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 EXPORT_SYMBOL(irq_desc);
  91
  92 int distribute_irqs = 1;
  93
  94 static inline notrace unsigned long get_hard_enabled(void)
  95 {
  96         unsigned long enabled;
  97
  98         __asm__ __volatile__("lbz %0,%1(13)"
  99         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 100
 101         return enabled;
 102 }
 103
 104 static inline notrace void set_soft_enabled(unsigned long enable)
 105 {
 106         __asm__ __volatile__("stb %0,%1(13)"
 107         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 108 }
 109
 110 notrace void raw_local_irq_restore(unsigned long en)
 111 {
 112         /*
 113          * get_paca()->soft_enabled = en;
 114          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 115          * That was allowed before, and in such a case we do need to take care
 116          * that gcc will set soft_enabled directly via r13, not choose to use
 117          * an intermediate register, lest we're preempted to a different cpu.
 118          */
 119         set_soft_enabled(en);
 120         if (!en)
 121                 return;
 122
 123 #ifdef CONFIG_PPC_STD_MMU_64
 124         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 125                 /*
 126                  * Do we need to disable preemption here?  Not really: in the
 127                  * unlikely event that we're preempted to a different cpu in
 128                  * between getting r13, loading its lppaca_ptr, and loading
 129                  * its any_int, we might call iseries_handle_interrupts without
 130                  * an interrupt pending on the new cpu, but that's no disaster,
 131                  * is it?  And the business of preempting us off the old cpu
 132                  * would itself involve a local_irq_restore which handles the
 133                  * interrupt to that cpu.
 134                  *
 135                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 136                  * to avoid any preemption checking added into get_paca().
 137                  */
 138                 if (local_paca->lppaca_ptr->int_dword.any_int)
 139                         iseries_handle_interrupts();
 140         }
 141 #endif /* CONFIG_PPC_STD_MMU_64 */
 142
 143         if (test_perf_event_pending()) {
 144                 clear_perf_event_pending();
 145                 perf_event_do_pending();
 146         }
 147
 148         /*
 149          * if (get_paca()->hard_enabled) return;
 150          * But again we need to take care that gcc gets hard_enabled directly
 151          * via r13, not choose to use an intermediate register, lest we're
 152          * preempted to a different cpu in between the two instructions.
 153          */
 154         if (get_hard_enabled())
 155                 return;
 156
 157         /*
 158          * Need to hard-enable interrupts here.  Since currently disabled,
 159          * no need to take further asm precautions against preemption; but
 160          * use local_paca instead of get_paca() to avoid preemption checking.
 161          */
 162         local_paca->hard_enabled = en;
 163         if ((int)mfspr(SPRN_DEC) < 0)
 164                 mtspr(SPRN_DEC, 1);
 165
 166         /*
 167          * Force the delivery of pending soft-disabled interrupts on PS3.
 168          * Any HV call will have this side effect.
 169          */
 170         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 171                 u64 tmp;
 172                 lv1_get_version_info(&tmp);
 173         }
 174
 175         __hard_irq_enable();
 176 }
 177 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 #ifdef CONFIG_IRQSTACKS
 262 static inline void handle_one_irq(unsigned int irq)
 263 {
 264         struct thread_info *curtp, *irqtp;
 265         unsigned long saved_sp_limit;
 266         struct irq_desc *desc;
 267
 268         /* Switch to the irq stack to handle this */
 269         curtp = current_thread_info();
 270         irqtp = hardirq_ctx[smp_processor_id()];
 271
 272         if (curtp == irqtp) {
 273                 /* We're already on the irq stack, just handle it */
 274                 generic_handle_irq(irq);
 275                 return;
 276         }
 277
 278         desc = irq_desc + irq;
 279         saved_sp_limit = current->thread.ksp_limit;
 280
 281         irqtp->task = curtp->task;
 282         irqtp->flags = 0;
 283
 284         /* Copy the softirq bits in preempt_count so that the
 285          * softirq checks work in the hardirq context. */
 286         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 287                                (curtp->preempt_count & SOFTIRQ_MASK);
 288
 289         current->thread.ksp_limit = (unsigned long)irqtp +
 290                 _ALIGN_UP(sizeof(struct thread_info), 16);
 291
 292         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 293         current->thread.ksp_limit = saved_sp_limit;
 294         irqtp->task = NULL;
 295
 296         /* Set any flag that may have been set on the
 297          * alternate stack
 298          */
 299         if (irqtp->flags)
 300                 set_bits(irqtp->flags, &curtp->flags);
 301 }
 302 #else
 303 static inline void handle_one_irq(unsigned int irq)
 304 {
 305         generic_handle_irq(irq);
 306 }
 307 #endif
 308
 309 static inline void check_stack_overflow(void)
 310 {
 311 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 312         long sp;
 313
 314         sp = __get_SP() & (THREAD_SIZE-1);
 315
 316         /* check for stack overflow: is there less than 2KB free? */
 317         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 318                 printk("do_IRQ: stack overflow: %ld\n",
 319                         sp - sizeof(struct thread_info));
 320                 dump_stack();
 321         }
 322 #endif
 323 }
 324
 325 void do_IRQ(struct pt_regs *regs)
 326 {
 327         struct pt_regs *old_regs = set_irq_regs(regs);
 328         unsigned int irq;
 329
 330         trace_irq_entry(regs);
 331
 332         irq_enter();
 333
 334         check_stack_overflow();
 335
 336         irq = ppc_md.get_irq();
 337
 338         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 339                 handle_one_irq(irq);
 340         else if (irq != NO_IRQ_IGNORE)
 341                 /* That's not SMP safe ... but who cares ? */
 342                 ppc_spurious_interrupts++;
 343
 344         irq_exit();
 345         set_irq_regs(old_regs);
 346
 347 #ifdef CONFIG_PPC_ISERIES
 348         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 349                         get_lppaca()->int_dword.fields.decr_int) {
 350                 get_lppaca()->int_dword.fields.decr_int = 0;
 351                 /* Signal a fake decrementer interrupt */
 352                 timer_interrupt(regs);
 353         }
 354 #endif
 355
 356         trace_irq_exit(regs);
 357 }
 358
 359 void __init init_IRQ(void)
 360 {
 361         if (ppc_md.init_IRQ)
 362                 ppc_md.init_IRQ();
 363
 364         exc_lvl_ctx_init();
 365
 366         irq_ctx_init();
 367 }
 368
 369 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 370 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 371 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 372 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 373
 374 void exc_lvl_ctx_init(void)
 375 {
 376         struct thread_info *tp;
 377         int i;
 378
 379         for_each_possible_cpu(i) {
 380                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 381                 tp = critirq_ctx[i];
 382                 tp->cpu = i;
 383                 tp->preempt_count = 0;
 384
 385 #ifdef CONFIG_BOOKE
 386                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 387                 tp = dbgirq_ctx[i];
 388                 tp->cpu = i;
 389                 tp->preempt_count = 0;
 390
 391                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 392                 tp = mcheckirq_ctx[i];
 393                 tp->cpu = i;
 394                 tp->preempt_count = HARDIRQ_OFFSET;
 395 #endif
 396         }
 397 }
 398 #endif
 399
 400 #ifdef CONFIG_IRQSTACKS
 401 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 402 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 403
 404 void irq_ctx_init(void)
 405 {
 406         struct thread_info *tp;
 407         int i;
 408
 409         for_each_possible_cpu(i) {
 410                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 411                 tp = softirq_ctx[i];
 412                 tp->cpu = i;
 413                 tp->preempt_count = 0;
 414
 415                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 416                 tp = hardirq_ctx[i];
 417                 tp->cpu = i;
 418                 tp->preempt_count = HARDIRQ_OFFSET;
 419         }
 420 }
 421
 422 static inline void do_softirq_onstack(void)
 423 {
 424         struct thread_info *curtp, *irqtp;
 425         unsigned long saved_sp_limit = current->thread.ksp_limit;
 426
 427         curtp = current_thread_info();
 428         irqtp = softirq_ctx[smp_processor_id()];
 429         irqtp->task = curtp->task;
 430         current->thread.ksp_limit = (unsigned long)irqtp +
 431                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 432         call_do_softirq(irqtp);
 433         current->thread.ksp_limit = saved_sp_limit;
 434         irqtp->task = NULL;
 435 }
 436
 437 #else
 438 #define do_softirq_onstack()    __do_softirq()
 439 #endif /* CONFIG_IRQSTACKS */
 440
 441 void do_softirq(void)
 442 {
 443         unsigned long flags;
 444
 445         if (in_interrupt())
 446                 return;
 447
 448         local_irq_save(flags);
 449
 450         if (local_softirq_pending())
 451                 do_softirq_onstack();
 452
 453         local_irq_restore(flags);
 454 }
 455
 456
 457 /*
 458  * IRQ controller and virtual interrupts
 459  */
 460
 461 static LIST_HEAD(irq_hosts);
 462 static DEFINE_SPINLOCK(irq_big_lock);
 463 static unsigned int revmap_trees_allocated;
 464 static DEFINE_MUTEX(revmap_trees_mutex);
 465 struct irq_map_entry irq_map[NR_IRQS];
 466 static unsigned int irq_virq_count = NR_IRQS;
 467 static struct irq_host *irq_default_host;
 468
 469 irq_hw_number_t virq_to_hw(unsigned int virq)
 470 {
 471         return irq_map[virq].hwirq;
 472 }
 473 EXPORT_SYMBOL_GPL(virq_to_hw);
 474
 475 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 476 {
 477         return h->of_node != NULL && h->of_node == np;
 478 }
 479
 480 struct irq_host *irq_alloc_host(struct device_node *of_node,
 481                                 unsigned int revmap_type,
 482                                 unsigned int revmap_arg,
 483                                 struct irq_host_ops *ops,
 484                                 irq_hw_number_t inval_irq)
 485 {
 486         struct irq_host *host;
 487         unsigned int size = sizeof(struct irq_host);
 488         unsigned int i;
 489         unsigned int *rmap;
 490         unsigned long flags;
 491
 492         /* Allocate structure and revmap table if using linear mapping */
 493         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 494                 size += revmap_arg * sizeof(unsigned int);
 495         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 496         if (host == NULL)
 497                 return NULL;
 498
 499         /* Fill structure */
 500         host->revmap_type = revmap_type;
 501         host->inval_irq = inval_irq;
 502         host->ops = ops;
 503         host->of_node = of_node_get(of_node);
 504
 505         if (host->ops->match == NULL)
 506                 host->ops->match = default_irq_host_match;
 507
 508         spin_lock_irqsave(&irq_big_lock, flags);
 509
 510         /* If it's a legacy controller, check for duplicates and
 511          * mark it as allocated (we use irq 0 host pointer for that
 512          */
 513         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 514                 if (irq_map[0].host != NULL) {
 515                         spin_unlock_irqrestore(&irq_big_lock, flags);
 516                         /* If we are early boot, we can't free the structure,
 517                          * too bad...
 518                          * this will be fixed once slab is made available early
 519                          * instead of the current cruft
 520                          */
 521                         if (mem_init_done)
 522                                 kfree(host);
 523                         return NULL;
 524                 }
 525                 irq_map[0].host = host;
 526         }
 527
 528         list_add(&host->link, &irq_hosts);
 529         spin_unlock_irqrestore(&irq_big_lock, flags);
 530
 531         /* Additional setups per revmap type */
 532         switch(revmap_type) {
 533         case IRQ_HOST_MAP_LEGACY:
 534                 /* 0 is always the invalid number for legacy */
 535                 host->inval_irq = 0;
 536                 /* setup us as the host for all legacy interrupts */
 537                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 538                         irq_map[i].hwirq = i;
 539                         smp_wmb();
 540                         irq_map[i].host = host;
 541                         smp_wmb();
 542
 543                         /* Clear norequest flags */
 544                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 545
 546                         /* Legacy flags are left to default at this point,
 547                          * one can then use irq_create_mapping() to
 548                          * explicitly change them
 549                          */
 550                         ops->map(host, i, i);
 551                 }
 552                 break;
 553         case IRQ_HOST_MAP_LINEAR:
 554                 rmap = (unsigned int *)(host + 1);
 555                 for (i = 0; i < revmap_arg; i++)
 556                         rmap[i] = NO_IRQ;
 557                 host->revmap_data.linear.size = revmap_arg;
 558                 smp_wmb();
 559                 host->revmap_data.linear.revmap = rmap;
 560                 break;
 561         default:
 562                 break;
 563         }
 564
 565         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 566
 567         return host;
 568 }
 569
 570 struct irq_host *irq_find_host(struct device_node *node)
 571 {
 572         struct irq_host *h, *found = NULL;
 573         unsigned long flags;
 574
 575         /* We might want to match the legacy controller last since
 576          * it might potentially be set to match all interrupts in
 577          * the absence of a device node. This isn't a problem so far
 578          * yet though...
 579          */
 580         spin_lock_irqsave(&irq_big_lock, flags);
 581         list_for_each_entry(h, &irq_hosts, link)
 582                 if (h->ops->match(h, node)) {
 583                         found = h;
 584                         break;
 585                 }
 586         spin_unlock_irqrestore(&irq_big_lock, flags);
 587         return found;
 588 }
 589 EXPORT_SYMBOL_GPL(irq_find_host);
 590
 591 void irq_set_default_host(struct irq_host *host)
 592 {
 593         pr_debug("irq: Default host set to @0x%p\n", host);
 594
 595         irq_default_host = host;
 596 }
 597
 598 void irq_set_virq_count(unsigned int count)
 599 {
 600         pr_debug("irq: Trying to set virq count to %d\n", count);
 601
 602         BUG_ON(count < NUM_ISA_INTERRUPTS);
 603         if (count < NR_IRQS)
 604                 irq_virq_count = count;
 605 }
 606
 607 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 608                             irq_hw_number_t hwirq)
 609 {
 610         /* Clear IRQ_NOREQUEST flag */
 611         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 612
 613         /* map it */
 614         smp_wmb();
 615         irq_map[virq].hwirq = hwirq;
 616         smp_mb();
 617
 618         if (host->ops->map(host, virq, hwirq)) {
 619                 pr_debug("irq: -> mapping failed, freeing\n");
 620                 irq_free_virt(virq, 1);
 621                 return -1;
 622         }
 623
 624         return 0;
 625 }
 626
 627 unsigned int irq_create_direct_mapping(struct irq_host *host)
 628 {
 629         unsigned int virq;
 630
 631         if (host == NULL)
 632                 host = irq_default_host;
 633
 634         BUG_ON(host == NULL);
 635         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 636
 637         virq = irq_alloc_virt(host, 1, 0);
 638         if (virq == NO_IRQ) {
 639                 pr_debug("irq: create_direct virq allocation failed\n");
 640                 return NO_IRQ;
 641         }
 642
 643         pr_debug("irq: create_direct obtained virq %d\n", virq);
 644
 645         if (irq_setup_virq(host, virq, virq))
 646                 return NO_IRQ;
 647
 648         return virq;
 649 }
 650
 651 unsigned int irq_create_mapping(struct irq_host *host,
 652                                 irq_hw_number_t hwirq)
 653 {
 654         unsigned int virq, hint;
 655
 656         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 657
 658         /* Look for default host if nececssary */
 659         if (host == NULL)
 660                 host = irq_default_host;
 661         if (host == NULL) {
 662                 printk(KERN_WARNING "irq_create_mapping called for"
 663                        " NULL host, hwirq=%lx\n", hwirq);
 664                 WARN_ON(1);
 665                 return NO_IRQ;
 666         }
 667         pr_debug("irq: -> using host @%p\n", host);
 668
 669         /* Check if mapping already exist, if it does, call
 670          * host->ops->map() to update the flags
 671          */
 672         virq = irq_find_mapping(host, hwirq);
 673         if (virq != NO_IRQ) {
 674                 if (host->ops->remap)
 675                         host->ops->remap(host, virq, hwirq);
 676                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 677                 return virq;
 678         }
 679
 680         /* Get a virtual interrupt number */
 681         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 682                 /* Handle legacy */
 683                 virq = (unsigned int)hwirq;
 684                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 685                         return NO_IRQ;
 686                 return virq;
 687         } else {
 688                 /* Allocate a virtual interrupt number */
 689                 hint = hwirq % irq_virq_count;
 690                 virq = irq_alloc_virt(host, 1, hint);
 691                 if (virq == NO_IRQ) {
 692                         pr_debug("irq: -> virq allocation failed\n");
 693                         return NO_IRQ;
 694                 }
 695         }
 696
 697         if (irq_setup_virq(host, virq, hwirq))
 698                 return NO_IRQ;
 699
 700         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 701                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 702
 703         return virq;
 704 }
 705 EXPORT_SYMBOL_GPL(irq_create_mapping);
 706
 707 unsigned int irq_create_of_mapping(struct device_node *controller,
 708                                    u32 *intspec, unsigned int intsize)
 709 {
 710         struct irq_host *host;
 711         irq_hw_number_t hwirq;
 712         unsigned int type = IRQ_TYPE_NONE;
 713         unsigned int virq;
 714
 715         if (controller == NULL)
 716                 host = irq_default_host;
 717         else
 718                 host = irq_find_host(controller);
 719         if (host == NULL) {
 720                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 721                        controller->full_name);
 722                 return NO_IRQ;
 723         }
 724
 725         /* If host has no translation, then we assume interrupt line */
 726         if (host->ops->xlate == NULL)
 727                 hwirq = intspec[0];
 728         else {
 729                 if (host->ops->xlate(host, controller, intspec, intsize,
 730                                      &hwirq, &type))
 731                         return NO_IRQ;
 732         }
 733
 734         /* Create mapping */
 735         virq = irq_create_mapping(host, hwirq);
 736         if (virq == NO_IRQ)
 737                 return virq;
 738
 739         /* Set type if specified and different than the current one */
 740         if (type != IRQ_TYPE_NONE &&
 741             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 742                 set_irq_type(virq, type);
 743         return virq;
 744 }
 745 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 746
 747 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 748 {
 749         struct of_irq oirq;
 750
 751         if (of_irq_map_one(dev, index, &oirq))
 752                 return NO_IRQ;
 753
 754         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 755                                      oirq.size);
 756 }
 757 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 758
 759 void irq_dispose_mapping(unsigned int virq)
 760 {
 761         struct irq_host *host;
 762         irq_hw_number_t hwirq;
 763
 764         if (virq == NO_IRQ)
 765                 return;
 766
 767         host = irq_map[virq].host;
 768         WARN_ON (host == NULL);
 769         if (host == NULL)
 770                 return;
 771
 772         /* Never unmap legacy interrupts */
 773         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 774                 return;
 775
 776         /* remove chip and handler */
 777         set_irq_chip_and_handler(virq, NULL, NULL);
 778
 779         /* Make sure it's completed */
 780         synchronize_irq(virq);
 781
 782         /* Tell the PIC about it */
 783         if (host->ops->unmap)
 784                 host->ops->unmap(host, virq);
 785         smp_mb();
 786
 787         /* Clear reverse map */
 788         hwirq = irq_map[virq].hwirq;
 789         switch(host->revmap_type) {
 790         case IRQ_HOST_MAP_LINEAR:
 791                 if (hwirq < host->revmap_data.linear.size)
 792                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 793                 break;
 794         case IRQ_HOST_MAP_TREE:
 795                 /*
 796                  * Check if radix tree allocated yet, if not then nothing to
 797                  * remove.
 798                  */
 799                 smp_rmb();
 800                 if (revmap_trees_allocated < 1)
 801                         break;
 802                 mutex_lock(&revmap_trees_mutex);
 803                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 804                 mutex_unlock(&revmap_trees_mutex);
 805                 break;
 806         }
 807
 808         /* Destroy map */
 809         smp_mb();
 810         irq_map[virq].hwirq = host->inval_irq;
 811
 812         /* Set some flags */
 813         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 814
 815         /* Free it */
 816         irq_free_virt(virq, 1);
 817 }
 818 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 819
 820 unsigned int irq_find_mapping(struct irq_host *host,
 821                               irq_hw_number_t hwirq)
 822 {
 823         unsigned int i;
 824         unsigned int hint = hwirq % irq_virq_count;
 825
 826         /* Look for default host if nececssary */
 827         if (host == NULL)
 828                 host = irq_default_host;
 829         if (host == NULL)
 830                 return NO_IRQ;
 831
 832         /* legacy -> bail early */
 833         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 834                 return hwirq;
 835
 836         /* Slow path does a linear search of the map */
 837         if (hint < NUM_ISA_INTERRUPTS)
 838                 hint = NUM_ISA_INTERRUPTS;
 839         i = hint;
 840         do  {
 841                 if (irq_map[i].host == host &&
 842                     irq_map[i].hwirq == hwirq)
 843                         return i;
 844                 i++;
 845                 if (i >= irq_virq_count)
 846                         i = NUM_ISA_INTERRUPTS;
 847         } while(i != hint);
 848         return NO_IRQ;
 849 }
 850 EXPORT_SYMBOL_GPL(irq_find_mapping);
 851
 852
 853 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 854                                      irq_hw_number_t hwirq)
 855 {
 856         struct irq_map_entry *ptr;
 857         unsigned int virq;
 858
 859         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 860
 861         /*
 862          * Check if the radix tree exists and has bee initialized.
 863          * If not, we fallback to slow mode
 864          */
 865         if (revmap_trees_allocated < 2)
 866                 return irq_find_mapping(host, hwirq);
 867
 868         /* Now try to resolve */
 869         /*
 870          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 871          * as it's referencing an entry in the static irq_map table.
 872          */
 873         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 874
 875         /*
 876          * If found in radix tree, then fine.
 877          * Else fallback to linear lookup - this should not happen in practice
 878          * as it means that we failed to insert the node in the radix tree.
 879          */
 880         if (ptr)
 881                 virq = ptr - irq_map;
 882         else
 883                 virq = irq_find_mapping(host, hwirq);
 884
 885         return virq;
 886 }
 887
 888 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 889                              irq_hw_number_t hwirq)
 890 {
 891
 892         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 893
 894         /*
 895          * Check if the radix tree exists yet.
 896          * If not, then the irq will be inserted into the tree when it gets
 897          * initialized.
 898          */
 899         smp_rmb();
 900         if (revmap_trees_allocated < 1)
 901                 return;
 902
 903         if (virq != NO_IRQ) {
 904                 mutex_lock(&revmap_trees_mutex);
 905                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 906                                   &irq_map[virq]);
 907                 mutex_unlock(&revmap_trees_mutex);
 908         }
 909 }
 910
 911 unsigned int irq_linear_revmap(struct irq_host *host,
 912                                irq_hw_number_t hwirq)
 913 {
 914         unsigned int *revmap;
 915
 916         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 917
 918         /* Check revmap bounds */
 919         if (unlikely(hwirq >= host->revmap_data.linear.size))
 920                 return irq_find_mapping(host, hwirq);
 921
 922         /* Check if revmap was allocated */
 923         revmap = host->revmap_data.linear.revmap;
 924         if (unlikely(revmap == NULL))
 925                 return irq_find_mapping(host, hwirq);
 926
 927         /* Fill up revmap with slow path if no mapping found */
 928         if (unlikely(revmap[hwirq] == NO_IRQ))
 929                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 930
 931         return revmap[hwirq];
 932 }
 933
 934 unsigned int irq_alloc_virt(struct irq_host *host,
 935                             unsigned int count,
 936                             unsigned int hint)
 937 {
 938         unsigned long flags;
 939         unsigned int i, j, found = NO_IRQ;
 940
 941         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 942                 return NO_IRQ;
 943
 944         spin_lock_irqsave(&irq_big_lock, flags);
 945
 946         /* Use hint for 1 interrupt if any */
 947         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 948             hint < irq_virq_count && irq_map[hint].host == NULL) {
 949                 found = hint;
 950                 goto hint_found;
 951         }
 952
 953         /* Look for count consecutive numbers in the allocatable
 954          * (non-legacy) space
 955          */
 956         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 957                 if (irq_map[i].host != NULL)
 958                         j = 0;
 959                 else
 960                         j++;
 961
 962                 if (j == count) {
 963                         found = i - count + 1;
 964                         break;
 965                 }
 966         }
 967         if (found == NO_IRQ) {
 968                 spin_unlock_irqrestore(&irq_big_lock, flags);
 969                 return NO_IRQ;
 970         }
 971  hint_found:
 972         for (i = found; i < (found + count); i++) {
 973                 irq_map[i].hwirq = host->inval_irq;
 974                 smp_wmb();
 975                 irq_map[i].host = host;
 976         }
 977         spin_unlock_irqrestore(&irq_big_lock, flags);
 978         return found;
 979 }
 980
 981 void irq_free_virt(unsigned int virq, unsigned int count)
 982 {
 983         unsigned long flags;
 984         unsigned int i;
 985
 986         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 987         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 988
 989         spin_lock_irqsave(&irq_big_lock, flags);
 990         for (i = virq; i < (virq + count); i++) {
 991                 struct irq_host *host;
 992
 993                 if (i < NUM_ISA_INTERRUPTS ||
 994                     (virq + count) > irq_virq_count)
 995                         continue;
 996
 997                 host = irq_map[i].host;
 998                 irq_map[i].hwirq = host->inval_irq;
 999                 smp_wmb();
1000                 irq_map[i].host = NULL;
1001         }
1002         spin_unlock_irqrestore(&irq_big_lock, flags);
1003 }
1004
1005 void irq_early_init(void)
1006 {
1007         unsigned int i;
1008
1009         for (i = 0; i < NR_IRQS; i++)
1010                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
1011 }
1012
1013 /* We need to create the radix trees late */
1014 static int irq_late_init(void)
1015 {
1016         struct irq_host *h;
1017         unsigned int i;
1018
1019         /*
1020          * No mutual exclusion with respect to accessors of the tree is needed
1021          * here as the synchronization is done via the state variable
1022          * revmap_trees_allocated.
1023          */
1024         list_for_each_entry(h, &irq_hosts, link) {
1025                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1026                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1027         }
1028
1029         /*
1030          * Make sure the radix trees inits are visible before setting
1031          * the flag
1032          */
1033         smp_wmb();
1034         revmap_trees_allocated = 1;
1035
1036         /*
1037          * Insert the reverse mapping for those interrupts already present
1038          * in irq_map[].
1039          */
1040         mutex_lock(&revmap_trees_mutex);
1041         for (i = 0; i < irq_virq_count; i++) {
1042                 if (irq_map[i].host &&
1043                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1044                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1045                                           irq_map[i].hwirq, &irq_map[i]);
1046         }
1047         mutex_unlock(&revmap_trees_mutex);
1048
1049         /*
1050          * Make sure the radix trees insertions are visible before setting
1051          * the flag
1052          */
1053         smp_wmb();
1054         revmap_trees_allocated = 2;
1055
1056         return 0;
1057 }
1058 arch_initcall(irq_late_init);
1059
1060 #ifdef CONFIG_VIRQ_DEBUG
1061 static int virq_debug_show(struct seq_file *m, void *private)
1062 {
1063         unsigned long flags;
1064         struct irq_desc *desc;
1065         const char *p;
1066         char none[] = "none";
1067         int i;
1068
1069         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1070                       "chip name", "host name");
1071
1072         for (i = 1; i < NR_IRQS; i++) {
1073                 desc = get_irq_desc(i);
1074                 spin_lock_irqsave(&desc->lock, flags);
1075
1076                 if (desc->action && desc->action->handler) {
1077                         seq_printf(m, "%5d  ", i);
1078                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1079
1080                         if (desc->chip && desc->chip->typename)
1081                                 p = desc->chip->typename;
1082                         else
1083                                 p = none;
1084                         seq_printf(m, "%-15s  ", p);
1085
1086                         if (irq_map[i].host && irq_map[i].host->of_node)
1087                                 p = irq_map[i].host->of_node->full_name;
1088                         else
1089                                 p = none;
1090                         seq_printf(m, "%s\n", p);
1091                 }
1092
1093                 spin_unlock_irqrestore(&desc->lock, flags);
1094         }
1095
1096         return 0;
1097 }
1098
1099 static int virq_debug_open(struct inode *inode, struct file *file)
1100 {
1101         return single_open(file, virq_debug_show, inode->i_private);
1102 }
1103
1104 static const struct file_operations virq_debug_fops = {
1105         .open = virq_debug_open,
1106         .read = seq_read,
1107         .llseek = seq_lseek,
1108         .release = single_release,
1109 };
1110
1111 static int __init irq_debugfs_init(void)
1112 {
1113         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1114                                  NULL, &virq_debug_fops) == NULL)
1115                 return -ENOMEM;
1116
1117         return 0;
1118 }
1119 __initcall(irq_debugfs_init);
1120 #endif /* CONFIG_VIRQ_DEBUG */
1121
1122 #ifdef CONFIG_PPC64
1123 static int __init setup_noirqdistrib(char *str)
1124 {
1125         distribute_irqs = 0;
1126         return 1;
1127 }
1128
1129 __setup("noirqdistrib", setup_noirqdistrib);
1130 #endif /* CONFIG_PPC64 */