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 #ifdef CONFIG_CRIS_MACH_ARTPEC3
 101 BUILD_TIMER_IRQ(0x31, 0)
 102 #else
 103 BUILD_IRQ(0x31)
 104 #endif
 105 BUILD_IRQ(0x32)
 106 BUILD_IRQ(0x33)
 107 BUILD_IRQ(0x34)
 108 BUILD_IRQ(0x35)
 109 BUILD_IRQ(0x36)
 110 BUILD_IRQ(0x37)
 111 BUILD_IRQ(0x38)
 112 BUILD_IRQ(0x39)
 113 BUILD_IRQ(0x3a)
 114 BUILD_IRQ(0x3b)
 115 BUILD_IRQ(0x3c)
 116 BUILD_IRQ(0x3d)
 117 BUILD_IRQ(0x3e)
 118 BUILD_IRQ(0x3f)
 119 BUILD_IRQ(0x40)
 120 BUILD_IRQ(0x41)
 121 BUILD_IRQ(0x42)
 122 BUILD_IRQ(0x43)
 123 BUILD_IRQ(0x44)
 124 BUILD_IRQ(0x45)
 125 BUILD_IRQ(0x46)
 126 BUILD_IRQ(0x47)
 127 BUILD_IRQ(0x48)
 128 BUILD_IRQ(0x49)
 129 BUILD_IRQ(0x4a)
 130 #ifdef CONFIG_ETRAXFS
 131 BUILD_TIMER_IRQ(0x4b, 0)
 132 #else
 133 BUILD_IRQ(0x4b)
 134 #endif
 135 BUILD_IRQ(0x4c)
 136 BUILD_IRQ(0x4d)
 137 BUILD_IRQ(0x4e)
 138 BUILD_IRQ(0x4f)
 139 BUILD_IRQ(0x50)
 140 #if MACH_IRQS > 32
 141 BUILD_IRQ(0x51)
 142 BUILD_IRQ(0x52)
 143 BUILD_IRQ(0x53)
 144 BUILD_IRQ(0x54)
 145 BUILD_IRQ(0x55)
 146 BUILD_IRQ(0x56)
 147 BUILD_IRQ(0x57)
 148 BUILD_IRQ(0x58)
 149 BUILD_IRQ(0x59)
 150 BUILD_IRQ(0x5a)
 151 BUILD_IRQ(0x5b)
 152 BUILD_IRQ(0x5c)
 153 BUILD_IRQ(0x5d)
 154 BUILD_IRQ(0x5e)
 155 BUILD_IRQ(0x5f)
 156 BUILD_IRQ(0x60)
 157 BUILD_IRQ(0x61)
 158 BUILD_IRQ(0x62)
 159 BUILD_IRQ(0x63)
 160 BUILD_IRQ(0x64)
 161 BUILD_IRQ(0x65)
 162 BUILD_IRQ(0x66)
 163 BUILD_IRQ(0x67)
 164 BUILD_IRQ(0x68)
 165 BUILD_IRQ(0x69)
 166 BUILD_IRQ(0x6a)
 167 BUILD_IRQ(0x6b)
 168 BUILD_IRQ(0x6c)
 169 BUILD_IRQ(0x6d)
 170 BUILD_IRQ(0x6e)
 171 BUILD_IRQ(0x6f)
 172 BUILD_IRQ(0x70)
 173 #endif
 174
 175 /* Pointers to the low-level handlers. */
 176 static void (*interrupt[MACH_IRQS])(void) = {
 177         IRQ0x31_interrupt, IRQ0x32_interrupt, IRQ0x33_interrupt,
 178         IRQ0x34_interrupt, IRQ0x35_interrupt, IRQ0x36_interrupt,
 179         IRQ0x37_interrupt, IRQ0x38_interrupt, IRQ0x39_interrupt,
 180         IRQ0x3a_interrupt, IRQ0x3b_interrupt, IRQ0x3c_interrupt,
 181         IRQ0x3d_interrupt, IRQ0x3e_interrupt, IRQ0x3f_interrupt,
 182         IRQ0x40_interrupt, IRQ0x41_interrupt, IRQ0x42_interrupt,
 183         IRQ0x43_interrupt, IRQ0x44_interrupt, IRQ0x45_interrupt,
 184         IRQ0x46_interrupt, IRQ0x47_interrupt, IRQ0x48_interrupt,
 185         IRQ0x49_interrupt, IRQ0x4a_interrupt, IRQ0x4b_interrupt,
 186         IRQ0x4c_interrupt, IRQ0x4d_interrupt, IRQ0x4e_interrupt,
 187         IRQ0x4f_interrupt, IRQ0x50_interrupt,
 188 #if MACH_IRQS > 32
 189         IRQ0x51_interrupt, IRQ0x52_interrupt, IRQ0x53_interrupt,
 190         IRQ0x54_interrupt, IRQ0x55_interrupt, IRQ0x56_interrupt,
 191         IRQ0x57_interrupt, IRQ0x58_interrupt, IRQ0x59_interrupt,
 192         IRQ0x5a_interrupt, IRQ0x5b_interrupt, IRQ0x5c_interrupt,
 193         IRQ0x5d_interrupt, IRQ0x5e_interrupt, IRQ0x5f_interrupt,
 194         IRQ0x60_interrupt, IRQ0x61_interrupt, IRQ0x62_interrupt,
 195         IRQ0x63_interrupt, IRQ0x64_interrupt, IRQ0x65_interrupt,
 196         IRQ0x66_interrupt, IRQ0x67_interrupt, IRQ0x68_interrupt,
 197         IRQ0x69_interrupt, IRQ0x6a_interrupt, IRQ0x6b_interrupt,
 198         IRQ0x6c_interrupt, IRQ0x6d_interrupt, IRQ0x6e_interrupt,
 199         IRQ0x6f_interrupt, IRQ0x70_interrupt,
 200 #endif
 201 };
 202
 203 void
 204 block_irq(int irq, int cpu)
 205 {
 206         int intr_mask;
 207         unsigned long flags;
 208
 209         spin_lock_irqsave(&irq_lock, flags);
 210         /* Remember, 1 let thru, 0 block. */
 211         if (irq - FIRST_IRQ < 32) {
 212                 intr_mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
 213                         rw_mask, 0);
 214                 intr_mask &= ~(1 << (irq - FIRST_IRQ));
 215                 REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask,
 216                         0, intr_mask);
 217         } else {
 218                 intr_mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
 219                         rw_mask, 1);
 220                 intr_mask &= ~(1 << (irq - FIRST_IRQ - 32));
 221                 REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask,
 222                         1, intr_mask);
 223         }
 224         spin_unlock_irqrestore(&irq_lock, flags);
 225 }
 226
 227 void
 228 unblock_irq(int irq, int cpu)
 229 {
 230         int intr_mask;
 231         unsigned long flags;
 232
 233         spin_lock_irqsave(&irq_lock, flags);
 234         /* Remember, 1 let thru, 0 block. */
 235         if (irq - FIRST_IRQ < 32) {
 236                 intr_mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
 237                         rw_mask, 0);
 238                 intr_mask |= (1 << (irq - FIRST_IRQ));
 239                 REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask,
 240                         0, intr_mask);
 241         } else {
 242                 intr_mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
 243                         rw_mask, 1);
 244                 intr_mask |= (1 << (irq - FIRST_IRQ - 32));
 245                 REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask,
 246                         1, intr_mask);
 247         }
 248         spin_unlock_irqrestore(&irq_lock, flags);
 249 }
 250
 251 /* Find out which CPU the irq should be allocated to. */
 252 static int irq_cpu(int irq)
 253 {
 254         int cpu;
 255         unsigned long flags;
 256
 257         spin_lock_irqsave(&irq_lock, flags);
 258         cpu = irq_allocations[irq - FIRST_IRQ].cpu;
 259
 260         /* Fixed interrupts stay on the local CPU. */
 261         if (cpu == CPU_FIXED)
 262         {
 263                 spin_unlock_irqrestore(&irq_lock, flags);
 264                 return smp_processor_id();
 265         }
 266
 267
 268         /* Let the interrupt stay if possible */
 269         if (cpu_isset(cpu, irq_allocations[irq - FIRST_IRQ].mask))
 270                 goto out;
 271
 272         /* IRQ must be moved to another CPU. */
 273         cpu = first_cpu(irq_allocations[irq - FIRST_IRQ].mask);
 274         irq_allocations[irq - FIRST_IRQ].cpu = cpu;
 275 out:
 276         spin_unlock_irqrestore(&irq_lock, flags);
 277         return cpu;
 278 }
 279
 280 void crisv32_mask_irq(int irq)
 281 {
 282         int cpu;
 283
 284         for (cpu = 0; cpu < NR_CPUS; cpu++)
 285                 block_irq(irq, cpu);
 286 }
 287
 288 void crisv32_unmask_irq(int irq)
 289 {
 290         unblock_irq(irq, irq_cpu(irq));
 291 }
 292
 293
 294 static void enable_crisv32_irq(struct irq_data *data)
 295 {
 296         crisv32_unmask_irq(data->irq);
 297 }
 298
 299 static void disable_crisv32_irq(struct irq_data *data)
 300 {
 301         crisv32_mask_irq(data->irq);
 302 }
 303
 304 static int set_affinity_crisv32_irq(struct irq_data *data,
 305                                     const struct cpumask *dest, bool force)
 306 {
 307         unsigned long flags;
 308
 309         spin_lock_irqsave(&irq_lock, flags);
 310         irq_allocations[data->irq - FIRST_IRQ].mask = *dest;
 311         spin_unlock_irqrestore(&irq_lock, flags);
 312         return 0;
 313 }
 314
 315 static struct irq_chip crisv32_irq_type = {
 316         .name                   = "CRISv32",
 317         .irq_shutdown           = disable_crisv32_irq,
 318         .irq_enable             = enable_crisv32_irq,
 319         .irq_disable            = disable_crisv32_irq,
 320         .irq_set_affinity       = set_affinity_crisv32_irq,
 321 };
 322
 323 void
 324 set_exception_vector(int n, irqvectptr addr)
 325 {
 326         etrax_irv->v[n] = (irqvectptr) addr;
 327 }
 328
 329 extern void do_IRQ(int irq, struct pt_regs * regs);
 330
 331 void
 332 crisv32_do_IRQ(int irq, int block, struct pt_regs* regs)
 333 {
 334         /* Interrupts that may not be moved to another CPU and
 335          * are IRQF_DISABLED may skip blocking. This is currently
 336          * only valid for the timer IRQ and the IPI and is used
 337          * for the timer interrupt to avoid watchdog starvation.
 338          */
 339         if (!block) {
 340                 do_IRQ(irq, regs);
 341                 return;
 342         }
 343
 344         block_irq(irq, smp_processor_id());
 345         do_IRQ(irq, regs);
 346
 347         unblock_irq(irq, irq_cpu(irq));
 348 }
 349
 350 /* If multiple interrupts occur simultaneously we get a multiple
 351  * interrupt from the CPU and software has to sort out which
 352  * interrupts that happened. There are two special cases here:
 353  *
 354  * 1. Timer interrupts may never be blocked because of the
 355  *    watchdog (refer to comment in include/asr/arch/irq.h)
 356  * 2. GDB serial port IRQs are unhandled here and will be handled
 357  *    as a single IRQ when it strikes again because the GDB
 358  *    stubb wants to save the registers in its own fashion.
 359  */
 360 void
 361 crisv32_do_multiple(struct pt_regs* regs)
 362 {
 363         int cpu;
 364         int mask;
 365         int masked[NBR_REGS];
 366         int bit;
 367         int i;
 368
 369         cpu = smp_processor_id();
 370
 371         /* An extra irq_enter here to prevent softIRQs to run after
 372          * each do_IRQ. This will decrease the interrupt latency.
 373          */
 374         irq_enter();
 375
 376         for (i = 0; i < NBR_REGS; i++) {
 377                 /* Get which IRQs that happened. */
 378                 masked[i] = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
 379                         r_masked_vect, i);
 380
 381                 /* Calculate new IRQ mask with these IRQs disabled. */
 382                 mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu], rw_mask, i);
 383                 mask &= ~masked[i];
 384
 385         /* Timer IRQ is never masked */
 386 #ifdef TIMER_VECT1
 387                 if ((i == 1) && (masked[0] & TIMER_MASK))
 388                         mask |= TIMER_MASK;
 389 #else
 390                 if ((i == 0) && (masked[0] & TIMER_MASK))
 391                         mask |= TIMER_MASK;
 392 #endif
 393                 /* Block all the IRQs */
 394                 REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask, i, mask);
 395
 396         /* Check for timer IRQ and handle it special. */
 397 #ifdef TIMER_VECT1
 398                 if ((i == 1) && (masked[i] & TIMER_MASK)) {
 399                         masked[i] &= ~TIMER_MASK;
 400                         do_IRQ(TIMER0_INTR_VECT, regs);
 401                 }
 402 #else
 403                 if ((i == 0) && (masked[i] & TIMER_MASK)) {
 404                          masked[i] &= ~TIMER_MASK;
 405                          do_IRQ(TIMER0_INTR_VECT, regs);
 406                 }
 407 #endif
 408         }
 409
 410 #ifdef IGNORE_MASK
 411         /* Remove IRQs that can't be handled as multiple. */
 412         masked[0] &= ~IGNORE_MASK;
 413 #endif
 414
 415         /* Handle the rest of the IRQs. */
 416         for (i = 0; i < NBR_REGS; i++) {
 417                 for (bit = 0; bit < 32; bit++) {
 418                         if (masked[i] & (1 << bit))
 419                                 do_IRQ(bit + FIRST_IRQ + i*32, regs);
 420                 }
 421         }
 422
 423         /* Unblock all the IRQs. */
 424         for (i = 0; i < NBR_REGS; i++) {
 425                 mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu], rw_mask, i);
 426                 mask |= masked[i];
 427                 REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask, i, mask);
 428         }
 429
 430         /* This irq_exit() will trigger the soft IRQs. */
 431         irq_exit();
 432 }
 433
 434 /*
 435  * This is called by start_kernel. It fixes the IRQ masks and setup the
 436  * interrupt vector table to point to bad_interrupt pointers.
 437  */
 438 void __init
 439 init_IRQ(void)
 440 {
 441         int i;
 442         int j;
 443         reg_intr_vect_rw_mask vect_mask = {0};
 444
 445         /* Clear all interrupts masks. */
 446         for (i = 0; i < NBR_REGS; i++)
 447                 REG_WR_VECT(intr_vect, regi_irq, rw_mask, i, vect_mask);
 448
 449         for (i = 0; i < 256; i++)
 450                 etrax_irv->v[i] = weird_irq;
 451
 452         /* Point all IRQ's to bad handlers. */
 453         for (i = FIRST_IRQ, j = 0; j < NR_IRQS; i++, j++) {
 454                 irq_set_chip_and_handler(j, &crisv32_irq_type,
 455                                          handle_simple_irq);
 456                 set_exception_vector(i, interrupt[j]);
 457         }
 458
 459         /* Mark Timer and IPI IRQs as CPU local */
 460         irq_allocations[TIMER0_INTR_VECT - FIRST_IRQ].cpu = CPU_FIXED;
 461         irq_set_status_flags(TIMER0_INTR_VECT, IRQ_PER_CPU);
 462         irq_allocations[IPI_INTR_VECT - FIRST_IRQ].cpu = CPU_FIXED;
 463         irq_set_status_flags(IPI_INTR_VECT, IRQ_PER_CPU);
 464
 465         set_exception_vector(0x00, nmi_interrupt);
 466         set_exception_vector(0x30, multiple_interrupt);
 467
 468         /* Set up handler for various MMU bus faults. */
 469         set_exception_vector(0x04, i_mmu_refill);
 470         set_exception_vector(0x05, i_mmu_invalid);
 471         set_exception_vector(0x06, i_mmu_access);
 472         set_exception_vector(0x07, i_mmu_execute);
 473         set_exception_vector(0x08, d_mmu_refill);
 474         set_exception_vector(0x09, d_mmu_invalid);
 475         set_exception_vector(0x0a, d_mmu_access);
 476         set_exception_vector(0x0b, d_mmu_write);
 477
 478 #ifdef CONFIG_BUG
 479         /* Break 14 handler, used to implement cheap BUG().  */
 480         set_exception_vector(0x1e, breakh_BUG);
 481 #endif
 482
 483         /* The system-call trap is reached by "break 13". */
 484         set_exception_vector(0x1d, system_call);
 485
 486         /* Exception handlers for debugging, both user-mode and kernel-mode. */
 487
 488         /* Break 8. */
 489         set_exception_vector(0x18, gdb_handle_exception);
 490         /* Hardware single step. */
 491         set_exception_vector(0x3, gdb_handle_exception);
 492         /* Hardware breakpoint. */
 493         set_exception_vector(0xc, gdb_handle_exception);
 494
 495 #ifdef CONFIG_ETRAX_KGDB
 496         kgdb_init();
 497         /* Everything is set up; now trap the kernel. */
 498         breakpoint();
 499 #endif
 500 }
 501