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  *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version
  15  * 2 of the License, or (at your option) any later version.
  16  *
  17  * This file contains the code used by various IRQ handling routines:
  18  * asking for different IRQ's should be done through these routines
  19  * instead of just grabbing them. Thus setups with different IRQ numbers
  20  * shouldn't result in any weird surprises, and installing new handlers
  21  * should be easier.
  22  *
  23  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
  24  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
  25  * mask register (of which only 16 are defined), hence the weird shifting
  26  * and complement of the cached_irq_mask.  I want to be able to stuff
  27  * this right into the SIU SMASK register.
  28  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
  29  * to reduce code space and undefined function references.
  30  */
  31
  32 #undef DEBUG
  33
  34 #include <linux/module.h>
  35 #include <linux/threads.h>
  36 #include <linux/kernel_stat.h>
  37 #include <linux/signal.h>
  38 #include <linux/sched.h>
  39 #include <linux/ptrace.h>
  40 #include <linux/ioport.h>
  41 #include <linux/interrupt.h>
  42 #include <linux/timex.h>
  43 #include <linux/init.h>
  44 #include <linux/slab.h>
  45 #include <linux/delay.h>
  46 #include <linux/irq.h>
  47 #include <linux/seq_file.h>
  48 #include <linux/cpumask.h>
  49 #include <linux/profile.h>
  50 #include <linux/bitops.h>
  51 #include <linux/list.h>
  52 #include <linux/radix-tree.h>
  53 #include <linux/mutex.h>
  54 #include <linux/bootmem.h>
  55 #include <linux/pci.h>
  56
  57 #include <asm/uaccess.h>
  58 #include <asm/system.h>
  59 #include <asm/io.h>
  60 #include <asm/pgtable.h>
  61 #include <asm/irq.h>
  62 #include <asm/cache.h>
  63 #include <asm/prom.h>
  64 #include <asm/ptrace.h>
  65 #include <asm/machdep.h>
  66 #include <asm/udbg.h>
  67 #ifdef CONFIG_PPC64
  68 #include <asm/paca.h>
  69 #include <asm/firmware.h>
  70 #include <asm/lv1call.h>
  71 #endif
  72
  73 int __irq_offset_value;
  74 static int ppc_spurious_interrupts;
  75
  76 #ifdef CONFIG_PPC32
  77 EXPORT_SYMBOL(__irq_offset_value);
  78 atomic_t ppc_n_lost_interrupts;
  79
  80 #ifndef CONFIG_PPC_MERGE
  81 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
  82 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
  83 #endif
  84
  85 #ifdef CONFIG_TAU_INT
  86 extern int tau_initialized;
  87 extern int tau_interrupts(int);
  88 #endif
  89 #endif /* CONFIG_PPC32 */
  90
  91 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
  92 extern atomic_t ipi_recv;
  93 extern atomic_t ipi_sent;
  94 #endif
  95
  96 #ifdef CONFIG_PPC64
  97 EXPORT_SYMBOL(irq_desc);
  98
  99 int distribute_irqs = 1;
 100
 101 static inline unsigned long get_hard_enabled(void)
 102 {
 103         unsigned long enabled;
 104
 105         __asm__ __volatile__("lbz %0,%1(13)"
 106         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 107
 108         return enabled;
 109 }
 110
 111 static inline void set_soft_enabled(unsigned long enable)
 112 {
 113         __asm__ __volatile__("stb %0,%1(13)"
 114         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 115 }
 116
 117 void local_irq_restore(unsigned long en)
 118 {
 119         /*
 120          * get_paca()->soft_enabled = en;
 121          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 122          * That was allowed before, and in such a case we do need to take care
 123          * that gcc will set soft_enabled directly via r13, not choose to use
 124          * an intermediate register, lest we're preempted to a different cpu.
 125          */
 126         set_soft_enabled(en);
 127         if (!en)
 128                 return;
 129
 130         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 131                 /*
 132                  * Do we need to disable preemption here?  Not really: in the
 133                  * unlikely event that we're preempted to a different cpu in
 134                  * between getting r13, loading its lppaca_ptr, and loading
 135                  * its any_int, we might call iseries_handle_interrupts without
 136                  * an interrupt pending on the new cpu, but that's no disaster,
 137                  * is it?  And the business of preempting us off the old cpu
 138                  * would itself involve a local_irq_restore which handles the
 139                  * interrupt to that cpu.
 140                  *
 141                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 142                  * to avoid any preemption checking added into get_paca().
 143                  */
 144                 if (local_paca->lppaca_ptr->int_dword.any_int)
 145                         iseries_handle_interrupts();
 146                 return;
 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 #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         irq_desc_t *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_cpu(j).irqs[i]);
 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 #ifdef CONFIG_PPC32
 220 #ifdef CONFIG_TAU_INT
 221                 if (tau_initialized){
 222                         seq_puts(p, "TAU: ");
 223                         for_each_online_cpu(j)
 224                                 seq_printf(p, "%10u ", tau_interrupts(j));
 225                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 226                 }
 227 #endif
 228 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
 229                 /* should this be per processor send/receive? */
 230                 seq_printf(p, "IPI (recv/sent): %10u/%u\n",
 231                                 atomic_read(&ipi_recv), atomic_read(&ipi_sent));
 232 #endif
 233 #endif /* CONFIG_PPC32 */
 234                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 235         }
 236         return 0;
 237 }
 238
 239 #ifdef CONFIG_HOTPLUG_CPU
 240 void fixup_irqs(cpumask_t map)
 241 {
 242         unsigned int irq;
 243         static int warned;
 244
 245         for_each_irq(irq) {
 246                 cpumask_t mask;
 247
 248                 if (irq_desc[irq].status & IRQ_PER_CPU)
 249                         continue;
 250
 251                 cpus_and(mask, irq_desc[irq].affinity, map);
 252                 if (any_online_cpu(mask) == NR_CPUS) {
 253                         printk("Breaking affinity for irq %i\n", irq);
 254                         mask = map;
 255                 }
 256                 if (irq_desc[irq].chip->set_affinity)
 257                         irq_desc[irq].chip->set_affinity(irq, mask);
 258                 else if (irq_desc[irq].action && !(warned++))
 259                         printk("Cannot set affinity for irq %i\n", irq);
 260         }
 261
 262         local_irq_enable();
 263         mdelay(1);
 264         local_irq_disable();
 265 }
 266 #endif
 267
 268 void do_IRQ(struct pt_regs *regs)
 269 {
 270         struct pt_regs *old_regs = set_irq_regs(regs);
 271         unsigned int irq;
 272 #ifdef CONFIG_IRQSTACKS
 273         struct thread_info *curtp, *irqtp;
 274 #endif
 275
 276         irq_enter();
 277
 278 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 279         /* Debugging check for stack overflow: is there less than 2KB free? */
 280         {
 281                 long sp;
 282
 283                 sp = __get_SP() & (THREAD_SIZE-1);
 284
 285                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 286                         printk("do_IRQ: stack overflow: %ld\n",
 287                                 sp - sizeof(struct thread_info));
 288                         dump_stack();
 289                 }
 290         }
 291 #endif
 292
 293         /*
 294          * Every platform is required to implement ppc_md.get_irq.
 295          * This function will either return an irq number or NO_IRQ to
 296          * indicate there are no more pending.
 297          * The value NO_IRQ_IGNORE is for buggy hardware and means that this
 298          * IRQ has already been handled. -- Tom
 299          */
 300         irq = ppc_md.get_irq();
 301
 302         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
 303 #ifdef CONFIG_IRQSTACKS
 304                 /* Switch to the irq stack to handle this */
 305                 curtp = current_thread_info();
 306                 irqtp = hardirq_ctx[smp_processor_id()];
 307                 if (curtp != irqtp) {
 308                         struct irq_desc *desc = irq_desc + irq;
 309                         void *handler = desc->handle_irq;
 310                         if (handler == NULL)
 311                                 handler = &__do_IRQ;
 312                         irqtp->task = curtp->task;
 313                         irqtp->flags = 0;
 314                         call_handle_irq(irq, desc, irqtp, handler);
 315                         irqtp->task = NULL;
 316                         if (irqtp->flags)
 317                                 set_bits(irqtp->flags, &curtp->flags);
 318                 } else
 319 #endif
 320                         generic_handle_irq(irq);
 321         } else if (irq != NO_IRQ_IGNORE)
 322                 /* That's not SMP safe ... but who cares ? */
 323                 ppc_spurious_interrupts++;
 324
 325         irq_exit();
 326         set_irq_regs(old_regs);
 327
 328 #ifdef CONFIG_PPC_ISERIES
 329         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 330                         get_lppaca()->int_dword.fields.decr_int) {
 331                 get_lppaca()->int_dword.fields.decr_int = 0;
 332                 /* Signal a fake decrementer interrupt */
 333                 timer_interrupt(regs);
 334         }
 335 #endif
 336 }
 337
 338 void __init init_IRQ(void)
 339 {
 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
 601 unsigned int irq_create_mapping(struct irq_host *host,
 602                                 irq_hw_number_t hwirq)
 603 {
 604         unsigned int virq, hint;
 605
 606         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 607
 608         /* Look for default host if nececssary */
 609         if (host == NULL)
 610                 host = irq_default_host;
 611         if (host == NULL) {
 612                 printk(KERN_WARNING "irq_create_mapping called for"
 613                        " NULL host, hwirq=%lx\n", hwirq);
 614                 WARN_ON(1);
 615                 return NO_IRQ;
 616         }
 617         pr_debug("irq: -> using host @%p\n", host);
 618
 619         /* Check if mapping already exist, if it does, call
 620          * host->ops->map() to update the flags
 621          */
 622         virq = irq_find_mapping(host, hwirq);
 623         if (virq != NO_IRQ) {
 624                 if (host->ops->remap)
 625                         host->ops->remap(host, virq, hwirq);
 626                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 627                 return virq;
 628         }
 629
 630         /* Get a virtual interrupt number */
 631         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 632                 /* Handle legacy */
 633                 virq = (unsigned int)hwirq;
 634                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 635                         return NO_IRQ;
 636                 return virq;
 637         } else {
 638                 /* Allocate a virtual interrupt number */
 639                 hint = hwirq % irq_virq_count;
 640                 virq = irq_alloc_virt(host, 1, hint);
 641                 if (virq == NO_IRQ) {
 642                         pr_debug("irq: -> virq allocation failed\n");
 643                         return NO_IRQ;
 644                 }
 645         }
 646         pr_debug("irq: -> obtained virq %d\n", virq);
 647
 648         /* Clear IRQ_NOREQUEST flag */
 649         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 650
 651         /* map it */
 652         smp_wmb();
 653         irq_map[virq].hwirq = hwirq;
 654         smp_mb();
 655         if (host->ops->map(host, virq, hwirq)) {
 656                 pr_debug("irq: -> mapping failed, freeing\n");
 657                 irq_free_virt(virq, 1);
 658                 return NO_IRQ;
 659         }
 660         return virq;
 661 }
 662 EXPORT_SYMBOL_GPL(irq_create_mapping);
 663
 664 unsigned int irq_create_of_mapping(struct device_node *controller,
 665                                    u32 *intspec, unsigned int intsize)
 666 {
 667         struct irq_host *host;
 668         irq_hw_number_t hwirq;
 669         unsigned int type = IRQ_TYPE_NONE;
 670         unsigned int virq;
 671
 672         if (controller == NULL)
 673                 host = irq_default_host;
 674         else
 675                 host = irq_find_host(controller);
 676         if (host == NULL) {
 677                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 678                        controller->full_name);
 679                 return NO_IRQ;
 680         }
 681
 682         /* If host has no translation, then we assume interrupt line */
 683         if (host->ops->xlate == NULL)
 684                 hwirq = intspec[0];
 685         else {
 686                 if (host->ops->xlate(host, controller, intspec, intsize,
 687                                      &hwirq, &type))
 688                         return NO_IRQ;
 689         }
 690
 691         /* Create mapping */
 692         virq = irq_create_mapping(host, hwirq);
 693         if (virq == NO_IRQ)
 694                 return virq;
 695
 696         /* Set type if specified and different than the current one */
 697         if (type != IRQ_TYPE_NONE &&
 698             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 699                 set_irq_type(virq, type);
 700         return virq;
 701 }
 702 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 703
 704 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 705 {
 706         struct of_irq oirq;
 707
 708         if (of_irq_map_one(dev, index, &oirq))
 709                 return NO_IRQ;
 710
 711         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 712                                      oirq.size);
 713 }
 714 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 715
 716 void irq_dispose_mapping(unsigned int virq)
 717 {
 718         struct irq_host *host;
 719         irq_hw_number_t hwirq;
 720         unsigned long flags;
 721
 722         if (virq == NO_IRQ)
 723                 return;
 724
 725         host = irq_map[virq].host;
 726         WARN_ON (host == NULL);
 727         if (host == NULL)
 728                 return;
 729
 730         /* Never unmap legacy interrupts */
 731         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 732                 return;
 733
 734         /* remove chip and handler */
 735         set_irq_chip_and_handler(virq, NULL, NULL);
 736
 737         /* Make sure it's completed */
 738         synchronize_irq(virq);
 739
 740         /* Tell the PIC about it */
 741         if (host->ops->unmap)
 742                 host->ops->unmap(host, virq);
 743         smp_mb();
 744
 745         /* Clear reverse map */
 746         hwirq = irq_map[virq].hwirq;
 747         switch(host->revmap_type) {
 748         case IRQ_HOST_MAP_LINEAR:
 749                 if (hwirq < host->revmap_data.linear.size)
 750                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 751                 break;
 752         case IRQ_HOST_MAP_TREE:
 753                 /* Check if radix tree allocated yet */
 754                 if (host->revmap_data.tree.gfp_mask == 0)
 755                         break;
 756                 irq_radix_wrlock(&flags);
 757                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 758                 irq_radix_wrunlock(flags);
 759                 break;
 760         }
 761
 762         /* Destroy map */
 763         smp_mb();
 764         irq_map[virq].hwirq = host->inval_irq;
 765
 766         /* Set some flags */
 767         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 768
 769         /* Free it */
 770         irq_free_virt(virq, 1);
 771 }
 772 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 773
 774 unsigned int irq_find_mapping(struct irq_host *host,
 775                               irq_hw_number_t hwirq)
 776 {
 777         unsigned int i;
 778         unsigned int hint = hwirq % irq_virq_count;
 779
 780         /* Look for default host if nececssary */
 781         if (host == NULL)
 782                 host = irq_default_host;
 783         if (host == NULL)
 784                 return NO_IRQ;
 785
 786         /* legacy -> bail early */
 787         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 788                 return hwirq;
 789
 790         /* Slow path does a linear search of the map */
 791         if (hint < NUM_ISA_INTERRUPTS)
 792                 hint = NUM_ISA_INTERRUPTS;
 793         i = hint;
 794         do  {
 795                 if (irq_map[i].host == host &&
 796                     irq_map[i].hwirq == hwirq)
 797                         return i;
 798                 i++;
 799                 if (i >= irq_virq_count)
 800                         i = NUM_ISA_INTERRUPTS;
 801         } while(i != hint);
 802         return NO_IRQ;
 803 }
 804 EXPORT_SYMBOL_GPL(irq_find_mapping);
 805
 806
 807 unsigned int irq_radix_revmap(struct irq_host *host,
 808                               irq_hw_number_t hwirq)
 809 {
 810         struct radix_tree_root *tree;
 811         struct irq_map_entry *ptr;
 812         unsigned int virq;
 813         unsigned long flags;
 814
 815         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 816
 817         /* Check if the radix tree exist yet. We test the value of
 818          * the gfp_mask for that. Sneaky but saves another int in the
 819          * structure. If not, we fallback to slow mode
 820          */
 821         tree = &host->revmap_data.tree;
 822         if (tree->gfp_mask == 0)
 823                 return irq_find_mapping(host, hwirq);
 824
 825         /* Now try to resolve */
 826         irq_radix_rdlock(&flags);
 827         ptr = radix_tree_lookup(tree, hwirq);
 828         irq_radix_rdunlock(flags);
 829
 830         /* Found it, return */
 831         if (ptr) {
 832                 virq = ptr - irq_map;
 833                 return virq;
 834         }
 835
 836         /* If not there, try to insert it */
 837         virq = irq_find_mapping(host, hwirq);
 838         if (virq != NO_IRQ) {
 839                 irq_radix_wrlock(&flags);
 840                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 841                 irq_radix_wrunlock(flags);
 842         }
 843         return virq;
 844 }
 845
 846 unsigned int irq_linear_revmap(struct irq_host *host,
 847                                irq_hw_number_t hwirq)
 848 {
 849         unsigned int *revmap;
 850
 851         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 852
 853         /* Check revmap bounds */
 854         if (unlikely(hwirq >= host->revmap_data.linear.size))
 855                 return irq_find_mapping(host, hwirq);
 856
 857         /* Check if revmap was allocated */
 858         revmap = host->revmap_data.linear.revmap;
 859         if (unlikely(revmap == NULL))
 860                 return irq_find_mapping(host, hwirq);
 861
 862         /* Fill up revmap with slow path if no mapping found */
 863         if (unlikely(revmap[hwirq] == NO_IRQ))
 864                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 865
 866         return revmap[hwirq];
 867 }
 868
 869 unsigned int irq_alloc_virt(struct irq_host *host,
 870                             unsigned int count,
 871                             unsigned int hint)
 872 {
 873         unsigned long flags;
 874         unsigned int i, j, found = NO_IRQ;
 875
 876         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 877                 return NO_IRQ;
 878
 879         spin_lock_irqsave(&irq_big_lock, flags);
 880
 881         /* Use hint for 1 interrupt if any */
 882         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 883             hint < irq_virq_count && irq_map[hint].host == NULL) {
 884                 found = hint;
 885                 goto hint_found;
 886         }
 887
 888         /* Look for count consecutive numbers in the allocatable
 889          * (non-legacy) space
 890          */
 891         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 892                 if (irq_map[i].host != NULL)
 893                         j = 0;
 894                 else
 895                         j++;
 896
 897                 if (j == count) {
 898                         found = i - count + 1;
 899                         break;
 900                 }
 901         }
 902         if (found == NO_IRQ) {
 903                 spin_unlock_irqrestore(&irq_big_lock, flags);
 904                 return NO_IRQ;
 905         }
 906  hint_found:
 907         for (i = found; i < (found + count); i++) {
 908                 irq_map[i].hwirq = host->inval_irq;
 909                 smp_wmb();
 910                 irq_map[i].host = host;
 911         }
 912         spin_unlock_irqrestore(&irq_big_lock, flags);
 913         return found;
 914 }
 915
 916 void irq_free_virt(unsigned int virq, unsigned int count)
 917 {
 918         unsigned long flags;
 919         unsigned int i;
 920
 921         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 922         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 923
 924         spin_lock_irqsave(&irq_big_lock, flags);
 925         for (i = virq; i < (virq + count); i++) {
 926                 struct irq_host *host;
 927
 928                 if (i < NUM_ISA_INTERRUPTS ||
 929                     (virq + count) > irq_virq_count)
 930                         continue;
 931
 932                 host = irq_map[i].host;
 933                 irq_map[i].hwirq = host->inval_irq;
 934                 smp_wmb();
 935                 irq_map[i].host = NULL;
 936         }
 937         spin_unlock_irqrestore(&irq_big_lock, flags);
 938 }
 939
 940 void irq_early_init(void)
 941 {
 942         unsigned int i;
 943
 944         for (i = 0; i < NR_IRQS; i++)
 945                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 946 }
 947
 948 /* We need to create the radix trees late */
 949 static int irq_late_init(void)
 950 {
 951         struct irq_host *h;
 952         unsigned long flags;
 953
 954         irq_radix_wrlock(&flags);
 955         list_for_each_entry(h, &irq_hosts, link) {
 956                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
 957                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
 958         }
 959         irq_radix_wrunlock(flags);
 960
 961         return 0;
 962 }
 963 arch_initcall(irq_late_init);
 964
 965 #endif /* CONFIG_PPC_MERGE */
 966
 967 #ifdef CONFIG_PPC64
 968 static int __init setup_noirqdistrib(char *str)
 969 {
 970         distribute_irqs = 0;
 971         return 1;
 972 }
 973
 974 __setup("noirqdistrib", setup_noirqdistrib);
 975 #endif /* CONFIG_PPC64 */