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