SAFE public projects git trees. - safe/jmp/linux-2.6/blob - arch/powerpc/kernel/irq.c

   1 /*
   2  *  Derived from arch/i386/kernel/irq.c
   3  *    Copyright (C) 1992 Linus Torvalds
   4  *  Adapted from arch/i386 by Gary Thomas
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
   7  *    Copyright (C) 1996-2001 Cort Dougan
   8  *  Adapted for Power Macintosh by Paul Mackerras
   9  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version
  14  * 2 of the License, or (at your option) any later version.
  15  *
  16  * This file contains the code used by various IRQ handling routines:
  17  * asking for different IRQ's should be done through these routines
  18  * instead of just grabbing them. Thus setups with different IRQ numbers
  19  * shouldn't result in any weird surprises, and installing new handlers
  20  * should be easier.
  21  *
  22  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
  23  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
  24  * mask register (of which only 16 are defined), hence the weird shifting
  25  * and complement of the cached_irq_mask.  I want to be able to stuff
  26  * this right into the SIU SMASK register.
  27  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
  28  * to reduce code space and undefined function references.
  29  */
  30
  31 #undef DEBUG
  32
  33 #include <linux/module.h>
  34 #include <linux/threads.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/signal.h>
  37 #include <linux/sched.h>
  38 #include <linux/ptrace.h>
  39 #include <linux/ioport.h>
  40 #include <linux/interrupt.h>
  41 #include <linux/timex.h>
  42 #include <linux/init.h>
  43 #include <linux/slab.h>
  44 #include <linux/delay.h>
  45 #include <linux/irq.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/cpumask.h>
  48 #include <linux/profile.h>
  49 #include <linux/bitops.h>
  50 #include <linux/list.h>
  51 #include <linux/radix-tree.h>
  52 #include <linux/mutex.h>
  53 #include <linux/bootmem.h>
  54 #include <linux/pci.h>
  55 #include <linux/debugfs.h>
  56
  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 #ifdef CONFIG_TAU_INT
  81 extern int tau_initialized;
  82 extern int tau_interrupts(int);
  83 #endif
  84 #endif /* CONFIG_PPC32 */
  85
  86 #ifdef CONFIG_PPC64
  87 EXPORT_SYMBOL(irq_desc);
  88
  89 int distribute_irqs = 1;
  90
  91 static inline notrace unsigned long get_hard_enabled(void)
  92 {
  93         unsigned long enabled;
  94
  95         __asm__ __volatile__("lbz %0,%1(13)"
  96         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
  97
  98         return enabled;
  99 }
 100
 101 static inline notrace void set_soft_enabled(unsigned long enable)
 102 {
 103         __asm__ __volatile__("stb %0,%1(13)"
 104         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 105 }
 106
 107 notrace void raw_local_irq_restore(unsigned long en)
 108 {
 109         /*
 110          * get_paca()->soft_enabled = en;
 111          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 112          * That was allowed before, and in such a case we do need to take care
 113          * that gcc will set soft_enabled directly via r13, not choose to use
 114          * an intermediate register, lest we're preempted to a different cpu.
 115          */
 116         set_soft_enabled(en);
 117         if (!en)
 118                 return;
 119
 120 #ifdef CONFIG_PPC_STD_MMU_64
 121         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 122                 /*
 123                  * Do we need to disable preemption here?  Not really: in the
 124                  * unlikely event that we're preempted to a different cpu in
 125                  * between getting r13, loading its lppaca_ptr, and loading
 126                  * its any_int, we might call iseries_handle_interrupts without
 127                  * an interrupt pending on the new cpu, but that's no disaster,
 128                  * is it?  And the business of preempting us off the old cpu
 129                  * would itself involve a local_irq_restore which handles the
 130                  * interrupt to that cpu.
 131                  *
 132                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 133                  * to avoid any preemption checking added into get_paca().
 134                  */
 135                 if (local_paca->lppaca_ptr->int_dword.any_int)
 136                         iseries_handle_interrupts();
 137         }
 138 #endif /* CONFIG_PPC_STD_MMU_64 */
 139
 140         /*
 141          * if (get_paca()->hard_enabled) return;
 142          * But again we need to take care that gcc gets hard_enabled directly
 143          * via r13, not choose to use an intermediate register, lest we're
 144          * preempted to a different cpu in between the two instructions.
 145          */
 146         if (get_hard_enabled())
 147                 return;
 148
 149         /*
 150          * Need to hard-enable interrupts here.  Since currently disabled,
 151          * no need to take further asm precautions against preemption; but
 152          * use local_paca instead of get_paca() to avoid preemption checking.
 153          */
 154         local_paca->hard_enabled = en;
 155         if ((int)mfspr(SPRN_DEC) < 0)
 156                 mtspr(SPRN_DEC, 1);
 157
 158         /*
 159          * Force the delivery of pending soft-disabled interrupts on PS3.
 160          * Any HV call will have this side effect.
 161          */
 162         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 163                 u64 tmp;
 164                 lv1_get_version_info(&tmp);
 165         }
 166
 167         __hard_irq_enable();
 168 }
 169 EXPORT_SYMBOL(raw_local_irq_restore);
 170 #endif /* CONFIG_PPC64 */
 171
 172 int show_interrupts(struct seq_file *p, void *v)
 173 {
 174         int i = *(loff_t *)v, j;
 175         struct irqaction *action;
 176         struct irq_desc *desc;
 177         unsigned long flags;
 178
 179         if (i == 0) {
 180                 seq_puts(p, "           ");
 181                 for_each_online_cpu(j)
 182                         seq_printf(p, "CPU%d       ", j);
 183                 seq_putc(p, '\n');
 184         }
 185
 186         if (i < NR_IRQS) {
 187                 desc = get_irq_desc(i);
 188                 spin_lock_irqsave(&desc->lock, flags);
 189                 action = desc->action;
 190                 if (!action || !action->handler)
 191                         goto skip;
 192                 seq_printf(p, "%3d: ", i);
 193 #ifdef CONFIG_SMP
 194                 for_each_online_cpu(j)
 195                         seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 196 #else
 197                 seq_printf(p, "%10u ", kstat_irqs(i));
 198 #endif /* CONFIG_SMP */
 199                 if (desc->chip)
 200                         seq_printf(p, " %s ", desc->chip->typename);
 201                 else
 202                         seq_puts(p, "  None      ");
 203                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 204                 seq_printf(p, "    %s", action->name);
 205                 for (action = action->next; action; action = action->next)
 206                         seq_printf(p, ", %s", action->name);
 207                 seq_putc(p, '\n');
 208 skip:
 209                 spin_unlock_irqrestore(&desc->lock, flags);
 210         } else if (i == NR_IRQS) {
 211 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 212                 if (tau_initialized){
 213                         seq_puts(p, "TAU: ");
 214                         for_each_online_cpu(j)
 215                                 seq_printf(p, "%10u ", tau_interrupts(j));
 216                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 217                 }
 218 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT*/
 219                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 220         }
 221         return 0;
 222 }
 223
 224 #ifdef CONFIG_HOTPLUG_CPU
 225 void fixup_irqs(cpumask_t map)
 226 {
 227         unsigned int irq;
 228         static int warned;
 229
 230         for_each_irq(irq) {
 231                 cpumask_t mask;
 232
 233                 if (irq_desc[irq].status & IRQ_PER_CPU)
 234                         continue;
 235
 236                 cpumask_and(&mask, irq_desc[irq].affinity, &map);
 237                 if (any_online_cpu(mask) == NR_CPUS) {
 238                         printk("Breaking affinity for irq %i\n", irq);
 239                         mask = map;
 240                 }
 241                 if (irq_desc[irq].chip->set_affinity)
 242                         irq_desc[irq].chip->set_affinity(irq, &mask);
 243                 else if (irq_desc[irq].action && !(warned++))
 244                         printk("Cannot set affinity for irq %i\n", irq);
 245         }
 246
 247         local_irq_enable();
 248         mdelay(1);
 249         local_irq_disable();
 250 }
 251 #endif
 252
 253 #ifdef CONFIG_IRQSTACKS
 254 static inline void handle_one_irq(unsigned int irq)
 255 {
 256         struct thread_info *curtp, *irqtp;
 257         unsigned long saved_sp_limit;
 258         struct irq_desc *desc;
 259
 260         /* Switch to the irq stack to handle this */
 261         curtp = current_thread_info();
 262         irqtp = hardirq_ctx[smp_processor_id()];
 263
 264         if (curtp == irqtp) {
 265                 /* We're already on the irq stack, just handle it */
 266                 generic_handle_irq(irq);
 267                 return;
 268         }
 269
 270         desc = irq_desc + irq;
 271         saved_sp_limit = current->thread.ksp_limit;
 272
 273         irqtp->task = curtp->task;
 274         irqtp->flags = 0;
 275
 276         /* Copy the softirq bits in preempt_count so that the
 277          * softirq checks work in the hardirq context. */
 278         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 279                                (curtp->preempt_count & SOFTIRQ_MASK);
 280
 281         current->thread.ksp_limit = (unsigned long)irqtp +
 282                 _ALIGN_UP(sizeof(struct thread_info), 16);
 283
 284         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 285         current->thread.ksp_limit = saved_sp_limit;
 286         irqtp->task = NULL;
 287
 288         /* Set any flag that may have been set on the
 289          * alternate stack
 290          */
 291         if (irqtp->flags)
 292                 set_bits(irqtp->flags, &curtp->flags);
 293 }
 294 #else
 295 static inline void handle_one_irq(unsigned int irq)
 296 {
 297         generic_handle_irq(irq);
 298 }
 299 #endif
 300
 301 static inline void check_stack_overflow(void)
 302 {
 303 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 304         long sp;
 305
 306         sp = __get_SP() & (THREAD_SIZE-1);
 307
 308         /* check for stack overflow: is there less than 2KB free? */
 309         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 310                 printk("do_IRQ: stack overflow: %ld\n",
 311                         sp - sizeof(struct thread_info));
 312                 dump_stack();
 313         }
 314 #endif
 315 }
 316
 317 void do_IRQ(struct pt_regs *regs)
 318 {
 319         struct pt_regs *old_regs = set_irq_regs(regs);
 320         unsigned int irq;
 321
 322         irq_enter();
 323
 324         check_stack_overflow();
 325
 326         irq = ppc_md.get_irq();
 327
 328         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 329                 handle_one_irq(irq);
 330         else if (irq != NO_IRQ_IGNORE)
 331                 /* That's not SMP safe ... but who cares ? */
 332                 ppc_spurious_interrupts++;
 333
 334         irq_exit();
 335         set_irq_regs(old_regs);
 336
 337 #ifdef CONFIG_PPC_ISERIES
 338         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 339                         get_lppaca()->int_dword.fields.decr_int) {
 340                 get_lppaca()->int_dword.fields.decr_int = 0;
 341                 /* Signal a fake decrementer interrupt */
 342                 timer_interrupt(regs);
 343         }
 344 #endif
 345 }
 346
 347 void __init init_IRQ(void)
 348 {
 349         if (ppc_md.init_IRQ)
 350                 ppc_md.init_IRQ();
 351
 352         exc_lvl_ctx_init();
 353
 354         irq_ctx_init();
 355 }
 356
 357 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 358 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 359 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 360 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 361
 362 void exc_lvl_ctx_init(void)
 363 {
 364         struct thread_info *tp;
 365         int i;
 366
 367         for_each_possible_cpu(i) {
 368                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 369                 tp = critirq_ctx[i];
 370                 tp->cpu = i;
 371                 tp->preempt_count = 0;
 372
 373 #ifdef CONFIG_BOOKE
 374                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 375                 tp = dbgirq_ctx[i];
 376                 tp->cpu = i;
 377                 tp->preempt_count = 0;
 378
 379                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 380                 tp = mcheckirq_ctx[i];
 381                 tp->cpu = i;
 382                 tp->preempt_count = HARDIRQ_OFFSET;
 383 #endif
 384         }
 385 }
 386 #endif
 387
 388 #ifdef CONFIG_IRQSTACKS
 389 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 390 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 391
 392 void irq_ctx_init(void)
 393 {
 394         struct thread_info *tp;
 395         int i;
 396
 397         for_each_possible_cpu(i) {
 398                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 399                 tp = softirq_ctx[i];
 400                 tp->cpu = i;
 401                 tp->preempt_count = 0;
 402
 403                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 404                 tp = hardirq_ctx[i];
 405                 tp->cpu = i;
 406                 tp->preempt_count = HARDIRQ_OFFSET;
 407         }
 408 }
 409
 410 static inline void do_softirq_onstack(void)
 411 {
 412         struct thread_info *curtp, *irqtp;
 413         unsigned long saved_sp_limit = current->thread.ksp_limit;
 414
 415         curtp = current_thread_info();
 416         irqtp = softirq_ctx[smp_processor_id()];
 417         irqtp->task = curtp->task;
 418         current->thread.ksp_limit = (unsigned long)irqtp +
 419                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 420         call_do_softirq(irqtp);
 421         current->thread.ksp_limit = saved_sp_limit;
 422         irqtp->task = NULL;
 423 }
 424
 425 #else
 426 #define do_softirq_onstack()    __do_softirq()
 427 #endif /* CONFIG_IRQSTACKS */
 428
 429 void do_softirq(void)
 430 {
 431         unsigned long flags;
 432
 433         if (in_interrupt())
 434                 return;
 435
 436         local_irq_save(flags);
 437
 438         if (local_softirq_pending())
 439                 do_softirq_onstack();
 440
 441         local_irq_restore(flags);
 442 }
 443
 444
 445 /*
 446  * IRQ controller and virtual interrupts
 447  */
 448
 449 static LIST_HEAD(irq_hosts);
 450 static DEFINE_SPINLOCK(irq_big_lock);
 451 static unsigned int revmap_trees_allocated;
 452 static DEFINE_MUTEX(revmap_trees_mutex);
 453 struct irq_map_entry irq_map[NR_IRQS];
 454 static unsigned int irq_virq_count = NR_IRQS;
 455 static struct irq_host *irq_default_host;
 456
 457 irq_hw_number_t virq_to_hw(unsigned int virq)
 458 {
 459         return irq_map[virq].hwirq;
 460 }
 461 EXPORT_SYMBOL_GPL(virq_to_hw);
 462
 463 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 464 {
 465         return h->of_node != NULL && h->of_node == np;
 466 }
 467
 468 struct irq_host *irq_alloc_host(struct device_node *of_node,
 469                                 unsigned int revmap_type,
 470                                 unsigned int revmap_arg,
 471                                 struct irq_host_ops *ops,
 472                                 irq_hw_number_t inval_irq)
 473 {
 474         struct irq_host *host;
 475         unsigned int size = sizeof(struct irq_host);
 476         unsigned int i;
 477         unsigned int *rmap;
 478         unsigned long flags;
 479
 480         /* Allocate structure and revmap table if using linear mapping */
 481         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 482                 size += revmap_arg * sizeof(unsigned int);
 483         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 484         if (host == NULL)
 485                 return NULL;
 486
 487         /* Fill structure */
 488         host->revmap_type = revmap_type;
 489         host->inval_irq = inval_irq;
 490         host->ops = ops;
 491         host->of_node = of_node_get(of_node);
 492
 493         if (host->ops->match == NULL)
 494                 host->ops->match = default_irq_host_match;
 495
 496         spin_lock_irqsave(&irq_big_lock, flags);
 497
 498         /* If it's a legacy controller, check for duplicates and
 499          * mark it as allocated (we use irq 0 host pointer for that
 500          */
 501         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 502                 if (irq_map[0].host != NULL) {
 503                         spin_unlock_irqrestore(&irq_big_lock, flags);
 504                         /* If we are early boot, we can't free the structure,
 505                          * too bad...
 506                          * this will be fixed once slab is made available early
 507                          * instead of the current cruft
 508                          */
 509                         if (mem_init_done)
 510                                 kfree(host);
 511                         return NULL;
 512                 }
 513                 irq_map[0].host = host;
 514         }
 515
 516         list_add(&host->link, &irq_hosts);
 517         spin_unlock_irqrestore(&irq_big_lock, flags);
 518
 519         /* Additional setups per revmap type */
 520         switch(revmap_type) {
 521         case IRQ_HOST_MAP_LEGACY:
 522                 /* 0 is always the invalid number for legacy */
 523                 host->inval_irq = 0;
 524                 /* setup us as the host for all legacy interrupts */
 525                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 526                         irq_map[i].hwirq = i;
 527                         smp_wmb();
 528                         irq_map[i].host = host;
 529                         smp_wmb();
 530
 531                         /* Clear norequest flags */
 532                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 533
 534                         /* Legacy flags are left to default at this point,
 535                          * one can then use irq_create_mapping() to
 536                          * explicitly change them
 537                          */
 538                         ops->map(host, i, i);
 539                 }
 540                 break;
 541         case IRQ_HOST_MAP_LINEAR:
 542                 rmap = (unsigned int *)(host + 1);
 543                 for (i = 0; i < revmap_arg; i++)
 544                         rmap[i] = NO_IRQ;
 545                 host->revmap_data.linear.size = revmap_arg;
 546                 smp_wmb();
 547                 host->revmap_data.linear.revmap = rmap;
 548                 break;
 549         default:
 550                 break;
 551         }
 552
 553         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 554
 555         return host;
 556 }
 557
 558 struct irq_host *irq_find_host(struct device_node *node)
 559 {
 560         struct irq_host *h, *found = NULL;
 561         unsigned long flags;
 562
 563         /* We might want to match the legacy controller last since
 564          * it might potentially be set to match all interrupts in
 565          * the absence of a device node. This isn't a problem so far
 566          * yet though...
 567          */
 568         spin_lock_irqsave(&irq_big_lock, flags);
 569         list_for_each_entry(h, &irq_hosts, link)
 570                 if (h->ops->match(h, node)) {
 571                         found = h;
 572                         break;
 573                 }
 574         spin_unlock_irqrestore(&irq_big_lock, flags);
 575         return found;
 576 }
 577 EXPORT_SYMBOL_GPL(irq_find_host);
 578
 579 void irq_set_default_host(struct irq_host *host)
 580 {
 581         pr_debug("irq: Default host set to @0x%p\n", host);
 582
 583         irq_default_host = host;
 584 }
 585
 586 void irq_set_virq_count(unsigned int count)
 587 {
 588         pr_debug("irq: Trying to set virq count to %d\n", count);
 589
 590         BUG_ON(count < NUM_ISA_INTERRUPTS);
 591         if (count < NR_IRQS)
 592                 irq_virq_count = count;
 593 }
 594
 595 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 596                             irq_hw_number_t hwirq)
 597 {
 598         /* Clear IRQ_NOREQUEST flag */
 599         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 600
 601         /* map it */
 602         smp_wmb();
 603         irq_map[virq].hwirq = hwirq;
 604         smp_mb();
 605
 606         if (host->ops->map(host, virq, hwirq)) {
 607                 pr_debug("irq: -> mapping failed, freeing\n");
 608                 irq_free_virt(virq, 1);
 609                 return -1;
 610         }
 611
 612         return 0;
 613 }
 614
 615 unsigned int irq_create_direct_mapping(struct irq_host *host)
 616 {
 617         unsigned int virq;
 618
 619         if (host == NULL)
 620                 host = irq_default_host;
 621
 622         BUG_ON(host == NULL);
 623         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 624
 625         virq = irq_alloc_virt(host, 1, 0);
 626         if (virq == NO_IRQ) {
 627                 pr_debug("irq: create_direct virq allocation failed\n");
 628                 return NO_IRQ;
 629         }
 630
 631         pr_debug("irq: create_direct obtained virq %d\n", virq);
 632
 633         if (irq_setup_virq(host, virq, virq))
 634                 return NO_IRQ;
 635
 636         return virq;
 637 }
 638
 639 unsigned int irq_create_mapping(struct irq_host *host,
 640                                 irq_hw_number_t hwirq)
 641 {
 642         unsigned int virq, hint;
 643
 644         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 645
 646         /* Look for default host if nececssary */
 647         if (host == NULL)
 648                 host = irq_default_host;
 649         if (host == NULL) {
 650                 printk(KERN_WARNING "irq_create_mapping called for"
 651                        " NULL host, hwirq=%lx\n", hwirq);
 652                 WARN_ON(1);
 653                 return NO_IRQ;
 654         }
 655         pr_debug("irq: -> using host @%p\n", host);
 656
 657         /* Check if mapping already exist, if it does, call
 658          * host->ops->map() to update the flags
 659          */
 660         virq = irq_find_mapping(host, hwirq);
 661         if (virq != NO_IRQ) {
 662                 if (host->ops->remap)
 663                         host->ops->remap(host, virq, hwirq);
 664                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 665                 return virq;
 666         }
 667
 668         /* Get a virtual interrupt number */
 669         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 670                 /* Handle legacy */
 671                 virq = (unsigned int)hwirq;
 672                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 673                         return NO_IRQ;
 674                 return virq;
 675         } else {
 676                 /* Allocate a virtual interrupt number */
 677                 hint = hwirq % irq_virq_count;
 678                 virq = irq_alloc_virt(host, 1, hint);
 679                 if (virq == NO_IRQ) {
 680                         pr_debug("irq: -> virq allocation failed\n");
 681                         return NO_IRQ;
 682                 }
 683         }
 684
 685         if (irq_setup_virq(host, virq, hwirq))
 686                 return NO_IRQ;
 687
 688         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 689                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 690
 691         return virq;
 692 }
 693 EXPORT_SYMBOL_GPL(irq_create_mapping);
 694
 695 unsigned int irq_create_of_mapping(struct device_node *controller,
 696                                    u32 *intspec, unsigned int intsize)
 697 {
 698         struct irq_host *host;
 699         irq_hw_number_t hwirq;
 700         unsigned int type = IRQ_TYPE_NONE;
 701         unsigned int virq;
 702
 703         if (controller == NULL)
 704                 host = irq_default_host;
 705         else
 706                 host = irq_find_host(controller);
 707         if (host == NULL) {
 708                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 709                        controller->full_name);
 710                 return NO_IRQ;
 711         }
 712
 713         /* If host has no translation, then we assume interrupt line */
 714         if (host->ops->xlate == NULL)
 715                 hwirq = intspec[0];
 716         else {
 717                 if (host->ops->xlate(host, controller, intspec, intsize,
 718                                      &hwirq, &type))
 719                         return NO_IRQ;
 720         }
 721
 722         /* Create mapping */
 723         virq = irq_create_mapping(host, hwirq);
 724         if (virq == NO_IRQ)
 725                 return virq;
 726
 727         /* Set type if specified and different than the current one */
 728         if (type != IRQ_TYPE_NONE &&
 729             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 730                 set_irq_type(virq, type);
 731         return virq;
 732 }
 733 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 734
 735 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 736 {
 737         struct of_irq oirq;
 738
 739         if (of_irq_map_one(dev, index, &oirq))
 740                 return NO_IRQ;
 741
 742         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 743                                      oirq.size);
 744 }
 745 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 746
 747 void irq_dispose_mapping(unsigned int virq)
 748 {
 749         struct irq_host *host;
 750         irq_hw_number_t hwirq;
 751
 752         if (virq == NO_IRQ)
 753                 return;
 754
 755         host = irq_map[virq].host;
 756         WARN_ON (host == NULL);
 757         if (host == NULL)
 758                 return;
 759
 760         /* Never unmap legacy interrupts */
 761         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 762                 return;
 763
 764         /* remove chip and handler */
 765         set_irq_chip_and_handler(virq, NULL, NULL);
 766
 767         /* Make sure it's completed */
 768         synchronize_irq(virq);
 769
 770         /* Tell the PIC about it */
 771         if (host->ops->unmap)
 772                 host->ops->unmap(host, virq);
 773         smp_mb();
 774
 775         /* Clear reverse map */
 776         hwirq = irq_map[virq].hwirq;
 777         switch(host->revmap_type) {
 778         case IRQ_HOST_MAP_LINEAR:
 779                 if (hwirq < host->revmap_data.linear.size)
 780                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 781                 break;
 782         case IRQ_HOST_MAP_TREE:
 783                 /*
 784                  * Check if radix tree allocated yet, if not then nothing to
 785                  * remove.
 786                  */
 787                 smp_rmb();
 788                 if (revmap_trees_allocated < 1)
 789                         break;
 790                 mutex_lock(&revmap_trees_mutex);
 791                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 792                 mutex_unlock(&revmap_trees_mutex);
 793                 break;
 794         }
 795
 796         /* Destroy map */
 797         smp_mb();
 798         irq_map[virq].hwirq = host->inval_irq;
 799
 800         /* Set some flags */
 801         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 802
 803         /* Free it */
 804         irq_free_virt(virq, 1);
 805 }
 806 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 807
 808 unsigned int irq_find_mapping(struct irq_host *host,
 809                               irq_hw_number_t hwirq)
 810 {
 811         unsigned int i;
 812         unsigned int hint = hwirq % irq_virq_count;
 813
 814         /* Look for default host if nececssary */
 815         if (host == NULL)
 816                 host = irq_default_host;
 817         if (host == NULL)
 818                 return NO_IRQ;
 819
 820         /* legacy -> bail early */
 821         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 822                 return hwirq;
 823
 824         /* Slow path does a linear search of the map */
 825         if (hint < NUM_ISA_INTERRUPTS)
 826                 hint = NUM_ISA_INTERRUPTS;
 827         i = hint;
 828         do  {
 829                 if (irq_map[i].host == host &&
 830                     irq_map[i].hwirq == hwirq)
 831                         return i;
 832                 i++;
 833                 if (i >= irq_virq_count)
 834                         i = NUM_ISA_INTERRUPTS;
 835         } while(i != hint);
 836         return NO_IRQ;
 837 }
 838 EXPORT_SYMBOL_GPL(irq_find_mapping);
 839
 840
 841 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 842                                      irq_hw_number_t hwirq)
 843 {
 844         struct irq_map_entry *ptr;
 845         unsigned int virq;
 846
 847         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 848
 849         /*
 850          * Check if the radix tree exists and has bee initialized.
 851          * If not, we fallback to slow mode
 852          */
 853         if (revmap_trees_allocated < 2)
 854                 return irq_find_mapping(host, hwirq);
 855
 856         /* Now try to resolve */
 857         /*
 858          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 859          * as it's referencing an entry in the static irq_map table.
 860          */
 861         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 862
 863         /*
 864          * If found in radix tree, then fine.
 865          * Else fallback to linear lookup - this should not happen in practice
 866          * as it means that we failed to insert the node in the radix tree.
 867          */
 868         if (ptr)
 869                 virq = ptr - irq_map;
 870         else
 871                 virq = irq_find_mapping(host, hwirq);
 872
 873         return virq;
 874 }
 875
 876 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 877                              irq_hw_number_t hwirq)
 878 {
 879
 880         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 881
 882         /*
 883          * Check if the radix tree exists yet.
 884          * If not, then the irq will be inserted into the tree when it gets
 885          * initialized.
 886          */
 887         smp_rmb();
 888         if (revmap_trees_allocated < 1)
 889                 return;
 890
 891         if (virq != NO_IRQ) {
 892                 mutex_lock(&revmap_trees_mutex);
 893                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 894                                   &irq_map[virq]);
 895                 mutex_unlock(&revmap_trees_mutex);
 896         }
 897 }
 898
 899 unsigned int irq_linear_revmap(struct irq_host *host,
 900                                irq_hw_number_t hwirq)
 901 {
 902         unsigned int *revmap;
 903
 904         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 905
 906         /* Check revmap bounds */
 907         if (unlikely(hwirq >= host->revmap_data.linear.size))
 908                 return irq_find_mapping(host, hwirq);
 909
 910         /* Check if revmap was allocated */
 911         revmap = host->revmap_data.linear.revmap;
 912         if (unlikely(revmap == NULL))
 913                 return irq_find_mapping(host, hwirq);
 914
 915         /* Fill up revmap with slow path if no mapping found */
 916         if (unlikely(revmap[hwirq] == NO_IRQ))
 917                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 918
 919         return revmap[hwirq];
 920 }
 921
 922 unsigned int irq_alloc_virt(struct irq_host *host,
 923                             unsigned int count,
 924                             unsigned int hint)
 925 {
 926         unsigned long flags;
 927         unsigned int i, j, found = NO_IRQ;
 928
 929         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 930                 return NO_IRQ;
 931
 932         spin_lock_irqsave(&irq_big_lock, flags);
 933
 934         /* Use hint for 1 interrupt if any */
 935         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 936             hint < irq_virq_count && irq_map[hint].host == NULL) {
 937                 found = hint;
 938                 goto hint_found;
 939         }
 940
 941         /* Look for count consecutive numbers in the allocatable
 942          * (non-legacy) space
 943          */
 944         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 945                 if (irq_map[i].host != NULL)
 946                         j = 0;
 947                 else
 948                         j++;
 949
 950                 if (j == count) {
 951                         found = i - count + 1;
 952                         break;
 953                 }
 954         }
 955         if (found == NO_IRQ) {
 956                 spin_unlock_irqrestore(&irq_big_lock, flags);
 957                 return NO_IRQ;
 958         }
 959  hint_found:
 960         for (i = found; i < (found + count); i++) {
 961                 irq_map[i].hwirq = host->inval_irq;
 962                 smp_wmb();
 963                 irq_map[i].host = host;
 964         }
 965         spin_unlock_irqrestore(&irq_big_lock, flags);
 966         return found;
 967 }
 968
 969 void irq_free_virt(unsigned int virq, unsigned int count)
 970 {
 971         unsigned long flags;
 972         unsigned int i;
 973
 974         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 975         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 976
 977         spin_lock_irqsave(&irq_big_lock, flags);
 978         for (i = virq; i < (virq + count); i++) {
 979                 struct irq_host *host;
 980
 981                 if (i < NUM_ISA_INTERRUPTS ||
 982                     (virq + count) > irq_virq_count)
 983                         continue;
 984
 985                 host = irq_map[i].host;
 986                 irq_map[i].hwirq = host->inval_irq;
 987                 smp_wmb();
 988                 irq_map[i].host = NULL;
 989         }
 990         spin_unlock_irqrestore(&irq_big_lock, flags);
 991 }
 992
 993 void irq_early_init(void)
 994 {
 995         unsigned int i;
 996
 997         for (i = 0; i < NR_IRQS; i++)
 998                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 999 }
1000
1001 /* We need to create the radix trees late */
1002 static int irq_late_init(void)
1003 {
1004         struct irq_host *h;
1005         unsigned int i;
1006
1007         /*
1008          * No mutual exclusion with respect to accessors of the tree is needed
1009          * here as the synchronization is done via the state variable
1010          * revmap_trees_allocated.
1011          */
1012         list_for_each_entry(h, &irq_hosts, link) {
1013                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1014                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1015         }
1016
1017         /*
1018          * Make sure the radix trees inits are visible before setting
1019          * the flag
1020          */
1021         smp_wmb();
1022         revmap_trees_allocated = 1;
1023
1024         /*
1025          * Insert the reverse mapping for those interrupts already present
1026          * in irq_map[].
1027          */
1028         mutex_lock(&revmap_trees_mutex);
1029         for (i = 0; i < irq_virq_count; i++) {
1030                 if (irq_map[i].host &&
1031                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1032                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1033                                           irq_map[i].hwirq, &irq_map[i]);
1034         }
1035         mutex_unlock(&revmap_trees_mutex);
1036
1037         /*
1038          * Make sure the radix trees insertions are visible before setting
1039          * the flag
1040          */
1041         smp_wmb();
1042         revmap_trees_allocated = 2;
1043
1044         return 0;
1045 }
1046 arch_initcall(irq_late_init);
1047
1048 #ifdef CONFIG_VIRQ_DEBUG
1049 static int virq_debug_show(struct seq_file *m, void *private)
1050 {
1051         unsigned long flags;
1052         struct irq_desc *desc;
1053         const char *p;
1054         char none[] = "none";
1055         int i;
1056
1057         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1058                       "chip name", "host name");
1059
1060         for (i = 1; i < NR_IRQS; i++) {
1061                 desc = get_irq_desc(i);
1062                 spin_lock_irqsave(&desc->lock, flags);
1063
1064                 if (desc->action && desc->action->handler) {
1065                         seq_printf(m, "%5d  ", i);
1066                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1067
1068                         if (desc->chip && desc->chip->typename)
1069                                 p = desc->chip->typename;
1070                         else
1071                                 p = none;
1072                         seq_printf(m, "%-15s  ", p);
1073
1074                         if (irq_map[i].host && irq_map[i].host->of_node)
1075                                 p = irq_map[i].host->of_node->full_name;
1076                         else
1077                                 p = none;
1078                         seq_printf(m, "%s\n", p);
1079                 }
1080
1081                 spin_unlock_irqrestore(&desc->lock, flags);
1082         }
1083
1084         return 0;
1085 }
1086
1087 static int virq_debug_open(struct inode *inode, struct file *file)
1088 {
1089         return single_open(file, virq_debug_show, inode->i_private);
1090 }
1091
1092 static const struct file_operations virq_debug_fops = {
1093         .open = virq_debug_open,
1094         .read = seq_read,
1095         .llseek = seq_lseek,
1096         .release = single_release,
1097 };
1098
1099 static int __init irq_debugfs_init(void)
1100 {
1101         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1102                                  NULL, &virq_debug_fops) == NULL)
1103                 return -ENOMEM;
1104
1105         return 0;
1106 }
1107 __initcall(irq_debugfs_init);
1108 #endif /* CONFIG_VIRQ_DEBUG */
1109
1110 #ifdef CONFIG_PPC64
1111 static int __init setup_noirqdistrib(char *str)
1112 {
1113         distribute_irqs = 0;
1114         return 1;
1115 }
1116
1117 __setup("noirqdistrib", setup_noirqdistrib);
1118 #endif /* CONFIG_PPC64 */