arch/cris/arch-v32/kernel/irq.c

   1 /*
   2  * Copyright (C) 2003, Axis Communications AB.
   3  */
   4
   5 #include <asm/irq.h>
   6 #include <linux/irq.h>
   7 #include <linux/interrupt.h>
   8 #include <linux/smp.h>
   9 #include <linux/kernel.h>
  10 #include <linux/errno.h>
  11 #include <linux/init.h>
  12 #include <linux/profile.h>
  13 #include <linux/proc_fs.h>
  14 #include <linux/seq_file.h>
  15 #include <linux/threads.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/kernel_stat.h>
  18 #include <hwregs/reg_map.h>
  19 #include <hwregs/reg_rdwr.h>
  20 #include <hwregs/intr_vect.h>
  21 #include <hwregs/intr_vect_defs.h>
  22
  23 #define CPU_FIXED -1
  24
  25 /* IRQ masks (refer to comment for crisv32_do_multiple) */
  26 #if TIMER0_INTR_VECT - FIRST_IRQ < 32
  27 #define TIMER_MASK (1 << (TIMER0_INTR_VECT - FIRST_IRQ))
  28 #undef TIMER_VECT1
  29 #else
  30 #define TIMER_MASK (1 << (TIMER0_INTR_VECT - FIRST_IRQ - 32))
  31 #define TIMER_VECT1
  32 #endif
  33 #ifdef CONFIG_ETRAX_KGDB
  34 #if defined(CONFIG_ETRAX_KGDB_PORT0)
  35 #define IGNOREMASK (1 << (SER0_INTR_VECT - FIRST_IRQ))
  36 #elif defined(CONFIG_ETRAX_KGDB_PORT1)
  37 #define IGNOREMASK (1 << (SER1_INTR_VECT - FIRST_IRQ))
  38 #elif defined(CONFIG_ETRAX_KGB_PORT2)
  39 #define IGNOREMASK (1 << (SER2_INTR_VECT - FIRST_IRQ))
  40 #elif defined(CONFIG_ETRAX_KGDB_PORT3)
  41 #define IGNOREMASK (1 << (SER3_INTR_VECT - FIRST_IRQ))
  42 #endif
  43 #endif
  44
  45 DEFINE_SPINLOCK(irq_lock);
  46
  47 struct cris_irq_allocation
  48 {
  49   int cpu; /* The CPU to which the IRQ is currently allocated. */
  50   cpumask_t mask; /* The CPUs to which the IRQ may be allocated. */
  51 };
  52
  53 struct cris_irq_allocation irq_allocations[NR_REAL_IRQS] =
  54   { [0 ... NR_REAL_IRQS - 1] = {0, CPU_MASK_ALL} };
  55
  56 static unsigned long irq_regs[NR_CPUS] =
  57 {
  58   regi_irq,
  59 #ifdef CONFIG_SMP
  60   regi_irq2,
  61 #endif
  62 };
  63
  64 #if NR_REAL_IRQS > 32
  65 #define NBR_REGS 2
  66 #else
  67 #define NBR_REGS 1
  68 #endif
  69
  70 unsigned long cpu_irq_counters[NR_CPUS];
  71 unsigned long irq_counters[NR_REAL_IRQS];
  72
  73 /* From irq.c. */
  74 extern void weird_irq(void);
  75
  76 /* From entry.S. */
  77 extern void system_call(void);
  78 extern void nmi_interrupt(void);
  79 extern void multiple_interrupt(void);
  80 extern void gdb_handle_exception(void);
  81 extern void i_mmu_refill(void);
  82 extern void i_mmu_invalid(void);
  83 extern void i_mmu_access(void);
  84 extern void i_mmu_execute(void);
  85 extern void d_mmu_refill(void);
  86 extern void d_mmu_invalid(void);
  87 extern void d_mmu_access(void);
  88 extern void d_mmu_write(void);
  89
  90 /* From kgdb.c. */
  91 extern void kgdb_init(void);
  92 extern void breakpoint(void);
  93
  94 /* From traps.c.  */
  95 extern void breakh_BUG(void);
  96
  97 /*
  98  * Build the IRQ handler stubs using macros from irq.h.
  99  */
 100 BUILD_IRQ(0x31)
 101 BUILD_IRQ(0x32)
 102 BUILD_IRQ(0x33)
 103 BUILD_IRQ(0x34)
 104 BUILD_IRQ(0x35)
 105 BUILD_IRQ(0x36)
 106 BUILD_IRQ(0x37)
 107 BUILD_IRQ(0x38)
 108 BUILD_IRQ(0x39)
 109 BUILD_IRQ(0x3a)
 110 BUILD_IRQ(0x3b)
 111 BUILD_IRQ(0x3c)
 112 BUILD_IRQ(0x3d)
 113 BUILD_IRQ(0x3e)
 114 BUILD_IRQ(0x3f)
 115 BUILD_IRQ(0x40)
 116 BUILD_IRQ(0x41)
 117 BUILD_IRQ(0x42)
 118 BUILD_IRQ(0x43)
 119 BUILD_IRQ(0x44)
 120 BUILD_IRQ(0x45)
 121 BUILD_IRQ(0x46)
 122 BUILD_IRQ(0x47)
 123 BUILD_IRQ(0x48)
 124 BUILD_IRQ(0x49)
 125 BUILD_IRQ(0x4a)
 126 BUILD_IRQ(0x4b)
 127 BUILD_IRQ(0x4c)
 128 BUILD_IRQ(0x4d)
 129 BUILD_IRQ(0x4e)
 130 BUILD_IRQ(0x4f)
 131 BUILD_IRQ(0x50)
 132 #if MACH_IRQS > 32
 133 BUILD_IRQ(0x51)
 134 BUILD_IRQ(0x52)
 135 BUILD_IRQ(0x53)
 136 BUILD_IRQ(0x54)
 137 BUILD_IRQ(0x55)
 138 BUILD_IRQ(0x56)
 139 BUILD_IRQ(0x57)
 140 BUILD_IRQ(0x58)
 141 BUILD_IRQ(0x59)
 142 BUILD_IRQ(0x5a)
 143 BUILD_IRQ(0x5b)
 144 BUILD_IRQ(0x5c)
 145 BUILD_IRQ(0x5d)
 146 BUILD_IRQ(0x5e)
 147 BUILD_IRQ(0x5f)
 148 BUILD_IRQ(0x60)
 149 BUILD_IRQ(0x61)
 150 BUILD_IRQ(0x62)
 151 BUILD_IRQ(0x63)
 152 BUILD_IRQ(0x64)
 153 BUILD_IRQ(0x65)
 154 BUILD_IRQ(0x66)
 155 BUILD_IRQ(0x67)
 156 BUILD_IRQ(0x68)
 157 BUILD_IRQ(0x69)
 158 BUILD_IRQ(0x6a)
 159 BUILD_IRQ(0x6b)
 160 BUILD_IRQ(0x6c)
 161 BUILD_IRQ(0x6d)
 162 BUILD_IRQ(0x6e)
 163 BUILD_IRQ(0x6f)
 164 BUILD_IRQ(0x70)
 165 #endif
 166
 167 /* Pointers to the low-level handlers. */
 168 static void (*interrupt[MACH_IRQS])(void) = {
 169         IRQ0x31_interrupt, IRQ0x32_interrupt, IRQ0x33_interrupt,
 170         IRQ0x34_interrupt, IRQ0x35_interrupt, IRQ0x36_interrupt,
 171         IRQ0x37_interrupt, IRQ0x38_interrupt, IRQ0x39_interrupt,
 172         IRQ0x3a_interrupt, IRQ0x3b_interrupt, IRQ0x3c_interrupt,
 173         IRQ0x3d_interrupt, IRQ0x3e_interrupt, IRQ0x3f_interrupt,
 174         IRQ0x40_interrupt, IRQ0x41_interrupt, IRQ0x42_interrupt,
 175         IRQ0x43_interrupt, IRQ0x44_interrupt, IRQ0x45_interrupt,
 176         IRQ0x46_interrupt, IRQ0x47_interrupt, IRQ0x48_interrupt,
 177         IRQ0x49_interrupt, IRQ0x4a_interrupt, IRQ0x4b_interrupt,
 178         IRQ0x4c_interrupt, IRQ0x4d_interrupt, IRQ0x4e_interrupt,
 179         IRQ0x4f_interrupt, IRQ0x50_interrupt,
 180 #if MACH_IRQS > 32
 181         IRQ0x51_interrupt, IRQ0x52_interrupt, IRQ0x53_interrupt,
 182         IRQ0x54_interrupt, IRQ0x55_interrupt, IRQ0x56_interrupt,
 183         IRQ0x57_interrupt, IRQ0x58_interrupt, IRQ0x59_interrupt,
 184         IRQ0x5a_interrupt, IRQ0x5b_interrupt, IRQ0x5c_interrupt,
 185         IRQ0x5d_interrupt, IRQ0x5e_interrupt, IRQ0x5f_interrupt,
 186         IRQ0x60_interrupt, IRQ0x61_interrupt, IRQ0x62_interrupt,
 187         IRQ0x63_interrupt, IRQ0x64_interrupt, IRQ0x65_interrupt,
 188         IRQ0x66_interrupt, IRQ0x67_interrupt, IRQ0x68_interrupt,
 189         IRQ0x69_interrupt, IRQ0x6a_interrupt, IRQ0x6b_interrupt,
 190         IRQ0x6c_interrupt, IRQ0x6d_interrupt, IRQ0x6e_interrupt,
 191         IRQ0x6f_interrupt, IRQ0x70_interrupt,
 192 #endif
 193 };
 194
 195 void
 196 block_irq(int irq, int cpu)
 197 {
 198         int intr_mask;
 199         unsigned long flags;
 200
 201         spin_lock_irqsave(&irq_lock, flags);
 202         if (irq - FIRST_IRQ < 32)
 203                 intr_mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
 204                         rw_mask, 0);
 205         else
 206                 intr_mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
 207                         rw_mask, 1);
 208
 209         /* Remember; 1 let thru, 0 block. */
 210         if (irq - FIRST_IRQ < 32)
 211                 intr_mask &= ~(1 << (irq - FIRST_IRQ));
 212         else
 213                 intr_mask &= ~(1 << (irq - FIRST_IRQ - 32));
 214
 215         if (irq - FIRST_IRQ < 32)
 216                 REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask,
 217                         0, intr_mask);
 218         else
 219                 REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask,
 220                         1, intr_mask);
 221         spin_unlock_irqrestore(&irq_lock, flags);
 222 }
 223
 224 void
 225 unblock_irq(int irq, int cpu)
 226 {
 227         int intr_mask;
 228         unsigned long flags;
 229
 230         spin_lock_irqsave(&irq_lock, flags);
 231         if (irq - FIRST_IRQ < 32)
 232                 intr_mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
 233                         rw_mask, 0);
 234         else
 235                 intr_mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
 236                         rw_mask, 1);
 237
 238         /* Remember; 1 let thru, 0 block. */
 239         if (irq - FIRST_IRQ < 32)
 240                 intr_mask |= (1 << (irq - FIRST_IRQ));
 241         else
 242                 intr_mask |= (1 << (irq - FIRST_IRQ - 32));
 243
 244         if (irq - FIRST_IRQ < 32)
 245                 REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask,
 246                         0, intr_mask);
 247         else
 248                 REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask,
 249                         1, intr_mask);
 250
 251         spin_unlock_irqrestore(&irq_lock, flags);
 252 }
 253
 254 /* Find out which CPU the irq should be allocated to. */
 255 static int irq_cpu(int irq)
 256 {
 257         int cpu;
 258         unsigned long flags;
 259
 260         spin_lock_irqsave(&irq_lock, flags);
 261         cpu = irq_allocations[irq - FIRST_IRQ].cpu;
 262
 263         /* Fixed interrupts stay on the local CPU. */
 264         if (cpu == CPU_FIXED)
 265         {
 266                 spin_unlock_irqrestore(&irq_lock, flags);
 267                 return smp_processor_id();
 268         }
 269
 270
 271         /* Let the interrupt stay if possible */
 272         if (cpu_isset(cpu, irq_allocations[irq - FIRST_IRQ].mask))
 273                 goto out;
 274
 275         /* IRQ must be moved to another CPU. */
 276         cpu = first_cpu(irq_allocations[irq - FIRST_IRQ].mask);
 277         irq_allocations[irq - FIRST_IRQ].cpu = cpu;
 278 out:
 279         spin_unlock_irqrestore(&irq_lock, flags);
 280         return cpu;
 281 }
 282
 283 void
 284 mask_irq(int irq)
 285 {
 286         int cpu;
 287
 288         for (cpu = 0; cpu < NR_CPUS; cpu++)
 289                 block_irq(irq, cpu);
 290 }
 291
 292 void
 293 unmask_irq(int irq)
 294 {
 295         unblock_irq(irq, irq_cpu(irq));
 296 }
 297
 298
 299 static unsigned int startup_crisv32_irq(unsigned int irq)
 300 {
 301         unmask_irq(irq);
 302         return 0;
 303 }
 304
 305 static void shutdown_crisv32_irq(unsigned int irq)
 306 {
 307         mask_irq(irq);
 308 }
 309
 310 static void enable_crisv32_irq(unsigned int irq)
 311 {
 312         unmask_irq(irq);
 313 }
 314
 315 static void disable_crisv32_irq(unsigned int irq)
 316 {
 317         mask_irq(irq);
 318 }
 319
 320 static void ack_crisv32_irq(unsigned int irq)
 321 {
 322 }
 323
 324 static void end_crisv32_irq(unsigned int irq)
 325 {
 326 }
 327
 328 void set_affinity_crisv32_irq(unsigned int irq, cpumask_t dest)
 329 {
 330         unsigned long flags;
 331         spin_lock_irqsave(&irq_lock, flags);
 332         irq_allocations[irq - FIRST_IRQ].mask = dest;
 333         spin_unlock_irqrestore(&irq_lock, flags);
 334 }
 335
 336 static struct hw_interrupt_type crisv32_irq_type = {
 337         .typename =    "CRISv32",
 338         .startup =     startup_crisv32_irq,
 339         .shutdown =    shutdown_crisv32_irq,
 340         .enable =      enable_crisv32_irq,
 341         .disable =     disable_crisv32_irq,
 342         .ack =         ack_crisv32_irq,
 343         .end =         end_crisv32_irq,
 344         .set_affinity = set_affinity_crisv32_irq
 345 };
 346
 347 void
 348 set_exception_vector(int n, irqvectptr addr)
 349 {
 350         etrax_irv->v[n] = (irqvectptr) addr;
 351 }
 352
 353 extern void do_IRQ(int irq, struct pt_regs * regs);
 354
 355 void
 356 crisv32_do_IRQ(int irq, int block, struct pt_regs* regs)
 357 {
 358         /* Interrupts that may not be moved to another CPU and
 359          * are IRQF_DISABLED may skip blocking. This is currently
 360          * only valid for the timer IRQ and the IPI and is used
 361          * for the timer interrupt to avoid watchdog starvation.
 362          */
 363         if (!block) {
 364                 do_IRQ(irq, regs);
 365                 return;
 366         }
 367
 368         block_irq(irq, smp_processor_id());
 369         do_IRQ(irq, regs);
 370
 371         unblock_irq(irq, irq_cpu(irq));
 372 }
 373
 374 /* If multiple interrupts occur simultaneously we get a multiple
 375  * interrupt from the CPU and software has to sort out which
 376  * interrupts that happened. There are two special cases here:
 377  *
 378  * 1. Timer interrupts may never be blocked because of the
 379  *    watchdog (refer to comment in include/asr/arch/irq.h)
 380  * 2. GDB serial port IRQs are unhandled here and will be handled
 381  *    as a single IRQ when it strikes again because the GDB
 382  *    stubb wants to save the registers in its own fashion.
 383  */
 384 void
 385 crisv32_do_multiple(struct pt_regs* regs)
 386 {
 387         int cpu;
 388         int mask;
 389         int masked[NBR_REGS];
 390         int bit;
 391         int i;
 392
 393         cpu = smp_processor_id();
 394
 395         /* An extra irq_enter here to prevent softIRQs to run after
 396          * each do_IRQ. This will decrease the interrupt latency.
 397          */
 398         irq_enter();
 399
 400         for (i = 0; i < NBR_REGS; i++) {
 401                 /* Get which IRQs that happend. */
 402                 masked[i] = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
 403                         r_masked_vect, i);
 404
 405                 /* Calculate new IRQ mask with these IRQs disabled. */
 406                 mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu], rw_mask, i);
 407                 mask &= ~masked[i];
 408
 409         /* Timer IRQ is never masked */
 410 #ifdef TIMER_VECT1
 411                 if ((i == 1) && (masked[0] & TIMER_MASK))
 412                         mask |= TIMER_MASK;
 413 #else
 414                 if ((i == 0) && (masked[0] & TIMER_MASK))
 415                         mask |= TIMER_MASK;
 416 #endif
 417                 /* Block all the IRQs */
 418                 REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask, i, mask);
 419
 420         /* Check for timer IRQ and handle it special. */
 421 #ifdef TIMER_VECT1
 422                 if ((i == 1) && (masked[i] & TIMER_MASK)) {
 423                         masked[i] &= ~TIMER_MASK;
 424                         do_IRQ(TIMER0_INTR_VECT, regs);
 425                 }
 426 #else
 427                 if ((i == 0) && (masked[i] & TIMER_MASK)) {
 428                          masked[i] &= ~TIMER_MASK;
 429                          do_IRQ(TIMER0_INTR_VECT, regs);
 430                 }
 431         }
 432 #endif
 433
 434 #ifdef IGNORE_MASK
 435         /* Remove IRQs that can't be handled as multiple. */
 436         masked[0] &= ~IGNORE_MASK;
 437 #endif
 438
 439         /* Handle the rest of the IRQs. */
 440         for (i = 0; i < NBR_REGS; i++) {
 441                 for (bit = 0; bit < 32; bit++) {
 442                         if (masked[i] & (1 << bit))
 443                                 do_IRQ(bit + FIRST_IRQ + i*32, regs);
 444                 }
 445         }
 446
 447         /* Unblock all the IRQs. */
 448         for (i = 0; i < NBR_REGS; i++) {
 449                 mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu], rw_mask, i);
 450                 mask |= masked[i];
 451                 REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask, i, mask);
 452         }
 453
 454         /* This irq_exit() will trigger the soft IRQs. */
 455         irq_exit();
 456 }
 457
 458 /*
 459  * This is called by start_kernel. It fixes the IRQ masks and setup the
 460  * interrupt vector table to point to bad_interrupt pointers.
 461  */
 462 void __init
 463 init_IRQ(void)
 464 {
 465         int i;
 466         int j;
 467         reg_intr_vect_rw_mask vect_mask = {0};
 468
 469         /* Clear all interrupts masks. */
 470         for (i = 0; i < NBR_REGS; i++)
 471                 REG_WR_VECT(intr_vect, regi_irq, rw_mask, i, vect_mask);
 472
 473         for (i = 0; i < 256; i++)
 474                 etrax_irv->v[i] = weird_irq;
 475
 476         /* Point all IRQ's to bad handlers. */
 477         for (i = FIRST_IRQ, j = 0; j < NR_IRQS; i++, j++) {
 478                 irq_desc[j].chip = &crisv32_irq_type;
 479                 set_exception_vector(i, interrupt[j]);
 480         }
 481
 482         /* Mark Timer and IPI IRQs as CPU local */
 483         irq_allocations[TIMER0_INTR_VECT - FIRST_IRQ].cpu = CPU_FIXED;
 484         irq_desc[TIMER0_INTR_VECT].status |= IRQ_PER_CPU;
 485         irq_allocations[IPI_INTR_VECT - FIRST_IRQ].cpu = CPU_FIXED;
 486         irq_desc[IPI_INTR_VECT].status |= IRQ_PER_CPU;
 487
 488         set_exception_vector(0x00, nmi_interrupt);
 489         set_exception_vector(0x30, multiple_interrupt);
 490
 491         /* Set up handler for various MMU bus faults. */
 492         set_exception_vector(0x04, i_mmu_refill);
 493         set_exception_vector(0x05, i_mmu_invalid);
 494         set_exception_vector(0x06, i_mmu_access);
 495         set_exception_vector(0x07, i_mmu_execute);
 496         set_exception_vector(0x08, d_mmu_refill);
 497         set_exception_vector(0x09, d_mmu_invalid);
 498         set_exception_vector(0x0a, d_mmu_access);
 499         set_exception_vector(0x0b, d_mmu_write);
 500
 501 #ifdef CONFIG_BUG
 502         /* Break 14 handler, used to implement cheap BUG().  */
 503         set_exception_vector(0x1e, breakh_BUG);
 504 #endif
 505
 506         /* The system-call trap is reached by "break 13". */
 507         set_exception_vector(0x1d, system_call);
 508
 509         /* Exception handlers for debugging, both user-mode and kernel-mode. */
 510
 511         /* Break 8. */
 512         set_exception_vector(0x18, gdb_handle_exception);
 513         /* Hardware single step. */
 514         set_exception_vector(0x3, gdb_handle_exception);
 515         /* Hardware breakpoint. */
 516         set_exception_vector(0xc, gdb_handle_exception);
 517
 518 #ifdef CONFIG_ETRAX_KGDB
 519         kgdb_init();
 520         /* Everything is set up; now trap the kernel. */
 521         breakpoint();
 522 #endif
 523 }
 524