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 #define CREATE_TRACE_POINTS
  73 #include <asm/trace.h>
  74
  75 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
  76 EXPORT_PER_CPU_SYMBOL(irq_stat);
  77
  78 int __irq_offset_value;
  79
  80 #ifdef CONFIG_PPC32
  81 EXPORT_SYMBOL(__irq_offset_value);
  82 atomic_t ppc_n_lost_interrupts;
  83
  84 #ifdef CONFIG_TAU_INT
  85 extern int tau_initialized;
  86 extern int tau_interrupts(int);
  87 #endif
  88 #endif /* CONFIG_PPC32 */
  89
  90 #ifdef CONFIG_PPC64
  91
  92 #ifndef CONFIG_SPARSE_IRQ
  93 EXPORT_SYMBOL(irq_desc);
  94 #endif
  95
  96 int distribute_irqs = 1;
  97
  98 static inline notrace unsigned long get_hard_enabled(void)
  99 {
 100         unsigned long enabled;
 101
 102         __asm__ __volatile__("lbz %0,%1(13)"
 103         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 104
 105         return enabled;
 106 }
 107
 108 static inline notrace void set_soft_enabled(unsigned long enable)
 109 {
 110         __asm__ __volatile__("stb %0,%1(13)"
 111         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 112 }
 113
 114 notrace void raw_local_irq_restore(unsigned long en)
 115 {
 116         /*
 117          * get_paca()->soft_enabled = en;
 118          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 119          * That was allowed before, and in such a case we do need to take care
 120          * that gcc will set soft_enabled directly via r13, not choose to use
 121          * an intermediate register, lest we're preempted to a different cpu.
 122          */
 123         set_soft_enabled(en);
 124         if (!en)
 125                 return;
 126
 127 #ifdef CONFIG_PPC_STD_MMU_64
 128         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 129                 /*
 130                  * Do we need to disable preemption here?  Not really: in the
 131                  * unlikely event that we're preempted to a different cpu in
 132                  * between getting r13, loading its lppaca_ptr, and loading
 133                  * its any_int, we might call iseries_handle_interrupts without
 134                  * an interrupt pending on the new cpu, but that's no disaster,
 135                  * is it?  And the business of preempting us off the old cpu
 136                  * would itself involve a local_irq_restore which handles the
 137                  * interrupt to that cpu.
 138                  *
 139                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 140                  * to avoid any preemption checking added into get_paca().
 141                  */
 142                 if (local_paca->lppaca_ptr->int_dword.any_int)
 143                         iseries_handle_interrupts();
 144         }
 145 #endif /* CONFIG_PPC_STD_MMU_64 */
 146
 147         /*
 148          * if (get_paca()->hard_enabled) return;
 149          * But again we need to take care that gcc gets hard_enabled directly
 150          * via r13, not choose to use an intermediate register, lest we're
 151          * preempted to a different cpu in between the two instructions.
 152          */
 153         if (get_hard_enabled())
 154                 return;
 155
 156         /*
 157          * Need to hard-enable interrupts here.  Since currently disabled,
 158          * no need to take further asm precautions against preemption; but
 159          * use local_paca instead of get_paca() to avoid preemption checking.
 160          */
 161         local_paca->hard_enabled = en;
 162         if ((int)mfspr(SPRN_DEC) < 0)
 163                 mtspr(SPRN_DEC, 1);
 164
 165         /*
 166          * Force the delivery of pending soft-disabled interrupts on PS3.
 167          * Any HV call will have this side effect.
 168          */
 169         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 170                 u64 tmp;
 171                 lv1_get_version_info(&tmp);
 172         }
 173
 174         __hard_irq_enable();
 175 }
 176 EXPORT_SYMBOL(raw_local_irq_restore);
 177 #endif /* CONFIG_PPC64 */
 178
 179 static int show_other_interrupts(struct seq_file *p, int prec)
 180 {
 181         int j;
 182
 183 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 184         if (tau_initialized) {
 185                 seq_printf(p, "%*s: ", prec, "TAU");
 186                 for_each_online_cpu(j)
 187                         seq_printf(p, "%10u ", tau_interrupts(j));
 188                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 189         }
 190 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
 191
 192         seq_printf(p, "%*s: ", prec, "LOC");
 193         for_each_online_cpu(j)
 194                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
 195         seq_printf(p, "  Local timer interrupts\n");
 196
 197         seq_printf(p, "%*s: ", prec, "SPU");
 198         for_each_online_cpu(j)
 199                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
 200         seq_printf(p, "  Spurious interrupts\n");
 201
 202         seq_printf(p, "%*s: ", prec, "CNT");
 203         for_each_online_cpu(j)
 204                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
 205         seq_printf(p, "  Performance monitoring interrupts\n");
 206
 207         seq_printf(p, "%*s: ", prec, "MCE");
 208         for_each_online_cpu(j)
 209                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
 210         seq_printf(p, "  Machine check exceptions\n");
 211
 212         return 0;
 213 }
 214
 215 int show_interrupts(struct seq_file *p, void *v)
 216 {
 217         unsigned long flags, any_count = 0;
 218         int i = *(loff_t *) v, j, prec;
 219         struct irqaction *action;
 220         struct irq_desc *desc;
 221
 222         if (i > nr_irqs)
 223                 return 0;
 224
 225         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
 226                 j *= 10;
 227
 228         if (i == nr_irqs)
 229                 return show_other_interrupts(p, prec);
 230
 231         /* print header */
 232         if (i == 0) {
 233                 seq_printf(p, "%*s", prec + 8, "");
 234                 for_each_online_cpu(j)
 235                         seq_printf(p, "CPU%-8d", j);
 236                 seq_putc(p, '\n');
 237         }
 238
 239         desc = irq_to_desc(i);
 240         if (!desc)
 241                 return 0;
 242
 243         raw_spin_lock_irqsave(&desc->lock, flags);
 244         for_each_online_cpu(j)
 245                 any_count |= kstat_irqs_cpu(i, j);
 246         action = desc->action;
 247         if (!action && !any_count)
 248                 goto out;
 249
 250         seq_printf(p, "%*d: ", prec, i);
 251         for_each_online_cpu(j)
 252                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 253
 254         if (desc->chip)
 255                 seq_printf(p, "  %-16s", desc->chip->name);
 256         else
 257                 seq_printf(p, "  %-16s", "None");
 258         seq_printf(p, " %-8s", (desc->status & IRQ_LEVEL) ? "Level" : "Edge");
 259
 260         if (action) {
 261                 seq_printf(p, "     %s", action->name);
 262                 while ((action = action->next) != NULL)
 263                         seq_printf(p, ", %s", action->name);
 264         }
 265
 266         seq_putc(p, '\n');
 267 out:
 268         raw_spin_unlock_irqrestore(&desc->lock, flags);
 269         return 0;
 270 }
 271
 272 /*
 273  * /proc/stat helpers
 274  */
 275 u64 arch_irq_stat_cpu(unsigned int cpu)
 276 {
 277         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
 278
 279         sum += per_cpu(irq_stat, cpu).pmu_irqs;
 280         sum += per_cpu(irq_stat, cpu).mce_exceptions;
 281         sum += per_cpu(irq_stat, cpu).spurious_irqs;
 282
 283         return sum;
 284 }
 285
 286 #ifdef CONFIG_HOTPLUG_CPU
 287 void fixup_irqs(cpumask_t map)
 288 {
 289         struct irq_desc *desc;
 290         unsigned int irq;
 291         static int warned;
 292
 293         for_each_irq(irq) {
 294                 cpumask_t mask;
 295
 296                 desc = irq_to_desc(irq);
 297                 if (desc && desc->status & IRQ_PER_CPU)
 298                         continue;
 299
 300                 cpumask_and(&mask, desc->affinity, &map);
 301                 if (any_online_cpu(mask) == NR_CPUS) {
 302                         printk("Breaking affinity for irq %i\n", irq);
 303                         mask = map;
 304                 }
 305                 if (desc->chip->set_affinity)
 306                         desc->chip->set_affinity(irq, &mask);
 307                 else if (desc->action && !(warned++))
 308                         printk("Cannot set affinity for irq %i\n", irq);
 309         }
 310
 311         local_irq_enable();
 312         mdelay(1);
 313         local_irq_disable();
 314 }
 315 #endif
 316
 317 #ifdef CONFIG_IRQSTACKS
 318 static inline void handle_one_irq(unsigned int irq)
 319 {
 320         struct thread_info *curtp, *irqtp;
 321         unsigned long saved_sp_limit;
 322         struct irq_desc *desc;
 323
 324         /* Switch to the irq stack to handle this */
 325         curtp = current_thread_info();
 326         irqtp = hardirq_ctx[smp_processor_id()];
 327
 328         if (curtp == irqtp) {
 329                 /* We're already on the irq stack, just handle it */
 330                 generic_handle_irq(irq);
 331                 return;
 332         }
 333
 334         desc = irq_to_desc(irq);
 335         saved_sp_limit = current->thread.ksp_limit;
 336
 337         irqtp->task = curtp->task;
 338         irqtp->flags = 0;
 339
 340         /* Copy the softirq bits in preempt_count so that the
 341          * softirq checks work in the hardirq context. */
 342         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 343                                (curtp->preempt_count & SOFTIRQ_MASK);
 344
 345         current->thread.ksp_limit = (unsigned long)irqtp +
 346                 _ALIGN_UP(sizeof(struct thread_info), 16);
 347
 348         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 349         current->thread.ksp_limit = saved_sp_limit;
 350         irqtp->task = NULL;
 351
 352         /* Set any flag that may have been set on the
 353          * alternate stack
 354          */
 355         if (irqtp->flags)
 356                 set_bits(irqtp->flags, &curtp->flags);
 357 }
 358 #else
 359 static inline void handle_one_irq(unsigned int irq)
 360 {
 361         generic_handle_irq(irq);
 362 }
 363 #endif
 364
 365 static inline void check_stack_overflow(void)
 366 {
 367 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 368         long sp;
 369
 370         sp = __get_SP() & (THREAD_SIZE-1);
 371
 372         /* check for stack overflow: is there less than 2KB free? */
 373         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 374                 printk("do_IRQ: stack overflow: %ld\n",
 375                         sp - sizeof(struct thread_info));
 376                 dump_stack();
 377         }
 378 #endif
 379 }
 380
 381 void do_IRQ(struct pt_regs *regs)
 382 {
 383         struct pt_regs *old_regs = set_irq_regs(regs);
 384         unsigned int irq;
 385
 386         trace_irq_entry(regs);
 387
 388         irq_enter();
 389
 390         check_stack_overflow();
 391
 392         irq = ppc_md.get_irq();
 393
 394         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 395                 handle_one_irq(irq);
 396         else if (irq != NO_IRQ_IGNORE)
 397                 __get_cpu_var(irq_stat).spurious_irqs++;
 398
 399         irq_exit();
 400         set_irq_regs(old_regs);
 401
 402 #ifdef CONFIG_PPC_ISERIES
 403         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 404                         get_lppaca()->int_dword.fields.decr_int) {
 405                 get_lppaca()->int_dword.fields.decr_int = 0;
 406                 /* Signal a fake decrementer interrupt */
 407                 timer_interrupt(regs);
 408         }
 409 #endif
 410
 411         trace_irq_exit(regs);
 412 }
 413
 414 void __init init_IRQ(void)
 415 {
 416         if (ppc_md.init_IRQ)
 417                 ppc_md.init_IRQ();
 418
 419         exc_lvl_ctx_init();
 420
 421         irq_ctx_init();
 422 }
 423
 424 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 425 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 426 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 427 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 428
 429 void exc_lvl_ctx_init(void)
 430 {
 431         struct thread_info *tp;
 432         int i;
 433
 434         for_each_possible_cpu(i) {
 435                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 436                 tp = critirq_ctx[i];
 437                 tp->cpu = i;
 438                 tp->preempt_count = 0;
 439
 440 #ifdef CONFIG_BOOKE
 441                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 442                 tp = dbgirq_ctx[i];
 443                 tp->cpu = i;
 444                 tp->preempt_count = 0;
 445
 446                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 447                 tp = mcheckirq_ctx[i];
 448                 tp->cpu = i;
 449                 tp->preempt_count = HARDIRQ_OFFSET;
 450 #endif
 451         }
 452 }
 453 #endif
 454
 455 #ifdef CONFIG_IRQSTACKS
 456 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 457 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 458
 459 void irq_ctx_init(void)
 460 {
 461         struct thread_info *tp;
 462         int i;
 463
 464         for_each_possible_cpu(i) {
 465                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 466                 tp = softirq_ctx[i];
 467                 tp->cpu = i;
 468                 tp->preempt_count = 0;
 469
 470                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 471                 tp = hardirq_ctx[i];
 472                 tp->cpu = i;
 473                 tp->preempt_count = HARDIRQ_OFFSET;
 474         }
 475 }
 476
 477 static inline void do_softirq_onstack(void)
 478 {
 479         struct thread_info *curtp, *irqtp;
 480         unsigned long saved_sp_limit = current->thread.ksp_limit;
 481
 482         curtp = current_thread_info();
 483         irqtp = softirq_ctx[smp_processor_id()];
 484         irqtp->task = curtp->task;
 485         current->thread.ksp_limit = (unsigned long)irqtp +
 486                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 487         call_do_softirq(irqtp);
 488         current->thread.ksp_limit = saved_sp_limit;
 489         irqtp->task = NULL;
 490 }
 491
 492 #else
 493 #define do_softirq_onstack()    __do_softirq()
 494 #endif /* CONFIG_IRQSTACKS */
 495
 496 void do_softirq(void)
 497 {
 498         unsigned long flags;
 499
 500         if (in_interrupt())
 501                 return;
 502
 503         local_irq_save(flags);
 504
 505         if (local_softirq_pending())
 506                 do_softirq_onstack();
 507
 508         local_irq_restore(flags);
 509 }
 510
 511
 512 /*
 513  * IRQ controller and virtual interrupts
 514  */
 515
 516 static LIST_HEAD(irq_hosts);
 517 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 518 static unsigned int revmap_trees_allocated;
 519 static DEFINE_MUTEX(revmap_trees_mutex);
 520 struct irq_map_entry irq_map[NR_IRQS];
 521 static unsigned int irq_virq_count = NR_IRQS;
 522 static struct irq_host *irq_default_host;
 523
 524 irq_hw_number_t virq_to_hw(unsigned int virq)
 525 {
 526         return irq_map[virq].hwirq;
 527 }
 528 EXPORT_SYMBOL_GPL(virq_to_hw);
 529
 530 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 531 {
 532         return h->of_node != NULL && h->of_node == np;
 533 }
 534
 535 struct irq_host *irq_alloc_host(struct device_node *of_node,
 536                                 unsigned int revmap_type,
 537                                 unsigned int revmap_arg,
 538                                 struct irq_host_ops *ops,
 539                                 irq_hw_number_t inval_irq)
 540 {
 541         struct irq_host *host;
 542         unsigned int size = sizeof(struct irq_host);
 543         unsigned int i;
 544         unsigned int *rmap;
 545         unsigned long flags;
 546
 547         /* Allocate structure and revmap table if using linear mapping */
 548         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 549                 size += revmap_arg * sizeof(unsigned int);
 550         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 551         if (host == NULL)
 552                 return NULL;
 553
 554         /* Fill structure */
 555         host->revmap_type = revmap_type;
 556         host->inval_irq = inval_irq;
 557         host->ops = ops;
 558         host->of_node = of_node_get(of_node);
 559
 560         if (host->ops->match == NULL)
 561                 host->ops->match = default_irq_host_match;
 562
 563         raw_spin_lock_irqsave(&irq_big_lock, flags);
 564
 565         /* If it's a legacy controller, check for duplicates and
 566          * mark it as allocated (we use irq 0 host pointer for that
 567          */
 568         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 569                 if (irq_map[0].host != NULL) {
 570                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 571                         /* If we are early boot, we can't free the structure,
 572                          * too bad...
 573                          * this will be fixed once slab is made available early
 574                          * instead of the current cruft
 575                          */
 576                         if (mem_init_done)
 577                                 kfree(host);
 578                         return NULL;
 579                 }
 580                 irq_map[0].host = host;
 581         }
 582
 583         list_add(&host->link, &irq_hosts);
 584         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 585
 586         /* Additional setups per revmap type */
 587         switch(revmap_type) {
 588         case IRQ_HOST_MAP_LEGACY:
 589                 /* 0 is always the invalid number for legacy */
 590                 host->inval_irq = 0;
 591                 /* setup us as the host for all legacy interrupts */
 592                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 593                         irq_map[i].hwirq = i;
 594                         smp_wmb();
 595                         irq_map[i].host = host;
 596                         smp_wmb();
 597
 598                         /* Clear norequest flags */
 599                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
 600
 601                         /* Legacy flags are left to default at this point,
 602                          * one can then use irq_create_mapping() to
 603                          * explicitly change them
 604                          */
 605                         ops->map(host, i, i);
 606                 }
 607                 break;
 608         case IRQ_HOST_MAP_LINEAR:
 609                 rmap = (unsigned int *)(host + 1);
 610                 for (i = 0; i < revmap_arg; i++)
 611                         rmap[i] = NO_IRQ;
 612                 host->revmap_data.linear.size = revmap_arg;
 613                 smp_wmb();
 614                 host->revmap_data.linear.revmap = rmap;
 615                 break;
 616         default:
 617                 break;
 618         }
 619
 620         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 621
 622         return host;
 623 }
 624
 625 struct irq_host *irq_find_host(struct device_node *node)
 626 {
 627         struct irq_host *h, *found = NULL;
 628         unsigned long flags;
 629
 630         /* We might want to match the legacy controller last since
 631          * it might potentially be set to match all interrupts in
 632          * the absence of a device node. This isn't a problem so far
 633          * yet though...
 634          */
 635         raw_spin_lock_irqsave(&irq_big_lock, flags);
 636         list_for_each_entry(h, &irq_hosts, link)
 637                 if (h->ops->match(h, node)) {
 638                         found = h;
 639                         break;
 640                 }
 641         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 642         return found;
 643 }
 644 EXPORT_SYMBOL_GPL(irq_find_host);
 645
 646 void irq_set_default_host(struct irq_host *host)
 647 {
 648         pr_debug("irq: Default host set to @0x%p\n", host);
 649
 650         irq_default_host = host;
 651 }
 652
 653 void irq_set_virq_count(unsigned int count)
 654 {
 655         pr_debug("irq: Trying to set virq count to %d\n", count);
 656
 657         BUG_ON(count < NUM_ISA_INTERRUPTS);
 658         if (count < NR_IRQS)
 659                 irq_virq_count = count;
 660 }
 661
 662 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 663                             irq_hw_number_t hwirq)
 664 {
 665         struct irq_desc *desc;
 666
 667         desc = irq_to_desc_alloc_node(virq, 0);
 668         if (!desc) {
 669                 pr_debug("irq: -> allocating desc failed\n");
 670                 goto error;
 671         }
 672
 673         /* Clear IRQ_NOREQUEST flag */
 674         desc->status &= ~IRQ_NOREQUEST;
 675
 676         /* map it */
 677         smp_wmb();
 678         irq_map[virq].hwirq = hwirq;
 679         smp_mb();
 680
 681         if (host->ops->map(host, virq, hwirq)) {
 682                 pr_debug("irq: -> mapping failed, freeing\n");
 683                 goto error;
 684         }
 685
 686         return 0;
 687
 688 error:
 689         irq_free_virt(virq, 1);
 690         return -1;
 691 }
 692
 693 unsigned int irq_create_direct_mapping(struct irq_host *host)
 694 {
 695         unsigned int virq;
 696
 697         if (host == NULL)
 698                 host = irq_default_host;
 699
 700         BUG_ON(host == NULL);
 701         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 702
 703         virq = irq_alloc_virt(host, 1, 0);
 704         if (virq == NO_IRQ) {
 705                 pr_debug("irq: create_direct virq allocation failed\n");
 706                 return NO_IRQ;
 707         }
 708
 709         pr_debug("irq: create_direct obtained virq %d\n", virq);
 710
 711         if (irq_setup_virq(host, virq, virq))
 712                 return NO_IRQ;
 713
 714         return virq;
 715 }
 716
 717 unsigned int irq_create_mapping(struct irq_host *host,
 718                                 irq_hw_number_t hwirq)
 719 {
 720         unsigned int virq, hint;
 721
 722         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 723
 724         /* Look for default host if nececssary */
 725         if (host == NULL)
 726                 host = irq_default_host;
 727         if (host == NULL) {
 728                 printk(KERN_WARNING "irq_create_mapping called for"
 729                        " NULL host, hwirq=%lx\n", hwirq);
 730                 WARN_ON(1);
 731                 return NO_IRQ;
 732         }
 733         pr_debug("irq: -> using host @%p\n", host);
 734
 735         /* Check if mapping already exist, if it does, call
 736          * host->ops->map() to update the flags
 737          */
 738         virq = irq_find_mapping(host, hwirq);
 739         if (virq != NO_IRQ) {
 740                 if (host->ops->remap)
 741                         host->ops->remap(host, virq, hwirq);
 742                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 743                 return virq;
 744         }
 745
 746         /* Get a virtual interrupt number */
 747         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 748                 /* Handle legacy */
 749                 virq = (unsigned int)hwirq;
 750                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 751                         return NO_IRQ;
 752                 return virq;
 753         } else {
 754                 /* Allocate a virtual interrupt number */
 755                 hint = hwirq % irq_virq_count;
 756                 virq = irq_alloc_virt(host, 1, hint);
 757                 if (virq == NO_IRQ) {
 758                         pr_debug("irq: -> virq allocation failed\n");
 759                         return NO_IRQ;
 760                 }
 761         }
 762
 763         if (irq_setup_virq(host, virq, hwirq))
 764                 return NO_IRQ;
 765
 766         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 767                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 768
 769         return virq;
 770 }
 771 EXPORT_SYMBOL_GPL(irq_create_mapping);
 772
 773 unsigned int irq_create_of_mapping(struct device_node *controller,
 774                                    const u32 *intspec, unsigned int intsize)
 775 {
 776         struct irq_host *host;
 777         irq_hw_number_t hwirq;
 778         unsigned int type = IRQ_TYPE_NONE;
 779         unsigned int virq;
 780
 781         if (controller == NULL)
 782                 host = irq_default_host;
 783         else
 784                 host = irq_find_host(controller);
 785         if (host == NULL) {
 786                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 787                        controller->full_name);
 788                 return NO_IRQ;
 789         }
 790
 791         /* If host has no translation, then we assume interrupt line */
 792         if (host->ops->xlate == NULL)
 793                 hwirq = intspec[0];
 794         else {
 795                 if (host->ops->xlate(host, controller, intspec, intsize,
 796                                      &hwirq, &type))
 797                         return NO_IRQ;
 798         }
 799
 800         /* Create mapping */
 801         virq = irq_create_mapping(host, hwirq);
 802         if (virq == NO_IRQ)
 803                 return virq;
 804
 805         /* Set type if specified and different than the current one */
 806         if (type != IRQ_TYPE_NONE &&
 807             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
 808                 set_irq_type(virq, type);
 809         return virq;
 810 }
 811 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 812
 813 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 814 {
 815         struct of_irq oirq;
 816
 817         if (of_irq_map_one(dev, index, &oirq))
 818                 return NO_IRQ;
 819
 820         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 821                                      oirq.size);
 822 }
 823 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 824
 825 void irq_dispose_mapping(unsigned int virq)
 826 {
 827         struct irq_host *host;
 828         irq_hw_number_t hwirq;
 829
 830         if (virq == NO_IRQ)
 831                 return;
 832
 833         host = irq_map[virq].host;
 834         WARN_ON (host == NULL);
 835         if (host == NULL)
 836                 return;
 837
 838         /* Never unmap legacy interrupts */
 839         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 840                 return;
 841
 842         /* remove chip and handler */
 843         set_irq_chip_and_handler(virq, NULL, NULL);
 844
 845         /* Make sure it's completed */
 846         synchronize_irq(virq);
 847
 848         /* Tell the PIC about it */
 849         if (host->ops->unmap)
 850                 host->ops->unmap(host, virq);
 851         smp_mb();
 852
 853         /* Clear reverse map */
 854         hwirq = irq_map[virq].hwirq;
 855         switch(host->revmap_type) {
 856         case IRQ_HOST_MAP_LINEAR:
 857                 if (hwirq < host->revmap_data.linear.size)
 858                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 859                 break;
 860         case IRQ_HOST_MAP_TREE:
 861                 /*
 862                  * Check if radix tree allocated yet, if not then nothing to
 863                  * remove.
 864                  */
 865                 smp_rmb();
 866                 if (revmap_trees_allocated < 1)
 867                         break;
 868                 mutex_lock(&revmap_trees_mutex);
 869                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 870                 mutex_unlock(&revmap_trees_mutex);
 871                 break;
 872         }
 873
 874         /* Destroy map */
 875         smp_mb();
 876         irq_map[virq].hwirq = host->inval_irq;
 877
 878         /* Set some flags */
 879         irq_to_desc(virq)->status |= IRQ_NOREQUEST;
 880
 881         /* Free it */
 882         irq_free_virt(virq, 1);
 883 }
 884 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 885
 886 unsigned int irq_find_mapping(struct irq_host *host,
 887                               irq_hw_number_t hwirq)
 888 {
 889         unsigned int i;
 890         unsigned int hint = hwirq % irq_virq_count;
 891
 892         /* Look for default host if nececssary */
 893         if (host == NULL)
 894                 host = irq_default_host;
 895         if (host == NULL)
 896                 return NO_IRQ;
 897
 898         /* legacy -> bail early */
 899         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 900                 return hwirq;
 901
 902         /* Slow path does a linear search of the map */
 903         if (hint < NUM_ISA_INTERRUPTS)
 904                 hint = NUM_ISA_INTERRUPTS;
 905         i = hint;
 906         do  {
 907                 if (irq_map[i].host == host &&
 908                     irq_map[i].hwirq == hwirq)
 909                         return i;
 910                 i++;
 911                 if (i >= irq_virq_count)
 912                         i = NUM_ISA_INTERRUPTS;
 913         } while(i != hint);
 914         return NO_IRQ;
 915 }
 916 EXPORT_SYMBOL_GPL(irq_find_mapping);
 917
 918
 919 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 920                                      irq_hw_number_t hwirq)
 921 {
 922         struct irq_map_entry *ptr;
 923         unsigned int virq;
 924
 925         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 926
 927         /*
 928          * Check if the radix tree exists and has bee initialized.
 929          * If not, we fallback to slow mode
 930          */
 931         if (revmap_trees_allocated < 2)
 932                 return irq_find_mapping(host, hwirq);
 933
 934         /* Now try to resolve */
 935         /*
 936          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 937          * as it's referencing an entry in the static irq_map table.
 938          */
 939         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 940
 941         /*
 942          * If found in radix tree, then fine.
 943          * Else fallback to linear lookup - this should not happen in practice
 944          * as it means that we failed to insert the node in the radix tree.
 945          */
 946         if (ptr)
 947                 virq = ptr - irq_map;
 948         else
 949                 virq = irq_find_mapping(host, hwirq);
 950
 951         return virq;
 952 }
 953
 954 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 955                              irq_hw_number_t hwirq)
 956 {
 957
 958         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 959
 960         /*
 961          * Check if the radix tree exists yet.
 962          * If not, then the irq will be inserted into the tree when it gets
 963          * initialized.
 964          */
 965         smp_rmb();
 966         if (revmap_trees_allocated < 1)
 967                 return;
 968
 969         if (virq != NO_IRQ) {
 970                 mutex_lock(&revmap_trees_mutex);
 971                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 972                                   &irq_map[virq]);
 973                 mutex_unlock(&revmap_trees_mutex);
 974         }
 975 }
 976
 977 unsigned int irq_linear_revmap(struct irq_host *host,
 978                                irq_hw_number_t hwirq)
 979 {
 980         unsigned int *revmap;
 981
 982         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 983
 984         /* Check revmap bounds */
 985         if (unlikely(hwirq >= host->revmap_data.linear.size))
 986                 return irq_find_mapping(host, hwirq);
 987
 988         /* Check if revmap was allocated */
 989         revmap = host->revmap_data.linear.revmap;
 990         if (unlikely(revmap == NULL))
 991                 return irq_find_mapping(host, hwirq);
 992
 993         /* Fill up revmap with slow path if no mapping found */
 994         if (unlikely(revmap[hwirq] == NO_IRQ))
 995                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 996
 997         return revmap[hwirq];
 998 }
 999
1000 unsigned int irq_alloc_virt(struct irq_host *host,
1001                             unsigned int count,
1002                             unsigned int hint)
1003 {
1004         unsigned long flags;
1005         unsigned int i, j, found = NO_IRQ;
1006
1007         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
1008                 return NO_IRQ;
1009
1010         raw_spin_lock_irqsave(&irq_big_lock, flags);
1011
1012         /* Use hint for 1 interrupt if any */
1013         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
1014             hint < irq_virq_count && irq_map[hint].host == NULL) {
1015                 found = hint;
1016                 goto hint_found;
1017         }
1018
1019         /* Look for count consecutive numbers in the allocatable
1020          * (non-legacy) space
1021          */
1022         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1023                 if (irq_map[i].host != NULL)
1024                         j = 0;
1025                 else
1026                         j++;
1027
1028                 if (j == count) {
1029                         found = i - count + 1;
1030                         break;
1031                 }
1032         }
1033         if (found == NO_IRQ) {
1034                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1035                 return NO_IRQ;
1036         }
1037  hint_found:
1038         for (i = found; i < (found + count); i++) {
1039                 irq_map[i].hwirq = host->inval_irq;
1040                 smp_wmb();
1041                 irq_map[i].host = host;
1042         }
1043         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1044         return found;
1045 }
1046
1047 void irq_free_virt(unsigned int virq, unsigned int count)
1048 {
1049         unsigned long flags;
1050         unsigned int i;
1051
1052         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1053         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1054
1055         raw_spin_lock_irqsave(&irq_big_lock, flags);
1056         for (i = virq; i < (virq + count); i++) {
1057                 struct irq_host *host;
1058
1059                 if (i < NUM_ISA_INTERRUPTS ||
1060                     (virq + count) > irq_virq_count)
1061                         continue;
1062
1063                 host = irq_map[i].host;
1064                 irq_map[i].hwirq = host->inval_irq;
1065                 smp_wmb();
1066                 irq_map[i].host = NULL;
1067         }
1068         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1069 }
1070
1071 int arch_early_irq_init(void)
1072 {
1073         struct irq_desc *desc;
1074         int i;
1075
1076         for (i = 0; i < NR_IRQS; i++) {
1077                 desc = irq_to_desc(i);
1078                 if (desc)
1079                         desc->status |= IRQ_NOREQUEST;
1080         }
1081
1082         return 0;
1083 }
1084
1085 int arch_init_chip_data(struct irq_desc *desc, int node)
1086 {
1087         desc->status |= IRQ_NOREQUEST;
1088         return 0;
1089 }
1090
1091 /* We need to create the radix trees late */
1092 static int irq_late_init(void)
1093 {
1094         struct irq_host *h;
1095         unsigned int i;
1096
1097         /*
1098          * No mutual exclusion with respect to accessors of the tree is needed
1099          * here as the synchronization is done via the state variable
1100          * revmap_trees_allocated.
1101          */
1102         list_for_each_entry(h, &irq_hosts, link) {
1103                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1104                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1105         }
1106
1107         /*
1108          * Make sure the radix trees inits are visible before setting
1109          * the flag
1110          */
1111         smp_wmb();
1112         revmap_trees_allocated = 1;
1113
1114         /*
1115          * Insert the reverse mapping for those interrupts already present
1116          * in irq_map[].
1117          */
1118         mutex_lock(&revmap_trees_mutex);
1119         for (i = 0; i < irq_virq_count; i++) {
1120                 if (irq_map[i].host &&
1121                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1122                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1123                                           irq_map[i].hwirq, &irq_map[i]);
1124         }
1125         mutex_unlock(&revmap_trees_mutex);
1126
1127         /*
1128          * Make sure the radix trees insertions are visible before setting
1129          * the flag
1130          */
1131         smp_wmb();
1132         revmap_trees_allocated = 2;
1133
1134         return 0;
1135 }
1136 arch_initcall(irq_late_init);
1137
1138 #ifdef CONFIG_VIRQ_DEBUG
1139 static int virq_debug_show(struct seq_file *m, void *private)
1140 {
1141         unsigned long flags;
1142         struct irq_desc *desc;
1143         const char *p;
1144         char none[] = "none";
1145         int i;
1146
1147         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1148                       "chip name", "host name");
1149
1150         for (i = 1; i < nr_irqs; i++) {
1151                 desc = irq_to_desc(i);
1152                 if (!desc)
1153                         continue;
1154
1155                 raw_spin_lock_irqsave(&desc->lock, flags);
1156
1157                 if (desc->action && desc->action->handler) {
1158                         seq_printf(m, "%5d  ", i);
1159                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1160
1161                         if (desc->chip && desc->chip->name)
1162                                 p = desc->chip->name;
1163                         else
1164                                 p = none;
1165                         seq_printf(m, "%-15s  ", p);
1166
1167                         if (irq_map[i].host && irq_map[i].host->of_node)
1168                                 p = irq_map[i].host->of_node->full_name;
1169                         else
1170                                 p = none;
1171                         seq_printf(m, "%s\n", p);
1172                 }
1173
1174                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1175         }
1176
1177         return 0;
1178 }
1179
1180 static int virq_debug_open(struct inode *inode, struct file *file)
1181 {
1182         return single_open(file, virq_debug_show, inode->i_private);
1183 }
1184
1185 static const struct file_operations virq_debug_fops = {
1186         .open = virq_debug_open,
1187         .read = seq_read,
1188         .llseek = seq_lseek,
1189         .release = single_release,
1190 };
1191
1192 static int __init irq_debugfs_init(void)
1193 {
1194         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1195                                  NULL, &virq_debug_fops) == NULL)
1196                 return -ENOMEM;
1197
1198         return 0;
1199 }
1200 __initcall(irq_debugfs_init);
1201 #endif /* CONFIG_VIRQ_DEBUG */
1202
1203 #ifdef CONFIG_PPC64
1204 static int __init setup_noirqdistrib(char *str)
1205 {
1206         distribute_irqs = 0;
1207         return 1;
1208 }
1209
1210 __setup("noirqdistrib", setup_noirqdistrib);
1211 #endif /* CONFIG_PPC64 */