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/perf_event.h>
  57
  58 #include <asm/uaccess.h>
  59 #include <asm/system.h>
  60 #include <asm/io.h>
  61 #include <asm/pgtable.h>
  62 #include <asm/irq.h>
  63 #include <asm/cache.h>
  64 #include <asm/prom.h>
  65 #include <asm/ptrace.h>
  66 #include <asm/machdep.h>
  67 #include <asm/udbg.h>
  68 #ifdef CONFIG_PPC64
  69 #include <asm/paca.h>
  70 #include <asm/firmware.h>
  71 #include <asm/lv1call.h>
  72 #endif
  73 #define CREATE_TRACE_POINTS
  74 #include <asm/trace.h>
  75
  76 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
  77 EXPORT_PER_CPU_SYMBOL(irq_stat);
  78
  79 int __irq_offset_value;
  80 static int ppc_spurious_interrupts;
  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         if (test_perf_event_pending()) {
 150                 clear_perf_event_pending();
 151                 perf_event_do_pending();
 152         }
 153
 154         /*
 155          * if (get_paca()->hard_enabled) return;
 156          * But again we need to take care that gcc gets hard_enabled directly
 157          * via r13, not choose to use an intermediate register, lest we're
 158          * preempted to a different cpu in between the two instructions.
 159          */
 160         if (get_hard_enabled())
 161                 return;
 162
 163         /*
 164          * Need to hard-enable interrupts here.  Since currently disabled,
 165          * no need to take further asm precautions against preemption; but
 166          * use local_paca instead of get_paca() to avoid preemption checking.
 167          */
 168         local_paca->hard_enabled = en;
 169         if ((int)mfspr(SPRN_DEC) < 0)
 170                 mtspr(SPRN_DEC, 1);
 171
 172         /*
 173          * Force the delivery of pending soft-disabled interrupts on PS3.
 174          * Any HV call will have this side effect.
 175          */
 176         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 177                 u64 tmp;
 178                 lv1_get_version_info(&tmp);
 179         }
 180
 181         __hard_irq_enable();
 182 }
 183 EXPORT_SYMBOL(raw_local_irq_restore);
 184 #endif /* CONFIG_PPC64 */
 185
 186 static int show_other_interrupts(struct seq_file *p, int prec)
 187 {
 188         int j;
 189
 190 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 191         if (tau_initialized) {
 192                 seq_printf(p, "%*s: ", prec, "TAU");
 193                 for_each_online_cpu(j)
 194                         seq_printf(p, "%10u ", tau_interrupts(j));
 195                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 196         }
 197 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
 198
 199         seq_printf(p, "%*s: ", prec, "LOC");
 200         for_each_online_cpu(j)
 201                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
 202         seq_printf(p, "  Local timer 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         seq_printf(p, "%*s: %10u\n", prec, "BAD", ppc_spurious_interrupts);
 215
 216         return 0;
 217 }
 218
 219 int show_interrupts(struct seq_file *p, void *v)
 220 {
 221         unsigned long flags, any_count = 0;
 222         int i = *(loff_t *) v, j, prec;
 223         struct irqaction *action;
 224         struct irq_desc *desc;
 225
 226         if (i > nr_irqs)
 227                 return 0;
 228
 229         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
 230                 j *= 10;
 231
 232         if (i == nr_irqs)
 233                 return show_other_interrupts(p, prec);
 234
 235         /* print header */
 236         if (i == 0) {
 237                 seq_printf(p, "%*s", prec + 8, "");
 238                 for_each_online_cpu(j)
 239                         seq_printf(p, "CPU%-8d", j);
 240                 seq_putc(p, '\n');
 241         }
 242
 243         desc = irq_to_desc(i);
 244         if (!desc)
 245                 return 0;
 246
 247         raw_spin_lock_irqsave(&desc->lock, flags);
 248         for_each_online_cpu(j)
 249                 any_count |= kstat_irqs_cpu(i, j);
 250         action = desc->action;
 251         if (!action && !any_count)
 252                 goto out;
 253
 254         seq_printf(p, "%*d: ", prec, i);
 255         for_each_online_cpu(j)
 256                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 257
 258         if (desc->chip)
 259                 seq_printf(p, "  %-16s", desc->chip->name);
 260         else
 261                 seq_printf(p, "  %-16s", "None");
 262         seq_printf(p, " %-8s", (desc->status & IRQ_LEVEL) ? "Level" : "Edge");
 263
 264         if (action) {
 265                 seq_printf(p, "     %s", action->name);
 266                 while ((action = action->next) != NULL)
 267                         seq_printf(p, ", %s", action->name);
 268         }
 269
 270         seq_putc(p, '\n');
 271 out:
 272         raw_spin_unlock_irqrestore(&desc->lock, flags);
 273         return 0;
 274 }
 275
 276 /*
 277  * /proc/stat helpers
 278  */
 279 u64 arch_irq_stat_cpu(unsigned int cpu)
 280 {
 281         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
 282
 283         sum += per_cpu(irq_stat, cpu).pmu_irqs;
 284         sum += per_cpu(irq_stat, cpu).mce_exceptions;
 285
 286         return sum;
 287 }
 288
 289 u64 arch_irq_stat(void)
 290 {
 291         u64 sum = ppc_spurious_interrupts;
 292
 293         return sum;
 294 }
 295
 296 #ifdef CONFIG_HOTPLUG_CPU
 297 void fixup_irqs(cpumask_t map)
 298 {
 299         struct irq_desc *desc;
 300         unsigned int irq;
 301         static int warned;
 302
 303         for_each_irq(irq) {
 304                 cpumask_t mask;
 305
 306                 desc = irq_to_desc(irq);
 307                 if (desc && desc->status & IRQ_PER_CPU)
 308                         continue;
 309
 310                 cpumask_and(&mask, desc->affinity, &map);
 311                 if (any_online_cpu(mask) == NR_CPUS) {
 312                         printk("Breaking affinity for irq %i\n", irq);
 313                         mask = map;
 314                 }
 315                 if (desc->chip->set_affinity)
 316                         desc->chip->set_affinity(irq, &mask);
 317                 else if (desc->action && !(warned++))
 318                         printk("Cannot set affinity for irq %i\n", irq);
 319         }
 320
 321         local_irq_enable();
 322         mdelay(1);
 323         local_irq_disable();
 324 }
 325 #endif
 326
 327 #ifdef CONFIG_IRQSTACKS
 328 static inline void handle_one_irq(unsigned int irq)
 329 {
 330         struct thread_info *curtp, *irqtp;
 331         unsigned long saved_sp_limit;
 332         struct irq_desc *desc;
 333
 334         /* Switch to the irq stack to handle this */
 335         curtp = current_thread_info();
 336         irqtp = hardirq_ctx[smp_processor_id()];
 337
 338         if (curtp == irqtp) {
 339                 /* We're already on the irq stack, just handle it */
 340                 generic_handle_irq(irq);
 341                 return;
 342         }
 343
 344         desc = irq_to_desc(irq);
 345         saved_sp_limit = current->thread.ksp_limit;
 346
 347         irqtp->task = curtp->task;
 348         irqtp->flags = 0;
 349
 350         /* Copy the softirq bits in preempt_count so that the
 351          * softirq checks work in the hardirq context. */
 352         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 353                                (curtp->preempt_count & SOFTIRQ_MASK);
 354
 355         current->thread.ksp_limit = (unsigned long)irqtp +
 356                 _ALIGN_UP(sizeof(struct thread_info), 16);
 357
 358         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 359         current->thread.ksp_limit = saved_sp_limit;
 360         irqtp->task = NULL;
 361
 362         /* Set any flag that may have been set on the
 363          * alternate stack
 364          */
 365         if (irqtp->flags)
 366                 set_bits(irqtp->flags, &curtp->flags);
 367 }
 368 #else
 369 static inline void handle_one_irq(unsigned int irq)
 370 {
 371         generic_handle_irq(irq);
 372 }
 373 #endif
 374
 375 static inline void check_stack_overflow(void)
 376 {
 377 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 378         long sp;
 379
 380         sp = __get_SP() & (THREAD_SIZE-1);
 381
 382         /* check for stack overflow: is there less than 2KB free? */
 383         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 384                 printk("do_IRQ: stack overflow: %ld\n",
 385                         sp - sizeof(struct thread_info));
 386                 dump_stack();
 387         }
 388 #endif
 389 }
 390
 391 void do_IRQ(struct pt_regs *regs)
 392 {
 393         struct pt_regs *old_regs = set_irq_regs(regs);
 394         unsigned int irq;
 395
 396         trace_irq_entry(regs);
 397
 398         irq_enter();
 399
 400         check_stack_overflow();
 401
 402         irq = ppc_md.get_irq();
 403
 404         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 405                 handle_one_irq(irq);
 406         else if (irq != NO_IRQ_IGNORE)
 407                 /* That's not SMP safe ... but who cares ? */
 408                 ppc_spurious_interrupts++;
 409
 410         irq_exit();
 411         set_irq_regs(old_regs);
 412
 413 #ifdef CONFIG_PPC_ISERIES
 414         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 415                         get_lppaca()->int_dword.fields.decr_int) {
 416                 get_lppaca()->int_dword.fields.decr_int = 0;
 417                 /* Signal a fake decrementer interrupt */
 418                 timer_interrupt(regs);
 419         }
 420 #endif
 421
 422         trace_irq_exit(regs);
 423 }
 424
 425 void __init init_IRQ(void)
 426 {
 427         if (ppc_md.init_IRQ)
 428                 ppc_md.init_IRQ();
 429
 430         exc_lvl_ctx_init();
 431
 432         irq_ctx_init();
 433 }
 434
 435 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 436 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 437 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 438 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 439
 440 void exc_lvl_ctx_init(void)
 441 {
 442         struct thread_info *tp;
 443         int i;
 444
 445         for_each_possible_cpu(i) {
 446                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 447                 tp = critirq_ctx[i];
 448                 tp->cpu = i;
 449                 tp->preempt_count = 0;
 450
 451 #ifdef CONFIG_BOOKE
 452                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 453                 tp = dbgirq_ctx[i];
 454                 tp->cpu = i;
 455                 tp->preempt_count = 0;
 456
 457                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 458                 tp = mcheckirq_ctx[i];
 459                 tp->cpu = i;
 460                 tp->preempt_count = HARDIRQ_OFFSET;
 461 #endif
 462         }
 463 }
 464 #endif
 465
 466 #ifdef CONFIG_IRQSTACKS
 467 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 468 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 469
 470 void irq_ctx_init(void)
 471 {
 472         struct thread_info *tp;
 473         int i;
 474
 475         for_each_possible_cpu(i) {
 476                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 477                 tp = softirq_ctx[i];
 478                 tp->cpu = i;
 479                 tp->preempt_count = 0;
 480
 481                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 482                 tp = hardirq_ctx[i];
 483                 tp->cpu = i;
 484                 tp->preempt_count = HARDIRQ_OFFSET;
 485         }
 486 }
 487
 488 static inline void do_softirq_onstack(void)
 489 {
 490         struct thread_info *curtp, *irqtp;
 491         unsigned long saved_sp_limit = current->thread.ksp_limit;
 492
 493         curtp = current_thread_info();
 494         irqtp = softirq_ctx[smp_processor_id()];
 495         irqtp->task = curtp->task;
 496         current->thread.ksp_limit = (unsigned long)irqtp +
 497                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 498         call_do_softirq(irqtp);
 499         current->thread.ksp_limit = saved_sp_limit;
 500         irqtp->task = NULL;
 501 }
 502
 503 #else
 504 #define do_softirq_onstack()    __do_softirq()
 505 #endif /* CONFIG_IRQSTACKS */
 506
 507 void do_softirq(void)
 508 {
 509         unsigned long flags;
 510
 511         if (in_interrupt())
 512                 return;
 513
 514         local_irq_save(flags);
 515
 516         if (local_softirq_pending())
 517                 do_softirq_onstack();
 518
 519         local_irq_restore(flags);
 520 }
 521
 522
 523 /*
 524  * IRQ controller and virtual interrupts
 525  */
 526
 527 static LIST_HEAD(irq_hosts);
 528 static DEFINE_SPINLOCK(irq_big_lock);
 529 static unsigned int revmap_trees_allocated;
 530 static DEFINE_MUTEX(revmap_trees_mutex);
 531 struct irq_map_entry irq_map[NR_IRQS];
 532 static unsigned int irq_virq_count = NR_IRQS;
 533 static struct irq_host *irq_default_host;
 534
 535 irq_hw_number_t virq_to_hw(unsigned int virq)
 536 {
 537         return irq_map[virq].hwirq;
 538 }
 539 EXPORT_SYMBOL_GPL(virq_to_hw);
 540
 541 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 542 {
 543         return h->of_node != NULL && h->of_node == np;
 544 }
 545
 546 struct irq_host *irq_alloc_host(struct device_node *of_node,
 547                                 unsigned int revmap_type,
 548                                 unsigned int revmap_arg,
 549                                 struct irq_host_ops *ops,
 550                                 irq_hw_number_t inval_irq)
 551 {
 552         struct irq_host *host;
 553         unsigned int size = sizeof(struct irq_host);
 554         unsigned int i;
 555         unsigned int *rmap;
 556         unsigned long flags;
 557
 558         /* Allocate structure and revmap table if using linear mapping */
 559         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 560                 size += revmap_arg * sizeof(unsigned int);
 561         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 562         if (host == NULL)
 563                 return NULL;
 564
 565         /* Fill structure */
 566         host->revmap_type = revmap_type;
 567         host->inval_irq = inval_irq;
 568         host->ops = ops;
 569         host->of_node = of_node_get(of_node);
 570
 571         if (host->ops->match == NULL)
 572                 host->ops->match = default_irq_host_match;
 573
 574         spin_lock_irqsave(&irq_big_lock, flags);
 575
 576         /* If it's a legacy controller, check for duplicates and
 577          * mark it as allocated (we use irq 0 host pointer for that
 578          */
 579         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 580                 if (irq_map[0].host != NULL) {
 581                         spin_unlock_irqrestore(&irq_big_lock, flags);
 582                         /* If we are early boot, we can't free the structure,
 583                          * too bad...
 584                          * this will be fixed once slab is made available early
 585                          * instead of the current cruft
 586                          */
 587                         if (mem_init_done)
 588                                 kfree(host);
 589                         return NULL;
 590                 }
 591                 irq_map[0].host = host;
 592         }
 593
 594         list_add(&host->link, &irq_hosts);
 595         spin_unlock_irqrestore(&irq_big_lock, flags);
 596
 597         /* Additional setups per revmap type */
 598         switch(revmap_type) {
 599         case IRQ_HOST_MAP_LEGACY:
 600                 /* 0 is always the invalid number for legacy */
 601                 host->inval_irq = 0;
 602                 /* setup us as the host for all legacy interrupts */
 603                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 604                         irq_map[i].hwirq = i;
 605                         smp_wmb();
 606                         irq_map[i].host = host;
 607                         smp_wmb();
 608
 609                         /* Clear norequest flags */
 610                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
 611
 612                         /* Legacy flags are left to default at this point,
 613                          * one can then use irq_create_mapping() to
 614                          * explicitly change them
 615                          */
 616                         ops->map(host, i, i);
 617                 }
 618                 break;
 619         case IRQ_HOST_MAP_LINEAR:
 620                 rmap = (unsigned int *)(host + 1);
 621                 for (i = 0; i < revmap_arg; i++)
 622                         rmap[i] = NO_IRQ;
 623                 host->revmap_data.linear.size = revmap_arg;
 624                 smp_wmb();
 625                 host->revmap_data.linear.revmap = rmap;
 626                 break;
 627         default:
 628                 break;
 629         }
 630
 631         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 632
 633         return host;
 634 }
 635
 636 struct irq_host *irq_find_host(struct device_node *node)
 637 {
 638         struct irq_host *h, *found = NULL;
 639         unsigned long flags;
 640
 641         /* We might want to match the legacy controller last since
 642          * it might potentially be set to match all interrupts in
 643          * the absence of a device node. This isn't a problem so far
 644          * yet though...
 645          */
 646         spin_lock_irqsave(&irq_big_lock, flags);
 647         list_for_each_entry(h, &irq_hosts, link)
 648                 if (h->ops->match(h, node)) {
 649                         found = h;
 650                         break;
 651                 }
 652         spin_unlock_irqrestore(&irq_big_lock, flags);
 653         return found;
 654 }
 655 EXPORT_SYMBOL_GPL(irq_find_host);
 656
 657 void irq_set_default_host(struct irq_host *host)
 658 {
 659         pr_debug("irq: Default host set to @0x%p\n", host);
 660
 661         irq_default_host = host;
 662 }
 663
 664 void irq_set_virq_count(unsigned int count)
 665 {
 666         pr_debug("irq: Trying to set virq count to %d\n", count);
 667
 668         BUG_ON(count < NUM_ISA_INTERRUPTS);
 669         if (count < NR_IRQS)
 670                 irq_virq_count = count;
 671 }
 672
 673 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 674                             irq_hw_number_t hwirq)
 675 {
 676         struct irq_desc *desc;
 677
 678         desc = irq_to_desc_alloc_node(virq, 0);
 679         if (!desc) {
 680                 pr_debug("irq: -> allocating desc failed\n");
 681                 goto error;
 682         }
 683
 684         /* Clear IRQ_NOREQUEST flag */
 685         desc->status &= ~IRQ_NOREQUEST;
 686
 687         /* map it */
 688         smp_wmb();
 689         irq_map[virq].hwirq = hwirq;
 690         smp_mb();
 691
 692         if (host->ops->map(host, virq, hwirq)) {
 693                 pr_debug("irq: -> mapping failed, freeing\n");
 694                 goto error;
 695         }
 696
 697         return 0;
 698
 699 error:
 700         irq_free_virt(virq, 1);
 701         return -1;
 702 }
 703
 704 unsigned int irq_create_direct_mapping(struct irq_host *host)
 705 {
 706         unsigned int virq;
 707
 708         if (host == NULL)
 709                 host = irq_default_host;
 710
 711         BUG_ON(host == NULL);
 712         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 713
 714         virq = irq_alloc_virt(host, 1, 0);
 715         if (virq == NO_IRQ) {
 716                 pr_debug("irq: create_direct virq allocation failed\n");
 717                 return NO_IRQ;
 718         }
 719
 720         pr_debug("irq: create_direct obtained virq %d\n", virq);
 721
 722         if (irq_setup_virq(host, virq, virq))
 723                 return NO_IRQ;
 724
 725         return virq;
 726 }
 727
 728 unsigned int irq_create_mapping(struct irq_host *host,
 729                                 irq_hw_number_t hwirq)
 730 {
 731         unsigned int virq, hint;
 732
 733         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 734
 735         /* Look for default host if nececssary */
 736         if (host == NULL)
 737                 host = irq_default_host;
 738         if (host == NULL) {
 739                 printk(KERN_WARNING "irq_create_mapping called for"
 740                        " NULL host, hwirq=%lx\n", hwirq);
 741                 WARN_ON(1);
 742                 return NO_IRQ;
 743         }
 744         pr_debug("irq: -> using host @%p\n", host);
 745
 746         /* Check if mapping already exist, if it does, call
 747          * host->ops->map() to update the flags
 748          */
 749         virq = irq_find_mapping(host, hwirq);
 750         if (virq != NO_IRQ) {
 751                 if (host->ops->remap)
 752                         host->ops->remap(host, virq, hwirq);
 753                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 754                 return virq;
 755         }
 756
 757         /* Get a virtual interrupt number */
 758         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 759                 /* Handle legacy */
 760                 virq = (unsigned int)hwirq;
 761                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 762                         return NO_IRQ;
 763                 return virq;
 764         } else {
 765                 /* Allocate a virtual interrupt number */
 766                 hint = hwirq % irq_virq_count;
 767                 virq = irq_alloc_virt(host, 1, hint);
 768                 if (virq == NO_IRQ) {
 769                         pr_debug("irq: -> virq allocation failed\n");
 770                         return NO_IRQ;
 771                 }
 772         }
 773
 774         if (irq_setup_virq(host, virq, hwirq))
 775                 return NO_IRQ;
 776
 777         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 778                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 779
 780         return virq;
 781 }
 782 EXPORT_SYMBOL_GPL(irq_create_mapping);
 783
 784 unsigned int irq_create_of_mapping(struct device_node *controller,
 785                                    const u32 *intspec, unsigned int intsize)
 786 {
 787         struct irq_host *host;
 788         irq_hw_number_t hwirq;
 789         unsigned int type = IRQ_TYPE_NONE;
 790         unsigned int virq;
 791
 792         if (controller == NULL)
 793                 host = irq_default_host;
 794         else
 795                 host = irq_find_host(controller);
 796         if (host == NULL) {
 797                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 798                        controller->full_name);
 799                 return NO_IRQ;
 800         }
 801
 802         /* If host has no translation, then we assume interrupt line */
 803         if (host->ops->xlate == NULL)
 804                 hwirq = intspec[0];
 805         else {
 806                 if (host->ops->xlate(host, controller, intspec, intsize,
 807                                      &hwirq, &type))
 808                         return NO_IRQ;
 809         }
 810
 811         /* Create mapping */
 812         virq = irq_create_mapping(host, hwirq);
 813         if (virq == NO_IRQ)
 814                 return virq;
 815
 816         /* Set type if specified and different than the current one */
 817         if (type != IRQ_TYPE_NONE &&
 818             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
 819                 set_irq_type(virq, type);
 820         return virq;
 821 }
 822 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 823
 824 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 825 {
 826         struct of_irq oirq;
 827
 828         if (of_irq_map_one(dev, index, &oirq))
 829                 return NO_IRQ;
 830
 831         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 832                                      oirq.size);
 833 }
 834 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 835
 836 void irq_dispose_mapping(unsigned int virq)
 837 {
 838         struct irq_host *host;
 839         irq_hw_number_t hwirq;
 840
 841         if (virq == NO_IRQ)
 842                 return;
 843
 844         host = irq_map[virq].host;
 845         WARN_ON (host == NULL);
 846         if (host == NULL)
 847                 return;
 848
 849         /* Never unmap legacy interrupts */
 850         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 851                 return;
 852
 853         /* remove chip and handler */
 854         set_irq_chip_and_handler(virq, NULL, NULL);
 855
 856         /* Make sure it's completed */
 857         synchronize_irq(virq);
 858
 859         /* Tell the PIC about it */
 860         if (host->ops->unmap)
 861                 host->ops->unmap(host, virq);
 862         smp_mb();
 863
 864         /* Clear reverse map */
 865         hwirq = irq_map[virq].hwirq;
 866         switch(host->revmap_type) {
 867         case IRQ_HOST_MAP_LINEAR:
 868                 if (hwirq < host->revmap_data.linear.size)
 869                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 870                 break;
 871         case IRQ_HOST_MAP_TREE:
 872                 /*
 873                  * Check if radix tree allocated yet, if not then nothing to
 874                  * remove.
 875                  */
 876                 smp_rmb();
 877                 if (revmap_trees_allocated < 1)
 878                         break;
 879                 mutex_lock(&revmap_trees_mutex);
 880                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 881                 mutex_unlock(&revmap_trees_mutex);
 882                 break;
 883         }
 884
 885         /* Destroy map */
 886         smp_mb();
 887         irq_map[virq].hwirq = host->inval_irq;
 888
 889         /* Set some flags */
 890         irq_to_desc(virq)->status |= IRQ_NOREQUEST;
 891
 892         /* Free it */
 893         irq_free_virt(virq, 1);
 894 }
 895 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 896
 897 unsigned int irq_find_mapping(struct irq_host *host,
 898                               irq_hw_number_t hwirq)
 899 {
 900         unsigned int i;
 901         unsigned int hint = hwirq % irq_virq_count;
 902
 903         /* Look for default host if nececssary */
 904         if (host == NULL)
 905                 host = irq_default_host;
 906         if (host == NULL)
 907                 return NO_IRQ;
 908
 909         /* legacy -> bail early */
 910         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 911                 return hwirq;
 912
 913         /* Slow path does a linear search of the map */
 914         if (hint < NUM_ISA_INTERRUPTS)
 915                 hint = NUM_ISA_INTERRUPTS;
 916         i = hint;
 917         do  {
 918                 if (irq_map[i].host == host &&
 919                     irq_map[i].hwirq == hwirq)
 920                         return i;
 921                 i++;
 922                 if (i >= irq_virq_count)
 923                         i = NUM_ISA_INTERRUPTS;
 924         } while(i != hint);
 925         return NO_IRQ;
 926 }
 927 EXPORT_SYMBOL_GPL(irq_find_mapping);
 928
 929
 930 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 931                                      irq_hw_number_t hwirq)
 932 {
 933         struct irq_map_entry *ptr;
 934         unsigned int virq;
 935
 936         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 937
 938         /*
 939          * Check if the radix tree exists and has bee initialized.
 940          * If not, we fallback to slow mode
 941          */
 942         if (revmap_trees_allocated < 2)
 943                 return irq_find_mapping(host, hwirq);
 944
 945         /* Now try to resolve */
 946         /*
 947          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 948          * as it's referencing an entry in the static irq_map table.
 949          */
 950         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 951
 952         /*
 953          * If found in radix tree, then fine.
 954          * Else fallback to linear lookup - this should not happen in practice
 955          * as it means that we failed to insert the node in the radix tree.
 956          */
 957         if (ptr)
 958                 virq = ptr - irq_map;
 959         else
 960                 virq = irq_find_mapping(host, hwirq);
 961
 962         return virq;
 963 }
 964
 965 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 966                              irq_hw_number_t hwirq)
 967 {
 968
 969         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 970
 971         /*
 972          * Check if the radix tree exists yet.
 973          * If not, then the irq will be inserted into the tree when it gets
 974          * initialized.
 975          */
 976         smp_rmb();
 977         if (revmap_trees_allocated < 1)
 978                 return;
 979
 980         if (virq != NO_IRQ) {
 981                 mutex_lock(&revmap_trees_mutex);
 982                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 983                                   &irq_map[virq]);
 984                 mutex_unlock(&revmap_trees_mutex);
 985         }
 986 }
 987
 988 unsigned int irq_linear_revmap(struct irq_host *host,
 989                                irq_hw_number_t hwirq)
 990 {
 991         unsigned int *revmap;
 992
 993         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 994
 995         /* Check revmap bounds */
 996         if (unlikely(hwirq >= host->revmap_data.linear.size))
 997                 return irq_find_mapping(host, hwirq);
 998
 999         /* Check if revmap was allocated */
1000         revmap = host->revmap_data.linear.revmap;
1001         if (unlikely(revmap == NULL))
1002                 return irq_find_mapping(host, hwirq);
1003
1004         /* Fill up revmap with slow path if no mapping found */
1005         if (unlikely(revmap[hwirq] == NO_IRQ))
1006                 revmap[hwirq] = irq_find_mapping(host, hwirq);
1007
1008         return revmap[hwirq];
1009 }
1010
1011 unsigned int irq_alloc_virt(struct irq_host *host,
1012                             unsigned int count,
1013                             unsigned int hint)
1014 {
1015         unsigned long flags;
1016         unsigned int i, j, found = NO_IRQ;
1017
1018         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
1019                 return NO_IRQ;
1020
1021         spin_lock_irqsave(&irq_big_lock, flags);
1022
1023         /* Use hint for 1 interrupt if any */
1024         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
1025             hint < irq_virq_count && irq_map[hint].host == NULL) {
1026                 found = hint;
1027                 goto hint_found;
1028         }
1029
1030         /* Look for count consecutive numbers in the allocatable
1031          * (non-legacy) space
1032          */
1033         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1034                 if (irq_map[i].host != NULL)
1035                         j = 0;
1036                 else
1037                         j++;
1038
1039                 if (j == count) {
1040                         found = i - count + 1;
1041                         break;
1042                 }
1043         }
1044         if (found == NO_IRQ) {
1045                 spin_unlock_irqrestore(&irq_big_lock, flags);
1046                 return NO_IRQ;
1047         }
1048  hint_found:
1049         for (i = found; i < (found + count); i++) {
1050                 irq_map[i].hwirq = host->inval_irq;
1051                 smp_wmb();
1052                 irq_map[i].host = host;
1053         }
1054         spin_unlock_irqrestore(&irq_big_lock, flags);
1055         return found;
1056 }
1057
1058 void irq_free_virt(unsigned int virq, unsigned int count)
1059 {
1060         unsigned long flags;
1061         unsigned int i;
1062
1063         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1064         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1065
1066         spin_lock_irqsave(&irq_big_lock, flags);
1067         for (i = virq; i < (virq + count); i++) {
1068                 struct irq_host *host;
1069
1070                 if (i < NUM_ISA_INTERRUPTS ||
1071                     (virq + count) > irq_virq_count)
1072                         continue;
1073
1074                 host = irq_map[i].host;
1075                 irq_map[i].hwirq = host->inval_irq;
1076                 smp_wmb();
1077                 irq_map[i].host = NULL;
1078         }
1079         spin_unlock_irqrestore(&irq_big_lock, flags);
1080 }
1081
1082 int arch_early_irq_init(void)
1083 {
1084         struct irq_desc *desc;
1085         int i;
1086
1087         for (i = 0; i < NR_IRQS; i++) {
1088                 desc = irq_to_desc(i);
1089                 if (desc)
1090                         desc->status |= IRQ_NOREQUEST;
1091         }
1092
1093         return 0;
1094 }
1095
1096 int arch_init_chip_data(struct irq_desc *desc, int node)
1097 {
1098         desc->status |= IRQ_NOREQUEST;
1099         return 0;
1100 }
1101
1102 /* We need to create the radix trees late */
1103 static int irq_late_init(void)
1104 {
1105         struct irq_host *h;
1106         unsigned int i;
1107
1108         /*
1109          * No mutual exclusion with respect to accessors of the tree is needed
1110          * here as the synchronization is done via the state variable
1111          * revmap_trees_allocated.
1112          */
1113         list_for_each_entry(h, &irq_hosts, link) {
1114                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1115                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1116         }
1117
1118         /*
1119          * Make sure the radix trees inits are visible before setting
1120          * the flag
1121          */
1122         smp_wmb();
1123         revmap_trees_allocated = 1;
1124
1125         /*
1126          * Insert the reverse mapping for those interrupts already present
1127          * in irq_map[].
1128          */
1129         mutex_lock(&revmap_trees_mutex);
1130         for (i = 0; i < irq_virq_count; i++) {
1131                 if (irq_map[i].host &&
1132                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1133                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1134                                           irq_map[i].hwirq, &irq_map[i]);
1135         }
1136         mutex_unlock(&revmap_trees_mutex);
1137
1138         /*
1139          * Make sure the radix trees insertions are visible before setting
1140          * the flag
1141          */
1142         smp_wmb();
1143         revmap_trees_allocated = 2;
1144
1145         return 0;
1146 }
1147 arch_initcall(irq_late_init);
1148
1149 #ifdef CONFIG_VIRQ_DEBUG
1150 static int virq_debug_show(struct seq_file *m, void *private)
1151 {
1152         unsigned long flags;
1153         struct irq_desc *desc;
1154         const char *p;
1155         char none[] = "none";
1156         int i;
1157
1158         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1159                       "chip name", "host name");
1160
1161         for (i = 1; i < nr_irqs; i++) {
1162                 desc = irq_to_desc(i);
1163                 if (!desc)
1164                         continue;
1165
1166                 raw_spin_lock_irqsave(&desc->lock, flags);
1167
1168                 if (desc->action && desc->action->handler) {
1169                         seq_printf(m, "%5d  ", i);
1170                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1171
1172                         if (desc->chip && desc->chip->name)
1173                                 p = desc->chip->name;
1174                         else
1175                                 p = none;
1176                         seq_printf(m, "%-15s  ", p);
1177
1178                         if (irq_map[i].host && irq_map[i].host->of_node)
1179                                 p = irq_map[i].host->of_node->full_name;
1180                         else
1181                                 p = none;
1182                         seq_printf(m, "%s\n", p);
1183                 }
1184
1185                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1186         }
1187
1188         return 0;
1189 }
1190
1191 static int virq_debug_open(struct inode *inode, struct file *file)
1192 {
1193         return single_open(file, virq_debug_show, inode->i_private);
1194 }
1195
1196 static const struct file_operations virq_debug_fops = {
1197         .open = virq_debug_open,
1198         .read = seq_read,
1199         .llseek = seq_lseek,
1200         .release = single_release,
1201 };
1202
1203 static int __init irq_debugfs_init(void)
1204 {
1205         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1206                                  NULL, &virq_debug_fops) == NULL)
1207                 return -ENOMEM;
1208
1209         return 0;
1210 }
1211 __initcall(irq_debugfs_init);
1212 #endif /* CONFIG_VIRQ_DEBUG */
1213
1214 #ifdef CONFIG_PPC64
1215 static int __init setup_noirqdistrib(char *str)
1216 {
1217         distribute_irqs = 0;
1218         return 1;
1219 }
1220
1221 __setup("noirqdistrib", setup_noirqdistrib);
1222 #endif /* CONFIG_PPC64 */