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)
 299                         continue;
 300
 301                 if (desc->status & IRQ_PER_CPU)
 302                         continue;
 303
 304                 cpumask_and(mask, desc->affinity, map);
 305                 if (cpumask_any(mask) >= nr_cpu_ids) {
 306                         printk("Breaking affinity for irq %i\n", irq);
 307                         cpumask_copy(mask, map);
 308                 }
 309                 if (desc->chip->set_affinity)
 310                         desc->chip->set_affinity(irq, mask);
 311                 else if (desc->action && !(warned++))
 312                         printk("Cannot set affinity for irq %i\n", irq);
 313         }
 314
 315         free_cpumask_var(mask);
 316
 317         local_irq_enable();
 318         mdelay(1);
 319         local_irq_disable();
 320 }
 321 #endif
 322
 323 static inline void handle_one_irq(unsigned int irq)
 324 {
 325         struct thread_info *curtp, *irqtp;
 326         unsigned long saved_sp_limit;
 327         struct irq_desc *desc;
 328
 329         /* Switch to the irq stack to handle this */
 330         curtp = current_thread_info();
 331         irqtp = hardirq_ctx[smp_processor_id()];
 332
 333         if (curtp == irqtp) {
 334                 /* We're already on the irq stack, just handle it */
 335                 generic_handle_irq(irq);
 336                 return;
 337         }
 338
 339         desc = irq_to_desc(irq);
 340         saved_sp_limit = current->thread.ksp_limit;
 341
 342         irqtp->task = curtp->task;
 343         irqtp->flags = 0;
 344
 345         /* Copy the softirq bits in preempt_count so that the
 346          * softirq checks work in the hardirq context. */
 347         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 348                                (curtp->preempt_count & SOFTIRQ_MASK);
 349
 350         current->thread.ksp_limit = (unsigned long)irqtp +
 351                 _ALIGN_UP(sizeof(struct thread_info), 16);
 352
 353         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 354         current->thread.ksp_limit = saved_sp_limit;
 355         irqtp->task = NULL;
 356
 357         /* Set any flag that may have been set on the
 358          * alternate stack
 359          */
 360         if (irqtp->flags)
 361                 set_bits(irqtp->flags, &curtp->flags);
 362 }
 363
 364 static inline void check_stack_overflow(void)
 365 {
 366 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 367         long sp;
 368
 369         sp = __get_SP() & (THREAD_SIZE-1);
 370
 371         /* check for stack overflow: is there less than 2KB free? */
 372         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 373                 printk("do_IRQ: stack overflow: %ld\n",
 374                         sp - sizeof(struct thread_info));
 375                 dump_stack();
 376         }
 377 #endif
 378 }
 379
 380 void do_IRQ(struct pt_regs *regs)
 381 {
 382         struct pt_regs *old_regs = set_irq_regs(regs);
 383         unsigned int irq;
 384
 385         trace_irq_entry(regs);
 386
 387         irq_enter();
 388
 389         check_stack_overflow();
 390
 391         irq = ppc_md.get_irq();
 392
 393         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 394                 handle_one_irq(irq);
 395         else if (irq != NO_IRQ_IGNORE)
 396                 __get_cpu_var(irq_stat).spurious_irqs++;
 397
 398         irq_exit();
 399         set_irq_regs(old_regs);
 400
 401 #ifdef CONFIG_PPC_ISERIES
 402         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 403                         get_lppaca()->int_dword.fields.decr_int) {
 404                 get_lppaca()->int_dword.fields.decr_int = 0;
 405                 /* Signal a fake decrementer interrupt */
 406                 timer_interrupt(regs);
 407         }
 408 #endif
 409
 410         trace_irq_exit(regs);
 411 }
 412
 413 void __init init_IRQ(void)
 414 {
 415         if (ppc_md.init_IRQ)
 416                 ppc_md.init_IRQ();
 417
 418         exc_lvl_ctx_init();
 419
 420         irq_ctx_init();
 421 }
 422
 423 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 424 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 425 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 426 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 427
 428 void exc_lvl_ctx_init(void)
 429 {
 430         struct thread_info *tp;
 431         int i;
 432
 433         for_each_possible_cpu(i) {
 434                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 435                 tp = critirq_ctx[i];
 436                 tp->cpu = i;
 437                 tp->preempt_count = 0;
 438
 439 #ifdef CONFIG_BOOKE
 440                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 441                 tp = dbgirq_ctx[i];
 442                 tp->cpu = i;
 443                 tp->preempt_count = 0;
 444
 445                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 446                 tp = mcheckirq_ctx[i];
 447                 tp->cpu = i;
 448                 tp->preempt_count = HARDIRQ_OFFSET;
 449 #endif
 450         }
 451 }
 452 #endif
 453
 454 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 455 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 456
 457 void irq_ctx_init(void)
 458 {
 459         struct thread_info *tp;
 460         int i;
 461
 462         for_each_possible_cpu(i) {
 463                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 464                 tp = softirq_ctx[i];
 465                 tp->cpu = i;
 466                 tp->preempt_count = 0;
 467
 468                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 469                 tp = hardirq_ctx[i];
 470                 tp->cpu = i;
 471                 tp->preempt_count = HARDIRQ_OFFSET;
 472         }
 473 }
 474
 475 static inline void do_softirq_onstack(void)
 476 {
 477         struct thread_info *curtp, *irqtp;
 478         unsigned long saved_sp_limit = current->thread.ksp_limit;
 479
 480         curtp = current_thread_info();
 481         irqtp = softirq_ctx[smp_processor_id()];
 482         irqtp->task = curtp->task;
 483         current->thread.ksp_limit = (unsigned long)irqtp +
 484                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 485         call_do_softirq(irqtp);
 486         current->thread.ksp_limit = saved_sp_limit;
 487         irqtp->task = NULL;
 488 }
 489
 490 void do_softirq(void)
 491 {
 492         unsigned long flags;
 493
 494         if (in_interrupt())
 495                 return;
 496
 497         local_irq_save(flags);
 498
 499         if (local_softirq_pending())
 500                 do_softirq_onstack();
 501
 502         local_irq_restore(flags);
 503 }
 504
 505
 506 /*
 507  * IRQ controller and virtual interrupts
 508  */
 509
 510 static LIST_HEAD(irq_hosts);
 511 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 512 static unsigned int revmap_trees_allocated;
 513 static DEFINE_MUTEX(revmap_trees_mutex);
 514 struct irq_map_entry irq_map[NR_IRQS];
 515 static unsigned int irq_virq_count = NR_IRQS;
 516 static struct irq_host *irq_default_host;
 517
 518 irq_hw_number_t virq_to_hw(unsigned int virq)
 519 {
 520         return irq_map[virq].hwirq;
 521 }
 522 EXPORT_SYMBOL_GPL(virq_to_hw);
 523
 524 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 525 {
 526         return h->of_node != NULL && h->of_node == np;
 527 }
 528
 529 struct irq_host *irq_alloc_host(struct device_node *of_node,
 530                                 unsigned int revmap_type,
 531                                 unsigned int revmap_arg,
 532                                 struct irq_host_ops *ops,
 533                                 irq_hw_number_t inval_irq)
 534 {
 535         struct irq_host *host;
 536         unsigned int size = sizeof(struct irq_host);
 537         unsigned int i;
 538         unsigned int *rmap;
 539         unsigned long flags;
 540
 541         /* Allocate structure and revmap table if using linear mapping */
 542         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 543                 size += revmap_arg * sizeof(unsigned int);
 544         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 545         if (host == NULL)
 546                 return NULL;
 547
 548         /* Fill structure */
 549         host->revmap_type = revmap_type;
 550         host->inval_irq = inval_irq;
 551         host->ops = ops;
 552         host->of_node = of_node_get(of_node);
 553
 554         if (host->ops->match == NULL)
 555                 host->ops->match = default_irq_host_match;
 556
 557         raw_spin_lock_irqsave(&irq_big_lock, flags);
 558
 559         /* If it's a legacy controller, check for duplicates and
 560          * mark it as allocated (we use irq 0 host pointer for that
 561          */
 562         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 563                 if (irq_map[0].host != NULL) {
 564                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 565                         /* If we are early boot, we can't free the structure,
 566                          * too bad...
 567                          * this will be fixed once slab is made available early
 568                          * instead of the current cruft
 569                          */
 570                         if (mem_init_done)
 571                                 kfree(host);
 572                         return NULL;
 573                 }
 574                 irq_map[0].host = host;
 575         }
 576
 577         list_add(&host->link, &irq_hosts);
 578         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 579
 580         /* Additional setups per revmap type */
 581         switch(revmap_type) {
 582         case IRQ_HOST_MAP_LEGACY:
 583                 /* 0 is always the invalid number for legacy */
 584                 host->inval_irq = 0;
 585                 /* setup us as the host for all legacy interrupts */
 586                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 587                         irq_map[i].hwirq = i;
 588                         smp_wmb();
 589                         irq_map[i].host = host;
 590                         smp_wmb();
 591
 592                         /* Clear norequest flags */
 593                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
 594
 595                         /* Legacy flags are left to default at this point,
 596                          * one can then use irq_create_mapping() to
 597                          * explicitly change them
 598                          */
 599                         ops->map(host, i, i);
 600                 }
 601                 break;
 602         case IRQ_HOST_MAP_LINEAR:
 603                 rmap = (unsigned int *)(host + 1);
 604                 for (i = 0; i < revmap_arg; i++)
 605                         rmap[i] = NO_IRQ;
 606                 host->revmap_data.linear.size = revmap_arg;
 607                 smp_wmb();
 608                 host->revmap_data.linear.revmap = rmap;
 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         struct irq_desc *desc;
 660
 661         desc = irq_to_desc_alloc_node(virq, 0);
 662         if (!desc) {
 663                 pr_debug("irq: -> allocating desc failed\n");
 664                 goto error;
 665         }
 666
 667         /* Clear IRQ_NOREQUEST flag */
 668         desc->status &= ~IRQ_NOREQUEST;
 669
 670         /* map it */
 671         smp_wmb();
 672         irq_map[virq].hwirq = hwirq;
 673         smp_mb();
 674
 675         if (host->ops->map(host, virq, hwirq)) {
 676                 pr_debug("irq: -> mapping failed, freeing\n");
 677                 goto error;
 678         }
 679
 680         return 0;
 681
 682 error:
 683         irq_free_virt(virq, 1);
 684         return -1;
 685 }
 686
 687 unsigned int irq_create_direct_mapping(struct irq_host *host)
 688 {
 689         unsigned int virq;
 690
 691         if (host == NULL)
 692                 host = irq_default_host;
 693
 694         BUG_ON(host == NULL);
 695         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 696
 697         virq = irq_alloc_virt(host, 1, 0);
 698         if (virq == NO_IRQ) {
 699                 pr_debug("irq: create_direct virq allocation failed\n");
 700                 return NO_IRQ;
 701         }
 702
 703         pr_debug("irq: create_direct obtained virq %d\n", virq);
 704
 705         if (irq_setup_virq(host, virq, virq))
 706                 return NO_IRQ;
 707
 708         return virq;
 709 }
 710
 711 unsigned int irq_create_mapping(struct irq_host *host,
 712                                 irq_hw_number_t hwirq)
 713 {
 714         unsigned int virq, hint;
 715
 716         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 717
 718         /* Look for default host if nececssary */
 719         if (host == NULL)
 720                 host = irq_default_host;
 721         if (host == NULL) {
 722                 printk(KERN_WARNING "irq_create_mapping called for"
 723                        " NULL host, hwirq=%lx\n", hwirq);
 724                 WARN_ON(1);
 725                 return NO_IRQ;
 726         }
 727         pr_debug("irq: -> using host @%p\n", host);
 728
 729         /* Check if mapping already exist, if it does, call
 730          * host->ops->map() to update the flags
 731          */
 732         virq = irq_find_mapping(host, hwirq);
 733         if (virq != NO_IRQ) {
 734                 if (host->ops->remap)
 735                         host->ops->remap(host, virq, hwirq);
 736                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 737                 return virq;
 738         }
 739
 740         /* Get a virtual interrupt number */
 741         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 742                 /* Handle legacy */
 743                 virq = (unsigned int)hwirq;
 744                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 745                         return NO_IRQ;
 746                 return virq;
 747         } else {
 748                 /* Allocate a virtual interrupt number */
 749                 hint = hwirq % irq_virq_count;
 750                 virq = irq_alloc_virt(host, 1, hint);
 751                 if (virq == NO_IRQ) {
 752                         pr_debug("irq: -> virq allocation failed\n");
 753                         return NO_IRQ;
 754                 }
 755         }
 756
 757         if (irq_setup_virq(host, virq, hwirq))
 758                 return NO_IRQ;
 759
 760         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 761                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 762
 763         return virq;
 764 }
 765 EXPORT_SYMBOL_GPL(irq_create_mapping);
 766
 767 unsigned int irq_create_of_mapping(struct device_node *controller,
 768                                    const u32 *intspec, unsigned int intsize)
 769 {
 770         struct irq_host *host;
 771         irq_hw_number_t hwirq;
 772         unsigned int type = IRQ_TYPE_NONE;
 773         unsigned int virq;
 774
 775         if (controller == NULL)
 776                 host = irq_default_host;
 777         else
 778                 host = irq_find_host(controller);
 779         if (host == NULL) {
 780                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 781                        controller->full_name);
 782                 return NO_IRQ;
 783         }
 784
 785         /* If host has no translation, then we assume interrupt line */
 786         if (host->ops->xlate == NULL)
 787                 hwirq = intspec[0];
 788         else {
 789                 if (host->ops->xlate(host, controller, intspec, intsize,
 790                                      &hwirq, &type))
 791                         return NO_IRQ;
 792         }
 793
 794         /* Create mapping */
 795         virq = irq_create_mapping(host, hwirq);
 796         if (virq == NO_IRQ)
 797                 return virq;
 798
 799         /* Set type if specified and different than the current one */
 800         if (type != IRQ_TYPE_NONE &&
 801             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
 802                 set_irq_type(virq, type);
 803         return virq;
 804 }
 805 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 806
 807 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 808 {
 809         struct of_irq oirq;
 810
 811         if (of_irq_map_one(dev, index, &oirq))
 812                 return NO_IRQ;
 813
 814         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 815                                      oirq.size);
 816 }
 817 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 818
 819 void irq_dispose_mapping(unsigned int virq)
 820 {
 821         struct irq_host *host;
 822         irq_hw_number_t hwirq;
 823
 824         if (virq == NO_IRQ)
 825                 return;
 826
 827         host = irq_map[virq].host;
 828         WARN_ON (host == NULL);
 829         if (host == NULL)
 830                 return;
 831
 832         /* Never unmap legacy interrupts */
 833         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 834                 return;
 835
 836         /* remove chip and handler */
 837         set_irq_chip_and_handler(virq, NULL, NULL);
 838
 839         /* Make sure it's completed */
 840         synchronize_irq(virq);
 841
 842         /* Tell the PIC about it */
 843         if (host->ops->unmap)
 844                 host->ops->unmap(host, virq);
 845         smp_mb();
 846
 847         /* Clear reverse map */
 848         hwirq = irq_map[virq].hwirq;
 849         switch(host->revmap_type) {
 850         case IRQ_HOST_MAP_LINEAR:
 851                 if (hwirq < host->revmap_data.linear.size)
 852                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 853                 break;
 854         case IRQ_HOST_MAP_TREE:
 855                 /*
 856                  * Check if radix tree allocated yet, if not then nothing to
 857                  * remove.
 858                  */
 859                 smp_rmb();
 860                 if (revmap_trees_allocated < 1)
 861                         break;
 862                 mutex_lock(&revmap_trees_mutex);
 863                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 864                 mutex_unlock(&revmap_trees_mutex);
 865                 break;
 866         }
 867
 868         /* Destroy map */
 869         smp_mb();
 870         irq_map[virq].hwirq = host->inval_irq;
 871
 872         /* Set some flags */
 873         irq_to_desc(virq)->status |= IRQ_NOREQUEST;
 874
 875         /* Free it */
 876         irq_free_virt(virq, 1);
 877 }
 878 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 879
 880 unsigned int irq_find_mapping(struct irq_host *host,
 881                               irq_hw_number_t hwirq)
 882 {
 883         unsigned int i;
 884         unsigned int hint = hwirq % irq_virq_count;
 885
 886         /* Look for default host if nececssary */
 887         if (host == NULL)
 888                 host = irq_default_host;
 889         if (host == NULL)
 890                 return NO_IRQ;
 891
 892         /* legacy -> bail early */
 893         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 894                 return hwirq;
 895
 896         /* Slow path does a linear search of the map */
 897         if (hint < NUM_ISA_INTERRUPTS)
 898                 hint = NUM_ISA_INTERRUPTS;
 899         i = hint;
 900         do  {
 901                 if (irq_map[i].host == host &&
 902                     irq_map[i].hwirq == hwirq)
 903                         return i;
 904                 i++;
 905                 if (i >= irq_virq_count)
 906                         i = NUM_ISA_INTERRUPTS;
 907         } while(i != hint);
 908         return NO_IRQ;
 909 }
 910 EXPORT_SYMBOL_GPL(irq_find_mapping);
 911
 912
 913 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 914                                      irq_hw_number_t hwirq)
 915 {
 916         struct irq_map_entry *ptr;
 917         unsigned int virq;
 918
 919         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 920
 921         /*
 922          * Check if the radix tree exists and has bee initialized.
 923          * If not, we fallback to slow mode
 924          */
 925         if (revmap_trees_allocated < 2)
 926                 return irq_find_mapping(host, hwirq);
 927
 928         /* Now try to resolve */
 929         /*
 930          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 931          * as it's referencing an entry in the static irq_map table.
 932          */
 933         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 934
 935         /*
 936          * If found in radix tree, then fine.
 937          * Else fallback to linear lookup - this should not happen in practice
 938          * as it means that we failed to insert the node in the radix tree.
 939          */
 940         if (ptr)
 941                 virq = ptr - irq_map;
 942         else
 943                 virq = irq_find_mapping(host, hwirq);
 944
 945         return virq;
 946 }
 947
 948 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 949                              irq_hw_number_t hwirq)
 950 {
 951
 952         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 953
 954         /*
 955          * Check if the radix tree exists yet.
 956          * If not, then the irq will be inserted into the tree when it gets
 957          * initialized.
 958          */
 959         smp_rmb();
 960         if (revmap_trees_allocated < 1)
 961                 return;
 962
 963         if (virq != NO_IRQ) {
 964                 mutex_lock(&revmap_trees_mutex);
 965                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 966                                   &irq_map[virq]);
 967                 mutex_unlock(&revmap_trees_mutex);
 968         }
 969 }
 970
 971 unsigned int irq_linear_revmap(struct irq_host *host,
 972                                irq_hw_number_t hwirq)
 973 {
 974         unsigned int *revmap;
 975
 976         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 977
 978         /* Check revmap bounds */
 979         if (unlikely(hwirq >= host->revmap_data.linear.size))
 980                 return irq_find_mapping(host, hwirq);
 981
 982         /* Check if revmap was allocated */
 983         revmap = host->revmap_data.linear.revmap;
 984         if (unlikely(revmap == NULL))
 985                 return irq_find_mapping(host, hwirq);
 986
 987         /* Fill up revmap with slow path if no mapping found */
 988         if (unlikely(revmap[hwirq] == NO_IRQ))
 989                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 990
 991         return revmap[hwirq];
 992 }
 993
 994 unsigned int irq_alloc_virt(struct irq_host *host,
 995                             unsigned int count,
 996                             unsigned int hint)
 997 {
 998         unsigned long flags;
 999         unsigned int i, j, found = NO_IRQ;
1000
1001         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
1002                 return NO_IRQ;
1003
1004         raw_spin_lock_irqsave(&irq_big_lock, flags);
1005
1006         /* Use hint for 1 interrupt if any */
1007         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
1008             hint < irq_virq_count && irq_map[hint].host == NULL) {
1009                 found = hint;
1010                 goto hint_found;
1011         }
1012
1013         /* Look for count consecutive numbers in the allocatable
1014          * (non-legacy) space
1015          */
1016         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1017                 if (irq_map[i].host != NULL)
1018                         j = 0;
1019                 else
1020                         j++;
1021
1022                 if (j == count) {
1023                         found = i - count + 1;
1024                         break;
1025                 }
1026         }
1027         if (found == NO_IRQ) {
1028                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1029                 return NO_IRQ;
1030         }
1031  hint_found:
1032         for (i = found; i < (found + count); i++) {
1033                 irq_map[i].hwirq = host->inval_irq;
1034                 smp_wmb();
1035                 irq_map[i].host = host;
1036         }
1037         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1038         return found;
1039 }
1040
1041 void irq_free_virt(unsigned int virq, unsigned int count)
1042 {
1043         unsigned long flags;
1044         unsigned int i;
1045
1046         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1047         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1048
1049         raw_spin_lock_irqsave(&irq_big_lock, flags);
1050         for (i = virq; i < (virq + count); i++) {
1051                 struct irq_host *host;
1052
1053                 if (i < NUM_ISA_INTERRUPTS ||
1054                     (virq + count) > irq_virq_count)
1055                         continue;
1056
1057                 host = irq_map[i].host;
1058                 irq_map[i].hwirq = host->inval_irq;
1059                 smp_wmb();
1060                 irq_map[i].host = NULL;
1061         }
1062         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1063 }
1064
1065 int arch_early_irq_init(void)
1066 {
1067         struct irq_desc *desc;
1068         int i;
1069
1070         for (i = 0; i < NR_IRQS; i++) {
1071                 desc = irq_to_desc(i);
1072                 if (desc)
1073                         desc->status |= IRQ_NOREQUEST;
1074         }
1075
1076         return 0;
1077 }
1078
1079 int arch_init_chip_data(struct irq_desc *desc, int node)
1080 {
1081         desc->status |= IRQ_NOREQUEST;
1082         return 0;
1083 }
1084
1085 /* We need to create the radix trees late */
1086 static int irq_late_init(void)
1087 {
1088         struct irq_host *h;
1089         unsigned int i;
1090
1091         /*
1092          * No mutual exclusion with respect to accessors of the tree is needed
1093          * here as the synchronization is done via the state variable
1094          * revmap_trees_allocated.
1095          */
1096         list_for_each_entry(h, &irq_hosts, link) {
1097                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1098                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1099         }
1100
1101         /*
1102          * Make sure the radix trees inits are visible before setting
1103          * the flag
1104          */
1105         smp_wmb();
1106         revmap_trees_allocated = 1;
1107
1108         /*
1109          * Insert the reverse mapping for those interrupts already present
1110          * in irq_map[].
1111          */
1112         mutex_lock(&revmap_trees_mutex);
1113         for (i = 0; i < irq_virq_count; i++) {
1114                 if (irq_map[i].host &&
1115                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1116                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1117                                           irq_map[i].hwirq, &irq_map[i]);
1118         }
1119         mutex_unlock(&revmap_trees_mutex);
1120
1121         /*
1122          * Make sure the radix trees insertions are visible before setting
1123          * the flag
1124          */
1125         smp_wmb();
1126         revmap_trees_allocated = 2;
1127
1128         return 0;
1129 }
1130 arch_initcall(irq_late_init);
1131
1132 #ifdef CONFIG_VIRQ_DEBUG
1133 static int virq_debug_show(struct seq_file *m, void *private)
1134 {
1135         unsigned long flags;
1136         struct irq_desc *desc;
1137         const char *p;
1138         char none[] = "none";
1139         int i;
1140
1141         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1142                       "chip name", "host name");
1143
1144         for (i = 1; i < nr_irqs; i++) {
1145                 desc = irq_to_desc(i);
1146                 if (!desc)
1147                         continue;
1148
1149                 raw_spin_lock_irqsave(&desc->lock, flags);
1150
1151                 if (desc->action && desc->action->handler) {
1152                         seq_printf(m, "%5d  ", i);
1153                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1154
1155                         if (desc->chip && desc->chip->name)
1156                                 p = desc->chip->name;
1157                         else
1158                                 p = none;
1159                         seq_printf(m, "%-15s  ", p);
1160
1161                         if (irq_map[i].host && irq_map[i].host->of_node)
1162                                 p = irq_map[i].host->of_node->full_name;
1163                         else
1164                                 p = none;
1165                         seq_printf(m, "%s\n", p);
1166                 }
1167
1168                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1169         }
1170
1171         return 0;
1172 }
1173
1174 static int virq_debug_open(struct inode *inode, struct file *file)
1175 {
1176         return single_open(file, virq_debug_show, inode->i_private);
1177 }
1178
1179 static const struct file_operations virq_debug_fops = {
1180         .open = virq_debug_open,
1181         .read = seq_read,
1182         .llseek = seq_lseek,
1183         .release = single_release,
1184 };
1185
1186 static int __init irq_debugfs_init(void)
1187 {
1188         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1189                                  NULL, &virq_debug_fops) == NULL)
1190                 return -ENOMEM;
1191
1192         return 0;
1193 }
1194 __initcall(irq_debugfs_init);
1195 #endif /* CONFIG_VIRQ_DEBUG */
1196
1197 #ifdef CONFIG_PPC64
1198 static int __init setup_noirqdistrib(char *str)
1199 {
1200         distribute_irqs = 0;
1201         return 1;
1202 }
1203
1204 __setup("noirqdistrib", setup_noirqdistrib);
1205 #endif /* CONFIG_PPC64 */