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/export.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         /*
 161          * Need to hard-enable interrupts here.  Since currently disabled,
 162          * no need to take further asm precautions against preemption; but
 163          * use local_paca instead of get_paca() to avoid preemption checking.
 164          */
 165         local_paca->hard_enabled = en;
 166
 167 #ifndef CONFIG_BOOKE
 168         /* On server, re-trigger the decrementer if it went negative since
 169          * some processors only trigger on edge transitions of the sign bit.
 170          *
 171          * BookE has a level sensitive decrementer (latches in TSR) so we
 172          * don't need that
 173          */
 174         if ((int)mfspr(SPRN_DEC) < 0)
 175                 mtspr(SPRN_DEC, 1);
 176 #endif /* CONFIG_BOOKE */
 177
 178         /*
 179          * Force the delivery of pending soft-disabled interrupts on PS3.
 180          * Any HV call will have this side effect.
 181          */
 182         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 183                 u64 tmp;
 184                 lv1_get_version_info(&tmp);
 185         }
 186
 187         __hard_irq_enable();
 188 }
 189 EXPORT_SYMBOL(arch_local_irq_restore);
 190 #endif /* CONFIG_PPC64 */
 191
 192 int arch_show_interrupts(struct seq_file *p, int prec)
 193 {
 194         int j;
 195
 196 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 197         if (tau_initialized) {
 198                 seq_printf(p, "%*s: ", prec, "TAU");
 199                 for_each_online_cpu(j)
 200                         seq_printf(p, "%10u ", tau_interrupts(j));
 201                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 202         }
 203 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
 204
 205         seq_printf(p, "%*s: ", prec, "LOC");
 206         for_each_online_cpu(j)
 207                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
 208         seq_printf(p, "  Local timer interrupts\n");
 209
 210         seq_printf(p, "%*s: ", prec, "SPU");
 211         for_each_online_cpu(j)
 212                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
 213         seq_printf(p, "  Spurious interrupts\n");
 214
 215         seq_printf(p, "%*s: ", prec, "CNT");
 216         for_each_online_cpu(j)
 217                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
 218         seq_printf(p, "  Performance monitoring interrupts\n");
 219
 220         seq_printf(p, "%*s: ", prec, "MCE");
 221         for_each_online_cpu(j)
 222                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
 223         seq_printf(p, "  Machine check exceptions\n");
 224
 225         return 0;
 226 }
 227
 228 /*
 229  * /proc/stat helpers
 230  */
 231 u64 arch_irq_stat_cpu(unsigned int cpu)
 232 {
 233         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
 234
 235         sum += per_cpu(irq_stat, cpu).pmu_irqs;
 236         sum += per_cpu(irq_stat, cpu).mce_exceptions;
 237         sum += per_cpu(irq_stat, cpu).spurious_irqs;
 238
 239         return sum;
 240 }
 241
 242 #ifdef CONFIG_HOTPLUG_CPU
 243 void migrate_irqs(void)
 244 {
 245         struct irq_desc *desc;
 246         unsigned int irq;
 247         static int warned;
 248         cpumask_var_t mask;
 249         const struct cpumask *map = cpu_online_mask;
 250
 251         alloc_cpumask_var(&mask, GFP_KERNEL);
 252
 253         for_each_irq(irq) {
 254                 struct irq_data *data;
 255                 struct irq_chip *chip;
 256
 257                 desc = irq_to_desc(irq);
 258                 if (!desc)
 259                         continue;
 260
 261                 data = irq_desc_get_irq_data(desc);
 262                 if (irqd_is_per_cpu(data))
 263                         continue;
 264
 265                 chip = irq_data_get_irq_chip(data);
 266
 267                 cpumask_and(mask, data->affinity, map);
 268                 if (cpumask_any(mask) >= nr_cpu_ids) {
 269                         printk("Breaking affinity for irq %i\n", irq);
 270                         cpumask_copy(mask, map);
 271                 }
 272                 if (chip->irq_set_affinity)
 273                         chip->irq_set_affinity(data, mask, true);
 274                 else if (desc->action && !(warned++))
 275                         printk("Cannot set affinity for irq %i\n", irq);
 276         }
 277
 278         free_cpumask_var(mask);
 279
 280         local_irq_enable();
 281         mdelay(1);
 282         local_irq_disable();
 283 }
 284 #endif
 285
 286 static inline void handle_one_irq(unsigned int irq)
 287 {
 288         struct thread_info *curtp, *irqtp;
 289         unsigned long saved_sp_limit;
 290         struct irq_desc *desc;
 291
 292         desc = irq_to_desc(irq);
 293         if (!desc)
 294                 return;
 295
 296         /* Switch to the irq stack to handle this */
 297         curtp = current_thread_info();
 298         irqtp = hardirq_ctx[smp_processor_id()];
 299
 300         if (curtp == irqtp) {
 301                 /* We're already on the irq stack, just handle it */
 302                 desc->handle_irq(irq, desc);
 303                 return;
 304         }
 305
 306         saved_sp_limit = current->thread.ksp_limit;
 307
 308         irqtp->task = curtp->task;
 309         irqtp->flags = 0;
 310
 311         /* Copy the softirq bits in preempt_count so that the
 312          * softirq checks work in the hardirq context. */
 313         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 314                                (curtp->preempt_count & SOFTIRQ_MASK);
 315
 316         current->thread.ksp_limit = (unsigned long)irqtp +
 317                 _ALIGN_UP(sizeof(struct thread_info), 16);
 318
 319         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 320         current->thread.ksp_limit = saved_sp_limit;
 321         irqtp->task = NULL;
 322
 323         /* Set any flag that may have been set on the
 324          * alternate stack
 325          */
 326         if (irqtp->flags)
 327                 set_bits(irqtp->flags, &curtp->flags);
 328 }
 329
 330 static inline void check_stack_overflow(void)
 331 {
 332 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 333         long sp;
 334
 335         sp = __get_SP() & (THREAD_SIZE-1);
 336
 337         /* check for stack overflow: is there less than 2KB free? */
 338         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 339                 printk("do_IRQ: stack overflow: %ld\n",
 340                         sp - sizeof(struct thread_info));
 341                 dump_stack();
 342         }
 343 #endif
 344 }
 345
 346 void do_IRQ(struct pt_regs *regs)
 347 {
 348         struct pt_regs *old_regs = set_irq_regs(regs);
 349         unsigned int irq;
 350
 351         trace_irq_entry(regs);
 352
 353         irq_enter();
 354
 355         check_stack_overflow();
 356
 357         irq = ppc_md.get_irq();
 358
 359         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 360                 handle_one_irq(irq);
 361         else if (irq != NO_IRQ_IGNORE)
 362                 __get_cpu_var(irq_stat).spurious_irqs++;
 363
 364         irq_exit();
 365         set_irq_regs(old_regs);
 366
 367 #ifdef CONFIG_PPC_ISERIES
 368         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 369                         get_lppaca()->int_dword.fields.decr_int) {
 370                 get_lppaca()->int_dword.fields.decr_int = 0;
 371                 /* Signal a fake decrementer interrupt */
 372                 timer_interrupt(regs);
 373         }
 374 #endif
 375
 376         trace_irq_exit(regs);
 377 }
 378
 379 void __init init_IRQ(void)
 380 {
 381         if (ppc_md.init_IRQ)
 382                 ppc_md.init_IRQ();
 383
 384         exc_lvl_ctx_init();
 385
 386         irq_ctx_init();
 387 }
 388
 389 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 390 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 391 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 392 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 393
 394 void exc_lvl_ctx_init(void)
 395 {
 396         struct thread_info *tp;
 397         int i, cpu_nr;
 398
 399         for_each_possible_cpu(i) {
 400 #ifdef CONFIG_PPC64
 401                 cpu_nr = i;
 402 #else
 403                 cpu_nr = get_hard_smp_processor_id(i);
 404 #endif
 405                 memset((void *)critirq_ctx[cpu_nr], 0, THREAD_SIZE);
 406                 tp = critirq_ctx[cpu_nr];
 407                 tp->cpu = cpu_nr;
 408                 tp->preempt_count = 0;
 409
 410 #ifdef CONFIG_BOOKE
 411                 memset((void *)dbgirq_ctx[cpu_nr], 0, THREAD_SIZE);
 412                 tp = dbgirq_ctx[cpu_nr];
 413                 tp->cpu = cpu_nr;
 414                 tp->preempt_count = 0;
 415
 416                 memset((void *)mcheckirq_ctx[cpu_nr], 0, THREAD_SIZE);
 417                 tp = mcheckirq_ctx[cpu_nr];
 418                 tp->cpu = cpu_nr;
 419                 tp->preempt_count = HARDIRQ_OFFSET;
 420 #endif
 421         }
 422 }
 423 #endif
 424
 425 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 426 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 427
 428 void irq_ctx_init(void)
 429 {
 430         struct thread_info *tp;
 431         int i;
 432
 433         for_each_possible_cpu(i) {
 434                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 435                 tp = softirq_ctx[i];
 436                 tp->cpu = i;
 437                 tp->preempt_count = 0;
 438
 439                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 440                 tp = hardirq_ctx[i];
 441                 tp->cpu = i;
 442                 tp->preempt_count = HARDIRQ_OFFSET;
 443         }
 444 }
 445
 446 static inline void do_softirq_onstack(void)
 447 {
 448         struct thread_info *curtp, *irqtp;
 449         unsigned long saved_sp_limit = current->thread.ksp_limit;
 450
 451         curtp = current_thread_info();
 452         irqtp = softirq_ctx[smp_processor_id()];
 453         irqtp->task = curtp->task;
 454         irqtp->flags = 0;
 455         current->thread.ksp_limit = (unsigned long)irqtp +
 456                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 457         call_do_softirq(irqtp);
 458         current->thread.ksp_limit = saved_sp_limit;
 459         irqtp->task = NULL;
 460
 461         /* Set any flag that may have been set on the
 462          * alternate stack
 463          */
 464         if (irqtp->flags)
 465                 set_bits(irqtp->flags, &curtp->flags);
 466 }
 467
 468 void do_softirq(void)
 469 {
 470         unsigned long flags;
 471
 472         if (in_interrupt())
 473                 return;
 474
 475         local_irq_save(flags);
 476
 477         if (local_softirq_pending())
 478                 do_softirq_onstack();
 479
 480         local_irq_restore(flags);
 481 }
 482
 483
 484 /*
 485  * IRQ controller and virtual interrupts
 486  */
 487
 488 /* The main irq map itself is an array of NR_IRQ entries containing the
 489  * associate host and irq number. An entry with a host of NULL is free.
 490  * An entry can be allocated if it's free, the allocator always then sets
 491  * hwirq first to the host's invalid irq number and then fills ops.
 492  */
 493 struct irq_map_entry {
 494         irq_hw_number_t hwirq;
 495         struct irq_host *host;
 496 };
 497
 498 static LIST_HEAD(irq_hosts);
 499 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 500 static DEFINE_MUTEX(revmap_trees_mutex);
 501 static struct irq_map_entry irq_map[NR_IRQS];
 502 static unsigned int irq_virq_count = NR_IRQS;
 503 static struct irq_host *irq_default_host;
 504
 505 irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
 506 {
 507         return irq_map[d->irq].hwirq;
 508 }
 509 EXPORT_SYMBOL_GPL(irqd_to_hwirq);
 510
 511 irq_hw_number_t virq_to_hw(unsigned int virq)
 512 {
 513         return irq_map[virq].hwirq;
 514 }
 515 EXPORT_SYMBOL_GPL(virq_to_hw);
 516
 517 bool virq_is_host(unsigned int virq, struct irq_host *host)
 518 {
 519         return irq_map[virq].host == host;
 520 }
 521 EXPORT_SYMBOL_GPL(virq_is_host);
 522
 523 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 524 {
 525         return h->of_node != NULL && h->of_node == np;
 526 }
 527
 528 struct irq_host *irq_alloc_host(struct device_node *of_node,
 529                                 unsigned int revmap_type,
 530                                 unsigned int revmap_arg,
 531                                 struct irq_host_ops *ops,
 532                                 irq_hw_number_t inval_irq)
 533 {
 534         struct irq_host *host;
 535         unsigned int size = sizeof(struct irq_host);
 536         unsigned int i;
 537         unsigned int *rmap;
 538         unsigned long flags;
 539
 540         /* Allocate structure and revmap table if using linear mapping */
 541         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 542                 size += revmap_arg * sizeof(unsigned int);
 543         host = kzalloc(size, GFP_KERNEL);
 544         if (host == NULL)
 545                 return NULL;
 546
 547         /* Fill structure */
 548         host->revmap_type = revmap_type;
 549         host->inval_irq = inval_irq;
 550         host->ops = ops;
 551         host->of_node = of_node_get(of_node);
 552
 553         if (host->ops->match == NULL)
 554                 host->ops->match = default_irq_host_match;
 555
 556         raw_spin_lock_irqsave(&irq_big_lock, flags);
 557
 558         /* If it's a legacy controller, check for duplicates and
 559          * mark it as allocated (we use irq 0 host pointer for that
 560          */
 561         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 562                 if (irq_map[0].host != NULL) {
 563                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 564                         of_node_put(host->of_node);
 565                         kfree(host);
 566                         return NULL;
 567                 }
 568                 irq_map[0].host = host;
 569         }
 570
 571         list_add(&host->link, &irq_hosts);
 572         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 573
 574         /* Additional setups per revmap type */
 575         switch(revmap_type) {
 576         case IRQ_HOST_MAP_LEGACY:
 577                 /* 0 is always the invalid number for legacy */
 578                 host->inval_irq = 0;
 579                 /* setup us as the host for all legacy interrupts */
 580                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 581                         irq_map[i].hwirq = i;
 582                         smp_wmb();
 583                         irq_map[i].host = host;
 584                         smp_wmb();
 585
 586                         /* Legacy flags are left to default at this point,
 587                          * one can then use irq_create_mapping() to
 588                          * explicitly change them
 589                          */
 590                         ops->map(host, i, i);
 591
 592                         /* Clear norequest flags */
 593                         irq_clear_status_flags(i, IRQ_NOREQUEST);
 594                 }
 595                 break;
 596         case IRQ_HOST_MAP_LINEAR:
 597                 rmap = (unsigned int *)(host + 1);
 598                 for (i = 0; i < revmap_arg; i++)
 599                         rmap[i] = NO_IRQ;
 600                 host->revmap_data.linear.size = revmap_arg;
 601                 smp_wmb();
 602                 host->revmap_data.linear.revmap = rmap;
 603                 break;
 604         case IRQ_HOST_MAP_TREE:
 605                 INIT_RADIX_TREE(&host->revmap_data.tree, GFP_KERNEL);
 606                 break;
 607         default:
 608                 break;
 609         }
 610
 611         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 612
 613         return host;
 614 }
 615
 616 struct irq_host *irq_find_host(struct device_node *node)
 617 {
 618         struct irq_host *h, *found = NULL;
 619         unsigned long flags;
 620
 621         /* We might want to match the legacy controller last since
 622          * it might potentially be set to match all interrupts in
 623          * the absence of a device node. This isn't a problem so far
 624          * yet though...
 625          */
 626         raw_spin_lock_irqsave(&irq_big_lock, flags);
 627         list_for_each_entry(h, &irq_hosts, link)
 628                 if (h->ops->match(h, node)) {
 629                         found = h;
 630                         break;
 631                 }
 632         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 633         return found;
 634 }
 635 EXPORT_SYMBOL_GPL(irq_find_host);
 636
 637 void irq_set_default_host(struct irq_host *host)
 638 {
 639         pr_debug("irq: Default host set to @0x%p\n", host);
 640
 641         irq_default_host = host;
 642 }
 643
 644 void irq_set_virq_count(unsigned int count)
 645 {
 646         pr_debug("irq: Trying to set virq count to %d\n", count);
 647
 648         BUG_ON(count < NUM_ISA_INTERRUPTS);
 649         if (count < NR_IRQS)
 650                 irq_virq_count = count;
 651 }
 652
 653 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 654                             irq_hw_number_t hwirq)
 655 {
 656         int res;
 657
 658         res = irq_alloc_desc_at(virq, 0);
 659         if (res != virq) {
 660                 pr_debug("irq: -> allocating desc failed\n");
 661                 goto error;
 662         }
 663
 664         /* map it */
 665         smp_wmb();
 666         irq_map[virq].hwirq = hwirq;
 667         smp_mb();
 668
 669         if (host->ops->map(host, virq, hwirq)) {
 670                 pr_debug("irq: -> mapping failed, freeing\n");
 671                 goto errdesc;
 672         }
 673
 674         irq_clear_status_flags(virq, IRQ_NOREQUEST);
 675
 676         return 0;
 677
 678 errdesc:
 679         irq_free_descs(virq, 1);
 680 error:
 681         irq_free_virt(virq, 1);
 682         return -1;
 683 }
 684
 685 unsigned int irq_create_direct_mapping(struct irq_host *host)
 686 {
 687         unsigned int virq;
 688
 689         if (host == NULL)
 690                 host = irq_default_host;
 691
 692         BUG_ON(host == NULL);
 693         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 694
 695         virq = irq_alloc_virt(host, 1, 0);
 696         if (virq == NO_IRQ) {
 697                 pr_debug("irq: create_direct virq allocation failed\n");
 698                 return NO_IRQ;
 699         }
 700
 701         pr_debug("irq: create_direct obtained virq %d\n", virq);
 702
 703         if (irq_setup_virq(host, virq, virq))
 704                 return NO_IRQ;
 705
 706         return virq;
 707 }
 708
 709 unsigned int irq_create_mapping(struct irq_host *host,
 710                                 irq_hw_number_t hwirq)
 711 {
 712         unsigned int virq, hint;
 713
 714         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 715
 716         /* Look for default host if nececssary */
 717         if (host == NULL)
 718                 host = irq_default_host;
 719         if (host == NULL) {
 720                 printk(KERN_WARNING "irq_create_mapping called for"
 721                        " NULL host, hwirq=%lx\n", hwirq);
 722                 WARN_ON(1);
 723                 return NO_IRQ;
 724         }
 725         pr_debug("irq: -> using host @%p\n", host);
 726
 727         /* Check if mapping already exists */
 728         virq = irq_find_mapping(host, hwirq);
 729         if (virq != NO_IRQ) {
 730                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 731                 return virq;
 732         }
 733
 734         /* Get a virtual interrupt number */
 735         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 736                 /* Handle legacy */
 737                 virq = (unsigned int)hwirq;
 738                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 739                         return NO_IRQ;
 740                 return virq;
 741         } else {
 742                 /* Allocate a virtual interrupt number */
 743                 hint = hwirq % irq_virq_count;
 744                 virq = irq_alloc_virt(host, 1, hint);
 745                 if (virq == NO_IRQ) {
 746                         pr_debug("irq: -> virq allocation failed\n");
 747                         return NO_IRQ;
 748                 }
 749         }
 750
 751         if (irq_setup_virq(host, virq, hwirq))
 752                 return NO_IRQ;
 753
 754         pr_debug("irq: irq %lu on host %s mapped to virtual irq %u\n",
 755                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 756
 757         return virq;
 758 }
 759 EXPORT_SYMBOL_GPL(irq_create_mapping);
 760
 761 unsigned int irq_create_of_mapping(struct device_node *controller,
 762                                    const u32 *intspec, unsigned int intsize)
 763 {
 764         struct irq_host *host;
 765         irq_hw_number_t hwirq;
 766         unsigned int type = IRQ_TYPE_NONE;
 767         unsigned int virq;
 768
 769         if (controller == NULL)
 770                 host = irq_default_host;
 771         else
 772                 host = irq_find_host(controller);
 773         if (host == NULL) {
 774                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 775                        controller->full_name);
 776                 return NO_IRQ;
 777         }
 778
 779         /* If host has no translation, then we assume interrupt line */
 780         if (host->ops->xlate == NULL)
 781                 hwirq = intspec[0];
 782         else {
 783                 if (host->ops->xlate(host, controller, intspec, intsize,
 784                                      &hwirq, &type))
 785                         return NO_IRQ;
 786         }
 787
 788         /* Create mapping */
 789         virq = irq_create_mapping(host, hwirq);
 790         if (virq == NO_IRQ)
 791                 return virq;
 792
 793         /* Set type if specified and different than the current one */
 794         if (type != IRQ_TYPE_NONE &&
 795             type != (irqd_get_trigger_type(irq_get_irq_data(virq))))
 796                 irq_set_irq_type(virq, type);
 797         return virq;
 798 }
 799 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 800
 801 void irq_dispose_mapping(unsigned int virq)
 802 {
 803         struct irq_host *host;
 804         irq_hw_number_t hwirq;
 805
 806         if (virq == NO_IRQ)
 807                 return;
 808
 809         host = irq_map[virq].host;
 810         if (WARN_ON(host == NULL))
 811                 return;
 812
 813         /* Never unmap legacy interrupts */
 814         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 815                 return;
 816
 817         irq_set_status_flags(virq, IRQ_NOREQUEST);
 818
 819         /* remove chip and handler */
 820         irq_set_chip_and_handler(virq, NULL, NULL);
 821
 822         /* Make sure it's completed */
 823         synchronize_irq(virq);
 824
 825         /* Tell the PIC about it */
 826         if (host->ops->unmap)
 827                 host->ops->unmap(host, virq);
 828         smp_mb();
 829
 830         /* Clear reverse map */
 831         hwirq = irq_map[virq].hwirq;
 832         switch(host->revmap_type) {
 833         case IRQ_HOST_MAP_LINEAR:
 834                 if (hwirq < host->revmap_data.linear.size)
 835                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 836                 break;
 837         case IRQ_HOST_MAP_TREE:
 838                 mutex_lock(&revmap_trees_mutex);
 839                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 840                 mutex_unlock(&revmap_trees_mutex);
 841                 break;
 842         }
 843
 844         /* Destroy map */
 845         smp_mb();
 846         irq_map[virq].hwirq = host->inval_irq;
 847
 848         irq_free_descs(virq, 1);
 849         /* Free it */
 850         irq_free_virt(virq, 1);
 851 }
 852 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 853
 854 unsigned int irq_find_mapping(struct irq_host *host,
 855                               irq_hw_number_t hwirq)
 856 {
 857         unsigned int i;
 858         unsigned int hint = hwirq % irq_virq_count;
 859
 860         /* Look for default host if nececssary */
 861         if (host == NULL)
 862                 host = irq_default_host;
 863         if (host == NULL)
 864                 return NO_IRQ;
 865
 866         /* legacy -> bail early */
 867         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 868                 return hwirq;
 869
 870         /* Slow path does a linear search of the map */
 871         if (hint < NUM_ISA_INTERRUPTS)
 872                 hint = NUM_ISA_INTERRUPTS;
 873         i = hint;
 874         do  {
 875                 if (irq_map[i].host == host &&
 876                     irq_map[i].hwirq == hwirq)
 877                         return i;
 878                 i++;
 879                 if (i >= irq_virq_count)
 880                         i = NUM_ISA_INTERRUPTS;
 881         } while(i != hint);
 882         return NO_IRQ;
 883 }
 884 EXPORT_SYMBOL_GPL(irq_find_mapping);
 885
 886 #ifdef CONFIG_SMP
 887 int irq_choose_cpu(const struct cpumask *mask)
 888 {
 889         int cpuid;
 890
 891         if (cpumask_equal(mask, cpu_all_mask)) {
 892                 static int irq_rover;
 893                 static DEFINE_RAW_SPINLOCK(irq_rover_lock);
 894                 unsigned long flags;
 895
 896                 /* Round-robin distribution... */
 897 do_round_robin:
 898                 raw_spin_lock_irqsave(&irq_rover_lock, flags);
 899
 900                 irq_rover = cpumask_next(irq_rover, cpu_online_mask);
 901                 if (irq_rover >= nr_cpu_ids)
 902                         irq_rover = cpumask_first(cpu_online_mask);
 903
 904                 cpuid = irq_rover;
 905
 906                 raw_spin_unlock_irqrestore(&irq_rover_lock, flags);
 907         } else {
 908                 cpuid = cpumask_first_and(mask, cpu_online_mask);
 909                 if (cpuid >= nr_cpu_ids)
 910                         goto do_round_robin;
 911         }
 912
 913         return get_hard_smp_processor_id(cpuid);
 914 }
 915 #else
 916 int irq_choose_cpu(const struct cpumask *mask)
 917 {
 918         return hard_smp_processor_id();
 919 }
 920 #endif
 921
 922 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 923                                      irq_hw_number_t hwirq)
 924 {
 925         struct irq_map_entry *ptr;
 926         unsigned int virq;
 927
 928         if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_TREE))
 929                 return irq_find_mapping(host, hwirq);
 930
 931         /*
 932          * The ptr returned references the static global irq_map.
 933          * but freeing an irq can delete nodes along the path to
 934          * do the lookup via call_rcu.
 935          */
 936         rcu_read_lock();
 937         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 938         rcu_read_unlock();
 939
 940         /*
 941          * If found in radix tree, then fine.
 942          * Else fallback to linear lookup - this should not happen in practice
 943          * as it means that we failed to insert the node in the radix tree.
 944          */
 945         if (ptr)
 946                 virq = ptr - irq_map;
 947         else
 948                 virq = irq_find_mapping(host, hwirq);
 949
 950         return virq;
 951 }
 952
 953 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 954                              irq_hw_number_t hwirq)
 955 {
 956         if (WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE))
 957                 return;
 958
 959         if (virq != NO_IRQ) {
 960                 mutex_lock(&revmap_trees_mutex);
 961                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 962                                   &irq_map[virq]);
 963                 mutex_unlock(&revmap_trees_mutex);
 964         }
 965 }
 966
 967 unsigned int irq_linear_revmap(struct irq_host *host,
 968                                irq_hw_number_t hwirq)
 969 {
 970         unsigned int *revmap;
 971
 972         if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_LINEAR))
 973                 return irq_find_mapping(host, hwirq);
 974
 975         /* Check revmap bounds */
 976         if (unlikely(hwirq >= host->revmap_data.linear.size))
 977                 return irq_find_mapping(host, hwirq);
 978
 979         /* Check if revmap was allocated */
 980         revmap = host->revmap_data.linear.revmap;
 981         if (unlikely(revmap == NULL))
 982                 return irq_find_mapping(host, hwirq);
 983
 984         /* Fill up revmap with slow path if no mapping found */
 985         if (unlikely(revmap[hwirq] == NO_IRQ))
 986                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 987
 988         return revmap[hwirq];
 989 }
 990
 991 unsigned int irq_alloc_virt(struct irq_host *host,
 992                             unsigned int count,
 993                             unsigned int hint)
 994 {
 995         unsigned long flags;
 996         unsigned int i, j, found = NO_IRQ;
 997
 998         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 999                 return NO_IRQ;
1000
1001         raw_spin_lock_irqsave(&irq_big_lock, flags);
1002
1003         /* Use hint for 1 interrupt if any */
1004         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
1005             hint < irq_virq_count && irq_map[hint].host == NULL) {
1006                 found = hint;
1007                 goto hint_found;
1008         }
1009
1010         /* Look for count consecutive numbers in the allocatable
1011          * (non-legacy) space
1012          */
1013         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1014                 if (irq_map[i].host != NULL)
1015                         j = 0;
1016                 else
1017                         j++;
1018
1019                 if (j == count) {
1020                         found = i - count + 1;
1021                         break;
1022                 }
1023         }
1024         if (found == NO_IRQ) {
1025                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1026                 return NO_IRQ;
1027         }
1028  hint_found:
1029         for (i = found; i < (found + count); i++) {
1030                 irq_map[i].hwirq = host->inval_irq;
1031                 smp_wmb();
1032                 irq_map[i].host = host;
1033         }
1034         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1035         return found;
1036 }
1037
1038 void irq_free_virt(unsigned int virq, unsigned int count)
1039 {
1040         unsigned long flags;
1041         unsigned int i;
1042
1043         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1044         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1045
1046         if (virq < NUM_ISA_INTERRUPTS) {
1047                 if (virq + count < NUM_ISA_INTERRUPTS)
1048                         return;
1049                 count  =- NUM_ISA_INTERRUPTS - virq;
1050                 virq = NUM_ISA_INTERRUPTS;
1051         }
1052
1053         if (count > irq_virq_count || virq > irq_virq_count - count) {
1054                 if (virq > irq_virq_count)
1055                         return;
1056                 count = irq_virq_count - virq;
1057         }
1058
1059         raw_spin_lock_irqsave(&irq_big_lock, flags);
1060         for (i = virq; i < (virq + count); i++) {
1061                 struct irq_host *host;
1062
1063                 host = irq_map[i].host;
1064                 irq_map[i].hwirq = host->inval_irq;
1065                 smp_wmb();
1066                 irq_map[i].host = NULL;
1067         }
1068         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1069 }
1070
1071 int arch_early_irq_init(void)
1072 {
1073         return 0;
1074 }
1075
1076 #ifdef CONFIG_VIRQ_DEBUG
1077 static int virq_debug_show(struct seq_file *m, void *private)
1078 {
1079         unsigned long flags;
1080         struct irq_desc *desc;
1081         const char *p;
1082         static const char none[] = "none";
1083         void *data;
1084         int i;
1085
1086         seq_printf(m, "%-5s  %-7s  %-15s  %-18s  %s\n", "virq", "hwirq",
1087                       "chip name", "chip data", "host name");
1088
1089         for (i = 1; i < nr_irqs; i++) {
1090                 desc = irq_to_desc(i);
1091                 if (!desc)
1092                         continue;
1093
1094                 raw_spin_lock_irqsave(&desc->lock, flags);
1095
1096                 if (desc->action && desc->action->handler) {
1097                         struct irq_chip *chip;
1098
1099                         seq_printf(m, "%5d  ", i);
1100                         seq_printf(m, "0x%05lx  ", irq_map[i].hwirq);
1101
1102                         chip = irq_desc_get_chip(desc);
1103                         if (chip && chip->name)
1104                                 p = chip->name;
1105                         else
1106                                 p = none;
1107                         seq_printf(m, "%-15s  ", p);
1108
1109                         data = irq_desc_get_chip_data(desc);
1110                         seq_printf(m, "0x%16p  ", data);
1111
1112                         if (irq_map[i].host && irq_map[i].host->of_node)
1113                                 p = irq_map[i].host->of_node->full_name;
1114                         else
1115                                 p = none;
1116                         seq_printf(m, "%s\n", p);
1117                 }
1118
1119                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1120         }
1121
1122         return 0;
1123 }
1124
1125 static int virq_debug_open(struct inode *inode, struct file *file)
1126 {
1127         return single_open(file, virq_debug_show, inode->i_private);
1128 }
1129
1130 static const struct file_operations virq_debug_fops = {
1131         .open = virq_debug_open,
1132         .read = seq_read,
1133         .llseek = seq_lseek,
1134         .release = single_release,
1135 };
1136
1137 static int __init irq_debugfs_init(void)
1138 {
1139         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1140                                  NULL, &virq_debug_fops) == NULL)
1141                 return -ENOMEM;
1142
1143         return 0;
1144 }
1145 __initcall(irq_debugfs_init);
1146 #endif /* CONFIG_VIRQ_DEBUG */
1147
1148 #ifdef CONFIG_PPC64
1149 static int __init setup_noirqdistrib(char *str)
1150 {
1151         distribute_irqs = 0;
1152         return 1;
1153 }
1154
1155 __setup("noirqdistrib", setup_noirqdistrib);
1156 #endif /* CONFIG_PPC64 */