #ifdef CONFIG_HOTPLUG_CPU
306 void fixup_irqs(const struct cpumask *map)
307 {
308         struct irq_desc *desc;
309         unsigned int irq;
310         static int warned;
311         cpumask_var_t mask;
312
313         alloc_cpumask_var(&mask, GFP_KERNEL);
314
315         for_each_irq(irq) {
316                 desc = irq_to_desc(irq);
317                 if (!desc)
318                         continue;
319
320                 if (desc->status & IRQ_PER_CPU)
321                         continue;
322
323                 cpumask_and(mask, desc->affinity, map);
324                 if (cpumask_any(mask) >= nr_cpu_ids) {
325                         printk("Breaking affinity for irq %i\n", irq);
326                         cpumask_copy(mask, map);
327                 }
328                 if (desc->chip->set_affinity)
329                         desc->chip->set_affinity(irq, mask);
330                 else if (desc->action && !(warned++))
331                         printk("Cannot set affinity for irq %i\n", irq);
332         }
333
334         free_cpumask_var(mask);
335
336         local_irq_enable();
337         mdelay(1);
338         local_irq_disable();
339 }
340 #endif
341
342 static inline void handle_one_irq(unsigned int irq)
343 {
344         struct thread_info *curtp, *irqtp;
345         unsigned long saved_sp_limit;
346         struct irq_desc *desc;
347
348         /* Switch to the irq stack to handle this */
349         curtp = current_thread_info();
350         irqtp = hardirq_ctx[smp_processor_id()];
351
352         if (curtp == irqtp) {
353                 /* We're already on the irq stack, just handle it */
354                 generic_handle_irq(irq);
355                 return;
356         }
357
358         desc = irq_to_desc(irq);
359         saved_sp_limit = current->thread.ksp_limit;
360
361         irqtp->task = curtp->task;
362         irqtp->flags = 0;
363
364         /* Copy the softirq bits in preempt_count so that the
365          * softirq checks work in the hardirq context. */
366         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
367                                (curtp->preempt_count & SOFTIRQ_MASK);
368
369         current->thread.ksp_limit = (unsigned long)irqtp +
370                 _ALIGN_UP(sizeof(struct thread_info), 16);
371
372         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
373         current->thread.ksp_limit = saved_sp_limit;
374         irqtp->task = NULL;
375
376         /* Set any flag that may have been set on the
377          * alternate stack
378          */
379         if (irqtp->flags)
380                 set_bits(irqtp->flags, &curtp->flags);
381 }
382
383 static inline void check_stack_overflow(void)
384 {
385 #ifdef CONFIG_DEBUG_STACKOVERFLOW
386         long sp;
387
388         sp = __get_SP() & (THREAD_SIZE-1);
389
390         /* check for stack overflow: is there less than 2KB free? */
391         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
392                 printk("do_IRQ: stack overflow: %ld\n",
393                         sp - sizeof(struct thread_info));
394                 dump_stack();
395         }
396 #endif
397 }
398
399 void do_IRQ(struct pt_regs *regs)
400 {
401         struct pt_regs *old_regs = set_irq_regs(regs);
402         unsigned int irq;
403
404         trace_irq_entry(regs);
405
406         irq_enter();
407
408         check_stack_overflow();
409
410         irq = ppc_md.get_irq();
411
412         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
413                 handle_one_irq(irq);
414         else if (irq != NO_IRQ_IGNORE)
415                 __get_cpu_var(irq_stat).spurious_irqs++;
416
417         irq_exit();
418         set_irq_regs(old_regs);
419
420 #ifdef CONFIG_PPC_ISERIES
421         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
422                         get_lppaca()->int_dword.fields.decr_int) {
423                 get_lppaca()->int_dword.fields.decr_int = 0;
424                 /* Signal a fake decrementer interrupt */
425                 timer_interrupt(regs);
426         }
427 #endif
428
429         trace_irq_exit(regs);
430 }
431
432 void __init init_IRQ(void)
433 {
434         if (ppc_md.init_IRQ)
435                 ppc_md.init_IRQ();
436
437         exc_lvl_ctx_init();
438
439         irq_ctx_init();
440 }
441
442 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
443 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
444 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
445 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
446
447 void exc_lvl_ctx_init(void)
448 {
449         struct thread_info *tp;
450         int i, hw_cpu;
451
452         for_each_possible_cpu(i) {
453                 hw_cpu = get_hard_smp_processor_id(i);
454                 memset((void *)critirq_ctx[hw_cpu], 0, THREAD_SIZE);
455                 tp = critirq_ctx[hw_cpu];
456                 tp->cpu = i;
457                 tp->preempt_count = 0;
458
459 #ifdef CONFIG_BOOKE
460                 memset((void *)dbgirq_ctx[hw_cpu], 0, THREAD_SIZE);
461                 tp = dbgirq_ctx[hw_cpu];
462                 tp->cpu = i;
463                 tp->preempt_count = 0;
464
465                 memset((void *)mcheckirq_ctx[hw_cpu], 0, THREAD_SIZE);
466                 tp = mcheckirq_ctx[hw_cpu];
467                 tp->cpu = i;
468                 tp->preempt_count = HARDIRQ_OFFSET;
469 #endif
470         }
471 }
472 #endif
473
474 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
475 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
476
477 void irq_ctx_init(void)
478 {
479         struct thread_info *tp;
480         int i;
481
482         for_each_possible_cpu(i) {
483                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
484                 tp = softirq_ctx[i];
485                 tp->cpu = i;
486                 tp->preempt_count = 0;
487
488                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
489                 tp = hardirq_ctx[i];
490                 tp->cpu = i;
491                 tp->preempt_count = HARDIRQ_OFFSET;
492         }
493 }
494
495 static inline void do_softirq_onstack(void)
496 {
497         struct thread_info *curtp, *irqtp;
498         unsigned long saved_sp_limit = current->thread.ksp_limit;
499
500         curtp = current_thread_info();
501         irqtp = softirq_ctx[smp_processor_id()];
502         irqtp->task = curtp->task;
503         current->thread.ksp_limit = (unsigned long)irqtp +
504                                     _ALIGN_UP(sizeof(struct thread_info), 16);
505         call_do_softirq(irqtp);
506         current->thread.ksp_limit = saved_sp_limit;
507         irqtp->task = NULL;
508 }
509
510 void do_softirq(void)
511 {
512         unsigned long flags;
513
514         if (in_interrupt())
515                 return;
516
517         local_irq_save(flags);
518
519         if (local_softirq_pending())
520                 do_softirq_onstack();
521
522         local_irq_restore(flags);
523 }
524
525
526 /*
527  * IRQ controller and virtual interrupts
528  */
529
530 static LIST_HEAD(irq_hosts);
531 static DEFINE_RAW_SPINLOCK(irq_big_lock);
532 static unsigned int revmap_trees_allocated;
533 static DEFINE_MUTEX(revmap_trees_mutex);
534 struct irq_map_entry irq_map[NR_IRQS];
535 static unsigned int irq_virq_count = NR_IRQS;
536 static struct irq_host *irq_default_host;
537
538 irq_hw_number_t virq_to_hw(unsigned int virq)
539 {
540         return irq_map[virq].hwirq;
541 }
542 EXPORT_SYMBOL_GPL(virq_to_hw);
543
544 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
545 {
546         return h->of_node != NULL && h->of_node == np;
547 }
548
549 struct irq_host *irq_alloc_host(struct device_node *of_node,
550                                 unsigned int revmap_type,
551                                 unsigned int revmap_arg,
552                                 struct irq_host_ops *ops,
553                                 irq_hw_number_t inval_irq)
554 {
555         struct irq_host *host;
556         unsigned int size = sizeof(struct irq_host);
557         unsigned int i;
558         unsigned int *rmap;
559         unsigned long flags;
560
561         /* Allocate structure and revmap table if using linear mapping */
562         if (revmap_type == IRQ_HOST_MAP_LINEAR)
563                 size += revmap_arg * sizeof(unsigned int);
564         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
565         if (host == NULL)
566                 return NULL;
567
568         /* Fill structure */
569         host->revmap_type = revmap_type;
570         host->inval_irq = inval_irq;
571         host->ops = ops;
572         host->of_node = of_node_get(of_node);
573
574         if (host->ops->match == NULL)
575                 host->ops->match = default_irq_host_match;
576
577         raw_spin_lock_irqsave(&irq_big_lock, flags);
578
579         /* If it's a legacy controller, check for duplicates and
580          * mark it as allocated (we use irq 0 host pointer for that
581          */
582         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
583                 if (irq_map[0].host != NULL) {
584                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
585                         /* If we are early boot, we can't free the structure,
586                          * too bad...
587                          * this will be fixed once slab is made available early
588                          * instead of the current cruft
589                          */
590                         if (mem_init_done) {
591                                 of_node_put(host->of_node);
592                                 kfree(host);
593                         }
594                         return NULL;
595                 }
596                 irq_map[0].host = host;
597         }
598
599         list_add(&host->link, &irq_hosts);
600         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
601
602         /* Additional setups per revmap type */
603         switch(revmap_type) {
604         case IRQ_HOST_MAP_LEGACY:
605                 /* 0 is always the invalid number for legacy */
606                 host->inval_irq = 0;
607                 /* setup us as the host for all legacy interrupts */
608                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
609                         irq_map[i].hwirq = i;
610                         smp_wmb();
611                         irq_map[i].host = host;
612                         smp_wmb();
613
614                         /* Clear norequest flags */
615                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
616
617                         /* Legacy flags are left to default at this point,
618                          * one can then use irq_create_mapping() to
619                          * explicitly change them
620                          */
621                         ops->map(host, i, i);
622                 }
623                 break;
624         case IRQ_HOST_MAP_LINEAR:
625                 rmap = (unsigned int *)(host + 1);
626                 for (i = 0; i < revmap_arg; i++)
627                         rmap[i] = NO_IRQ;
628                 host->revmap_data.linear.size = revmap_arg;
629                 smp_wmb();
630                 host->revmap_data.linear.revmap = rmap;
631                 break;
632         default:
633                 break;
634         }
635
636         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
637
638         return host;
639 }
640
641 struct irq_host *irq_find_host(struct device_node *node)
642 {
643         struct irq_host *h, *found = NULL;
644         unsigned long flags;
645
646         /* We might want to match the legacy controller last since
647          * it might potentially be set to match all interrupts in
648          * the absence of a device node. This isn't a problem so far
649          * yet though...
650          */
651         raw_spin_lock_irqsave(&irq_big_lock, flags);
652         list_for_each_entry(h, &irq_hosts, link)
653                 if (h->ops->match(h, node)) {
654                         found = h;
655                         break;
656                 }
657         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
658         return found;
659 }
660 EXPORT_SYMBOL_GPL(irq_find_host);
661
662 void irq_set_default_host(struct irq_host *host)
663 {
664         pr_debug("irq: Default host set to @0x%p\n", host);
665
666         irq_default_host = host;
667 }
668
669 void irq_set_virq_count(unsigned int count)
670 {
671         pr_debug("irq: Trying to set virq count to %d\n", count);
672
673         BUG_ON(count < NUM_ISA_INTERRUPTS);
674         if (count < NR_IRQS)
675                 irq_virq_count = count;
676 }
677
678 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
679                             irq_hw_number_t hwirq)
680 {
681         struct irq_desc *desc;
682
683         desc = irq_to_desc_alloc_node(virq, 0);
684         if (!desc) {
685                 pr_debug("irq: -> allocating desc failed\n");
686                 goto error;
687         }
688
689         /* Clear IRQ_NOREQUEST flag */
690         desc->status &= ~IRQ_NOREQUEST;
691
692         /* map it */
693         smp_wmb();
694         irq_map[virq].hwirq = hwirq;
695         smp_mb();
696
697         if (host->ops->map(host, virq, hwirq)) {
698                 pr_debug("irq: -> mapping failed, freeing\n");
699                 goto error;
700         }
701
702         return 0;
703
704 error:
705         irq_free_virt(virq, 1);
706         return -1;
707 }
708
709 unsigned int irq_create_direct_mapping(struct irq_host *host)
710 {
711         unsigned int virq;
712
713         if (host == NULL)
714                 host = irq_default_host;
715
716         BUG_ON(host == NULL);
717         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
718
719         virq = irq_alloc_virt(host, 1, 0);
720         if (virq == NO_IRQ) {
721                 pr_debug("irq: create_direct virq allocation failed\n");
722                 return NO_IRQ;
723         }
724
725         pr_debug("irq: create_direct obtained virq %d\n", virq);
726
727         if (irq_setup_virq(host, virq, virq))
728                 return NO_IRQ;
729
730         return virq;
731 }
732
733 unsigned int irq_create_mapping(struct irq_host *host,
734                                 irq_hw_number_t hwirq)
735 {
736         unsigned int virq, hint;
737
738         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
739
740         /* Look for default host if nececssary */
741         if (host == NULL)
742                 host = irq_default_host;
743         if (host == NULL) {
744                 printk(KERN_WARNING "irq_create_mapping called for"
745                        " NULL host, hwirq=%lx\n", hwirq);
746                 WARN_ON(1);
747                 return NO_IRQ;
748         }
749         pr_debug("irq: -> using host @%p\n", host);
750
751         /* Check if mapping already exist, if it does, call
752          * host->ops->map() to update the flags
753          */
754         virq = irq_find_mapping(host, hwirq);
755         if (virq != NO_IRQ) {
756                 if (host->ops->remap)
757                         host->ops->remap(host, virq, hwirq);
758                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
759                 return virq;
760         }
761
762         /* Get a virtual interrupt number */
763         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
764                 /* Handle legacy */
765                 virq = (unsigned int)hwirq;
766                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
767                         return NO_IRQ;
768                 return virq;
769         } else {
770                 /* Allocate a virtual interrupt number */
771                 hint = hwirq % irq_virq_count;
772                 virq = irq_alloc_virt(host, 1, hint);
773                 if (virq == NO_IRQ) {
774                         pr_debug("irq: -> virq allocation failed\n");
775                         return NO_IRQ;
776                 }
777         }
778
779         if (irq_setup_virq(host, virq, hwirq))
780                 return NO_IRQ;
781
782         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
783                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
784
785         return virq;
786 }
787 EXPORT_SYMBOL_GPL(irq_create_mapping);
788
789 unsigned int irq_create_of_mapping(struct device_node *controller,
790                                    const u32 *intspec, unsigned int intsize)
791 {
792         struct irq_host *host;
793         irq_hw_number_t hwirq;
794         unsigned int type = IRQ_TYPE_NONE;
795         unsigned int virq;
796
797         if (controller == NULL)
798                 host = irq_default_host;
799         else
800                 host = irq_find_host(controller);
801         if (host == NULL) {
802                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
803                        controller->full_name);
804                 return NO_IRQ;
805         }
806
807         /* If host has no translation, then we assume interrupt line */
808         if (host->ops->xlate == NULL)
809                 hwirq = intspec[0];
810         else {
811                 if (host->ops->xlate(host, controller, intspec, intsize,
812                                      &hwirq, &type))
813                         return NO_IRQ;
814         }
815
816         /* Create mapping */
817         virq = irq_create_mapping(host, hwirq);
818         if (virq == NO_IRQ)
819                 return virq;
820
821         /* Set type if specified and different than the current one */
822         if (type != IRQ_TYPE_NONE &&
823             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
824                 set_irq_type(virq, type);
825         return virq;
826 }
827 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
828
829 void irq_dispose_mapping(unsigned int virq)
830 {
831         struct irq_host *host;
832         irq_hw_number_t hwirq;
833
834         if (virq == NO_IRQ)
835                 return;
836
837         host = irq_map[virq].host;
838         WARN_ON (host == NULL);
839         if (host == NULL)
840                 return;
841
842         /* Never unmap legacy interrupts */
843         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
844                 return;
845
846         /* remove chip and handler */
847         set_irq_chip_and_handler(virq, NULL, NULL);
848
849         /* Make sure it's completed */
850         synchronize_irq(virq);
851
852         /* Tell the PIC about it */
853         if (host->ops->unmap)
854                 host->ops->unmap(host, virq);
855         smp_mb();
856
857         /* Clear reverse map */
858         hwirq = irq_map[virq].hwirq;
859         switch(host->revmap_type) {
860         case IRQ_HOST_MAP_LINEAR:
861                 if (hwirq < host->revmap_data.linear.size)
862                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
863                 break;
864         case IRQ_HOST_MAP_TREE:
865                 /*
866                  * Check if radix tree allocated yet, if not then nothing to
867                  * remove.
868                  */
869                 smp_rmb();
870                 if (revmap_trees_allocated < 1)
871                         break;
872                 mutex_lock(&revmap_trees_mutex);
873                 radix_tree_delete(&host->revmap_data.tree, hwirq);
874                 mutex_unlock(&revmap_trees_mutex);
875                 break;
876         }
877
878         /* Destroy map */
879         smp_mb();
880         irq_map[virq].hwirq = host->inval_irq;
881
882         /* Set some flags */
883         irq_to_desc(virq)->status |= IRQ_NOREQUEST;
884
885         /* Free it */
886         irq_free_virt(virq, 1);
887 }
888 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
889
890 unsigned int irq_find_mapping(struct irq_host *host,
891                               irq_hw_number_t hwirq)
892 {
893         unsigned int i;
894         unsigned int hint = hwirq % irq_virq_count;
895
896         /* Look for default host if nececssary */
897         if (host == NULL)
898                 host = irq_default_host;
899         if (host == NULL)
900                 return NO_IRQ;
901
902         /* legacy -> bail early */
903         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
904                 return hwirq;
905
906         /* Slow path does a linear search of the map */
907         if (hint < NUM_ISA_INTERRUPTS)
908                 hint = NUM_ISA_INTERRUPTS;
909         i = hint;
910         do  {
911                 if (irq_map[i].host == host &&
912                     irq_map[i].hwirq == hwirq)
913                         return i;
914                 i++;
915                 if (i >= irq_virq_count)
916                         i = NUM_ISA_INTERRUPTS;
917         } while(i != hint);
918         return NO_IRQ;
919 }
920 EXPORT_SYMBOL_GPL(irq_find_mapping);
921
922
923 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
924                                      irq_hw_number_t hwirq)
925 {
926         struct irq_map_entry *ptr;
927         unsigned int virq;
928
929         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
930
931         /*
932          * Check if the radix tree exists and has bee initialized.
933          * If not, we fallback to slow mode
934          */
935         if (revmap_trees_allocated < 2)
936                 return irq_find_mapping(host, hwirq);
937
938         /* Now try to resolve */
939         /*
940          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
941          * as it's referencing an entry in the static irq_map table.
942          */
943         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
944
945         /*
946          * If found in radix tree, then fine.
947          * Else fallback to linear lookup - this should not happen in practice
948          * as it means that we failed to insert the node in the radix tree.
949          */
950         if (ptr)
951                 virq = ptr - irq_map;
952         else
953                 virq = irq_find_mapping(host, hwirq);
954
955         return virq;
956 }
957
958 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
959                              irq_hw_number_t hwirq)
960 {
961
962         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
963
964         /*
965          * Check if the radix tree exists yet.
966          * If not, then the irq will be inserted into the tree when it gets
967          * initialized.
968          */
969         smp_rmb();
970         if (revmap_trees_allocated < 1)
971                 return;
972
973         if (virq != NO_IRQ) {
974                 mutex_lock(&revmap_trees_mutex);
975                 radix_tree_insert(&host->revmap_data.tree, hwirq,
976                                   &irq_map[virq]);
977                 mutex_unlock(&revmap_trees_mutex);
978         }
979 }
980
981 unsigned int irq_linear_revmap(struct irq_host *host,
982                                irq_hw_number_t hwirq)
983 {
984         unsigned int *revmap;
985
986         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
987
988         /* Check revmap bounds */
989         if (unlikely(hwirq >= host->revmap_data.linear.size))
990                 return irq_find_mapping(host, hwirq);
991
992         /* Check if revmap was allocated */
993         revmap = host->revmap_data.linear.revmap;
994         if (unlikely(revmap == NULL))
995                 return irq_find_mapping(host, hwirq);
996
997         /* Fill up revmap with slow path if no mapping found */
998         if (unlikely(revmap[hwirq] == NO_IRQ))
999                 revmap[hwirq] = irq_find_mapping(host, hwirq);
1000
1001         return revmap[hwirq];
1002 }
1003
1004 unsigned int irq_alloc_virt(struct irq_host *host,
1005                             unsigned int count,
1006                             unsigned int hint)
1007 {
1008         unsigned long flags;
1009         unsigned int i, j, found = NO_IRQ;
1010
1011         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
1012                 return NO_IRQ;
1013
1014         raw_spin_lock_irqsave(&irq_big_lock, flags);
1015
1016         /* Use hint for 1 interrupt if any */
1017         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
1018             hint < irq_virq_count && irq_map[hint].host == NULL) {
1019                 found = hint;
1020                 goto hint_found;
1021         }
1022
1023         /* Look for count consecutive numbers in the allocatable
1024          * (non-legacy) space
1025          */
1026         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1027                 if (irq_map[i].host != NULL)
1028                         j = 0;
1029                 else
1030                         j++;
1031
1032                 if (j == count) {
1033                         found = i - count + 1;
1034                         break;
1035                 }
1036         }
1037         if (found == NO_IRQ) {
1038                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1039                 return NO_IRQ;
1040         }
1041  hint_found:
1042         for (i = found; i < (found + count); i++) {
1043                 irq_map[i].hwirq = host->inval_irq;
1044                 smp_wmb();
1045                 irq_map[i].host = host;
1046         }
1047         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1048         return found;
1049 }
1050
1051 void irq_free_virt(unsigned int virq, unsigned int count)
1052 {
1053         unsigned long flags;
1054         unsigned int i;
1055
1056         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1057         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1058
1059         raw_spin_lock_irqsave(&irq_big_lock, flags);
1060         for (i = virq; i < (virq + count); i++) {
1061                 struct irq_host *host;
1062
1063                 if (i < NUM_ISA_INTERRUPTS ||
1064                     (virq + count) > irq_virq_count)
1065                         continue;
1066
1067                 host = irq_map[i].host;
1068                 irq_map[i].hwirq = host->inval_irq;
1069                 smp_wmb();
1070                 irq_map[i].host = NULL;
1071         }
1072         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1073 }
1074
1075 int arch_early_irq_init(void)
1076 {
1077         struct irq_desc *desc;
1078         int i;
1079
1080         for (i = 0; i < NR_IRQS; i++) {
1081                 desc = irq_to_desc(i);
1082                 if (desc)
1083                         desc->status |= IRQ_NOREQUEST;
1084         }
1085
1086         return 0;
1087 }
1088
1089 int arch_init_chip_data(struct irq_desc *desc, int node)
1090 {
1091         desc->status |= IRQ_NOREQUEST;
1092         return 0;
1093 }
1094
1095 /* We need to create the radix trees late */
1096 static int irq_late_init(void)
1097 {
1098         struct irq_host *h;
1099         unsigned int i;
1100
1101         /*
1102          * No mutual exclusion with respect to accessors of the tree is needed
1103          * here as the synchronization is done via the state variable
1104          * revmap_trees_allocated.
1105          */
1106         list_for_each_entry(h, &irq_hosts, link) {
1107                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1108                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1109         }
1110
1111         /*
1112          * Make sure the radix trees inits are visible before setting
1113          * the flag
1114          */
1115         smp_wmb();
1116         revmap_trees_allocated = 1;
1117
1118         /*
1119          * Insert the reverse mapping for those interrupts already present
1120          * in irq_map[].
1121          */
1122         mutex_lock(&revmap_trees_mutex);
1123         for (i = 0; i < irq_virq_count; i++) {
1124                 if (irq_map[i].host &&
1125                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1126                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1127                                           irq_map[i].hwirq, &irq_map[i]);
1128         }
1129         mutex_unlock(&revmap_trees_mutex);
1130
1131         /*
1132          * Make sure the radix trees insertions are visible before setting
1133          * the flag
1134          */
1135         smp_wmb();
1136         revmap_trees_allocated = 2;
1137
1138         return 0;
1139 }
1140 arch_initcall(irq_late_init);
1141
1142 #ifdef CONFIG_VIRQ_DEBUG
1143 static int virq_debug_show(struct seq_file *m, void *private)
1144 {
1145         unsigned long flags;
1146         struct irq_desc *desc;
1147         const char *p;
1148         static const char none[] = "none";
1149         int i;
1150
1151         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1152                       "chip name", "host name");
1153
1154         for (i = 1; i < nr_irqs; i++) {
1155                 desc = irq_to_desc(i);
1156                 if (!desc)
1157                         continue;
1158
1159                 raw_spin_lock_irqsave(&desc->lock, flags);
1160
1161                 if (desc->action && desc->action->handler) {
1162                         seq_printf(m, "%5d  ", i);
1163                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1164
1165                         if (desc->chip && desc->chip->name)
1166                                 p = desc->chip->name;
1167                         else
1168                                 p = none;
1169                         seq_printf(m, "%-15s  ", p);
1170
1171                         if (irq_map[i].host && irq_map[i].host->of_node)
1172                                 p = irq_map[i].host->of_node->full_name;
1173                         else
1174                                 p = none;
1175                         seq_printf(m, "%s\n", p);
1176                 }
1177
1178                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1179         }
1180
1181         return 0;
1182 }
1183
1184 static int virq_debug_open(struct inode *inode, struct file *file)
1185 {
1186         return single_open(file, virq_debug_show, inode->i_private);
1187 }
1188
1189 static const struct file_operations virq_debug_fops = {
1190         .open = virq_debug_open,
1191         .read = seq_read,
1192         .llseek = seq_lseek,
1193         .release = single_release,
1194 };
1195
1196 static int __init irq_debugfs_init(void)
1197 {
1198         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1199                                  NULL, &virq_debug_fops) == NULL)
1200                 return -ENOMEM;
1201
1202         return 0;
1203 }
1204 __initcall(irq_debugfs_init);
1205 #endif /* CONFIG_VIRQ_DEBUG */
1206
1207 #ifdef CONFIG_PPC64
1208 static int __init setup_noirqdistrib(char *str)
1209 {
1210         distribute_irqs = 0;
1211         return 1;
1212 }
1213
1214 __setup("noirqdistrib", setup_noirqdistrib);
1215 #endif /* CONFIG_PPC64 */