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 #include <linux/bitops.h>
18 #include <asm/atomic.h>
19 #include <asm/system.h>
21 #include <asm/hw_irq.h>
22 #include <asm/pgtable.h>
23 #include <asm/delay.h>
28 * Common place to define all x86 IRQ vectors
30 * This builds up the IRQ handler stubs using some ugly macros in irq.h
32 * These macros create the low-level assembly IRQ routines that save
33 * register context and call do_IRQ(). do_IRQ() then does all the
34 * operations that are needed to keep the AT (or SMP IOAPIC)
35 * interrupt-controller happy.
41 #define BUILD_16_IRQS(x) \
42 BI(x,0) BI(x,1) BI(x,2) BI(x,3) \
43 BI(x,4) BI(x,5) BI(x,6) BI(x,7) \
44 BI(x,8) BI(x,9) BI(x,a) BI(x,b) \
45 BI(x,c) BI(x,d) BI(x,e) BI(x,f)
47 #define BUILD_14_IRQS(x) \
48 BI(x,0) BI(x,1) BI(x,2) BI(x,3) \
49 BI(x,4) BI(x,5) BI(x,6) BI(x,7) \
50 BI(x,8) BI(x,9) BI(x,a) BI(x,b) \
54 * ISA PIC or low IO-APIC triggered (INTA-cycle or APIC) interrupts:
55 * (these are usually mapped to vectors 0x20-0x2f)
59 #ifdef CONFIG_X86_LOCAL_APIC
61 * The IO-APIC gives us many more interrupt sources. Most of these
62 * are unused but an SMP system is supposed to have enough memory ...
63 * sometimes (mostly wrt. hw bugs) we get corrupted vectors all
64 * across the spectrum, so we really want to be prepared to get all
65 * of these. Plus, more powerful systems might have more than 64
68 * (these are usually mapped into the 0x30-0xff vector range)
70 BUILD_16_IRQS(0x1) BUILD_16_IRQS(0x2) BUILD_16_IRQS(0x3)
71 BUILD_16_IRQS(0x4) BUILD_16_IRQS(0x5) BUILD_16_IRQS(0x6) BUILD_16_IRQS(0x7)
72 BUILD_16_IRQS(0x8) BUILD_16_IRQS(0x9) BUILD_16_IRQS(0xa) BUILD_16_IRQS(0xb)
73 BUILD_16_IRQS(0xc) BUILD_16_IRQS(0xd)
89 #define IRQLIST_16(x) \
90 IRQ(x,0), IRQ(x,1), IRQ(x,2), IRQ(x,3), \
91 IRQ(x,4), IRQ(x,5), IRQ(x,6), IRQ(x,7), \
92 IRQ(x,8), IRQ(x,9), IRQ(x,a), IRQ(x,b), \
93 IRQ(x,c), IRQ(x,d), IRQ(x,e), IRQ(x,f)
95 #define IRQLIST_14(x) \
96 IRQ(x,0), IRQ(x,1), IRQ(x,2), IRQ(x,3), \
97 IRQ(x,4), IRQ(x,5), IRQ(x,6), IRQ(x,7), \
98 IRQ(x,8), IRQ(x,9), IRQ(x,a), IRQ(x,b), \
101 void (*interrupt[NR_IRQS])(void) = {
104 #ifdef CONFIG_X86_IO_APIC
105 IRQLIST_16(0x1), IRQLIST_16(0x2), IRQLIST_16(0x3),
106 IRQLIST_16(0x4), IRQLIST_16(0x5), IRQLIST_16(0x6), IRQLIST_16(0x7),
107 IRQLIST_16(0x8), IRQLIST_16(0x9), IRQLIST_16(0xa), IRQLIST_16(0xb),
108 IRQLIST_16(0xc), IRQLIST_16(0xd)
110 #ifdef CONFIG_PCI_MSI
122 * This is the 'legacy' 8259A Programmable Interrupt Controller,
123 * present in the majority of PC/AT boxes.
124 * plus some generic x86 specific things if generic specifics makes
126 * this file should become arch/i386/kernel/irq.c when the old irq.c
127 * moves to arch independent land
130 DEFINE_SPINLOCK(i8259A_lock);
132 static void end_8259A_irq (unsigned int irq)
136 printk("return %p stack %p ti %p\n", __builtin_return_address(0), &var, task_thread_info(current));
141 if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)) &&
142 irq_desc[irq].action)
143 enable_8259A_irq(irq);
146 #define shutdown_8259A_irq disable_8259A_irq
148 static void mask_and_ack_8259A(unsigned int);
150 static unsigned int startup_8259A_irq(unsigned int irq)
152 enable_8259A_irq(irq);
153 return 0; /* never anything pending */
156 static struct hw_interrupt_type i8259A_irq_type = {
157 .typename = "XT-PIC",
158 .startup = startup_8259A_irq,
159 .shutdown = shutdown_8259A_irq,
160 .enable = enable_8259A_irq,
161 .disable = disable_8259A_irq,
162 .ack = mask_and_ack_8259A,
163 .end = end_8259A_irq,
167 * 8259A PIC functions to handle ISA devices:
171 * This contains the irq mask for both 8259A irq controllers,
173 static unsigned int cached_irq_mask = 0xffff;
175 #define __byte(x,y) (((unsigned char *)&(y))[x])
176 #define cached_21 (__byte(0,cached_irq_mask))
177 #define cached_A1 (__byte(1,cached_irq_mask))
180 * Not all IRQs can be routed through the IO-APIC, eg. on certain (older)
181 * boards the timer interrupt is not really connected to any IO-APIC pin,
182 * it's fed to the master 8259A's IR0 line only.
184 * Any '1' bit in this mask means the IRQ is routed through the IO-APIC.
185 * this 'mixed mode' IRQ handling costs nothing because it's only used
188 unsigned long io_apic_irqs;
190 void disable_8259A_irq(unsigned int irq)
192 unsigned int mask = 1 << irq;
195 spin_lock_irqsave(&i8259A_lock, flags);
196 cached_irq_mask |= mask;
198 outb(cached_A1,0xA1);
200 outb(cached_21,0x21);
201 spin_unlock_irqrestore(&i8259A_lock, flags);
204 void enable_8259A_irq(unsigned int irq)
206 unsigned int mask = ~(1 << irq);
209 spin_lock_irqsave(&i8259A_lock, flags);
210 cached_irq_mask &= mask;
212 outb(cached_A1,0xA1);
214 outb(cached_21,0x21);
215 spin_unlock_irqrestore(&i8259A_lock, flags);
218 int i8259A_irq_pending(unsigned int irq)
220 unsigned int mask = 1<<irq;
224 spin_lock_irqsave(&i8259A_lock, flags);
226 ret = inb(0x20) & mask;
228 ret = inb(0xA0) & (mask >> 8);
229 spin_unlock_irqrestore(&i8259A_lock, flags);
234 void make_8259A_irq(unsigned int irq)
236 disable_irq_nosync(irq);
237 io_apic_irqs &= ~(1<<irq);
238 irq_desc[irq].handler = &i8259A_irq_type;
243 * This function assumes to be called rarely. Switching between
244 * 8259A registers is slow.
245 * This has to be protected by the irq controller spinlock
246 * before being called.
248 static inline int i8259A_irq_real(unsigned int irq)
251 int irqmask = 1<<irq;
254 outb(0x0B,0x20); /* ISR register */
255 value = inb(0x20) & irqmask;
256 outb(0x0A,0x20); /* back to the IRR register */
259 outb(0x0B,0xA0); /* ISR register */
260 value = inb(0xA0) & (irqmask >> 8);
261 outb(0x0A,0xA0); /* back to the IRR register */
266 * Careful! The 8259A is a fragile beast, it pretty
267 * much _has_ to be done exactly like this (mask it
268 * first, _then_ send the EOI, and the order of EOI
269 * to the two 8259s is important!
271 static void mask_and_ack_8259A(unsigned int irq)
273 unsigned int irqmask = 1 << irq;
276 spin_lock_irqsave(&i8259A_lock, flags);
278 * Lightweight spurious IRQ detection. We do not want
279 * to overdo spurious IRQ handling - it's usually a sign
280 * of hardware problems, so we only do the checks we can
281 * do without slowing down good hardware unnecesserily.
283 * Note that IRQ7 and IRQ15 (the two spurious IRQs
284 * usually resulting from the 8259A-1|2 PICs) occur
285 * even if the IRQ is masked in the 8259A. Thus we
286 * can check spurious 8259A IRQs without doing the
287 * quite slow i8259A_irq_real() call for every IRQ.
288 * This does not cover 100% of spurious interrupts,
289 * but should be enough to warn the user that there
290 * is something bad going on ...
292 if (cached_irq_mask & irqmask)
293 goto spurious_8259A_irq;
294 cached_irq_mask |= irqmask;
298 inb(0xA1); /* DUMMY - (do we need this?) */
299 outb(cached_A1,0xA1);
300 outb(0x60+(irq&7),0xA0);/* 'Specific EOI' to slave */
301 outb(0x62,0x20); /* 'Specific EOI' to master-IRQ2 */
303 inb(0x21); /* DUMMY - (do we need this?) */
304 outb(cached_21,0x21);
305 outb(0x60+irq,0x20); /* 'Specific EOI' to master */
307 spin_unlock_irqrestore(&i8259A_lock, flags);
312 * this is the slow path - should happen rarely.
314 if (i8259A_irq_real(irq))
316 * oops, the IRQ _is_ in service according to the
317 * 8259A - not spurious, go handle it.
319 goto handle_real_irq;
322 static int spurious_irq_mask;
324 * At this point we can be sure the IRQ is spurious,
325 * lets ACK and report it. [once per IRQ]
327 if (!(spurious_irq_mask & irqmask)) {
328 printk(KERN_DEBUG "spurious 8259A interrupt: IRQ%d.\n", irq);
329 spurious_irq_mask |= irqmask;
331 atomic_inc(&irq_err_count);
333 * Theoretically we do not have to handle this IRQ,
334 * but in Linux this does not cause problems and is
337 goto handle_real_irq;
341 void init_8259A(int auto_eoi)
345 spin_lock_irqsave(&i8259A_lock, flags);
347 outb(0xff, 0x21); /* mask all of 8259A-1 */
348 outb(0xff, 0xA1); /* mask all of 8259A-2 */
351 * outb_p - this has to work on a wide range of PC hardware.
353 outb_p(0x11, 0x20); /* ICW1: select 8259A-1 init */
354 outb_p(0x20 + 0, 0x21); /* ICW2: 8259A-1 IR0-7 mapped to 0x20-0x27 */
355 outb_p(0x04, 0x21); /* 8259A-1 (the master) has a slave on IR2 */
357 outb_p(0x03, 0x21); /* master does Auto EOI */
359 outb_p(0x01, 0x21); /* master expects normal EOI */
361 outb_p(0x11, 0xA0); /* ICW1: select 8259A-2 init */
362 outb_p(0x20 + 8, 0xA1); /* ICW2: 8259A-2 IR0-7 mapped to 0x28-0x2f */
363 outb_p(0x02, 0xA1); /* 8259A-2 is a slave on master's IR2 */
364 outb_p(0x01, 0xA1); /* (slave's support for AEOI in flat mode
365 is to be investigated) */
369 * in AEOI mode we just have to mask the interrupt
372 i8259A_irq_type.ack = disable_8259A_irq;
374 i8259A_irq_type.ack = mask_and_ack_8259A;
376 udelay(100); /* wait for 8259A to initialize */
378 outb(cached_21, 0x21); /* restore master IRQ mask */
379 outb(cached_A1, 0xA1); /* restore slave IRQ mask */
381 spin_unlock_irqrestore(&i8259A_lock, flags);
384 static char irq_trigger[2];
386 * ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
388 static void restore_ELCR(char *trigger)
390 outb(trigger[0], 0x4d0);
391 outb(trigger[1], 0x4d1);
394 static void save_ELCR(char *trigger)
396 /* IRQ 0,1,2,8,13 are marked as reserved */
397 trigger[0] = inb(0x4d0) & 0xF8;
398 trigger[1] = inb(0x4d1) & 0xDE;
401 static int i8259A_resume(struct sys_device *dev)
404 restore_ELCR(irq_trigger);
408 static int i8259A_suspend(struct sys_device *dev, pm_message_t state)
410 save_ELCR(irq_trigger);
414 static int i8259A_shutdown(struct sys_device *dev)
416 /* Put the i8259A into a quiescent state that
417 * the kernel initialization code can get it
420 outb(0xff, 0x21); /* mask all of 8259A-1 */
421 outb(0xff, 0xA1); /* mask all of 8259A-1 */
425 static struct sysdev_class i8259_sysdev_class = {
426 set_kset_name("i8259"),
427 .suspend = i8259A_suspend,
428 .resume = i8259A_resume,
429 .shutdown = i8259A_shutdown,
432 static struct sys_device device_i8259A = {
434 .cls = &i8259_sysdev_class,
437 static int __init i8259A_init_sysfs(void)
439 int error = sysdev_class_register(&i8259_sysdev_class);
441 error = sysdev_register(&device_i8259A);
445 device_initcall(i8259A_init_sysfs);
448 * IRQ2 is cascade interrupt to second interrupt controller
451 static struct irqaction irq2 = { no_action, 0, CPU_MASK_NONE, "cascade", NULL, NULL};
453 void __init init_ISA_irqs (void)
457 #ifdef CONFIG_X86_LOCAL_APIC
462 for (i = 0; i < NR_IRQS; i++) {
463 irq_desc[i].status = IRQ_DISABLED;
464 irq_desc[i].action = NULL;
465 irq_desc[i].depth = 1;
469 * 16 old-style INTA-cycle interrupts:
471 irq_desc[i].handler = &i8259A_irq_type;
474 * 'high' PCI IRQs filled in on demand
476 irq_desc[i].handler = &no_irq_type;
481 void apic_timer_interrupt(void);
482 void spurious_interrupt(void);
483 void error_interrupt(void);
484 void reschedule_interrupt(void);
485 void call_function_interrupt(void);
486 void invalidate_interrupt0(void);
487 void invalidate_interrupt1(void);
488 void invalidate_interrupt2(void);
489 void invalidate_interrupt3(void);
490 void invalidate_interrupt4(void);
491 void invalidate_interrupt5(void);
492 void invalidate_interrupt6(void);
493 void invalidate_interrupt7(void);
494 void thermal_interrupt(void);
495 void threshold_interrupt(void);
496 void i8254_timer_resume(void);
498 static void setup_timer_hardware(void)
500 outb_p(0x34,0x43); /* binary, mode 2, LSB/MSB, ch 0 */
502 outb_p(LATCH & 0xff , 0x40); /* LSB */
504 outb(LATCH >> 8 , 0x40); /* MSB */
507 static int timer_resume(struct sys_device *dev)
509 setup_timer_hardware();
513 void i8254_timer_resume(void)
515 setup_timer_hardware();
518 static struct sysdev_class timer_sysclass = {
519 set_kset_name("timer_pit"),
520 .resume = timer_resume,
523 static struct sys_device device_timer = {
525 .cls = &timer_sysclass,
528 static int __init init_timer_sysfs(void)
530 int error = sysdev_class_register(&timer_sysclass);
532 error = sysdev_register(&device_timer);
536 device_initcall(init_timer_sysfs);
538 void __init init_IRQ(void)
544 * Cover the whole vector space, no vector can escape
545 * us. (some of these will be overridden and become
546 * 'special' SMP interrupts)
548 for (i = 0; i < (NR_VECTORS - FIRST_EXTERNAL_VECTOR); i++) {
549 int vector = FIRST_EXTERNAL_VECTOR + i;
552 if (vector != IA32_SYSCALL_VECTOR)
553 set_intr_gate(vector, interrupt[i]);
558 * IRQ0 must be given a fixed assignment and initialized,
559 * because it's used before the IO-APIC is set up.
561 set_intr_gate(FIRST_DEVICE_VECTOR, interrupt[0]);
564 * The reschedule interrupt is a CPU-to-CPU reschedule-helper
565 * IPI, driven by wakeup.
567 set_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
569 /* IPIs for invalidation */
570 set_intr_gate(INVALIDATE_TLB_VECTOR_START+0, invalidate_interrupt0);
571 set_intr_gate(INVALIDATE_TLB_VECTOR_START+1, invalidate_interrupt1);
572 set_intr_gate(INVALIDATE_TLB_VECTOR_START+2, invalidate_interrupt2);
573 set_intr_gate(INVALIDATE_TLB_VECTOR_START+3, invalidate_interrupt3);
574 set_intr_gate(INVALIDATE_TLB_VECTOR_START+4, invalidate_interrupt4);
575 set_intr_gate(INVALIDATE_TLB_VECTOR_START+5, invalidate_interrupt5);
576 set_intr_gate(INVALIDATE_TLB_VECTOR_START+6, invalidate_interrupt6);
577 set_intr_gate(INVALIDATE_TLB_VECTOR_START+7, invalidate_interrupt7);
579 /* IPI for generic function call */
580 set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
582 set_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
583 set_intr_gate(THRESHOLD_APIC_VECTOR, threshold_interrupt);
585 #ifdef CONFIG_X86_LOCAL_APIC
586 /* self generated IPI for local APIC timer */
587 set_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
589 /* IPI vectors for APIC spurious and error interrupts */
590 set_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
591 set_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
595 * Set the clock to HZ Hz, we already have a valid
598 setup_timer_hardware();