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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  *  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 #include <linux/pci.h>
  56
  57 #include <asm/uaccess.h>
  58 #include <asm/system.h>
  59 #include <asm/io.h>
  60 #include <asm/pgtable.h>
  61 #include <asm/irq.h>
  62 #include <asm/cache.h>
  63 #include <asm/prom.h>
  64 #include <asm/ptrace.h>
  65 #include <asm/machdep.h>
  66 #include <asm/udbg.h>
  67 #ifdef CONFIG_PPC64
  68 #include <asm/paca.h>
  69 #include <asm/firmware.h>
  70 #endif
  71
  72 int __irq_offset_value;
  73 static int ppc_spurious_interrupts;
  74
  75 #ifdef CONFIG_PPC32
  76 EXPORT_SYMBOL(__irq_offset_value);
  77 atomic_t ppc_n_lost_interrupts;
  78
  79 #ifndef CONFIG_PPC_MERGE
  80 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
  81 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
  82 #endif
  83
  84 #ifdef CONFIG_TAU_INT
  85 extern int tau_initialized;
  86 extern int tau_interrupts(int);
  87 #endif
  88 #endif /* CONFIG_PPC32 */
  89
  90 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
  91 extern atomic_t ipi_recv;
  92 extern atomic_t ipi_sent;
  93 #endif
  94
  95 #ifdef CONFIG_PPC64
  96 EXPORT_SYMBOL(irq_desc);
  97
  98 int distribute_irqs = 1;
  99
 100 void local_irq_restore(unsigned long en)
 101 {
 102         get_paca()->soft_enabled = en;
 103         if (!en)
 104                 return;
 105
 106         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 107                 if (get_paca()->lppaca_ptr->int_dword.any_int)
 108                         iseries_handle_interrupts();
 109                 return;
 110         }
 111
 112         if (get_paca()->hard_enabled)
 113                 return;
 114         /* need to hard-enable interrupts here */
 115         get_paca()->hard_enabled = en;
 116         if ((int)mfspr(SPRN_DEC) < 0)
 117                 mtspr(SPRN_DEC, 1);
 118         hard_irq_enable();
 119 }
 120 #endif /* CONFIG_PPC64 */
 121
 122 int show_interrupts(struct seq_file *p, void *v)
 123 {
 124         int i = *(loff_t *)v, j;
 125         struct irqaction *action;
 126         irq_desc_t *desc;
 127         unsigned long flags;
 128
 129         if (i == 0) {
 130                 seq_puts(p, "           ");
 131                 for_each_online_cpu(j)
 132                         seq_printf(p, "CPU%d       ", j);
 133                 seq_putc(p, '\n');
 134         }
 135
 136         if (i < NR_IRQS) {
 137                 desc = get_irq_desc(i);
 138                 spin_lock_irqsave(&desc->lock, flags);
 139                 action = desc->action;
 140                 if (!action || !action->handler)
 141                         goto skip;
 142                 seq_printf(p, "%3d: ", i);
 143 #ifdef CONFIG_SMP
 144                 for_each_online_cpu(j)
 145                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 146 #else
 147                 seq_printf(p, "%10u ", kstat_irqs(i));
 148 #endif /* CONFIG_SMP */
 149                 if (desc->chip)
 150                         seq_printf(p, " %s ", desc->chip->typename);
 151                 else
 152                         seq_puts(p, "  None      ");
 153                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 154                 seq_printf(p, "    %s", action->name);
 155                 for (action = action->next; action; action = action->next)
 156                         seq_printf(p, ", %s", action->name);
 157                 seq_putc(p, '\n');
 158 skip:
 159                 spin_unlock_irqrestore(&desc->lock, flags);
 160         } else if (i == NR_IRQS) {
 161 #ifdef CONFIG_PPC32
 162 #ifdef CONFIG_TAU_INT
 163                 if (tau_initialized){
 164                         seq_puts(p, "TAU: ");
 165                         for_each_online_cpu(j)
 166                                 seq_printf(p, "%10u ", tau_interrupts(j));
 167                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 168                 }
 169 #endif
 170 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
 171                 /* should this be per processor send/receive? */
 172                 seq_printf(p, "IPI (recv/sent): %10u/%u\n",
 173                                 atomic_read(&ipi_recv), atomic_read(&ipi_sent));
 174 #endif
 175 #endif /* CONFIG_PPC32 */
 176                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 177         }
 178         return 0;
 179 }
 180
 181 #ifdef CONFIG_HOTPLUG_CPU
 182 void fixup_irqs(cpumask_t map)
 183 {
 184         unsigned int irq;
 185         static int warned;
 186
 187         for_each_irq(irq) {
 188                 cpumask_t mask;
 189
 190                 if (irq_desc[irq].status & IRQ_PER_CPU)
 191                         continue;
 192
 193                 cpus_and(mask, irq_desc[irq].affinity, map);
 194                 if (any_online_cpu(mask) == NR_CPUS) {
 195                         printk("Breaking affinity for irq %i\n", irq);
 196                         mask = map;
 197                 }
 198                 if (irq_desc[irq].chip->set_affinity)
 199                         irq_desc[irq].chip->set_affinity(irq, mask);
 200                 else if (irq_desc[irq].action && !(warned++))
 201                         printk("Cannot set affinity for irq %i\n", irq);
 202         }
 203
 204         local_irq_enable();
 205         mdelay(1);
 206         local_irq_disable();
 207 }
 208 #endif
 209
 210 void do_IRQ(struct pt_regs *regs)
 211 {
 212         struct pt_regs *old_regs = set_irq_regs(regs);
 213         unsigned int irq;
 214 #ifdef CONFIG_IRQSTACKS
 215         struct thread_info *curtp, *irqtp;
 216 #endif
 217
 218         irq_enter();
 219
 220 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 221         /* Debugging check for stack overflow: is there less than 2KB free? */
 222         {
 223                 long sp;
 224
 225                 sp = __get_SP() & (THREAD_SIZE-1);
 226
 227                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 228                         printk("do_IRQ: stack overflow: %ld\n",
 229                                 sp - sizeof(struct thread_info));
 230                         dump_stack();
 231                 }
 232         }
 233 #endif
 234
 235         /*
 236          * Every platform is required to implement ppc_md.get_irq.
 237          * This function will either return an irq number or -1 to
 238          * indicate there are no more pending.
 239          * The value -2 is for buggy hardware and means that this IRQ
 240          * has already been handled. -- Tom
 241          */
 242         irq = ppc_md.get_irq();
 243
 244         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
 245 #ifdef CONFIG_IRQSTACKS
 246                 /* Switch to the irq stack to handle this */
 247                 curtp = current_thread_info();
 248                 irqtp = hardirq_ctx[smp_processor_id()];
 249                 if (curtp != irqtp) {
 250                         struct irq_desc *desc = irq_desc + irq;
 251                         void *handler = desc->handle_irq;
 252                         if (handler == NULL)
 253                                 handler = &__do_IRQ;
 254                         irqtp->task = curtp->task;
 255                         irqtp->flags = 0;
 256                         call_handle_irq(irq, desc, irqtp, handler);
 257                         irqtp->task = NULL;
 258                         if (irqtp->flags)
 259                                 set_bits(irqtp->flags, &curtp->flags);
 260                 } else
 261 #endif
 262                         generic_handle_irq(irq);
 263         } else if (irq != NO_IRQ_IGNORE)
 264                 /* That's not SMP safe ... but who cares ? */
 265                 ppc_spurious_interrupts++;
 266
 267         irq_exit();
 268         set_irq_regs(old_regs);
 269
 270 #ifdef CONFIG_PPC_ISERIES
 271         if (get_lppaca()->int_dword.fields.decr_int) {
 272                 get_lppaca()->int_dword.fields.decr_int = 0;
 273                 /* Signal a fake decrementer interrupt */
 274                 timer_interrupt(regs);
 275         }
 276 #endif
 277 }
 278
 279 void __init init_IRQ(void)
 280 {
 281         ppc_md.init_IRQ();
 282 #ifdef CONFIG_PPC64
 283         irq_ctx_init();
 284 #endif
 285 }
 286
 287
 288 #ifdef CONFIG_IRQSTACKS
 289 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 290 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 291
 292 void irq_ctx_init(void)
 293 {
 294         struct thread_info *tp;
 295         int i;
 296
 297         for_each_possible_cpu(i) {
 298                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 299                 tp = softirq_ctx[i];
 300                 tp->cpu = i;
 301                 tp->preempt_count = SOFTIRQ_OFFSET;
 302
 303                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 304                 tp = hardirq_ctx[i];
 305                 tp->cpu = i;
 306                 tp->preempt_count = HARDIRQ_OFFSET;
 307         }
 308 }
 309
 310 static inline void do_softirq_onstack(void)
 311 {
 312         struct thread_info *curtp, *irqtp;
 313
 314         curtp = current_thread_info();
 315         irqtp = softirq_ctx[smp_processor_id()];
 316         irqtp->task = curtp->task;
 317         call_do_softirq(irqtp);
 318         irqtp->task = NULL;
 319 }
 320
 321 #else
 322 #define do_softirq_onstack()    __do_softirq()
 323 #endif /* CONFIG_IRQSTACKS */
 324
 325 void do_softirq(void)
 326 {
 327         unsigned long flags;
 328
 329         if (in_interrupt())
 330                 return;
 331
 332         local_irq_save(flags);
 333
 334         if (local_softirq_pending())
 335                 do_softirq_onstack();
 336
 337         local_irq_restore(flags);
 338 }
 339 EXPORT_SYMBOL(do_softirq);
 340
 341
 342 /*
 343  * IRQ controller and virtual interrupts
 344  */
 345
 346 #ifdef CONFIG_PPC_MERGE
 347
 348 static LIST_HEAD(irq_hosts);
 349 static spinlock_t irq_big_lock = SPIN_LOCK_UNLOCKED;
 350 static DEFINE_PER_CPU(unsigned int, irq_radix_reader);
 351 static unsigned int irq_radix_writer;
 352 struct irq_map_entry irq_map[NR_IRQS];
 353 static unsigned int irq_virq_count = NR_IRQS;
 354 static struct irq_host *irq_default_host;
 355
 356 struct irq_host *irq_alloc_host(unsigned int revmap_type,
 357                                 unsigned int revmap_arg,
 358                                 struct irq_host_ops *ops,
 359                                 irq_hw_number_t inval_irq)
 360 {
 361         struct irq_host *host;
 362         unsigned int size = sizeof(struct irq_host);
 363         unsigned int i;
 364         unsigned int *rmap;
 365         unsigned long flags;
 366
 367         /* Allocate structure and revmap table if using linear mapping */
 368         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 369                 size += revmap_arg * sizeof(unsigned int);
 370         if (mem_init_done)
 371                 host = kzalloc(size, GFP_KERNEL);
 372         else {
 373                 host = alloc_bootmem(size);
 374                 if (host)
 375                         memset(host, 0, size);
 376         }
 377         if (host == NULL)
 378                 return NULL;
 379
 380         /* Fill structure */
 381         host->revmap_type = revmap_type;
 382         host->inval_irq = inval_irq;
 383         host->ops = ops;
 384
 385         spin_lock_irqsave(&irq_big_lock, flags);
 386
 387         /* If it's a legacy controller, check for duplicates and
 388          * mark it as allocated (we use irq 0 host pointer for that
 389          */
 390         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 391                 if (irq_map[0].host != NULL) {
 392                         spin_unlock_irqrestore(&irq_big_lock, flags);
 393                         /* If we are early boot, we can't free the structure,
 394                          * too bad...
 395                          * this will be fixed once slab is made available early
 396                          * instead of the current cruft
 397                          */
 398                         if (mem_init_done)
 399                                 kfree(host);
 400                         return NULL;
 401                 }
 402                 irq_map[0].host = host;
 403         }
 404
 405         list_add(&host->link, &irq_hosts);
 406         spin_unlock_irqrestore(&irq_big_lock, flags);
 407
 408         /* Additional setups per revmap type */
 409         switch(revmap_type) {
 410         case IRQ_HOST_MAP_LEGACY:
 411                 /* 0 is always the invalid number for legacy */
 412                 host->inval_irq = 0;
 413                 /* setup us as the host for all legacy interrupts */
 414                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 415                         irq_map[i].hwirq = 0;
 416                         smp_wmb();
 417                         irq_map[i].host = host;
 418                         smp_wmb();
 419
 420                         /* Clear norequest flags */
 421                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 422
 423                         /* Legacy flags are left to default at this point,
 424                          * one can then use irq_create_mapping() to
 425                          * explicitely change them
 426                          */
 427                         ops->map(host, i, i);
 428                 }
 429                 break;
 430         case IRQ_HOST_MAP_LINEAR:
 431                 rmap = (unsigned int *)(host + 1);
 432                 for (i = 0; i < revmap_arg; i++)
 433                         rmap[i] = IRQ_NONE;
 434                 host->revmap_data.linear.size = revmap_arg;
 435                 smp_wmb();
 436                 host->revmap_data.linear.revmap = rmap;
 437                 break;
 438         default:
 439                 break;
 440         }
 441
 442         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 443
 444         return host;
 445 }
 446
 447 struct irq_host *irq_find_host(struct device_node *node)
 448 {
 449         struct irq_host *h, *found = NULL;
 450         unsigned long flags;
 451
 452         /* We might want to match the legacy controller last since
 453          * it might potentially be set to match all interrupts in
 454          * the absence of a device node. This isn't a problem so far
 455          * yet though...
 456          */
 457         spin_lock_irqsave(&irq_big_lock, flags);
 458         list_for_each_entry(h, &irq_hosts, link)
 459                 if (h->ops->match == NULL || h->ops->match(h, node)) {
 460                         found = h;
 461                         break;
 462                 }
 463         spin_unlock_irqrestore(&irq_big_lock, flags);
 464         return found;
 465 }
 466 EXPORT_SYMBOL_GPL(irq_find_host);
 467
 468 void irq_set_default_host(struct irq_host *host)
 469 {
 470         pr_debug("irq: Default host set to @0x%p\n", host);
 471
 472         irq_default_host = host;
 473 }
 474
 475 void irq_set_virq_count(unsigned int count)
 476 {
 477         pr_debug("irq: Trying to set virq count to %d\n", count);
 478
 479         BUG_ON(count < NUM_ISA_INTERRUPTS);
 480         if (count < NR_IRQS)
 481                 irq_virq_count = count;
 482 }
 483
 484 /* radix tree not lockless safe ! we use a brlock-type mecanism
 485  * for now, until we can use a lockless radix tree
 486  */
 487 static void irq_radix_wrlock(unsigned long *flags)
 488 {
 489         unsigned int cpu, ok;
 490
 491         spin_lock_irqsave(&irq_big_lock, *flags);
 492         irq_radix_writer = 1;
 493         smp_mb();
 494         do {
 495                 barrier();
 496                 ok = 1;
 497                 for_each_possible_cpu(cpu) {
 498                         if (per_cpu(irq_radix_reader, cpu)) {
 499                                 ok = 0;
 500                                 break;
 501                         }
 502                 }
 503                 if (!ok)
 504                         cpu_relax();
 505         } while(!ok);
 506 }
 507
 508 static void irq_radix_wrunlock(unsigned long flags)
 509 {
 510         smp_wmb();
 511         irq_radix_writer = 0;
 512         spin_unlock_irqrestore(&irq_big_lock, flags);
 513 }
 514
 515 static void irq_radix_rdlock(unsigned long *flags)
 516 {
 517         local_irq_save(*flags);
 518         __get_cpu_var(irq_radix_reader) = 1;
 519         smp_mb();
 520         if (likely(irq_radix_writer == 0))
 521                 return;
 522         __get_cpu_var(irq_radix_reader) = 0;
 523         smp_wmb();
 524         spin_lock(&irq_big_lock);
 525         __get_cpu_var(irq_radix_reader) = 1;
 526         spin_unlock(&irq_big_lock);
 527 }
 528
 529 static void irq_radix_rdunlock(unsigned long flags)
 530 {
 531         __get_cpu_var(irq_radix_reader) = 0;
 532         local_irq_restore(flags);
 533 }
 534
 535
 536 unsigned int irq_create_mapping(struct irq_host *host,
 537                                 irq_hw_number_t hwirq)
 538 {
 539         unsigned int virq, hint;
 540
 541         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 542
 543         /* Look for default host if nececssary */
 544         if (host == NULL)
 545                 host = irq_default_host;
 546         if (host == NULL) {
 547                 printk(KERN_WARNING "irq_create_mapping called for"
 548                        " NULL host, hwirq=%lx\n", hwirq);
 549                 WARN_ON(1);
 550                 return NO_IRQ;
 551         }
 552         pr_debug("irq: -> using host @%p\n", host);
 553
 554         /* Check if mapping already exist, if it does, call
 555          * host->ops->map() to update the flags
 556          */
 557         virq = irq_find_mapping(host, hwirq);
 558         if (virq != IRQ_NONE) {
 559                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 560                 return virq;
 561         }
 562
 563         /* Get a virtual interrupt number */
 564         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 565                 /* Handle legacy */
 566                 virq = (unsigned int)hwirq;
 567                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 568                         return NO_IRQ;
 569                 return virq;
 570         } else {
 571                 /* Allocate a virtual interrupt number */
 572                 hint = hwirq % irq_virq_count;
 573                 virq = irq_alloc_virt(host, 1, hint);
 574                 if (virq == NO_IRQ) {
 575                         pr_debug("irq: -> virq allocation failed\n");
 576                         return NO_IRQ;
 577                 }
 578         }
 579         pr_debug("irq: -> obtained virq %d\n", virq);
 580
 581         /* Clear IRQ_NOREQUEST flag */
 582         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 583
 584         /* map it */
 585         smp_wmb();
 586         irq_map[virq].hwirq = hwirq;
 587         smp_mb();
 588         if (host->ops->map(host, virq, hwirq)) {
 589                 pr_debug("irq: -> mapping failed, freeing\n");
 590                 irq_free_virt(virq, 1);
 591                 return NO_IRQ;
 592         }
 593         return virq;
 594 }
 595 EXPORT_SYMBOL_GPL(irq_create_mapping);
 596
 597 unsigned int irq_create_of_mapping(struct device_node *controller,
 598                                    u32 *intspec, unsigned int intsize)
 599 {
 600         struct irq_host *host;
 601         irq_hw_number_t hwirq;
 602         unsigned int type = IRQ_TYPE_NONE;
 603         unsigned int virq;
 604
 605         if (controller == NULL)
 606                 host = irq_default_host;
 607         else
 608                 host = irq_find_host(controller);
 609         if (host == NULL) {
 610                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 611                        controller->full_name);
 612                 return NO_IRQ;
 613         }
 614
 615         /* If host has no translation, then we assume interrupt line */
 616         if (host->ops->xlate == NULL)
 617                 hwirq = intspec[0];
 618         else {
 619                 if (host->ops->xlate(host, controller, intspec, intsize,
 620                                      &hwirq, &type))
 621                         return NO_IRQ;
 622         }
 623
 624         /* Create mapping */
 625         virq = irq_create_mapping(host, hwirq);
 626         if (virq == NO_IRQ)
 627                 return virq;
 628
 629         /* Set type if specified and different than the current one */
 630         if (type != IRQ_TYPE_NONE &&
 631             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 632                 set_irq_type(virq, type);
 633         return virq;
 634 }
 635 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 636
 637 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 638 {
 639         struct of_irq oirq;
 640
 641         if (of_irq_map_one(dev, index, &oirq))
 642                 return NO_IRQ;
 643
 644         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 645                                      oirq.size);
 646 }
 647 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 648
 649 void irq_dispose_mapping(unsigned int virq)
 650 {
 651         struct irq_host *host = irq_map[virq].host;
 652         irq_hw_number_t hwirq;
 653         unsigned long flags;
 654
 655         WARN_ON (host == NULL);
 656         if (host == NULL)
 657                 return;
 658
 659         /* Never unmap legacy interrupts */
 660         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 661                 return;
 662
 663         /* remove chip and handler */
 664         set_irq_chip_and_handler(virq, NULL, NULL);
 665
 666         /* Make sure it's completed */
 667         synchronize_irq(virq);
 668
 669         /* Tell the PIC about it */
 670         if (host->ops->unmap)
 671                 host->ops->unmap(host, virq);
 672         smp_mb();
 673
 674         /* Clear reverse map */
 675         hwirq = irq_map[virq].hwirq;
 676         switch(host->revmap_type) {
 677         case IRQ_HOST_MAP_LINEAR:
 678                 if (hwirq < host->revmap_data.linear.size)
 679                         host->revmap_data.linear.revmap[hwirq] = IRQ_NONE;
 680                 break;
 681         case IRQ_HOST_MAP_TREE:
 682                 /* Check if radix tree allocated yet */
 683                 if (host->revmap_data.tree.gfp_mask == 0)
 684                         break;
 685                 irq_radix_wrlock(&flags);
 686                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 687                 irq_radix_wrunlock(flags);
 688                 break;
 689         }
 690
 691         /* Destroy map */
 692         smp_mb();
 693         irq_map[virq].hwirq = host->inval_irq;
 694
 695         /* Set some flags */
 696         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 697
 698         /* Free it */
 699         irq_free_virt(virq, 1);
 700 }
 701 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 702
 703 unsigned int irq_find_mapping(struct irq_host *host,
 704                               irq_hw_number_t hwirq)
 705 {
 706         unsigned int i;
 707         unsigned int hint = hwirq % irq_virq_count;
 708
 709         /* Look for default host if nececssary */
 710         if (host == NULL)
 711                 host = irq_default_host;
 712         if (host == NULL)
 713                 return NO_IRQ;
 714
 715         /* legacy -> bail early */
 716         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 717                 return hwirq;
 718
 719         /* Slow path does a linear search of the map */
 720         if (hint < NUM_ISA_INTERRUPTS)
 721                 hint = NUM_ISA_INTERRUPTS;
 722         i = hint;
 723         do  {
 724                 if (irq_map[i].host == host &&
 725                     irq_map[i].hwirq == hwirq)
 726                         return i;
 727                 i++;
 728                 if (i >= irq_virq_count)
 729                         i = NUM_ISA_INTERRUPTS;
 730         } while(i != hint);
 731         return NO_IRQ;
 732 }
 733 EXPORT_SYMBOL_GPL(irq_find_mapping);
 734
 735
 736 unsigned int irq_radix_revmap(struct irq_host *host,
 737                               irq_hw_number_t hwirq)
 738 {
 739         struct radix_tree_root *tree;
 740         struct irq_map_entry *ptr;
 741         unsigned int virq;
 742         unsigned long flags;
 743
 744         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 745
 746         /* Check if the radix tree exist yet. We test the value of
 747          * the gfp_mask for that. Sneaky but saves another int in the
 748          * structure. If not, we fallback to slow mode
 749          */
 750         tree = &host->revmap_data.tree;
 751         if (tree->gfp_mask == 0)
 752                 return irq_find_mapping(host, hwirq);
 753
 754         /* Now try to resolve */
 755         irq_radix_rdlock(&flags);
 756         ptr = radix_tree_lookup(tree, hwirq);
 757         irq_radix_rdunlock(flags);
 758
 759         /* Found it, return */
 760         if (ptr) {
 761                 virq = ptr - irq_map;
 762                 return virq;
 763         }
 764
 765         /* If not there, try to insert it */
 766         virq = irq_find_mapping(host, hwirq);
 767         if (virq != NO_IRQ) {
 768                 irq_radix_wrlock(&flags);
 769                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 770                 irq_radix_wrunlock(flags);
 771         }
 772         return virq;
 773 }
 774
 775 unsigned int irq_linear_revmap(struct irq_host *host,
 776                                irq_hw_number_t hwirq)
 777 {
 778         unsigned int *revmap;
 779
 780         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 781
 782         /* Check revmap bounds */
 783         if (unlikely(hwirq >= host->revmap_data.linear.size))
 784                 return irq_find_mapping(host, hwirq);
 785
 786         /* Check if revmap was allocated */
 787         revmap = host->revmap_data.linear.revmap;
 788         if (unlikely(revmap == NULL))
 789                 return irq_find_mapping(host, hwirq);
 790
 791         /* Fill up revmap with slow path if no mapping found */
 792         if (unlikely(revmap[hwirq] == NO_IRQ))
 793                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 794
 795         return revmap[hwirq];
 796 }
 797
 798 unsigned int irq_alloc_virt(struct irq_host *host,
 799                             unsigned int count,
 800                             unsigned int hint)
 801 {
 802         unsigned long flags;
 803         unsigned int i, j, found = NO_IRQ;
 804
 805         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 806                 return NO_IRQ;
 807
 808         spin_lock_irqsave(&irq_big_lock, flags);
 809
 810         /* Use hint for 1 interrupt if any */
 811         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 812             hint < irq_virq_count && irq_map[hint].host == NULL) {
 813                 found = hint;
 814                 goto hint_found;
 815         }
 816
 817         /* Look for count consecutive numbers in the allocatable
 818          * (non-legacy) space
 819          */
 820         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 821                 if (irq_map[i].host != NULL)
 822                         j = 0;
 823                 else
 824                         j++;
 825
 826                 if (j == count) {
 827                         found = i - count + 1;
 828                         break;
 829                 }
 830         }
 831         if (found == NO_IRQ) {
 832                 spin_unlock_irqrestore(&irq_big_lock, flags);
 833                 return NO_IRQ;
 834         }
 835  hint_found:
 836         for (i = found; i < (found + count); i++) {
 837                 irq_map[i].hwirq = host->inval_irq;
 838                 smp_wmb();
 839                 irq_map[i].host = host;
 840         }
 841         spin_unlock_irqrestore(&irq_big_lock, flags);
 842         return found;
 843 }
 844
 845 void irq_free_virt(unsigned int virq, unsigned int count)
 846 {
 847         unsigned long flags;
 848         unsigned int i;
 849
 850         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 851         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 852
 853         spin_lock_irqsave(&irq_big_lock, flags);
 854         for (i = virq; i < (virq + count); i++) {
 855                 struct irq_host *host;
 856
 857                 if (i < NUM_ISA_INTERRUPTS ||
 858                     (virq + count) > irq_virq_count)
 859                         continue;
 860
 861                 host = irq_map[i].host;
 862                 irq_map[i].hwirq = host->inval_irq;
 863                 smp_wmb();
 864                 irq_map[i].host = NULL;
 865         }
 866         spin_unlock_irqrestore(&irq_big_lock, flags);
 867 }
 868
 869 void irq_early_init(void)
 870 {
 871         unsigned int i;
 872
 873         for (i = 0; i < NR_IRQS; i++)
 874                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 875 }
 876
 877 /* We need to create the radix trees late */
 878 static int irq_late_init(void)
 879 {
 880         struct irq_host *h;
 881         unsigned long flags;
 882
 883         irq_radix_wrlock(&flags);
 884         list_for_each_entry(h, &irq_hosts, link) {
 885                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
 886                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
 887         }
 888         irq_radix_wrunlock(flags);
 889
 890         return 0;
 891 }
 892 arch_initcall(irq_late_init);
 893
 894 #endif /* CONFIG_PPC_MERGE */
 895
 896 #ifdef CONFIG_PCI_MSI
 897 int pci_enable_msi(struct pci_dev * pdev)
 898 {
 899         if (ppc_md.enable_msi)
 900                 return ppc_md.enable_msi(pdev);
 901         else
 902                 return -1;
 903 }
 904 EXPORT_SYMBOL(pci_enable_msi);
 905
 906 void pci_disable_msi(struct pci_dev * pdev)
 907 {
 908         if (ppc_md.disable_msi)
 909                 ppc_md.disable_msi(pdev);
 910 }
 911 EXPORT_SYMBOL(pci_disable_msi);
 912
 913 void pci_scan_msi_device(struct pci_dev *dev) {}
 914 int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) {return -1;}
 915 void pci_disable_msix(struct pci_dev *dev) {}
 916 void msi_remove_pci_irq_vectors(struct pci_dev *dev) {}
 917 void disable_msi_mode(struct pci_dev *dev, int pos, int type) {}
 918 void pci_no_msi(void) {}
 919 EXPORT_SYMBOL(pci_enable_msix);
 920 EXPORT_SYMBOL(pci_disable_msix);
 921
 922 #endif
 923
 924 #ifdef CONFIG_PPC64
 925 static int __init setup_noirqdistrib(char *str)
 926 {
 927         distribute_irqs = 0;
 928         return 1;
 929 }
 930
 931 __setup("noirqdistrib", setup_noirqdistrib);
 932 #endif /* CONFIG_PPC64 */