arch/x86_64/kernel/i8259.c

   1 #include <linux/linkage.h>
   2 #include <linux/config.h>
   3 #include <linux/errno.h>
   4 #include <linux/signal.h>
   5 #include <linux/sched.h>
   6 #include <linux/ioport.h>
   7 #include <linux/interrupt.h>
   8 #include <linux/timex.h>
   9 #include <linux/slab.h>
  10 #include <linux/random.h>
  11 #include <linux/smp_lock.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel_stat.h>
  14 #include <linux/sysdev.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/irq.h>
  21 #include <asm/hw_irq.h>
  22 #include <asm/bitops.h>
  23 #include <asm/pgtable.h>
  24 #include <asm/delay.h>
  25 #include <asm/desc.h>
  26 #include <asm/apic.h>
  27
  28 #include <linux/irq.h>
  29
  30 /*
  31  * Common place to define all x86 IRQ vectors
  32  *
  33  * This builds up the IRQ handler stubs using some ugly macros in irq.h
  34  *
  35  * These macros create the low-level assembly IRQ routines that save
  36  * register context and call do_IRQ(). do_IRQ() then does all the
  37  * operations that are needed to keep the AT (or SMP IOAPIC)
  38  * interrupt-controller happy.
  39  */
  40
  41 #define BI(x,y) \
  42         BUILD_IRQ(x##y)
  43
  44 #define BUILD_16_IRQS(x) \
  45         BI(x,0) BI(x,1) BI(x,2) BI(x,3) \
  46         BI(x,4) BI(x,5) BI(x,6) BI(x,7) \
  47         BI(x,8) BI(x,9) BI(x,a) BI(x,b) \
  48         BI(x,c) BI(x,d) BI(x,e) BI(x,f)
  49
  50 #define BUILD_14_IRQS(x) \
  51         BI(x,0) BI(x,1) BI(x,2) BI(x,3) \
  52         BI(x,4) BI(x,5) BI(x,6) BI(x,7) \
  53         BI(x,8) BI(x,9) BI(x,a) BI(x,b) \
  54         BI(x,c) BI(x,d)
  55
  56 /*
  57  * ISA PIC or low IO-APIC triggered (INTA-cycle or APIC) interrupts:
  58  * (these are usually mapped to vectors 0x20-0x2f)
  59  */
  60 BUILD_16_IRQS(0x0)
  61
  62 #ifdef CONFIG_X86_LOCAL_APIC
  63 /*
  64  * The IO-APIC gives us many more interrupt sources. Most of these
  65  * are unused but an SMP system is supposed to have enough memory ...
  66  * sometimes (mostly wrt. hw bugs) we get corrupted vectors all
  67  * across the spectrum, so we really want to be prepared to get all
  68  * of these. Plus, more powerful systems might have more than 64
  69  * IO-APIC registers.
  70  *
  71  * (these are usually mapped into the 0x30-0xff vector range)
  72  */
  73                    BUILD_16_IRQS(0x1) BUILD_16_IRQS(0x2) BUILD_16_IRQS(0x3)
  74 BUILD_16_IRQS(0x4) BUILD_16_IRQS(0x5) BUILD_16_IRQS(0x6) BUILD_16_IRQS(0x7)
  75 BUILD_16_IRQS(0x8) BUILD_16_IRQS(0x9) BUILD_16_IRQS(0xa) BUILD_16_IRQS(0xb)
  76 BUILD_16_IRQS(0xc) BUILD_16_IRQS(0xd)
  77
  78 #ifdef CONFIG_PCI_MSI
  79         BUILD_14_IRQS(0xe)
  80 #endif
  81
  82 #endif
  83
  84 #undef BUILD_16_IRQS
  85 #undef BUILD_14_IRQS
  86 #undef BI
  87
  88
  89 #define IRQ(x,y) \
  90         IRQ##x##y##_interrupt
  91
  92 #define IRQLIST_16(x) \
  93         IRQ(x,0), IRQ(x,1), IRQ(x,2), IRQ(x,3), \
  94         IRQ(x,4), IRQ(x,5), IRQ(x,6), IRQ(x,7), \
  95         IRQ(x,8), IRQ(x,9), IRQ(x,a), IRQ(x,b), \
  96         IRQ(x,c), IRQ(x,d), IRQ(x,e), IRQ(x,f)
  97
  98 #define IRQLIST_14(x) \
  99         IRQ(x,0), IRQ(x,1), IRQ(x,2), IRQ(x,3), \
 100         IRQ(x,4), IRQ(x,5), IRQ(x,6), IRQ(x,7), \
 101         IRQ(x,8), IRQ(x,9), IRQ(x,a), IRQ(x,b), \
 102         IRQ(x,c), IRQ(x,d)
 103
 104 void (*interrupt[NR_IRQS])(void) = {
 105         IRQLIST_16(0x0),
 106
 107 #ifdef CONFIG_X86_IO_APIC
 108                          IRQLIST_16(0x1), IRQLIST_16(0x2), IRQLIST_16(0x3),
 109         IRQLIST_16(0x4), IRQLIST_16(0x5), IRQLIST_16(0x6), IRQLIST_16(0x7),
 110         IRQLIST_16(0x8), IRQLIST_16(0x9), IRQLIST_16(0xa), IRQLIST_16(0xb),
 111         IRQLIST_16(0xc), IRQLIST_16(0xd)
 112
 113 #ifdef CONFIG_PCI_MSI
 114         , IRQLIST_14(0xe)
 115 #endif
 116
 117 #endif
 118 };
 119
 120 #undef IRQ
 121 #undef IRQLIST_16
 122 #undef IRQLIST_14
 123
 124 /*
 125  * This is the 'legacy' 8259A Programmable Interrupt Controller,
 126  * present in the majority of PC/AT boxes.
 127  * plus some generic x86 specific things if generic specifics makes
 128  * any sense at all.
 129  * this file should become arch/i386/kernel/irq.c when the old irq.c
 130  * moves to arch independent land
 131  */
 132
 133 spinlock_t i8259A_lock = SPIN_LOCK_UNLOCKED;
 134
 135 static void end_8259A_irq (unsigned int irq)
 136 {
 137         if (irq > 256) {
 138                 char var;
 139                 printk("return %p stack %p ti %p\n", __builtin_return_address(0), &var, current->thread_info);
 140
 141                 BUG();
 142         }
 143
 144         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)) &&
 145             irq_desc[irq].action)
 146                 enable_8259A_irq(irq);
 147 }
 148
 149 #define shutdown_8259A_irq      disable_8259A_irq
 150
 151 void mask_and_ack_8259A(unsigned int);
 152
 153 static unsigned int startup_8259A_irq(unsigned int irq)
 154 {
 155         enable_8259A_irq(irq);
 156         return 0; /* never anything pending */
 157 }
 158
 159 static struct hw_interrupt_type i8259A_irq_type = {
 160         "XT-PIC",
 161         startup_8259A_irq,
 162         shutdown_8259A_irq,
 163         enable_8259A_irq,
 164         disable_8259A_irq,
 165         mask_and_ack_8259A,
 166         end_8259A_irq,
 167         NULL
 168 };
 169
 170 /*
 171  * 8259A PIC functions to handle ISA devices:
 172  */
 173
 174 /*
 175  * This contains the irq mask for both 8259A irq controllers,
 176  */
 177 static unsigned int cached_irq_mask = 0xffff;
 178
 179 #define __byte(x,y)     (((unsigned char *)&(y))[x])
 180 #define cached_21       (__byte(0,cached_irq_mask))
 181 #define cached_A1       (__byte(1,cached_irq_mask))
 182
 183 /*
 184  * Not all IRQs can be routed through the IO-APIC, eg. on certain (older)
 185  * boards the timer interrupt is not really connected to any IO-APIC pin,
 186  * it's fed to the master 8259A's IR0 line only.
 187  *
 188  * Any '1' bit in this mask means the IRQ is routed through the IO-APIC.
 189  * this 'mixed mode' IRQ handling costs nothing because it's only used
 190  * at IRQ setup time.
 191  */
 192 unsigned long io_apic_irqs;
 193
 194 void disable_8259A_irq(unsigned int irq)
 195 {
 196         unsigned int mask = 1 << irq;
 197         unsigned long flags;
 198
 199         spin_lock_irqsave(&i8259A_lock, flags);
 200         cached_irq_mask |= mask;
 201         if (irq & 8)
 202                 outb(cached_A1,0xA1);
 203         else
 204                 outb(cached_21,0x21);
 205         spin_unlock_irqrestore(&i8259A_lock, flags);
 206 }
 207
 208 void enable_8259A_irq(unsigned int irq)
 209 {
 210         unsigned int mask = ~(1 << irq);
 211         unsigned long flags;
 212
 213         spin_lock_irqsave(&i8259A_lock, flags);
 214         cached_irq_mask &= mask;
 215         if (irq & 8)
 216                 outb(cached_A1,0xA1);
 217         else
 218                 outb(cached_21,0x21);
 219         spin_unlock_irqrestore(&i8259A_lock, flags);
 220 }
 221
 222 int i8259A_irq_pending(unsigned int irq)
 223 {
 224         unsigned int mask = 1<<irq;
 225         unsigned long flags;
 226         int ret;
 227
 228         spin_lock_irqsave(&i8259A_lock, flags);
 229         if (irq < 8)
 230                 ret = inb(0x20) & mask;
 231         else
 232                 ret = inb(0xA0) & (mask >> 8);
 233         spin_unlock_irqrestore(&i8259A_lock, flags);
 234
 235         return ret;
 236 }
 237
 238 void make_8259A_irq(unsigned int irq)
 239 {
 240         disable_irq_nosync(irq);
 241         io_apic_irqs &= ~(1<<irq);
 242         irq_desc[irq].handler = &i8259A_irq_type;
 243         enable_irq(irq);
 244 }
 245
 246 /*
 247  * This function assumes to be called rarely. Switching between
 248  * 8259A registers is slow.
 249  * This has to be protected by the irq controller spinlock
 250  * before being called.
 251  */
 252 static inline int i8259A_irq_real(unsigned int irq)
 253 {
 254         int value;
 255         int irqmask = 1<<irq;
 256
 257         if (irq < 8) {
 258                 outb(0x0B,0x20);                /* ISR register */
 259                 value = inb(0x20) & irqmask;
 260                 outb(0x0A,0x20);                /* back to the IRR register */
 261                 return value;
 262         }
 263         outb(0x0B,0xA0);                /* ISR register */
 264         value = inb(0xA0) & (irqmask >> 8);
 265         outb(0x0A,0xA0);                /* back to the IRR register */
 266         return value;
 267 }
 268
 269 /*
 270  * Careful! The 8259A is a fragile beast, it pretty
 271  * much _has_ to be done exactly like this (mask it
 272  * first, _then_ send the EOI, and the order of EOI
 273  * to the two 8259s is important!
 274  */
 275 void mask_and_ack_8259A(unsigned int irq)
 276 {
 277         unsigned int irqmask = 1 << irq;
 278         unsigned long flags;
 279
 280         spin_lock_irqsave(&i8259A_lock, flags);
 281         /*
 282          * Lightweight spurious IRQ detection. We do not want
 283          * to overdo spurious IRQ handling - it's usually a sign
 284          * of hardware problems, so we only do the checks we can
 285          * do without slowing down good hardware unnecesserily.
 286          *
 287          * Note that IRQ7 and IRQ15 (the two spurious IRQs
 288          * usually resulting from the 8259A-1|2 PICs) occur
 289          * even if the IRQ is masked in the 8259A. Thus we
 290          * can check spurious 8259A IRQs without doing the
 291          * quite slow i8259A_irq_real() call for every IRQ.
 292          * This does not cover 100% of spurious interrupts,
 293          * but should be enough to warn the user that there
 294          * is something bad going on ...
 295          */
 296         if (cached_irq_mask & irqmask)
 297                 goto spurious_8259A_irq;
 298         cached_irq_mask |= irqmask;
 299
 300 handle_real_irq:
 301         if (irq & 8) {
 302                 inb(0xA1);              /* DUMMY - (do we need this?) */
 303                 outb(cached_A1,0xA1);
 304                 outb(0x60+(irq&7),0xA0);/* 'Specific EOI' to slave */
 305                 outb(0x62,0x20);        /* 'Specific EOI' to master-IRQ2 */
 306         } else {
 307                 inb(0x21);              /* DUMMY - (do we need this?) */
 308                 outb(cached_21,0x21);
 309                 outb(0x60+irq,0x20);    /* 'Specific EOI' to master */
 310         }
 311         spin_unlock_irqrestore(&i8259A_lock, flags);
 312         return;
 313
 314 spurious_8259A_irq:
 315         /*
 316          * this is the slow path - should happen rarely.
 317          */
 318         if (i8259A_irq_real(irq))
 319                 /*
 320                  * oops, the IRQ _is_ in service according to the
 321                  * 8259A - not spurious, go handle it.
 322                  */
 323                 goto handle_real_irq;
 324
 325         {
 326                 static int spurious_irq_mask;
 327                 /*
 328                  * At this point we can be sure the IRQ is spurious,
 329                  * lets ACK and report it. [once per IRQ]
 330                  */
 331                 if (!(spurious_irq_mask & irqmask)) {
 332                         printk(KERN_DEBUG "spurious 8259A interrupt: IRQ%d.\n", irq);
 333                         spurious_irq_mask |= irqmask;
 334                 }
 335                 atomic_inc(&irq_err_count);
 336                 /*
 337                  * Theoretically we do not have to handle this IRQ,
 338                  * but in Linux this does not cause problems and is
 339                  * simpler for us.
 340                  */
 341                 goto handle_real_irq;
 342         }
 343 }
 344
 345 void init_8259A(int auto_eoi)
 346 {
 347         unsigned long flags;
 348
 349         spin_lock_irqsave(&i8259A_lock, flags);
 350
 351         outb(0xff, 0x21);       /* mask all of 8259A-1 */
 352         outb(0xff, 0xA1);       /* mask all of 8259A-2 */
 353
 354         /*
 355          * outb_p - this has to work on a wide range of PC hardware.
 356          */
 357         outb_p(0x11, 0x20);     /* ICW1: select 8259A-1 init */
 358         outb_p(0x20 + 0, 0x21); /* ICW2: 8259A-1 IR0-7 mapped to 0x20-0x27 */
 359         outb_p(0x04, 0x21);     /* 8259A-1 (the master) has a slave on IR2 */
 360         if (auto_eoi)
 361                 outb_p(0x03, 0x21);     /* master does Auto EOI */
 362         else
 363                 outb_p(0x01, 0x21);     /* master expects normal EOI */
 364
 365         outb_p(0x11, 0xA0);     /* ICW1: select 8259A-2 init */
 366         outb_p(0x20 + 8, 0xA1); /* ICW2: 8259A-2 IR0-7 mapped to 0x28-0x2f */
 367         outb_p(0x02, 0xA1);     /* 8259A-2 is a slave on master's IR2 */
 368         outb_p(0x01, 0xA1);     /* (slave's support for AEOI in flat mode
 369                                     is to be investigated) */
 370
 371         if (auto_eoi)
 372                 /*
 373                  * in AEOI mode we just have to mask the interrupt
 374                  * when acking.
 375                  */
 376                 i8259A_irq_type.ack = disable_8259A_irq;
 377         else
 378                 i8259A_irq_type.ack = mask_and_ack_8259A;
 379
 380         udelay(100);            /* wait for 8259A to initialize */
 381
 382         outb(cached_21, 0x21);  /* restore master IRQ mask */
 383         outb(cached_A1, 0xA1);  /* restore slave IRQ mask */
 384
 385         spin_unlock_irqrestore(&i8259A_lock, flags);
 386 }
 387
 388 static char irq_trigger[2];
 389 /**
 390  * ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
 391  */
 392 static void restore_ELCR(char *trigger)
 393 {
 394         outb(trigger[0], 0x4d0);
 395         outb(trigger[1], 0x4d1);
 396 }
 397
 398 static void save_ELCR(char *trigger)
 399 {
 400         /* IRQ 0,1,2,8,13 are marked as reserved */
 401         trigger[0] = inb(0x4d0) & 0xF8;
 402         trigger[1] = inb(0x4d1) & 0xDE;
 403 }
 404
 405 static int i8259A_resume(struct sys_device *dev)
 406 {
 407         init_8259A(0);
 408         restore_ELCR(irq_trigger);
 409         return 0;
 410 }
 411
 412 static int i8259A_suspend(struct sys_device *dev, u32 state)
 413 {
 414         save_ELCR(irq_trigger);
 415         return 0;
 416 }
 417
 418 static struct sysdev_class i8259_sysdev_class = {
 419         set_kset_name("i8259"),
 420         .suspend = i8259A_suspend,
 421         .resume = i8259A_resume,
 422 };
 423
 424 static struct sys_device device_i8259A = {
 425         .id     = 0,
 426         .cls    = &i8259_sysdev_class,
 427 };
 428
 429 static int __init i8259A_init_sysfs(void)
 430 {
 431         int error = sysdev_class_register(&i8259_sysdev_class);
 432         if (!error)
 433                 error = sysdev_register(&device_i8259A);
 434         return error;
 435 }
 436
 437 device_initcall(i8259A_init_sysfs);
 438
 439 /*
 440  * IRQ2 is cascade interrupt to second interrupt controller
 441  */
 442
 443 static struct irqaction irq2 = { no_action, 0, CPU_MASK_NONE, "cascade", NULL, NULL};
 444
 445 void __init init_ISA_irqs (void)
 446 {
 447         int i;
 448
 449 #ifdef CONFIG_X86_LOCAL_APIC
 450         init_bsp_APIC();
 451 #endif
 452         init_8259A(0);
 453
 454         for (i = 0; i < NR_IRQS; i++) {
 455                 irq_desc[i].status = IRQ_DISABLED;
 456                 irq_desc[i].action = NULL;
 457                 irq_desc[i].depth = 1;
 458
 459                 if (i < 16) {
 460                         /*
 461                          * 16 old-style INTA-cycle interrupts:
 462                          */
 463                         irq_desc[i].handler = &i8259A_irq_type;
 464                 } else {
 465                         /*
 466                          * 'high' PCI IRQs filled in on demand
 467                          */
 468                         irq_desc[i].handler = &no_irq_type;
 469                 }
 470         }
 471 }
 472
 473 void apic_timer_interrupt(void);
 474 void spurious_interrupt(void);
 475 void error_interrupt(void);
 476 void reschedule_interrupt(void);
 477 void call_function_interrupt(void);
 478 void invalidate_interrupt(void);
 479
 480 static void setup_timer(void)
 481 {
 482         outb_p(0x34,0x43);              /* binary, mode 2, LSB/MSB, ch 0 */
 483         udelay(10);
 484         outb_p(LATCH & 0xff , 0x40);    /* LSB */
 485         udelay(10);
 486         outb(LATCH >> 8 , 0x40);        /* MSB */
 487 }
 488
 489 static int timer_resume(struct sys_device *dev)
 490 {
 491         setup_timer();
 492         return 0;
 493 }
 494
 495 static struct sysdev_class timer_sysclass = {
 496         set_kset_name("timer"),
 497         .resume         = timer_resume,
 498 };
 499
 500 static struct sys_device device_timer = {
 501         .id             = 0,
 502         .cls            = &timer_sysclass,
 503 };
 504
 505 static int __init init_timer_sysfs(void)
 506 {
 507         int error = sysdev_class_register(&timer_sysclass);
 508         if (!error)
 509                 error = sysdev_register(&device_timer);
 510         return error;
 511 }
 512
 513 device_initcall(init_timer_sysfs);
 514
 515 void __init init_IRQ(void)
 516 {
 517         int i;
 518
 519         init_ISA_irqs();
 520         /*
 521          * Cover the whole vector space, no vector can escape
 522          * us. (some of these will be overridden and become
 523          * 'special' SMP interrupts)
 524          */
 525         for (i = 0; i < (NR_VECTORS - FIRST_EXTERNAL_VECTOR); i++) {
 526                 int vector = FIRST_EXTERNAL_VECTOR + i;
 527                 if (i >= NR_IRQS)
 528                         break;
 529                 if (vector != IA32_SYSCALL_VECTOR && vector != KDB_VECTOR) {
 530                         set_intr_gate(vector, interrupt[i]);
 531         }
 532         }
 533
 534 #ifdef CONFIG_SMP
 535         /*
 536          * IRQ0 must be given a fixed assignment and initialized,
 537          * because it's used before the IO-APIC is set up.
 538          */
 539         set_intr_gate(FIRST_DEVICE_VECTOR, interrupt[0]);
 540
 541         /*
 542          * The reschedule interrupt is a CPU-to-CPU reschedule-helper
 543          * IPI, driven by wakeup.
 544          */
 545         set_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
 546
 547         /* IPI for invalidation */
 548         set_intr_gate(INVALIDATE_TLB_VECTOR, invalidate_interrupt);
 549
 550         /* IPI for generic function call */
 551         set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
 552 #endif
 553
 554 #ifdef CONFIG_X86_LOCAL_APIC
 555         /* self generated IPI for local APIC timer */
 556         set_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
 557
 558         /* IPI vectors for APIC spurious and error interrupts */
 559         set_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
 560         set_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
 561 #endif
 562
 563         /*
 564          * Set the clock to HZ Hz, we already have a valid
 565          * vector now:
 566          */
 567         setup_timer();
 568
 569         if (!acpi_ioapic)
 570                 setup_irq(2, &irq2);
 571 }