arch/powerpc/kernel/irq.c

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