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_event.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 #define CREATE_TRACE_POINTS
  74 #include <asm/trace.h>
  75
  76 int __irq_offset_value;
  77 static int ppc_spurious_interrupts;
  78
  79 #ifdef CONFIG_PPC32
  80 EXPORT_SYMBOL(__irq_offset_value);
  81 atomic_t ppc_n_lost_interrupts;
  82
  83 #ifdef CONFIG_TAU_INT
  84 extern int tau_initialized;
  85 extern int tau_interrupts(int);
  86 #endif
  87 #endif /* CONFIG_PPC32 */
  88
  89 #ifdef CONFIG_PPC64
  90
  91 #ifndef CONFIG_SPARSE_IRQ
  92 EXPORT_SYMBOL(irq_desc);
  93 #endif
  94
  95 int distribute_irqs = 1;
  96
  97 static inline notrace unsigned long get_hard_enabled(void)
  98 {
  99         unsigned long enabled;
 100
 101         __asm__ __volatile__("lbz %0,%1(13)"
 102         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 103
 104         return enabled;
 105 }
 106
 107 static inline notrace void set_soft_enabled(unsigned long enable)
 108 {
 109         __asm__ __volatile__("stb %0,%1(13)"
 110         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 111 }
 112
 113 notrace void raw_local_irq_restore(unsigned long en)
 114 {
 115         /*
 116          * get_paca()->soft_enabled = en;
 117          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 118          * That was allowed before, and in such a case we do need to take care
 119          * that gcc will set soft_enabled directly via r13, not choose to use
 120          * an intermediate register, lest we're preempted to a different cpu.
 121          */
 122         set_soft_enabled(en);
 123         if (!en)
 124                 return;
 125
 126 #ifdef CONFIG_PPC_STD_MMU_64
 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 #endif /* CONFIG_PPC_STD_MMU_64 */
 145
 146         if (test_perf_event_pending()) {
 147                 clear_perf_event_pending();
 148                 perf_event_do_pending();
 149         }
 150
 151         /*
 152          * if (get_paca()->hard_enabled) return;
 153          * But again we need to take care that gcc gets hard_enabled directly
 154          * via r13, not choose to use an intermediate register, lest we're
 155          * preempted to a different cpu in between the two instructions.
 156          */
 157         if (get_hard_enabled())
 158                 return;
 159
 160         /*
 161          * Need to hard-enable interrupts here.  Since currently disabled,
 162          * no need to take further asm precautions against preemption; but
 163          * use local_paca instead of get_paca() to avoid preemption checking.
 164          */
 165         local_paca->hard_enabled = en;
 166         if ((int)mfspr(SPRN_DEC) < 0)
 167                 mtspr(SPRN_DEC, 1);
 168
 169         /*
 170          * Force the delivery of pending soft-disabled interrupts on PS3.
 171          * Any HV call will have this side effect.
 172          */
 173         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 174                 u64 tmp;
 175                 lv1_get_version_info(&tmp);
 176         }
 177
 178         __hard_irq_enable();
 179 }
 180 EXPORT_SYMBOL(raw_local_irq_restore);
 181 #endif /* CONFIG_PPC64 */
 182
 183 int show_interrupts(struct seq_file *p, void *v)
 184 {
 185         int i = *(loff_t *)v, j;
 186         struct irqaction *action;
 187         struct irq_desc *desc;
 188         unsigned long flags;
 189
 190         if (i == 0) {
 191                 seq_puts(p, "           ");
 192                 for_each_online_cpu(j)
 193                         seq_printf(p, "CPU%d       ", j);
 194                 seq_putc(p, '\n');
 195         } else if (i == nr_irqs) {
 196 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 197                 if (tau_initialized){
 198                         seq_puts(p, "TAU: ");
 199                         for_each_online_cpu(j)
 200                                 seq_printf(p, "%10u ", tau_interrupts(j));
 201                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 202                 }
 203 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT*/
 204                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 205
 206                 return 0;
 207         }
 208
 209         desc = irq_to_desc(i);
 210         if (!desc)
 211                 return 0;
 212
 213         raw_spin_lock_irqsave(&desc->lock, flags);
 214
 215         action = desc->action;
 216         if (!action || !action->handler)
 217                 goto skip;
 218
 219         seq_printf(p, "%3d: ", i);
 220 #ifdef CONFIG_SMP
 221         for_each_online_cpu(j)
 222                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 223 #else
 224         seq_printf(p, "%10u ", kstat_irqs(i));
 225 #endif /* CONFIG_SMP */
 226
 227         if (desc->chip)
 228                 seq_printf(p, " %s ", desc->chip->name);
 229         else
 230                 seq_puts(p, "  None      ");
 231
 232         seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 233         seq_printf(p, "    %s", action->name);
 234
 235         for (action = action->next; action; action = action->next)
 236                 seq_printf(p, ", %s", action->name);
 237         seq_putc(p, '\n');
 238
 239 skip:
 240         raw_spin_unlock_irqrestore(&desc->lock, flags);
 241
 242         return 0;
 243 }
 244
 245 #ifdef CONFIG_HOTPLUG_CPU
 246 void fixup_irqs(cpumask_t map)
 247 {
 248         struct irq_desc *desc;
 249         unsigned int irq;
 250         static int warned;
 251
 252         for_each_irq(irq) {
 253                 cpumask_t mask;
 254
 255                 desc = irq_to_desc(irq);
 256                 if (desc && desc->status & IRQ_PER_CPU)
 257                         continue;
 258
 259                 cpumask_and(&mask, desc->affinity, &map);
 260                 if (any_online_cpu(mask) == NR_CPUS) {
 261                         printk("Breaking affinity for irq %i\n", irq);
 262                         mask = map;
 263                 }
 264                 if (desc->chip->set_affinity)
 265                         desc->chip->set_affinity(irq, &mask);
 266                 else if (desc->action && !(warned++))
 267                         printk("Cannot set affinity for irq %i\n", irq);
 268         }
 269
 270         local_irq_enable();
 271         mdelay(1);
 272         local_irq_disable();
 273 }
 274 #endif
 275
 276 #ifdef CONFIG_IRQSTACKS
 277 static inline void handle_one_irq(unsigned int irq)
 278 {
 279         struct thread_info *curtp, *irqtp;
 280         unsigned long saved_sp_limit;
 281         struct irq_desc *desc;
 282
 283         /* Switch to the irq stack to handle this */
 284         curtp = current_thread_info();
 285         irqtp = hardirq_ctx[smp_processor_id()];
 286
 287         if (curtp == irqtp) {
 288                 /* We're already on the irq stack, just handle it */
 289                 generic_handle_irq(irq);
 290                 return;
 291         }
 292
 293         desc = irq_to_desc(irq);
 294         saved_sp_limit = current->thread.ksp_limit;
 295
 296         irqtp->task = curtp->task;
 297         irqtp->flags = 0;
 298
 299         /* Copy the softirq bits in preempt_count so that the
 300          * softirq checks work in the hardirq context. */
 301         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 302                                (curtp->preempt_count & SOFTIRQ_MASK);
 303
 304         current->thread.ksp_limit = (unsigned long)irqtp +
 305                 _ALIGN_UP(sizeof(struct thread_info), 16);
 306
 307         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 308         current->thread.ksp_limit = saved_sp_limit;
 309         irqtp->task = NULL;
 310
 311         /* Set any flag that may have been set on the
 312          * alternate stack
 313          */
 314         if (irqtp->flags)
 315                 set_bits(irqtp->flags, &curtp->flags);
 316 }
 317 #else
 318 static inline void handle_one_irq(unsigned int irq)
 319 {
 320         generic_handle_irq(irq);
 321 }
 322 #endif
 323
 324 static inline void check_stack_overflow(void)
 325 {
 326 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 327         long sp;
 328
 329         sp = __get_SP() & (THREAD_SIZE-1);
 330
 331         /* check for stack overflow: is there less than 2KB free? */
 332         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 333                 printk("do_IRQ: stack overflow: %ld\n",
 334                         sp - sizeof(struct thread_info));
 335                 dump_stack();
 336         }
 337 #endif
 338 }
 339
 340 void do_IRQ(struct pt_regs *regs)
 341 {
 342         struct pt_regs *old_regs = set_irq_regs(regs);
 343         unsigned int irq;
 344
 345         trace_irq_entry(regs);
 346
 347         irq_enter();
 348
 349         check_stack_overflow();
 350
 351         irq = ppc_md.get_irq();
 352
 353         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 354                 handle_one_irq(irq);
 355         else if (irq != NO_IRQ_IGNORE)
 356                 /* That's not SMP safe ... but who cares ? */
 357                 ppc_spurious_interrupts++;
 358
 359         irq_exit();
 360         set_irq_regs(old_regs);
 361
 362 #ifdef CONFIG_PPC_ISERIES
 363         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 364                         get_lppaca()->int_dword.fields.decr_int) {
 365                 get_lppaca()->int_dword.fields.decr_int = 0;
 366                 /* Signal a fake decrementer interrupt */
 367                 timer_interrupt(regs);
 368         }
 369 #endif
 370
 371         trace_irq_exit(regs);
 372 }
 373
 374 void __init init_IRQ(void)
 375 {
 376         if (ppc_md.init_IRQ)
 377                 ppc_md.init_IRQ();
 378
 379         exc_lvl_ctx_init();
 380
 381         irq_ctx_init();
 382 }
 383
 384 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 385 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 386 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 387 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 388
 389 void exc_lvl_ctx_init(void)
 390 {
 391         struct thread_info *tp;
 392         int i;
 393
 394         for_each_possible_cpu(i) {
 395                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 396                 tp = critirq_ctx[i];
 397                 tp->cpu = i;
 398                 tp->preempt_count = 0;
 399
 400 #ifdef CONFIG_BOOKE
 401                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 402                 tp = dbgirq_ctx[i];
 403                 tp->cpu = i;
 404                 tp->preempt_count = 0;
 405
 406                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 407                 tp = mcheckirq_ctx[i];
 408                 tp->cpu = i;
 409                 tp->preempt_count = HARDIRQ_OFFSET;
 410 #endif
 411         }
 412 }
 413 #endif
 414
 415 #ifdef CONFIG_IRQSTACKS
 416 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 417 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 418
 419 void irq_ctx_init(void)
 420 {
 421         struct thread_info *tp;
 422         int i;
 423
 424         for_each_possible_cpu(i) {
 425                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 426                 tp = softirq_ctx[i];
 427                 tp->cpu = i;
 428                 tp->preempt_count = 0;
 429
 430                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 431                 tp = hardirq_ctx[i];
 432                 tp->cpu = i;
 433                 tp->preempt_count = HARDIRQ_OFFSET;
 434         }
 435 }
 436
 437 static inline void do_softirq_onstack(void)
 438 {
 439         struct thread_info *curtp, *irqtp;
 440         unsigned long saved_sp_limit = current->thread.ksp_limit;
 441
 442         curtp = current_thread_info();
 443         irqtp = softirq_ctx[smp_processor_id()];
 444         irqtp->task = curtp->task;
 445         current->thread.ksp_limit = (unsigned long)irqtp +
 446                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 447         call_do_softirq(irqtp);
 448         current->thread.ksp_limit = saved_sp_limit;
 449         irqtp->task = NULL;
 450 }
 451
 452 #else
 453 #define do_softirq_onstack()    __do_softirq()
 454 #endif /* CONFIG_IRQSTACKS */
 455
 456 void do_softirq(void)
 457 {
 458         unsigned long flags;
 459
 460         if (in_interrupt())
 461                 return;
 462
 463         local_irq_save(flags);
 464
 465         if (local_softirq_pending())
 466                 do_softirq_onstack();
 467
 468         local_irq_restore(flags);
 469 }
 470
 471
 472 /*
 473  * IRQ controller and virtual interrupts
 474  */
 475
 476 static LIST_HEAD(irq_hosts);
 477 static DEFINE_SPINLOCK(irq_big_lock);
 478 static unsigned int revmap_trees_allocated;
 479 static DEFINE_MUTEX(revmap_trees_mutex);
 480 struct irq_map_entry irq_map[NR_IRQS];
 481 static unsigned int irq_virq_count = NR_IRQS;
 482 static struct irq_host *irq_default_host;
 483
 484 irq_hw_number_t virq_to_hw(unsigned int virq)
 485 {
 486         return irq_map[virq].hwirq;
 487 }
 488 EXPORT_SYMBOL_GPL(virq_to_hw);
 489
 490 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 491 {
 492         return h->of_node != NULL && h->of_node == np;
 493 }
 494
 495 struct irq_host *irq_alloc_host(struct device_node *of_node,
 496                                 unsigned int revmap_type,
 497                                 unsigned int revmap_arg,
 498                                 struct irq_host_ops *ops,
 499                                 irq_hw_number_t inval_irq)
 500 {
 501         struct irq_host *host;
 502         unsigned int size = sizeof(struct irq_host);
 503         unsigned int i;
 504         unsigned int *rmap;
 505         unsigned long flags;
 506
 507         /* Allocate structure and revmap table if using linear mapping */
 508         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 509                 size += revmap_arg * sizeof(unsigned int);
 510         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 511         if (host == NULL)
 512                 return NULL;
 513
 514         /* Fill structure */
 515         host->revmap_type = revmap_type;
 516         host->inval_irq = inval_irq;
 517         host->ops = ops;
 518         host->of_node = of_node_get(of_node);
 519
 520         if (host->ops->match == NULL)
 521                 host->ops->match = default_irq_host_match;
 522
 523         spin_lock_irqsave(&irq_big_lock, flags);
 524
 525         /* If it's a legacy controller, check for duplicates and
 526          * mark it as allocated (we use irq 0 host pointer for that
 527          */
 528         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 529                 if (irq_map[0].host != NULL) {
 530                         spin_unlock_irqrestore(&irq_big_lock, flags);
 531                         /* If we are early boot, we can't free the structure,
 532                          * too bad...
 533                          * this will be fixed once slab is made available early
 534                          * instead of the current cruft
 535                          */
 536                         if (mem_init_done)
 537                                 kfree(host);
 538                         return NULL;
 539                 }
 540                 irq_map[0].host = host;
 541         }
 542
 543         list_add(&host->link, &irq_hosts);
 544         spin_unlock_irqrestore(&irq_big_lock, flags);
 545
 546         /* Additional setups per revmap type */
 547         switch(revmap_type) {
 548         case IRQ_HOST_MAP_LEGACY:
 549                 /* 0 is always the invalid number for legacy */
 550                 host->inval_irq = 0;
 551                 /* setup us as the host for all legacy interrupts */
 552                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 553                         irq_map[i].hwirq = i;
 554                         smp_wmb();
 555                         irq_map[i].host = host;
 556                         smp_wmb();
 557
 558                         /* Clear norequest flags */
 559                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
 560
 561                         /* Legacy flags are left to default at this point,
 562                          * one can then use irq_create_mapping() to
 563                          * explicitly change them
 564                          */
 565                         ops->map(host, i, i);
 566                 }
 567                 break;
 568         case IRQ_HOST_MAP_LINEAR:
 569                 rmap = (unsigned int *)(host + 1);
 570                 for (i = 0; i < revmap_arg; i++)
 571                         rmap[i] = NO_IRQ;
 572                 host->revmap_data.linear.size = revmap_arg;
 573                 smp_wmb();
 574                 host->revmap_data.linear.revmap = rmap;
 575                 break;
 576         default:
 577                 break;
 578         }
 579
 580         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 581
 582         return host;
 583 }
 584
 585 struct irq_host *irq_find_host(struct device_node *node)
 586 {
 587         struct irq_host *h, *found = NULL;
 588         unsigned long flags;
 589
 590         /* We might want to match the legacy controller last since
 591          * it might potentially be set to match all interrupts in
 592          * the absence of a device node. This isn't a problem so far
 593          * yet though...
 594          */
 595         spin_lock_irqsave(&irq_big_lock, flags);
 596         list_for_each_entry(h, &irq_hosts, link)
 597                 if (h->ops->match(h, node)) {
 598                         found = h;
 599                         break;
 600                 }
 601         spin_unlock_irqrestore(&irq_big_lock, flags);
 602         return found;
 603 }
 604 EXPORT_SYMBOL_GPL(irq_find_host);
 605
 606 void irq_set_default_host(struct irq_host *host)
 607 {
 608         pr_debug("irq: Default host set to @0x%p\n", host);
 609
 610         irq_default_host = host;
 611 }
 612
 613 void irq_set_virq_count(unsigned int count)
 614 {
 615         pr_debug("irq: Trying to set virq count to %d\n", count);
 616
 617         BUG_ON(count < NUM_ISA_INTERRUPTS);
 618         if (count < NR_IRQS)
 619                 irq_virq_count = count;
 620 }
 621
 622 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 623                             irq_hw_number_t hwirq)
 624 {
 625         struct irq_desc *desc;
 626
 627         desc = irq_to_desc_alloc_node(virq, 0);
 628         if (!desc) {
 629                 pr_debug("irq: -> allocating desc failed\n");
 630                 goto error;
 631         }
 632
 633         /* Clear IRQ_NOREQUEST flag */
 634         desc->status &= ~IRQ_NOREQUEST;
 635
 636         /* map it */
 637         smp_wmb();
 638         irq_map[virq].hwirq = hwirq;
 639         smp_mb();
 640
 641         if (host->ops->map(host, virq, hwirq)) {
 642                 pr_debug("irq: -> mapping failed, freeing\n");
 643                 goto error;
 644         }
 645
 646         return 0;
 647
 648 error:
 649         irq_free_virt(virq, 1);
 650         return -1;
 651 }
 652
 653 unsigned int irq_create_direct_mapping(struct irq_host *host)
 654 {
 655         unsigned int virq;
 656
 657         if (host == NULL)
 658                 host = irq_default_host;
 659
 660         BUG_ON(host == NULL);
 661         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 662
 663         virq = irq_alloc_virt(host, 1, 0);
 664         if (virq == NO_IRQ) {
 665                 pr_debug("irq: create_direct virq allocation failed\n");
 666                 return NO_IRQ;
 667         }
 668
 669         pr_debug("irq: create_direct obtained virq %d\n", virq);
 670
 671         if (irq_setup_virq(host, virq, virq))
 672                 return NO_IRQ;
 673
 674         return virq;
 675 }
 676
 677 unsigned int irq_create_mapping(struct irq_host *host,
 678                                 irq_hw_number_t hwirq)
 679 {
 680         unsigned int virq, hint;
 681
 682         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 683
 684         /* Look for default host if nececssary */
 685         if (host == NULL)
 686                 host = irq_default_host;
 687         if (host == NULL) {
 688                 printk(KERN_WARNING "irq_create_mapping called for"
 689                        " NULL host, hwirq=%lx\n", hwirq);
 690                 WARN_ON(1);
 691                 return NO_IRQ;
 692         }
 693         pr_debug("irq: -> using host @%p\n", host);
 694
 695         /* Check if mapping already exist, if it does, call
 696          * host->ops->map() to update the flags
 697          */
 698         virq = irq_find_mapping(host, hwirq);
 699         if (virq != NO_IRQ) {
 700                 if (host->ops->remap)
 701                         host->ops->remap(host, virq, hwirq);
 702                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 703                 return virq;
 704         }
 705
 706         /* Get a virtual interrupt number */
 707         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 708                 /* Handle legacy */
 709                 virq = (unsigned int)hwirq;
 710                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 711                         return NO_IRQ;
 712                 return virq;
 713         } else {
 714                 /* Allocate a virtual interrupt number */
 715                 hint = hwirq % irq_virq_count;
 716                 virq = irq_alloc_virt(host, 1, hint);
 717                 if (virq == NO_IRQ) {
 718                         pr_debug("irq: -> virq allocation failed\n");
 719                         return NO_IRQ;
 720                 }
 721         }
 722
 723         if (irq_setup_virq(host, virq, hwirq))
 724                 return NO_IRQ;
 725
 726         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 727                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 728
 729         return virq;
 730 }
 731 EXPORT_SYMBOL_GPL(irq_create_mapping);
 732
 733 unsigned int irq_create_of_mapping(struct device_node *controller,
 734                                    const u32 *intspec, unsigned int intsize)
 735 {
 736         struct irq_host *host;
 737         irq_hw_number_t hwirq;
 738         unsigned int type = IRQ_TYPE_NONE;
 739         unsigned int virq;
 740
 741         if (controller == NULL)
 742                 host = irq_default_host;
 743         else
 744                 host = irq_find_host(controller);
 745         if (host == NULL) {
 746                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 747                        controller->full_name);
 748                 return NO_IRQ;
 749         }
 750
 751         /* If host has no translation, then we assume interrupt line */
 752         if (host->ops->xlate == NULL)
 753                 hwirq = intspec[0];
 754         else {
 755                 if (host->ops->xlate(host, controller, intspec, intsize,
 756                                      &hwirq, &type))
 757                         return NO_IRQ;
 758         }
 759
 760         /* Create mapping */
 761         virq = irq_create_mapping(host, hwirq);
 762         if (virq == NO_IRQ)
 763                 return virq;
 764
 765         /* Set type if specified and different than the current one */
 766         if (type != IRQ_TYPE_NONE &&
 767             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
 768                 set_irq_type(virq, type);
 769         return virq;
 770 }
 771 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 772
 773 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 774 {
 775         struct of_irq oirq;
 776
 777         if (of_irq_map_one(dev, index, &oirq))
 778                 return NO_IRQ;
 779
 780         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 781                                      oirq.size);
 782 }
 783 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 784
 785 void irq_dispose_mapping(unsigned int virq)
 786 {
 787         struct irq_host *host;
 788         irq_hw_number_t hwirq;
 789
 790         if (virq == NO_IRQ)
 791                 return;
 792
 793         host = irq_map[virq].host;
 794         WARN_ON (host == NULL);
 795         if (host == NULL)
 796                 return;
 797
 798         /* Never unmap legacy interrupts */
 799         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 800                 return;
 801
 802         /* remove chip and handler */
 803         set_irq_chip_and_handler(virq, NULL, NULL);
 804
 805         /* Make sure it's completed */
 806         synchronize_irq(virq);
 807
 808         /* Tell the PIC about it */
 809         if (host->ops->unmap)
 810                 host->ops->unmap(host, virq);
 811         smp_mb();
 812
 813         /* Clear reverse map */
 814         hwirq = irq_map[virq].hwirq;
 815         switch(host->revmap_type) {
 816         case IRQ_HOST_MAP_LINEAR:
 817                 if (hwirq < host->revmap_data.linear.size)
 818                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 819                 break;
 820         case IRQ_HOST_MAP_TREE:
 821                 /*
 822                  * Check if radix tree allocated yet, if not then nothing to
 823                  * remove.
 824                  */
 825                 smp_rmb();
 826                 if (revmap_trees_allocated < 1)
 827                         break;
 828                 mutex_lock(&revmap_trees_mutex);
 829                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 830                 mutex_unlock(&revmap_trees_mutex);
 831                 break;
 832         }
 833
 834         /* Destroy map */
 835         smp_mb();
 836         irq_map[virq].hwirq = host->inval_irq;
 837
 838         /* Set some flags */
 839         irq_to_desc(virq)->status |= IRQ_NOREQUEST;
 840
 841         /* Free it */
 842         irq_free_virt(virq, 1);
 843 }
 844 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 845
 846 unsigned int irq_find_mapping(struct irq_host *host,
 847                               irq_hw_number_t hwirq)
 848 {
 849         unsigned int i;
 850         unsigned int hint = hwirq % irq_virq_count;
 851
 852         /* Look for default host if nececssary */
 853         if (host == NULL)
 854                 host = irq_default_host;
 855         if (host == NULL)
 856                 return NO_IRQ;
 857
 858         /* legacy -> bail early */
 859         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 860                 return hwirq;
 861
 862         /* Slow path does a linear search of the map */
 863         if (hint < NUM_ISA_INTERRUPTS)
 864                 hint = NUM_ISA_INTERRUPTS;
 865         i = hint;
 866         do  {
 867                 if (irq_map[i].host == host &&
 868                     irq_map[i].hwirq == hwirq)
 869                         return i;
 870                 i++;
 871                 if (i >= irq_virq_count)
 872                         i = NUM_ISA_INTERRUPTS;
 873         } while(i != hint);
 874         return NO_IRQ;
 875 }
 876 EXPORT_SYMBOL_GPL(irq_find_mapping);
 877
 878
 879 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 880                                      irq_hw_number_t hwirq)
 881 {
 882         struct irq_map_entry *ptr;
 883         unsigned int virq;
 884
 885         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 886
 887         /*
 888          * Check if the radix tree exists and has bee initialized.
 889          * If not, we fallback to slow mode
 890          */
 891         if (revmap_trees_allocated < 2)
 892                 return irq_find_mapping(host, hwirq);
 893
 894         /* Now try to resolve */
 895         /*
 896          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 897          * as it's referencing an entry in the static irq_map table.
 898          */
 899         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 900
 901         /*
 902          * If found in radix tree, then fine.
 903          * Else fallback to linear lookup - this should not happen in practice
 904          * as it means that we failed to insert the node in the radix tree.
 905          */
 906         if (ptr)
 907                 virq = ptr - irq_map;
 908         else
 909                 virq = irq_find_mapping(host, hwirq);
 910
 911         return virq;
 912 }
 913
 914 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 915                              irq_hw_number_t hwirq)
 916 {
 917
 918         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 919
 920         /*
 921          * Check if the radix tree exists yet.
 922          * If not, then the irq will be inserted into the tree when it gets
 923          * initialized.
 924          */
 925         smp_rmb();
 926         if (revmap_trees_allocated < 1)
 927                 return;
 928
 929         if (virq != NO_IRQ) {
 930                 mutex_lock(&revmap_trees_mutex);
 931                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 932                                   &irq_map[virq]);
 933                 mutex_unlock(&revmap_trees_mutex);
 934         }
 935 }
 936
 937 unsigned int irq_linear_revmap(struct irq_host *host,
 938                                irq_hw_number_t hwirq)
 939 {
 940         unsigned int *revmap;
 941
 942         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 943
 944         /* Check revmap bounds */
 945         if (unlikely(hwirq >= host->revmap_data.linear.size))
 946                 return irq_find_mapping(host, hwirq);
 947
 948         /* Check if revmap was allocated */
 949         revmap = host->revmap_data.linear.revmap;
 950         if (unlikely(revmap == NULL))
 951                 return irq_find_mapping(host, hwirq);
 952
 953         /* Fill up revmap with slow path if no mapping found */
 954         if (unlikely(revmap[hwirq] == NO_IRQ))
 955                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 956
 957         return revmap[hwirq];
 958 }
 959
 960 unsigned int irq_alloc_virt(struct irq_host *host,
 961                             unsigned int count,
 962                             unsigned int hint)
 963 {
 964         unsigned long flags;
 965         unsigned int i, j, found = NO_IRQ;
 966
 967         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 968                 return NO_IRQ;
 969
 970         spin_lock_irqsave(&irq_big_lock, flags);
 971
 972         /* Use hint for 1 interrupt if any */
 973         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 974             hint < irq_virq_count && irq_map[hint].host == NULL) {
 975                 found = hint;
 976                 goto hint_found;
 977         }
 978
 979         /* Look for count consecutive numbers in the allocatable
 980          * (non-legacy) space
 981          */
 982         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 983                 if (irq_map[i].host != NULL)
 984                         j = 0;
 985                 else
 986                         j++;
 987
 988                 if (j == count) {
 989                         found = i - count + 1;
 990                         break;
 991                 }
 992         }
 993         if (found == NO_IRQ) {
 994                 spin_unlock_irqrestore(&irq_big_lock, flags);
 995                 return NO_IRQ;
 996         }
 997  hint_found:
 998         for (i = found; i < (found + count); i++) {
 999                 irq_map[i].hwirq = host->inval_irq;
1000                 smp_wmb();
1001                 irq_map[i].host = host;
1002         }
1003         spin_unlock_irqrestore(&irq_big_lock, flags);
1004         return found;
1005 }
1006
1007 void irq_free_virt(unsigned int virq, unsigned int count)
1008 {
1009         unsigned long flags;
1010         unsigned int i;
1011
1012         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1013         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1014
1015         spin_lock_irqsave(&irq_big_lock, flags);
1016         for (i = virq; i < (virq + count); i++) {
1017                 struct irq_host *host;
1018
1019                 if (i < NUM_ISA_INTERRUPTS ||
1020                     (virq + count) > irq_virq_count)
1021                         continue;
1022
1023                 host = irq_map[i].host;
1024                 irq_map[i].hwirq = host->inval_irq;
1025                 smp_wmb();
1026                 irq_map[i].host = NULL;
1027         }
1028         spin_unlock_irqrestore(&irq_big_lock, flags);
1029 }
1030
1031 int arch_early_irq_init(void)
1032 {
1033         struct irq_desc *desc;
1034         int i;
1035
1036         for (i = 0; i < NR_IRQS; i++) {
1037                 desc = irq_to_desc(i);
1038                 if (desc)
1039                         desc->status |= IRQ_NOREQUEST;
1040         }
1041
1042         return 0;
1043 }
1044
1045 int arch_init_chip_data(struct irq_desc *desc, int node)
1046 {
1047         desc->status |= IRQ_NOREQUEST;
1048         return 0;
1049 }
1050
1051 /* We need to create the radix trees late */
1052 static int irq_late_init(void)
1053 {
1054         struct irq_host *h;
1055         unsigned int i;
1056
1057         /*
1058          * No mutual exclusion with respect to accessors of the tree is needed
1059          * here as the synchronization is done via the state variable
1060          * revmap_trees_allocated.
1061          */
1062         list_for_each_entry(h, &irq_hosts, link) {
1063                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1064                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1065         }
1066
1067         /*
1068          * Make sure the radix trees inits are visible before setting
1069          * the flag
1070          */
1071         smp_wmb();
1072         revmap_trees_allocated = 1;
1073
1074         /*
1075          * Insert the reverse mapping for those interrupts already present
1076          * in irq_map[].
1077          */
1078         mutex_lock(&revmap_trees_mutex);
1079         for (i = 0; i < irq_virq_count; i++) {
1080                 if (irq_map[i].host &&
1081                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1082                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1083                                           irq_map[i].hwirq, &irq_map[i]);
1084         }
1085         mutex_unlock(&revmap_trees_mutex);
1086
1087         /*
1088          * Make sure the radix trees insertions are visible before setting
1089          * the flag
1090          */
1091         smp_wmb();
1092         revmap_trees_allocated = 2;
1093
1094         return 0;
1095 }
1096 arch_initcall(irq_late_init);
1097
1098 #ifdef CONFIG_VIRQ_DEBUG
1099 static int virq_debug_show(struct seq_file *m, void *private)
1100 {
1101         unsigned long flags;
1102         struct irq_desc *desc;
1103         const char *p;
1104         char none[] = "none";
1105         int i;
1106
1107         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1108                       "chip name", "host name");
1109
1110         for (i = 1; i < nr_irqs; i++) {
1111                 desc = irq_to_desc(i);
1112                 if (!desc)
1113                         continue;
1114
1115                 raw_spin_lock_irqsave(&desc->lock, flags);
1116
1117                 if (desc->action && desc->action->handler) {
1118                         seq_printf(m, "%5d  ", i);
1119                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1120
1121                         if (desc->chip && desc->chip->name)
1122                                 p = desc->chip->name;
1123                         else
1124                                 p = none;
1125                         seq_printf(m, "%-15s  ", p);
1126
1127                         if (irq_map[i].host && irq_map[i].host->of_node)
1128                                 p = irq_map[i].host->of_node->full_name;
1129                         else
1130                                 p = none;
1131                         seq_printf(m, "%s\n", p);
1132                 }
1133
1134                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1135         }
1136
1137         return 0;
1138 }
1139
1140 static int virq_debug_open(struct inode *inode, struct file *file)
1141 {
1142         return single_open(file, virq_debug_show, inode->i_private);
1143 }
1144
1145 static const struct file_operations virq_debug_fops = {
1146         .open = virq_debug_open,
1147         .read = seq_read,
1148         .llseek = seq_lseek,
1149         .release = single_release,
1150 };
1151
1152 static int __init irq_debugfs_init(void)
1153 {
1154         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1155                                  NULL, &virq_debug_fops) == NULL)
1156                 return -ENOMEM;
1157
1158         return 0;
1159 }
1160 __initcall(irq_debugfs_init);
1161 #endif /* CONFIG_VIRQ_DEBUG */
1162
1163 #ifdef CONFIG_PPC64
1164 static int __init setup_noirqdistrib(char *str)
1165 {
1166         distribute_irqs = 0;
1167         return 1;
1168 }
1169
1170 __setup("noirqdistrib", setup_noirqdistrib);
1171 #endif /* CONFIG_PPC64 */