arch/powerpc/kernel/irq.c

   1 /*
   2  *  Derived from arch/i386/kernel/irq.c
   3  *    Copyright (C) 1992 Linus Torvalds
   4  *  Adapted from arch/i386 by Gary Thomas
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
   7  *    Copyright (C) 1996-2001 Cort Dougan
   8  *  Adapted for Power Macintosh by Paul Mackerras
   9  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version
  14  * 2 of the License, or (at your option) any later version.
  15  *
  16  * This file contains the code used by various IRQ handling routines:
  17  * asking for different IRQ's should be done through these routines
  18  * instead of just grabbing them. Thus setups with different IRQ numbers
  19  * shouldn't result in any weird surprises, and installing new handlers
  20  * should be easier.
  21  *
  22  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
  23  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
  24  * mask register (of which only 16 are defined), hence the weird shifting
  25  * and complement of the cached_irq_mask.  I want to be able to stuff
  26  * this right into the SIU SMASK register.
  27  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
  28  * to reduce code space and undefined function references.
  29  */
  30
  31 #undef DEBUG
  32
  33 #include <linux/module.h>
  34 #include <linux/threads.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/signal.h>
  37 #include <linux/sched.h>
  38 #include <linux/ptrace.h>
  39 #include <linux/ioport.h>
  40 #include <linux/interrupt.h>
  41 #include <linux/timex.h>
  42 #include <linux/init.h>
  43 #include <linux/slab.h>
  44 #include <linux/delay.h>
  45 #include <linux/irq.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/cpumask.h>
  48 #include <linux/profile.h>
  49 #include <linux/bitops.h>
  50 #include <linux/list.h>
  51 #include <linux/radix-tree.h>
  52 #include <linux/mutex.h>
  53 #include <linux/bootmem.h>
  54 #include <linux/pci.h>
  55 #include <linux/debugfs.h>
  56
  57 #include <asm/uaccess.h>
  58 #include <asm/system.h>
  59 #include <asm/io.h>
  60 #include <asm/pgtable.h>
  61 #include <asm/irq.h>
  62 #include <asm/cache.h>
  63 #include <asm/prom.h>
  64 #include <asm/ptrace.h>
  65 #include <asm/machdep.h>
  66 #include <asm/udbg.h>
  67 #ifdef CONFIG_PPC64
  68 #include <asm/paca.h>
  69 #include <asm/firmware.h>
  70 #include <asm/lv1call.h>
  71 #endif
  72
  73 int __irq_offset_value;
  74 static int ppc_spurious_interrupts;
  75
  76 #ifdef CONFIG_PPC32
  77 EXPORT_SYMBOL(__irq_offset_value);
  78 atomic_t ppc_n_lost_interrupts;
  79
  80 #ifndef CONFIG_PPC_MERGE
  81 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
  82 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
  83 #endif
  84
  85 #ifdef CONFIG_TAU_INT
  86 extern int tau_initialized;
  87 extern int tau_interrupts(int);
  88 #endif
  89 #endif /* CONFIG_PPC32 */
  90
  91 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
  92 extern atomic_t ipi_recv;
  93 extern atomic_t ipi_sent;
  94 #endif
  95
  96 #ifdef CONFIG_PPC64
  97 EXPORT_SYMBOL(irq_desc);
  98
  99 int distribute_irqs = 1;
 100
 101 static inline unsigned long get_hard_enabled(void)
 102 {
 103         unsigned long enabled;
 104
 105         __asm__ __volatile__("lbz %0,%1(13)"
 106         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 107
 108         return enabled;
 109 }
 110
 111 static inline void set_soft_enabled(unsigned long enable)
 112 {
 113         __asm__ __volatile__("stb %0,%1(13)"
 114         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 115 }
 116
 117 void local_irq_restore(unsigned long en)
 118 {
 119         /*
 120          * get_paca()->soft_enabled = en;
 121          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 122          * That was allowed before, and in such a case we do need to take care
 123          * that gcc will set soft_enabled directly via r13, not choose to use
 124          * an intermediate register, lest we're preempted to a different cpu.
 125          */
 126         set_soft_enabled(en);
 127         if (!en)
 128                 return;
 129
 130         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 131                 /*
 132                  * Do we need to disable preemption here?  Not really: in the
 133                  * unlikely event that we're preempted to a different cpu in
 134                  * between getting r13, loading its lppaca_ptr, and loading
 135                  * its any_int, we might call iseries_handle_interrupts without
 136                  * an interrupt pending on the new cpu, but that's no disaster,
 137                  * is it?  And the business of preempting us off the old cpu
 138                  * would itself involve a local_irq_restore which handles the
 139                  * interrupt to that cpu.
 140                  *
 141                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 142                  * to avoid any preemption checking added into get_paca().
 143                  */
 144                 if (local_paca->lppaca_ptr->int_dword.any_int)
 145                         iseries_handle_interrupts();
 146                 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 EXPORT_SYMBOL(do_softirq);
 400
 401
 402 /*
 403  * IRQ controller and virtual interrupts
 404  */
 405
 406 #ifdef CONFIG_PPC_MERGE
 407
 408 static LIST_HEAD(irq_hosts);
 409 static DEFINE_SPINLOCK(irq_big_lock);
 410 static DEFINE_PER_CPU(unsigned int, irq_radix_reader);
 411 static unsigned int irq_radix_writer;
 412 struct irq_map_entry irq_map[NR_IRQS];
 413 static unsigned int irq_virq_count = NR_IRQS;
 414 static struct irq_host *irq_default_host;
 415
 416 irq_hw_number_t virq_to_hw(unsigned int virq)
 417 {
 418         return irq_map[virq].hwirq;
 419 }
 420 EXPORT_SYMBOL_GPL(virq_to_hw);
 421
 422 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 423 {
 424         return h->of_node != NULL && h->of_node == np;
 425 }
 426
 427 __init_refok struct irq_host *irq_alloc_host(struct device_node *of_node,
 428                                 unsigned int revmap_type,
 429                                 unsigned int revmap_arg,
 430                                 struct irq_host_ops *ops,
 431                                 irq_hw_number_t inval_irq)
 432 {
 433         struct irq_host *host;
 434         unsigned int size = sizeof(struct irq_host);
 435         unsigned int i;
 436         unsigned int *rmap;
 437         unsigned long flags;
 438
 439         /* Allocate structure and revmap table if using linear mapping */
 440         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 441                 size += revmap_arg * sizeof(unsigned int);
 442         if (mem_init_done)
 443                 host = kzalloc(size, GFP_KERNEL);
 444         else {
 445                 host = alloc_bootmem(size);
 446                 if (host)
 447                         memset(host, 0, size);
 448         }
 449         if (host == NULL)
 450                 return NULL;
 451
 452         /* Fill structure */
 453         host->revmap_type = revmap_type;
 454         host->inval_irq = inval_irq;
 455         host->ops = ops;
 456         host->of_node = of_node;
 457
 458         if (host->ops->match == NULL)
 459                 host->ops->match = default_irq_host_match;
 460
 461         spin_lock_irqsave(&irq_big_lock, flags);
 462
 463         /* If it's a legacy controller, check for duplicates and
 464          * mark it as allocated (we use irq 0 host pointer for that
 465          */
 466         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 467                 if (irq_map[0].host != NULL) {
 468                         spin_unlock_irqrestore(&irq_big_lock, flags);
 469                         /* If we are early boot, we can't free the structure,
 470                          * too bad...
 471                          * this will be fixed once slab is made available early
 472                          * instead of the current cruft
 473                          */
 474                         if (mem_init_done)
 475                                 kfree(host);
 476                         return NULL;
 477                 }
 478                 irq_map[0].host = host;
 479         }
 480
 481         list_add(&host->link, &irq_hosts);
 482         spin_unlock_irqrestore(&irq_big_lock, flags);
 483
 484         /* Additional setups per revmap type */
 485         switch(revmap_type) {
 486         case IRQ_HOST_MAP_LEGACY:
 487                 /* 0 is always the invalid number for legacy */
 488                 host->inval_irq = 0;
 489                 /* setup us as the host for all legacy interrupts */
 490                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 491                         irq_map[i].hwirq = i;
 492                         smp_wmb();
 493                         irq_map[i].host = host;
 494                         smp_wmb();
 495
 496                         /* Clear norequest flags */
 497                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 498
 499                         /* Legacy flags are left to default at this point,
 500                          * one can then use irq_create_mapping() to
 501                          * explicitely change them
 502                          */
 503                         ops->map(host, i, i);
 504                 }
 505                 break;
 506         case IRQ_HOST_MAP_LINEAR:
 507                 rmap = (unsigned int *)(host + 1);
 508                 for (i = 0; i < revmap_arg; i++)
 509                         rmap[i] = NO_IRQ;
 510                 host->revmap_data.linear.size = revmap_arg;
 511                 smp_wmb();
 512                 host->revmap_data.linear.revmap = rmap;
 513                 break;
 514         default:
 515                 break;
 516         }
 517
 518         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 519
 520         return host;
 521 }
 522
 523 struct irq_host *irq_find_host(struct device_node *node)
 524 {
 525         struct irq_host *h, *found = NULL;
 526         unsigned long flags;
 527
 528         /* We might want to match the legacy controller last since
 529          * it might potentially be set to match all interrupts in
 530          * the absence of a device node. This isn't a problem so far
 531          * yet though...
 532          */
 533         spin_lock_irqsave(&irq_big_lock, flags);
 534         list_for_each_entry(h, &irq_hosts, link)
 535                 if (h->ops->match(h, node)) {
 536                         found = h;
 537                         break;
 538                 }
 539         spin_unlock_irqrestore(&irq_big_lock, flags);
 540         return found;
 541 }
 542 EXPORT_SYMBOL_GPL(irq_find_host);
 543
 544 void irq_set_default_host(struct irq_host *host)
 545 {
 546         pr_debug("irq: Default host set to @0x%p\n", host);
 547
 548         irq_default_host = host;
 549 }
 550
 551 void irq_set_virq_count(unsigned int count)
 552 {
 553         pr_debug("irq: Trying to set virq count to %d\n", count);
 554
 555         BUG_ON(count < NUM_ISA_INTERRUPTS);
 556         if (count < NR_IRQS)
 557                 irq_virq_count = count;
 558 }
 559
 560 /* radix tree not lockless safe ! we use a brlock-type mecanism
 561  * for now, until we can use a lockless radix tree
 562  */
 563 static void irq_radix_wrlock(unsigned long *flags)
 564 {
 565         unsigned int cpu, ok;
 566
 567         spin_lock_irqsave(&irq_big_lock, *flags);
 568         irq_radix_writer = 1;
 569         smp_mb();
 570         do {
 571                 barrier();
 572                 ok = 1;
 573                 for_each_possible_cpu(cpu) {
 574                         if (per_cpu(irq_radix_reader, cpu)) {
 575                                 ok = 0;
 576                                 break;
 577                         }
 578                 }
 579                 if (!ok)
 580                         cpu_relax();
 581         } while(!ok);
 582 }
 583
 584 static void irq_radix_wrunlock(unsigned long flags)
 585 {
 586         smp_wmb();
 587         irq_radix_writer = 0;
 588         spin_unlock_irqrestore(&irq_big_lock, flags);
 589 }
 590
 591 static void irq_radix_rdlock(unsigned long *flags)
 592 {
 593         local_irq_save(*flags);
 594         __get_cpu_var(irq_radix_reader) = 1;
 595         smp_mb();
 596         if (likely(irq_radix_writer == 0))
 597                 return;
 598         __get_cpu_var(irq_radix_reader) = 0;
 599         smp_wmb();
 600         spin_lock(&irq_big_lock);
 601         __get_cpu_var(irq_radix_reader) = 1;
 602         spin_unlock(&irq_big_lock);
 603 }
 604
 605 static void irq_radix_rdunlock(unsigned long flags)
 606 {
 607         __get_cpu_var(irq_radix_reader) = 0;
 608         local_irq_restore(flags);
 609 }
 610
 611 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 612                             irq_hw_number_t hwirq)
 613 {
 614         /* Clear IRQ_NOREQUEST flag */
 615         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 616
 617         /* map it */
 618         smp_wmb();
 619         irq_map[virq].hwirq = hwirq;
 620         smp_mb();
 621
 622         if (host->ops->map(host, virq, hwirq)) {
 623                 pr_debug("irq: -> mapping failed, freeing\n");
 624                 irq_free_virt(virq, 1);
 625                 return -1;
 626         }
 627
 628         return 0;
 629 }
 630
 631 unsigned int irq_create_direct_mapping(struct irq_host *host)
 632 {
 633         unsigned int virq;
 634
 635         if (host == NULL)
 636                 host = irq_default_host;
 637
 638         BUG_ON(host == NULL);
 639         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 640
 641         virq = irq_alloc_virt(host, 1, 0);
 642         if (virq == NO_IRQ) {
 643                 pr_debug("irq: create_direct virq allocation failed\n");
 644                 return NO_IRQ;
 645         }
 646
 647         pr_debug("irq: create_direct obtained virq %d\n", virq);
 648
 649         if (irq_setup_virq(host, virq, virq))
 650                 return NO_IRQ;
 651
 652         return virq;
 653 }
 654
 655 unsigned int irq_create_mapping(struct irq_host *host,
 656                                 irq_hw_number_t hwirq)
 657 {
 658         unsigned int virq, hint;
 659
 660         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 661
 662         /* Look for default host if nececssary */
 663         if (host == NULL)
 664                 host = irq_default_host;
 665         if (host == NULL) {
 666                 printk(KERN_WARNING "irq_create_mapping called for"
 667                        " NULL host, hwirq=%lx\n", hwirq);
 668                 WARN_ON(1);
 669                 return NO_IRQ;
 670         }
 671         pr_debug("irq: -> using host @%p\n", host);
 672
 673         /* Check if mapping already exist, if it does, call
 674          * host->ops->map() to update the flags
 675          */
 676         virq = irq_find_mapping(host, hwirq);
 677         if (virq != NO_IRQ) {
 678                 if (host->ops->remap)
 679                         host->ops->remap(host, virq, hwirq);
 680                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 681                 return virq;
 682         }
 683
 684         /* Get a virtual interrupt number */
 685         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 686                 /* Handle legacy */
 687                 virq = (unsigned int)hwirq;
 688                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 689                         return NO_IRQ;
 690                 return virq;
 691         } else {
 692                 /* Allocate a virtual interrupt number */
 693                 hint = hwirq % irq_virq_count;
 694                 virq = irq_alloc_virt(host, 1, hint);
 695                 if (virq == NO_IRQ) {
 696                         pr_debug("irq: -> virq allocation failed\n");
 697                         return NO_IRQ;
 698                 }
 699         }
 700         pr_debug("irq: -> obtained virq %d\n", virq);
 701
 702         if (irq_setup_virq(host, virq, hwirq))
 703                 return NO_IRQ;
 704
 705         return virq;
 706 }
 707 EXPORT_SYMBOL_GPL(irq_create_mapping);
 708
 709 unsigned int irq_create_of_mapping(struct device_node *controller,
 710                                    u32 *intspec, unsigned int intsize)
 711 {
 712         struct irq_host *host;
 713         irq_hw_number_t hwirq;
 714         unsigned int type = IRQ_TYPE_NONE;
 715         unsigned int virq;
 716
 717         if (controller == NULL)
 718                 host = irq_default_host;
 719         else
 720                 host = irq_find_host(controller);
 721         if (host == NULL) {
 722                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 723                        controller->full_name);
 724                 return NO_IRQ;
 725         }
 726
 727         /* If host has no translation, then we assume interrupt line */
 728         if (host->ops->xlate == NULL)
 729                 hwirq = intspec[0];
 730         else {
 731                 if (host->ops->xlate(host, controller, intspec, intsize,
 732                                      &hwirq, &type))
 733                         return NO_IRQ;
 734         }
 735
 736         /* Create mapping */
 737         virq = irq_create_mapping(host, hwirq);
 738         if (virq == NO_IRQ)
 739                 return virq;
 740
 741         /* Set type if specified and different than the current one */
 742         if (type != IRQ_TYPE_NONE &&
 743             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 744                 set_irq_type(virq, type);
 745         return virq;
 746 }
 747 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 748
 749 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 750 {
 751         struct of_irq oirq;
 752
 753         if (of_irq_map_one(dev, index, &oirq))
 754                 return NO_IRQ;
 755
 756         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 757                                      oirq.size);
 758 }
 759 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 760
 761 void irq_dispose_mapping(unsigned int virq)
 762 {
 763         struct irq_host *host;
 764         irq_hw_number_t hwirq;
 765         unsigned long flags;
 766
 767         if (virq == NO_IRQ)
 768                 return;
 769
 770         host = irq_map[virq].host;
 771         WARN_ON (host == NULL);
 772         if (host == NULL)
 773                 return;
 774
 775         /* Never unmap legacy interrupts */
 776         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 777                 return;
 778
 779         /* remove chip and handler */
 780         set_irq_chip_and_handler(virq, NULL, NULL);
 781
 782         /* Make sure it's completed */
 783         synchronize_irq(virq);
 784
 785         /* Tell the PIC about it */
 786         if (host->ops->unmap)
 787                 host->ops->unmap(host, virq);
 788         smp_mb();
 789
 790         /* Clear reverse map */
 791         hwirq = irq_map[virq].hwirq;
 792         switch(host->revmap_type) {
 793         case IRQ_HOST_MAP_LINEAR:
 794                 if (hwirq < host->revmap_data.linear.size)
 795                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 796                 break;
 797         case IRQ_HOST_MAP_TREE:
 798                 /* Check if radix tree allocated yet */
 799                 if (host->revmap_data.tree.gfp_mask == 0)
 800                         break;
 801                 irq_radix_wrlock(&flags);
 802                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 803                 irq_radix_wrunlock(flags);
 804                 break;
 805         }
 806
 807         /* Destroy map */
 808         smp_mb();
 809         irq_map[virq].hwirq = host->inval_irq;
 810
 811         /* Set some flags */
 812         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 813
 814         /* Free it */
 815         irq_free_virt(virq, 1);
 816 }
 817 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 818
 819 unsigned int irq_find_mapping(struct irq_host *host,
 820                               irq_hw_number_t hwirq)
 821 {
 822         unsigned int i;
 823         unsigned int hint = hwirq % irq_virq_count;
 824
 825         /* Look for default host if nececssary */
 826         if (host == NULL)
 827                 host = irq_default_host;
 828         if (host == NULL)
 829                 return NO_IRQ;
 830
 831         /* legacy -> bail early */
 832         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 833                 return hwirq;
 834
 835         /* Slow path does a linear search of the map */
 836         if (hint < NUM_ISA_INTERRUPTS)
 837                 hint = NUM_ISA_INTERRUPTS;
 838         i = hint;
 839         do  {
 840                 if (irq_map[i].host == host &&
 841                     irq_map[i].hwirq == hwirq)
 842                         return i;
 843                 i++;
 844                 if (i >= irq_virq_count)
 845                         i = NUM_ISA_INTERRUPTS;
 846         } while(i != hint);
 847         return NO_IRQ;
 848 }
 849 EXPORT_SYMBOL_GPL(irq_find_mapping);
 850
 851
 852 unsigned int irq_radix_revmap(struct irq_host *host,
 853                               irq_hw_number_t hwirq)
 854 {
 855         struct radix_tree_root *tree;
 856         struct irq_map_entry *ptr;
 857         unsigned int virq;
 858         unsigned long flags;
 859
 860         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 861
 862         /* Check if the radix tree exist yet. We test the value of
 863          * the gfp_mask for that. Sneaky but saves another int in the
 864          * structure. If not, we fallback to slow mode
 865          */
 866         tree = &host->revmap_data.tree;
 867         if (tree->gfp_mask == 0)
 868                 return irq_find_mapping(host, hwirq);
 869
 870         /* Now try to resolve */
 871         irq_radix_rdlock(&flags);
 872         ptr = radix_tree_lookup(tree, hwirq);
 873         irq_radix_rdunlock(flags);
 874
 875         /* Found it, return */
 876         if (ptr) {
 877                 virq = ptr - irq_map;
 878                 return virq;
 879         }
 880
 881         /* If not there, try to insert it */
 882         virq = irq_find_mapping(host, hwirq);
 883         if (virq != NO_IRQ) {
 884                 irq_radix_wrlock(&flags);
 885                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 886                 irq_radix_wrunlock(flags);
 887         }
 888         return virq;
 889 }
 890
 891 unsigned int irq_linear_revmap(struct irq_host *host,
 892                                irq_hw_number_t hwirq)
 893 {
 894         unsigned int *revmap;
 895
 896         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 897
 898         /* Check revmap bounds */
 899         if (unlikely(hwirq >= host->revmap_data.linear.size))
 900                 return irq_find_mapping(host, hwirq);
 901
 902         /* Check if revmap was allocated */
 903         revmap = host->revmap_data.linear.revmap;
 904         if (unlikely(revmap == NULL))
 905                 return irq_find_mapping(host, hwirq);
 906
 907         /* Fill up revmap with slow path if no mapping found */
 908         if (unlikely(revmap[hwirq] == NO_IRQ))
 909                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 910
 911         return revmap[hwirq];
 912 }
 913
 914 unsigned int irq_alloc_virt(struct irq_host *host,
 915                             unsigned int count,
 916                             unsigned int hint)
 917 {
 918         unsigned long flags;
 919         unsigned int i, j, found = NO_IRQ;
 920
 921         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 922                 return NO_IRQ;
 923
 924         spin_lock_irqsave(&irq_big_lock, flags);
 925
 926         /* Use hint for 1 interrupt if any */
 927         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 928             hint < irq_virq_count && irq_map[hint].host == NULL) {
 929                 found = hint;
 930                 goto hint_found;
 931         }
 932
 933         /* Look for count consecutive numbers in the allocatable
 934          * (non-legacy) space
 935          */
 936         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 937                 if (irq_map[i].host != NULL)
 938                         j = 0;
 939                 else
 940                         j++;
 941
 942                 if (j == count) {
 943                         found = i - count + 1;
 944                         break;
 945                 }
 946         }
 947         if (found == NO_IRQ) {
 948                 spin_unlock_irqrestore(&irq_big_lock, flags);
 949                 return NO_IRQ;
 950         }
 951  hint_found:
 952         for (i = found; i < (found + count); i++) {
 953                 irq_map[i].hwirq = host->inval_irq;
 954                 smp_wmb();
 955                 irq_map[i].host = host;
 956         }
 957         spin_unlock_irqrestore(&irq_big_lock, flags);
 958         return found;
 959 }
 960
 961 void irq_free_virt(unsigned int virq, unsigned int count)
 962 {
 963         unsigned long flags;
 964         unsigned int i;
 965
 966         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 967         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 968
 969         spin_lock_irqsave(&irq_big_lock, flags);
 970         for (i = virq; i < (virq + count); i++) {
 971                 struct irq_host *host;
 972
 973                 if (i < NUM_ISA_INTERRUPTS ||
 974                     (virq + count) > irq_virq_count)
 975                         continue;
 976
 977                 host = irq_map[i].host;
 978                 irq_map[i].hwirq = host->inval_irq;
 979                 smp_wmb();
 980                 irq_map[i].host = NULL;
 981         }
 982         spin_unlock_irqrestore(&irq_big_lock, flags);
 983 }
 984
 985 void irq_early_init(void)
 986 {
 987         unsigned int i;
 988
 989         for (i = 0; i < NR_IRQS; i++)
 990                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 991 }
 992
 993 /* We need to create the radix trees late */
 994 static int irq_late_init(void)
 995 {
 996         struct irq_host *h;
 997         unsigned long flags;
 998
 999         irq_radix_wrlock(&flags);
1000         list_for_each_entry(h, &irq_hosts, link) {
1001                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1002                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
1003         }
1004         irq_radix_wrunlock(flags);
1005
1006         return 0;
1007 }
1008 arch_initcall(irq_late_init);
1009
1010 #ifdef CONFIG_VIRQ_DEBUG
1011 static int virq_debug_show(struct seq_file *m, void *private)
1012 {
1013         unsigned long flags;
1014         irq_desc_t *desc;
1015         const char *p;
1016         char none[] = "none";
1017         int i;
1018
1019         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1020                       "chip name", "host name");
1021
1022         for (i = 1; i < NR_IRQS; i++) {
1023                 desc = get_irq_desc(i);
1024                 spin_lock_irqsave(&desc->lock, flags);
1025
1026                 if (desc->action && desc->action->handler) {
1027                         seq_printf(m, "%5d  ", i);
1028                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1029
1030                         if (desc->chip && desc->chip->typename)
1031                                 p = desc->chip->typename;
1032                         else
1033                                 p = none;
1034                         seq_printf(m, "%-15s  ", p);
1035
1036                         if (irq_map[i].host && irq_map[i].host->of_node)
1037                                 p = irq_map[i].host->of_node->full_name;
1038                         else
1039                                 p = none;
1040                         seq_printf(m, "%s\n", p);
1041                 }
1042
1043                 spin_unlock_irqrestore(&desc->lock, flags);
1044         }
1045
1046         return 0;
1047 }
1048
1049 static int virq_debug_open(struct inode *inode, struct file *file)
1050 {
1051         return single_open(file, virq_debug_show, inode->i_private);
1052 }
1053
1054 static const struct file_operations virq_debug_fops = {
1055         .open = virq_debug_open,
1056         .read = seq_read,
1057         .llseek = seq_lseek,
1058         .release = single_release,
1059 };
1060
1061 static int __init irq_debugfs_init(void)
1062 {
1063         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1064                                  NULL, &virq_debug_fops))
1065                 return -ENOMEM;
1066
1067         return 0;
1068 }
1069 __initcall(irq_debugfs_init);
1070 #endif /* CONFIG_VIRQ_DEBUG */
1071
1072 #endif /* CONFIG_PPC_MERGE */
1073
1074 #ifdef CONFIG_PPC64
1075 static int __init setup_noirqdistrib(char *str)
1076 {
1077         distribute_irqs = 0;
1078         return 1;
1079 }
1080
1081 __setup("noirqdistrib", setup_noirqdistrib);
1082 #endif /* CONFIG_PPC64 */