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  * Levels 3-6 vary by machine type. For VIA or RBV Macintoshes:
  30  *
  31  *      3       - unused (?)
  32  *
  33  *      4       - SCC
  34  *
  35  *      5       - unused (?)
  36  *                [serial errors or special conditions seem to raise level 6
  37  *                interrupts on some models (LC4xx?)]
  38  *
  39  *      6       - off switch (?)
  40  *
  41  * Machines with Quadra-like VIA hardware, except PSC and PMU machines, support
  42  * an alternate interrupt mapping, as used by A/UX. It spreads ethernet and
  43  * sound out to their own autovector IRQs and gives VIA1 a higher priority:
  44  *
  45  *      1       - unused (?)
  46  *
  47  *      3       - on-board SONIC
  48  *
  49  *      5       - Apple Sound Chip (ASC)
  50  *
  51  *      6       - VIA1
  52  *
  53  * For OSS Macintoshes (IIfx only), we apply an interrupt mapping similar to
  54  * the Quadra (A/UX) mapping:
  55  *
  56  *      1       - ISM IOP (ADB)
  57  *
  58  *      2       - SCSI
  59  *
  60  *      3       - NuBus
  61  *
  62  *      4       - SCC IOP
  63  *
  64  *      6       - VIA1
  65  *
  66  * For PSC Macintoshes (660AV, 840AV):
  67  *
  68  *      3       - PSC level 3
  69  *                - slot 0: MACE
  70  *
  71  *      4       - PSC level 4
  72  *                - slot 1: SCC channel A interrupt
  73  *                - slot 2: SCC channel B interrupt
  74  *                - slot 3: MACE DMA
  75  *
  76  *      5       - PSC level 5
  77  *
  78  *      6       - PSC level 6
  79  *
  80  * Finally we have good 'ole level 7, the non-maskable interrupt:
  81  *
  82  *      7       - NMI (programmer's switch on the back of some Macs)
  83  *                Also RAM parity error on models which support it (IIc, IIfx?)
  84  *
  85  * The current interrupt logic looks something like this:
  86  *
  87  * - We install dispatchers for the autovector interrupts (1-7). These
  88  *   dispatchers are responsible for querying the hardware (the
  89  *   VIA/RBV/OSS/PSC chips) to determine the actual interrupt source. Using
  90  *   this information a machspec interrupt number is generated by placing the
  91  *   index of the interrupt hardware into the low three bits and the original
  92  *   autovector interrupt number in the upper 5 bits. The handlers for the
  93  *   resulting machspec interrupt are then called.
  94  *
  95  * - Nubus is a special case because its interrupts are hidden behind two
  96  *   layers of hardware. Nubus interrupts come in as index 1 on VIA #2,
  97  *   which translates to IRQ number 17. In this spot we install _another_
  98  *   dispatcher. This dispatcher finds the interrupting slot number (9-F) and
  99  *   then forms a new machspec interrupt number as above with the slot number
 100  *   minus 9 in the low three bits and the pseudo-level 7 in the upper five
 101  *   bits.  The handlers for this new machspec interrupt number are then
 102  *   called. This puts Nubus interrupts into the range 56-62.
 103  *
 104  * - The Baboon interrupts (used on some PowerBooks) are an even more special
 105  *   case. They're hidden behind the Nubus slot $C interrupt thus adding a
 106  *   third layer of indirection. Why oh why did the Apple engineers do that?
 107  *
 108  */
 109
 110 #include <linux/types.h>
 111 #include <linux/kernel.h>
 112 #include <linux/sched.h>
 113 #include <linux/interrupt.h>
 114 #include <linux/irq.h>
 115 #include <linux/delay.h>
 116
 117 #include <asm/irq.h>
 118 #include <asm/macintosh.h>
 119 #include <asm/macints.h>
 120 #include <asm/mac_via.h>
 121 #include <asm/mac_psc.h>
 122 #include <asm/mac_oss.h>
 123 #include <asm/mac_iop.h>
 124 #include <asm/mac_baboon.h>
 125 #include <asm/hwtest.h>
 126 #include <asm/irq_regs.h>
 127
 128 #define SHUTUP_SONIC
 129
 130 /*
 131  * console_loglevel determines NMI handler function
 132  */
 133
 134 irqreturn_t mac_nmi_handler(int, void *);
 135 irqreturn_t mac_debug_handler(int, void *);
 136
 137 /* #define DEBUG_MACINTS */
 138
 139 static unsigned int mac_irq_startup(struct irq_data *);
 140 static void mac_irq_shutdown(struct irq_data *);
 141
 142 static struct irq_chip mac_irq_chip = {
 143         .name           = "mac",
 144         .irq_enable     = mac_irq_enable,
 145         .irq_disable    = mac_irq_disable,
 146         .irq_startup    = mac_irq_startup,
 147         .irq_shutdown   = mac_irq_shutdown,
 148 };
 149
 150 void __init mac_init_IRQ(void)
 151 {
 152 #ifdef DEBUG_MACINTS
 153         printk("mac_init_IRQ(): Setting things up...\n");
 154 #endif
 155         m68k_setup_irq_controller(&mac_irq_chip, handle_simple_irq, IRQ_USER,
 156                                   NUM_MAC_SOURCES - IRQ_USER);
 157         /* Make sure the SONIC interrupt is cleared or things get ugly */
 158 #ifdef SHUTUP_SONIC
 159         printk("Killing onboard sonic... ");
 160         /* This address should hopefully be mapped already */
 161         if (hwreg_present((void*)(0x50f0a000))) {
 162                 *(long *)(0x50f0a014) = 0x7fffL;
 163                 *(long *)(0x50f0a010) = 0L;
 164         }
 165         printk("Done.\n");
 166 #endif /* SHUTUP_SONIC */
 167
 168         /*
 169          * Now register the handlers for the master IRQ handlers
 170          * at levels 1-7. Most of the work is done elsewhere.
 171          */
 172
 173         if (oss_present)
 174                 oss_register_interrupts();
 175         else
 176                 via_register_interrupts();
 177         if (psc_present)
 178                 psc_register_interrupts();
 179         if (baboon_present)
 180                 baboon_register_interrupts();
 181         iop_register_interrupts();
 182         if (request_irq(IRQ_AUTO_7, mac_nmi_handler, 0, "NMI",
 183                         mac_nmi_handler))
 184                 pr_err("Couldn't register NMI\n");
 185 #ifdef DEBUG_MACINTS
 186         printk("mac_init_IRQ(): Done!\n");
 187 #endif
 188 }
 189
 190 /*
 191  *  mac_irq_enable - enable an interrupt source
 192  * mac_irq_disable - disable an interrupt source
 193  *
 194  * These routines are just dispatchers to the VIA/OSS/PSC routines.
 195  */
 196
 197 void mac_irq_enable(struct irq_data *data)
 198 {
 199         int irq = data->irq;
 200         int irq_src = IRQ_SRC(irq);
 201
 202         switch(irq_src) {
 203         case 1:
 204         case 2:
 205         case 7:
 206                 if (oss_present)
 207                         oss_irq_enable(irq);
 208                 else
 209                         via_irq_enable(irq);
 210                 break;
 211         case 3:
 212         case 4:
 213         case 5:
 214         case 6:
 215                 if (psc_present)
 216                         psc_irq_enable(irq);
 217                 else if (oss_present)
 218                         oss_irq_enable(irq);
 219                 break;
 220         case 8:
 221                 if (baboon_present)
 222                         baboon_irq_enable(irq);
 223                 break;
 224         }
 225 }
 226
 227 void mac_irq_disable(struct irq_data *data)
 228 {
 229         int irq = data->irq;
 230         int irq_src = IRQ_SRC(irq);
 231
 232         switch(irq_src) {
 233         case 1:
 234         case 2:
 235         case 7:
 236                 if (oss_present)
 237                         oss_irq_disable(irq);
 238                 else
 239                         via_irq_disable(irq);
 240                 break;
 241         case 3:
 242         case 4:
 243         case 5:
 244         case 6:
 245                 if (psc_present)
 246                         psc_irq_disable(irq);
 247                 else if (oss_present)
 248                         oss_irq_disable(irq);
 249                 break;
 250         case 8:
 251                 if (baboon_present)
 252                         baboon_irq_disable(irq);
 253                 break;
 254         }
 255 }
 256
 257 static unsigned int mac_irq_startup(struct irq_data *data)
 258 {
 259         int irq = data->irq;
 260
 261         if (IRQ_SRC(irq) == 7 && !oss_present)
 262                 via_nubus_irq_startup(irq);
 263         else
 264                 mac_irq_enable(data);
 265
 266         return 0;
 267 }
 268
 269 static void mac_irq_shutdown(struct irq_data *data)
 270 {
 271         int irq = data->irq;
 272
 273         if (IRQ_SRC(irq) == 7 && !oss_present)
 274                 via_nubus_irq_shutdown(irq);
 275         else
 276                 mac_irq_disable(data);
 277 }
 278
 279 static int num_debug[8];
 280
 281 irqreturn_t mac_debug_handler(int irq, void *dev_id)
 282 {
 283         if (num_debug[irq] < 10) {
 284                 printk("DEBUG: Unexpected IRQ %d\n", irq);
 285                 num_debug[irq]++;
 286         }
 287         return IRQ_HANDLED;
 288 }
 289
 290 static int in_nmi;
 291 static volatile int nmi_hold;
 292
 293 irqreturn_t mac_nmi_handler(int irq, void *dev_id)
 294 {
 295         int i;
 296         /*
 297          * generate debug output on NMI switch if 'debug' kernel option given
 298          * (only works with Penguin!)
 299          */
 300
 301         in_nmi++;
 302         for (i=0; i<100; i++)
 303                 udelay(1000);
 304
 305         if (in_nmi == 1) {
 306                 nmi_hold = 1;
 307                 printk("... pausing, press NMI to resume ...");
 308         } else {
 309                 printk(" ok!\n");
 310                 nmi_hold = 0;
 311         }
 312
 313         barrier();
 314
 315         while (nmi_hold == 1)
 316                 udelay(1000);
 317
 318         if (console_loglevel >= 8) {
 319 #if 0
 320                 struct pt_regs *fp = get_irq_regs();
 321                 show_state();
 322                 printk("PC: %08lx\nSR: %04x  SP: %p\n", fp->pc, fp->sr, fp);
 323                 printk("d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
 324                        fp->d0, fp->d1, fp->d2, fp->d3);
 325                 printk("d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
 326                        fp->d4, fp->d5, fp->a0, fp->a1);
 327
 328                 if (STACK_MAGIC != *(unsigned long *)current->kernel_stack_page)
 329                         printk("Corrupted stack page\n");
 330                 printk("Process %s (pid: %d, stackpage=%08lx)\n",
 331                         current->comm, current->pid, current->kernel_stack_page);
 332                 if (intr_count == 1)
 333                         dump_stack((struct frame *)fp);
 334 #else
 335                 /* printk("NMI "); */
 336 #endif
 337         }
 338         in_nmi--;
 339         return IRQ_HANDLED;
 340 }