[POWERPC] Add new interrupt mapping core and change platforms to use it
[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  *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License
14  * as published by the Free Software Foundation; either version
15  * 2 of the License, or (at your option) any later version.
16  *
17  * This file contains the code used by various IRQ handling routines:
18  * asking for different IRQ's should be done through these routines
19  * instead of just grabbing them. Thus setups with different IRQ numbers
20  * shouldn't result in any weird surprises, and installing new handlers
21  * should be easier.
22  *
23  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
24  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
25  * mask register (of which only 16 are defined), hence the weird shifting
26  * and complement of the cached_irq_mask.  I want to be able to stuff
27  * this right into the SIU SMASK register.
28  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
29  * to reduce code space and undefined function references.
30  */
31
32 #undef DEBUG
33
34 #include <linux/module.h>
35 #include <linux/threads.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/signal.h>
38 #include <linux/sched.h>
39 #include <linux/ptrace.h>
40 #include <linux/ioport.h>
41 #include <linux/interrupt.h>
42 #include <linux/timex.h>
43 #include <linux/init.h>
44 #include <linux/slab.h>
45 #include <linux/delay.h>
46 #include <linux/irq.h>
47 #include <linux/seq_file.h>
48 #include <linux/cpumask.h>
49 #include <linux/profile.h>
50 #include <linux/bitops.h>
51 #include <linux/list.h>
52 #include <linux/radix-tree.h>
53 #include <linux/mutex.h>
54 #include <linux/bootmem.h>
55
56 #include <asm/uaccess.h>
57 #include <asm/system.h>
58 #include <asm/io.h>
59 #include <asm/pgtable.h>
60 #include <asm/irq.h>
61 #include <asm/cache.h>
62 #include <asm/prom.h>
63 #include <asm/ptrace.h>
64 #include <asm/machdep.h>
65 #include <asm/udbg.h>
66 #ifdef CONFIG_PPC_ISERIES
67 #include <asm/paca.h>
68 #endif
69
70 int __irq_offset_value;
71 static int ppc_spurious_interrupts;
72
73 #ifdef CONFIG_PPC32
74 EXPORT_SYMBOL(__irq_offset_value);
75 atomic_t ppc_n_lost_interrupts;
76
77 #ifndef CONFIG_PPC_MERGE
78 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
79 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
80 #endif
81
82 #ifdef CONFIG_TAU_INT
83 extern int tau_initialized;
84 extern int tau_interrupts(int);
85 #endif
86 #endif /* CONFIG_PPC32 */
87
88 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
89 extern atomic_t ipi_recv;
90 extern atomic_t ipi_sent;
91 #endif
92
93 #ifdef CONFIG_PPC64
94 EXPORT_SYMBOL(irq_desc);
95
96 int distribute_irqs = 1;
97 #endif /* CONFIG_PPC64 */
98
99 int show_interrupts(struct seq_file *p, void *v)
100 {
101         int i = *(loff_t *)v, j;
102         struct irqaction *action;
103         irq_desc_t *desc;
104         unsigned long flags;
105
106         if (i == 0) {
107                 seq_puts(p, "           ");
108                 for_each_online_cpu(j)
109                         seq_printf(p, "CPU%d       ", j);
110                 seq_putc(p, '\n');
111         }
112
113         if (i < NR_IRQS) {
114                 desc = get_irq_desc(i);
115                 spin_lock_irqsave(&desc->lock, flags);
116                 action = desc->action;
117                 if (!action || !action->handler)
118                         goto skip;
119                 seq_printf(p, "%3d: ", i);
120 #ifdef CONFIG_SMP
121                 for_each_online_cpu(j)
122                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
123 #else
124                 seq_printf(p, "%10u ", kstat_irqs(i));
125 #endif /* CONFIG_SMP */
126                 if (desc->chip)
127                         seq_printf(p, " %s ", desc->chip->typename);
128                 else
129                         seq_puts(p, "  None      ");
130                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
131                 seq_printf(p, "    %s", action->name);
132                 for (action = action->next; action; action = action->next)
133                         seq_printf(p, ", %s", action->name);
134                 seq_putc(p, '\n');
135 skip:
136                 spin_unlock_irqrestore(&desc->lock, flags);
137         } else if (i == NR_IRQS) {
138 #ifdef CONFIG_PPC32
139 #ifdef CONFIG_TAU_INT
140                 if (tau_initialized){
141                         seq_puts(p, "TAU: ");
142                         for_each_online_cpu(j)
143                                 seq_printf(p, "%10u ", tau_interrupts(j));
144                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
145                 }
146 #endif
147 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
148                 /* should this be per processor send/receive? */
149                 seq_printf(p, "IPI (recv/sent): %10u/%u\n",
150                                 atomic_read(&ipi_recv), atomic_read(&ipi_sent));
151 #endif
152 #endif /* CONFIG_PPC32 */
153                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
154         }
155         return 0;
156 }
157
158 #ifdef CONFIG_HOTPLUG_CPU
159 void fixup_irqs(cpumask_t map)
160 {
161         unsigned int irq;
162         static int warned;
163
164         for_each_irq(irq) {
165                 cpumask_t mask;
166
167                 if (irq_desc[irq].status & IRQ_PER_CPU)
168                         continue;
169
170                 cpus_and(mask, irq_desc[irq].affinity, map);
171                 if (any_online_cpu(mask) == NR_CPUS) {
172                         printk("Breaking affinity for irq %i\n", irq);
173                         mask = map;
174                 }
175                 if (irq_desc[irq].chip->set_affinity)
176                         irq_desc[irq].chip->set_affinity(irq, mask);
177                 else if (irq_desc[irq].action && !(warned++))
178                         printk("Cannot set affinity for irq %i\n", irq);
179         }
180
181         local_irq_enable();
182         mdelay(1);
183         local_irq_disable();
184 }
185 #endif
186
187 void do_IRQ(struct pt_regs *regs)
188 {
189         unsigned int irq;
190 #ifdef CONFIG_IRQSTACKS
191         struct thread_info *curtp, *irqtp;
192 #endif
193
194         irq_enter();
195
196 #ifdef CONFIG_DEBUG_STACKOVERFLOW
197         /* Debugging check for stack overflow: is there less than 2KB free? */
198         {
199                 long sp;
200
201                 sp = __get_SP() & (THREAD_SIZE-1);
202
203                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
204                         printk("do_IRQ: stack overflow: %ld\n",
205                                 sp - sizeof(struct thread_info));
206                         dump_stack();
207                 }
208         }
209 #endif
210
211         /*
212          * Every platform is required to implement ppc_md.get_irq.
213          * This function will either return an irq number or -1 to
214          * indicate there are no more pending.
215          * The value -2 is for buggy hardware and means that this IRQ
216          * has already been handled. -- Tom
217          */
218         irq = ppc_md.get_irq(regs);
219
220         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
221 #ifdef CONFIG_IRQSTACKS
222                 /* Switch to the irq stack to handle this */
223                 curtp = current_thread_info();
224                 irqtp = hardirq_ctx[smp_processor_id()];
225                 if (curtp != irqtp) {
226                         struct irq_desc *desc = irq_desc + irq;
227                         void *handler = desc->handle_irq;
228                         if (handler == NULL)
229                                 handler = &__do_IRQ;
230                         irqtp->task = curtp->task;
231                         irqtp->flags = 0;
232                         call_handle_irq(irq, desc, regs, irqtp, handler);
233                         irqtp->task = NULL;
234                         if (irqtp->flags)
235                                 set_bits(irqtp->flags, &curtp->flags);
236                 } else
237 #endif
238                         generic_handle_irq(irq, regs);
239         } else if (irq != NO_IRQ_IGNORE)
240                 /* That's not SMP safe ... but who cares ? */
241                 ppc_spurious_interrupts++;
242
243         irq_exit();
244
245 #ifdef CONFIG_PPC_ISERIES
246         if (get_lppaca()->int_dword.fields.decr_int) {
247                 get_lppaca()->int_dword.fields.decr_int = 0;
248                 /* Signal a fake decrementer interrupt */
249                 timer_interrupt(regs);
250         }
251 #endif
252 }
253
254 void __init init_IRQ(void)
255 {
256         ppc_md.init_IRQ();
257 #ifdef CONFIG_PPC64
258         irq_ctx_init();
259 #endif
260 }
261
262
263 #ifdef CONFIG_IRQSTACKS
264 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
265 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
266
267 void irq_ctx_init(void)
268 {
269         struct thread_info *tp;
270         int i;
271
272         for_each_possible_cpu(i) {
273                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
274                 tp = softirq_ctx[i];
275                 tp->cpu = i;
276                 tp->preempt_count = SOFTIRQ_OFFSET;
277
278                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
279                 tp = hardirq_ctx[i];
280                 tp->cpu = i;
281                 tp->preempt_count = HARDIRQ_OFFSET;
282         }
283 }
284
285 static inline void do_softirq_onstack(void)
286 {
287         struct thread_info *curtp, *irqtp;
288
289         curtp = current_thread_info();
290         irqtp = softirq_ctx[smp_processor_id()];
291         irqtp->task = curtp->task;
292         call_do_softirq(irqtp);
293         irqtp->task = NULL;
294 }
295
296 #else
297 #define do_softirq_onstack()    __do_softirq()
298 #endif /* CONFIG_IRQSTACKS */
299
300 void do_softirq(void)
301 {
302         unsigned long flags;
303
304         if (in_interrupt())
305                 return;
306
307         local_irq_save(flags);
308
309         if (local_softirq_pending()) {
310                 account_system_vtime(current);
311                 local_bh_disable();
312                 do_softirq_onstack();
313                 account_system_vtime(current);
314                 __local_bh_enable();
315         }
316
317         local_irq_restore(flags);
318 }
319 EXPORT_SYMBOL(do_softirq);
320
321
322 /*
323  * IRQ controller and virtual interrupts
324  */
325
326 #ifdef CONFIG_PPC_MERGE
327
328 static LIST_HEAD(irq_hosts);
329 static spinlock_t irq_big_lock = SPIN_LOCK_UNLOCKED;
330
331 struct irq_map_entry irq_map[NR_IRQS];
332 static unsigned int irq_virq_count = NR_IRQS;
333 static struct irq_host *irq_default_host;
334
335 struct irq_host *irq_alloc_host(unsigned int revmap_type,
336                                 unsigned int revmap_arg,
337                                 struct irq_host_ops *ops,
338                                 irq_hw_number_t inval_irq)
339 {
340         struct irq_host *host;
341         unsigned int size = sizeof(struct irq_host);
342         unsigned int i;
343         unsigned int *rmap;
344         unsigned long flags;
345
346         /* Allocate structure and revmap table if using linear mapping */
347         if (revmap_type == IRQ_HOST_MAP_LINEAR)
348                 size += revmap_arg * sizeof(unsigned int);
349         if (mem_init_done)
350                 host = kzalloc(size, GFP_KERNEL);
351         else {
352                 host = alloc_bootmem(size);
353                 if (host)
354                         memset(host, 0, size);
355         }
356         if (host == NULL)
357                 return NULL;
358
359         /* Fill structure */
360         host->revmap_type = revmap_type;
361         host->inval_irq = inval_irq;
362         host->ops = ops;
363
364         spin_lock_irqsave(&irq_big_lock, flags);
365
366         /* If it's a legacy controller, check for duplicates and
367          * mark it as allocated (we use irq 0 host pointer for that
368          */
369         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
370                 if (irq_map[0].host != NULL) {
371                         spin_unlock_irqrestore(&irq_big_lock, flags);
372                         /* If we are early boot, we can't free the structure,
373                          * too bad...
374                          * this will be fixed once slab is made available early
375                          * instead of the current cruft
376                          */
377                         if (mem_init_done)
378                                 kfree(host);
379                         return NULL;
380                 }
381                 irq_map[0].host = host;
382         }
383
384         list_add(&host->link, &irq_hosts);
385         spin_unlock_irqrestore(&irq_big_lock, flags);
386
387         /* Additional setups per revmap type */
388         switch(revmap_type) {
389         case IRQ_HOST_MAP_LEGACY:
390                 /* 0 is always the invalid number for legacy */
391                 host->inval_irq = 0;
392                 /* setup us as the host for all legacy interrupts */
393                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
394                         irq_map[i].hwirq = 0;
395                         smp_wmb();
396                         irq_map[i].host = host;
397                         smp_wmb();
398
399                         /* Clear some flags */
400                         get_irq_desc(i)->status
401                                 &= ~(IRQ_NOREQUEST | IRQ_LEVEL);
402
403                         /* Legacy flags are left to default at this point,
404                          * one can then use irq_create_mapping() to
405                          * explicitely change them
406                          */
407                         ops->map(host, i, i, 0);
408                 }
409                 break;
410         case IRQ_HOST_MAP_LINEAR:
411                 rmap = (unsigned int *)(host + 1);
412                 for (i = 0; i < revmap_arg; i++)
413                         rmap[i] = IRQ_NONE;
414                 host->revmap_data.linear.size = revmap_arg;
415                 smp_wmb();
416                 host->revmap_data.linear.revmap = rmap;
417                 break;
418         default:
419                 break;
420         }
421
422         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
423
424         return host;
425 }
426
427 struct irq_host *irq_find_host(struct device_node *node)
428 {
429         struct irq_host *h, *found = NULL;
430         unsigned long flags;
431
432         /* We might want to match the legacy controller last since
433          * it might potentially be set to match all interrupts in
434          * the absence of a device node. This isn't a problem so far
435          * yet though...
436          */
437         spin_lock_irqsave(&irq_big_lock, flags);
438         list_for_each_entry(h, &irq_hosts, link)
439                 if (h->ops->match == NULL || h->ops->match(h, node)) {
440                         found = h;
441                         break;
442                 }
443         spin_unlock_irqrestore(&irq_big_lock, flags);
444         return found;
445 }
446 EXPORT_SYMBOL_GPL(irq_find_host);
447
448 void irq_set_default_host(struct irq_host *host)
449 {
450         pr_debug("irq: Default host set to @0x%p\n", host);
451
452         irq_default_host = host;
453 }
454
455 void irq_set_virq_count(unsigned int count)
456 {
457         pr_debug("irq: Trying to set virq count to %d\n", count);
458
459         BUG_ON(count < NUM_ISA_INTERRUPTS);
460         if (count < NR_IRQS)
461                 irq_virq_count = count;
462 }
463
464 unsigned int irq_create_mapping(struct irq_host *host,
465                                 irq_hw_number_t hwirq,
466                                 unsigned int flags)
467 {
468         unsigned int virq, hint;
469
470         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx, 0x%x)\n",
471                  host, hwirq, flags);
472
473         /* Look for default host if nececssary */
474         if (host == NULL)
475                 host = irq_default_host;
476         if (host == NULL) {
477                 printk(KERN_WARNING "irq_create_mapping called for"
478                        " NULL host, hwirq=%lx\n", hwirq);
479                 WARN_ON(1);
480                 return NO_IRQ;
481         }
482         pr_debug("irq: -> using host @%p\n", host);
483
484         /* Check if mapping already exist, if it does, call
485          * host->ops->map() to update the flags
486          */
487         virq = irq_find_mapping(host, hwirq);
488         if (virq != IRQ_NONE) {
489                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
490                 host->ops->map(host, virq, hwirq, flags);
491                 return virq;
492         }
493
494         /* Get a virtual interrupt number */
495         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
496                 /* Handle legacy */
497                 virq = (unsigned int)hwirq;
498                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
499                         return NO_IRQ;
500                 return virq;
501         } else {
502                 /* Allocate a virtual interrupt number */
503                 hint = hwirq % irq_virq_count;
504                 virq = irq_alloc_virt(host, 1, hint);
505                 if (virq == NO_IRQ) {
506                         pr_debug("irq: -> virq allocation failed\n");
507                         return NO_IRQ;
508                 }
509         }
510         pr_debug("irq: -> obtained virq %d\n", virq);
511
512         /* Clear some flags */
513         get_irq_desc(virq)->status &= ~(IRQ_NOREQUEST | IRQ_LEVEL);
514
515         /* map it */
516         if (host->ops->map(host, virq, hwirq, flags)) {
517                 pr_debug("irq: -> mapping failed, freeing\n");
518                 irq_free_virt(virq, 1);
519                 return NO_IRQ;
520         }
521         smp_wmb();
522         irq_map[virq].hwirq = hwirq;
523         smp_mb();
524         return virq;
525 }
526 EXPORT_SYMBOL_GPL(irq_create_mapping);
527
528 extern unsigned int irq_create_of_mapping(struct device_node *controller,
529                                           u32 *intspec, unsigned int intsize)
530 {
531         struct irq_host *host;
532         irq_hw_number_t hwirq;
533         unsigned int flags = IRQ_TYPE_NONE;
534
535         if (controller == NULL)
536                 host = irq_default_host;
537         else
538                 host = irq_find_host(controller);
539         if (host == NULL)
540                 return NO_IRQ;
541
542         /* If host has no translation, then we assume interrupt line */
543         if (host->ops->xlate == NULL)
544                 hwirq = intspec[0];
545         else {
546                 if (host->ops->xlate(host, controller, intspec, intsize,
547                                      &hwirq, &flags))
548                         return NO_IRQ;
549         }
550
551         return irq_create_mapping(host, hwirq, flags);
552 }
553 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
554
555 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
556 {
557         struct of_irq oirq;
558
559         if (of_irq_map_one(dev, index, &oirq))
560                 return NO_IRQ;
561
562         return irq_create_of_mapping(oirq.controller, oirq.specifier,
563                                      oirq.size);
564 }
565 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
566
567 void irq_dispose_mapping(unsigned int virq)
568 {
569         struct irq_host *host = irq_map[virq].host;
570         irq_hw_number_t hwirq;
571         unsigned long flags;
572
573         WARN_ON (host == NULL);
574         if (host == NULL)
575                 return;
576
577         /* Never unmap legacy interrupts */
578         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
579                 return;
580
581         /* remove chip and handler */
582         set_irq_chip_and_handler(virq, NULL, NULL);
583
584         /* Make sure it's completed */
585         synchronize_irq(virq);
586
587         /* Tell the PIC about it */
588         if (host->ops->unmap)
589                 host->ops->unmap(host, virq);
590         smp_mb();
591
592         /* Clear reverse map */
593         hwirq = irq_map[virq].hwirq;
594         switch(host->revmap_type) {
595         case IRQ_HOST_MAP_LINEAR:
596                 if (hwirq < host->revmap_data.linear.size)
597                         host->revmap_data.linear.revmap[hwirq] = IRQ_NONE;
598                 break;
599         case IRQ_HOST_MAP_TREE:
600                 /* Check if radix tree allocated yet */
601                 if (host->revmap_data.tree.gfp_mask == 0)
602                         break;
603                 /* XXX radix tree not safe ! remove lock whem it becomes safe
604                  * and use some RCU sync to make sure everything is ok before we
605                  * can re-use that map entry
606                  */
607                 spin_lock_irqsave(&irq_big_lock, flags);
608                 radix_tree_delete(&host->revmap_data.tree, hwirq);
609                 spin_unlock_irqrestore(&irq_big_lock, flags);
610                 break;
611         }
612
613         /* Destroy map */
614         smp_mb();
615         irq_map[virq].hwirq = host->inval_irq;
616
617         /* Set some flags */
618         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
619
620         /* Free it */
621         irq_free_virt(virq, 1);
622 }
623 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
624
625 unsigned int irq_find_mapping(struct irq_host *host,
626                               irq_hw_number_t hwirq)
627 {
628         unsigned int i;
629         unsigned int hint = hwirq % irq_virq_count;
630
631         /* Look for default host if nececssary */
632         if (host == NULL)
633                 host = irq_default_host;
634         if (host == NULL)
635                 return NO_IRQ;
636
637         /* legacy -> bail early */
638         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
639                 return hwirq;
640
641         /* Slow path does a linear search of the map */
642         if (hint < NUM_ISA_INTERRUPTS)
643                 hint = NUM_ISA_INTERRUPTS;
644         i = hint;
645         do  {
646                 if (irq_map[i].host == host &&
647                     irq_map[i].hwirq == hwirq)
648                         return i;
649                 i++;
650                 if (i >= irq_virq_count)
651                         i = NUM_ISA_INTERRUPTS;
652         } while(i != hint);
653         return NO_IRQ;
654 }
655 EXPORT_SYMBOL_GPL(irq_find_mapping);
656
657
658 unsigned int irq_radix_revmap(struct irq_host *host,
659                               irq_hw_number_t hwirq)
660 {
661         struct radix_tree_root *tree;
662         struct irq_map_entry *ptr;
663         unsigned int virq;
664         unsigned long flags;
665
666         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
667
668         /* Check if the radix tree exist yet. We test the value of
669          * the gfp_mask for that. Sneaky but saves another int in the
670          * structure. If not, we fallback to slow mode
671          */
672         tree = &host->revmap_data.tree;
673         if (tree->gfp_mask == 0)
674                 return irq_find_mapping(host, hwirq);
675
676         /* XXX Current radix trees are NOT SMP safe !!! Remove that lock
677          * when that is fixed (when Nick's patch gets in
678          */
679         spin_lock_irqsave(&irq_big_lock, flags);
680
681         /* Now try to resolve */
682         ptr = radix_tree_lookup(tree, hwirq);
683         /* Found it, return */
684         if (ptr) {
685                 virq = ptr - irq_map;
686                 goto bail;
687         }
688
689         /* If not there, try to insert it */
690         virq = irq_find_mapping(host, hwirq);
691         if (virq != NO_IRQ)
692                 radix_tree_insert(tree, virq, &irq_map[virq]);
693  bail:
694         spin_unlock_irqrestore(&irq_big_lock, flags);
695         return virq;
696 }
697
698 unsigned int irq_linear_revmap(struct irq_host *host,
699                                irq_hw_number_t hwirq)
700 {
701         unsigned int *revmap;
702
703         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
704
705         /* Check revmap bounds */
706         if (unlikely(hwirq >= host->revmap_data.linear.size))
707                 return irq_find_mapping(host, hwirq);
708
709         /* Check if revmap was allocated */
710         revmap = host->revmap_data.linear.revmap;
711         if (unlikely(revmap == NULL))
712                 return irq_find_mapping(host, hwirq);
713
714         /* Fill up revmap with slow path if no mapping found */
715         if (unlikely(revmap[hwirq] == NO_IRQ))
716                 revmap[hwirq] = irq_find_mapping(host, hwirq);
717
718         return revmap[hwirq];
719 }
720
721 unsigned int irq_alloc_virt(struct irq_host *host,
722                             unsigned int count,
723                             unsigned int hint)
724 {
725         unsigned long flags;
726         unsigned int i, j, found = NO_IRQ;
727         unsigned int limit = irq_virq_count - count;
728
729         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
730                 return NO_IRQ;
731
732         spin_lock_irqsave(&irq_big_lock, flags);
733
734         /* Use hint for 1 interrupt if any */
735         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
736             hint < irq_virq_count && irq_map[hint].host == NULL) {
737                 found = hint;
738                 goto hint_found;
739         }
740
741         /* Look for count consecutive numbers in the allocatable
742          * (non-legacy) space
743          */
744         for (i = NUM_ISA_INTERRUPTS; i <= limit; ) {
745                 for (j = i; j < (i + count); j++)
746                         if (irq_map[j].host != NULL) {
747                                 i = j + 1;
748                                 continue;
749                         }
750                 found = i;
751                 break;
752         }
753         if (found == NO_IRQ) {
754                 spin_unlock_irqrestore(&irq_big_lock, flags);
755                 return NO_IRQ;
756         }
757  hint_found:
758         for (i = found; i < (found + count); i++) {
759                 irq_map[i].hwirq = host->inval_irq;
760                 smp_wmb();
761                 irq_map[i].host = host;
762         }
763         spin_unlock_irqrestore(&irq_big_lock, flags);
764         return found;
765 }
766
767 void irq_free_virt(unsigned int virq, unsigned int count)
768 {
769         unsigned long flags;
770         unsigned int i;
771
772         WARN_ON (virq < NUM_ISA_INTERRUPTS);
773         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
774
775         spin_lock_irqsave(&irq_big_lock, flags);
776         for (i = virq; i < (virq + count); i++) {
777                 struct irq_host *host;
778
779                 if (i < NUM_ISA_INTERRUPTS ||
780                     (virq + count) > irq_virq_count)
781                         continue;
782
783                 host = irq_map[i].host;
784                 irq_map[i].hwirq = host->inval_irq;
785                 smp_wmb();
786                 irq_map[i].host = NULL;
787         }
788         spin_unlock_irqrestore(&irq_big_lock, flags);
789 }
790
791 void irq_early_init(void)
792 {
793         unsigned int i;
794
795         for (i = 0; i < NR_IRQS; i++)
796                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
797 }
798
799 /* We need to create the radix trees late */
800 static int irq_late_init(void)
801 {
802         struct irq_host *h;
803         unsigned long flags;
804
805         spin_lock_irqsave(&irq_big_lock, flags);
806         list_for_each_entry(h, &irq_hosts, link) {
807                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
808                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
809         }
810         spin_unlock_irqrestore(&irq_big_lock, flags);
811
812         return 0;
813 }
814 arch_initcall(irq_late_init);
815
816 #endif /* CONFIG_PPC_MERGE */
817
818 #ifdef CONFIG_PCI_MSI
819 int pci_enable_msi(struct pci_dev * pdev)
820 {
821         if (ppc_md.enable_msi)
822                 return ppc_md.enable_msi(pdev);
823         else
824                 return -1;
825 }
826
827 void pci_disable_msi(struct pci_dev * pdev)
828 {
829         if (ppc_md.disable_msi)
830                 ppc_md.disable_msi(pdev);
831 }
832
833 void pci_scan_msi_device(struct pci_dev *dev) {}
834 int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) {return -1;}
835 void pci_disable_msix(struct pci_dev *dev) {}
836 void msi_remove_pci_irq_vectors(struct pci_dev *dev) {}
837 void disable_msi_mode(struct pci_dev *dev, int pos, int type) {}
838 void pci_no_msi(void) {}
839
840 #endif
841
842 #ifdef CONFIG_PPC64
843 static int __init setup_noirqdistrib(char *str)
844 {
845         distribute_irqs = 0;
846         return 1;
847 }
848
849 __setup("noirqdistrib", setup_noirqdistrib);
850 #endif /* CONFIG_PPC64 */