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 #include <linux/of.h>
  57 #include <linux/of_irq.h>
  58
  59 #include <asm/uaccess.h>
  60 #include <asm/system.h>
  61 #include <asm/io.h>
  62 #include <asm/pgtable.h>
  63 #include <asm/irq.h>
  64 #include <asm/cache.h>
  65 #include <asm/prom.h>
  66 #include <asm/ptrace.h>
  67 #include <asm/machdep.h>
  68 #include <asm/udbg.h>
  69 #include <asm/dbell.h>
  70 #include <asm/smp.h>
  71
  72 #ifdef CONFIG_PPC64
  73 #include <asm/paca.h>
  74 #include <asm/firmware.h>
  75 #include <asm/lv1call.h>
  76 #endif
  77 #define CREATE_TRACE_POINTS
  78 #include <asm/trace.h>
  79
  80 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
  81 EXPORT_PER_CPU_SYMBOL(irq_stat);
  82
  83 int __irq_offset_value;
  84
  85 #ifdef CONFIG_PPC32
  86 EXPORT_SYMBOL(__irq_offset_value);
  87 atomic_t ppc_n_lost_interrupts;
  88
  89 #ifdef CONFIG_TAU_INT
  90 extern int tau_initialized;
  91 extern int tau_interrupts(int);
  92 #endif
  93 #endif /* CONFIG_PPC32 */
  94
  95 #ifdef CONFIG_PPC64
  96
  97 #ifndef CONFIG_SPARSE_IRQ
  98 EXPORT_SYMBOL(irq_desc);
  99 #endif
 100
 101 int distribute_irqs = 1;
 102
 103 static inline notrace unsigned long get_hard_enabled(void)
 104 {
 105         unsigned long enabled;
 106
 107         __asm__ __volatile__("lbz %0,%1(13)"
 108         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 109
 110         return enabled;
 111 }
 112
 113 static inline notrace void set_soft_enabled(unsigned long enable)
 114 {
 115         __asm__ __volatile__("stb %0,%1(13)"
 116         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 117 }
 118
 119 notrace void arch_local_irq_restore(unsigned long en)
 120 {
 121         /*
 122          * get_paca()->soft_enabled = en;
 123          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 124          * That was allowed before, and in such a case we do need to take care
 125          * that gcc will set soft_enabled directly via r13, not choose to use
 126          * an intermediate register, lest we're preempted to a different cpu.
 127          */
 128         set_soft_enabled(en);
 129         if (!en)
 130                 return;
 131
 132 #ifdef CONFIG_PPC_STD_MMU_64
 133         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 134                 /*
 135                  * Do we need to disable preemption here?  Not really: in the
 136                  * unlikely event that we're preempted to a different cpu in
 137                  * between getting r13, loading its lppaca_ptr, and loading
 138                  * its any_int, we might call iseries_handle_interrupts without
 139                  * an interrupt pending on the new cpu, but that's no disaster,
 140                  * is it?  And the business of preempting us off the old cpu
 141                  * would itself involve a local_irq_restore which handles the
 142                  * interrupt to that cpu.
 143                  *
 144                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 145                  * to avoid any preemption checking added into get_paca().
 146                  */
 147                 if (local_paca->lppaca_ptr->int_dword.any_int)
 148                         iseries_handle_interrupts();
 149         }
 150 #endif /* CONFIG_PPC_STD_MMU_64 */
 151
 152         /*
 153          * if (get_paca()->hard_enabled) return;
 154          * But again we need to take care that gcc gets hard_enabled directly
 155          * via r13, not choose to use an intermediate register, lest we're
 156          * preempted to a different cpu in between the two instructions.
 157          */
 158         if (get_hard_enabled())
 159                 return;
 160
 161 #if defined(CONFIG_BOOKE) && defined(CONFIG_SMP)
 162         /* Check for pending doorbell interrupts and resend to ourself */
 163         doorbell_check_self();
 164 #endif
 165
 166         /*
 167          * Need to hard-enable interrupts here.  Since currently disabled,
 168          * no need to take further asm precautions against preemption; but
 169          * use local_paca instead of get_paca() to avoid preemption checking.
 170          */
 171         local_paca->hard_enabled = en;
 172
 173 #ifndef CONFIG_BOOKE
 174         /* On server, re-trigger the decrementer if it went negative since
 175          * some processors only trigger on edge transitions of the sign bit.
 176          *
 177          * BookE has a level sensitive decrementer (latches in TSR) so we
 178          * don't need that
 179          */
 180         if ((int)mfspr(SPRN_DEC) < 0)
 181                 mtspr(SPRN_DEC, 1);
 182 #endif /* CONFIG_BOOKE */
 183
 184         /*
 185          * Force the delivery of pending soft-disabled interrupts on PS3.
 186          * Any HV call will have this side effect.
 187          */
 188         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 189                 u64 tmp;
 190                 lv1_get_version_info(&tmp);
 191         }
 192
 193         __hard_irq_enable();
 194 }
 195 EXPORT_SYMBOL(arch_local_irq_restore);
 196 #endif /* CONFIG_PPC64 */
 197
 198 int arch_show_interrupts(struct seq_file *p, int prec)
 199 {
 200         int j;
 201
 202 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 203         if (tau_initialized) {
 204                 seq_printf(p, "%*s: ", prec, "TAU");
 205                 for_each_online_cpu(j)
 206                         seq_printf(p, "%10u ", tau_interrupts(j));
 207                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 208         }
 209 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
 210
 211         seq_printf(p, "%*s: ", prec, "LOC");
 212         for_each_online_cpu(j)
 213                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
 214         seq_printf(p, "  Local timer interrupts\n");
 215
 216         seq_printf(p, "%*s: ", prec, "SPU");
 217         for_each_online_cpu(j)
 218                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
 219         seq_printf(p, "  Spurious interrupts\n");
 220
 221         seq_printf(p, "%*s: ", prec, "CNT");
 222         for_each_online_cpu(j)
 223                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
 224         seq_printf(p, "  Performance monitoring interrupts\n");
 225
 226         seq_printf(p, "%*s: ", prec, "MCE");
 227         for_each_online_cpu(j)
 228                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
 229         seq_printf(p, "  Machine check exceptions\n");
 230
 231         return 0;
 232 }
 233
 234 /*
 235  * /proc/stat helpers
 236  */
 237 u64 arch_irq_stat_cpu(unsigned int cpu)
 238 {
 239         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
 240
 241         sum += per_cpu(irq_stat, cpu).pmu_irqs;
 242         sum += per_cpu(irq_stat, cpu).mce_exceptions;
 243         sum += per_cpu(irq_stat, cpu).spurious_irqs;
 244
 245         return sum;
 246 }
 247
 248 #ifdef CONFIG_HOTPLUG_CPU
 249 void migrate_irqs(void)
 250 {
 251         struct irq_desc *desc;
 252         unsigned int irq;
 253         static int warned;
 254         cpumask_var_t mask;
 255         const struct cpumask *map = cpu_online_mask;
 256
 257         alloc_cpumask_var(&mask, GFP_KERNEL);
 258
 259         for_each_irq(irq) {
 260                 struct irq_data *data;
 261                 struct irq_chip *chip;
 262
 263                 desc = irq_to_desc(irq);
 264                 if (!desc)
 265                         continue;
 266
 267                 data = irq_desc_get_irq_data(desc);
 268                 if (irqd_is_per_cpu(data))
 269                         continue;
 270
 271                 chip = irq_data_get_irq_chip(data);
 272
 273                 cpumask_and(mask, data->affinity, map);
 274                 if (cpumask_any(mask) >= nr_cpu_ids) {
 275                         printk("Breaking affinity for irq %i\n", irq);
 276                         cpumask_copy(mask, map);
 277                 }
 278                 if (chip->irq_set_affinity)
 279                         chip->irq_set_affinity(data, mask, true);
 280                 else if (desc->action && !(warned++))
 281                         printk("Cannot set affinity for irq %i\n", irq);
 282         }
 283
 284         free_cpumask_var(mask);
 285
 286         local_irq_enable();
 287         mdelay(1);
 288         local_irq_disable();
 289 }
 290 #endif
 291
 292 static inline void handle_one_irq(unsigned int irq)
 293 {
 294         struct thread_info *curtp, *irqtp;
 295         unsigned long saved_sp_limit;
 296         struct irq_desc *desc;
 297
 298         /* Switch to the irq stack to handle this */
 299         curtp = current_thread_info();
 300         irqtp = hardirq_ctx[smp_processor_id()];
 301
 302         if (curtp == irqtp) {
 303                 /* We're already on the irq stack, just handle it */
 304                 generic_handle_irq(irq);
 305                 return;
 306         }
 307
 308         desc = irq_to_desc(irq);
 309         saved_sp_limit = current->thread.ksp_limit;
 310
 311         irqtp->task = curtp->task;
 312         irqtp->flags = 0;
 313
 314         /* Copy the softirq bits in preempt_count so that the
 315          * softirq checks work in the hardirq context. */
 316         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 317                                (curtp->preempt_count & SOFTIRQ_MASK);
 318
 319         current->thread.ksp_limit = (unsigned long)irqtp +
 320                 _ALIGN_UP(sizeof(struct thread_info), 16);
 321
 322         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 323         current->thread.ksp_limit = saved_sp_limit;
 324         irqtp->task = NULL;
 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 }
 332
 333 static inline void check_stack_overflow(void)
 334 {
 335 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 336         long sp;
 337
 338         sp = __get_SP() & (THREAD_SIZE-1);
 339
 340         /* check for stack overflow: is there less than 2KB free? */
 341         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 342                 printk("do_IRQ: stack overflow: %ld\n",
 343                         sp - sizeof(struct thread_info));
 344                 dump_stack();
 345         }
 346 #endif
 347 }
 348
 349 void do_IRQ(struct pt_regs *regs)
 350 {
 351         struct pt_regs *old_regs = set_irq_regs(regs);
 352         unsigned int irq;
 353
 354         trace_irq_entry(regs);
 355
 356         irq_enter();
 357
 358         check_stack_overflow();
 359
 360         irq = ppc_md.get_irq();
 361
 362         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 363                 handle_one_irq(irq);
 364         else if (irq != NO_IRQ_IGNORE)
 365                 __get_cpu_var(irq_stat).spurious_irqs++;
 366
 367         irq_exit();
 368         set_irq_regs(old_regs);
 369
 370 #ifdef CONFIG_PPC_ISERIES
 371         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 372                         get_lppaca()->int_dword.fields.decr_int) {
 373                 get_lppaca()->int_dword.fields.decr_int = 0;
 374                 /* Signal a fake decrementer interrupt */
 375                 timer_interrupt(regs);
 376         }
 377 #endif
 378
 379         trace_irq_exit(regs);
 380 }
 381
 382 void __init init_IRQ(void)
 383 {
 384         if (ppc_md.init_IRQ)
 385                 ppc_md.init_IRQ();
 386
 387         exc_lvl_ctx_init();
 388
 389         irq_ctx_init();
 390 }
 391
 392 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 393 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 394 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 395 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 396
 397 void exc_lvl_ctx_init(void)
 398 {
 399         struct thread_info *tp;
 400         int i, cpu_nr;
 401
 402         for_each_possible_cpu(i) {
 403 #ifdef CONFIG_PPC64
 404                 cpu_nr = i;
 405 #else
 406                 cpu_nr = get_hard_smp_processor_id(i);
 407 #endif
 408                 memset((void *)critirq_ctx[cpu_nr], 0, THREAD_SIZE);
 409                 tp = critirq_ctx[cpu_nr];
 410                 tp->cpu = cpu_nr;
 411                 tp->preempt_count = 0;
 412
 413 #ifdef CONFIG_BOOKE
 414                 memset((void *)dbgirq_ctx[cpu_nr], 0, THREAD_SIZE);
 415                 tp = dbgirq_ctx[cpu_nr];
 416                 tp->cpu = cpu_nr;
 417                 tp->preempt_count = 0;
 418
 419                 memset((void *)mcheckirq_ctx[cpu_nr], 0, THREAD_SIZE);
 420                 tp = mcheckirq_ctx[cpu_nr];
 421                 tp->cpu = cpu_nr;
 422                 tp->preempt_count = HARDIRQ_OFFSET;
 423 #endif
 424         }
 425 }
 426 #endif
 427
 428 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 429 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 430
 431 void irq_ctx_init(void)
 432 {
 433         struct thread_info *tp;
 434         int i;
 435
 436         for_each_possible_cpu(i) {
 437                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 438                 tp = softirq_ctx[i];
 439                 tp->cpu = i;
 440                 tp->preempt_count = 0;
 441
 442                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 443                 tp = hardirq_ctx[i];
 444                 tp->cpu = i;
 445                 tp->preempt_count = HARDIRQ_OFFSET;
 446         }
 447 }
 448
 449 static inline void do_softirq_onstack(void)
 450 {
 451         struct thread_info *curtp, *irqtp;
 452         unsigned long saved_sp_limit = current->thread.ksp_limit;
 453
 454         curtp = current_thread_info();
 455         irqtp = softirq_ctx[smp_processor_id()];
 456         irqtp->task = curtp->task;
 457         current->thread.ksp_limit = (unsigned long)irqtp +
 458                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 459         call_do_softirq(irqtp);
 460         current->thread.ksp_limit = saved_sp_limit;
 461         irqtp->task = NULL;
 462 }
 463
 464 void do_softirq(void)
 465 {
 466         unsigned long flags;
 467
 468         if (in_interrupt())
 469                 return;
 470
 471         local_irq_save(flags);
 472
 473         if (local_softirq_pending())
 474                 do_softirq_onstack();
 475
 476         local_irq_restore(flags);
 477 }
 478
 479
 480 /*
 481  * IRQ controller and virtual interrupts
 482  */
 483
 484 static LIST_HEAD(irq_hosts);
 485 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 486 static unsigned int revmap_trees_allocated;
 487 static DEFINE_MUTEX(revmap_trees_mutex);
 488 struct irq_map_entry irq_map[NR_IRQS];
 489 static unsigned int irq_virq_count = NR_IRQS;
 490 static struct irq_host *irq_default_host;
 491
 492 irq_hw_number_t virq_to_hw(unsigned int virq)
 493 {
 494         return irq_map[virq].hwirq;
 495 }
 496 EXPORT_SYMBOL_GPL(virq_to_hw);
 497
 498 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 499 {
 500         return h->of_node != NULL && h->of_node == np;
 501 }
 502
 503 struct irq_host *irq_alloc_host(struct device_node *of_node,
 504                                 unsigned int revmap_type,
 505                                 unsigned int revmap_arg,
 506                                 struct irq_host_ops *ops,
 507                                 irq_hw_number_t inval_irq)
 508 {
 509         struct irq_host *host;
 510         unsigned int size = sizeof(struct irq_host);
 511         unsigned int i;
 512         unsigned int *rmap;
 513         unsigned long flags;
 514
 515         /* Allocate structure and revmap table if using linear mapping */
 516         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 517                 size += revmap_arg * sizeof(unsigned int);
 518         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 519         if (host == NULL)
 520                 return NULL;
 521
 522         /* Fill structure */
 523         host->revmap_type = revmap_type;
 524         host->inval_irq = inval_irq;
 525         host->ops = ops;
 526         host->of_node = of_node_get(of_node);
 527
 528         if (host->ops->match == NULL)
 529                 host->ops->match = default_irq_host_match;
 530
 531         raw_spin_lock_irqsave(&irq_big_lock, flags);
 532
 533         /* If it's a legacy controller, check for duplicates and
 534          * mark it as allocated (we use irq 0 host pointer for that
 535          */
 536         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 537                 if (irq_map[0].host != NULL) {
 538                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 539                         /* If we are early boot, we can't free the structure,
 540                          * too bad...
 541                          * this will be fixed once slab is made available early
 542                          * instead of the current cruft
 543                          */
 544                         if (mem_init_done) {
 545                                 of_node_put(host->of_node);
 546                                 kfree(host);
 547                         }
 548                         return NULL;
 549                 }
 550                 irq_map[0].host = host;
 551         }
 552
 553         list_add(&host->link, &irq_hosts);
 554         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 555
 556         /* Additional setups per revmap type */
 557         switch(revmap_type) {
 558         case IRQ_HOST_MAP_LEGACY:
 559                 /* 0 is always the invalid number for legacy */
 560                 host->inval_irq = 0;
 561                 /* setup us as the host for all legacy interrupts */
 562                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 563                         irq_map[i].hwirq = i;
 564                         smp_wmb();
 565                         irq_map[i].host = host;
 566                         smp_wmb();
 567
 568                         /* Clear norequest flags */
 569                         irq_clear_status_flags(i, IRQ_NOREQUEST);
 570
 571                         /* Legacy flags are left to default at this point,
 572                          * one can then use irq_create_mapping() to
 573                          * explicitly change them
 574                          */
 575                         ops->map(host, i, i);
 576                 }
 577                 break;
 578         case IRQ_HOST_MAP_LINEAR:
 579                 rmap = (unsigned int *)(host + 1);
 580                 for (i = 0; i < revmap_arg; i++)
 581                         rmap[i] = NO_IRQ;
 582                 host->revmap_data.linear.size = revmap_arg;
 583                 smp_wmb();
 584                 host->revmap_data.linear.revmap = rmap;
 585                 break;
 586         default:
 587                 break;
 588         }
 589
 590         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 591
 592         return host;
 593 }
 594
 595 struct irq_host *irq_find_host(struct device_node *node)
 596 {
 597         struct irq_host *h, *found = NULL;
 598         unsigned long flags;
 599
 600         /* We might want to match the legacy controller last since
 601          * it might potentially be set to match all interrupts in
 602          * the absence of a device node. This isn't a problem so far
 603          * yet though...
 604          */
 605         raw_spin_lock_irqsave(&irq_big_lock, flags);
 606         list_for_each_entry(h, &irq_hosts, link)
 607                 if (h->ops->match(h, node)) {
 608                         found = h;
 609                         break;
 610                 }
 611         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 612         return found;
 613 }
 614 EXPORT_SYMBOL_GPL(irq_find_host);
 615
 616 void irq_set_default_host(struct irq_host *host)
 617 {
 618         pr_debug("irq: Default host set to @0x%p\n", host);
 619
 620         irq_default_host = host;
 621 }
 622
 623 void irq_set_virq_count(unsigned int count)
 624 {
 625         pr_debug("irq: Trying to set virq count to %d\n", count);
 626
 627         BUG_ON(count < NUM_ISA_INTERRUPTS);
 628         if (count < NR_IRQS)
 629                 irq_virq_count = count;
 630 }
 631
 632 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 633                             irq_hw_number_t hwirq)
 634 {
 635         int res;
 636
 637         res = irq_alloc_desc_at(virq, 0);
 638         if (res != virq) {
 639                 pr_debug("irq: -> allocating desc failed\n");
 640                 goto error;
 641         }
 642
 643         irq_clear_status_flags(virq, IRQ_NOREQUEST);
 644
 645         /* map it */
 646         smp_wmb();
 647         irq_map[virq].hwirq = hwirq;
 648         smp_mb();
 649
 650         if (host->ops->map(host, virq, hwirq)) {
 651                 pr_debug("irq: -> mapping failed, freeing\n");
 652                 goto errdesc;
 653         }
 654
 655         return 0;
 656
 657 errdesc:
 658         irq_free_descs(virq, 1);
 659 error:
 660         irq_free_virt(virq, 1);
 661         return -1;
 662 }
 663
 664 unsigned int irq_create_direct_mapping(struct irq_host *host)
 665 {
 666         unsigned int virq;
 667
 668         if (host == NULL)
 669                 host = irq_default_host;
 670
 671         BUG_ON(host == NULL);
 672         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 673
 674         virq = irq_alloc_virt(host, 1, 0);
 675         if (virq == NO_IRQ) {
 676                 pr_debug("irq: create_direct virq allocation failed\n");
 677                 return NO_IRQ;
 678         }
 679
 680         pr_debug("irq: create_direct obtained virq %d\n", virq);
 681
 682         if (irq_setup_virq(host, virq, virq))
 683                 return NO_IRQ;
 684
 685         return virq;
 686 }
 687
 688 unsigned int irq_create_mapping(struct irq_host *host,
 689                                 irq_hw_number_t hwirq)
 690 {
 691         unsigned int virq, hint;
 692
 693         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 694
 695         /* Look for default host if nececssary */
 696         if (host == NULL)
 697                 host = irq_default_host;
 698         if (host == NULL) {
 699                 printk(KERN_WARNING "irq_create_mapping called for"
 700                        " NULL host, hwirq=%lx\n", hwirq);
 701                 WARN_ON(1);
 702                 return NO_IRQ;
 703         }
 704         pr_debug("irq: -> using host @%p\n", host);
 705
 706         /* Check if mapping already exist, if it does, call
 707          * host->ops->map() to update the flags
 708          */
 709         virq = irq_find_mapping(host, hwirq);
 710         if (virq != NO_IRQ) {
 711                 if (host->ops->remap)
 712                         host->ops->remap(host, virq, hwirq);
 713                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 714                 return virq;
 715         }
 716
 717         /* Get a virtual interrupt number */
 718         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 719                 /* Handle legacy */
 720                 virq = (unsigned int)hwirq;
 721                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 722                         return NO_IRQ;
 723                 return virq;
 724         } else {
 725                 /* Allocate a virtual interrupt number */
 726                 hint = hwirq % irq_virq_count;
 727                 virq = irq_alloc_virt(host, 1, hint);
 728                 if (virq == NO_IRQ) {
 729                         pr_debug("irq: -> virq allocation failed\n");
 730                         return NO_IRQ;
 731                 }
 732         }
 733
 734         if (irq_setup_virq(host, virq, hwirq))
 735                 return NO_IRQ;
 736
 737         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 738                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 739
 740         return virq;
 741 }
 742 EXPORT_SYMBOL_GPL(irq_create_mapping);
 743
 744 unsigned int irq_create_of_mapping(struct device_node *controller,
 745                                    const u32 *intspec, unsigned int intsize)
 746 {
 747         struct irq_host *host;
 748         irq_hw_number_t hwirq;
 749         unsigned int type = IRQ_TYPE_NONE;
 750         unsigned int virq;
 751
 752         if (controller == NULL)
 753                 host = irq_default_host;
 754         else
 755                 host = irq_find_host(controller);
 756         if (host == NULL) {
 757                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 758                        controller->full_name);
 759                 return NO_IRQ;
 760         }
 761
 762         /* If host has no translation, then we assume interrupt line */
 763         if (host->ops->xlate == NULL)
 764                 hwirq = intspec[0];
 765         else {
 766                 if (host->ops->xlate(host, controller, intspec, intsize,
 767                                      &hwirq, &type))
 768                         return NO_IRQ;
 769         }
 770
 771         /* Create mapping */
 772         virq = irq_create_mapping(host, hwirq);
 773         if (virq == NO_IRQ)
 774                 return virq;
 775
 776         /* Set type if specified and different than the current one */
 777         if (type != IRQ_TYPE_NONE &&
 778             type != (irqd_get_trigger_type(irq_get_irq_data(virq))))
 779                 irq_set_irq_type(virq, type);
 780         return virq;
 781 }
 782 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 783
 784 void irq_dispose_mapping(unsigned int virq)
 785 {
 786         struct irq_host *host;
 787         irq_hw_number_t hwirq;
 788
 789         if (virq == NO_IRQ)
 790                 return;
 791
 792         host = irq_map[virq].host;
 793         WARN_ON (host == NULL);
 794         if (host == NULL)
 795                 return;
 796
 797         /* Never unmap legacy interrupts */
 798         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 799                 return;
 800
 801         /* remove chip and handler */
 802         irq_set_chip_and_handler(virq, NULL, NULL);
 803
 804         /* Make sure it's completed */
 805         synchronize_irq(virq);
 806
 807         /* Tell the PIC about it */
 808         if (host->ops->unmap)
 809                 host->ops->unmap(host, virq);
 810         smp_mb();
 811
 812         /* Clear reverse map */
 813         hwirq = irq_map[virq].hwirq;
 814         switch(host->revmap_type) {
 815         case IRQ_HOST_MAP_LINEAR:
 816                 if (hwirq < host->revmap_data.linear.size)
 817                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 818                 break;
 819         case IRQ_HOST_MAP_TREE:
 820                 /*
 821                  * Check if radix tree allocated yet, if not then nothing to
 822                  * remove.
 823                  */
 824                 smp_rmb();
 825                 if (revmap_trees_allocated < 1)
 826                         break;
 827                 mutex_lock(&revmap_trees_mutex);
 828                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 829                 mutex_unlock(&revmap_trees_mutex);
 830                 break;
 831         }
 832
 833         /* Destroy map */
 834         smp_mb();
 835         irq_map[virq].hwirq = host->inval_irq;
 836
 837         irq_set_status_flags(virq, IRQ_NOREQUEST);
 838
 839         irq_free_descs(virq, 1);
 840         /* Free it */
 841         irq_free_virt(virq, 1);
 842 }
 843 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 844
 845 unsigned int irq_find_mapping(struct irq_host *host,
 846                               irq_hw_number_t hwirq)
 847 {
 848         unsigned int i;
 849         unsigned int hint = hwirq % irq_virq_count;
 850
 851         /* Look for default host if nececssary */
 852         if (host == NULL)
 853                 host = irq_default_host;
 854         if (host == NULL)
 855                 return NO_IRQ;
 856
 857         /* legacy -> bail early */
 858         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 859                 return hwirq;
 860
 861         /* Slow path does a linear search of the map */
 862         if (hint < NUM_ISA_INTERRUPTS)
 863                 hint = NUM_ISA_INTERRUPTS;
 864         i = hint;
 865         do  {
 866                 if (irq_map[i].host == host &&
 867                     irq_map[i].hwirq == hwirq)
 868                         return i;
 869                 i++;
 870                 if (i >= irq_virq_count)
 871                         i = NUM_ISA_INTERRUPTS;
 872         } while(i != hint);
 873         return NO_IRQ;
 874 }
 875 EXPORT_SYMBOL_GPL(irq_find_mapping);
 876
 877
 878 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 879                                      irq_hw_number_t hwirq)
 880 {
 881         struct irq_map_entry *ptr;
 882         unsigned int virq;
 883
 884         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 885
 886         /*
 887          * Check if the radix tree exists and has bee initialized.
 888          * If not, we fallback to slow mode
 889          */
 890         if (revmap_trees_allocated < 2)
 891                 return irq_find_mapping(host, hwirq);
 892
 893         /* Now try to resolve */
 894         /*
 895          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 896          * as it's referencing an entry in the static irq_map table.
 897          */
 898         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 899
 900         /*
 901          * If found in radix tree, then fine.
 902          * Else fallback to linear lookup - this should not happen in practice
 903          * as it means that we failed to insert the node in the radix tree.
 904          */
 905         if (ptr)
 906                 virq = ptr - irq_map;
 907         else
 908                 virq = irq_find_mapping(host, hwirq);
 909
 910         return virq;
 911 }
 912
 913 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 914                              irq_hw_number_t hwirq)
 915 {
 916
 917         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 918
 919         /*
 920          * Check if the radix tree exists yet.
 921          * If not, then the irq will be inserted into the tree when it gets
 922          * initialized.
 923          */
 924         smp_rmb();
 925         if (revmap_trees_allocated < 1)
 926                 return;
 927
 928         if (virq != NO_IRQ) {
 929                 mutex_lock(&revmap_trees_mutex);
 930                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 931                                   &irq_map[virq]);
 932                 mutex_unlock(&revmap_trees_mutex);
 933         }
 934 }
 935
 936 unsigned int irq_linear_revmap(struct irq_host *host,
 937                                irq_hw_number_t hwirq)
 938 {
 939         unsigned int *revmap;
 940
 941         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 942
 943         /* Check revmap bounds */
 944         if (unlikely(hwirq >= host->revmap_data.linear.size))
 945                 return irq_find_mapping(host, hwirq);
 946
 947         /* Check if revmap was allocated */
 948         revmap = host->revmap_data.linear.revmap;
 949         if (unlikely(revmap == NULL))
 950                 return irq_find_mapping(host, hwirq);
 951
 952         /* Fill up revmap with slow path if no mapping found */
 953         if (unlikely(revmap[hwirq] == NO_IRQ))
 954                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 955
 956         return revmap[hwirq];
 957 }
 958
 959 unsigned int irq_alloc_virt(struct irq_host *host,
 960                             unsigned int count,
 961                             unsigned int hint)
 962 {
 963         unsigned long flags;
 964         unsigned int i, j, found = NO_IRQ;
 965
 966         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 967                 return NO_IRQ;
 968
 969         raw_spin_lock_irqsave(&irq_big_lock, flags);
 970
 971         /* Use hint for 1 interrupt if any */
 972         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 973             hint < irq_virq_count && irq_map[hint].host == NULL) {
 974                 found = hint;
 975                 goto hint_found;
 976         }
 977
 978         /* Look for count consecutive numbers in the allocatable
 979          * (non-legacy) space
 980          */
 981         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 982                 if (irq_map[i].host != NULL)
 983                         j = 0;
 984                 else
 985                         j++;
 986
 987                 if (j == count) {
 988                         found = i - count + 1;
 989                         break;
 990                 }
 991         }
 992         if (found == NO_IRQ) {
 993                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 994                 return NO_IRQ;
 995         }
 996  hint_found:
 997         for (i = found; i < (found + count); i++) {
 998                 irq_map[i].hwirq = host->inval_irq;
 999                 smp_wmb();
1000                 irq_map[i].host = host;
1001         }
1002         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1003         return found;
1004 }
1005
1006 void irq_free_virt(unsigned int virq, unsigned int count)
1007 {
1008         unsigned long flags;
1009         unsigned int i;
1010
1011         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1012         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1013
1014         raw_spin_lock_irqsave(&irq_big_lock, flags);
1015         for (i = virq; i < (virq + count); i++) {
1016                 struct irq_host *host;
1017
1018                 if (i < NUM_ISA_INTERRUPTS ||
1019                     (virq + count) > irq_virq_count)
1020                         continue;
1021
1022                 host = irq_map[i].host;
1023                 irq_map[i].hwirq = host->inval_irq;
1024                 smp_wmb();
1025                 irq_map[i].host = NULL;
1026         }
1027         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1028 }
1029
1030 int arch_early_irq_init(void)
1031 {
1032         return 0;
1033 }
1034
1035 /* We need to create the radix trees late */
1036 static int irq_late_init(void)
1037 {
1038         struct irq_host *h;
1039         unsigned int i;
1040
1041         /*
1042          * No mutual exclusion with respect to accessors of the tree is needed
1043          * here as the synchronization is done via the state variable
1044          * revmap_trees_allocated.
1045          */
1046         list_for_each_entry(h, &irq_hosts, link) {
1047                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1048                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1049         }
1050
1051         /*
1052          * Make sure the radix trees inits are visible before setting
1053          * the flag
1054          */
1055         smp_wmb();
1056         revmap_trees_allocated = 1;
1057
1058         /*
1059          * Insert the reverse mapping for those interrupts already present
1060          * in irq_map[].
1061          */
1062         mutex_lock(&revmap_trees_mutex);
1063         for (i = 0; i < irq_virq_count; i++) {
1064                 if (irq_map[i].host &&
1065                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1066                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1067                                           irq_map[i].hwirq, &irq_map[i]);
1068         }
1069         mutex_unlock(&revmap_trees_mutex);
1070
1071         /*
1072          * Make sure the radix trees insertions are visible before setting
1073          * the flag
1074          */
1075         smp_wmb();
1076         revmap_trees_allocated = 2;
1077
1078         return 0;
1079 }
1080 arch_initcall(irq_late_init);
1081
1082 #ifdef CONFIG_VIRQ_DEBUG
1083 static int virq_debug_show(struct seq_file *m, void *private)
1084 {
1085         unsigned long flags;
1086         struct irq_desc *desc;
1087         const char *p;
1088         static const char none[] = "none";
1089         int i;
1090
1091         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1092                       "chip name", "host name");
1093
1094         for (i = 1; i < nr_irqs; i++) {
1095                 desc = irq_to_desc(i);
1096                 if (!desc)
1097                         continue;
1098
1099                 raw_spin_lock_irqsave(&desc->lock, flags);
1100
1101                 if (desc->action && desc->action->handler) {
1102                         struct irq_chip *chip;
1103
1104                         seq_printf(m, "%5d  ", i);
1105                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1106
1107                         chip = irq_desc_get_chip(desc);
1108                         if (chip && chip->name)
1109                                 p = chip->name;
1110                         else
1111                                 p = none;
1112                         seq_printf(m, "%-15s  ", p);
1113
1114                         if (irq_map[i].host && irq_map[i].host->of_node)
1115                                 p = irq_map[i].host->of_node->full_name;
1116                         else
1117                                 p = none;
1118                         seq_printf(m, "%s\n", p);
1119                 }
1120
1121                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1122         }
1123
1124         return 0;
1125 }
1126
1127 static int virq_debug_open(struct inode *inode, struct file *file)
1128 {
1129         return single_open(file, virq_debug_show, inode->i_private);
1130 }
1131
1132 static const struct file_operations virq_debug_fops = {
1133         .open = virq_debug_open,
1134         .read = seq_read,
1135         .llseek = seq_lseek,
1136         .release = single_release,
1137 };
1138
1139 static int __init irq_debugfs_init(void)
1140 {
1141         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1142                                  NULL, &virq_debug_fops) == NULL)
1143                 return -ENOMEM;
1144
1145         return 0;
1146 }
1147 __initcall(irq_debugfs_init);
1148 #endif /* CONFIG_VIRQ_DEBUG */
1149
1150 #ifdef CONFIG_PPC64
1151 static int __init setup_noirqdistrib(char *str)
1152 {
1153         distribute_irqs = 0;
1154         return 1;
1155 }
1156
1157 __setup("noirqdistrib", setup_noirqdistrib);
1158 #endif /* CONFIG_PPC64 */