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 #ifdef CONFIG_TAU_INT
  81 extern int tau_initialized;
  82 extern int tau_interrupts(int);
  83 #endif
  84 #endif /* CONFIG_PPC32 */
  85
  86 #ifdef CONFIG_PPC64
  87 EXPORT_SYMBOL(irq_desc);
  88
  89 int distribute_irqs = 1;
  90
  91 static inline notrace unsigned long get_hard_enabled(void)
  92 {
  93         unsigned long enabled;
  94
  95         __asm__ __volatile__("lbz %0,%1(13)"
  96         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
  97
  98         return enabled;
  99 }
 100
 101 static inline notrace void set_soft_enabled(unsigned long enable)
 102 {
 103         __asm__ __volatile__("stb %0,%1(13)"
 104         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 105 }
 106
 107 #ifdef CONFIG_PERF_COUNTERS
 108 notrace void __weak perf_counter_do_pending(void)
 109 {
 110         set_perf_counter_pending(0);
 111 }
 112 #endif
 113
 114 notrace void raw_local_irq_restore(unsigned long en)
 115 {
 116         /*
 117          * get_paca()->soft_enabled = en;
 118          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 119          * That was allowed before, and in such a case we do need to take care
 120          * that gcc will set soft_enabled directly via r13, not choose to use
 121          * an intermediate register, lest we're preempted to a different cpu.
 122          */
 123         set_soft_enabled(en);
 124         if (!en)
 125                 return;
 126
 127         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 128                 /*
 129                  * Do we need to disable preemption here?  Not really: in the
 130                  * unlikely event that we're preempted to a different cpu in
 131                  * between getting r13, loading its lppaca_ptr, and loading
 132                  * its any_int, we might call iseries_handle_interrupts without
 133                  * an interrupt pending on the new cpu, but that's no disaster,
 134                  * is it?  And the business of preempting us off the old cpu
 135                  * would itself involve a local_irq_restore which handles the
 136                  * interrupt to that cpu.
 137                  *
 138                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 139                  * to avoid any preemption checking added into get_paca().
 140                  */
 141                 if (local_paca->lppaca_ptr->int_dword.any_int)
 142                         iseries_handle_interrupts();
 143         }
 144
 145         if (get_perf_counter_pending())
 146                 perf_counter_do_pending();
 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 EXPORT_SYMBOL(raw_local_irq_restore);
 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         struct irq_desc *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_irqs_cpu(i, j));
 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 #if defined(CONFIG_PPC32) && defined(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 /* CONFIG_PPC32 && CONFIG_TAU_INT*/
 227                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 228         }
 229         return 0;
 230 }
 231
 232 #ifdef CONFIG_HOTPLUG_CPU
 233 void fixup_irqs(cpumask_t map)
 234 {
 235         unsigned int irq;
 236         static int warned;
 237
 238         for_each_irq(irq) {
 239                 cpumask_t mask;
 240
 241                 if (irq_desc[irq].status & IRQ_PER_CPU)
 242                         continue;
 243
 244                 cpumask_and(&mask, irq_desc[irq].affinity, &map);
 245                 if (any_online_cpu(mask) == NR_CPUS) {
 246                         printk("Breaking affinity for irq %i\n", irq);
 247                         mask = map;
 248                 }
 249                 if (irq_desc[irq].chip->set_affinity)
 250                         irq_desc[irq].chip->set_affinity(irq, &mask);
 251                 else if (irq_desc[irq].action && !(warned++))
 252                         printk("Cannot set affinity for irq %i\n", irq);
 253         }
 254
 255         local_irq_enable();
 256         mdelay(1);
 257         local_irq_disable();
 258 }
 259 #endif
 260
 261 void do_IRQ(struct pt_regs *regs)
 262 {
 263         struct pt_regs *old_regs = set_irq_regs(regs);
 264         unsigned int irq;
 265 #ifdef CONFIG_IRQSTACKS
 266         struct thread_info *curtp, *irqtp;
 267 #endif
 268
 269         irq_enter();
 270
 271 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 272         /* Debugging check for stack overflow: is there less than 2KB free? */
 273         {
 274                 long sp;
 275
 276                 sp = __get_SP() & (THREAD_SIZE-1);
 277
 278                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 279                         printk("do_IRQ: stack overflow: %ld\n",
 280                                 sp - sizeof(struct thread_info));
 281                         dump_stack();
 282                 }
 283         }
 284 #endif
 285
 286         /*
 287          * Every platform is required to implement ppc_md.get_irq.
 288          * This function will either return an irq number or NO_IRQ to
 289          * indicate there are no more pending.
 290          * The value NO_IRQ_IGNORE is for buggy hardware and means that this
 291          * IRQ has already been handled. -- Tom
 292          */
 293         irq = ppc_md.get_irq();
 294
 295         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
 296 #ifdef CONFIG_IRQSTACKS
 297                 /* Switch to the irq stack to handle this */
 298                 curtp = current_thread_info();
 299                 irqtp = hardirq_ctx[smp_processor_id()];
 300                 if (curtp != irqtp) {
 301                         struct irq_desc *desc = irq_desc + irq;
 302                         void *handler = desc->handle_irq;
 303                         unsigned long saved_sp_limit = current->thread.ksp_limit;
 304                         if (handler == NULL)
 305                                 handler = &__do_IRQ;
 306                         irqtp->task = curtp->task;
 307                         irqtp->flags = 0;
 308
 309                         /* Copy the softirq bits in preempt_count so that the
 310                          * softirq checks work in the hardirq context.
 311                          */
 312                         irqtp->preempt_count =
 313                                 (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 314                                 (curtp->preempt_count & SOFTIRQ_MASK);
 315
 316                         current->thread.ksp_limit = (unsigned long)irqtp +
 317                                 _ALIGN_UP(sizeof(struct thread_info), 16);
 318                         call_handle_irq(irq, desc, irqtp, handler);
 319                         current->thread.ksp_limit = saved_sp_limit;
 320                         irqtp->task = NULL;
 321
 322
 323                         /* Set any flag that may have been set on the
 324                          * alternate stack
 325                          */
 326                         if (irqtp->flags)
 327                                 set_bits(irqtp->flags, &curtp->flags);
 328                 } else
 329 #endif
 330                         generic_handle_irq(irq);
 331         } else if (irq != NO_IRQ_IGNORE)
 332                 /* That's not SMP safe ... but who cares ? */
 333                 ppc_spurious_interrupts++;
 334
 335         irq_exit();
 336         set_irq_regs(old_regs);
 337
 338 #ifdef CONFIG_PPC_ISERIES
 339         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 340                         get_lppaca()->int_dword.fields.decr_int) {
 341                 get_lppaca()->int_dword.fields.decr_int = 0;
 342                 /* Signal a fake decrementer interrupt */
 343                 timer_interrupt(regs);
 344         }
 345 #endif
 346 }
 347
 348 void __init init_IRQ(void)
 349 {
 350         if (ppc_md.init_IRQ)
 351                 ppc_md.init_IRQ();
 352
 353         exc_lvl_ctx_init();
 354
 355         irq_ctx_init();
 356 }
 357
 358 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 359 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 360 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 361 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 362
 363 void exc_lvl_ctx_init(void)
 364 {
 365         struct thread_info *tp;
 366         int i;
 367
 368         for_each_possible_cpu(i) {
 369                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 370                 tp = critirq_ctx[i];
 371                 tp->cpu = i;
 372                 tp->preempt_count = 0;
 373
 374 #ifdef CONFIG_BOOKE
 375                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 376                 tp = dbgirq_ctx[i];
 377                 tp->cpu = i;
 378                 tp->preempt_count = 0;
 379
 380                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 381                 tp = mcheckirq_ctx[i];
 382                 tp->cpu = i;
 383                 tp->preempt_count = HARDIRQ_OFFSET;
 384 #endif
 385         }
 386 }
 387 #endif
 388
 389 #ifdef CONFIG_IRQSTACKS
 390 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 391 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 392
 393 void irq_ctx_init(void)
 394 {
 395         struct thread_info *tp;
 396         int i;
 397
 398         for_each_possible_cpu(i) {
 399                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 400                 tp = softirq_ctx[i];
 401                 tp->cpu = i;
 402                 tp->preempt_count = 0;
 403
 404                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 405                 tp = hardirq_ctx[i];
 406                 tp->cpu = i;
 407                 tp->preempt_count = HARDIRQ_OFFSET;
 408         }
 409 }
 410
 411 static inline void do_softirq_onstack(void)
 412 {
 413         struct thread_info *curtp, *irqtp;
 414         unsigned long saved_sp_limit = current->thread.ksp_limit;
 415
 416         curtp = current_thread_info();
 417         irqtp = softirq_ctx[smp_processor_id()];
 418         irqtp->task = curtp->task;
 419         current->thread.ksp_limit = (unsigned long)irqtp +
 420                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 421         call_do_softirq(irqtp);
 422         current->thread.ksp_limit = saved_sp_limit;
 423         irqtp->task = NULL;
 424 }
 425
 426 #else
 427 #define do_softirq_onstack()    __do_softirq()
 428 #endif /* CONFIG_IRQSTACKS */
 429
 430 void do_softirq(void)
 431 {
 432         unsigned long flags;
 433
 434         if (in_interrupt())
 435                 return;
 436
 437         local_irq_save(flags);
 438
 439         if (local_softirq_pending())
 440                 do_softirq_onstack();
 441
 442         local_irq_restore(flags);
 443 }
 444
 445
 446 /*
 447  * IRQ controller and virtual interrupts
 448  */
 449
 450 static LIST_HEAD(irq_hosts);
 451 static DEFINE_SPINLOCK(irq_big_lock);
 452 static unsigned int revmap_trees_allocated;
 453 static DEFINE_MUTEX(revmap_trees_mutex);
 454 struct irq_map_entry irq_map[NR_IRQS];
 455 static unsigned int irq_virq_count = NR_IRQS;
 456 static struct irq_host *irq_default_host;
 457
 458 irq_hw_number_t virq_to_hw(unsigned int virq)
 459 {
 460         return irq_map[virq].hwirq;
 461 }
 462 EXPORT_SYMBOL_GPL(virq_to_hw);
 463
 464 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 465 {
 466         return h->of_node != NULL && h->of_node == np;
 467 }
 468
 469 struct irq_host *irq_alloc_host(struct device_node *of_node,
 470                                 unsigned int revmap_type,
 471                                 unsigned int revmap_arg,
 472                                 struct irq_host_ops *ops,
 473                                 irq_hw_number_t inval_irq)
 474 {
 475         struct irq_host *host;
 476         unsigned int size = sizeof(struct irq_host);
 477         unsigned int i;
 478         unsigned int *rmap;
 479         unsigned long flags;
 480
 481         /* Allocate structure and revmap table if using linear mapping */
 482         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 483                 size += revmap_arg * sizeof(unsigned int);
 484         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 485         if (host == NULL)
 486                 return NULL;
 487
 488         /* Fill structure */
 489         host->revmap_type = revmap_type;
 490         host->inval_irq = inval_irq;
 491         host->ops = ops;
 492         host->of_node = of_node_get(of_node);
 493
 494         if (host->ops->match == NULL)
 495                 host->ops->match = default_irq_host_match;
 496
 497         spin_lock_irqsave(&irq_big_lock, flags);
 498
 499         /* If it's a legacy controller, check for duplicates and
 500          * mark it as allocated (we use irq 0 host pointer for that
 501          */
 502         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 503                 if (irq_map[0].host != NULL) {
 504                         spin_unlock_irqrestore(&irq_big_lock, flags);
 505                         /* If we are early boot, we can't free the structure,
 506                          * too bad...
 507                          * this will be fixed once slab is made available early
 508                          * instead of the current cruft
 509                          */
 510                         if (mem_init_done)
 511                                 kfree(host);
 512                         return NULL;
 513                 }
 514                 irq_map[0].host = host;
 515         }
 516
 517         list_add(&host->link, &irq_hosts);
 518         spin_unlock_irqrestore(&irq_big_lock, flags);
 519
 520         /* Additional setups per revmap type */
 521         switch(revmap_type) {
 522         case IRQ_HOST_MAP_LEGACY:
 523                 /* 0 is always the invalid number for legacy */
 524                 host->inval_irq = 0;
 525                 /* setup us as the host for all legacy interrupts */
 526                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 527                         irq_map[i].hwirq = i;
 528                         smp_wmb();
 529                         irq_map[i].host = host;
 530                         smp_wmb();
 531
 532                         /* Clear norequest flags */
 533                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 534
 535                         /* Legacy flags are left to default at this point,
 536                          * one can then use irq_create_mapping() to
 537                          * explicitly change them
 538                          */
 539                         ops->map(host, i, i);
 540                 }
 541                 break;
 542         case IRQ_HOST_MAP_LINEAR:
 543                 rmap = (unsigned int *)(host + 1);
 544                 for (i = 0; i < revmap_arg; i++)
 545                         rmap[i] = NO_IRQ;
 546                 host->revmap_data.linear.size = revmap_arg;
 547                 smp_wmb();
 548                 host->revmap_data.linear.revmap = rmap;
 549                 break;
 550         default:
 551                 break;
 552         }
 553
 554         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 555
 556         return host;
 557 }
 558
 559 struct irq_host *irq_find_host(struct device_node *node)
 560 {
 561         struct irq_host *h, *found = NULL;
 562         unsigned long flags;
 563
 564         /* We might want to match the legacy controller last since
 565          * it might potentially be set to match all interrupts in
 566          * the absence of a device node. This isn't a problem so far
 567          * yet though...
 568          */
 569         spin_lock_irqsave(&irq_big_lock, flags);
 570         list_for_each_entry(h, &irq_hosts, link)
 571                 if (h->ops->match(h, node)) {
 572                         found = h;
 573                         break;
 574                 }
 575         spin_unlock_irqrestore(&irq_big_lock, flags);
 576         return found;
 577 }
 578 EXPORT_SYMBOL_GPL(irq_find_host);
 579
 580 void irq_set_default_host(struct irq_host *host)
 581 {
 582         pr_debug("irq: Default host set to @0x%p\n", host);
 583
 584         irq_default_host = host;
 585 }
 586
 587 void irq_set_virq_count(unsigned int count)
 588 {
 589         pr_debug("irq: Trying to set virq count to %d\n", count);
 590
 591         BUG_ON(count < NUM_ISA_INTERRUPTS);
 592         if (count < NR_IRQS)
 593                 irq_virq_count = count;
 594 }
 595
 596 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 597                             irq_hw_number_t hwirq)
 598 {
 599         /* Clear IRQ_NOREQUEST flag */
 600         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 601
 602         /* map it */
 603         smp_wmb();
 604         irq_map[virq].hwirq = hwirq;
 605         smp_mb();
 606
 607         if (host->ops->map(host, virq, hwirq)) {
 608                 pr_debug("irq: -> mapping failed, freeing\n");
 609                 irq_free_virt(virq, 1);
 610                 return -1;
 611         }
 612
 613         return 0;
 614 }
 615
 616 unsigned int irq_create_direct_mapping(struct irq_host *host)
 617 {
 618         unsigned int virq;
 619
 620         if (host == NULL)
 621                 host = irq_default_host;
 622
 623         BUG_ON(host == NULL);
 624         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 625
 626         virq = irq_alloc_virt(host, 1, 0);
 627         if (virq == NO_IRQ) {
 628                 pr_debug("irq: create_direct virq allocation failed\n");
 629                 return NO_IRQ;
 630         }
 631
 632         pr_debug("irq: create_direct obtained virq %d\n", virq);
 633
 634         if (irq_setup_virq(host, virq, virq))
 635                 return NO_IRQ;
 636
 637         return virq;
 638 }
 639
 640 unsigned int irq_create_mapping(struct irq_host *host,
 641                                 irq_hw_number_t hwirq)
 642 {
 643         unsigned int virq, hint;
 644
 645         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 646
 647         /* Look for default host if nececssary */
 648         if (host == NULL)
 649                 host = irq_default_host;
 650         if (host == NULL) {
 651                 printk(KERN_WARNING "irq_create_mapping called for"
 652                        " NULL host, hwirq=%lx\n", hwirq);
 653                 WARN_ON(1);
 654                 return NO_IRQ;
 655         }
 656         pr_debug("irq: -> using host @%p\n", host);
 657
 658         /* Check if mapping already exist, if it does, call
 659          * host->ops->map() to update the flags
 660          */
 661         virq = irq_find_mapping(host, hwirq);
 662         if (virq != NO_IRQ) {
 663                 if (host->ops->remap)
 664                         host->ops->remap(host, virq, hwirq);
 665                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 666                 return virq;
 667         }
 668
 669         /* Get a virtual interrupt number */
 670         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 671                 /* Handle legacy */
 672                 virq = (unsigned int)hwirq;
 673                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 674                         return NO_IRQ;
 675                 return virq;
 676         } else {
 677                 /* Allocate a virtual interrupt number */
 678                 hint = hwirq % irq_virq_count;
 679                 virq = irq_alloc_virt(host, 1, hint);
 680                 if (virq == NO_IRQ) {
 681                         pr_debug("irq: -> virq allocation failed\n");
 682                         return NO_IRQ;
 683                 }
 684         }
 685         pr_debug("irq: -> obtained virq %d\n", virq);
 686
 687         if (irq_setup_virq(host, virq, hwirq))
 688                 return NO_IRQ;
 689
 690         return virq;
 691 }
 692 EXPORT_SYMBOL_GPL(irq_create_mapping);
 693
 694 unsigned int irq_create_of_mapping(struct device_node *controller,
 695                                    u32 *intspec, unsigned int intsize)
 696 {
 697         struct irq_host *host;
 698         irq_hw_number_t hwirq;
 699         unsigned int type = IRQ_TYPE_NONE;
 700         unsigned int virq;
 701
 702         if (controller == NULL)
 703                 host = irq_default_host;
 704         else
 705                 host = irq_find_host(controller);
 706         if (host == NULL) {
 707                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 708                        controller->full_name);
 709                 return NO_IRQ;
 710         }
 711
 712         /* If host has no translation, then we assume interrupt line */
 713         if (host->ops->xlate == NULL)
 714                 hwirq = intspec[0];
 715         else {
 716                 if (host->ops->xlate(host, controller, intspec, intsize,
 717                                      &hwirq, &type))
 718                         return NO_IRQ;
 719         }
 720
 721         /* Create mapping */
 722         virq = irq_create_mapping(host, hwirq);
 723         if (virq == NO_IRQ)
 724                 return virq;
 725
 726         /* Set type if specified and different than the current one */
 727         if (type != IRQ_TYPE_NONE &&
 728             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 729                 set_irq_type(virq, type);
 730         return virq;
 731 }
 732 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 733
 734 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 735 {
 736         struct of_irq oirq;
 737
 738         if (of_irq_map_one(dev, index, &oirq))
 739                 return NO_IRQ;
 740
 741         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 742                                      oirq.size);
 743 }
 744 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 745
 746 void irq_dispose_mapping(unsigned int virq)
 747 {
 748         struct irq_host *host;
 749         irq_hw_number_t hwirq;
 750
 751         if (virq == NO_IRQ)
 752                 return;
 753
 754         host = irq_map[virq].host;
 755         WARN_ON (host == NULL);
 756         if (host == NULL)
 757                 return;
 758
 759         /* Never unmap legacy interrupts */
 760         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 761                 return;
 762
 763         /* remove chip and handler */
 764         set_irq_chip_and_handler(virq, NULL, NULL);
 765
 766         /* Make sure it's completed */
 767         synchronize_irq(virq);
 768
 769         /* Tell the PIC about it */
 770         if (host->ops->unmap)
 771                 host->ops->unmap(host, virq);
 772         smp_mb();
 773
 774         /* Clear reverse map */
 775         hwirq = irq_map[virq].hwirq;
 776         switch(host->revmap_type) {
 777         case IRQ_HOST_MAP_LINEAR:
 778                 if (hwirq < host->revmap_data.linear.size)
 779                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 780                 break;
 781         case IRQ_HOST_MAP_TREE:
 782                 /*
 783                  * Check if radix tree allocated yet, if not then nothing to
 784                  * remove.
 785                  */
 786                 smp_rmb();
 787                 if (revmap_trees_allocated < 1)
 788                         break;
 789                 mutex_lock(&revmap_trees_mutex);
 790                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 791                 mutex_unlock(&revmap_trees_mutex);
 792                 break;
 793         }
 794
 795         /* Destroy map */
 796         smp_mb();
 797         irq_map[virq].hwirq = host->inval_irq;
 798
 799         /* Set some flags */
 800         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 801
 802         /* Free it */
 803         irq_free_virt(virq, 1);
 804 }
 805 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 806
 807 unsigned int irq_find_mapping(struct irq_host *host,
 808                               irq_hw_number_t hwirq)
 809 {
 810         unsigned int i;
 811         unsigned int hint = hwirq % irq_virq_count;
 812
 813         /* Look for default host if nececssary */
 814         if (host == NULL)
 815                 host = irq_default_host;
 816         if (host == NULL)
 817                 return NO_IRQ;
 818
 819         /* legacy -> bail early */
 820         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 821                 return hwirq;
 822
 823         /* Slow path does a linear search of the map */
 824         if (hint < NUM_ISA_INTERRUPTS)
 825                 hint = NUM_ISA_INTERRUPTS;
 826         i = hint;
 827         do  {
 828                 if (irq_map[i].host == host &&
 829                     irq_map[i].hwirq == hwirq)
 830                         return i;
 831                 i++;
 832                 if (i >= irq_virq_count)
 833                         i = NUM_ISA_INTERRUPTS;
 834         } while(i != hint);
 835         return NO_IRQ;
 836 }
 837 EXPORT_SYMBOL_GPL(irq_find_mapping);
 838
 839
 840 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 841                                      irq_hw_number_t hwirq)
 842 {
 843         struct irq_map_entry *ptr;
 844         unsigned int virq;
 845
 846         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 847
 848         /*
 849          * Check if the radix tree exists and has bee initialized.
 850          * If not, we fallback to slow mode
 851          */
 852         if (revmap_trees_allocated < 2)
 853                 return irq_find_mapping(host, hwirq);
 854
 855         /* Now try to resolve */
 856         /*
 857          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 858          * as it's referencing an entry in the static irq_map table.
 859          */
 860         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 861
 862         /*
 863          * If found in radix tree, then fine.
 864          * Else fallback to linear lookup - this should not happen in practice
 865          * as it means that we failed to insert the node in the radix tree.
 866          */
 867         if (ptr)
 868                 virq = ptr - irq_map;
 869         else
 870                 virq = irq_find_mapping(host, hwirq);
 871
 872         return virq;
 873 }
 874
 875 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 876                              irq_hw_number_t hwirq)
 877 {
 878
 879         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 880
 881         /*
 882          * Check if the radix tree exists yet.
 883          * If not, then the irq will be inserted into the tree when it gets
 884          * initialized.
 885          */
 886         smp_rmb();
 887         if (revmap_trees_allocated < 1)
 888                 return;
 889
 890         if (virq != NO_IRQ) {
 891                 mutex_lock(&revmap_trees_mutex);
 892                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 893                                   &irq_map[virq]);
 894                 mutex_unlock(&revmap_trees_mutex);
 895         }
 896 }
 897
 898 unsigned int irq_linear_revmap(struct irq_host *host,
 899                                irq_hw_number_t hwirq)
 900 {
 901         unsigned int *revmap;
 902
 903         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 904
 905         /* Check revmap bounds */
 906         if (unlikely(hwirq >= host->revmap_data.linear.size))
 907                 return irq_find_mapping(host, hwirq);
 908
 909         /* Check if revmap was allocated */
 910         revmap = host->revmap_data.linear.revmap;
 911         if (unlikely(revmap == NULL))
 912                 return irq_find_mapping(host, hwirq);
 913
 914         /* Fill up revmap with slow path if no mapping found */
 915         if (unlikely(revmap[hwirq] == NO_IRQ))
 916                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 917
 918         return revmap[hwirq];
 919 }
 920
 921 unsigned int irq_alloc_virt(struct irq_host *host,
 922                             unsigned int count,
 923                             unsigned int hint)
 924 {
 925         unsigned long flags;
 926         unsigned int i, j, found = NO_IRQ;
 927
 928         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 929                 return NO_IRQ;
 930
 931         spin_lock_irqsave(&irq_big_lock, flags);
 932
 933         /* Use hint for 1 interrupt if any */
 934         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 935             hint < irq_virq_count && irq_map[hint].host == NULL) {
 936                 found = hint;
 937                 goto hint_found;
 938         }
 939
 940         /* Look for count consecutive numbers in the allocatable
 941          * (non-legacy) space
 942          */
 943         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 944                 if (irq_map[i].host != NULL)
 945                         j = 0;
 946                 else
 947                         j++;
 948
 949                 if (j == count) {
 950                         found = i - count + 1;
 951                         break;
 952                 }
 953         }
 954         if (found == NO_IRQ) {
 955                 spin_unlock_irqrestore(&irq_big_lock, flags);
 956                 return NO_IRQ;
 957         }
 958  hint_found:
 959         for (i = found; i < (found + count); i++) {
 960                 irq_map[i].hwirq = host->inval_irq;
 961                 smp_wmb();
 962                 irq_map[i].host = host;
 963         }
 964         spin_unlock_irqrestore(&irq_big_lock, flags);
 965         return found;
 966 }
 967
 968 void irq_free_virt(unsigned int virq, unsigned int count)
 969 {
 970         unsigned long flags;
 971         unsigned int i;
 972
 973         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 974         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 975
 976         spin_lock_irqsave(&irq_big_lock, flags);
 977         for (i = virq; i < (virq + count); i++) {
 978                 struct irq_host *host;
 979
 980                 if (i < NUM_ISA_INTERRUPTS ||
 981                     (virq + count) > irq_virq_count)
 982                         continue;
 983
 984                 host = irq_map[i].host;
 985                 irq_map[i].hwirq = host->inval_irq;
 986                 smp_wmb();
 987                 irq_map[i].host = NULL;
 988         }
 989         spin_unlock_irqrestore(&irq_big_lock, flags);
 990 }
 991
 992 void irq_early_init(void)
 993 {
 994         unsigned int i;
 995
 996         for (i = 0; i < NR_IRQS; i++)
 997                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 998 }
 999
1000 /* We need to create the radix trees late */
1001 static int irq_late_init(void)
1002 {
1003         struct irq_host *h;
1004         unsigned int i;
1005
1006         /*
1007          * No mutual exclusion with respect to accessors of the tree is needed
1008          * here as the synchronization is done via the state variable
1009          * revmap_trees_allocated.
1010          */
1011         list_for_each_entry(h, &irq_hosts, link) {
1012                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1013                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1014         }
1015
1016         /*
1017          * Make sure the radix trees inits are visible before setting
1018          * the flag
1019          */
1020         smp_wmb();
1021         revmap_trees_allocated = 1;
1022
1023         /*
1024          * Insert the reverse mapping for those interrupts already present
1025          * in irq_map[].
1026          */
1027         mutex_lock(&revmap_trees_mutex);
1028         for (i = 0; i < irq_virq_count; i++) {
1029                 if (irq_map[i].host &&
1030                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1031                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1032                                           irq_map[i].hwirq, &irq_map[i]);
1033         }
1034         mutex_unlock(&revmap_trees_mutex);
1035
1036         /*
1037          * Make sure the radix trees insertions are visible before setting
1038          * the flag
1039          */
1040         smp_wmb();
1041         revmap_trees_allocated = 2;
1042
1043         return 0;
1044 }
1045 arch_initcall(irq_late_init);
1046
1047 #ifdef CONFIG_VIRQ_DEBUG
1048 static int virq_debug_show(struct seq_file *m, void *private)
1049 {
1050         unsigned long flags;
1051         struct irq_desc *desc;
1052         const char *p;
1053         char none[] = "none";
1054         int i;
1055
1056         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1057                       "chip name", "host name");
1058
1059         for (i = 1; i < NR_IRQS; i++) {
1060                 desc = get_irq_desc(i);
1061                 spin_lock_irqsave(&desc->lock, flags);
1062
1063                 if (desc->action && desc->action->handler) {
1064                         seq_printf(m, "%5d  ", i);
1065                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1066
1067                         if (desc->chip && desc->chip->typename)
1068                                 p = desc->chip->typename;
1069                         else
1070                                 p = none;
1071                         seq_printf(m, "%-15s  ", p);
1072
1073                         if (irq_map[i].host && irq_map[i].host->of_node)
1074                                 p = irq_map[i].host->of_node->full_name;
1075                         else
1076                                 p = none;
1077                         seq_printf(m, "%s\n", p);
1078                 }
1079
1080                 spin_unlock_irqrestore(&desc->lock, flags);
1081         }
1082
1083         return 0;
1084 }
1085
1086 static int virq_debug_open(struct inode *inode, struct file *file)
1087 {
1088         return single_open(file, virq_debug_show, inode->i_private);
1089 }
1090
1091 static const struct file_operations virq_debug_fops = {
1092         .open = virq_debug_open,
1093         .read = seq_read,
1094         .llseek = seq_lseek,
1095         .release = single_release,
1096 };
1097
1098 static int __init irq_debugfs_init(void)
1099 {
1100         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1101                                  NULL, &virq_debug_fops) == NULL)
1102                 return -ENOMEM;
1103
1104         return 0;
1105 }
1106 __initcall(irq_debugfs_init);
1107 #endif /* CONFIG_VIRQ_DEBUG */
1108
1109 #ifdef CONFIG_PPC64
1110 static int __init setup_noirqdistrib(char *str)
1111 {
1112         distribute_irqs = 0;
1113         return 1;
1114 }
1115
1116 __setup("noirqdistrib", setup_noirqdistrib);
1117 #endif /* CONFIG_PPC64 */