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
  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_PPC_ISERIES
  67 #include <asm/paca.h>
  68 #endif
  69
  70 int __irq_offset_value;
  71 static int ppc_spurious_interrupts;
  72
  73 #ifdef CONFIG_PPC32
  74 EXPORT_SYMBOL(__irq_offset_value);
  75 atomic_t ppc_n_lost_interrupts;
  76
  77 #ifndef CONFIG_PPC_MERGE
  78 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
  79 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
  80 #endif
  81
  82 #ifdef CONFIG_TAU_INT
  83 extern int tau_initialized;
  84 extern int tau_interrupts(int);
  85 #endif
  86 #endif /* CONFIG_PPC32 */
  87
  88 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
  89 extern atomic_t ipi_recv;
  90 extern atomic_t ipi_sent;
  91 #endif
  92
  93 #ifdef CONFIG_PPC64
  94 EXPORT_SYMBOL(irq_desc);
  95
  96 int distribute_irqs = 1;
  97 #endif /* CONFIG_PPC64 */
  98
  99 int show_interrupts(struct seq_file *p, void *v)
 100 {
 101         int i = *(loff_t *)v, j;
 102         struct irqaction *action;
 103         irq_desc_t *desc;
 104         unsigned long flags;
 105
 106         if (i == 0) {
 107                 seq_puts(p, "           ");
 108                 for_each_online_cpu(j)
 109                         seq_printf(p, "CPU%d       ", j);
 110                 seq_putc(p, '\n');
 111         }
 112
 113         if (i < NR_IRQS) {
 114                 desc = get_irq_desc(i);
 115                 spin_lock_irqsave(&desc->lock, flags);
 116                 action = desc->action;
 117                 if (!action || !action->handler)
 118                         goto skip;
 119                 seq_printf(p, "%3d: ", i);
 120 #ifdef CONFIG_SMP
 121                 for_each_online_cpu(j)
 122                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 123 #else
 124                 seq_printf(p, "%10u ", kstat_irqs(i));
 125 #endif /* CONFIG_SMP */
 126                 if (desc->chip)
 127                         seq_printf(p, " %s ", desc->chip->typename);
 128                 else
 129                         seq_puts(p, "  None      ");
 130                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 131                 seq_printf(p, "    %s", action->name);
 132                 for (action = action->next; action; action = action->next)
 133                         seq_printf(p, ", %s", action->name);
 134                 seq_putc(p, '\n');
 135 skip:
 136                 spin_unlock_irqrestore(&desc->lock, flags);
 137         } else if (i == NR_IRQS) {
 138 #ifdef CONFIG_PPC32
 139 #ifdef CONFIG_TAU_INT
 140                 if (tau_initialized){
 141                         seq_puts(p, "TAU: ");
 142                         for_each_online_cpu(j)
 143                                 seq_printf(p, "%10u ", tau_interrupts(j));
 144                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 145                 }
 146 #endif
 147 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
 148                 /* should this be per processor send/receive? */
 149                 seq_printf(p, "IPI (recv/sent): %10u/%u\n",
 150                                 atomic_read(&ipi_recv), atomic_read(&ipi_sent));
 151 #endif
 152 #endif /* CONFIG_PPC32 */
 153                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 154         }
 155         return 0;
 156 }
 157
 158 #ifdef CONFIG_HOTPLUG_CPU
 159 void fixup_irqs(cpumask_t map)
 160 {
 161         unsigned int irq;
 162         static int warned;
 163
 164         for_each_irq(irq) {
 165                 cpumask_t mask;
 166
 167                 if (irq_desc[irq].status & IRQ_PER_CPU)
 168                         continue;
 169
 170                 cpus_and(mask, irq_desc[irq].affinity, map);
 171                 if (any_online_cpu(mask) == NR_CPUS) {
 172                         printk("Breaking affinity for irq %i\n", irq);
 173                         mask = map;
 174                 }
 175                 if (irq_desc[irq].chip->set_affinity)
 176                         irq_desc[irq].chip->set_affinity(irq, mask);
 177                 else if (irq_desc[irq].action && !(warned++))
 178                         printk("Cannot set affinity for irq %i\n", irq);
 179         }
 180
 181         local_irq_enable();
 182         mdelay(1);
 183         local_irq_disable();
 184 }
 185 #endif
 186
 187 void do_IRQ(struct pt_regs *regs)
 188 {
 189         unsigned int irq;
 190 #ifdef CONFIG_IRQSTACKS
 191         struct thread_info *curtp, *irqtp;
 192 #endif
 193
 194         irq_enter();
 195
 196 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 197         /* Debugging check for stack overflow: is there less than 2KB free? */
 198         {
 199                 long sp;
 200
 201                 sp = __get_SP() & (THREAD_SIZE-1);
 202
 203                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 204                         printk("do_IRQ: stack overflow: %ld\n",
 205                                 sp - sizeof(struct thread_info));
 206                         dump_stack();
 207                 }
 208         }
 209 #endif
 210
 211         /*
 212          * Every platform is required to implement ppc_md.get_irq.
 213          * This function will either return an irq number or -1 to
 214          * indicate there are no more pending.
 215          * The value -2 is for buggy hardware and means that this IRQ
 216          * has already been handled. -- Tom
 217          */
 218         irq = ppc_md.get_irq(regs);
 219
 220         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
 221 #ifdef CONFIG_IRQSTACKS
 222                 /* Switch to the irq stack to handle this */
 223                 curtp = current_thread_info();
 224                 irqtp = hardirq_ctx[smp_processor_id()];
 225                 if (curtp != irqtp) {
 226                         struct irq_desc *desc = irq_desc + irq;
 227                         void *handler = desc->handle_irq;
 228                         if (handler == NULL)
 229                                 handler = &__do_IRQ;
 230                         irqtp->task = curtp->task;
 231                         irqtp->flags = 0;
 232                         call_handle_irq(irq, desc, regs, irqtp, handler);
 233                         irqtp->task = NULL;
 234                         if (irqtp->flags)
 235                                 set_bits(irqtp->flags, &curtp->flags);
 236                 } else
 237 #endif
 238                         generic_handle_irq(irq, regs);
 239         } else if (irq != NO_IRQ_IGNORE)
 240                 /* That's not SMP safe ... but who cares ? */
 241                 ppc_spurious_interrupts++;
 242
 243         irq_exit();
 244
 245 #ifdef CONFIG_PPC_ISERIES
 246         if (get_lppaca()->int_dword.fields.decr_int) {
 247                 get_lppaca()->int_dword.fields.decr_int = 0;
 248                 /* Signal a fake decrementer interrupt */
 249                 timer_interrupt(regs);
 250         }
 251 #endif
 252 }
 253
 254 void __init init_IRQ(void)
 255 {
 256         ppc_md.init_IRQ();
 257 #ifdef CONFIG_PPC64
 258         irq_ctx_init();
 259 #endif
 260 }
 261
 262
 263 #ifdef CONFIG_IRQSTACKS
 264 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 265 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 266
 267 void irq_ctx_init(void)
 268 {
 269         struct thread_info *tp;
 270         int i;
 271
 272         for_each_possible_cpu(i) {
 273                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 274                 tp = softirq_ctx[i];
 275                 tp->cpu = i;
 276                 tp->preempt_count = SOFTIRQ_OFFSET;
 277
 278                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 279                 tp = hardirq_ctx[i];
 280                 tp->cpu = i;
 281                 tp->preempt_count = HARDIRQ_OFFSET;
 282         }
 283 }
 284
 285 static inline void do_softirq_onstack(void)
 286 {
 287         struct thread_info *curtp, *irqtp;
 288
 289         curtp = current_thread_info();
 290         irqtp = softirq_ctx[smp_processor_id()];
 291         irqtp->task = curtp->task;
 292         call_do_softirq(irqtp);
 293         irqtp->task = NULL;
 294 }
 295
 296 #else
 297 #define do_softirq_onstack()    __do_softirq()
 298 #endif /* CONFIG_IRQSTACKS */
 299
 300 void do_softirq(void)
 301 {
 302         unsigned long flags;
 303
 304         if (in_interrupt())
 305                 return;
 306
 307         local_irq_save(flags);
 308
 309         if (local_softirq_pending())
 310                 do_softirq_onstack();
 311
 312         local_irq_restore(flags);
 313 }
 314 EXPORT_SYMBOL(do_softirq);
 315
 316
 317 /*
 318  * IRQ controller and virtual interrupts
 319  */
 320
 321 #ifdef CONFIG_PPC_MERGE
 322
 323 static LIST_HEAD(irq_hosts);
 324 static spinlock_t irq_big_lock = SPIN_LOCK_UNLOCKED;
 325
 326 struct irq_map_entry irq_map[NR_IRQS];
 327 static unsigned int irq_virq_count = NR_IRQS;
 328 static struct irq_host *irq_default_host;
 329
 330 struct irq_host *irq_alloc_host(unsigned int revmap_type,
 331                                 unsigned int revmap_arg,
 332                                 struct irq_host_ops *ops,
 333                                 irq_hw_number_t inval_irq)
 334 {
 335         struct irq_host *host;
 336         unsigned int size = sizeof(struct irq_host);
 337         unsigned int i;
 338         unsigned int *rmap;
 339         unsigned long flags;
 340
 341         /* Allocate structure and revmap table if using linear mapping */
 342         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 343                 size += revmap_arg * sizeof(unsigned int);
 344         if (mem_init_done)
 345                 host = kzalloc(size, GFP_KERNEL);
 346         else {
 347                 host = alloc_bootmem(size);
 348                 if (host)
 349                         memset(host, 0, size);
 350         }
 351         if (host == NULL)
 352                 return NULL;
 353
 354         /* Fill structure */
 355         host->revmap_type = revmap_type;
 356         host->inval_irq = inval_irq;
 357         host->ops = ops;
 358
 359         spin_lock_irqsave(&irq_big_lock, flags);
 360
 361         /* If it's a legacy controller, check for duplicates and
 362          * mark it as allocated (we use irq 0 host pointer for that
 363          */
 364         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 365                 if (irq_map[0].host != NULL) {
 366                         spin_unlock_irqrestore(&irq_big_lock, flags);
 367                         /* If we are early boot, we can't free the structure,
 368                          * too bad...
 369                          * this will be fixed once slab is made available early
 370                          * instead of the current cruft
 371                          */
 372                         if (mem_init_done)
 373                                 kfree(host);
 374                         return NULL;
 375                 }
 376                 irq_map[0].host = host;
 377         }
 378
 379         list_add(&host->link, &irq_hosts);
 380         spin_unlock_irqrestore(&irq_big_lock, flags);
 381
 382         /* Additional setups per revmap type */
 383         switch(revmap_type) {
 384         case IRQ_HOST_MAP_LEGACY:
 385                 /* 0 is always the invalid number for legacy */
 386                 host->inval_irq = 0;
 387                 /* setup us as the host for all legacy interrupts */
 388                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 389                         irq_map[i].hwirq = 0;
 390                         smp_wmb();
 391                         irq_map[i].host = host;
 392                         smp_wmb();
 393
 394                         /* Clear some flags */
 395                         get_irq_desc(i)->status
 396                                 &= ~(IRQ_NOREQUEST | IRQ_LEVEL);
 397
 398                         /* Legacy flags are left to default at this point,
 399                          * one can then use irq_create_mapping() to
 400                          * explicitely change them
 401                          */
 402                         ops->map(host, i, i, 0);
 403                 }
 404                 break;
 405         case IRQ_HOST_MAP_LINEAR:
 406                 rmap = (unsigned int *)(host + 1);
 407                 for (i = 0; i < revmap_arg; i++)
 408                         rmap[i] = IRQ_NONE;
 409                 host->revmap_data.linear.size = revmap_arg;
 410                 smp_wmb();
 411                 host->revmap_data.linear.revmap = rmap;
 412                 break;
 413         default:
 414                 break;
 415         }
 416
 417         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 418
 419         return host;
 420 }
 421
 422 struct irq_host *irq_find_host(struct device_node *node)
 423 {
 424         struct irq_host *h, *found = NULL;
 425         unsigned long flags;
 426
 427         /* We might want to match the legacy controller last since
 428          * it might potentially be set to match all interrupts in
 429          * the absence of a device node. This isn't a problem so far
 430          * yet though...
 431          */
 432         spin_lock_irqsave(&irq_big_lock, flags);
 433         list_for_each_entry(h, &irq_hosts, link)
 434                 if (h->ops->match == NULL || h->ops->match(h, node)) {
 435                         found = h;
 436                         break;
 437                 }
 438         spin_unlock_irqrestore(&irq_big_lock, flags);
 439         return found;
 440 }
 441 EXPORT_SYMBOL_GPL(irq_find_host);
 442
 443 void irq_set_default_host(struct irq_host *host)
 444 {
 445         pr_debug("irq: Default host set to @0x%p\n", host);
 446
 447         irq_default_host = host;
 448 }
 449
 450 void irq_set_virq_count(unsigned int count)
 451 {
 452         pr_debug("irq: Trying to set virq count to %d\n", count);
 453
 454         BUG_ON(count < NUM_ISA_INTERRUPTS);
 455         if (count < NR_IRQS)
 456                 irq_virq_count = count;
 457 }
 458
 459 unsigned int irq_create_mapping(struct irq_host *host,
 460                                 irq_hw_number_t hwirq,
 461                                 unsigned int flags)
 462 {
 463         unsigned int virq, hint;
 464
 465         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx, 0x%x)\n",
 466                  host, hwirq, flags);
 467
 468         /* Look for default host if nececssary */
 469         if (host == NULL)
 470                 host = irq_default_host;
 471         if (host == NULL) {
 472                 printk(KERN_WARNING "irq_create_mapping called for"
 473                        " NULL host, hwirq=%lx\n", hwirq);
 474                 WARN_ON(1);
 475                 return NO_IRQ;
 476         }
 477         pr_debug("irq: -> using host @%p\n", host);
 478
 479         /* Check if mapping already exist, if it does, call
 480          * host->ops->map() to update the flags
 481          */
 482         virq = irq_find_mapping(host, hwirq);
 483         if (virq != IRQ_NONE) {
 484                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 485                 host->ops->map(host, virq, hwirq, flags);
 486                 return virq;
 487         }
 488
 489         /* Get a virtual interrupt number */
 490         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 491                 /* Handle legacy */
 492                 virq = (unsigned int)hwirq;
 493                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 494                         return NO_IRQ;
 495                 return virq;
 496         } else {
 497                 /* Allocate a virtual interrupt number */
 498                 hint = hwirq % irq_virq_count;
 499                 virq = irq_alloc_virt(host, 1, hint);
 500                 if (virq == NO_IRQ) {
 501                         pr_debug("irq: -> virq allocation failed\n");
 502                         return NO_IRQ;
 503                 }
 504         }
 505         pr_debug("irq: -> obtained virq %d\n", virq);
 506
 507         /* Clear some flags */
 508         get_irq_desc(virq)->status &= ~(IRQ_NOREQUEST | IRQ_LEVEL);
 509
 510         /* map it */
 511         if (host->ops->map(host, virq, hwirq, flags)) {
 512                 pr_debug("irq: -> mapping failed, freeing\n");
 513                 irq_free_virt(virq, 1);
 514                 return NO_IRQ;
 515         }
 516         smp_wmb();
 517         irq_map[virq].hwirq = hwirq;
 518         smp_mb();
 519         return virq;
 520 }
 521 EXPORT_SYMBOL_GPL(irq_create_mapping);
 522
 523 extern unsigned int irq_create_of_mapping(struct device_node *controller,
 524                                           u32 *intspec, unsigned int intsize)
 525 {
 526         struct irq_host *host;
 527         irq_hw_number_t hwirq;
 528         unsigned int flags = IRQ_TYPE_NONE;
 529
 530         if (controller == NULL)
 531                 host = irq_default_host;
 532         else
 533                 host = irq_find_host(controller);
 534         if (host == NULL)
 535                 return NO_IRQ;
 536
 537         /* If host has no translation, then we assume interrupt line */
 538         if (host->ops->xlate == NULL)
 539                 hwirq = intspec[0];
 540         else {
 541                 if (host->ops->xlate(host, controller, intspec, intsize,
 542                                      &hwirq, &flags))
 543                         return NO_IRQ;
 544         }
 545
 546         return irq_create_mapping(host, hwirq, flags);
 547 }
 548 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 549
 550 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 551 {
 552         struct of_irq oirq;
 553
 554         if (of_irq_map_one(dev, index, &oirq))
 555                 return NO_IRQ;
 556
 557         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 558                                      oirq.size);
 559 }
 560 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 561
 562 void irq_dispose_mapping(unsigned int virq)
 563 {
 564         struct irq_host *host = irq_map[virq].host;
 565         irq_hw_number_t hwirq;
 566         unsigned long flags;
 567
 568         WARN_ON (host == NULL);
 569         if (host == NULL)
 570                 return;
 571
 572         /* Never unmap legacy interrupts */
 573         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 574                 return;
 575
 576         /* remove chip and handler */
 577         set_irq_chip_and_handler(virq, NULL, NULL);
 578
 579         /* Make sure it's completed */
 580         synchronize_irq(virq);
 581
 582         /* Tell the PIC about it */
 583         if (host->ops->unmap)
 584                 host->ops->unmap(host, virq);
 585         smp_mb();
 586
 587         /* Clear reverse map */
 588         hwirq = irq_map[virq].hwirq;
 589         switch(host->revmap_type) {
 590         case IRQ_HOST_MAP_LINEAR:
 591                 if (hwirq < host->revmap_data.linear.size)
 592                         host->revmap_data.linear.revmap[hwirq] = IRQ_NONE;
 593                 break;
 594         case IRQ_HOST_MAP_TREE:
 595                 /* Check if radix tree allocated yet */
 596                 if (host->revmap_data.tree.gfp_mask == 0)
 597                         break;
 598                 /* XXX radix tree not safe ! remove lock whem it becomes safe
 599                  * and use some RCU sync to make sure everything is ok before we
 600                  * can re-use that map entry
 601                  */
 602                 spin_lock_irqsave(&irq_big_lock, flags);
 603                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 604                 spin_unlock_irqrestore(&irq_big_lock, flags);
 605                 break;
 606         }
 607
 608         /* Destroy map */
 609         smp_mb();
 610         irq_map[virq].hwirq = host->inval_irq;
 611
 612         /* Set some flags */
 613         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 614
 615         /* Free it */
 616         irq_free_virt(virq, 1);
 617 }
 618 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 619
 620 unsigned int irq_find_mapping(struct irq_host *host,
 621                               irq_hw_number_t hwirq)
 622 {
 623         unsigned int i;
 624         unsigned int hint = hwirq % irq_virq_count;
 625
 626         /* Look for default host if nececssary */
 627         if (host == NULL)
 628                 host = irq_default_host;
 629         if (host == NULL)
 630                 return NO_IRQ;
 631
 632         /* legacy -> bail early */
 633         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 634                 return hwirq;
 635
 636         /* Slow path does a linear search of the map */
 637         if (hint < NUM_ISA_INTERRUPTS)
 638                 hint = NUM_ISA_INTERRUPTS;
 639         i = hint;
 640         do  {
 641                 if (irq_map[i].host == host &&
 642                     irq_map[i].hwirq == hwirq)
 643                         return i;
 644                 i++;
 645                 if (i >= irq_virq_count)
 646                         i = NUM_ISA_INTERRUPTS;
 647         } while(i != hint);
 648         return NO_IRQ;
 649 }
 650 EXPORT_SYMBOL_GPL(irq_find_mapping);
 651
 652
 653 unsigned int irq_radix_revmap(struct irq_host *host,
 654                               irq_hw_number_t hwirq)
 655 {
 656         struct radix_tree_root *tree;
 657         struct irq_map_entry *ptr;
 658         unsigned int virq;
 659         unsigned long flags;
 660
 661         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 662
 663         /* Check if the radix tree exist yet. We test the value of
 664          * the gfp_mask for that. Sneaky but saves another int in the
 665          * structure. If not, we fallback to slow mode
 666          */
 667         tree = &host->revmap_data.tree;
 668         if (tree->gfp_mask == 0)
 669                 return irq_find_mapping(host, hwirq);
 670
 671         /* XXX Current radix trees are NOT SMP safe !!! Remove that lock
 672          * when that is fixed (when Nick's patch gets in
 673          */
 674         spin_lock_irqsave(&irq_big_lock, flags);
 675
 676         /* Now try to resolve */
 677         ptr = radix_tree_lookup(tree, hwirq);
 678         /* Found it, return */
 679         if (ptr) {
 680                 virq = ptr - irq_map;
 681                 goto bail;
 682         }
 683
 684         /* If not there, try to insert it */
 685         virq = irq_find_mapping(host, hwirq);
 686         if (virq != NO_IRQ)
 687                 radix_tree_insert(tree, virq, &irq_map[virq]);
 688  bail:
 689         spin_unlock_irqrestore(&irq_big_lock, flags);
 690         return virq;
 691 }
 692
 693 unsigned int irq_linear_revmap(struct irq_host *host,
 694                                irq_hw_number_t hwirq)
 695 {
 696         unsigned int *revmap;
 697
 698         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 699
 700         /* Check revmap bounds */
 701         if (unlikely(hwirq >= host->revmap_data.linear.size))
 702                 return irq_find_mapping(host, hwirq);
 703
 704         /* Check if revmap was allocated */
 705         revmap = host->revmap_data.linear.revmap;
 706         if (unlikely(revmap == NULL))
 707                 return irq_find_mapping(host, hwirq);
 708
 709         /* Fill up revmap with slow path if no mapping found */
 710         if (unlikely(revmap[hwirq] == NO_IRQ))
 711                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 712
 713         return revmap[hwirq];
 714 }
 715
 716 unsigned int irq_alloc_virt(struct irq_host *host,
 717                             unsigned int count,
 718                             unsigned int hint)
 719 {
 720         unsigned long flags;
 721         unsigned int i, j, found = NO_IRQ;
 722         unsigned int limit = irq_virq_count - count;
 723
 724         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 725                 return NO_IRQ;
 726
 727         spin_lock_irqsave(&irq_big_lock, flags);
 728
 729         /* Use hint for 1 interrupt if any */
 730         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 731             hint < irq_virq_count && irq_map[hint].host == NULL) {
 732                 found = hint;
 733                 goto hint_found;
 734         }
 735
 736         /* Look for count consecutive numbers in the allocatable
 737          * (non-legacy) space
 738          */
 739         for (i = NUM_ISA_INTERRUPTS; i <= limit; ) {
 740                 for (j = i; j < (i + count); j++)
 741                         if (irq_map[j].host != NULL) {
 742                                 i = j + 1;
 743                                 continue;
 744                         }
 745                 found = i;
 746                 break;
 747         }
 748         if (found == NO_IRQ) {
 749                 spin_unlock_irqrestore(&irq_big_lock, flags);
 750                 return NO_IRQ;
 751         }
 752  hint_found:
 753         for (i = found; i < (found + count); i++) {
 754                 irq_map[i].hwirq = host->inval_irq;
 755                 smp_wmb();
 756                 irq_map[i].host = host;
 757         }
 758         spin_unlock_irqrestore(&irq_big_lock, flags);
 759         return found;
 760 }
 761
 762 void irq_free_virt(unsigned int virq, unsigned int count)
 763 {
 764         unsigned long flags;
 765         unsigned int i;
 766
 767         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 768         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 769
 770         spin_lock_irqsave(&irq_big_lock, flags);
 771         for (i = virq; i < (virq + count); i++) {
 772                 struct irq_host *host;
 773
 774                 if (i < NUM_ISA_INTERRUPTS ||
 775                     (virq + count) > irq_virq_count)
 776                         continue;
 777
 778                 host = irq_map[i].host;
 779                 irq_map[i].hwirq = host->inval_irq;
 780                 smp_wmb();
 781                 irq_map[i].host = NULL;
 782         }
 783         spin_unlock_irqrestore(&irq_big_lock, flags);
 784 }
 785
 786 void irq_early_init(void)
 787 {
 788         unsigned int i;
 789
 790         for (i = 0; i < NR_IRQS; i++)
 791                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 792 }
 793
 794 /* We need to create the radix trees late */
 795 static int irq_late_init(void)
 796 {
 797         struct irq_host *h;
 798         unsigned long flags;
 799
 800         spin_lock_irqsave(&irq_big_lock, flags);
 801         list_for_each_entry(h, &irq_hosts, link) {
 802                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
 803                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
 804         }
 805         spin_unlock_irqrestore(&irq_big_lock, flags);
 806
 807         return 0;
 808 }
 809 arch_initcall(irq_late_init);
 810
 811 #endif /* CONFIG_PPC_MERGE */
 812
 813 #ifdef CONFIG_PCI_MSI
 814 int pci_enable_msi(struct pci_dev * pdev)
 815 {
 816         if (ppc_md.enable_msi)
 817                 return ppc_md.enable_msi(pdev);
 818         else
 819                 return -1;
 820 }
 821
 822 void pci_disable_msi(struct pci_dev * pdev)
 823 {
 824         if (ppc_md.disable_msi)
 825                 ppc_md.disable_msi(pdev);
 826 }
 827
 828 void pci_scan_msi_device(struct pci_dev *dev) {}
 829 int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) {return -1;}
 830 void pci_disable_msix(struct pci_dev *dev) {}
 831 void msi_remove_pci_irq_vectors(struct pci_dev *dev) {}
 832 void disable_msi_mode(struct pci_dev *dev, int pos, int type) {}
 833 void pci_no_msi(void) {}
 834
 835 #endif
 836
 837 #ifdef CONFIG_PPC64
 838 static int __init setup_noirqdistrib(char *str)
 839 {
 840         distribute_irqs = 0;
 841         return 1;
 842 }
 843
 844 __setup("noirqdistrib", setup_noirqdistrib);
 845 #endif /* CONFIG_PPC64 */