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(const struct cpumask *map)
 288 {
 289         struct irq_desc *desc;
 290         unsigned int irq;
 291         static int warned;
 292         cpumask_var_t mask;
 293
 294         alloc_cpumask_var(&mask, GFP_KERNEL);
 295
 296         for_each_irq(irq) {
 297                 desc = irq_to_desc(irq);
 298                 if (desc && desc->status & IRQ_PER_CPU)
 299                         continue;
 300
 301                 cpumask_and(mask, desc->affinity, map);
 302                 if (cpumask_any(mask) >= nr_cpu_ids) {
 303                         printk("Breaking affinity for irq %i\n", irq);
 304                         cpumask_copy(mask, map);
 305                 }
 306                 if (desc->chip->set_affinity)
 307                         desc->chip->set_affinity(irq, mask);
 308                 else if (desc->action && !(warned++))
 309                         printk("Cannot set affinity for irq %i\n", irq);
 310         }
 311
 312         free_cpumask_var(mask);
 313
 314         local_irq_enable();
 315         mdelay(1);
 316         local_irq_disable();
 317 }
 318 #endif
 319
 320 #ifdef CONFIG_IRQSTACKS
 321 static inline void handle_one_irq(unsigned int irq)
 322 {
 323         struct thread_info *curtp, *irqtp;
 324         unsigned long saved_sp_limit;
 325         struct irq_desc *desc;
 326
 327         /* Switch to the irq stack to handle this */
 328         curtp = current_thread_info();
 329         irqtp = hardirq_ctx[smp_processor_id()];
 330
 331         if (curtp == irqtp) {
 332                 /* We're already on the irq stack, just handle it */
 333                 generic_handle_irq(irq);
 334                 return;
 335         }
 336
 337         desc = irq_to_desc(irq);
 338         saved_sp_limit = current->thread.ksp_limit;
 339
 340         irqtp->task = curtp->task;
 341         irqtp->flags = 0;
 342
 343         /* Copy the softirq bits in preempt_count so that the
 344          * softirq checks work in the hardirq context. */
 345         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 346                                (curtp->preempt_count & SOFTIRQ_MASK);
 347
 348         current->thread.ksp_limit = (unsigned long)irqtp +
 349                 _ALIGN_UP(sizeof(struct thread_info), 16);
 350
 351         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 352         current->thread.ksp_limit = saved_sp_limit;
 353         irqtp->task = NULL;
 354
 355         /* Set any flag that may have been set on the
 356          * alternate stack
 357          */
 358         if (irqtp->flags)
 359                 set_bits(irqtp->flags, &curtp->flags);
 360 }
 361 #else
 362 static inline void handle_one_irq(unsigned int irq)
 363 {
 364         generic_handle_irq(irq);
 365 }
 366 #endif
 367
 368 static inline void check_stack_overflow(void)
 369 {
 370 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 371         long sp;
 372
 373         sp = __get_SP() & (THREAD_SIZE-1);
 374
 375         /* check for stack overflow: is there less than 2KB free? */
 376         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 377                 printk("do_IRQ: stack overflow: %ld\n",
 378                         sp - sizeof(struct thread_info));
 379                 dump_stack();
 380         }
 381 #endif
 382 }
 383
 384 void do_IRQ(struct pt_regs *regs)
 385 {
 386         struct pt_regs *old_regs = set_irq_regs(regs);
 387         unsigned int irq;
 388
 389         trace_irq_entry(regs);
 390
 391         irq_enter();
 392
 393         check_stack_overflow();
 394
 395         irq = ppc_md.get_irq();
 396
 397         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 398                 handle_one_irq(irq);
 399         else if (irq != NO_IRQ_IGNORE)
 400                 __get_cpu_var(irq_stat).spurious_irqs++;
 401
 402         irq_exit();
 403         set_irq_regs(old_regs);
 404
 405 #ifdef CONFIG_PPC_ISERIES
 406         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 407                         get_lppaca()->int_dword.fields.decr_int) {
 408                 get_lppaca()->int_dword.fields.decr_int = 0;
 409                 /* Signal a fake decrementer interrupt */
 410                 timer_interrupt(regs);
 411         }
 412 #endif
 413
 414         trace_irq_exit(regs);
 415 }
 416
 417 void __init init_IRQ(void)
 418 {
 419         if (ppc_md.init_IRQ)
 420                 ppc_md.init_IRQ();
 421
 422         exc_lvl_ctx_init();
 423
 424         irq_ctx_init();
 425 }
 426
 427 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 428 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 429 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 430 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 431
 432 void exc_lvl_ctx_init(void)
 433 {
 434         struct thread_info *tp;
 435         int i;
 436
 437         for_each_possible_cpu(i) {
 438                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 439                 tp = critirq_ctx[i];
 440                 tp->cpu = i;
 441                 tp->preempt_count = 0;
 442
 443 #ifdef CONFIG_BOOKE
 444                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 445                 tp = dbgirq_ctx[i];
 446                 tp->cpu = i;
 447                 tp->preempt_count = 0;
 448
 449                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 450                 tp = mcheckirq_ctx[i];
 451                 tp->cpu = i;
 452                 tp->preempt_count = HARDIRQ_OFFSET;
 453 #endif
 454         }
 455 }
 456 #endif
 457
 458 #ifdef CONFIG_IRQSTACKS
 459 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 460 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 461
 462 void irq_ctx_init(void)
 463 {
 464         struct thread_info *tp;
 465         int i;
 466
 467         for_each_possible_cpu(i) {
 468                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 469                 tp = softirq_ctx[i];
 470                 tp->cpu = i;
 471                 tp->preempt_count = 0;
 472
 473                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 474                 tp = hardirq_ctx[i];
 475                 tp->cpu = i;
 476                 tp->preempt_count = HARDIRQ_OFFSET;
 477         }
 478 }
 479
 480 static inline void do_softirq_onstack(void)
 481 {
 482         struct thread_info *curtp, *irqtp;
 483         unsigned long saved_sp_limit = current->thread.ksp_limit;
 484
 485         curtp = current_thread_info();
 486         irqtp = softirq_ctx[smp_processor_id()];
 487         irqtp->task = curtp->task;
 488         current->thread.ksp_limit = (unsigned long)irqtp +
 489                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 490         call_do_softirq(irqtp);
 491         current->thread.ksp_limit = saved_sp_limit;
 492         irqtp->task = NULL;
 493 }
 494
 495 #else
 496 #define do_softirq_onstack()    __do_softirq()
 497 #endif /* CONFIG_IRQSTACKS */
 498
 499 void do_softirq(void)
 500 {
 501         unsigned long flags;
 502
 503         if (in_interrupt())
 504                 return;
 505
 506         local_irq_save(flags);
 507
 508         if (local_softirq_pending())
 509                 do_softirq_onstack();
 510
 511         local_irq_restore(flags);
 512 }
 513
 514
 515 /*
 516  * IRQ controller and virtual interrupts
 517  */
 518
 519 static LIST_HEAD(irq_hosts);
 520 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 521 static unsigned int revmap_trees_allocated;
 522 static DEFINE_MUTEX(revmap_trees_mutex);
 523 struct irq_map_entry irq_map[NR_IRQS];
 524 static unsigned int irq_virq_count = NR_IRQS;
 525 static struct irq_host *irq_default_host;
 526
 527 irq_hw_number_t virq_to_hw(unsigned int virq)
 528 {
 529         return irq_map[virq].hwirq;
 530 }
 531 EXPORT_SYMBOL_GPL(virq_to_hw);
 532
 533 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 534 {
 535         return h->of_node != NULL && h->of_node == np;
 536 }
 537
 538 struct irq_host *irq_alloc_host(struct device_node *of_node,
 539                                 unsigned int revmap_type,
 540                                 unsigned int revmap_arg,
 541                                 struct irq_host_ops *ops,
 542                                 irq_hw_number_t inval_irq)
 543 {
 544         struct irq_host *host;
 545         unsigned int size = sizeof(struct irq_host);
 546         unsigned int i;
 547         unsigned int *rmap;
 548         unsigned long flags;
 549
 550         /* Allocate structure and revmap table if using linear mapping */
 551         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 552                 size += revmap_arg * sizeof(unsigned int);
 553         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 554         if (host == NULL)
 555                 return NULL;
 556
 557         /* Fill structure */
 558         host->revmap_type = revmap_type;
 559         host->inval_irq = inval_irq;
 560         host->ops = ops;
 561         host->of_node = of_node_get(of_node);
 562
 563         if (host->ops->match == NULL)
 564                 host->ops->match = default_irq_host_match;
 565
 566         raw_spin_lock_irqsave(&irq_big_lock, flags);
 567
 568         /* If it's a legacy controller, check for duplicates and
 569          * mark it as allocated (we use irq 0 host pointer for that
 570          */
 571         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 572                 if (irq_map[0].host != NULL) {
 573                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 574                         /* If we are early boot, we can't free the structure,
 575                          * too bad...
 576                          * this will be fixed once slab is made available early
 577                          * instead of the current cruft
 578                          */
 579                         if (mem_init_done)
 580                                 kfree(host);
 581                         return NULL;
 582                 }
 583                 irq_map[0].host = host;
 584         }
 585
 586         list_add(&host->link, &irq_hosts);
 587         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 588
 589         /* Additional setups per revmap type */
 590         switch(revmap_type) {
 591         case IRQ_HOST_MAP_LEGACY:
 592                 /* 0 is always the invalid number for legacy */
 593                 host->inval_irq = 0;
 594                 /* setup us as the host for all legacy interrupts */
 595                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 596                         irq_map[i].hwirq = i;
 597                         smp_wmb();
 598                         irq_map[i].host = host;
 599                         smp_wmb();
 600
 601                         /* Clear norequest flags */
 602                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
 603
 604                         /* Legacy flags are left to default at this point,
 605                          * one can then use irq_create_mapping() to
 606                          * explicitly change them
 607                          */
 608                         ops->map(host, i, i);
 609                 }
 610                 break;
 611         case IRQ_HOST_MAP_LINEAR:
 612                 rmap = (unsigned int *)(host + 1);
 613                 for (i = 0; i < revmap_arg; i++)
 614                         rmap[i] = NO_IRQ;
 615                 host->revmap_data.linear.size = revmap_arg;
 616                 smp_wmb();
 617                 host->revmap_data.linear.revmap = rmap;
 618                 break;
 619         default:
 620                 break;
 621         }
 622
 623         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 624
 625         return host;
 626 }
 627
 628 struct irq_host *irq_find_host(struct device_node *node)
 629 {
 630         struct irq_host *h, *found = NULL;
 631         unsigned long flags;
 632
 633         /* We might want to match the legacy controller last since
 634          * it might potentially be set to match all interrupts in
 635          * the absence of a device node. This isn't a problem so far
 636          * yet though...
 637          */
 638         raw_spin_lock_irqsave(&irq_big_lock, flags);
 639         list_for_each_entry(h, &irq_hosts, link)
 640                 if (h->ops->match(h, node)) {
 641                         found = h;
 642                         break;
 643                 }
 644         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 645         return found;
 646 }
 647 EXPORT_SYMBOL_GPL(irq_find_host);
 648
 649 void irq_set_default_host(struct irq_host *host)
 650 {
 651         pr_debug("irq: Default host set to @0x%p\n", host);
 652
 653         irq_default_host = host;
 654 }
 655
 656 void irq_set_virq_count(unsigned int count)
 657 {
 658         pr_debug("irq: Trying to set virq count to %d\n", count);
 659
 660         BUG_ON(count < NUM_ISA_INTERRUPTS);
 661         if (count < NR_IRQS)
 662                 irq_virq_count = count;
 663 }
 664
 665 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 666                             irq_hw_number_t hwirq)
 667 {
 668         struct irq_desc *desc;
 669
 670         desc = irq_to_desc_alloc_node(virq, 0);
 671         if (!desc) {
 672                 pr_debug("irq: -> allocating desc failed\n");
 673                 goto error;
 674         }
 675
 676         /* Clear IRQ_NOREQUEST flag */
 677         desc->status &= ~IRQ_NOREQUEST;
 678
 679         /* map it */
 680         smp_wmb();
 681         irq_map[virq].hwirq = hwirq;
 682         smp_mb();
 683
 684         if (host->ops->map(host, virq, hwirq)) {
 685                 pr_debug("irq: -> mapping failed, freeing\n");
 686                 goto error;
 687         }
 688
 689         return 0;
 690
 691 error:
 692         irq_free_virt(virq, 1);
 693         return -1;
 694 }
 695
 696 unsigned int irq_create_direct_mapping(struct irq_host *host)
 697 {
 698         unsigned int virq;
 699
 700         if (host == NULL)
 701                 host = irq_default_host;
 702
 703         BUG_ON(host == NULL);
 704         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 705
 706         virq = irq_alloc_virt(host, 1, 0);
 707         if (virq == NO_IRQ) {
 708                 pr_debug("irq: create_direct virq allocation failed\n");
 709                 return NO_IRQ;
 710         }
 711
 712         pr_debug("irq: create_direct obtained virq %d\n", virq);
 713
 714         if (irq_setup_virq(host, virq, virq))
 715                 return NO_IRQ;
 716
 717         return virq;
 718 }
 719
 720 unsigned int irq_create_mapping(struct irq_host *host,
 721                                 irq_hw_number_t hwirq)
 722 {
 723         unsigned int virq, hint;
 724
 725         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 726
 727         /* Look for default host if nececssary */
 728         if (host == NULL)
 729                 host = irq_default_host;
 730         if (host == NULL) {
 731                 printk(KERN_WARNING "irq_create_mapping called for"
 732                        " NULL host, hwirq=%lx\n", hwirq);
 733                 WARN_ON(1);
 734                 return NO_IRQ;
 735         }
 736         pr_debug("irq: -> using host @%p\n", host);
 737
 738         /* Check if mapping already exist, if it does, call
 739          * host->ops->map() to update the flags
 740          */
 741         virq = irq_find_mapping(host, hwirq);
 742         if (virq != NO_IRQ) {
 743                 if (host->ops->remap)
 744                         host->ops->remap(host, virq, hwirq);
 745                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 746                 return virq;
 747         }
 748
 749         /* Get a virtual interrupt number */
 750         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 751                 /* Handle legacy */
 752                 virq = (unsigned int)hwirq;
 753                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 754                         return NO_IRQ;
 755                 return virq;
 756         } else {
 757                 /* Allocate a virtual interrupt number */
 758                 hint = hwirq % irq_virq_count;
 759                 virq = irq_alloc_virt(host, 1, hint);
 760                 if (virq == NO_IRQ) {
 761                         pr_debug("irq: -> virq allocation failed\n");
 762                         return NO_IRQ;
 763                 }
 764         }
 765
 766         if (irq_setup_virq(host, virq, hwirq))
 767                 return NO_IRQ;
 768
 769         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 770                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 771
 772         return virq;
 773 }
 774 EXPORT_SYMBOL_GPL(irq_create_mapping);
 775
 776 unsigned int irq_create_of_mapping(struct device_node *controller,
 777                                    const u32 *intspec, unsigned int intsize)
 778 {
 779         struct irq_host *host;
 780         irq_hw_number_t hwirq;
 781         unsigned int type = IRQ_TYPE_NONE;
 782         unsigned int virq;
 783
 784         if (controller == NULL)
 785                 host = irq_default_host;
 786         else
 787                 host = irq_find_host(controller);
 788         if (host == NULL) {
 789                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 790                        controller->full_name);
 791                 return NO_IRQ;
 792         }
 793
 794         /* If host has no translation, then we assume interrupt line */
 795         if (host->ops->xlate == NULL)
 796                 hwirq = intspec[0];
 797         else {
 798                 if (host->ops->xlate(host, controller, intspec, intsize,
 799                                      &hwirq, &type))
 800                         return NO_IRQ;
 801         }
 802
 803         /* Create mapping */
 804         virq = irq_create_mapping(host, hwirq);
 805         if (virq == NO_IRQ)
 806                 return virq;
 807
 808         /* Set type if specified and different than the current one */
 809         if (type != IRQ_TYPE_NONE &&
 810             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
 811                 set_irq_type(virq, type);
 812         return virq;
 813 }
 814 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 815
 816 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 817 {
 818         struct of_irq oirq;
 819
 820         if (of_irq_map_one(dev, index, &oirq))
 821                 return NO_IRQ;
 822
 823         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 824                                      oirq.size);
 825 }
 826 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 827
 828 void irq_dispose_mapping(unsigned int virq)
 829 {
 830         struct irq_host *host;
 831         irq_hw_number_t hwirq;
 832
 833         if (virq == NO_IRQ)
 834                 return;
 835
 836         host = irq_map[virq].host;
 837         WARN_ON (host == NULL);
 838         if (host == NULL)
 839                 return;
 840
 841         /* Never unmap legacy interrupts */
 842         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 843                 return;
 844
 845         /* remove chip and handler */
 846         set_irq_chip_and_handler(virq, NULL, NULL);
 847
 848         /* Make sure it's completed */
 849         synchronize_irq(virq);
 850
 851         /* Tell the PIC about it */
 852         if (host->ops->unmap)
 853                 host->ops->unmap(host, virq);
 854         smp_mb();
 855
 856         /* Clear reverse map */
 857         hwirq = irq_map[virq].hwirq;
 858         switch(host->revmap_type) {
 859         case IRQ_HOST_MAP_LINEAR:
 860                 if (hwirq < host->revmap_data.linear.size)
 861                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 862                 break;
 863         case IRQ_HOST_MAP_TREE:
 864                 /*
 865                  * Check if radix tree allocated yet, if not then nothing to
 866                  * remove.
 867                  */
 868                 smp_rmb();
 869                 if (revmap_trees_allocated < 1)
 870                         break;
 871                 mutex_lock(&revmap_trees_mutex);
 872                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 873                 mutex_unlock(&revmap_trees_mutex);
 874                 break;
 875         }
 876
 877         /* Destroy map */
 878         smp_mb();
 879         irq_map[virq].hwirq = host->inval_irq;
 880
 881         /* Set some flags */
 882         irq_to_desc(virq)->status |= IRQ_NOREQUEST;
 883
 884         /* Free it */
 885         irq_free_virt(virq, 1);
 886 }
 887 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 888
 889 unsigned int irq_find_mapping(struct irq_host *host,
 890                               irq_hw_number_t hwirq)
 891 {
 892         unsigned int i;
 893         unsigned int hint = hwirq % irq_virq_count;
 894
 895         /* Look for default host if nececssary */
 896         if (host == NULL)
 897                 host = irq_default_host;
 898         if (host == NULL)
 899                 return NO_IRQ;
 900
 901         /* legacy -> bail early */
 902         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 903                 return hwirq;
 904
 905         /* Slow path does a linear search of the map */
 906         if (hint < NUM_ISA_INTERRUPTS)
 907                 hint = NUM_ISA_INTERRUPTS;
 908         i = hint;
 909         do  {
 910                 if (irq_map[i].host == host &&
 911                     irq_map[i].hwirq == hwirq)
 912                         return i;
 913                 i++;
 914                 if (i >= irq_virq_count)
 915                         i = NUM_ISA_INTERRUPTS;
 916         } while(i != hint);
 917         return NO_IRQ;
 918 }
 919 EXPORT_SYMBOL_GPL(irq_find_mapping);
 920
 921
 922 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 923                                      irq_hw_number_t hwirq)
 924 {
 925         struct irq_map_entry *ptr;
 926         unsigned int virq;
 927
 928         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 929
 930         /*
 931          * Check if the radix tree exists and has bee initialized.
 932          * If not, we fallback to slow mode
 933          */
 934         if (revmap_trees_allocated < 2)
 935                 return irq_find_mapping(host, hwirq);
 936
 937         /* Now try to resolve */
 938         /*
 939          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 940          * as it's referencing an entry in the static irq_map table.
 941          */
 942         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 943
 944         /*
 945          * If found in radix tree, then fine.
 946          * Else fallback to linear lookup - this should not happen in practice
 947          * as it means that we failed to insert the node in the radix tree.
 948          */
 949         if (ptr)
 950                 virq = ptr - irq_map;
 951         else
 952                 virq = irq_find_mapping(host, hwirq);
 953
 954         return virq;
 955 }
 956
 957 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 958                              irq_hw_number_t hwirq)
 959 {
 960
 961         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 962
 963         /*
 964          * Check if the radix tree exists yet.
 965          * If not, then the irq will be inserted into the tree when it gets
 966          * initialized.
 967          */
 968         smp_rmb();
 969         if (revmap_trees_allocated < 1)
 970                 return;
 971
 972         if (virq != NO_IRQ) {
 973                 mutex_lock(&revmap_trees_mutex);
 974                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 975                                   &irq_map[virq]);
 976                 mutex_unlock(&revmap_trees_mutex);
 977         }
 978 }
 979
 980 unsigned int irq_linear_revmap(struct irq_host *host,
 981                                irq_hw_number_t hwirq)
 982 {
 983         unsigned int *revmap;
 984
 985         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 986
 987         /* Check revmap bounds */
 988         if (unlikely(hwirq >= host->revmap_data.linear.size))
 989                 return irq_find_mapping(host, hwirq);
 990
 991         /* Check if revmap was allocated */
 992         revmap = host->revmap_data.linear.revmap;
 993         if (unlikely(revmap == NULL))
 994                 return irq_find_mapping(host, hwirq);
 995
 996         /* Fill up revmap with slow path if no mapping found */
 997         if (unlikely(revmap[hwirq] == NO_IRQ))
 998                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 999
1000         return revmap[hwirq];
1001 }
1002
1003 unsigned int irq_alloc_virt(struct irq_host *host,
1004                             unsigned int count,
1005                             unsigned int hint)
1006 {
1007         unsigned long flags;
1008         unsigned int i, j, found = NO_IRQ;
1009
1010         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
1011                 return NO_IRQ;
1012
1013         raw_spin_lock_irqsave(&irq_big_lock, flags);
1014
1015         /* Use hint for 1 interrupt if any */
1016         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
1017             hint < irq_virq_count && irq_map[hint].host == NULL) {
1018                 found = hint;
1019                 goto hint_found;
1020         }
1021
1022         /* Look for count consecutive numbers in the allocatable
1023          * (non-legacy) space
1024          */
1025         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1026                 if (irq_map[i].host != NULL)
1027                         j = 0;
1028                 else
1029                         j++;
1030
1031                 if (j == count) {
1032                         found = i - count + 1;
1033                         break;
1034                 }
1035         }
1036         if (found == NO_IRQ) {
1037                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1038                 return NO_IRQ;
1039         }
1040  hint_found:
1041         for (i = found; i < (found + count); i++) {
1042                 irq_map[i].hwirq = host->inval_irq;
1043                 smp_wmb();
1044                 irq_map[i].host = host;
1045         }
1046         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1047         return found;
1048 }
1049
1050 void irq_free_virt(unsigned int virq, unsigned int count)
1051 {
1052         unsigned long flags;
1053         unsigned int i;
1054
1055         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1056         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1057
1058         raw_spin_lock_irqsave(&irq_big_lock, flags);
1059         for (i = virq; i < (virq + count); i++) {
1060                 struct irq_host *host;
1061
1062                 if (i < NUM_ISA_INTERRUPTS ||
1063                     (virq + count) > irq_virq_count)
1064                         continue;
1065
1066                 host = irq_map[i].host;
1067                 irq_map[i].hwirq = host->inval_irq;
1068                 smp_wmb();
1069                 irq_map[i].host = NULL;
1070         }
1071         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1072 }
1073
1074 int arch_early_irq_init(void)
1075 {
1076         struct irq_desc *desc;
1077         int i;
1078
1079         for (i = 0; i < NR_IRQS; i++) {
1080                 desc = irq_to_desc(i);
1081                 if (desc)
1082                         desc->status |= IRQ_NOREQUEST;
1083         }
1084
1085         return 0;
1086 }
1087
1088 int arch_init_chip_data(struct irq_desc *desc, int node)
1089 {
1090         desc->status |= IRQ_NOREQUEST;
1091         return 0;
1092 }
1093
1094 /* We need to create the radix trees late */
1095 static int irq_late_init(void)
1096 {
1097         struct irq_host *h;
1098         unsigned int i;
1099
1100         /*
1101          * No mutual exclusion with respect to accessors of the tree is needed
1102          * here as the synchronization is done via the state variable
1103          * revmap_trees_allocated.
1104          */
1105         list_for_each_entry(h, &irq_hosts, link) {
1106                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1107                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1108         }
1109
1110         /*
1111          * Make sure the radix trees inits are visible before setting
1112          * the flag
1113          */
1114         smp_wmb();
1115         revmap_trees_allocated = 1;
1116
1117         /*
1118          * Insert the reverse mapping for those interrupts already present
1119          * in irq_map[].
1120          */
1121         mutex_lock(&revmap_trees_mutex);
1122         for (i = 0; i < irq_virq_count; i++) {
1123                 if (irq_map[i].host &&
1124                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1125                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1126                                           irq_map[i].hwirq, &irq_map[i]);
1127         }
1128         mutex_unlock(&revmap_trees_mutex);
1129
1130         /*
1131          * Make sure the radix trees insertions are visible before setting
1132          * the flag
1133          */
1134         smp_wmb();
1135         revmap_trees_allocated = 2;
1136
1137         return 0;
1138 }
1139 arch_initcall(irq_late_init);
1140
1141 #ifdef CONFIG_VIRQ_DEBUG
1142 static int virq_debug_show(struct seq_file *m, void *private)
1143 {
1144         unsigned long flags;
1145         struct irq_desc *desc;
1146         const char *p;
1147         char none[] = "none";
1148         int i;
1149
1150         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1151                       "chip name", "host name");
1152
1153         for (i = 1; i < nr_irqs; i++) {
1154                 desc = irq_to_desc(i);
1155                 if (!desc)
1156                         continue;
1157
1158                 raw_spin_lock_irqsave(&desc->lock, flags);
1159
1160                 if (desc->action && desc->action->handler) {
1161                         seq_printf(m, "%5d  ", i);
1162                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1163
1164                         if (desc->chip && desc->chip->name)
1165                                 p = desc->chip->name;
1166                         else
1167                                 p = none;
1168                         seq_printf(m, "%-15s  ", p);
1169
1170                         if (irq_map[i].host && irq_map[i].host->of_node)
1171                                 p = irq_map[i].host->of_node->full_name;
1172                         else
1173                                 p = none;
1174                         seq_printf(m, "%s\n", p);
1175                 }
1176
1177                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1178         }
1179
1180         return 0;
1181 }
1182
1183 static int virq_debug_open(struct inode *inode, struct file *file)
1184 {
1185         return single_open(file, virq_debug_show, inode->i_private);
1186 }
1187
1188 static const struct file_operations virq_debug_fops = {
1189         .open = virq_debug_open,
1190         .read = seq_read,
1191         .llseek = seq_lseek,
1192         .release = single_release,
1193 };
1194
1195 static int __init irq_debugfs_init(void)
1196 {
1197         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1198                                  NULL, &virq_debug_fops) == NULL)
1199                 return -ENOMEM;
1200
1201         return 0;
1202 }
1203 __initcall(irq_debugfs_init);
1204 #endif /* CONFIG_VIRQ_DEBUG */
1205
1206 #ifdef CONFIG_PPC64
1207 static int __init setup_noirqdistrib(char *str)
1208 {
1209         distribute_irqs = 0;
1210         return 1;
1211 }
1212
1213 __setup("noirqdistrib", setup_noirqdistrib);
1214 #endif /* CONFIG_PPC64 */