arch/alpha/kernel/irq.c

/* */
This source file includes following definitions.
mask_irq
unmask_irq
disable_irq
enable_irq
get_irq_list
ack_irq
request_irq
free_irq
handle_nmi
unexpected_irq
handle_irq
device_interrupt
isa_device_interrupt
cabriolet_and_eb66p_device_interrupt
eb66_and_eb64p_device_interrupt
srm_device_interrupt
probe_irq_on
probe_irq_off
machine_check
do_entInt
init_IRQ
   1 /*
   2  *      linux/arch/alpha/kernel/irq.c
   3  *
   4  *      Copyright (C) 1995 Linus Torvalds
   5  *
   6  * This file contains the code used by various IRQ handling routines:
   7  * asking for different IRQ's should be done through these routines
   8  * instead of just grabbing them. Thus setups with different IRQ numbers
   9  * shouldn't result in any weird surprises, and installing new handlers
  10  * should be easier.
  11  */
  12 
  13 #include <linux/config.h>
  14 #include <linux/ptrace.h>
  15 #include <linux/errno.h>
  16 #include <linux/kernel_stat.h>
  17 #include <linux/signal.h>
  18 #include <linux/sched.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/malloc.h>
  21 #include <linux/random.h>
  22 
  23 #include <asm/system.h>
  24 #include <asm/io.h>
  25 #include <asm/irq.h>
  26 #include <asm/bitops.h>
  27 #include <asm/dma.h>
  28 
  29 extern void timer_interrupt(struct pt_regs * regs);
  30 
  31 static unsigned char cache_21 = 0xff;
  32 static unsigned char cache_A1 = 0xff;
  33 
  34 #if NR_IRQS == 33
  35   static unsigned int  cache_804 = 0x00ffffef;
  36 #elif NR_IRQS == 32
  37   static unsigned char cache_26 = 0xdf;
  38   static unsigned char cache_27 = 0xff;
  39 #endif
  40 
  41 static void mask_irq(int irq)
     /*  */
  42 {
  43         unsigned long mask;
  44 
  45         if (irq < 16) {
  46                 mask = 1 << (irq & 7);
  47                 if (irq < 8) {
  48                         cache_21 |= mask;
  49                         outb(cache_21, 0x21);
  50                 } else {
  51                         cache_A1 |= mask;
  52                         outb(cache_A1, 0xA1);
  53                 }
  54 #if NR_IRQS == 33
  55         } else {
  56                 mask = 1 << (irq - 16);
  57                 cache_804 |= mask;
  58                 outl(cache_804, 0x804);
  59 #elif NR_IRQS == 32
  60         } else {
  61                 mask = 1 << (irq & 7);
  62                 if (irq < 24) {
  63                         cache_26 |= mask;
  64                         outb(cache_26, 0x26);
  65                 } else {
  66                         cache_27 |= mask;
  67                         outb(cache_27, 0x27);
  68                 }
  69 #endif
  70         }
  71 }
  72 
  73 static void unmask_irq(unsigned long irq)
     /*  */
  74 {
  75         unsigned long mask;
  76 
  77         if (irq < 16) {
  78                 mask = ~(1 << (irq & 7));
  79                 if (irq < 8) {
  80                         cache_21 &= mask;
  81                         outb(cache_21, 0x21);
  82                 } else {
  83                         cache_A1 &= mask;
  84                         outb(cache_A1, 0xA1);
  85                 }
  86 #if NR_IRQS == 33
  87         } else {
  88                 mask = ~(1 << (irq - 16));
  89                 cache_804 &= mask;
  90                 outl(cache_804, 0x804);
  91 #elif NR_IRQS == 32
  92         } else {
  93                 mask = ~(1 << (irq & 7));
  94 
  95                 if (irq < 24) {
  96                         cache_26 &= mask;
  97                         outb(cache_26, 0x26);
  98                 } else {
  99                         cache_27 &= mask;
 100                         outb(cache_27, 0x27);
 101                 }
 102 #endif
 103         }
 104 }
 105 
 106 void disable_irq(unsigned int irq_nr)
     /*  */
 107 {
 108         unsigned long flags;
 109 
 110         save_flags(flags);
 111         cli();
 112         mask_irq(irq_nr);
 113         restore_flags(flags);
 114 }
 115 
 116 void enable_irq(unsigned int irq_nr)
     /*  */
 117 {
 118         unsigned long flags, mask;
 119 
 120         mask = ~(1 << (irq_nr & 7));
 121         save_flags(flags);
 122         cli();
 123         unmask_irq(irq_nr);
 124         restore_flags(flags);
 125 }
 126 
 127 /*
 128  * Initial irq handlers.
 129  */
 130 static struct irqaction *irq_action[NR_IRQS];
 131 
 132 int get_irq_list(char *buf)
     /*  */
 133 {
 134         int i, len = 0;
 135         struct irqaction * action;
 136 
 137         for (i = 0 ; i < NR_IRQS ; i++) {
 138                 action = irq_action[i];
 139                 if (!action) 
 140                         continue;
 141                 len += sprintf(buf+len, "%2d: %8d %c %s",
 142                         i, kstat.interrupts[i],
 143                         (action->flags & SA_INTERRUPT) ? '+' : ' ',
 144                         action->name);
 145                 for (action=action->next; action; action = action->next) {
 146                         len += sprintf(buf+len, ",%s %s",
 147                                 (action->flags & SA_INTERRUPT) ? " +" : "",
 148                                 action->name);
 149                 }
 150                 len += sprintf(buf+len, "\n");
 151         }
 152         return len;
 153 }
 154 
 155 static inline void ack_irq(int irq)
     /*  */
 156 {
 157         if (irq < 16) {
 158                 /* ACK the interrupt making it the lowest priority */
 159                 /*  First the slave .. */
 160                 if (irq > 7) {
 161                         outb(0xE0 | (irq - 8), 0xa0);
 162                         irq = 2;
 163                 }
 164                 /* .. then the master */
 165                 outb(0xE0 | irq, 0x20);
 166         }
 167 }
 168 
 169 int request_irq(unsigned int irq, 
     /*  */
 170                 void (*handler)(int, void *, struct pt_regs *),
 171                 unsigned long irqflags, 
 172                 const char * devname,
 173                 void *dev_id)
 174 {
 175         int shared = 0;
 176         struct irqaction * action, **p;
 177         unsigned long flags;
 178 
 179         if (irq >= NR_IRQS)
 180                 return -EINVAL;
 181         if (!handler)
 182                 return -EINVAL;
 183         p = irq_action + irq;
 184         action = *p;
 185         if (action) {
 186                 /* Can't share interrupts unless both agree to */
 187                 if (!(action->flags & irqflags & SA_SHIRQ))
 188                         return -EBUSY;
 189 
 190                 /* Can't share interrupts unless both are same type */
 191                 if ((action->flags ^ irqflags) & SA_INTERRUPT)
 192                         return -EBUSY;
 193 
 194                 /* add new interrupt at end of irq queue */
 195                 do {
 196                         p = &action->next;
 197                         action = *p;
 198                 } while (action);
 199                 shared = 1;
 200         }
 201 
 202         action = (struct irqaction *)kmalloc(sizeof(struct irqaction), GFP_KERNEL);
 203         if (!action)
 204                 return -ENOMEM;
 205 
 206         if (irqflags & SA_SAMPLE_RANDOM)
 207                 rand_initialize_irq(irq);
 208 
 209         action->handler = handler;
 210         action->flags = irqflags;
 211         action->mask = 0;
 212         action->name = devname;
 213         action->next = NULL;
 214         action->dev_id = dev_id;
 215 
 216         save_flags(flags);
 217         cli();
 218         *p = action;
 219 
 220         if (!shared)
 221                 unmask_irq(irq);
 222 
 223         restore_flags(flags);
 224         return 0;
 225 }
 226                 
 227 void free_irq(unsigned int irq, void *dev_id)
     /*  */
 228 {
 229         struct irqaction * action, **p;
 230         unsigned long flags;
 231 
 232         if (irq >= NR_IRQS) {
 233                 printk("Trying to free IRQ%d\n",irq);
 234                 return;
 235         }
 236         for (p = irq + irq_action; (action = *p) != NULL; p = &action->next) {
 237                 if (action->dev_id != dev_id)
 238                         continue;
 239 
 240                 /* Found it - now free it */
 241                 save_flags(flags);
 242                 cli();
 243                 *p = action->next;
 244                 if (!irq[irq_action])
 245                         mask_irq(irq);
 246                 restore_flags(flags);
 247                 kfree(action);
 248                 return;
 249         }
 250         printk("Trying to free free IRQ%d\n",irq);
 251 }
 252 
 253 static inline void handle_nmi(struct pt_regs * regs)
     /*  */
 254 {
 255         printk("Whee.. NMI received. Probable hardware error\n");
 256         printk("61=%02x, 461=%02x\n", inb(0x61), inb(0x461));
 257 }
 258 
 259 static void unexpected_irq(int irq, struct pt_regs * regs)
     /*  */
 260 {
 261         struct irqaction *action;
 262         int i;
 263 
 264         printk("IO device interrupt, irq = %d\n", irq);
 265         printk("PC = %016lx PS=%04lx\n", regs->pc, regs->ps);
 266         printk("Expecting: ");
 267         for (i = 0; i < 16; i++)
 268                 if ((action = irq_action[i]))
 269                         while (action->handler) {
 270                                 printk("[%s:%d] ", action->name, i);
 271                                 action = action->next;
 272                         }
 273         printk("\n");
 274 #if defined(CONFIG_ALPHA_JENSEN)
 275         printk("64=%02x, 60=%02x, 3fa=%02x 2fa=%02x\n",
 276                 inb(0x64), inb(0x60), inb(0x3fa), inb(0x2fa));
 277         outb(0x0c, 0x3fc);
 278         outb(0x0c, 0x2fc);
 279         outb(0,0x61);
 280         outb(0,0x461);
 281 #endif
 282 }
 283 
 284 static inline void handle_irq(int irq, void *dev_id, struct pt_regs * regs)
     /*  */
 285 {
 286         struct irqaction * action = irq_action[irq];
 287 
 288         kstat.interrupts[irq]++;
 289         if (!action) {
 290                 unexpected_irq(irq, regs);
 291                 return;
 292         }
 293         do {
 294                 action->handler(irq, action->dev_id, regs);
 295                 action = action->next;
 296         } while (action);
 297 }
 298 
 299 static inline void device_interrupt(int irq, int ack, struct pt_regs * regs)
     /*  */
 300 {
 301         struct irqaction * action;
 302 
 303         if ((unsigned) irq > NR_IRQS) {
 304                 printk("device_interrupt: unexpected interrupt %d\n", irq);
 305                 return;
 306         }
 307 
 308         kstat.interrupts[irq]++;
 309         action = irq_action[irq];
 310         if (action) {
 311                 /* quick interrupts get executed with no extra overhead */
 312                 if (action->flags & SA_INTERRUPT) {
 313                         while (action) {
 314                                 action->handler(irq, action->dev_id, regs);
 315                                 action = action->next;
 316                         }
 317                         ack_irq(ack);
 318                         return;
 319                 }
 320         }
 321         /*
 322          * For normal interrupts, we mask it out, and then ACK it.
 323          * This way another (more timing-critical) interrupt can
 324          * come through while we're doing this one.
 325          *
 326          * Note! A irq without a handler gets masked and acked, but
 327          * never unmasked. The autoirq stuff depends on this (it looks
 328          * at the masks before and after doing the probing).
 329          */
 330         mask_irq(ack);
 331         ack_irq(ack);
 332         if (!action)
 333                 return;
 334         if (action->flags & SA_SAMPLE_RANDOM)
 335                 add_interrupt_randomness(irq);
 336         while (action) {
 337                 action->handler(irq, action->dev_id, regs);
 338                 action = action->next;
 339         }
 340         unmask_irq(ack);
 341 }
 342 
 343 /*
 344  * Handle ISA interrupt via the PICs.
 345  */
 346 static inline void isa_device_interrupt(unsigned long vector,
     /*  */
 347                                         struct pt_regs * regs)
 348 {
 349 #if defined(CONFIG_ALPHA_APECS)
 350 #       define IACK_SC  APECS_IACK_SC
 351 #elif defined(CONFIG_ALPHA_LCA)
 352 #       define IACK_SC  LCA_IACK_SC
 353 #elif defined(CONFIG_ALPHA_ALCOR)
 354 #       define IACK_SC  ALCOR_IACK_SC
 355 #else
 356         /*
 357          * This is bogus but necessary to get it to compile
 358          * on all platforms.  If you try to use this on any
 359          * other than the intended platforms, you'll notice
 360          * real fast...
 361          */
 362 #       define IACK_SC  1L
 363 #endif
 364         int j;
 365 
 366 #if 1
 367         /*
 368          * Generate a PCI interrupt acknowledge cycle.  The PIC will
 369          * respond with the interrupt vector of the highest priority
 370          * interrupt that is pending.  The PALcode sets up the
 371          * interrupts vectors such that irq level L generates vector
 372          * L.
 373          */
 374         j = *(volatile int *) IACK_SC;
 375         j &= 0xff;
 376         if (j == 7) {
 377                 if (!(inb(0x20) & 0x80)) {
 378                         /* it's only a passive release... */
 379                         return;
 380                 }
 381         }
 382         device_interrupt(j, j, regs);
 383 #else
 384         unsigned long pic;
 385 
 386         /*
 387          * It seems to me that the probability of two or more *device*
 388          * interrupts occuring at almost exactly the same time is
 389          * pretty low.  So why pay the price of checking for
 390          * additional interrupts here if the common case can be
 391          * handled so much easier?
 392          */
 393         /* 
 394          *  The first read of gives you *all* interrupting lines.
 395          *  Therefore, read the mask register and and out those lines
 396          *  not enabled.  Note that some documentation has 21 and a1 
 397          *  write only.  This is not true.
 398          */
 399         pic = inb(0x20) | (inb(0xA0) << 8);     /* read isr */
 400         pic &= ~((cache_A1 << 8) | cache_21);   /* apply mask */
 401         pic &= 0xFFFB;                          /* mask out cascade */
 402 
 403         while (pic) {
 404                 j = ffz(~pic);
 405                 pic &= pic - 1;
 406                 device_interrupt(j, j, regs);
 407         }
 408 #endif
 409 }
 410 
 411 static inline void cabriolet_and_eb66p_device_interrupt(unsigned long vector,
     /*  */
 412                                                         struct pt_regs * regs)
 413 {
 414         unsigned long pld;
 415         unsigned int i;
 416         unsigned long flags;
 417 
 418         save_flags(flags);
 419         cli();
 420 
 421         /* read the interrupt summary registers */
 422         pld = inb(0x804) | (inb(0x805) << 8) | (inb(0x806) << 16);
 423 
 424 #if 0
 425         printk("[0x%04X/0x%04X]", pld, inb(0x20) | (inb(0xA0) << 8));
 426 #endif
 427 
 428         /*
 429          * Now for every possible bit set, work through them and call
 430          * the appropriate interrupt handler.
 431          */
 432         while (pld) {
 433                 i = ffz(~pld);
 434                 pld &= pld - 1; /* clear least bit set */
 435                 if (i == 4) {
 436                         isa_device_interrupt(vector, regs);
 437                 } else {
 438                         device_interrupt(16 + i, 16 + i, regs);
 439                 }
 440         }
 441         restore_flags(flags);
 442 }
 443 
 444 static inline void eb66_and_eb64p_device_interrupt(unsigned long vector,
     /*  */
 445                                                    struct pt_regs * regs)
 446 {
 447         unsigned long pld;
 448         unsigned int i;
 449         unsigned long flags;
 450 
 451         save_flags(flags);
 452         cli();
 453 
 454         /* read the interrupt summary registers */
 455         pld = inb(0x26) | (inb(0x27) << 8);
 456         /*
 457          * Now, for every possible bit set, work through
 458          * them and call the appropriate interrupt handler.
 459          */
 460         while (pld) {
 461                 i = ffz(~pld);
 462                 pld &= pld - 1; /* clear least bit set */
 463 
 464                 if (i == 5) {
 465                         isa_device_interrupt(vector, regs);
 466                 } else {
 467                         device_interrupt(16 + i, 16 + i, regs);
 468                 }
 469         }
 470         restore_flags(flags);
 471 }
 472 
 473 /*
 474  * Jensen is special: the vector is 0x8X0 for EISA interrupt X, and
 475  * 0x9X0 for the local motherboard interrupts..
 476  *
 477  *      0x660 - NMI
 478  *
 479  *      0x800 - IRQ0  interval timer (not used, as we use the RTC timer)
 480  *      0x810 - IRQ1  line printer (duh..)
 481  *      0x860 - IRQ6  floppy disk
 482  *      0x8E0 - IRQ14 SCSI controller
 483  *
 484  *      0x900 - COM1
 485  *      0x920 - COM2
 486  *      0x980 - keyboard
 487  *      0x990 - mouse
 488  *
 489  * PCI-based systems are more sane: they don't have the local
 490  * interrupts at all, and have only normal PCI interrupts from
 491  * devices.  Happily it's easy enough to do a sane mapping from the
 492  * Jensen..  Note that this means that we may have to do a hardware
 493  * "ack" to a different interrupt than we report to the rest of the
 494  * world.
 495  */
 496 static inline void srm_device_interrupt(unsigned long vector, struct pt_regs * regs)
     /*  */
 497 {
 498         int irq, ack;
 499         unsigned long flags;
 500 
 501         save_flags(flags);
 502         cli();
 503 
 504 
 505         ack = irq = (vector - 0x800) >> 4;
 506 
 507 #ifdef CONFIG_ALPHA_JENSEN
 508         switch (vector) {
 509               case 0x660: handle_nmi(regs); return;
 510                 /* local device interrupts: */
 511               case 0x900: handle_irq(4, regs); return;  /* com1 -> irq 4 */
 512               case 0x920: handle_irq(3, regs); return;  /* com2 -> irq 3 */
 513               case 0x980: handle_irq(1, regs); return;  /* kbd -> irq 1 */
 514               case 0x990: handle_irq(9, regs); return;  /* mouse -> irq 9 */
 515               default:
 516                 if (vector > 0x900) {
 517                         printk("Unknown local interrupt %lx\n", vector);
 518                 }
 519         }
 520         /* irq1 is supposed to be the keyboard, silly Jensen (is this really needed??) */
 521         if (irq == 1)
 522                 irq = 7;
 523 #endif /* CONFIG_ALPHA_JENSEN */
 524 
 525         device_interrupt(irq, ack, regs);
 526 
 527         restore_flags(flags) ;
 528 }
 529 
 530 #if NR_IRQS > 64
 531 #  error Number of irqs limited to 64 due to interrupt-probing.
 532 #endif
 533 
 534 /*
 535  * Start listening for interrupts..
 536  */
 537 unsigned long probe_irq_on(void)
     /*  */
 538 {
 539         struct irqaction * action;
 540         unsigned long irqs = 0, irqmask;
 541         unsigned long delay;
 542         unsigned int i;
 543 
 544         for (i = NR_IRQS - 1; i > 0; i--) {
 545                 action = irq_action[i];
 546                 if (!action) {
 547                         enable_irq(i);
 548                         irqs |= (1 << i);
 549                 }
 550         }
 551 
 552         /* wait for spurious interrupts to mask themselves out again */
 553         for (delay = jiffies + HZ/10; delay > jiffies; )
 554                 /* about 100 ms delay */;
 555         
 556         /* now filter out any obviously spurious interrupts */
 557         irqmask = (((unsigned long)cache_A1)<<8) | (unsigned long) cache_21;
 558 #if NR_IRQS == 33
 559         irqmask |= (unsigned long) cache_804 << 16;
 560 #elif NR_IRQS == 32
 561         irqmask |= ((((unsigned long)cache_26)<<16) |
 562                     (((unsigned long)cache_27)<<24));
 563 #endif
 564         irqs &= ~irqmask;
 565         return irqs;
 566 }
 567 
 568 /*
 569  * Get the result of the IRQ probe.. A negative result means that
 570  * we have several candidates (but we return the lowest-numbered
 571  * one).
 572  */
 573 int probe_irq_off(unsigned long irqs)
     /*  */
 574 {
 575         unsigned long irqmask;
 576         int i;
 577         
 578         irqmask = (((unsigned int)cache_A1)<<8) | (unsigned int)cache_21;
 579 #if NR_IRQS == 33
 580         irqmask |= (unsigned long) cache_804 << 16;
 581 #elif NR_IRQS == 32
 582         irqmask |= ((((unsigned long)cache_26)<<16) |
 583                     (((unsigned long)cache_27)<<24));
 584 #endif
 585         irqs &= irqmask & ~1;   /* always mask out irq 0---it's the unused timer */
 586 #ifdef CONFIG_ALPHA_P2K
 587         irqs &= ~(1 << 8);      /* mask out irq 8 since that's the unused RTC input to PIC */
 588 #endif
 589         if (!irqs)
 590                 return 0;
 591         i = ffz(~irqs);
 592         if (irqs != (1UL << i))
 593                 i = -i;
 594         return i;
 595 }
 596 
 597 static void machine_check(unsigned long vector, unsigned long la, struct pt_regs * regs)
     /*  */
 598 {
 599 #if defined(CONFIG_ALPHA_LCA)
 600         extern void lca_machine_check (unsigned long vector, unsigned long la,
 601                                        struct pt_regs *regs);
 602         lca_machine_check(vector, la, regs);
 603 #elif defined(CONFIG_ALPHA_APECS)
 604         extern void apecs_machine_check(unsigned long vector, unsigned long la,
 605                                         struct pt_regs * regs);
 606         apecs_machine_check(vector, la, regs);
 607 #elif defined(CONFIG_ALPHA_ALCOR)
 608         extern void alcor_machine_check(unsigned long vector, unsigned long la,
 609                                         struct pt_regs * regs);
 610         alcor_machine_check(vector, la, regs);
 611 #else
 612         printk("Machine check\n");
 613 #endif
 614 }
 615 
 616 asmlinkage void do_entInt(unsigned long type, unsigned long vector, unsigned long la_ptr,
     /*  */
 617         unsigned long a3, unsigned long a4, unsigned long a5,
 618         struct pt_regs regs)
 619 {
 620         switch (type) {
 621                 case 0:
 622                         printk("Interprocessor interrupt? You must be kidding\n");
 623                         break;
 624                 case 1:
 625                         timer_interrupt(&regs);
 626                         return;
 627                 case 2:
 628                         machine_check(vector, la_ptr, &regs);
 629                         return;
 630                 case 3:
 631 #if defined(CONFIG_ALPHA_JENSEN) || defined(CONFIG_ALPHA_NONAME) || \
 632     defined(CONFIG_ALPHA_P2K) || defined(CONFIG_ALPHA_SRM)
 633                         srm_device_interrupt(vector, &regs);
 634 #elif NR_IRQS == 33
 635                         cabriolet_and_eb66p_device_interrupt(vector, &regs);
 636 #elif NR_IRQS == 32
 637                         eb66_and_eb64p_device_interrupt(vector, &regs);
 638 #elif NR_IRQS == 16
 639                         isa_device_interrupt(vector, &regs);
 640 #endif
 641                         return;
 642                 case 4:
 643                         printk("Performance counter interrupt\n");
 644                         break;;
 645                 default:
 646                         printk("Hardware intr %ld %lx? Huh?\n", type, vector);
 647         }
 648         printk("PC = %016lx PS=%04lx\n", regs.pc, regs.ps);
 649 }
 650 
 651 extern asmlinkage void entInt(void);
 652 
 653 void init_IRQ(void)
     /*  */
 654 {
 655         wrent(entInt, 0);
 656         dma_outb(0, DMA1_RESET_REG);
 657         dma_outb(0, DMA2_RESET_REG);
 658         dma_outb(0, DMA1_CLR_MASK_REG);
 659         dma_outb(0, DMA2_CLR_MASK_REG);
 660 #if NR_IRQS == 33
 661         outl(cache_804, 0x804);
 662 #elif NR_IRQS == 32
 663         outb(cache_26, 0x26);
 664         outb(cache_27, 0x27);
 665 #endif
 666         enable_irq(2);          /* enable cascade */
 667 }
/* */
root/arch/alpha/kernel/irq.c

DEFINITIONS
