arch/mips/bcm63xx/irq.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
   7  * Copyright (C) 2008 Nicolas Schichan <nschichan@freebox.fr>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/module.h>
  14 #include <linux/irq.h>
  15 #include <asm/irq_cpu.h>
  16 #include <asm/mipsregs.h>
  17 #include <bcm63xx_cpu.h>
  18 #include <bcm63xx_regs.h>
  19 #include <bcm63xx_io.h>
  20 #include <bcm63xx_irq.h>
  21
  22 static void __dispatch_internal(void) __maybe_unused;
  23 static void __dispatch_internal_64(void) __maybe_unused;
  24 static void __internal_irq_mask_32(unsigned int irq) __maybe_unused;
  25 static void __internal_irq_mask_64(unsigned int irq) __maybe_unused;
  26 static void __internal_irq_unmask_32(unsigned int irq) __maybe_unused;
  27 static void __internal_irq_unmask_64(unsigned int irq) __maybe_unused;
  28
  29 #ifndef BCMCPU_RUNTIME_DETECT
  30 #ifdef CONFIG_BCM63XX_CPU_3368
  31 #define irq_stat_reg            PERF_IRQSTAT_3368_REG
  32 #define irq_mask_reg            PERF_IRQMASK_3368_REG
  33 #define irq_bits                32
  34 #define is_ext_irq_cascaded     0
  35 #define ext_irq_start           0
  36 #define ext_irq_end             0
  37 #define ext_irq_count           4
  38 #define ext_irq_cfg_reg1        PERF_EXTIRQ_CFG_REG_3368
  39 #define ext_irq_cfg_reg2        0
  40 #endif
  41 #ifdef CONFIG_BCM63XX_CPU_6328
  42 #define irq_stat_reg            PERF_IRQSTAT_6328_REG
  43 #define irq_mask_reg            PERF_IRQMASK_6328_REG
  44 #define irq_bits                64
  45 #define is_ext_irq_cascaded     1
  46 #define ext_irq_start           (BCM_6328_EXT_IRQ0 - IRQ_INTERNAL_BASE)
  47 #define ext_irq_end             (BCM_6328_EXT_IRQ3 - IRQ_INTERNAL_BASE)
  48 #define ext_irq_count           4
  49 #define ext_irq_cfg_reg1        PERF_EXTIRQ_CFG_REG_6328
  50 #define ext_irq_cfg_reg2        0
  51 #endif
  52 #ifdef CONFIG_BCM63XX_CPU_6338
  53 #define irq_stat_reg            PERF_IRQSTAT_6338_REG
  54 #define irq_mask_reg            PERF_IRQMASK_6338_REG
  55 #define irq_bits                32
  56 #define is_ext_irq_cascaded     0
  57 #define ext_irq_start           0
  58 #define ext_irq_end             0
  59 #define ext_irq_count           4
  60 #define ext_irq_cfg_reg1        PERF_EXTIRQ_CFG_REG_6338
  61 #define ext_irq_cfg_reg2        0
  62 #endif
  63 #ifdef CONFIG_BCM63XX_CPU_6345
  64 #define irq_stat_reg            PERF_IRQSTAT_6345_REG
  65 #define irq_mask_reg            PERF_IRQMASK_6345_REG
  66 #define irq_bits                32
  67 #define is_ext_irq_cascaded     0
  68 #define ext_irq_start           0
  69 #define ext_irq_end             0
  70 #define ext_irq_count           4
  71 #define ext_irq_cfg_reg1        PERF_EXTIRQ_CFG_REG_6345
  72 #define ext_irq_cfg_reg2        0
  73 #endif
  74 #ifdef CONFIG_BCM63XX_CPU_6348
  75 #define irq_stat_reg            PERF_IRQSTAT_6348_REG
  76 #define irq_mask_reg            PERF_IRQMASK_6348_REG
  77 #define irq_bits                32
  78 #define is_ext_irq_cascaded     0
  79 #define ext_irq_start           0
  80 #define ext_irq_end             0
  81 #define ext_irq_count           4
  82 #define ext_irq_cfg_reg1        PERF_EXTIRQ_CFG_REG_6348
  83 #define ext_irq_cfg_reg2        0
  84 #endif
  85 #ifdef CONFIG_BCM63XX_CPU_6358
  86 #define irq_stat_reg            PERF_IRQSTAT_6358_REG
  87 #define irq_mask_reg            PERF_IRQMASK_6358_REG
  88 #define irq_bits                32
  89 #define is_ext_irq_cascaded     1
  90 #define ext_irq_start           (BCM_6358_EXT_IRQ0 - IRQ_INTERNAL_BASE)
  91 #define ext_irq_end             (BCM_6358_EXT_IRQ3 - IRQ_INTERNAL_BASE)
  92 #define ext_irq_count           4
  93 #define ext_irq_cfg_reg1        PERF_EXTIRQ_CFG_REG_6358
  94 #define ext_irq_cfg_reg2        0
  95 #endif
  96 #ifdef CONFIG_BCM63XX_CPU_6362
  97 #define irq_stat_reg            PERF_IRQSTAT_6362_REG
  98 #define irq_mask_reg            PERF_IRQMASK_6362_REG
  99 #define irq_bits                64
 100 #define is_ext_irq_cascaded     1
 101 #define ext_irq_start           (BCM_6362_EXT_IRQ0 - IRQ_INTERNAL_BASE)
 102 #define ext_irq_end             (BCM_6362_EXT_IRQ3 - IRQ_INTERNAL_BASE)
 103 #define ext_irq_count           4
 104 #define ext_irq_cfg_reg1        PERF_EXTIRQ_CFG_REG_6362
 105 #define ext_irq_cfg_reg2        0
 106 #endif
 107 #ifdef CONFIG_BCM63XX_CPU_6368
 108 #define irq_stat_reg            PERF_IRQSTAT_6368_REG
 109 #define irq_mask_reg            PERF_IRQMASK_6368_REG
 110 #define irq_bits                64
 111 #define is_ext_irq_cascaded     1
 112 #define ext_irq_start           (BCM_6368_EXT_IRQ0 - IRQ_INTERNAL_BASE)
 113 #define ext_irq_end             (BCM_6368_EXT_IRQ5 - IRQ_INTERNAL_BASE)
 114 #define ext_irq_count           6
 115 #define ext_irq_cfg_reg1        PERF_EXTIRQ_CFG_REG_6368
 116 #define ext_irq_cfg_reg2        PERF_EXTIRQ_CFG_REG2_6368
 117 #endif
 118
 119 #if irq_bits == 32
 120 #define dispatch_internal                       __dispatch_internal
 121 #define internal_irq_mask                       __internal_irq_mask_32
 122 #define internal_irq_unmask                     __internal_irq_unmask_32
 123 #else
 124 #define dispatch_internal                       __dispatch_internal_64
 125 #define internal_irq_mask                       __internal_irq_mask_64
 126 #define internal_irq_unmask                     __internal_irq_unmask_64
 127 #endif
 128
 129 #define irq_stat_addr   (bcm63xx_regset_address(RSET_PERF) + irq_stat_reg)
 130 #define irq_mask_addr   (bcm63xx_regset_address(RSET_PERF) + irq_mask_reg)
 131
 132 static inline void bcm63xx_init_irq(void)
 133 {
 134 }
 135 #else /* ! BCMCPU_RUNTIME_DETECT */
 136
 137 static u32 irq_stat_addr, irq_mask_addr;
 138 static void (*dispatch_internal)(void);
 139 static int is_ext_irq_cascaded;
 140 static unsigned int ext_irq_count;
 141 static unsigned int ext_irq_start, ext_irq_end;
 142 static unsigned int ext_irq_cfg_reg1, ext_irq_cfg_reg2;
 143 static void (*internal_irq_mask)(unsigned int irq);
 144 static void (*internal_irq_unmask)(unsigned int irq);
 145
 146 static void bcm63xx_init_irq(void)
 147 {
 148         int irq_bits;
 149
 150         irq_stat_addr = bcm63xx_regset_address(RSET_PERF);
 151         irq_mask_addr = bcm63xx_regset_address(RSET_PERF);
 152
 153         switch (bcm63xx_get_cpu_id()) {
 154         case BCM3368_CPU_ID:
 155                 irq_stat_addr += PERF_IRQSTAT_3368_REG;
 156                 irq_mask_addr += PERF_IRQMASK_3368_REG;
 157                 irq_bits = 32;
 158                 ext_irq_count = 4;
 159                 ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_3368;
 160                 break;
 161         case BCM6328_CPU_ID:
 162                 irq_stat_addr += PERF_IRQSTAT_6328_REG;
 163                 irq_mask_addr += PERF_IRQMASK_6328_REG;
 164                 irq_bits = 64;
 165                 ext_irq_count = 4;
 166                 is_ext_irq_cascaded = 1;
 167                 ext_irq_start = BCM_6328_EXT_IRQ0 - IRQ_INTERNAL_BASE;
 168                 ext_irq_end = BCM_6328_EXT_IRQ3 - IRQ_INTERNAL_BASE;
 169                 ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6328;
 170                 break;
 171         case BCM6338_CPU_ID:
 172                 irq_stat_addr += PERF_IRQSTAT_6338_REG;
 173                 irq_mask_addr += PERF_IRQMASK_6338_REG;
 174                 irq_bits = 32;
 175                 ext_irq_count = 4;
 176                 ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6338;
 177                 break;
 178         case BCM6345_CPU_ID:
 179                 irq_stat_addr += PERF_IRQSTAT_6345_REG;
 180                 irq_mask_addr += PERF_IRQMASK_6345_REG;
 181                 irq_bits = 32;
 182                 ext_irq_count = 4;
 183                 ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6345;
 184                 break;
 185         case BCM6348_CPU_ID:
 186                 irq_stat_addr += PERF_IRQSTAT_6348_REG;
 187                 irq_mask_addr += PERF_IRQMASK_6348_REG;
 188                 irq_bits = 32;
 189                 ext_irq_count = 4;
 190                 ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6348;
 191                 break;
 192         case BCM6358_CPU_ID:
 193                 irq_stat_addr += PERF_IRQSTAT_6358_REG;
 194                 irq_mask_addr += PERF_IRQMASK_6358_REG;
 195                 irq_bits = 32;
 196                 ext_irq_count = 4;
 197                 is_ext_irq_cascaded = 1;
 198                 ext_irq_start = BCM_6358_EXT_IRQ0 - IRQ_INTERNAL_BASE;
 199                 ext_irq_end = BCM_6358_EXT_IRQ3 - IRQ_INTERNAL_BASE;
 200                 ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6358;
 201                 break;
 202         case BCM6362_CPU_ID:
 203                 irq_stat_addr += PERF_IRQSTAT_6362_REG;
 204                 irq_mask_addr += PERF_IRQMASK_6362_REG;
 205                 irq_bits = 64;
 206                 ext_irq_count = 4;
 207                 is_ext_irq_cascaded = 1;
 208                 ext_irq_start = BCM_6362_EXT_IRQ0 - IRQ_INTERNAL_BASE;
 209                 ext_irq_end = BCM_6362_EXT_IRQ3 - IRQ_INTERNAL_BASE;
 210                 ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6362;
 211                 break;
 212         case BCM6368_CPU_ID:
 213                 irq_stat_addr += PERF_IRQSTAT_6368_REG;
 214                 irq_mask_addr += PERF_IRQMASK_6368_REG;
 215                 irq_bits = 64;
 216                 ext_irq_count = 6;
 217                 is_ext_irq_cascaded = 1;
 218                 ext_irq_start = BCM_6368_EXT_IRQ0 - IRQ_INTERNAL_BASE;
 219                 ext_irq_end = BCM_6368_EXT_IRQ5 - IRQ_INTERNAL_BASE;
 220                 ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6368;
 221                 ext_irq_cfg_reg2 = PERF_EXTIRQ_CFG_REG2_6368;
 222                 break;
 223         default:
 224                 BUG();
 225         }
 226
 227         if (irq_bits == 32) {
 228                 dispatch_internal = __dispatch_internal;
 229                 internal_irq_mask = __internal_irq_mask_32;
 230                 internal_irq_unmask = __internal_irq_unmask_32;
 231         } else {
 232                 dispatch_internal = __dispatch_internal_64;
 233                 internal_irq_mask = __internal_irq_mask_64;
 234                 internal_irq_unmask = __internal_irq_unmask_64;
 235         }
 236 }
 237 #endif /* ! BCMCPU_RUNTIME_DETECT */
 238
 239 static inline u32 get_ext_irq_perf_reg(int irq)
 240 {
 241         if (irq < 4)
 242                 return ext_irq_cfg_reg1;
 243         return ext_irq_cfg_reg2;
 244 }
 245
 246 static inline void handle_internal(int intbit)
 247 {
 248         if (is_ext_irq_cascaded &&
 249             intbit >= ext_irq_start && intbit <= ext_irq_end)
 250                 do_IRQ(intbit - ext_irq_start + IRQ_EXTERNAL_BASE);
 251         else
 252                 do_IRQ(intbit + IRQ_INTERNAL_BASE);
 253 }
 254
 255 /*
 256  * dispatch internal devices IRQ (uart, enet, watchdog, ...). do not
 257  * prioritize any interrupt relatively to another. the static counter
 258  * will resume the loop where it ended the last time we left this
 259  * function.
 260  */
 261 static void __dispatch_internal(void)
 262 {
 263         u32 pending;
 264         static int i;
 265
 266         pending = bcm_readl(irq_stat_addr) & bcm_readl(irq_mask_addr);
 267
 268         if (!pending)
 269                 return ;
 270
 271         while (1) {
 272                 int to_call = i;
 273
 274                 i = (i + 1) & 0x1f;
 275                 if (pending & (1 << to_call)) {
 276                         handle_internal(to_call);
 277                         break;
 278                 }
 279         }
 280 }
 281
 282 static void __dispatch_internal_64(void)
 283 {
 284         u64 pending;
 285         static int i;
 286
 287         pending = bcm_readq(irq_stat_addr) & bcm_readq(irq_mask_addr);
 288
 289         if (!pending)
 290                 return ;
 291
 292         while (1) {
 293                 int to_call = i;
 294
 295                 i = (i + 1) & 0x3f;
 296                 if (pending & (1ull << to_call)) {
 297                         handle_internal(to_call);
 298                         break;
 299                 }
 300         }
 301 }
 302
 303 asmlinkage void plat_irq_dispatch(void)
 304 {
 305         u32 cause;
 306
 307         do {
 308                 cause = read_c0_cause() & read_c0_status() & ST0_IM;
 309
 310                 if (!cause)
 311                         break;
 312
 313                 if (cause & CAUSEF_IP7)
 314                         do_IRQ(7);
 315                 if (cause & CAUSEF_IP0)
 316                         do_IRQ(0);
 317                 if (cause & CAUSEF_IP1)
 318                         do_IRQ(1);
 319                 if (cause & CAUSEF_IP2)
 320                         dispatch_internal();
 321                 if (!is_ext_irq_cascaded) {
 322                         if (cause & CAUSEF_IP3)
 323                                 do_IRQ(IRQ_EXT_0);
 324                         if (cause & CAUSEF_IP4)
 325                                 do_IRQ(IRQ_EXT_1);
 326                         if (cause & CAUSEF_IP5)
 327                                 do_IRQ(IRQ_EXT_2);
 328                         if (cause & CAUSEF_IP6)
 329                                 do_IRQ(IRQ_EXT_3);
 330                 }
 331         } while (1);
 332 }
 333
 334 /*
 335  * internal IRQs operations: only mask/unmask on PERF irq mask
 336  * register.
 337  */
 338 static void __internal_irq_mask_32(unsigned int irq)
 339 {
 340         u32 mask;
 341
 342         mask = bcm_readl(irq_mask_addr);
 343         mask &= ~(1 << irq);
 344         bcm_writel(mask, irq_mask_addr);
 345 }
 346
 347 static void __internal_irq_mask_64(unsigned int irq)
 348 {
 349         u64 mask;
 350
 351         mask = bcm_readq(irq_mask_addr);
 352         mask &= ~(1ull << irq);
 353         bcm_writeq(mask, irq_mask_addr);
 354 }
 355
 356 static void __internal_irq_unmask_32(unsigned int irq)
 357 {
 358         u32 mask;
 359
 360         mask = bcm_readl(irq_mask_addr);
 361         mask |= (1 << irq);
 362         bcm_writel(mask, irq_mask_addr);
 363 }
 364
 365 static void __internal_irq_unmask_64(unsigned int irq)
 366 {
 367         u64 mask;
 368
 369         mask = bcm_readq(irq_mask_addr);
 370         mask |= (1ull << irq);
 371         bcm_writeq(mask, irq_mask_addr);
 372 }
 373
 374 static void bcm63xx_internal_irq_mask(struct irq_data *d)
 375 {
 376         internal_irq_mask(d->irq - IRQ_INTERNAL_BASE);
 377 }
 378
 379 static void bcm63xx_internal_irq_unmask(struct irq_data *d)
 380 {
 381         internal_irq_unmask(d->irq - IRQ_INTERNAL_BASE);
 382 }
 383
 384 /*
 385  * external IRQs operations: mask/unmask and clear on PERF external
 386  * irq control register.
 387  */
 388 static void bcm63xx_external_irq_mask(struct irq_data *d)
 389 {
 390         unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
 391         u32 reg, regaddr;
 392
 393         regaddr = get_ext_irq_perf_reg(irq);
 394         reg = bcm_perf_readl(regaddr);
 395
 396         if (BCMCPU_IS_6348())
 397                 reg &= ~EXTIRQ_CFG_MASK_6348(irq % 4);
 398         else
 399                 reg &= ~EXTIRQ_CFG_MASK(irq % 4);
 400
 401         bcm_perf_writel(reg, regaddr);
 402         if (is_ext_irq_cascaded)
 403                 internal_irq_mask(irq + ext_irq_start);
 404 }
 405
 406 static void bcm63xx_external_irq_unmask(struct irq_data *d)
 407 {
 408         unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
 409         u32 reg, regaddr;
 410
 411         regaddr = get_ext_irq_perf_reg(irq);
 412         reg = bcm_perf_readl(regaddr);
 413
 414         if (BCMCPU_IS_6348())
 415                 reg |= EXTIRQ_CFG_MASK_6348(irq % 4);
 416         else
 417                 reg |= EXTIRQ_CFG_MASK(irq % 4);
 418
 419         bcm_perf_writel(reg, regaddr);
 420
 421         if (is_ext_irq_cascaded)
 422                 internal_irq_unmask(irq + ext_irq_start);
 423 }
 424
 425 static void bcm63xx_external_irq_clear(struct irq_data *d)
 426 {
 427         unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
 428         u32 reg, regaddr;
 429
 430         regaddr = get_ext_irq_perf_reg(irq);
 431         reg = bcm_perf_readl(regaddr);
 432
 433         if (BCMCPU_IS_6348())
 434                 reg |= EXTIRQ_CFG_CLEAR_6348(irq % 4);
 435         else
 436                 reg |= EXTIRQ_CFG_CLEAR(irq % 4);
 437
 438         bcm_perf_writel(reg, regaddr);
 439 }
 440
 441 static int bcm63xx_external_irq_set_type(struct irq_data *d,
 442                                          unsigned int flow_type)
 443 {
 444         unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
 445         u32 reg, regaddr;
 446         int levelsense, sense, bothedge;
 447
 448         flow_type &= IRQ_TYPE_SENSE_MASK;
 449
 450         if (flow_type == IRQ_TYPE_NONE)
 451                 flow_type = IRQ_TYPE_LEVEL_LOW;
 452
 453         levelsense = sense = bothedge = 0;
 454         switch (flow_type) {
 455         case IRQ_TYPE_EDGE_BOTH:
 456                 bothedge = 1;
 457                 break;
 458
 459         case IRQ_TYPE_EDGE_RISING:
 460                 sense = 1;
 461                 break;
 462
 463         case IRQ_TYPE_EDGE_FALLING:
 464                 break;
 465
 466         case IRQ_TYPE_LEVEL_HIGH:
 467                 levelsense = 1;
 468                 sense = 1;
 469                 break;
 470
 471         case IRQ_TYPE_LEVEL_LOW:
 472                 levelsense = 1;
 473                 break;
 474
 475         default:
 476                 printk(KERN_ERR "bogus flow type combination given !\n");
 477                 return -EINVAL;
 478         }
 479
 480         regaddr = get_ext_irq_perf_reg(irq);
 481         reg = bcm_perf_readl(regaddr);
 482         irq %= 4;
 483
 484         switch (bcm63xx_get_cpu_id()) {
 485         case BCM6348_CPU_ID:
 486                 if (levelsense)
 487                         reg |= EXTIRQ_CFG_LEVELSENSE_6348(irq);
 488                 else
 489                         reg &= ~EXTIRQ_CFG_LEVELSENSE_6348(irq);
 490                 if (sense)
 491                         reg |= EXTIRQ_CFG_SENSE_6348(irq);
 492                 else
 493                         reg &= ~EXTIRQ_CFG_SENSE_6348(irq);
 494                 if (bothedge)
 495                         reg |= EXTIRQ_CFG_BOTHEDGE_6348(irq);
 496                 else
 497                         reg &= ~EXTIRQ_CFG_BOTHEDGE_6348(irq);
 498                 break;
 499
 500         case BCM3368_CPU_ID:
 501         case BCM6328_CPU_ID:
 502         case BCM6338_CPU_ID:
 503         case BCM6345_CPU_ID:
 504         case BCM6358_CPU_ID:
 505         case BCM6362_CPU_ID:
 506         case BCM6368_CPU_ID:
 507                 if (levelsense)
 508                         reg |= EXTIRQ_CFG_LEVELSENSE(irq);
 509                 else
 510                         reg &= ~EXTIRQ_CFG_LEVELSENSE(irq);
 511                 if (sense)
 512                         reg |= EXTIRQ_CFG_SENSE(irq);
 513                 else
 514                         reg &= ~EXTIRQ_CFG_SENSE(irq);
 515                 if (bothedge)
 516                         reg |= EXTIRQ_CFG_BOTHEDGE(irq);
 517                 else
 518                         reg &= ~EXTIRQ_CFG_BOTHEDGE(irq);
 519                 break;
 520         default:
 521                 BUG();
 522         }
 523
 524         bcm_perf_writel(reg, regaddr);
 525
 526         irqd_set_trigger_type(d, flow_type);
 527         if (flow_type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
 528                 __irq_set_handler_locked(d->irq, handle_level_irq);
 529         else
 530                 __irq_set_handler_locked(d->irq, handle_edge_irq);
 531
 532         return IRQ_SET_MASK_OK_NOCOPY;
 533 }
 534
 535 static struct irq_chip bcm63xx_internal_irq_chip = {
 536         .name           = "bcm63xx_ipic",
 537         .irq_mask       = bcm63xx_internal_irq_mask,
 538         .irq_unmask     = bcm63xx_internal_irq_unmask,
 539 };
 540
 541 static struct irq_chip bcm63xx_external_irq_chip = {
 542         .name           = "bcm63xx_epic",
 543         .irq_ack        = bcm63xx_external_irq_clear,
 544
 545         .irq_mask       = bcm63xx_external_irq_mask,
 546         .irq_unmask     = bcm63xx_external_irq_unmask,
 547
 548         .irq_set_type   = bcm63xx_external_irq_set_type,
 549 };
 550
 551 static struct irqaction cpu_ip2_cascade_action = {
 552         .handler        = no_action,
 553         .name           = "cascade_ip2",
 554         .flags          = IRQF_NO_THREAD,
 555 };
 556
 557 static struct irqaction cpu_ext_cascade_action = {
 558         .handler        = no_action,
 559         .name           = "cascade_extirq",
 560         .flags          = IRQF_NO_THREAD,
 561 };
 562
 563 void __init arch_init_irq(void)
 564 {
 565         int i;
 566
 567         bcm63xx_init_irq();
 568         mips_cpu_irq_init();
 569         for (i = IRQ_INTERNAL_BASE; i < NR_IRQS; ++i)
 570                 irq_set_chip_and_handler(i, &bcm63xx_internal_irq_chip,
 571                                          handle_level_irq);
 572
 573         for (i = IRQ_EXTERNAL_BASE; i < IRQ_EXTERNAL_BASE + ext_irq_count; ++i)
 574                 irq_set_chip_and_handler(i, &bcm63xx_external_irq_chip,
 575                                          handle_edge_irq);
 576
 577         if (!is_ext_irq_cascaded) {
 578                 for (i = 3; i < 3 + ext_irq_count; ++i)
 579                         setup_irq(MIPS_CPU_IRQ_BASE + i, &cpu_ext_cascade_action);
 580         }
 581
 582         setup_irq(MIPS_CPU_IRQ_BASE + 2, &cpu_ip2_cascade_action);
 583 }