arch/powerpc/kernel/irq.c

   1 /*
   2  *  Derived from arch/i386/kernel/irq.c
   3  *    Copyright (C) 1992 Linus Torvalds
   4  *  Adapted from arch/i386 by Gary Thomas
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
   7  *    Copyright (C) 1996-2001 Cort Dougan
   8  *  Adapted for Power Macintosh by Paul Mackerras
   9  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version
  14  * 2 of the License, or (at your option) any later version.
  15  *
  16  * This file contains the code used by various IRQ handling routines:
  17  * asking for different IRQ's should be done through these routines
  18  * instead of just grabbing them. Thus setups with different IRQ numbers
  19  * shouldn't result in any weird surprises, and installing new handlers
  20  * should be easier.
  21  *
  22  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
  23  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
  24  * mask register (of which only 16 are defined), hence the weird shifting
  25  * and complement of the cached_irq_mask.  I want to be able to stuff
  26  * this right into the SIU SMASK register.
  27  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
  28  * to reduce code space and undefined function references.
  29  */
  30
  31 #undef DEBUG
  32
  33 #include <linux/module.h>
  34 #include <linux/threads.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/signal.h>
  37 #include <linux/sched.h>
  38 #include <linux/ptrace.h>
  39 #include <linux/ioport.h>
  40 #include <linux/interrupt.h>
  41 #include <linux/timex.h>
  42 #include <linux/init.h>
  43 #include <linux/slab.h>
  44 #include <linux/delay.h>
  45 #include <linux/irq.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/cpumask.h>
  48 #include <linux/profile.h>
  49 #include <linux/bitops.h>
  50 #include <linux/list.h>
  51 #include <linux/radix-tree.h>
  52 #include <linux/mutex.h>
  53 #include <linux/bootmem.h>
  54 #include <linux/pci.h>
  55 #include <linux/debugfs.h>
  56
  57 #include <asm/uaccess.h>
  58 #include <asm/system.h>
  59 #include <asm/io.h>
  60 #include <asm/pgtable.h>
  61 #include <asm/irq.h>
  62 #include <asm/cache.h>
  63 #include <asm/prom.h>
  64 #include <asm/ptrace.h>
  65 #include <asm/machdep.h>
  66 #include <asm/udbg.h>
  67 #include <asm/dbell.h>
  68
  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 #if defined(CONFIG_BOOKE) && defined(CONFIG_SMP)
 159         /* Check for pending doorbell interrupts on SMP */
 160         doorbell_exception(NULL);
 161 #endif
 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
 170 #ifndef CONFIG_BOOKE
 171         /* On server, re-trigger the decrementer if it went negative since
 172          * some processors only trigger on edge transitions of the sign bit.
 173          *
 174          * BookE has a level sensitive decrementer (latches in TSR) so we
 175          * don't need that
 176          */
 177         if ((int)mfspr(SPRN_DEC) < 0)
 178                 mtspr(SPRN_DEC, 1);
 179 #endif /* CONFIG_BOOKE */
 180
 181         /*
 182          * Force the delivery of pending soft-disabled interrupts on PS3.
 183          * Any HV call will have this side effect.
 184          */
 185         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 186                 u64 tmp;
 187                 lv1_get_version_info(&tmp);
 188         }
 189
 190         __hard_irq_enable();
 191 }
 192 EXPORT_SYMBOL(raw_local_irq_restore);
 193 #endif /* CONFIG_PPC64 */
 194
 195 static int show_other_interrupts(struct seq_file *p, int prec)
 196 {
 197         int j;
 198
 199 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 200         if (tau_initialized) {
 201                 seq_printf(p, "%*s: ", prec, "TAU");
 202                 for_each_online_cpu(j)
 203                         seq_printf(p, "%10u ", tau_interrupts(j));
 204                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 205         }
 206 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
 207
 208         seq_printf(p, "%*s: ", prec, "LOC");
 209         for_each_online_cpu(j)
 210                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
 211         seq_printf(p, "  Local timer interrupts\n");
 212
 213         seq_printf(p, "%*s: ", prec, "SPU");
 214         for_each_online_cpu(j)
 215                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
 216         seq_printf(p, "  Spurious interrupts\n");
 217
 218         seq_printf(p, "%*s: ", prec, "CNT");
 219         for_each_online_cpu(j)
 220                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
 221         seq_printf(p, "  Performance monitoring interrupts\n");
 222
 223         seq_printf(p, "%*s: ", prec, "MCE");
 224         for_each_online_cpu(j)
 225                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
 226         seq_printf(p, "  Machine check exceptions\n");
 227
 228         return 0;
 229 }
 230
 231 int show_interrupts(struct seq_file *p, void *v)
 232 {
 233         unsigned long flags, any_count = 0;
 234         int i = *(loff_t *) v, j, prec;
 235         struct irqaction *action;
 236         struct irq_desc *desc;
 237
 238         if (i > nr_irqs)
 239                 return 0;
 240
 241         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
 242                 j *= 10;
 243
 244         if (i == nr_irqs)
 245                 return show_other_interrupts(p, prec);
 246
 247         /* print header */
 248         if (i == 0) {
 249                 seq_printf(p, "%*s", prec + 8, "");
 250                 for_each_online_cpu(j)
 251                         seq_printf(p, "CPU%-8d", j);
 252                 seq_putc(p, '\n');
 253         }
 254
 255         desc = irq_to_desc(i);
 256         if (!desc)
 257                 return 0;
 258
 259         raw_spin_lock_irqsave(&desc->lock, flags);
 260         for_each_online_cpu(j)
 261                 any_count |= kstat_irqs_cpu(i, j);
 262         action = desc->action;
 263         if (!action && !any_count)
 264                 goto out;
 265
 266         seq_printf(p, "%*d: ", prec, i);
 267         for_each_online_cpu(j)
 268                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 269
 270         if (desc->chip)
 271                 seq_printf(p, "  %-16s", desc->chip->name);
 272         else
 273                 seq_printf(p, "  %-16s", "None");
 274         seq_printf(p, " %-8s", (desc->status & IRQ_LEVEL) ? "Level" : "Edge");
 275
 276         if (action) {
 277                 seq_printf(p, "     %s", action->name);
 278                 while ((action = action->next) != NULL)
 279                         seq_printf(p, ", %s", action->name);
 280         }
 281
 282         seq_putc(p, '\n');
 283 out:
 284         raw_spin_unlock_irqrestore(&desc->lock, flags);
 285         return 0;
 286 }
 287
 288 /*
 289  * /proc/stat helpers
 290  */
 291 u64 arch_irq_stat_cpu(unsigned int cpu)
 292 {
 293         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
 294
 295         sum += per_cpu(irq_stat, cpu).pmu_irqs;
 296         sum += per_cpu(irq_stat, cpu).mce_exceptions;
 297         sum += per_cpu(irq_stat, cpu).spurious_irqs;
 298
 299         return sum;
 300 }
 301
 302 #ifdef CONFIG_HOTPLUG_CPU
 303 void fixup_irqs(const struct cpumask *map)
 304 {
 305         struct irq_desc *desc;
 306         unsigned int irq;
 307         static int warned;
 308         cpumask_var_t mask;
 309
 310         alloc_cpumask_var(&mask, GFP_KERNEL);
 311
 312         for_each_irq(irq) {
 313                 desc = irq_to_desc(irq);
 314                 if (!desc)
 315                         continue;
 316
 317                 if (desc->status & IRQ_PER_CPU)
 318                         continue;
 319
 320                 cpumask_and(mask, desc->affinity, map);
 321                 if (cpumask_any(mask) >= nr_cpu_ids) {
 322                         printk("Breaking affinity for irq %i\n", irq);
 323                         cpumask_copy(mask, map);
 324                 }
 325                 if (desc->chip->set_affinity)
 326                         desc->chip->set_affinity(irq, mask);
 327                 else if (desc->action && !(warned++))
 328                         printk("Cannot set affinity for irq %i\n", irq);
 329         }
 330
 331         free_cpumask_var(mask);
 332
 333         local_irq_enable();
 334         mdelay(1);
 335         local_irq_disable();
 336 }
 337 #endif
 338
 339 static inline void handle_one_irq(unsigned int irq)
 340 {
 341         struct thread_info *curtp, *irqtp;
 342         unsigned long saved_sp_limit;
 343         struct irq_desc *desc;
 344
 345         /* Switch to the irq stack to handle this */
 346         curtp = current_thread_info();
 347         irqtp = hardirq_ctx[smp_processor_id()];
 348
 349         if (curtp == irqtp) {
 350                 /* We're already on the irq stack, just handle it */
 351                 generic_handle_irq(irq);
 352                 return;
 353         }
 354
 355         desc = irq_to_desc(irq);
 356         saved_sp_limit = current->thread.ksp_limit;
 357
 358         irqtp->task = curtp->task;
 359         irqtp->flags = 0;
 360
 361         /* Copy the softirq bits in preempt_count so that the
 362          * softirq checks work in the hardirq context. */
 363         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 364                                (curtp->preempt_count & SOFTIRQ_MASK);
 365
 366         current->thread.ksp_limit = (unsigned long)irqtp +
 367                 _ALIGN_UP(sizeof(struct thread_info), 16);
 368
 369         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 370         current->thread.ksp_limit = saved_sp_limit;
 371         irqtp->task = NULL;
 372
 373         /* Set any flag that may have been set on the
 374          * alternate stack
 375          */
 376         if (irqtp->flags)
 377                 set_bits(irqtp->flags, &curtp->flags);
 378 }
 379
 380 static inline void check_stack_overflow(void)
 381 {
 382 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 383         long sp;
 384
 385         sp = __get_SP() & (THREAD_SIZE-1);
 386
 387         /* check for stack overflow: is there less than 2KB free? */
 388         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 389                 printk("do_IRQ: stack overflow: %ld\n",
 390                         sp - sizeof(struct thread_info));
 391                 dump_stack();
 392         }
 393 #endif
 394 }
 395
 396 void do_IRQ(struct pt_regs *regs)
 397 {
 398         struct pt_regs *old_regs = set_irq_regs(regs);
 399         unsigned int irq;
 400
 401         trace_irq_entry(regs);
 402
 403         irq_enter();
 404
 405         check_stack_overflow();
 406
 407         irq = ppc_md.get_irq();
 408
 409         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 410                 handle_one_irq(irq);
 411         else if (irq != NO_IRQ_IGNORE)
 412                 __get_cpu_var(irq_stat).spurious_irqs++;
 413
 414         irq_exit();
 415         set_irq_regs(old_regs);
 416
 417 #ifdef CONFIG_PPC_ISERIES
 418         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 419                         get_lppaca()->int_dword.fields.decr_int) {
 420                 get_lppaca()->int_dword.fields.decr_int = 0;
 421                 /* Signal a fake decrementer interrupt */
 422                 timer_interrupt(regs);
 423         }
 424 #endif
 425
 426         trace_irq_exit(regs);
 427 }
 428
 429 void __init init_IRQ(void)
 430 {
 431         if (ppc_md.init_IRQ)
 432                 ppc_md.init_IRQ();
 433
 434         exc_lvl_ctx_init();
 435
 436         irq_ctx_init();
 437 }
 438
 439 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 440 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 441 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 442 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 443
 444 void exc_lvl_ctx_init(void)
 445 {
 446         struct thread_info *tp;
 447         int i;
 448
 449         for_each_possible_cpu(i) {
 450                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 451                 tp = critirq_ctx[i];
 452                 tp->cpu = i;
 453                 tp->preempt_count = 0;
 454
 455 #ifdef CONFIG_BOOKE
 456                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 457                 tp = dbgirq_ctx[i];
 458                 tp->cpu = i;
 459                 tp->preempt_count = 0;
 460
 461                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 462                 tp = mcheckirq_ctx[i];
 463                 tp->cpu = i;
 464                 tp->preempt_count = HARDIRQ_OFFSET;
 465 #endif
 466         }
 467 }
 468 #endif
 469
 470 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 471 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 472
 473 void irq_ctx_init(void)
 474 {
 475         struct thread_info *tp;
 476         int i;
 477
 478         for_each_possible_cpu(i) {
 479                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 480                 tp = softirq_ctx[i];
 481                 tp->cpu = i;
 482                 tp->preempt_count = 0;
 483
 484                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 485                 tp = hardirq_ctx[i];
 486                 tp->cpu = i;
 487                 tp->preempt_count = HARDIRQ_OFFSET;
 488         }
 489 }
 490
 491 static inline void do_softirq_onstack(void)
 492 {
 493         struct thread_info *curtp, *irqtp;
 494         unsigned long saved_sp_limit = current->thread.ksp_limit;
 495
 496         curtp = current_thread_info();
 497         irqtp = softirq_ctx[smp_processor_id()];
 498         irqtp->task = curtp->task;
 499         current->thread.ksp_limit = (unsigned long)irqtp +
 500                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 501         call_do_softirq(irqtp);
 502         current->thread.ksp_limit = saved_sp_limit;
 503         irqtp->task = NULL;
 504 }
 505
 506 void do_softirq(void)
 507 {
 508         unsigned long flags;
 509
 510         if (in_interrupt())
 511                 return;
 512
 513         local_irq_save(flags);
 514
 515         if (local_softirq_pending())
 516                 do_softirq_onstack();
 517
 518         local_irq_restore(flags);
 519 }
 520
 521
 522 /*
 523  * IRQ controller and virtual interrupts
 524  */
 525
 526 static LIST_HEAD(irq_hosts);
 527 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 528 static unsigned int revmap_trees_allocated;
 529 static DEFINE_MUTEX(revmap_trees_mutex);
 530 struct irq_map_entry irq_map[NR_IRQS];
 531 static unsigned int irq_virq_count = NR_IRQS;
 532 static struct irq_host *irq_default_host;
 533
 534 irq_hw_number_t virq_to_hw(unsigned int virq)
 535 {
 536         return irq_map[virq].hwirq;
 537 }
 538 EXPORT_SYMBOL_GPL(virq_to_hw);
 539
 540 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 541 {
 542         return h->of_node != NULL && h->of_node == np;
 543 }
 544
 545 struct irq_host *irq_alloc_host(struct device_node *of_node,
 546                                 unsigned int revmap_type,
 547                                 unsigned int revmap_arg,
 548                                 struct irq_host_ops *ops,
 549                                 irq_hw_number_t inval_irq)
 550 {
 551         struct irq_host *host;
 552         unsigned int size = sizeof(struct irq_host);
 553         unsigned int i;
 554         unsigned int *rmap;
 555         unsigned long flags;
 556
 557         /* Allocate structure and revmap table if using linear mapping */
 558         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 559                 size += revmap_arg * sizeof(unsigned int);
 560         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 561         if (host == NULL)
 562                 return NULL;
 563
 564         /* Fill structure */
 565         host->revmap_type = revmap_type;
 566         host->inval_irq = inval_irq;
 567         host->ops = ops;
 568         host->of_node = of_node_get(of_node);
 569
 570         if (host->ops->match == NULL)
 571                 host->ops->match = default_irq_host_match;
 572
 573         raw_spin_lock_irqsave(&irq_big_lock, flags);
 574
 575         /* If it's a legacy controller, check for duplicates and
 576          * mark it as allocated (we use irq 0 host pointer for that
 577          */
 578         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 579                 if (irq_map[0].host != NULL) {
 580                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 581                         /* If we are early boot, we can't free the structure,
 582                          * too bad...
 583                          * this will be fixed once slab is made available early
 584                          * instead of the current cruft
 585                          */
 586                         if (mem_init_done)
 587                                 kfree(host);
 588                         return NULL;
 589                 }
 590                 irq_map[0].host = host;
 591         }
 592
 593         list_add(&host->link, &irq_hosts);
 594         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 595
 596         /* Additional setups per revmap type */
 597         switch(revmap_type) {
 598         case IRQ_HOST_MAP_LEGACY:
 599                 /* 0 is always the invalid number for legacy */
 600                 host->inval_irq = 0;
 601                 /* setup us as the host for all legacy interrupts */
 602                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 603                         irq_map[i].hwirq = i;
 604                         smp_wmb();
 605                         irq_map[i].host = host;
 606                         smp_wmb();
 607
 608                         /* Clear norequest flags */
 609                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
 610
 611                         /* Legacy flags are left to default at this point,
 612                          * one can then use irq_create_mapping() to
 613                          * explicitly change them
 614                          */
 615                         ops->map(host, i, i);
 616                 }
 617                 break;
 618         case IRQ_HOST_MAP_LINEAR:
 619                 rmap = (unsigned int *)(host + 1);
 620                 for (i = 0; i < revmap_arg; i++)
 621                         rmap[i] = NO_IRQ;
 622                 host->revmap_data.linear.size = revmap_arg;
 623                 smp_wmb();
 624                 host->revmap_data.linear.revmap = rmap;
 625                 break;
 626         default:
 627                 break;
 628         }
 629
 630         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 631
 632         return host;
 633 }
 634
 635 struct irq_host *irq_find_host(struct device_node *node)
 636 {
 637         struct irq_host *h, *found = NULL;
 638         unsigned long flags;
 639
 640         /* We might want to match the legacy controller last since
 641          * it might potentially be set to match all interrupts in
 642          * the absence of a device node. This isn't a problem so far
 643          * yet though...
 644          */
 645         raw_spin_lock_irqsave(&irq_big_lock, flags);
 646         list_for_each_entry(h, &irq_hosts, link)
 647                 if (h->ops->match(h, node)) {
 648                         found = h;
 649                         break;
 650                 }
 651         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 652         return found;
 653 }
 654 EXPORT_SYMBOL_GPL(irq_find_host);
 655
 656 void irq_set_default_host(struct irq_host *host)
 657 {
 658         pr_debug("irq: Default host set to @0x%p\n", host);
 659
 660         irq_default_host = host;
 661 }
 662
 663 void irq_set_virq_count(unsigned int count)
 664 {
 665         pr_debug("irq: Trying to set virq count to %d\n", count);
 666
 667         BUG_ON(count < NUM_ISA_INTERRUPTS);
 668         if (count < NR_IRQS)
 669                 irq_virq_count = count;
 670 }
 671
 672 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 673                             irq_hw_number_t hwirq)
 674 {
 675         struct irq_desc *desc;
 676
 677         desc = irq_to_desc_alloc_node(virq, 0);
 678         if (!desc) {
 679                 pr_debug("irq: -> allocating desc failed\n");
 680                 goto error;
 681         }
 682
 683         /* Clear IRQ_NOREQUEST flag */
 684         desc->status &= ~IRQ_NOREQUEST;
 685
 686         /* map it */
 687         smp_wmb();
 688         irq_map[virq].hwirq = hwirq;
 689         smp_mb();
 690
 691         if (host->ops->map(host, virq, hwirq)) {
 692                 pr_debug("irq: -> mapping failed, freeing\n");
 693                 goto error;
 694         }
 695
 696         return 0;
 697
 698 error:
 699         irq_free_virt(virq, 1);
 700         return -1;
 701 }
 702
 703 unsigned int irq_create_direct_mapping(struct irq_host *host)
 704 {
 705         unsigned int virq;
 706
 707         if (host == NULL)
 708                 host = irq_default_host;
 709
 710         BUG_ON(host == NULL);
 711         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 712
 713         virq = irq_alloc_virt(host, 1, 0);
 714         if (virq == NO_IRQ) {
 715                 pr_debug("irq: create_direct virq allocation failed\n");
 716                 return NO_IRQ;
 717         }
 718
 719         pr_debug("irq: create_direct obtained virq %d\n", virq);
 720
 721         if (irq_setup_virq(host, virq, virq))
 722                 return NO_IRQ;
 723
 724         return virq;
 725 }
 726
 727 unsigned int irq_create_mapping(struct irq_host *host,
 728                                 irq_hw_number_t hwirq)
 729 {
 730         unsigned int virq, hint;
 731
 732         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 733
 734         /* Look for default host if nececssary */
 735         if (host == NULL)
 736                 host = irq_default_host;
 737         if (host == NULL) {
 738                 printk(KERN_WARNING "irq_create_mapping called for"
 739                        " NULL host, hwirq=%lx\n", hwirq);
 740                 WARN_ON(1);
 741                 return NO_IRQ;
 742         }
 743         pr_debug("irq: -> using host @%p\n", host);
 744
 745         /* Check if mapping already exist, if it does, call
 746          * host->ops->map() to update the flags
 747          */
 748         virq = irq_find_mapping(host, hwirq);
 749         if (virq != NO_IRQ) {
 750                 if (host->ops->remap)
 751                         host->ops->remap(host, virq, hwirq);
 752                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 753                 return virq;
 754         }
 755
 756         /* Get a virtual interrupt number */
 757         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 758                 /* Handle legacy */
 759                 virq = (unsigned int)hwirq;
 760                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 761                         return NO_IRQ;
 762                 return virq;
 763         } else {
 764                 /* Allocate a virtual interrupt number */
 765                 hint = hwirq % irq_virq_count;
 766                 virq = irq_alloc_virt(host, 1, hint);
 767                 if (virq == NO_IRQ) {
 768                         pr_debug("irq: -> virq allocation failed\n");
 769                         return NO_IRQ;
 770                 }
 771         }
 772
 773         if (irq_setup_virq(host, virq, hwirq))
 774                 return NO_IRQ;
 775
 776         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 777                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 778
 779         return virq;
 780 }
 781 EXPORT_SYMBOL_GPL(irq_create_mapping);
 782
 783 unsigned int irq_create_of_mapping(struct device_node *controller,
 784                                    const u32 *intspec, unsigned int intsize)
 785 {
 786         struct irq_host *host;
 787         irq_hw_number_t hwirq;
 788         unsigned int type = IRQ_TYPE_NONE;
 789         unsigned int virq;
 790
 791         if (controller == NULL)
 792                 host = irq_default_host;
 793         else
 794                 host = irq_find_host(controller);
 795         if (host == NULL) {
 796                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 797                        controller->full_name);
 798                 return NO_IRQ;
 799         }
 800
 801         /* If host has no translation, then we assume interrupt line */
 802         if (host->ops->xlate == NULL)
 803                 hwirq = intspec[0];
 804         else {
 805                 if (host->ops->xlate(host, controller, intspec, intsize,
 806                                      &hwirq, &type))
 807                         return NO_IRQ;
 808         }
 809
 810         /* Create mapping */
 811         virq = irq_create_mapping(host, hwirq);
 812         if (virq == NO_IRQ)
 813                 return virq;
 814
 815         /* Set type if specified and different than the current one */
 816         if (type != IRQ_TYPE_NONE &&
 817             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
 818                 set_irq_type(virq, type);
 819         return virq;
 820 }
 821 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 822
 823 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 824 {
 825         struct of_irq oirq;
 826
 827         if (of_irq_map_one(dev, index, &oirq))
 828                 return NO_IRQ;
 829
 830         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 831                                      oirq.size);
 832 }
 833 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 834
 835 void irq_dispose_mapping(unsigned int virq)
 836 {
 837         struct irq_host *host;
 838         irq_hw_number_t hwirq;
 839
 840         if (virq == NO_IRQ)
 841                 return;
 842
 843         host = irq_map[virq].host;
 844         WARN_ON (host == NULL);
 845         if (host == NULL)
 846                 return;
 847
 848         /* Never unmap legacy interrupts */
 849         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 850                 return;
 851
 852         /* remove chip and handler */
 853         set_irq_chip_and_handler(virq, NULL, NULL);
 854
 855         /* Make sure it's completed */
 856         synchronize_irq(virq);
 857
 858         /* Tell the PIC about it */
 859         if (host->ops->unmap)
 860                 host->ops->unmap(host, virq);
 861         smp_mb();
 862
 863         /* Clear reverse map */
 864         hwirq = irq_map[virq].hwirq;
 865         switch(host->revmap_type) {
 866         case IRQ_HOST_MAP_LINEAR:
 867                 if (hwirq < host->revmap_data.linear.size)
 868                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 869                 break;
 870         case IRQ_HOST_MAP_TREE:
 871                 /*
 872                  * Check if radix tree allocated yet, if not then nothing to
 873                  * remove.
 874                  */
 875                 smp_rmb();
 876                 if (revmap_trees_allocated < 1)
 877                         break;
 878                 mutex_lock(&revmap_trees_mutex);
 879                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 880                 mutex_unlock(&revmap_trees_mutex);
 881                 break;
 882         }
 883
 884         /* Destroy map */
 885         smp_mb();
 886         irq_map[virq].hwirq = host->inval_irq;
 887
 888         /* Set some flags */
 889         irq_to_desc(virq)->status |= IRQ_NOREQUEST;
 890
 891         /* Free it */
 892         irq_free_virt(virq, 1);
 893 }
 894 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 895
 896 unsigned int irq_find_mapping(struct irq_host *host,
 897                               irq_hw_number_t hwirq)
 898 {
 899         unsigned int i;
 900         unsigned int hint = hwirq % irq_virq_count;
 901
 902         /* Look for default host if nececssary */
 903         if (host == NULL)
 904                 host = irq_default_host;
 905         if (host == NULL)
 906                 return NO_IRQ;
 907
 908         /* legacy -> bail early */
 909         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 910                 return hwirq;
 911
 912         /* Slow path does a linear search of the map */
 913         if (hint < NUM_ISA_INTERRUPTS)
 914                 hint = NUM_ISA_INTERRUPTS;
 915         i = hint;
 916         do  {
 917                 if (irq_map[i].host == host &&
 918                     irq_map[i].hwirq == hwirq)
 919                         return i;
 920                 i++;
 921                 if (i >= irq_virq_count)
 922                         i = NUM_ISA_INTERRUPTS;
 923         } while(i != hint);
 924         return NO_IRQ;
 925 }
 926 EXPORT_SYMBOL_GPL(irq_find_mapping);
 927
 928
 929 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 930                                      irq_hw_number_t hwirq)
 931 {
 932         struct irq_map_entry *ptr;
 933         unsigned int virq;
 934
 935         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 936
 937         /*
 938          * Check if the radix tree exists and has bee initialized.
 939          * If not, we fallback to slow mode
 940          */
 941         if (revmap_trees_allocated < 2)
 942                 return irq_find_mapping(host, hwirq);
 943
 944         /* Now try to resolve */
 945         /*
 946          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 947          * as it's referencing an entry in the static irq_map table.
 948          */
 949         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 950
 951         /*
 952          * If found in radix tree, then fine.
 953          * Else fallback to linear lookup - this should not happen in practice
 954          * as it means that we failed to insert the node in the radix tree.
 955          */
 956         if (ptr)
 957                 virq = ptr - irq_map;
 958         else
 959                 virq = irq_find_mapping(host, hwirq);
 960
 961         return virq;
 962 }
 963
 964 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 965                              irq_hw_number_t hwirq)
 966 {
 967
 968         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 969
 970         /*
 971          * Check if the radix tree exists yet.
 972          * If not, then the irq will be inserted into the tree when it gets
 973          * initialized.
 974          */
 975         smp_rmb();
 976         if (revmap_trees_allocated < 1)
 977                 return;
 978
 979         if (virq != NO_IRQ) {
 980                 mutex_lock(&revmap_trees_mutex);
 981                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 982                                   &irq_map[virq]);
 983                 mutex_unlock(&revmap_trees_mutex);
 984         }
 985 }
 986
 987 unsigned int irq_linear_revmap(struct irq_host *host,
 988                                irq_hw_number_t hwirq)
 989 {
 990         unsigned int *revmap;
 991
 992         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 993
 994         /* Check revmap bounds */
 995         if (unlikely(hwirq >= host->revmap_data.linear.size))
 996                 return irq_find_mapping(host, hwirq);
 997
 998         /* Check if revmap was allocated */
 999         revmap = host->revmap_data.linear.revmap;
1000         if (unlikely(revmap == NULL))
1001                 return irq_find_mapping(host, hwirq);
1002
1003         /* Fill up revmap with slow path if no mapping found */
1004         if (unlikely(revmap[hwirq] == NO_IRQ))
1005                 revmap[hwirq] = irq_find_mapping(host, hwirq);
1006
1007         return revmap[hwirq];
1008 }
1009
1010 unsigned int irq_alloc_virt(struct irq_host *host,
1011                             unsigned int count,
1012                             unsigned int hint)
1013 {
1014         unsigned long flags;
1015         unsigned int i, j, found = NO_IRQ;
1016
1017         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
1018                 return NO_IRQ;
1019
1020         raw_spin_lock_irqsave(&irq_big_lock, flags);
1021
1022         /* Use hint for 1 interrupt if any */
1023         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
1024             hint < irq_virq_count && irq_map[hint].host == NULL) {
1025                 found = hint;
1026                 goto hint_found;
1027         }
1028
1029         /* Look for count consecutive numbers in the allocatable
1030          * (non-legacy) space
1031          */
1032         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1033                 if (irq_map[i].host != NULL)
1034                         j = 0;
1035                 else
1036                         j++;
1037
1038                 if (j == count) {
1039                         found = i - count + 1;
1040                         break;
1041                 }
1042         }
1043         if (found == NO_IRQ) {
1044                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1045                 return NO_IRQ;
1046         }
1047  hint_found:
1048         for (i = found; i < (found + count); i++) {
1049                 irq_map[i].hwirq = host->inval_irq;
1050                 smp_wmb();
1051                 irq_map[i].host = host;
1052         }
1053         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1054         return found;
1055 }
1056
1057 void irq_free_virt(unsigned int virq, unsigned int count)
1058 {
1059         unsigned long flags;
1060         unsigned int i;
1061
1062         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1063         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1064
1065         raw_spin_lock_irqsave(&irq_big_lock, flags);
1066         for (i = virq; i < (virq + count); i++) {
1067                 struct irq_host *host;
1068
1069                 if (i < NUM_ISA_INTERRUPTS ||
1070                     (virq + count) > irq_virq_count)
1071                         continue;
1072
1073                 host = irq_map[i].host;
1074                 irq_map[i].hwirq = host->inval_irq;
1075                 smp_wmb();
1076                 irq_map[i].host = NULL;
1077         }
1078         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1079 }
1080
1081 int arch_early_irq_init(void)
1082 {
1083         struct irq_desc *desc;
1084         int i;
1085
1086         for (i = 0; i < NR_IRQS; i++) {
1087                 desc = irq_to_desc(i);
1088                 if (desc)
1089                         desc->status |= IRQ_NOREQUEST;
1090         }
1091
1092         return 0;
1093 }
1094
1095 int arch_init_chip_data(struct irq_desc *desc, int node)
1096 {
1097         desc->status |= IRQ_NOREQUEST;
1098         return 0;
1099 }
1100
1101 /* We need to create the radix trees late */
1102 static int irq_late_init(void)
1103 {
1104         struct irq_host *h;
1105         unsigned int i;
1106
1107         /*
1108          * No mutual exclusion with respect to accessors of the tree is needed
1109          * here as the synchronization is done via the state variable
1110          * revmap_trees_allocated.
1111          */
1112         list_for_each_entry(h, &irq_hosts, link) {
1113                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1114                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1115         }
1116
1117         /*
1118          * Make sure the radix trees inits are visible before setting
1119          * the flag
1120          */
1121         smp_wmb();
1122         revmap_trees_allocated = 1;
1123
1124         /*
1125          * Insert the reverse mapping for those interrupts already present
1126          * in irq_map[].
1127          */
1128         mutex_lock(&revmap_trees_mutex);
1129         for (i = 0; i < irq_virq_count; i++) {
1130                 if (irq_map[i].host &&
1131                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1132                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1133                                           irq_map[i].hwirq, &irq_map[i]);
1134         }
1135         mutex_unlock(&revmap_trees_mutex);
1136
1137         /*
1138          * Make sure the radix trees insertions are visible before setting
1139          * the flag
1140          */
1141         smp_wmb();
1142         revmap_trees_allocated = 2;
1143
1144         return 0;
1145 }
1146 arch_initcall(irq_late_init);
1147
1148 #ifdef CONFIG_VIRQ_DEBUG
1149 static int virq_debug_show(struct seq_file *m, void *private)
1150 {
1151         unsigned long flags;
1152         struct irq_desc *desc;
1153         const char *p;
1154         char none[] = "none";
1155         int i;
1156
1157         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1158                       "chip name", "host name");
1159
1160         for (i = 1; i < nr_irqs; i++) {
1161                 desc = irq_to_desc(i);
1162                 if (!desc)
1163                         continue;
1164
1165                 raw_spin_lock_irqsave(&desc->lock, flags);
1166
1167                 if (desc->action && desc->action->handler) {
1168                         seq_printf(m, "%5d  ", i);
1169                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1170
1171                         if (desc->chip && desc->chip->name)
1172                                 p = desc->chip->name;
1173                         else
1174                                 p = none;
1175                         seq_printf(m, "%-15s  ", p);
1176
1177                         if (irq_map[i].host && irq_map[i].host->of_node)
1178                                 p = irq_map[i].host->of_node->full_name;
1179                         else
1180                                 p = none;
1181                         seq_printf(m, "%s\n", p);
1182                 }
1183
1184                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1185         }
1186
1187         return 0;
1188 }
1189
1190 static int virq_debug_open(struct inode *inode, struct file *file)
1191 {
1192         return single_open(file, virq_debug_show, inode->i_private);
1193 }
1194
1195 static const struct file_operations virq_debug_fops = {
1196         .open = virq_debug_open,
1197         .read = seq_read,
1198         .llseek = seq_lseek,
1199         .release = single_release,
1200 };
1201
1202 static int __init irq_debugfs_init(void)
1203 {
1204         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1205                                  NULL, &virq_debug_fops) == NULL)
1206                 return -ENOMEM;
1207
1208         return 0;
1209 }
1210 __initcall(irq_debugfs_init);
1211 #endif /* CONFIG_VIRQ_DEBUG */
1212
1213 #ifdef CONFIG_PPC64
1214 static int __init setup_noirqdistrib(char *str)
1215 {
1216         distribute_irqs = 0;
1217         return 1;
1218 }
1219
1220 __setup("noirqdistrib", setup_noirqdistrib);
1221 #endif /* CONFIG_PPC64 */