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
  56 #include <asm/uaccess.h>
  57 #include <asm/system.h>
  58 #include <asm/io.h>
  59 #include <asm/pgtable.h>
  60 #include <asm/irq.h>
  61 #include <asm/cache.h>
  62 #include <asm/prom.h>
  63 #include <asm/ptrace.h>
  64 #include <asm/machdep.h>
  65 #include <asm/udbg.h>
  66 #ifdef CONFIG_PPC64
  67 #include <asm/paca.h>
  68 #include <asm/firmware.h>
  69 #include <asm/lv1call.h>
  70 #endif
  71
  72 int __irq_offset_value;
  73 static int ppc_spurious_interrupts;
  74
  75 #ifdef CONFIG_PPC32
  76 EXPORT_SYMBOL(__irq_offset_value);
  77 atomic_t ppc_n_lost_interrupts;
  78
  79 #ifndef CONFIG_PPC_MERGE
  80 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
  81 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
  82 #endif
  83
  84 #ifdef CONFIG_TAU_INT
  85 extern int tau_initialized;
  86 extern int tau_interrupts(int);
  87 #endif
  88 #endif /* CONFIG_PPC32 */
  89
  90 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
  91 extern atomic_t ipi_recv;
  92 extern atomic_t ipi_sent;
  93 #endif
  94
  95 #ifdef CONFIG_PPC64
  96 EXPORT_SYMBOL(irq_desc);
  97
  98 int distribute_irqs = 1;
  99
 100 static inline unsigned long get_hard_enabled(void)
 101 {
 102         unsigned long enabled;
 103
 104         __asm__ __volatile__("lbz %0,%1(13)"
 105         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 106
 107         return enabled;
 108 }
 109
 110 static inline void set_soft_enabled(unsigned long enable)
 111 {
 112         __asm__ __volatile__("stb %0,%1(13)"
 113         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 114 }
 115
 116 void local_irq_restore(unsigned long en)
 117 {
 118         /*
 119          * get_paca()->soft_enabled = en;
 120          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 121          * That was allowed before, and in such a case we do need to take care
 122          * that gcc will set soft_enabled directly via r13, not choose to use
 123          * an intermediate register, lest we're preempted to a different cpu.
 124          */
 125         set_soft_enabled(en);
 126         if (!en)
 127                 return;
 128
 129         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 130                 /*
 131                  * Do we need to disable preemption here?  Not really: in the
 132                  * unlikely event that we're preempted to a different cpu in
 133                  * between getting r13, loading its lppaca_ptr, and loading
 134                  * its any_int, we might call iseries_handle_interrupts without
 135                  * an interrupt pending on the new cpu, but that's no disaster,
 136                  * is it?  And the business of preempting us off the old cpu
 137                  * would itself involve a local_irq_restore which handles the
 138                  * interrupt to that cpu.
 139                  *
 140                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 141                  * to avoid any preemption checking added into get_paca().
 142                  */
 143                 if (local_paca->lppaca_ptr->int_dword.any_int)
 144                         iseries_handle_interrupts();
 145                 return;
 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 #endif /* CONFIG_PPC64 */
 178
 179 int show_interrupts(struct seq_file *p, void *v)
 180 {
 181         int i = *(loff_t *)v, j;
 182         struct irqaction *action;
 183         irq_desc_t *desc;
 184         unsigned long flags;
 185
 186         if (i == 0) {
 187                 seq_puts(p, "           ");
 188                 for_each_online_cpu(j)
 189                         seq_printf(p, "CPU%d       ", j);
 190                 seq_putc(p, '\n');
 191         }
 192
 193         if (i < NR_IRQS) {
 194                 desc = get_irq_desc(i);
 195                 spin_lock_irqsave(&desc->lock, flags);
 196                 action = desc->action;
 197                 if (!action || !action->handler)
 198                         goto skip;
 199                 seq_printf(p, "%3d: ", i);
 200 #ifdef CONFIG_SMP
 201                 for_each_online_cpu(j)
 202                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 203 #else
 204                 seq_printf(p, "%10u ", kstat_irqs(i));
 205 #endif /* CONFIG_SMP */
 206                 if (desc->chip)
 207                         seq_printf(p, " %s ", desc->chip->typename);
 208                 else
 209                         seq_puts(p, "  None      ");
 210                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 211                 seq_printf(p, "    %s", action->name);
 212                 for (action = action->next; action; action = action->next)
 213                         seq_printf(p, ", %s", action->name);
 214                 seq_putc(p, '\n');
 215 skip:
 216                 spin_unlock_irqrestore(&desc->lock, flags);
 217         } else if (i == NR_IRQS) {
 218 #ifdef CONFIG_PPC32
 219 #ifdef 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
 227 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
 228                 /* should this be per processor send/receive? */
 229                 seq_printf(p, "IPI (recv/sent): %10u/%u\n",
 230                                 atomic_read(&ipi_recv), atomic_read(&ipi_sent));
 231 #endif
 232 #endif /* CONFIG_PPC32 */
 233                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 234         }
 235         return 0;
 236 }
 237
 238 #ifdef CONFIG_HOTPLUG_CPU
 239 void fixup_irqs(cpumask_t map)
 240 {
 241         unsigned int irq;
 242         static int warned;
 243
 244         for_each_irq(irq) {
 245                 cpumask_t mask;
 246
 247                 if (irq_desc[irq].status & IRQ_PER_CPU)
 248                         continue;
 249
 250                 cpus_and(mask, irq_desc[irq].affinity, map);
 251                 if (any_online_cpu(mask) == NR_CPUS) {
 252                         printk("Breaking affinity for irq %i\n", irq);
 253                         mask = map;
 254                 }
 255                 if (irq_desc[irq].chip->set_affinity)
 256                         irq_desc[irq].chip->set_affinity(irq, mask);
 257                 else if (irq_desc[irq].action && !(warned++))
 258                         printk("Cannot set affinity for irq %i\n", irq);
 259         }
 260
 261         local_irq_enable();
 262         mdelay(1);
 263         local_irq_disable();
 264 }
 265 #endif
 266
 267 void do_IRQ(struct pt_regs *regs)
 268 {
 269         struct pt_regs *old_regs = set_irq_regs(regs);
 270         unsigned int irq;
 271 #ifdef CONFIG_IRQSTACKS
 272         struct thread_info *curtp, *irqtp;
 273 #endif
 274
 275         irq_enter();
 276
 277 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 278         /* Debugging check for stack overflow: is there less than 2KB free? */
 279         {
 280                 long sp;
 281
 282                 sp = __get_SP() & (THREAD_SIZE-1);
 283
 284                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 285                         printk("do_IRQ: stack overflow: %ld\n",
 286                                 sp - sizeof(struct thread_info));
 287                         dump_stack();
 288                 }
 289         }
 290 #endif
 291
 292         /*
 293          * Every platform is required to implement ppc_md.get_irq.
 294          * This function will either return an irq number or NO_IRQ to
 295          * indicate there are no more pending.
 296          * The value NO_IRQ_IGNORE is for buggy hardware and means that this
 297          * IRQ has already been handled. -- Tom
 298          */
 299         irq = ppc_md.get_irq();
 300
 301         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
 302 #ifdef CONFIG_IRQSTACKS
 303                 /* Switch to the irq stack to handle this */
 304                 curtp = current_thread_info();
 305                 irqtp = hardirq_ctx[smp_processor_id()];
 306                 if (curtp != irqtp) {
 307                         struct irq_desc *desc = irq_desc + irq;
 308                         void *handler = desc->handle_irq;
 309                         if (handler == NULL)
 310                                 handler = &__do_IRQ;
 311                         irqtp->task = curtp->task;
 312                         irqtp->flags = 0;
 313                         call_handle_irq(irq, desc, irqtp, handler);
 314                         irqtp->task = NULL;
 315                         if (irqtp->flags)
 316                                 set_bits(irqtp->flags, &curtp->flags);
 317                 } else
 318 #endif
 319                         generic_handle_irq(irq);
 320         } else if (irq != NO_IRQ_IGNORE)
 321                 /* That's not SMP safe ... but who cares ? */
 322                 ppc_spurious_interrupts++;
 323
 324         irq_exit();
 325         set_irq_regs(old_regs);
 326
 327 #ifdef CONFIG_PPC_ISERIES
 328         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 329                         get_lppaca()->int_dword.fields.decr_int) {
 330                 get_lppaca()->int_dword.fields.decr_int = 0;
 331                 /* Signal a fake decrementer interrupt */
 332                 timer_interrupt(regs);
 333         }
 334 #endif
 335 }
 336
 337 void __init init_IRQ(void)
 338 {
 339         if (ppc_md.init_IRQ)
 340                 ppc_md.init_IRQ();
 341 #ifdef CONFIG_PPC64
 342         irq_ctx_init();
 343 #endif
 344 }
 345
 346
 347 #ifdef CONFIG_IRQSTACKS
 348 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 349 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 350
 351 void irq_ctx_init(void)
 352 {
 353         struct thread_info *tp;
 354         int i;
 355
 356         for_each_possible_cpu(i) {
 357                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 358                 tp = softirq_ctx[i];
 359                 tp->cpu = i;
 360                 tp->preempt_count = SOFTIRQ_OFFSET;
 361
 362                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 363                 tp = hardirq_ctx[i];
 364                 tp->cpu = i;
 365                 tp->preempt_count = HARDIRQ_OFFSET;
 366         }
 367 }
 368
 369 static inline void do_softirq_onstack(void)
 370 {
 371         struct thread_info *curtp, *irqtp;
 372
 373         curtp = current_thread_info();
 374         irqtp = softirq_ctx[smp_processor_id()];
 375         irqtp->task = curtp->task;
 376         call_do_softirq(irqtp);
 377         irqtp->task = NULL;
 378 }
 379
 380 #else
 381 #define do_softirq_onstack()    __do_softirq()
 382 #endif /* CONFIG_IRQSTACKS */
 383
 384 void do_softirq(void)
 385 {
 386         unsigned long flags;
 387
 388         if (in_interrupt())
 389                 return;
 390
 391         local_irq_save(flags);
 392
 393         if (local_softirq_pending())
 394                 do_softirq_onstack();
 395
 396         local_irq_restore(flags);
 397 }
 398 EXPORT_SYMBOL(do_softirq);
 399
 400
 401 /*
 402  * IRQ controller and virtual interrupts
 403  */
 404
 405 #ifdef CONFIG_PPC_MERGE
 406
 407 static LIST_HEAD(irq_hosts);
 408 static DEFINE_SPINLOCK(irq_big_lock);
 409 static DEFINE_PER_CPU(unsigned int, irq_radix_reader);
 410 static unsigned int irq_radix_writer;
 411 struct irq_map_entry irq_map[NR_IRQS];
 412 static unsigned int irq_virq_count = NR_IRQS;
 413 static struct irq_host *irq_default_host;
 414
 415 irq_hw_number_t virq_to_hw(unsigned int virq)
 416 {
 417         return irq_map[virq].hwirq;
 418 }
 419 EXPORT_SYMBOL_GPL(virq_to_hw);
 420
 421 struct irq_host *irq_alloc_host(unsigned int revmap_type,
 422                                 unsigned int revmap_arg,
 423                                 struct irq_host_ops *ops,
 424                                 irq_hw_number_t inval_irq)
 425 {
 426         struct irq_host *host;
 427         unsigned int size = sizeof(struct irq_host);
 428         unsigned int i;
 429         unsigned int *rmap;
 430         unsigned long flags;
 431
 432         /* Allocate structure and revmap table if using linear mapping */
 433         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 434                 size += revmap_arg * sizeof(unsigned int);
 435         if (mem_init_done)
 436                 host = kzalloc(size, GFP_KERNEL);
 437         else {
 438                 host = alloc_bootmem(size);
 439                 if (host)
 440                         memset(host, 0, size);
 441         }
 442         if (host == NULL)
 443                 return NULL;
 444
 445         /* Fill structure */
 446         host->revmap_type = revmap_type;
 447         host->inval_irq = inval_irq;
 448         host->ops = ops;
 449
 450         spin_lock_irqsave(&irq_big_lock, flags);
 451
 452         /* If it's a legacy controller, check for duplicates and
 453          * mark it as allocated (we use irq 0 host pointer for that
 454          */
 455         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 456                 if (irq_map[0].host != NULL) {
 457                         spin_unlock_irqrestore(&irq_big_lock, flags);
 458                         /* If we are early boot, we can't free the structure,
 459                          * too bad...
 460                          * this will be fixed once slab is made available early
 461                          * instead of the current cruft
 462                          */
 463                         if (mem_init_done)
 464                                 kfree(host);
 465                         return NULL;
 466                 }
 467                 irq_map[0].host = host;
 468         }
 469
 470         list_add(&host->link, &irq_hosts);
 471         spin_unlock_irqrestore(&irq_big_lock, flags);
 472
 473         /* Additional setups per revmap type */
 474         switch(revmap_type) {
 475         case IRQ_HOST_MAP_LEGACY:
 476                 /* 0 is always the invalid number for legacy */
 477                 host->inval_irq = 0;
 478                 /* setup us as the host for all legacy interrupts */
 479                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 480                         irq_map[i].hwirq = 0;
 481                         smp_wmb();
 482                         irq_map[i].host = host;
 483                         smp_wmb();
 484
 485                         /* Clear norequest flags */
 486                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 487
 488                         /* Legacy flags are left to default at this point,
 489                          * one can then use irq_create_mapping() to
 490                          * explicitely change them
 491                          */
 492                         ops->map(host, i, i);
 493                 }
 494                 break;
 495         case IRQ_HOST_MAP_LINEAR:
 496                 rmap = (unsigned int *)(host + 1);
 497                 for (i = 0; i < revmap_arg; i++)
 498                         rmap[i] = NO_IRQ;
 499                 host->revmap_data.linear.size = revmap_arg;
 500                 smp_wmb();
 501                 host->revmap_data.linear.revmap = rmap;
 502                 break;
 503         default:
 504                 break;
 505         }
 506
 507         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 508
 509         return host;
 510 }
 511
 512 struct irq_host *irq_find_host(struct device_node *node)
 513 {
 514         struct irq_host *h, *found = NULL;
 515         unsigned long flags;
 516
 517         /* We might want to match the legacy controller last since
 518          * it might potentially be set to match all interrupts in
 519          * the absence of a device node. This isn't a problem so far
 520          * yet though...
 521          */
 522         spin_lock_irqsave(&irq_big_lock, flags);
 523         list_for_each_entry(h, &irq_hosts, link)
 524                 if (h->ops->match == NULL || h->ops->match(h, node)) {
 525                         found = h;
 526                         break;
 527                 }
 528         spin_unlock_irqrestore(&irq_big_lock, flags);
 529         return found;
 530 }
 531 EXPORT_SYMBOL_GPL(irq_find_host);
 532
 533 void irq_set_default_host(struct irq_host *host)
 534 {
 535         pr_debug("irq: Default host set to @0x%p\n", host);
 536
 537         irq_default_host = host;
 538 }
 539
 540 void irq_set_virq_count(unsigned int count)
 541 {
 542         pr_debug("irq: Trying to set virq count to %d\n", count);
 543
 544         BUG_ON(count < NUM_ISA_INTERRUPTS);
 545         if (count < NR_IRQS)
 546                 irq_virq_count = count;
 547 }
 548
 549 /* radix tree not lockless safe ! we use a brlock-type mecanism
 550  * for now, until we can use a lockless radix tree
 551  */
 552 static void irq_radix_wrlock(unsigned long *flags)
 553 {
 554         unsigned int cpu, ok;
 555
 556         spin_lock_irqsave(&irq_big_lock, *flags);
 557         irq_radix_writer = 1;
 558         smp_mb();
 559         do {
 560                 barrier();
 561                 ok = 1;
 562                 for_each_possible_cpu(cpu) {
 563                         if (per_cpu(irq_radix_reader, cpu)) {
 564                                 ok = 0;
 565                                 break;
 566                         }
 567                 }
 568                 if (!ok)
 569                         cpu_relax();
 570         } while(!ok);
 571 }
 572
 573 static void irq_radix_wrunlock(unsigned long flags)
 574 {
 575         smp_wmb();
 576         irq_radix_writer = 0;
 577         spin_unlock_irqrestore(&irq_big_lock, flags);
 578 }
 579
 580 static void irq_radix_rdlock(unsigned long *flags)
 581 {
 582         local_irq_save(*flags);
 583         __get_cpu_var(irq_radix_reader) = 1;
 584         smp_mb();
 585         if (likely(irq_radix_writer == 0))
 586                 return;
 587         __get_cpu_var(irq_radix_reader) = 0;
 588         smp_wmb();
 589         spin_lock(&irq_big_lock);
 590         __get_cpu_var(irq_radix_reader) = 1;
 591         spin_unlock(&irq_big_lock);
 592 }
 593
 594 static void irq_radix_rdunlock(unsigned long flags)
 595 {
 596         __get_cpu_var(irq_radix_reader) = 0;
 597         local_irq_restore(flags);
 598 }
 599
 600 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 601                             irq_hw_number_t hwirq)
 602 {
 603         /* Clear IRQ_NOREQUEST flag */
 604         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 605
 606         /* map it */
 607         smp_wmb();
 608         irq_map[virq].hwirq = hwirq;
 609         smp_mb();
 610
 611         if (host->ops->map(host, virq, hwirq)) {
 612                 pr_debug("irq: -> mapping failed, freeing\n");
 613                 irq_free_virt(virq, 1);
 614                 return -1;
 615         }
 616
 617         return 0;
 618 }
 619
 620 unsigned int irq_create_direct_mapping(struct irq_host *host)
 621 {
 622         unsigned int virq;
 623
 624         if (host == NULL)
 625                 host = irq_default_host;
 626
 627         BUG_ON(host == NULL);
 628         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 629
 630         virq = irq_alloc_virt(host, 1, 0);
 631         if (virq == NO_IRQ) {
 632                 pr_debug("irq: create_direct virq allocation failed\n");
 633                 return NO_IRQ;
 634         }
 635
 636         pr_debug("irq: create_direct obtained virq %d\n", virq);
 637
 638         if (irq_setup_virq(host, virq, virq))
 639                 return NO_IRQ;
 640
 641         return virq;
 642 }
 643
 644 unsigned int irq_create_mapping(struct irq_host *host,
 645                                 irq_hw_number_t hwirq)
 646 {
 647         unsigned int virq, hint;
 648
 649         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 650
 651         /* Look for default host if nececssary */
 652         if (host == NULL)
 653                 host = irq_default_host;
 654         if (host == NULL) {
 655                 printk(KERN_WARNING "irq_create_mapping called for"
 656                        " NULL host, hwirq=%lx\n", hwirq);
 657                 WARN_ON(1);
 658                 return NO_IRQ;
 659         }
 660         pr_debug("irq: -> using host @%p\n", host);
 661
 662         /* Check if mapping already exist, if it does, call
 663          * host->ops->map() to update the flags
 664          */
 665         virq = irq_find_mapping(host, hwirq);
 666         if (virq != NO_IRQ) {
 667                 if (host->ops->remap)
 668                         host->ops->remap(host, virq, hwirq);
 669                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 670                 return virq;
 671         }
 672
 673         /* Get a virtual interrupt number */
 674         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 675                 /* Handle legacy */
 676                 virq = (unsigned int)hwirq;
 677                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 678                         return NO_IRQ;
 679                 return virq;
 680         } else {
 681                 /* Allocate a virtual interrupt number */
 682                 hint = hwirq % irq_virq_count;
 683                 virq = irq_alloc_virt(host, 1, hint);
 684                 if (virq == NO_IRQ) {
 685                         pr_debug("irq: -> virq allocation failed\n");
 686                         return NO_IRQ;
 687                 }
 688         }
 689         pr_debug("irq: -> obtained virq %d\n", virq);
 690
 691         if (irq_setup_virq(host, virq, hwirq))
 692                 return NO_IRQ;
 693
 694         return virq;
 695 }
 696 EXPORT_SYMBOL_GPL(irq_create_mapping);
 697
 698 unsigned int irq_create_of_mapping(struct device_node *controller,
 699                                    u32 *intspec, unsigned int intsize)
 700 {
 701         struct irq_host *host;
 702         irq_hw_number_t hwirq;
 703         unsigned int type = IRQ_TYPE_NONE;
 704         unsigned int virq;
 705
 706         if (controller == NULL)
 707                 host = irq_default_host;
 708         else
 709                 host = irq_find_host(controller);
 710         if (host == NULL) {
 711                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 712                        controller->full_name);
 713                 return NO_IRQ;
 714         }
 715
 716         /* If host has no translation, then we assume interrupt line */
 717         if (host->ops->xlate == NULL)
 718                 hwirq = intspec[0];
 719         else {
 720                 if (host->ops->xlate(host, controller, intspec, intsize,
 721                                      &hwirq, &type))
 722                         return NO_IRQ;
 723         }
 724
 725         /* Create mapping */
 726         virq = irq_create_mapping(host, hwirq);
 727         if (virq == NO_IRQ)
 728                 return virq;
 729
 730         /* Set type if specified and different than the current one */
 731         if (type != IRQ_TYPE_NONE &&
 732             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 733                 set_irq_type(virq, type);
 734         return virq;
 735 }
 736 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 737
 738 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 739 {
 740         struct of_irq oirq;
 741
 742         if (of_irq_map_one(dev, index, &oirq))
 743                 return NO_IRQ;
 744
 745         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 746                                      oirq.size);
 747 }
 748 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 749
 750 void irq_dispose_mapping(unsigned int virq)
 751 {
 752         struct irq_host *host;
 753         irq_hw_number_t hwirq;
 754         unsigned long flags;
 755
 756         if (virq == NO_IRQ)
 757                 return;
 758
 759         host = irq_map[virq].host;
 760         WARN_ON (host == NULL);
 761         if (host == NULL)
 762                 return;
 763
 764         /* Never unmap legacy interrupts */
 765         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 766                 return;
 767
 768         /* remove chip and handler */
 769         set_irq_chip_and_handler(virq, NULL, NULL);
 770
 771         /* Make sure it's completed */
 772         synchronize_irq(virq);
 773
 774         /* Tell the PIC about it */
 775         if (host->ops->unmap)
 776                 host->ops->unmap(host, virq);
 777         smp_mb();
 778
 779         /* Clear reverse map */
 780         hwirq = irq_map[virq].hwirq;
 781         switch(host->revmap_type) {
 782         case IRQ_HOST_MAP_LINEAR:
 783                 if (hwirq < host->revmap_data.linear.size)
 784                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 785                 break;
 786         case IRQ_HOST_MAP_TREE:
 787                 /* Check if radix tree allocated yet */
 788                 if (host->revmap_data.tree.gfp_mask == 0)
 789                         break;
 790                 irq_radix_wrlock(&flags);
 791                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 792                 irq_radix_wrunlock(flags);
 793                 break;
 794         }
 795
 796         /* Destroy map */
 797         smp_mb();
 798         irq_map[virq].hwirq = host->inval_irq;
 799
 800         /* Set some flags */
 801         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 802
 803         /* Free it */
 804         irq_free_virt(virq, 1);
 805 }
 806 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 807
 808 unsigned int irq_find_mapping(struct irq_host *host,
 809                               irq_hw_number_t hwirq)
 810 {
 811         unsigned int i;
 812         unsigned int hint = hwirq % irq_virq_count;
 813
 814         /* Look for default host if nececssary */
 815         if (host == NULL)
 816                 host = irq_default_host;
 817         if (host == NULL)
 818                 return NO_IRQ;
 819
 820         /* legacy -> bail early */
 821         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 822                 return hwirq;
 823
 824         /* Slow path does a linear search of the map */
 825         if (hint < NUM_ISA_INTERRUPTS)
 826                 hint = NUM_ISA_INTERRUPTS;
 827         i = hint;
 828         do  {
 829                 if (irq_map[i].host == host &&
 830                     irq_map[i].hwirq == hwirq)
 831                         return i;
 832                 i++;
 833                 if (i >= irq_virq_count)
 834                         i = NUM_ISA_INTERRUPTS;
 835         } while(i != hint);
 836         return NO_IRQ;
 837 }
 838 EXPORT_SYMBOL_GPL(irq_find_mapping);
 839
 840
 841 unsigned int irq_radix_revmap(struct irq_host *host,
 842                               irq_hw_number_t hwirq)
 843 {
 844         struct radix_tree_root *tree;
 845         struct irq_map_entry *ptr;
 846         unsigned int virq;
 847         unsigned long flags;
 848
 849         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 850
 851         /* Check if the radix tree exist yet. We test the value of
 852          * the gfp_mask for that. Sneaky but saves another int in the
 853          * structure. If not, we fallback to slow mode
 854          */
 855         tree = &host->revmap_data.tree;
 856         if (tree->gfp_mask == 0)
 857                 return irq_find_mapping(host, hwirq);
 858
 859         /* Now try to resolve */
 860         irq_radix_rdlock(&flags);
 861         ptr = radix_tree_lookup(tree, hwirq);
 862         irq_radix_rdunlock(flags);
 863
 864         /* Found it, return */
 865         if (ptr) {
 866                 virq = ptr - irq_map;
 867                 return virq;
 868         }
 869
 870         /* If not there, try to insert it */
 871         virq = irq_find_mapping(host, hwirq);
 872         if (virq != NO_IRQ) {
 873                 irq_radix_wrlock(&flags);
 874                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 875                 irq_radix_wrunlock(flags);
 876         }
 877         return virq;
 878 }
 879
 880 unsigned int irq_linear_revmap(struct irq_host *host,
 881                                irq_hw_number_t hwirq)
 882 {
 883         unsigned int *revmap;
 884
 885         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 886
 887         /* Check revmap bounds */
 888         if (unlikely(hwirq >= host->revmap_data.linear.size))
 889                 return irq_find_mapping(host, hwirq);
 890
 891         /* Check if revmap was allocated */
 892         revmap = host->revmap_data.linear.revmap;
 893         if (unlikely(revmap == NULL))
 894                 return irq_find_mapping(host, hwirq);
 895
 896         /* Fill up revmap with slow path if no mapping found */
 897         if (unlikely(revmap[hwirq] == NO_IRQ))
 898                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 899
 900         return revmap[hwirq];
 901 }
 902
 903 unsigned int irq_alloc_virt(struct irq_host *host,
 904                             unsigned int count,
 905                             unsigned int hint)
 906 {
 907         unsigned long flags;
 908         unsigned int i, j, found = NO_IRQ;
 909
 910         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 911                 return NO_IRQ;
 912
 913         spin_lock_irqsave(&irq_big_lock, flags);
 914
 915         /* Use hint for 1 interrupt if any */
 916         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 917             hint < irq_virq_count && irq_map[hint].host == NULL) {
 918                 found = hint;
 919                 goto hint_found;
 920         }
 921
 922         /* Look for count consecutive numbers in the allocatable
 923          * (non-legacy) space
 924          */
 925         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 926                 if (irq_map[i].host != NULL)
 927                         j = 0;
 928                 else
 929                         j++;
 930
 931                 if (j == count) {
 932                         found = i - count + 1;
 933                         break;
 934                 }
 935         }
 936         if (found == NO_IRQ) {
 937                 spin_unlock_irqrestore(&irq_big_lock, flags);
 938                 return NO_IRQ;
 939         }
 940  hint_found:
 941         for (i = found; i < (found + count); i++) {
 942                 irq_map[i].hwirq = host->inval_irq;
 943                 smp_wmb();
 944                 irq_map[i].host = host;
 945         }
 946         spin_unlock_irqrestore(&irq_big_lock, flags);
 947         return found;
 948 }
 949
 950 void irq_free_virt(unsigned int virq, unsigned int count)
 951 {
 952         unsigned long flags;
 953         unsigned int i;
 954
 955         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 956         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 957
 958         spin_lock_irqsave(&irq_big_lock, flags);
 959         for (i = virq; i < (virq + count); i++) {
 960                 struct irq_host *host;
 961
 962                 if (i < NUM_ISA_INTERRUPTS ||
 963                     (virq + count) > irq_virq_count)
 964                         continue;
 965
 966                 host = irq_map[i].host;
 967                 irq_map[i].hwirq = host->inval_irq;
 968                 smp_wmb();
 969                 irq_map[i].host = NULL;
 970         }
 971         spin_unlock_irqrestore(&irq_big_lock, flags);
 972 }
 973
 974 void irq_early_init(void)
 975 {
 976         unsigned int i;
 977
 978         for (i = 0; i < NR_IRQS; i++)
 979                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 980 }
 981
 982 /* We need to create the radix trees late */
 983 static int irq_late_init(void)
 984 {
 985         struct irq_host *h;
 986         unsigned long flags;
 987
 988         irq_radix_wrlock(&flags);
 989         list_for_each_entry(h, &irq_hosts, link) {
 990                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
 991                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
 992         }
 993         irq_radix_wrunlock(flags);
 994
 995         return 0;
 996 }
 997 arch_initcall(irq_late_init);
 998
 999 #endif /* CONFIG_PPC_MERGE */
1000
1001 #ifdef CONFIG_PPC64
1002 static int __init setup_noirqdistrib(char *str)
1003 {
1004         distribute_irqs = 0;
1005         return 1;
1006 }
1007
1008 __setup("noirqdistrib", setup_noirqdistrib);
1009 #endif /* CONFIG_PPC64 */