arch/powerpc/kernel/irq.c

   1 /*
   2  *  Derived from arch/i386/kernel/irq.c
   3  *    Copyright (C) 1992 Linus Torvalds
   4  *  Adapted from arch/i386 by Gary Thomas
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
   7  *    Copyright (C) 1996-2001 Cort Dougan
   8  *  Adapted for Power Macintosh by Paul Mackerras
   9  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version
  14  * 2 of the License, or (at your option) any later version.
  15  *
  16  * This file contains the code used by various IRQ handling routines:
  17  * asking for different IRQ's should be done through these routines
  18  * instead of just grabbing them. Thus setups with different IRQ numbers
  19  * shouldn't result in any weird surprises, and installing new handlers
  20  * should be easier.
  21  *
  22  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
  23  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
  24  * mask register (of which only 16 are defined), hence the weird shifting
  25  * and complement of the cached_irq_mask.  I want to be able to stuff
  26  * this right into the SIU SMASK register.
  27  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
  28  * to reduce code space and undefined function references.
  29  */
  30
  31 #undef DEBUG
  32
  33 #include <linux/module.h>
  34 #include <linux/threads.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/signal.h>
  37 #include <linux/sched.h>
  38 #include <linux/ptrace.h>
  39 #include <linux/ioport.h>
  40 #include <linux/interrupt.h>
  41 #include <linux/timex.h>
  42 #include <linux/init.h>
  43 #include <linux/slab.h>
  44 #include <linux/delay.h>
  45 #include <linux/irq.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/cpumask.h>
  48 #include <linux/profile.h>
  49 #include <linux/bitops.h>
  50 #include <linux/list.h>
  51 #include <linux/radix-tree.h>
  52 #include <linux/mutex.h>
  53 #include <linux/bootmem.h>
  54 #include <linux/pci.h>
  55 #include <linux/debugfs.h>
  56
  57 #include <asm/uaccess.h>
  58 #include <asm/system.h>
  59 #include <asm/io.h>
  60 #include <asm/pgtable.h>
  61 #include <asm/irq.h>
  62 #include <asm/cache.h>
  63 #include <asm/prom.h>
  64 #include <asm/ptrace.h>
  65 #include <asm/machdep.h>
  66 #include <asm/udbg.h>
  67 #ifdef CONFIG_PPC64
  68 #include <asm/paca.h>
  69 #include <asm/firmware.h>
  70 #include <asm/lv1call.h>
  71 #endif
  72
  73 int __irq_offset_value;
  74 static int ppc_spurious_interrupts;
  75
  76 #ifdef CONFIG_PPC32
  77 EXPORT_SYMBOL(__irq_offset_value);
  78 atomic_t ppc_n_lost_interrupts;
  79
  80 #ifndef CONFIG_PPC_MERGE
  81 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
  82 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
  83 #endif
  84
  85 #ifdef CONFIG_TAU_INT
  86 extern int tau_initialized;
  87 extern int tau_interrupts(int);
  88 #endif
  89 #endif /* CONFIG_PPC32 */
  90
  91 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
  92 extern atomic_t ipi_recv;
  93 extern atomic_t ipi_sent;
  94 #endif
  95
  96 #ifdef CONFIG_PPC64
  97 EXPORT_SYMBOL(irq_desc);
  98
  99 int distribute_irqs = 1;
 100
 101 static inline unsigned long get_hard_enabled(void)
 102 {
 103         unsigned long enabled;
 104
 105         __asm__ __volatile__("lbz %0,%1(13)"
 106         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 107
 108         return enabled;
 109 }
 110
 111 static inline void set_soft_enabled(unsigned long enable)
 112 {
 113         __asm__ __volatile__("stb %0,%1(13)"
 114         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 115 }
 116
 117 void local_irq_restore(unsigned long en)
 118 {
 119         /*
 120          * get_paca()->soft_enabled = en;
 121          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 122          * That was allowed before, and in such a case we do need to take care
 123          * that gcc will set soft_enabled directly via r13, not choose to use
 124          * an intermediate register, lest we're preempted to a different cpu.
 125          */
 126         set_soft_enabled(en);
 127         if (!en)
 128                 return;
 129
 130         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 131                 /*
 132                  * Do we need to disable preemption here?  Not really: in the
 133                  * unlikely event that we're preempted to a different cpu in
 134                  * between getting r13, loading its lppaca_ptr, and loading
 135                  * its any_int, we might call iseries_handle_interrupts without
 136                  * an interrupt pending on the new cpu, but that's no disaster,
 137                  * is it?  And the business of preempting us off the old cpu
 138                  * would itself involve a local_irq_restore which handles the
 139                  * interrupt to that cpu.
 140                  *
 141                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 142                  * to avoid any preemption checking added into get_paca().
 143                  */
 144                 if (local_paca->lppaca_ptr->int_dword.any_int)
 145                         iseries_handle_interrupts();
 146         }
 147
 148         /*
 149          * if (get_paca()->hard_enabled) return;
 150          * But again we need to take care that gcc gets hard_enabled directly
 151          * via r13, not choose to use an intermediate register, lest we're
 152          * preempted to a different cpu in between the two instructions.
 153          */
 154         if (get_hard_enabled())
 155                 return;
 156
 157         /*
 158          * Need to hard-enable interrupts here.  Since currently disabled,
 159          * no need to take further asm precautions against preemption; but
 160          * use local_paca instead of get_paca() to avoid preemption checking.
 161          */
 162         local_paca->hard_enabled = en;
 163         if ((int)mfspr(SPRN_DEC) < 0)
 164                 mtspr(SPRN_DEC, 1);
 165
 166         /*
 167          * Force the delivery of pending soft-disabled interrupts on PS3.
 168          * Any HV call will have this side effect.
 169          */
 170         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 171                 u64 tmp;
 172                 lv1_get_version_info(&tmp);
 173         }
 174
 175         __hard_irq_enable();
 176 }
 177 #endif /* CONFIG_PPC64 */
 178
 179 int show_interrupts(struct seq_file *p, void *v)
 180 {
 181         int i = *(loff_t *)v, j;
 182         struct irqaction *action;
 183         irq_desc_t *desc;
 184         unsigned long flags;
 185
 186         if (i == 0) {
 187                 seq_puts(p, "           ");
 188                 for_each_online_cpu(j)
 189                         seq_printf(p, "CPU%d       ", j);
 190                 seq_putc(p, '\n');
 191         }
 192
 193         if (i < NR_IRQS) {
 194                 desc = get_irq_desc(i);
 195                 spin_lock_irqsave(&desc->lock, flags);
 196                 action = desc->action;
 197                 if (!action || !action->handler)
 198                         goto skip;
 199                 seq_printf(p, "%3d: ", i);
 200 #ifdef CONFIG_SMP
 201                 for_each_online_cpu(j)
 202                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 203 #else
 204                 seq_printf(p, "%10u ", kstat_irqs(i));
 205 #endif /* CONFIG_SMP */
 206                 if (desc->chip)
 207                         seq_printf(p, " %s ", desc->chip->typename);
 208                 else
 209                         seq_puts(p, "  None      ");
 210                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 211                 seq_printf(p, "    %s", action->name);
 212                 for (action = action->next; action; action = action->next)
 213                         seq_printf(p, ", %s", action->name);
 214                 seq_putc(p, '\n');
 215 skip:
 216                 spin_unlock_irqrestore(&desc->lock, flags);
 217         } else if (i == NR_IRQS) {
 218 #ifdef CONFIG_PPC32
 219 #ifdef CONFIG_TAU_INT
 220                 if (tau_initialized){
 221                         seq_puts(p, "TAU: ");
 222                         for_each_online_cpu(j)
 223                                 seq_printf(p, "%10u ", tau_interrupts(j));
 224                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 225                 }
 226 #endif
 227 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
 228                 /* should this be per processor send/receive? */
 229                 seq_printf(p, "IPI (recv/sent): %10u/%u\n",
 230                                 atomic_read(&ipi_recv), atomic_read(&ipi_sent));
 231 #endif
 232 #endif /* CONFIG_PPC32 */
 233                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 234         }
 235         return 0;
 236 }
 237
 238 #ifdef CONFIG_HOTPLUG_CPU
 239 void fixup_irqs(cpumask_t map)
 240 {
 241         unsigned int irq;
 242         static int warned;
 243
 244         for_each_irq(irq) {
 245                 cpumask_t mask;
 246
 247                 if (irq_desc[irq].status & IRQ_PER_CPU)
 248                         continue;
 249
 250                 cpus_and(mask, irq_desc[irq].affinity, map);
 251                 if (any_online_cpu(mask) == NR_CPUS) {
 252                         printk("Breaking affinity for irq %i\n", irq);
 253                         mask = map;
 254                 }
 255                 if (irq_desc[irq].chip->set_affinity)
 256                         irq_desc[irq].chip->set_affinity(irq, mask);
 257                 else if (irq_desc[irq].action && !(warned++))
 258                         printk("Cannot set affinity for irq %i\n", irq);
 259         }
 260
 261         local_irq_enable();
 262         mdelay(1);
 263         local_irq_disable();
 264 }
 265 #endif
 266
 267 void do_IRQ(struct pt_regs *regs)
 268 {
 269         struct pt_regs *old_regs = set_irq_regs(regs);
 270         unsigned int irq;
 271 #ifdef CONFIG_IRQSTACKS
 272         struct thread_info *curtp, *irqtp;
 273 #endif
 274
 275         irq_enter();
 276
 277 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 278         /* Debugging check for stack overflow: is there less than 2KB free? */
 279         {
 280                 long sp;
 281
 282                 sp = __get_SP() & (THREAD_SIZE-1);
 283
 284                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 285                         printk("do_IRQ: stack overflow: %ld\n",
 286                                 sp - sizeof(struct thread_info));
 287                         dump_stack();
 288                 }
 289         }
 290 #endif
 291
 292         /*
 293          * Every platform is required to implement ppc_md.get_irq.
 294          * This function will either return an irq number or NO_IRQ to
 295          * indicate there are no more pending.
 296          * The value NO_IRQ_IGNORE is for buggy hardware and means that this
 297          * IRQ has already been handled. -- Tom
 298          */
 299         irq = ppc_md.get_irq();
 300
 301         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
 302 #ifdef CONFIG_IRQSTACKS
 303                 /* Switch to the irq stack to handle this */
 304                 curtp = current_thread_info();
 305                 irqtp = hardirq_ctx[smp_processor_id()];
 306                 if (curtp != irqtp) {
 307                         struct irq_desc *desc = irq_desc + irq;
 308                         void *handler = desc->handle_irq;
 309                         if (handler == NULL)
 310                                 handler = &__do_IRQ;
 311                         irqtp->task = curtp->task;
 312                         irqtp->flags = 0;
 313
 314                         /* Copy the softirq bits in preempt_count so that the
 315                          * softirq checks work in the hardirq context.
 316                          */
 317                         irqtp->preempt_count =
 318                                 (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 319                                 (curtp->preempt_count & SOFTIRQ_MASK);
 320
 321                         call_handle_irq(irq, desc, irqtp, handler);
 322                         irqtp->task = NULL;
 323
 324
 325                         /* Set any flag that may have been set on the
 326                          * alternate stack
 327                          */
 328                         if (irqtp->flags)
 329                                 set_bits(irqtp->flags, &curtp->flags);
 330                 } else
 331 #endif
 332                         generic_handle_irq(irq);
 333         } else if (irq != NO_IRQ_IGNORE)
 334                 /* That's not SMP safe ... but who cares ? */
 335                 ppc_spurious_interrupts++;
 336
 337         irq_exit();
 338         set_irq_regs(old_regs);
 339
 340 #ifdef CONFIG_PPC_ISERIES
 341         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 342                         get_lppaca()->int_dword.fields.decr_int) {
 343                 get_lppaca()->int_dword.fields.decr_int = 0;
 344                 /* Signal a fake decrementer interrupt */
 345                 timer_interrupt(regs);
 346         }
 347 #endif
 348 }
 349
 350 void __init init_IRQ(void)
 351 {
 352         if (ppc_md.init_IRQ)
 353                 ppc_md.init_IRQ();
 354 #ifdef CONFIG_PPC64
 355         irq_ctx_init();
 356 #endif
 357 }
 358
 359
 360 #ifdef CONFIG_IRQSTACKS
 361 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 362 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 363
 364 void irq_ctx_init(void)
 365 {
 366         struct thread_info *tp;
 367         int i;
 368
 369         for_each_possible_cpu(i) {
 370                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 371                 tp = softirq_ctx[i];
 372                 tp->cpu = i;
 373                 tp->preempt_count = 0;
 374
 375                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 376                 tp = hardirq_ctx[i];
 377                 tp->cpu = i;
 378                 tp->preempt_count = HARDIRQ_OFFSET;
 379         }
 380 }
 381
 382 static inline void do_softirq_onstack(void)
 383 {
 384         struct thread_info *curtp, *irqtp;
 385
 386         curtp = current_thread_info();
 387         irqtp = softirq_ctx[smp_processor_id()];
 388         irqtp->task = curtp->task;
 389         call_do_softirq(irqtp);
 390         irqtp->task = NULL;
 391 }
 392
 393 #else
 394 #define do_softirq_onstack()    __do_softirq()
 395 #endif /* CONFIG_IRQSTACKS */
 396
 397 void do_softirq(void)
 398 {
 399         unsigned long flags;
 400
 401         if (in_interrupt())
 402                 return;
 403
 404         local_irq_save(flags);
 405
 406         if (local_softirq_pending())
 407                 do_softirq_onstack();
 408
 409         local_irq_restore(flags);
 410 }
 411
 412
 413 /*
 414  * IRQ controller and virtual interrupts
 415  */
 416
 417 #ifdef CONFIG_PPC_MERGE
 418
 419 static LIST_HEAD(irq_hosts);
 420 static DEFINE_SPINLOCK(irq_big_lock);
 421 static DEFINE_PER_CPU(unsigned int, irq_radix_reader);
 422 static unsigned int irq_radix_writer;
 423 struct irq_map_entry irq_map[NR_IRQS];
 424 static unsigned int irq_virq_count = NR_IRQS;
 425 static struct irq_host *irq_default_host;
 426
 427 irq_hw_number_t virq_to_hw(unsigned int virq)
 428 {
 429         return irq_map[virq].hwirq;
 430 }
 431 EXPORT_SYMBOL_GPL(virq_to_hw);
 432
 433 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 434 {
 435         return h->of_node != NULL && h->of_node == np;
 436 }
 437
 438 struct irq_host *irq_alloc_host(struct device_node *of_node,
 439                                 unsigned int revmap_type,
 440                                 unsigned int revmap_arg,
 441                                 struct irq_host_ops *ops,
 442                                 irq_hw_number_t inval_irq)
 443 {
 444         struct irq_host *host;
 445         unsigned int size = sizeof(struct irq_host);
 446         unsigned int i;
 447         unsigned int *rmap;
 448         unsigned long flags;
 449
 450         /* Allocate structure and revmap table if using linear mapping */
 451         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 452                 size += revmap_arg * sizeof(unsigned int);
 453         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 454         if (host == NULL)
 455                 return NULL;
 456
 457         /* Fill structure */
 458         host->revmap_type = revmap_type;
 459         host->inval_irq = inval_irq;
 460         host->ops = ops;
 461         host->of_node = of_node;
 462
 463         if (host->ops->match == NULL)
 464                 host->ops->match = default_irq_host_match;
 465
 466         spin_lock_irqsave(&irq_big_lock, flags);
 467
 468         /* If it's a legacy controller, check for duplicates and
 469          * mark it as allocated (we use irq 0 host pointer for that
 470          */
 471         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 472                 if (irq_map[0].host != NULL) {
 473                         spin_unlock_irqrestore(&irq_big_lock, flags);
 474                         /* If we are early boot, we can't free the structure,
 475                          * too bad...
 476                          * this will be fixed once slab is made available early
 477                          * instead of the current cruft
 478                          */
 479                         if (mem_init_done)
 480                                 kfree(host);
 481                         return NULL;
 482                 }
 483                 irq_map[0].host = host;
 484         }
 485
 486         list_add(&host->link, &irq_hosts);
 487         spin_unlock_irqrestore(&irq_big_lock, flags);
 488
 489         /* Additional setups per revmap type */
 490         switch(revmap_type) {
 491         case IRQ_HOST_MAP_LEGACY:
 492                 /* 0 is always the invalid number for legacy */
 493                 host->inval_irq = 0;
 494                 /* setup us as the host for all legacy interrupts */
 495                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 496                         irq_map[i].hwirq = i;
 497                         smp_wmb();
 498                         irq_map[i].host = host;
 499                         smp_wmb();
 500
 501                         /* Clear norequest flags */
 502                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 503
 504                         /* Legacy flags are left to default at this point,
 505                          * one can then use irq_create_mapping() to
 506                          * explicitly change them
 507                          */
 508                         ops->map(host, i, i);
 509                 }
 510                 break;
 511         case IRQ_HOST_MAP_LINEAR:
 512                 rmap = (unsigned int *)(host + 1);
 513                 for (i = 0; i < revmap_arg; i++)
 514                         rmap[i] = NO_IRQ;
 515                 host->revmap_data.linear.size = revmap_arg;
 516                 smp_wmb();
 517                 host->revmap_data.linear.revmap = rmap;
 518                 break;
 519         default:
 520                 break;
 521         }
 522
 523         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 524
 525         return host;
 526 }
 527
 528 struct irq_host *irq_find_host(struct device_node *node)
 529 {
 530         struct irq_host *h, *found = NULL;
 531         unsigned long flags;
 532
 533         /* We might want to match the legacy controller last since
 534          * it might potentially be set to match all interrupts in
 535          * the absence of a device node. This isn't a problem so far
 536          * yet though...
 537          */
 538         spin_lock_irqsave(&irq_big_lock, flags);
 539         list_for_each_entry(h, &irq_hosts, link)
 540                 if (h->ops->match(h, node)) {
 541                         found = h;
 542                         break;
 543                 }
 544         spin_unlock_irqrestore(&irq_big_lock, flags);
 545         return found;
 546 }
 547 EXPORT_SYMBOL_GPL(irq_find_host);
 548
 549 void irq_set_default_host(struct irq_host *host)
 550 {
 551         pr_debug("irq: Default host set to @0x%p\n", host);
 552
 553         irq_default_host = host;
 554 }
 555
 556 void irq_set_virq_count(unsigned int count)
 557 {
 558         pr_debug("irq: Trying to set virq count to %d\n", count);
 559
 560         BUG_ON(count < NUM_ISA_INTERRUPTS);
 561         if (count < NR_IRQS)
 562                 irq_virq_count = count;
 563 }
 564
 565 /* radix tree not lockless safe ! we use a brlock-type mecanism
 566  * for now, until we can use a lockless radix tree
 567  */
 568 static void irq_radix_wrlock(unsigned long *flags)
 569 {
 570         unsigned int cpu, ok;
 571
 572         spin_lock_irqsave(&irq_big_lock, *flags);
 573         irq_radix_writer = 1;
 574         smp_mb();
 575         do {
 576                 barrier();
 577                 ok = 1;
 578                 for_each_possible_cpu(cpu) {
 579                         if (per_cpu(irq_radix_reader, cpu)) {
 580                                 ok = 0;
 581                                 break;
 582                         }
 583                 }
 584                 if (!ok)
 585                         cpu_relax();
 586         } while(!ok);
 587 }
 588
 589 static void irq_radix_wrunlock(unsigned long flags)
 590 {
 591         smp_wmb();
 592         irq_radix_writer = 0;
 593         spin_unlock_irqrestore(&irq_big_lock, flags);
 594 }
 595
 596 static void irq_radix_rdlock(unsigned long *flags)
 597 {
 598         local_irq_save(*flags);
 599         __get_cpu_var(irq_radix_reader) = 1;
 600         smp_mb();
 601         if (likely(irq_radix_writer == 0))
 602                 return;
 603         __get_cpu_var(irq_radix_reader) = 0;
 604         smp_wmb();
 605         spin_lock(&irq_big_lock);
 606         __get_cpu_var(irq_radix_reader) = 1;
 607         spin_unlock(&irq_big_lock);
 608 }
 609
 610 static void irq_radix_rdunlock(unsigned long flags)
 611 {
 612         __get_cpu_var(irq_radix_reader) = 0;
 613         local_irq_restore(flags);
 614 }
 615
 616 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 617                             irq_hw_number_t hwirq)
 618 {
 619         /* Clear IRQ_NOREQUEST flag */
 620         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 621
 622         /* map it */
 623         smp_wmb();
 624         irq_map[virq].hwirq = hwirq;
 625         smp_mb();
 626
 627         if (host->ops->map(host, virq, hwirq)) {
 628                 pr_debug("irq: -> mapping failed, freeing\n");
 629                 irq_free_virt(virq, 1);
 630                 return -1;
 631         }
 632
 633         return 0;
 634 }
 635
 636 unsigned int irq_create_direct_mapping(struct irq_host *host)
 637 {
 638         unsigned int virq;
 639
 640         if (host == NULL)
 641                 host = irq_default_host;
 642
 643         BUG_ON(host == NULL);
 644         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 645
 646         virq = irq_alloc_virt(host, 1, 0);
 647         if (virq == NO_IRQ) {
 648                 pr_debug("irq: create_direct virq allocation failed\n");
 649                 return NO_IRQ;
 650         }
 651
 652         pr_debug("irq: create_direct obtained virq %d\n", virq);
 653
 654         if (irq_setup_virq(host, virq, virq))
 655                 return NO_IRQ;
 656
 657         return virq;
 658 }
 659
 660 unsigned int irq_create_mapping(struct irq_host *host,
 661                                 irq_hw_number_t hwirq)
 662 {
 663         unsigned int virq, hint;
 664
 665         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 666
 667         /* Look for default host if nececssary */
 668         if (host == NULL)
 669                 host = irq_default_host;
 670         if (host == NULL) {
 671                 printk(KERN_WARNING "irq_create_mapping called for"
 672                        " NULL host, hwirq=%lx\n", hwirq);
 673                 WARN_ON(1);
 674                 return NO_IRQ;
 675         }
 676         pr_debug("irq: -> using host @%p\n", host);
 677
 678         /* Check if mapping already exist, if it does, call
 679          * host->ops->map() to update the flags
 680          */
 681         virq = irq_find_mapping(host, hwirq);
 682         if (virq != NO_IRQ) {
 683                 if (host->ops->remap)
 684                         host->ops->remap(host, virq, hwirq);
 685                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 686                 return virq;
 687         }
 688
 689         /* Get a virtual interrupt number */
 690         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 691                 /* Handle legacy */
 692                 virq = (unsigned int)hwirq;
 693                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 694                         return NO_IRQ;
 695                 return virq;
 696         } else {
 697                 /* Allocate a virtual interrupt number */
 698                 hint = hwirq % irq_virq_count;
 699                 virq = irq_alloc_virt(host, 1, hint);
 700                 if (virq == NO_IRQ) {
 701                         pr_debug("irq: -> virq allocation failed\n");
 702                         return NO_IRQ;
 703                 }
 704         }
 705         pr_debug("irq: -> obtained virq %d\n", virq);
 706
 707         if (irq_setup_virq(host, virq, hwirq))
 708                 return NO_IRQ;
 709
 710         return virq;
 711 }
 712 EXPORT_SYMBOL_GPL(irq_create_mapping);
 713
 714 unsigned int irq_create_of_mapping(struct device_node *controller,
 715                                    u32 *intspec, unsigned int intsize)
 716 {
 717         struct irq_host *host;
 718         irq_hw_number_t hwirq;
 719         unsigned int type = IRQ_TYPE_NONE;
 720         unsigned int virq;
 721
 722         if (controller == NULL)
 723                 host = irq_default_host;
 724         else
 725                 host = irq_find_host(controller);
 726         if (host == NULL) {
 727                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 728                        controller->full_name);
 729                 return NO_IRQ;
 730         }
 731
 732         /* If host has no translation, then we assume interrupt line */
 733         if (host->ops->xlate == NULL)
 734                 hwirq = intspec[0];
 735         else {
 736                 if (host->ops->xlate(host, controller, intspec, intsize,
 737                                      &hwirq, &type))
 738                         return NO_IRQ;
 739         }
 740
 741         /* Create mapping */
 742         virq = irq_create_mapping(host, hwirq);
 743         if (virq == NO_IRQ)
 744                 return virq;
 745
 746         /* Set type if specified and different than the current one */
 747         if (type != IRQ_TYPE_NONE &&
 748             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 749                 set_irq_type(virq, type);
 750         return virq;
 751 }
 752 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 753
 754 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 755 {
 756         struct of_irq oirq;
 757
 758         if (of_irq_map_one(dev, index, &oirq))
 759                 return NO_IRQ;
 760
 761         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 762                                      oirq.size);
 763 }
 764 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 765
 766 void irq_dispose_mapping(unsigned int virq)
 767 {
 768         struct irq_host *host;
 769         irq_hw_number_t hwirq;
 770         unsigned long flags;
 771
 772         if (virq == NO_IRQ)
 773                 return;
 774
 775         host = irq_map[virq].host;
 776         WARN_ON (host == NULL);
 777         if (host == NULL)
 778                 return;
 779
 780         /* Never unmap legacy interrupts */
 781         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 782                 return;
 783
 784         /* remove chip and handler */
 785         set_irq_chip_and_handler(virq, NULL, NULL);
 786
 787         /* Make sure it's completed */
 788         synchronize_irq(virq);
 789
 790         /* Tell the PIC about it */
 791         if (host->ops->unmap)
 792                 host->ops->unmap(host, virq);
 793         smp_mb();
 794
 795         /* Clear reverse map */
 796         hwirq = irq_map[virq].hwirq;
 797         switch(host->revmap_type) {
 798         case IRQ_HOST_MAP_LINEAR:
 799                 if (hwirq < host->revmap_data.linear.size)
 800                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 801                 break;
 802         case IRQ_HOST_MAP_TREE:
 803                 /* Check if radix tree allocated yet */
 804                 if (host->revmap_data.tree.gfp_mask == 0)
 805                         break;
 806                 irq_radix_wrlock(&flags);
 807                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 808                 irq_radix_wrunlock(flags);
 809                 break;
 810         }
 811
 812         /* Destroy map */
 813         smp_mb();
 814         irq_map[virq].hwirq = host->inval_irq;
 815
 816         /* Set some flags */
 817         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 818
 819         /* Free it */
 820         irq_free_virt(virq, 1);
 821 }
 822 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 823
 824 unsigned int irq_find_mapping(struct irq_host *host,
 825                               irq_hw_number_t hwirq)
 826 {
 827         unsigned int i;
 828         unsigned int hint = hwirq % irq_virq_count;
 829
 830         /* Look for default host if nececssary */
 831         if (host == NULL)
 832                 host = irq_default_host;
 833         if (host == NULL)
 834                 return NO_IRQ;
 835
 836         /* legacy -> bail early */
 837         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 838                 return hwirq;
 839
 840         /* Slow path does a linear search of the map */
 841         if (hint < NUM_ISA_INTERRUPTS)
 842                 hint = NUM_ISA_INTERRUPTS;
 843         i = hint;
 844         do  {
 845                 if (irq_map[i].host == host &&
 846                     irq_map[i].hwirq == hwirq)
 847                         return i;
 848                 i++;
 849                 if (i >= irq_virq_count)
 850                         i = NUM_ISA_INTERRUPTS;
 851         } while(i != hint);
 852         return NO_IRQ;
 853 }
 854 EXPORT_SYMBOL_GPL(irq_find_mapping);
 855
 856
 857 unsigned int irq_radix_revmap(struct irq_host *host,
 858                               irq_hw_number_t hwirq)
 859 {
 860         struct radix_tree_root *tree;
 861         struct irq_map_entry *ptr;
 862         unsigned int virq;
 863         unsigned long flags;
 864
 865         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 866
 867         /* Check if the radix tree exist yet. We test the value of
 868          * the gfp_mask for that. Sneaky but saves another int in the
 869          * structure. If not, we fallback to slow mode
 870          */
 871         tree = &host->revmap_data.tree;
 872         if (tree->gfp_mask == 0)
 873                 return irq_find_mapping(host, hwirq);
 874
 875         /* Now try to resolve */
 876         irq_radix_rdlock(&flags);
 877         ptr = radix_tree_lookup(tree, hwirq);
 878         irq_radix_rdunlock(flags);
 879
 880         /* Found it, return */
 881         if (ptr) {
 882                 virq = ptr - irq_map;
 883                 return virq;
 884         }
 885
 886         /* If not there, try to insert it */
 887         virq = irq_find_mapping(host, hwirq);
 888         if (virq != NO_IRQ) {
 889                 irq_radix_wrlock(&flags);
 890                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 891                 irq_radix_wrunlock(flags);
 892         }
 893         return virq;
 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 long flags;
1003
1004         irq_radix_wrlock(&flags);
1005         list_for_each_entry(h, &irq_hosts, link) {
1006                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1007                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
1008         }
1009         irq_radix_wrunlock(flags);
1010
1011         return 0;
1012 }
1013 arch_initcall(irq_late_init);
1014
1015 #ifdef CONFIG_VIRQ_DEBUG
1016 static int virq_debug_show(struct seq_file *m, void *private)
1017 {
1018         unsigned long flags;
1019         irq_desc_t *desc;
1020         const char *p;
1021         char none[] = "none";
1022         int i;
1023
1024         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1025                       "chip name", "host name");
1026
1027         for (i = 1; i < NR_IRQS; i++) {
1028                 desc = get_irq_desc(i);
1029                 spin_lock_irqsave(&desc->lock, flags);
1030
1031                 if (desc->action && desc->action->handler) {
1032                         seq_printf(m, "%5d  ", i);
1033                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1034
1035                         if (desc->chip && desc->chip->typename)
1036                                 p = desc->chip->typename;
1037                         else
1038                                 p = none;
1039                         seq_printf(m, "%-15s  ", p);
1040
1041                         if (irq_map[i].host && irq_map[i].host->of_node)
1042                                 p = irq_map[i].host->of_node->full_name;
1043                         else
1044                                 p = none;
1045                         seq_printf(m, "%s\n", p);
1046                 }
1047
1048                 spin_unlock_irqrestore(&desc->lock, flags);
1049         }
1050
1051         return 0;
1052 }
1053
1054 static int virq_debug_open(struct inode *inode, struct file *file)
1055 {
1056         return single_open(file, virq_debug_show, inode->i_private);
1057 }
1058
1059 static const struct file_operations virq_debug_fops = {
1060         .open = virq_debug_open,
1061         .read = seq_read,
1062         .llseek = seq_lseek,
1063         .release = single_release,
1064 };
1065
1066 static int __init irq_debugfs_init(void)
1067 {
1068         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1069                                  NULL, &virq_debug_fops))
1070                 return -ENOMEM;
1071
1072         return 0;
1073 }
1074 __initcall(irq_debugfs_init);
1075 #endif /* CONFIG_VIRQ_DEBUG */
1076
1077 #endif /* CONFIG_PPC_MERGE */
1078
1079 #ifdef CONFIG_PPC64
1080 static int __init setup_noirqdistrib(char *str)
1081 {
1082         distribute_irqs = 0;
1083         return 1;
1084 }
1085
1086 __setup("noirqdistrib", setup_noirqdistrib);
1087 #endif /* CONFIG_PPC64 */