arch/powerpc/kernel/irq.c

   1 /*
   2  *  Derived from arch/i386/kernel/irq.c
   3  *    Copyright (C) 1992 Linus Torvalds
   4  *  Adapted from arch/i386 by Gary Thomas
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
   7  *    Copyright (C) 1996-2001 Cort Dougan
   8  *  Adapted for Power Macintosh by Paul Mackerras
   9  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version
  14  * 2 of the License, or (at your option) any later version.
  15  *
  16  * This file contains the code used by various IRQ handling routines:
  17  * asking for different IRQ's should be done through these routines
  18  * instead of just grabbing them. Thus setups with different IRQ numbers
  19  * shouldn't result in any weird surprises, and installing new handlers
  20  * should be easier.
  21  *
  22  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
  23  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
  24  * mask register (of which only 16 are defined), hence the weird shifting
  25  * and complement of the cached_irq_mask.  I want to be able to stuff
  26  * this right into the SIU SMASK register.
  27  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
  28  * to reduce code space and undefined function references.
  29  */
  30
  31 #undef DEBUG
  32
  33 #include <linux/module.h>
  34 #include <linux/threads.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/signal.h>
  37 #include <linux/sched.h>
  38 #include <linux/ptrace.h>
  39 #include <linux/ioport.h>
  40 #include <linux/interrupt.h>
  41 #include <linux/timex.h>
  42 #include <linux/init.h>
  43 #include <linux/slab.h>
  44 #include <linux/delay.h>
  45 #include <linux/irq.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/cpumask.h>
  48 #include <linux/profile.h>
  49 #include <linux/bitops.h>
  50 #include <linux/list.h>
  51 #include <linux/radix-tree.h>
  52 #include <linux/mutex.h>
  53 #include <linux/bootmem.h>
  54 #include <linux/pci.h>
  55 #include <linux/debugfs.h>
  56 #include <linux/of.h>
  57 #include <linux/of_irq.h>
  58
  59 #include <asm/uaccess.h>
  60 #include <asm/system.h>
  61 #include <asm/io.h>
  62 #include <asm/pgtable.h>
  63 #include <asm/irq.h>
  64 #include <asm/cache.h>
  65 #include <asm/prom.h>
  66 #include <asm/ptrace.h>
  67 #include <asm/machdep.h>
  68 #include <asm/udbg.h>
  69 #include <asm/dbell.h>
  70 #include <asm/smp.h>
  71
  72 #ifdef CONFIG_PPC64
  73 #include <asm/paca.h>
  74 #include <asm/firmware.h>
  75 #include <asm/lv1call.h>
  76 #endif
  77 #define CREATE_TRACE_POINTS
  78 #include <asm/trace.h>
  79
  80 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
  81 EXPORT_PER_CPU_SYMBOL(irq_stat);
  82
  83 int __irq_offset_value;
  84
  85 #ifdef CONFIG_PPC32
  86 EXPORT_SYMBOL(__irq_offset_value);
  87 atomic_t ppc_n_lost_interrupts;
  88
  89 #ifdef CONFIG_TAU_INT
  90 extern int tau_initialized;
  91 extern int tau_interrupts(int);
  92 #endif
  93 #endif /* CONFIG_PPC32 */
  94
  95 #ifdef CONFIG_PPC64
  96
  97 #ifndef CONFIG_SPARSE_IRQ
  98 EXPORT_SYMBOL(irq_desc);
  99 #endif
 100
 101 int distribute_irqs = 1;
 102
 103 static inline notrace unsigned long get_hard_enabled(void)
 104 {
 105         unsigned long enabled;
 106
 107         __asm__ __volatile__("lbz %0,%1(13)"
 108         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 109
 110         return enabled;
 111 }
 112
 113 static inline notrace void set_soft_enabled(unsigned long enable)
 114 {
 115         __asm__ __volatile__("stb %0,%1(13)"
 116         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 117 }
 118
 119 notrace void arch_local_irq_restore(unsigned long en)
 120 {
 121         /*
 122          * get_paca()->soft_enabled = en;
 123          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 124          * That was allowed before, and in such a case we do need to take care
 125          * that gcc will set soft_enabled directly via r13, not choose to use
 126          * an intermediate register, lest we're preempted to a different cpu.
 127          */
 128         set_soft_enabled(en);
 129         if (!en)
 130                 return;
 131
 132 #ifdef CONFIG_PPC_STD_MMU_64
 133         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 134                 /*
 135                  * Do we need to disable preemption here?  Not really: in the
 136                  * unlikely event that we're preempted to a different cpu in
 137                  * between getting r13, loading its lppaca_ptr, and loading
 138                  * its any_int, we might call iseries_handle_interrupts without
 139                  * an interrupt pending on the new cpu, but that's no disaster,
 140                  * is it?  And the business of preempting us off the old cpu
 141                  * would itself involve a local_irq_restore which handles the
 142                  * interrupt to that cpu.
 143                  *
 144                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 145                  * to avoid any preemption checking added into get_paca().
 146                  */
 147                 if (local_paca->lppaca_ptr->int_dword.any_int)
 148                         iseries_handle_interrupts();
 149         }
 150 #endif /* CONFIG_PPC_STD_MMU_64 */
 151
 152         /*
 153          * if (get_paca()->hard_enabled) return;
 154          * But again we need to take care that gcc gets hard_enabled directly
 155          * via r13, not choose to use an intermediate register, lest we're
 156          * preempted to a different cpu in between the two instructions.
 157          */
 158         if (get_hard_enabled())
 159                 return;
 160
 161 #if defined(CONFIG_BOOKE) && defined(CONFIG_SMP)
 162         /* Check for pending doorbell interrupts and resend to ourself */
 163         doorbell_check_self();
 164 #endif
 165
 166         /*
 167          * Need to hard-enable interrupts here.  Since currently disabled,
 168          * no need to take further asm precautions against preemption; but
 169          * use local_paca instead of get_paca() to avoid preemption checking.
 170          */
 171         local_paca->hard_enabled = en;
 172
 173 #ifndef CONFIG_BOOKE
 174         /* On server, re-trigger the decrementer if it went negative since
 175          * some processors only trigger on edge transitions of the sign bit.
 176          *
 177          * BookE has a level sensitive decrementer (latches in TSR) so we
 178          * don't need that
 179          */
 180         if ((int)mfspr(SPRN_DEC) < 0)
 181                 mtspr(SPRN_DEC, 1);
 182 #endif /* CONFIG_BOOKE */
 183
 184         /*
 185          * Force the delivery of pending soft-disabled interrupts on PS3.
 186          * Any HV call will have this side effect.
 187          */
 188         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 189                 u64 tmp;
 190                 lv1_get_version_info(&tmp);
 191         }
 192
 193         __hard_irq_enable();
 194 }
 195 EXPORT_SYMBOL(arch_local_irq_restore);
 196 #endif /* CONFIG_PPC64 */
 197
 198 static int show_other_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 int show_interrupts(struct seq_file *p, void *v)
 235 {
 236         unsigned long flags, any_count = 0;
 237         int i = *(loff_t *) v, j, prec;
 238         struct irqaction *action;
 239         struct irq_desc *desc;
 240         struct irq_chip *chip;
 241
 242         if (i > nr_irqs)
 243                 return 0;
 244
 245         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
 246                 j *= 10;
 247
 248         if (i == nr_irqs)
 249                 return show_other_interrupts(p, prec);
 250
 251         /* print header */
 252         if (i == 0) {
 253                 seq_printf(p, "%*s", prec + 8, "");
 254                 for_each_online_cpu(j)
 255                         seq_printf(p, "CPU%-8d", j);
 256                 seq_putc(p, '\n');
 257         }
 258
 259         desc = irq_to_desc(i);
 260         if (!desc)
 261                 return 0;
 262
 263         raw_spin_lock_irqsave(&desc->lock, flags);
 264         for_each_online_cpu(j)
 265                 any_count |= kstat_irqs_cpu(i, j);
 266         action = desc->action;
 267         if (!action && !any_count)
 268                 goto out;
 269
 270         seq_printf(p, "%*d: ", prec, i);
 271         for_each_online_cpu(j)
 272                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 273
 274         chip = get_irq_desc_chip(desc);
 275         if (chip)
 276                 seq_printf(p, "  %-16s", chip->name);
 277         else
 278                 seq_printf(p, "  %-16s", "None");
 279         seq_printf(p, " %-8s", (desc->status & IRQ_LEVEL) ? "Level" : "Edge");
 280
 281         if (action) {
 282                 seq_printf(p, "     %s", action->name);
 283                 while ((action = action->next) != NULL)
 284                         seq_printf(p, ", %s", action->name);
 285         }
 286
 287         seq_putc(p, '\n');
 288 out:
 289         raw_spin_unlock_irqrestore(&desc->lock, flags);
 290         return 0;
 291 }
 292
 293 /*
 294  * /proc/stat helpers
 295  */
 296 u64 arch_irq_stat_cpu(unsigned int cpu)
 297 {
 298         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
 299
 300         sum += per_cpu(irq_stat, cpu).pmu_irqs;
 301         sum += per_cpu(irq_stat, cpu).mce_exceptions;
 302         sum += per_cpu(irq_stat, cpu).spurious_irqs;
 303
 304         return sum;
 305 }
 306
 307 #ifdef CONFIG_HOTPLUG_CPU
 308 void fixup_irqs(const struct cpumask *map)
 309 {
 310         struct irq_desc *desc;
 311         unsigned int irq;
 312         static int warned;
 313         cpumask_var_t mask;
 314
 315         alloc_cpumask_var(&mask, GFP_KERNEL);
 316
 317         for_each_irq(irq) {
 318                 struct irq_chip *chip;
 319
 320                 desc = irq_to_desc(irq);
 321                 if (!desc)
 322                         continue;
 323
 324                 if (desc->status & IRQ_PER_CPU)
 325                         continue;
 326
 327                 chip = get_irq_desc_chip(desc);
 328
 329                 cpumask_and(mask, desc->irq_data.affinity, map);
 330                 if (cpumask_any(mask) >= nr_cpu_ids) {
 331                         printk("Breaking affinity for irq %i\n", irq);
 332                         cpumask_copy(mask, map);
 333                 }
 334                 if (chip->irq_set_affinity)
 335                         chip->irq_set_affinity(&desc->irq_data, mask, true);
 336                 else if (desc->action && !(warned++))
 337                         printk("Cannot set affinity for irq %i\n", irq);
 338         }
 339
 340         free_cpumask_var(mask);
 341
 342         local_irq_enable();
 343         mdelay(1);
 344         local_irq_disable();
 345 }
 346 #endif
 347
 348 static inline void handle_one_irq(unsigned int irq)
 349 {
 350         struct thread_info *curtp, *irqtp;
 351         unsigned long saved_sp_limit;
 352         struct irq_desc *desc;
 353
 354         /* Switch to the irq stack to handle this */
 355         curtp = current_thread_info();
 356         irqtp = hardirq_ctx[smp_processor_id()];
 357
 358         if (curtp == irqtp) {
 359                 /* We're already on the irq stack, just handle it */
 360                 generic_handle_irq(irq);
 361                 return;
 362         }
 363
 364         desc = irq_to_desc(irq);
 365         saved_sp_limit = current->thread.ksp_limit;
 366
 367         irqtp->task = curtp->task;
 368         irqtp->flags = 0;
 369
 370         /* Copy the softirq bits in preempt_count so that the
 371          * softirq checks work in the hardirq context. */
 372         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 373                                (curtp->preempt_count & SOFTIRQ_MASK);
 374
 375         current->thread.ksp_limit = (unsigned long)irqtp +
 376                 _ALIGN_UP(sizeof(struct thread_info), 16);
 377
 378         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 379         current->thread.ksp_limit = saved_sp_limit;
 380         irqtp->task = NULL;
 381
 382         /* Set any flag that may have been set on the
 383          * alternate stack
 384          */
 385         if (irqtp->flags)
 386                 set_bits(irqtp->flags, &curtp->flags);
 387 }
 388
 389 static inline void check_stack_overflow(void)
 390 {
 391 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 392         long sp;
 393
 394         sp = __get_SP() & (THREAD_SIZE-1);
 395
 396         /* check for stack overflow: is there less than 2KB free? */
 397         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 398                 printk("do_IRQ: stack overflow: %ld\n",
 399                         sp - sizeof(struct thread_info));
 400                 dump_stack();
 401         }
 402 #endif
 403 }
 404
 405 void do_IRQ(struct pt_regs *regs)
 406 {
 407         struct pt_regs *old_regs = set_irq_regs(regs);
 408         unsigned int irq;
 409
 410         trace_irq_entry(regs);
 411
 412         irq_enter();
 413
 414         check_stack_overflow();
 415
 416         irq = ppc_md.get_irq();
 417
 418         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 419                 handle_one_irq(irq);
 420         else if (irq != NO_IRQ_IGNORE)
 421                 __get_cpu_var(irq_stat).spurious_irqs++;
 422
 423         irq_exit();
 424         set_irq_regs(old_regs);
 425
 426 #ifdef CONFIG_PPC_ISERIES
 427         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 428                         get_lppaca()->int_dword.fields.decr_int) {
 429                 get_lppaca()->int_dword.fields.decr_int = 0;
 430                 /* Signal a fake decrementer interrupt */
 431                 timer_interrupt(regs);
 432         }
 433 #endif
 434
 435         trace_irq_exit(regs);
 436 }
 437
 438 void __init init_IRQ(void)
 439 {
 440         if (ppc_md.init_IRQ)
 441                 ppc_md.init_IRQ();
 442
 443         exc_lvl_ctx_init();
 444
 445         irq_ctx_init();
 446 }
 447
 448 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 449 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 450 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 451 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 452
 453 void exc_lvl_ctx_init(void)
 454 {
 455         struct thread_info *tp;
 456         int i, hw_cpu;
 457
 458         for_each_possible_cpu(i) {
 459                 hw_cpu = get_hard_smp_processor_id(i);
 460                 memset((void *)critirq_ctx[hw_cpu], 0, THREAD_SIZE);
 461                 tp = critirq_ctx[hw_cpu];
 462                 tp->cpu = i;
 463                 tp->preempt_count = 0;
 464
 465 #ifdef CONFIG_BOOKE
 466                 memset((void *)dbgirq_ctx[hw_cpu], 0, THREAD_SIZE);
 467                 tp = dbgirq_ctx[hw_cpu];
 468                 tp->cpu = i;
 469                 tp->preempt_count = 0;
 470
 471                 memset((void *)mcheckirq_ctx[hw_cpu], 0, THREAD_SIZE);
 472                 tp = mcheckirq_ctx[hw_cpu];
 473                 tp->cpu = i;
 474                 tp->preempt_count = HARDIRQ_OFFSET;
 475 #endif
 476         }
 477 }
 478 #endif
 479
 480 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 481 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 482
 483 void irq_ctx_init(void)
 484 {
 485         struct thread_info *tp;
 486         int i;
 487
 488         for_each_possible_cpu(i) {
 489                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 490                 tp = softirq_ctx[i];
 491                 tp->cpu = i;
 492                 tp->preempt_count = 0;
 493
 494                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 495                 tp = hardirq_ctx[i];
 496                 tp->cpu = i;
 497                 tp->preempt_count = HARDIRQ_OFFSET;
 498         }
 499 }
 500
 501 static inline void do_softirq_onstack(void)
 502 {
 503         struct thread_info *curtp, *irqtp;
 504         unsigned long saved_sp_limit = current->thread.ksp_limit;
 505
 506         curtp = current_thread_info();
 507         irqtp = softirq_ctx[smp_processor_id()];
 508         irqtp->task = curtp->task;
 509         current->thread.ksp_limit = (unsigned long)irqtp +
 510                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 511         call_do_softirq(irqtp);
 512         current->thread.ksp_limit = saved_sp_limit;
 513         irqtp->task = NULL;
 514 }
 515
 516 void do_softirq(void)
 517 {
 518         unsigned long flags;
 519
 520         if (in_interrupt())
 521                 return;
 522
 523         local_irq_save(flags);
 524
 525         if (local_softirq_pending())
 526                 do_softirq_onstack();
 527
 528         local_irq_restore(flags);
 529 }
 530
 531
 532 /*
 533  * IRQ controller and virtual interrupts
 534  */
 535
 536 static LIST_HEAD(irq_hosts);
 537 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 538 static unsigned int revmap_trees_allocated;
 539 static DEFINE_MUTEX(revmap_trees_mutex);
 540 struct irq_map_entry irq_map[NR_IRQS];
 541 static unsigned int irq_virq_count = NR_IRQS;
 542 static struct irq_host *irq_default_host;
 543
 544 irq_hw_number_t virq_to_hw(unsigned int virq)
 545 {
 546         return irq_map[virq].hwirq;
 547 }
 548 EXPORT_SYMBOL_GPL(virq_to_hw);
 549
 550 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 551 {
 552         return h->of_node != NULL && h->of_node == np;
 553 }
 554
 555 struct irq_host *irq_alloc_host(struct device_node *of_node,
 556                                 unsigned int revmap_type,
 557                                 unsigned int revmap_arg,
 558                                 struct irq_host_ops *ops,
 559                                 irq_hw_number_t inval_irq)
 560 {
 561         struct irq_host *host;
 562         unsigned int size = sizeof(struct irq_host);
 563         unsigned int i;
 564         unsigned int *rmap;
 565         unsigned long flags;
 566
 567         /* Allocate structure and revmap table if using linear mapping */
 568         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 569                 size += revmap_arg * sizeof(unsigned int);
 570         host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 571         if (host == NULL)
 572                 return NULL;
 573
 574         /* Fill structure */
 575         host->revmap_type = revmap_type;
 576         host->inval_irq = inval_irq;
 577         host->ops = ops;
 578         host->of_node = of_node_get(of_node);
 579
 580         if (host->ops->match == NULL)
 581                 host->ops->match = default_irq_host_match;
 582
 583         raw_spin_lock_irqsave(&irq_big_lock, flags);
 584
 585         /* If it's a legacy controller, check for duplicates and
 586          * mark it as allocated (we use irq 0 host pointer for that
 587          */
 588         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 589                 if (irq_map[0].host != NULL) {
 590                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 591                         /* If we are early boot, we can't free the structure,
 592                          * too bad...
 593                          * this will be fixed once slab is made available early
 594                          * instead of the current cruft
 595                          */
 596                         if (mem_init_done) {
 597                                 of_node_put(host->of_node);
 598                                 kfree(host);
 599                         }
 600                         return NULL;
 601                 }
 602                 irq_map[0].host = host;
 603         }
 604
 605         list_add(&host->link, &irq_hosts);
 606         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 607
 608         /* Additional setups per revmap type */
 609         switch(revmap_type) {
 610         case IRQ_HOST_MAP_LEGACY:
 611                 /* 0 is always the invalid number for legacy */
 612                 host->inval_irq = 0;
 613                 /* setup us as the host for all legacy interrupts */
 614                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 615                         irq_map[i].hwirq = i;
 616                         smp_wmb();
 617                         irq_map[i].host = host;
 618                         smp_wmb();
 619
 620                         /* Clear norequest flags */
 621                         irq_to_desc(i)->status &= ~IRQ_NOREQUEST;
 622
 623                         /* Legacy flags are left to default at this point,
 624                          * one can then use irq_create_mapping() to
 625                          * explicitly change them
 626                          */
 627                         ops->map(host, i, i);
 628                 }
 629                 break;
 630         case IRQ_HOST_MAP_LINEAR:
 631                 rmap = (unsigned int *)(host + 1);
 632                 for (i = 0; i < revmap_arg; i++)
 633                         rmap[i] = NO_IRQ;
 634                 host->revmap_data.linear.size = revmap_arg;
 635                 smp_wmb();
 636                 host->revmap_data.linear.revmap = rmap;
 637                 break;
 638         default:
 639                 break;
 640         }
 641
 642         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 643
 644         return host;
 645 }
 646
 647 struct irq_host *irq_find_host(struct device_node *node)
 648 {
 649         struct irq_host *h, *found = NULL;
 650         unsigned long flags;
 651
 652         /* We might want to match the legacy controller last since
 653          * it might potentially be set to match all interrupts in
 654          * the absence of a device node. This isn't a problem so far
 655          * yet though...
 656          */
 657         raw_spin_lock_irqsave(&irq_big_lock, flags);
 658         list_for_each_entry(h, &irq_hosts, link)
 659                 if (h->ops->match(h, node)) {
 660                         found = h;
 661                         break;
 662                 }
 663         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 664         return found;
 665 }
 666 EXPORT_SYMBOL_GPL(irq_find_host);
 667
 668 void irq_set_default_host(struct irq_host *host)
 669 {
 670         pr_debug("irq: Default host set to @0x%p\n", host);
 671
 672         irq_default_host = host;
 673 }
 674
 675 void irq_set_virq_count(unsigned int count)
 676 {
 677         pr_debug("irq: Trying to set virq count to %d\n", count);
 678
 679         BUG_ON(count < NUM_ISA_INTERRUPTS);
 680         if (count < NR_IRQS)
 681                 irq_virq_count = count;
 682 }
 683
 684 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 685                             irq_hw_number_t hwirq)
 686 {
 687         int res;
 688
 689         res = irq_alloc_desc_at(virq, 0);
 690         if (res != virq) {
 691                 pr_debug("irq: -> allocating desc failed\n");
 692                 goto error;
 693         }
 694
 695         irq_clear_status_flags(virq, IRQ_NOREQUEST);
 696
 697         /* map it */
 698         smp_wmb();
 699         irq_map[virq].hwirq = hwirq;
 700         smp_mb();
 701
 702         if (host->ops->map(host, virq, hwirq)) {
 703                 pr_debug("irq: -> mapping failed, freeing\n");
 704                 goto errdesc;
 705         }
 706
 707         return 0;
 708
 709 errdesc:
 710         irq_free_descs(virq, 1);
 711 error:
 712         irq_free_virt(virq, 1);
 713         return -1;
 714 }
 715
 716 unsigned int irq_create_direct_mapping(struct irq_host *host)
 717 {
 718         unsigned int virq;
 719
 720         if (host == NULL)
 721                 host = irq_default_host;
 722
 723         BUG_ON(host == NULL);
 724         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 725
 726         virq = irq_alloc_virt(host, 1, 0);
 727         if (virq == NO_IRQ) {
 728                 pr_debug("irq: create_direct virq allocation failed\n");
 729                 return NO_IRQ;
 730         }
 731
 732         pr_debug("irq: create_direct obtained virq %d\n", virq);
 733
 734         if (irq_setup_virq(host, virq, virq))
 735                 return NO_IRQ;
 736
 737         return virq;
 738 }
 739
 740 unsigned int irq_create_mapping(struct irq_host *host,
 741                                 irq_hw_number_t hwirq)
 742 {
 743         unsigned int virq, hint;
 744
 745         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 746
 747         /* Look for default host if nececssary */
 748         if (host == NULL)
 749                 host = irq_default_host;
 750         if (host == NULL) {
 751                 printk(KERN_WARNING "irq_create_mapping called for"
 752                        " NULL host, hwirq=%lx\n", hwirq);
 753                 WARN_ON(1);
 754                 return NO_IRQ;
 755         }
 756         pr_debug("irq: -> using host @%p\n", host);
 757
 758         /* Check if mapping already exist, if it does, call
 759          * host->ops->map() to update the flags
 760          */
 761         virq = irq_find_mapping(host, hwirq);
 762         if (virq != NO_IRQ) {
 763                 if (host->ops->remap)
 764                         host->ops->remap(host, virq, hwirq);
 765                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 766                 return virq;
 767         }
 768
 769         /* Get a virtual interrupt number */
 770         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 771                 /* Handle legacy */
 772                 virq = (unsigned int)hwirq;
 773                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 774                         return NO_IRQ;
 775                 return virq;
 776         } else {
 777                 /* Allocate a virtual interrupt number */
 778                 hint = hwirq % irq_virq_count;
 779                 virq = irq_alloc_virt(host, 1, hint);
 780                 if (virq == NO_IRQ) {
 781                         pr_debug("irq: -> virq allocation failed\n");
 782                         return NO_IRQ;
 783                 }
 784         }
 785
 786         if (irq_setup_virq(host, virq, hwirq))
 787                 return NO_IRQ;
 788
 789         printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
 790                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 791
 792         return virq;
 793 }
 794 EXPORT_SYMBOL_GPL(irq_create_mapping);
 795
 796 unsigned int irq_create_of_mapping(struct device_node *controller,
 797                                    const u32 *intspec, unsigned int intsize)
 798 {
 799         struct irq_host *host;
 800         irq_hw_number_t hwirq;
 801         unsigned int type = IRQ_TYPE_NONE;
 802         unsigned int virq;
 803
 804         if (controller == NULL)
 805                 host = irq_default_host;
 806         else
 807                 host = irq_find_host(controller);
 808         if (host == NULL) {
 809                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 810                        controller->full_name);
 811                 return NO_IRQ;
 812         }
 813
 814         /* If host has no translation, then we assume interrupt line */
 815         if (host->ops->xlate == NULL)
 816                 hwirq = intspec[0];
 817         else {
 818                 if (host->ops->xlate(host, controller, intspec, intsize,
 819                                      &hwirq, &type))
 820                         return NO_IRQ;
 821         }
 822
 823         /* Create mapping */
 824         virq = irq_create_mapping(host, hwirq);
 825         if (virq == NO_IRQ)
 826                 return virq;
 827
 828         /* Set type if specified and different than the current one */
 829         if (type != IRQ_TYPE_NONE &&
 830             type != (irq_to_desc(virq)->status & IRQF_TRIGGER_MASK))
 831                 set_irq_type(virq, type);
 832         return virq;
 833 }
 834 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 835
 836 void irq_dispose_mapping(unsigned int virq)
 837 {
 838         struct irq_host *host;
 839         irq_hw_number_t hwirq;
 840
 841         if (virq == NO_IRQ)
 842                 return;
 843
 844         host = irq_map[virq].host;
 845         WARN_ON (host == NULL);
 846         if (host == NULL)
 847                 return;
 848
 849         /* Never unmap legacy interrupts */
 850         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 851                 return;
 852
 853         /* remove chip and handler */
 854         set_irq_chip_and_handler(virq, NULL, NULL);
 855
 856         /* Make sure it's completed */
 857         synchronize_irq(virq);
 858
 859         /* Tell the PIC about it */
 860         if (host->ops->unmap)
 861                 host->ops->unmap(host, virq);
 862         smp_mb();
 863
 864         /* Clear reverse map */
 865         hwirq = irq_map[virq].hwirq;
 866         switch(host->revmap_type) {
 867         case IRQ_HOST_MAP_LINEAR:
 868                 if (hwirq < host->revmap_data.linear.size)
 869                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 870                 break;
 871         case IRQ_HOST_MAP_TREE:
 872                 /*
 873                  * Check if radix tree allocated yet, if not then nothing to
 874                  * remove.
 875                  */
 876                 smp_rmb();
 877                 if (revmap_trees_allocated < 1)
 878                         break;
 879                 mutex_lock(&revmap_trees_mutex);
 880                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 881                 mutex_unlock(&revmap_trees_mutex);
 882                 break;
 883         }
 884
 885         /* Destroy map */
 886         smp_mb();
 887         irq_map[virq].hwirq = host->inval_irq;
 888
 889         irq_set_status_flags(virq, IRQ_NOREQUEST);
 890
 891         irq_free_descs(virq, 1);
 892         /* Free it */
 893         irq_free_virt(virq, 1);
 894 }
 895 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 896
 897 unsigned int irq_find_mapping(struct irq_host *host,
 898                               irq_hw_number_t hwirq)
 899 {
 900         unsigned int i;
 901         unsigned int hint = hwirq % irq_virq_count;
 902
 903         /* Look for default host if nececssary */
 904         if (host == NULL)
 905                 host = irq_default_host;
 906         if (host == NULL)
 907                 return NO_IRQ;
 908
 909         /* legacy -> bail early */
 910         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 911                 return hwirq;
 912
 913         /* Slow path does a linear search of the map */
 914         if (hint < NUM_ISA_INTERRUPTS)
 915                 hint = NUM_ISA_INTERRUPTS;
 916         i = hint;
 917         do  {
 918                 if (irq_map[i].host == host &&
 919                     irq_map[i].hwirq == hwirq)
 920                         return i;
 921                 i++;
 922                 if (i >= irq_virq_count)
 923                         i = NUM_ISA_INTERRUPTS;
 924         } while(i != hint);
 925         return NO_IRQ;
 926 }
 927 EXPORT_SYMBOL_GPL(irq_find_mapping);
 928
 929
 930 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 931                                      irq_hw_number_t hwirq)
 932 {
 933         struct irq_map_entry *ptr;
 934         unsigned int virq;
 935
 936         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 937
 938         /*
 939          * Check if the radix tree exists and has bee initialized.
 940          * If not, we fallback to slow mode
 941          */
 942         if (revmap_trees_allocated < 2)
 943                 return irq_find_mapping(host, hwirq);
 944
 945         /* Now try to resolve */
 946         /*
 947          * No rcu_read_lock(ing) needed, the ptr returned can't go under us
 948          * as it's referencing an entry in the static irq_map table.
 949          */
 950         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 951
 952         /*
 953          * If found in radix tree, then fine.
 954          * Else fallback to linear lookup - this should not happen in practice
 955          * as it means that we failed to insert the node in the radix tree.
 956          */
 957         if (ptr)
 958                 virq = ptr - irq_map;
 959         else
 960                 virq = irq_find_mapping(host, hwirq);
 961
 962         return virq;
 963 }
 964
 965 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 966                              irq_hw_number_t hwirq)
 967 {
 968
 969         WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 970
 971         /*
 972          * Check if the radix tree exists yet.
 973          * If not, then the irq will be inserted into the tree when it gets
 974          * initialized.
 975          */
 976         smp_rmb();
 977         if (revmap_trees_allocated < 1)
 978                 return;
 979
 980         if (virq != NO_IRQ) {
 981                 mutex_lock(&revmap_trees_mutex);
 982                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 983                                   &irq_map[virq]);
 984                 mutex_unlock(&revmap_trees_mutex);
 985         }
 986 }
 987
 988 unsigned int irq_linear_revmap(struct irq_host *host,
 989                                irq_hw_number_t hwirq)
 990 {
 991         unsigned int *revmap;
 992
 993         WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
 994
 995         /* Check revmap bounds */
 996         if (unlikely(hwirq >= host->revmap_data.linear.size))
 997                 return irq_find_mapping(host, hwirq);
 998
 999         /* Check if revmap was allocated */
1000         revmap = host->revmap_data.linear.revmap;
1001         if (unlikely(revmap == NULL))
1002                 return irq_find_mapping(host, hwirq);
1003
1004         /* Fill up revmap with slow path if no mapping found */
1005         if (unlikely(revmap[hwirq] == NO_IRQ))
1006                 revmap[hwirq] = irq_find_mapping(host, hwirq);
1007
1008         return revmap[hwirq];
1009 }
1010
1011 unsigned int irq_alloc_virt(struct irq_host *host,
1012                             unsigned int count,
1013                             unsigned int hint)
1014 {
1015         unsigned long flags;
1016         unsigned int i, j, found = NO_IRQ;
1017
1018         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
1019                 return NO_IRQ;
1020
1021         raw_spin_lock_irqsave(&irq_big_lock, flags);
1022
1023         /* Use hint for 1 interrupt if any */
1024         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
1025             hint < irq_virq_count && irq_map[hint].host == NULL) {
1026                 found = hint;
1027                 goto hint_found;
1028         }
1029
1030         /* Look for count consecutive numbers in the allocatable
1031          * (non-legacy) space
1032          */
1033         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1034                 if (irq_map[i].host != NULL)
1035                         j = 0;
1036                 else
1037                         j++;
1038
1039                 if (j == count) {
1040                         found = i - count + 1;
1041                         break;
1042                 }
1043         }
1044         if (found == NO_IRQ) {
1045                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1046                 return NO_IRQ;
1047         }
1048  hint_found:
1049         for (i = found; i < (found + count); i++) {
1050                 irq_map[i].hwirq = host->inval_irq;
1051                 smp_wmb();
1052                 irq_map[i].host = host;
1053         }
1054         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1055         return found;
1056 }
1057
1058 void irq_free_virt(unsigned int virq, unsigned int count)
1059 {
1060         unsigned long flags;
1061         unsigned int i;
1062
1063         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1064         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1065
1066         raw_spin_lock_irqsave(&irq_big_lock, flags);
1067         for (i = virq; i < (virq + count); i++) {
1068                 struct irq_host *host;
1069
1070                 if (i < NUM_ISA_INTERRUPTS ||
1071                     (virq + count) > irq_virq_count)
1072                         continue;
1073
1074                 host = irq_map[i].host;
1075                 irq_map[i].hwirq = host->inval_irq;
1076                 smp_wmb();
1077                 irq_map[i].host = NULL;
1078         }
1079         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1080 }
1081
1082 int arch_early_irq_init(void)
1083 {
1084         return 0;
1085 }
1086
1087 /* We need to create the radix trees late */
1088 static int irq_late_init(void)
1089 {
1090         struct irq_host *h;
1091         unsigned int i;
1092
1093         /*
1094          * No mutual exclusion with respect to accessors of the tree is needed
1095          * here as the synchronization is done via the state variable
1096          * revmap_trees_allocated.
1097          */
1098         list_for_each_entry(h, &irq_hosts, link) {
1099                 if (h->revmap_type == IRQ_HOST_MAP_TREE)
1100                         INIT_RADIX_TREE(&h->revmap_data.tree, GFP_KERNEL);
1101         }
1102
1103         /*
1104          * Make sure the radix trees inits are visible before setting
1105          * the flag
1106          */
1107         smp_wmb();
1108         revmap_trees_allocated = 1;
1109
1110         /*
1111          * Insert the reverse mapping for those interrupts already present
1112          * in irq_map[].
1113          */
1114         mutex_lock(&revmap_trees_mutex);
1115         for (i = 0; i < irq_virq_count; i++) {
1116                 if (irq_map[i].host &&
1117                     (irq_map[i].host->revmap_type == IRQ_HOST_MAP_TREE))
1118                         radix_tree_insert(&irq_map[i].host->revmap_data.tree,
1119                                           irq_map[i].hwirq, &irq_map[i]);
1120         }
1121         mutex_unlock(&revmap_trees_mutex);
1122
1123         /*
1124          * Make sure the radix trees insertions are visible before setting
1125          * the flag
1126          */
1127         smp_wmb();
1128         revmap_trees_allocated = 2;
1129
1130         return 0;
1131 }
1132 arch_initcall(irq_late_init);
1133
1134 #ifdef CONFIG_VIRQ_DEBUG
1135 static int virq_debug_show(struct seq_file *m, void *private)
1136 {
1137         unsigned long flags;
1138         struct irq_desc *desc;
1139         const char *p;
1140         static const char none[] = "none";
1141         int i;
1142
1143         seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",
1144                       "chip name", "host name");
1145
1146         for (i = 1; i < nr_irqs; i++) {
1147                 desc = irq_to_desc(i);
1148                 if (!desc)
1149                         continue;
1150
1151                 raw_spin_lock_irqsave(&desc->lock, flags);
1152
1153                 if (desc->action && desc->action->handler) {
1154                         struct irq_chip *chip;
1155
1156                         seq_printf(m, "%5d  ", i);
1157                         seq_printf(m, "0x%05lx  ", virq_to_hw(i));
1158
1159                         chip = get_irq_desc_chip(desc);
1160                         if (chip && chip->name)
1161                                 p = chip->name;
1162                         else
1163                                 p = none;
1164                         seq_printf(m, "%-15s  ", p);
1165
1166                         if (irq_map[i].host && irq_map[i].host->of_node)
1167                                 p = irq_map[i].host->of_node->full_name;
1168                         else
1169                                 p = none;
1170                         seq_printf(m, "%s\n", p);
1171                 }
1172
1173                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1174         }
1175
1176         return 0;
1177 }
1178
1179 static int virq_debug_open(struct inode *inode, struct file *file)
1180 {
1181         return single_open(file, virq_debug_show, inode->i_private);
1182 }
1183
1184 static const struct file_operations virq_debug_fops = {
1185         .open = virq_debug_open,
1186         .read = seq_read,
1187         .llseek = seq_lseek,
1188         .release = single_release,
1189 };
1190
1191 static int __init irq_debugfs_init(void)
1192 {
1193         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1194                                  NULL, &virq_debug_fops) == NULL)
1195                 return -ENOMEM;
1196
1197         return 0;
1198 }
1199 __initcall(irq_debugfs_init);
1200 #endif /* CONFIG_VIRQ_DEBUG */
1201
1202 #ifdef CONFIG_PPC64
1203 static int __init setup_noirqdistrib(char *str)
1204 {
1205         distribute_irqs = 0;
1206         return 1;
1207 }
1208
1209 __setup("noirqdistrib", setup_noirqdistrib);
1210 #endif /* CONFIG_PPC64 */