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                 do_softirq_onstack();
 311
 312         local_irq_restore(flags);
 313 }
 314 EXPORT_SYMBOL(do_softirq);
 315
 316
 317 /*
 318  * IRQ controller and virtual interrupts
 319  */
 320
 321 #ifdef CONFIG_PPC_MERGE
 322
 323 static LIST_HEAD(irq_hosts);
 324 static spinlock_t irq_big_lock = SPIN_LOCK_UNLOCKED;
 325 static DEFINE_PER_CPU(unsigned int, irq_radix_reader);
 326 static unsigned int irq_radix_writer;
 327 struct irq_map_entry irq_map[NR_IRQS];
 328 static unsigned int irq_virq_count = NR_IRQS;
 329 static struct irq_host *irq_default_host;
 330
 331 struct irq_host *irq_alloc_host(unsigned int revmap_type,
 332                                 unsigned int revmap_arg,
 333                                 struct irq_host_ops *ops,
 334                                 irq_hw_number_t inval_irq)
 335 {
 336         struct irq_host *host;
 337         unsigned int size = sizeof(struct irq_host);
 338         unsigned int i;
 339         unsigned int *rmap;
 340         unsigned long flags;
 341
 342         /* Allocate structure and revmap table if using linear mapping */
 343         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 344                 size += revmap_arg * sizeof(unsigned int);
 345         if (mem_init_done)
 346                 host = kzalloc(size, GFP_KERNEL);
 347         else {
 348                 host = alloc_bootmem(size);
 349                 if (host)
 350                         memset(host, 0, size);
 351         }
 352         if (host == NULL)
 353                 return NULL;
 354
 355         /* Fill structure */
 356         host->revmap_type = revmap_type;
 357         host->inval_irq = inval_irq;
 358         host->ops = ops;
 359
 360         spin_lock_irqsave(&irq_big_lock, flags);
 361
 362         /* If it's a legacy controller, check for duplicates and
 363          * mark it as allocated (we use irq 0 host pointer for that
 364          */
 365         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 366                 if (irq_map[0].host != NULL) {
 367                         spin_unlock_irqrestore(&irq_big_lock, flags);
 368                         /* If we are early boot, we can't free the structure,
 369                          * too bad...
 370                          * this will be fixed once slab is made available early
 371                          * instead of the current cruft
 372                          */
 373                         if (mem_init_done)
 374                                 kfree(host);
 375                         return NULL;
 376                 }
 377                 irq_map[0].host = host;
 378         }
 379
 380         list_add(&host->link, &irq_hosts);
 381         spin_unlock_irqrestore(&irq_big_lock, flags);
 382
 383         /* Additional setups per revmap type */
 384         switch(revmap_type) {
 385         case IRQ_HOST_MAP_LEGACY:
 386                 /* 0 is always the invalid number for legacy */
 387                 host->inval_irq = 0;
 388                 /* setup us as the host for all legacy interrupts */
 389                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 390                         irq_map[i].hwirq = 0;
 391                         smp_wmb();
 392                         irq_map[i].host = host;
 393                         smp_wmb();
 394
 395                         /* Clear norequest flags */
 396                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 397
 398                         /* Legacy flags are left to default at this point,
 399                          * one can then use irq_create_mapping() to
 400                          * explicitely change them
 401                          */
 402                         ops->map(host, i, i);
 403                 }
 404                 break;
 405         case IRQ_HOST_MAP_LINEAR:
 406                 rmap = (unsigned int *)(host + 1);
 407                 for (i = 0; i < revmap_arg; i++)
 408                         rmap[i] = IRQ_NONE;
 409                 host->revmap_data.linear.size = revmap_arg;
 410                 smp_wmb();
 411                 host->revmap_data.linear.revmap = rmap;
 412                 break;
 413         default:
 414                 break;
 415         }
 416
 417         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 418
 419         return host;
 420 }
 421
 422 struct irq_host *irq_find_host(struct device_node *node)
 423 {
 424         struct irq_host *h, *found = NULL;
 425         unsigned long flags;
 426
 427         /* We might want to match the legacy controller last since
 428          * it might potentially be set to match all interrupts in
 429          * the absence of a device node. This isn't a problem so far
 430          * yet though...
 431          */
 432         spin_lock_irqsave(&irq_big_lock, flags);
 433         list_for_each_entry(h, &irq_hosts, link)
 434                 if (h->ops->match == NULL || h->ops->match(h, node)) {
 435                         found = h;
 436                         break;
 437                 }
 438         spin_unlock_irqrestore(&irq_big_lock, flags);
 439         return found;
 440 }
 441 EXPORT_SYMBOL_GPL(irq_find_host);
 442
 443 void irq_set_default_host(struct irq_host *host)
 444 {
 445         pr_debug("irq: Default host set to @0x%p\n", host);
 446
 447         irq_default_host = host;
 448 }
 449
 450 void irq_set_virq_count(unsigned int count)
 451 {
 452         pr_debug("irq: Trying to set virq count to %d\n", count);
 453
 454         BUG_ON(count < NUM_ISA_INTERRUPTS);
 455         if (count < NR_IRQS)
 456                 irq_virq_count = count;
 457 }
 458
 459 /* radix tree not lockless safe ! we use a brlock-type mecanism
 460  * for now, until we can use a lockless radix tree
 461  */
 462 static void irq_radix_wrlock(unsigned long *flags)
 463 {
 464         unsigned int cpu, ok;
 465
 466         spin_lock_irqsave(&irq_big_lock, *flags);
 467         irq_radix_writer = 1;
 468         smp_mb();
 469         do {
 470                 barrier();
 471                 ok = 1;
 472                 for_each_possible_cpu(cpu) {
 473                         if (per_cpu(irq_radix_reader, cpu)) {
 474                                 ok = 0;
 475                                 break;
 476                         }
 477                 }
 478                 if (!ok)
 479                         cpu_relax();
 480         } while(!ok);
 481 }
 482
 483 static void irq_radix_wrunlock(unsigned long flags)
 484 {
 485         smp_wmb();
 486         irq_radix_writer = 0;
 487         spin_unlock_irqrestore(&irq_big_lock, flags);
 488 }
 489
 490 static void irq_radix_rdlock(unsigned long *flags)
 491 {
 492         local_irq_save(*flags);
 493         __get_cpu_var(irq_radix_reader) = 1;
 494         smp_mb();
 495         if (likely(irq_radix_writer == 0))
 496                 return;
 497         __get_cpu_var(irq_radix_reader) = 0;
 498         smp_wmb();
 499         spin_lock(&irq_big_lock);
 500         __get_cpu_var(irq_radix_reader) = 1;
 501         spin_unlock(&irq_big_lock);
 502 }
 503
 504 static void irq_radix_rdunlock(unsigned long flags)
 505 {
 506         __get_cpu_var(irq_radix_reader) = 0;
 507         local_irq_restore(flags);
 508 }
 509
 510
 511 unsigned int irq_create_mapping(struct irq_host *host,
 512                                 irq_hw_number_t hwirq)
 513 {
 514         unsigned int virq, hint;
 515
 516         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 517
 518         /* Look for default host if nececssary */
 519         if (host == NULL)
 520                 host = irq_default_host;
 521         if (host == NULL) {
 522                 printk(KERN_WARNING "irq_create_mapping called for"
 523                        " NULL host, hwirq=%lx\n", hwirq);
 524                 WARN_ON(1);
 525                 return NO_IRQ;
 526         }
 527         pr_debug("irq: -> using host @%p\n", host);
 528
 529         /* Check if mapping already exist, if it does, call
 530          * host->ops->map() to update the flags
 531          */
 532         virq = irq_find_mapping(host, hwirq);
 533         if (virq != IRQ_NONE) {
 534                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 535                 return virq;
 536         }
 537
 538         /* Get a virtual interrupt number */
 539         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 540                 /* Handle legacy */
 541                 virq = (unsigned int)hwirq;
 542                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 543                         return NO_IRQ;
 544                 return virq;
 545         } else {
 546                 /* Allocate a virtual interrupt number */
 547                 hint = hwirq % irq_virq_count;
 548                 virq = irq_alloc_virt(host, 1, hint);
 549                 if (virq == NO_IRQ) {
 550                         pr_debug("irq: -> virq allocation failed\n");
 551                         return NO_IRQ;
 552                 }
 553         }
 554         pr_debug("irq: -> obtained virq %d\n", virq);
 555
 556         /* Clear IRQ_NOREQUEST flag */
 557         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 558
 559         /* map it */
 560         smp_wmb();
 561         irq_map[virq].hwirq = hwirq;
 562         smp_mb();
 563         if (host->ops->map(host, virq, hwirq)) {
 564                 pr_debug("irq: -> mapping failed, freeing\n");
 565                 irq_free_virt(virq, 1);
 566                 return NO_IRQ;
 567         }
 568         return virq;
 569 }
 570 EXPORT_SYMBOL_GPL(irq_create_mapping);
 571
 572 extern unsigned int irq_create_of_mapping(struct device_node *controller,
 573                                           u32 *intspec, unsigned int intsize)
 574 {
 575         struct irq_host *host;
 576         irq_hw_number_t hwirq;
 577         unsigned int type = IRQ_TYPE_NONE;
 578         unsigned int virq;
 579
 580         if (controller == NULL)
 581                 host = irq_default_host;
 582         else
 583                 host = irq_find_host(controller);
 584         if (host == NULL) {
 585                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 586                        controller->full_name);
 587                 return NO_IRQ;
 588         }
 589
 590         /* If host has no translation, then we assume interrupt line */
 591         if (host->ops->xlate == NULL)
 592                 hwirq = intspec[0];
 593         else {
 594                 if (host->ops->xlate(host, controller, intspec, intsize,
 595                                      &hwirq, &type))
 596                         return NO_IRQ;
 597         }
 598
 599         /* Create mapping */
 600         virq = irq_create_mapping(host, hwirq);
 601         if (virq == NO_IRQ)
 602                 return virq;
 603
 604         /* Set type if specified and different than the current one */
 605         if (type != IRQ_TYPE_NONE &&
 606             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 607                 set_irq_type(virq, type);
 608         return virq;
 609 }
 610 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 611
 612 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 613 {
 614         struct of_irq oirq;
 615
 616         if (of_irq_map_one(dev, index, &oirq))
 617                 return NO_IRQ;
 618
 619         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 620                                      oirq.size);
 621 }
 622 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 623
 624 void irq_dispose_mapping(unsigned int virq)
 625 {
 626         struct irq_host *host = irq_map[virq].host;
 627         irq_hw_number_t hwirq;
 628         unsigned long flags;
 629
 630         WARN_ON (host == NULL);
 631         if (host == NULL)
 632                 return;
 633
 634         /* Never unmap legacy interrupts */
 635         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 636                 return;
 637
 638         /* remove chip and handler */
 639         set_irq_chip_and_handler(virq, NULL, NULL);
 640
 641         /* Make sure it's completed */
 642         synchronize_irq(virq);
 643
 644         /* Tell the PIC about it */
 645         if (host->ops->unmap)
 646                 host->ops->unmap(host, virq);
 647         smp_mb();
 648
 649         /* Clear reverse map */
 650         hwirq = irq_map[virq].hwirq;
 651         switch(host->revmap_type) {
 652         case IRQ_HOST_MAP_LINEAR:
 653                 if (hwirq < host->revmap_data.linear.size)
 654                         host->revmap_data.linear.revmap[hwirq] = IRQ_NONE;
 655                 break;
 656         case IRQ_HOST_MAP_TREE:
 657                 /* Check if radix tree allocated yet */
 658                 if (host->revmap_data.tree.gfp_mask == 0)
 659                         break;
 660                 irq_radix_wrlock(&flags);
 661                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 662                 irq_radix_wrunlock(flags);
 663                 break;
 664         }
 665
 666         /* Destroy map */
 667         smp_mb();
 668         irq_map[virq].hwirq = host->inval_irq;
 669
 670         /* Set some flags */
 671         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 672
 673         /* Free it */
 674         irq_free_virt(virq, 1);
 675 }
 676 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 677
 678 unsigned int irq_find_mapping(struct irq_host *host,
 679                               irq_hw_number_t hwirq)
 680 {
 681         unsigned int i;
 682         unsigned int hint = hwirq % irq_virq_count;
 683
 684         /* Look for default host if nececssary */
 685         if (host == NULL)
 686                 host = irq_default_host;
 687         if (host == NULL)
 688                 return NO_IRQ;
 689
 690         /* legacy -> bail early */
 691         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 692                 return hwirq;
 693
 694         /* Slow path does a linear search of the map */
 695         if (hint < NUM_ISA_INTERRUPTS)
 696                 hint = NUM_ISA_INTERRUPTS;
 697         i = hint;
 698         do  {
 699                 if (irq_map[i].host == host &&
 700                     irq_map[i].hwirq == hwirq)
 701                         return i;
 702                 i++;
 703                 if (i >= irq_virq_count)
 704                         i = NUM_ISA_INTERRUPTS;
 705         } while(i != hint);
 706         return NO_IRQ;
 707 }
 708 EXPORT_SYMBOL_GPL(irq_find_mapping);
 709
 710
 711 unsigned int irq_radix_revmap(struct irq_host *host,
 712                               irq_hw_number_t hwirq)
 713 {
 714         struct radix_tree_root *tree;
 715         struct irq_map_entry *ptr;
 716         unsigned int virq;
 717         unsigned long flags;
 718
 719         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 720
 721         /* Check if the radix tree exist yet. We test the value of
 722          * the gfp_mask for that. Sneaky but saves another int in the
 723          * structure. If not, we fallback to slow mode
 724          */
 725         tree = &host->revmap_data.tree;
 726         if (tree->gfp_mask == 0)
 727                 return irq_find_mapping(host, hwirq);
 728
 729         /* Now try to resolve */
 730         irq_radix_rdlock(&flags);
 731         ptr = radix_tree_lookup(tree, hwirq);
 732         irq_radix_rdunlock(flags);
 733
 734         /* Found it, return */
 735         if (ptr) {
 736                 virq = ptr - irq_map;
 737                 return virq;
 738         }
 739
 740         /* If not there, try to insert it */
 741         virq = irq_find_mapping(host, hwirq);
 742         if (virq != NO_IRQ) {
 743                 irq_radix_wrlock(&flags);
 744                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 745                 irq_radix_wrunlock(flags);
 746         }
 747         return virq;
 748 }
 749
 750 unsigned int irq_linear_revmap(struct irq_host *host,
 751                                irq_hw_number_t hwirq)
 752 {
 753         unsigned int *revmap;
 754
 755         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 756
 757         /* Check revmap bounds */
 758         if (unlikely(hwirq >= host->revmap_data.linear.size))
 759                 return irq_find_mapping(host, hwirq);
 760
 761         /* Check if revmap was allocated */
 762         revmap = host->revmap_data.linear.revmap;
 763         if (unlikely(revmap == NULL))
 764                 return irq_find_mapping(host, hwirq);
 765
 766         /* Fill up revmap with slow path if no mapping found */
 767         if (unlikely(revmap[hwirq] == NO_IRQ))
 768                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 769
 770         return revmap[hwirq];
 771 }
 772
 773 unsigned int irq_alloc_virt(struct irq_host *host,
 774                             unsigned int count,
 775                             unsigned int hint)
 776 {
 777         unsigned long flags;
 778         unsigned int i, j, found = NO_IRQ;
 779         unsigned int limit = irq_virq_count - count;
 780
 781         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 782                 return NO_IRQ;
 783
 784         spin_lock_irqsave(&irq_big_lock, flags);
 785
 786         /* Use hint for 1 interrupt if any */
 787         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 788             hint < irq_virq_count && irq_map[hint].host == NULL) {
 789                 found = hint;
 790                 goto hint_found;
 791         }
 792
 793         /* Look for count consecutive numbers in the allocatable
 794          * (non-legacy) space
 795          */
 796         for (i = NUM_ISA_INTERRUPTS; i <= limit; ) {
 797                 for (j = i; j < (i + count); j++)
 798                         if (irq_map[j].host != NULL) {
 799                                 i = j + 1;
 800                                 continue;
 801                         }
 802                 found = i;
 803                 break;
 804         }
 805         if (found == NO_IRQ) {
 806                 spin_unlock_irqrestore(&irq_big_lock, flags);
 807                 return NO_IRQ;
 808         }
 809  hint_found:
 810         for (i = found; i < (found + count); i++) {
 811                 irq_map[i].hwirq = host->inval_irq;
 812                 smp_wmb();
 813                 irq_map[i].host = host;
 814         }
 815         spin_unlock_irqrestore(&irq_big_lock, flags);
 816         return found;
 817 }
 818
 819 void irq_free_virt(unsigned int virq, unsigned int count)
 820 {
 821         unsigned long flags;
 822         unsigned int i;
 823
 824         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 825         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 826
 827         spin_lock_irqsave(&irq_big_lock, flags);
 828         for (i = virq; i < (virq + count); i++) {
 829                 struct irq_host *host;
 830
 831                 if (i < NUM_ISA_INTERRUPTS ||
 832                     (virq + count) > irq_virq_count)
 833                         continue;
 834
 835                 host = irq_map[i].host;
 836                 irq_map[i].hwirq = host->inval_irq;
 837                 smp_wmb();
 838                 irq_map[i].host = NULL;
 839         }
 840         spin_unlock_irqrestore(&irq_big_lock, flags);
 841 }
 842
 843 void irq_early_init(void)
 844 {
 845         unsigned int i;
 846
 847         for (i = 0; i < NR_IRQS; i++)
 848                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 849 }
 850
 851 /* We need to create the radix trees late */
 852 static int irq_late_init(void)
 853 {
 854         struct irq_host *h;
 855         unsigned long flags;
 856
 857         irq_radix_wrlock(&flags);
 858         list_for_each_entry(h, &irq_hosts, link) {
 859                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
 860                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
 861         }
 862         irq_radix_wrunlock(flags);
 863
 864         return 0;
 865 }
 866 arch_initcall(irq_late_init);
 867
 868 #endif /* CONFIG_PPC_MERGE */
 869
 870 #ifdef CONFIG_PCI_MSI
 871 int pci_enable_msi(struct pci_dev * pdev)
 872 {
 873         if (ppc_md.enable_msi)
 874                 return ppc_md.enable_msi(pdev);
 875         else
 876                 return -1;
 877 }
 878
 879 void pci_disable_msi(struct pci_dev * pdev)
 880 {
 881         if (ppc_md.disable_msi)
 882                 ppc_md.disable_msi(pdev);
 883 }
 884
 885 void pci_scan_msi_device(struct pci_dev *dev) {}
 886 int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) {return -1;}
 887 void pci_disable_msix(struct pci_dev *dev) {}
 888 void msi_remove_pci_irq_vectors(struct pci_dev *dev) {}
 889 void disable_msi_mode(struct pci_dev *dev, int pos, int type) {}
 890 void pci_no_msi(void) {}
 891
 892 #endif
 893
 894 #ifdef CONFIG_PPC64
 895 static int __init setup_noirqdistrib(char *str)
 896 {
 897         distribute_irqs = 0;
 898         return 1;
 899 }
 900
 901 __setup("noirqdistrib", setup_noirqdistrib);
 902 #endif /* CONFIG_PPC64 */