arch/mips/sgi-ip22/ip22-int.c

   1 /*
   2  * ip22-int.c: Routines for generic manipulation of the INT[23] ASIC
   3  *             found on INDY and Indigo2 workstations.
   4  *
   5  * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
   6  * Copyright (C) 1997, 1998 Ralf Baechle (ralf@gnu.org)
   7  * Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu)
   8  *                    - Indigo2 changes
   9  *                    - Interrupt handling fixes
  10  * Copyright (C) 2001, 2003 Ladislav Michl (ladis@linux-mips.org)
  11  */
  12 #include <linux/types.h>
  13 #include <linux/init.h>
  14 #include <linux/kernel_stat.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ftrace.h>
  17
  18 #include <asm/irq_cpu.h>
  19 #include <asm/sgi/hpc3.h>
  20 #include <asm/sgi/ip22.h>
  21
  22 /* So far nothing hangs here */
  23 #undef USE_LIO3_IRQ
  24
  25 struct sgint_regs *sgint;
  26
  27 static char lc0msk_to_irqnr[256];
  28 static char lc1msk_to_irqnr[256];
  29 static char lc2msk_to_irqnr[256];
  30 static char lc3msk_to_irqnr[256];
  31
  32 extern int ip22_eisa_init(void);
  33
  34 static void enable_local0_irq(struct irq_data *d)
  35 {
  36         /* don't allow mappable interrupt to be enabled from setup_irq,
  37          * we have our own way to do so */
  38         if (d->irq != SGI_MAP_0_IRQ)
  39                 sgint->imask0 |= (1 << (d->irq - SGINT_LOCAL0));
  40 }
  41
  42 static void disable_local0_irq(struct irq_data *d)
  43 {
  44         sgint->imask0 &= ~(1 << (d->irq - SGINT_LOCAL0));
  45 }
  46
  47 static struct irq_chip ip22_local0_irq_type = {
  48         .name           = "IP22 local 0",
  49         .irq_mask       = disable_local0_irq,
  50         .irq_unmask     = enable_local0_irq,
  51 };
  52
  53 static void enable_local1_irq(struct irq_data *d)
  54 {
  55         /* don't allow mappable interrupt to be enabled from setup_irq,
  56          * we have our own way to do so */
  57         if (d->irq != SGI_MAP_1_IRQ)
  58                 sgint->imask1 |= (1 << (d->irq - SGINT_LOCAL1));
  59 }
  60
  61 static void disable_local1_irq(struct irq_data *d)
  62 {
  63         sgint->imask1 &= ~(1 << (d->irq - SGINT_LOCAL1));
  64 }
  65
  66 static struct irq_chip ip22_local1_irq_type = {
  67         .name           = "IP22 local 1",
  68         .irq_mask       = disable_local1_irq,
  69         .irq_unmask     = enable_local1_irq,
  70 };
  71
  72 static void enable_local2_irq(struct irq_data *d)
  73 {
  74         sgint->imask0 |= (1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
  75         sgint->cmeimask0 |= (1 << (d->irq - SGINT_LOCAL2));
  76 }
  77
  78 static void disable_local2_irq(struct irq_data *d)
  79 {
  80         sgint->cmeimask0 &= ~(1 << (d->irq - SGINT_LOCAL2));
  81         if (!sgint->cmeimask0)
  82                 sgint->imask0 &= ~(1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
  83 }
  84
  85 static struct irq_chip ip22_local2_irq_type = {
  86         .name           = "IP22 local 2",
  87         .irq_mask       = disable_local2_irq,
  88         .irq_unmask     = enable_local2_irq,
  89 };
  90
  91 static void enable_local3_irq(struct irq_data *d)
  92 {
  93         sgint->imask1 |= (1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
  94         sgint->cmeimask1 |= (1 << (d->irq - SGINT_LOCAL3));
  95 }
  96
  97 static void disable_local3_irq(struct irq_data *d)
  98 {
  99         sgint->cmeimask1 &= ~(1 << (d->irq - SGINT_LOCAL3));
 100         if (!sgint->cmeimask1)
 101                 sgint->imask1 &= ~(1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
 102 }
 103
 104 static struct irq_chip ip22_local3_irq_type = {
 105         .name           = "IP22 local 3",
 106         .irq_mask       = disable_local3_irq,
 107         .irq_unmask     = enable_local3_irq,
 108 };
 109
 110 static void indy_local0_irqdispatch(void)
 111 {
 112         u8 mask = sgint->istat0 & sgint->imask0;
 113         u8 mask2;
 114         int irq;
 115
 116         if (mask & SGINT_ISTAT0_LIO2) {
 117                 mask2 = sgint->vmeistat & sgint->cmeimask0;
 118                 irq = lc2msk_to_irqnr[mask2];
 119         } else
 120                 irq = lc0msk_to_irqnr[mask];
 121
 122         /*
 123          * workaround for INT2 bug; if irq == 0, INT2 has seen a fifo full
 124          * irq, but failed to latch it into status register
 125          */
 126         if (irq)
 127                 do_IRQ(irq);
 128         else
 129                 do_IRQ(SGINT_LOCAL0 + 0);
 130 }
 131
 132 static void indy_local1_irqdispatch(void)
 133 {
 134         u8 mask = sgint->istat1 & sgint->imask1;
 135         u8 mask2;
 136         int irq;
 137
 138         if (mask & SGINT_ISTAT1_LIO3) {
 139                 mask2 = sgint->vmeistat & sgint->cmeimask1;
 140                 irq = lc3msk_to_irqnr[mask2];
 141         } else
 142                 irq = lc1msk_to_irqnr[mask];
 143
 144         /* if irq == 0, then the interrupt has already been cleared */
 145         if (irq)
 146                 do_IRQ(irq);
 147 }
 148
 149 extern void ip22_be_interrupt(int irq);
 150
 151 static void __irq_entry indy_buserror_irq(void)
 152 {
 153         int irq = SGI_BUSERR_IRQ;
 154
 155         irq_enter();
 156         kstat_incr_irq_this_cpu(irq);
 157         ip22_be_interrupt(irq);
 158         irq_exit();
 159 }
 160
 161 static struct irqaction local0_cascade = {
 162         .handler        = no_action,
 163         .flags          = IRQF_NO_THREAD,
 164         .name           = "local0 cascade",
 165 };
 166
 167 static struct irqaction local1_cascade = {
 168         .handler        = no_action,
 169         .flags          = IRQF_NO_THREAD,
 170         .name           = "local1 cascade",
 171 };
 172
 173 static struct irqaction buserr = {
 174         .handler        = no_action,
 175         .flags          = IRQF_NO_THREAD,
 176         .name           = "Bus Error",
 177 };
 178
 179 static struct irqaction map0_cascade = {
 180         .handler        = no_action,
 181         .flags          = IRQF_NO_THREAD,
 182         .name           = "mapable0 cascade",
 183 };
 184
 185 #ifdef USE_LIO3_IRQ
 186 static struct irqaction map1_cascade = {
 187         .handler        = no_action,
 188         .flags          = IRQF_NO_THREAD,
 189         .name           = "mapable1 cascade",
 190 };
 191 #define SGI_INTERRUPTS  SGINT_END
 192 #else
 193 #define SGI_INTERRUPTS  SGINT_LOCAL3
 194 #endif
 195
 196 extern void indy_8254timer_irq(void);
 197
 198 /*
 199  * IRQs on the INDY look basically (barring software IRQs which we don't use
 200  * at all) like:
 201  *
 202  *      MIPS IRQ        Source
 203  *      --------        ------
 204  *             0        Software (ignored)
 205  *             1        Software (ignored)
 206  *             2        Local IRQ level zero
 207  *             3        Local IRQ level one
 208  *             4        8254 Timer zero
 209  *             5        8254 Timer one
 210  *             6        Bus Error
 211  *             7        R4k timer (what we use)
 212  *
 213  * We handle the IRQ according to _our_ priority which is:
 214  *
 215  * Highest ----     R4k Timer
 216  *                  Local IRQ zero
 217  *                  Local IRQ one
 218  *                  Bus Error
 219  *                  8254 Timer zero
 220  * Lowest  ----     8254 Timer one
 221  *
 222  * then we just return, if multiple IRQs are pending then we will just take
 223  * another exception, big deal.
 224  */
 225
 226 asmlinkage void plat_irq_dispatch(void)
 227 {
 228         unsigned int pending = read_c0_status() & read_c0_cause();
 229
 230         /*
 231          * First we check for r4k counter/timer IRQ.
 232          */
 233         if (pending & CAUSEF_IP7)
 234                 do_IRQ(SGI_TIMER_IRQ);
 235         else if (pending & CAUSEF_IP2)
 236                 indy_local0_irqdispatch();
 237         else if (pending & CAUSEF_IP3)
 238                 indy_local1_irqdispatch();
 239         else if (pending & CAUSEF_IP6)
 240                 indy_buserror_irq();
 241         else if (pending & (CAUSEF_IP4 | CAUSEF_IP5))
 242                 indy_8254timer_irq();
 243 }
 244
 245 void __init arch_init_irq(void)
 246 {
 247         int i;
 248
 249         /* Init local mask --> irq tables. */
 250         for (i = 0; i < 256; i++) {
 251                 if (i & 0x80) {
 252                         lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 7;
 253                         lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 7;
 254                         lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 7;
 255                         lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 7;
 256                 } else if (i & 0x40) {
 257                         lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 6;
 258                         lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 6;
 259                         lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 6;
 260                         lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 6;
 261                 } else if (i & 0x20) {
 262                         lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 5;
 263                         lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 5;
 264                         lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 5;
 265                         lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 5;
 266                 } else if (i & 0x10) {
 267                         lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 4;
 268                         lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 4;
 269                         lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 4;
 270                         lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 4;
 271                 } else if (i & 0x08) {
 272                         lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 3;
 273                         lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 3;
 274                         lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 3;
 275                         lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 3;
 276                 } else if (i & 0x04) {
 277                         lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 2;
 278                         lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 2;
 279                         lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 2;
 280                         lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 2;
 281                 } else if (i & 0x02) {
 282                         lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 1;
 283                         lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 1;
 284                         lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 1;
 285                         lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 1;
 286                 } else if (i & 0x01) {
 287                         lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 0;
 288                         lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 0;
 289                         lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 0;
 290                         lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 0;
 291                 } else {
 292                         lc0msk_to_irqnr[i] = 0;
 293                         lc1msk_to_irqnr[i] = 0;
 294                         lc2msk_to_irqnr[i] = 0;
 295                         lc3msk_to_irqnr[i] = 0;
 296                 }
 297         }
 298
 299         /* Mask out all interrupts. */
 300         sgint->imask0 = 0;
 301         sgint->imask1 = 0;
 302         sgint->cmeimask0 = 0;
 303         sgint->cmeimask1 = 0;
 304
 305         /* init CPU irqs */
 306         mips_cpu_irq_init();
 307
 308         for (i = SGINT_LOCAL0; i < SGI_INTERRUPTS; i++) {
 309                 struct irq_chip *handler;
 310
 311                 if (i < SGINT_LOCAL1)
 312                         handler         = &ip22_local0_irq_type;
 313                 else if (i < SGINT_LOCAL2)
 314                         handler         = &ip22_local1_irq_type;
 315                 else if (i < SGINT_LOCAL3)
 316                         handler         = &ip22_local2_irq_type;
 317                 else
 318                         handler         = &ip22_local3_irq_type;
 319
 320                 irq_set_chip_and_handler(i, handler, handle_level_irq);
 321         }
 322
 323         /* vector handler. this register the IRQ as non-sharable */
 324         setup_irq(SGI_LOCAL_0_IRQ, &local0_cascade);
 325         setup_irq(SGI_LOCAL_1_IRQ, &local1_cascade);
 326         setup_irq(SGI_BUSERR_IRQ, &buserr);
 327
 328         /* cascade in cascade. i love Indy ;-) */
 329         setup_irq(SGI_MAP_0_IRQ, &map0_cascade);
 330 #ifdef USE_LIO3_IRQ
 331         setup_irq(SGI_MAP_1_IRQ, &map1_cascade);
 332 #endif
 333
 334 #ifdef CONFIG_EISA
 335         if (ip22_is_fullhouse())        /* Only Indigo-2 has EISA stuff */
 336                 ip22_eisa_init();
 337 #endif
 338 }