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 #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 (firmware_has_feature(FW_FEATURE_ISERIES) &&
 272                         get_lppaca()->int_dword.fields.decr_int) {
 273                 get_lppaca()->int_dword.fields.decr_int = 0;
 274                 /* Signal a fake decrementer interrupt */
 275                 timer_interrupt(regs);
 276         }
 277 #endif
 278 }
 279
 280 void __init init_IRQ(void)
 281 {
 282         ppc_md.init_IRQ();
 283 #ifdef CONFIG_PPC64
 284         irq_ctx_init();
 285 #endif
 286 }
 287
 288
 289 #ifdef CONFIG_IRQSTACKS
 290 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 291 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 292
 293 void irq_ctx_init(void)
 294 {
 295         struct thread_info *tp;
 296         int i;
 297
 298         for_each_possible_cpu(i) {
 299                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 300                 tp = softirq_ctx[i];
 301                 tp->cpu = i;
 302                 tp->preempt_count = SOFTIRQ_OFFSET;
 303
 304                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 305                 tp = hardirq_ctx[i];
 306                 tp->cpu = i;
 307                 tp->preempt_count = HARDIRQ_OFFSET;
 308         }
 309 }
 310
 311 static inline void do_softirq_onstack(void)
 312 {
 313         struct thread_info *curtp, *irqtp;
 314
 315         curtp = current_thread_info();
 316         irqtp = softirq_ctx[smp_processor_id()];
 317         irqtp->task = curtp->task;
 318         call_do_softirq(irqtp);
 319         irqtp->task = NULL;
 320 }
 321
 322 #else
 323 #define do_softirq_onstack()    __do_softirq()
 324 #endif /* CONFIG_IRQSTACKS */
 325
 326 void do_softirq(void)
 327 {
 328         unsigned long flags;
 329
 330         if (in_interrupt())
 331                 return;
 332
 333         local_irq_save(flags);
 334
 335         if (local_softirq_pending())
 336                 do_softirq_onstack();
 337
 338         local_irq_restore(flags);
 339 }
 340 EXPORT_SYMBOL(do_softirq);
 341
 342
 343 /*
 344  * IRQ controller and virtual interrupts
 345  */
 346
 347 #ifdef CONFIG_PPC_MERGE
 348
 349 static LIST_HEAD(irq_hosts);
 350 static spinlock_t irq_big_lock = SPIN_LOCK_UNLOCKED;
 351 static DEFINE_PER_CPU(unsigned int, irq_radix_reader);
 352 static unsigned int irq_radix_writer;
 353 struct irq_map_entry irq_map[NR_IRQS];
 354 static unsigned int irq_virq_count = NR_IRQS;
 355 static struct irq_host *irq_default_host;
 356
 357 struct irq_host *irq_alloc_host(unsigned int revmap_type,
 358                                 unsigned int revmap_arg,
 359                                 struct irq_host_ops *ops,
 360                                 irq_hw_number_t inval_irq)
 361 {
 362         struct irq_host *host;
 363         unsigned int size = sizeof(struct irq_host);
 364         unsigned int i;
 365         unsigned int *rmap;
 366         unsigned long flags;
 367
 368         /* Allocate structure and revmap table if using linear mapping */
 369         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 370                 size += revmap_arg * sizeof(unsigned int);
 371         if (mem_init_done)
 372                 host = kzalloc(size, GFP_KERNEL);
 373         else {
 374                 host = alloc_bootmem(size);
 375                 if (host)
 376                         memset(host, 0, size);
 377         }
 378         if (host == NULL)
 379                 return NULL;
 380
 381         /* Fill structure */
 382         host->revmap_type = revmap_type;
 383         host->inval_irq = inval_irq;
 384         host->ops = ops;
 385
 386         spin_lock_irqsave(&irq_big_lock, flags);
 387
 388         /* If it's a legacy controller, check for duplicates and
 389          * mark it as allocated (we use irq 0 host pointer for that
 390          */
 391         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 392                 if (irq_map[0].host != NULL) {
 393                         spin_unlock_irqrestore(&irq_big_lock, flags);
 394                         /* If we are early boot, we can't free the structure,
 395                          * too bad...
 396                          * this will be fixed once slab is made available early
 397                          * instead of the current cruft
 398                          */
 399                         if (mem_init_done)
 400                                 kfree(host);
 401                         return NULL;
 402                 }
 403                 irq_map[0].host = host;
 404         }
 405
 406         list_add(&host->link, &irq_hosts);
 407         spin_unlock_irqrestore(&irq_big_lock, flags);
 408
 409         /* Additional setups per revmap type */
 410         switch(revmap_type) {
 411         case IRQ_HOST_MAP_LEGACY:
 412                 /* 0 is always the invalid number for legacy */
 413                 host->inval_irq = 0;
 414                 /* setup us as the host for all legacy interrupts */
 415                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 416                         irq_map[i].hwirq = 0;
 417                         smp_wmb();
 418                         irq_map[i].host = host;
 419                         smp_wmb();
 420
 421                         /* Clear norequest flags */
 422                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 423
 424                         /* Legacy flags are left to default at this point,
 425                          * one can then use irq_create_mapping() to
 426                          * explicitely change them
 427                          */
 428                         ops->map(host, i, i);
 429                 }
 430                 break;
 431         case IRQ_HOST_MAP_LINEAR:
 432                 rmap = (unsigned int *)(host + 1);
 433                 for (i = 0; i < revmap_arg; i++)
 434                         rmap[i] = IRQ_NONE;
 435                 host->revmap_data.linear.size = revmap_arg;
 436                 smp_wmb();
 437                 host->revmap_data.linear.revmap = rmap;
 438                 break;
 439         default:
 440                 break;
 441         }
 442
 443         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 444
 445         return host;
 446 }
 447
 448 struct irq_host *irq_find_host(struct device_node *node)
 449 {
 450         struct irq_host *h, *found = NULL;
 451         unsigned long flags;
 452
 453         /* We might want to match the legacy controller last since
 454          * it might potentially be set to match all interrupts in
 455          * the absence of a device node. This isn't a problem so far
 456          * yet though...
 457          */
 458         spin_lock_irqsave(&irq_big_lock, flags);
 459         list_for_each_entry(h, &irq_hosts, link)
 460                 if (h->ops->match == NULL || h->ops->match(h, node)) {
 461                         found = h;
 462                         break;
 463                 }
 464         spin_unlock_irqrestore(&irq_big_lock, flags);
 465         return found;
 466 }
 467 EXPORT_SYMBOL_GPL(irq_find_host);
 468
 469 void irq_set_default_host(struct irq_host *host)
 470 {
 471         pr_debug("irq: Default host set to @0x%p\n", host);
 472
 473         irq_default_host = host;
 474 }
 475
 476 void irq_set_virq_count(unsigned int count)
 477 {
 478         pr_debug("irq: Trying to set virq count to %d\n", count);
 479
 480         BUG_ON(count < NUM_ISA_INTERRUPTS);
 481         if (count < NR_IRQS)
 482                 irq_virq_count = count;
 483 }
 484
 485 /* radix tree not lockless safe ! we use a brlock-type mecanism
 486  * for now, until we can use a lockless radix tree
 487  */
 488 static void irq_radix_wrlock(unsigned long *flags)
 489 {
 490         unsigned int cpu, ok;
 491
 492         spin_lock_irqsave(&irq_big_lock, *flags);
 493         irq_radix_writer = 1;
 494         smp_mb();
 495         do {
 496                 barrier();
 497                 ok = 1;
 498                 for_each_possible_cpu(cpu) {
 499                         if (per_cpu(irq_radix_reader, cpu)) {
 500                                 ok = 0;
 501                                 break;
 502                         }
 503                 }
 504                 if (!ok)
 505                         cpu_relax();
 506         } while(!ok);
 507 }
 508
 509 static void irq_radix_wrunlock(unsigned long flags)
 510 {
 511         smp_wmb();
 512         irq_radix_writer = 0;
 513         spin_unlock_irqrestore(&irq_big_lock, flags);
 514 }
 515
 516 static void irq_radix_rdlock(unsigned long *flags)
 517 {
 518         local_irq_save(*flags);
 519         __get_cpu_var(irq_radix_reader) = 1;
 520         smp_mb();
 521         if (likely(irq_radix_writer == 0))
 522                 return;
 523         __get_cpu_var(irq_radix_reader) = 0;
 524         smp_wmb();
 525         spin_lock(&irq_big_lock);
 526         __get_cpu_var(irq_radix_reader) = 1;
 527         spin_unlock(&irq_big_lock);
 528 }
 529
 530 static void irq_radix_rdunlock(unsigned long flags)
 531 {
 532         __get_cpu_var(irq_radix_reader) = 0;
 533         local_irq_restore(flags);
 534 }
 535
 536
 537 unsigned int irq_create_mapping(struct irq_host *host,
 538                                 irq_hw_number_t hwirq)
 539 {
 540         unsigned int virq, hint;
 541
 542         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 543
 544         /* Look for default host if nececssary */
 545         if (host == NULL)
 546                 host = irq_default_host;
 547         if (host == NULL) {
 548                 printk(KERN_WARNING "irq_create_mapping called for"
 549                        " NULL host, hwirq=%lx\n", hwirq);
 550                 WARN_ON(1);
 551                 return NO_IRQ;
 552         }
 553         pr_debug("irq: -> using host @%p\n", host);
 554
 555         /* Check if mapping already exist, if it does, call
 556          * host->ops->map() to update the flags
 557          */
 558         virq = irq_find_mapping(host, hwirq);
 559         if (virq != IRQ_NONE) {
 560                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 561                 return virq;
 562         }
 563
 564         /* Get a virtual interrupt number */
 565         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 566                 /* Handle legacy */
 567                 virq = (unsigned int)hwirq;
 568                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 569                         return NO_IRQ;
 570                 return virq;
 571         } else {
 572                 /* Allocate a virtual interrupt number */
 573                 hint = hwirq % irq_virq_count;
 574                 virq = irq_alloc_virt(host, 1, hint);
 575                 if (virq == NO_IRQ) {
 576                         pr_debug("irq: -> virq allocation failed\n");
 577                         return NO_IRQ;
 578                 }
 579         }
 580         pr_debug("irq: -> obtained virq %d\n", virq);
 581
 582         /* Clear IRQ_NOREQUEST flag */
 583         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 584
 585         /* map it */
 586         smp_wmb();
 587         irq_map[virq].hwirq = hwirq;
 588         smp_mb();
 589         if (host->ops->map(host, virq, hwirq)) {
 590                 pr_debug("irq: -> mapping failed, freeing\n");
 591                 irq_free_virt(virq, 1);
 592                 return NO_IRQ;
 593         }
 594         return virq;
 595 }
 596 EXPORT_SYMBOL_GPL(irq_create_mapping);
 597
 598 unsigned int irq_create_of_mapping(struct device_node *controller,
 599                                    u32 *intspec, unsigned int intsize)
 600 {
 601         struct irq_host *host;
 602         irq_hw_number_t hwirq;
 603         unsigned int type = IRQ_TYPE_NONE;
 604         unsigned int virq;
 605
 606         if (controller == NULL)
 607                 host = irq_default_host;
 608         else
 609                 host = irq_find_host(controller);
 610         if (host == NULL) {
 611                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 612                        controller->full_name);
 613                 return NO_IRQ;
 614         }
 615
 616         /* If host has no translation, then we assume interrupt line */
 617         if (host->ops->xlate == NULL)
 618                 hwirq = intspec[0];
 619         else {
 620                 if (host->ops->xlate(host, controller, intspec, intsize,
 621                                      &hwirq, &type))
 622                         return NO_IRQ;
 623         }
 624
 625         /* Create mapping */
 626         virq = irq_create_mapping(host, hwirq);
 627         if (virq == NO_IRQ)
 628                 return virq;
 629
 630         /* Set type if specified and different than the current one */
 631         if (type != IRQ_TYPE_NONE &&
 632             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 633                 set_irq_type(virq, type);
 634         return virq;
 635 }
 636 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 637
 638 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 639 {
 640         struct of_irq oirq;
 641
 642         if (of_irq_map_one(dev, index, &oirq))
 643                 return NO_IRQ;
 644
 645         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 646                                      oirq.size);
 647 }
 648 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 649
 650 void irq_dispose_mapping(unsigned int virq)
 651 {
 652         struct irq_host *host;
 653         irq_hw_number_t hwirq;
 654         unsigned long flags;
 655
 656         if (virq == NO_IRQ)
 657                 return;
 658
 659         host = irq_map[virq].host;
 660         WARN_ON (host == NULL);
 661         if (host == NULL)
 662                 return;
 663
 664         /* Never unmap legacy interrupts */
 665         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 666                 return;
 667
 668         /* remove chip and handler */
 669         set_irq_chip_and_handler(virq, NULL, NULL);
 670
 671         /* Make sure it's completed */
 672         synchronize_irq(virq);
 673
 674         /* Tell the PIC about it */
 675         if (host->ops->unmap)
 676                 host->ops->unmap(host, virq);
 677         smp_mb();
 678
 679         /* Clear reverse map */
 680         hwirq = irq_map[virq].hwirq;
 681         switch(host->revmap_type) {
 682         case IRQ_HOST_MAP_LINEAR:
 683                 if (hwirq < host->revmap_data.linear.size)
 684                         host->revmap_data.linear.revmap[hwirq] = IRQ_NONE;
 685                 break;
 686         case IRQ_HOST_MAP_TREE:
 687                 /* Check if radix tree allocated yet */
 688                 if (host->revmap_data.tree.gfp_mask == 0)
 689                         break;
 690                 irq_radix_wrlock(&flags);
 691                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 692                 irq_radix_wrunlock(flags);
 693                 break;
 694         }
 695
 696         /* Destroy map */
 697         smp_mb();
 698         irq_map[virq].hwirq = host->inval_irq;
 699
 700         /* Set some flags */
 701         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 702
 703         /* Free it */
 704         irq_free_virt(virq, 1);
 705 }
 706 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 707
 708 unsigned int irq_find_mapping(struct irq_host *host,
 709                               irq_hw_number_t hwirq)
 710 {
 711         unsigned int i;
 712         unsigned int hint = hwirq % irq_virq_count;
 713
 714         /* Look for default host if nececssary */
 715         if (host == NULL)
 716                 host = irq_default_host;
 717         if (host == NULL)
 718                 return NO_IRQ;
 719
 720         /* legacy -> bail early */
 721         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 722                 return hwirq;
 723
 724         /* Slow path does a linear search of the map */
 725         if (hint < NUM_ISA_INTERRUPTS)
 726                 hint = NUM_ISA_INTERRUPTS;
 727         i = hint;
 728         do  {
 729                 if (irq_map[i].host == host &&
 730                     irq_map[i].hwirq == hwirq)
 731                         return i;
 732                 i++;
 733                 if (i >= irq_virq_count)
 734                         i = NUM_ISA_INTERRUPTS;
 735         } while(i != hint);
 736         return NO_IRQ;
 737 }
 738 EXPORT_SYMBOL_GPL(irq_find_mapping);
 739
 740
 741 unsigned int irq_radix_revmap(struct irq_host *host,
 742                               irq_hw_number_t hwirq)
 743 {
 744         struct radix_tree_root *tree;
 745         struct irq_map_entry *ptr;
 746         unsigned int virq;
 747         unsigned long flags;
 748
 749         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 750
 751         /* Check if the radix tree exist yet. We test the value of
 752          * the gfp_mask for that. Sneaky but saves another int in the
 753          * structure. If not, we fallback to slow mode
 754          */
 755         tree = &host->revmap_data.tree;
 756         if (tree->gfp_mask == 0)
 757                 return irq_find_mapping(host, hwirq);
 758
 759         /* Now try to resolve */
 760         irq_radix_rdlock(&flags);
 761         ptr = radix_tree_lookup(tree, hwirq);
 762         irq_radix_rdunlock(flags);
 763
 764         /* Found it, return */
 765         if (ptr) {
 766                 virq = ptr - irq_map;
 767                 return virq;
 768         }
 769
 770         /* If not there, try to insert it */
 771         virq = irq_find_mapping(host, hwirq);
 772         if (virq != NO_IRQ) {
 773                 irq_radix_wrlock(&flags);
 774                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 775                 irq_radix_wrunlock(flags);
 776         }
 777         return virq;
 778 }
 779
 780 unsigned int irq_linear_revmap(struct irq_host *host,
 781                                irq_hw_number_t hwirq)
 782 {
 783         unsigned int *revmap;
 784
 785         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 786
 787         /* Check revmap bounds */
 788         if (unlikely(hwirq >= host->revmap_data.linear.size))
 789                 return irq_find_mapping(host, hwirq);
 790
 791         /* Check if revmap was allocated */
 792         revmap = host->revmap_data.linear.revmap;
 793         if (unlikely(revmap == NULL))
 794                 return irq_find_mapping(host, hwirq);
 795
 796         /* Fill up revmap with slow path if no mapping found */
 797         if (unlikely(revmap[hwirq] == NO_IRQ))
 798                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 799
 800         return revmap[hwirq];
 801 }
 802
 803 unsigned int irq_alloc_virt(struct irq_host *host,
 804                             unsigned int count,
 805                             unsigned int hint)
 806 {
 807         unsigned long flags;
 808         unsigned int i, j, found = NO_IRQ;
 809
 810         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 811                 return NO_IRQ;
 812
 813         spin_lock_irqsave(&irq_big_lock, flags);
 814
 815         /* Use hint for 1 interrupt if any */
 816         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 817             hint < irq_virq_count && irq_map[hint].host == NULL) {
 818                 found = hint;
 819                 goto hint_found;
 820         }
 821
 822         /* Look for count consecutive numbers in the allocatable
 823          * (non-legacy) space
 824          */
 825         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 826                 if (irq_map[i].host != NULL)
 827                         j = 0;
 828                 else
 829                         j++;
 830
 831                 if (j == count) {
 832                         found = i - count + 1;
 833                         break;
 834                 }
 835         }
 836         if (found == NO_IRQ) {
 837                 spin_unlock_irqrestore(&irq_big_lock, flags);
 838                 return NO_IRQ;
 839         }
 840  hint_found:
 841         for (i = found; i < (found + count); i++) {
 842                 irq_map[i].hwirq = host->inval_irq;
 843                 smp_wmb();
 844                 irq_map[i].host = host;
 845         }
 846         spin_unlock_irqrestore(&irq_big_lock, flags);
 847         return found;
 848 }
 849
 850 void irq_free_virt(unsigned int virq, unsigned int count)
 851 {
 852         unsigned long flags;
 853         unsigned int i;
 854
 855         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 856         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 857
 858         spin_lock_irqsave(&irq_big_lock, flags);
 859         for (i = virq; i < (virq + count); i++) {
 860                 struct irq_host *host;
 861
 862                 if (i < NUM_ISA_INTERRUPTS ||
 863                     (virq + count) > irq_virq_count)
 864                         continue;
 865
 866                 host = irq_map[i].host;
 867                 irq_map[i].hwirq = host->inval_irq;
 868                 smp_wmb();
 869                 irq_map[i].host = NULL;
 870         }
 871         spin_unlock_irqrestore(&irq_big_lock, flags);
 872 }
 873
 874 void irq_early_init(void)
 875 {
 876         unsigned int i;
 877
 878         for (i = 0; i < NR_IRQS; i++)
 879                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 880 }
 881
 882 /* We need to create the radix trees late */
 883 static int irq_late_init(void)
 884 {
 885         struct irq_host *h;
 886         unsigned long flags;
 887
 888         irq_radix_wrlock(&flags);
 889         list_for_each_entry(h, &irq_hosts, link) {
 890                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
 891                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
 892         }
 893         irq_radix_wrunlock(flags);
 894
 895         return 0;
 896 }
 897 arch_initcall(irq_late_init);
 898
 899 #endif /* CONFIG_PPC_MERGE */
 900
 901 #ifdef CONFIG_PCI_MSI
 902 int pci_enable_msi(struct pci_dev * pdev)
 903 {
 904         if (ppc_md.enable_msi)
 905                 return ppc_md.enable_msi(pdev);
 906         else
 907                 return -1;
 908 }
 909 EXPORT_SYMBOL(pci_enable_msi);
 910
 911 void pci_disable_msi(struct pci_dev * pdev)
 912 {
 913         if (ppc_md.disable_msi)
 914                 ppc_md.disable_msi(pdev);
 915 }
 916 EXPORT_SYMBOL(pci_disable_msi);
 917
 918 void pci_scan_msi_device(struct pci_dev *dev) {}
 919 int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) {return -1;}
 920 void pci_disable_msix(struct pci_dev *dev) {}
 921 void msi_remove_pci_irq_vectors(struct pci_dev *dev) {}
 922 void disable_msi_mode(struct pci_dev *dev, int pos, int type) {}
 923 void pci_no_msi(void) {}
 924 EXPORT_SYMBOL(pci_enable_msix);
 925 EXPORT_SYMBOL(pci_disable_msix);
 926
 927 #endif
 928
 929 #ifdef CONFIG_PPC64
 930 static int __init setup_noirqdistrib(char *str)
 931 {
 932         distribute_irqs = 0;
 933         return 1;
 934 }
 935
 936 __setup("noirqdistrib", setup_noirqdistrib);
 937 #endif /* CONFIG_PPC64 */