git.oblomov.eu Git - linux-2.6/blob - 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         /*
 139          * if (get_paca()->hard_enabled) return;
 140          * But again we need to take care that gcc gets hard_enabled directly
 141          * via r13, not choose to use an intermediate register, lest we're
 142          * preempted to a different cpu in between the two instructions.
 143          */
 144         if (get_hard_enabled())
 145                 return;
 146
 147         /*
 148          * Need to hard-enable interrupts here.  Since currently disabled,
 149          * no need to take further asm precautions against preemption; but
 150          * use local_paca instead of get_paca() to avoid preemption checking.
 151          */
 152         local_paca->hard_enabled = en;
 153         if ((int)mfspr(SPRN_DEC) < 0)
 154                 mtspr(SPRN_DEC, 1);
 155
 156         /*
 157          * Force the delivery of pending soft-disabled interrupts on PS3.
 158          * Any HV call will have this side effect.
 159          */
 160         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 161                 u64 tmp;
 162                 lv1_get_version_info(&tmp);
 163         }
 164
 165         __hard_irq_enable();
 166 }
 167 EXPORT_SYMBOL(raw_local_irq_restore);
 168 #endif /* CONFIG_PPC64 */
 169
 170 int show_interrupts(struct seq_file *p, void *v)
 171 {
 172         int i = *(loff_t *)v, j;
 173         struct irqaction *action;
 174         struct irq_desc *desc;
 175         unsigned long flags;
 176
 177         if (i == 0) {
 178                 seq_puts(p, "           ");
 179                 for_each_online_cpu(j)
 180                         seq_printf(p, "CPU%d       ", j);
 181                 seq_putc(p, '\n');
 182         }
 183
 184         if (i < NR_IRQS) {
 185                 desc = get_irq_desc(i);
 186                 spin_lock_irqsave(&desc->lock, flags);
 187                 action = desc->action;
 188                 if (!action || !action->handler)
 189                         goto skip;
 190                 seq_printf(p, "%3d: ", i);
 191 #ifdef CONFIG_SMP
 192                 for_each_online_cpu(j)
 193                         seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 194 #else
 195                 seq_printf(p, "%10u ", kstat_irqs(i));
 196 #endif /* CONFIG_SMP */
 197                 if (desc->chip)
 198                         seq_printf(p, " %s ", desc->chip->typename);
 199                 else
 200                         seq_puts(p, "  None      ");
 201                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 202                 seq_printf(p, "    %s", action->name);
 203                 for (action = action->next; action; action = action->next)
 204                         seq_printf(p, ", %s", action->name);
 205                 seq_putc(p, '\n');
 206 skip:
 207                 spin_unlock_irqrestore(&desc->lock, flags);
 208         } else if (i == NR_IRQS) {
 209 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 210                 if (tau_initialized){
 211                         seq_puts(p, "TAU: ");
 212                         for_each_online_cpu(j)
 213                                 seq_printf(p, "%10u ", tau_interrupts(j));
 214                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 215                 }
 216 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT*/
 217                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 218         }
 219         return 0;
 220 }
 221
 222 #ifdef CONFIG_HOTPLUG_CPU
 223 void fixup_irqs(cpumask_t map)
 224 {
 225         unsigned int irq;
 226         static int warned;
 227
 228         for_each_irq(irq) {
 229                 cpumask_t mask;
 230
 231                 if (irq_desc[irq].status & IRQ_PER_CPU)
 232                         continue;
 233
 234                 cpumask_and(&mask, irq_desc[irq].affinity, &map);
 235                 if (any_online_cpu(mask) == NR_CPUS) {
 236                         printk("Breaking affinity for irq %i\n", irq);
 237                         mask = map;
 238                 }
 239                 if (irq_desc[irq].chip->set_affinity)
 240                         irq_desc[irq].chip->set_affinity(irq, &mask);
 241                 else if (irq_desc[irq].action && !(warned++))
 242                         printk("Cannot set affinity for irq %i\n", irq);
 243         }
 244
 245         local_irq_enable();
 246         mdelay(1);
 247         local_irq_disable();
 248 }
 249 #endif
 250
 251 #ifdef CONFIG_IRQSTACKS
 252 static inline void handle_one_irq(unsigned int irq)
 253 {
 254         struct thread_info *curtp, *irqtp;
 255         unsigned long saved_sp_limit;
 256         struct irq_desc *desc;
 257
 258         /* Switch to the irq stack to handle this */
 259         curtp = current_thread_info();
 260         irqtp = hardirq_ctx[smp_processor_id()];
 261
 262         if (curtp == irqtp) {
 263                 /* We're already on the irq stack, just handle it */
 264                 generic_handle_irq(irq);
 265                 return;
 266         }
 267
 268         desc = irq_desc + irq;
 269         saved_sp_limit = current->thread.ksp_limit;
 270
 271         irqtp->task = curtp->task;
 272         irqtp->flags = 0;
 273
 274         /* Copy the softirq bits in preempt_count so that the
 275          * softirq checks work in the hardirq context. */
 276         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 277                                (curtp->preempt_count & SOFTIRQ_MASK);
 278
 279         current->thread.ksp_limit = (unsigned long)irqtp +
 280                 _ALIGN_UP(sizeof(struct thread_info), 16);
 281
 282         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 283         current->thread.ksp_limit = saved_sp_limit;
 284         irqtp->task = NULL;
 285
 286         /* Set any flag that may have been set on the
 287          * alternate stack
 288          */
 289         if (irqtp->flags)
 290                 set_bits(irqtp->flags, &curtp->flags);
 291 }
 292 #else
 293 static inline void handle_one_irq(unsigned int irq)
 294 {
 295         generic_handle_irq(irq);
 296 }
 297 #endif
 298
 299 static inline void check_stack_overflow(void)
 300 {
 301 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 302         long sp;
 303
 304         sp = __get_SP() & (THREAD_SIZE-1);
 305
 306         /* check for stack overflow: is there less than 2KB free? */
 307         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 308                 printk("do_IRQ: stack overflow: %ld\n",
 309                         sp - sizeof(struct thread_info));
 310                 dump_stack();
 311         }
 312 #endif
 313 }
 314
 315 void do_IRQ(struct pt_regs *regs)
 316 {
 317         struct pt_regs *old_regs = set_irq_regs(regs);
 318         unsigned int irq;
 319
 320         irq_enter();
 321
 322         check_stack_overflow();
 323
 324         irq = ppc_md.get_irq();
 325
 326         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 327                 handle_one_irq(irq);
 328         else if (irq != NO_IRQ_IGNORE)
 329                 /* That's not SMP safe ... but who cares ? */
 330                 ppc_spurious_interrupts++;
 331
 332         irq_exit();
 333         set_irq_regs(old_regs);
 334
 335 #ifdef CONFIG_PPC_ISERIES
 336         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 337                         get_lppaca()->int_dword.fields.decr_int) {
 338                 get_lppaca()->int_dword.fields.decr_int = 0;
 339                 /* Signal a fake decrementer interrupt */
 340                 timer_interrupt(regs);
 341         }
 342 #endif
 343 }
 344
 345 void __init init_IRQ(void)
 346 {
 347         if (ppc_md.init_IRQ)
 348                 ppc_md.init_IRQ();
 349
 350         exc_lvl_ctx_init();
 351
 352         irq_ctx_init();
 353 }
 354
 355 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 356 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 357 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 358 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 359
 360 void exc_lvl_ctx_init(void)
 361 {
 362         struct thread_info *tp;
 363         int i;
 364
 365         for_each_possible_cpu(i) {
 366                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 367                 tp = critirq_ctx[i];
 368                 tp->cpu = i;
 369                 tp->preempt_count = 0;
 370
 371 #ifdef CONFIG_BOOKE
 372                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 373                 tp = dbgirq_ctx[i];
 374                 tp->cpu = i;
 375                 tp->preempt_count = 0;
 376
 377                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 378                 tp = mcheckirq_ctx[i];
 379                 tp->cpu = i;
 380                 tp->preempt_count = HARDIRQ_OFFSET;
 381 #endif
 382         }
 383 }
 384 #endif
 385
 386 #ifdef CONFIG_IRQSTACKS
 387 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 388 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 389
 390 void irq_ctx_init(void)
 391 {
 392         struct thread_info *tp;
 393         int i;
 394
 395         for_each_possible_cpu(i) {
 396                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 397                 tp = softirq_ctx[i];
 398                 tp->cpu = i;
 399                 tp->preempt_count = 0;
 400
 401                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 402                 tp = hardirq_ctx[i];
 403                 tp->cpu = i;
 404                 tp->preempt_count = HARDIRQ_OFFSET;
 405         }
 406 }
 407
 408 static inline void do_softirq_onstack(void)
 409 {
 410         struct thread_info *curtp, *irqtp;
 411         unsigned long saved_sp_limit = current->thread.ksp_limit;
 412
 413         curtp = current_thread_info();
 414         irqtp = softirq_ctx[smp_processor_id()];
 415         irqtp->task = curtp->task;
 416         current->thread.ksp_limit = (unsigned long)irqtp +
 417                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 418         call_do_softirq(irqtp);
 419         current->thread.ksp_limit = saved_sp_limit;
 420         irqtp->task = NULL;
 421 }
 422
 423 #else
 424 #define do_softirq_onstack()    __do_softirq()
 425 #endif /* CONFIG_IRQSTACKS */
 426
 427 void do_softirq(void)
 428 {
 429         unsigned long flags;
 430
 431         if (in_interrupt())
 432                 return;
 433
 434         local_irq_save(flags);
 435
 436         if (local_softirq_pending())
 437                 do_softirq_onstack();
 438
 439         local_irq_restore(flags);
 440 }
 441
 442
 443 /*
 444  * IRQ controller and virtual interrupts
 445  */
 446
 447 static LIST_HEAD(irq_hosts);
 448 static DEFINE_SPINLOCK(irq_big_lock);
 449 static unsigned int revmap_trees_allocated;
 450 static DEFINE_MUTEX(revmap_trees_mutex);
 451 struct irq_map_entry irq_map[NR_IRQS];
 452 static unsigned int irq_virq_count = NR_IRQS;
 453 static struct irq_host *irq_default_host;
 454
 455 irq_hw_number_t virq_to_hw(unsigned int virq)
 456 {
 457         return irq_map[virq].hwirq;
 458 }
 459 EXPORT_SYMBOL_GPL(virq_to_hw);
 460
 461 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 462 {
 463         return h->of_node != NULL && h->of_node == np;
 464 }
 465
 466 struct irq_host *irq_alloc_host(struct device_node *of_node,
 467                                 unsigned int revmap_type,
 468                                 unsigned int revmap_arg,
 469                                 struct irq_host_ops *ops,
 470                                 irq_hw_number_t inval_irq)
 471 {
 472         struct irq_host *host;
 473         unsigned int size = sizeof(struct irq_host);
 474         unsigned int i;
 475         unsigned int *rmap;
 476         unsigned long flags;
 477
 478         /* Allocate structure and revmap table if using linear mapping */
 479         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 480                 size += revmap_arg * sizeof(unsigned int);
 481         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 482         if (host == NULL)
 483                 return NULL;
 484
 485         /* Fill structure */
 486         host->revmap_type = revmap_type;
 487         host->inval_irq = inval_irq;
 488         host->ops = ops;
 489         host->of_node = of_node_get(of_node);
 490
 491         if (host->ops->match == NULL)
 492                 host->ops->match = default_irq_host_match;
 493
 494         spin_lock_irqsave(&irq_big_lock, flags);
 495
 496         /* If it's a legacy controller, check for duplicates and
 497          * mark it as allocated (we use irq 0 host pointer for that
 498          */
 499         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 500                 if (irq_map[0].host != NULL) {
 501                         spin_unlock_irqrestore(&irq_big_lock, flags);
 502                         /* If we are early boot, we can't free the structure,
 503                          * too bad...
 504                          * this will be fixed once slab is made available early
 505                          * instead of the current cruft
 506                          */
 507                         if (mem_init_done)
 508                                 kfree(host);
 509                         return NULL;
 510                 }
 511                 irq_map[0].host = host;
 512         }
 513
 514         list_add(&host->link, &irq_hosts);
 515         spin_unlock_irqrestore(&irq_big_lock, flags);
 516
 517         /* Additional setups per revmap type */
 518         switch(revmap_type) {
 519         case IRQ_HOST_MAP_LEGACY:
 520                 /* 0 is always the invalid number for legacy */
 521                 host->inval_irq = 0;
 522                 /* setup us as the host for all legacy interrupts */
 523                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 524                         irq_map[i].hwirq = i;
 525                         smp_wmb();
 526                         irq_map[i].host = host;
 527                         smp_wmb();
 528
 529                         /* Clear norequest flags */
 530                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 531
 532                         /* Legacy flags are left to default at this point,
 533                          * one can then use irq_create_mapping() to
 534                          * explicitly change them
 535                          */
 536                         ops->map(host, i, i);
 537                 }
 538                 break;
 539         case IRQ_HOST_MAP_LINEAR:
 540                 rmap = (unsigned int *)(host + 1);
 541                 for (i = 0; i < revmap_arg; i++)
 542                         rmap[i] = NO_IRQ;
 543                 host->revmap_data.linear.size = revmap_arg;
 544                 smp_wmb();
 545                 host->revmap_data.linear.revmap = rmap;
 546                 break;
 547         default:
 548                 break;
 549         }
 550
 551         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 552
 553         return host;
 554 }
 555
 556 struct irq_host *irq_find_host(struct device_node *node)
 557 {
 558         struct irq_host *h, *found = NULL;
 559         unsigned long flags;
 560
 561         /* We might want to match the legacy controller last since
 562          * it might potentially be set to match all interrupts in
 563          * the absence of a device node. This isn't a problem so far
 564          * yet though...
 565          */
 566         spin_lock_irqsave(&irq_big_lock, flags);
 567         list_for_each_entry(h, &irq_hosts, link)
 568                 if (h->ops->match(h, node)) {
 569                         found = h;
 570                         break;
 571                 }
 572         spin_unlock_irqrestore(&irq_big_lock, flags);
 573         return found;
 574 }
 575 EXPORT_SYMBOL_GPL(irq_find_host);
 576
 577 void irq_set_default_host(struct irq_host *host)
 578 {
 579         pr_debug("irq: Default host set to @0x%p\n", host);
 580
 581         irq_default_host = host;
 582 }
 583
 584 void irq_set_virq_count(unsigned int count)
 585 {
 586         pr_debug("irq: Trying to set virq count to %d\n", count);
 587
 588         BUG_ON(count < NUM_ISA_INTERRUPTS);
 589         if (count < NR_IRQS)
 590                 irq_virq_count = count;
 591 }
 592
 593 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 594                             irq_hw_number_t hwirq)
 595 {
 596         /* Clear IRQ_NOREQUEST flag */
 597         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 598
 599         /* map it */
 600         smp_wmb();
 601         irq_map[virq].hwirq = hwirq;
 602         smp_mb();
 603
 604         if (host->ops->map(host, virq, hwirq)) {
 605                 pr_debug("irq: -> mapping failed, freeing\n");
 606                 irq_free_virt(virq, 1);
 607                 return -1;
 608         }
 609
 610         return 0;
 611 }
 612
 613 unsigned int irq_create_direct_mapping(struct irq_host *host)
 614 {
 615         unsigned int virq;
 616
 617         if (host == NULL)
 618                 host = irq_default_host;
 619
 620         BUG_ON(host == NULL);
 621         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 622
 623         virq = irq_alloc_virt(host, 1, 0);
 624         if (virq == NO_IRQ) {
 625                 pr_debug("irq: create_direct virq allocation failed\n");
 626                 return NO_IRQ;
 627         }
 628
 629         pr_debug("irq: create_direct obtained virq %d\n", virq);
 630
 631         if (irq_setup_virq(host, virq, virq))
 632                 return NO_IRQ;
 633
 634         return virq;
 635 }
 636
 637 unsigned int irq_create_mapping(struct irq_host *host,
 638                                 irq_hw_number_t hwirq)
 639 {
 640         unsigned int virq, hint;
 641
 642         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 643
 644         /* Look for default host if nececssary */
 645         if (host == NULL)
 646                 host = irq_default_host;
 647         if (host == NULL) {
 648                 printk(KERN_WARNING "irq_create_mapping called for"
 649                        " NULL host, hwirq=%lx\n", hwirq);
 650                 WARN_ON(1);
 651                 return NO_IRQ;
 652         }
 653         pr_debug("irq: -> using host @%p\n", host);
 654
 655         /* Check if mapping already exist, if it does, call
 656          * host->ops->map() to update the flags
 657          */
 658         virq = irq_find_mapping(host, hwirq);
 659         if (virq != NO_IRQ) {
 660                 if (host->ops->remap)
 661                         host->ops->remap(host, virq, hwirq);
 662                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 663                 return virq;
 664         }
 665
 666         /* Get a virtual interrupt number */
 667         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 668                 /* Handle legacy */
 669                 virq = (unsigned int)hwirq;
 670                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 671                         return NO_IRQ;
 672                 return virq;
 673         } else {
 674                 /* Allocate a virtual interrupt number */
 675                 hint = hwirq % irq_virq_count;
 676                 virq = irq_alloc_virt(host, 1, hint);
 677                 if (virq == NO_IRQ) {
 678                         pr_debug("irq: -> virq allocation failed\n");
 679                         return NO_IRQ;
 680                 }
 681         }
 682
 683         if (irq_setup_virq(host, virq, hwirq))
 684                 return NO_IRQ;
 685
 686         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 687                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 688
 689         return virq;
 690 }
 691 EXPORT_SYMBOL_GPL(irq_create_mapping);
 692
 693 unsigned int irq_create_of_mapping(struct device_node *controller,
 694                                    u32 *intspec, unsigned int intsize)
 695 {
 696         struct irq_host *host;
 697         irq_hw_number_t hwirq;
 698         unsigned int type = IRQ_TYPE_NONE;
 699         unsigned int virq;
 700
 701         if (controller == NULL)
 702                 host = irq_default_host;
 703         else
 704                 host = irq_find_host(controller);
 705         if (host == NULL) {
 706                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 707                        controller->full_name);
 708                 return NO_IRQ;
 709         }
 710
 711         /* If host has no translation, then we assume interrupt line */
 712         if (host->ops->xlate == NULL)
 713                 hwirq = intspec[0];
 714         else {
 715                 if (host->ops->xlate(host, controller, intspec, intsize,
 716                                      &hwirq, &type))
 717                         return NO_IRQ;
 718         }
 719
 720         /* Create mapping */
 721         virq = irq_create_mapping(host, hwirq);
 722         if (virq == NO_IRQ)
 723                 return virq;
 724
 725         /* Set type if specified and different than the current one */
 726         if (type != IRQ_TYPE_NONE &&
 727             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 728                 set_irq_type(virq, type);
 729         return virq;
 730 }
 731 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 732
 733 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 734 {
 735         struct of_irq oirq;
 736
 737         if (of_irq_map_one(dev, index, &oirq))
 738                 return NO_IRQ;
 739
 740         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 741                                      oirq.size);
 742 }
 743 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 744
 745 void irq_dispose_mapping(unsigned int virq)
 746 {
 747         struct irq_host *host;
 748         irq_hw_number_t hwirq;
 749
 750         if (virq == NO_IRQ)
 751                 return;
 752
 753         host = irq_map[virq].host;
 754         WARN_ON (host == NULL);
 755         if (host == NULL)
 756                 return;
 757
 758         /* Never unmap legacy interrupts */
 759         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 760                 return;
 761
 762         /* remove chip and handler */
 763         set_irq_chip_and_handler(virq, NULL, NULL);
 764
 765         /* Make sure it's completed */
 766         synchronize_irq(virq);
 767
 768         /* Tell the PIC about it */
 769         if (host->ops->unmap)
 770                 host->ops->unmap(host, virq);
 771         smp_mb();
 772
 773         /* Clear reverse map */
 774         hwirq = irq_map[virq].hwirq;
 775         switch(host->revmap_type) {
 776         case IRQ_HOST_MAP_LINEAR:
 777                 if (hwirq < host->revmap_data.linear.size)
 778                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 779                 break;
 780         case IRQ_HOST_MAP_TREE:
 781                 /*
 782                  * Check if radix tree allocated yet, if not then nothing to
 783                  * remove.
 784                  */
 785                 smp_rmb();
 786                 if (revmap_trees_allocated < 1)
 787                         break;
 788                 mutex_lock(&revmap_trees_mutex);
 789                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 790                 mutex_unlock(&revmap_trees_mutex);
 791                 break;
 792         }
 793
 794         /* Destroy map */
 795         smp_mb();
 796         irq_map[virq].hwirq = host->inval_irq;
 797
 798         /* Set some flags */
 799         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 800
 801         /* Free it */
 802         irq_free_virt(virq, 1);
 803 }
 804 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 805
 806 unsigned int irq_find_mapping(struct irq_host *host,
 807                               irq_hw_number_t hwirq)
 808 {
 809         unsigned int i;
 810         unsigned int hint = hwirq % irq_virq_count;
 811
 812         /* Look for default host if nececssary */
 813         if (host == NULL)
 814                 host = irq_default_host;
 815         if (host == NULL)
 816                 return NO_IRQ;
 817
 818         /* legacy -> bail early */
 819         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 820                 return hwirq;
 821
 822         /* Slow path does a linear search of the map */
 823         if (hint < NUM_ISA_INTERRUPTS)
 824                 hint = NUM_ISA_INTERRUPTS;
 825         i = hint;
 826         do  {
 827                 if (irq_map[i].host == host &&
 828                     irq_map[i].hwirq == hwirq)
 829                         return i;
 830                 i++;
 831                 if (i >= irq_virq_count)
 832                         i = NUM_ISA_INTERRUPTS;
 833         } while(i != hint);
 834         return NO_IRQ;
 835 }
 836 EXPORT_SYMBOL_GPL(irq_find_mapping);
 837
 838
 839 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 840                                      irq_hw_number_t hwirq)
 841 {
 842         struct irq_map_entry *ptr;
 843         unsigned int virq;
 844
 845         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 846
 847         /*
 848          * Check if the radix tree exists and has bee initialized.
 849          * If not, we fallback to slow mode
 850          */
 851         if (revmap_trees_allocated < 2)
 852                 return irq_find_mapping(host, hwirq);
 853
 854         /* Now try to resolve */
 855         /*
 856          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 857          * as it's referencing an entry in the static irq_map table.
 858          */
 859         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 860
 861         /*
 862          * If found in radix tree, then fine.
 863          * Else fallback to linear lookup - this should not happen in practice
 864          * as it means that we failed to insert the node in the radix tree.
 865          */
 866         if (ptr)
 867                 virq = ptr - irq_map;
 868         else
 869                 virq = irq_find_mapping(host, hwirq);
 870
 871         return virq;
 872 }
 873
 874 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 875                              irq_hw_number_t hwirq)
 876 {
 877
 878         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 879
 880         /*
 881          * Check if the radix tree exists yet.
 882          * If not, then the irq will be inserted into the tree when it gets
 883          * initialized.
 884          */
 885         smp_rmb();
 886         if (revmap_trees_allocated < 1)
 887                 return;
 888
 889         if (virq != NO_IRQ) {
 890                 mutex_lock(&revmap_trees_mutex);
 891                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 892                                   &irq_map[virq]);
 893                 mutex_unlock(&revmap_trees_mutex);
 894         }
 895 }
 896
 897 unsigned int irq_linear_revmap(struct irq_host *host,
 898                                irq_hw_number_t hwirq)
 899 {
 900         unsigned int *revmap;
 901
 902         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 903
 904         /* Check revmap bounds */
 905         if (unlikely(hwirq >= host->revmap_data.linear.size))
 906                 return irq_find_mapping(host, hwirq);
 907
 908         /* Check if revmap was allocated */
 909         revmap = host->revmap_data.linear.revmap;
 910         if (unlikely(revmap == NULL))
 911                 return irq_find_mapping(host, hwirq);
 912
 913         /* Fill up revmap with slow path if no mapping found */
 914         if (unlikely(revmap[hwirq] == NO_IRQ))
 915                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 916
 917         return revmap[hwirq];
 918 }
 919
 920 unsigned int irq_alloc_virt(struct irq_host *host,
 921                             unsigned int count,
 922                             unsigned int hint)
 923 {
 924         unsigned long flags;
 925         unsigned int i, j, found = NO_IRQ;
 926
 927         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 928                 return NO_IRQ;
 929
 930         spin_lock_irqsave(&irq_big_lock, flags);
 931
 932         /* Use hint for 1 interrupt if any */
 933         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 934             hint < irq_virq_count && irq_map[hint].host == NULL) {
 935                 found = hint;
 936                 goto hint_found;
 937         }
 938
 939         /* Look for count consecutive numbers in the allocatable
 940          * (non-legacy) space
 941          */
 942         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 943                 if (irq_map[i].host != NULL)
 944                         j = 0;
 945                 else
 946                         j++;
 947
 948                 if (j == count) {
 949                         found = i - count + 1;
 950                         break;
 951                 }
 952         }
 953         if (found == NO_IRQ) {
 954                 spin_unlock_irqrestore(&irq_big_lock, flags);
 955                 return NO_IRQ;
 956         }
 957  hint_found:
 958         for (i = found; i < (found + count); i++) {
 959                 irq_map[i].hwirq = host->inval_irq;
 960                 smp_wmb();
 961                 irq_map[i].host = host;
 962         }
 963         spin_unlock_irqrestore(&irq_big_lock, flags);
 964         return found;
 965 }
 966
 967 void irq_free_virt(unsigned int virq, unsigned int count)
 968 {
 969         unsigned long flags;
 970         unsigned int i;
 971
 972         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 973         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 974
 975         spin_lock_irqsave(&irq_big_lock, flags);
 976         for (i = virq; i < (virq + count); i++) {
 977                 struct irq_host *host;
 978
 979                 if (i < NUM_ISA_INTERRUPTS ||
 980                     (virq + count) > irq_virq_count)
 981                         continue;
 982
 983                 host = irq_map[i].host;
 984                 irq_map[i].hwirq = host->inval_irq;
 985                 smp_wmb();
 986                 irq_map[i].host = NULL;
 987         }
 988         spin_unlock_irqrestore(&irq_big_lock, flags);
 989 }
 990
 991 void irq_early_init(void)
 992 {
 993         unsigned int i;
 994
 995         for (i = 0; i < NR_IRQS; i++)
 996                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 997 }
 998
 999 /* We need to create the radix trees late */
1000 static int irq_late_init(void)
1001 {
1002         struct irq_host *h;
1003         unsigned int i;
1004
1005         /*
1006          * No mutual exclusion with respect to accessors of the tree is needed
1007          * here as the synchronization is done via the state variable
1008          * revmap_trees_allocated.
1009          */
1010         list_for_each_entry(h, &irq_hosts, link) {
1011                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1012                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1013         }
1014
1015         /*
1016          * Make sure the radix trees inits are visible before setting
1017          * the flag
1018          */
1019         smp_wmb();
1020         revmap_trees_allocated = 1;
1021
1022         /*
1023          * Insert the reverse mapping for those interrupts already present
1024          * in irq_map[].
1025          */
1026         mutex_lock(&revmap_trees_mutex);
1027         for (i = 0; i < irq_virq_count; i++) {
1028                 if (irq_map[i].host &&
1029                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1030                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1031                                           irq_map[i].hwirq, &irq_map[i]);
1032         }
1033         mutex_unlock(&revmap_trees_mutex);
1034
1035         /*
1036          * Make sure the radix trees insertions are visible before setting
1037          * the flag
1038          */
1039         smp_wmb();
1040         revmap_trees_allocated = 2;
1041
1042         return 0;
1043 }
1044 arch_initcall(irq_late_init);
1045
1046 #ifdef CONFIG_VIRQ_DEBUG
1047 static int virq_debug_show(struct seq_file *m, void *private)
1048 {
1049         unsigned long flags;
1050         struct irq_desc *desc;
1051         const char *p;
1052         char none[] = "none";
1053         int i;
1054
1055         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1056                       "chip name", "host name");
1057
1058         for (i = 1; i < NR_IRQS; i++) {
1059                 desc = get_irq_desc(i);
1060                 spin_lock_irqsave(&desc->lock, flags);
1061
1062                 if (desc->action && desc->action->handler) {
1063                         seq_printf(m, "%5d  ", i);
1064                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1065
1066                         if (desc->chip && desc->chip->typename)
1067                                 p = desc->chip->typename;
1068                         else
1069                                 p = none;
1070                         seq_printf(m, "%-15s  ", p);
1071
1072                         if (irq_map[i].host && irq_map[i].host->of_node)
1073                                 p = irq_map[i].host->of_node->full_name;
1074                         else
1075                                 p = none;
1076                         seq_printf(m, "%s\n", p);
1077                 }
1078
1079                 spin_unlock_irqrestore(&desc->lock, flags);
1080         }
1081
1082         return 0;
1083 }
1084
1085 static int virq_debug_open(struct inode *inode, struct file *file)
1086 {
1087         return single_open(file, virq_debug_show, inode->i_private);
1088 }
1089
1090 static const struct file_operations virq_debug_fops = {
1091         .open = virq_debug_open,
1092         .read = seq_read,
1093         .llseek = seq_lseek,
1094         .release = single_release,
1095 };
1096
1097 static int __init irq_debugfs_init(void)
1098 {
1099         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1100                                  NULL, &virq_debug_fops) == NULL)
1101                 return -ENOMEM;
1102
1103         return 0;
1104 }
1105 __initcall(irq_debugfs_init);
1106 #endif /* CONFIG_VIRQ_DEBUG */
1107
1108 #ifdef CONFIG_PPC64
1109 static int __init setup_noirqdistrib(char *str)
1110 {
1111         distribute_irqs = 0;
1112         return 1;
1113 }
1114
1115 __setup("noirqdistrib", setup_noirqdistrib);
1116 #endif /* CONFIG_PPC64 */