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_chip mac_irq_chip = {
 197         .name           = "mac",
 198         .irq_enable     = mac_enable_irq,
 199         .irq_disable    = mac_disable_irq,
 200 };
 201
 202 void __init mac_init_IRQ(void)
 203 {
 204 #ifdef DEBUG_MACINTS
 205         printk("mac_init_IRQ(): Setting things up...\n");
 206 #endif
 207         m68k_setup_irq_chip(&mac_irq_chip, IRQ_USER,
 208                                   NUM_MAC_SOURCES - IRQ_USER);
 209         /* Make sure the SONIC interrupt is cleared or things get ugly */
 210 #ifdef SHUTUP_SONIC
 211         printk("Killing onboard sonic... ");
 212         /* This address should hopefully be mapped already */
 213         if (hwreg_present((void*)(0x50f0a000))) {
 214                 *(long *)(0x50f0a014) = 0x7fffL;
 215                 *(long *)(0x50f0a010) = 0L;
 216         }
 217         printk("Done.\n");
 218 #endif /* SHUTUP_SONIC */
 219
 220         /*
 221          * Now register the handlers for the master IRQ handlers
 222          * at levels 1-7. Most of the work is done elsewhere.
 223          */
 224
 225         if (oss_present)
 226                 oss_register_interrupts();
 227         else
 228                 via_register_interrupts();
 229         if (psc_present)
 230                 psc_register_interrupts();
 231         if (baboon_present)
 232                 baboon_register_interrupts();
 233         iop_register_interrupts();
 234         if (request_irq(IRQ_AUTO_7, mac_nmi_handler, 0, "NMI",
 235                         mac_nmi_handler))
 236                 pr_err("Couldn't register NMI\n");
 237 #ifdef DEBUG_MACINTS
 238         printk("mac_init_IRQ(): Done!\n");
 239 #endif
 240 }
 241
 242 /*
 243  *  mac_enable_irq - enable an interrupt source
 244  * mac_disable_irq - disable an interrupt source
 245  *   mac_clear_irq - clears a pending interrupt
 246  * mac_pending_irq - Returns the pending status of an IRQ (nonzero = pending)
 247  *
 248  * These routines are just dispatchers to the VIA/OSS/PSC routines.
 249  */
 250
 251 void mac_enable_irq(unsigned int irq)
 252 {
 253         int irq_src = IRQ_SRC(irq);
 254
 255         switch(irq_src) {
 256         case 1:
 257                 via_irq_enable(irq);
 258                 break;
 259         case 2:
 260         case 7:
 261                 if (oss_present)
 262                         oss_irq_enable(irq);
 263                 else
 264                         via_irq_enable(irq);
 265                 break;
 266         case 3:
 267         case 5:
 268         case 6:
 269                 if (psc_present)
 270                         psc_irq_enable(irq);
 271                 else if (oss_present)
 272                         oss_irq_enable(irq);
 273                 break;
 274         case 4:
 275                 if (psc_present)
 276                         psc_irq_enable(irq);
 277                 break;
 278         case 8:
 279                 if (baboon_present)
 280                         baboon_irq_enable(irq);
 281                 break;
 282         }
 283 }
 284
 285 void mac_disable_irq(unsigned int irq)
 286 {
 287         int irq_src = IRQ_SRC(irq);
 288
 289         switch(irq_src) {
 290         case 1:
 291                 via_irq_disable(irq);
 292                 break;
 293         case 2:
 294         case 7:
 295                 if (oss_present)
 296                         oss_irq_disable(irq);
 297                 else
 298                         via_irq_disable(irq);
 299                 break;
 300         case 3:
 301         case 5:
 302         case 6:
 303                 if (psc_present)
 304                         psc_irq_disable(irq);
 305                 else if (oss_present)
 306                         oss_irq_disable(irq);
 307                 break;
 308         case 4:
 309                 if (psc_present)
 310                         psc_irq_disable(irq);
 311                 break;
 312         case 8:
 313                 if (baboon_present)
 314                         baboon_irq_disable(irq);
 315                 break;
 316         }
 317 }
 318
 319 void mac_clear_irq(unsigned int irq)
 320 {
 321         switch(IRQ_SRC(irq)) {
 322         case 1:
 323                 via_irq_clear(irq);
 324                 break;
 325         case 2:
 326         case 7:
 327                 if (oss_present)
 328                         oss_irq_clear(irq);
 329                 else
 330                         via_irq_clear(irq);
 331                 break;
 332         case 3:
 333         case 5:
 334         case 6:
 335                 if (psc_present)
 336                         psc_irq_clear(irq);
 337                 else if (oss_present)
 338                         oss_irq_clear(irq);
 339                 break;
 340         case 4:
 341                 if (psc_present)
 342                         psc_irq_clear(irq);
 343                 break;
 344         case 8:
 345                 if (baboon_present)
 346                         baboon_irq_clear(irq);
 347                 break;
 348         }
 349 }
 350
 351 int mac_irq_pending(unsigned int irq)
 352 {
 353         switch(IRQ_SRC(irq)) {
 354         case 1:
 355                 return via_irq_pending(irq);
 356         case 2:
 357         case 7:
 358                 if (oss_present)
 359                         return oss_irq_pending(irq);
 360                 else
 361                         return via_irq_pending(irq);
 362         case 3:
 363         case 5:
 364         case 6:
 365                 if (psc_present)
 366                         return psc_irq_pending(irq);
 367                 else if (oss_present)
 368                         return oss_irq_pending(irq);
 369                 break;
 370         case 4:
 371                 if (psc_present)
 372                         return psc_irq_pending(irq);
 373                 break;
 374         }
 375         return 0;
 376 }
 377 EXPORT_SYMBOL(mac_irq_pending);
 378
 379 static int num_debug[8];
 380
 381 irqreturn_t mac_debug_handler(int irq, void *dev_id)
 382 {
 383         if (num_debug[irq] < 10) {
 384                 printk("DEBUG: Unexpected IRQ %d\n", irq);
 385                 num_debug[irq]++;
 386         }
 387         return IRQ_HANDLED;
 388 }
 389
 390 static int in_nmi;
 391 static volatile int nmi_hold;
 392
 393 irqreturn_t mac_nmi_handler(int irq, void *dev_id)
 394 {
 395         int i;
 396         /*
 397          * generate debug output on NMI switch if 'debug' kernel option given
 398          * (only works with Penguin!)
 399          */
 400
 401         in_nmi++;
 402         for (i=0; i<100; i++)
 403                 udelay(1000);
 404
 405         if (in_nmi == 1) {
 406                 nmi_hold = 1;
 407                 printk("... pausing, press NMI to resume ...");
 408         } else {
 409                 printk(" ok!\n");
 410                 nmi_hold = 0;
 411         }
 412
 413         barrier();
 414
 415         while (nmi_hold == 1)
 416                 udelay(1000);
 417
 418         if (console_loglevel >= 8) {
 419 #if 0
 420                 struct pt_regs *fp = get_irq_regs();
 421                 show_state();
 422                 printk("PC: %08lx\nSR: %04x  SP: %p\n", fp->pc, fp->sr, fp);
 423                 printk("d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
 424                        fp->d0, fp->d1, fp->d2, fp->d3);
 425                 printk("d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
 426                        fp->d4, fp->d5, fp->a0, fp->a1);
 427
 428                 if (STACK_MAGIC != *(unsigned long *)current->kernel_stack_page)
 429                         printk("Corrupted stack page\n");
 430                 printk("Process %s (pid: %d, stackpage=%08lx)\n",
 431                         current->comm, current->pid, current->kernel_stack_page);
 432                 if (intr_count == 1)
 433                         dump_stack((struct frame *)fp);
 434 #else
 435                 /* printk("NMI "); */
 436 #endif
 437         }
 438         in_nmi--;
 439         return IRQ_HANDLED;
 440 }