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   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
  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 notrace 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 notrace 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 notrace void raw_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         }
 147
 148         /*
 149          * if (get_paca()->hard_enabled) return;
 150          * But again we need to take care that gcc gets hard_enabled directly
 151          * via r13, not choose to use an intermediate register, lest we're
 152          * preempted to a different cpu in between the two instructions.
 153          */
 154         if (get_hard_enabled())
 155                 return;
 156
 157         /*
 158          * Need to hard-enable interrupts here.  Since currently disabled,
 159          * no need to take further asm precautions against preemption; but
 160          * use local_paca instead of get_paca() to avoid preemption checking.
 161          */
 162         local_paca->hard_enabled = en;
 163         if ((int)mfspr(SPRN_DEC) < 0)
 164                 mtspr(SPRN_DEC, 1);
 165
 166         /*
 167          * Force the delivery of pending soft-disabled interrupts on PS3.
 168          * Any HV call will have this side effect.
 169          */
 170         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 171                 u64 tmp;
 172                 lv1_get_version_info(&tmp);
 173         }
 174
 175         __hard_irq_enable();
 176 }
 177 EXPORT_SYMBOL(raw_local_irq_restore);
 178 #endif /* CONFIG_PPC64 */
 179
 180 int show_interrupts(struct seq_file *p, void *v)
 181 {
 182         int i = *(loff_t *)v, j;
 183         struct irqaction *action;
 184         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                         unsigned long saved_sp_limit = current->thread.ksp_limit;
 311                         if (handler == NULL)
 312                                 handler = &__do_IRQ;
 313                         irqtp->task = curtp->task;
 314                         irqtp->flags = 0;
 315
 316                         /* Copy the softirq bits in preempt_count so that the
 317                          * softirq checks work in the hardirq context.
 318                          */
 319                         irqtp->preempt_count =
 320                                 (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 321                                 (curtp->preempt_count & SOFTIRQ_MASK);
 322
 323                         current->thread.ksp_limit = (unsigned long)irqtp +
 324                                 _ALIGN_UP(sizeof(struct thread_info), 16);
 325                         call_handle_irq(irq, desc, irqtp, handler);
 326                         current->thread.ksp_limit = saved_sp_limit;
 327                         irqtp->task = NULL;
 328
 329
 330                         /* Set any flag that may have been set on the
 331                          * alternate stack
 332                          */
 333                         if (irqtp->flags)
 334                                 set_bits(irqtp->flags, &curtp->flags);
 335                 } else
 336 #endif
 337                         generic_handle_irq(irq);
 338         } else if (irq != NO_IRQ_IGNORE)
 339                 /* That's not SMP safe ... but who cares ? */
 340                 ppc_spurious_interrupts++;
 341
 342         irq_exit();
 343         set_irq_regs(old_regs);
 344
 345 #ifdef CONFIG_PPC_ISERIES
 346         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 347                         get_lppaca()->int_dword.fields.decr_int) {
 348                 get_lppaca()->int_dword.fields.decr_int = 0;
 349                 /* Signal a fake decrementer interrupt */
 350                 timer_interrupt(regs);
 351         }
 352 #endif
 353 }
 354
 355 void __init init_IRQ(void)
 356 {
 357         if (ppc_md.init_IRQ)
 358                 ppc_md.init_IRQ();
 359
 360         exc_lvl_ctx_init();
 361
 362         irq_ctx_init();
 363 }
 364
 365 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 366 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 367 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 368 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 369
 370 void exc_lvl_ctx_init(void)
 371 {
 372         struct thread_info *tp;
 373         int i;
 374
 375         for_each_possible_cpu(i) {
 376                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 377                 tp = critirq_ctx[i];
 378                 tp->cpu = i;
 379                 tp->preempt_count = 0;
 380
 381 #ifdef CONFIG_BOOKE
 382                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 383                 tp = dbgirq_ctx[i];
 384                 tp->cpu = i;
 385                 tp->preempt_count = 0;
 386
 387                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 388                 tp = mcheckirq_ctx[i];
 389                 tp->cpu = i;
 390                 tp->preempt_count = HARDIRQ_OFFSET;
 391 #endif
 392         }
 393 }
 394 #endif
 395
 396 #ifdef CONFIG_IRQSTACKS
 397 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 398 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 399
 400 void irq_ctx_init(void)
 401 {
 402         struct thread_info *tp;
 403         int i;
 404
 405         for_each_possible_cpu(i) {
 406                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 407                 tp = softirq_ctx[i];
 408                 tp->cpu = i;
 409                 tp->preempt_count = 0;
 410
 411                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 412                 tp = hardirq_ctx[i];
 413                 tp->cpu = i;
 414                 tp->preempt_count = HARDIRQ_OFFSET;
 415         }
 416 }
 417
 418 static inline void do_softirq_onstack(void)
 419 {
 420         struct thread_info *curtp, *irqtp;
 421         unsigned long saved_sp_limit = current->thread.ksp_limit;
 422
 423         curtp = current_thread_info();
 424         irqtp = softirq_ctx[smp_processor_id()];
 425         irqtp->task = curtp->task;
 426         current->thread.ksp_limit = (unsigned long)irqtp +
 427                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 428         call_do_softirq(irqtp);
 429         current->thread.ksp_limit = saved_sp_limit;
 430         irqtp->task = NULL;
 431 }
 432
 433 #else
 434 #define do_softirq_onstack()    __do_softirq()
 435 #endif /* CONFIG_IRQSTACKS */
 436
 437 void do_softirq(void)
 438 {
 439         unsigned long flags;
 440
 441         if (in_interrupt())
 442                 return;
 443
 444         local_irq_save(flags);
 445
 446         if (local_softirq_pending())
 447                 do_softirq_onstack();
 448
 449         local_irq_restore(flags);
 450 }
 451
 452
 453 /*
 454  * IRQ controller and virtual interrupts
 455  */
 456
 457 #ifdef CONFIG_PPC_MERGE
 458
 459 static LIST_HEAD(irq_hosts);
 460 static DEFINE_SPINLOCK(irq_big_lock);
 461 static DEFINE_PER_CPU(unsigned int, irq_radix_reader);
 462 static unsigned int irq_radix_writer;
 463 struct irq_map_entry irq_map[NR_IRQS];
 464 static unsigned int irq_virq_count = NR_IRQS;
 465 static struct irq_host *irq_default_host;
 466
 467 irq_hw_number_t virq_to_hw(unsigned int virq)
 468 {
 469         return irq_map[virq].hwirq;
 470 }
 471 EXPORT_SYMBOL_GPL(virq_to_hw);
 472
 473 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 474 {
 475         return h->of_node != NULL && h->of_node == np;
 476 }
 477
 478 struct irq_host *irq_alloc_host(struct device_node *of_node,
 479                                 unsigned int revmap_type,
 480                                 unsigned int revmap_arg,
 481                                 struct irq_host_ops *ops,
 482                                 irq_hw_number_t inval_irq)
 483 {
 484         struct irq_host *host;
 485         unsigned int size = sizeof(struct irq_host);
 486         unsigned int i;
 487         unsigned int *rmap;
 488         unsigned long flags;
 489
 490         /* Allocate structure and revmap table if using linear mapping */
 491         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 492                 size += revmap_arg * sizeof(unsigned int);
 493         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 494         if (host == NULL)
 495                 return NULL;
 496
 497         /* Fill structure */
 498         host->revmap_type = revmap_type;
 499         host->inval_irq = inval_irq;
 500         host->ops = ops;
 501         host->of_node = of_node_get(of_node);
 502
 503         if (host->ops->match == NULL)
 504                 host->ops->match = default_irq_host_match;
 505
 506         spin_lock_irqsave(&irq_big_lock, flags);
 507
 508         /* If it's a legacy controller, check for duplicates and
 509          * mark it as allocated (we use irq 0 host pointer for that
 510          */
 511         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 512                 if (irq_map[0].host != NULL) {
 513                         spin_unlock_irqrestore(&irq_big_lock, flags);
 514                         /* If we are early boot, we can't free the structure,
 515                          * too bad...
 516                          * this will be fixed once slab is made available early
 517                          * instead of the current cruft
 518                          */
 519                         if (mem_init_done)
 520                                 kfree(host);
 521                         return NULL;
 522                 }
 523                 irq_map[0].host = host;
 524         }
 525
 526         list_add(&host->link, &irq_hosts);
 527         spin_unlock_irqrestore(&irq_big_lock, flags);
 528
 529         /* Additional setups per revmap type */
 530         switch(revmap_type) {
 531         case IRQ_HOST_MAP_LEGACY:
 532                 /* 0 is always the invalid number for legacy */
 533                 host->inval_irq = 0;
 534                 /* setup us as the host for all legacy interrupts */
 535                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 536                         irq_map[i].hwirq = i;
 537                         smp_wmb();
 538                         irq_map[i].host = host;
 539                         smp_wmb();
 540
 541                         /* Clear norequest flags */
 542                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 543
 544                         /* Legacy flags are left to default at this point,
 545                          * one can then use irq_create_mapping() to
 546                          * explicitly change them
 547                          */
 548                         ops->map(host, i, i);
 549                 }
 550                 break;
 551         case IRQ_HOST_MAP_LINEAR:
 552                 rmap = (unsigned int *)(host + 1);
 553                 for (i = 0; i < revmap_arg; i++)
 554                         rmap[i] = NO_IRQ;
 555                 host->revmap_data.linear.size = revmap_arg;
 556                 smp_wmb();
 557                 host->revmap_data.linear.revmap = rmap;
 558                 break;
 559         default:
 560                 break;
 561         }
 562
 563         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 564
 565         return host;
 566 }
 567
 568 struct irq_host *irq_find_host(struct device_node *node)
 569 {
 570         struct irq_host *h, *found = NULL;
 571         unsigned long flags;
 572
 573         /* We might want to match the legacy controller last since
 574          * it might potentially be set to match all interrupts in
 575          * the absence of a device node. This isn't a problem so far
 576          * yet though...
 577          */
 578         spin_lock_irqsave(&irq_big_lock, flags);
 579         list_for_each_entry(h, &irq_hosts, link)
 580                 if (h->ops->match(h, node)) {
 581                         found = h;
 582                         break;
 583                 }
 584         spin_unlock_irqrestore(&irq_big_lock, flags);
 585         return found;
 586 }
 587 EXPORT_SYMBOL_GPL(irq_find_host);
 588
 589 void irq_set_default_host(struct irq_host *host)
 590 {
 591         pr_debug("irq: Default host set to @0x%p\n", host);
 592
 593         irq_default_host = host;
 594 }
 595
 596 void irq_set_virq_count(unsigned int count)
 597 {
 598         pr_debug("irq: Trying to set virq count to %d\n", count);
 599
 600         BUG_ON(count < NUM_ISA_INTERRUPTS);
 601         if (count < NR_IRQS)
 602                 irq_virq_count = count;
 603 }
 604
 605 /* radix tree not lockless safe ! we use a brlock-type mecanism
 606  * for now, until we can use a lockless radix tree
 607  */
 608 static void irq_radix_wrlock(unsigned long *flags)
 609 {
 610         unsigned int cpu, ok;
 611
 612         spin_lock_irqsave(&irq_big_lock, *flags);
 613         irq_radix_writer = 1;
 614         smp_mb();
 615         do {
 616                 barrier();
 617                 ok = 1;
 618                 for_each_possible_cpu(cpu) {
 619                         if (per_cpu(irq_radix_reader, cpu)) {
 620                                 ok = 0;
 621                                 break;
 622                         }
 623                 }
 624                 if (!ok)
 625                         cpu_relax();
 626         } while(!ok);
 627 }
 628
 629 static void irq_radix_wrunlock(unsigned long flags)
 630 {
 631         smp_wmb();
 632         irq_radix_writer = 0;
 633         spin_unlock_irqrestore(&irq_big_lock, flags);
 634 }
 635
 636 static void irq_radix_rdlock(unsigned long *flags)
 637 {
 638         local_irq_save(*flags);
 639         __get_cpu_var(irq_radix_reader) = 1;
 640         smp_mb();
 641         if (likely(irq_radix_writer == 0))
 642                 return;
 643         __get_cpu_var(irq_radix_reader) = 0;
 644         smp_wmb();
 645         spin_lock(&irq_big_lock);
 646         __get_cpu_var(irq_radix_reader) = 1;
 647         spin_unlock(&irq_big_lock);
 648 }
 649
 650 static void irq_radix_rdunlock(unsigned long flags)
 651 {
 652         __get_cpu_var(irq_radix_reader) = 0;
 653         local_irq_restore(flags);
 654 }
 655
 656 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 657                             irq_hw_number_t hwirq)
 658 {
 659         /* Clear IRQ_NOREQUEST flag */
 660         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 661
 662         /* map it */
 663         smp_wmb();
 664         irq_map[virq].hwirq = hwirq;
 665         smp_mb();
 666
 667         if (host->ops->map(host, virq, hwirq)) {
 668                 pr_debug("irq: -> mapping failed, freeing\n");
 669                 irq_free_virt(virq, 1);
 670                 return -1;
 671         }
 672
 673         return 0;
 674 }
 675
 676 unsigned int irq_create_direct_mapping(struct irq_host *host)
 677 {
 678         unsigned int virq;
 679
 680         if (host == NULL)
 681                 host = irq_default_host;
 682
 683         BUG_ON(host == NULL);
 684         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 685
 686         virq = irq_alloc_virt(host, 1, 0);
 687         if (virq == NO_IRQ) {
 688                 pr_debug("irq: create_direct virq allocation failed\n");
 689                 return NO_IRQ;
 690         }
 691
 692         pr_debug("irq: create_direct obtained virq %d\n", virq);
 693
 694         if (irq_setup_virq(host, virq, virq))
 695                 return NO_IRQ;
 696
 697         return virq;
 698 }
 699
 700 unsigned int irq_create_mapping(struct irq_host *host,
 701                                 irq_hw_number_t hwirq)
 702 {
 703         unsigned int virq, hint;
 704
 705         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 706
 707         /* Look for default host if nececssary */
 708         if (host == NULL)
 709                 host = irq_default_host;
 710         if (host == NULL) {
 711                 printk(KERN_WARNING "irq_create_mapping called for"
 712                        " NULL host, hwirq=%lx\n", hwirq);
 713                 WARN_ON(1);
 714                 return NO_IRQ;
 715         }
 716         pr_debug("irq: -> using host @%p\n", host);
 717
 718         /* Check if mapping already exist, if it does, call
 719          * host->ops->map() to update the flags
 720          */
 721         virq = irq_find_mapping(host, hwirq);
 722         if (virq != NO_IRQ) {
 723                 if (host->ops->remap)
 724                         host->ops->remap(host, virq, hwirq);
 725                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 726                 return virq;
 727         }
 728
 729         /* Get a virtual interrupt number */
 730         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 731                 /* Handle legacy */
 732                 virq = (unsigned int)hwirq;
 733                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 734                         return NO_IRQ;
 735                 return virq;
 736         } else {
 737                 /* Allocate a virtual interrupt number */
 738                 hint = hwirq % irq_virq_count;
 739                 virq = irq_alloc_virt(host, 1, hint);
 740                 if (virq == NO_IRQ) {
 741                         pr_debug("irq: -> virq allocation failed\n");
 742                         return NO_IRQ;
 743                 }
 744         }
 745         pr_debug("irq: -> obtained virq %d\n", virq);
 746
 747         if (irq_setup_virq(host, virq, hwirq))
 748                 return NO_IRQ;
 749
 750         return virq;
 751 }
 752 EXPORT_SYMBOL_GPL(irq_create_mapping);
 753
 754 unsigned int irq_create_of_mapping(struct device_node *controller,
 755                                    u32 *intspec, unsigned int intsize)
 756 {
 757         struct irq_host *host;
 758         irq_hw_number_t hwirq;
 759         unsigned int type = IRQ_TYPE_NONE;
 760         unsigned int virq;
 761
 762         if (controller == NULL)
 763                 host = irq_default_host;
 764         else
 765                 host = irq_find_host(controller);
 766         if (host == NULL) {
 767                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 768                        controller->full_name);
 769                 return NO_IRQ;
 770         }
 771
 772         /* If host has no translation, then we assume interrupt line */
 773         if (host->ops->xlate == NULL)
 774                 hwirq = intspec[0];
 775         else {
 776                 if (host->ops->xlate(host, controller, intspec, intsize,
 777                                      &hwirq, &type))
 778                         return NO_IRQ;
 779         }
 780
 781         /* Create mapping */
 782         virq = irq_create_mapping(host, hwirq);
 783         if (virq == NO_IRQ)
 784                 return virq;
 785
 786         /* Set type if specified and different than the current one */
 787         if (type != IRQ_TYPE_NONE &&
 788             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 789                 set_irq_type(virq, type);
 790         return virq;
 791 }
 792 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 793
 794 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 795 {
 796         struct of_irq oirq;
 797
 798         if (of_irq_map_one(dev, index, &oirq))
 799                 return NO_IRQ;
 800
 801         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 802                                      oirq.size);
 803 }
 804 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 805
 806 void irq_dispose_mapping(unsigned int virq)
 807 {
 808         struct irq_host *host;
 809         irq_hw_number_t hwirq;
 810         unsigned long flags;
 811
 812         if (virq == NO_IRQ)
 813                 return;
 814
 815         host = irq_map[virq].host;
 816         WARN_ON (host == NULL);
 817         if (host == NULL)
 818                 return;
 819
 820         /* Never unmap legacy interrupts */
 821         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 822                 return;
 823
 824         /* remove chip and handler */
 825         set_irq_chip_and_handler(virq, NULL, NULL);
 826
 827         /* Make sure it's completed */
 828         synchronize_irq(virq);
 829
 830         /* Tell the PIC about it */
 831         if (host->ops->unmap)
 832                 host->ops->unmap(host, virq);
 833         smp_mb();
 834
 835         /* Clear reverse map */
 836         hwirq = irq_map[virq].hwirq;
 837         switch(host->revmap_type) {
 838         case IRQ_HOST_MAP_LINEAR:
 839                 if (hwirq < host->revmap_data.linear.size)
 840                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 841                 break;
 842         case IRQ_HOST_MAP_TREE:
 843                 /* Check if radix tree allocated yet */
 844                 if (host->revmap_data.tree.gfp_mask == 0)
 845                         break;
 846                 irq_radix_wrlock(&flags);
 847                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 848                 irq_radix_wrunlock(flags);
 849                 break;
 850         }
 851
 852         /* Destroy map */
 853         smp_mb();
 854         irq_map[virq].hwirq = host->inval_irq;
 855
 856         /* Set some flags */
 857         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 858
 859         /* Free it */
 860         irq_free_virt(virq, 1);
 861 }
 862 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 863
 864 unsigned int irq_find_mapping(struct irq_host *host,
 865                               irq_hw_number_t hwirq)
 866 {
 867         unsigned int i;
 868         unsigned int hint = hwirq % irq_virq_count;
 869
 870         /* Look for default host if nececssary */
 871         if (host == NULL)
 872                 host = irq_default_host;
 873         if (host == NULL)
 874                 return NO_IRQ;
 875
 876         /* legacy -> bail early */
 877         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 878                 return hwirq;
 879
 880         /* Slow path does a linear search of the map */
 881         if (hint < NUM_ISA_INTERRUPTS)
 882                 hint = NUM_ISA_INTERRUPTS;
 883         i = hint;
 884         do  {
 885                 if (irq_map[i].host == host &&
 886                     irq_map[i].hwirq == hwirq)
 887                         return i;
 888                 i++;
 889                 if (i >= irq_virq_count)
 890                         i = NUM_ISA_INTERRUPTS;
 891         } while(i != hint);
 892         return NO_IRQ;
 893 }
 894 EXPORT_SYMBOL_GPL(irq_find_mapping);
 895
 896
 897 unsigned int irq_radix_revmap(struct irq_host *host,
 898                               irq_hw_number_t hwirq)
 899 {
 900         struct radix_tree_root *tree;
 901         struct irq_map_entry *ptr;
 902         unsigned int virq;
 903         unsigned long flags;
 904
 905         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 906
 907         /* Check if the radix tree exist yet. We test the value of
 908          * the gfp_mask for that. Sneaky but saves another int in the
 909          * structure. If not, we fallback to slow mode
 910          */
 911         tree = &host->revmap_data.tree;
 912         if (tree->gfp_mask == 0)
 913                 return irq_find_mapping(host, hwirq);
 914
 915         /* Now try to resolve */
 916         irq_radix_rdlock(&flags);
 917         ptr = radix_tree_lookup(tree, hwirq);
 918         irq_radix_rdunlock(flags);
 919
 920         /* Found it, return */
 921         if (ptr) {
 922                 virq = ptr - irq_map;
 923                 return virq;
 924         }
 925
 926         /* If not there, try to insert it */
 927         virq = irq_find_mapping(host, hwirq);
 928         if (virq != NO_IRQ) {
 929                 irq_radix_wrlock(&flags);
 930                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 931                 irq_radix_wrunlock(flags);
 932         }
 933         return virq;
 934 }
 935
 936 unsigned int irq_linear_revmap(struct irq_host *host,
 937                                irq_hw_number_t hwirq)
 938 {
 939         unsigned int *revmap;
 940
 941         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 942
 943         /* Check revmap bounds */
 944         if (unlikely(hwirq >= host->revmap_data.linear.size))
 945                 return irq_find_mapping(host, hwirq);
 946
 947         /* Check if revmap was allocated */
 948         revmap = host->revmap_data.linear.revmap;
 949         if (unlikely(revmap == NULL))
 950                 return irq_find_mapping(host, hwirq);
 951
 952         /* Fill up revmap with slow path if no mapping found */
 953         if (unlikely(revmap[hwirq] == NO_IRQ))
 954                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 955
 956         return revmap[hwirq];
 957 }
 958
 959 unsigned int irq_alloc_virt(struct irq_host *host,
 960                             unsigned int count,
 961                             unsigned int hint)
 962 {
 963         unsigned long flags;
 964         unsigned int i, j, found = NO_IRQ;
 965
 966         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 967                 return NO_IRQ;
 968
 969         spin_lock_irqsave(&irq_big_lock, flags);
 970
 971         /* Use hint for 1 interrupt if any */
 972         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 973             hint < irq_virq_count && irq_map[hint].host == NULL) {
 974                 found = hint;
 975                 goto hint_found;
 976         }
 977
 978         /* Look for count consecutive numbers in the allocatable
 979          * (non-legacy) space
 980          */
 981         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 982                 if (irq_map[i].host != NULL)
 983                         j = 0;
 984                 else
 985                         j++;
 986
 987                 if (j == count) {
 988                         found = i - count + 1;
 989                         break;
 990                 }
 991         }
 992         if (found == NO_IRQ) {
 993                 spin_unlock_irqrestore(&irq_big_lock, flags);
 994                 return NO_IRQ;
 995         }
 996  hint_found:
 997         for (i = found; i < (found + count); i++) {
 998                 irq_map[i].hwirq = host->inval_irq;
 999                 smp_wmb();
1000                 irq_map[i].host = host;
1001         }
1002         spin_unlock_irqrestore(&irq_big_lock, flags);
1003         return found;
1004 }
1005
1006 void irq_free_virt(unsigned int virq, unsigned int count)
1007 {
1008         unsigned long flags;
1009         unsigned int i;
1010
1011         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1012         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1013
1014         spin_lock_irqsave(&irq_big_lock, flags);
1015         for (i = virq; i < (virq + count); i++) {
1016                 struct irq_host *host;
1017
1018                 if (i < NUM_ISA_INTERRUPTS ||
1019                     (virq + count) > irq_virq_count)
1020                         continue;
1021
1022                 host = irq_map[i].host;
1023                 irq_map[i].hwirq = host->inval_irq;
1024                 smp_wmb();
1025                 irq_map[i].host = NULL;
1026         }
1027         spin_unlock_irqrestore(&irq_big_lock, flags);
1028 }
1029
1030 void irq_early_init(void)
1031 {
1032         unsigned int i;
1033
1034         for (i = 0; i < NR_IRQS; i++)
1035                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
1036 }
1037
1038 /* We need to create the radix trees late */
1039 static int irq_late_init(void)
1040 {
1041         struct irq_host *h;
1042         unsigned long flags;
1043
1044         irq_radix_wrlock(&flags);
1045         list_for_each_entry(h, &irq_hosts, link) {
1046                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1047                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
1048         }
1049         irq_radix_wrunlock(flags);
1050
1051         return 0;
1052 }
1053 arch_initcall(irq_late_init);
1054
1055 #ifdef CONFIG_VIRQ_DEBUG
1056 static int virq_debug_show(struct seq_file *m, void *private)
1057 {
1058         unsigned long flags;
1059         irq_desc_t *desc;
1060         const char *p;
1061         char none[] = "none";
1062         int i;
1063
1064         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1065                       "chip name", "host name");
1066
1067         for (i = 1; i < NR_IRQS; i++) {
1068                 desc = get_irq_desc(i);
1069                 spin_lock_irqsave(&desc->lock, flags);
1070
1071                 if (desc->action && desc->action->handler) {
1072                         seq_printf(m, "%5d  ", i);
1073                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1074
1075                         if (desc->chip && desc->chip->typename)
1076                                 p = desc->chip->typename;
1077                         else
1078                                 p = none;
1079                         seq_printf(m, "%-15s  ", p);
1080
1081                         if (irq_map[i].host && irq_map[i].host->of_node)
1082                                 p = irq_map[i].host->of_node->full_name;
1083                         else
1084                                 p = none;
1085                         seq_printf(m, "%s\n", p);
1086                 }
1087
1088                 spin_unlock_irqrestore(&desc->lock, flags);
1089         }
1090
1091         return 0;
1092 }
1093
1094 static int virq_debug_open(struct inode *inode, struct file *file)
1095 {
1096         return single_open(file, virq_debug_show, inode->i_private);
1097 }
1098
1099 static const struct file_operations virq_debug_fops = {
1100         .open = virq_debug_open,
1101         .read = seq_read,
1102         .llseek = seq_lseek,
1103         .release = single_release,
1104 };
1105
1106 static int __init irq_debugfs_init(void)
1107 {
1108         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1109                                  NULL, &virq_debug_fops) == NULL)
1110                 return -ENOMEM;
1111
1112         return 0;
1113 }
1114 __initcall(irq_debugfs_init);
1115 #endif /* CONFIG_VIRQ_DEBUG */
1116
1117 #endif /* CONFIG_PPC_MERGE */
1118
1119 #ifdef CONFIG_PPC64
1120 static int __init setup_noirqdistrib(char *str)
1121 {
1122         distribute_irqs = 0;
1123         return 1;
1124 }
1125
1126 __setup("noirqdistrib", setup_noirqdistrib);
1127 #endif /* CONFIG_PPC64 */