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
  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
  89 #ifndef CONFIG_SPARSE_IRQ
  90 EXPORT_SYMBOL(irq_desc);
  91 #endif
  92
  93 int distribute_irqs = 1;
  94
  95 static inline notrace unsigned long get_hard_enabled(void)
  96 {
  97         unsigned long enabled;
  98
  99         __asm__ __volatile__("lbz %0,%1(13)"
 100         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 101
 102         return enabled;
 103 }
 104
 105 static inline notrace void set_soft_enabled(unsigned long enable)
 106 {
 107         __asm__ __volatile__("stb %0,%1(13)"
 108         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 109 }
 110
 111 notrace void raw_local_irq_restore(unsigned long en)
 112 {
 113         /*
 114          * get_paca()->soft_enabled = en;
 115          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 116          * That was allowed before, and in such a case we do need to take care
 117          * that gcc will set soft_enabled directly via r13, not choose to use
 118          * an intermediate register, lest we're preempted to a different cpu.
 119          */
 120         set_soft_enabled(en);
 121         if (!en)
 122                 return;
 123
 124 #ifdef CONFIG_PPC_STD_MMU_64
 125         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 126                 /*
 127                  * Do we need to disable preemption here?  Not really: in the
 128                  * unlikely event that we're preempted to a different cpu in
 129                  * between getting r13, loading its lppaca_ptr, and loading
 130                  * its any_int, we might call iseries_handle_interrupts without
 131                  * an interrupt pending on the new cpu, but that's no disaster,
 132                  * is it?  And the business of preempting us off the old cpu
 133                  * would itself involve a local_irq_restore which handles the
 134                  * interrupt to that cpu.
 135                  *
 136                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 137                  * to avoid any preemption checking added into get_paca().
 138                  */
 139                 if (local_paca->lppaca_ptr->int_dword.any_int)
 140                         iseries_handle_interrupts();
 141         }
 142 #endif /* CONFIG_PPC_STD_MMU_64 */
 143
 144         if (test_perf_event_pending()) {
 145                 clear_perf_event_pending();
 146                 perf_event_do_pending();
 147         }
 148
 149         /*
 150          * if (get_paca()->hard_enabled) return;
 151          * But again we need to take care that gcc gets hard_enabled directly
 152          * via r13, not choose to use an intermediate register, lest we're
 153          * preempted to a different cpu in between the two instructions.
 154          */
 155         if (get_hard_enabled())
 156                 return;
 157
 158         /*
 159          * Need to hard-enable interrupts here.  Since currently disabled,
 160          * no need to take further asm precautions against preemption; but
 161          * use local_paca instead of get_paca() to avoid preemption checking.
 162          */
 163         local_paca->hard_enabled = en;
 164         if ((int)mfspr(SPRN_DEC) < 0)
 165                 mtspr(SPRN_DEC, 1);
 166
 167         /*
 168          * Force the delivery of pending soft-disabled interrupts on PS3.
 169          * Any HV call will have this side effect.
 170          */
 171         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 172                 u64 tmp;
 173                 lv1_get_version_info(&tmp);
 174         }
 175
 176         __hard_irq_enable();
 177 }
 178 EXPORT_SYMBOL(raw_local_irq_restore);
 179 #endif /* CONFIG_PPC64 */
 180
 181 int show_interrupts(struct seq_file *p, void *v)
 182 {
 183         int i = *(loff_t *)v, j;
 184         struct irqaction *action;
 185         struct irq_desc *desc;
 186         unsigned long flags;
 187
 188         if (i == 0) {
 189                 seq_puts(p, "           ");
 190                 for_each_online_cpu(j)
 191                         seq_printf(p, "CPU%d       ", j);
 192                 seq_putc(p, '\n');
 193         } else if (i == nr_irqs) {
 194 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 195                 if (tau_initialized){
 196                         seq_puts(p, "TAU: ");
 197                         for_each_online_cpu(j)
 198                                 seq_printf(p, "%10u ", tau_interrupts(j));
 199                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 200                 }
 201 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT*/
 202                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 203
 204                 return 0;
 205         }
 206
 207         desc = irq_to_desc(i);
 208         if (!desc)
 209                 return 0;
 210
 211         spin_lock_irqsave(&desc->lock, flags);
 212
 213         action = desc->action;
 214         if (!action || !action->handler)
 215                 goto skip;
 216
 217         seq_printf(p, "%3d: ", i);
 218 #ifdef CONFIG_SMP
 219         for_each_online_cpu(j)
 220                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 221 #else
 222         seq_printf(p, "%10u ", kstat_irqs(i));
 223 #endif /* CONFIG_SMP */
 224
 225         if (desc->chip)
 226                 seq_printf(p, " %s ", desc->chip->name);
 227         else
 228                 seq_puts(p, "  None      ");
 229
 230         seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 231         seq_printf(p, "    %s", action->name);
 232
 233         for (action = action->next; action; action = action->next)
 234                 seq_printf(p, ", %s", action->name);
 235         seq_putc(p, '\n');
 236
 237 skip:
 238         spin_unlock_irqrestore(&desc->lock, flags);
 239
 240         return 0;
 241 }
 242
 243 #ifdef CONFIG_HOTPLUG_CPU
 244 void fixup_irqs(cpumask_t map)
 245 {
 246         struct irq_desc *desc;
 247         unsigned int irq;
 248         static int warned;
 249
 250         for_each_irq(irq) {
 251                 cpumask_t mask;
 252
 253                 desc = irq_to_desc(irq);
 254                 if (desc && desc->status & IRQ_PER_CPU)
 255                         continue;
 256
 257                 cpumask_and(&mask, desc->affinity, &map);
 258                 if (any_online_cpu(mask) == NR_CPUS) {
 259                         printk("Breaking affinity for irq %i\n", irq);
 260                         mask = map;
 261                 }
 262                 if (desc->chip->set_affinity)
 263                         desc->chip->set_affinity(irq, &mask);
 264                 else if (desc->action && !(warned++))
 265                         printk("Cannot set affinity for irq %i\n", irq);
 266         }
 267
 268         local_irq_enable();
 269         mdelay(1);
 270         local_irq_disable();
 271 }
 272 #endif
 273
 274 #ifdef CONFIG_IRQSTACKS
 275 static inline void handle_one_irq(unsigned int irq)
 276 {
 277         struct thread_info *curtp, *irqtp;
 278         unsigned long saved_sp_limit;
 279         struct irq_desc *desc;
 280
 281         /* Switch to the irq stack to handle this */
 282         curtp = current_thread_info();
 283         irqtp = hardirq_ctx[smp_processor_id()];
 284
 285         if (curtp == irqtp) {
 286                 /* We're already on the irq stack, just handle it */
 287                 generic_handle_irq(irq);
 288                 return;
 289         }
 290
 291         desc = irq_to_desc(irq);
 292         saved_sp_limit = current->thread.ksp_limit;
 293
 294         irqtp->task = curtp->task;
 295         irqtp->flags = 0;
 296
 297         /* Copy the softirq bits in preempt_count so that the
 298          * softirq checks work in the hardirq context. */
 299         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 300                                (curtp->preempt_count & SOFTIRQ_MASK);
 301
 302         current->thread.ksp_limit = (unsigned long)irqtp +
 303                 _ALIGN_UP(sizeof(struct thread_info), 16);
 304
 305         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 306         current->thread.ksp_limit = saved_sp_limit;
 307         irqtp->task = NULL;
 308
 309         /* Set any flag that may have been set on the
 310          * alternate stack
 311          */
 312         if (irqtp->flags)
 313                 set_bits(irqtp->flags, &curtp->flags);
 314 }
 315 #else
 316 static inline void handle_one_irq(unsigned int irq)
 317 {
 318         generic_handle_irq(irq);
 319 }
 320 #endif
 321
 322 static inline void check_stack_overflow(void)
 323 {
 324 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 325         long sp;
 326
 327         sp = __get_SP() & (THREAD_SIZE-1);
 328
 329         /* check for stack overflow: is there less than 2KB free? */
 330         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 331                 printk("do_IRQ: stack overflow: %ld\n",
 332                         sp - sizeof(struct thread_info));
 333                 dump_stack();
 334         }
 335 #endif
 336 }
 337
 338 void do_IRQ(struct pt_regs *regs)
 339 {
 340         struct pt_regs *old_regs = set_irq_regs(regs);
 341         unsigned int irq;
 342
 343         irq_enter();
 344
 345         check_stack_overflow();
 346
 347         irq = ppc_md.get_irq();
 348
 349         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 350                 handle_one_irq(irq);
 351         else if (irq != NO_IRQ_IGNORE)
 352                 /* That's not SMP safe ... but who cares ? */
 353                 ppc_spurious_interrupts++;
 354
 355         irq_exit();
 356         set_irq_regs(old_regs);
 357
 358 #ifdef CONFIG_PPC_ISERIES
 359         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 360                         get_lppaca()->int_dword.fields.decr_int) {
 361                 get_lppaca()->int_dword.fields.decr_int = 0;
 362                 /* Signal a fake decrementer interrupt */
 363                 timer_interrupt(regs);
 364         }
 365 #endif
 366 }
 367
 368 void __init init_IRQ(void)
 369 {
 370         if (ppc_md.init_IRQ)
 371                 ppc_md.init_IRQ();
 372
 373         exc_lvl_ctx_init();
 374
 375         irq_ctx_init();
 376 }
 377
 378 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 379 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 380 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 381 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 382
 383 void exc_lvl_ctx_init(void)
 384 {
 385         struct thread_info *tp;
 386         int i;
 387
 388         for_each_possible_cpu(i) {
 389                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 390                 tp = critirq_ctx[i];
 391                 tp->cpu = i;
 392                 tp->preempt_count = 0;
 393
 394 #ifdef CONFIG_BOOKE
 395                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 396                 tp = dbgirq_ctx[i];
 397                 tp->cpu = i;
 398                 tp->preempt_count = 0;
 399
 400                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 401                 tp = mcheckirq_ctx[i];
 402                 tp->cpu = i;
 403                 tp->preempt_count = HARDIRQ_OFFSET;
 404 #endif
 405         }
 406 }
 407 #endif
 408
 409 #ifdef CONFIG_IRQSTACKS
 410 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 411 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 412
 413 void irq_ctx_init(void)
 414 {
 415         struct thread_info *tp;
 416         int i;
 417
 418         for_each_possible_cpu(i) {
 419                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 420                 tp = softirq_ctx[i];
 421                 tp->cpu = i;
 422                 tp->preempt_count = 0;
 423
 424                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 425                 tp = hardirq_ctx[i];
 426                 tp->cpu = i;
 427                 tp->preempt_count = HARDIRQ_OFFSET;
 428         }
 429 }
 430
 431 static inline void do_softirq_onstack(void)
 432 {
 433         struct thread_info *curtp, *irqtp;
 434         unsigned long saved_sp_limit = current->thread.ksp_limit;
 435
 436         curtp = current_thread_info();
 437         irqtp = softirq_ctx[smp_processor_id()];
 438         irqtp->task = curtp->task;
 439         current->thread.ksp_limit = (unsigned long)irqtp +
 440                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 441         call_do_softirq(irqtp);
 442         current->thread.ksp_limit = saved_sp_limit;
 443         irqtp->task = NULL;
 444 }
 445
 446 #else
 447 #define do_softirq_onstack()    __do_softirq()
 448 #endif /* CONFIG_IRQSTACKS */
 449
 450 void do_softirq(void)
 451 {
 452         unsigned long flags;
 453
 454         if (in_interrupt())
 455                 return;
 456
 457         local_irq_save(flags);
 458
 459         if (local_softirq_pending())
 460                 do_softirq_onstack();
 461
 462         local_irq_restore(flags);
 463 }
 464
 465
 466 /*
 467  * IRQ controller and virtual interrupts
 468  */
 469
 470 static LIST_HEAD(irq_hosts);
 471 static DEFINE_SPINLOCK(irq_big_lock);
 472 static unsigned int revmap_trees_allocated;
 473 static DEFINE_MUTEX(revmap_trees_mutex);
 474 struct irq_map_entry irq_map[NR_IRQS];
 475 static unsigned int irq_virq_count = NR_IRQS;
 476 static struct irq_host *irq_default_host;
 477
 478 irq_hw_number_t virq_to_hw(unsigned int virq)
 479 {
 480         return irq_map[virq].hwirq;
 481 }
 482 EXPORT_SYMBOL_GPL(virq_to_hw);
 483
 484 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 485 {
 486         return h->of_node != NULL && h->of_node == np;
 487 }
 488
 489 struct irq_host *irq_alloc_host(struct device_node *of_node,
 490                                 unsigned int revmap_type,
 491                                 unsigned int revmap_arg,
 492                                 struct irq_host_ops *ops,
 493                                 irq_hw_number_t inval_irq)
 494 {
 495         struct irq_host *host;
 496         unsigned int size = sizeof(struct irq_host);
 497         unsigned int i;
 498         unsigned int *rmap;
 499         unsigned long flags;
 500
 501         /* Allocate structure and revmap table if using linear mapping */
 502         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 503                 size += revmap_arg * sizeof(unsigned int);
 504         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 505         if (host == NULL)
 506                 return NULL;
 507
 508         /* Fill structure */
 509         host->revmap_type = revmap_type;
 510         host->inval_irq = inval_irq;
 511         host->ops = ops;
 512         host->of_node = of_node_get(of_node);
 513
 514         if (host->ops->match == NULL)
 515                 host->ops->match = default_irq_host_match;
 516
 517         spin_lock_irqsave(&irq_big_lock, flags);
 518
 519         /* If it's a legacy controller, check for duplicates and
 520          * mark it as allocated (we use irq 0 host pointer for that
 521          */
 522         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 523                 if (irq_map[0].host != NULL) {
 524                         spin_unlock_irqrestore(&irq_big_lock, flags);
 525                         /* If we are early boot, we can't free the structure,
 526                          * too bad...
 527                          * this will be fixed once slab is made available early
 528                          * instead of the current cruft
 529                          */
 530                         if (mem_init_done)
 531                                 kfree(host);
 532                         return NULL;
 533                 }
 534                 irq_map[0].host = host;
 535         }
 536
 537         list_add(&host->link, &irq_hosts);
 538         spin_unlock_irqrestore(&irq_big_lock, flags);
 539
 540         /* Additional setups per revmap type */
 541         switch(revmap_type) {
 542         case IRQ_HOST_MAP_LEGACY:
 543                 /* 0 is always the invalid number for legacy */
 544                 host->inval_irq = 0;
 545                 /* setup us as the host for all legacy interrupts */
 546                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 547                         irq_map[i].hwirq = i;
 548                         smp_wmb();
 549                         irq_map[i].host = host;
 550                         smp_wmb();
 551
 552                         /* Clear norequest flags */
 553                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
 554
 555                         /* Legacy flags are left to default at this point,
 556                          * one can then use irq_create_mapping() to
 557                          * explicitly change them
 558                          */
 559                         ops->map(host, i, i);
 560                 }
 561                 break;
 562         case IRQ_HOST_MAP_LINEAR:
 563                 rmap = (unsigned int *)(host + 1);
 564                 for (i = 0; i < revmap_arg; i++)
 565                         rmap[i] = NO_IRQ;
 566                 host->revmap_data.linear.size = revmap_arg;
 567                 smp_wmb();
 568                 host->revmap_data.linear.revmap = rmap;
 569                 break;
 570         default:
 571                 break;
 572         }
 573
 574         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 575
 576         return host;
 577 }
 578
 579 struct irq_host *irq_find_host(struct device_node *node)
 580 {
 581         struct irq_host *h, *found = NULL;
 582         unsigned long flags;
 583
 584         /* We might want to match the legacy controller last since
 585          * it might potentially be set to match all interrupts in
 586          * the absence of a device node. This isn't a problem so far
 587          * yet though...
 588          */
 589         spin_lock_irqsave(&irq_big_lock, flags);
 590         list_for_each_entry(h, &irq_hosts, link)
 591                 if (h->ops->match(h, node)) {
 592                         found = h;
 593                         break;
 594                 }
 595         spin_unlock_irqrestore(&irq_big_lock, flags);
 596         return found;
 597 }
 598 EXPORT_SYMBOL_GPL(irq_find_host);
 599
 600 void irq_set_default_host(struct irq_host *host)
 601 {
 602         pr_debug("irq: Default host set to @0x%p\n", host);
 603
 604         irq_default_host = host;
 605 }
 606
 607 void irq_set_virq_count(unsigned int count)
 608 {
 609         pr_debug("irq: Trying to set virq count to %d\n", count);
 610
 611         BUG_ON(count < NUM_ISA_INTERRUPTS);
 612         if (count < NR_IRQS)
 613                 irq_virq_count = count;
 614 }
 615
 616 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 617                             irq_hw_number_t hwirq)
 618 {
 619         struct irq_desc *desc;
 620
 621         desc = irq_to_desc_alloc_node(virq, 0);
 622         if (!desc) {
 623                 pr_debug("irq: -> allocating desc failed\n");
 624                 goto error;
 625         }
 626
 627         /* Clear IRQ_NOREQUEST flag */
 628         desc->status &= ~IRQ_NOREQUEST;
 629
 630         /* map it */
 631         smp_wmb();
 632         irq_map[virq].hwirq = hwirq;
 633         smp_mb();
 634
 635         if (host->ops->map(host, virq, hwirq)) {
 636                 pr_debug("irq: -> mapping failed, freeing\n");
 637                 goto error;
 638         }
 639
 640         return 0;
 641
 642 error:
 643         irq_free_virt(virq, 1);
 644         return -1;
 645 }
 646
 647 unsigned int irq_create_direct_mapping(struct irq_host *host)
 648 {
 649         unsigned int virq;
 650
 651         if (host == NULL)
 652                 host = irq_default_host;
 653
 654         BUG_ON(host == NULL);
 655         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 656
 657         virq = irq_alloc_virt(host, 1, 0);
 658         if (virq == NO_IRQ) {
 659                 pr_debug("irq: create_direct virq allocation failed\n");
 660                 return NO_IRQ;
 661         }
 662
 663         pr_debug("irq: create_direct obtained virq %d\n", virq);
 664
 665         if (irq_setup_virq(host, virq, virq))
 666                 return NO_IRQ;
 667
 668         return virq;
 669 }
 670
 671 unsigned int irq_create_mapping(struct irq_host *host,
 672                                 irq_hw_number_t hwirq)
 673 {
 674         unsigned int virq, hint;
 675
 676         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 677
 678         /* Look for default host if nececssary */
 679         if (host == NULL)
 680                 host = irq_default_host;
 681         if (host == NULL) {
 682                 printk(KERN_WARNING "irq_create_mapping called for"
 683                        " NULL host, hwirq=%lx\n", hwirq);
 684                 WARN_ON(1);
 685                 return NO_IRQ;
 686         }
 687         pr_debug("irq: -> using host @%p\n", host);
 688
 689         /* Check if mapping already exist, if it does, call
 690          * host->ops->map() to update the flags
 691          */
 692         virq = irq_find_mapping(host, hwirq);
 693         if (virq != NO_IRQ) {
 694                 if (host->ops->remap)
 695                         host->ops->remap(host, virq, hwirq);
 696                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 697                 return virq;
 698         }
 699
 700         /* Get a virtual interrupt number */
 701         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 702                 /* Handle legacy */
 703                 virq = (unsigned int)hwirq;
 704                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 705                         return NO_IRQ;
 706                 return virq;
 707         } else {
 708                 /* Allocate a virtual interrupt number */
 709                 hint = hwirq % irq_virq_count;
 710                 virq = irq_alloc_virt(host, 1, hint);
 711                 if (virq == NO_IRQ) {
 712                         pr_debug("irq: -> virq allocation failed\n");
 713                         return NO_IRQ;
 714                 }
 715         }
 716
 717         if (irq_setup_virq(host, virq, hwirq))
 718                 return NO_IRQ;
 719
 720         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 721                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 722
 723         return virq;
 724 }
 725 EXPORT_SYMBOL_GPL(irq_create_mapping);
 726
 727 unsigned int irq_create_of_mapping(struct device_node *controller,
 728                                    u32 *intspec, unsigned int intsize)
 729 {
 730         struct irq_host *host;
 731         irq_hw_number_t hwirq;
 732         unsigned int type = IRQ_TYPE_NONE;
 733         unsigned int virq;
 734
 735         if (controller == NULL)
 736                 host = irq_default_host;
 737         else
 738                 host = irq_find_host(controller);
 739         if (host == NULL) {
 740                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 741                        controller->full_name);
 742                 return NO_IRQ;
 743         }
 744
 745         /* If host has no translation, then we assume interrupt line */
 746         if (host->ops->xlate == NULL)
 747                 hwirq = intspec[0];
 748         else {
 749                 if (host->ops->xlate(host, controller, intspec, intsize,
 750                                      &hwirq, &type))
 751                         return NO_IRQ;
 752         }
 753
 754         /* Create mapping */
 755         virq = irq_create_mapping(host, hwirq);
 756         if (virq == NO_IRQ)
 757                 return virq;
 758
 759         /* Set type if specified and different than the current one */
 760         if (type != IRQ_TYPE_NONE &&
 761             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
 762                 set_irq_type(virq, type);
 763         return virq;
 764 }
 765 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 766
 767 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 768 {
 769         struct of_irq oirq;
 770
 771         if (of_irq_map_one(dev, index, &oirq))
 772                 return NO_IRQ;
 773
 774         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 775                                      oirq.size);
 776 }
 777 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 778
 779 void irq_dispose_mapping(unsigned int virq)
 780 {
 781         struct irq_host *host;
 782         irq_hw_number_t hwirq;
 783
 784         if (virq == NO_IRQ)
 785                 return;
 786
 787         host = irq_map[virq].host;
 788         WARN_ON (host == NULL);
 789         if (host == NULL)
 790                 return;
 791
 792         /* Never unmap legacy interrupts */
 793         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 794                 return;
 795
 796         /* remove chip and handler */
 797         set_irq_chip_and_handler(virq, NULL, NULL);
 798
 799         /* Make sure it's completed */
 800         synchronize_irq(virq);
 801
 802         /* Tell the PIC about it */
 803         if (host->ops->unmap)
 804                 host->ops->unmap(host, virq);
 805         smp_mb();
 806
 807         /* Clear reverse map */
 808         hwirq = irq_map[virq].hwirq;
 809         switch(host->revmap_type) {
 810         case IRQ_HOST_MAP_LINEAR:
 811                 if (hwirq < host->revmap_data.linear.size)
 812                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 813                 break;
 814         case IRQ_HOST_MAP_TREE:
 815                 /*
 816                  * Check if radix tree allocated yet, if not then nothing to
 817                  * remove.
 818                  */
 819                 smp_rmb();
 820                 if (revmap_trees_allocated < 1)
 821                         break;
 822                 mutex_lock(&revmap_trees_mutex);
 823                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 824                 mutex_unlock(&revmap_trees_mutex);
 825                 break;
 826         }
 827
 828         /* Destroy map */
 829         smp_mb();
 830         irq_map[virq].hwirq = host->inval_irq;
 831
 832         /* Set some flags */
 833         irq_to_desc(virq)->status |= IRQ_NOREQUEST;
 834
 835         /* Free it */
 836         irq_free_virt(virq, 1);
 837 }
 838 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 839
 840 unsigned int irq_find_mapping(struct irq_host *host,
 841                               irq_hw_number_t hwirq)
 842 {
 843         unsigned int i;
 844         unsigned int hint = hwirq % irq_virq_count;
 845
 846         /* Look for default host if nececssary */
 847         if (host == NULL)
 848                 host = irq_default_host;
 849         if (host == NULL)
 850                 return NO_IRQ;
 851
 852         /* legacy -> bail early */
 853         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 854                 return hwirq;
 855
 856         /* Slow path does a linear search of the map */
 857         if (hint < NUM_ISA_INTERRUPTS)
 858                 hint = NUM_ISA_INTERRUPTS;
 859         i = hint;
 860         do  {
 861                 if (irq_map[i].host == host &&
 862                     irq_map[i].hwirq == hwirq)
 863                         return i;
 864                 i++;
 865                 if (i >= irq_virq_count)
 866                         i = NUM_ISA_INTERRUPTS;
 867         } while(i != hint);
 868         return NO_IRQ;
 869 }
 870 EXPORT_SYMBOL_GPL(irq_find_mapping);
 871
 872
 873 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 874                                      irq_hw_number_t hwirq)
 875 {
 876         struct irq_map_entry *ptr;
 877         unsigned int virq;
 878
 879         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 880
 881         /*
 882          * Check if the radix tree exists and has bee initialized.
 883          * If not, we fallback to slow mode
 884          */
 885         if (revmap_trees_allocated < 2)
 886                 return irq_find_mapping(host, hwirq);
 887
 888         /* Now try to resolve */
 889         /*
 890          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 891          * as it's referencing an entry in the static irq_map table.
 892          */
 893         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 894
 895         /*
 896          * If found in radix tree, then fine.
 897          * Else fallback to linear lookup - this should not happen in practice
 898          * as it means that we failed to insert the node in the radix tree.
 899          */
 900         if (ptr)
 901                 virq = ptr - irq_map;
 902         else
 903                 virq = irq_find_mapping(host, hwirq);
 904
 905         return virq;
 906 }
 907
 908 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 909                              irq_hw_number_t hwirq)
 910 {
 911
 912         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 913
 914         /*
 915          * Check if the radix tree exists yet.
 916          * If not, then the irq will be inserted into the tree when it gets
 917          * initialized.
 918          */
 919         smp_rmb();
 920         if (revmap_trees_allocated < 1)
 921                 return;
 922
 923         if (virq != NO_IRQ) {
 924                 mutex_lock(&revmap_trees_mutex);
 925                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 926                                   &irq_map[virq]);
 927                 mutex_unlock(&revmap_trees_mutex);
 928         }
 929 }
 930
 931 unsigned int irq_linear_revmap(struct irq_host *host,
 932                                irq_hw_number_t hwirq)
 933 {
 934         unsigned int *revmap;
 935
 936         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 937
 938         /* Check revmap bounds */
 939         if (unlikely(hwirq >= host->revmap_data.linear.size))
 940                 return irq_find_mapping(host, hwirq);
 941
 942         /* Check if revmap was allocated */
 943         revmap = host->revmap_data.linear.revmap;
 944         if (unlikely(revmap == NULL))
 945                 return irq_find_mapping(host, hwirq);
 946
 947         /* Fill up revmap with slow path if no mapping found */
 948         if (unlikely(revmap[hwirq] == NO_IRQ))
 949                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 950
 951         return revmap[hwirq];
 952 }
 953
 954 unsigned int irq_alloc_virt(struct irq_host *host,
 955                             unsigned int count,
 956                             unsigned int hint)
 957 {
 958         unsigned long flags;
 959         unsigned int i, j, found = NO_IRQ;
 960
 961         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 962                 return NO_IRQ;
 963
 964         spin_lock_irqsave(&irq_big_lock, flags);
 965
 966         /* Use hint for 1 interrupt if any */
 967         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 968             hint < irq_virq_count && irq_map[hint].host == NULL) {
 969                 found = hint;
 970                 goto hint_found;
 971         }
 972
 973         /* Look for count consecutive numbers in the allocatable
 974          * (non-legacy) space
 975          */
 976         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 977                 if (irq_map[i].host != NULL)
 978                         j = 0;
 979                 else
 980                         j++;
 981
 982                 if (j == count) {
 983                         found = i - count + 1;
 984                         break;
 985                 }
 986         }
 987         if (found == NO_IRQ) {
 988                 spin_unlock_irqrestore(&irq_big_lock, flags);
 989                 return NO_IRQ;
 990         }
 991  hint_found:
 992         for (i = found; i < (found + count); i++) {
 993                 irq_map[i].hwirq = host->inval_irq;
 994                 smp_wmb();
 995                 irq_map[i].host = host;
 996         }
 997         spin_unlock_irqrestore(&irq_big_lock, flags);
 998         return found;
 999 }
1000
1001 void irq_free_virt(unsigned int virq, unsigned int count)
1002 {
1003         unsigned long flags;
1004         unsigned int i;
1005
1006         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1007         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1008
1009         spin_lock_irqsave(&irq_big_lock, flags);
1010         for (i = virq; i < (virq + count); i++) {
1011                 struct irq_host *host;
1012
1013                 if (i < NUM_ISA_INTERRUPTS ||
1014                     (virq + count) > irq_virq_count)
1015                         continue;
1016
1017                 host = irq_map[i].host;
1018                 irq_map[i].hwirq = host->inval_irq;
1019                 smp_wmb();
1020                 irq_map[i].host = NULL;
1021         }
1022         spin_unlock_irqrestore(&irq_big_lock, flags);
1023 }
1024
1025 int arch_early_irq_init(void)
1026 {
1027         struct irq_desc *desc;
1028         int i;
1029
1030         for (i = 0; i < NR_IRQS; i++) {
1031                 desc = irq_to_desc(i);
1032                 if (desc)
1033                         desc->status |= IRQ_NOREQUEST;
1034         }
1035
1036         return 0;
1037 }
1038
1039 int arch_init_chip_data(struct irq_desc *desc, int node)
1040 {
1041         desc->status |= IRQ_NOREQUEST;
1042         return 0;
1043 }
1044
1045 /* We need to create the radix trees late */
1046 static int irq_late_init(void)
1047 {
1048         struct irq_host *h;
1049         unsigned int i;
1050
1051         /*
1052          * No mutual exclusion with respect to accessors of the tree is needed
1053          * here as the synchronization is done via the state variable
1054          * revmap_trees_allocated.
1055          */
1056         list_for_each_entry(h, &irq_hosts, link) {
1057                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1058                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1059         }
1060
1061         /*
1062          * Make sure the radix trees inits are visible before setting
1063          * the flag
1064          */
1065         smp_wmb();
1066         revmap_trees_allocated = 1;
1067
1068         /*
1069          * Insert the reverse mapping for those interrupts already present
1070          * in irq_map[].
1071          */
1072         mutex_lock(&revmap_trees_mutex);
1073         for (i = 0; i < irq_virq_count; i++) {
1074                 if (irq_map[i].host &&
1075                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1076                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1077                                           irq_map[i].hwirq, &irq_map[i]);
1078         }
1079         mutex_unlock(&revmap_trees_mutex);
1080
1081         /*
1082          * Make sure the radix trees insertions are visible before setting
1083          * the flag
1084          */
1085         smp_wmb();
1086         revmap_trees_allocated = 2;
1087
1088         return 0;
1089 }
1090 arch_initcall(irq_late_init);
1091
1092 #ifdef CONFIG_VIRQ_DEBUG
1093 static int virq_debug_show(struct seq_file *m, void *private)
1094 {
1095         unsigned long flags;
1096         struct irq_desc *desc;
1097         const char *p;
1098         char none[] = "none";
1099         int i;
1100
1101         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1102                       "chip name", "host name");
1103
1104         for (i = 1; i < nr_irqs; i++) {
1105                 desc = irq_to_desc(i);
1106                 if (!desc)
1107                         continue;
1108
1109                 spin_lock_irqsave(&desc->lock, flags);
1110
1111                 if (desc->action && desc->action->handler) {
1112                         seq_printf(m, "%5d  ", i);
1113                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1114
1115                         if (desc->chip && desc->chip->name)
1116                                 p = desc->chip->name;
1117                         else
1118                                 p = none;
1119                         seq_printf(m, "%-15s  ", p);
1120
1121                         if (irq_map[i].host && irq_map[i].host->of_node)
1122                                 p = irq_map[i].host->of_node->full_name;
1123                         else
1124                                 p = none;
1125                         seq_printf(m, "%s\n", p);
1126                 }
1127
1128                 spin_unlock_irqrestore(&desc->lock, flags);
1129         }
1130
1131         return 0;
1132 }
1133
1134 static int virq_debug_open(struct inode *inode, struct file *file)
1135 {
1136         return single_open(file, virq_debug_show, inode->i_private);
1137 }
1138
1139 static const struct file_operations virq_debug_fops = {
1140         .open = virq_debug_open,
1141         .read = seq_read,
1142         .llseek = seq_lseek,
1143         .release = single_release,
1144 };
1145
1146 static int __init irq_debugfs_init(void)
1147 {
1148         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1149                                  NULL, &virq_debug_fops) == NULL)
1150                 return -ENOMEM;
1151
1152         return 0;
1153 }
1154 __initcall(irq_debugfs_init);
1155 #endif /* CONFIG_VIRQ_DEBUG */
1156
1157 #ifdef CONFIG_PPC64
1158 static int __init setup_noirqdistrib(char *str)
1159 {
1160         distribute_irqs = 0;
1161         return 1;
1162 }
1163
1164 __setup("noirqdistrib", setup_noirqdistrib);
1165 #endif /* CONFIG_PPC64 */