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   1 /*
   2  *  Derived from arch/i386/kernel/irq.c
   3  *    Copyright (C) 1992 Linus Torvalds
   4  *  Adapted from arch/i386 by Gary Thomas
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
   7  *    Copyright (C) 1996-2001 Cort Dougan
   8  *  Adapted for Power Macintosh by Paul Mackerras
   9  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
  10  *
  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 #include <linux/perf_counter.h>
  57
  58 #include <asm/uaccess.h>
  59 #include <asm/system.h>
  60 #include <asm/io.h>
  61 #include <asm/pgtable.h>
  62 #include <asm/irq.h>
  63 #include <asm/cache.h>
  64 #include <asm/prom.h>
  65 #include <asm/ptrace.h>
  66 #include <asm/machdep.h>
  67 #include <asm/udbg.h>
  68 #ifdef CONFIG_PPC64
  69 #include <asm/paca.h>
  70 #include <asm/firmware.h>
  71 #include <asm/lv1call.h>
  72 #endif
  73
  74 int __irq_offset_value;
  75 static int ppc_spurious_interrupts;
  76
  77 #ifdef CONFIG_PPC32
  78 EXPORT_SYMBOL(__irq_offset_value);
  79 atomic_t ppc_n_lost_interrupts;
  80
  81 #ifdef CONFIG_TAU_INT
  82 extern int tau_initialized;
  83 extern int tau_interrupts(int);
  84 #endif
  85 #endif /* CONFIG_PPC32 */
  86
  87 #ifdef CONFIG_PPC64
  88 EXPORT_SYMBOL(irq_desc);
  89
  90 int distribute_irqs = 1;
  91
  92 static inline notrace unsigned long get_hard_enabled(void)
  93 {
  94         unsigned long enabled;
  95
  96         __asm__ __volatile__("lbz %0,%1(13)"
  97         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
  98
  99         return enabled;
 100 }
 101
 102 static inline notrace void set_soft_enabled(unsigned long enable)
 103 {
 104         __asm__ __volatile__("stb %0,%1(13)"
 105         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 106 }
 107
 108 notrace void raw_local_irq_restore(unsigned long en)
 109 {
 110         /*
 111          * get_paca()->soft_enabled = en;
 112          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 113          * That was allowed before, and in such a case we do need to take care
 114          * that gcc will set soft_enabled directly via r13, not choose to use
 115          * an intermediate register, lest we're preempted to a different cpu.
 116          */
 117         set_soft_enabled(en);
 118         if (!en)
 119                 return;
 120
 121         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 122                 /*
 123                  * Do we need to disable preemption here?  Not really: in the
 124                  * unlikely event that we're preempted to a different cpu in
 125                  * between getting r13, loading its lppaca_ptr, and loading
 126                  * its any_int, we might call iseries_handle_interrupts without
 127                  * an interrupt pending on the new cpu, but that's no disaster,
 128                  * is it?  And the business of preempting us off the old cpu
 129                  * would itself involve a local_irq_restore which handles the
 130                  * interrupt to that cpu.
 131                  *
 132                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 133                  * to avoid any preemption checking added into get_paca().
 134                  */
 135                 if (local_paca->lppaca_ptr->int_dword.any_int)
 136                         iseries_handle_interrupts();
 137         }
 138
 139         if (test_perf_counter_pending()) {
 140                 clear_perf_counter_pending();
 141                 perf_counter_do_pending();
 142         }
 143
 144         /*
 145          * if (get_paca()->hard_enabled) return;
 146          * But again we need to take care that gcc gets hard_enabled directly
 147          * via r13, not choose to use an intermediate register, lest we're
 148          * preempted to a different cpu in between the two instructions.
 149          */
 150         if (get_hard_enabled())
 151                 return;
 152
 153         /*
 154          * Need to hard-enable interrupts here.  Since currently disabled,
 155          * no need to take further asm precautions against preemption; but
 156          * use local_paca instead of get_paca() to avoid preemption checking.
 157          */
 158         local_paca->hard_enabled = en;
 159         if ((int)mfspr(SPRN_DEC) < 0)
 160                 mtspr(SPRN_DEC, 1);
 161
 162         /*
 163          * Force the delivery of pending soft-disabled interrupts on PS3.
 164          * Any HV call will have this side effect.
 165          */
 166         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 167                 u64 tmp;
 168                 lv1_get_version_info(&tmp);
 169         }
 170
 171         __hard_irq_enable();
 172 }
 173 EXPORT_SYMBOL(raw_local_irq_restore);
 174 #endif /* CONFIG_PPC64 */
 175
 176 int show_interrupts(struct seq_file *p, void *v)
 177 {
 178         int i = *(loff_t *)v, j;
 179         struct irqaction *action;
 180         struct irq_desc *desc;
 181         unsigned long flags;
 182
 183         if (i == 0) {
 184                 seq_puts(p, "           ");
 185                 for_each_online_cpu(j)
 186                         seq_printf(p, "CPU%d       ", j);
 187                 seq_putc(p, '\n');
 188         }
 189
 190         if (i < NR_IRQS) {
 191                 desc = get_irq_desc(i);
 192                 spin_lock_irqsave(&desc->lock, flags);
 193                 action = desc->action;
 194                 if (!action || !action->handler)
 195                         goto skip;
 196                 seq_printf(p, "%3d: ", i);
 197 #ifdef CONFIG_SMP
 198                 for_each_online_cpu(j)
 199                         seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 200 #else
 201                 seq_printf(p, "%10u ", kstat_irqs(i));
 202 #endif /* CONFIG_SMP */
 203                 if (desc->chip)
 204                         seq_printf(p, " %s ", desc->chip->typename);
 205                 else
 206                         seq_puts(p, "  None      ");
 207                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 208                 seq_printf(p, "    %s", action->name);
 209                 for (action = action->next; action; action = action->next)
 210                         seq_printf(p, ", %s", action->name);
 211                 seq_putc(p, '\n');
 212 skip:
 213                 spin_unlock_irqrestore(&desc->lock, flags);
 214         } else if (i == NR_IRQS) {
 215 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 216                 if (tau_initialized){
 217                         seq_puts(p, "TAU: ");
 218                         for_each_online_cpu(j)
 219                                 seq_printf(p, "%10u ", tau_interrupts(j));
 220                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 221                 }
 222 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT*/
 223                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 224         }
 225         return 0;
 226 }
 227
 228 #ifdef CONFIG_HOTPLUG_CPU
 229 void fixup_irqs(cpumask_t map)
 230 {
 231         unsigned int irq;
 232         static int warned;
 233
 234         for_each_irq(irq) {
 235                 cpumask_t mask;
 236
 237                 if (irq_desc[irq].status & IRQ_PER_CPU)
 238                         continue;
 239
 240                 cpumask_and(&mask, irq_desc[irq].affinity, &map);
 241                 if (any_online_cpu(mask) == NR_CPUS) {
 242                         printk("Breaking affinity for irq %i\n", irq);
 243                         mask = map;
 244                 }
 245                 if (irq_desc[irq].chip->set_affinity)
 246                         irq_desc[irq].chip->set_affinity(irq, &mask);
 247                 else if (irq_desc[irq].action && !(warned++))
 248                         printk("Cannot set affinity for irq %i\n", irq);
 249         }
 250
 251         local_irq_enable();
 252         mdelay(1);
 253         local_irq_disable();
 254 }
 255 #endif
 256
 257 void do_IRQ(struct pt_regs *regs)
 258 {
 259         struct pt_regs *old_regs = set_irq_regs(regs);
 260         unsigned int irq;
 261 #ifdef CONFIG_IRQSTACKS
 262         struct thread_info *curtp, *irqtp;
 263 #endif
 264
 265         irq_enter();
 266
 267 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 268         /* Debugging check for stack overflow: is there less than 2KB free? */
 269         {
 270                 long sp;
 271
 272                 sp = __get_SP() & (THREAD_SIZE-1);
 273
 274                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 275                         printk("do_IRQ: stack overflow: %ld\n",
 276                                 sp - sizeof(struct thread_info));
 277                         dump_stack();
 278                 }
 279         }
 280 #endif
 281
 282         /*
 283          * Every platform is required to implement ppc_md.get_irq.
 284          * This function will either return an irq number or NO_IRQ to
 285          * indicate there are no more pending.
 286          * The value NO_IRQ_IGNORE is for buggy hardware and means that this
 287          * IRQ has already been handled. -- Tom
 288          */
 289         irq = ppc_md.get_irq();
 290
 291         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
 292 #ifdef CONFIG_IRQSTACKS
 293                 /* Switch to the irq stack to handle this */
 294                 curtp = current_thread_info();
 295                 irqtp = hardirq_ctx[smp_processor_id()];
 296                 if (curtp != irqtp) {
 297                         struct irq_desc *desc = irq_desc + irq;
 298                         void *handler = desc->handle_irq;
 299                         unsigned long saved_sp_limit = current->thread.ksp_limit;
 300                         if (handler == NULL)
 301                                 handler = &__do_IRQ;
 302                         irqtp->task = curtp->task;
 303                         irqtp->flags = 0;
 304
 305                         /* Copy the softirq bits in preempt_count so that the
 306                          * softirq checks work in the hardirq context.
 307                          */
 308                         irqtp->preempt_count =
 309                                 (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 310                                 (curtp->preempt_count & SOFTIRQ_MASK);
 311
 312                         current->thread.ksp_limit = (unsigned long)irqtp +
 313                                 _ALIGN_UP(sizeof(struct thread_info), 16);
 314                         call_handle_irq(irq, desc, irqtp, handler);
 315                         current->thread.ksp_limit = saved_sp_limit;
 316                         irqtp->task = NULL;
 317
 318
 319                         /* Set any flag that may have been set on the
 320                          * alternate stack
 321                          */
 322                         if (irqtp->flags)
 323                                 set_bits(irqtp->flags, &curtp->flags);
 324                 } else
 325 #endif
 326                         generic_handle_irq(irq);
 327         } else if (irq != NO_IRQ_IGNORE)
 328                 /* That's not SMP safe ... but who cares ? */
 329                 ppc_spurious_interrupts++;
 330
 331         irq_exit();
 332         set_irq_regs(old_regs);
 333
 334 #ifdef CONFIG_PPC_ISERIES
 335         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 336                         get_lppaca()->int_dword.fields.decr_int) {
 337                 get_lppaca()->int_dword.fields.decr_int = 0;
 338                 /* Signal a fake decrementer interrupt */
 339                 timer_interrupt(regs);
 340         }
 341 #endif
 342 }
 343
 344 void __init init_IRQ(void)
 345 {
 346         if (ppc_md.init_IRQ)
 347                 ppc_md.init_IRQ();
 348
 349         exc_lvl_ctx_init();
 350
 351         irq_ctx_init();
 352 }
 353
 354 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 355 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 356 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 357 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 358
 359 void exc_lvl_ctx_init(void)
 360 {
 361         struct thread_info *tp;
 362         int i;
 363
 364         for_each_possible_cpu(i) {
 365                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 366                 tp = critirq_ctx[i];
 367                 tp->cpu = i;
 368                 tp->preempt_count = 0;
 369
 370 #ifdef CONFIG_BOOKE
 371                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 372                 tp = dbgirq_ctx[i];
 373                 tp->cpu = i;
 374                 tp->preempt_count = 0;
 375
 376                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 377                 tp = mcheckirq_ctx[i];
 378                 tp->cpu = i;
 379                 tp->preempt_count = HARDIRQ_OFFSET;
 380 #endif
 381         }
 382 }
 383 #endif
 384
 385 #ifdef CONFIG_IRQSTACKS
 386 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 387 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 388
 389 void irq_ctx_init(void)
 390 {
 391         struct thread_info *tp;
 392         int i;
 393
 394         for_each_possible_cpu(i) {
 395                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 396                 tp = softirq_ctx[i];
 397                 tp->cpu = i;
 398                 tp->preempt_count = 0;
 399
 400                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 401                 tp = hardirq_ctx[i];
 402                 tp->cpu = i;
 403                 tp->preempt_count = HARDIRQ_OFFSET;
 404         }
 405 }
 406
 407 static inline void do_softirq_onstack(void)
 408 {
 409         struct thread_info *curtp, *irqtp;
 410         unsigned long saved_sp_limit = current->thread.ksp_limit;
 411
 412         curtp = current_thread_info();
 413         irqtp = softirq_ctx[smp_processor_id()];
 414         irqtp->task = curtp->task;
 415         current->thread.ksp_limit = (unsigned long)irqtp +
 416                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 417         call_do_softirq(irqtp);
 418         current->thread.ksp_limit = saved_sp_limit;
 419         irqtp->task = NULL;
 420 }
 421
 422 #else
 423 #define do_softirq_onstack()    __do_softirq()
 424 #endif /* CONFIG_IRQSTACKS */
 425
 426 void do_softirq(void)
 427 {
 428         unsigned long flags;
 429
 430         if (in_interrupt())
 431                 return;
 432
 433         local_irq_save(flags);
 434
 435         if (local_softirq_pending())
 436                 do_softirq_onstack();
 437
 438         local_irq_restore(flags);
 439 }
 440
 441
 442 /*
 443  * IRQ controller and virtual interrupts
 444  */
 445
 446 static LIST_HEAD(irq_hosts);
 447 static DEFINE_SPINLOCK(irq_big_lock);
 448 static unsigned int revmap_trees_allocated;
 449 static DEFINE_MUTEX(revmap_trees_mutex);
 450 struct irq_map_entry irq_map[NR_IRQS];
 451 static unsigned int irq_virq_count = NR_IRQS;
 452 static struct irq_host *irq_default_host;
 453
 454 irq_hw_number_t virq_to_hw(unsigned int virq)
 455 {
 456         return irq_map[virq].hwirq;
 457 }
 458 EXPORT_SYMBOL_GPL(virq_to_hw);
 459
 460 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 461 {
 462         return h->of_node != NULL && h->of_node == np;
 463 }
 464
 465 struct irq_host *irq_alloc_host(struct device_node *of_node,
 466                                 unsigned int revmap_type,
 467                                 unsigned int revmap_arg,
 468                                 struct irq_host_ops *ops,
 469                                 irq_hw_number_t inval_irq)
 470 {
 471         struct irq_host *host;
 472         unsigned int size = sizeof(struct irq_host);
 473         unsigned int i;
 474         unsigned int *rmap;
 475         unsigned long flags;
 476
 477         /* Allocate structure and revmap table if using linear mapping */
 478         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 479                 size += revmap_arg * sizeof(unsigned int);
 480         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 481         if (host == NULL)
 482                 return NULL;
 483
 484         /* Fill structure */
 485         host->revmap_type = revmap_type;
 486         host->inval_irq = inval_irq;
 487         host->ops = ops;
 488         host->of_node = of_node_get(of_node);
 489
 490         if (host->ops->match == NULL)
 491                 host->ops->match = default_irq_host_match;
 492
 493         spin_lock_irqsave(&irq_big_lock, flags);
 494
 495         /* If it's a legacy controller, check for duplicates and
 496          * mark it as allocated (we use irq 0 host pointer for that
 497          */
 498         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 499                 if (irq_map[0].host != NULL) {
 500                         spin_unlock_irqrestore(&irq_big_lock, flags);
 501                         /* If we are early boot, we can't free the structure,
 502                          * too bad...
 503                          * this will be fixed once slab is made available early
 504                          * instead of the current cruft
 505                          */
 506                         if (mem_init_done)
 507                                 kfree(host);
 508                         return NULL;
 509                 }
 510                 irq_map[0].host = host;
 511         }
 512
 513         list_add(&host->link, &irq_hosts);
 514         spin_unlock_irqrestore(&irq_big_lock, flags);
 515
 516         /* Additional setups per revmap type */
 517         switch(revmap_type) {
 518         case IRQ_HOST_MAP_LEGACY:
 519                 /* 0 is always the invalid number for legacy */
 520                 host->inval_irq = 0;
 521                 /* setup us as the host for all legacy interrupts */
 522                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 523                         irq_map[i].hwirq = i;
 524                         smp_wmb();
 525                         irq_map[i].host = host;
 526                         smp_wmb();
 527
 528                         /* Clear norequest flags */
 529                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 530
 531                         /* Legacy flags are left to default at this point,
 532                          * one can then use irq_create_mapping() to
 533                          * explicitly change them
 534                          */
 535                         ops->map(host, i, i);
 536                 }
 537                 break;
 538         case IRQ_HOST_MAP_LINEAR:
 539                 rmap = (unsigned int *)(host + 1);
 540                 for (i = 0; i < revmap_arg; i++)
 541                         rmap[i] = NO_IRQ;
 542                 host->revmap_data.linear.size = revmap_arg;
 543                 smp_wmb();
 544                 host->revmap_data.linear.revmap = rmap;
 545                 break;
 546         default:
 547                 break;
 548         }
 549
 550         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 551
 552         return host;
 553 }
 554
 555 struct irq_host *irq_find_host(struct device_node *node)
 556 {
 557         struct irq_host *h, *found = NULL;
 558         unsigned long flags;
 559
 560         /* We might want to match the legacy controller last since
 561          * it might potentially be set to match all interrupts in
 562          * the absence of a device node. This isn't a problem so far
 563          * yet though...
 564          */
 565         spin_lock_irqsave(&irq_big_lock, flags);
 566         list_for_each_entry(h, &irq_hosts, link)
 567                 if (h->ops->match(h, node)) {
 568                         found = h;
 569                         break;
 570                 }
 571         spin_unlock_irqrestore(&irq_big_lock, flags);
 572         return found;
 573 }
 574 EXPORT_SYMBOL_GPL(irq_find_host);
 575
 576 void irq_set_default_host(struct irq_host *host)
 577 {
 578         pr_debug("irq: Default host set to @0x%p\n", host);
 579
 580         irq_default_host = host;
 581 }
 582
 583 void irq_set_virq_count(unsigned int count)
 584 {
 585         pr_debug("irq: Trying to set virq count to %d\n", count);
 586
 587         BUG_ON(count < NUM_ISA_INTERRUPTS);
 588         if (count < NR_IRQS)
 589                 irq_virq_count = count;
 590 }
 591
 592 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 593                             irq_hw_number_t hwirq)
 594 {
 595         /* Clear IRQ_NOREQUEST flag */
 596         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 597
 598         /* map it */
 599         smp_wmb();
 600         irq_map[virq].hwirq = hwirq;
 601         smp_mb();
 602
 603         if (host->ops->map(host, virq, hwirq)) {
 604                 pr_debug("irq: -> mapping failed, freeing\n");
 605                 irq_free_virt(virq, 1);
 606                 return -1;
 607         }
 608
 609         return 0;
 610 }
 611
 612 unsigned int irq_create_direct_mapping(struct irq_host *host)
 613 {
 614         unsigned int virq;
 615
 616         if (host == NULL)
 617                 host = irq_default_host;
 618
 619         BUG_ON(host == NULL);
 620         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 621
 622         virq = irq_alloc_virt(host, 1, 0);
 623         if (virq == NO_IRQ) {
 624                 pr_debug("irq: create_direct virq allocation failed\n");
 625                 return NO_IRQ;
 626         }
 627
 628         pr_debug("irq: create_direct obtained virq %d\n", virq);
 629
 630         if (irq_setup_virq(host, virq, virq))
 631                 return NO_IRQ;
 632
 633         return virq;
 634 }
 635
 636 unsigned int irq_create_mapping(struct irq_host *host,
 637                                 irq_hw_number_t hwirq)
 638 {
 639         unsigned int virq, hint;
 640
 641         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 642
 643         /* Look for default host if nececssary */
 644         if (host == NULL)
 645                 host = irq_default_host;
 646         if (host == NULL) {
 647                 printk(KERN_WARNING "irq_create_mapping called for"
 648                        " NULL host, hwirq=%lx\n", hwirq);
 649                 WARN_ON(1);
 650                 return NO_IRQ;
 651         }
 652         pr_debug("irq: -> using host @%p\n", host);
 653
 654         /* Check if mapping already exist, if it does, call
 655          * host->ops->map() to update the flags
 656          */
 657         virq = irq_find_mapping(host, hwirq);
 658         if (virq != NO_IRQ) {
 659                 if (host->ops->remap)
 660                         host->ops->remap(host, virq, hwirq);
 661                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 662                 return virq;
 663         }
 664
 665         /* Get a virtual interrupt number */
 666         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 667                 /* Handle legacy */
 668                 virq = (unsigned int)hwirq;
 669                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 670                         return NO_IRQ;
 671                 return virq;
 672         } else {
 673                 /* Allocate a virtual interrupt number */
 674                 hint = hwirq % irq_virq_count;
 675                 virq = irq_alloc_virt(host, 1, hint);
 676                 if (virq == NO_IRQ) {
 677                         pr_debug("irq: -> virq allocation failed\n");
 678                         return NO_IRQ;
 679                 }
 680         }
 681
 682         if (irq_setup_virq(host, virq, hwirq))
 683                 return NO_IRQ;
 684
 685         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 686                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 687
 688         return virq;
 689 }
 690 EXPORT_SYMBOL_GPL(irq_create_mapping);
 691
 692 unsigned int irq_create_of_mapping(struct device_node *controller,
 693                                    u32 *intspec, unsigned int intsize)
 694 {
 695         struct irq_host *host;
 696         irq_hw_number_t hwirq;
 697         unsigned int type = IRQ_TYPE_NONE;
 698         unsigned int virq;
 699
 700         if (controller == NULL)
 701                 host = irq_default_host;
 702         else
 703                 host = irq_find_host(controller);
 704         if (host == NULL) {
 705                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 706                        controller->full_name);
 707                 return NO_IRQ;
 708         }
 709
 710         /* If host has no translation, then we assume interrupt line */
 711         if (host->ops->xlate == NULL)
 712                 hwirq = intspec[0];
 713         else {
 714                 if (host->ops->xlate(host, controller, intspec, intsize,
 715                                      &hwirq, &type))
 716                         return NO_IRQ;
 717         }
 718
 719         /* Create mapping */
 720         virq = irq_create_mapping(host, hwirq);
 721         if (virq == NO_IRQ)
 722                 return virq;
 723
 724         /* Set type if specified and different than the current one */
 725         if (type != IRQ_TYPE_NONE &&
 726             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 727                 set_irq_type(virq, type);
 728         return virq;
 729 }
 730 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 731
 732 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 733 {
 734         struct of_irq oirq;
 735
 736         if (of_irq_map_one(dev, index, &oirq))
 737                 return NO_IRQ;
 738
 739         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 740                                      oirq.size);
 741 }
 742 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 743
 744 void irq_dispose_mapping(unsigned int virq)
 745 {
 746         struct irq_host *host;
 747         irq_hw_number_t hwirq;
 748
 749         if (virq == NO_IRQ)
 750                 return;
 751
 752         host = irq_map[virq].host;
 753         WARN_ON (host == NULL);
 754         if (host == NULL)
 755                 return;
 756
 757         /* Never unmap legacy interrupts */
 758         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 759                 return;
 760
 761         /* remove chip and handler */
 762         set_irq_chip_and_handler(virq, NULL, NULL);
 763
 764         /* Make sure it's completed */
 765         synchronize_irq(virq);
 766
 767         /* Tell the PIC about it */
 768         if (host->ops->unmap)
 769                 host->ops->unmap(host, virq);
 770         smp_mb();
 771
 772         /* Clear reverse map */
 773         hwirq = irq_map[virq].hwirq;
 774         switch(host->revmap_type) {
 775         case IRQ_HOST_MAP_LINEAR:
 776                 if (hwirq < host->revmap_data.linear.size)
 777                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 778                 break;
 779         case IRQ_HOST_MAP_TREE:
 780                 /*
 781                  * Check if radix tree allocated yet, if not then nothing to
 782                  * remove.
 783                  */
 784                 smp_rmb();
 785                 if (revmap_trees_allocated < 1)
 786                         break;
 787                 mutex_lock(&revmap_trees_mutex);
 788                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 789                 mutex_unlock(&revmap_trees_mutex);
 790                 break;
 791         }
 792
 793         /* Destroy map */
 794         smp_mb();
 795         irq_map[virq].hwirq = host->inval_irq;
 796
 797         /* Set some flags */
 798         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 799
 800         /* Free it */
 801         irq_free_virt(virq, 1);
 802 }
 803 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 804
 805 unsigned int irq_find_mapping(struct irq_host *host,
 806                               irq_hw_number_t hwirq)
 807 {
 808         unsigned int i;
 809         unsigned int hint = hwirq % irq_virq_count;
 810
 811         /* Look for default host if nececssary */
 812         if (host == NULL)
 813                 host = irq_default_host;
 814         if (host == NULL)
 815                 return NO_IRQ;
 816
 817         /* legacy -> bail early */
 818         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 819                 return hwirq;
 820
 821         /* Slow path does a linear search of the map */
 822         if (hint < NUM_ISA_INTERRUPTS)
 823                 hint = NUM_ISA_INTERRUPTS;
 824         i = hint;
 825         do  {
 826                 if (irq_map[i].host == host &&
 827                     irq_map[i].hwirq == hwirq)
 828                         return i;
 829                 i++;
 830                 if (i >= irq_virq_count)
 831                         i = NUM_ISA_INTERRUPTS;
 832         } while(i != hint);
 833         return NO_IRQ;
 834 }
 835 EXPORT_SYMBOL_GPL(irq_find_mapping);
 836
 837
 838 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 839                                      irq_hw_number_t hwirq)
 840 {
 841         struct irq_map_entry *ptr;
 842         unsigned int virq;
 843
 844         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 845
 846         /*
 847          * Check if the radix tree exists and has bee initialized.
 848          * If not, we fallback to slow mode
 849          */
 850         if (revmap_trees_allocated < 2)
 851                 return irq_find_mapping(host, hwirq);
 852
 853         /* Now try to resolve */
 854         /*
 855          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 856          * as it's referencing an entry in the static irq_map table.
 857          */
 858         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 859
 860         /*
 861          * If found in radix tree, then fine.
 862          * Else fallback to linear lookup - this should not happen in practice
 863          * as it means that we failed to insert the node in the radix tree.
 864          */
 865         if (ptr)
 866                 virq = ptr - irq_map;
 867         else
 868                 virq = irq_find_mapping(host, hwirq);
 869
 870         return virq;
 871 }
 872
 873 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 874                              irq_hw_number_t hwirq)
 875 {
 876
 877         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 878
 879         /*
 880          * Check if the radix tree exists yet.
 881          * If not, then the irq will be inserted into the tree when it gets
 882          * initialized.
 883          */
 884         smp_rmb();
 885         if (revmap_trees_allocated < 1)
 886                 return;
 887
 888         if (virq != NO_IRQ) {
 889                 mutex_lock(&revmap_trees_mutex);
 890                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 891                                   &irq_map[virq]);
 892                 mutex_unlock(&revmap_trees_mutex);
 893         }
 894 }
 895
 896 unsigned int irq_linear_revmap(struct irq_host *host,
 897                                irq_hw_number_t hwirq)
 898 {
 899         unsigned int *revmap;
 900
 901         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 902
 903         /* Check revmap bounds */
 904         if (unlikely(hwirq >= host->revmap_data.linear.size))
 905                 return irq_find_mapping(host, hwirq);
 906
 907         /* Check if revmap was allocated */
 908         revmap = host->revmap_data.linear.revmap;
 909         if (unlikely(revmap == NULL))
 910                 return irq_find_mapping(host, hwirq);
 911
 912         /* Fill up revmap with slow path if no mapping found */
 913         if (unlikely(revmap[hwirq] == NO_IRQ))
 914                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 915
 916         return revmap[hwirq];
 917 }
 918
 919 unsigned int irq_alloc_virt(struct irq_host *host,
 920                             unsigned int count,
 921                             unsigned int hint)
 922 {
 923         unsigned long flags;
 924         unsigned int i, j, found = NO_IRQ;
 925
 926         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 927                 return NO_IRQ;
 928
 929         spin_lock_irqsave(&irq_big_lock, flags);
 930
 931         /* Use hint for 1 interrupt if any */
 932         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 933             hint < irq_virq_count && irq_map[hint].host == NULL) {
 934                 found = hint;
 935                 goto hint_found;
 936         }
 937
 938         /* Look for count consecutive numbers in the allocatable
 939          * (non-legacy) space
 940          */
 941         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 942                 if (irq_map[i].host != NULL)
 943                         j = 0;
 944                 else
 945                         j++;
 946
 947                 if (j == count) {
 948                         found = i - count + 1;
 949                         break;
 950                 }
 951         }
 952         if (found == NO_IRQ) {
 953                 spin_unlock_irqrestore(&irq_big_lock, flags);
 954                 return NO_IRQ;
 955         }
 956  hint_found:
 957         for (i = found; i < (found + count); i++) {
 958                 irq_map[i].hwirq = host->inval_irq;
 959                 smp_wmb();
 960                 irq_map[i].host = host;
 961         }
 962         spin_unlock_irqrestore(&irq_big_lock, flags);
 963         return found;
 964 }
 965
 966 void irq_free_virt(unsigned int virq, unsigned int count)
 967 {
 968         unsigned long flags;
 969         unsigned int i;
 970
 971         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 972         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 973
 974         spin_lock_irqsave(&irq_big_lock, flags);
 975         for (i = virq; i < (virq + count); i++) {
 976                 struct irq_host *host;
 977
 978                 if (i < NUM_ISA_INTERRUPTS ||
 979                     (virq + count) > irq_virq_count)
 980                         continue;
 981
 982                 host = irq_map[i].host;
 983                 irq_map[i].hwirq = host->inval_irq;
 984                 smp_wmb();
 985                 irq_map[i].host = NULL;
 986         }
 987         spin_unlock_irqrestore(&irq_big_lock, flags);
 988 }
 989
 990 void irq_early_init(void)
 991 {
 992         unsigned int i;
 993
 994         for (i = 0; i < NR_IRQS; i++)
 995                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 996 }
 997
 998 /* We need to create the radix trees late */
 999 static int irq_late_init(void)
1000 {
1001         struct irq_host *h;
1002         unsigned int i;
1003
1004         /*
1005          * No mutual exclusion with respect to accessors of the tree is needed
1006          * here as the synchronization is done via the state variable
1007          * revmap_trees_allocated.
1008          */
1009         list_for_each_entry(h, &irq_hosts, link) {
1010                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1011                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1012         }
1013
1014         /*
1015          * Make sure the radix trees inits are visible before setting
1016          * the flag
1017          */
1018         smp_wmb();
1019         revmap_trees_allocated = 1;
1020
1021         /*
1022          * Insert the reverse mapping for those interrupts already present
1023          * in irq_map[].
1024          */
1025         mutex_lock(&revmap_trees_mutex);
1026         for (i = 0; i < irq_virq_count; i++) {
1027                 if (irq_map[i].host &&
1028                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1029                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1030                                           irq_map[i].hwirq, &irq_map[i]);
1031         }
1032         mutex_unlock(&revmap_trees_mutex);
1033
1034         /*
1035          * Make sure the radix trees insertions are visible before setting
1036          * the flag
1037          */
1038         smp_wmb();
1039         revmap_trees_allocated = 2;
1040
1041         return 0;
1042 }
1043 arch_initcall(irq_late_init);
1044
1045 #ifdef CONFIG_VIRQ_DEBUG
1046 static int virq_debug_show(struct seq_file *m, void *private)
1047 {
1048         unsigned long flags;
1049         struct irq_desc *desc;
1050         const char *p;
1051         char none[] = "none";
1052         int i;
1053
1054         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1055                       "chip name", "host name");
1056
1057         for (i = 1; i < NR_IRQS; i++) {
1058                 desc = get_irq_desc(i);
1059                 spin_lock_irqsave(&desc->lock, flags);
1060
1061                 if (desc->action && desc->action->handler) {
1062                         seq_printf(m, "%5d  ", i);
1063                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1064
1065                         if (desc->chip && desc->chip->typename)
1066                                 p = desc->chip->typename;
1067                         else
1068                                 p = none;
1069                         seq_printf(m, "%-15s  ", p);
1070
1071                         if (irq_map[i].host && irq_map[i].host->of_node)
1072                                 p = irq_map[i].host->of_node->full_name;
1073                         else
1074                                 p = none;
1075                         seq_printf(m, "%s\n", p);
1076                 }
1077
1078                 spin_unlock_irqrestore(&desc->lock, flags);
1079         }
1080
1081         return 0;
1082 }
1083
1084 static int virq_debug_open(struct inode *inode, struct file *file)
1085 {
1086         return single_open(file, virq_debug_show, inode->i_private);
1087 }
1088
1089 static const struct file_operations virq_debug_fops = {
1090         .open = virq_debug_open,
1091         .read = seq_read,
1092         .llseek = seq_lseek,
1093         .release = single_release,
1094 };
1095
1096 static int __init irq_debugfs_init(void)
1097 {
1098         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1099                                  NULL, &virq_debug_fops) == NULL)
1100                 return -ENOMEM;
1101
1102         return 0;
1103 }
1104 __initcall(irq_debugfs_init);
1105 #endif /* CONFIG_VIRQ_DEBUG */
1106
1107 #ifdef CONFIG_PPC64
1108 static int __init setup_noirqdistrib(char *str)
1109 {
1110         distribute_irqs = 0;
1111         return 1;
1112 }
1113
1114 __setup("noirqdistrib", setup_noirqdistrib);
1115 #endif /* CONFIG_PPC64 */