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