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/module.h>
  35 #include <linux/threads.h>
  36 #include <linux/kernel_stat.h>
  37 #include <linux/signal.h>
  38 #include <linux/sched.h>
  39 #include <linux/ptrace.h>
  40 #include <linux/ioport.h>
  41 #include <linux/interrupt.h>
  42 #include <linux/timex.h>
  43 #include <linux/config.h>
  44 #include <linux/init.h>
  45 #include <linux/slab.h>
  46 #include <linux/delay.h>
  47 #include <linux/irq.h>
  48 #include <linux/seq_file.h>
  49 #include <linux/cpumask.h>
  50 #include <linux/profile.h>
  51 #include <linux/bitops.h>
  52
  53 #include <asm/uaccess.h>
  54 #include <asm/system.h>
  55 #include <asm/io.h>
  56 #include <asm/pgtable.h>
  57 #include <asm/irq.h>
  58 #include <asm/cache.h>
  59 #include <asm/prom.h>
  60 #include <asm/ptrace.h>
  61 #include <asm/machdep.h>
  62 #ifdef CONFIG_PPC_ISERIES
  63 #include <asm/paca.h>
  64 #endif
  65
  66 int __irq_offset_value;
  67 #ifdef CONFIG_PPC32
  68 EXPORT_SYMBOL(__irq_offset_value);
  69 #endif
  70
  71 static int ppc_spurious_interrupts;
  72
  73 #ifdef CONFIG_PPC32
  74 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
  75
  76 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
  77 atomic_t ppc_n_lost_interrupts;
  78
  79 #ifdef CONFIG_TAU_INT
  80 extern int tau_initialized;
  81 extern int tau_interrupts(int);
  82 #endif
  83
  84 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
  85 extern atomic_t ipi_recv;
  86 extern atomic_t ipi_sent;
  87 #endif
  88 #endif /* CONFIG_PPC32 */
  89
  90 #ifdef CONFIG_PPC64
  91 EXPORT_SYMBOL(irq_desc);
  92
  93 int distribute_irqs = 1;
  94 u64 ppc64_interrupt_controller;
  95 #endif /* CONFIG_PPC64 */
  96
  97 int show_interrupts(struct seq_file *p, void *v)
  98 {
  99         int i = *(loff_t *)v, j;
 100         struct irqaction *action;
 101         irq_desc_t *desc;
 102         unsigned long flags;
 103
 104         if (i == 0) {
 105                 seq_puts(p, "           ");
 106                 for_each_online_cpu(j)
 107                         seq_printf(p, "CPU%d       ", j);
 108                 seq_putc(p, '\n');
 109         }
 110
 111         if (i < NR_IRQS) {
 112                 desc = get_irq_desc(i);
 113                 spin_lock_irqsave(&desc->lock, flags);
 114                 action = desc->action;
 115                 if (!action || !action->handler)
 116                         goto skip;
 117                 seq_printf(p, "%3d: ", i);
 118 #ifdef CONFIG_SMP
 119                 for_each_online_cpu(j)
 120                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 121 #else
 122                 seq_printf(p, "%10u ", kstat_irqs(i));
 123 #endif /* CONFIG_SMP */
 124                 if (desc->handler)
 125                         seq_printf(p, " %s ", desc->handler->typename);
 126                 else
 127                         seq_puts(p, "  None      ");
 128                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 129                 seq_printf(p, "    %s", action->name);
 130                 for (action = action->next; action; action = action->next)
 131                         seq_printf(p, ", %s", action->name);
 132                 seq_putc(p, '\n');
 133 skip:
 134                 spin_unlock_irqrestore(&desc->lock, flags);
 135         } else if (i == NR_IRQS) {
 136 #ifdef CONFIG_PPC32
 137 #ifdef CONFIG_TAU_INT
 138                 if (tau_initialized){
 139                         seq_puts(p, "TAU: ");
 140                         for (j = 0; j < NR_CPUS; j++)
 141                                 if (cpu_online(j))
 142                                         seq_printf(p, "%10u ", tau_interrupts(j));
 143                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 144                 }
 145 #endif
 146 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
 147                 /* should this be per processor send/receive? */
 148                 seq_printf(p, "IPI (recv/sent): %10u/%u\n",
 149                                 atomic_read(&ipi_recv), atomic_read(&ipi_sent));
 150 #endif
 151 #endif /* CONFIG_PPC32 */
 152                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 153         }
 154         return 0;
 155 }
 156
 157 #ifdef CONFIG_HOTPLUG_CPU
 158 void fixup_irqs(cpumask_t map)
 159 {
 160         unsigned int irq;
 161         static int warned;
 162
 163         for_each_irq(irq) {
 164                 cpumask_t mask;
 165
 166                 if (irq_desc[irq].status & IRQ_PER_CPU)
 167                         continue;
 168
 169                 cpus_and(mask, irq_affinity[irq], map);
 170                 if (any_online_cpu(mask) == NR_CPUS) {
 171                         printk("Breaking affinity for irq %i\n", irq);
 172                         mask = map;
 173                 }
 174                 if (irq_desc[irq].handler->set_affinity)
 175                         irq_desc[irq].handler->set_affinity(irq, mask);
 176                 else if (irq_desc[irq].action && !(warned++))
 177                         printk("Cannot set affinity for irq %i\n", irq);
 178         }
 179
 180         local_irq_enable();
 181         mdelay(1);
 182         local_irq_disable();
 183 }
 184 #endif
 185
 186 void do_IRQ(struct pt_regs *regs)
 187 {
 188         int irq;
 189 #ifdef CONFIG_IRQSTACKS
 190         struct thread_info *curtp, *irqtp;
 191 #endif
 192
 193         irq_enter();
 194
 195 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 196         /* Debugging check for stack overflow: is there less than 2KB free? */
 197         {
 198                 long sp;
 199
 200                 sp = __get_SP() & (THREAD_SIZE-1);
 201
 202                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 203                         printk("do_IRQ: stack overflow: %ld\n",
 204                                 sp - sizeof(struct thread_info));
 205                         dump_stack();
 206                 }
 207         }
 208 #endif
 209
 210         /*
 211          * Every platform is required to implement ppc_md.get_irq.
 212          * This function will either return an irq number or -1 to
 213          * indicate there are no more pending.
 214          * The value -2 is for buggy hardware and means that this IRQ
 215          * has already been handled. -- Tom
 216          */
 217         irq = ppc_md.get_irq(regs);
 218
 219         if (irq >= 0) {
 220 #ifdef CONFIG_IRQSTACKS
 221                 /* Switch to the irq stack to handle this */
 222                 curtp = current_thread_info();
 223                 irqtp = hardirq_ctx[smp_processor_id()];
 224                 if (curtp != irqtp) {
 225                         irqtp->task = curtp->task;
 226                         irqtp->flags = 0;
 227                         call___do_IRQ(irq, regs, irqtp);
 228                         irqtp->task = NULL;
 229                         if (irqtp->flags)
 230                                 set_bits(irqtp->flags, &curtp->flags);
 231                 } else
 232 #endif
 233                         __do_IRQ(irq, regs);
 234         } else if (irq != -2)
 235                 /* That's not SMP safe ... but who cares ? */
 236                 ppc_spurious_interrupts++;
 237
 238         irq_exit();
 239
 240 #ifdef CONFIG_PPC_ISERIES
 241         {
 242                 struct paca_struct *lpaca = get_paca();
 243
 244                 if (lpaca->lppaca.int_dword.fields.decr_int) {
 245                         lpaca->lppaca.int_dword.fields.decr_int = 0;
 246                         /* Signal a fake decrementer interrupt */
 247                         timer_interrupt(regs);
 248                 }
 249         }
 250 #endif
 251 }
 252
 253 void __init init_IRQ(void)
 254 {
 255 #ifdef CONFIG_PPC64
 256         static int once = 0;
 257
 258         if (once)
 259                 return;
 260
 261         once++;
 262
 263 #endif
 264         ppc_md.init_IRQ();
 265 #ifdef CONFIG_PPC64
 266         irq_ctx_init();
 267 #endif
 268 }
 269
 270 #ifdef CONFIG_PPC64
 271 /*
 272  * Virtual IRQ mapping code, used on systems with XICS interrupt controllers.
 273  */
 274
 275 #define UNDEFINED_IRQ 0xffffffff
 276 unsigned int virt_irq_to_real_map[NR_IRQS];
 277
 278 /*
 279  * Don't use virtual irqs 0, 1, 2 for devices.
 280  * The pcnet32 driver considers interrupt numbers < 2 to be invalid,
 281  * and 2 is the XICS IPI interrupt.
 282  * We limit virtual irqs to 17 less than NR_IRQS so that when we
 283  * offset them by 16 (to reserve the first 16 for ISA interrupts)
 284  * we don't end up with an interrupt number >= NR_IRQS.
 285  */
 286 #define MIN_VIRT_IRQ    3
 287 #define MAX_VIRT_IRQ    (NR_IRQS - NUM_ISA_INTERRUPTS - 1)
 288 #define NR_VIRT_IRQS    (MAX_VIRT_IRQ - MIN_VIRT_IRQ + 1)
 289
 290 void
 291 virt_irq_init(void)
 292 {
 293         int i;
 294         for (i = 0; i < NR_IRQS; i++)
 295                 virt_irq_to_real_map[i] = UNDEFINED_IRQ;
 296 }
 297
 298 /* Create a mapping for a real_irq if it doesn't already exist.
 299  * Return the virtual irq as a convenience.
 300  */
 301 int virt_irq_create_mapping(unsigned int real_irq)
 302 {
 303         unsigned int virq, first_virq;
 304         static int warned;
 305
 306         if (ppc64_interrupt_controller == IC_OPEN_PIC)
 307                 return real_irq;        /* no mapping for openpic (for now) */
 308
 309         if (ppc64_interrupt_controller == IC_CELL_PIC)
 310                 return real_irq;        /* no mapping for iic either */
 311
 312         /* don't map interrupts < MIN_VIRT_IRQ */
 313         if (real_irq < MIN_VIRT_IRQ) {
 314                 virt_irq_to_real_map[real_irq] = real_irq;
 315                 return real_irq;
 316         }
 317
 318         /* map to a number between MIN_VIRT_IRQ and MAX_VIRT_IRQ */
 319         virq = real_irq;
 320         if (virq > MAX_VIRT_IRQ)
 321                 virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
 322
 323         /* search for this number or a free slot */
 324         first_virq = virq;
 325         while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) {
 326                 if (virt_irq_to_real_map[virq] == real_irq)
 327                         return virq;
 328                 if (++virq > MAX_VIRT_IRQ)
 329                         virq = MIN_VIRT_IRQ;
 330                 if (virq == first_virq)
 331                         goto nospace;   /* oops, no free slots */
 332         }
 333
 334         virt_irq_to_real_map[virq] = real_irq;
 335         return virq;
 336
 337  nospace:
 338         if (!warned) {
 339                 printk(KERN_CRIT "Interrupt table is full\n");
 340                 printk(KERN_CRIT "Increase NR_IRQS (currently %d) "
 341                        "in your kernel sources and rebuild.\n", NR_IRQS);
 342                 warned = 1;
 343         }
 344         return NO_IRQ;
 345 }
 346
 347 /*
 348  * In most cases will get a hit on the very first slot checked in the
 349  * virt_irq_to_real_map.  Only when there are a large number of
 350  * IRQs will this be expensive.
 351  */
 352 unsigned int real_irq_to_virt_slowpath(unsigned int real_irq)
 353 {
 354         unsigned int virq;
 355         unsigned int first_virq;
 356
 357         virq = real_irq;
 358
 359         if (virq > MAX_VIRT_IRQ)
 360                 virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
 361
 362         first_virq = virq;
 363
 364         do {
 365                 if (virt_irq_to_real_map[virq] == real_irq)
 366                         return virq;
 367
 368                 virq++;
 369
 370                 if (virq >= MAX_VIRT_IRQ)
 371                         virq = 0;
 372
 373         } while (first_virq != virq);
 374
 375         return NO_IRQ;
 376
 377 }
 378
 379 #ifdef CONFIG_IRQSTACKS
 380 struct thread_info *softirq_ctx[NR_CPUS];
 381 struct thread_info *hardirq_ctx[NR_CPUS];
 382
 383 void irq_ctx_init(void)
 384 {
 385         struct thread_info *tp;
 386         int i;
 387
 388         for_each_cpu(i) {
 389                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 390                 tp = softirq_ctx[i];
 391                 tp->cpu = i;
 392                 tp->preempt_count = SOFTIRQ_OFFSET;
 393
 394                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 395                 tp = hardirq_ctx[i];
 396                 tp->cpu = i;
 397                 tp->preempt_count = HARDIRQ_OFFSET;
 398         }
 399 }
 400
 401 void do_softirq(void)
 402 {
 403         unsigned long flags;
 404         struct thread_info *curtp, *irqtp;
 405
 406         if (in_interrupt())
 407                 return;
 408
 409         local_irq_save(flags);
 410
 411         if (local_softirq_pending()) {
 412                 curtp = current_thread_info();
 413                 irqtp = softirq_ctx[smp_processor_id()];
 414                 irqtp->task = curtp->task;
 415                 call_do_softirq(irqtp);
 416                 irqtp->task = NULL;
 417         }
 418
 419         local_irq_restore(flags);
 420 }
 421 EXPORT_SYMBOL(do_softirq);
 422
 423 #endif /* CONFIG_IRQSTACKS */
 424
 425 static int __init setup_noirqdistrib(char *str)
 426 {
 427         distribute_irqs = 0;
 428         return 1;
 429 }
 430
 431 __setup("noirqdistrib", setup_noirqdistrib);
 432 #endif /* CONFIG_PPC64 */