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 #include <linux/perf_counter.h>
  57
  58 #include <asm/uaccess.h>
  59 #include <asm/system.h>
  60 #include <asm/io.h>
  61 #include <asm/pgtable.h>
  62 #include <asm/irq.h>
  63 #include <asm/cache.h>
  64 #include <asm/prom.h>
  65 #include <asm/ptrace.h>
  66 #include <asm/machdep.h>
  67 #include <asm/udbg.h>
  68 #ifdef CONFIG_PPC64
  69 #include <asm/paca.h>
  70 #include <asm/firmware.h>
  71 #include <asm/lv1call.h>
  72 #endif
  73
  74 int __irq_offset_value;
  75 static int ppc_spurious_interrupts;
  76
  77 #ifdef CONFIG_PPC32
  78 EXPORT_SYMBOL(__irq_offset_value);
  79 atomic_t ppc_n_lost_interrupts;
  80
  81 #ifdef CONFIG_TAU_INT
  82 extern int tau_initialized;
  83 extern int tau_interrupts(int);
  84 #endif
  85 #endif /* CONFIG_PPC32 */
  86
  87 #ifdef CONFIG_PPC64
  88 EXPORT_SYMBOL(irq_desc);
  89
  90 int distribute_irqs = 1;
  91
  92 static inline notrace unsigned long get_hard_enabled(void)
  93 {
  94         unsigned long enabled;
  95
  96         __asm__ __volatile__("lbz %0,%1(13)"
  97         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
  98
  99         return enabled;
 100 }
 101
 102 static inline notrace void set_soft_enabled(unsigned long enable)
 103 {
 104         __asm__ __volatile__("stb %0,%1(13)"
 105         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 106 }
 107
 108 notrace void raw_local_irq_restore(unsigned long en)
 109 {
 110         /*
 111          * get_paca()->soft_enabled = en;
 112          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 113          * That was allowed before, and in such a case we do need to take care
 114          * that gcc will set soft_enabled directly via r13, not choose to use
 115          * an intermediate register, lest we're preempted to a different cpu.
 116          */
 117         set_soft_enabled(en);
 118         if (!en)
 119                 return;
 120
 121 #ifdef CONFIG_PPC_STD_MMU_64
 122         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 123                 /*
 124                  * Do we need to disable preemption here?  Not really: in the
 125                  * unlikely event that we're preempted to a different cpu in
 126                  * between getting r13, loading its lppaca_ptr, and loading
 127                  * its any_int, we might call iseries_handle_interrupts without
 128                  * an interrupt pending on the new cpu, but that's no disaster,
 129                  * is it?  And the business of preempting us off the old cpu
 130                  * would itself involve a local_irq_restore which handles the
 131                  * interrupt to that cpu.
 132                  *
 133                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 134                  * to avoid any preemption checking added into get_paca().
 135                  */
 136                 if (local_paca->lppaca_ptr->int_dword.any_int)
 137                         iseries_handle_interrupts();
 138         }
 139 #endif /* CONFIG_PPC_STD_MMU_64 */
 140
 141         if (test_perf_counter_pending()) {
 142                 clear_perf_counter_pending();
 143                 perf_counter_do_pending();
 144         }
 145
 146         /*
 147          * if (get_paca()->hard_enabled) return;
 148          * But again we need to take care that gcc gets hard_enabled directly
 149          * via r13, not choose to use an intermediate register, lest we're
 150          * preempted to a different cpu in between the two instructions.
 151          */
 152         if (get_hard_enabled())
 153                 return;
 154
 155         /*
 156          * Need to hard-enable interrupts here.  Since currently disabled,
 157          * no need to take further asm precautions against preemption; but
 158          * use local_paca instead of get_paca() to avoid preemption checking.
 159          */
 160         local_paca->hard_enabled = en;
 161         if ((int)mfspr(SPRN_DEC) < 0)
 162                 mtspr(SPRN_DEC, 1);
 163
 164         /*
 165          * Force the delivery of pending soft-disabled interrupts on PS3.
 166          * Any HV call will have this side effect.
 167          */
 168         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 169                 u64 tmp;
 170                 lv1_get_version_info(&tmp);
 171         }
 172
 173         __hard_irq_enable();
 174 }
 175 EXPORT_SYMBOL(raw_local_irq_restore);
 176 #endif /* CONFIG_PPC64 */
 177
 178 int show_interrupts(struct seq_file *p, void *v)
 179 {
 180         int i = *(loff_t *)v, j;
 181         struct irqaction *action;
 182         struct irq_desc *desc;
 183         unsigned long flags;
 184
 185         if (i == 0) {
 186                 seq_puts(p, "           ");
 187                 for_each_online_cpu(j)
 188                         seq_printf(p, "CPU%d       ", j);
 189                 seq_putc(p, '\n');
 190         }
 191
 192         if (i < NR_IRQS) {
 193                 desc = get_irq_desc(i);
 194                 spin_lock_irqsave(&desc->lock, flags);
 195                 action = desc->action;
 196                 if (!action || !action->handler)
 197                         goto skip;
 198                 seq_printf(p, "%3d: ", i);
 199 #ifdef CONFIG_SMP
 200                 for_each_online_cpu(j)
 201                         seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 202 #else
 203                 seq_printf(p, "%10u ", kstat_irqs(i));
 204 #endif /* CONFIG_SMP */
 205                 if (desc->chip)
 206                         seq_printf(p, " %s ", desc->chip->typename);
 207                 else
 208                         seq_puts(p, "  None      ");
 209                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 210                 seq_printf(p, "    %s", action->name);
 211                 for (action = action->next; action; action = action->next)
 212                         seq_printf(p, ", %s", action->name);
 213                 seq_putc(p, '\n');
 214 skip:
 215                 spin_unlock_irqrestore(&desc->lock, flags);
 216         } else if (i == NR_IRQS) {
 217 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 218                 if (tau_initialized){
 219                         seq_puts(p, "TAU: ");
 220                         for_each_online_cpu(j)
 221                                 seq_printf(p, "%10u ", tau_interrupts(j));
 222                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 223                 }
 224 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT*/
 225                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 226         }
 227         return 0;
 228 }
 229
 230 #ifdef CONFIG_HOTPLUG_CPU
 231 void fixup_irqs(cpumask_t map)
 232 {
 233         unsigned int irq;
 234         static int warned;
 235
 236         for_each_irq(irq) {
 237                 cpumask_t mask;
 238
 239                 if (irq_desc[irq].status & IRQ_PER_CPU)
 240                         continue;
 241
 242                 cpumask_and(&mask, irq_desc[irq].affinity, &map);
 243                 if (any_online_cpu(mask) == NR_CPUS) {
 244                         printk("Breaking affinity for irq %i\n", irq);
 245                         mask = map;
 246                 }
 247                 if (irq_desc[irq].chip->set_affinity)
 248                         irq_desc[irq].chip->set_affinity(irq, &mask);
 249                 else if (irq_desc[irq].action && !(warned++))
 250                         printk("Cannot set affinity for irq %i\n", irq);
 251         }
 252
 253         local_irq_enable();
 254         mdelay(1);
 255         local_irq_disable();
 256 }
 257 #endif
 258
 259 #ifdef CONFIG_IRQSTACKS
 260 static inline void handle_one_irq(unsigned int irq)
 261 {
 262         struct thread_info *curtp, *irqtp;
 263         unsigned long saved_sp_limit;
 264         struct irq_desc *desc;
 265
 266         /* Switch to the irq stack to handle this */
 267         curtp = current_thread_info();
 268         irqtp = hardirq_ctx[smp_processor_id()];
 269
 270         if (curtp == irqtp) {
 271                 /* We're already on the irq stack, just handle it */
 272                 generic_handle_irq(irq);
 273                 return;
 274         }
 275
 276         desc = irq_desc + irq;
 277         saved_sp_limit = current->thread.ksp_limit;
 278
 279         irqtp->task = curtp->task;
 280         irqtp->flags = 0;
 281
 282         /* Copy the softirq bits in preempt_count so that the
 283          * softirq checks work in the hardirq context. */
 284         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 285                                (curtp->preempt_count & SOFTIRQ_MASK);
 286
 287         current->thread.ksp_limit = (unsigned long)irqtp +
 288                 _ALIGN_UP(sizeof(struct thread_info), 16);
 289
 290         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 291         current->thread.ksp_limit = saved_sp_limit;
 292         irqtp->task = NULL;
 293
 294         /* Set any flag that may have been set on the
 295          * alternate stack
 296          */
 297         if (irqtp->flags)
 298                 set_bits(irqtp->flags, &curtp->flags);
 299 }
 300 #else
 301 static inline void handle_one_irq(unsigned int irq)
 302 {
 303         generic_handle_irq(irq);
 304 }
 305 #endif
 306
 307 static inline void check_stack_overflow(void)
 308 {
 309 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 310         long sp;
 311
 312         sp = __get_SP() & (THREAD_SIZE-1);
 313
 314         /* check for stack overflow: is there less than 2KB free? */
 315         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 316                 printk("do_IRQ: stack overflow: %ld\n",
 317                         sp - sizeof(struct thread_info));
 318                 dump_stack();
 319         }
 320 #endif
 321 }
 322
 323 void do_IRQ(struct pt_regs *regs)
 324 {
 325         struct pt_regs *old_regs = set_irq_regs(regs);
 326         unsigned int irq;
 327
 328         irq_enter();
 329
 330         check_stack_overflow();
 331
 332         irq = ppc_md.get_irq();
 333
 334         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 335                 handle_one_irq(irq);
 336         else if (irq != NO_IRQ_IGNORE)
 337                 /* That's not SMP safe ... but who cares ? */
 338                 ppc_spurious_interrupts++;
 339
 340         irq_exit();
 341         set_irq_regs(old_regs);
 342
 343 #ifdef CONFIG_PPC_ISERIES
 344         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 345                         get_lppaca()->int_dword.fields.decr_int) {
 346                 get_lppaca()->int_dword.fields.decr_int = 0;
 347                 /* Signal a fake decrementer interrupt */
 348                 timer_interrupt(regs);
 349         }
 350 #endif
 351 }
 352
 353 void __init init_IRQ(void)
 354 {
 355         if (ppc_md.init_IRQ)
 356                 ppc_md.init_IRQ();
 357
 358         exc_lvl_ctx_init();
 359
 360         irq_ctx_init();
 361 }
 362
 363 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 364 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 365 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 366 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 367
 368 void exc_lvl_ctx_init(void)
 369 {
 370         struct thread_info *tp;
 371         int i;
 372
 373         for_each_possible_cpu(i) {
 374                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 375                 tp = critirq_ctx[i];
 376                 tp->cpu = i;
 377                 tp->preempt_count = 0;
 378
 379 #ifdef CONFIG_BOOKE
 380                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 381                 tp = dbgirq_ctx[i];
 382                 tp->cpu = i;
 383                 tp->preempt_count = 0;
 384
 385                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 386                 tp = mcheckirq_ctx[i];
 387                 tp->cpu = i;
 388                 tp->preempt_count = HARDIRQ_OFFSET;
 389 #endif
 390         }
 391 }
 392 #endif
 393
 394 #ifdef CONFIG_IRQSTACKS
 395 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 396 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 397
 398 void irq_ctx_init(void)
 399 {
 400         struct thread_info *tp;
 401         int i;
 402
 403         for_each_possible_cpu(i) {
 404                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 405                 tp = softirq_ctx[i];
 406                 tp->cpu = i;
 407                 tp->preempt_count = 0;
 408
 409                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 410                 tp = hardirq_ctx[i];
 411                 tp->cpu = i;
 412                 tp->preempt_count = HARDIRQ_OFFSET;
 413         }
 414 }
 415
 416 static inline void do_softirq_onstack(void)
 417 {
 418         struct thread_info *curtp, *irqtp;
 419         unsigned long saved_sp_limit = current->thread.ksp_limit;
 420
 421         curtp = current_thread_info();
 422         irqtp = softirq_ctx[smp_processor_id()];
 423         irqtp->task = curtp->task;
 424         current->thread.ksp_limit = (unsigned long)irqtp +
 425                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 426         call_do_softirq(irqtp);
 427         current->thread.ksp_limit = saved_sp_limit;
 428         irqtp->task = NULL;
 429 }
 430
 431 #else
 432 #define do_softirq_onstack()    __do_softirq()
 433 #endif /* CONFIG_IRQSTACKS */
 434
 435 void do_softirq(void)
 436 {
 437         unsigned long flags;
 438
 439         if (in_interrupt())
 440                 return;
 441
 442         local_irq_save(flags);
 443
 444         if (local_softirq_pending())
 445                 do_softirq_onstack();
 446
 447         local_irq_restore(flags);
 448 }
 449
 450
 451 /*
 452  * IRQ controller and virtual interrupts
 453  */
 454
 455 static LIST_HEAD(irq_hosts);
 456 static DEFINE_SPINLOCK(irq_big_lock);
 457 static unsigned int revmap_trees_allocated;
 458 static DEFINE_MUTEX(revmap_trees_mutex);
 459 struct irq_map_entry irq_map[NR_IRQS];
 460 static unsigned int irq_virq_count = NR_IRQS;
 461 static struct irq_host *irq_default_host;
 462
 463 irq_hw_number_t virq_to_hw(unsigned int virq)
 464 {
 465         return irq_map[virq].hwirq;
 466 }
 467 EXPORT_SYMBOL_GPL(virq_to_hw);
 468
 469 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 470 {
 471         return h->of_node != NULL && h->of_node == np;
 472 }
 473
 474 struct irq_host *irq_alloc_host(struct device_node *of_node,
 475                                 unsigned int revmap_type,
 476                                 unsigned int revmap_arg,
 477                                 struct irq_host_ops *ops,
 478                                 irq_hw_number_t inval_irq)
 479 {
 480         struct irq_host *host;
 481         unsigned int size = sizeof(struct irq_host);
 482         unsigned int i;
 483         unsigned int *rmap;
 484         unsigned long flags;
 485
 486         /* Allocate structure and revmap table if using linear mapping */
 487         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 488                 size += revmap_arg * sizeof(unsigned int);
 489         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 490         if (host == NULL)
 491                 return NULL;
 492
 493         /* Fill structure */
 494         host->revmap_type = revmap_type;
 495         host->inval_irq = inval_irq;
 496         host->ops = ops;
 497         host->of_node = of_node_get(of_node);
 498
 499         if (host->ops->match == NULL)
 500                 host->ops->match = default_irq_host_match;
 501
 502         spin_lock_irqsave(&irq_big_lock, flags);
 503
 504         /* If it's a legacy controller, check for duplicates and
 505          * mark it as allocated (we use irq 0 host pointer for that
 506          */
 507         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 508                 if (irq_map[0].host != NULL) {
 509                         spin_unlock_irqrestore(&irq_big_lock, flags);
 510                         /* If we are early boot, we can't free the structure,
 511                          * too bad...
 512                          * this will be fixed once slab is made available early
 513                          * instead of the current cruft
 514                          */
 515                         if (mem_init_done)
 516                                 kfree(host);
 517                         return NULL;
 518                 }
 519                 irq_map[0].host = host;
 520         }
 521
 522         list_add(&host->link, &irq_hosts);
 523         spin_unlock_irqrestore(&irq_big_lock, flags);
 524
 525         /* Additional setups per revmap type */
 526         switch(revmap_type) {
 527         case IRQ_HOST_MAP_LEGACY:
 528                 /* 0 is always the invalid number for legacy */
 529                 host->inval_irq = 0;
 530                 /* setup us as the host for all legacy interrupts */
 531                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 532                         irq_map[i].hwirq = i;
 533                         smp_wmb();
 534                         irq_map[i].host = host;
 535                         smp_wmb();
 536
 537                         /* Clear norequest flags */
 538                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 539
 540                         /* Legacy flags are left to default at this point,
 541                          * one can then use irq_create_mapping() to
 542                          * explicitly change them
 543                          */
 544                         ops->map(host, i, i);
 545                 }
 546                 break;
 547         case IRQ_HOST_MAP_LINEAR:
 548                 rmap = (unsigned int *)(host + 1);
 549                 for (i = 0; i < revmap_arg; i++)
 550                         rmap[i] = NO_IRQ;
 551                 host->revmap_data.linear.size = revmap_arg;
 552                 smp_wmb();
 553                 host->revmap_data.linear.revmap = rmap;
 554                 break;
 555         default:
 556                 break;
 557         }
 558
 559         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 560
 561         return host;
 562 }
 563
 564 struct irq_host *irq_find_host(struct device_node *node)
 565 {
 566         struct irq_host *h, *found = NULL;
 567         unsigned long flags;
 568
 569         /* We might want to match the legacy controller last since
 570          * it might potentially be set to match all interrupts in
 571          * the absence of a device node. This isn't a problem so far
 572          * yet though...
 573          */
 574         spin_lock_irqsave(&irq_big_lock, flags);
 575         list_for_each_entry(h, &irq_hosts, link)
 576                 if (h->ops->match(h, node)) {
 577                         found = h;
 578                         break;
 579                 }
 580         spin_unlock_irqrestore(&irq_big_lock, flags);
 581         return found;
 582 }
 583 EXPORT_SYMBOL_GPL(irq_find_host);
 584
 585 void irq_set_default_host(struct irq_host *host)
 586 {
 587         pr_debug("irq: Default host set to @0x%p\n", host);
 588
 589         irq_default_host = host;
 590 }
 591
 592 void irq_set_virq_count(unsigned int count)
 593 {
 594         pr_debug("irq: Trying to set virq count to %d\n", count);
 595
 596         BUG_ON(count < NUM_ISA_INTERRUPTS);
 597         if (count < NR_IRQS)
 598                 irq_virq_count = count;
 599 }
 600
 601 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 602                             irq_hw_number_t hwirq)
 603 {
 604         /* Clear IRQ_NOREQUEST flag */
 605         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 606
 607         /* map it */
 608         smp_wmb();
 609         irq_map[virq].hwirq = hwirq;
 610         smp_mb();
 611
 612         if (host->ops->map(host, virq, hwirq)) {
 613                 pr_debug("irq: -> mapping failed, freeing\n");
 614                 irq_free_virt(virq, 1);
 615                 return -1;
 616         }
 617
 618         return 0;
 619 }
 620
 621 unsigned int irq_create_direct_mapping(struct irq_host *host)
 622 {
 623         unsigned int virq;
 624
 625         if (host == NULL)
 626                 host = irq_default_host;
 627
 628         BUG_ON(host == NULL);
 629         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 630
 631         virq = irq_alloc_virt(host, 1, 0);
 632         if (virq == NO_IRQ) {
 633                 pr_debug("irq: create_direct virq allocation failed\n");
 634                 return NO_IRQ;
 635         }
 636
 637         pr_debug("irq: create_direct obtained virq %d\n", virq);
 638
 639         if (irq_setup_virq(host, virq, virq))
 640                 return NO_IRQ;
 641
 642         return virq;
 643 }
 644
 645 unsigned int irq_create_mapping(struct irq_host *host,
 646                                 irq_hw_number_t hwirq)
 647 {
 648         unsigned int virq, hint;
 649
 650         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 651
 652         /* Look for default host if nececssary */
 653         if (host == NULL)
 654                 host = irq_default_host;
 655         if (host == NULL) {
 656                 printk(KERN_WARNING "irq_create_mapping called for"
 657                        " NULL host, hwirq=%lx\n", hwirq);
 658                 WARN_ON(1);
 659                 return NO_IRQ;
 660         }
 661         pr_debug("irq: -> using host @%p\n", host);
 662
 663         /* Check if mapping already exist, if it does, call
 664          * host->ops->map() to update the flags
 665          */
 666         virq = irq_find_mapping(host, hwirq);
 667         if (virq != NO_IRQ) {
 668                 if (host->ops->remap)
 669                         host->ops->remap(host, virq, hwirq);
 670                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 671                 return virq;
 672         }
 673
 674         /* Get a virtual interrupt number */
 675         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 676                 /* Handle legacy */
 677                 virq = (unsigned int)hwirq;
 678                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 679                         return NO_IRQ;
 680                 return virq;
 681         } else {
 682                 /* Allocate a virtual interrupt number */
 683                 hint = hwirq % irq_virq_count;
 684                 virq = irq_alloc_virt(host, 1, hint);
 685                 if (virq == NO_IRQ) {
 686                         pr_debug("irq: -> virq allocation failed\n");
 687                         return NO_IRQ;
 688                 }
 689         }
 690
 691         if (irq_setup_virq(host, virq, hwirq))
 692                 return NO_IRQ;
 693
 694         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 695                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 696
 697         return virq;
 698 }
 699 EXPORT_SYMBOL_GPL(irq_create_mapping);
 700
 701 unsigned int irq_create_of_mapping(struct device_node *controller,
 702                                    u32 *intspec, unsigned int intsize)
 703 {
 704         struct irq_host *host;
 705         irq_hw_number_t hwirq;
 706         unsigned int type = IRQ_TYPE_NONE;
 707         unsigned int virq;
 708
 709         if (controller == NULL)
 710                 host = irq_default_host;
 711         else
 712                 host = irq_find_host(controller);
 713         if (host == NULL) {
 714                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 715                        controller->full_name);
 716                 return NO_IRQ;
 717         }
 718
 719         /* If host has no translation, then we assume interrupt line */
 720         if (host->ops->xlate == NULL)
 721                 hwirq = intspec[0];
 722         else {
 723                 if (host->ops->xlate(host, controller, intspec, intsize,
 724                                      &hwirq, &type))
 725                         return NO_IRQ;
 726         }
 727
 728         /* Create mapping */
 729         virq = irq_create_mapping(host, hwirq);
 730         if (virq == NO_IRQ)
 731                 return virq;
 732
 733         /* Set type if specified and different than the current one */
 734         if (type != IRQ_TYPE_NONE &&
 735             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 736                 set_irq_type(virq, type);
 737         return virq;
 738 }
 739 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 740
 741 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 742 {
 743         struct of_irq oirq;
 744
 745         if (of_irq_map_one(dev, index, &oirq))
 746                 return NO_IRQ;
 747
 748         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 749                                      oirq.size);
 750 }
 751 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 752
 753 void irq_dispose_mapping(unsigned int virq)
 754 {
 755         struct irq_host *host;
 756         irq_hw_number_t hwirq;
 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                 /*
 790                  * Check if radix tree allocated yet, if not then nothing to
 791                  * remove.
 792                  */
 793                 smp_rmb();
 794                 if (revmap_trees_allocated < 1)
 795                         break;
 796                 mutex_lock(&revmap_trees_mutex);
 797                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 798                 mutex_unlock(&revmap_trees_mutex);
 799                 break;
 800         }
 801
 802         /* Destroy map */
 803         smp_mb();
 804         irq_map[virq].hwirq = host->inval_irq;
 805
 806         /* Set some flags */
 807         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 808
 809         /* Free it */
 810         irq_free_virt(virq, 1);
 811 }
 812 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 813
 814 unsigned int irq_find_mapping(struct irq_host *host,
 815                               irq_hw_number_t hwirq)
 816 {
 817         unsigned int i;
 818         unsigned int hint = hwirq % irq_virq_count;
 819
 820         /* Look for default host if nececssary */
 821         if (host == NULL)
 822                 host = irq_default_host;
 823         if (host == NULL)
 824                 return NO_IRQ;
 825
 826         /* legacy -> bail early */
 827         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 828                 return hwirq;
 829
 830         /* Slow path does a linear search of the map */
 831         if (hint < NUM_ISA_INTERRUPTS)
 832                 hint = NUM_ISA_INTERRUPTS;
 833         i = hint;
 834         do  {
 835                 if (irq_map[i].host == host &&
 836                     irq_map[i].hwirq == hwirq)
 837                         return i;
 838                 i++;
 839                 if (i >= irq_virq_count)
 840                         i = NUM_ISA_INTERRUPTS;
 841         } while(i != hint);
 842         return NO_IRQ;
 843 }
 844 EXPORT_SYMBOL_GPL(irq_find_mapping);
 845
 846
 847 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 848                                      irq_hw_number_t hwirq)
 849 {
 850         struct irq_map_entry *ptr;
 851         unsigned int virq;
 852
 853         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 854
 855         /*
 856          * Check if the radix tree exists and has bee initialized.
 857          * If not, we fallback to slow mode
 858          */
 859         if (revmap_trees_allocated < 2)
 860                 return irq_find_mapping(host, hwirq);
 861
 862         /* Now try to resolve */
 863         /*
 864          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 865          * as it's referencing an entry in the static irq_map table.
 866          */
 867         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 868
 869         /*
 870          * If found in radix tree, then fine.
 871          * Else fallback to linear lookup - this should not happen in practice
 872          * as it means that we failed to insert the node in the radix tree.
 873          */
 874         if (ptr)
 875                 virq = ptr - irq_map;
 876         else
 877                 virq = irq_find_mapping(host, hwirq);
 878
 879         return virq;
 880 }
 881
 882 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 883                              irq_hw_number_t hwirq)
 884 {
 885
 886         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 887
 888         /*
 889          * Check if the radix tree exists yet.
 890          * If not, then the irq will be inserted into the tree when it gets
 891          * initialized.
 892          */
 893         smp_rmb();
 894         if (revmap_trees_allocated < 1)
 895                 return;
 896
 897         if (virq != NO_IRQ) {
 898                 mutex_lock(&revmap_trees_mutex);
 899                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 900                                   &irq_map[virq]);
 901                 mutex_unlock(&revmap_trees_mutex);
 902         }
 903 }
 904
 905 unsigned int irq_linear_revmap(struct irq_host *host,
 906                                irq_hw_number_t hwirq)
 907 {
 908         unsigned int *revmap;
 909
 910         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 911
 912         /* Check revmap bounds */
 913         if (unlikely(hwirq >= host->revmap_data.linear.size))
 914                 return irq_find_mapping(host, hwirq);
 915
 916         /* Check if revmap was allocated */
 917         revmap = host->revmap_data.linear.revmap;
 918         if (unlikely(revmap == NULL))
 919                 return irq_find_mapping(host, hwirq);
 920
 921         /* Fill up revmap with slow path if no mapping found */
 922         if (unlikely(revmap[hwirq] == NO_IRQ))
 923                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 924
 925         return revmap[hwirq];
 926 }
 927
 928 unsigned int irq_alloc_virt(struct irq_host *host,
 929                             unsigned int count,
 930                             unsigned int hint)
 931 {
 932         unsigned long flags;
 933         unsigned int i, j, found = NO_IRQ;
 934
 935         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 936                 return NO_IRQ;
 937
 938         spin_lock_irqsave(&irq_big_lock, flags);
 939
 940         /* Use hint for 1 interrupt if any */
 941         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 942             hint < irq_virq_count && irq_map[hint].host == NULL) {
 943                 found = hint;
 944                 goto hint_found;
 945         }
 946
 947         /* Look for count consecutive numbers in the allocatable
 948          * (non-legacy) space
 949          */
 950         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 951                 if (irq_map[i].host != NULL)
 952                         j = 0;
 953                 else
 954                         j++;
 955
 956                 if (j == count) {
 957                         found = i - count + 1;
 958                         break;
 959                 }
 960         }
 961         if (found == NO_IRQ) {
 962                 spin_unlock_irqrestore(&irq_big_lock, flags);
 963                 return NO_IRQ;
 964         }
 965  hint_found:
 966         for (i = found; i < (found + count); i++) {
 967                 irq_map[i].hwirq = host->inval_irq;
 968                 smp_wmb();
 969                 irq_map[i].host = host;
 970         }
 971         spin_unlock_irqrestore(&irq_big_lock, flags);
 972         return found;
 973 }
 974
 975 void irq_free_virt(unsigned int virq, unsigned int count)
 976 {
 977         unsigned long flags;
 978         unsigned int i;
 979
 980         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 981         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 982
 983         spin_lock_irqsave(&irq_big_lock, flags);
 984         for (i = virq; i < (virq + count); i++) {
 985                 struct irq_host *host;
 986
 987                 if (i < NUM_ISA_INTERRUPTS ||
 988                     (virq + count) > irq_virq_count)
 989                         continue;
 990
 991                 host = irq_map[i].host;
 992                 irq_map[i].hwirq = host->inval_irq;
 993                 smp_wmb();
 994                 irq_map[i].host = NULL;
 995         }
 996         spin_unlock_irqrestore(&irq_big_lock, flags);
 997 }
 998
 999 void irq_early_init(void)
1000 {
1001         unsigned int i;
1002
1003         for (i = 0; i < NR_IRQS; i++)
1004                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
1005 }
1006
1007 /* We need to create the radix trees late */
1008 static int irq_late_init(void)
1009 {
1010         struct irq_host *h;
1011         unsigned int i;
1012
1013         /*
1014          * No mutual exclusion with respect to accessors of the tree is needed
1015          * here as the synchronization is done via the state variable
1016          * revmap_trees_allocated.
1017          */
1018         list_for_each_entry(h, &irq_hosts, link) {
1019                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1020                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1021         }
1022
1023         /*
1024          * Make sure the radix trees inits are visible before setting
1025          * the flag
1026          */
1027         smp_wmb();
1028         revmap_trees_allocated = 1;
1029
1030         /*
1031          * Insert the reverse mapping for those interrupts already present
1032          * in irq_map[].
1033          */
1034         mutex_lock(&revmap_trees_mutex);
1035         for (i = 0; i < irq_virq_count; i++) {
1036                 if (irq_map[i].host &&
1037                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1038                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1039                                           irq_map[i].hwirq, &irq_map[i]);
1040         }
1041         mutex_unlock(&revmap_trees_mutex);
1042
1043         /*
1044          * Make sure the radix trees insertions are visible before setting
1045          * the flag
1046          */
1047         smp_wmb();
1048         revmap_trees_allocated = 2;
1049
1050         return 0;
1051 }
1052 arch_initcall(irq_late_init);
1053
1054 #ifdef CONFIG_VIRQ_DEBUG
1055 static int virq_debug_show(struct seq_file *m, void *private)
1056 {
1057         unsigned long flags;
1058         struct irq_desc *desc;
1059         const char *p;
1060         char none[] = "none";
1061         int i;
1062
1063         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1064                       "chip name", "host name");
1065
1066         for (i = 1; i < NR_IRQS; i++) {
1067                 desc = get_irq_desc(i);
1068                 spin_lock_irqsave(&desc->lock, flags);
1069
1070                 if (desc->action && desc->action->handler) {
1071                         seq_printf(m, "%5d  ", i);
1072                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1073
1074                         if (desc->chip && desc->chip->typename)
1075                                 p = desc->chip->typename;
1076                         else
1077                                 p = none;
1078                         seq_printf(m, "%-15s  ", p);
1079
1080                         if (irq_map[i].host && irq_map[i].host->of_node)
1081                                 p = irq_map[i].host->of_node->full_name;
1082                         else
1083                                 p = none;
1084                         seq_printf(m, "%s\n", p);
1085                 }
1086
1087                 spin_unlock_irqrestore(&desc->lock, flags);
1088         }
1089
1090         return 0;
1091 }
1092
1093 static int virq_debug_open(struct inode *inode, struct file *file)
1094 {
1095         return single_open(file, virq_debug_show, inode->i_private);
1096 }
1097
1098 static const struct file_operations virq_debug_fops = {
1099         .open = virq_debug_open,
1100         .read = seq_read,
1101         .llseek = seq_lseek,
1102         .release = single_release,
1103 };
1104
1105 static int __init irq_debugfs_init(void)
1106 {
1107         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1108                                  NULL, &virq_debug_fops) == NULL)
1109                 return -ENOMEM;
1110
1111         return 0;
1112 }
1113 __initcall(irq_debugfs_init);
1114 #endif /* CONFIG_VIRQ_DEBUG */
1115
1116 #ifdef CONFIG_PPC64
1117 static int __init setup_noirqdistrib(char *str)
1118 {
1119         distribute_irqs = 0;
1120         return 1;
1121 }
1122
1123 __setup("noirqdistrib", setup_noirqdistrib);
1124 #endif /* CONFIG_PPC64 */