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  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version
  14  * 2 of the License, or (at your option) any later version.
  15  *
  16  * This file contains the code used by various IRQ handling routines:
  17  * asking for different IRQ's should be done through these routines
  18  * instead of just grabbing them. Thus setups with different IRQ numbers
  19  * shouldn't result in any weird surprises, and installing new handlers
  20  * should be easier.
  21  *
  22  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
  23  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
  24  * mask register (of which only 16 are defined), hence the weird shifting
  25  * and complement of the cached_irq_mask.  I want to be able to stuff
  26  * this right into the SIU SMASK register.
  27  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
  28  * to reduce code space and undefined function references.
  29  */
  30
  31 #undef DEBUG
  32
  33 #include <linux/module.h>
  34 #include <linux/threads.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/signal.h>
  37 #include <linux/sched.h>
  38 #include <linux/ptrace.h>
  39 #include <linux/ioport.h>
  40 #include <linux/interrupt.h>
  41 #include <linux/timex.h>
  42 #include <linux/init.h>
  43 #include <linux/slab.h>
  44 #include <linux/delay.h>
  45 #include <linux/irq.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/cpumask.h>
  48 #include <linux/profile.h>
  49 #include <linux/bitops.h>
  50 #include <linux/list.h>
  51 #include <linux/radix-tree.h>
  52 #include <linux/mutex.h>
  53 #include <linux/bootmem.h>
  54 #include <linux/pci.h>
  55
  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_PPC64
  67 #include <asm/paca.h>
  68 #include <asm/firmware.h>
  69 #include <asm/lv1call.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 static inline unsigned long get_hard_enabled(void)
 101 {
 102         unsigned long enabled;
 103
 104         __asm__ __volatile__("lbz %0,%1(13)"
 105         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 106
 107         return enabled;
 108 }
 109
 110 static inline void set_soft_enabled(unsigned long enable)
 111 {
 112         __asm__ __volatile__("stb %0,%1(13)"
 113         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 114 }
 115
 116 void local_irq_restore(unsigned long en)
 117 {
 118         /*
 119          * get_paca()->soft_enabled = en;
 120          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 121          * That was allowed before, and in such a case we do need to take care
 122          * that gcc will set soft_enabled directly via r13, not choose to use
 123          * an intermediate register, lest we're preempted to a different cpu.
 124          */
 125         set_soft_enabled(en);
 126         if (!en)
 127                 return;
 128
 129         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 130                 /*
 131                  * Do we need to disable preemption here?  Not really: in the
 132                  * unlikely event that we're preempted to a different cpu in
 133                  * between getting r13, loading its lppaca_ptr, and loading
 134                  * its any_int, we might call iseries_handle_interrupts without
 135                  * an interrupt pending on the new cpu, but that's no disaster,
 136                  * is it?  And the business of preempting us off the old cpu
 137                  * would itself involve a local_irq_restore which handles the
 138                  * interrupt to that cpu.
 139                  *
 140                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 141                  * to avoid any preemption checking added into get_paca().
 142                  */
 143                 if (local_paca->lppaca_ptr->int_dword.any_int)
 144                         iseries_handle_interrupts();
 145                 return;
 146         }
 147
 148         /*
 149          * if (get_paca()->hard_enabled) return;
 150          * But again we need to take care that gcc gets hard_enabled directly
 151          * via r13, not choose to use an intermediate register, lest we're
 152          * preempted to a different cpu in between the two instructions.
 153          */
 154         if (get_hard_enabled())
 155                 return;
 156
 157         /*
 158          * Need to hard-enable interrupts here.  Since currently disabled,
 159          * no need to take further asm precautions against preemption; but
 160          * use local_paca instead of get_paca() to avoid preemption checking.
 161          */
 162         local_paca->hard_enabled = en;
 163         if ((int)mfspr(SPRN_DEC) < 0)
 164                 mtspr(SPRN_DEC, 1);
 165
 166         /*
 167          * Force the delivery of pending soft-disabled interrupts on PS3.
 168          * Any HV call will have this side effect.
 169          */
 170         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 171                 u64 tmp;
 172                 lv1_get_version_info(&tmp);
 173         }
 174
 175         __hard_irq_enable();
 176 }
 177 #endif /* CONFIG_PPC64 */
 178
 179 int show_interrupts(struct seq_file *p, void *v)
 180 {
 181         int i = *(loff_t *)v, j;
 182         struct irqaction *action;
 183         irq_desc_t *desc;
 184         unsigned long flags;
 185
 186         if (i == 0) {
 187                 seq_puts(p, "           ");
 188                 for_each_online_cpu(j)
 189                         seq_printf(p, "CPU%d       ", j);
 190                 seq_putc(p, '\n');
 191         }
 192
 193         if (i < NR_IRQS) {
 194                 desc = get_irq_desc(i);
 195                 spin_lock_irqsave(&desc->lock, flags);
 196                 action = desc->action;
 197                 if (!action || !action->handler)
 198                         goto skip;
 199                 seq_printf(p, "%3d: ", i);
 200 #ifdef CONFIG_SMP
 201                 for_each_online_cpu(j)
 202                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 203 #else
 204                 seq_printf(p, "%10u ", kstat_irqs(i));
 205 #endif /* CONFIG_SMP */
 206                 if (desc->chip)
 207                         seq_printf(p, " %s ", desc->chip->typename);
 208                 else
 209                         seq_puts(p, "  None      ");
 210                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 211                 seq_printf(p, "    %s", action->name);
 212                 for (action = action->next; action; action = action->next)
 213                         seq_printf(p, ", %s", action->name);
 214                 seq_putc(p, '\n');
 215 skip:
 216                 spin_unlock_irqrestore(&desc->lock, flags);
 217         } else if (i == NR_IRQS) {
 218 #ifdef CONFIG_PPC32
 219 #ifdef CONFIG_TAU_INT
 220                 if (tau_initialized){
 221                         seq_puts(p, "TAU: ");
 222                         for_each_online_cpu(j)
 223                                 seq_printf(p, "%10u ", tau_interrupts(j));
 224                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 225                 }
 226 #endif
 227 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
 228                 /* should this be per processor send/receive? */
 229                 seq_printf(p, "IPI (recv/sent): %10u/%u\n",
 230                                 atomic_read(&ipi_recv), atomic_read(&ipi_sent));
 231 #endif
 232 #endif /* CONFIG_PPC32 */
 233                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 234         }
 235         return 0;
 236 }
 237
 238 #ifdef CONFIG_HOTPLUG_CPU
 239 void fixup_irqs(cpumask_t map)
 240 {
 241         unsigned int irq;
 242         static int warned;
 243
 244         for_each_irq(irq) {
 245                 cpumask_t mask;
 246
 247                 if (irq_desc[irq].status & IRQ_PER_CPU)
 248                         continue;
 249
 250                 cpus_and(mask, irq_desc[irq].affinity, map);
 251                 if (any_online_cpu(mask) == NR_CPUS) {
 252                         printk("Breaking affinity for irq %i\n", irq);
 253                         mask = map;
 254                 }
 255                 if (irq_desc[irq].chip->set_affinity)
 256                         irq_desc[irq].chip->set_affinity(irq, mask);
 257                 else if (irq_desc[irq].action && !(warned++))
 258                         printk("Cannot set affinity for irq %i\n", irq);
 259         }
 260
 261         local_irq_enable();
 262         mdelay(1);
 263         local_irq_disable();
 264 }
 265 #endif
 266
 267 void do_IRQ(struct pt_regs *regs)
 268 {
 269         struct pt_regs *old_regs = set_irq_regs(regs);
 270         unsigned int irq;
 271 #ifdef CONFIG_IRQSTACKS
 272         struct thread_info *curtp, *irqtp;
 273 #endif
 274
 275         irq_enter();
 276
 277 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 278         /* Debugging check for stack overflow: is there less than 2KB free? */
 279         {
 280                 long sp;
 281
 282                 sp = __get_SP() & (THREAD_SIZE-1);
 283
 284                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 285                         printk("do_IRQ: stack overflow: %ld\n",
 286                                 sp - sizeof(struct thread_info));
 287                         dump_stack();
 288                 }
 289         }
 290 #endif
 291
 292         /*
 293          * Every platform is required to implement ppc_md.get_irq.
 294          * This function will either return an irq number or NO_IRQ to
 295          * indicate there are no more pending.
 296          * The value NO_IRQ_IGNORE is for buggy hardware and means that this
 297          * IRQ has already been handled. -- Tom
 298          */
 299         irq = ppc_md.get_irq();
 300
 301         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
 302 #ifdef CONFIG_IRQSTACKS
 303                 /* Switch to the irq stack to handle this */
 304                 curtp = current_thread_info();
 305                 irqtp = hardirq_ctx[smp_processor_id()];
 306                 if (curtp != irqtp) {
 307                         struct irq_desc *desc = irq_desc + irq;
 308                         void *handler = desc->handle_irq;
 309                         if (handler == NULL)
 310                                 handler = &__do_IRQ;
 311                         irqtp->task = curtp->task;
 312                         irqtp->flags = 0;
 313                         call_handle_irq(irq, desc, irqtp, handler);
 314                         irqtp->task = NULL;
 315                         if (irqtp->flags)
 316                                 set_bits(irqtp->flags, &curtp->flags);
 317                 } else
 318 #endif
 319                         generic_handle_irq(irq);
 320         } else if (irq != NO_IRQ_IGNORE)
 321                 /* That's not SMP safe ... but who cares ? */
 322                 ppc_spurious_interrupts++;
 323
 324         irq_exit();
 325         set_irq_regs(old_regs);
 326
 327 #ifdef CONFIG_PPC_ISERIES
 328         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 329                         get_lppaca()->int_dword.fields.decr_int) {
 330                 get_lppaca()->int_dword.fields.decr_int = 0;
 331                 /* Signal a fake decrementer interrupt */
 332                 timer_interrupt(regs);
 333         }
 334 #endif
 335 }
 336
 337 void __init init_IRQ(void)
 338 {
 339         ppc_md.init_IRQ();
 340 #ifdef CONFIG_PPC64
 341         irq_ctx_init();
 342 #endif
 343 }
 344
 345
 346 #ifdef CONFIG_IRQSTACKS
 347 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 348 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 349
 350 void irq_ctx_init(void)
 351 {
 352         struct thread_info *tp;
 353         int i;
 354
 355         for_each_possible_cpu(i) {
 356                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 357                 tp = softirq_ctx[i];
 358                 tp->cpu = i;
 359                 tp->preempt_count = SOFTIRQ_OFFSET;
 360
 361                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 362                 tp = hardirq_ctx[i];
 363                 tp->cpu = i;
 364                 tp->preempt_count = HARDIRQ_OFFSET;
 365         }
 366 }
 367
 368 static inline void do_softirq_onstack(void)
 369 {
 370         struct thread_info *curtp, *irqtp;
 371
 372         curtp = current_thread_info();
 373         irqtp = softirq_ctx[smp_processor_id()];
 374         irqtp->task = curtp->task;
 375         call_do_softirq(irqtp);
 376         irqtp->task = NULL;
 377 }
 378
 379 #else
 380 #define do_softirq_onstack()    __do_softirq()
 381 #endif /* CONFIG_IRQSTACKS */
 382
 383 void do_softirq(void)
 384 {
 385         unsigned long flags;
 386
 387         if (in_interrupt())
 388                 return;
 389
 390         local_irq_save(flags);
 391
 392         if (local_softirq_pending())
 393                 do_softirq_onstack();
 394
 395         local_irq_restore(flags);
 396 }
 397 EXPORT_SYMBOL(do_softirq);
 398
 399
 400 /*
 401  * IRQ controller and virtual interrupts
 402  */
 403
 404 #ifdef CONFIG_PPC_MERGE
 405
 406 static LIST_HEAD(irq_hosts);
 407 static DEFINE_SPINLOCK(irq_big_lock);
 408 static DEFINE_PER_CPU(unsigned int, irq_radix_reader);
 409 static unsigned int irq_radix_writer;
 410 struct irq_map_entry irq_map[NR_IRQS];
 411 static unsigned int irq_virq_count = NR_IRQS;
 412 static struct irq_host *irq_default_host;
 413
 414 irq_hw_number_t virq_to_hw(unsigned int virq)
 415 {
 416         return irq_map[virq].hwirq;
 417 }
 418 EXPORT_SYMBOL_GPL(virq_to_hw);
 419
 420 struct irq_host *irq_alloc_host(unsigned int revmap_type,
 421                                 unsigned int revmap_arg,
 422                                 struct irq_host_ops *ops,
 423                                 irq_hw_number_t inval_irq)
 424 {
 425         struct irq_host *host;
 426         unsigned int size = sizeof(struct irq_host);
 427         unsigned int i;
 428         unsigned int *rmap;
 429         unsigned long flags;
 430
 431         /* Allocate structure and revmap table if using linear mapping */
 432         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 433                 size += revmap_arg * sizeof(unsigned int);
 434         if (mem_init_done)
 435                 host = kzalloc(size, GFP_KERNEL);
 436         else {
 437                 host = alloc_bootmem(size);
 438                 if (host)
 439                         memset(host, 0, size);
 440         }
 441         if (host == NULL)
 442                 return NULL;
 443
 444         /* Fill structure */
 445         host->revmap_type = revmap_type;
 446         host->inval_irq = inval_irq;
 447         host->ops = ops;
 448
 449         spin_lock_irqsave(&irq_big_lock, flags);
 450
 451         /* If it's a legacy controller, check for duplicates and
 452          * mark it as allocated (we use irq 0 host pointer for that
 453          */
 454         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 455                 if (irq_map[0].host != NULL) {
 456                         spin_unlock_irqrestore(&irq_big_lock, flags);
 457                         /* If we are early boot, we can't free the structure,
 458                          * too bad...
 459                          * this will be fixed once slab is made available early
 460                          * instead of the current cruft
 461                          */
 462                         if (mem_init_done)
 463                                 kfree(host);
 464                         return NULL;
 465                 }
 466                 irq_map[0].host = host;
 467         }
 468
 469         list_add(&host->link, &irq_hosts);
 470         spin_unlock_irqrestore(&irq_big_lock, flags);
 471
 472         /* Additional setups per revmap type */
 473         switch(revmap_type) {
 474         case IRQ_HOST_MAP_LEGACY:
 475                 /* 0 is always the invalid number for legacy */
 476                 host->inval_irq = 0;
 477                 /* setup us as the host for all legacy interrupts */
 478                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 479                         irq_map[i].hwirq = 0;
 480                         smp_wmb();
 481                         irq_map[i].host = host;
 482                         smp_wmb();
 483
 484                         /* Clear norequest flags */
 485                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 486
 487                         /* Legacy flags are left to default at this point,
 488                          * one can then use irq_create_mapping() to
 489                          * explicitely change them
 490                          */
 491                         ops->map(host, i, i);
 492                 }
 493                 break;
 494         case IRQ_HOST_MAP_LINEAR:
 495                 rmap = (unsigned int *)(host + 1);
 496                 for (i = 0; i < revmap_arg; i++)
 497                         rmap[i] = NO_IRQ;
 498                 host->revmap_data.linear.size = revmap_arg;
 499                 smp_wmb();
 500                 host->revmap_data.linear.revmap = rmap;
 501                 break;
 502         default:
 503                 break;
 504         }
 505
 506         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 507
 508         return host;
 509 }
 510
 511 struct irq_host *irq_find_host(struct device_node *node)
 512 {
 513         struct irq_host *h, *found = NULL;
 514         unsigned long flags;
 515
 516         /* We might want to match the legacy controller last since
 517          * it might potentially be set to match all interrupts in
 518          * the absence of a device node. This isn't a problem so far
 519          * yet though...
 520          */
 521         spin_lock_irqsave(&irq_big_lock, flags);
 522         list_for_each_entry(h, &irq_hosts, link)
 523                 if (h->ops->match == NULL || h->ops->match(h, node)) {
 524                         found = h;
 525                         break;
 526                 }
 527         spin_unlock_irqrestore(&irq_big_lock, flags);
 528         return found;
 529 }
 530 EXPORT_SYMBOL_GPL(irq_find_host);
 531
 532 void irq_set_default_host(struct irq_host *host)
 533 {
 534         pr_debug("irq: Default host set to @0x%p\n", host);
 535
 536         irq_default_host = host;
 537 }
 538
 539 void irq_set_virq_count(unsigned int count)
 540 {
 541         pr_debug("irq: Trying to set virq count to %d\n", count);
 542
 543         BUG_ON(count < NUM_ISA_INTERRUPTS);
 544         if (count < NR_IRQS)
 545                 irq_virq_count = count;
 546 }
 547
 548 /* radix tree not lockless safe ! we use a brlock-type mecanism
 549  * for now, until we can use a lockless radix tree
 550  */
 551 static void irq_radix_wrlock(unsigned long *flags)
 552 {
 553         unsigned int cpu, ok;
 554
 555         spin_lock_irqsave(&irq_big_lock, *flags);
 556         irq_radix_writer = 1;
 557         smp_mb();
 558         do {
 559                 barrier();
 560                 ok = 1;
 561                 for_each_possible_cpu(cpu) {
 562                         if (per_cpu(irq_radix_reader, cpu)) {
 563                                 ok = 0;
 564                                 break;
 565                         }
 566                 }
 567                 if (!ok)
 568                         cpu_relax();
 569         } while(!ok);
 570 }
 571
 572 static void irq_radix_wrunlock(unsigned long flags)
 573 {
 574         smp_wmb();
 575         irq_radix_writer = 0;
 576         spin_unlock_irqrestore(&irq_big_lock, flags);
 577 }
 578
 579 static void irq_radix_rdlock(unsigned long *flags)
 580 {
 581         local_irq_save(*flags);
 582         __get_cpu_var(irq_radix_reader) = 1;
 583         smp_mb();
 584         if (likely(irq_radix_writer == 0))
 585                 return;
 586         __get_cpu_var(irq_radix_reader) = 0;
 587         smp_wmb();
 588         spin_lock(&irq_big_lock);
 589         __get_cpu_var(irq_radix_reader) = 1;
 590         spin_unlock(&irq_big_lock);
 591 }
 592
 593 static void irq_radix_rdunlock(unsigned long flags)
 594 {
 595         __get_cpu_var(irq_radix_reader) = 0;
 596         local_irq_restore(flags);
 597 }
 598
 599 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 600                             irq_hw_number_t hwirq)
 601 {
 602         /* Clear IRQ_NOREQUEST flag */
 603         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 604
 605         /* map it */
 606         smp_wmb();
 607         irq_map[virq].hwirq = hwirq;
 608         smp_mb();
 609
 610         if (host->ops->map(host, virq, hwirq)) {
 611                 pr_debug("irq: -> mapping failed, freeing\n");
 612                 irq_free_virt(virq, 1);
 613                 return -1;
 614         }
 615
 616         return 0;
 617 }
 618
 619 unsigned int irq_create_mapping(struct irq_host *host,
 620                                 irq_hw_number_t hwirq)
 621 {
 622         unsigned int virq, hint;
 623
 624         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 625
 626         /* Look for default host if nececssary */
 627         if (host == NULL)
 628                 host = irq_default_host;
 629         if (host == NULL) {
 630                 printk(KERN_WARNING "irq_create_mapping called for"
 631                        " NULL host, hwirq=%lx\n", hwirq);
 632                 WARN_ON(1);
 633                 return NO_IRQ;
 634         }
 635         pr_debug("irq: -> using host @%p\n", host);
 636
 637         /* Check if mapping already exist, if it does, call
 638          * host->ops->map() to update the flags
 639          */
 640         virq = irq_find_mapping(host, hwirq);
 641         if (virq != NO_IRQ) {
 642                 if (host->ops->remap)
 643                         host->ops->remap(host, virq, hwirq);
 644                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 645                 return virq;
 646         }
 647
 648         /* Get a virtual interrupt number */
 649         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 650                 /* Handle legacy */
 651                 virq = (unsigned int)hwirq;
 652                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 653                         return NO_IRQ;
 654                 return virq;
 655         } else {
 656                 /* Allocate a virtual interrupt number */
 657                 hint = hwirq % irq_virq_count;
 658                 virq = irq_alloc_virt(host, 1, hint);
 659                 if (virq == NO_IRQ) {
 660                         pr_debug("irq: -> virq allocation failed\n");
 661                         return NO_IRQ;
 662                 }
 663         }
 664         pr_debug("irq: -> obtained virq %d\n", virq);
 665
 666         if (irq_setup_virq(host, virq, hwirq))
 667                 return NO_IRQ;
 668
 669         return virq;
 670 }
 671 EXPORT_SYMBOL_GPL(irq_create_mapping);
 672
 673 unsigned int irq_create_of_mapping(struct device_node *controller,
 674                                    u32 *intspec, unsigned int intsize)
 675 {
 676         struct irq_host *host;
 677         irq_hw_number_t hwirq;
 678         unsigned int type = IRQ_TYPE_NONE;
 679         unsigned int virq;
 680
 681         if (controller == NULL)
 682                 host = irq_default_host;
 683         else
 684                 host = irq_find_host(controller);
 685         if (host == NULL) {
 686                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 687                        controller->full_name);
 688                 return NO_IRQ;
 689         }
 690
 691         /* If host has no translation, then we assume interrupt line */
 692         if (host->ops->xlate == NULL)
 693                 hwirq = intspec[0];
 694         else {
 695                 if (host->ops->xlate(host, controller, intspec, intsize,
 696                                      &hwirq, &type))
 697                         return NO_IRQ;
 698         }
 699
 700         /* Create mapping */
 701         virq = irq_create_mapping(host, hwirq);
 702         if (virq == NO_IRQ)
 703                 return virq;
 704
 705         /* Set type if specified and different than the current one */
 706         if (type != IRQ_TYPE_NONE &&
 707             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 708                 set_irq_type(virq, type);
 709         return virq;
 710 }
 711 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 712
 713 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 714 {
 715         struct of_irq oirq;
 716
 717         if (of_irq_map_one(dev, index, &oirq))
 718                 return NO_IRQ;
 719
 720         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 721                                      oirq.size);
 722 }
 723 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 724
 725 void irq_dispose_mapping(unsigned int virq)
 726 {
 727         struct irq_host *host;
 728         irq_hw_number_t hwirq;
 729         unsigned long flags;
 730
 731         if (virq == NO_IRQ)
 732                 return;
 733
 734         host = irq_map[virq].host;
 735         WARN_ON (host == NULL);
 736         if (host == NULL)
 737                 return;
 738
 739         /* Never unmap legacy interrupts */
 740         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 741                 return;
 742
 743         /* remove chip and handler */
 744         set_irq_chip_and_handler(virq, NULL, NULL);
 745
 746         /* Make sure it's completed */
 747         synchronize_irq(virq);
 748
 749         /* Tell the PIC about it */
 750         if (host->ops->unmap)
 751                 host->ops->unmap(host, virq);
 752         smp_mb();
 753
 754         /* Clear reverse map */
 755         hwirq = irq_map[virq].hwirq;
 756         switch(host->revmap_type) {
 757         case IRQ_HOST_MAP_LINEAR:
 758                 if (hwirq < host->revmap_data.linear.size)
 759                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 760                 break;
 761         case IRQ_HOST_MAP_TREE:
 762                 /* Check if radix tree allocated yet */
 763                 if (host->revmap_data.tree.gfp_mask == 0)
 764                         break;
 765                 irq_radix_wrlock(&flags);
 766                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 767                 irq_radix_wrunlock(flags);
 768                 break;
 769         }
 770
 771         /* Destroy map */
 772         smp_mb();
 773         irq_map[virq].hwirq = host->inval_irq;
 774
 775         /* Set some flags */
 776         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 777
 778         /* Free it */
 779         irq_free_virt(virq, 1);
 780 }
 781 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 782
 783 unsigned int irq_find_mapping(struct irq_host *host,
 784                               irq_hw_number_t hwirq)
 785 {
 786         unsigned int i;
 787         unsigned int hint = hwirq % irq_virq_count;
 788
 789         /* Look for default host if nececssary */
 790         if (host == NULL)
 791                 host = irq_default_host;
 792         if (host == NULL)
 793                 return NO_IRQ;
 794
 795         /* legacy -> bail early */
 796         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 797                 return hwirq;
 798
 799         /* Slow path does a linear search of the map */
 800         if (hint < NUM_ISA_INTERRUPTS)
 801                 hint = NUM_ISA_INTERRUPTS;
 802         i = hint;
 803         do  {
 804                 if (irq_map[i].host == host &&
 805                     irq_map[i].hwirq == hwirq)
 806                         return i;
 807                 i++;
 808                 if (i >= irq_virq_count)
 809                         i = NUM_ISA_INTERRUPTS;
 810         } while(i != hint);
 811         return NO_IRQ;
 812 }
 813 EXPORT_SYMBOL_GPL(irq_find_mapping);
 814
 815
 816 unsigned int irq_radix_revmap(struct irq_host *host,
 817                               irq_hw_number_t hwirq)
 818 {
 819         struct radix_tree_root *tree;
 820         struct irq_map_entry *ptr;
 821         unsigned int virq;
 822         unsigned long flags;
 823
 824         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 825
 826         /* Check if the radix tree exist yet. We test the value of
 827          * the gfp_mask for that. Sneaky but saves another int in the
 828          * structure. If not, we fallback to slow mode
 829          */
 830         tree = &host->revmap_data.tree;
 831         if (tree->gfp_mask == 0)
 832                 return irq_find_mapping(host, hwirq);
 833
 834         /* Now try to resolve */
 835         irq_radix_rdlock(&flags);
 836         ptr = radix_tree_lookup(tree, hwirq);
 837         irq_radix_rdunlock(flags);
 838
 839         /* Found it, return */
 840         if (ptr) {
 841                 virq = ptr - irq_map;
 842                 return virq;
 843         }
 844
 845         /* If not there, try to insert it */
 846         virq = irq_find_mapping(host, hwirq);
 847         if (virq != NO_IRQ) {
 848                 irq_radix_wrlock(&flags);
 849                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 850                 irq_radix_wrunlock(flags);
 851         }
 852         return virq;
 853 }
 854
 855 unsigned int irq_linear_revmap(struct irq_host *host,
 856                                irq_hw_number_t hwirq)
 857 {
 858         unsigned int *revmap;
 859
 860         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 861
 862         /* Check revmap bounds */
 863         if (unlikely(hwirq >= host->revmap_data.linear.size))
 864                 return irq_find_mapping(host, hwirq);
 865
 866         /* Check if revmap was allocated */
 867         revmap = host->revmap_data.linear.revmap;
 868         if (unlikely(revmap == NULL))
 869                 return irq_find_mapping(host, hwirq);
 870
 871         /* Fill up revmap with slow path if no mapping found */
 872         if (unlikely(revmap[hwirq] == NO_IRQ))
 873                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 874
 875         return revmap[hwirq];
 876 }
 877
 878 unsigned int irq_alloc_virt(struct irq_host *host,
 879                             unsigned int count,
 880                             unsigned int hint)
 881 {
 882         unsigned long flags;
 883         unsigned int i, j, found = NO_IRQ;
 884
 885         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 886                 return NO_IRQ;
 887
 888         spin_lock_irqsave(&irq_big_lock, flags);
 889
 890         /* Use hint for 1 interrupt if any */
 891         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 892             hint < irq_virq_count && irq_map[hint].host == NULL) {
 893                 found = hint;
 894                 goto hint_found;
 895         }
 896
 897         /* Look for count consecutive numbers in the allocatable
 898          * (non-legacy) space
 899          */
 900         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 901                 if (irq_map[i].host != NULL)
 902                         j = 0;
 903                 else
 904                         j++;
 905
 906                 if (j == count) {
 907                         found = i - count + 1;
 908                         break;
 909                 }
 910         }
 911         if (found == NO_IRQ) {
 912                 spin_unlock_irqrestore(&irq_big_lock, flags);
 913                 return NO_IRQ;
 914         }
 915  hint_found:
 916         for (i = found; i < (found + count); i++) {
 917                 irq_map[i].hwirq = host->inval_irq;
 918                 smp_wmb();
 919                 irq_map[i].host = host;
 920         }
 921         spin_unlock_irqrestore(&irq_big_lock, flags);
 922         return found;
 923 }
 924
 925 void irq_free_virt(unsigned int virq, unsigned int count)
 926 {
 927         unsigned long flags;
 928         unsigned int i;
 929
 930         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 931         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 932
 933         spin_lock_irqsave(&irq_big_lock, flags);
 934         for (i = virq; i < (virq + count); i++) {
 935                 struct irq_host *host;
 936
 937                 if (i < NUM_ISA_INTERRUPTS ||
 938                     (virq + count) > irq_virq_count)
 939                         continue;
 940
 941                 host = irq_map[i].host;
 942                 irq_map[i].hwirq = host->inval_irq;
 943                 smp_wmb();
 944                 irq_map[i].host = NULL;
 945         }
 946         spin_unlock_irqrestore(&irq_big_lock, flags);
 947 }
 948
 949 void irq_early_init(void)
 950 {
 951         unsigned int i;
 952
 953         for (i = 0; i < NR_IRQS; i++)
 954                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 955 }
 956
 957 /* We need to create the radix trees late */
 958 static int irq_late_init(void)
 959 {
 960         struct irq_host *h;
 961         unsigned long flags;
 962
 963         irq_radix_wrlock(&flags);
 964         list_for_each_entry(h, &irq_hosts, link) {
 965                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
 966                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
 967         }
 968         irq_radix_wrunlock(flags);
 969
 970         return 0;
 971 }
 972 arch_initcall(irq_late_init);
 973
 974 #endif /* CONFIG_PPC_MERGE */
 975
 976 #ifdef CONFIG_PPC64
 977 static int __init setup_noirqdistrib(char *str)
 978 {
 979         distribute_irqs = 0;
 980         return 1;
 981 }
 982
 983 __setup("noirqdistrib", setup_noirqdistrib);
 984 #endif /* CONFIG_PPC64 */