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
  71 #ifdef CONFIG_PPC64
  72 #include <asm/paca.h>
  73 #include <asm/firmware.h>
  74 #include <asm/lv1call.h>
  75 #endif
  76 #define CREATE_TRACE_POINTS
  77 #include <asm/trace.h>
  78
  79 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
  80 EXPORT_PER_CPU_SYMBOL(irq_stat);
  81
  82 int __irq_offset_value;
  83
  84 #ifdef CONFIG_PPC32
  85 EXPORT_SYMBOL(__irq_offset_value);
  86 atomic_t ppc_n_lost_interrupts;
  87
  88 #ifdef CONFIG_TAU_INT
  89 extern int tau_initialized;
  90 extern int tau_interrupts(int);
  91 #endif
  92 #endif /* CONFIG_PPC32 */
  93
  94 #ifdef CONFIG_PPC64
  95
  96 #ifndef CONFIG_SPARSE_IRQ
  97 EXPORT_SYMBOL(irq_desc);
  98 #endif
  99
 100 int distribute_irqs = 1;
 101
 102 static inline notrace unsigned long get_hard_enabled(void)
 103 {
 104         unsigned long enabled;
 105
 106         __asm__ __volatile__("lbz %0,%1(13)"
 107         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 108
 109         return enabled;
 110 }
 111
 112 static inline notrace void set_soft_enabled(unsigned long enable)
 113 {
 114         __asm__ __volatile__("stb %0,%1(13)"
 115         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 116 }
 117
 118 notrace void raw_local_irq_restore(unsigned long en)
 119 {
 120         /*
 121          * get_paca()->soft_enabled = en;
 122          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 123          * That was allowed before, and in such a case we do need to take care
 124          * that gcc will set soft_enabled directly via r13, not choose to use
 125          * an intermediate register, lest we're preempted to a different cpu.
 126          */
 127         set_soft_enabled(en);
 128         if (!en)
 129                 return;
 130
 131 #ifdef CONFIG_PPC_STD_MMU_64
 132         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 133                 /*
 134                  * Do we need to disable preemption here?  Not really: in the
 135                  * unlikely event that we're preempted to a different cpu in
 136                  * between getting r13, loading its lppaca_ptr, and loading
 137                  * its any_int, we might call iseries_handle_interrupts without
 138                  * an interrupt pending on the new cpu, but that's no disaster,
 139                  * is it?  And the business of preempting us off the old cpu
 140                  * would itself involve a local_irq_restore which handles the
 141                  * interrupt to that cpu.
 142                  *
 143                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 144                  * to avoid any preemption checking added into get_paca().
 145                  */
 146                 if (local_paca->lppaca_ptr->int_dword.any_int)
 147                         iseries_handle_interrupts();
 148         }
 149 #endif /* CONFIG_PPC_STD_MMU_64 */
 150
 151         /*
 152          * if (get_paca()->hard_enabled) return;
 153          * But again we need to take care that gcc gets hard_enabled directly
 154          * via r13, not choose to use an intermediate register, lest we're
 155          * preempted to a different cpu in between the two instructions.
 156          */
 157         if (get_hard_enabled())
 158                 return;
 159
 160 #if defined(CONFIG_BOOKE) && defined(CONFIG_SMP)
 161         /* Check for pending doorbell interrupts and resend to ourself */
 162         doorbell_check_self();
 163 #endif
 164
 165         /*
 166          * Need to hard-enable interrupts here.  Since currently disabled,
 167          * no need to take further asm precautions against preemption; but
 168          * use local_paca instead of get_paca() to avoid preemption checking.
 169          */
 170         local_paca->hard_enabled = en;
 171
 172 #ifndef CONFIG_BOOKE
 173         /* On server, re-trigger the decrementer if it went negative since
 174          * some processors only trigger on edge transitions of the sign bit.
 175          *
 176          * BookE has a level sensitive decrementer (latches in TSR) so we
 177          * don't need that
 178          */
 179         if ((int)mfspr(SPRN_DEC) < 0)
 180                 mtspr(SPRN_DEC, 1);
 181 #endif /* CONFIG_BOOKE */
 182
 183         /*
 184          * Force the delivery of pending soft-disabled interrupts on PS3.
 185          * Any HV call will have this side effect.
 186          */
 187         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 188                 u64 tmp;
 189                 lv1_get_version_info(&tmp);
 190         }
 191
 192         __hard_irq_enable();
 193 }
 194 EXPORT_SYMBOL(raw_local_irq_restore);
 195 #endif /* CONFIG_PPC64 */
 196
 197 static int show_other_interrupts(struct seq_file *p, int prec)
 198 {
 199         int j;
 200
 201 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 202         if (tau_initialized) {
 203                 seq_printf(p, "%*s: ", prec, "TAU");
 204                 for_each_online_cpu(j)
 205                         seq_printf(p, "%10u ", tau_interrupts(j));
 206                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 207         }
 208 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
 209
 210         seq_printf(p, "%*s: ", prec, "LOC");
 211         for_each_online_cpu(j)
 212                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
 213         seq_printf(p, "  Local timer interrupts\n");
 214
 215         seq_printf(p, "%*s: ", prec, "SPU");
 216         for_each_online_cpu(j)
 217                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
 218         seq_printf(p, "  Spurious interrupts\n");
 219
 220         seq_printf(p, "%*s: ", prec, "CNT");
 221         for_each_online_cpu(j)
 222                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
 223         seq_printf(p, "  Performance monitoring interrupts\n");
 224
 225         seq_printf(p, "%*s: ", prec, "MCE");
 226         for_each_online_cpu(j)
 227                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
 228         seq_printf(p, "  Machine check exceptions\n");
 229
 230         return 0;
 231 }
 232
 233 int show_interrupts(struct seq_file *p, void *v)
 234 {
 235         unsigned long flags, any_count = 0;
 236         int i = *(loff_t *) v, j, prec;
 237         struct irqaction *action;
 238         struct irq_desc *desc;
 239
 240         if (i > nr_irqs)
 241                 return 0;
 242
 243         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
 244                 j *= 10;
 245
 246         if (i == nr_irqs)
 247                 return show_other_interrupts(p, prec);
 248
 249         /* print header */
 250         if (i == 0) {
 251                 seq_printf(p, "%*s", prec + 8, "");
 252                 for_each_online_cpu(j)
 253                         seq_printf(p, "CPU%-8d", j);
 254                 seq_putc(p, '\n');
 255         }
 256
 257         desc = irq_to_desc(i);
 258         if (!desc)
 259                 return 0;
 260
 261         raw_spin_lock_irqsave(&desc->lock, flags);
 262         for_each_online_cpu(j)
 263                 any_count |= kstat_irqs_cpu(i, j);
 264         action = desc->action;
 265         if (!action && !any_count)
 266                 goto out;
 267
 268         seq_printf(p, "%*d: ", prec, i);
 269         for_each_online_cpu(j)
 270                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 271
 272         if (desc->chip)
 273                 seq_printf(p, "  %-16s", desc->chip->name);
 274         else
 275                 seq_printf(p, "  %-16s", "None");
 276         seq_printf(p, " %-8s", (desc->status & IRQ_LEVEL) ? "Level" : "Edge");
 277
 278         if (action) {
 279                 seq_printf(p, "     %s", action->name);
 280                 while ((action = action->next) != NULL)
 281                         seq_printf(p, ", %s", action->name);
 282         }
 283
 284         seq_putc(p, '\n');
 285 out:
 286         raw_spin_unlock_irqrestore(&desc->lock, flags);
 287         return 0;
 288 }
 289
 290 /*
 291  * /proc/stat helpers
 292  */
 293 u64 arch_irq_stat_cpu(unsigned int cpu)
 294 {
 295         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
 296
 297         sum += per_cpu(irq_stat, cpu).pmu_irqs;
 298         sum += per_cpu(irq_stat, cpu).mce_exceptions;
 299         sum += per_cpu(irq_stat, cpu).spurious_irqs;
 300
 301         return sum;
 302 }
 303
 304 #ifdef CONFIG_HOTPLUG_CPU
 305 void fixup_irqs(const struct cpumask *map)
 306 {
 307         struct irq_desc *desc;
 308         unsigned int irq;
 309         static int warned;
 310         cpumask_var_t mask;
 311
 312         alloc_cpumask_var(&mask, GFP_KERNEL);
 313
 314         for_each_irq(irq) {
 315                 desc = irq_to_desc(irq);
 316                 if (!desc)
 317                         continue;
 318
 319                 if (desc->status & IRQ_PER_CPU)
 320                         continue;
 321
 322                 cpumask_and(mask, desc->affinity, map);
 323                 if (cpumask_any(mask) >= nr_cpu_ids) {
 324                         printk("Breaking affinity for irq %i\n", irq);
 325                         cpumask_copy(mask, map);
 326                 }
 327                 if (desc->chip->set_affinity)
 328                         desc->chip->set_affinity(irq, mask);
 329                 else if (desc->action && !(warned++))
 330                         printk("Cannot set affinity for irq %i\n", irq);
 331         }
 332
 333         free_cpumask_var(mask);
 334
 335         local_irq_enable();
 336         mdelay(1);
 337         local_irq_disable();
 338 }
 339 #endif
 340
 341 static inline void handle_one_irq(unsigned int irq)
 342 {
 343         struct thread_info *curtp, *irqtp;
 344         unsigned long saved_sp_limit;
 345         struct irq_desc *desc;
 346
 347         /* Switch to the irq stack to handle this */
 348         curtp = current_thread_info();
 349         irqtp = hardirq_ctx[smp_processor_id()];
 350
 351         if (curtp == irqtp) {
 352                 /* We're already on the irq stack, just handle it */
 353                 generic_handle_irq(irq);
 354                 return;
 355         }
 356
 357         desc = irq_to_desc(irq);
 358         saved_sp_limit = current->thread.ksp_limit;
 359
 360         irqtp->task = curtp->task;
 361         irqtp->flags = 0;
 362
 363         /* Copy the softirq bits in preempt_count so that the
 364          * softirq checks work in the hardirq context. */
 365         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 366                                (curtp->preempt_count & SOFTIRQ_MASK);
 367
 368         current->thread.ksp_limit = (unsigned long)irqtp +
 369                 _ALIGN_UP(sizeof(struct thread_info), 16);
 370
 371         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 372         current->thread.ksp_limit = saved_sp_limit;
 373         irqtp->task = NULL;
 374
 375         /* Set any flag that may have been set on the
 376          * alternate stack
 377          */
 378         if (irqtp->flags)
 379                 set_bits(irqtp->flags, &curtp->flags);
 380 }
 381
 382 static inline void check_stack_overflow(void)
 383 {
 384 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 385         long sp;
 386
 387         sp = __get_SP() & (THREAD_SIZE-1);
 388
 389         /* check for stack overflow: is there less than 2KB free? */
 390         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 391                 printk("do_IRQ: stack overflow: %ld\n",
 392                         sp - sizeof(struct thread_info));
 393                 dump_stack();
 394         }
 395 #endif
 396 }
 397
 398 void do_IRQ(struct pt_regs *regs)
 399 {
 400         struct pt_regs *old_regs = set_irq_regs(regs);
 401         unsigned int irq;
 402
 403         trace_irq_entry(regs);
 404
 405         irq_enter();
 406
 407         check_stack_overflow();
 408
 409         irq = ppc_md.get_irq();
 410
 411         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 412                 handle_one_irq(irq);
 413         else if (irq != NO_IRQ_IGNORE)
 414                 __get_cpu_var(irq_stat).spurious_irqs++;
 415
 416         irq_exit();
 417         set_irq_regs(old_regs);
 418
 419 #ifdef CONFIG_PPC_ISERIES
 420         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 421                         get_lppaca()->int_dword.fields.decr_int) {
 422                 get_lppaca()->int_dword.fields.decr_int = 0;
 423                 /* Signal a fake decrementer interrupt */
 424                 timer_interrupt(regs);
 425         }
 426 #endif
 427
 428         trace_irq_exit(regs);
 429 }
 430
 431 void __init init_IRQ(void)
 432 {
 433         if (ppc_md.init_IRQ)
 434                 ppc_md.init_IRQ();
 435
 436         exc_lvl_ctx_init();
 437
 438         irq_ctx_init();
 439 }
 440
 441 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 442 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 443 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 444 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 445
 446 void exc_lvl_ctx_init(void)
 447 {
 448         struct thread_info *tp;
 449         int i;
 450
 451         for_each_possible_cpu(i) {
 452                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 453                 tp = critirq_ctx[i];
 454                 tp->cpu = i;
 455                 tp->preempt_count = 0;
 456
 457 #ifdef CONFIG_BOOKE
 458                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 459                 tp = dbgirq_ctx[i];
 460                 tp->cpu = i;
 461                 tp->preempt_count = 0;
 462
 463                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 464                 tp = mcheckirq_ctx[i];
 465                 tp->cpu = i;
 466                 tp->preempt_count = HARDIRQ_OFFSET;
 467 #endif
 468         }
 469 }
 470 #endif
 471
 472 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 473 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 474
 475 void irq_ctx_init(void)
 476 {
 477         struct thread_info *tp;
 478         int i;
 479
 480         for_each_possible_cpu(i) {
 481                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 482                 tp = softirq_ctx[i];
 483                 tp->cpu = i;
 484                 tp->preempt_count = 0;
 485
 486                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 487                 tp = hardirq_ctx[i];
 488                 tp->cpu = i;
 489                 tp->preempt_count = HARDIRQ_OFFSET;
 490         }
 491 }
 492
 493 static inline void do_softirq_onstack(void)
 494 {
 495         struct thread_info *curtp, *irqtp;
 496         unsigned long saved_sp_limit = current->thread.ksp_limit;
 497
 498         curtp = current_thread_info();
 499         irqtp = softirq_ctx[smp_processor_id()];
 500         irqtp->task = curtp->task;
 501         current->thread.ksp_limit = (unsigned long)irqtp +
 502                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 503         call_do_softirq(irqtp);
 504         current->thread.ksp_limit = saved_sp_limit;
 505         irqtp->task = NULL;
 506 }
 507
 508 void do_softirq(void)
 509 {
 510         unsigned long flags;
 511
 512         if (in_interrupt())
 513                 return;
 514
 515         local_irq_save(flags);
 516
 517         if (local_softirq_pending())
 518                 do_softirq_onstack();
 519
 520         local_irq_restore(flags);
 521 }
 522
 523
 524 /*
 525  * IRQ controller and virtual interrupts
 526  */
 527
 528 static LIST_HEAD(irq_hosts);
 529 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 530 static unsigned int revmap_trees_allocated;
 531 static DEFINE_MUTEX(revmap_trees_mutex);
 532 struct irq_map_entry irq_map[NR_IRQS];
 533 static unsigned int irq_virq_count = NR_IRQS;
 534 static struct irq_host *irq_default_host;
 535
 536 irq_hw_number_t virq_to_hw(unsigned int virq)
 537 {
 538         return irq_map[virq].hwirq;
 539 }
 540 EXPORT_SYMBOL_GPL(virq_to_hw);
 541
 542 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 543 {
 544         return h->of_node != NULL && h->of_node == np;
 545 }
 546
 547 struct irq_host *irq_alloc_host(struct device_node *of_node,
 548                                 unsigned int revmap_type,
 549                                 unsigned int revmap_arg,
 550                                 struct irq_host_ops *ops,
 551                                 irq_hw_number_t inval_irq)
 552 {
 553         struct irq_host *host;
 554         unsigned int size = sizeof(struct irq_host);
 555         unsigned int i;
 556         unsigned int *rmap;
 557         unsigned long flags;
 558
 559         /* Allocate structure and revmap table if using linear mapping */
 560         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 561                 size += revmap_arg * sizeof(unsigned int);
 562         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 563         if (host == NULL)
 564                 return NULL;
 565
 566         /* Fill structure */
 567         host->revmap_type = revmap_type;
 568         host->inval_irq = inval_irq;
 569         host->ops = ops;
 570         host->of_node = of_node_get(of_node);
 571
 572         if (host->ops->match == NULL)
 573                 host->ops->match = default_irq_host_match;
 574
 575         raw_spin_lock_irqsave(&irq_big_lock, flags);
 576
 577         /* If it's a legacy controller, check for duplicates and
 578          * mark it as allocated (we use irq 0 host pointer for that
 579          */
 580         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 581                 if (irq_map[0].host != NULL) {
 582                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 583                         /* If we are early boot, we can't free the structure,
 584                          * too bad...
 585                          * this will be fixed once slab is made available early
 586                          * instead of the current cruft
 587                          */
 588                         if (mem_init_done)
 589                                 kfree(host);
 590                         return NULL;
 591                 }
 592                 irq_map[0].host = host;
 593         }
 594
 595         list_add(&host->link, &irq_hosts);
 596         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 597
 598         /* Additional setups per revmap type */
 599         switch(revmap_type) {
 600         case IRQ_HOST_MAP_LEGACY:
 601                 /* 0 is always the invalid number for legacy */
 602                 host->inval_irq = 0;
 603                 /* setup us as the host for all legacy interrupts */
 604                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 605                         irq_map[i].hwirq = i;
 606                         smp_wmb();
 607                         irq_map[i].host = host;
 608                         smp_wmb();
 609
 610                         /* Clear norequest flags */
 611                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
 612
 613                         /* Legacy flags are left to default at this point,
 614                          * one can then use irq_create_mapping() to
 615                          * explicitly change them
 616                          */
 617                         ops->map(host, i, i);
 618                 }
 619                 break;
 620         case IRQ_HOST_MAP_LINEAR:
 621                 rmap = (unsigned int *)(host + 1);
 622                 for (i = 0; i < revmap_arg; i++)
 623                         rmap[i] = NO_IRQ;
 624                 host->revmap_data.linear.size = revmap_arg;
 625                 smp_wmb();
 626                 host->revmap_data.linear.revmap = rmap;
 627                 break;
 628         default:
 629                 break;
 630         }
 631
 632         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 633
 634         return host;
 635 }
 636
 637 struct irq_host *irq_find_host(struct device_node *node)
 638 {
 639         struct irq_host *h, *found = NULL;
 640         unsigned long flags;
 641
 642         /* We might want to match the legacy controller last since
 643          * it might potentially be set to match all interrupts in
 644          * the absence of a device node. This isn't a problem so far
 645          * yet though...
 646          */
 647         raw_spin_lock_irqsave(&irq_big_lock, flags);
 648         list_for_each_entry(h, &irq_hosts, link)
 649                 if (h->ops->match(h, node)) {
 650                         found = h;
 651                         break;
 652                 }
 653         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 654         return found;
 655 }
 656 EXPORT_SYMBOL_GPL(irq_find_host);
 657
 658 void irq_set_default_host(struct irq_host *host)
 659 {
 660         pr_debug("irq: Default host set to @0x%p\n", host);
 661
 662         irq_default_host = host;
 663 }
 664
 665 void irq_set_virq_count(unsigned int count)
 666 {
 667         pr_debug("irq: Trying to set virq count to %d\n", count);
 668
 669         BUG_ON(count < NUM_ISA_INTERRUPTS);
 670         if (count < NR_IRQS)
 671                 irq_virq_count = count;
 672 }
 673
 674 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 675                             irq_hw_number_t hwirq)
 676 {
 677         struct irq_desc *desc;
 678
 679         desc = irq_to_desc_alloc_node(virq, 0);
 680         if (!desc) {
 681                 pr_debug("irq: -> allocating desc failed\n");
 682                 goto error;
 683         }
 684
 685         /* Clear IRQ_NOREQUEST flag */
 686         desc->status &= ~IRQ_NOREQUEST;
 687
 688         /* map it */
 689         smp_wmb();
 690         irq_map[virq].hwirq = hwirq;
 691         smp_mb();
 692
 693         if (host->ops->map(host, virq, hwirq)) {
 694                 pr_debug("irq: -> mapping failed, freeing\n");
 695                 goto error;
 696         }
 697
 698         return 0;
 699
 700 error:
 701         irq_free_virt(virq, 1);
 702         return -1;
 703 }
 704
 705 unsigned int irq_create_direct_mapping(struct irq_host *host)
 706 {
 707         unsigned int virq;
 708
 709         if (host == NULL)
 710                 host = irq_default_host;
 711
 712         BUG_ON(host == NULL);
 713         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 714
 715         virq = irq_alloc_virt(host, 1, 0);
 716         if (virq == NO_IRQ) {
 717                 pr_debug("irq: create_direct virq allocation failed\n");
 718                 return NO_IRQ;
 719         }
 720
 721         pr_debug("irq: create_direct obtained virq %d\n", virq);
 722
 723         if (irq_setup_virq(host, virq, virq))
 724                 return NO_IRQ;
 725
 726         return virq;
 727 }
 728
 729 unsigned int irq_create_mapping(struct irq_host *host,
 730                                 irq_hw_number_t hwirq)
 731 {
 732         unsigned int virq, hint;
 733
 734         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 735
 736         /* Look for default host if nececssary */
 737         if (host == NULL)
 738                 host = irq_default_host;
 739         if (host == NULL) {
 740                 printk(KERN_WARNING "irq_create_mapping called for"
 741                        " NULL host, hwirq=%lx\n", hwirq);
 742                 WARN_ON(1);
 743                 return NO_IRQ;
 744         }
 745         pr_debug("irq: -> using host @%p\n", host);
 746
 747         /* Check if mapping already exist, if it does, call
 748          * host->ops->map() to update the flags
 749          */
 750         virq = irq_find_mapping(host, hwirq);
 751         if (virq != NO_IRQ) {
 752                 if (host->ops->remap)
 753                         host->ops->remap(host, virq, hwirq);
 754                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 755                 return virq;
 756         }
 757
 758         /* Get a virtual interrupt number */
 759         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 760                 /* Handle legacy */
 761                 virq = (unsigned int)hwirq;
 762                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 763                         return NO_IRQ;
 764                 return virq;
 765         } else {
 766                 /* Allocate a virtual interrupt number */
 767                 hint = hwirq % irq_virq_count;
 768                 virq = irq_alloc_virt(host, 1, hint);
 769                 if (virq == NO_IRQ) {
 770                         pr_debug("irq: -> virq allocation failed\n");
 771                         return NO_IRQ;
 772                 }
 773         }
 774
 775         if (irq_setup_virq(host, virq, hwirq))
 776                 return NO_IRQ;
 777
 778         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 779                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 780
 781         return virq;
 782 }
 783 EXPORT_SYMBOL_GPL(irq_create_mapping);
 784
 785 unsigned int irq_create_of_mapping(struct device_node *controller,
 786                                    const u32 *intspec, unsigned int intsize)
 787 {
 788         struct irq_host *host;
 789         irq_hw_number_t hwirq;
 790         unsigned int type = IRQ_TYPE_NONE;
 791         unsigned int virq;
 792
 793         if (controller == NULL)
 794                 host = irq_default_host;
 795         else
 796                 host = irq_find_host(controller);
 797         if (host == NULL) {
 798                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 799                        controller->full_name);
 800                 return NO_IRQ;
 801         }
 802
 803         /* If host has no translation, then we assume interrupt line */
 804         if (host->ops->xlate == NULL)
 805                 hwirq = intspec[0];
 806         else {
 807                 if (host->ops->xlate(host, controller, intspec, intsize,
 808                                      &hwirq, &type))
 809                         return NO_IRQ;
 810         }
 811
 812         /* Create mapping */
 813         virq = irq_create_mapping(host, hwirq);
 814         if (virq == NO_IRQ)
 815                 return virq;
 816
 817         /* Set type if specified and different than the current one */
 818         if (type != IRQ_TYPE_NONE &&
 819             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
 820                 set_irq_type(virq, type);
 821         return virq;
 822 }
 823 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 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 */