arch/powerpc/kernel/irq.c

   1 /*
   2  *  arch/ppc/kernel/irq.c
   3  *
   4  *  Derived from arch/i386/kernel/irq.c
   5  *    Copyright (C) 1992 Linus Torvalds
   6  *  Adapted from arch/i386 by Gary Thomas
   7  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   8  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
   9  *    Copyright (C) 1996-2001 Cort Dougan
  10  *  Adapted for Power Macintosh by Paul Mackerras
  11  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
  12  *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License
  16  * as published by the Free Software Foundation; either version
  17  * 2 of the License, or (at your option) any later version.
  18  *
  19  * This file contains the code used by various IRQ handling routines:
  20  * asking for different IRQ's should be done through these routines
  21  * instead of just grabbing them. Thus setups with different IRQ numbers
  22  * shouldn't result in any weird surprises, and installing new handlers
  23  * should be easier.
  24  *
  25  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
  26  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
  27  * mask register (of which only 16 are defined), hence the weird shifting
  28  * and complement of the cached_irq_mask.  I want to be able to stuff
  29  * this right into the SIU SMASK register.
  30  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
  31  * to reduce code space and undefined function references.
  32  */
  33
  34 #include <linux/errno.h>
  35 #include <linux/module.h>
  36 #include <linux/threads.h>
  37 #include <linux/kernel_stat.h>
  38 #include <linux/signal.h>
  39 #include <linux/sched.h>
  40 #include <linux/ptrace.h>
  41 #include <linux/ioport.h>
  42 #include <linux/interrupt.h>
  43 #include <linux/timex.h>
  44 #include <linux/config.h>
  45 #include <linux/init.h>
  46 #include <linux/slab.h>
  47 #include <linux/pci.h>
  48 #include <linux/delay.h>
  49 #include <linux/irq.h>
  50 #include <linux/proc_fs.h>
  51 #include <linux/random.h>
  52 #include <linux/seq_file.h>
  53 #include <linux/cpumask.h>
  54 #include <linux/profile.h>
  55 #include <linux/bitops.h>
  56 #ifdef CONFIG_PPC64
  57 #include <linux/kallsyms.h>
  58 #endif
  59
  60 #include <asm/uaccess.h>
  61 #include <asm/system.h>
  62 #include <asm/io.h>
  63 #include <asm/pgtable.h>
  64 #include <asm/irq.h>
  65 #include <asm/cache.h>
  66 #include <asm/prom.h>
  67 #include <asm/ptrace.h>
  68 #include <asm/machdep.h>
  69 #ifdef CONFIG_PPC64
  70 #include <asm/iseries/it_lp_queue.h>
  71 #include <asm/paca.h>
  72 #endif
  73
  74 int __irq_offset_value;
  75 #ifdef CONFIG_PPC32
  76 EXPORT_SYMBOL(__irq_offset_value);
  77 #endif
  78
  79 static int ppc_spurious_interrupts;
  80
  81 #if defined(CONFIG_PPC_ISERIES) && defined(CONFIG_SMP)
  82 extern void iSeries_smp_message_recv(struct pt_regs *);
  83 #endif
  84
  85 #ifdef CONFIG_PPC32
  86 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
  87
  88 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
  89 atomic_t ppc_n_lost_interrupts;
  90
  91 #ifdef CONFIG_TAU_INT
  92 extern int tau_initialized;
  93 extern int tau_interrupts(int);
  94 #endif
  95
  96 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
  97 extern atomic_t ipi_recv;
  98 extern atomic_t ipi_sent;
  99 #endif
 100 #endif /* CONFIG_PPC32 */
 101
 102 #ifdef CONFIG_PPC64
 103 EXPORT_SYMBOL(irq_desc);
 104
 105 int distribute_irqs = 1;
 106 u64 ppc64_interrupt_controller;
 107 #endif /* CONFIG_PPC64 */
 108
 109 int show_interrupts(struct seq_file *p, void *v)
 110 {
 111         int i = *(loff_t *)v, j;
 112         struct irqaction *action;
 113         irq_desc_t *desc;
 114         unsigned long flags;
 115
 116         if (i == 0) {
 117                 seq_puts(p, "           ");
 118                 for_each_online_cpu(j)
 119                         seq_printf(p, "CPU%d       ", j);
 120                 seq_putc(p, '\n');
 121         }
 122
 123         if (i < NR_IRQS) {
 124                 desc = get_irq_desc(i);
 125                 spin_lock_irqsave(&desc->lock, flags);
 126                 action = desc->action;
 127                 if (!action || !action->handler)
 128                         goto skip;
 129                 seq_printf(p, "%3d: ", i);
 130 #ifdef CONFIG_SMP
 131                 for_each_online_cpu(j)
 132                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 133 #else
 134                 seq_printf(p, "%10u ", kstat_irqs(i));
 135 #endif /* CONFIG_SMP */
 136                 if (desc->handler)
 137                         seq_printf(p, " %s ", desc->handler->typename);
 138                 else
 139                         seq_puts(p, "  None      ");
 140                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 141                 seq_printf(p, "    %s", action->name);
 142                 for (action = action->next; action; action = action->next)
 143                         seq_printf(p, ", %s", action->name);
 144                 seq_putc(p, '\n');
 145 skip:
 146                 spin_unlock_irqrestore(&desc->lock, flags);
 147         } else if (i == NR_IRQS) {
 148 #ifdef CONFIG_PPC32
 149 #ifdef CONFIG_TAU_INT
 150                 if (tau_initialized){
 151                         seq_puts(p, "TAU: ");
 152                         for (j = 0; j < NR_CPUS; j++)
 153                                 if (cpu_online(j))
 154                                         seq_printf(p, "%10u ", tau_interrupts(j));
 155                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 156                 }
 157 #endif
 158 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
 159                 /* should this be per processor send/receive? */
 160                 seq_printf(p, "IPI (recv/sent): %10u/%u\n",
 161                                 atomic_read(&ipi_recv), atomic_read(&ipi_sent));
 162 #endif
 163 #endif /* CONFIG_PPC32 */
 164                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 165         }
 166         return 0;
 167 }
 168
 169 #ifdef CONFIG_HOTPLUG_CPU
 170 void fixup_irqs(cpumask_t map)
 171 {
 172         unsigned int irq;
 173         static int warned;
 174
 175         for_each_irq(irq) {
 176                 cpumask_t mask;
 177
 178                 if (irq_desc[irq].status & IRQ_PER_CPU)
 179                         continue;
 180
 181                 cpus_and(mask, irq_affinity[irq], map);
 182                 if (any_online_cpu(mask) == NR_CPUS) {
 183                         printk("Breaking affinity for irq %i\n", irq);
 184                         mask = map;
 185                 }
 186                 if (irq_desc[irq].handler->set_affinity)
 187                         irq_desc[irq].handler->set_affinity(irq, mask);
 188                 else if (irq_desc[irq].action && !(warned++))
 189                         printk("Cannot set affinity for irq %i\n", irq);
 190         }
 191
 192         local_irq_enable();
 193         mdelay(1);
 194         local_irq_disable();
 195 }
 196 #endif
 197
 198 #ifdef CONFIG_PPC_ISERIES
 199 void do_IRQ(struct pt_regs *regs)
 200 {
 201         struct paca_struct *lpaca;
 202
 203         irq_enter();
 204
 205 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 206         /* Debugging check for stack overflow: is there less than 2KB free? */
 207         {
 208                 long sp;
 209
 210                 sp = __get_SP() & (THREAD_SIZE-1);
 211
 212                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 213                         printk("do_IRQ: stack overflow: %ld\n",
 214                                 sp - sizeof(struct thread_info));
 215                         dump_stack();
 216                 }
 217         }
 218 #endif
 219
 220         lpaca = get_paca();
 221 #ifdef CONFIG_SMP
 222         if (lpaca->lppaca.int_dword.fields.ipi_cnt) {
 223                 lpaca->lppaca.int_dword.fields.ipi_cnt = 0;
 224                 iSeries_smp_message_recv(regs);
 225         }
 226 #endif /* CONFIG_SMP */
 227         if (hvlpevent_is_pending())
 228                 process_hvlpevents(regs);
 229
 230         irq_exit();
 231
 232         if (lpaca->lppaca.int_dword.fields.decr_int) {
 233                 lpaca->lppaca.int_dword.fields.decr_int = 0;
 234                 /* Signal a fake decrementer interrupt */
 235                 timer_interrupt(regs);
 236         }
 237 }
 238
 239 #else   /* CONFIG_PPC_ISERIES */
 240
 241 void do_IRQ(struct pt_regs *regs)
 242 {
 243         int irq;
 244 #ifdef CONFIG_IRQSTACKS
 245         struct thread_info *curtp, *irqtp;
 246 #endif
 247
 248         irq_enter();
 249
 250 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 251         /* Debugging check for stack overflow: is there less than 2KB free? */
 252         {
 253                 long sp;
 254
 255                 sp = __get_SP() & (THREAD_SIZE-1);
 256
 257                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 258                         printk("do_IRQ: stack overflow: %ld\n",
 259                                 sp - sizeof(struct thread_info));
 260                         dump_stack();
 261                 }
 262         }
 263 #endif
 264
 265         /*
 266          * Every platform is required to implement ppc_md.get_irq.
 267          * This function will either return an irq number or -1 to
 268          * indicate there are no more pending.
 269          * The value -2 is for buggy hardware and means that this IRQ
 270          * has already been handled. -- Tom
 271          */
 272         irq = ppc_md.get_irq(regs);
 273
 274         if (irq >= 0) {
 275 #ifdef CONFIG_IRQSTACKS
 276                 /* Switch to the irq stack to handle this */
 277                 curtp = current_thread_info();
 278                 irqtp = hardirq_ctx[smp_processor_id()];
 279                 if (curtp != irqtp) {
 280                         irqtp->task = curtp->task;
 281                         irqtp->flags = 0;
 282                         call___do_IRQ(irq, regs, irqtp);
 283                         irqtp->task = NULL;
 284                         if (irqtp->flags)
 285                                 set_bits(irqtp->flags, &curtp->flags);
 286                 } else
 287 #endif
 288                         __do_IRQ(irq, regs);
 289         } else
 290 #ifdef CONFIG_PPC32
 291                 if (irq != -2)
 292 #endif
 293                         /* That's not SMP safe ... but who cares ? */
 294                         ppc_spurious_interrupts++;
 295         irq_exit();
 296 }
 297
 298 #endif  /* CONFIG_PPC_ISERIES */
 299
 300 void __init init_IRQ(void)
 301 {
 302 #ifdef CONFIG_PPC64
 303         static int once = 0;
 304
 305         if (once)
 306                 return;
 307
 308         once++;
 309
 310 #endif
 311         ppc_md.init_IRQ();
 312 #ifdef CONFIG_PPC64
 313         irq_ctx_init();
 314 #endif
 315 }
 316
 317 #ifdef CONFIG_PPC64
 318 /*
 319  * Virtual IRQ mapping code, used on systems with XICS interrupt controllers.
 320  */
 321
 322 #define UNDEFINED_IRQ 0xffffffff
 323 unsigned int virt_irq_to_real_map[NR_IRQS];
 324
 325 /*
 326  * Don't use virtual irqs 0, 1, 2 for devices.
 327  * The pcnet32 driver considers interrupt numbers < 2 to be invalid,
 328  * and 2 is the XICS IPI interrupt.
 329  * We limit virtual irqs to 17 less than NR_IRQS so that when we
 330  * offset them by 16 (to reserve the first 16 for ISA interrupts)
 331  * we don't end up with an interrupt number >= NR_IRQS.
 332  */
 333 #define MIN_VIRT_IRQ    3
 334 #define MAX_VIRT_IRQ    (NR_IRQS - NUM_ISA_INTERRUPTS - 1)
 335 #define NR_VIRT_IRQS    (MAX_VIRT_IRQ - MIN_VIRT_IRQ + 1)
 336
 337 void
 338 virt_irq_init(void)
 339 {
 340         int i;
 341         for (i = 0; i < NR_IRQS; i++)
 342                 virt_irq_to_real_map[i] = UNDEFINED_IRQ;
 343 }
 344
 345 /* Create a mapping for a real_irq if it doesn't already exist.
 346  * Return the virtual irq as a convenience.
 347  */
 348 int virt_irq_create_mapping(unsigned int real_irq)
 349 {
 350         unsigned int virq, first_virq;
 351         static int warned;
 352
 353         if (ppc64_interrupt_controller == IC_OPEN_PIC)
 354                 return real_irq;        /* no mapping for openpic (for now) */
 355
 356         if (ppc64_interrupt_controller == IC_CELL_PIC)
 357                 return real_irq;        /* no mapping for iic either */
 358
 359         /* don't map interrupts < MIN_VIRT_IRQ */
 360         if (real_irq < MIN_VIRT_IRQ) {
 361                 virt_irq_to_real_map[real_irq] = real_irq;
 362                 return real_irq;
 363         }
 364
 365         /* map to a number between MIN_VIRT_IRQ and MAX_VIRT_IRQ */
 366         virq = real_irq;
 367         if (virq > MAX_VIRT_IRQ)
 368                 virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
 369
 370         /* search for this number or a free slot */
 371         first_virq = virq;
 372         while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) {
 373                 if (virt_irq_to_real_map[virq] == real_irq)
 374                         return virq;
 375                 if (++virq > MAX_VIRT_IRQ)
 376                         virq = MIN_VIRT_IRQ;
 377                 if (virq == first_virq)
 378                         goto nospace;   /* oops, no free slots */
 379         }
 380
 381         virt_irq_to_real_map[virq] = real_irq;
 382         return virq;
 383
 384  nospace:
 385         if (!warned) {
 386                 printk(KERN_CRIT "Interrupt table is full\n");
 387                 printk(KERN_CRIT "Increase NR_IRQS (currently %d) "
 388                        "in your kernel sources and rebuild.\n", NR_IRQS);
 389                 warned = 1;
 390         }
 391         return NO_IRQ;
 392 }
 393
 394 /*
 395  * In most cases will get a hit on the very first slot checked in the
 396  * virt_irq_to_real_map.  Only when there are a large number of
 397  * IRQs will this be expensive.
 398  */
 399 unsigned int real_irq_to_virt_slowpath(unsigned int real_irq)
 400 {
 401         unsigned int virq;
 402         unsigned int first_virq;
 403
 404         virq = real_irq;
 405
 406         if (virq > MAX_VIRT_IRQ)
 407                 virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
 408
 409         first_virq = virq;
 410
 411         do {
 412                 if (virt_irq_to_real_map[virq] == real_irq)
 413                         return virq;
 414
 415                 virq++;
 416
 417                 if (virq >= MAX_VIRT_IRQ)
 418                         virq = 0;
 419
 420         } while (first_virq != virq);
 421
 422         return NO_IRQ;
 423
 424 }
 425
 426 #ifdef CONFIG_IRQSTACKS
 427 struct thread_info *softirq_ctx[NR_CPUS];
 428 struct thread_info *hardirq_ctx[NR_CPUS];
 429
 430 void irq_ctx_init(void)
 431 {
 432         struct thread_info *tp;
 433         int i;
 434
 435         for_each_cpu(i) {
 436                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 437                 tp = softirq_ctx[i];
 438                 tp->cpu = i;
 439                 tp->preempt_count = SOFTIRQ_OFFSET;
 440
 441                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 442                 tp = hardirq_ctx[i];
 443                 tp->cpu = i;
 444                 tp->preempt_count = HARDIRQ_OFFSET;
 445         }
 446 }
 447
 448 void do_softirq(void)
 449 {
 450         unsigned long flags;
 451         struct thread_info *curtp, *irqtp;
 452
 453         if (in_interrupt())
 454                 return;
 455
 456         local_irq_save(flags);
 457
 458         if (local_softirq_pending()) {
 459                 curtp = current_thread_info();
 460                 irqtp = softirq_ctx[smp_processor_id()];
 461                 irqtp->task = curtp->task;
 462                 call_do_softirq(irqtp);
 463                 irqtp->task = NULL;
 464         }
 465
 466         local_irq_restore(flags);
 467 }
 468 EXPORT_SYMBOL(do_softirq);
 469
 470 #endif /* CONFIG_IRQSTACKS */
 471
 472 static int __init setup_noirqdistrib(char *str)
 473 {
 474         distribute_irqs = 0;
 475         return 1;
 476 }
 477
 478 __setup("noirqdistrib", setup_noirqdistrib);
 479 #endif /* CONFIG_PPC64 */