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/export.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/smp.h>
  70
  71 #ifdef CONFIG_PPC64
  72 #include <asm/paca.h>
  73 #include <asm/firmware.h>
  74 #include <asm/lv1call.h>
  75 #endif
  76 #define CREATE_TRACE_POINTS
  77 #include <asm/trace.h>
  78
  79 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
  80 EXPORT_PER_CPU_SYMBOL(irq_stat);
  81
  82 int __irq_offset_value;
  83
  84 #ifdef CONFIG_PPC32
  85 EXPORT_SYMBOL(__irq_offset_value);
  86 atomic_t ppc_n_lost_interrupts;
  87
  88 #ifdef CONFIG_TAU_INT
  89 extern int tau_initialized;
  90 extern int tau_interrupts(int);
  91 #endif
  92 #endif /* CONFIG_PPC32 */
  93
  94 #ifdef CONFIG_PPC64
  95
  96 #ifndef CONFIG_SPARSE_IRQ
  97 EXPORT_SYMBOL(irq_desc);
  98 #endif
  99
 100 int distribute_irqs = 1;
 101
 102 static inline notrace unsigned long get_hard_enabled(void)
 103 {
 104         unsigned long enabled;
 105
 106         __asm__ __volatile__("lbz %0,%1(13)"
 107         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 108
 109         return enabled;
 110 }
 111
 112 static inline notrace void set_soft_enabled(unsigned long enable)
 113 {
 114         __asm__ __volatile__("stb %0,%1(13)"
 115         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 116 }
 117
 118 static inline notrace void decrementer_check_overflow(void)
 119 {
 120         u64 now = get_tb_or_rtc();
 121         u64 *next_tb;
 122
 123         preempt_disable();
 124         next_tb = &__get_cpu_var(decrementers_next_tb);
 125
 126         if (now >= *next_tb)
 127                 set_dec(1);
 128         preempt_enable();
 129 }
 130
 131 notrace void arch_local_irq_restore(unsigned long en)
 132 {
 133         /*
 134          * get_paca()->soft_enabled = en;
 135          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 136          * That was allowed before, and in such a case we do need to take care
 137          * that gcc will set soft_enabled directly via r13, not choose to use
 138          * an intermediate register, lest we're preempted to a different cpu.
 139          */
 140         set_soft_enabled(en);
 141         if (!en)
 142                 return;
 143
 144 #ifdef CONFIG_PPC_STD_MMU_64
 145         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 146                 /*
 147                  * Do we need to disable preemption here?  Not really: in the
 148                  * unlikely event that we're preempted to a different cpu in
 149                  * between getting r13, loading its lppaca_ptr, and loading
 150                  * its any_int, we might call iseries_handle_interrupts without
 151                  * an interrupt pending on the new cpu, but that's no disaster,
 152                  * is it?  And the business of preempting us off the old cpu
 153                  * would itself involve a local_irq_restore which handles the
 154                  * interrupt to that cpu.
 155                  *
 156                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 157                  * to avoid any preemption checking added into get_paca().
 158                  */
 159                 if (local_paca->lppaca_ptr->int_dword.any_int)
 160                         iseries_handle_interrupts();
 161         }
 162 #endif /* CONFIG_PPC_STD_MMU_64 */
 163
 164         /*
 165          * if (get_paca()->hard_enabled) return;
 166          * But again we need to take care that gcc gets hard_enabled directly
 167          * via r13, not choose to use an intermediate register, lest we're
 168          * preempted to a different cpu in between the two instructions.
 169          */
 170         if (get_hard_enabled())
 171                 return;
 172
 173         /*
 174          * Need to hard-enable interrupts here.  Since currently disabled,
 175          * no need to take further asm precautions against preemption; but
 176          * use local_paca instead of get_paca() to avoid preemption checking.
 177          */
 178         local_paca->hard_enabled = en;
 179
 180         /*
 181          * Trigger the decrementer if we have a pending event. Some processors
 182          * only trigger on edge transitions of the sign bit. We might also
 183          * have disabled interrupts long enough that the decrementer wrapped
 184          * to positive.
 185          */
 186         decrementer_check_overflow();
 187
 188         /*
 189          * Force the delivery of pending soft-disabled interrupts on PS3.
 190          * Any HV call will have this side effect.
 191          */
 192         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 193                 u64 tmp, tmp2;
 194                 lv1_get_version_info(&tmp, &tmp2);
 195         }
 196
 197         __hard_irq_enable();
 198 }
 199 EXPORT_SYMBOL(arch_local_irq_restore);
 200 #endif /* CONFIG_PPC64 */
 201
 202 int arch_show_interrupts(struct seq_file *p, int prec)
 203 {
 204         int j;
 205
 206 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 207         if (tau_initialized) {
 208                 seq_printf(p, "%*s: ", prec, "TAU");
 209                 for_each_online_cpu(j)
 210                         seq_printf(p, "%10u ", tau_interrupts(j));
 211                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 212         }
 213 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
 214
 215         seq_printf(p, "%*s: ", prec, "LOC");
 216         for_each_online_cpu(j)
 217                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
 218         seq_printf(p, "  Local timer interrupts\n");
 219
 220         seq_printf(p, "%*s: ", prec, "SPU");
 221         for_each_online_cpu(j)
 222                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
 223         seq_printf(p, "  Spurious interrupts\n");
 224
 225         seq_printf(p, "%*s: ", prec, "CNT");
 226         for_each_online_cpu(j)
 227                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
 228         seq_printf(p, "  Performance monitoring interrupts\n");
 229
 230         seq_printf(p, "%*s: ", prec, "MCE");
 231         for_each_online_cpu(j)
 232                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
 233         seq_printf(p, "  Machine check exceptions\n");
 234
 235         return 0;
 236 }
 237
 238 /*
 239  * /proc/stat helpers
 240  */
 241 u64 arch_irq_stat_cpu(unsigned int cpu)
 242 {
 243         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
 244
 245         sum += per_cpu(irq_stat, cpu).pmu_irqs;
 246         sum += per_cpu(irq_stat, cpu).mce_exceptions;
 247         sum += per_cpu(irq_stat, cpu).spurious_irqs;
 248
 249         return sum;
 250 }
 251
 252 #ifdef CONFIG_HOTPLUG_CPU
 253 void migrate_irqs(void)
 254 {
 255         struct irq_desc *desc;
 256         unsigned int irq;
 257         static int warned;
 258         cpumask_var_t mask;
 259         const struct cpumask *map = cpu_online_mask;
 260
 261         alloc_cpumask_var(&mask, GFP_KERNEL);
 262
 263         for_each_irq(irq) {
 264                 struct irq_data *data;
 265                 struct irq_chip *chip;
 266
 267                 desc = irq_to_desc(irq);
 268                 if (!desc)
 269                         continue;
 270
 271                 data = irq_desc_get_irq_data(desc);
 272                 if (irqd_is_per_cpu(data))
 273                         continue;
 274
 275                 chip = irq_data_get_irq_chip(data);
 276
 277                 cpumask_and(mask, data->affinity, map);
 278                 if (cpumask_any(mask) >= nr_cpu_ids) {
 279                         printk("Breaking affinity for irq %i\n", irq);
 280                         cpumask_copy(mask, map);
 281                 }
 282                 if (chip->irq_set_affinity)
 283                         chip->irq_set_affinity(data, mask, true);
 284                 else if (desc->action && !(warned++))
 285                         printk("Cannot set affinity for irq %i\n", irq);
 286         }
 287
 288         free_cpumask_var(mask);
 289
 290         local_irq_enable();
 291         mdelay(1);
 292         local_irq_disable();
 293 }
 294 #endif
 295
 296 static inline void handle_one_irq(unsigned int irq)
 297 {
 298         struct thread_info *curtp, *irqtp;
 299         unsigned long saved_sp_limit;
 300         struct irq_desc *desc;
 301
 302         desc = irq_to_desc(irq);
 303         if (!desc)
 304                 return;
 305
 306         /* Switch to the irq stack to handle this */
 307         curtp = current_thread_info();
 308         irqtp = hardirq_ctx[smp_processor_id()];
 309
 310         if (curtp == irqtp) {
 311                 /* We're already on the irq stack, just handle it */
 312                 desc->handle_irq(irq, desc);
 313                 return;
 314         }
 315
 316         saved_sp_limit = current->thread.ksp_limit;
 317
 318         irqtp->task = curtp->task;
 319         irqtp->flags = 0;
 320
 321         /* Copy the softirq bits in preempt_count so that the
 322          * softirq checks work in the hardirq context. */
 323         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 324                                (curtp->preempt_count & SOFTIRQ_MASK);
 325
 326         current->thread.ksp_limit = (unsigned long)irqtp +
 327                 _ALIGN_UP(sizeof(struct thread_info), 16);
 328
 329         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 330         current->thread.ksp_limit = saved_sp_limit;
 331         irqtp->task = NULL;
 332
 333         /* Set any flag that may have been set on the
 334          * alternate stack
 335          */
 336         if (irqtp->flags)
 337                 set_bits(irqtp->flags, &curtp->flags);
 338 }
 339
 340 static inline void check_stack_overflow(void)
 341 {
 342 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 343         long sp;
 344
 345         sp = __get_SP() & (THREAD_SIZE-1);
 346
 347         /* check for stack overflow: is there less than 2KB free? */
 348         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 349                 printk("do_IRQ: stack overflow: %ld\n",
 350                         sp - sizeof(struct thread_info));
 351                 dump_stack();
 352         }
 353 #endif
 354 }
 355
 356 void do_IRQ(struct pt_regs *regs)
 357 {
 358         struct pt_regs *old_regs = set_irq_regs(regs);
 359         unsigned int irq;
 360
 361         trace_irq_entry(regs);
 362
 363         irq_enter();
 364
 365         check_stack_overflow();
 366
 367         irq = ppc_md.get_irq();
 368
 369         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 370                 handle_one_irq(irq);
 371         else if (irq != NO_IRQ_IGNORE)
 372                 __get_cpu_var(irq_stat).spurious_irqs++;
 373
 374         irq_exit();
 375         set_irq_regs(old_regs);
 376
 377 #ifdef CONFIG_PPC_ISERIES
 378         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 379                         get_lppaca()->int_dword.fields.decr_int) {
 380                 get_lppaca()->int_dword.fields.decr_int = 0;
 381                 /* Signal a fake decrementer interrupt */
 382                 timer_interrupt(regs);
 383         }
 384 #endif
 385
 386         trace_irq_exit(regs);
 387 }
 388
 389 void __init init_IRQ(void)
 390 {
 391         if (ppc_md.init_IRQ)
 392                 ppc_md.init_IRQ();
 393
 394         exc_lvl_ctx_init();
 395
 396         irq_ctx_init();
 397 }
 398
 399 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 400 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 401 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 402 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 403
 404 void exc_lvl_ctx_init(void)
 405 {
 406         struct thread_info *tp;
 407         int i, cpu_nr;
 408
 409         for_each_possible_cpu(i) {
 410 #ifdef CONFIG_PPC64
 411                 cpu_nr = i;
 412 #else
 413                 cpu_nr = get_hard_smp_processor_id(i);
 414 #endif
 415                 memset((void *)critirq_ctx[cpu_nr], 0, THREAD_SIZE);
 416                 tp = critirq_ctx[cpu_nr];
 417                 tp->cpu = cpu_nr;
 418                 tp->preempt_count = 0;
 419
 420 #ifdef CONFIG_BOOKE
 421                 memset((void *)dbgirq_ctx[cpu_nr], 0, THREAD_SIZE);
 422                 tp = dbgirq_ctx[cpu_nr];
 423                 tp->cpu = cpu_nr;
 424                 tp->preempt_count = 0;
 425
 426                 memset((void *)mcheckirq_ctx[cpu_nr], 0, THREAD_SIZE);
 427                 tp = mcheckirq_ctx[cpu_nr];
 428                 tp->cpu = cpu_nr;
 429                 tp->preempt_count = HARDIRQ_OFFSET;
 430 #endif
 431         }
 432 }
 433 #endif
 434
 435 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 436 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 437
 438 void irq_ctx_init(void)
 439 {
 440         struct thread_info *tp;
 441         int i;
 442
 443         for_each_possible_cpu(i) {
 444                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 445                 tp = softirq_ctx[i];
 446                 tp->cpu = i;
 447                 tp->preempt_count = 0;
 448
 449                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 450                 tp = hardirq_ctx[i];
 451                 tp->cpu = i;
 452                 tp->preempt_count = HARDIRQ_OFFSET;
 453         }
 454 }
 455
 456 static inline void do_softirq_onstack(void)
 457 {
 458         struct thread_info *curtp, *irqtp;
 459         unsigned long saved_sp_limit = current->thread.ksp_limit;
 460
 461         curtp = current_thread_info();
 462         irqtp = softirq_ctx[smp_processor_id()];
 463         irqtp->task = curtp->task;
 464         irqtp->flags = 0;
 465         current->thread.ksp_limit = (unsigned long)irqtp +
 466                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 467         call_do_softirq(irqtp);
 468         current->thread.ksp_limit = saved_sp_limit;
 469         irqtp->task = NULL;
 470
 471         /* Set any flag that may have been set on the
 472          * alternate stack
 473          */
 474         if (irqtp->flags)
 475                 set_bits(irqtp->flags, &curtp->flags);
 476 }
 477
 478 void do_softirq(void)
 479 {
 480         unsigned long flags;
 481
 482         if (in_interrupt())
 483                 return;
 484
 485         local_irq_save(flags);
 486
 487         if (local_softirq_pending())
 488                 do_softirq_onstack();
 489
 490         local_irq_restore(flags);
 491 }
 492
 493
 494 /*
 495  * IRQ controller and virtual interrupts
 496  */
 497
 498 /* The main irq map itself is an array of NR_IRQ entries containing the
 499  * associate host and irq number. An entry with a host of NULL is free.
 500  * An entry can be allocated if it's free, the allocator always then sets
 501  * hwirq first to the host's invalid irq number and then fills ops.
 502  */
 503 struct irq_map_entry {
 504         irq_hw_number_t hwirq;
 505         struct irq_host *host;
 506 };
 507
 508 static LIST_HEAD(irq_hosts);
 509 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 510 static DEFINE_MUTEX(revmap_trees_mutex);
 511 static struct irq_map_entry irq_map[NR_IRQS];
 512 static unsigned int irq_virq_count = NR_IRQS;
 513 static struct irq_host *irq_default_host;
 514
 515 irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
 516 {
 517         return irq_map[d->irq].hwirq;
 518 }
 519 EXPORT_SYMBOL_GPL(irqd_to_hwirq);
 520
 521 irq_hw_number_t virq_to_hw(unsigned int virq)
 522 {
 523         return irq_map[virq].hwirq;
 524 }
 525 EXPORT_SYMBOL_GPL(virq_to_hw);
 526
 527 bool virq_is_host(unsigned int virq, struct irq_host *host)
 528 {
 529         return irq_map[virq].host == host;
 530 }
 531 EXPORT_SYMBOL_GPL(virq_is_host);
 532
 533 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 534 {
 535         return h->of_node != NULL && h->of_node == np;
 536 }
 537
 538 struct irq_host *irq_alloc_host(struct device_node *of_node,
 539                                 unsigned int revmap_type,
 540                                 unsigned int revmap_arg,
 541                                 struct irq_host_ops *ops,
 542                                 irq_hw_number_t inval_irq)
 543 {
 544         struct irq_host *host;
 545         unsigned int size = sizeof(struct irq_host);
 546         unsigned int i;
 547         unsigned int *rmap;
 548         unsigned long flags;
 549
 550         /* Allocate structure and revmap table if using linear mapping */
 551         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 552                 size += revmap_arg * sizeof(unsigned int);
 553         host = kzalloc(size, GFP_KERNEL);
 554         if (host == NULL)
 555                 return NULL;
 556
 557         /* Fill structure */
 558         host->revmap_type = revmap_type;
 559         host->inval_irq = inval_irq;
 560         host->ops = ops;
 561         host->of_node = of_node_get(of_node);
 562
 563         if (host->ops->match == NULL)
 564                 host->ops->match = default_irq_host_match;
 565
 566         raw_spin_lock_irqsave(&irq_big_lock, flags);
 567
 568         /* If it's a legacy controller, check for duplicates and
 569          * mark it as allocated (we use irq 0 host pointer for that
 570          */
 571         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 572                 if (irq_map[0].host != NULL) {
 573                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 574                         of_node_put(host->of_node);
 575                         kfree(host);
 576                         return NULL;
 577                 }
 578                 irq_map[0].host = host;
 579         }
 580
 581         list_add(&host->link, &irq_hosts);
 582         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 583
 584         /* Additional setups per revmap type */
 585         switch(revmap_type) {
 586         case IRQ_HOST_MAP_LEGACY:
 587                 /* 0 is always the invalid number for legacy */
 588                 host->inval_irq = 0;
 589                 /* setup us as the host for all legacy interrupts */
 590                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 591                         irq_map[i].hwirq = i;
 592                         smp_wmb();
 593                         irq_map[i].host = host;
 594                         smp_wmb();
 595
 596                         /* Legacy flags are left to default at this point,
 597                          * one can then use irq_create_mapping() to
 598                          * explicitly change them
 599                          */
 600                         ops->map(host, i, i);
 601
 602                         /* Clear norequest flags */
 603                         irq_clear_status_flags(i, IRQ_NOREQUEST);
 604                 }
 605                 break;
 606         case IRQ_HOST_MAP_LINEAR:
 607                 rmap = (unsigned int *)(host + 1);
 608                 for (i = 0; i < revmap_arg; i++)
 609                         rmap[i] = NO_IRQ;
 610                 host->revmap_data.linear.size = revmap_arg;
 611                 smp_wmb();
 612                 host->revmap_data.linear.revmap = rmap;
 613                 break;
 614         case IRQ_HOST_MAP_TREE:
 615                 INIT_RADIX_TREE(&host->revmap_data.tree, GFP_KERNEL);
 616                 break;
 617         default:
 618                 break;
 619         }
 620
 621         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 622
 623         return host;
 624 }
 625
 626 struct irq_host *irq_find_host(struct device_node *node)
 627 {
 628         struct irq_host *h, *found = NULL;
 629         unsigned long flags;
 630
 631         /* We might want to match the legacy controller last since
 632          * it might potentially be set to match all interrupts in
 633          * the absence of a device node. This isn't a problem so far
 634          * yet though...
 635          */
 636         raw_spin_lock_irqsave(&irq_big_lock, flags);
 637         list_for_each_entry(h, &irq_hosts, link)
 638                 if (h->ops->match(h, node)) {
 639                         found = h;
 640                         break;
 641                 }
 642         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 643         return found;
 644 }
 645 EXPORT_SYMBOL_GPL(irq_find_host);
 646
 647 void irq_set_default_host(struct irq_host *host)
 648 {
 649         pr_debug("irq: Default host set to @0x%p\n", host);
 650
 651         irq_default_host = host;
 652 }
 653
 654 void irq_set_virq_count(unsigned int count)
 655 {
 656         pr_debug("irq: Trying to set virq count to %d\n", count);
 657
 658         BUG_ON(count < NUM_ISA_INTERRUPTS);
 659         if (count < NR_IRQS)
 660                 irq_virq_count = count;
 661 }
 662
 663 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 664                             irq_hw_number_t hwirq)
 665 {
 666         int res;
 667
 668         res = irq_alloc_desc_at(virq, 0);
 669         if (res != virq) {
 670                 pr_debug("irq: -> allocating desc failed\n");
 671                 goto error;
 672         }
 673
 674         /* map it */
 675         smp_wmb();
 676         irq_map[virq].hwirq = hwirq;
 677         smp_mb();
 678
 679         if (host->ops->map(host, virq, hwirq)) {
 680                 pr_debug("irq: -> mapping failed, freeing\n");
 681                 goto errdesc;
 682         }
 683
 684         irq_clear_status_flags(virq, IRQ_NOREQUEST);
 685
 686         return 0;
 687
 688 errdesc:
 689         irq_free_descs(virq, 1);
 690 error:
 691         irq_free_virt(virq, 1);
 692         return -1;
 693 }
 694
 695 unsigned int irq_create_direct_mapping(struct irq_host *host)
 696 {
 697         unsigned int virq;
 698
 699         if (host == NULL)
 700                 host = irq_default_host;
 701
 702         BUG_ON(host == NULL);
 703         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 704
 705         virq = irq_alloc_virt(host, 1, 0);
 706         if (virq == NO_IRQ) {
 707                 pr_debug("irq: create_direct virq allocation failed\n");
 708                 return NO_IRQ;
 709         }
 710
 711         pr_debug("irq: create_direct obtained virq %d\n", virq);
 712
 713         if (irq_setup_virq(host, virq, virq))
 714                 return NO_IRQ;
 715
 716         return virq;
 717 }
 718
 719 unsigned int irq_create_mapping(struct irq_host *host,
 720                                 irq_hw_number_t hwirq)
 721 {
 722         unsigned int virq, hint;
 723
 724         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 725
 726         /* Look for default host if nececssary */
 727         if (host == NULL)
 728                 host = irq_default_host;
 729         if (host == NULL) {
 730                 printk(KERN_WARNING "irq_create_mapping called for"
 731                        " NULL host, hwirq=%lx\n", hwirq);
 732                 WARN_ON(1);
 733                 return NO_IRQ;
 734         }
 735         pr_debug("irq: -> using host @%p\n", host);
 736
 737         /* Check if mapping already exists */
 738         virq = irq_find_mapping(host, hwirq);
 739         if (virq != NO_IRQ) {
 740                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 741                 return virq;
 742         }
 743
 744         /* Get a virtual interrupt number */
 745         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 746                 /* Handle legacy */
 747                 virq = (unsigned int)hwirq;
 748                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 749                         return NO_IRQ;
 750                 return virq;
 751         } else {
 752                 /* Allocate a virtual interrupt number */
 753                 hint = hwirq % irq_virq_count;
 754                 virq = irq_alloc_virt(host, 1, hint);
 755                 if (virq == NO_IRQ) {
 756                         pr_debug("irq: -> virq allocation failed\n");
 757                         return NO_IRQ;
 758                 }
 759         }
 760
 761         if (irq_setup_virq(host, virq, hwirq))
 762                 return NO_IRQ;
 763
 764         pr_debug("irq: irq %lu on host %s mapped to virtual irq %u\n",
 765                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 766
 767         return virq;
 768 }
 769 EXPORT_SYMBOL_GPL(irq_create_mapping);
 770
 771 unsigned int irq_create_of_mapping(struct device_node *controller,
 772                                    const u32 *intspec, unsigned int intsize)
 773 {
 774         struct irq_host *host;
 775         irq_hw_number_t hwirq;
 776         unsigned int type = IRQ_TYPE_NONE;
 777         unsigned int virq;
 778
 779         if (controller == NULL)
 780                 host = irq_default_host;
 781         else
 782                 host = irq_find_host(controller);
 783         if (host == NULL) {
 784                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 785                        controller->full_name);
 786                 return NO_IRQ;
 787         }
 788
 789         /* If host has no translation, then we assume interrupt line */
 790         if (host->ops->xlate == NULL)
 791                 hwirq = intspec[0];
 792         else {
 793                 if (host->ops->xlate(host, controller, intspec, intsize,
 794                                      &hwirq, &type))
 795                         return NO_IRQ;
 796         }
 797
 798         /* Create mapping */
 799         virq = irq_create_mapping(host, hwirq);
 800         if (virq == NO_IRQ)
 801                 return virq;
 802
 803         /* Set type if specified and different than the current one */
 804         if (type != IRQ_TYPE_NONE &&
 805             type != (irqd_get_trigger_type(irq_get_irq_data(virq))))
 806                 irq_set_irq_type(virq, type);
 807         return virq;
 808 }
 809 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 810
 811 void irq_dispose_mapping(unsigned int virq)
 812 {
 813         struct irq_host *host;
 814         irq_hw_number_t hwirq;
 815
 816         if (virq == NO_IRQ)
 817                 return;
 818
 819         host = irq_map[virq].host;
 820         if (WARN_ON(host == NULL))
 821                 return;
 822
 823         /* Never unmap legacy interrupts */
 824         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 825                 return;
 826
 827         irq_set_status_flags(virq, IRQ_NOREQUEST);
 828
 829         /* remove chip and handler */
 830         irq_set_chip_and_handler(virq, NULL, NULL);
 831
 832         /* Make sure it's completed */
 833         synchronize_irq(virq);
 834
 835         /* Tell the PIC about it */
 836         if (host->ops->unmap)
 837                 host->ops->unmap(host, virq);
 838         smp_mb();
 839
 840         /* Clear reverse map */
 841         hwirq = irq_map[virq].hwirq;
 842         switch(host->revmap_type) {
 843         case IRQ_HOST_MAP_LINEAR:
 844                 if (hwirq < host->revmap_data.linear.size)
 845                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 846                 break;
 847         case IRQ_HOST_MAP_TREE:
 848                 mutex_lock(&revmap_trees_mutex);
 849                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 850                 mutex_unlock(&revmap_trees_mutex);
 851                 break;
 852         }
 853
 854         /* Destroy map */
 855         smp_mb();
 856         irq_map[virq].hwirq = host->inval_irq;
 857
 858         irq_free_descs(virq, 1);
 859         /* Free it */
 860         irq_free_virt(virq, 1);
 861 }
 862 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 863
 864 unsigned int irq_find_mapping(struct irq_host *host,
 865                               irq_hw_number_t hwirq)
 866 {
 867         unsigned int i;
 868         unsigned int hint = hwirq % irq_virq_count;
 869
 870         /* Look for default host if nececssary */
 871         if (host == NULL)
 872                 host = irq_default_host;
 873         if (host == NULL)
 874                 return NO_IRQ;
 875
 876         /* legacy -> bail early */
 877         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 878                 return hwirq;
 879
 880         /* Slow path does a linear search of the map */
 881         if (hint < NUM_ISA_INTERRUPTS)
 882                 hint = NUM_ISA_INTERRUPTS;
 883         i = hint;
 884         do  {
 885                 if (irq_map[i].host == host &&
 886                     irq_map[i].hwirq == hwirq)
 887                         return i;
 888                 i++;
 889                 if (i >= irq_virq_count)
 890                         i = NUM_ISA_INTERRUPTS;
 891         } while(i != hint);
 892         return NO_IRQ;
 893 }
 894 EXPORT_SYMBOL_GPL(irq_find_mapping);
 895
 896 #ifdef CONFIG_SMP
 897 int irq_choose_cpu(const struct cpumask *mask)
 898 {
 899         int cpuid;
 900
 901         if (cpumask_equal(mask, cpu_all_mask)) {
 902                 static int irq_rover;
 903                 static DEFINE_RAW_SPINLOCK(irq_rover_lock);
 904                 unsigned long flags;
 905
 906                 /* Round-robin distribution... */
 907 do_round_robin:
 908                 raw_spin_lock_irqsave(&irq_rover_lock, flags);
 909
 910                 irq_rover = cpumask_next(irq_rover, cpu_online_mask);
 911                 if (irq_rover >= nr_cpu_ids)
 912                         irq_rover = cpumask_first(cpu_online_mask);
 913
 914                 cpuid = irq_rover;
 915
 916                 raw_spin_unlock_irqrestore(&irq_rover_lock, flags);
 917         } else {
 918                 cpuid = cpumask_first_and(mask, cpu_online_mask);
 919                 if (cpuid >= nr_cpu_ids)
 920                         goto do_round_robin;
 921         }
 922
 923         return get_hard_smp_processor_id(cpuid);
 924 }
 925 #else
 926 int irq_choose_cpu(const struct cpumask *mask)
 927 {
 928         return hard_smp_processor_id();
 929 }
 930 #endif
 931
 932 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 933                                      irq_hw_number_t hwirq)
 934 {
 935         struct irq_map_entry *ptr;
 936         unsigned int virq;
 937
 938         if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_TREE))
 939                 return irq_find_mapping(host, hwirq);
 940
 941         /*
 942          * The ptr returned references the static global irq_map.
 943          * but freeing an irq can delete nodes along the path to
 944          * do the lookup via call_rcu.
 945          */
 946         rcu_read_lock();
 947         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 948         rcu_read_unlock();
 949
 950         /*
 951          * If found in radix tree, then fine.
 952          * Else fallback to linear lookup - this should not happen in practice
 953          * as it means that we failed to insert the node in the radix tree.
 954          */
 955         if (ptr)
 956                 virq = ptr - irq_map;
 957         else
 958                 virq = irq_find_mapping(host, hwirq);
 959
 960         return virq;
 961 }
 962
 963 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 964                              irq_hw_number_t hwirq)
 965 {
 966         if (WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE))
 967                 return;
 968
 969         if (virq != NO_IRQ) {
 970                 mutex_lock(&revmap_trees_mutex);
 971                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 972                                   &irq_map[virq]);
 973                 mutex_unlock(&revmap_trees_mutex);
 974         }
 975 }
 976
 977 unsigned int irq_linear_revmap(struct irq_host *host,
 978                                irq_hw_number_t hwirq)
 979 {
 980         unsigned int *revmap;
 981
 982         if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_LINEAR))
 983                 return irq_find_mapping(host, hwirq);
 984
 985         /* Check revmap bounds */
 986         if (unlikely(hwirq >= host->revmap_data.linear.size))
 987                 return irq_find_mapping(host, hwirq);
 988
 989         /* Check if revmap was allocated */
 990         revmap = host->revmap_data.linear.revmap;
 991         if (unlikely(revmap == NULL))
 992                 return irq_find_mapping(host, hwirq);
 993
 994         /* Fill up revmap with slow path if no mapping found */
 995         if (unlikely(revmap[hwirq] == NO_IRQ))
 996                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 997
 998         return revmap[hwirq];
 999 }
1000
1001 unsigned int irq_alloc_virt(struct irq_host *host,
1002                             unsigned int count,
1003                             unsigned int hint)
1004 {
1005         unsigned long flags;
1006         unsigned int i, j, found = NO_IRQ;
1007
1008         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
1009                 return NO_IRQ;
1010
1011         raw_spin_lock_irqsave(&irq_big_lock, flags);
1012
1013         /* Use hint for 1 interrupt if any */
1014         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
1015             hint < irq_virq_count && irq_map[hint].host == NULL) {
1016                 found = hint;
1017                 goto hint_found;
1018         }
1019
1020         /* Look for count consecutive numbers in the allocatable
1021          * (non-legacy) space
1022          */
1023         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1024                 if (irq_map[i].host != NULL)
1025                         j = 0;
1026                 else
1027                         j++;
1028
1029                 if (j == count) {
1030                         found = i - count + 1;
1031                         break;
1032                 }
1033         }
1034         if (found == NO_IRQ) {
1035                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1036                 return NO_IRQ;
1037         }
1038  hint_found:
1039         for (i = found; i < (found + count); i++) {
1040                 irq_map[i].hwirq = host->inval_irq;
1041                 smp_wmb();
1042                 irq_map[i].host = host;
1043         }
1044         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1045         return found;
1046 }
1047
1048 void irq_free_virt(unsigned int virq, unsigned int count)
1049 {
1050         unsigned long flags;
1051         unsigned int i;
1052
1053         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1054         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1055
1056         if (virq < NUM_ISA_INTERRUPTS) {
1057                 if (virq + count < NUM_ISA_INTERRUPTS)
1058                         return;
1059                 count  =- NUM_ISA_INTERRUPTS - virq;
1060                 virq = NUM_ISA_INTERRUPTS;
1061         }
1062
1063         if (count > irq_virq_count || virq > irq_virq_count - count) {
1064                 if (virq > irq_virq_count)
1065                         return;
1066                 count = irq_virq_count - virq;
1067         }
1068
1069         raw_spin_lock_irqsave(&irq_big_lock, flags);
1070         for (i = virq; i < (virq + count); i++) {
1071                 struct irq_host *host;
1072
1073                 host = irq_map[i].host;
1074                 irq_map[i].hwirq = host->inval_irq;
1075                 smp_wmb();
1076                 irq_map[i].host = NULL;
1077         }
1078         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1079 }
1080
1081 int arch_early_irq_init(void)
1082 {
1083         return 0;
1084 }
1085
1086 #ifdef CONFIG_VIRQ_DEBUG
1087 static int virq_debug_show(struct seq_file *m, void *private)
1088 {
1089         unsigned long flags;
1090         struct irq_desc *desc;
1091         const char *p;
1092         static const char none[] = "none";
1093         void *data;
1094         int i;
1095
1096         seq_printf(m, "%-5s  %-7s  %-15s  %-18s  %s\n", "virq", "hwirq",
1097                       "chip name", "chip data", "host name");
1098
1099         for (i = 1; i < nr_irqs; i++) {
1100                 desc = irq_to_desc(i);
1101                 if (!desc)
1102                         continue;
1103
1104                 raw_spin_lock_irqsave(&desc->lock, flags);
1105
1106                 if (desc->action && desc->action->handler) {
1107                         struct irq_chip *chip;
1108
1109                         seq_printf(m, "%5d  ", i);
1110                         seq_printf(m, "0x%05lx  ", irq_map[i].hwirq);
1111
1112                         chip = irq_desc_get_chip(desc);
1113                         if (chip && chip->name)
1114                                 p = chip->name;
1115                         else
1116                                 p = none;
1117                         seq_printf(m, "%-15s  ", p);
1118
1119                         data = irq_desc_get_chip_data(desc);
1120                         seq_printf(m, "0x%16p  ", data);
1121
1122                         if (irq_map[i].host && irq_map[i].host->of_node)
1123                                 p = irq_map[i].host->of_node->full_name;
1124                         else
1125                                 p = none;
1126                         seq_printf(m, "%s\n", p);
1127                 }
1128
1129                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1130         }
1131
1132         return 0;
1133 }
1134
1135 static int virq_debug_open(struct inode *inode, struct file *file)
1136 {
1137         return single_open(file, virq_debug_show, inode->i_private);
1138 }
1139
1140 static const struct file_operations virq_debug_fops = {
1141         .open = virq_debug_open,
1142         .read = seq_read,
1143         .llseek = seq_lseek,
1144         .release = single_release,
1145 };
1146
1147 static int __init irq_debugfs_init(void)
1148 {
1149         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1150                                  NULL, &virq_debug_fops) == NULL)
1151                 return -ENOMEM;
1152
1153         return 0;
1154 }
1155 __initcall(irq_debugfs_init);
1156 #endif /* CONFIG_VIRQ_DEBUG */
1157
1158 #ifdef CONFIG_PPC64
1159 static int __init setup_noirqdistrib(char *str)
1160 {
1161         distribute_irqs = 0;
1162         return 1;
1163 }
1164
1165 __setup("noirqdistrib", setup_noirqdistrib);
1166 #endif /* CONFIG_PPC64 */