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