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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/x86_64/kernel/i8259.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/x86_64/kernel/i8259.c')
-rw-r--r--arch/x86_64/kernel/i8259.c579
1 files changed, 579 insertions, 0 deletions
diff --git a/arch/x86_64/kernel/i8259.c b/arch/x86_64/kernel/i8259.c
new file mode 100644
index 000000000000..d52701246010
--- /dev/null
+++ b/arch/x86_64/kernel/i8259.c
@@ -0,0 +1,579 @@
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>
16
17#include <asm/acpi.h>
18#include <asm/atomic.h>
19#include <asm/system.h>
20#include <asm/io.h>
21#include <asm/irq.h>
22#include <asm/hw_irq.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 */
60BUILD_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)
74BUILD_16_IRQS(0x4) BUILD_16_IRQS(0x5) BUILD_16_IRQS(0x6) BUILD_16_IRQS(0x7)
75BUILD_16_IRQS(0x8) BUILD_16_IRQS(0x9) BUILD_16_IRQS(0xa) BUILD_16_IRQS(0xb)
76BUILD_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
104void (*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
133DEFINE_SPINLOCK(i8259A_lock);
134
135static 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
151static void mask_and_ack_8259A(unsigned int);
152
153static unsigned int startup_8259A_irq(unsigned int irq)
154{
155 enable_8259A_irq(irq);
156 return 0; /* never anything pending */
157}
158
159static 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 */
177static 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 */
192unsigned long io_apic_irqs;
193
194void 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
208void 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
222int 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
238void 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 */
252static 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 */
275static 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
300handle_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
314spurious_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
345void 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
388static char irq_trigger[2];
389/**
390 * ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
391 */
392static void restore_ELCR(char *trigger)
393{
394 outb(trigger[0], 0x4d0);
395 outb(trigger[1], 0x4d1);
396}
397
398static 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
405static int i8259A_resume(struct sys_device *dev)
406{
407 init_8259A(0);
408 restore_ELCR(irq_trigger);
409 return 0;
410}
411
412static int i8259A_suspend(struct sys_device *dev, u32 state)
413{
414 save_ELCR(irq_trigger);
415 return 0;
416}
417
418static struct sysdev_class i8259_sysdev_class = {
419 set_kset_name("i8259"),
420 .suspend = i8259A_suspend,
421 .resume = i8259A_resume,
422};
423
424static struct sys_device device_i8259A = {
425 .id = 0,
426 .cls = &i8259_sysdev_class,
427};
428
429static 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
437device_initcall(i8259A_init_sysfs);
438
439/*
440 * IRQ2 is cascade interrupt to second interrupt controller
441 */
442
443static struct irqaction irq2 = { no_action, 0, CPU_MASK_NONE, "cascade", NULL, NULL};
444
445void __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
473void apic_timer_interrupt(void);
474void spurious_interrupt(void);
475void error_interrupt(void);
476void reschedule_interrupt(void);
477void call_function_interrupt(void);
478void invalidate_interrupt(void);
479void thermal_interrupt(void);
480void i8254_timer_resume(void);
481
482static void setup_timer(void)
483{
484 outb_p(0x34,0x43); /* binary, mode 2, LSB/MSB, ch 0 */
485 udelay(10);
486 outb_p(LATCH & 0xff , 0x40); /* LSB */
487 udelay(10);
488 outb(LATCH >> 8 , 0x40); /* MSB */
489}
490
491static int timer_resume(struct sys_device *dev)
492{
493 setup_timer();
494 return 0;
495}
496
497void i8254_timer_resume(void)
498{
499 setup_timer();
500}
501
502static struct sysdev_class timer_sysclass = {
503 set_kset_name("timer"),
504 .resume = timer_resume,
505};
506
507static struct sys_device device_timer = {
508 .id = 0,
509 .cls = &timer_sysclass,
510};
511
512static int __init init_timer_sysfs(void)
513{
514 int error = sysdev_class_register(&timer_sysclass);
515 if (!error)
516 error = sysdev_register(&device_timer);
517 return error;
518}
519
520device_initcall(init_timer_sysfs);
521
522void __init init_IRQ(void)
523{
524 int i;
525
526 init_ISA_irqs();
527 /*
528 * Cover the whole vector space, no vector can escape
529 * us. (some of these will be overridden and become
530 * 'special' SMP interrupts)
531 */
532 for (i = 0; i < (NR_VECTORS - FIRST_EXTERNAL_VECTOR); i++) {
533 int vector = FIRST_EXTERNAL_VECTOR + i;
534 if (i >= NR_IRQS)
535 break;
536 if (vector != IA32_SYSCALL_VECTOR && vector != KDB_VECTOR) {
537 set_intr_gate(vector, interrupt[i]);
538 }
539 }
540
541#ifdef CONFIG_SMP
542 /*
543 * IRQ0 must be given a fixed assignment and initialized,
544 * because it's used before the IO-APIC is set up.
545 */
546 set_intr_gate(FIRST_DEVICE_VECTOR, interrupt[0]);
547
548 /*
549 * The reschedule interrupt is a CPU-to-CPU reschedule-helper
550 * IPI, driven by wakeup.
551 */
552 set_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
553
554 /* IPI for invalidation */
555 set_intr_gate(INVALIDATE_TLB_VECTOR, invalidate_interrupt);
556
557 /* IPI for generic function call */
558 set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
559#endif
560 set_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
561
562#ifdef CONFIG_X86_LOCAL_APIC
563 /* self generated IPI for local APIC timer */
564 set_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
565
566 /* IPI vectors for APIC spurious and error interrupts */
567 set_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
568 set_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
569#endif
570
571 /*
572 * Set the clock to HZ Hz, we already have a valid
573 * vector now:
574 */
575 setup_timer();
576
577 if (!acpi_ioapic)
578 setup_irq(2, &irq2);
579}