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 #include <linux/debugfs.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 #include <asm/lv1call.h>
  71 #endif
  72
  73 int __irq_offset_value;
  74 static int ppc_spurious_interrupts;
  75
  76 #ifdef CONFIG_PPC32
  77 EXPORT_SYMBOL(__irq_offset_value);
  78 atomic_t ppc_n_lost_interrupts;
  79
  80 #ifndef CONFIG_PPC_MERGE
  81 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
  82 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
  83 #endif
  84
  85 #ifdef CONFIG_TAU_INT
  86 extern int tau_initialized;
  87 extern int tau_interrupts(int);
  88 #endif
  89 #endif /* CONFIG_PPC32 */
  90
  91 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
  92 extern atomic_t ipi_recv;
  93 extern atomic_t ipi_sent;
  94 #endif
  95
  96 #ifdef CONFIG_PPC64
  97 EXPORT_SYMBOL(irq_desc);
  98
  99 int distribute_irqs = 1;
 100
 101 static inline unsigned long get_hard_enabled(void)
 102 {
 103         unsigned long enabled;
 104
 105         __asm__ __volatile__("lbz %0,%1(13)"
 106         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 107
 108         return enabled;
 109 }
 110
 111 static inline void set_soft_enabled(unsigned long enable)
 112 {
 113         __asm__ __volatile__("stb %0,%1(13)"
 114         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 115 }
 116
 117 void local_irq_restore(unsigned long en)
 118 {
 119         /*
 120          * get_paca()->soft_enabled = en;
 121          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 122          * That was allowed before, and in such a case we do need to take care
 123          * that gcc will set soft_enabled directly via r13, not choose to use
 124          * an intermediate register, lest we're preempted to a different cpu.
 125          */
 126         set_soft_enabled(en);
 127         if (!en)
 128                 return;
 129
 130         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 131                 /*
 132                  * Do we need to disable preemption here?  Not really: in the
 133                  * unlikely event that we're preempted to a different cpu in
 134                  * between getting r13, loading its lppaca_ptr, and loading
 135                  * its any_int, we might call iseries_handle_interrupts without
 136                  * an interrupt pending on the new cpu, but that's no disaster,
 137                  * is it?  And the business of preempting us off the old cpu
 138                  * would itself involve a local_irq_restore which handles the
 139                  * interrupt to that cpu.
 140                  *
 141                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 142                  * to avoid any preemption checking added into get_paca().
 143                  */
 144                 if (local_paca->lppaca_ptr->int_dword.any_int)
 145                         iseries_handle_interrupts();
 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         if (ppc_md.init_IRQ)
 340                 ppc_md.init_IRQ();
 341 #ifdef CONFIG_PPC64
 342         irq_ctx_init();
 343 #endif
 344 }
 345
 346
 347 #ifdef CONFIG_IRQSTACKS
 348 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 349 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 350
 351 void irq_ctx_init(void)
 352 {
 353         struct thread_info *tp;
 354         int i;
 355
 356         for_each_possible_cpu(i) {
 357                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 358                 tp = softirq_ctx[i];
 359                 tp->cpu = i;
 360                 tp->preempt_count = SOFTIRQ_OFFSET;
 361
 362                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 363                 tp = hardirq_ctx[i];
 364                 tp->cpu = i;
 365                 tp->preempt_count = HARDIRQ_OFFSET;
 366         }
 367 }
 368
 369 static inline void do_softirq_onstack(void)
 370 {
 371         struct thread_info *curtp, *irqtp;
 372
 373         curtp = current_thread_info();
 374         irqtp = softirq_ctx[smp_processor_id()];
 375         irqtp->task = curtp->task;
 376         call_do_softirq(irqtp);
 377         irqtp->task = NULL;
 378 }
 379
 380 #else
 381 #define do_softirq_onstack()    __do_softirq()
 382 #endif /* CONFIG_IRQSTACKS */
 383
 384 void do_softirq(void)
 385 {
 386         unsigned long flags;
 387
 388         if (in_interrupt())
 389                 return;
 390
 391         local_irq_save(flags);
 392
 393         if (local_softirq_pending())
 394                 do_softirq_onstack();
 395
 396         local_irq_restore(flags);
 397 }
 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 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 421 {
 422         return h->of_node != NULL && h->of_node == np;
 423 }
 424
 425 struct irq_host *irq_alloc_host(struct device_node *of_node,
 426                                 unsigned int revmap_type,
 427                                 unsigned int revmap_arg,
 428                                 struct irq_host_ops *ops,
 429                                 irq_hw_number_t inval_irq)
 430 {
 431         struct irq_host *host;
 432         unsigned int size = sizeof(struct irq_host);
 433         unsigned int i;
 434         unsigned int *rmap;
 435         unsigned long flags;
 436
 437         /* Allocate structure and revmap table if using linear mapping */
 438         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 439                 size += revmap_arg * sizeof(unsigned int);
 440         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 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         host->of_node = of_node;
 449
 450         if (host->ops->match == NULL)
 451                 host->ops->match = default_irq_host_match;
 452
 453         spin_lock_irqsave(&irq_big_lock, flags);
 454
 455         /* If it's a legacy controller, check for duplicates and
 456          * mark it as allocated (we use irq 0 host pointer for that
 457          */
 458         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 459                 if (irq_map[0].host != NULL) {
 460                         spin_unlock_irqrestore(&irq_big_lock, flags);
 461                         /* If we are early boot, we can't free the structure,
 462                          * too bad...
 463                          * this will be fixed once slab is made available early
 464                          * instead of the current cruft
 465                          */
 466                         if (mem_init_done)
 467                                 kfree(host);
 468                         return NULL;
 469                 }
 470                 irq_map[0].host = host;
 471         }
 472
 473         list_add(&host->link, &irq_hosts);
 474         spin_unlock_irqrestore(&irq_big_lock, flags);
 475
 476         /* Additional setups per revmap type */
 477         switch(revmap_type) {
 478         case IRQ_HOST_MAP_LEGACY:
 479                 /* 0 is always the invalid number for legacy */
 480                 host->inval_irq = 0;
 481                 /* setup us as the host for all legacy interrupts */
 482                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 483                         irq_map[i].hwirq = i;
 484                         smp_wmb();
 485                         irq_map[i].host = host;
 486                         smp_wmb();
 487
 488                         /* Clear norequest flags */
 489                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 490
 491                         /* Legacy flags are left to default at this point,
 492                          * one can then use irq_create_mapping() to
 493                          * explicitly change them
 494                          */
 495                         ops->map(host, i, i);
 496                 }
 497                 break;
 498         case IRQ_HOST_MAP_LINEAR:
 499                 rmap = (unsigned int *)(host + 1);
 500                 for (i = 0; i < revmap_arg; i++)
 501                         rmap[i] = NO_IRQ;
 502                 host->revmap_data.linear.size = revmap_arg;
 503                 smp_wmb();
 504                 host->revmap_data.linear.revmap = rmap;
 505                 break;
 506         default:
 507                 break;
 508         }
 509
 510         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 511
 512         return host;
 513 }
 514
 515 struct irq_host *irq_find_host(struct device_node *node)
 516 {
 517         struct irq_host *h, *found = NULL;
 518         unsigned long flags;
 519
 520         /* We might want to match the legacy controller last since
 521          * it might potentially be set to match all interrupts in
 522          * the absence of a device node. This isn't a problem so far
 523          * yet though...
 524          */
 525         spin_lock_irqsave(&irq_big_lock, flags);
 526         list_for_each_entry(h, &irq_hosts, link)
 527                 if (h->ops->match(h, node)) {
 528                         found = h;
 529                         break;
 530                 }
 531         spin_unlock_irqrestore(&irq_big_lock, flags);
 532         return found;
 533 }
 534 EXPORT_SYMBOL_GPL(irq_find_host);
 535
 536 void irq_set_default_host(struct irq_host *host)
 537 {
 538         pr_debug("irq: Default host set to @0x%p\n", host);
 539
 540         irq_default_host = host;
 541 }
 542
 543 void irq_set_virq_count(unsigned int count)
 544 {
 545         pr_debug("irq: Trying to set virq count to %d\n", count);
 546
 547         BUG_ON(count < NUM_ISA_INTERRUPTS);
 548         if (count < NR_IRQS)
 549                 irq_virq_count = count;
 550 }
 551
 552 /* radix tree not lockless safe ! we use a brlock-type mecanism
 553  * for now, until we can use a lockless radix tree
 554  */
 555 static void irq_radix_wrlock(unsigned long *flags)
 556 {
 557         unsigned int cpu, ok;
 558
 559         spin_lock_irqsave(&irq_big_lock, *flags);
 560         irq_radix_writer = 1;
 561         smp_mb();
 562         do {
 563                 barrier();
 564                 ok = 1;
 565                 for_each_possible_cpu(cpu) {
 566                         if (per_cpu(irq_radix_reader, cpu)) {
 567                                 ok = 0;
 568                                 break;
 569                         }
 570                 }
 571                 if (!ok)
 572                         cpu_relax();
 573         } while(!ok);
 574 }
 575
 576 static void irq_radix_wrunlock(unsigned long flags)
 577 {
 578         smp_wmb();
 579         irq_radix_writer = 0;
 580         spin_unlock_irqrestore(&irq_big_lock, flags);
 581 }
 582
 583 static void irq_radix_rdlock(unsigned long *flags)
 584 {
 585         local_irq_save(*flags);
 586         __get_cpu_var(irq_radix_reader) = 1;
 587         smp_mb();
 588         if (likely(irq_radix_writer == 0))
 589                 return;
 590         __get_cpu_var(irq_radix_reader) = 0;
 591         smp_wmb();
 592         spin_lock(&irq_big_lock);
 593         __get_cpu_var(irq_radix_reader) = 1;
 594         spin_unlock(&irq_big_lock);
 595 }
 596
 597 static void irq_radix_rdunlock(unsigned long flags)
 598 {
 599         __get_cpu_var(irq_radix_reader) = 0;
 600         local_irq_restore(flags);
 601 }
 602
 603 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 604                             irq_hw_number_t hwirq)
 605 {
 606         /* Clear IRQ_NOREQUEST flag */
 607         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 608
 609         /* map it */
 610         smp_wmb();
 611         irq_map[virq].hwirq = hwirq;
 612         smp_mb();
 613
 614         if (host->ops->map(host, virq, hwirq)) {
 615                 pr_debug("irq: -> mapping failed, freeing\n");
 616                 irq_free_virt(virq, 1);
 617                 return -1;
 618         }
 619
 620         return 0;
 621 }
 622
 623 unsigned int irq_create_direct_mapping(struct irq_host *host)
 624 {
 625         unsigned int virq;
 626
 627         if (host == NULL)
 628                 host = irq_default_host;
 629
 630         BUG_ON(host == NULL);
 631         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 632
 633         virq = irq_alloc_virt(host, 1, 0);
 634         if (virq == NO_IRQ) {
 635                 pr_debug("irq: create_direct virq allocation failed\n");
 636                 return NO_IRQ;
 637         }
 638
 639         pr_debug("irq: create_direct obtained virq %d\n", virq);
 640
 641         if (irq_setup_virq(host, virq, virq))
 642                 return NO_IRQ;
 643
 644         return virq;
 645 }
 646
 647 unsigned int irq_create_mapping(struct irq_host *host,
 648                                 irq_hw_number_t hwirq)
 649 {
 650         unsigned int virq, hint;
 651
 652         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 653
 654         /* Look for default host if nececssary */
 655         if (host == NULL)
 656                 host = irq_default_host;
 657         if (host == NULL) {
 658                 printk(KERN_WARNING "irq_create_mapping called for"
 659                        " NULL host, hwirq=%lx\n", hwirq);
 660                 WARN_ON(1);
 661                 return NO_IRQ;
 662         }
 663         pr_debug("irq: -> using host @%p\n", host);
 664
 665         /* Check if mapping already exist, if it does, call
 666          * host->ops->map() to update the flags
 667          */
 668         virq = irq_find_mapping(host, hwirq);
 669         if (virq != NO_IRQ) {
 670                 if (host->ops->remap)
 671                         host->ops->remap(host, virq, hwirq);
 672                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 673                 return virq;
 674         }
 675
 676         /* Get a virtual interrupt number */
 677         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 678                 /* Handle legacy */
 679                 virq = (unsigned int)hwirq;
 680                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 681                         return NO_IRQ;
 682                 return virq;
 683         } else {
 684                 /* Allocate a virtual interrupt number */
 685                 hint = hwirq % irq_virq_count;
 686                 virq = irq_alloc_virt(host, 1, hint);
 687                 if (virq == NO_IRQ) {
 688                         pr_debug("irq: -> virq allocation failed\n");
 689                         return NO_IRQ;
 690                 }
 691         }
 692         pr_debug("irq: -> obtained virq %d\n", virq);
 693
 694         if (irq_setup_virq(host, virq, hwirq))
 695                 return NO_IRQ;
 696
 697         return virq;
 698 }
 699 EXPORT_SYMBOL_GPL(irq_create_mapping);
 700
 701 unsigned int irq_create_of_mapping(struct device_node *controller,
 702                                    u32 *intspec, unsigned int intsize)
 703 {
 704         struct irq_host *host;
 705         irq_hw_number_t hwirq;
 706         unsigned int type = IRQ_TYPE_NONE;
 707         unsigned int virq;
 708
 709         if (controller == NULL)
 710                 host = irq_default_host;
 711         else
 712                 host = irq_find_host(controller);
 713         if (host == NULL) {
 714                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 715                        controller->full_name);
 716                 return NO_IRQ;
 717         }
 718
 719         /* If host has no translation, then we assume interrupt line */
 720         if (host->ops->xlate == NULL)
 721                 hwirq = intspec[0];
 722         else {
 723                 if (host->ops->xlate(host, controller, intspec, intsize,
 724                                      &hwirq, &type))
 725                         return NO_IRQ;
 726         }
 727
 728         /* Create mapping */
 729         virq = irq_create_mapping(host, hwirq);
 730         if (virq == NO_IRQ)
 731                 return virq;
 732
 733         /* Set type if specified and different than the current one */
 734         if (type != IRQ_TYPE_NONE &&
 735             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 736                 set_irq_type(virq, type);
 737         return virq;
 738 }
 739 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 740
 741 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 742 {
 743         struct of_irq oirq;
 744
 745         if (of_irq_map_one(dev, index, &oirq))
 746                 return NO_IRQ;
 747
 748         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 749                                      oirq.size);
 750 }
 751 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 752
 753 void irq_dispose_mapping(unsigned int virq)
 754 {
 755         struct irq_host *host;
 756         irq_hw_number_t hwirq;
 757         unsigned long flags;
 758
 759         if (virq == NO_IRQ)
 760                 return;
 761
 762         host = irq_map[virq].host;
 763         WARN_ON (host == NULL);
 764         if (host == NULL)
 765                 return;
 766
 767         /* Never unmap legacy interrupts */
 768         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 769                 return;
 770
 771         /* remove chip and handler */
 772         set_irq_chip_and_handler(virq, NULL, NULL);
 773
 774         /* Make sure it's completed */
 775         synchronize_irq(virq);
 776
 777         /* Tell the PIC about it */
 778         if (host->ops->unmap)
 779                 host->ops->unmap(host, virq);
 780         smp_mb();
 781
 782         /* Clear reverse map */
 783         hwirq = irq_map[virq].hwirq;
 784         switch(host->revmap_type) {
 785         case IRQ_HOST_MAP_LINEAR:
 786                 if (hwirq < host->revmap_data.linear.size)
 787                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 788                 break;
 789         case IRQ_HOST_MAP_TREE:
 790                 /* Check if radix tree allocated yet */
 791                 if (host->revmap_data.tree.gfp_mask == 0)
 792                         break;
 793                 irq_radix_wrlock(&flags);
 794                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 795                 irq_radix_wrunlock(flags);
 796                 break;
 797         }
 798
 799         /* Destroy map */
 800         smp_mb();
 801         irq_map[virq].hwirq = host->inval_irq;
 802
 803         /* Set some flags */
 804         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 805
 806         /* Free it */
 807         irq_free_virt(virq, 1);
 808 }
 809 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 810
 811 unsigned int irq_find_mapping(struct irq_host *host,
 812                               irq_hw_number_t hwirq)
 813 {
 814         unsigned int i;
 815         unsigned int hint = hwirq % irq_virq_count;
 816
 817         /* Look for default host if nececssary */
 818         if (host == NULL)
 819                 host = irq_default_host;
 820         if (host == NULL)
 821                 return NO_IRQ;
 822
 823         /* legacy -> bail early */
 824         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 825                 return hwirq;
 826
 827         /* Slow path does a linear search of the map */
 828         if (hint < NUM_ISA_INTERRUPTS)
 829                 hint = NUM_ISA_INTERRUPTS;
 830         i = hint;
 831         do  {
 832                 if (irq_map[i].host == host &&
 833                     irq_map[i].hwirq == hwirq)
 834                         return i;
 835                 i++;
 836                 if (i >= irq_virq_count)
 837                         i = NUM_ISA_INTERRUPTS;
 838         } while(i != hint);
 839         return NO_IRQ;
 840 }
 841 EXPORT_SYMBOL_GPL(irq_find_mapping);
 842
 843
 844 unsigned int irq_radix_revmap(struct irq_host *host,
 845                               irq_hw_number_t hwirq)
 846 {
 847         struct radix_tree_root *tree;
 848         struct irq_map_entry *ptr;
 849         unsigned int virq;
 850         unsigned long flags;
 851
 852         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 853
 854         /* Check if the radix tree exist yet. We test the value of
 855          * the gfp_mask for that. Sneaky but saves another int in the
 856          * structure. If not, we fallback to slow mode
 857          */
 858         tree = &host->revmap_data.tree;
 859         if (tree->gfp_mask == 0)
 860                 return irq_find_mapping(host, hwirq);
 861
 862         /* Now try to resolve */
 863         irq_radix_rdlock(&flags);
 864         ptr = radix_tree_lookup(tree, hwirq);
 865         irq_radix_rdunlock(flags);
 866
 867         /* Found it, return */
 868         if (ptr) {
 869                 virq = ptr - irq_map;
 870                 return virq;
 871         }
 872
 873         /* If not there, try to insert it */
 874         virq = irq_find_mapping(host, hwirq);
 875         if (virq != NO_IRQ) {
 876                 irq_radix_wrlock(&flags);
 877                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 878                 irq_radix_wrunlock(flags);
 879         }
 880         return virq;
 881 }
 882
 883 unsigned int irq_linear_revmap(struct irq_host *host,
 884                                irq_hw_number_t hwirq)
 885 {
 886         unsigned int *revmap;
 887
 888         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 889
 890         /* Check revmap bounds */
 891         if (unlikely(hwirq >= host->revmap_data.linear.size))
 892                 return irq_find_mapping(host, hwirq);
 893
 894         /* Check if revmap was allocated */
 895         revmap = host->revmap_data.linear.revmap;
 896         if (unlikely(revmap == NULL))
 897                 return irq_find_mapping(host, hwirq);
 898
 899         /* Fill up revmap with slow path if no mapping found */
 900         if (unlikely(revmap[hwirq] == NO_IRQ))
 901                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 902
 903         return revmap[hwirq];
 904 }
 905
 906 unsigned int irq_alloc_virt(struct irq_host *host,
 907                             unsigned int count,
 908                             unsigned int hint)
 909 {
 910         unsigned long flags;
 911         unsigned int i, j, found = NO_IRQ;
 912
 913         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 914                 return NO_IRQ;
 915
 916         spin_lock_irqsave(&irq_big_lock, flags);
 917
 918         /* Use hint for 1 interrupt if any */
 919         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 920             hint < irq_virq_count && irq_map[hint].host == NULL) {
 921                 found = hint;
 922                 goto hint_found;
 923         }
 924
 925         /* Look for count consecutive numbers in the allocatable
 926          * (non-legacy) space
 927          */
 928         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 929                 if (irq_map[i].host != NULL)
 930                         j = 0;
 931                 else
 932                         j++;
 933
 934                 if (j == count) {
 935                         found = i - count + 1;
 936                         break;
 937                 }
 938         }
 939         if (found == NO_IRQ) {
 940                 spin_unlock_irqrestore(&irq_big_lock, flags);
 941                 return NO_IRQ;
 942         }
 943  hint_found:
 944         for (i = found; i < (found + count); i++) {
 945                 irq_map[i].hwirq = host->inval_irq;
 946                 smp_wmb();
 947                 irq_map[i].host = host;
 948         }
 949         spin_unlock_irqrestore(&irq_big_lock, flags);
 950         return found;
 951 }
 952
 953 void irq_free_virt(unsigned int virq, unsigned int count)
 954 {
 955         unsigned long flags;
 956         unsigned int i;
 957
 958         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 959         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 960
 961         spin_lock_irqsave(&irq_big_lock, flags);
 962         for (i = virq; i < (virq + count); i++) {
 963                 struct irq_host *host;
 964
 965                 if (i < NUM_ISA_INTERRUPTS ||
 966                     (virq + count) > irq_virq_count)
 967                         continue;
 968
 969                 host = irq_map[i].host;
 970                 irq_map[i].hwirq = host->inval_irq;
 971                 smp_wmb();
 972                 irq_map[i].host = NULL;
 973         }
 974         spin_unlock_irqrestore(&irq_big_lock, flags);
 975 }
 976
 977 void irq_early_init(void)
 978 {
 979         unsigned int i;
 980
 981         for (i = 0; i < NR_IRQS; i++)
 982                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 983 }
 984
 985 /* We need to create the radix trees late */
 986 static int irq_late_init(void)
 987 {
 988         struct irq_host *h;
 989         unsigned long flags;
 990
 991         irq_radix_wrlock(&flags);
 992         list_for_each_entry(h, &irq_hosts, link) {
 993                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
 994                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
 995         }
 996         irq_radix_wrunlock(flags);
 997
 998         return 0;
 999 }
1000 arch_initcall(irq_late_init);
1001
1002 #ifdef CONFIG_VIRQ_DEBUG
1003 static int virq_debug_show(struct seq_file *m, void *private)
1004 {
1005         unsigned long flags;
1006         irq_desc_t *desc;
1007         const char *p;
1008         char none[] = "none";
1009         int i;
1010
1011         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1012                       "chip name", "host name");
1013
1014         for (i = 1; i < NR_IRQS; i++) {
1015                 desc = get_irq_desc(i);
1016                 spin_lock_irqsave(&desc->lock, flags);
1017
1018                 if (desc->action && desc->action->handler) {
1019                         seq_printf(m, "%5d  ", i);
1020                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1021
1022                         if (desc->chip && desc->chip->typename)
1023                                 p = desc->chip->typename;
1024                         else
1025                                 p = none;
1026                         seq_printf(m, "%-15s  ", p);
1027
1028                         if (irq_map[i].host && irq_map[i].host->of_node)
1029                                 p = irq_map[i].host->of_node->full_name;
1030                         else
1031                                 p = none;
1032                         seq_printf(m, "%s\n", p);
1033                 }
1034
1035                 spin_unlock_irqrestore(&desc->lock, flags);
1036         }
1037
1038         return 0;
1039 }
1040
1041 static int virq_debug_open(struct inode *inode, struct file *file)
1042 {
1043         return single_open(file, virq_debug_show, inode->i_private);
1044 }
1045
1046 static const struct file_operations virq_debug_fops = {
1047         .open = virq_debug_open,
1048         .read = seq_read,
1049         .llseek = seq_lseek,
1050         .release = single_release,
1051 };
1052
1053 static int __init irq_debugfs_init(void)
1054 {
1055         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1056                                  NULL, &virq_debug_fops))
1057                 return -ENOMEM;
1058
1059         return 0;
1060 }
1061 __initcall(irq_debugfs_init);
1062 #endif /* CONFIG_VIRQ_DEBUG */
1063
1064 #endif /* CONFIG_PPC_MERGE */
1065
1066 #ifdef CONFIG_PPC64
1067 static int __init setup_noirqdistrib(char *str)
1068 {
1069         distribute_irqs = 0;
1070         return 1;
1071 }
1072
1073 __setup("noirqdistrib", setup_noirqdistrib);
1074 #endif /* CONFIG_PPC64 */