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   1 /*
   2  *  Derived from arch/i386/kernel/irq.c
   3  *    Copyright (C) 1992 Linus Torvalds
   4  *  Adapted from arch/i386 by Gary Thomas
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
   7  *    Copyright (C) 1996-2001 Cort Dougan
   8  *  Adapted for Power Macintosh by Paul Mackerras
   9  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version
  14  * 2 of the License, or (at your option) any later version.
  15  *
  16  * This file contains the code used by various IRQ handling routines:
  17  * asking for different IRQ's should be done through these routines
  18  * instead of just grabbing them. Thus setups with different IRQ numbers
  19  * shouldn't result in any weird surprises, and installing new handlers
  20  * should be easier.
  21  *
  22  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
  23  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
  24  * mask register (of which only 16 are defined), hence the weird shifting
  25  * and complement of the cached_irq_mask.  I want to be able to stuff
  26  * this right into the SIU SMASK register.
  27  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
  28  * to reduce code space and undefined function references.
  29  */
  30
  31 #undef DEBUG
  32
  33 #include <linux/module.h>
  34 #include <linux/threads.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/signal.h>
  37 #include <linux/sched.h>
  38 #include <linux/ptrace.h>
  39 #include <linux/ioport.h>
  40 #include <linux/interrupt.h>
  41 #include <linux/timex.h>
  42 #include <linux/init.h>
  43 #include <linux/slab.h>
  44 #include <linux/delay.h>
  45 #include <linux/irq.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/cpumask.h>
  48 #include <linux/profile.h>
  49 #include <linux/bitops.h>
  50 #include <linux/list.h>
  51 #include <linux/radix-tree.h>
  52 #include <linux/mutex.h>
  53 #include <linux/bootmem.h>
  54 #include <linux/pci.h>
  55 #include <linux/debugfs.h>
  56
  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                 return;
 147         }
 148
 149         /*
 150          * if (get_paca()->hard_enabled) return;
 151          * But again we need to take care that gcc gets hard_enabled directly
 152          * via r13, not choose to use an intermediate register, lest we're
 153          * preempted to a different cpu in between the two instructions.
 154          */
 155         if (get_hard_enabled())
 156                 return;
 157
 158         /*
 159          * Need to hard-enable interrupts here.  Since currently disabled,
 160          * no need to take further asm precautions against preemption; but
 161          * use local_paca instead of get_paca() to avoid preemption checking.
 162          */
 163         local_paca->hard_enabled = en;
 164         if ((int)mfspr(SPRN_DEC) < 0)
 165                 mtspr(SPRN_DEC, 1);
 166
 167         /*
 168          * Force the delivery of pending soft-disabled interrupts on PS3.
 169          * Any HV call will have this side effect.
 170          */
 171         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 172                 u64 tmp;
 173                 lv1_get_version_info(&tmp);
 174         }
 175
 176         __hard_irq_enable();
 177 }
 178 #endif /* CONFIG_PPC64 */
 179
 180 int show_interrupts(struct seq_file *p, void *v)
 181 {
 182         int i = *(loff_t *)v, j;
 183         struct irqaction *action;
 184         irq_desc_t *desc;
 185         unsigned long flags;
 186
 187         if (i == 0) {
 188                 seq_puts(p, "           ");
 189                 for_each_online_cpu(j)
 190                         seq_printf(p, "CPU%d       ", j);
 191                 seq_putc(p, '\n');
 192         }
 193
 194         if (i < NR_IRQS) {
 195                 desc = get_irq_desc(i);
 196                 spin_lock_irqsave(&desc->lock, flags);
 197                 action = desc->action;
 198                 if (!action || !action->handler)
 199                         goto skip;
 200                 seq_printf(p, "%3d: ", i);
 201 #ifdef CONFIG_SMP
 202                 for_each_online_cpu(j)
 203                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 204 #else
 205                 seq_printf(p, "%10u ", kstat_irqs(i));
 206 #endif /* CONFIG_SMP */
 207                 if (desc->chip)
 208                         seq_printf(p, " %s ", desc->chip->typename);
 209                 else
 210                         seq_puts(p, "  None      ");
 211                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 212                 seq_printf(p, "    %s", action->name);
 213                 for (action = action->next; action; action = action->next)
 214                         seq_printf(p, ", %s", action->name);
 215                 seq_putc(p, '\n');
 216 skip:
 217                 spin_unlock_irqrestore(&desc->lock, flags);
 218         } else if (i == NR_IRQS) {
 219 #ifdef CONFIG_PPC32
 220 #ifdef CONFIG_TAU_INT
 221                 if (tau_initialized){
 222                         seq_puts(p, "TAU: ");
 223                         for_each_online_cpu(j)
 224                                 seq_printf(p, "%10u ", tau_interrupts(j));
 225                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 226                 }
 227 #endif
 228 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
 229                 /* should this be per processor send/receive? */
 230                 seq_printf(p, "IPI (recv/sent): %10u/%u\n",
 231                                 atomic_read(&ipi_recv), atomic_read(&ipi_sent));
 232 #endif
 233 #endif /* CONFIG_PPC32 */
 234                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 235         }
 236         return 0;
 237 }
 238
 239 #ifdef CONFIG_HOTPLUG_CPU
 240 void fixup_irqs(cpumask_t map)
 241 {
 242         unsigned int irq;
 243         static int warned;
 244
 245         for_each_irq(irq) {
 246                 cpumask_t mask;
 247
 248                 if (irq_desc[irq].status & IRQ_PER_CPU)
 249                         continue;
 250
 251                 cpus_and(mask, irq_desc[irq].affinity, map);
 252                 if (any_online_cpu(mask) == NR_CPUS) {
 253                         printk("Breaking affinity for irq %i\n", irq);
 254                         mask = map;
 255                 }
 256                 if (irq_desc[irq].chip->set_affinity)
 257                         irq_desc[irq].chip->set_affinity(irq, mask);
 258                 else if (irq_desc[irq].action && !(warned++))
 259                         printk("Cannot set affinity for irq %i\n", irq);
 260         }
 261
 262         local_irq_enable();
 263         mdelay(1);
 264         local_irq_disable();
 265 }
 266 #endif
 267
 268 void do_IRQ(struct pt_regs *regs)
 269 {
 270         struct pt_regs *old_regs = set_irq_regs(regs);
 271         unsigned int irq;
 272 #ifdef CONFIG_IRQSTACKS
 273         struct thread_info *curtp, *irqtp;
 274 #endif
 275
 276         irq_enter();
 277
 278 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 279         /* Debugging check for stack overflow: is there less than 2KB free? */
 280         {
 281                 long sp;
 282
 283                 sp = __get_SP() & (THREAD_SIZE-1);
 284
 285                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 286                         printk("do_IRQ: stack overflow: %ld\n",
 287                                 sp - sizeof(struct thread_info));
 288                         dump_stack();
 289                 }
 290         }
 291 #endif
 292
 293         /*
 294          * Every platform is required to implement ppc_md.get_irq.
 295          * This function will either return an irq number or NO_IRQ to
 296          * indicate there are no more pending.
 297          * The value NO_IRQ_IGNORE is for buggy hardware and means that this
 298          * IRQ has already been handled. -- Tom
 299          */
 300         irq = ppc_md.get_irq();
 301
 302         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
 303 #ifdef CONFIG_IRQSTACKS
 304                 /* Switch to the irq stack to handle this */
 305                 curtp = current_thread_info();
 306                 irqtp = hardirq_ctx[smp_processor_id()];
 307                 if (curtp != irqtp) {
 308                         struct irq_desc *desc = irq_desc + irq;
 309                         void *handler = desc->handle_irq;
 310                         if (handler == NULL)
 311                                 handler = &__do_IRQ;
 312                         irqtp->task = curtp->task;
 313                         irqtp->flags = 0;
 314                         call_handle_irq(irq, desc, irqtp, handler);
 315                         irqtp->task = NULL;
 316                         if (irqtp->flags)
 317                                 set_bits(irqtp->flags, &curtp->flags);
 318                 } else
 319 #endif
 320                         generic_handle_irq(irq);
 321         } else if (irq != NO_IRQ_IGNORE)
 322                 /* That's not SMP safe ... but who cares ? */
 323                 ppc_spurious_interrupts++;
 324
 325         irq_exit();
 326         set_irq_regs(old_regs);
 327
 328 #ifdef CONFIG_PPC_ISERIES
 329         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 330                         get_lppaca()->int_dword.fields.decr_int) {
 331                 get_lppaca()->int_dword.fields.decr_int = 0;
 332                 /* Signal a fake decrementer interrupt */
 333                 timer_interrupt(regs);
 334         }
 335 #endif
 336 }
 337
 338 void __init init_IRQ(void)
 339 {
 340         if (ppc_md.init_IRQ)
 341                 ppc_md.init_IRQ();
 342 #ifdef CONFIG_PPC64
 343         irq_ctx_init();
 344 #endif
 345 }
 346
 347
 348 #ifdef CONFIG_IRQSTACKS
 349 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 350 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 351
 352 void irq_ctx_init(void)
 353 {
 354         struct thread_info *tp;
 355         int i;
 356
 357         for_each_possible_cpu(i) {
 358                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 359                 tp = softirq_ctx[i];
 360                 tp->cpu = i;
 361                 tp->preempt_count = SOFTIRQ_OFFSET;
 362
 363                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 364                 tp = hardirq_ctx[i];
 365                 tp->cpu = i;
 366                 tp->preempt_count = HARDIRQ_OFFSET;
 367         }
 368 }
 369
 370 static inline void do_softirq_onstack(void)
 371 {
 372         struct thread_info *curtp, *irqtp;
 373
 374         curtp = current_thread_info();
 375         irqtp = softirq_ctx[smp_processor_id()];
 376         irqtp->task = curtp->task;
 377         call_do_softirq(irqtp);
 378         irqtp->task = NULL;
 379 }
 380
 381 #else
 382 #define do_softirq_onstack()    __do_softirq()
 383 #endif /* CONFIG_IRQSTACKS */
 384
 385 void do_softirq(void)
 386 {
 387         unsigned long flags;
 388
 389         if (in_interrupt())
 390                 return;
 391
 392         local_irq_save(flags);
 393
 394         if (local_softirq_pending())
 395                 do_softirq_onstack();
 396
 397         local_irq_restore(flags);
 398 }
 399
 400
 401 /*
 402  * IRQ controller and virtual interrupts
 403  */
 404
 405 #ifdef CONFIG_PPC_MERGE
 406
 407 static LIST_HEAD(irq_hosts);
 408 static DEFINE_SPINLOCK(irq_big_lock);
 409 static DEFINE_PER_CPU(unsigned int, irq_radix_reader);
 410 static unsigned int irq_radix_writer;
 411 struct irq_map_entry irq_map[NR_IRQS];
 412 static unsigned int irq_virq_count = NR_IRQS;
 413 static struct irq_host *irq_default_host;
 414
 415 irq_hw_number_t virq_to_hw(unsigned int virq)
 416 {
 417         return irq_map[virq].hwirq;
 418 }
 419 EXPORT_SYMBOL_GPL(virq_to_hw);
 420
 421 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 422 {
 423         return h->of_node != NULL && h->of_node == np;
 424 }
 425
 426 struct irq_host *irq_alloc_host(struct device_node *of_node,
 427                                 unsigned int revmap_type,
 428                                 unsigned int revmap_arg,
 429                                 struct irq_host_ops *ops,
 430                                 irq_hw_number_t inval_irq)
 431 {
 432         struct irq_host *host;
 433         unsigned int size = sizeof(struct irq_host);
 434         unsigned int i;
 435         unsigned int *rmap;
 436         unsigned long flags;
 437
 438         /* Allocate structure and revmap table if using linear mapping */
 439         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 440                 size += revmap_arg * sizeof(unsigned int);
 441         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 442         if (host == NULL)
 443                 return NULL;
 444
 445         /* Fill structure */
 446         host->revmap_type = revmap_type;
 447         host->inval_irq = inval_irq;
 448         host->ops = ops;
 449         host->of_node = of_node;
 450
 451         if (host->ops->match == NULL)
 452                 host->ops->match = default_irq_host_match;
 453
 454         spin_lock_irqsave(&irq_big_lock, flags);
 455
 456         /* If it's a legacy controller, check for duplicates and
 457          * mark it as allocated (we use irq 0 host pointer for that
 458          */
 459         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 460                 if (irq_map[0].host != NULL) {
 461                         spin_unlock_irqrestore(&irq_big_lock, flags);
 462                         /* If we are early boot, we can't free the structure,
 463                          * too bad...
 464                          * this will be fixed once slab is made available early
 465                          * instead of the current cruft
 466                          */
 467                         if (mem_init_done)
 468                                 kfree(host);
 469                         return NULL;
 470                 }
 471                 irq_map[0].host = host;
 472         }
 473
 474         list_add(&host->link, &irq_hosts);
 475         spin_unlock_irqrestore(&irq_big_lock, flags);
 476
 477         /* Additional setups per revmap type */
 478         switch(revmap_type) {
 479         case IRQ_HOST_MAP_LEGACY:
 480                 /* 0 is always the invalid number for legacy */
 481                 host->inval_irq = 0;
 482                 /* setup us as the host for all legacy interrupts */
 483                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 484                         irq_map[i].hwirq = i;
 485                         smp_wmb();
 486                         irq_map[i].host = host;
 487                         smp_wmb();
 488
 489                         /* Clear norequest flags */
 490                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 491
 492                         /* Legacy flags are left to default at this point,
 493                          * one can then use irq_create_mapping() to
 494                          * explicitly change them
 495                          */
 496                         ops->map(host, i, i);
 497                 }
 498                 break;
 499         case IRQ_HOST_MAP_LINEAR:
 500                 rmap = (unsigned int *)(host + 1);
 501                 for (i = 0; i < revmap_arg; i++)
 502                         rmap[i] = NO_IRQ;
 503                 host->revmap_data.linear.size = revmap_arg;
 504                 smp_wmb();
 505                 host->revmap_data.linear.revmap = rmap;
 506                 break;
 507         default:
 508                 break;
 509         }
 510
 511         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 512
 513         return host;
 514 }
 515
 516 struct irq_host *irq_find_host(struct device_node *node)
 517 {
 518         struct irq_host *h, *found = NULL;
 519         unsigned long flags;
 520
 521         /* We might want to match the legacy controller last since
 522          * it might potentially be set to match all interrupts in
 523          * the absence of a device node. This isn't a problem so far
 524          * yet though...
 525          */
 526         spin_lock_irqsave(&irq_big_lock, flags);
 527         list_for_each_entry(h, &irq_hosts, link)
 528                 if (h->ops->match(h, node)) {
 529                         found = h;
 530                         break;
 531                 }
 532         spin_unlock_irqrestore(&irq_big_lock, flags);
 533         return found;
 534 }
 535 EXPORT_SYMBOL_GPL(irq_find_host);
 536
 537 void irq_set_default_host(struct irq_host *host)
 538 {
 539         pr_debug("irq: Default host set to @0x%p\n", host);
 540
 541         irq_default_host = host;
 542 }
 543
 544 void irq_set_virq_count(unsigned int count)
 545 {
 546         pr_debug("irq: Trying to set virq count to %d\n", count);
 547
 548         BUG_ON(count < NUM_ISA_INTERRUPTS);
 549         if (count < NR_IRQS)
 550                 irq_virq_count = count;
 551 }
 552
 553 /* radix tree not lockless safe ! we use a brlock-type mecanism
 554  * for now, until we can use a lockless radix tree
 555  */
 556 static void irq_radix_wrlock(unsigned long *flags)
 557 {
 558         unsigned int cpu, ok;
 559
 560         spin_lock_irqsave(&irq_big_lock, *flags);
 561         irq_radix_writer = 1;
 562         smp_mb();
 563         do {
 564                 barrier();
 565                 ok = 1;
 566                 for_each_possible_cpu(cpu) {
 567                         if (per_cpu(irq_radix_reader, cpu)) {
 568                                 ok = 0;
 569                                 break;
 570                         }
 571                 }
 572                 if (!ok)
 573                         cpu_relax();
 574         } while(!ok);
 575 }
 576
 577 static void irq_radix_wrunlock(unsigned long flags)
 578 {
 579         smp_wmb();
 580         irq_radix_writer = 0;
 581         spin_unlock_irqrestore(&irq_big_lock, flags);
 582 }
 583
 584 static void irq_radix_rdlock(unsigned long *flags)
 585 {
 586         local_irq_save(*flags);
 587         __get_cpu_var(irq_radix_reader) = 1;
 588         smp_mb();
 589         if (likely(irq_radix_writer == 0))
 590                 return;
 591         __get_cpu_var(irq_radix_reader) = 0;
 592         smp_wmb();
 593         spin_lock(&irq_big_lock);
 594         __get_cpu_var(irq_radix_reader) = 1;
 595         spin_unlock(&irq_big_lock);
 596 }
 597
 598 static void irq_radix_rdunlock(unsigned long flags)
 599 {
 600         __get_cpu_var(irq_radix_reader) = 0;
 601         local_irq_restore(flags);
 602 }
 603
 604 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 605                             irq_hw_number_t hwirq)
 606 {
 607         /* Clear IRQ_NOREQUEST flag */
 608         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 609
 610         /* map it */
 611         smp_wmb();
 612         irq_map[virq].hwirq = hwirq;
 613         smp_mb();
 614
 615         if (host->ops->map(host, virq, hwirq)) {
 616                 pr_debug("irq: -> mapping failed, freeing\n");
 617                 irq_free_virt(virq, 1);
 618                 return -1;
 619         }
 620
 621         return 0;
 622 }
 623
 624 unsigned int irq_create_direct_mapping(struct irq_host *host)
 625 {
 626         unsigned int virq;
 627
 628         if (host == NULL)
 629                 host = irq_default_host;
 630
 631         BUG_ON(host == NULL);
 632         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 633
 634         virq = irq_alloc_virt(host, 1, 0);
 635         if (virq == NO_IRQ) {
 636                 pr_debug("irq: create_direct virq allocation failed\n");
 637                 return NO_IRQ;
 638         }
 639
 640         pr_debug("irq: create_direct obtained virq %d\n", virq);
 641
 642         if (irq_setup_virq(host, virq, virq))
 643                 return NO_IRQ;
 644
 645         return virq;
 646 }
 647
 648 unsigned int irq_create_mapping(struct irq_host *host,
 649                                 irq_hw_number_t hwirq)
 650 {
 651         unsigned int virq, hint;
 652
 653         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 654
 655         /* Look for default host if nececssary */
 656         if (host == NULL)
 657                 host = irq_default_host;
 658         if (host == NULL) {
 659                 printk(KERN_WARNING "irq_create_mapping called for"
 660                        " NULL host, hwirq=%lx\n", hwirq);
 661                 WARN_ON(1);
 662                 return NO_IRQ;
 663         }
 664         pr_debug("irq: -> using host @%p\n", host);
 665
 666         /* Check if mapping already exist, if it does, call
 667          * host->ops->map() to update the flags
 668          */
 669         virq = irq_find_mapping(host, hwirq);
 670         if (virq != NO_IRQ) {
 671                 if (host->ops->remap)
 672                         host->ops->remap(host, virq, hwirq);
 673                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 674                 return virq;
 675         }
 676
 677         /* Get a virtual interrupt number */
 678         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 679                 /* Handle legacy */
 680                 virq = (unsigned int)hwirq;
 681                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 682                         return NO_IRQ;
 683                 return virq;
 684         } else {
 685                 /* Allocate a virtual interrupt number */
 686                 hint = hwirq % irq_virq_count;
 687                 virq = irq_alloc_virt(host, 1, hint);
 688                 if (virq == NO_IRQ) {
 689                         pr_debug("irq: -> virq allocation failed\n");
 690                         return NO_IRQ;
 691                 }
 692         }
 693         pr_debug("irq: -> obtained virq %d\n", virq);
 694
 695         if (irq_setup_virq(host, virq, hwirq))
 696                 return NO_IRQ;
 697
 698         return virq;
 699 }
 700 EXPORT_SYMBOL_GPL(irq_create_mapping);
 701
 702 unsigned int irq_create_of_mapping(struct device_node *controller,
 703                                    u32 *intspec, unsigned int intsize)
 704 {
 705         struct irq_host *host;
 706         irq_hw_number_t hwirq;
 707         unsigned int type = IRQ_TYPE_NONE;
 708         unsigned int virq;
 709
 710         if (controller == NULL)
 711                 host = irq_default_host;
 712         else
 713                 host = irq_find_host(controller);
 714         if (host == NULL) {
 715                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 716                        controller->full_name);
 717                 return NO_IRQ;
 718         }
 719
 720         /* If host has no translation, then we assume interrupt line */
 721         if (host->ops->xlate == NULL)
 722                 hwirq = intspec[0];
 723         else {
 724                 if (host->ops->xlate(host, controller, intspec, intsize,
 725                                      &hwirq, &type))
 726                         return NO_IRQ;
 727         }
 728
 729         /* Create mapping */
 730         virq = irq_create_mapping(host, hwirq);
 731         if (virq == NO_IRQ)
 732                 return virq;
 733
 734         /* Set type if specified and different than the current one */
 735         if (type != IRQ_TYPE_NONE &&
 736             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 737                 set_irq_type(virq, type);
 738         return virq;
 739 }
 740 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 741
 742 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 743 {
 744         struct of_irq oirq;
 745
 746         if (of_irq_map_one(dev, index, &oirq))
 747                 return NO_IRQ;
 748
 749         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 750                                      oirq.size);
 751 }
 752 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 753
 754 void irq_dispose_mapping(unsigned int virq)
 755 {
 756         struct irq_host *host;
 757         irq_hw_number_t hwirq;
 758         unsigned long flags;
 759
 760         if (virq == NO_IRQ)
 761                 return;
 762
 763         host = irq_map[virq].host;
 764         WARN_ON (host == NULL);
 765         if (host == NULL)
 766                 return;
 767
 768         /* Never unmap legacy interrupts */
 769         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 770                 return;
 771
 772         /* remove chip and handler */
 773         set_irq_chip_and_handler(virq, NULL, NULL);
 774
 775         /* Make sure it's completed */
 776         synchronize_irq(virq);
 777
 778         /* Tell the PIC about it */
 779         if (host->ops->unmap)
 780                 host->ops->unmap(host, virq);
 781         smp_mb();
 782
 783         /* Clear reverse map */
 784         hwirq = irq_map[virq].hwirq;
 785         switch(host->revmap_type) {
 786         case IRQ_HOST_MAP_LINEAR:
 787                 if (hwirq < host->revmap_data.linear.size)
 788                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 789                 break;
 790         case IRQ_HOST_MAP_TREE:
 791                 /* Check if radix tree allocated yet */
 792                 if (host->revmap_data.tree.gfp_mask == 0)
 793                         break;
 794                 irq_radix_wrlock(&flags);
 795                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 796                 irq_radix_wrunlock(flags);
 797                 break;
 798         }
 799
 800         /* Destroy map */
 801         smp_mb();
 802         irq_map[virq].hwirq = host->inval_irq;
 803
 804         /* Set some flags */
 805         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 806
 807         /* Free it */
 808         irq_free_virt(virq, 1);
 809 }
 810 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 811
 812 unsigned int irq_find_mapping(struct irq_host *host,
 813                               irq_hw_number_t hwirq)
 814 {
 815         unsigned int i;
 816         unsigned int hint = hwirq % irq_virq_count;
 817
 818         /* Look for default host if nececssary */
 819         if (host == NULL)
 820                 host = irq_default_host;
 821         if (host == NULL)
 822                 return NO_IRQ;
 823
 824         /* legacy -> bail early */
 825         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 826                 return hwirq;
 827
 828         /* Slow path does a linear search of the map */
 829         if (hint < NUM_ISA_INTERRUPTS)
 830                 hint = NUM_ISA_INTERRUPTS;
 831         i = hint;
 832         do  {
 833                 if (irq_map[i].host == host &&
 834                     irq_map[i].hwirq == hwirq)
 835                         return i;
 836                 i++;
 837                 if (i >= irq_virq_count)
 838                         i = NUM_ISA_INTERRUPTS;
 839         } while(i != hint);
 840         return NO_IRQ;
 841 }
 842 EXPORT_SYMBOL_GPL(irq_find_mapping);
 843
 844
 845 unsigned int irq_radix_revmap(struct irq_host *host,
 846                               irq_hw_number_t hwirq)
 847 {
 848         struct radix_tree_root *tree;
 849         struct irq_map_entry *ptr;
 850         unsigned int virq;
 851         unsigned long flags;
 852
 853         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 854
 855         /* Check if the radix tree exist yet. We test the value of
 856          * the gfp_mask for that. Sneaky but saves another int in the
 857          * structure. If not, we fallback to slow mode
 858          */
 859         tree = &host->revmap_data.tree;
 860         if (tree->gfp_mask == 0)
 861                 return irq_find_mapping(host, hwirq);
 862
 863         /* Now try to resolve */
 864         irq_radix_rdlock(&flags);
 865         ptr = radix_tree_lookup(tree, hwirq);
 866         irq_radix_rdunlock(flags);
 867
 868         /* Found it, return */
 869         if (ptr) {
 870                 virq = ptr - irq_map;
 871                 return virq;
 872         }
 873
 874         /* If not there, try to insert it */
 875         virq = irq_find_mapping(host, hwirq);
 876         if (virq != NO_IRQ) {
 877                 irq_radix_wrlock(&flags);
 878                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 879                 irq_radix_wrunlock(flags);
 880         }
 881         return virq;
 882 }
 883
 884 unsigned int irq_linear_revmap(struct irq_host *host,
 885                                irq_hw_number_t hwirq)
 886 {
 887         unsigned int *revmap;
 888
 889         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 890
 891         /* Check revmap bounds */
 892         if (unlikely(hwirq >= host->revmap_data.linear.size))
 893                 return irq_find_mapping(host, hwirq);
 894
 895         /* Check if revmap was allocated */
 896         revmap = host->revmap_data.linear.revmap;
 897         if (unlikely(revmap == NULL))
 898                 return irq_find_mapping(host, hwirq);
 899
 900         /* Fill up revmap with slow path if no mapping found */
 901         if (unlikely(revmap[hwirq] == NO_IRQ))
 902                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 903
 904         return revmap[hwirq];
 905 }
 906
 907 unsigned int irq_alloc_virt(struct irq_host *host,
 908                             unsigned int count,
 909                             unsigned int hint)
 910 {
 911         unsigned long flags;
 912         unsigned int i, j, found = NO_IRQ;
 913
 914         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 915                 return NO_IRQ;
 916
 917         spin_lock_irqsave(&irq_big_lock, flags);
 918
 919         /* Use hint for 1 interrupt if any */
 920         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 921             hint < irq_virq_count && irq_map[hint].host == NULL) {
 922                 found = hint;
 923                 goto hint_found;
 924         }
 925
 926         /* Look for count consecutive numbers in the allocatable
 927          * (non-legacy) space
 928          */
 929         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 930                 if (irq_map[i].host != NULL)
 931                         j = 0;
 932                 else
 933                         j++;
 934
 935                 if (j == count) {
 936                         found = i - count + 1;
 937                         break;
 938                 }
 939         }
 940         if (found == NO_IRQ) {
 941                 spin_unlock_irqrestore(&irq_big_lock, flags);
 942                 return NO_IRQ;
 943         }
 944  hint_found:
 945         for (i = found; i < (found + count); i++) {
 946                 irq_map[i].hwirq = host->inval_irq;
 947                 smp_wmb();
 948                 irq_map[i].host = host;
 949         }
 950         spin_unlock_irqrestore(&irq_big_lock, flags);
 951         return found;
 952 }
 953
 954 void irq_free_virt(unsigned int virq, unsigned int count)
 955 {
 956         unsigned long flags;
 957         unsigned int i;
 958
 959         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 960         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 961
 962         spin_lock_irqsave(&irq_big_lock, flags);
 963         for (i = virq; i < (virq + count); i++) {
 964                 struct irq_host *host;
 965
 966                 if (i < NUM_ISA_INTERRUPTS ||
 967                     (virq + count) > irq_virq_count)
 968                         continue;
 969
 970                 host = irq_map[i].host;
 971                 irq_map[i].hwirq = host->inval_irq;
 972                 smp_wmb();
 973                 irq_map[i].host = NULL;
 974         }
 975         spin_unlock_irqrestore(&irq_big_lock, flags);
 976 }
 977
 978 void irq_early_init(void)
 979 {
 980         unsigned int i;
 981
 982         for (i = 0; i < NR_IRQS; i++)
 983                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 984 }
 985
 986 /* We need to create the radix trees late */
 987 static int irq_late_init(void)
 988 {
 989         struct irq_host *h;
 990         unsigned long flags;
 991
 992         irq_radix_wrlock(&flags);
 993         list_for_each_entry(h, &irq_hosts, link) {
 994                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
 995                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
 996         }
 997         irq_radix_wrunlock(flags);
 998
 999         return 0;
1000 }
1001 arch_initcall(irq_late_init);
1002
1003 #ifdef CONFIG_VIRQ_DEBUG
1004 static int virq_debug_show(struct seq_file *m, void *private)
1005 {
1006         unsigned long flags;
1007         irq_desc_t *desc;
1008         const char *p;
1009         char none[] = "none";
1010         int i;
1011
1012         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1013                       "chip name", "host name");
1014
1015         for (i = 1; i < NR_IRQS; i++) {
1016                 desc = get_irq_desc(i);
1017                 spin_lock_irqsave(&desc->lock, flags);
1018
1019                 if (desc->action && desc->action->handler) {
1020                         seq_printf(m, "%5d  ", i);
1021                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1022
1023                         if (desc->chip && desc->chip->typename)
1024                                 p = desc->chip->typename;
1025                         else
1026                                 p = none;
1027                         seq_printf(m, "%-15s  ", p);
1028
1029                         if (irq_map[i].host && irq_map[i].host->of_node)
1030                                 p = irq_map[i].host->of_node->full_name;
1031                         else
1032                                 p = none;
1033                         seq_printf(m, "%s\n", p);
1034                 }
1035
1036                 spin_unlock_irqrestore(&desc->lock, flags);
1037         }
1038
1039         return 0;
1040 }
1041
1042 static int virq_debug_open(struct inode *inode, struct file *file)
1043 {
1044         return single_open(file, virq_debug_show, inode->i_private);
1045 }
1046
1047 static const struct file_operations virq_debug_fops = {
1048         .open = virq_debug_open,
1049         .read = seq_read,
1050         .llseek = seq_lseek,
1051         .release = single_release,
1052 };
1053
1054 static int __init irq_debugfs_init(void)
1055 {
1056         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1057                                  NULL, &virq_debug_fops))
1058                 return -ENOMEM;
1059
1060         return 0;
1061 }
1062 __initcall(irq_debugfs_init);
1063 #endif /* CONFIG_VIRQ_DEBUG */
1064
1065 #endif /* CONFIG_PPC_MERGE */
1066
1067 #ifdef CONFIG_PPC64
1068 static int __init setup_noirqdistrib(char *str)
1069 {
1070         distribute_irqs = 0;
1071         return 1;
1072 }
1073
1074 __setup("noirqdistrib", setup_noirqdistrib);
1075 #endif /* CONFIG_PPC64 */