arch/powerpc/kernel/irq.c

   1 /*
   2  *  Derived from arch/i386/kernel/irq.c
   3  *    Copyright (C) 1992 Linus Torvalds
   4  *  Adapted from arch/i386 by Gary Thomas
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
   7  *    Copyright (C) 1996-2001 Cort Dougan
   8  *  Adapted for Power Macintosh by Paul Mackerras
   9  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version
  14  * 2 of the License, or (at your option) any later version.
  15  *
  16  * This file contains the code used by various IRQ handling routines:
  17  * asking for different IRQ's should be done through these routines
  18  * instead of just grabbing them. Thus setups with different IRQ numbers
  19  * shouldn't result in any weird surprises, and installing new handlers
  20  * should be easier.
  21  *
  22  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
  23  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
  24  * mask register (of which only 16 are defined), hence the weird shifting
  25  * and complement of the cached_irq_mask.  I want to be able to stuff
  26  * this right into the SIU SMASK register.
  27  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
  28  * to reduce code space and undefined function references.
  29  */
  30
  31 #undef DEBUG
  32
  33 #include <linux/module.h>
  34 #include <linux/threads.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/signal.h>
  37 #include <linux/sched.h>
  38 #include <linux/ptrace.h>
  39 #include <linux/ioport.h>
  40 #include <linux/interrupt.h>
  41 #include <linux/timex.h>
  42 #include <linux/init.h>
  43 #include <linux/slab.h>
  44 #include <linux/delay.h>
  45 #include <linux/irq.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/cpumask.h>
  48 #include <linux/profile.h>
  49 #include <linux/bitops.h>
  50 #include <linux/list.h>
  51 #include <linux/radix-tree.h>
  52 #include <linux/mutex.h>
  53 #include <linux/bootmem.h>
  54 #include <linux/pci.h>
  55 #include <linux/debugfs.h>
  56 #include <linux/perf_event.h>
  57
  58 #include <asm/uaccess.h>
  59 #include <asm/system.h>
  60 #include <asm/io.h>
  61 #include <asm/pgtable.h>
  62 #include <asm/irq.h>
  63 #include <asm/cache.h>
  64 #include <asm/prom.h>
  65 #include <asm/ptrace.h>
  66 #include <asm/machdep.h>
  67 #include <asm/udbg.h>
  68 #ifdef CONFIG_PPC64
  69 #include <asm/paca.h>
  70 #include <asm/firmware.h>
  71 #include <asm/lv1call.h>
  72 #endif
  73 #define CREATE_TRACE_POINTS
  74 #include <asm/trace.h>
  75
  76 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
  77 EXPORT_PER_CPU_SYMBOL(irq_stat);
  78
  79 int __irq_offset_value;
  80
  81 #ifdef CONFIG_PPC32
  82 EXPORT_SYMBOL(__irq_offset_value);
  83 atomic_t ppc_n_lost_interrupts;
  84
  85 #ifdef CONFIG_TAU_INT
  86 extern int tau_initialized;
  87 extern int tau_interrupts(int);
  88 #endif
  89 #endif /* CONFIG_PPC32 */
  90
  91 #ifdef CONFIG_PPC64
  92
  93 #ifndef CONFIG_SPARSE_IRQ
  94 EXPORT_SYMBOL(irq_desc);
  95 #endif
  96
  97 int distribute_irqs = 1;
  98
  99 static inline notrace unsigned long get_hard_enabled(void)
 100 {
 101         unsigned long enabled;
 102
 103         __asm__ __volatile__("lbz %0,%1(13)"
 104         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 105
 106         return enabled;
 107 }
 108
 109 static inline notrace void set_soft_enabled(unsigned long enable)
 110 {
 111         __asm__ __volatile__("stb %0,%1(13)"
 112         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 113 }
 114
 115 notrace void raw_local_irq_restore(unsigned long en)
 116 {
 117         /*
 118          * get_paca()->soft_enabled = en;
 119          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 120          * That was allowed before, and in such a case we do need to take care
 121          * that gcc will set soft_enabled directly via r13, not choose to use
 122          * an intermediate register, lest we're preempted to a different cpu.
 123          */
 124         set_soft_enabled(en);
 125         if (!en)
 126                 return;
 127
 128 #ifdef CONFIG_PPC_STD_MMU_64
 129         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 130                 /*
 131                  * Do we need to disable preemption here?  Not really: in the
 132                  * unlikely event that we're preempted to a different cpu in
 133                  * between getting r13, loading its lppaca_ptr, and loading
 134                  * its any_int, we might call iseries_handle_interrupts without
 135                  * an interrupt pending on the new cpu, but that's no disaster,
 136                  * is it?  And the business of preempting us off the old cpu
 137                  * would itself involve a local_irq_restore which handles the
 138                  * interrupt to that cpu.
 139                  *
 140                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 141                  * to avoid any preemption checking added into get_paca().
 142                  */
 143                 if (local_paca->lppaca_ptr->int_dword.any_int)
 144                         iseries_handle_interrupts();
 145         }
 146 #endif /* CONFIG_PPC_STD_MMU_64 */
 147
 148         if (test_perf_event_pending()) {
 149                 clear_perf_event_pending();
 150                 perf_event_do_pending();
 151         }
 152
 153         /*
 154          * if (get_paca()->hard_enabled) return;
 155          * But again we need to take care that gcc gets hard_enabled directly
 156          * via r13, not choose to use an intermediate register, lest we're
 157          * preempted to a different cpu in between the two instructions.
 158          */
 159         if (get_hard_enabled())
 160                 return;
 161
 162         /*
 163          * Need to hard-enable interrupts here.  Since currently disabled,
 164          * no need to take further asm precautions against preemption; but
 165          * use local_paca instead of get_paca() to avoid preemption checking.
 166          */
 167         local_paca->hard_enabled = en;
 168         if ((int)mfspr(SPRN_DEC) < 0)
 169                 mtspr(SPRN_DEC, 1);
 170
 171         /*
 172          * Force the delivery of pending soft-disabled interrupts on PS3.
 173          * Any HV call will have this side effect.
 174          */
 175         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 176                 u64 tmp;
 177                 lv1_get_version_info(&tmp);
 178         }
 179
 180         __hard_irq_enable();
 181 }
 182 EXPORT_SYMBOL(raw_local_irq_restore);
 183 #endif /* CONFIG_PPC64 */
 184
 185 static int show_other_interrupts(struct seq_file *p, int prec)
 186 {
 187         int j;
 188
 189 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 190         if (tau_initialized) {
 191                 seq_printf(p, "%*s: ", prec, "TAU");
 192                 for_each_online_cpu(j)
 193                         seq_printf(p, "%10u ", tau_interrupts(j));
 194                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 195         }
 196 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
 197
 198         seq_printf(p, "%*s: ", prec, "LOC");
 199         for_each_online_cpu(j)
 200                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
 201         seq_printf(p, "  Local timer interrupts\n");
 202
 203         seq_printf(p, "%*s: ", prec, "SPU");
 204         for_each_online_cpu(j)
 205                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
 206         seq_printf(p, "  Spurious interrupts\n");
 207
 208         seq_printf(p, "%*s: ", prec, "CNT");
 209         for_each_online_cpu(j)
 210                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
 211         seq_printf(p, "  Performance monitoring interrupts\n");
 212
 213         seq_printf(p, "%*s: ", prec, "MCE");
 214         for_each_online_cpu(j)
 215                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
 216         seq_printf(p, "  Machine check exceptions\n");
 217
 218         return 0;
 219 }
 220
 221 int show_interrupts(struct seq_file *p, void *v)
 222 {
 223         unsigned long flags, any_count = 0;
 224         int i = *(loff_t *) v, j, prec;
 225         struct irqaction *action;
 226         struct irq_desc *desc;
 227
 228         if (i > nr_irqs)
 229                 return 0;
 230
 231         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
 232                 j *= 10;
 233
 234         if (i == nr_irqs)
 235                 return show_other_interrupts(p, prec);
 236
 237         /* print header */
 238         if (i == 0) {
 239                 seq_printf(p, "%*s", prec + 8, "");
 240                 for_each_online_cpu(j)
 241                         seq_printf(p, "CPU%-8d", j);
 242                 seq_putc(p, '\n');
 243         }
 244
 245         desc = irq_to_desc(i);
 246         if (!desc)
 247                 return 0;
 248
 249         raw_spin_lock_irqsave(&desc->lock, flags);
 250         for_each_online_cpu(j)
 251                 any_count |= kstat_irqs_cpu(i, j);
 252         action = desc->action;
 253         if (!action && !any_count)
 254                 goto out;
 255
 256         seq_printf(p, "%*d: ", prec, i);
 257         for_each_online_cpu(j)
 258                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 259
 260         if (desc->chip)
 261                 seq_printf(p, "  %-16s", desc->chip->name);
 262         else
 263                 seq_printf(p, "  %-16s", "None");
 264         seq_printf(p, " %-8s", (desc->status & IRQ_LEVEL) ? "Level" : "Edge");
 265
 266         if (action) {
 267                 seq_printf(p, "     %s", action->name);
 268                 while ((action = action->next) != NULL)
 269                         seq_printf(p, ", %s", action->name);
 270         }
 271
 272         seq_putc(p, '\n');
 273 out:
 274         raw_spin_unlock_irqrestore(&desc->lock, flags);
 275         return 0;
 276 }
 277
 278 /*
 279  * /proc/stat helpers
 280  */
 281 u64 arch_irq_stat_cpu(unsigned int cpu)
 282 {
 283         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
 284
 285         sum += per_cpu(irq_stat, cpu).pmu_irqs;
 286         sum += per_cpu(irq_stat, cpu).mce_exceptions;
 287         sum += per_cpu(irq_stat, cpu).spurious_irqs;
 288
 289         return sum;
 290 }
 291
 292 #ifdef CONFIG_HOTPLUG_CPU
 293 void fixup_irqs(cpumask_t map)
 294 {
 295         struct irq_desc *desc;
 296         unsigned int irq;
 297         static int warned;
 298
 299         for_each_irq(irq) {
 300                 cpumask_t mask;
 301
 302                 desc = irq_to_desc(irq);
 303                 if (desc && desc->status & IRQ_PER_CPU)
 304                         continue;
 305
 306                 cpumask_and(&mask, desc->affinity, &map);
 307                 if (any_online_cpu(mask) == NR_CPUS) {
 308                         printk("Breaking affinity for irq %i\n", irq);
 309                         mask = map;
 310                 }
 311                 if (desc->chip->set_affinity)
 312                         desc->chip->set_affinity(irq, &mask);
 313                 else if (desc->action && !(warned++))
 314                         printk("Cannot set affinity for irq %i\n", irq);
 315         }
 316
 317         local_irq_enable();
 318         mdelay(1);
 319         local_irq_disable();
 320 }
 321 #endif
 322
 323 #ifdef CONFIG_IRQSTACKS
 324 static inline void handle_one_irq(unsigned int irq)
 325 {
 326         struct thread_info *curtp, *irqtp;
 327         unsigned long saved_sp_limit;
 328         struct irq_desc *desc;
 329
 330         /* Switch to the irq stack to handle this */
 331         curtp = current_thread_info();
 332         irqtp = hardirq_ctx[smp_processor_id()];
 333
 334         if (curtp == irqtp) {
 335                 /* We're already on the irq stack, just handle it */
 336                 generic_handle_irq(irq);
 337                 return;
 338         }
 339
 340         desc = irq_to_desc(irq);
 341         saved_sp_limit = current->thread.ksp_limit;
 342
 343         irqtp->task = curtp->task;
 344         irqtp->flags = 0;
 345
 346         /* Copy the softirq bits in preempt_count so that the
 347          * softirq checks work in the hardirq context. */
 348         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 349                                (curtp->preempt_count & SOFTIRQ_MASK);
 350
 351         current->thread.ksp_limit = (unsigned long)irqtp +
 352                 _ALIGN_UP(sizeof(struct thread_info), 16);
 353
 354         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 355         current->thread.ksp_limit = saved_sp_limit;
 356         irqtp->task = NULL;
 357
 358         /* Set any flag that may have been set on the
 359          * alternate stack
 360          */
 361         if (irqtp->flags)
 362                 set_bits(irqtp->flags, &curtp->flags);
 363 }
 364 #else
 365 static inline void handle_one_irq(unsigned int irq)
 366 {
 367         generic_handle_irq(irq);
 368 }
 369 #endif
 370
 371 static inline void check_stack_overflow(void)
 372 {
 373 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 374         long sp;
 375
 376         sp = __get_SP() & (THREAD_SIZE-1);
 377
 378         /* check for stack overflow: is there less than 2KB free? */
 379         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 380                 printk("do_IRQ: stack overflow: %ld\n",
 381                         sp - sizeof(struct thread_info));
 382                 dump_stack();
 383         }
 384 #endif
 385 }
 386
 387 void do_IRQ(struct pt_regs *regs)
 388 {
 389         struct pt_regs *old_regs = set_irq_regs(regs);
 390         unsigned int irq;
 391
 392         trace_irq_entry(regs);
 393
 394         irq_enter();
 395
 396         check_stack_overflow();
 397
 398         irq = ppc_md.get_irq();
 399
 400         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 401                 handle_one_irq(irq);
 402         else if (irq != NO_IRQ_IGNORE)
 403                 __get_cpu_var(irq_stat).spurious_irqs++;
 404
 405         irq_exit();
 406         set_irq_regs(old_regs);
 407
 408 #ifdef CONFIG_PPC_ISERIES
 409         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 410                         get_lppaca()->int_dword.fields.decr_int) {
 411                 get_lppaca()->int_dword.fields.decr_int = 0;
 412                 /* Signal a fake decrementer interrupt */
 413                 timer_interrupt(regs);
 414         }
 415 #endif
 416
 417         trace_irq_exit(regs);
 418 }
 419
 420 void __init init_IRQ(void)
 421 {
 422         if (ppc_md.init_IRQ)
 423                 ppc_md.init_IRQ();
 424
 425         exc_lvl_ctx_init();
 426
 427         irq_ctx_init();
 428 }
 429
 430 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 431 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 432 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 433 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 434
 435 void exc_lvl_ctx_init(void)
 436 {
 437         struct thread_info *tp;
 438         int i;
 439
 440         for_each_possible_cpu(i) {
 441                 memset((void *)critirq_ctx[i], 0, THREAD_SIZE);
 442                 tp = critirq_ctx[i];
 443                 tp->cpu = i;
 444                 tp->preempt_count = 0;
 445
 446 #ifdef CONFIG_BOOKE
 447                 memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE);
 448                 tp = dbgirq_ctx[i];
 449                 tp->cpu = i;
 450                 tp->preempt_count = 0;
 451
 452                 memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE);
 453                 tp = mcheckirq_ctx[i];
 454                 tp->cpu = i;
 455                 tp->preempt_count = HARDIRQ_OFFSET;
 456 #endif
 457         }
 458 }
 459 #endif
 460
 461 #ifdef CONFIG_IRQSTACKS
 462 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 463 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 464
 465 void irq_ctx_init(void)
 466 {
 467         struct thread_info *tp;
 468         int i;
 469
 470         for_each_possible_cpu(i) {
 471                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 472                 tp = softirq_ctx[i];
 473                 tp->cpu = i;
 474                 tp->preempt_count = 0;
 475
 476                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 477                 tp = hardirq_ctx[i];
 478                 tp->cpu = i;
 479                 tp->preempt_count = HARDIRQ_OFFSET;
 480         }
 481 }
 482
 483 static inline void do_softirq_onstack(void)
 484 {
 485         struct thread_info *curtp, *irqtp;
 486         unsigned long saved_sp_limit = current->thread.ksp_limit;
 487
 488         curtp = current_thread_info();
 489         irqtp = softirq_ctx[smp_processor_id()];
 490         irqtp->task = curtp->task;
 491         current->thread.ksp_limit = (unsigned long)irqtp +
 492                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 493         call_do_softirq(irqtp);
 494         current->thread.ksp_limit = saved_sp_limit;
 495         irqtp->task = NULL;
 496 }
 497
 498 #else
 499 #define do_softirq_onstack()    __do_softirq()
 500 #endif /* CONFIG_IRQSTACKS */
 501
 502 void do_softirq(void)
 503 {
 504         unsigned long flags;
 505
 506         if (in_interrupt())
 507                 return;
 508
 509         local_irq_save(flags);
 510
 511         if (local_softirq_pending())
 512                 do_softirq_onstack();
 513
 514         local_irq_restore(flags);
 515 }
 516
 517
 518 /*
 519  * IRQ controller and virtual interrupts
 520  */
 521
 522 static LIST_HEAD(irq_hosts);
 523 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 524 static unsigned int revmap_trees_allocated;
 525 static DEFINE_MUTEX(revmap_trees_mutex);
 526 struct irq_map_entry irq_map[NR_IRQS];
 527 static unsigned int irq_virq_count = NR_IRQS;
 528 static struct irq_host *irq_default_host;
 529
 530 irq_hw_number_t virq_to_hw(unsigned int virq)
 531 {
 532         return irq_map[virq].hwirq;
 533 }
 534 EXPORT_SYMBOL_GPL(virq_to_hw);
 535
 536 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 537 {
 538         return h->of_node != NULL && h->of_node == np;
 539 }
 540
 541 struct irq_host *irq_alloc_host(struct device_node *of_node,
 542                                 unsigned int revmap_type,
 543                                 unsigned int revmap_arg,
 544                                 struct irq_host_ops *ops,
 545                                 irq_hw_number_t inval_irq)
 546 {
 547         struct irq_host *host;
 548         unsigned int size = sizeof(struct irq_host);
 549         unsigned int i;
 550         unsigned int *rmap;
 551         unsigned long flags;
 552
 553         /* Allocate structure and revmap table if using linear mapping */
 554         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 555                 size += revmap_arg * sizeof(unsigned int);
 556         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 557         if (host == NULL)
 558                 return NULL;
 559
 560         /* Fill structure */
 561         host->revmap_type = revmap_type;
 562         host->inval_irq = inval_irq;
 563         host->ops = ops;
 564         host->of_node = of_node_get(of_node);
 565
 566         if (host->ops->match == NULL)
 567                 host->ops->match = default_irq_host_match;
 568
 569         raw_spin_lock_irqsave(&irq_big_lock, flags);
 570
 571         /* If it's a legacy controller, check for duplicates and
 572          * mark it as allocated (we use irq 0 host pointer for that
 573          */
 574         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 575                 if (irq_map[0].host != NULL) {
 576                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 577                         /* If we are early boot, we can't free the structure,
 578                          * too bad...
 579                          * this will be fixed once slab is made available early
 580                          * instead of the current cruft
 581                          */
 582                         if (mem_init_done)
 583                                 kfree(host);
 584                         return NULL;
 585                 }
 586                 irq_map[0].host = host;
 587         }
 588
 589         list_add(&host->link, &irq_hosts);
 590         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 591
 592         /* Additional setups per revmap type */
 593         switch(revmap_type) {
 594         case IRQ_HOST_MAP_LEGACY:
 595                 /* 0 is always the invalid number for legacy */
 596                 host->inval_irq = 0;
 597                 /* setup us as the host for all legacy interrupts */
 598                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 599                         irq_map[i].hwirq = i;
 600                         smp_wmb();
 601                         irq_map[i].host = host;
 602                         smp_wmb();
 603
 604                         /* Clear norequest flags */
 605                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
 606
 607                         /* Legacy flags are left to default at this point,
 608                          * one can then use irq_create_mapping() to
 609                          * explicitly change them
 610                          */
 611                         ops->map(host, i, i);
 612                 }
 613                 break;
 614         case IRQ_HOST_MAP_LINEAR:
 615                 rmap = (unsigned int *)(host + 1);
 616                 for (i = 0; i < revmap_arg; i++)
 617                         rmap[i] = NO_IRQ;
 618                 host->revmap_data.linear.size = revmap_arg;
 619                 smp_wmb();
 620                 host->revmap_data.linear.revmap = rmap;
 621                 break;
 622         default:
 623                 break;
 624         }
 625
 626         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 627
 628         return host;
 629 }
 630
 631 struct irq_host *irq_find_host(struct device_node *node)
 632 {
 633         struct irq_host *h, *found = NULL;
 634         unsigned long flags;
 635
 636         /* We might want to match the legacy controller last since
 637          * it might potentially be set to match all interrupts in
 638          * the absence of a device node. This isn't a problem so far
 639          * yet though...
 640          */
 641         raw_spin_lock_irqsave(&irq_big_lock, flags);
 642         list_for_each_entry(h, &irq_hosts, link)
 643                 if (h->ops->match(h, node)) {
 644                         found = h;
 645                         break;
 646                 }
 647         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 648         return found;
 649 }
 650 EXPORT_SYMBOL_GPL(irq_find_host);
 651
 652 void irq_set_default_host(struct irq_host *host)
 653 {
 654         pr_debug("irq: Default host set to @0x%p\n", host);
 655
 656         irq_default_host = host;
 657 }
 658
 659 void irq_set_virq_count(unsigned int count)
 660 {
 661         pr_debug("irq: Trying to set virq count to %d\n", count);
 662
 663         BUG_ON(count < NUM_ISA_INTERRUPTS);
 664         if (count < NR_IRQS)
 665                 irq_virq_count = count;
 666 }
 667
 668 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 669                             irq_hw_number_t hwirq)
 670 {
 671         struct irq_desc *desc;
 672
 673         desc = irq_to_desc_alloc_node(virq, 0);
 674         if (!desc) {
 675                 pr_debug("irq: -> allocating desc failed\n");
 676                 goto error;
 677         }
 678
 679         /* Clear IRQ_NOREQUEST flag */
 680         desc->status &= ~IRQ_NOREQUEST;
 681
 682         /* map it */
 683         smp_wmb();
 684         irq_map[virq].hwirq = hwirq;
 685         smp_mb();
 686
 687         if (host->ops->map(host, virq, hwirq)) {
 688                 pr_debug("irq: -> mapping failed, freeing\n");
 689                 goto error;
 690         }
 691
 692         return 0;
 693
 694 error:
 695         irq_free_virt(virq, 1);
 696         return -1;
 697 }
 698
 699 unsigned int irq_create_direct_mapping(struct irq_host *host)
 700 {
 701         unsigned int virq;
 702
 703         if (host == NULL)
 704                 host = irq_default_host;
 705
 706         BUG_ON(host == NULL);
 707         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 708
 709         virq = irq_alloc_virt(host, 1, 0);
 710         if (virq == NO_IRQ) {
 711                 pr_debug("irq: create_direct virq allocation failed\n");
 712                 return NO_IRQ;
 713         }
 714
 715         pr_debug("irq: create_direct obtained virq %d\n", virq);
 716
 717         if (irq_setup_virq(host, virq, virq))
 718                 return NO_IRQ;
 719
 720         return virq;
 721 }
 722
 723 unsigned int irq_create_mapping(struct irq_host *host,
 724                                 irq_hw_number_t hwirq)
 725 {
 726         unsigned int virq, hint;
 727
 728         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 729
 730         /* Look for default host if nececssary */
 731         if (host == NULL)
 732                 host = irq_default_host;
 733         if (host == NULL) {
 734                 printk(KERN_WARNING "irq_create_mapping called for"
 735                        " NULL host, hwirq=%lx\n", hwirq);
 736                 WARN_ON(1);
 737                 return NO_IRQ;
 738         }
 739         pr_debug("irq: -> using host @%p\n", host);
 740
 741         /* Check if mapping already exist, if it does, call
 742          * host->ops->map() to update the flags
 743          */
 744         virq = irq_find_mapping(host, hwirq);
 745         if (virq != NO_IRQ) {
 746                 if (host->ops->remap)
 747                         host->ops->remap(host, virq, hwirq);
 748                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 749                 return virq;
 750         }
 751
 752         /* Get a virtual interrupt number */
 753         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 754                 /* Handle legacy */
 755                 virq = (unsigned int)hwirq;
 756                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 757                         return NO_IRQ;
 758                 return virq;
 759         } else {
 760                 /* Allocate a virtual interrupt number */
 761                 hint = hwirq % irq_virq_count;
 762                 virq = irq_alloc_virt(host, 1, hint);
 763                 if (virq == NO_IRQ) {
 764                         pr_debug("irq: -> virq allocation failed\n");
 765                         return NO_IRQ;
 766                 }
 767         }
 768
 769         if (irq_setup_virq(host, virq, hwirq))
 770                 return NO_IRQ;
 771
 772         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 773                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 774
 775         return virq;
 776 }
 777 EXPORT_SYMBOL_GPL(irq_create_mapping);
 778
 779 unsigned int irq_create_of_mapping(struct device_node *controller,
 780                                    const u32 *intspec, unsigned int intsize)
 781 {
 782         struct irq_host *host;
 783         irq_hw_number_t hwirq;
 784         unsigned int type = IRQ_TYPE_NONE;
 785         unsigned int virq;
 786
 787         if (controller == NULL)
 788                 host = irq_default_host;
 789         else
 790                 host = irq_find_host(controller);
 791         if (host == NULL) {
 792                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 793                        controller->full_name);
 794                 return NO_IRQ;
 795         }
 796
 797         /* If host has no translation, then we assume interrupt line */
 798         if (host->ops->xlate == NULL)
 799                 hwirq = intspec[0];
 800         else {
 801                 if (host->ops->xlate(host, controller, intspec, intsize,
 802                                      &hwirq, &type))
 803                         return NO_IRQ;
 804         }
 805
 806         /* Create mapping */
 807         virq = irq_create_mapping(host, hwirq);
 808         if (virq == NO_IRQ)
 809                 return virq;
 810
 811         /* Set type if specified and different than the current one */
 812         if (type != IRQ_TYPE_NONE &&
 813             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
 814                 set_irq_type(virq, type);
 815         return virq;
 816 }
 817 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 818
 819 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 820 {
 821         struct of_irq oirq;
 822
 823         if (of_irq_map_one(dev, index, &oirq))
 824                 return NO_IRQ;
 825
 826         return irq_create_of_mapping(oirq.controller, oirq.specifier,
 827                                      oirq.size);
 828 }
 829 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 830
 831 void irq_dispose_mapping(unsigned int virq)
 832 {
 833         struct irq_host *host;
 834         irq_hw_number_t hwirq;
 835
 836         if (virq == NO_IRQ)
 837                 return;
 838
 839         host = irq_map[virq].host;
 840         WARN_ON (host == NULL);
 841         if (host == NULL)
 842                 return;
 843
 844         /* Never unmap legacy interrupts */
 845         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 846                 return;
 847
 848         /* remove chip and handler */
 849         set_irq_chip_and_handler(virq, NULL, NULL);
 850
 851         /* Make sure it's completed */
 852         synchronize_irq(virq);
 853
 854         /* Tell the PIC about it */
 855         if (host->ops->unmap)
 856                 host->ops->unmap(host, virq);
 857         smp_mb();
 858
 859         /* Clear reverse map */
 860         hwirq = irq_map[virq].hwirq;
 861         switch(host->revmap_type) {
 862         case IRQ_HOST_MAP_LINEAR:
 863                 if (hwirq < host->revmap_data.linear.size)
 864                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 865                 break;
 866         case IRQ_HOST_MAP_TREE:
 867                 /*
 868                  * Check if radix tree allocated yet, if not then nothing to
 869                  * remove.
 870                  */
 871                 smp_rmb();
 872                 if (revmap_trees_allocated < 1)
 873                         break;
 874                 mutex_lock(&revmap_trees_mutex);
 875                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 876                 mutex_unlock(&revmap_trees_mutex);
 877                 break;
 878         }
 879
 880         /* Destroy map */
 881         smp_mb();
 882         irq_map[virq].hwirq = host->inval_irq;
 883
 884         /* Set some flags */
 885         irq_to_desc(virq)->status |= IRQ_NOREQUEST;
 886
 887         /* Free it */
 888         irq_free_virt(virq, 1);
 889 }
 890 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 891
 892 unsigned int irq_find_mapping(struct irq_host *host,
 893                               irq_hw_number_t hwirq)
 894 {
 895         unsigned int i;
 896         unsigned int hint = hwirq % irq_virq_count;
 897
 898         /* Look for default host if nececssary */
 899         if (host == NULL)
 900                 host = irq_default_host;
 901         if (host == NULL)
 902                 return NO_IRQ;
 903
 904         /* legacy -> bail early */
 905         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 906                 return hwirq;
 907
 908         /* Slow path does a linear search of the map */
 909         if (hint < NUM_ISA_INTERRUPTS)
 910                 hint = NUM_ISA_INTERRUPTS;
 911         i = hint;
 912         do  {
 913                 if (irq_map[i].host == host &&
 914                     irq_map[i].hwirq == hwirq)
 915                         return i;
 916                 i++;
 917                 if (i >= irq_virq_count)
 918                         i = NUM_ISA_INTERRUPTS;
 919         } while(i != hint);
 920         return NO_IRQ;
 921 }
 922 EXPORT_SYMBOL_GPL(irq_find_mapping);
 923
 924
 925 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 926                                      irq_hw_number_t hwirq)
 927 {
 928         struct irq_map_entry *ptr;
 929         unsigned int virq;
 930
 931         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 932
 933         /*
 934          * Check if the radix tree exists and has bee initialized.
 935          * If not, we fallback to slow mode
 936          */
 937         if (revmap_trees_allocated < 2)
 938                 return irq_find_mapping(host, hwirq);
 939
 940         /* Now try to resolve */
 941         /*
 942          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 943          * as it's referencing an entry in the static irq_map table.
 944          */
 945         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 946
 947         /*
 948          * If found in radix tree, then fine.
 949          * Else fallback to linear lookup - this should not happen in practice
 950          * as it means that we failed to insert the node in the radix tree.
 951          */
 952         if (ptr)
 953                 virq = ptr - irq_map;
 954         else
 955                 virq = irq_find_mapping(host, hwirq);
 956
 957         return virq;
 958 }
 959
 960 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 961                              irq_hw_number_t hwirq)
 962 {
 963
 964         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 965
 966         /*
 967          * Check if the radix tree exists yet.
 968          * If not, then the irq will be inserted into the tree when it gets
 969          * initialized.
 970          */
 971         smp_rmb();
 972         if (revmap_trees_allocated < 1)
 973                 return;
 974
 975         if (virq != NO_IRQ) {
 976                 mutex_lock(&revmap_trees_mutex);
 977                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 978                                   &irq_map[virq]);
 979                 mutex_unlock(&revmap_trees_mutex);
 980         }
 981 }
 982
 983 unsigned int irq_linear_revmap(struct irq_host *host,
 984                                irq_hw_number_t hwirq)
 985 {
 986         unsigned int *revmap;
 987
 988         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 989
 990         /* Check revmap bounds */
 991         if (unlikely(hwirq >= host->revmap_data.linear.size))
 992                 return irq_find_mapping(host, hwirq);
 993
 994         /* Check if revmap was allocated */
 995         revmap = host->revmap_data.linear.revmap;
 996         if (unlikely(revmap == NULL))
 997                 return irq_find_mapping(host, hwirq);
 998
 999         /* Fill up revmap with slow path if no mapping found */
1000         if (unlikely(revmap[hwirq] == NO_IRQ))
1001                 revmap[hwirq] = irq_find_mapping(host, hwirq);
1002
1003         return revmap[hwirq];
1004 }
1005
1006 unsigned int irq_alloc_virt(struct irq_host *host,
1007                             unsigned int count,
1008                             unsigned int hint)
1009 {
1010         unsigned long flags;
1011         unsigned int i, j, found = NO_IRQ;
1012
1013         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
1014                 return NO_IRQ;
1015
1016         raw_spin_lock_irqsave(&irq_big_lock, flags);
1017
1018         /* Use hint for 1 interrupt if any */
1019         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
1020             hint < irq_virq_count && irq_map[hint].host == NULL) {
1021                 found = hint;
1022                 goto hint_found;
1023         }
1024
1025         /* Look for count consecutive numbers in the allocatable
1026          * (non-legacy) space
1027          */
1028         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1029                 if (irq_map[i].host != NULL)
1030                         j = 0;
1031                 else
1032                         j++;
1033
1034                 if (j == count) {
1035                         found = i - count + 1;
1036                         break;
1037                 }
1038         }
1039         if (found == NO_IRQ) {
1040                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1041                 return NO_IRQ;
1042         }
1043  hint_found:
1044         for (i = found; i < (found + count); i++) {
1045                 irq_map[i].hwirq = host->inval_irq;
1046                 smp_wmb();
1047                 irq_map[i].host = host;
1048         }
1049         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1050         return found;
1051 }
1052
1053 void irq_free_virt(unsigned int virq, unsigned int count)
1054 {
1055         unsigned long flags;
1056         unsigned int i;
1057
1058         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1059         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1060
1061         raw_spin_lock_irqsave(&irq_big_lock, flags);
1062         for (i = virq; i < (virq + count); i++) {
1063                 struct irq_host *host;
1064
1065                 if (i < NUM_ISA_INTERRUPTS ||
1066                     (virq + count) > irq_virq_count)
1067                         continue;
1068
1069                 host = irq_map[i].host;
1070                 irq_map[i].hwirq = host->inval_irq;
1071                 smp_wmb();
1072                 irq_map[i].host = NULL;
1073         }
1074         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1075 }
1076
1077 int arch_early_irq_init(void)
1078 {
1079         struct irq_desc *desc;
1080         int i;
1081
1082         for (i = 0; i < NR_IRQS; i++) {
1083                 desc = irq_to_desc(i);
1084                 if (desc)
1085                         desc->status |= IRQ_NOREQUEST;
1086         }
1087
1088         return 0;
1089 }
1090
1091 int arch_init_chip_data(struct irq_desc *desc, int node)
1092 {
1093         desc->status |= IRQ_NOREQUEST;
1094         return 0;
1095 }
1096
1097 /* We need to create the radix trees late */
1098 static int irq_late_init(void)
1099 {
1100         struct irq_host *h;
1101         unsigned int i;
1102
1103         /*
1104          * No mutual exclusion with respect to accessors of the tree is needed
1105          * here as the synchronization is done via the state variable
1106          * revmap_trees_allocated.
1107          */
1108         list_for_each_entry(h, &irq_hosts, link) {
1109                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1110                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1111         }
1112
1113         /*
1114          * Make sure the radix trees inits are visible before setting
1115          * the flag
1116          */
1117         smp_wmb();
1118         revmap_trees_allocated = 1;
1119
1120         /*
1121          * Insert the reverse mapping for those interrupts already present
1122          * in irq_map[].
1123          */
1124         mutex_lock(&revmap_trees_mutex);
1125         for (i = 0; i < irq_virq_count; i++) {
1126                 if (irq_map[i].host &&
1127                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1128                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1129                                           irq_map[i].hwirq, &irq_map[i]);
1130         }
1131         mutex_unlock(&revmap_trees_mutex);
1132
1133         /*
1134          * Make sure the radix trees insertions are visible before setting
1135          * the flag
1136          */
1137         smp_wmb();
1138         revmap_trees_allocated = 2;
1139
1140         return 0;
1141 }
1142 arch_initcall(irq_late_init);
1143
1144 #ifdef CONFIG_VIRQ_DEBUG
1145 static int virq_debug_show(struct seq_file *m, void *private)
1146 {
1147         unsigned long flags;
1148         struct irq_desc *desc;
1149         const char *p;
1150         char none[] = "none";
1151         int i;
1152
1153         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1154                       "chip name", "host name");
1155
1156         for (i = 1; i < nr_irqs; i++) {
1157                 desc = irq_to_desc(i);
1158                 if (!desc)
1159                         continue;
1160
1161                 raw_spin_lock_irqsave(&desc->lock, flags);
1162
1163                 if (desc->action && desc->action->handler) {
1164                         seq_printf(m, "%5d  ", i);
1165                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1166
1167                         if (desc->chip && desc->chip->name)
1168                                 p = desc->chip->name;
1169                         else
1170                                 p = none;
1171                         seq_printf(m, "%-15s  ", p);
1172
1173                         if (irq_map[i].host && irq_map[i].host->of_node)
1174                                 p = irq_map[i].host->of_node->full_name;
1175                         else
1176                                 p = none;
1177                         seq_printf(m, "%s\n", p);
1178                 }
1179
1180                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1181         }
1182
1183         return 0;
1184 }
1185
1186 static int virq_debug_open(struct inode *inode, struct file *file)
1187 {
1188         return single_open(file, virq_debug_show, inode->i_private);
1189 }
1190
1191 static const struct file_operations virq_debug_fops = {
1192         .open = virq_debug_open,
1193         .read = seq_read,
1194         .llseek = seq_lseek,
1195         .release = single_release,
1196 };
1197
1198 static int __init irq_debugfs_init(void)
1199 {
1200         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1201                                  NULL, &virq_debug_fops) == NULL)
1202                 return -ENOMEM;
1203
1204         return 0;
1205 }
1206 __initcall(irq_debugfs_init);
1207 #endif /* CONFIG_VIRQ_DEBUG */
1208
1209 #ifdef CONFIG_PPC64
1210 static int __init setup_noirqdistrib(char *str)
1211 {
1212         distribute_irqs = 0;
1213         return 1;
1214 }
1215
1216 __setup("noirqdistrib", setup_noirqdistrib);
1217 #endif /* CONFIG_PPC64 */