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 #ifdef CONFIG_PPC64
  70 #include <asm/paca.h>
  71 #include <asm/firmware.h>
  72 #include <asm/lv1call.h>
  73 #endif
  74 #define CREATE_TRACE_POINTS
  75 #include <asm/trace.h>
  76
  77 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
  78 EXPORT_PER_CPU_SYMBOL(irq_stat);
  79
  80 int __irq_offset_value;
  81
  82 #ifdef CONFIG_PPC32
  83 EXPORT_SYMBOL(__irq_offset_value);
  84 atomic_t ppc_n_lost_interrupts;
  85
  86 #ifdef CONFIG_TAU_INT
  87 extern int tau_initialized;
  88 extern int tau_interrupts(int);
  89 #endif
  90 #endif /* CONFIG_PPC32 */
  91
  92 #ifdef CONFIG_PPC64
  93
  94 #ifndef CONFIG_SPARSE_IRQ
  95 EXPORT_SYMBOL(irq_desc);
  96 #endif
  97
  98 int distribute_irqs = 1;
  99
 100 static inline notrace unsigned long get_hard_enabled(void)
 101 {
 102         unsigned long enabled;
 103
 104         __asm__ __volatile__("lbz %0,%1(13)"
 105         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 106
 107         return enabled;
 108 }
 109
 110 static inline notrace void set_soft_enabled(unsigned long enable)
 111 {
 112         __asm__ __volatile__("stb %0,%1(13)"
 113         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 114 }
 115
 116 notrace void raw_local_irq_restore(unsigned long en)
 117 {
 118         /*
 119          * get_paca()->soft_enabled = en;
 120          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 121          * That was allowed before, and in such a case we do need to take care
 122          * that gcc will set soft_enabled directly via r13, not choose to use
 123          * an intermediate register, lest we're preempted to a different cpu.
 124          */
 125         set_soft_enabled(en);
 126         if (!en)
 127                 return;
 128
 129 #ifdef CONFIG_PPC_STD_MMU_64
 130         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 131                 /*
 132                  * Do we need to disable preemption here?  Not really: in the
 133                  * unlikely event that we're preempted to a different cpu in
 134                  * between getting r13, loading its lppaca_ptr, and loading
 135                  * its any_int, we might call iseries_handle_interrupts without
 136                  * an interrupt pending on the new cpu, but that's no disaster,
 137                  * is it?  And the business of preempting us off the old cpu
 138                  * would itself involve a local_irq_restore which handles the
 139                  * interrupt to that cpu.
 140                  *
 141                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 142                  * to avoid any preemption checking added into get_paca().
 143                  */
 144                 if (local_paca->lppaca_ptr->int_dword.any_int)
 145                         iseries_handle_interrupts();
 146         }
 147 #endif /* CONFIG_PPC_STD_MMU_64 */
 148
 149         /*
 150          * if (get_paca()->hard_enabled) return;
 151          * But again we need to take care that gcc gets hard_enabled directly
 152          * via r13, not choose to use an intermediate register, lest we're
 153          * preempted to a different cpu in between the two instructions.
 154          */
 155         if (get_hard_enabled())
 156                 return;
 157
 158         /*
 159          * Need to hard-enable interrupts here.  Since currently disabled,
 160          * no need to take further asm precautions against preemption; but
 161          * use local_paca instead of get_paca() to avoid preemption checking.
 162          */
 163         local_paca->hard_enabled = en;
 164         if ((int)mfspr(SPRN_DEC) < 0)
 165                 mtspr(SPRN_DEC, 1);
 166
 167         /*
 168          * Force the delivery of pending soft-disabled interrupts on PS3.
 169          * Any HV call will have this side effect.
 170          */
 171         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 172                 u64 tmp;
 173                 lv1_get_version_info(&tmp);
 174         }
 175
 176         __hard_irq_enable();
 177 }
 178 EXPORT_SYMBOL(raw_local_irq_restore);
 179 #endif /* CONFIG_PPC64 */
 180
 181 static int show_other_interrupts(struct seq_file *p, int prec)
 182 {
 183         int j;
 184
 185 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 186         if (tau_initialized) {
 187                 seq_printf(p, "%*s: ", prec, "TAU");
 188                 for_each_online_cpu(j)
 189                         seq_printf(p, "%10u ", tau_interrupts(j));
 190                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 191         }
 192 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
 193
 194         seq_printf(p, "%*s: ", prec, "LOC");
 195         for_each_online_cpu(j)
 196                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
 197         seq_printf(p, "  Local timer interrupts\n");
 198
 199         seq_printf(p, "%*s: ", prec, "SPU");
 200         for_each_online_cpu(j)
 201                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
 202         seq_printf(p, "  Spurious interrupts\n");
 203
 204         seq_printf(p, "%*s: ", prec, "CNT");
 205         for_each_online_cpu(j)
 206                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
 207         seq_printf(p, "  Performance monitoring interrupts\n");
 208
 209         seq_printf(p, "%*s: ", prec, "MCE");
 210         for_each_online_cpu(j)
 211                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
 212         seq_printf(p, "  Machine check exceptions\n");
 213
 214         return 0;
 215 }
 216
 217 int show_interrupts(struct seq_file *p, void *v)
 218 {
 219         unsigned long flags, any_count = 0;
 220         int i = *(loff_t *) v, j, prec;
 221         struct irqaction *action;
 222         struct irq_desc *desc;
 223
 224         if (i > nr_irqs)
 225                 return 0;
 226
 227         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
 228                 j *= 10;
 229
 230         if (i == nr_irqs)
 231                 return show_other_interrupts(p, prec);
 232
 233         /* print header */
 234         if (i == 0) {
 235                 seq_printf(p, "%*s", prec + 8, "");
 236                 for_each_online_cpu(j)
 237                         seq_printf(p, "CPU%-8d", j);
 238                 seq_putc(p, '\n');
 239         }
 240
 241         desc = irq_to_desc(i);
 242         if (!desc)
 243                 return 0;
 244
 245         raw_spin_lock_irqsave(&desc->lock, flags);
 246         for_each_online_cpu(j)
 247                 any_count |= kstat_irqs_cpu(i, j);
 248         action = desc->action;
 249         if (!action && !any_count)
 250                 goto out;
 251
 252         seq_printf(p, "%*d: ", prec, i);
 253         for_each_online_cpu(j)
 254                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 255
 256         if (desc->chip)
 257                 seq_printf(p, "  %-16s", desc->chip->name);
 258         else
 259                 seq_printf(p, "  %-16s", "None");
 260         seq_printf(p, " %-8s", (desc->status & IRQ_LEVEL) ? "Level" : "Edge");
 261
 262         if (action) {
 263                 seq_printf(p, "     %s", action->name);
 264                 while ((action = action->next) != NULL)
 265                         seq_printf(p, ", %s", action->name);
 266         }
 267
 268         seq_putc(p, '\n');
 269 out:
 270         raw_spin_unlock_irqrestore(&desc->lock, flags);
 271         return 0;
 272 }
 273
 274 /*
 275  * /proc/stat helpers
 276  */
 277 u64 arch_irq_stat_cpu(unsigned int cpu)
 278 {
 279         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
 280
 281         sum += per_cpu(irq_stat, cpu).pmu_irqs;
 282         sum += per_cpu(irq_stat, cpu).mce_exceptions;
 283         sum += per_cpu(irq_stat, cpu).spurious_irqs;
 284
 285         return sum;
 286 }
 287
 288 #ifdef CONFIG_HOTPLUG_CPU
 289 void fixup_irqs(const struct cpumask *map)
 290 {
 291         struct irq_desc *desc;
 292         unsigned int irq;
 293         static int warned;
 294         cpumask_var_t mask;
 295
 296         alloc_cpumask_var(&mask, GFP_KERNEL);
 297
 298         for_each_irq(irq) {
 299                 desc = irq_to_desc(irq);
 300                 if (!desc)
 301                         continue;
 302
 303                 if (desc->status & IRQ_PER_CPU)
 304                         continue;
 305
 306                 cpumask_and(mask, desc->affinity, map);
 307                 if (cpumask_any(mask) >= nr_cpu_ids) {
 308                         printk("Breaking affinity for irq %i\n", irq);
 309                         cpumask_copy(mask, map);
 310                 }
 311                 if (desc->chip->set_affinity)
 312                         desc->chip->set_affinity(irq, mask);
 313                 else if (desc->action && !(warned++))
 314                         printk("Cannot set affinity for irq %i\n", irq);
 315         }
 316
 317         free_cpumask_var(mask);
 318
 319         local_irq_enable();
 320         mdelay(1);
 321         local_irq_disable();
 322 }
 323 #endif
 324
 325 static inline void handle_one_irq(unsigned int irq)
 326 {
 327         struct thread_info *curtp, *irqtp;
 328         unsigned long saved_sp_limit;
 329         struct irq_desc *desc;
 330
 331         /* Switch to the irq stack to handle this */
 332         curtp = current_thread_info();
 333         irqtp = hardirq_ctx[smp_processor_id()];
 334
 335         if (curtp == irqtp) {
 336                 /* We're already on the irq stack, just handle it */
 337                 generic_handle_irq(irq);
 338                 return;
 339         }
 340
 341         desc = irq_to_desc(irq);
 342         saved_sp_limit = current->thread.ksp_limit;
 343
 344         irqtp->task = curtp->task;
 345         irqtp->flags = 0;
 346
 347         /* Copy the softirq bits in preempt_count so that the
 348          * softirq checks work in the hardirq context. */
 349         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 350                                (curtp->preempt_count & SOFTIRQ_MASK);
 351
 352         current->thread.ksp_limit = (unsigned long)irqtp +
 353                 _ALIGN_UP(sizeof(struct thread_info), 16);
 354
 355         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 356         current->thread.ksp_limit = saved_sp_limit;
 357         irqtp->task = NULL;
 358
 359         /* Set any flag that may have been set on the
 360          * alternate stack
 361          */
 362         if (irqtp->flags)
 363                 set_bits(irqtp->flags, &curtp->flags);
 364 }
 365
 366 static inline void check_stack_overflow(void)
 367 {
 368 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 369         long sp;
 370
 371         sp = __get_SP() & (THREAD_SIZE-1);
 372
 373         /* check for stack overflow: is there less than 2KB free? */
 374         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 375                 printk("do_IRQ: stack overflow: %ld\n",
 376                         sp - sizeof(struct thread_info));
 377                 dump_stack();
 378         }
 379 #endif
 380 }
 381
 382 void do_IRQ(struct pt_regs *regs)
 383 {
 384         struct pt_regs *old_regs = set_irq_regs(regs);
 385         unsigned int irq;
 386
 387         trace_irq_entry(regs);
 388
 389         irq_enter();
 390
 391         check_stack_overflow();
 392
 393         irq = ppc_md.get_irq();
 394
 395         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 396                 handle_one_irq(irq);
 397         else if (irq != NO_IRQ_IGNORE)
 398                 __get_cpu_var(irq_stat).spurious_irqs++;
 399
 400         irq_exit();
 401         set_irq_regs(old_regs);
 402
 403 #ifdef CONFIG_PPC_ISERIES
 404         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 405                         get_lppaca()->int_dword.fields.decr_int) {
 406                 get_lppaca()->int_dword.fields.decr_int = 0;
 407                 /* Signal a fake decrementer interrupt */
 408                 timer_interrupt(regs);
 409         }
 410 #endif
 411
 412         trace_irq_exit(regs);
 413 }
 414
 415 void __init init_IRQ(void)
 416 {
 417         if (ppc_md.init_IRQ)
 418                 ppc_md.init_IRQ();
 419
 420         exc_lvl_ctx_init();
 421
 422         irq_ctx_init();
 423 }
 424
 425 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 426 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 427 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 428 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 429
 430 void exc_lvl_ctx_init(void)
 431 {
 432         struct thread_info *tp;
 433         int i;
 434
 435         for_each_possible_cpu(i) {
 436                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 437                 tp = critirq_ctx[i];
 438                 tp->cpu = i;
 439                 tp->preempt_count = 0;
 440
 441 #ifdef CONFIG_BOOKE
 442                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 443                 tp = dbgirq_ctx[i];
 444                 tp->cpu = i;
 445                 tp->preempt_count = 0;
 446
 447                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 448                 tp = mcheckirq_ctx[i];
 449                 tp->cpu = i;
 450                 tp->preempt_count = HARDIRQ_OFFSET;
 451 #endif
 452         }
 453 }
 454 #endif
 455
 456 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 457 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 458
 459 void irq_ctx_init(void)
 460 {
 461         struct thread_info *tp;
 462         int i;
 463
 464         for_each_possible_cpu(i) {
 465                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 466                 tp = softirq_ctx[i];
 467                 tp->cpu = i;
 468                 tp->preempt_count = 0;
 469
 470                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 471                 tp = hardirq_ctx[i];
 472                 tp->cpu = i;
 473                 tp->preempt_count = HARDIRQ_OFFSET;
 474         }
 475 }
 476
 477 static inline void do_softirq_onstack(void)
 478 {
 479         struct thread_info *curtp, *irqtp;
 480         unsigned long saved_sp_limit = current->thread.ksp_limit;
 481
 482         curtp = current_thread_info();
 483         irqtp = softirq_ctx[smp_processor_id()];
 484         irqtp->task = curtp->task;
 485         current->thread.ksp_limit = (unsigned long)irqtp +
 486                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 487         call_do_softirq(irqtp);
 488         current->thread.ksp_limit = saved_sp_limit;
 489         irqtp->task = NULL;
 490 }
 491
 492 void do_softirq(void)
 493 {
 494         unsigned long flags;
 495
 496         if (in_interrupt())
 497                 return;
 498
 499         local_irq_save(flags);
 500
 501         if (local_softirq_pending())
 502                 do_softirq_onstack();
 503
 504         local_irq_restore(flags);
 505 }
 506
 507
 508 /*
 509  * IRQ controller and virtual interrupts
 510  */
 511
 512 static LIST_HEAD(irq_hosts);
 513 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 514 static unsigned int revmap_trees_allocated;
 515 static DEFINE_MUTEX(revmap_trees_mutex);
 516 struct irq_map_entry irq_map[NR_IRQS];
 517 static unsigned int irq_virq_count = NR_IRQS;
 518 static struct irq_host *irq_default_host;
 519
 520 irq_hw_number_t virq_to_hw(unsigned int virq)
 521 {
 522         return irq_map[virq].hwirq;
 523 }
 524 EXPORT_SYMBOL_GPL(virq_to_hw);
 525
 526 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 527 {
 528         return h->of_node != NULL && h->of_node == np;
 529 }
 530
 531 struct irq_host *irq_alloc_host(struct device_node *of_node,
 532                                 unsigned int revmap_type,
 533                                 unsigned int revmap_arg,
 534                                 struct irq_host_ops *ops,
 535                                 irq_hw_number_t inval_irq)
 536 {
 537         struct irq_host *host;
 538         unsigned int size = sizeof(struct irq_host);
 539         unsigned int i;
 540         unsigned int *rmap;
 541         unsigned long flags;
 542
 543         /* Allocate structure and revmap table if using linear mapping */
 544         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 545                 size += revmap_arg * sizeof(unsigned int);
 546         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 547         if (host == NULL)
 548                 return NULL;
 549
 550         /* Fill structure */
 551         host->revmap_type = revmap_type;
 552         host->inval_irq = inval_irq;
 553         host->ops = ops;
 554         host->of_node = of_node_get(of_node);
 555
 556         if (host->ops->match == NULL)
 557                 host->ops->match = default_irq_host_match;
 558
 559         raw_spin_lock_irqsave(&irq_big_lock, flags);
 560
 561         /* If it's a legacy controller, check for duplicates and
 562          * mark it as allocated (we use irq 0 host pointer for that
 563          */
 564         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 565                 if (irq_map[0].host != NULL) {
 566                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 567                         /* If we are early boot, we can't free the structure,
 568                          * too bad...
 569                          * this will be fixed once slab is made available early
 570                          * instead of the current cruft
 571                          */
 572                         if (mem_init_done)
 573                                 kfree(host);
 574                         return NULL;
 575                 }
 576                 irq_map[0].host = host;
 577         }
 578
 579         list_add(&host->link, &irq_hosts);
 580         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 581
 582         /* Additional setups per revmap type */
 583         switch(revmap_type) {
 584         case IRQ_HOST_MAP_LEGACY:
 585                 /* 0 is always the invalid number for legacy */
 586                 host->inval_irq = 0;
 587                 /* setup us as the host for all legacy interrupts */
 588                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 589                         irq_map[i].hwirq = i;
 590                         smp_wmb();
 591                         irq_map[i].host = host;
 592                         smp_wmb();
 593
 594                         /* Clear norequest flags */
 595                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
 596
 597                         /* Legacy flags are left to default at this point,
 598                          * one can then use irq_create_mapping() to
 599                          * explicitly change them
 600                          */
 601                         ops->map(host, i, i);
 602                 }
 603                 break;
 604         case IRQ_HOST_MAP_LINEAR:
 605                 rmap = (unsigned int *)(host + 1);
 606                 for (i = 0; i < revmap_arg; i++)
 607                         rmap[i] = NO_IRQ;
 608                 host->revmap_data.linear.size = revmap_arg;
 609                 smp_wmb();
 610                 host->revmap_data.linear.revmap = rmap;
 611                 break;
 612         default:
 613                 break;
 614         }
 615
 616         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 617
 618         return host;
 619 }
 620
 621 struct irq_host *irq_find_host(struct device_node *node)
 622 {
 623         struct irq_host *h, *found = NULL;
 624         unsigned long flags;
 625
 626         /* We might want to match the legacy controller last since
 627          * it might potentially be set to match all interrupts in
 628          * the absence of a device node. This isn't a problem so far
 629          * yet though...
 630          */
 631         raw_spin_lock_irqsave(&irq_big_lock, flags);
 632         list_for_each_entry(h, &irq_hosts, link)
 633                 if (h->ops->match(h, node)) {
 634                         found = h;
 635                         break;
 636                 }
 637         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 638         return found;
 639 }
 640 EXPORT_SYMBOL_GPL(irq_find_host);
 641
 642 void irq_set_default_host(struct irq_host *host)
 643 {
 644         pr_debug("irq: Default host set to @0x%p\n", host);
 645
 646         irq_default_host = host;
 647 }
 648
 649 void irq_set_virq_count(unsigned int count)
 650 {
 651         pr_debug("irq: Trying to set virq count to %d\n", count);
 652
 653         BUG_ON(count < NUM_ISA_INTERRUPTS);
 654         if (count < NR_IRQS)
 655                 irq_virq_count = count;
 656 }
 657
 658 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 659                             irq_hw_number_t hwirq)
 660 {
 661         struct irq_desc *desc;
 662
 663         desc = irq_to_desc_alloc_node(virq, 0);
 664         if (!desc) {
 665                 pr_debug("irq: -> allocating desc failed\n");
 666                 goto error;
 667         }
 668
 669         /* Clear IRQ_NOREQUEST flag */
 670         desc->status &= ~IRQ_NOREQUEST;
 671
 672         /* map it */
 673         smp_wmb();
 674         irq_map[virq].hwirq = hwirq;
 675         smp_mb();
 676
 677         if (host->ops->map(host, virq, hwirq)) {
 678                 pr_debug("irq: -> mapping failed, freeing\n");
 679                 goto error;
 680         }
 681
 682         return 0;
 683
 684 error:
 685         irq_free_virt(virq, 1);
 686         return -1;
 687 }
 688
 689 unsigned int irq_create_direct_mapping(struct irq_host *host)
 690 {
 691         unsigned int virq;
 692
 693         if (host == NULL)
 694                 host = irq_default_host;
 695
 696         BUG_ON(host == NULL);
 697         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 698
 699         virq = irq_alloc_virt(host, 1, 0);
 700         if (virq == NO_IRQ) {
 701                 pr_debug("irq: create_direct virq allocation failed\n");
 702                 return NO_IRQ;
 703         }
 704
 705         pr_debug("irq: create_direct obtained virq %d\n", virq);
 706
 707         if (irq_setup_virq(host, virq, virq))
 708                 return NO_IRQ;
 709
 710         return virq;
 711 }
 712
 713 unsigned int irq_create_mapping(struct irq_host *host,
 714                                 irq_hw_number_t hwirq)
 715 {
 716         unsigned int virq, hint;
 717
 718         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 719
 720         /* Look for default host if nececssary */
 721         if (host == NULL)
 722                 host = irq_default_host;
 723         if (host == NULL) {
 724                 printk(KERN_WARNING "irq_create_mapping called for"
 725                        " NULL host, hwirq=%lx\n", hwirq);
 726                 WARN_ON(1);
 727                 return NO_IRQ;
 728         }
 729         pr_debug("irq: -> using host @%p\n", host);
 730
 731         /* Check if mapping already exist, if it does, call
 732          * host->ops->map() to update the flags
 733          */
 734         virq = irq_find_mapping(host, hwirq);
 735         if (virq != NO_IRQ) {
 736                 if (host->ops->remap)
 737                         host->ops->remap(host, virq, hwirq);
 738                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 739                 return virq;
 740         }
 741
 742         /* Get a virtual interrupt number */
 743         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 744                 /* Handle legacy */
 745                 virq = (unsigned int)hwirq;
 746                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 747                         return NO_IRQ;
 748                 return virq;
 749         } else {
 750                 /* Allocate a virtual interrupt number */
 751                 hint = hwirq % irq_virq_count;
 752                 virq = irq_alloc_virt(host, 1, hint);
 753                 if (virq == NO_IRQ) {
 754                         pr_debug("irq: -> virq allocation failed\n");
 755                         return NO_IRQ;
 756                 }
 757         }
 758
 759         if (irq_setup_virq(host, virq, hwirq))
 760                 return NO_IRQ;
 761
 762         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 763                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 764
 765         return virq;
 766 }
 767 EXPORT_SYMBOL_GPL(irq_create_mapping);
 768
 769 unsigned int irq_create_of_mapping(struct device_node *controller,
 770                                    const u32 *intspec, unsigned int intsize)
 771 {
 772         struct irq_host *host;
 773         irq_hw_number_t hwirq;
 774         unsigned int type = IRQ_TYPE_NONE;
 775         unsigned int virq;
 776
 777         if (controller == NULL)
 778                 host = irq_default_host;
 779         else
 780                 host = irq_find_host(controller);
 781         if (host == NULL) {
 782                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 783                        controller->full_name);
 784                 return NO_IRQ;
 785         }
 786
 787         /* If host has no translation, then we assume interrupt line */
 788         if (host->ops->xlate == NULL)
 789                 hwirq = intspec[0];
 790         else {
 791                 if (host->ops->xlate(host, controller, intspec, intsize,
 792                                      &hwirq, &type))
 793                         return NO_IRQ;
 794         }
 795
 796         /* Create mapping */
 797         virq = irq_create_mapping(host, hwirq);
 798         if (virq == NO_IRQ)
 799                 return virq;
 800
 801         /* Set type if specified and different than the current one */
 802         if (type != IRQ_TYPE_NONE &&
 803             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
 804                 set_irq_type(virq, type);
 805         return virq;
 806 }
 807 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 808
 809 void irq_dispose_mapping(unsigned int virq)
 810 {
 811         struct irq_host *host;
 812         irq_hw_number_t hwirq;
 813
 814         if (virq == NO_IRQ)
 815                 return;
 816
 817         host = irq_map[virq].host;
 818         WARN_ON (host == NULL);
 819         if (host == NULL)
 820                 return;
 821
 822         /* Never unmap legacy interrupts */
 823         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 824                 return;
 825
 826         /* remove chip and handler */
 827         set_irq_chip_and_handler(virq, NULL, NULL);
 828
 829         /* Make sure it's completed */
 830         synchronize_irq(virq);
 831
 832         /* Tell the PIC about it */
 833         if (host->ops->unmap)
 834                 host->ops->unmap(host, virq);
 835         smp_mb();
 836
 837         /* Clear reverse map */
 838         hwirq = irq_map[virq].hwirq;
 839         switch(host->revmap_type) {
 840         case IRQ_HOST_MAP_LINEAR:
 841                 if (hwirq < host->revmap_data.linear.size)
 842                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 843                 break;
 844         case IRQ_HOST_MAP_TREE:
 845                 /*
 846                  * Check if radix tree allocated yet, if not then nothing to
 847                  * remove.
 848                  */
 849                 smp_rmb();
 850                 if (revmap_trees_allocated < 1)
 851                         break;
 852                 mutex_lock(&revmap_trees_mutex);
 853                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 854                 mutex_unlock(&revmap_trees_mutex);
 855                 break;
 856         }
 857
 858         /* Destroy map */
 859         smp_mb();
 860         irq_map[virq].hwirq = host->inval_irq;
 861
 862         /* Set some flags */
 863         irq_to_desc(virq)->status |= IRQ_NOREQUEST;
 864
 865         /* Free it */
 866         irq_free_virt(virq, 1);
 867 }
 868 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 869
 870 unsigned int irq_find_mapping(struct irq_host *host,
 871                               irq_hw_number_t hwirq)
 872 {
 873         unsigned int i;
 874         unsigned int hint = hwirq % irq_virq_count;
 875
 876         /* Look for default host if nececssary */
 877         if (host == NULL)
 878                 host = irq_default_host;
 879         if (host == NULL)
 880                 return NO_IRQ;
 881
 882         /* legacy -> bail early */
 883         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 884                 return hwirq;
 885
 886         /* Slow path does a linear search of the map */
 887         if (hint < NUM_ISA_INTERRUPTS)
 888                 hint = NUM_ISA_INTERRUPTS;
 889         i = hint;
 890         do  {
 891                 if (irq_map[i].host == host &&
 892                     irq_map[i].hwirq == hwirq)
 893                         return i;
 894                 i++;
 895                 if (i >= irq_virq_count)
 896                         i = NUM_ISA_INTERRUPTS;
 897         } while(i != hint);
 898         return NO_IRQ;
 899 }
 900 EXPORT_SYMBOL_GPL(irq_find_mapping);
 901
 902
 903 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 904                                      irq_hw_number_t hwirq)
 905 {
 906         struct irq_map_entry *ptr;
 907         unsigned int virq;
 908
 909         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 910
 911         /*
 912          * Check if the radix tree exists and has bee initialized.
 913          * If not, we fallback to slow mode
 914          */
 915         if (revmap_trees_allocated < 2)
 916                 return irq_find_mapping(host, hwirq);
 917
 918         /* Now try to resolve */
 919         /*
 920          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 921          * as it's referencing an entry in the static irq_map table.
 922          */
 923         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 924
 925         /*
 926          * If found in radix tree, then fine.
 927          * Else fallback to linear lookup - this should not happen in practice
 928          * as it means that we failed to insert the node in the radix tree.
 929          */
 930         if (ptr)
 931                 virq = ptr - irq_map;
 932         else
 933                 virq = irq_find_mapping(host, hwirq);
 934
 935         return virq;
 936 }
 937
 938 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 939                              irq_hw_number_t hwirq)
 940 {
 941
 942         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 943
 944         /*
 945          * Check if the radix tree exists yet.
 946          * If not, then the irq will be inserted into the tree when it gets
 947          * initialized.
 948          */
 949         smp_rmb();
 950         if (revmap_trees_allocated < 1)
 951                 return;
 952
 953         if (virq != NO_IRQ) {
 954                 mutex_lock(&revmap_trees_mutex);
 955                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 956                                   &irq_map[virq]);
 957                 mutex_unlock(&revmap_trees_mutex);
 958         }
 959 }
 960
 961 unsigned int irq_linear_revmap(struct irq_host *host,
 962                                irq_hw_number_t hwirq)
 963 {
 964         unsigned int *revmap;
 965
 966         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 967
 968         /* Check revmap bounds */
 969         if (unlikely(hwirq >= host->revmap_data.linear.size))
 970                 return irq_find_mapping(host, hwirq);
 971
 972         /* Check if revmap was allocated */
 973         revmap = host->revmap_data.linear.revmap;
 974         if (unlikely(revmap == NULL))
 975                 return irq_find_mapping(host, hwirq);
 976
 977         /* Fill up revmap with slow path if no mapping found */
 978         if (unlikely(revmap[hwirq] == NO_IRQ))
 979                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 980
 981         return revmap[hwirq];
 982 }
 983
 984 unsigned int irq_alloc_virt(struct irq_host *host,
 985                             unsigned int count,
 986                             unsigned int hint)
 987 {
 988         unsigned long flags;
 989         unsigned int i, j, found = NO_IRQ;
 990
 991         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 992                 return NO_IRQ;
 993
 994         raw_spin_lock_irqsave(&irq_big_lock, flags);
 995
 996         /* Use hint for 1 interrupt if any */
 997         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 998             hint < irq_virq_count && irq_map[hint].host == NULL) {
 999                 found = hint;
1000                 goto hint_found;
1001         }
1002
1003         /* Look for count consecutive numbers in the allocatable
1004          * (non-legacy) space
1005          */
1006         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1007                 if (irq_map[i].host != NULL)
1008                         j = 0;
1009                 else
1010                         j++;
1011
1012                 if (j == count) {
1013                         found = i - count + 1;
1014                         break;
1015                 }
1016         }
1017         if (found == NO_IRQ) {
1018                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1019                 return NO_IRQ;
1020         }
1021  hint_found:
1022         for (i = found; i < (found + count); i++) {
1023                 irq_map[i].hwirq = host->inval_irq;
1024                 smp_wmb();
1025                 irq_map[i].host = host;
1026         }
1027         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1028         return found;
1029 }
1030
1031 void irq_free_virt(unsigned int virq, unsigned int count)
1032 {
1033         unsigned long flags;
1034         unsigned int i;
1035
1036         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1037         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1038
1039         raw_spin_lock_irqsave(&irq_big_lock, flags);
1040         for (i = virq; i < (virq + count); i++) {
1041                 struct irq_host *host;
1042
1043                 if (i < NUM_ISA_INTERRUPTS ||
1044                     (virq + count) > irq_virq_count)
1045                         continue;
1046
1047                 host = irq_map[i].host;
1048                 irq_map[i].hwirq = host->inval_irq;
1049                 smp_wmb();
1050                 irq_map[i].host = NULL;
1051         }
1052         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1053 }
1054
1055 int arch_early_irq_init(void)
1056 {
1057         struct irq_desc *desc;
1058         int i;
1059
1060         for (i = 0; i < NR_IRQS; i++) {
1061                 desc = irq_to_desc(i);
1062                 if (desc)
1063                         desc->status |= IRQ_NOREQUEST;
1064         }
1065
1066         return 0;
1067 }
1068
1069 int arch_init_chip_data(struct irq_desc *desc, int node)
1070 {
1071         desc->status |= IRQ_NOREQUEST;
1072         return 0;
1073 }
1074
1075 /* We need to create the radix trees late */
1076 static int irq_late_init(void)
1077 {
1078         struct irq_host *h;
1079         unsigned int i;
1080
1081         /*
1082          * No mutual exclusion with respect to accessors of the tree is needed
1083          * here as the synchronization is done via the state variable
1084          * revmap_trees_allocated.
1085          */
1086         list_for_each_entry(h, &irq_hosts, link) {
1087                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1088                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1089         }
1090
1091         /*
1092          * Make sure the radix trees inits are visible before setting
1093          * the flag
1094          */
1095         smp_wmb();
1096         revmap_trees_allocated = 1;
1097
1098         /*
1099          * Insert the reverse mapping for those interrupts already present
1100          * in irq_map[].
1101          */
1102         mutex_lock(&revmap_trees_mutex);
1103         for (i = 0; i < irq_virq_count; i++) {
1104                 if (irq_map[i].host &&
1105                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1106                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1107                                           irq_map[i].hwirq, &irq_map[i]);
1108         }
1109         mutex_unlock(&revmap_trees_mutex);
1110
1111         /*
1112          * Make sure the radix trees insertions are visible before setting
1113          * the flag
1114          */
1115         smp_wmb();
1116         revmap_trees_allocated = 2;
1117
1118         return 0;
1119 }
1120 arch_initcall(irq_late_init);
1121
1122 #ifdef CONFIG_VIRQ_DEBUG
1123 static int virq_debug_show(struct seq_file *m, void *private)
1124 {
1125         unsigned long flags;
1126         struct irq_desc *desc;
1127         const char *p;
1128         char none[] = "none";
1129         int i;
1130
1131         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1132                       "chip name", "host name");
1133
1134         for (i = 1; i < nr_irqs; i++) {
1135                 desc = irq_to_desc(i);
1136                 if (!desc)
1137                         continue;
1138
1139                 raw_spin_lock_irqsave(&desc->lock, flags);
1140
1141                 if (desc->action && desc->action->handler) {
1142                         seq_printf(m, "%5d  ", i);
1143                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1144
1145                         if (desc->chip && desc->chip->name)
1146                                 p = desc->chip->name;
1147                         else
1148                                 p = none;
1149                         seq_printf(m, "%-15s  ", p);
1150
1151                         if (irq_map[i].host && irq_map[i].host->of_node)
1152                                 p = irq_map[i].host->of_node->full_name;
1153                         else
1154                                 p = none;
1155                         seq_printf(m, "%s\n", p);
1156                 }
1157
1158                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1159         }
1160
1161         return 0;
1162 }
1163
1164 static int virq_debug_open(struct inode *inode, struct file *file)
1165 {
1166         return single_open(file, virq_debug_show, inode->i_private);
1167 }
1168
1169 static const struct file_operations virq_debug_fops = {
1170         .open = virq_debug_open,
1171         .read = seq_read,
1172         .llseek = seq_lseek,
1173         .release = single_release,
1174 };
1175
1176 static int __init irq_debugfs_init(void)
1177 {
1178         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1179                                  NULL, &virq_debug_fops) == NULL)
1180                 return -ENOMEM;
1181
1182         return 0;
1183 }
1184 __initcall(irq_debugfs_init);
1185 #endif /* CONFIG_VIRQ_DEBUG */
1186
1187 #ifdef CONFIG_PPC64
1188 static int __init setup_noirqdistrib(char *str)
1189 {
1190         distribute_irqs = 0;
1191         return 1;
1192 }
1193
1194 __setup("noirqdistrib", setup_noirqdistrib);
1195 #endif /* CONFIG_PPC64 */