arch/m68k/mac/macints.c

   1 /*
   2  *      Macintosh interrupts
   3  *
   4  * General design:
   5  * In contrary to the Amiga and Atari platforms, the Mac hardware seems to
   6  * exclusively use the autovector interrupts (the 'generic level0-level7'
   7  * interrupts with exception vectors 0x19-0x1f). The following interrupt levels
   8  * are used:
   9  *      1       - VIA1
  10  *                - slot 0: one second interrupt (CA2)
  11  *                - slot 1: VBlank (CA1)
  12  *                - slot 2: ADB data ready (SR full)
  13  *                - slot 3: ADB data  (CB2)
  14  *                - slot 4: ADB clock (CB1)
  15  *                - slot 5: timer 2
  16  *                - slot 6: timer 1
  17  *                - slot 7: status of IRQ; signals 'any enabled int.'
  18  *
  19  *      2       - VIA2 or RBV
  20  *                - slot 0: SCSI DRQ (CA2)
  21  *                - slot 1: NUBUS IRQ (CA1) need to read port A to find which
  22  *                - slot 2: /EXP IRQ (only on IIci)
  23  *                - slot 3: SCSI IRQ (CB2)
  24  *                - slot 4: ASC IRQ (CB1)
  25  *                - slot 5: timer 2 (not on IIci)
  26  *                - slot 6: timer 1 (not on IIci)
  27  *                - slot 7: status of IRQ; signals 'any enabled int.'
  28  *
  29  *      2       - OSS (IIfx only?)
  30  *                - slot 0: SCSI interrupt
  31  *                - slot 1: Sound interrupt
  32  *
  33  * Levels 3-6 vary by machine type. For VIA or RBV Macintoshes:
  34  *
  35  *      3       - unused (?)
  36  *
  37  *      4       - SCC
  38  *
  39  *      5       - unused (?)
  40  *                [serial errors or special conditions seem to raise level 6
  41  *                interrupts on some models (LC4xx?)]
  42  *
  43  *      6       - off switch (?)
  44  *
  45  * For OSS Macintoshes (IIfx only at this point):
  46  *
  47  *      3       - Nubus interrupt
  48  *                - slot 0: Slot $9
  49  *                - slot 1: Slot $A
  50  *                - slot 2: Slot $B
  51  *                - slot 3: Slot $C
  52  *                - slot 4: Slot $D
  53  *                - slot 5: Slot $E
  54  *
  55  *      4       - SCC IOP
  56  *
  57  *      5       - ISM IOP (ADB?)
  58  *
  59  *      6       - unused
  60  *
  61  * For PSC Macintoshes (660AV, 840AV):
  62  *
  63  *      3       - PSC level 3
  64  *                - slot 0: MACE
  65  *
  66  *      4       - PSC level 4
  67  *                - slot 1: SCC channel A interrupt
  68  *                - slot 2: SCC channel B interrupt
  69  *                - slot 3: MACE DMA
  70  *
  71  *      5       - PSC level 5
  72  *
  73  *      6       - PSC level 6
  74  *
  75  * Finally we have good 'ole level 7, the non-maskable interrupt:
  76  *
  77  *      7       - NMI (programmer's switch on the back of some Macs)
  78  *                Also RAM parity error on models which support it (IIc, IIfx?)
  79  *
  80  * The current interrupt logic looks something like this:
  81  *
  82  * - We install dispatchers for the autovector interrupts (1-7). These
  83  *   dispatchers are responsible for querying the hardware (the
  84  *   VIA/RBV/OSS/PSC chips) to determine the actual interrupt source. Using
  85  *   this information a machspec interrupt number is generated by placing the
  86  *   index of the interrupt hardware into the low three bits and the original
  87  *   autovector interrupt number in the upper 5 bits. The handlers for the
  88  *   resulting machspec interrupt are then called.
  89  *
  90  * - Nubus is a special case because its interrupts are hidden behind two
  91  *   layers of hardware. Nubus interrupts come in as index 1 on VIA #2,
  92  *   which translates to IRQ number 17. In this spot we install _another_
  93  *   dispatcher. This dispatcher finds the interrupting slot number (9-F) and
  94  *   then forms a new machspec interrupt number as above with the slot number
  95  *   minus 9 in the low three bits and the pseudo-level 7 in the upper five
  96  *   bits.  The handlers for this new machspec interrupt number are then
  97  *   called. This puts Nubus interrupts into the range 56-62.
  98  *
  99  * - The Baboon interrupts (used on some PowerBooks) are an even more special
 100  *   case. They're hidden behind the Nubus slot $C interrupt thus adding a
 101  *   third layer of indirection. Why oh why did the Apple engineers do that?
 102  *
 103  * - We support "fast" and "slow" handlers, just like the Amiga port. The
 104  *   fast handlers are called first and with all interrupts disabled. They
 105  *   are expected to execute quickly (hence the name). The slow handlers are
 106  *   called last with interrupts enabled and the interrupt level restored.
 107  *   They must therefore be reentrant.
 108  *
 109  *   TODO:
 110  *
 111  */
 112
 113 #include <linux/module.h>
 114 #include <linux/types.h>
 115 #include <linux/kernel.h>
 116 #include <linux/sched.h>
 117 #include <linux/kernel_stat.h>
 118 #include <linux/interrupt.h> /* for intr_count */
 119 #include <linux/delay.h>
 120 #include <linux/seq_file.h>
 121
 122 #include <asm/system.h>
 123 #include <asm/irq.h>
 124 #include <asm/traps.h>
 125 #include <asm/bootinfo.h>
 126 #include <asm/macintosh.h>
 127 #include <asm/mac_via.h>
 128 #include <asm/mac_psc.h>
 129 #include <asm/hwtest.h>
 130 #include <asm/errno.h>
 131 #include <asm/macints.h>
 132 #include <asm/irq_regs.h>
 133 #include <asm/mac_oss.h>
 134
 135 #define SHUTUP_SONIC
 136
 137 /*
 138  * VIA/RBV hooks
 139  */
 140
 141 extern void via_register_interrupts(void);
 142 extern void via_irq_enable(int);
 143 extern void via_irq_disable(int);
 144 extern void via_irq_clear(int);
 145 extern int  via_irq_pending(int);
 146
 147 /*
 148  * OSS hooks
 149  */
 150
 151 extern void oss_register_interrupts(void);
 152 extern void oss_irq_enable(int);
 153 extern void oss_irq_disable(int);
 154 extern void oss_irq_clear(int);
 155 extern int  oss_irq_pending(int);
 156
 157 /*
 158  * PSC hooks
 159  */
 160
 161 extern void psc_register_interrupts(void);
 162 extern void psc_irq_enable(int);
 163 extern void psc_irq_disable(int);
 164 extern void psc_irq_clear(int);
 165 extern int  psc_irq_pending(int);
 166
 167 /*
 168  * IOP hooks
 169  */
 170
 171 extern void iop_register_interrupts(void);
 172
 173 /*
 174  * Baboon hooks
 175  */
 176
 177 extern int baboon_present;
 178
 179 extern void baboon_register_interrupts(void);
 180 extern void baboon_irq_enable(int);
 181 extern void baboon_irq_disable(int);
 182 extern void baboon_irq_clear(int);
 183
 184 /*
 185  * console_loglevel determines NMI handler function
 186  */
 187
 188 irqreturn_t mac_nmi_handler(int, void *);
 189 irqreturn_t mac_debug_handler(int, void *);
 190
 191 /* #define DEBUG_MACINTS */
 192
 193 void mac_enable_irq(unsigned int irq);
 194 void mac_disable_irq(unsigned int irq);
 195
 196 static struct irq_controller mac_irq_controller = {
 197         .name           = "mac",
 198         .lock           = __SPIN_LOCK_UNLOCKED(mac_irq_controller.lock),
 199         .enable         = mac_enable_irq,
 200         .disable        = mac_disable_irq,
 201 };
 202
 203 void __init mac_init_IRQ(void)
 204 {
 205 #ifdef DEBUG_MACINTS
 206         printk("mac_init_IRQ(): Setting things up...\n");
 207 #endif
 208         m68k_setup_irq_controller(&mac_irq_controller, IRQ_USER,
 209                                   NUM_MAC_SOURCES - IRQ_USER);
 210         /* Make sure the SONIC interrupt is cleared or things get ugly */
 211 #ifdef SHUTUP_SONIC
 212         printk("Killing onboard sonic... ");
 213         /* This address should hopefully be mapped already */
 214         if (hwreg_present((void*)(0x50f0a000))) {
 215                 *(long *)(0x50f0a014) = 0x7fffL;
 216                 *(long *)(0x50f0a010) = 0L;
 217         }
 218         printk("Done.\n");
 219 #endif /* SHUTUP_SONIC */
 220
 221         /*
 222          * Now register the handlers for the master IRQ handlers
 223          * at levels 1-7. Most of the work is done elsewhere.
 224          */
 225
 226         if (oss_present)
 227                 oss_register_interrupts();
 228         else
 229                 via_register_interrupts();
 230         if (psc_present)
 231                 psc_register_interrupts();
 232         if (baboon_present)
 233                 baboon_register_interrupts();
 234         iop_register_interrupts();
 235         if (request_irq(IRQ_AUTO_7, mac_nmi_handler, 0, "NMI",
 236                         mac_nmi_handler))
 237                 pr_err("Couldn't register NMI\n");
 238 #ifdef DEBUG_MACINTS
 239         printk("mac_init_IRQ(): Done!\n");
 240 #endif
 241 }
 242
 243 /*
 244  *  mac_enable_irq - enable an interrupt source
 245  * mac_disable_irq - disable an interrupt source
 246  *   mac_clear_irq - clears a pending interrupt
 247  * mac_pending_irq - Returns the pending status of an IRQ (nonzero = pending)
 248  *
 249  * These routines are just dispatchers to the VIA/OSS/PSC routines.
 250  */
 251
 252 void mac_enable_irq(unsigned int irq)
 253 {
 254         int irq_src = IRQ_SRC(irq);
 255
 256         switch(irq_src) {
 257         case 1:
 258                 via_irq_enable(irq);
 259                 break;
 260         case 2:
 261         case 7:
 262                 if (oss_present)
 263                         oss_irq_enable(irq);
 264                 else
 265                         via_irq_enable(irq);
 266                 break;
 267         case 3:
 268         case 5:
 269         case 6:
 270                 if (psc_present)
 271                         psc_irq_enable(irq);
 272                 else if (oss_present)
 273                         oss_irq_enable(irq);
 274                 break;
 275         case 4:
 276                 if (psc_present)
 277                         psc_irq_enable(irq);
 278                 break;
 279         case 8:
 280                 if (baboon_present)
 281                         baboon_irq_enable(irq);
 282                 break;
 283         }
 284 }
 285
 286 void mac_disable_irq(unsigned int irq)
 287 {
 288         int irq_src = IRQ_SRC(irq);
 289
 290         switch(irq_src) {
 291         case 1:
 292                 via_irq_disable(irq);
 293                 break;
 294         case 2:
 295         case 7:
 296                 if (oss_present)
 297                         oss_irq_disable(irq);
 298                 else
 299                         via_irq_disable(irq);
 300                 break;
 301         case 3:
 302         case 5:
 303         case 6:
 304                 if (psc_present)
 305                         psc_irq_disable(irq);
 306                 else if (oss_present)
 307                         oss_irq_disable(irq);
 308                 break;
 309         case 4:
 310                 if (psc_present)
 311                         psc_irq_disable(irq);
 312                 break;
 313         case 8:
 314                 if (baboon_present)
 315                         baboon_irq_disable(irq);
 316                 break;
 317         }
 318 }
 319
 320 void mac_clear_irq(unsigned int irq)
 321 {
 322         switch(IRQ_SRC(irq)) {
 323         case 1:
 324                 via_irq_clear(irq);
 325                 break;
 326         case 2:
 327         case 7:
 328                 if (oss_present)
 329                         oss_irq_clear(irq);
 330                 else
 331                         via_irq_clear(irq);
 332                 break;
 333         case 3:
 334         case 5:
 335         case 6:
 336                 if (psc_present)
 337                         psc_irq_clear(irq);
 338                 else if (oss_present)
 339                         oss_irq_clear(irq);
 340                 break;
 341         case 4:
 342                 if (psc_present)
 343                         psc_irq_clear(irq);
 344                 break;
 345         case 8:
 346                 if (baboon_present)
 347                         baboon_irq_clear(irq);
 348                 break;
 349         }
 350 }
 351
 352 int mac_irq_pending(unsigned int irq)
 353 {
 354         switch(IRQ_SRC(irq)) {
 355         case 1:
 356                 return via_irq_pending(irq);
 357         case 2:
 358         case 7:
 359                 if (oss_present)
 360                         return oss_irq_pending(irq);
 361                 else
 362                         return via_irq_pending(irq);
 363         case 3:
 364         case 5:
 365         case 6:
 366                 if (psc_present)
 367                         return psc_irq_pending(irq);
 368                 else if (oss_present)
 369                         return oss_irq_pending(irq);
 370                 break;
 371         case 4:
 372                 if (psc_present)
 373                         return psc_irq_pending(irq);
 374                 break;
 375         }
 376         return 0;
 377 }
 378 EXPORT_SYMBOL(mac_irq_pending);
 379
 380 static int num_debug[8];
 381
 382 irqreturn_t mac_debug_handler(int irq, void *dev_id)
 383 {
 384         if (num_debug[irq] < 10) {
 385                 printk("DEBUG: Unexpected IRQ %d\n", irq);
 386                 num_debug[irq]++;
 387         }
 388         return IRQ_HANDLED;
 389 }
 390
 391 static int in_nmi;
 392 static volatile int nmi_hold;
 393
 394 irqreturn_t mac_nmi_handler(int irq, void *dev_id)
 395 {
 396         int i;
 397         /*
 398          * generate debug output on NMI switch if 'debug' kernel option given
 399          * (only works with Penguin!)
 400          */
 401
 402         in_nmi++;
 403         for (i=0; i<100; i++)
 404                 udelay(1000);
 405
 406         if (in_nmi == 1) {
 407                 nmi_hold = 1;
 408                 printk("... pausing, press NMI to resume ...");
 409         } else {
 410                 printk(" ok!\n");
 411                 nmi_hold = 0;
 412         }
 413
 414         barrier();
 415
 416         while (nmi_hold == 1)
 417                 udelay(1000);
 418
 419         if (console_loglevel >= 8) {
 420 #if 0
 421                 struct pt_regs *fp = get_irq_regs();
 422                 show_state();
 423                 printk("PC: %08lx\nSR: %04x  SP: %p\n", fp->pc, fp->sr, fp);
 424                 printk("d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
 425                        fp->d0, fp->d1, fp->d2, fp->d3);
 426                 printk("d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
 427                        fp->d4, fp->d5, fp->a0, fp->a1);
 428
 429                 if (STACK_MAGIC != *(unsigned long *)current->kernel_stack_page)
 430                         printk("Corrupted stack page\n");
 431                 printk("Process %s (pid: %d, stackpage=%08lx)\n",
 432                         current->comm, current->pid, current->kernel_stack_page);
 433                 if (intr_count == 1)
 434                         dump_stack((struct frame *)fp);
 435 #else
 436                 /* printk("NMI "); */
 437 #endif
 438         }
 439         in_nmi--;
 440         return IRQ_HANDLED;
 441 }