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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
  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 __init_refok struct irq_host *irq_alloc_host(struct device_node *of_node,
 422                                 unsigned int revmap_type,
 423                                 unsigned int revmap_arg,
 424                                 struct irq_host_ops *ops,
 425                                 irq_hw_number_t inval_irq)
 426 {
 427         struct irq_host *host;
 428         unsigned int size = sizeof(struct irq_host);
 429         unsigned int i;
 430         unsigned int *rmap;
 431         unsigned long flags;
 432
 433         /* Allocate structure and revmap table if using linear mapping */
 434         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 435                 size += revmap_arg * sizeof(unsigned int);
 436         if (mem_init_done)
 437                 host = kzalloc(size, GFP_KERNEL);
 438         else {
 439                 host = alloc_bootmem(size);
 440                 if (host)
 441                         memset(host, 0, size);
 442         }
 443         if (host == NULL)
 444                 return NULL;
 445
 446         /* Fill structure */
 447         host->revmap_type = revmap_type;
 448         host->inval_irq = inval_irq;
 449         host->ops = ops;
 450         host->of_node = of_node;
 451
 452         spin_lock_irqsave(&irq_big_lock, flags);
 453
 454         /* If it's a legacy controller, check for duplicates and
 455          * mark it as allocated (we use irq 0 host pointer for that
 456          */
 457         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 458                 if (irq_map[0].host != NULL) {
 459                         spin_unlock_irqrestore(&irq_big_lock, flags);
 460                         /* If we are early boot, we can't free the structure,
 461                          * too bad...
 462                          * this will be fixed once slab is made available early
 463                          * instead of the current cruft
 464                          */
 465                         if (mem_init_done)
 466                                 kfree(host);
 467                         return NULL;
 468                 }
 469                 irq_map[0].host = host;
 470         }
 471
 472         list_add(&host->link, &irq_hosts);
 473         spin_unlock_irqrestore(&irq_big_lock, flags);
 474
 475         /* Additional setups per revmap type */
 476         switch(revmap_type) {
 477         case IRQ_HOST_MAP_LEGACY:
 478                 /* 0 is always the invalid number for legacy */
 479                 host->inval_irq = 0;
 480                 /* setup us as the host for all legacy interrupts */
 481                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 482                         irq_map[i].hwirq = 0;
 483                         smp_wmb();
 484                         irq_map[i].host = host;
 485                         smp_wmb();
 486
 487                         /* Clear norequest flags */
 488                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 489
 490                         /* Legacy flags are left to default at this point,
 491                          * one can then use irq_create_mapping() to
 492                          * explicitely change them
 493                          */
 494                         ops->map(host, i, i);
 495                 }
 496                 break;
 497         case IRQ_HOST_MAP_LINEAR:
 498                 rmap = (unsigned int *)(host + 1);
 499                 for (i = 0; i < revmap_arg; i++)
 500                         rmap[i] = NO_IRQ;
 501                 host->revmap_data.linear.size = revmap_arg;
 502                 smp_wmb();
 503                 host->revmap_data.linear.revmap = rmap;
 504                 break;
 505         default:
 506                 break;
 507         }
 508
 509         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 510
 511         return host;
 512 }
 513
 514 struct irq_host *irq_find_host(struct device_node *node)
 515 {
 516         struct irq_host *h, *found = NULL;
 517         unsigned long flags;
 518
 519         /* We might want to match the legacy controller last since
 520          * it might potentially be set to match all interrupts in
 521          * the absence of a device node. This isn't a problem so far
 522          * yet though...
 523          */
 524         spin_lock_irqsave(&irq_big_lock, flags);
 525         list_for_each_entry(h, &irq_hosts, link)
 526                 if (h->ops->match != NULL && h->ops->match(h, node)) {
 527                         found = h;
 528                         break;
 529                 }
 530         spin_unlock_irqrestore(&irq_big_lock, flags);
 531         return found;
 532 }
 533 EXPORT_SYMBOL_GPL(irq_find_host);
 534
 535 void irq_set_default_host(struct irq_host *host)
 536 {
 537         pr_debug("irq: Default host set to @0x%p\n", host);
 538
 539         irq_default_host = host;
 540 }
 541
 542 void irq_set_virq_count(unsigned int count)
 543 {
 544         pr_debug("irq: Trying to set virq count to %d\n", count);
 545
 546         BUG_ON(count < NUM_ISA_INTERRUPTS);
 547         if (count < NR_IRQS)
 548                 irq_virq_count = count;
 549 }
 550
 551 /* radix tree not lockless safe ! we use a brlock-type mecanism
 552  * for now, until we can use a lockless radix tree
 553  */
 554 static void irq_radix_wrlock(unsigned long *flags)
 555 {
 556         unsigned int cpu, ok;
 557
 558         spin_lock_irqsave(&irq_big_lock, *flags);
 559         irq_radix_writer = 1;
 560         smp_mb();
 561         do {
 562                 barrier();
 563                 ok = 1;
 564                 for_each_possible_cpu(cpu) {
 565                         if (per_cpu(irq_radix_reader, cpu)) {
 566                                 ok = 0;
 567                                 break;
 568                         }
 569                 }
 570                 if (!ok)
 571                         cpu_relax();
 572         } while(!ok);
 573 }
 574
 575 static void irq_radix_wrunlock(unsigned long flags)
 576 {
 577         smp_wmb();
 578         irq_radix_writer = 0;
 579         spin_unlock_irqrestore(&irq_big_lock, flags);
 580 }
 581
 582 static void irq_radix_rdlock(unsigned long *flags)
 583 {
 584         local_irq_save(*flags);
 585         __get_cpu_var(irq_radix_reader) = 1;
 586         smp_mb();
 587         if (likely(irq_radix_writer == 0))
 588                 return;
 589         __get_cpu_var(irq_radix_reader) = 0;
 590         smp_wmb();
 591         spin_lock(&irq_big_lock);
 592         __get_cpu_var(irq_radix_reader) = 1;
 593         spin_unlock(&irq_big_lock);
 594 }
 595
 596 static void irq_radix_rdunlock(unsigned long flags)
 597 {
 598         __get_cpu_var(irq_radix_reader) = 0;
 599         local_irq_restore(flags);
 600 }
 601
 602 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 603                             irq_hw_number_t hwirq)
 604 {
 605         /* Clear IRQ_NOREQUEST flag */
 606         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 607
 608         /* map it */
 609         smp_wmb();
 610         irq_map[virq].hwirq = hwirq;
 611         smp_mb();
 612
 613         if (host->ops->map(host, virq, hwirq)) {
 614                 pr_debug("irq: -> mapping failed, freeing\n");
 615                 irq_free_virt(virq, 1);
 616                 return -1;
 617         }
 618
 619         return 0;
 620 }
 621
 622 unsigned int irq_create_direct_mapping(struct irq_host *host)
 623 {
 624         unsigned int virq;
 625
 626         if (host == NULL)
 627                 host = irq_default_host;
 628
 629         BUG_ON(host == NULL);
 630         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 631
 632         virq = irq_alloc_virt(host, 1, 0);
 633         if (virq == NO_IRQ) {
 634                 pr_debug("irq: create_direct virq allocation failed\n");
 635                 return NO_IRQ;
 636         }
 637
 638         pr_debug("irq: create_direct obtained virq %d\n", virq);
 639
 640         if (irq_setup_virq(host, virq, virq))
 641                 return NO_IRQ;
 642
 643         return virq;
 644 }
 645
 646 unsigned int irq_create_mapping(struct irq_host *host,
 647                                 irq_hw_number_t hwirq)
 648 {
 649         unsigned int virq, hint;
 650
 651         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 652
 653         /* Look for default host if nececssary */
 654         if (host == NULL)
 655                 host = irq_default_host;
 656         if (host == NULL) {
 657                 printk(KERN_WARNING "irq_create_mapping called for"
 658                        " NULL host, hwirq=%lx\n", hwirq);
 659                 WARN_ON(1);
 660                 return NO_IRQ;
 661         }
 662         pr_debug("irq: -> using host @%p\n", host);
 663
 664         /* Check if mapping already exist, if it does, call
 665          * host->ops->map() to update the flags
 666          */
 667         virq = irq_find_mapping(host, hwirq);
 668         if (virq != NO_IRQ) {
 669                 if (host->ops->remap)
 670                         host->ops->remap(host, virq, hwirq);
 671                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 672                 return virq;
 673         }
 674
 675         /* Get a virtual interrupt number */
 676         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 677                 /* Handle legacy */
 678                 virq = (unsigned int)hwirq;
 679                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 680                         return NO_IRQ;
 681                 return virq;
 682         } else {
 683                 /* Allocate a virtual interrupt number */
 684                 hint = hwirq % irq_virq_count;
 685                 virq = irq_alloc_virt(host, 1, hint);
 686                 if (virq == NO_IRQ) {
 687                         pr_debug("irq: -> virq allocation failed\n");
 688                         return NO_IRQ;
 689                 }
 690         }
 691         pr_debug("irq: -> obtained virq %d\n", virq);
 692
 693         if (irq_setup_virq(host, virq, hwirq))
 694                 return NO_IRQ;
 695
 696         return virq;
 697 }
 698 EXPORT_SYMBOL_GPL(irq_create_mapping);
 699
 700 unsigned int irq_create_of_mapping(struct device_node *controller,
 701                                    u32 *intspec, unsigned int intsize)
 702 {
 703         struct irq_host *host;
 704         irq_hw_number_t hwirq;
 705         unsigned int type = IRQ_TYPE_NONE;
 706         unsigned int virq;
 707
 708         if (controller == NULL)
 709                 host = irq_default_host;
 710         else
 711                 host = irq_find_host(controller);
 712         if (host == NULL) {
 713                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 714                        controller->full_name);
 715                 return NO_IRQ;
 716         }
 717
 718         /* If host has no translation, then we assume interrupt line */
 719         if (host->ops->xlate == NULL)
 720                 hwirq = intspec[0];
 721         else {
 722                 if (host->ops->xlate(host, controller, intspec, intsize,
 723                                      &hwirq, &type))
 724                         return NO_IRQ;
 725         }
 726
 727         /* Create mapping */
 728         virq = irq_create_mapping(host, hwirq);
 729         if (virq == NO_IRQ)
 730                 return virq;
 731
 732         /* Set type if specified and different than the current one */
 733         if (type != IRQ_TYPE_NONE &&
 734             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 735                 set_irq_type(virq, type);
 736         return virq;
 737 }
 738 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 739
 740 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 741 {
 742         struct of_irq oirq;
 743
 744         if (of_irq_map_one(dev, index, &oirq))
 745                 return NO_IRQ;
 746
 747         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 748                                      oirq.size);
 749 }
 750 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 751
 752 void irq_dispose_mapping(unsigned int virq)
 753 {
 754         struct irq_host *host;
 755         irq_hw_number_t hwirq;
 756         unsigned long flags;
 757
 758         if (virq == NO_IRQ)
 759                 return;
 760
 761         host = irq_map[virq].host;
 762         WARN_ON (host == NULL);
 763         if (host == NULL)
 764                 return;
 765
 766         /* Never unmap legacy interrupts */
 767         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 768                 return;
 769
 770         /* remove chip and handler */
 771         set_irq_chip_and_handler(virq, NULL, NULL);
 772
 773         /* Make sure it's completed */
 774         synchronize_irq(virq);
 775
 776         /* Tell the PIC about it */
 777         if (host->ops->unmap)
 778                 host->ops->unmap(host, virq);
 779         smp_mb();
 780
 781         /* Clear reverse map */
 782         hwirq = irq_map[virq].hwirq;
 783         switch(host->revmap_type) {
 784         case IRQ_HOST_MAP_LINEAR:
 785                 if (hwirq < host->revmap_data.linear.size)
 786                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 787                 break;
 788         case IRQ_HOST_MAP_TREE:
 789                 /* Check if radix tree allocated yet */
 790                 if (host->revmap_data.tree.gfp_mask == 0)
 791                         break;
 792                 irq_radix_wrlock(&flags);
 793                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 794                 irq_radix_wrunlock(flags);
 795                 break;
 796         }
 797
 798         /* Destroy map */
 799         smp_mb();
 800         irq_map[virq].hwirq = host->inval_irq;
 801
 802         /* Set some flags */
 803         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 804
 805         /* Free it */
 806         irq_free_virt(virq, 1);
 807 }
 808 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 809
 810 unsigned int irq_find_mapping(struct irq_host *host,
 811                               irq_hw_number_t hwirq)
 812 {
 813         unsigned int i;
 814         unsigned int hint = hwirq % irq_virq_count;
 815
 816         /* Look for default host if nececssary */
 817         if (host == NULL)
 818                 host = irq_default_host;
 819         if (host == NULL)
 820                 return NO_IRQ;
 821
 822         /* legacy -> bail early */
 823         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 824                 return hwirq;
 825
 826         /* Slow path does a linear search of the map */
 827         if (hint < NUM_ISA_INTERRUPTS)
 828                 hint = NUM_ISA_INTERRUPTS;
 829         i = hint;
 830         do  {
 831                 if (irq_map[i].host == host &&
 832                     irq_map[i].hwirq == hwirq)
 833                         return i;
 834                 i++;
 835                 if (i >= irq_virq_count)
 836                         i = NUM_ISA_INTERRUPTS;
 837         } while(i != hint);
 838         return NO_IRQ;
 839 }
 840 EXPORT_SYMBOL_GPL(irq_find_mapping);
 841
 842
 843 unsigned int irq_radix_revmap(struct irq_host *host,
 844                               irq_hw_number_t hwirq)
 845 {
 846         struct radix_tree_root *tree;
 847         struct irq_map_entry *ptr;
 848         unsigned int virq;
 849         unsigned long flags;
 850
 851         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 852
 853         /* Check if the radix tree exist yet. We test the value of
 854          * the gfp_mask for that. Sneaky but saves another int in the
 855          * structure. If not, we fallback to slow mode
 856          */
 857         tree = &host->revmap_data.tree;
 858         if (tree->gfp_mask == 0)
 859                 return irq_find_mapping(host, hwirq);
 860
 861         /* Now try to resolve */
 862         irq_radix_rdlock(&flags);
 863         ptr = radix_tree_lookup(tree, hwirq);
 864         irq_radix_rdunlock(flags);
 865
 866         /* Found it, return */
 867         if (ptr) {
 868                 virq = ptr - irq_map;
 869                 return virq;
 870         }
 871
 872         /* If not there, try to insert it */
 873         virq = irq_find_mapping(host, hwirq);
 874         if (virq != NO_IRQ) {
 875                 irq_radix_wrlock(&flags);
 876                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 877                 irq_radix_wrunlock(flags);
 878         }
 879         return virq;
 880 }
 881
 882 unsigned int irq_linear_revmap(struct irq_host *host,
 883                                irq_hw_number_t hwirq)
 884 {
 885         unsigned int *revmap;
 886
 887         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 888
 889         /* Check revmap bounds */
 890         if (unlikely(hwirq >= host->revmap_data.linear.size))
 891                 return irq_find_mapping(host, hwirq);
 892
 893         /* Check if revmap was allocated */
 894         revmap = host->revmap_data.linear.revmap;
 895         if (unlikely(revmap == NULL))
 896                 return irq_find_mapping(host, hwirq);
 897
 898         /* Fill up revmap with slow path if no mapping found */
 899         if (unlikely(revmap[hwirq] == NO_IRQ))
 900                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 901
 902         return revmap[hwirq];
 903 }
 904
 905 unsigned int irq_alloc_virt(struct irq_host *host,
 906                             unsigned int count,
 907                             unsigned int hint)
 908 {
 909         unsigned long flags;
 910         unsigned int i, j, found = NO_IRQ;
 911
 912         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 913                 return NO_IRQ;
 914
 915         spin_lock_irqsave(&irq_big_lock, flags);
 916
 917         /* Use hint for 1 interrupt if any */
 918         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 919             hint < irq_virq_count && irq_map[hint].host == NULL) {
 920                 found = hint;
 921                 goto hint_found;
 922         }
 923
 924         /* Look for count consecutive numbers in the allocatable
 925          * (non-legacy) space
 926          */
 927         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 928                 if (irq_map[i].host != NULL)
 929                         j = 0;
 930                 else
 931                         j++;
 932
 933                 if (j == count) {
 934                         found = i - count + 1;
 935                         break;
 936                 }
 937         }
 938         if (found == NO_IRQ) {
 939                 spin_unlock_irqrestore(&irq_big_lock, flags);
 940                 return NO_IRQ;
 941         }
 942  hint_found:
 943         for (i = found; i < (found + count); i++) {
 944                 irq_map[i].hwirq = host->inval_irq;
 945                 smp_wmb();
 946                 irq_map[i].host = host;
 947         }
 948         spin_unlock_irqrestore(&irq_big_lock, flags);
 949         return found;
 950 }
 951
 952 void irq_free_virt(unsigned int virq, unsigned int count)
 953 {
 954         unsigned long flags;
 955         unsigned int i;
 956
 957         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 958         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 959
 960         spin_lock_irqsave(&irq_big_lock, flags);
 961         for (i = virq; i < (virq + count); i++) {
 962                 struct irq_host *host;
 963
 964                 if (i < NUM_ISA_INTERRUPTS ||
 965                     (virq + count) > irq_virq_count)
 966                         continue;
 967
 968                 host = irq_map[i].host;
 969                 irq_map[i].hwirq = host->inval_irq;
 970                 smp_wmb();
 971                 irq_map[i].host = NULL;
 972         }
 973         spin_unlock_irqrestore(&irq_big_lock, flags);
 974 }
 975
 976 void irq_early_init(void)
 977 {
 978         unsigned int i;
 979
 980         for (i = 0; i < NR_IRQS; i++)
 981                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 982 }
 983
 984 /* We need to create the radix trees late */
 985 static int irq_late_init(void)
 986 {
 987         struct irq_host *h;
 988         unsigned long flags;
 989
 990         irq_radix_wrlock(&flags);
 991         list_for_each_entry(h, &irq_hosts, link) {
 992                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
 993                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
 994         }
 995         irq_radix_wrunlock(flags);
 996
 997         return 0;
 998 }
 999 arch_initcall(irq_late_init);
1000
1001 #endif /* CONFIG_PPC_MERGE */
1002
1003 #ifdef CONFIG_PPC64
1004 static int __init setup_noirqdistrib(char *str)
1005 {
1006         distribute_irqs = 0;
1007         return 1;
1008 }
1009
1010 __setup("noirqdistrib", setup_noirqdistrib);
1011 #endif /* CONFIG_PPC64 */