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 #ifdef CONFIG_PPC64
  68 #include <asm/paca.h>
  69 #include <asm/firmware.h>
  70 #include <asm/lv1call.h>
  71 #endif
  72 #define CREATE_TRACE_POINTS
  73 #include <asm/trace.h>
  74
  75 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
  76 EXPORT_PER_CPU_SYMBOL(irq_stat);
  77
  78 int __irq_offset_value;
  79
  80 #ifdef CONFIG_PPC32
  81 EXPORT_SYMBOL(__irq_offset_value);
  82 atomic_t ppc_n_lost_interrupts;
  83
  84 #ifdef CONFIG_TAU_INT
  85 extern int tau_initialized;
  86 extern int tau_interrupts(int);
  87 #endif
  88 #endif /* CONFIG_PPC32 */
  89
  90 #ifdef CONFIG_PPC64
  91
  92 #ifndef CONFIG_SPARSE_IRQ
  93 EXPORT_SYMBOL(irq_desc);
  94 #endif
  95
  96 int distribute_irqs = 1;
  97
  98 static inline notrace unsigned long get_hard_enabled(void)
  99 {
 100         unsigned long enabled;
 101
 102         __asm__ __volatile__("lbz %0,%1(13)"
 103         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 104
 105         return enabled;
 106 }
 107
 108 static inline notrace void set_soft_enabled(unsigned long enable)
 109 {
 110         __asm__ __volatile__("stb %0,%1(13)"
 111         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 112 }
 113
 114 notrace void raw_local_irq_restore(unsigned long en)
 115 {
 116         /*
 117          * get_paca()->soft_enabled = en;
 118          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 119          * That was allowed before, and in such a case we do need to take care
 120          * that gcc will set soft_enabled directly via r13, not choose to use
 121          * an intermediate register, lest we're preempted to a different cpu.
 122          */
 123         set_soft_enabled(en);
 124         if (!en)
 125                 return;
 126
 127 #ifdef CONFIG_PPC_STD_MMU_64
 128         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 129                 /*
 130                  * Do we need to disable preemption here?  Not really: in the
 131                  * unlikely event that we're preempted to a different cpu in
 132                  * between getting r13, loading its lppaca_ptr, and loading
 133                  * its any_int, we might call iseries_handle_interrupts without
 134                  * an interrupt pending on the new cpu, but that's no disaster,
 135                  * is it?  And the business of preempting us off the old cpu
 136                  * would itself involve a local_irq_restore which handles the
 137                  * interrupt to that cpu.
 138                  *
 139                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 140                  * to avoid any preemption checking added into get_paca().
 141                  */
 142                 if (local_paca->lppaca_ptr->int_dword.any_int)
 143                         iseries_handle_interrupts();
 144         }
 145 #endif /* CONFIG_PPC_STD_MMU_64 */
 146
 147         /*
 148          * if (get_paca()->hard_enabled) return;
 149          * But again we need to take care that gcc gets hard_enabled directly
 150          * via r13, not choose to use an intermediate register, lest we're
 151          * preempted to a different cpu in between the two instructions.
 152          */
 153         if (get_hard_enabled())
 154                 return;
 155
 156         /*
 157          * Need to hard-enable interrupts here.  Since currently disabled,
 158          * no need to take further asm precautions against preemption; but
 159          * use local_paca instead of get_paca() to avoid preemption checking.
 160          */
 161         local_paca->hard_enabled = en;
 162         if ((int)mfspr(SPRN_DEC) < 0)
 163                 mtspr(SPRN_DEC, 1);
 164
 165         /*
 166          * Force the delivery of pending soft-disabled interrupts on PS3.
 167          * Any HV call will have this side effect.
 168          */
 169         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 170                 u64 tmp;
 171                 lv1_get_version_info(&tmp);
 172         }
 173
 174         __hard_irq_enable();
 175 }
 176 EXPORT_SYMBOL(raw_local_irq_restore);
 177 #endif /* CONFIG_PPC64 */
 178
 179 static int show_other_interrupts(struct seq_file *p, int prec)
 180 {
 181         int j;
 182
 183 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 184         if (tau_initialized) {
 185                 seq_printf(p, "%*s: ", prec, "TAU");
 186                 for_each_online_cpu(j)
 187                         seq_printf(p, "%10u ", tau_interrupts(j));
 188                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 189         }
 190 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
 191
 192         seq_printf(p, "%*s: ", prec, "LOC");
 193         for_each_online_cpu(j)
 194                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
 195         seq_printf(p, "  Local timer interrupts\n");
 196
 197         seq_printf(p, "%*s: ", prec, "SPU");
 198         for_each_online_cpu(j)
 199                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
 200         seq_printf(p, "  Spurious interrupts\n");
 201
 202         seq_printf(p, "%*s: ", prec, "CNT");
 203         for_each_online_cpu(j)
 204                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
 205         seq_printf(p, "  Performance monitoring interrupts\n");
 206
 207         seq_printf(p, "%*s: ", prec, "MCE");
 208         for_each_online_cpu(j)
 209                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
 210         seq_printf(p, "  Machine check exceptions\n");
 211
 212         return 0;
 213 }
 214
 215 int show_interrupts(struct seq_file *p, void *v)
 216 {
 217         unsigned long flags, any_count = 0;
 218         int i = *(loff_t *) v, j, prec;
 219         struct irqaction *action;
 220         struct irq_desc *desc;
 221
 222         if (i > nr_irqs)
 223                 return 0;
 224
 225         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
 226                 j *= 10;
 227
 228         if (i == nr_irqs)
 229                 return show_other_interrupts(p, prec);
 230
 231         /* print header */
 232         if (i == 0) {
 233                 seq_printf(p, "%*s", prec + 8, "");
 234                 for_each_online_cpu(j)
 235                         seq_printf(p, "CPU%-8d", j);
 236                 seq_putc(p, '\n');
 237         }
 238
 239         desc = irq_to_desc(i);
 240         if (!desc)
 241                 return 0;
 242
 243         raw_spin_lock_irqsave(&desc->lock, flags);
 244         for_each_online_cpu(j)
 245                 any_count |= kstat_irqs_cpu(i, j);
 246         action = desc->action;
 247         if (!action && !any_count)
 248                 goto out;
 249
 250         seq_printf(p, "%*d: ", prec, i);
 251         for_each_online_cpu(j)
 252                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 253
 254         if (desc->chip)
 255                 seq_printf(p, "  %-16s", desc->chip->name);
 256         else
 257                 seq_printf(p, "  %-16s", "None");
 258         seq_printf(p, " %-8s", (desc->status & IRQ_LEVEL) ? "Level" : "Edge");
 259
 260         if (action) {
 261                 seq_printf(p, "     %s", action->name);
 262                 while ((action = action->next) != NULL)
 263                         seq_printf(p, ", %s", action->name);
 264         }
 265
 266         seq_putc(p, '\n');
 267 out:
 268         raw_spin_unlock_irqrestore(&desc->lock, flags);
 269         return 0;
 270 }
 271
 272 /*
 273  * /proc/stat helpers
 274  */
 275 u64 arch_irq_stat_cpu(unsigned int cpu)
 276 {
 277         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
 278
 279         sum += per_cpu(irq_stat, cpu).pmu_irqs;
 280         sum += per_cpu(irq_stat, cpu).mce_exceptions;
 281         sum += per_cpu(irq_stat, cpu).spurious_irqs;
 282
 283         return sum;
 284 }
 285
 286 #ifdef CONFIG_HOTPLUG_CPU
 287 void fixup_irqs(const struct cpumask *map)
 288 {
 289         struct irq_desc *desc;
 290         unsigned int irq;
 291         static int warned;
 292         cpumask_var_t mask;
 293
 294         alloc_cpumask_var(&mask, GFP_KERNEL);
 295
 296         for_each_irq(irq) {
 297                 desc = irq_to_desc(irq);
 298                 if (desc && desc->status & IRQ_PER_CPU)
 299                         continue;
 300
 301                 cpumask_and(mask, desc->affinity, map);
 302                 if (cpumask_any(mask) >= nr_cpu_ids) {
 303                         printk("Breaking affinity for irq %i\n", irq);
 304                         cpumask_copy(mask, map);
 305                 }
 306                 if (desc->chip->set_affinity)
 307                         desc->chip->set_affinity(irq, mask);
 308                 else if (desc->action && !(warned++))
 309                         printk("Cannot set affinity for irq %i\n", irq);
 310         }
 311
 312         free_cpumask_var(mask);
 313
 314         local_irq_enable();
 315         mdelay(1);
 316         local_irq_disable();
 317 }
 318 #endif
 319
 320 static inline void handle_one_irq(unsigned int irq)
 321 {
 322         struct thread_info *curtp, *irqtp;
 323         unsigned long saved_sp_limit;
 324         struct irq_desc *desc;
 325
 326         /* Switch to the irq stack to handle this */
 327         curtp = current_thread_info();
 328         irqtp = hardirq_ctx[smp_processor_id()];
 329
 330         if (curtp == irqtp) {
 331                 /* We're already on the irq stack, just handle it */
 332                 generic_handle_irq(irq);
 333                 return;
 334         }
 335
 336         desc = irq_to_desc(irq);
 337         saved_sp_limit = current->thread.ksp_limit;
 338
 339         irqtp->task = curtp->task;
 340         irqtp->flags = 0;
 341
 342         /* Copy the softirq bits in preempt_count so that the
 343          * softirq checks work in the hardirq context. */
 344         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 345                                (curtp->preempt_count & SOFTIRQ_MASK);
 346
 347         current->thread.ksp_limit = (unsigned long)irqtp +
 348                 _ALIGN_UP(sizeof(struct thread_info), 16);
 349
 350         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 351         current->thread.ksp_limit = saved_sp_limit;
 352         irqtp->task = NULL;
 353
 354         /* Set any flag that may have been set on the
 355          * alternate stack
 356          */
 357         if (irqtp->flags)
 358                 set_bits(irqtp->flags, &curtp->flags);
 359 }
 360
 361 static inline void check_stack_overflow(void)
 362 {
 363 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 364         long sp;
 365
 366         sp = __get_SP() & (THREAD_SIZE-1);
 367
 368         /* check for stack overflow: is there less than 2KB free? */
 369         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 370                 printk("do_IRQ: stack overflow: %ld\n",
 371                         sp - sizeof(struct thread_info));
 372                 dump_stack();
 373         }
 374 #endif
 375 }
 376
 377 void do_IRQ(struct pt_regs *regs)
 378 {
 379         struct pt_regs *old_regs = set_irq_regs(regs);
 380         unsigned int irq;
 381
 382         trace_irq_entry(regs);
 383
 384         irq_enter();
 385
 386         check_stack_overflow();
 387
 388         irq = ppc_md.get_irq();
 389
 390         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 391                 handle_one_irq(irq);
 392         else if (irq != NO_IRQ_IGNORE)
 393                 __get_cpu_var(irq_stat).spurious_irqs++;
 394
 395         irq_exit();
 396         set_irq_regs(old_regs);
 397
 398 #ifdef CONFIG_PPC_ISERIES
 399         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 400                         get_lppaca()->int_dword.fields.decr_int) {
 401                 get_lppaca()->int_dword.fields.decr_int = 0;
 402                 /* Signal a fake decrementer interrupt */
 403                 timer_interrupt(regs);
 404         }
 405 #endif
 406
 407         trace_irq_exit(regs);
 408 }
 409
 410 void __init init_IRQ(void)
 411 {
 412         if (ppc_md.init_IRQ)
 413                 ppc_md.init_IRQ();
 414
 415         exc_lvl_ctx_init();
 416
 417         irq_ctx_init();
 418 }
 419
 420 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 421 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 422 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 423 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 424
 425 void exc_lvl_ctx_init(void)
 426 {
 427         struct thread_info *tp;
 428         int i;
 429
 430         for_each_possible_cpu(i) {
 431                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 432                 tp = critirq_ctx[i];
 433                 tp->cpu = i;
 434                 tp->preempt_count = 0;
 435
 436 #ifdef CONFIG_BOOKE
 437                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 438                 tp = dbgirq_ctx[i];
 439                 tp->cpu = i;
 440                 tp->preempt_count = 0;
 441
 442                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 443                 tp = mcheckirq_ctx[i];
 444                 tp->cpu = i;
 445                 tp->preempt_count = HARDIRQ_OFFSET;
 446 #endif
 447         }
 448 }
 449 #endif
 450
 451 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 452 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 453
 454 void irq_ctx_init(void)
 455 {
 456         struct thread_info *tp;
 457         int i;
 458
 459         for_each_possible_cpu(i) {
 460                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 461                 tp = softirq_ctx[i];
 462                 tp->cpu = i;
 463                 tp->preempt_count = 0;
 464
 465                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 466                 tp = hardirq_ctx[i];
 467                 tp->cpu = i;
 468                 tp->preempt_count = HARDIRQ_OFFSET;
 469         }
 470 }
 471
 472 static inline void do_softirq_onstack(void)
 473 {
 474         struct thread_info *curtp, *irqtp;
 475         unsigned long saved_sp_limit = current->thread.ksp_limit;
 476
 477         curtp = current_thread_info();
 478         irqtp = softirq_ctx[smp_processor_id()];
 479         irqtp->task = curtp->task;
 480         current->thread.ksp_limit = (unsigned long)irqtp +
 481                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 482         call_do_softirq(irqtp);
 483         current->thread.ksp_limit = saved_sp_limit;
 484         irqtp->task = NULL;
 485 }
 486
 487 void do_softirq(void)
 488 {
 489         unsigned long flags;
 490
 491         if (in_interrupt())
 492                 return;
 493
 494         local_irq_save(flags);
 495
 496         if (local_softirq_pending())
 497                 do_softirq_onstack();
 498
 499         local_irq_restore(flags);
 500 }
 501
 502
 503 /*
 504  * IRQ controller and virtual interrupts
 505  */
 506
 507 static LIST_HEAD(irq_hosts);
 508 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 509 static unsigned int revmap_trees_allocated;
 510 static DEFINE_MUTEX(revmap_trees_mutex);
 511 struct irq_map_entry irq_map[NR_IRQS];
 512 static unsigned int irq_virq_count = NR_IRQS;
 513 static struct irq_host *irq_default_host;
 514
 515 irq_hw_number_t virq_to_hw(unsigned int virq)
 516 {
 517         return irq_map[virq].hwirq;
 518 }
 519 EXPORT_SYMBOL_GPL(virq_to_hw);
 520
 521 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 522 {
 523         return h->of_node != NULL && h->of_node == np;
 524 }
 525
 526 struct irq_host *irq_alloc_host(struct device_node *of_node,
 527                                 unsigned int revmap_type,
 528                                 unsigned int revmap_arg,
 529                                 struct irq_host_ops *ops,
 530                                 irq_hw_number_t inval_irq)
 531 {
 532         struct irq_host *host;
 533         unsigned int size = sizeof(struct irq_host);
 534         unsigned int i;
 535         unsigned int *rmap;
 536         unsigned long flags;
 537
 538         /* Allocate structure and revmap table if using linear mapping */
 539         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 540                 size += revmap_arg * sizeof(unsigned int);
 541         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 542         if (host == NULL)
 543                 return NULL;
 544
 545         /* Fill structure */
 546         host->revmap_type = revmap_type;
 547         host->inval_irq = inval_irq;
 548         host->ops = ops;
 549         host->of_node = of_node_get(of_node);
 550
 551         if (host->ops->match == NULL)
 552                 host->ops->match = default_irq_host_match;
 553
 554         raw_spin_lock_irqsave(&irq_big_lock, flags);
 555
 556         /* If it's a legacy controller, check for duplicates and
 557          * mark it as allocated (we use irq 0 host pointer for that
 558          */
 559         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 560                 if (irq_map[0].host != NULL) {
 561                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 562                         /* If we are early boot, we can't free the structure,
 563                          * too bad...
 564                          * this will be fixed once slab is made available early
 565                          * instead of the current cruft
 566                          */
 567                         if (mem_init_done)
 568                                 kfree(host);
 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                         /* Clear norequest flags */
 590                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
 591
 592                         /* Legacy flags are left to default at this point,
 593                          * one can then use irq_create_mapping() to
 594                          * explicitly change them
 595                          */
 596                         ops->map(host, i, i);
 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         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         struct irq_desc *desc;
 657
 658         desc = irq_to_desc_alloc_node(virq, 0);
 659         if (!desc) {
 660                 pr_debug("irq: -> allocating desc failed\n");
 661                 goto error;
 662         }
 663
 664         /* Clear IRQ_NOREQUEST flag */
 665         desc->status &= ~IRQ_NOREQUEST;
 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 error;
 675         }
 676
 677         return 0;
 678
 679 error:
 680         irq_free_virt(virq, 1);
 681         return -1;
 682 }
 683
 684 unsigned int irq_create_direct_mapping(struct irq_host *host)
 685 {
 686         unsigned int virq;
 687
 688         if (host == NULL)
 689                 host = irq_default_host;
 690
 691         BUG_ON(host == NULL);
 692         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 693
 694         virq = irq_alloc_virt(host, 1, 0);
 695         if (virq == NO_IRQ) {
 696                 pr_debug("irq: create_direct virq allocation failed\n");
 697                 return NO_IRQ;
 698         }
 699
 700         pr_debug("irq: create_direct obtained virq %d\n", virq);
 701
 702         if (irq_setup_virq(host, virq, virq))
 703                 return NO_IRQ;
 704
 705         return virq;
 706 }
 707
 708 unsigned int irq_create_mapping(struct irq_host *host,
 709                                 irq_hw_number_t hwirq)
 710 {
 711         unsigned int virq, hint;
 712
 713         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 714
 715         /* Look for default host if nececssary */
 716         if (host == NULL)
 717                 host = irq_default_host;
 718         if (host == NULL) {
 719                 printk(KERN_WARNING "irq_create_mapping called for"
 720                        " NULL host, hwirq=%lx\n", hwirq);
 721                 WARN_ON(1);
 722                 return NO_IRQ;
 723         }
 724         pr_debug("irq: -> using host @%p\n", host);
 725
 726         /* Check if mapping already exist, if it does, call
 727          * host->ops->map() to update the flags
 728          */
 729         virq = irq_find_mapping(host, hwirq);
 730         if (virq != NO_IRQ) {
 731                 if (host->ops->remap)
 732                         host->ops->remap(host, virq, hwirq);
 733                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 734                 return virq;
 735         }
 736
 737         /* Get a virtual interrupt number */
 738         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 739                 /* Handle legacy */
 740                 virq = (unsigned int)hwirq;
 741                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 742                         return NO_IRQ;
 743                 return virq;
 744         } else {
 745                 /* Allocate a virtual interrupt number */
 746                 hint = hwirq % irq_virq_count;
 747                 virq = irq_alloc_virt(host, 1, hint);
 748                 if (virq == NO_IRQ) {
 749                         pr_debug("irq: -> virq allocation failed\n");
 750                         return NO_IRQ;
 751                 }
 752         }
 753
 754         if (irq_setup_virq(host, virq, hwirq))
 755                 return NO_IRQ;
 756
 757         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 758                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 759
 760         return virq;
 761 }
 762 EXPORT_SYMBOL_GPL(irq_create_mapping);
 763
 764 unsigned int irq_create_of_mapping(struct device_node *controller,
 765                                    const u32 *intspec, unsigned int intsize)
 766 {
 767         struct irq_host *host;
 768         irq_hw_number_t hwirq;
 769         unsigned int type = IRQ_TYPE_NONE;
 770         unsigned int virq;
 771
 772         if (controller == NULL)
 773                 host = irq_default_host;
 774         else
 775                 host = irq_find_host(controller);
 776         if (host == NULL) {
 777                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 778                        controller->full_name);
 779                 return NO_IRQ;
 780         }
 781
 782         /* If host has no translation, then we assume interrupt line */
 783         if (host->ops->xlate == NULL)
 784                 hwirq = intspec[0];
 785         else {
 786                 if (host->ops->xlate(host, controller, intspec, intsize,
 787                                      &hwirq, &type))
 788                         return NO_IRQ;
 789         }
 790
 791         /* Create mapping */
 792         virq = irq_create_mapping(host, hwirq);
 793         if (virq == NO_IRQ)
 794                 return virq;
 795
 796         /* Set type if specified and different than the current one */
 797         if (type != IRQ_TYPE_NONE &&
 798             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
 799                 set_irq_type(virq, type);
 800         return virq;
 801 }
 802 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 803
 804 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 805 {
 806         struct of_irq oirq;
 807
 808         if (of_irq_map_one(dev, index, &oirq))
 809                 return NO_IRQ;
 810
 811         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 812                                      oirq.size);
 813 }
 814 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 815
 816 void irq_dispose_mapping(unsigned int virq)
 817 {
 818         struct irq_host *host;
 819         irq_hw_number_t hwirq;
 820
 821         if (virq == NO_IRQ)
 822                 return;
 823
 824         host = irq_map[virq].host;
 825         WARN_ON (host == NULL);
 826         if (host == NULL)
 827                 return;
 828
 829         /* Never unmap legacy interrupts */
 830         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 831                 return;
 832
 833         /* remove chip and handler */
 834         set_irq_chip_and_handler(virq, NULL, NULL);
 835
 836         /* Make sure it's completed */
 837         synchronize_irq(virq);
 838
 839         /* Tell the PIC about it */
 840         if (host->ops->unmap)
 841                 host->ops->unmap(host, virq);
 842         smp_mb();
 843
 844         /* Clear reverse map */
 845         hwirq = irq_map[virq].hwirq;
 846         switch(host->revmap_type) {
 847         case IRQ_HOST_MAP_LINEAR:
 848                 if (hwirq < host->revmap_data.linear.size)
 849                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 850                 break;
 851         case IRQ_HOST_MAP_TREE:
 852                 /*
 853                  * Check if radix tree allocated yet, if not then nothing to
 854                  * remove.
 855                  */
 856                 smp_rmb();
 857                 if (revmap_trees_allocated < 1)
 858                         break;
 859                 mutex_lock(&revmap_trees_mutex);
 860                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 861                 mutex_unlock(&revmap_trees_mutex);
 862                 break;
 863         }
 864
 865         /* Destroy map */
 866         smp_mb();
 867         irq_map[virq].hwirq = host->inval_irq;
 868
 869         /* Set some flags */
 870         irq_to_desc(virq)->status |= IRQ_NOREQUEST;
 871
 872         /* Free it */
 873         irq_free_virt(virq, 1);
 874 }
 875 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 876
 877 unsigned int irq_find_mapping(struct irq_host *host,
 878                               irq_hw_number_t hwirq)
 879 {
 880         unsigned int i;
 881         unsigned int hint = hwirq % irq_virq_count;
 882
 883         /* Look for default host if nececssary */
 884         if (host == NULL)
 885                 host = irq_default_host;
 886         if (host == NULL)
 887                 return NO_IRQ;
 888
 889         /* legacy -> bail early */
 890         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 891                 return hwirq;
 892
 893         /* Slow path does a linear search of the map */
 894         if (hint < NUM_ISA_INTERRUPTS)
 895                 hint = NUM_ISA_INTERRUPTS;
 896         i = hint;
 897         do  {
 898                 if (irq_map[i].host == host &&
 899                     irq_map[i].hwirq == hwirq)
 900                         return i;
 901                 i++;
 902                 if (i >= irq_virq_count)
 903                         i = NUM_ISA_INTERRUPTS;
 904         } while(i != hint);
 905         return NO_IRQ;
 906 }
 907 EXPORT_SYMBOL_GPL(irq_find_mapping);
 908
 909
 910 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 911                                      irq_hw_number_t hwirq)
 912 {
 913         struct irq_map_entry *ptr;
 914         unsigned int virq;
 915
 916         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 917
 918         /*
 919          * Check if the radix tree exists and has bee initialized.
 920          * If not, we fallback to slow mode
 921          */
 922         if (revmap_trees_allocated < 2)
 923                 return irq_find_mapping(host, hwirq);
 924
 925         /* Now try to resolve */
 926         /*
 927          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 928          * as it's referencing an entry in the static irq_map table.
 929          */
 930         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 931
 932         /*
 933          * If found in radix tree, then fine.
 934          * Else fallback to linear lookup - this should not happen in practice
 935          * as it means that we failed to insert the node in the radix tree.
 936          */
 937         if (ptr)
 938                 virq = ptr - irq_map;
 939         else
 940                 virq = irq_find_mapping(host, hwirq);
 941
 942         return virq;
 943 }
 944
 945 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 946                              irq_hw_number_t hwirq)
 947 {
 948
 949         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 950
 951         /*
 952          * Check if the radix tree exists yet.
 953          * If not, then the irq will be inserted into the tree when it gets
 954          * initialized.
 955          */
 956         smp_rmb();
 957         if (revmap_trees_allocated < 1)
 958                 return;
 959
 960         if (virq != NO_IRQ) {
 961                 mutex_lock(&revmap_trees_mutex);
 962                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 963                                   &irq_map[virq]);
 964                 mutex_unlock(&revmap_trees_mutex);
 965         }
 966 }
 967
 968 unsigned int irq_linear_revmap(struct irq_host *host,
 969                                irq_hw_number_t hwirq)
 970 {
 971         unsigned int *revmap;
 972
 973         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 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         raw_spin_lock_irqsave(&irq_big_lock, flags);
1047         for (i = virq; i < (virq + count); i++) {
1048                 struct irq_host *host;
1049
1050                 if (i < NUM_ISA_INTERRUPTS ||
1051                     (virq + count) > irq_virq_count)
1052                         continue;
1053
1054                 host = irq_map[i].host;
1055                 irq_map[i].hwirq = host->inval_irq;
1056                 smp_wmb();
1057                 irq_map[i].host = NULL;
1058         }
1059         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1060 }
1061
1062 int arch_early_irq_init(void)
1063 {
1064         struct irq_desc *desc;
1065         int i;
1066
1067         for (i = 0; i < NR_IRQS; i++) {
1068                 desc = irq_to_desc(i);
1069                 if (desc)
1070                         desc->status |= IRQ_NOREQUEST;
1071         }
1072
1073         return 0;
1074 }
1075
1076 int arch_init_chip_data(struct irq_desc *desc, int node)
1077 {
1078         desc->status |= IRQ_NOREQUEST;
1079         return 0;
1080 }
1081
1082 /* We need to create the radix trees late */
1083 static int irq_late_init(void)
1084 {
1085         struct irq_host *h;
1086         unsigned int i;
1087
1088         /*
1089          * No mutual exclusion with respect to accessors of the tree is needed
1090          * here as the synchronization is done via the state variable
1091          * revmap_trees_allocated.
1092          */
1093         list_for_each_entry(h, &irq_hosts, link) {
1094                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1095                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1096         }
1097
1098         /*
1099          * Make sure the radix trees inits are visible before setting
1100          * the flag
1101          */
1102         smp_wmb();
1103         revmap_trees_allocated = 1;
1104
1105         /*
1106          * Insert the reverse mapping for those interrupts already present
1107          * in irq_map[].
1108          */
1109         mutex_lock(&revmap_trees_mutex);
1110         for (i = 0; i < irq_virq_count; i++) {
1111                 if (irq_map[i].host &&
1112                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1113                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1114                                           irq_map[i].hwirq, &irq_map[i]);
1115         }
1116         mutex_unlock(&revmap_trees_mutex);
1117
1118         /*
1119          * Make sure the radix trees insertions are visible before setting
1120          * the flag
1121          */
1122         smp_wmb();
1123         revmap_trees_allocated = 2;
1124
1125         return 0;
1126 }
1127 arch_initcall(irq_late_init);
1128
1129 #ifdef CONFIG_VIRQ_DEBUG
1130 static int virq_debug_show(struct seq_file *m, void *private)
1131 {
1132         unsigned long flags;
1133         struct irq_desc *desc;
1134         const char *p;
1135         char none[] = "none";
1136         int i;
1137
1138         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1139                       "chip name", "host name");
1140
1141         for (i = 1; i < nr_irqs; i++) {
1142                 desc = irq_to_desc(i);
1143                 if (!desc)
1144                         continue;
1145
1146                 raw_spin_lock_irqsave(&desc->lock, flags);
1147
1148                 if (desc->action && desc->action->handler) {
1149                         seq_printf(m, "%5d  ", i);
1150                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1151
1152                         if (desc->chip && desc->chip->name)
1153                                 p = desc->chip->name;
1154                         else
1155                                 p = none;
1156                         seq_printf(m, "%-15s  ", p);
1157
1158                         if (irq_map[i].host && irq_map[i].host->of_node)
1159                                 p = irq_map[i].host->of_node->full_name;
1160                         else
1161                                 p = none;
1162                         seq_printf(m, "%s\n", p);
1163                 }
1164
1165                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1166         }
1167
1168         return 0;
1169 }
1170
1171 static int virq_debug_open(struct inode *inode, struct file *file)
1172 {
1173         return single_open(file, virq_debug_show, inode->i_private);
1174 }
1175
1176 static const struct file_operations virq_debug_fops = {
1177         .open = virq_debug_open,
1178         .read = seq_read,
1179         .llseek = seq_lseek,
1180         .release = single_release,
1181 };
1182
1183 static int __init irq_debugfs_init(void)
1184 {
1185         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1186                                  NULL, &virq_debug_fops) == NULL)
1187                 return -ENOMEM;
1188
1189         return 0;
1190 }
1191 __initcall(irq_debugfs_init);
1192 #endif /* CONFIG_VIRQ_DEBUG */
1193
1194 #ifdef CONFIG_PPC64
1195 static int __init setup_noirqdistrib(char *str)
1196 {
1197         distribute_irqs = 0;
1198         return 1;
1199 }
1200
1201 __setup("noirqdistrib", setup_noirqdistrib);
1202 #endif /* CONFIG_PPC64 */