arch/x86_64/kernel/i8259.c

   1 #include <linux/linkage.h>
   2 #include <linux/errno.h>
   3 #include <linux/signal.h>
   4 #include <linux/sched.h>
   5 #include <linux/ioport.h>
   6 #include <linux/interrupt.h>
   7 #include <linux/timex.h>
   8 #include <linux/slab.h>
   9 #include <linux/random.h>
  10 #include <linux/smp_lock.h>
  11 #include <linux/init.h>
  12 #include <linux/kernel_stat.h>
  13 #include <linux/sysdev.h>
  14 #include <linux/bitops.h>
  15
  16 #include <asm/acpi.h>
  17 #include <asm/atomic.h>
  18 #include <asm/system.h>
  19 #include <asm/io.h>
  20 #include <asm/hw_irq.h>
  21 #include <asm/pgtable.h>
  22 #include <asm/delay.h>
  23 #include <asm/desc.h>
  24 #include <asm/apic.h>
  25
  26 /*
  27  * Common place to define all x86 IRQ vectors
  28  *
  29  * This builds up the IRQ handler stubs using some ugly macros in irq.h
  30  *
  31  * These macros create the low-level assembly IRQ routines that save
  32  * register context and call do_IRQ(). do_IRQ() then does all the
  33  * operations that are needed to keep the AT (or SMP IOAPIC)
  34  * interrupt-controller happy.
  35  */
  36
  37 #define BI(x,y) \
  38         BUILD_IRQ(x##y)
  39
  40 #define BUILD_16_IRQS(x) \
  41         BI(x,0) BI(x,1) BI(x,2) BI(x,3) \
  42         BI(x,4) BI(x,5) BI(x,6) BI(x,7) \
  43         BI(x,8) BI(x,9) BI(x,a) BI(x,b) \
  44         BI(x,c) BI(x,d) BI(x,e) BI(x,f)
  45
  46 /*
  47  * ISA PIC or low IO-APIC triggered (INTA-cycle or APIC) interrupts:
  48  * (these are usually mapped to vectors 0x20-0x2f)
  49  */
  50
  51 /*
  52  * The IO-APIC gives us many more interrupt sources. Most of these
  53  * are unused but an SMP system is supposed to have enough memory ...
  54  * sometimes (mostly wrt. hw bugs) we get corrupted vectors all
  55  * across the spectrum, so we really want to be prepared to get all
  56  * of these. Plus, more powerful systems might have more than 64
  57  * IO-APIC registers.
  58  *
  59  * (these are usually mapped into the 0x30-0xff vector range)
  60  */
  61                                       BUILD_16_IRQS(0x2) BUILD_16_IRQS(0x3)
  62 BUILD_16_IRQS(0x4) BUILD_16_IRQS(0x5) BUILD_16_IRQS(0x6) BUILD_16_IRQS(0x7)
  63 BUILD_16_IRQS(0x8) BUILD_16_IRQS(0x9) BUILD_16_IRQS(0xa) BUILD_16_IRQS(0xb)
  64 BUILD_16_IRQS(0xc) BUILD_16_IRQS(0xd) BUILD_16_IRQS(0xe) BUILD_16_IRQS(0xf)
  65
  66 #undef BUILD_16_IRQS
  67 #undef BI
  68
  69
  70 #define IRQ(x,y) \
  71         IRQ##x##y##_interrupt
  72
  73 #define IRQLIST_16(x) \
  74         IRQ(x,0), IRQ(x,1), IRQ(x,2), IRQ(x,3), \
  75         IRQ(x,4), IRQ(x,5), IRQ(x,6), IRQ(x,7), \
  76         IRQ(x,8), IRQ(x,9), IRQ(x,a), IRQ(x,b), \
  77         IRQ(x,c), IRQ(x,d), IRQ(x,e), IRQ(x,f)
  78
  79 void (*interrupt[NR_IRQS])(void) = {
  80                                           IRQLIST_16(0x2), IRQLIST_16(0x3),
  81         IRQLIST_16(0x4), IRQLIST_16(0x5), IRQLIST_16(0x6), IRQLIST_16(0x7),
  82         IRQLIST_16(0x8), IRQLIST_16(0x9), IRQLIST_16(0xa), IRQLIST_16(0xb),
  83         IRQLIST_16(0xc), IRQLIST_16(0xd), IRQLIST_16(0xe), IRQLIST_16(0xf)
  84 };
  85
  86 #undef IRQ
  87 #undef IRQLIST_16
  88
  89 /*
  90  * This is the 'legacy' 8259A Programmable Interrupt Controller,
  91  * present in the majority of PC/AT boxes.
  92  * plus some generic x86 specific things if generic specifics makes
  93  * any sense at all.
  94  * this file should become arch/i386/kernel/irq.c when the old irq.c
  95  * moves to arch independent land
  96  */
  97
  98 static int i8259A_auto_eoi;
  99 DEFINE_SPINLOCK(i8259A_lock);
 100 static void mask_and_ack_8259A(unsigned int);
 101
 102 static struct irq_chip i8259A_chip = {
 103         .name           = "XT-PIC",
 104         .mask           = disable_8259A_irq,
 105         .unmask         = enable_8259A_irq,
 106         .mask_ack       = mask_and_ack_8259A,
 107 };
 108
 109 /*
 110  * 8259A PIC functions to handle ISA devices:
 111  */
 112
 113 /*
 114  * This contains the irq mask for both 8259A irq controllers,
 115  */
 116 static unsigned int cached_irq_mask = 0xffff;
 117
 118 #define __byte(x,y)     (((unsigned char *)&(y))[x])
 119 #define cached_21       (__byte(0,cached_irq_mask))
 120 #define cached_A1       (__byte(1,cached_irq_mask))
 121
 122 /*
 123  * Not all IRQs can be routed through the IO-APIC, eg. on certain (older)
 124  * boards the timer interrupt is not really connected to any IO-APIC pin,
 125  * it's fed to the master 8259A's IR0 line only.
 126  *
 127  * Any '1' bit in this mask means the IRQ is routed through the IO-APIC.
 128  * this 'mixed mode' IRQ handling costs nothing because it's only used
 129  * at IRQ setup time.
 130  */
 131 unsigned long io_apic_irqs;
 132
 133 void disable_8259A_irq(unsigned int irq)
 134 {
 135         unsigned int mask = 1 << irq;
 136         unsigned long flags;
 137
 138         spin_lock_irqsave(&i8259A_lock, flags);
 139         cached_irq_mask |= mask;
 140         if (irq & 8)
 141                 outb(cached_A1,0xA1);
 142         else
 143                 outb(cached_21,0x21);
 144         spin_unlock_irqrestore(&i8259A_lock, flags);
 145 }
 146
 147 void enable_8259A_irq(unsigned int irq)
 148 {
 149         unsigned int mask = ~(1 << irq);
 150         unsigned long flags;
 151
 152         spin_lock_irqsave(&i8259A_lock, flags);
 153         cached_irq_mask &= mask;
 154         if (irq & 8)
 155                 outb(cached_A1,0xA1);
 156         else
 157                 outb(cached_21,0x21);
 158         spin_unlock_irqrestore(&i8259A_lock, flags);
 159 }
 160
 161 int i8259A_irq_pending(unsigned int irq)
 162 {
 163         unsigned int mask = 1<<irq;
 164         unsigned long flags;
 165         int ret;
 166
 167         spin_lock_irqsave(&i8259A_lock, flags);
 168         if (irq < 8)
 169                 ret = inb(0x20) & mask;
 170         else
 171                 ret = inb(0xA0) & (mask >> 8);
 172         spin_unlock_irqrestore(&i8259A_lock, flags);
 173
 174         return ret;
 175 }
 176
 177 void make_8259A_irq(unsigned int irq)
 178 {
 179         disable_irq_nosync(irq);
 180         io_apic_irqs &= ~(1<<irq);
 181         set_irq_chip_and_handler_name(irq, &i8259A_chip, handle_level_irq,
 182                                       "XT");
 183         enable_irq(irq);
 184 }
 185
 186 /*
 187  * This function assumes to be called rarely. Switching between
 188  * 8259A registers is slow.
 189  * This has to be protected by the irq controller spinlock
 190  * before being called.
 191  */
 192 static inline int i8259A_irq_real(unsigned int irq)
 193 {
 194         int value;
 195         int irqmask = 1<<irq;
 196
 197         if (irq < 8) {
 198                 outb(0x0B,0x20);                /* ISR register */
 199                 value = inb(0x20) & irqmask;
 200                 outb(0x0A,0x20);                /* back to the IRR register */
 201                 return value;
 202         }
 203         outb(0x0B,0xA0);                /* ISR register */
 204         value = inb(0xA0) & (irqmask >> 8);
 205         outb(0x0A,0xA0);                /* back to the IRR register */
 206         return value;
 207 }
 208
 209 /*
 210  * Careful! The 8259A is a fragile beast, it pretty
 211  * much _has_ to be done exactly like this (mask it
 212  * first, _then_ send the EOI, and the order of EOI
 213  * to the two 8259s is important!
 214  */
 215 static void mask_and_ack_8259A(unsigned int irq)
 216 {
 217         unsigned int irqmask = 1 << irq;
 218         unsigned long flags;
 219
 220         spin_lock_irqsave(&i8259A_lock, flags);
 221         /*
 222          * Lightweight spurious IRQ detection. We do not want
 223          * to overdo spurious IRQ handling - it's usually a sign
 224          * of hardware problems, so we only do the checks we can
 225          * do without slowing down good hardware unnecessarily.
 226          *
 227          * Note that IRQ7 and IRQ15 (the two spurious IRQs
 228          * usually resulting from the 8259A-1|2 PICs) occur
 229          * even if the IRQ is masked in the 8259A. Thus we
 230          * can check spurious 8259A IRQs without doing the
 231          * quite slow i8259A_irq_real() call for every IRQ.
 232          * This does not cover 100% of spurious interrupts,
 233          * but should be enough to warn the user that there
 234          * is something bad going on ...
 235          */
 236         if (cached_irq_mask & irqmask)
 237                 goto spurious_8259A_irq;
 238         cached_irq_mask |= irqmask;
 239
 240 handle_real_irq:
 241         if (irq & 8) {
 242                 inb(0xA1);              /* DUMMY - (do we need this?) */
 243                 outb(cached_A1,0xA1);
 244                 outb(0x60+(irq&7),0xA0);/* 'Specific EOI' to slave */
 245                 outb(0x62,0x20);        /* 'Specific EOI' to master-IRQ2 */
 246         } else {
 247                 inb(0x21);              /* DUMMY - (do we need this?) */
 248                 outb(cached_21,0x21);
 249                 outb(0x60+irq,0x20);    /* 'Specific EOI' to master */
 250         }
 251         spin_unlock_irqrestore(&i8259A_lock, flags);
 252         return;
 253
 254 spurious_8259A_irq:
 255         /*
 256          * this is the slow path - should happen rarely.
 257          */
 258         if (i8259A_irq_real(irq))
 259                 /*
 260                  * oops, the IRQ _is_ in service according to the
 261                  * 8259A - not spurious, go handle it.
 262                  */
 263                 goto handle_real_irq;
 264
 265         {
 266                 static int spurious_irq_mask;
 267                 /*
 268                  * At this point we can be sure the IRQ is spurious,
 269                  * lets ACK and report it. [once per IRQ]
 270                  */
 271                 if (!(spurious_irq_mask & irqmask)) {
 272                         printk(KERN_DEBUG "spurious 8259A interrupt: IRQ%d.\n", irq);
 273                         spurious_irq_mask |= irqmask;
 274                 }
 275                 atomic_inc(&irq_err_count);
 276                 /*
 277                  * Theoretically we do not have to handle this IRQ,
 278                  * but in Linux this does not cause problems and is
 279                  * simpler for us.
 280                  */
 281                 goto handle_real_irq;
 282         }
 283 }
 284
 285 void init_8259A(int auto_eoi)
 286 {
 287         unsigned long flags;
 288
 289         i8259A_auto_eoi = auto_eoi;
 290
 291         spin_lock_irqsave(&i8259A_lock, flags);
 292
 293         outb(0xff, 0x21);       /* mask all of 8259A-1 */
 294         outb(0xff, 0xA1);       /* mask all of 8259A-2 */
 295
 296         /*
 297          * outb_p - this has to work on a wide range of PC hardware.
 298          */
 299         outb_p(0x11, 0x20);     /* ICW1: select 8259A-1 init */
 300         outb_p(0x20 + 0, 0x21); /* ICW2: 8259A-1 IR0-7 mapped to 0x20-0x27 */
 301         outb_p(0x04, 0x21);     /* 8259A-1 (the master) has a slave on IR2 */
 302         if (auto_eoi)
 303                 outb_p(0x03, 0x21);     /* master does Auto EOI */
 304         else
 305                 outb_p(0x01, 0x21);     /* master expects normal EOI */
 306
 307         outb_p(0x11, 0xA0);     /* ICW1: select 8259A-2 init */
 308         outb_p(0x20 + 8, 0xA1); /* ICW2: 8259A-2 IR0-7 mapped to 0x28-0x2f */
 309         outb_p(0x02, 0xA1);     /* 8259A-2 is a slave on master's IR2 */
 310         outb_p(0x01, 0xA1);     /* (slave's support for AEOI in flat mode
 311                                     is to be investigated) */
 312
 313         if (auto_eoi)
 314                 /*
 315                  * in AEOI mode we just have to mask the interrupt
 316                  * when acking.
 317                  */
 318                 i8259A_chip.mask_ack = disable_8259A_irq;
 319         else
 320                 i8259A_chip.mask_ack = mask_and_ack_8259A;
 321
 322         udelay(100);            /* wait for 8259A to initialize */
 323
 324         outb(cached_21, 0x21);  /* restore master IRQ mask */
 325         outb(cached_A1, 0xA1);  /* restore slave IRQ mask */
 326
 327         spin_unlock_irqrestore(&i8259A_lock, flags);
 328 }
 329
 330 static char irq_trigger[2];
 331 /**
 332  * ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
 333  */
 334 static void restore_ELCR(char *trigger)
 335 {
 336         outb(trigger[0], 0x4d0);
 337         outb(trigger[1], 0x4d1);
 338 }
 339
 340 static void save_ELCR(char *trigger)
 341 {
 342         /* IRQ 0,1,2,8,13 are marked as reserved */
 343         trigger[0] = inb(0x4d0) & 0xF8;
 344         trigger[1] = inb(0x4d1) & 0xDE;
 345 }
 346
 347 static int i8259A_resume(struct sys_device *dev)
 348 {
 349         init_8259A(i8259A_auto_eoi);
 350         restore_ELCR(irq_trigger);
 351         return 0;
 352 }
 353
 354 static int i8259A_suspend(struct sys_device *dev, pm_message_t state)
 355 {
 356         save_ELCR(irq_trigger);
 357         return 0;
 358 }
 359
 360 static int i8259A_shutdown(struct sys_device *dev)
 361 {
 362         /* Put the i8259A into a quiescent state that
 363          * the kernel initialization code can get it
 364          * out of.
 365          */
 366         outb(0xff, 0x21);       /* mask all of 8259A-1 */
 367         outb(0xff, 0xA1);       /* mask all of 8259A-1 */
 368         return 0;
 369 }
 370
 371 static struct sysdev_class i8259_sysdev_class = {
 372         set_kset_name("i8259"),
 373         .suspend = i8259A_suspend,
 374         .resume = i8259A_resume,
 375         .shutdown = i8259A_shutdown,
 376 };
 377
 378 static struct sys_device device_i8259A = {
 379         .id     = 0,
 380         .cls    = &i8259_sysdev_class,
 381 };
 382
 383 static int __init i8259A_init_sysfs(void)
 384 {
 385         int error = sysdev_class_register(&i8259_sysdev_class);
 386         if (!error)
 387                 error = sysdev_register(&device_i8259A);
 388         return error;
 389 }
 390
 391 device_initcall(i8259A_init_sysfs);
 392
 393 /*
 394  * IRQ2 is cascade interrupt to second interrupt controller
 395  */
 396
 397 static struct irqaction irq2 = { no_action, 0, CPU_MASK_NONE, "cascade", NULL, NULL};
 398 DEFINE_PER_CPU(vector_irq_t, vector_irq) = {
 399         [0 ... FIRST_EXTERNAL_VECTOR - 1] = -1,
 400         [FIRST_EXTERNAL_VECTOR + 0] = 0,
 401         [FIRST_EXTERNAL_VECTOR + 1] = 1,
 402         [FIRST_EXTERNAL_VECTOR + 2] = 2,
 403         [FIRST_EXTERNAL_VECTOR + 3] = 3,
 404         [FIRST_EXTERNAL_VECTOR + 4] = 4,
 405         [FIRST_EXTERNAL_VECTOR + 5] = 5,
 406         [FIRST_EXTERNAL_VECTOR + 6] = 6,
 407         [FIRST_EXTERNAL_VECTOR + 7] = 7,
 408         [FIRST_EXTERNAL_VECTOR + 8] = 8,
 409         [FIRST_EXTERNAL_VECTOR + 9] = 9,
 410         [FIRST_EXTERNAL_VECTOR + 10] = 10,
 411         [FIRST_EXTERNAL_VECTOR + 11] = 11,
 412         [FIRST_EXTERNAL_VECTOR + 12] = 12,
 413         [FIRST_EXTERNAL_VECTOR + 13] = 13,
 414         [FIRST_EXTERNAL_VECTOR + 14] = 14,
 415         [FIRST_EXTERNAL_VECTOR + 15] = 15,
 416         [FIRST_EXTERNAL_VECTOR + 16 ... NR_VECTORS - 1] = -1
 417 };
 418
 419 void __init init_ISA_irqs (void)
 420 {
 421         int i;
 422
 423         init_bsp_APIC();
 424         init_8259A(0);
 425
 426         for (i = 0; i < NR_IRQS; i++) {
 427                 irq_desc[i].status = IRQ_DISABLED;
 428                 irq_desc[i].action = NULL;
 429                 irq_desc[i].depth = 1;
 430
 431                 if (i < 16) {
 432                         /*
 433                          * 16 old-style INTA-cycle interrupts:
 434                          */
 435                         set_irq_chip_and_handler_name(i, &i8259A_chip,
 436                                                       handle_level_irq, "XT");
 437                 } else {
 438                         /*
 439                          * 'high' PCI IRQs filled in on demand
 440                          */
 441                         irq_desc[i].chip = &no_irq_chip;
 442                 }
 443         }
 444 }
 445
 446 void apic_timer_interrupt(void);
 447 void spurious_interrupt(void);
 448 void error_interrupt(void);
 449 void reschedule_interrupt(void);
 450 void call_function_interrupt(void);
 451 void invalidate_interrupt0(void);
 452 void invalidate_interrupt1(void);
 453 void invalidate_interrupt2(void);
 454 void invalidate_interrupt3(void);
 455 void invalidate_interrupt4(void);
 456 void invalidate_interrupt5(void);
 457 void invalidate_interrupt6(void);
 458 void invalidate_interrupt7(void);
 459 void thermal_interrupt(void);
 460 void threshold_interrupt(void);
 461 void i8254_timer_resume(void);
 462
 463 static void setup_timer_hardware(void)
 464 {
 465         outb_p(0x34,0x43);              /* binary, mode 2, LSB/MSB, ch 0 */
 466         udelay(10);
 467         outb_p(LATCH & 0xff , 0x40);    /* LSB */
 468         udelay(10);
 469         outb(LATCH >> 8 , 0x40);        /* MSB */
 470 }
 471
 472 static int timer_resume(struct sys_device *dev)
 473 {
 474         setup_timer_hardware();
 475         return 0;
 476 }
 477
 478 void i8254_timer_resume(void)
 479 {
 480         setup_timer_hardware();
 481 }
 482
 483 static struct sysdev_class timer_sysclass = {
 484         set_kset_name("timer_pit"),
 485         .resume         = timer_resume,
 486 };
 487
 488 static struct sys_device device_timer = {
 489         .id             = 0,
 490         .cls            = &timer_sysclass,
 491 };
 492
 493 static int __init init_timer_sysfs(void)
 494 {
 495         int error = sysdev_class_register(&timer_sysclass);
 496         if (!error)
 497                 error = sysdev_register(&device_timer);
 498         return error;
 499 }
 500
 501 device_initcall(init_timer_sysfs);
 502
 503 void __init init_IRQ(void)
 504 {
 505         int i;
 506
 507         init_ISA_irqs();
 508         /*
 509          * Cover the whole vector space, no vector can escape
 510          * us. (some of these will be overridden and become
 511          * 'special' SMP interrupts)
 512          */
 513         for (i = 0; i < (NR_VECTORS - FIRST_EXTERNAL_VECTOR); i++) {
 514                 int vector = FIRST_EXTERNAL_VECTOR + i;
 515                 if (vector != IA32_SYSCALL_VECTOR)
 516                         set_intr_gate(vector, interrupt[i]);
 517         }
 518
 519 #ifdef CONFIG_SMP
 520         /*
 521          * IRQ0 must be given a fixed assignment and initialized,
 522          * because it's used before the IO-APIC is set up.
 523          */
 524         __get_cpu_var(vector_irq)[FIRST_DEVICE_VECTOR] = 0;
 525
 526         /*
 527          * The reschedule interrupt is a CPU-to-CPU reschedule-helper
 528          * IPI, driven by wakeup.
 529          */
 530         set_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
 531
 532         /* IPIs for invalidation */
 533         set_intr_gate(INVALIDATE_TLB_VECTOR_START+0, invalidate_interrupt0);
 534         set_intr_gate(INVALIDATE_TLB_VECTOR_START+1, invalidate_interrupt1);
 535         set_intr_gate(INVALIDATE_TLB_VECTOR_START+2, invalidate_interrupt2);
 536         set_intr_gate(INVALIDATE_TLB_VECTOR_START+3, invalidate_interrupt3);
 537         set_intr_gate(INVALIDATE_TLB_VECTOR_START+4, invalidate_interrupt4);
 538         set_intr_gate(INVALIDATE_TLB_VECTOR_START+5, invalidate_interrupt5);
 539         set_intr_gate(INVALIDATE_TLB_VECTOR_START+6, invalidate_interrupt6);
 540         set_intr_gate(INVALIDATE_TLB_VECTOR_START+7, invalidate_interrupt7);
 541
 542         /* IPI for generic function call */
 543         set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
 544 #endif
 545         set_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
 546         set_intr_gate(THRESHOLD_APIC_VECTOR, threshold_interrupt);
 547
 548         /* self generated IPI for local APIC timer */
 549         set_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
 550
 551         /* IPI vectors for APIC spurious and error interrupts */
 552         set_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
 553         set_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
 554
 555         /*
 556          * Set the clock to HZ Hz, we already have a valid
 557          * vector now:
 558          */
 559         setup_timer_hardware();
 560
 561         if (!acpi_ioapic)
 562                 setup_irq(2, &irq2);
 563 }