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 #ifndef CONFIG_PPC_MERGE
  81 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
  82 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
  83 #endif
  84
  85 #ifdef CONFIG_TAU_INT
  86 extern int tau_initialized;
  87 extern int tau_interrupts(int);
  88 #endif
  89 #endif /* CONFIG_PPC32 */
  90
  91 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
  92 extern atomic_t ipi_recv;
  93 extern atomic_t ipi_sent;
  94 #endif
  95
  96 #ifdef CONFIG_PPC64
  97 EXPORT_SYMBOL(irq_desc);
  98
  99 int distribute_irqs = 1;
 100
 101 static inline unsigned long get_hard_enabled(void)
 102 {
 103         unsigned long enabled;
 104
 105         __asm__ __volatile__("lbz %0,%1(13)"
 106         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 107
 108         return enabled;
 109 }
 110
 111 static inline void set_soft_enabled(unsigned long enable)
 112 {
 113         __asm__ __volatile__("stb %0,%1(13)"
 114         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 115 }
 116
 117 void 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                         if (handler == NULL)
 311                                 handler = &__do_IRQ;
 312                         irqtp->task = curtp->task;
 313                         irqtp->flags = 0;
 314
 315                         /* Copy the softirq bits in preempt_count so that the
 316                          * softirq checks work in the hardirq context.
 317                          */
 318                         irqtp->preempt_count =
 319                                 (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 320                                 (curtp->preempt_count & SOFTIRQ_MASK);
 321
 322                         call_handle_irq(irq, desc, irqtp, handler);
 323                         irqtp->task = NULL;
 324
 325
 326                         /* Set any flag that may have been set on the
 327                          * alternate stack
 328                          */
 329                         if (irqtp->flags)
 330                                 set_bits(irqtp->flags, &curtp->flags);
 331                 } else
 332 #endif
 333                         generic_handle_irq(irq);
 334         } else if (irq != NO_IRQ_IGNORE)
 335                 /* That's not SMP safe ... but who cares ? */
 336                 ppc_spurious_interrupts++;
 337
 338         irq_exit();
 339         set_irq_regs(old_regs);
 340
 341 #ifdef CONFIG_PPC_ISERIES
 342         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 343                         get_lppaca()->int_dword.fields.decr_int) {
 344                 get_lppaca()->int_dword.fields.decr_int = 0;
 345                 /* Signal a fake decrementer interrupt */
 346                 timer_interrupt(regs);
 347         }
 348 #endif
 349 }
 350
 351 void __init init_IRQ(void)
 352 {
 353         if (ppc_md.init_IRQ)
 354                 ppc_md.init_IRQ();
 355 #ifdef CONFIG_PPC64
 356         irq_ctx_init();
 357 #endif
 358 }
 359
 360
 361 #ifdef CONFIG_IRQSTACKS
 362 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 363 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 364
 365 void irq_ctx_init(void)
 366 {
 367         struct thread_info *tp;
 368         int i;
 369
 370         for_each_possible_cpu(i) {
 371                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 372                 tp = softirq_ctx[i];
 373                 tp->cpu = i;
 374                 tp->preempt_count = 0;
 375
 376                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 377                 tp = hardirq_ctx[i];
 378                 tp->cpu = i;
 379                 tp->preempt_count = HARDIRQ_OFFSET;
 380         }
 381 }
 382
 383 static inline void do_softirq_onstack(void)
 384 {
 385         struct thread_info *curtp, *irqtp;
 386
 387         curtp = current_thread_info();
 388         irqtp = softirq_ctx[smp_processor_id()];
 389         irqtp->task = curtp->task;
 390         call_do_softirq(irqtp);
 391         irqtp->task = NULL;
 392 }
 393
 394 #else
 395 #define do_softirq_onstack()    __do_softirq()
 396 #endif /* CONFIG_IRQSTACKS */
 397
 398 void do_softirq(void)
 399 {
 400         unsigned long flags;
 401
 402         if (in_interrupt())
 403                 return;
 404
 405         local_irq_save(flags);
 406
 407         if (local_softirq_pending())
 408                 do_softirq_onstack();
 409
 410         local_irq_restore(flags);
 411 }
 412
 413
 414 /*
 415  * IRQ controller and virtual interrupts
 416  */
 417
 418 #ifdef CONFIG_PPC_MERGE
 419
 420 static LIST_HEAD(irq_hosts);
 421 static DEFINE_SPINLOCK(irq_big_lock);
 422 static DEFINE_PER_CPU(unsigned int, irq_radix_reader);
 423 static unsigned int irq_radix_writer;
 424 struct irq_map_entry irq_map[NR_IRQS];
 425 static unsigned int irq_virq_count = NR_IRQS;
 426 static struct irq_host *irq_default_host;
 427
 428 irq_hw_number_t virq_to_hw(unsigned int virq)
 429 {
 430         return irq_map[virq].hwirq;
 431 }
 432 EXPORT_SYMBOL_GPL(virq_to_hw);
 433
 434 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 435 {
 436         return h->of_node != NULL && h->of_node == np;
 437 }
 438
 439 struct irq_host *irq_alloc_host(struct device_node *of_node,
 440                                 unsigned int revmap_type,
 441                                 unsigned int revmap_arg,
 442                                 struct irq_host_ops *ops,
 443                                 irq_hw_number_t inval_irq)
 444 {
 445         struct irq_host *host;
 446         unsigned int size = sizeof(struct irq_host);
 447         unsigned int i;
 448         unsigned int *rmap;
 449         unsigned long flags;
 450
 451         /* Allocate structure and revmap table if using linear mapping */
 452         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 453                 size += revmap_arg * sizeof(unsigned int);
 454         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 455         if (host == NULL)
 456                 return NULL;
 457
 458         /* Fill structure */
 459         host->revmap_type = revmap_type;
 460         host->inval_irq = inval_irq;
 461         host->ops = ops;
 462         host->of_node = of_node;
 463
 464         if (host->ops->match == NULL)
 465                 host->ops->match = default_irq_host_match;
 466
 467         spin_lock_irqsave(&irq_big_lock, flags);
 468
 469         /* If it's a legacy controller, check for duplicates and
 470          * mark it as allocated (we use irq 0 host pointer for that
 471          */
 472         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 473                 if (irq_map[0].host != NULL) {
 474                         spin_unlock_irqrestore(&irq_big_lock, flags);
 475                         /* If we are early boot, we can't free the structure,
 476                          * too bad...
 477                          * this will be fixed once slab is made available early
 478                          * instead of the current cruft
 479                          */
 480                         if (mem_init_done)
 481                                 kfree(host);
 482                         return NULL;
 483                 }
 484                 irq_map[0].host = host;
 485         }
 486
 487         list_add(&host->link, &irq_hosts);
 488         spin_unlock_irqrestore(&irq_big_lock, flags);
 489
 490         /* Additional setups per revmap type */
 491         switch(revmap_type) {
 492         case IRQ_HOST_MAP_LEGACY:
 493                 /* 0 is always the invalid number for legacy */
 494                 host->inval_irq = 0;
 495                 /* setup us as the host for all legacy interrupts */
 496                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 497                         irq_map[i].hwirq = i;
 498                         smp_wmb();
 499                         irq_map[i].host = host;
 500                         smp_wmb();
 501
 502                         /* Clear norequest flags */
 503                         get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
 504
 505                         /* Legacy flags are left to default at this point,
 506                          * one can then use irq_create_mapping() to
 507                          * explicitly change them
 508                          */
 509                         ops->map(host, i, i);
 510                 }
 511                 break;
 512         case IRQ_HOST_MAP_LINEAR:
 513                 rmap = (unsigned int *)(host + 1);
 514                 for (i = 0; i < revmap_arg; i++)
 515                         rmap[i] = NO_IRQ;
 516                 host->revmap_data.linear.size = revmap_arg;
 517                 smp_wmb();
 518                 host->revmap_data.linear.revmap = rmap;
 519                 break;
 520         default:
 521                 break;
 522         }
 523
 524         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 525
 526         return host;
 527 }
 528
 529 struct irq_host *irq_find_host(struct device_node *node)
 530 {
 531         struct irq_host *h, *found = NULL;
 532         unsigned long flags;
 533
 534         /* We might want to match the legacy controller last since
 535          * it might potentially be set to match all interrupts in
 536          * the absence of a device node. This isn't a problem so far
 537          * yet though...
 538          */
 539         spin_lock_irqsave(&irq_big_lock, flags);
 540         list_for_each_entry(h, &irq_hosts, link)
 541                 if (h->ops->match(h, node)) {
 542                         found = h;
 543                         break;
 544                 }
 545         spin_unlock_irqrestore(&irq_big_lock, flags);
 546         return found;
 547 }
 548 EXPORT_SYMBOL_GPL(irq_find_host);
 549
 550 void irq_set_default_host(struct irq_host *host)
 551 {
 552         pr_debug("irq: Default host set to @0x%p\n", host);
 553
 554         irq_default_host = host;
 555 }
 556
 557 void irq_set_virq_count(unsigned int count)
 558 {
 559         pr_debug("irq: Trying to set virq count to %d\n", count);
 560
 561         BUG_ON(count < NUM_ISA_INTERRUPTS);
 562         if (count < NR_IRQS)
 563                 irq_virq_count = count;
 564 }
 565
 566 /* radix tree not lockless safe ! we use a brlock-type mecanism
 567  * for now, until we can use a lockless radix tree
 568  */
 569 static void irq_radix_wrlock(unsigned long *flags)
 570 {
 571         unsigned int cpu, ok;
 572
 573         spin_lock_irqsave(&irq_big_lock, *flags);
 574         irq_radix_writer = 1;
 575         smp_mb();
 576         do {
 577                 barrier();
 578                 ok = 1;
 579                 for_each_possible_cpu(cpu) {
 580                         if (per_cpu(irq_radix_reader, cpu)) {
 581                                 ok = 0;
 582                                 break;
 583                         }
 584                 }
 585                 if (!ok)
 586                         cpu_relax();
 587         } while(!ok);
 588 }
 589
 590 static void irq_radix_wrunlock(unsigned long flags)
 591 {
 592         smp_wmb();
 593         irq_radix_writer = 0;
 594         spin_unlock_irqrestore(&irq_big_lock, flags);
 595 }
 596
 597 static void irq_radix_rdlock(unsigned long *flags)
 598 {
 599         local_irq_save(*flags);
 600         __get_cpu_var(irq_radix_reader) = 1;
 601         smp_mb();
 602         if (likely(irq_radix_writer == 0))
 603                 return;
 604         __get_cpu_var(irq_radix_reader) = 0;
 605         smp_wmb();
 606         spin_lock(&irq_big_lock);
 607         __get_cpu_var(irq_radix_reader) = 1;
 608         spin_unlock(&irq_big_lock);
 609 }
 610
 611 static void irq_radix_rdunlock(unsigned long flags)
 612 {
 613         __get_cpu_var(irq_radix_reader) = 0;
 614         local_irq_restore(flags);
 615 }
 616
 617 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 618                             irq_hw_number_t hwirq)
 619 {
 620         /* Clear IRQ_NOREQUEST flag */
 621         get_irq_desc(virq)->status &= ~IRQ_NOREQUEST;
 622
 623         /* map it */
 624         smp_wmb();
 625         irq_map[virq].hwirq = hwirq;
 626         smp_mb();
 627
 628         if (host->ops->map(host, virq, hwirq)) {
 629                 pr_debug("irq: -> mapping failed, freeing\n");
 630                 irq_free_virt(virq, 1);
 631                 return -1;
 632         }
 633
 634         return 0;
 635 }
 636
 637 unsigned int irq_create_direct_mapping(struct irq_host *host)
 638 {
 639         unsigned int virq;
 640
 641         if (host == NULL)
 642                 host = irq_default_host;
 643
 644         BUG_ON(host == NULL);
 645         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 646
 647         virq = irq_alloc_virt(host, 1, 0);
 648         if (virq == NO_IRQ) {
 649                 pr_debug("irq: create_direct virq allocation failed\n");
 650                 return NO_IRQ;
 651         }
 652
 653         pr_debug("irq: create_direct obtained virq %d\n", virq);
 654
 655         if (irq_setup_virq(host, virq, virq))
 656                 return NO_IRQ;
 657
 658         return virq;
 659 }
 660
 661 unsigned int irq_create_mapping(struct irq_host *host,
 662                                 irq_hw_number_t hwirq)
 663 {
 664         unsigned int virq, hint;
 665
 666         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 667
 668         /* Look for default host if nececssary */
 669         if (host == NULL)
 670                 host = irq_default_host;
 671         if (host == NULL) {
 672                 printk(KERN_WARNING "irq_create_mapping called for"
 673                        " NULL host, hwirq=%lx\n", hwirq);
 674                 WARN_ON(1);
 675                 return NO_IRQ;
 676         }
 677         pr_debug("irq: -> using host @%p\n", host);
 678
 679         /* Check if mapping already exist, if it does, call
 680          * host->ops->map() to update the flags
 681          */
 682         virq = irq_find_mapping(host, hwirq);
 683         if (virq != NO_IRQ) {
 684                 if (host->ops->remap)
 685                         host->ops->remap(host, virq, hwirq);
 686                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 687                 return virq;
 688         }
 689
 690         /* Get a virtual interrupt number */
 691         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 692                 /* Handle legacy */
 693                 virq = (unsigned int)hwirq;
 694                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 695                         return NO_IRQ;
 696                 return virq;
 697         } else {
 698                 /* Allocate a virtual interrupt number */
 699                 hint = hwirq % irq_virq_count;
 700                 virq = irq_alloc_virt(host, 1, hint);
 701                 if (virq == NO_IRQ) {
 702                         pr_debug("irq: -> virq allocation failed\n");
 703                         return NO_IRQ;
 704                 }
 705         }
 706         pr_debug("irq: -> obtained virq %d\n", virq);
 707
 708         if (irq_setup_virq(host, virq, hwirq))
 709                 return NO_IRQ;
 710
 711         return virq;
 712 }
 713 EXPORT_SYMBOL_GPL(irq_create_mapping);
 714
 715 unsigned int irq_create_of_mapping(struct device_node *controller,
 716                                    u32 *intspec, unsigned int intsize)
 717 {
 718         struct irq_host *host;
 719         irq_hw_number_t hwirq;
 720         unsigned int type = IRQ_TYPE_NONE;
 721         unsigned int virq;
 722
 723         if (controller == NULL)
 724                 host = irq_default_host;
 725         else
 726                 host = irq_find_host(controller);
 727         if (host == NULL) {
 728                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 729                        controller->full_name);
 730                 return NO_IRQ;
 731         }
 732
 733         /* If host has no translation, then we assume interrupt line */
 734         if (host->ops->xlate == NULL)
 735                 hwirq = intspec[0];
 736         else {
 737                 if (host->ops->xlate(host, controller, intspec, intsize,
 738                                      &hwirq, &type))
 739                         return NO_IRQ;
 740         }
 741
 742         /* Create mapping */
 743         virq = irq_create_mapping(host, hwirq);
 744         if (virq == NO_IRQ)
 745                 return virq;
 746
 747         /* Set type if specified and different than the current one */
 748         if (type != IRQ_TYPE_NONE &&
 749             type != (get_irq_desc(virq)->status & IRQF_TRIGGER_MASK))
 750                 set_irq_type(virq, type);
 751         return virq;
 752 }
 753 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 754
 755 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 756 {
 757         struct of_irq oirq;
 758
 759         if (of_irq_map_one(dev, index, &oirq))
 760                 return NO_IRQ;
 761
 762         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 763                                      oirq.size);
 764 }
 765 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 766
 767 void irq_dispose_mapping(unsigned int virq)
 768 {
 769         struct irq_host *host;
 770         irq_hw_number_t hwirq;
 771         unsigned long flags;
 772
 773         if (virq == NO_IRQ)
 774                 return;
 775
 776         host = irq_map[virq].host;
 777         WARN_ON (host == NULL);
 778         if (host == NULL)
 779                 return;
 780
 781         /* Never unmap legacy interrupts */
 782         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 783                 return;
 784
 785         /* remove chip and handler */
 786         set_irq_chip_and_handler(virq, NULL, NULL);
 787
 788         /* Make sure it's completed */
 789         synchronize_irq(virq);
 790
 791         /* Tell the PIC about it */
 792         if (host->ops->unmap)
 793                 host->ops->unmap(host, virq);
 794         smp_mb();
 795
 796         /* Clear reverse map */
 797         hwirq = irq_map[virq].hwirq;
 798         switch(host->revmap_type) {
 799         case IRQ_HOST_MAP_LINEAR:
 800                 if (hwirq < host->revmap_data.linear.size)
 801                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 802                 break;
 803         case IRQ_HOST_MAP_TREE:
 804                 /* Check if radix tree allocated yet */
 805                 if (host->revmap_data.tree.gfp_mask == 0)
 806                         break;
 807                 irq_radix_wrlock(&flags);
 808                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 809                 irq_radix_wrunlock(flags);
 810                 break;
 811         }
 812
 813         /* Destroy map */
 814         smp_mb();
 815         irq_map[virq].hwirq = host->inval_irq;
 816
 817         /* Set some flags */
 818         get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 819
 820         /* Free it */
 821         irq_free_virt(virq, 1);
 822 }
 823 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 824
 825 unsigned int irq_find_mapping(struct irq_host *host,
 826                               irq_hw_number_t hwirq)
 827 {
 828         unsigned int i;
 829         unsigned int hint = hwirq % irq_virq_count;
 830
 831         /* Look for default host if nececssary */
 832         if (host == NULL)
 833                 host = irq_default_host;
 834         if (host == NULL)
 835                 return NO_IRQ;
 836
 837         /* legacy -> bail early */
 838         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 839                 return hwirq;
 840
 841         /* Slow path does a linear search of the map */
 842         if (hint < NUM_ISA_INTERRUPTS)
 843                 hint = NUM_ISA_INTERRUPTS;
 844         i = hint;
 845         do  {
 846                 if (irq_map[i].host == host &&
 847                     irq_map[i].hwirq == hwirq)
 848                         return i;
 849                 i++;
 850                 if (i >= irq_virq_count)
 851                         i = NUM_ISA_INTERRUPTS;
 852         } while(i != hint);
 853         return NO_IRQ;
 854 }
 855 EXPORT_SYMBOL_GPL(irq_find_mapping);
 856
 857
 858 unsigned int irq_radix_revmap(struct irq_host *host,
 859                               irq_hw_number_t hwirq)
 860 {
 861         struct radix_tree_root *tree;
 862         struct irq_map_entry *ptr;
 863         unsigned int virq;
 864         unsigned long flags;
 865
 866         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 867
 868         /* Check if the radix tree exist yet. We test the value of
 869          * the gfp_mask for that. Sneaky but saves another int in the
 870          * structure. If not, we fallback to slow mode
 871          */
 872         tree = &host->revmap_data.tree;
 873         if (tree->gfp_mask == 0)
 874                 return irq_find_mapping(host, hwirq);
 875
 876         /* Now try to resolve */
 877         irq_radix_rdlock(&flags);
 878         ptr = radix_tree_lookup(tree, hwirq);
 879         irq_radix_rdunlock(flags);
 880
 881         /* Found it, return */
 882         if (ptr) {
 883                 virq = ptr - irq_map;
 884                 return virq;
 885         }
 886
 887         /* If not there, try to insert it */
 888         virq = irq_find_mapping(host, hwirq);
 889         if (virq != NO_IRQ) {
 890                 irq_radix_wrlock(&flags);
 891                 radix_tree_insert(tree, hwirq, &irq_map[virq]);
 892                 irq_radix_wrunlock(flags);
 893         }
 894         return virq;
 895 }
 896
 897 unsigned int irq_linear_revmap(struct irq_host *host,
 898                                irq_hw_number_t hwirq)
 899 {
 900         unsigned int *revmap;
 901
 902         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 903
 904         /* Check revmap bounds */
 905         if (unlikely(hwirq >= host->revmap_data.linear.size))
 906                 return irq_find_mapping(host, hwirq);
 907
 908         /* Check if revmap was allocated */
 909         revmap = host->revmap_data.linear.revmap;
 910         if (unlikely(revmap == NULL))
 911                 return irq_find_mapping(host, hwirq);
 912
 913         /* Fill up revmap with slow path if no mapping found */
 914         if (unlikely(revmap[hwirq] == NO_IRQ))
 915                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 916
 917         return revmap[hwirq];
 918 }
 919
 920 unsigned int irq_alloc_virt(struct irq_host *host,
 921                             unsigned int count,
 922                             unsigned int hint)
 923 {
 924         unsigned long flags;
 925         unsigned int i, j, found = NO_IRQ;
 926
 927         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 928                 return NO_IRQ;
 929
 930         spin_lock_irqsave(&irq_big_lock, flags);
 931
 932         /* Use hint for 1 interrupt if any */
 933         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 934             hint < irq_virq_count && irq_map[hint].host == NULL) {
 935                 found = hint;
 936                 goto hint_found;
 937         }
 938
 939         /* Look for count consecutive numbers in the allocatable
 940          * (non-legacy) space
 941          */
 942         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 943                 if (irq_map[i].host != NULL)
 944                         j = 0;
 945                 else
 946                         j++;
 947
 948                 if (j == count) {
 949                         found = i - count + 1;
 950                         break;
 951                 }
 952         }
 953         if (found == NO_IRQ) {
 954                 spin_unlock_irqrestore(&irq_big_lock, flags);
 955                 return NO_IRQ;
 956         }
 957  hint_found:
 958         for (i = found; i < (found + count); i++) {
 959                 irq_map[i].hwirq = host->inval_irq;
 960                 smp_wmb();
 961                 irq_map[i].host = host;
 962         }
 963         spin_unlock_irqrestore(&irq_big_lock, flags);
 964         return found;
 965 }
 966
 967 void irq_free_virt(unsigned int virq, unsigned int count)
 968 {
 969         unsigned long flags;
 970         unsigned int i;
 971
 972         WARN_ON (virq < NUM_ISA_INTERRUPTS);
 973         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 974
 975         spin_lock_irqsave(&irq_big_lock, flags);
 976         for (i = virq; i < (virq + count); i++) {
 977                 struct irq_host *host;
 978
 979                 if (i < NUM_ISA_INTERRUPTS ||
 980                     (virq + count) > irq_virq_count)
 981                         continue;
 982
 983                 host = irq_map[i].host;
 984                 irq_map[i].hwirq = host->inval_irq;
 985                 smp_wmb();
 986                 irq_map[i].host = NULL;
 987         }
 988         spin_unlock_irqrestore(&irq_big_lock, flags);
 989 }
 990
 991 void irq_early_init(void)
 992 {
 993         unsigned int i;
 994
 995         for (i = 0; i < NR_IRQS; i++)
 996                 get_irq_desc(i)->status |= IRQ_NOREQUEST;
 997 }
 998
 999 /* We need to create the radix trees late */
1000 static int irq_late_init(void)
1001 {
1002         struct irq_host *h;
1003         unsigned long flags;
1004
1005         irq_radix_wrlock(&flags);
1006         list_for_each_entry(h, &irq_hosts, link) {
1007                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1008                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
1009         }
1010         irq_radix_wrunlock(flags);
1011
1012         return 0;
1013 }
1014 arch_initcall(irq_late_init);
1015
1016 #ifdef CONFIG_VIRQ_DEBUG
1017 static int virq_debug_show(struct seq_file *m, void *private)
1018 {
1019         unsigned long flags;
1020         irq_desc_t *desc;
1021         const char *p;
1022         char none[] = "none";
1023         int i;
1024
1025         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1026                       "chip name", "host name");
1027
1028         for (i = 1; i < NR_IRQS; i++) {
1029                 desc = get_irq_desc(i);
1030                 spin_lock_irqsave(&desc->lock, flags);
1031
1032                 if (desc->action && desc->action->handler) {
1033                         seq_printf(m, "%5d  ", i);
1034                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1035
1036                         if (desc->chip && desc->chip->typename)
1037                                 p = desc->chip->typename;
1038                         else
1039                                 p = none;
1040                         seq_printf(m, "%-15s  ", p);
1041
1042                         if (irq_map[i].host && irq_map[i].host->of_node)
1043                                 p = irq_map[i].host->of_node->full_name;
1044                         else
1045                                 p = none;
1046                         seq_printf(m, "%s\n", p);
1047                 }
1048
1049                 spin_unlock_irqrestore(&desc->lock, flags);
1050         }
1051
1052         return 0;
1053 }
1054
1055 static int virq_debug_open(struct inode *inode, struct file *file)
1056 {
1057         return single_open(file, virq_debug_show, inode->i_private);
1058 }
1059
1060 static const struct file_operations virq_debug_fops = {
1061         .open = virq_debug_open,
1062         .read = seq_read,
1063         .llseek = seq_lseek,
1064         .release = single_release,
1065 };
1066
1067 static int __init irq_debugfs_init(void)
1068 {
1069         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1070                                  NULL, &virq_debug_fops))
1071                 return -ENOMEM;
1072
1073         return 0;
1074 }
1075 __initcall(irq_debugfs_init);
1076 #endif /* CONFIG_VIRQ_DEBUG */
1077
1078 #endif /* CONFIG_PPC_MERGE */
1079
1080 #ifdef CONFIG_PPC64
1081 static int __init setup_noirqdistrib(char *str)
1082 {
1083         distribute_irqs = 0;
1084         return 1;
1085 }
1086
1087 __setup("noirqdistrib", setup_noirqdistrib);
1088 #endif /* CONFIG_PPC64 */