arch/powerpc/kernel/irq.c

   1 /*
   2  *  Derived from arch/i386/kernel/irq.c
   3  *    Copyright (C) 1992 Linus Torvalds
   4  *  Adapted from arch/i386 by Gary Thomas
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
   7  *    Copyright (C) 1996-2001 Cort Dougan
   8  *  Adapted for Power Macintosh by Paul Mackerras
   9  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version
  14  * 2 of the License, or (at your option) any later version.
  15  *
  16  * This file contains the code used by various IRQ handling routines:
  17  * asking for different IRQ's should be done through these routines
  18  * instead of just grabbing them. Thus setups with different IRQ numbers
  19  * shouldn't result in any weird surprises, and installing new handlers
  20  * should be easier.
  21  *
  22  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
  23  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
  24  * mask register (of which only 16 are defined), hence the weird shifting
  25  * and complement of the cached_irq_mask.  I want to be able to stuff
  26  * this right into the SIU SMASK register.
  27  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
  28  * to reduce code space and undefined function references.
  29  */
  30
  31 #undef DEBUG
  32
  33 #include <linux/module.h>
  34 #include <linux/threads.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/signal.h>
  37 #include <linux/sched.h>
  38 #include <linux/ptrace.h>
  39 #include <linux/ioport.h>
  40 #include <linux/interrupt.h>
  41 #include <linux/timex.h>
  42 #include <linux/init.h>
  43 #include <linux/slab.h>
  44 #include <linux/delay.h>
  45 #include <linux/irq.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/cpumask.h>
  48 #include <linux/profile.h>
  49 #include <linux/bitops.h>
  50 #include <linux/list.h>
  51 #include <linux/radix-tree.h>
  52 #include <linux/mutex.h>
  53 #include <linux/bootmem.h>
  54 #include <linux/pci.h>
  55 #include <linux/debugfs.h>
  56 #include <linux/of.h>
  57 #include <linux/of_irq.h>
  58
  59 #include <asm/uaccess.h>
  60 #include <asm/system.h>
  61 #include <asm/io.h>
  62 #include <asm/pgtable.h>
  63 #include <asm/irq.h>
  64 #include <asm/cache.h>
  65 #include <asm/prom.h>
  66 #include <asm/ptrace.h>
  67 #include <asm/machdep.h>
  68 #include <asm/udbg.h>
  69 #include <asm/smp.h>
  70
  71 #ifdef CONFIG_PPC64
  72 #include <asm/paca.h>
  73 #include <asm/firmware.h>
  74 #include <asm/lv1call.h>
  75 #endif
  76 #define CREATE_TRACE_POINTS
  77 #include <asm/trace.h>
  78
  79 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
  80 EXPORT_PER_CPU_SYMBOL(irq_stat);
  81
  82 int __irq_offset_value;
  83
  84 #ifdef CONFIG_PPC32
  85 EXPORT_SYMBOL(__irq_offset_value);
  86 atomic_t ppc_n_lost_interrupts;
  87
  88 #ifdef CONFIG_TAU_INT
  89 extern int tau_initialized;
  90 extern int tau_interrupts(int);
  91 #endif
  92 #endif /* CONFIG_PPC32 */
  93
  94 #ifdef CONFIG_PPC64
  95
  96 #ifndef CONFIG_SPARSE_IRQ
  97 EXPORT_SYMBOL(irq_desc);
  98 #endif
  99
 100 int distribute_irqs = 1;
 101
 102 static inline notrace unsigned long get_hard_enabled(void)
 103 {
 104         unsigned long enabled;
 105
 106         __asm__ __volatile__("lbz %0,%1(13)"
 107         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 108
 109         return enabled;
 110 }
 111
 112 static inline notrace void set_soft_enabled(unsigned long enable)
 113 {
 114         __asm__ __volatile__("stb %0,%1(13)"
 115         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 116 }
 117
 118 notrace void arch_local_irq_restore(unsigned long en)
 119 {
 120         /*
 121          * get_paca()->soft_enabled = en;
 122          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 123          * That was allowed before, and in such a case we do need to take care
 124          * that gcc will set soft_enabled directly via r13, not choose to use
 125          * an intermediate register, lest we're preempted to a different cpu.
 126          */
 127         set_soft_enabled(en);
 128         if (!en)
 129                 return;
 130
 131 #ifdef CONFIG_PPC_STD_MMU_64
 132         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 133                 /*
 134                  * Do we need to disable preemption here?  Not really: in the
 135                  * unlikely event that we're preempted to a different cpu in
 136                  * between getting r13, loading its lppaca_ptr, and loading
 137                  * its any_int, we might call iseries_handle_interrupts without
 138                  * an interrupt pending on the new cpu, but that's no disaster,
 139                  * is it?  And the business of preempting us off the old cpu
 140                  * would itself involve a local_irq_restore which handles the
 141                  * interrupt to that cpu.
 142                  *
 143                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 144                  * to avoid any preemption checking added into get_paca().
 145                  */
 146                 if (local_paca->lppaca_ptr->int_dword.any_int)
 147                         iseries_handle_interrupts();
 148         }
 149 #endif /* CONFIG_PPC_STD_MMU_64 */
 150
 151         /*
 152          * if (get_paca()->hard_enabled) return;
 153          * But again we need to take care that gcc gets hard_enabled directly
 154          * via r13, not choose to use an intermediate register, lest we're
 155          * preempted to a different cpu in between the two instructions.
 156          */
 157         if (get_hard_enabled())
 158                 return;
 159
 160 #if defined(CONFIG_BOOKE) && defined(CONFIG_SMP)
 161         /* Check for pending doorbell interrupts and resend to ourself */
 162         if (cpu_has_feature(CPU_FTR_DBELL))
 163                 smp_muxed_ipi_resend();
 164 #endif
 165
 166         /*
 167          * Need to hard-enable interrupts here.  Since currently disabled,
 168          * no need to take further asm precautions against preemption; but
 169          * use local_paca instead of get_paca() to avoid preemption checking.
 170          */
 171         local_paca->hard_enabled = en;
 172
 173 #ifndef CONFIG_BOOKE
 174         /* On server, re-trigger the decrementer if it went negative since
 175          * some processors only trigger on edge transitions of the sign bit.
 176          *
 177          * BookE has a level sensitive decrementer (latches in TSR) so we
 178          * don't need that
 179          */
 180         if ((int)mfspr(SPRN_DEC) < 0)
 181                 mtspr(SPRN_DEC, 1);
 182 #endif /* CONFIG_BOOKE */
 183
 184         /*
 185          * Force the delivery of pending soft-disabled interrupts on PS3.
 186          * Any HV call will have this side effect.
 187          */
 188         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 189                 u64 tmp;
 190                 lv1_get_version_info(&tmp);
 191         }
 192
 193         __hard_irq_enable();
 194 }
 195 EXPORT_SYMBOL(arch_local_irq_restore);
 196 #endif /* CONFIG_PPC64 */
 197
 198 int arch_show_interrupts(struct seq_file *p, int prec)
 199 {
 200         int j;
 201
 202 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 203         if (tau_initialized) {
 204                 seq_printf(p, "%*s: ", prec, "TAU");
 205                 for_each_online_cpu(j)
 206                         seq_printf(p, "%10u ", tau_interrupts(j));
 207                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 208         }
 209 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
 210
 211         seq_printf(p, "%*s: ", prec, "LOC");
 212         for_each_online_cpu(j)
 213                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
 214         seq_printf(p, "  Local timer interrupts\n");
 215
 216         seq_printf(p, "%*s: ", prec, "SPU");
 217         for_each_online_cpu(j)
 218                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
 219         seq_printf(p, "  Spurious interrupts\n");
 220
 221         seq_printf(p, "%*s: ", prec, "CNT");
 222         for_each_online_cpu(j)
 223                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
 224         seq_printf(p, "  Performance monitoring interrupts\n");
 225
 226         seq_printf(p, "%*s: ", prec, "MCE");
 227         for_each_online_cpu(j)
 228                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
 229         seq_printf(p, "  Machine check exceptions\n");
 230
 231         return 0;
 232 }
 233
 234 /*
 235  * /proc/stat helpers
 236  */
 237 u64 arch_irq_stat_cpu(unsigned int cpu)
 238 {
 239         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
 240
 241         sum += per_cpu(irq_stat, cpu).pmu_irqs;
 242         sum += per_cpu(irq_stat, cpu).mce_exceptions;
 243         sum += per_cpu(irq_stat, cpu).spurious_irqs;
 244
 245         return sum;
 246 }
 247
 248 #ifdef CONFIG_HOTPLUG_CPU
 249 void migrate_irqs(void)
 250 {
 251         struct irq_desc *desc;
 252         unsigned int irq;
 253         static int warned;
 254         cpumask_var_t mask;
 255         const struct cpumask *map = cpu_online_mask;
 256
 257         alloc_cpumask_var(&mask, GFP_KERNEL);
 258
 259         for_each_irq(irq) {
 260                 struct irq_data *data;
 261                 struct irq_chip *chip;
 262
 263                 desc = irq_to_desc(irq);
 264                 if (!desc)
 265                         continue;
 266
 267                 data = irq_desc_get_irq_data(desc);
 268                 if (irqd_is_per_cpu(data))
 269                         continue;
 270
 271                 chip = irq_data_get_irq_chip(data);
 272
 273                 cpumask_and(mask, data->affinity, map);
 274                 if (cpumask_any(mask) >= nr_cpu_ids) {
 275                         printk("Breaking affinity for irq %i\n", irq);
 276                         cpumask_copy(mask, map);
 277                 }
 278                 if (chip->irq_set_affinity)
 279                         chip->irq_set_affinity(data, mask, true);
 280                 else if (desc->action && !(warned++))
 281                         printk("Cannot set affinity for irq %i\n", irq);
 282         }
 283
 284         free_cpumask_var(mask);
 285
 286         local_irq_enable();
 287         mdelay(1);
 288         local_irq_disable();
 289 }
 290 #endif
 291
 292 static inline void handle_one_irq(unsigned int irq)
 293 {
 294         struct thread_info *curtp, *irqtp;
 295         unsigned long saved_sp_limit;
 296         struct irq_desc *desc;
 297
 298         /* Switch to the irq stack to handle this */
 299         curtp = current_thread_info();
 300         irqtp = hardirq_ctx[smp_processor_id()];
 301
 302         if (curtp == irqtp) {
 303                 /* We're already on the irq stack, just handle it */
 304                 generic_handle_irq(irq);
 305                 return;
 306         }
 307
 308         desc = irq_to_desc(irq);
 309         saved_sp_limit = current->thread.ksp_limit;
 310
 311         irqtp->task = curtp->task;
 312         irqtp->flags = 0;
 313
 314         /* Copy the softirq bits in preempt_count so that the
 315          * softirq checks work in the hardirq context. */
 316         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 317                                (curtp->preempt_count & SOFTIRQ_MASK);
 318
 319         current->thread.ksp_limit = (unsigned long)irqtp +
 320                 _ALIGN_UP(sizeof(struct thread_info), 16);
 321
 322         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 323         current->thread.ksp_limit = saved_sp_limit;
 324         irqtp->task = NULL;
 325
 326         /* Set any flag that may have been set on the
 327          * alternate stack
 328          */
 329         if (irqtp->flags)
 330                 set_bits(irqtp->flags, &curtp->flags);
 331 }
 332
 333 static inline void check_stack_overflow(void)
 334 {
 335 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 336         long sp;
 337
 338         sp = __get_SP() & (THREAD_SIZE-1);
 339
 340         /* check for stack overflow: is there less than 2KB free? */
 341         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 342                 printk("do_IRQ: stack overflow: %ld\n",
 343                         sp - sizeof(struct thread_info));
 344                 dump_stack();
 345         }
 346 #endif
 347 }
 348
 349 void do_IRQ(struct pt_regs *regs)
 350 {
 351         struct pt_regs *old_regs = set_irq_regs(regs);
 352         unsigned int irq;
 353
 354         trace_irq_entry(regs);
 355
 356         irq_enter();
 357
 358         check_stack_overflow();
 359
 360         irq = ppc_md.get_irq();
 361
 362         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 363                 handle_one_irq(irq);
 364         else if (irq != NO_IRQ_IGNORE)
 365                 __get_cpu_var(irq_stat).spurious_irqs++;
 366
 367         irq_exit();
 368         set_irq_regs(old_regs);
 369
 370 #ifdef CONFIG_PPC_ISERIES
 371         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 372                         get_lppaca()->int_dword.fields.decr_int) {
 373                 get_lppaca()->int_dword.fields.decr_int = 0;
 374                 /* Signal a fake decrementer interrupt */
 375                 timer_interrupt(regs);
 376         }
 377 #endif
 378
 379         trace_irq_exit(regs);
 380 }
 381
 382 void __init init_IRQ(void)
 383 {
 384         if (ppc_md.init_IRQ)
 385                 ppc_md.init_IRQ();
 386
 387         exc_lvl_ctx_init();
 388
 389         irq_ctx_init();
 390 }
 391
 392 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 393 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 394 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 395 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 396
 397 void exc_lvl_ctx_init(void)
 398 {
 399         struct thread_info *tp;
 400         int i, cpu_nr;
 401
 402         for_each_possible_cpu(i) {
 403 #ifdef CONFIG_PPC64
 404                 cpu_nr = i;
 405 #else
 406                 cpu_nr = get_hard_smp_processor_id(i);
 407 #endif
 408                 memset((void *)critirq_ctx[cpu_nr], 0, THREAD_SIZE);
 409                 tp = critirq_ctx[cpu_nr];
 410                 tp->cpu = cpu_nr;
 411                 tp->preempt_count = 0;
 412
 413 #ifdef CONFIG_BOOKE
 414                 memset((void *)dbgirq_ctx[cpu_nr], 0, THREAD_SIZE);
 415                 tp = dbgirq_ctx[cpu_nr];
 416                 tp->cpu = cpu_nr;
 417                 tp->preempt_count = 0;
 418
 419                 memset((void *)mcheckirq_ctx[cpu_nr], 0, THREAD_SIZE);
 420                 tp = mcheckirq_ctx[cpu_nr];
 421                 tp->cpu = cpu_nr;
 422                 tp->preempt_count = HARDIRQ_OFFSET;
 423 #endif
 424         }
 425 }
 426 #endif
 427
 428 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 429 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 430
 431 void irq_ctx_init(void)
 432 {
 433         struct thread_info *tp;
 434         int i;
 435
 436         for_each_possible_cpu(i) {
 437                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 438                 tp = softirq_ctx[i];
 439                 tp->cpu = i;
 440                 tp->preempt_count = 0;
 441
 442                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 443                 tp = hardirq_ctx[i];
 444                 tp->cpu = i;
 445                 tp->preempt_count = HARDIRQ_OFFSET;
 446         }
 447 }
 448
 449 static inline void do_softirq_onstack(void)
 450 {
 451         struct thread_info *curtp, *irqtp;
 452         unsigned long saved_sp_limit = current->thread.ksp_limit;
 453
 454         curtp = current_thread_info();
 455         irqtp = softirq_ctx[smp_processor_id()];
 456         irqtp->task = curtp->task;
 457         current->thread.ksp_limit = (unsigned long)irqtp +
 458                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 459         call_do_softirq(irqtp);
 460         current->thread.ksp_limit = saved_sp_limit;
 461         irqtp->task = NULL;
 462 }
 463
 464 void do_softirq(void)
 465 {
 466         unsigned long flags;
 467
 468         if (in_interrupt())
 469                 return;
 470
 471         local_irq_save(flags);
 472
 473         if (local_softirq_pending())
 474                 do_softirq_onstack();
 475
 476         local_irq_restore(flags);
 477 }
 478
 479
 480 /*
 481  * IRQ controller and virtual interrupts
 482  */
 483
 484 /* The main irq map itself is an array of NR_IRQ entries containing the
 485  * associate host and irq number. An entry with a host of NULL is free.
 486  * An entry can be allocated if it's free, the allocator always then sets
 487  * hwirq first to the host's invalid irq number and then fills ops.
 488  */
 489 struct irq_map_entry {
 490         irq_hw_number_t hwirq;
 491         struct irq_host *host;
 492 };
 493
 494 static LIST_HEAD(irq_hosts);
 495 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 496 static DEFINE_MUTEX(revmap_trees_mutex);
 497 static struct irq_map_entry irq_map[NR_IRQS];
 498 static unsigned int irq_virq_count = NR_IRQS;
 499 static struct irq_host *irq_default_host;
 500
 501 irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
 502 {
 503         return irq_map[d->irq].hwirq;
 504 }
 505 EXPORT_SYMBOL_GPL(irqd_to_hwirq);
 506
 507 irq_hw_number_t virq_to_hw(unsigned int virq)
 508 {
 509         return irq_map[virq].hwirq;
 510 }
 511 EXPORT_SYMBOL_GPL(virq_to_hw);
 512
 513 bool virq_is_host(unsigned int virq, struct irq_host *host)
 514 {
 515         return irq_map[virq].host == host;
 516 }
 517 EXPORT_SYMBOL_GPL(virq_is_host);
 518
 519 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 520 {
 521         return h->of_node != NULL && h->of_node == np;
 522 }
 523
 524 struct irq_host *irq_alloc_host(struct device_node *of_node,
 525                                 unsigned int revmap_type,
 526                                 unsigned int revmap_arg,
 527                                 struct irq_host_ops *ops,
 528                                 irq_hw_number_t inval_irq)
 529 {
 530         struct irq_host *host;
 531         unsigned int size = sizeof(struct irq_host);
 532         unsigned int i;
 533         unsigned int *rmap;
 534         unsigned long flags;
 535
 536         /* Allocate structure and revmap table if using linear mapping */
 537         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 538                 size += revmap_arg * sizeof(unsigned int);
 539         host = kzalloc(size, GFP_KERNEL);
 540         if (host == NULL)
 541                 return NULL;
 542
 543         /* Fill structure */
 544         host->revmap_type = revmap_type;
 545         host->inval_irq = inval_irq;
 546         host->ops = ops;
 547         host->of_node = of_node_get(of_node);
 548
 549         if (host->ops->match == NULL)
 550                 host->ops->match = default_irq_host_match;
 551
 552         raw_spin_lock_irqsave(&irq_big_lock, flags);
 553
 554         /* If it's a legacy controller, check for duplicates and
 555          * mark it as allocated (we use irq 0 host pointer for that
 556          */
 557         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 558                 if (irq_map[0].host != NULL) {
 559                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 560                         /* If we are early boot, we can't free the structure,
 561                          * too bad...
 562                          * this will be fixed once slab is made available early
 563                          * instead of the current cruft
 564                          */
 565                         if (mem_init_done) {
 566                                 of_node_put(host->of_node);
 567                                 kfree(host);
 568                         }
 569                         return NULL;
 570                 }
 571                 irq_map[0].host = host;
 572         }
 573
 574         list_add(&host->link, &irq_hosts);
 575         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 576
 577         /* Additional setups per revmap type */
 578         switch(revmap_type) {
 579         case IRQ_HOST_MAP_LEGACY:
 580                 /* 0 is always the invalid number for legacy */
 581                 host->inval_irq = 0;
 582                 /* setup us as the host for all legacy interrupts */
 583                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 584                         irq_map[i].hwirq = i;
 585                         smp_wmb();
 586                         irq_map[i].host = host;
 587                         smp_wmb();
 588
 589                         /* Legacy flags are left to default at this point,
 590                          * one can then use irq_create_mapping() to
 591                          * explicitly change them
 592                          */
 593                         ops->map(host, i, i);
 594
 595                         /* Clear norequest flags */
 596                         irq_clear_status_flags(i, IRQ_NOREQUEST);
 597                 }
 598                 break;
 599         case IRQ_HOST_MAP_LINEAR:
 600                 rmap = (unsigned int *)(host + 1);
 601                 for (i = 0; i < revmap_arg; i++)
 602                         rmap[i] = NO_IRQ;
 603                 host->revmap_data.linear.size = revmap_arg;
 604                 smp_wmb();
 605                 host->revmap_data.linear.revmap = rmap;
 606                 break;
 607         case IRQ_HOST_MAP_TREE:
 608                 INIT_RADIX_TREE(&host->revmap_data.tree, GFP_KERNEL);
 609                 break;
 610         default:
 611                 break;
 612         }
 613
 614         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 615
 616         return host;
 617 }
 618
 619 struct irq_host *irq_find_host(struct device_node *node)
 620 {
 621         struct irq_host *h, *found = NULL;
 622         unsigned long flags;
 623
 624         /* We might want to match the legacy controller last since
 625          * it might potentially be set to match all interrupts in
 626          * the absence of a device node. This isn't a problem so far
 627          * yet though...
 628          */
 629         raw_spin_lock_irqsave(&irq_big_lock, flags);
 630         list_for_each_entry(h, &irq_hosts, link)
 631                 if (h->ops->match(h, node)) {
 632                         found = h;
 633                         break;
 634                 }
 635         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 636         return found;
 637 }
 638 EXPORT_SYMBOL_GPL(irq_find_host);
 639
 640 void irq_set_default_host(struct irq_host *host)
 641 {
 642         pr_debug("irq: Default host set to @0x%p\n", host);
 643
 644         irq_default_host = host;
 645 }
 646
 647 void irq_set_virq_count(unsigned int count)
 648 {
 649         pr_debug("irq: Trying to set virq count to %d\n", count);
 650
 651         BUG_ON(count < NUM_ISA_INTERRUPTS);
 652         if (count < NR_IRQS)
 653                 irq_virq_count = count;
 654 }
 655
 656 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 657                             irq_hw_number_t hwirq)
 658 {
 659         int res;
 660
 661         res = irq_alloc_desc_at(virq, 0);
 662         if (res != virq) {
 663                 pr_debug("irq: -> allocating desc failed\n");
 664                 goto error;
 665         }
 666
 667         /* map it */
 668         smp_wmb();
 669         irq_map[virq].hwirq = hwirq;
 670         smp_mb();
 671
 672         if (host->ops->map(host, virq, hwirq)) {
 673                 pr_debug("irq: -> mapping failed, freeing\n");
 674                 goto errdesc;
 675         }
 676
 677         irq_clear_status_flags(virq, IRQ_NOREQUEST);
 678
 679         return 0;
 680
 681 errdesc:
 682         irq_free_descs(virq, 1);
 683 error:
 684         irq_free_virt(virq, 1);
 685         return -1;
 686 }
 687
 688 unsigned int irq_create_direct_mapping(struct irq_host *host)
 689 {
 690         unsigned int virq;
 691
 692         if (host == NULL)
 693                 host = irq_default_host;
 694
 695         BUG_ON(host == NULL);
 696         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 697
 698         virq = irq_alloc_virt(host, 1, 0);
 699         if (virq == NO_IRQ) {
 700                 pr_debug("irq: create_direct virq allocation failed\n");
 701                 return NO_IRQ;
 702         }
 703
 704         pr_debug("irq: create_direct obtained virq %d\n", virq);
 705
 706         if (irq_setup_virq(host, virq, virq))
 707                 return NO_IRQ;
 708
 709         return virq;
 710 }
 711
 712 unsigned int irq_create_mapping(struct irq_host *host,
 713                                 irq_hw_number_t hwirq)
 714 {
 715         unsigned int virq, hint;
 716
 717         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 718
 719         /* Look for default host if nececssary */
 720         if (host == NULL)
 721                 host = irq_default_host;
 722         if (host == NULL) {
 723                 printk(KERN_WARNING "irq_create_mapping called for"
 724                        " NULL host, hwirq=%lx\n", hwirq);
 725                 WARN_ON(1);
 726                 return NO_IRQ;
 727         }
 728         pr_debug("irq: -> using host @%p\n", host);
 729
 730         /* Check if mapping already exist, if it does, call
 731          * host->ops->map() to update the flags
 732          */
 733         virq = irq_find_mapping(host, hwirq);
 734         if (virq != NO_IRQ) {
 735                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 736                 return virq;
 737         }
 738
 739         /* Get a virtual interrupt number */
 740         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 741                 /* Handle legacy */
 742                 virq = (unsigned int)hwirq;
 743                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 744                         return NO_IRQ;
 745                 return virq;
 746         } else {
 747                 /* Allocate a virtual interrupt number */
 748                 hint = hwirq % irq_virq_count;
 749                 virq = irq_alloc_virt(host, 1, hint);
 750                 if (virq == NO_IRQ) {
 751                         pr_debug("irq: -> virq allocation failed\n");
 752                         return NO_IRQ;
 753                 }
 754         }
 755
 756         if (irq_setup_virq(host, virq, hwirq))
 757                 return NO_IRQ;
 758
 759         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 760                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 761
 762         return virq;
 763 }
 764 EXPORT_SYMBOL_GPL(irq_create_mapping);
 765
 766 unsigned int irq_create_of_mapping(struct device_node *controller,
 767                                    const u32 *intspec, unsigned int intsize)
 768 {
 769         struct irq_host *host;
 770         irq_hw_number_t hwirq;
 771         unsigned int type = IRQ_TYPE_NONE;
 772         unsigned int virq;
 773
 774         if (controller == NULL)
 775                 host = irq_default_host;
 776         else
 777                 host = irq_find_host(controller);
 778         if (host == NULL) {
 779                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 780                        controller->full_name);
 781                 return NO_IRQ;
 782         }
 783
 784         /* If host has no translation, then we assume interrupt line */
 785         if (host->ops->xlate == NULL)
 786                 hwirq = intspec[0];
 787         else {
 788                 if (host->ops->xlate(host, controller, intspec, intsize,
 789                                      &hwirq, &type))
 790                         return NO_IRQ;
 791         }
 792
 793         /* Create mapping */
 794         virq = irq_create_mapping(host, hwirq);
 795         if (virq == NO_IRQ)
 796                 return virq;
 797
 798         /* Set type if specified and different than the current one */
 799         if (type != IRQ_TYPE_NONE &&
 800             type != (irqd_get_trigger_type(irq_get_irq_data(virq))))
 801                 irq_set_irq_type(virq, type);
 802         return virq;
 803 }
 804 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 805
 806 void irq_dispose_mapping(unsigned int virq)
 807 {
 808         struct irq_host *host;
 809         irq_hw_number_t hwirq;
 810
 811         if (virq == NO_IRQ)
 812                 return;
 813
 814         host = irq_map[virq].host;
 815         if (WARN_ON(host == NULL))
 816                 return;
 817
 818         /* Never unmap legacy interrupts */
 819         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 820                 return;
 821
 822         irq_set_status_flags(virq, IRQ_NOREQUEST);
 823
 824         /* remove chip and handler */
 825         irq_set_chip_and_handler(virq, NULL, NULL);
 826
 827         /* Make sure it's completed */
 828         synchronize_irq(virq);
 829
 830         /* Tell the PIC about it */
 831         if (host->ops->unmap)
 832                 host->ops->unmap(host, virq);
 833         smp_mb();
 834
 835         /* Clear reverse map */
 836         hwirq = irq_map[virq].hwirq;
 837         switch(host->revmap_type) {
 838         case IRQ_HOST_MAP_LINEAR:
 839                 if (hwirq < host->revmap_data.linear.size)
 840                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 841                 break;
 842         case IRQ_HOST_MAP_TREE:
 843                 mutex_lock(&revmap_trees_mutex);
 844                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 845                 mutex_unlock(&revmap_trees_mutex);
 846                 break;
 847         }
 848
 849         /* Destroy map */
 850         smp_mb();
 851         irq_map[virq].hwirq = host->inval_irq;
 852
 853         irq_free_descs(virq, 1);
 854         /* Free it */
 855         irq_free_virt(virq, 1);
 856 }
 857 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 858
 859 unsigned int irq_find_mapping(struct irq_host *host,
 860                               irq_hw_number_t hwirq)
 861 {
 862         unsigned int i;
 863         unsigned int hint = hwirq % irq_virq_count;
 864
 865         /* Look for default host if nececssary */
 866         if (host == NULL)
 867                 host = irq_default_host;
 868         if (host == NULL)
 869                 return NO_IRQ;
 870
 871         /* legacy -> bail early */
 872         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 873                 return hwirq;
 874
 875         /* Slow path does a linear search of the map */
 876         if (hint < NUM_ISA_INTERRUPTS)
 877                 hint = NUM_ISA_INTERRUPTS;
 878         i = hint;
 879         do  {
 880                 if (irq_map[i].host == host &&
 881                     irq_map[i].hwirq == hwirq)
 882                         return i;
 883                 i++;
 884                 if (i >= irq_virq_count)
 885                         i = NUM_ISA_INTERRUPTS;
 886         } while(i != hint);
 887         return NO_IRQ;
 888 }
 889 EXPORT_SYMBOL_GPL(irq_find_mapping);
 890
 891
 892 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 893                                      irq_hw_number_t hwirq)
 894 {
 895         struct irq_map_entry *ptr;
 896         unsigned int virq;
 897
 898         if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_TREE))
 899                 return irq_find_mapping(host, hwirq);
 900
 901         /*
 902          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 903          * as it's referencing an entry in the static irq_map table.
 904          */
 905         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 906
 907         /*
 908          * If found in radix tree, then fine.
 909          * Else fallback to linear lookup - this should not happen in practice
 910          * as it means that we failed to insert the node in the radix tree.
 911          */
 912         if (ptr)
 913                 virq = ptr - irq_map;
 914         else
 915                 virq = irq_find_mapping(host, hwirq);
 916
 917         return virq;
 918 }
 919
 920 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 921                              irq_hw_number_t hwirq)
 922 {
 923         if (WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE))
 924                 return;
 925
 926         if (virq != NO_IRQ) {
 927                 mutex_lock(&revmap_trees_mutex);
 928                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 929                                   &irq_map[virq]);
 930                 mutex_unlock(&revmap_trees_mutex);
 931         }
 932 }
 933
 934 unsigned int irq_linear_revmap(struct irq_host *host,
 935                                irq_hw_number_t hwirq)
 936 {
 937         unsigned int *revmap;
 938
 939         if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_LINEAR))
 940                 return irq_find_mapping(host, hwirq);
 941
 942         /* Check revmap bounds */
 943         if (unlikely(hwirq >= host->revmap_data.linear.size))
 944                 return irq_find_mapping(host, hwirq);
 945
 946         /* Check if revmap was allocated */
 947         revmap = host->revmap_data.linear.revmap;
 948         if (unlikely(revmap == NULL))
 949                 return irq_find_mapping(host, hwirq);
 950
 951         /* Fill up revmap with slow path if no mapping found */
 952         if (unlikely(revmap[hwirq] == NO_IRQ))
 953                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 954
 955         return revmap[hwirq];
 956 }
 957
 958 unsigned int irq_alloc_virt(struct irq_host *host,
 959                             unsigned int count,
 960                             unsigned int hint)
 961 {
 962         unsigned long flags;
 963         unsigned int i, j, found = NO_IRQ;
 964
 965         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 966                 return NO_IRQ;
 967
 968         raw_spin_lock_irqsave(&irq_big_lock, flags);
 969
 970         /* Use hint for 1 interrupt if any */
 971         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
 972             hint < irq_virq_count && irq_map[hint].host == NULL) {
 973                 found = hint;
 974                 goto hint_found;
 975         }
 976
 977         /* Look for count consecutive numbers in the allocatable
 978          * (non-legacy) space
 979          */
 980         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
 981                 if (irq_map[i].host != NULL)
 982                         j = 0;
 983                 else
 984                         j++;
 985
 986                 if (j == count) {
 987                         found = i - count + 1;
 988                         break;
 989                 }
 990         }
 991         if (found == NO_IRQ) {
 992                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 993                 return NO_IRQ;
 994         }
 995  hint_found:
 996         for (i = found; i < (found + count); i++) {
 997                 irq_map[i].hwirq = host->inval_irq;
 998                 smp_wmb();
 999                 irq_map[i].host = host;
1000         }
1001         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1002         return found;
1003 }
1004
1005 void irq_free_virt(unsigned int virq, unsigned int count)
1006 {
1007         unsigned long flags;
1008         unsigned int i;
1009
1010         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1011         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1012
1013         raw_spin_lock_irqsave(&irq_big_lock, flags);
1014         for (i = virq; i < (virq + count); i++) {
1015                 struct irq_host *host;
1016
1017                 if (i < NUM_ISA_INTERRUPTS ||
1018                     (virq + count) > irq_virq_count)
1019                         continue;
1020
1021                 host = irq_map[i].host;
1022                 irq_map[i].hwirq = host->inval_irq;
1023                 smp_wmb();
1024                 irq_map[i].host = NULL;
1025         }
1026         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1027 }
1028
1029 int arch_early_irq_init(void)
1030 {
1031         return 0;
1032 }
1033
1034 #ifdef CONFIG_VIRQ_DEBUG
1035 static int virq_debug_show(struct seq_file *m, void *private)
1036 {
1037         unsigned long flags;
1038         struct irq_desc *desc;
1039         const char *p;
1040         static const char none[] = "none";
1041         void *data;
1042         int i;
1043
1044         seq_printf(m, "%-5s  %-7s  %-15s  %-18s  %s\n", "virq", "hwirq",
1045                       "chip name", "chip data", "host name");
1046
1047         for (i = 1; i < nr_irqs; i++) {
1048                 desc = irq_to_desc(i);
1049                 if (!desc)
1050                         continue;
1051
1052                 raw_spin_lock_irqsave(&desc->lock, flags);
1053
1054                 if (desc->action && desc->action->handler) {
1055                         struct irq_chip *chip;
1056
1057                         seq_printf(m, "%5d  ", i);
1058                         seq_printf(m, "0x%05lx  ", irq_map[i].hwirq);
1059
1060                         chip = irq_desc_get_chip(desc);
1061                         if (chip && chip->name)
1062                                 p = chip->name;
1063                         else
1064                                 p = none;
1065                         seq_printf(m, "%-15s  ", p);
1066
1067                         data = irq_desc_get_chip_data(desc);
1068                         seq_printf(m, "0x%16p  ", data);
1069
1070                         if (irq_map[i].host && irq_map[i].host->of_node)
1071                                 p = irq_map[i].host->of_node->full_name;
1072                         else
1073                                 p = none;
1074                         seq_printf(m, "%s\n", p);
1075                 }
1076
1077                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1078         }
1079
1080         return 0;
1081 }
1082
1083 static int virq_debug_open(struct inode *inode, struct file *file)
1084 {
1085         return single_open(file, virq_debug_show, inode->i_private);
1086 }
1087
1088 static const struct file_operations virq_debug_fops = {
1089         .open = virq_debug_open,
1090         .read = seq_read,
1091         .llseek = seq_lseek,
1092         .release = single_release,
1093 };
1094
1095 static int __init irq_debugfs_init(void)
1096 {
1097         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1098                                  NULL, &virq_debug_fops) == NULL)
1099                 return -ENOMEM;
1100
1101         return 0;
1102 }
1103 __initcall(irq_debugfs_init);
1104 #endif /* CONFIG_VIRQ_DEBUG */
1105
1106 #ifdef CONFIG_PPC64
1107 static int __init setup_noirqdistrib(char *str)
1108 {
1109         distribute_irqs = 0;
1110         return 1;
1111 }
1112
1113 __setup("noirqdistrib", setup_noirqdistrib);
1114 #endif /* CONFIG_PPC64 */