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
  56 #include <asm/uaccess.h>
  57 #include <asm/system.h>
  58 #include <asm/io.h>
  59 #include <asm/pgtable.h>
  60 #include <asm/irq.h>
  61 #include <asm/cache.h>
  62 #include <asm/prom.h>
  63 #include <asm/ptrace.h>
  64 #include <asm/machdep.h>
  65 #include <asm/udbg.h>
  66 #ifdef CONFIG_PPC64
  67 #include <asm/paca.h>
  68 #include <asm/firmware.h>
  69 #include <asm/lv1call.h>
  70 #endif
  71
  72 int __irq_offset_value;
  73 static int ppc_spurious_interrupts;
  74
  75 #ifdef CONFIG_PPC32
  76 EXPORT_SYMBOL(__irq_offset_value);
  77 atomic_t ppc_n_lost_interrupts;
  78
  79 #ifndef CONFIG_PPC_MERGE
  80 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
  81 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
  82 #endif
  83
  84 #ifdef CONFIG_TAU_INT
  85 extern int tau_initialized;
  86 extern int tau_interrupts(int);
  87 #endif
  88 #endif /* CONFIG_PPC32 */
  89
  90 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
  91 extern atomic_t ipi_recv;
  92 extern atomic_t ipi_sent;
  93 #endif
  94
  95 #ifdef CONFIG_PPC64
  96 EXPORT_SYMBOL(irq_desc);
  97
  98 int distribute_irqs = 1;
  99
 100 static inline unsigned long get_hard_enabled(void)
 101 {
 102         unsigned long enabled;
 103
 104         __asm__ __volatile__("lbz %0,%1(13)"
 105         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 106
 107         return enabled;
 108 }
 109
 110 static inline void set_soft_enabled(unsigned long enable)
 111 {
 112         __asm__ __volatile__("stb %0,%1(13)"
 113         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 114 }
 115
 116 void local_irq_restore(unsigned long en)
 117 {
 118         /*
 119          * get_paca()->soft_enabled = en;
 120          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 121          * That was allowed before, and in such a case we do need to take care
 122          * that gcc will set soft_enabled directly via r13, not choose to use
 123          * an intermediate register, lest we're preempted to a different cpu.
 124          */
 125         set_soft_enabled(en);
 126         if (!en)
 127                 return;
 128
 129         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 130                 /*
 131                  * Do we need to disable preemption here?  Not really: in the
 132                  * unlikely event that we're preempted to a different cpu in
 133                  * between getting r13, loading its lppaca_ptr, and loading
 134                  * its any_int, we might call iseries_handle_interrupts without
 135                  * an interrupt pending on the new cpu, but that's no disaster,
 136                  * is it?  And the business of preempting us off the old cpu
 137                  * would itself involve a local_irq_restore which handles the
 138                  * interrupt to that cpu.
 139                  *
 140                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 141                  * to avoid any preemption checking added into get_paca().
 142                  */
 143                 if (local_paca->lppaca_ptr->int_dword.any_int)
 144                         iseries_handle_interrupts();
 145                 return;
 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                         call_handle_irq(irq, desc, irqtp, handler);
 314                         irqtp->task = NULL;
 315                         if (irqtp->flags)
 316                                 set_bits(irqtp->flags, &curtp->flags);
 317                 } else
 318 #endif
 319                         generic_handle_irq(irq);
 320         } else if (irq != NO_IRQ_IGNORE)
 321                 /* That's not SMP safe ... but who cares ? */
 322                 ppc_spurious_interrupts++;
 323
 324         irq_exit();
 325         set_irq_regs(old_regs);
 326
 327 #ifdef CONFIG_PPC_ISERIES
 328         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 329                         get_lppaca()->int_dword.fields.decr_int) {
 330                 get_lppaca()->int_dword.fields.decr_int = 0;
 331                 /* Signal a fake decrementer interrupt */
 332                 timer_interrupt(regs);
 333         }
 334 #endif
 335 }
 336
 337 void __init init_IRQ(void)
 338 {
 339         if (ppc_md.init_IRQ)
 340                 ppc_md.init_IRQ();
 341 #ifdef CONFIG_PPC64
 342         irq_ctx_init();
 343 #endif
 344 }
 345
 346
 347 #ifdef CONFIG_IRQSTACKS
 348 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 349 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 350
 351 void irq_ctx_init(void)
 352 {
 353         struct thread_info *tp;
 354         int i;
 355
 356         for_each_possible_cpu(i) {
 357                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 358                 tp = softirq_ctx[i];
 359                 tp->cpu = i;
 360                 tp->preempt_count = SOFTIRQ_OFFSET;
 361
 362                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 363                 tp = hardirq_ctx[i];
 364                 tp->cpu = i;
 365                 tp->preempt_count = HARDIRQ_OFFSET;
 366         }
 367 }
 368
 369 static inline void do_softirq_onstack(void)
 370 {
 371         struct thread_info *curtp, *irqtp;
 372
 373         curtp = current_thread_info();
 374         irqtp = softirq_ctx[smp_processor_id()];
 375         irqtp->task = curtp->task;
 376         call_do_softirq(irqtp);
 377         irqtp->task = NULL;
 378 }
 379
 380 #else
 381 #define do_softirq_onstack()    __do_softirq()
 382 #endif /* CONFIG_IRQSTACKS */
 383
 384 void do_softirq(void)
 385 {
 386         unsigned long flags;
 387
 388         if (in_interrupt())
 389                 return;
 390
 391         local_irq_save(flags);
 392
 393         if (local_softirq_pending())
 394                 do_softirq_onstack();
 395
 396         local_irq_restore(flags);
 397 }
 398 EXPORT_SYMBOL(do_softirq);
 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 __init_refok 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         if (mem_init_done)
 442                 host = kzalloc(size, GFP_KERNEL);
 443         else {
 444                 host = alloc_bootmem(size);
 445                 if (host)
 446                         memset(host, 0, size);
 447         }
 448         if (host == NULL)
 449                 return NULL;
 450
 451         /* Fill structure */
 452         host->revmap_type = revmap_type;
 453         host->inval_irq = inval_irq;
 454         host->ops = ops;
 455         host->of_node = of_node;
 456
 457         if (host->ops->match == NULL)
 458                 host->ops->match = default_irq_host_match;
 459
 460         spin_lock_irqsave(&irq_big_lock, flags);
 461
 462         /* If it's a legacy controller, check for duplicates and
 463          * mark it as allocated (we use irq 0 host pointer for that
 464          */
 465         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 466                 if (irq_map[0].host != NULL) {
 467                         spin_unlock_irqrestore(&irq_big_lock, flags);
 468                         /* If we are early boot, we can't free the structure,
 469                          * too bad...
 470                          * this will be fixed once slab is made available early
 471                          * instead of the current cruft
 472                          */
 473                         if (mem_init_done)
 474                                 kfree(host);
 475                         return NULL;
 476                 }
 477                 irq_map[0].host = host;
 478         }
 479
 480         list_add(&host->link, &irq_hosts);
 481         spin_unlock_irqrestore(&irq_big_lock, flags);
 482
 483         /* Additional setups per revmap type */
 484         switch(revmap_type) {
 485         case IRQ_HOST_MAP_LEGACY:
 486                 /* 0 is always the invalid number for legacy */
 487                 host->inval_irq = 0;
 488                 /* setup us as the host for all legacy interrupts */
 489                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 490                         irq_map[i].hwirq = 0;
 491                         smp_wmb();
 492                         irq_map[i].host = host;
 493                         smp_wmb();
 494
 495                         /* Clear norequest flags */
 496                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 497
 498                         /* Legacy flags are left to default at this point,
 499                          * one can then use irq_create_mapping() to
 500                          * explicitely change them
 501                          */
 502                         ops->map(host, i, i);
 503                 }
 504                 break;
 505         case IRQ_HOST_MAP_LINEAR:
 506                 rmap = (unsigned int *)(host + 1);
 507                 for (i = 0; i < revmap_arg; i++)
 508                         rmap[i] = NO_IRQ;
 509                 host->revmap_data.linear.size = revmap_arg;
 510                 smp_wmb();
 511                 host->revmap_data.linear.revmap = rmap;
 512                 break;
 513         default:
 514                 break;
 515         }
 516
 517         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 518
 519         return host;
 520 }
 521
 522 struct irq_host *irq_find_host(struct device_node *node)
 523 {
 524         struct irq_host *h, *found = NULL;
 525         unsigned long flags;
 526
 527         /* We might want to match the legacy controller last since
 528          * it might potentially be set to match all interrupts in
 529          * the absence of a device node. This isn't a problem so far
 530          * yet though...
 531          */
 532         spin_lock_irqsave(&irq_big_lock, flags);
 533         list_for_each_entry(h, &irq_hosts, link)
 534                 if (h->ops->match(h, node)) {
 535                         found = h;
 536                         break;
 537                 }
 538         spin_unlock_irqrestore(&irq_big_lock, flags);
 539         return found;
 540 }
 541 EXPORT_SYMBOL_GPL(irq_find_host);
 542
 543 void irq_set_default_host(struct irq_host *host)
 544 {
 545         pr_debug("irq: Default host set to @0x%p\n", host);
 546
 547         irq_default_host = host;
 548 }
 549
 550 void irq_set_virq_count(unsigned int count)
 551 {
 552         pr_debug("irq: Trying to set virq count to %d\n", count);
 553
 554         BUG_ON(count < NUM_ISA_INTERRUPTS);
 555         if (count < NR_IRQS)
 556                 irq_virq_count = count;
 557 }
 558
 559 /* radix tree not lockless safe ! we use a brlock-type mecanism
 560  * for now, until we can use a lockless radix tree
 561  */
 562 static void irq_radix_wrlock(unsigned long *flags)
 563 {
 564         unsigned int cpu, ok;
 565
 566         spin_lock_irqsave(&irq_big_lock, *flags);
 567         irq_radix_writer = 1;
 568         smp_mb();
 569         do {
 570                 barrier();
 571                 ok = 1;
 572                 for_each_possible_cpu(cpu) {
 573                         if (per_cpu(irq_radix_reader, cpu)) {
 574                                 ok = 0;
 575                                 break;
 576                         }
 577                 }
 578                 if (!ok)
 579                         cpu_relax();
 580         } while(!ok);
 581 }
 582
 583 static void irq_radix_wrunlock(unsigned long flags)
 584 {
 585         smp_wmb();
 586         irq_radix_writer = 0;
 587         spin_unlock_irqrestore(&irq_big_lock, flags);
 588 }
 589
 590 static void irq_radix_rdlock(unsigned long *flags)
 591 {
 592         local_irq_save(*flags);
 593         __get_cpu_var(irq_radix_reader) = 1;
 594         smp_mb();
 595         if (likely(irq_radix_writer == 0))
 596                 return;
 597         __get_cpu_var(irq_radix_reader) = 0;
 598         smp_wmb();
 599         spin_lock(&irq_big_lock);
 600         __get_cpu_var(irq_radix_reader) = 1;
 601         spin_unlock(&irq_big_lock);
 602 }
 603
 604 static void irq_radix_rdunlock(unsigned long flags)
 605 {
 606         __get_cpu_var(irq_radix_reader) = 0;
 607         local_irq_restore(flags);
 608 }
 609
 610 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 611                             irq_hw_number_t hwirq)
 612 {
 613         /* Clear IRQ_NOREQUEST flag */
 614         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 615
 616         /* map it */
 617         smp_wmb();
 618         irq_map[virq].hwirq = hwirq;
 619         smp_mb();
 620
 621         if (host->ops->map(host, virq, hwirq)) {
 622                 pr_debug("irq: -> mapping failed, freeing\n");
 623                 irq_free_virt(virq, 1);
 624                 return -1;
 625         }
 626
 627         return 0;
 628 }
 629
 630 unsigned int irq_create_direct_mapping(struct irq_host *host)
 631 {
 632         unsigned int virq;
 633
 634         if (host == NULL)
 635                 host = irq_default_host;
 636
 637         BUG_ON(host == NULL);
 638         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 639
 640         virq = irq_alloc_virt(host, 1, 0);
 641         if (virq == NO_IRQ) {
 642                 pr_debug("irq: create_direct virq allocation failed\n");
 643                 return NO_IRQ;
 644         }
 645
 646         pr_debug("irq: create_direct obtained virq %d\n", virq);
 647
 648         if (irq_setup_virq(host, virq, virq))
 649                 return NO_IRQ;
 650
 651         return virq;
 652 }
 653
 654 unsigned int irq_create_mapping(struct irq_host *host,
 655                                 irq_hw_number_t hwirq)
 656 {
 657         unsigned int virq, hint;
 658
 659         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 660
 661         /* Look for default host if nececssary */
 662         if (host == NULL)
 663                 host = irq_default_host;
 664         if (host == NULL) {
 665                 printk(KERN_WARNING "irq_create_mapping called for"
 666                        " NULL host, hwirq=%lx\n", hwirq);
 667                 WARN_ON(1);
 668                 return NO_IRQ;
 669         }
 670         pr_debug("irq: -> using host @%p\n", host);
 671
 672         /* Check if mapping already exist, if it does, call
 673          * host->ops->map() to update the flags
 674          */
 675         virq = irq_find_mapping(host, hwirq);
 676         if (virq != NO_IRQ) {
 677                 if (host->ops->remap)
 678                         host->ops->remap(host, virq, hwirq);
 679                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 680                 return virq;
 681         }
 682
 683         /* Get a virtual interrupt number */
 684         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 685                 /* Handle legacy */
 686                 virq = (unsigned int)hwirq;
 687                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 688                         return NO_IRQ;
 689                 return virq;
 690         } else {
 691                 /* Allocate a virtual interrupt number */
 692                 hint = hwirq % irq_virq_count;
 693                 virq = irq_alloc_virt(host, 1, hint);
 694                 if (virq == NO_IRQ) {
 695                         pr_debug("irq: -> virq allocation failed\n");
 696                         return NO_IRQ;
 697                 }
 698         }
 699         pr_debug("irq: -> obtained virq %d\n", virq);
 700
 701         if (irq_setup_virq(host, virq, hwirq))
 702                 return NO_IRQ;
 703
 704         return virq;
 705 }
 706 EXPORT_SYMBOL_GPL(irq_create_mapping);
 707
 708 unsigned int irq_create_of_mapping(struct device_node *controller,
 709                                    u32 *intspec, unsigned int intsize)
 710 {
 711         struct irq_host *host;
 712         irq_hw_number_t hwirq;
 713         unsigned int type = IRQ_TYPE_NONE;
 714         unsigned int virq;
 715
 716         if (controller == NULL)
 717                 host = irq_default_host;
 718         else
 719                 host = irq_find_host(controller);
 720         if (host == NULL) {
 721                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 722                        controller->full_name);
 723                 return NO_IRQ;
 724         }
 725
 726         /* If host has no translation, then we assume interrupt line */
 727         if (host->ops->xlate == NULL)
 728                 hwirq = intspec[0];
 729         else {
 730                 if (host->ops->xlate(host, controller, intspec, intsize,
 731                                      &hwirq, &type))
 732                         return NO_IRQ;
 733         }
 734
 735         /* Create mapping */
 736         virq = irq_create_mapping(host, hwirq);
 737         if (virq == NO_IRQ)
 738                 return virq;
 739
 740         /* Set type if specified and different than the current one */
 741         if (type != IRQ_TYPE_NONE &&
 742             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 743                 set_irq_type(virq, type);
 744         return virq;
 745 }
 746 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 747
 748 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 749 {
 750         struct of_irq oirq;
 751
 752         if (of_irq_map_one(dev, index, &oirq))
 753                 return NO_IRQ;
 754
 755         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 756                                      oirq.size);
 757 }
 758 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 759
 760 void irq_dispose_mapping(unsigned int virq)
 761 {
 762         struct irq_host *host;
 763         irq_hw_number_t hwirq;
 764         unsigned long flags;
 765
 766         if (virq == NO_IRQ)
 767                 return;
 768
 769         host = irq_map[virq].host;
 770         WARN_ON (host == NULL);
 771         if (host == NULL)
 772                 return;
 773
 774         /* Never unmap legacy interrupts */
 775         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 776                 return;
 777
 778         /* remove chip and handler */
 779         set_irq_chip_and_handler(virq, NULL, NULL);
 780
 781         /* Make sure it's completed */
 782         synchronize_irq(virq);
 783
 784         /* Tell the PIC about it */
 785         if (host->ops->unmap)
 786                 host->ops->unmap(host, virq);
 787         smp_mb();
 788
 789         /* Clear reverse map */
 790         hwirq = irq_map[virq].hwirq;
 791         switch(host->revmap_type) {
 792         case IRQ_HOST_MAP_LINEAR:
 793                 if (hwirq < host->revmap_data.linear.size)
 794                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 795                 break;
 796         case IRQ_HOST_MAP_TREE:
 797                 /* Check if radix tree allocated yet */
 798                 if (host->revmap_data.tree.gfp_mask == 0)
 799                         break;
 800                 irq_radix_wrlock(&flags);
 801                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 802                 irq_radix_wrunlock(flags);
 803                 break;
 804         }
 805
 806         /* Destroy map */
 807         smp_mb();
 808         irq_map[virq].hwirq = host->inval_irq;
 809
 810         /* Set some flags */
 811         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 812
 813         /* Free it */
 814         irq_free_virt(virq, 1);
 815 }
 816 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 817
 818 unsigned int irq_find_mapping(struct irq_host *host,
 819                               irq_hw_number_t hwirq)
 820 {
 821         unsigned int i;
 822         unsigned int hint = hwirq % irq_virq_count;
 823
 824         /* Look for default host if nececssary */
 825         if (host == NULL)
 826                 host = irq_default_host;
 827         if (host == NULL)
 828                 return NO_IRQ;
 829
 830         /* legacy -> bail early */
 831         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 832                 return hwirq;
 833
 834         /* Slow path does a linear search of the map */
 835         if (hint < NUM_ISA_INTERRUPTS)
 836                 hint = NUM_ISA_INTERRUPTS;
 837         i = hint;
 838         do  {
 839                 if (irq_map[i].host == host &&
 840                     irq_map[i].hwirq == hwirq)
 841                         return i;
 842                 i++;
 843                 if (i >= irq_virq_count)
 844                         i = NUM_ISA_INTERRUPTS;
 845         } while(i != hint);
 846         return NO_IRQ;
 847 }
 848 EXPORT_SYMBOL_GPL(irq_find_mapping);
 849
 850
 851 unsigned int irq_radix_revmap(struct irq_host *host,
 852                               irq_hw_number_t hwirq)
 853 {
 854         struct radix_tree_root *tree;
 855         struct irq_map_entry *ptr;
 856         unsigned int virq;
 857         unsigned long flags;
 858
 859         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 860
 861         /* Check if the radix tree exist yet. We test the value of
 862          * the gfp_mask for that. Sneaky but saves another int in the
 863          * structure. If not, we fallback to slow mode
 864          */
 865         tree = &host->revmap_data.tree;
 866         if (tree->gfp_mask == 0)
 867                 return irq_find_mapping(host, hwirq);
 868
 869         /* Now try to resolve */
 870         irq_radix_rdlock(&flags);
 871         ptr = radix_tree_lookup(tree, hwirq);
 872         irq_radix_rdunlock(flags);
 873
 874         /* Found it, return */
 875         if (ptr) {
 876                 virq = ptr - irq_map;
 877                 return virq;
 878         }
 879
 880         /* If not there, try to insert it */
 881         virq = irq_find_mapping(host, hwirq);
 882         if (virq != NO_IRQ) {
 883                 irq_radix_wrlock(&flags);
 884                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 885                 irq_radix_wrunlock(flags);
 886         }
 887         return virq;
 888 }
 889
 890 unsigned int irq_linear_revmap(struct irq_host *host,
 891                                irq_hw_number_t hwirq)
 892 {
 893         unsigned int *revmap;
 894
 895         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 896
 897         /* Check revmap bounds */
 898         if (unlikely(hwirq >= host->revmap_data.linear.size))
 899                 return irq_find_mapping(host, hwirq);
 900
 901         /* Check if revmap was allocated */
 902         revmap = host->revmap_data.linear.revmap;
 903         if (unlikely(revmap == NULL))
 904                 return irq_find_mapping(host, hwirq);
 905
 906         /* Fill up revmap with slow path if no mapping found */
 907         if (unlikely(revmap[hwirq] == NO_IRQ))
 908                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 909
 910         return revmap[hwirq];
 911 }
 912
 913 unsigned int irq_alloc_virt(struct irq_host *host,
 914                             unsigned int count,
 915                             unsigned int hint)
 916 {
 917         unsigned long flags;
 918         unsigned int i, j, found = NO_IRQ;
 919
 920         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 921                 return NO_IRQ;
 922
 923         spin_lock_irqsave(&irq_big_lock, flags);
 924
 925         /* Use hint for 1 interrupt if any */
 926         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 927             hint < irq_virq_count && irq_map[hint].host == NULL) {
 928                 found = hint;
 929                 goto hint_found;
 930         }
 931
 932         /* Look for count consecutive numbers in the allocatable
 933          * (non-legacy) space
 934          */
 935         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 936                 if (irq_map[i].host != NULL)
 937                         j = 0;
 938                 else
 939                         j++;
 940
 941                 if (j == count) {
 942                         found = i - count + 1;
 943                         break;
 944                 }
 945         }
 946         if (found == NO_IRQ) {
 947                 spin_unlock_irqrestore(&irq_big_lock, flags);
 948                 return NO_IRQ;
 949         }
 950  hint_found:
 951         for (i = found; i < (found + count); i++) {
 952                 irq_map[i].hwirq = host->inval_irq;
 953                 smp_wmb();
 954                 irq_map[i].host = host;
 955         }
 956         spin_unlock_irqrestore(&irq_big_lock, flags);
 957         return found;
 958 }
 959
 960 void irq_free_virt(unsigned int virq, unsigned int count)
 961 {
 962         unsigned long flags;
 963         unsigned int i;
 964
 965         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 966         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 967
 968         spin_lock_irqsave(&irq_big_lock, flags);
 969         for (i = virq; i < (virq + count); i++) {
 970                 struct irq_host *host;
 971
 972                 if (i < NUM_ISA_INTERRUPTS ||
 973                     (virq + count) > irq_virq_count)
 974                         continue;
 975
 976                 host = irq_map[i].host;
 977                 irq_map[i].hwirq = host->inval_irq;
 978                 smp_wmb();
 979                 irq_map[i].host = NULL;
 980         }
 981         spin_unlock_irqrestore(&irq_big_lock, flags);
 982 }
 983
 984 void irq_early_init(void)
 985 {
 986         unsigned int i;
 987
 988         for (i = 0; i < NR_IRQS; i++)
 989                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 990 }
 991
 992 /* We need to create the radix trees late */
 993 static int irq_late_init(void)
 994 {
 995         struct irq_host *h;
 996         unsigned long flags;
 997
 998         irq_radix_wrlock(&flags);
 999         list_for_each_entry(h, &irq_hosts, link) {
1000                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1001                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
1002         }
1003         irq_radix_wrunlock(flags);
1004
1005         return 0;
1006 }
1007 arch_initcall(irq_late_init);
1008
1009 #endif /* CONFIG_PPC_MERGE */
1010
1011 #ifdef CONFIG_PPC64
1012 static int __init setup_noirqdistrib(char *str)
1013 {
1014         distribute_irqs = 0;
1015         return 1;
1016 }
1017
1018 __setup("noirqdistrib", setup_noirqdistrib);
1019 #endif /* CONFIG_PPC64 */