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 = &__get_cpu_var(decrementers_next_tb);
 122
 123         if (now >= *next_tb)
 124                 set_dec(1);
 125 }
 126
 127 notrace void arch_local_irq_restore(unsigned long en)
 128 {
 129         /*
 130          * get_paca()->soft_enabled = en;
 131          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 132          * That was allowed before, and in such a case we do need to take care
 133          * that gcc will set soft_enabled directly via r13, not choose to use
 134          * an intermediate register, lest we're preempted to a different cpu.
 135          */
 136         set_soft_enabled(en);
 137         if (!en)
 138                 return;
 139
 140 #ifdef CONFIG_PPC_STD_MMU_64
 141         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 142                 /*
 143                  * Do we need to disable preemption here?  Not really: in the
 144                  * unlikely event that we're preempted to a different cpu in
 145                  * between getting r13, loading its lppaca_ptr, and loading
 146                  * its any_int, we might call iseries_handle_interrupts without
 147                  * an interrupt pending on the new cpu, but that's no disaster,
 148                  * is it?  And the business of preempting us off the old cpu
 149                  * would itself involve a local_irq_restore which handles the
 150                  * interrupt to that cpu.
 151                  *
 152                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 153                  * to avoid any preemption checking added into get_paca().
 154                  */
 155                 if (local_paca->lppaca_ptr->int_dword.any_int)
 156                         iseries_handle_interrupts();
 157         }
 158 #endif /* CONFIG_PPC_STD_MMU_64 */
 159
 160         /*
 161          * if (get_paca()->hard_enabled) return;
 162          * But again we need to take care that gcc gets hard_enabled directly
 163          * via r13, not choose to use an intermediate register, lest we're
 164          * preempted to a different cpu in between the two instructions.
 165          */
 166         if (get_hard_enabled())
 167                 return;
 168
 169         /*
 170          * Need to hard-enable interrupts here.  Since currently disabled,
 171          * no need to take further asm precautions against preemption; but
 172          * use local_paca instead of get_paca() to avoid preemption checking.
 173          */
 174         local_paca->hard_enabled = en;
 175
 176         /*
 177          * Trigger the decrementer if we have a pending event. Some processors
 178          * only trigger on edge transitions of the sign bit. We might also
 179          * have disabled interrupts long enough that the decrementer wrapped
 180          * to positive.
 181          */
 182         decrementer_check_overflow();
 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, tmp2;
 190                 lv1_get_version_info(&tmp, &tmp2);
 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         irqtp->flags = 0;
 461         current->thread.ksp_limit = (unsigned long)irqtp +
 462                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 463         call_do_softirq(irqtp);
 464         current->thread.ksp_limit = saved_sp_limit;
 465         irqtp->task = NULL;
 466
 467         /* Set any flag that may have been set on the
 468          * alternate stack
 469          */
 470         if (irqtp->flags)
 471                 set_bits(irqtp->flags, &curtp->flags);
 472 }
 473
 474 void do_softirq(void)
 475 {
 476         unsigned long flags;
 477
 478         if (in_interrupt())
 479                 return;
 480
 481         local_irq_save(flags);
 482
 483         if (local_softirq_pending())
 484                 do_softirq_onstack();
 485
 486         local_irq_restore(flags);
 487 }
 488
 489
 490 /*
 491  * IRQ controller and virtual interrupts
 492  */
 493
 494 /* The main irq map itself is an array of NR_IRQ entries containing the
 495  * associate host and irq number. An entry with a host of NULL is free.
 496  * An entry can be allocated if it's free, the allocator always then sets
 497  * hwirq first to the host's invalid irq number and then fills ops.
 498  */
 499 struct irq_map_entry {
 500         irq_hw_number_t hwirq;
 501         struct irq_domain       *host;
 502 };
 503
 504 static LIST_HEAD(irq_domain_list);
 505 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 506 static DEFINE_MUTEX(revmap_trees_mutex);
 507 static struct irq_map_entry irq_map[NR_IRQS];
 508 static unsigned int irq_virq_count = NR_IRQS;
 509 static struct irq_domain *irq_default_host;
 510
 511 irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
 512 {
 513         return irq_map[d->irq].hwirq;
 514 }
 515 EXPORT_SYMBOL_GPL(irqd_to_hwirq);
 516
 517 irq_hw_number_t virq_to_hw(unsigned int virq)
 518 {
 519         return irq_map[virq].hwirq;
 520 }
 521 EXPORT_SYMBOL_GPL(virq_to_hw);
 522
 523 bool virq_is_host(unsigned int virq, struct irq_domain *host)
 524 {
 525         return irq_map[virq].host == host;
 526 }
 527 EXPORT_SYMBOL_GPL(virq_is_host);
 528
 529 static int default_irq_host_match(struct irq_domain *h, struct device_node *np)
 530 {
 531         return h->of_node != NULL && h->of_node == np;
 532 }
 533
 534 struct irq_domain *irq_alloc_host(struct device_node *of_node,
 535                                 unsigned int revmap_type,
 536                                 unsigned int revmap_arg,
 537                                 struct irq_domain_ops *ops,
 538                                 irq_hw_number_t inval_irq)
 539 {
 540         struct irq_domain *host;
 541         unsigned int size = sizeof(struct irq_domain);
 542         unsigned int i;
 543         unsigned int *rmap;
 544         unsigned long flags;
 545
 546         /* Allocate structure and revmap table if using linear mapping */
 547         if (revmap_type == IRQ_DOMAIN_MAP_LINEAR)
 548                 size += revmap_arg * sizeof(unsigned int);
 549         host = kzalloc(size, GFP_KERNEL);
 550         if (host == NULL)
 551                 return NULL;
 552
 553         /* Fill structure */
 554         host->revmap_type = revmap_type;
 555         host->inval_irq = inval_irq;
 556         host->ops = ops;
 557         host->of_node = of_node_get(of_node);
 558
 559         if (host->ops->match == NULL)
 560                 host->ops->match = default_irq_host_match;
 561
 562         raw_spin_lock_irqsave(&irq_big_lock, flags);
 563
 564         /* If it's a legacy controller, check for duplicates and
 565          * mark it as allocated (we use irq 0 host pointer for that
 566          */
 567         if (revmap_type == IRQ_DOMAIN_MAP_LEGACY) {
 568                 if (irq_map[0].host != NULL) {
 569                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 570                         of_node_put(host->of_node);
 571                         kfree(host);
 572                         return NULL;
 573                 }
 574                 irq_map[0].host = host;
 575         }
 576
 577         list_add(&host->link, &irq_domain_list);
 578         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 579
 580         /* Additional setups per revmap type */
 581         switch(revmap_type) {
 582         case IRQ_DOMAIN_MAP_LEGACY:
 583                 /* 0 is always the invalid number for legacy */
 584                 host->inval_irq = 0;
 585                 /* setup us as the host for all legacy interrupts */
 586                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 587                         irq_map[i].hwirq = i;
 588                         smp_wmb();
 589                         irq_map[i].host = host;
 590                         smp_wmb();
 591
 592                         /* Legacy flags are left to default at this point,
 593                          * one can then use irq_create_mapping() to
 594                          * explicitly change them
 595                          */
 596                         ops->map(host, i, i);
 597
 598                         /* Clear norequest flags */
 599                         irq_clear_status_flags(i, IRQ_NOREQUEST);
 600                 }
 601                 break;
 602         case IRQ_DOMAIN_MAP_LINEAR:
 603                 rmap = (unsigned int *)(host + 1);
 604                 for (i = 0; i < revmap_arg; i++)
 605                         rmap[i] = NO_IRQ;
 606                 host->revmap_data.linear.size = revmap_arg;
 607                 smp_wmb();
 608                 host->revmap_data.linear.revmap = rmap;
 609                 break;
 610         case IRQ_DOMAIN_MAP_TREE:
 611                 INIT_RADIX_TREE(&host->revmap_data.tree, GFP_KERNEL);
 612                 break;
 613         default:
 614                 break;
 615         }
 616
 617         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 618
 619         return host;
 620 }
 621
 622 struct irq_domain *irq_find_host(struct device_node *node)
 623 {
 624         struct irq_domain *h, *found = NULL;
 625         unsigned long flags;
 626
 627         /* We might want to match the legacy controller last since
 628          * it might potentially be set to match all interrupts in
 629          * the absence of a device node. This isn't a problem so far
 630          * yet though...
 631          */
 632         raw_spin_lock_irqsave(&irq_big_lock, flags);
 633         list_for_each_entry(h, &irq_domain_list, link)
 634                 if (h->ops->match(h, node)) {
 635                         found = h;
 636                         break;
 637                 }
 638         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 639         return found;
 640 }
 641 EXPORT_SYMBOL_GPL(irq_find_host);
 642
 643 void irq_set_default_host(struct irq_domain *host)
 644 {
 645         pr_debug("irq: Default host set to @0x%p\n", host);
 646
 647         irq_default_host = host;
 648 }
 649
 650 void irq_set_virq_count(unsigned int count)
 651 {
 652         pr_debug("irq: Trying to set virq count to %d\n", count);
 653
 654         BUG_ON(count < NUM_ISA_INTERRUPTS);
 655         if (count < NR_IRQS)
 656                 irq_virq_count = count;
 657 }
 658
 659 static int irq_setup_virq(struct irq_domain *host, unsigned int virq,
 660                             irq_hw_number_t hwirq)
 661 {
 662         int res;
 663
 664         res = irq_alloc_desc_at(virq, 0);
 665         if (res != virq) {
 666                 pr_debug("irq: -> allocating desc failed\n");
 667                 goto error;
 668         }
 669
 670         /* map it */
 671         smp_wmb();
 672         irq_map[virq].hwirq = hwirq;
 673         smp_mb();
 674
 675         if (host->ops->map(host, virq, hwirq)) {
 676                 pr_debug("irq: -> mapping failed, freeing\n");
 677                 goto errdesc;
 678         }
 679
 680         irq_clear_status_flags(virq, IRQ_NOREQUEST);
 681
 682         return 0;
 683
 684 errdesc:
 685         irq_free_descs(virq, 1);
 686 error:
 687         irq_free_virt(virq, 1);
 688         return -1;
 689 }
 690
 691 unsigned int irq_create_direct_mapping(struct irq_domain *host)
 692 {
 693         unsigned int virq;
 694
 695         if (host == NULL)
 696                 host = irq_default_host;
 697
 698         BUG_ON(host == NULL);
 699         WARN_ON(host->revmap_type != IRQ_DOMAIN_MAP_NOMAP);
 700
 701         virq = irq_alloc_virt(host, 1, 0);
 702         if (virq == NO_IRQ) {
 703                 pr_debug("irq: create_direct virq allocation failed\n");
 704                 return NO_IRQ;
 705         }
 706
 707         pr_debug("irq: create_direct obtained virq %d\n", virq);
 708
 709         if (irq_setup_virq(host, virq, virq))
 710                 return NO_IRQ;
 711
 712         return virq;
 713 }
 714
 715 unsigned int irq_create_mapping(struct irq_domain *host,
 716                                 irq_hw_number_t hwirq)
 717 {
 718         unsigned int virq, hint;
 719
 720         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 721
 722         /* Look for default host if nececssary */
 723         if (host == NULL)
 724                 host = irq_default_host;
 725         if (host == NULL) {
 726                 printk(KERN_WARNING "irq_create_mapping called for"
 727                        " NULL host, hwirq=%lx\n", hwirq);
 728                 WARN_ON(1);
 729                 return NO_IRQ;
 730         }
 731         pr_debug("irq: -> using host @%p\n", host);
 732
 733         /* Check if mapping already exists */
 734         virq = irq_find_mapping(host, hwirq);
 735         if (virq != NO_IRQ) {
 736                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 737                 return virq;
 738         }
 739
 740         /* Get a virtual interrupt number */
 741         if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY) {
 742                 /* Handle legacy */
 743                 virq = (unsigned int)hwirq;
 744                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 745                         return NO_IRQ;
 746                 return virq;
 747         } else {
 748                 /* Allocate a virtual interrupt number */
 749                 hint = hwirq % irq_virq_count;
 750                 virq = irq_alloc_virt(host, 1, hint);
 751                 if (virq == NO_IRQ) {
 752                         pr_debug("irq: -> virq allocation failed\n");
 753                         return NO_IRQ;
 754                 }
 755         }
 756
 757         if (irq_setup_virq(host, virq, hwirq))
 758                 return NO_IRQ;
 759
 760         pr_debug("irq: irq %lu on host %s mapped to virtual irq %u\n",
 761                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 762
 763         return virq;
 764 }
 765 EXPORT_SYMBOL_GPL(irq_create_mapping);
 766
 767 unsigned int irq_create_of_mapping(struct device_node *controller,
 768                                    const u32 *intspec, unsigned int intsize)
 769 {
 770         struct irq_domain *host;
 771         irq_hw_number_t hwirq;
 772         unsigned int type = IRQ_TYPE_NONE;
 773         unsigned int virq;
 774
 775         if (controller == NULL)
 776                 host = irq_default_host;
 777         else
 778                 host = irq_find_host(controller);
 779         if (host == NULL) {
 780                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 781                        controller->full_name);
 782                 return NO_IRQ;
 783         }
 784
 785         /* If host has no translation, then we assume interrupt line */
 786         if (host->ops->xlate == NULL)
 787                 hwirq = intspec[0];
 788         else {
 789                 if (host->ops->xlate(host, controller, intspec, intsize,
 790                                      &hwirq, &type))
 791                         return NO_IRQ;
 792         }
 793
 794         /* Create mapping */
 795         virq = irq_create_mapping(host, hwirq);
 796         if (virq == NO_IRQ)
 797                 return virq;
 798
 799         /* Set type if specified and different than the current one */
 800         if (type != IRQ_TYPE_NONE &&
 801             type != (irqd_get_trigger_type(irq_get_irq_data(virq))))
 802                 irq_set_irq_type(virq, type);
 803         return virq;
 804 }
 805 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 806
 807 void irq_dispose_mapping(unsigned int virq)
 808 {
 809         struct irq_domain *host;
 810         irq_hw_number_t hwirq;
 811
 812         if (virq == NO_IRQ)
 813                 return;
 814
 815         host = irq_map[virq].host;
 816         if (WARN_ON(host == NULL))
 817                 return;
 818
 819         /* Never unmap legacy interrupts */
 820         if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
 821                 return;
 822
 823         irq_set_status_flags(virq, IRQ_NOREQUEST);
 824
 825         /* remove chip and handler */
 826         irq_set_chip_and_handler(virq, NULL, NULL);
 827
 828         /* Make sure it's completed */
 829         synchronize_irq(virq);
 830
 831         /* Tell the PIC about it */
 832         if (host->ops->unmap)
 833                 host->ops->unmap(host, virq);
 834         smp_mb();
 835
 836         /* Clear reverse map */
 837         hwirq = irq_map[virq].hwirq;
 838         switch(host->revmap_type) {
 839         case IRQ_DOMAIN_MAP_LINEAR:
 840                 if (hwirq < host->revmap_data.linear.size)
 841                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 842                 break;
 843         case IRQ_DOMAIN_MAP_TREE:
 844                 mutex_lock(&revmap_trees_mutex);
 845                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 846                 mutex_unlock(&revmap_trees_mutex);
 847                 break;
 848         }
 849
 850         /* Destroy map */
 851         smp_mb();
 852         irq_map[virq].hwirq = host->inval_irq;
 853
 854         irq_free_descs(virq, 1);
 855         /* Free it */
 856         irq_free_virt(virq, 1);
 857 }
 858 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 859
 860 unsigned int irq_find_mapping(struct irq_domain *host,
 861                               irq_hw_number_t hwirq)
 862 {
 863         unsigned int i;
 864         unsigned int hint = hwirq % irq_virq_count;
 865
 866         /* Look for default host if nececssary */
 867         if (host == NULL)
 868                 host = irq_default_host;
 869         if (host == NULL)
 870                 return NO_IRQ;
 871
 872         /* legacy -> bail early */
 873         if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
 874                 return hwirq;
 875
 876         /* Slow path does a linear search of the map */
 877         if (hint < NUM_ISA_INTERRUPTS)
 878                 hint = NUM_ISA_INTERRUPTS;
 879         i = hint;
 880         do  {
 881                 if (irq_map[i].host == host &&
 882                     irq_map[i].hwirq == hwirq)
 883                         return i;
 884                 i++;
 885                 if (i >= irq_virq_count)
 886                         i = NUM_ISA_INTERRUPTS;
 887         } while(i != hint);
 888         return NO_IRQ;
 889 }
 890 EXPORT_SYMBOL_GPL(irq_find_mapping);
 891
 892 #ifdef CONFIG_SMP
 893 int irq_choose_cpu(const struct cpumask *mask)
 894 {
 895         int cpuid;
 896
 897         if (cpumask_equal(mask, cpu_all_mask)) {
 898                 static int irq_rover;
 899                 static DEFINE_RAW_SPINLOCK(irq_rover_lock);
 900                 unsigned long flags;
 901
 902                 /* Round-robin distribution... */
 903 do_round_robin:
 904                 raw_spin_lock_irqsave(&irq_rover_lock, flags);
 905
 906                 irq_rover = cpumask_next(irq_rover, cpu_online_mask);
 907                 if (irq_rover >= nr_cpu_ids)
 908                         irq_rover = cpumask_first(cpu_online_mask);
 909
 910                 cpuid = irq_rover;
 911
 912                 raw_spin_unlock_irqrestore(&irq_rover_lock, flags);
 913         } else {
 914                 cpuid = cpumask_first_and(mask, cpu_online_mask);
 915                 if (cpuid >= nr_cpu_ids)
 916                         goto do_round_robin;
 917         }
 918
 919         return get_hard_smp_processor_id(cpuid);
 920 }
 921 #else
 922 int irq_choose_cpu(const struct cpumask *mask)
 923 {
 924         return hard_smp_processor_id();
 925 }
 926 #endif
 927
 928 unsigned int irq_radix_revmap_lookup(struct irq_domain *host,
 929                                      irq_hw_number_t hwirq)
 930 {
 931         struct irq_map_entry *ptr;
 932         unsigned int virq;
 933
 934         if (WARN_ON_ONCE(host->revmap_type != IRQ_DOMAIN_MAP_TREE))
 935                 return irq_find_mapping(host, hwirq);
 936
 937         /*
 938          * The ptr returned references the static global irq_map.
 939          * but freeing an irq can delete nodes along the path to
 940          * do the lookup via call_rcu.
 941          */
 942         rcu_read_lock();
 943         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 944         rcu_read_unlock();
 945
 946         /*
 947          * If found in radix tree, then fine.
 948          * Else fallback to linear lookup - this should not happen in practice
 949          * as it means that we failed to insert the node in the radix tree.
 950          */
 951         if (ptr)
 952                 virq = ptr - irq_map;
 953         else
 954                 virq = irq_find_mapping(host, hwirq);
 955
 956         return virq;
 957 }
 958
 959 void irq_radix_revmap_insert(struct irq_domain *host, unsigned int virq,
 960                              irq_hw_number_t hwirq)
 961 {
 962         if (WARN_ON(host->revmap_type != IRQ_DOMAIN_MAP_TREE))
 963                 return;
 964
 965         if (virq != NO_IRQ) {
 966                 mutex_lock(&revmap_trees_mutex);
 967                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 968                                   &irq_map[virq]);
 969                 mutex_unlock(&revmap_trees_mutex);
 970         }
 971 }
 972
 973 unsigned int irq_linear_revmap(struct irq_domain *host,
 974                                irq_hw_number_t hwirq)
 975 {
 976         unsigned int *revmap;
 977
 978         if (WARN_ON_ONCE(host->revmap_type != IRQ_DOMAIN_MAP_LINEAR))
 979                 return irq_find_mapping(host, hwirq);
 980
 981         /* Check revmap bounds */
 982         if (unlikely(hwirq >= host->revmap_data.linear.size))
 983                 return irq_find_mapping(host, hwirq);
 984
 985         /* Check if revmap was allocated */
 986         revmap = host->revmap_data.linear.revmap;
 987         if (unlikely(revmap == NULL))
 988                 return irq_find_mapping(host, hwirq);
 989
 990         /* Fill up revmap with slow path if no mapping found */
 991         if (unlikely(revmap[hwirq] == NO_IRQ))
 992                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 993
 994         return revmap[hwirq];
 995 }
 996
 997 unsigned int irq_alloc_virt(struct irq_domain *host,
 998                             unsigned int count,
 999                             unsigned int hint)
1000 {
1001         unsigned long flags;
1002         unsigned int i, j, found = NO_IRQ;
1003
1004         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
1005                 return NO_IRQ;
1006
1007         raw_spin_lock_irqsave(&irq_big_lock, flags);
1008
1009         /* Use hint for 1 interrupt if any */
1010         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
1011             hint < irq_virq_count && irq_map[hint].host == NULL) {
1012                 found = hint;
1013                 goto hint_found;
1014         }
1015
1016         /* Look for count consecutive numbers in the allocatable
1017          * (non-legacy) space
1018          */
1019         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1020                 if (irq_map[i].host != NULL)
1021                         j = 0;
1022                 else
1023                         j++;
1024
1025                 if (j == count) {
1026                         found = i - count + 1;
1027                         break;
1028                 }
1029         }
1030         if (found == NO_IRQ) {
1031                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1032                 return NO_IRQ;
1033         }
1034  hint_found:
1035         for (i = found; i < (found + count); i++) {
1036                 irq_map[i].hwirq = host->inval_irq;
1037                 smp_wmb();
1038                 irq_map[i].host = host;
1039         }
1040         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1041         return found;
1042 }
1043
1044 void irq_free_virt(unsigned int virq, unsigned int count)
1045 {
1046         unsigned long flags;
1047         unsigned int i;
1048
1049         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1050         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1051
1052         if (virq < NUM_ISA_INTERRUPTS) {
1053                 if (virq + count < NUM_ISA_INTERRUPTS)
1054                         return;
1055                 count  =- NUM_ISA_INTERRUPTS - virq;
1056                 virq = NUM_ISA_INTERRUPTS;
1057         }
1058
1059         if (count > irq_virq_count || virq > irq_virq_count - count) {
1060                 if (virq > irq_virq_count)
1061                         return;
1062                 count = irq_virq_count - virq;
1063         }
1064
1065         raw_spin_lock_irqsave(&irq_big_lock, flags);
1066         for (i = virq; i < (virq + count); i++) {
1067                 struct irq_domain *host;
1068
1069                 host = irq_map[i].host;
1070                 irq_map[i].hwirq = host->inval_irq;
1071                 smp_wmb();
1072                 irq_map[i].host = NULL;
1073         }
1074         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1075 }
1076
1077 int arch_early_irq_init(void)
1078 {
1079         return 0;
1080 }
1081
1082 #ifdef CONFIG_VIRQ_DEBUG
1083 static int virq_debug_show(struct seq_file *m, void *private)
1084 {
1085         unsigned long flags;
1086         struct irq_desc *desc;
1087         const char *p;
1088         static const char none[] = "none";
1089         void *data;
1090         int i;
1091
1092         seq_printf(m, "%-5s  %-7s  %-15s  %-18s  %s\n", "virq", "hwirq",
1093                       "chip name", "chip data", "host name");
1094
1095         for (i = 1; i < nr_irqs; i++) {
1096                 desc = irq_to_desc(i);
1097                 if (!desc)
1098                         continue;
1099
1100                 raw_spin_lock_irqsave(&desc->lock, flags);
1101
1102                 if (desc->action && desc->action->handler) {
1103                         struct irq_chip *chip;
1104
1105                         seq_printf(m, "%5d  ", i);
1106                         seq_printf(m, "0x%05lx  ", irq_map[i].hwirq);
1107
1108                         chip = irq_desc_get_chip(desc);
1109                         if (chip && chip->name)
1110                                 p = chip->name;
1111                         else
1112                                 p = none;
1113                         seq_printf(m, "%-15s  ", p);
1114
1115                         data = irq_desc_get_chip_data(desc);
1116                         seq_printf(m, "0x%16p  ", data);
1117
1118                         if (irq_map[i].host && irq_map[i].host->of_node)
1119                                 p = irq_map[i].host->of_node->full_name;
1120                         else
1121                                 p = none;
1122                         seq_printf(m, "%s\n", p);
1123                 }
1124
1125                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1126         }
1127
1128         return 0;
1129 }
1130
1131 static int virq_debug_open(struct inode *inode, struct file *file)
1132 {
1133         return single_open(file, virq_debug_show, inode->i_private);
1134 }
1135
1136 static const struct file_operations virq_debug_fops = {
1137         .open = virq_debug_open,
1138         .read = seq_read,
1139         .llseek = seq_lseek,
1140         .release = single_release,
1141 };
1142
1143 static int __init irq_debugfs_init(void)
1144 {
1145         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1146                                  NULL, &virq_debug_fops) == NULL)
1147                 return -ENOMEM;
1148
1149         return 0;
1150 }
1151 __initcall(irq_debugfs_init);
1152 #endif /* CONFIG_VIRQ_DEBUG */
1153
1154 #ifdef CONFIG_PPC64
1155 static int __init setup_noirqdistrib(char *str)
1156 {
1157         distribute_irqs = 0;
1158         return 1;
1159 }
1160
1161 __setup("noirqdistrib", setup_noirqdistrib);
1162 #endif /* CONFIG_PPC64 */