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1.1 root 1: /*
2: * QEMU 8259 interrupt controller emulation
3: *
4: * Copyright (c) 2003-2004 Fabrice Bellard
5: *
6: * Permission is hereby granted, free of charge, to any person obtaining a copy
7: * of this software and associated documentation files (the "Software"), to deal
8: * in the Software without restriction, including without limitation the rights
9: * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10: * copies of the Software, and to permit persons to whom the Software is
11: * furnished to do so, subject to the following conditions:
12: *
13: * The above copyright notice and this permission notice shall be included in
14: * all copies or substantial portions of the Software.
15: *
16: * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17: * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18: * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19: * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20: * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21: * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22: * THE SOFTWARE.
23: */
24: #include "vl.h"
25:
26: /* debug PIC */
27: //#define DEBUG_PIC
28:
29: //#define DEBUG_IRQ_LATENCY
30: //#define DEBUG_IRQ_COUNT
31:
32: typedef struct PicState {
33: uint8_t last_irr; /* edge detection */
34: uint8_t irr; /* interrupt request register */
35: uint8_t imr; /* interrupt mask register */
36: uint8_t isr; /* interrupt service register */
37: uint8_t priority_add; /* highest irq priority */
38: uint8_t irq_base;
39: uint8_t read_reg_select;
40: uint8_t poll;
41: uint8_t special_mask;
42: uint8_t init_state;
43: uint8_t auto_eoi;
44: uint8_t rotate_on_auto_eoi;
45: uint8_t special_fully_nested_mode;
46: uint8_t init4; /* true if 4 byte init */
47: uint8_t elcr; /* PIIX edge/trigger selection*/
48: uint8_t elcr_mask;
49: PicState2 *pics_state;
50: } PicState;
51:
52: struct PicState2 {
53: /* 0 is master pic, 1 is slave pic */
54: /* XXX: better separation between the two pics */
55: PicState pics[2];
56: IRQRequestFunc *irq_request;
57: void *irq_request_opaque;
58: /* IOAPIC callback support */
59: SetIRQFunc *alt_irq_func;
60: void *alt_irq_opaque;
61: };
62:
63: #if defined(DEBUG_PIC) || defined (DEBUG_IRQ_COUNT)
64: static int irq_level[16];
65: #endif
66: #ifdef DEBUG_IRQ_COUNT
67: static uint64_t irq_count[16];
68: #endif
69:
70: /* set irq level. If an edge is detected, then the IRR is set to 1 */
71: static inline void pic_set_irq1(PicState *s, int irq, int level)
72: {
73: int mask;
74: mask = 1 << irq;
75: if (s->elcr & mask) {
76: /* level triggered */
77: if (level) {
78: s->irr |= mask;
79: s->last_irr |= mask;
80: } else {
81: s->irr &= ~mask;
82: s->last_irr &= ~mask;
83: }
84: } else {
85: /* edge triggered */
86: if (level) {
87: if ((s->last_irr & mask) == 0)
88: s->irr |= mask;
89: s->last_irr |= mask;
90: } else {
91: s->last_irr &= ~mask;
92: }
93: }
94: }
95:
96: /* return the highest priority found in mask (highest = smallest
97: number). Return 8 if no irq */
98: static inline int get_priority(PicState *s, int mask)
99: {
100: int priority;
101: if (mask == 0)
102: return 8;
103: priority = 0;
104: while ((mask & (1 << ((priority + s->priority_add) & 7))) == 0)
105: priority++;
106: return priority;
107: }
108:
109: /* return the pic wanted interrupt. return -1 if none */
110: static int pic_get_irq(PicState *s)
111: {
112: int mask, cur_priority, priority;
113:
114: mask = s->irr & ~s->imr;
115: priority = get_priority(s, mask);
116: if (priority == 8)
117: return -1;
118: /* compute current priority. If special fully nested mode on the
119: master, the IRQ coming from the slave is not taken into account
120: for the priority computation. */
121: mask = s->isr;
122: if (s->special_fully_nested_mode && s == &s->pics_state->pics[0])
123: mask &= ~(1 << 2);
124: cur_priority = get_priority(s, mask);
125: if (priority < cur_priority) {
126: /* higher priority found: an irq should be generated */
127: return (priority + s->priority_add) & 7;
128: } else {
129: return -1;
130: }
131: }
132:
133: /* raise irq to CPU if necessary. must be called every time the active
134: irq may change */
135: /* XXX: should not export it, but it is needed for an APIC kludge */
136: void pic_update_irq(PicState2 *s)
137: {
138: int irq2, irq;
139:
140: /* first look at slave pic */
141: irq2 = pic_get_irq(&s->pics[1]);
142: if (irq2 >= 0) {
143: /* if irq request by slave pic, signal master PIC */
144: pic_set_irq1(&s->pics[0], 2, 1);
145: pic_set_irq1(&s->pics[0], 2, 0);
146: }
147: /* look at requested irq */
148: irq = pic_get_irq(&s->pics[0]);
149: if (irq >= 0) {
150: #if defined(DEBUG_PIC)
151: {
152: int i;
153: for(i = 0; i < 2; i++) {
154: printf("pic%d: imr=%x irr=%x padd=%d\n",
155: i, s->pics[i].imr, s->pics[i].irr,
156: s->pics[i].priority_add);
157:
158: }
159: }
160: printf("pic: cpu_interrupt\n");
161: #endif
162: s->irq_request(s->irq_request_opaque, 1);
163: }
164: }
165:
166: #ifdef DEBUG_IRQ_LATENCY
167: int64_t irq_time[16];
168: #endif
169:
170: void pic_set_irq_new(void *opaque, int irq, int level)
171: {
172: PicState2 *s = opaque;
173:
174: #if defined(DEBUG_PIC) || defined(DEBUG_IRQ_COUNT)
175: if (level != irq_level[irq]) {
176: #if defined(DEBUG_PIC)
177: printf("pic_set_irq: irq=%d level=%d\n", irq, level);
178: #endif
179: irq_level[irq] = level;
180: #ifdef DEBUG_IRQ_COUNT
181: if (level == 1)
182: irq_count[irq]++;
183: #endif
184: }
185: #endif
186: #ifdef DEBUG_IRQ_LATENCY
187: if (level) {
188: irq_time[irq] = qemu_get_clock(vm_clock);
189: }
190: #endif
191: pic_set_irq1(&s->pics[irq >> 3], irq & 7, level);
192: /* used for IOAPIC irqs */
193: if (s->alt_irq_func)
194: s->alt_irq_func(s->alt_irq_opaque, irq, level);
195: pic_update_irq(s);
196: }
197:
198: /* obsolete function */
199: void pic_set_irq(int irq, int level)
200: {
201: pic_set_irq_new(isa_pic, irq, level);
202: }
203:
204: /* acknowledge interrupt 'irq' */
205: static inline void pic_intack(PicState *s, int irq)
206: {
207: if (s->auto_eoi) {
208: if (s->rotate_on_auto_eoi)
209: s->priority_add = (irq + 1) & 7;
210: } else {
211: s->isr |= (1 << irq);
212: }
213: /* We don't clear a level sensitive interrupt here */
214: if (!(s->elcr & (1 << irq)))
215: s->irr &= ~(1 << irq);
216: }
217:
218: int pic_read_irq(PicState2 *s)
219: {
220: int irq, irq2, intno;
221:
222: irq = pic_get_irq(&s->pics[0]);
223: if (irq >= 0) {
224: pic_intack(&s->pics[0], irq);
225: if (irq == 2) {
226: irq2 = pic_get_irq(&s->pics[1]);
227: if (irq2 >= 0) {
228: pic_intack(&s->pics[1], irq2);
229: } else {
230: /* spurious IRQ on slave controller */
231: irq2 = 7;
232: }
233: intno = s->pics[1].irq_base + irq2;
234: irq = irq2 + 8;
235: } else {
236: intno = s->pics[0].irq_base + irq;
237: }
238: } else {
239: /* spurious IRQ on host controller */
240: irq = 7;
241: intno = s->pics[0].irq_base + irq;
242: }
243: pic_update_irq(s);
244:
245: #ifdef DEBUG_IRQ_LATENCY
246: printf("IRQ%d latency=%0.3fus\n",
247: irq,
248: (double)(qemu_get_clock(vm_clock) - irq_time[irq]) * 1000000.0 / ticks_per_sec);
249: #endif
250: #if defined(DEBUG_PIC)
251: printf("pic_interrupt: irq=%d\n", irq);
252: #endif
253: return intno;
254: }
255:
256: static void pic_reset(void *opaque)
257: {
258: PicState *s = opaque;
259:
260: s->last_irr = 0;
261: s->irr = 0;
262: s->imr = 0;
263: s->isr = 0;
264: s->priority_add = 0;
265: s->irq_base = 0;
266: s->read_reg_select = 0;
267: s->poll = 0;
268: s->special_mask = 0;
269: s->init_state = 0;
270: s->auto_eoi = 0;
271: s->rotate_on_auto_eoi = 0;
272: s->special_fully_nested_mode = 0;
273: s->init4 = 0;
1.1.1.2 root 274: /* Note: ELCR is not reset */
1.1 root 275: }
276:
277: static void pic_ioport_write(void *opaque, uint32_t addr, uint32_t val)
278: {
279: PicState *s = opaque;
280: int priority, cmd, irq;
281:
282: #ifdef DEBUG_PIC
283: printf("pic_write: addr=0x%02x val=0x%02x\n", addr, val);
284: #endif
285: addr &= 1;
286: if (addr == 0) {
287: if (val & 0x10) {
288: /* init */
289: pic_reset(s);
290: /* deassert a pending interrupt */
291: s->pics_state->irq_request(s->pics_state->irq_request_opaque, 0);
292: s->init_state = 1;
293: s->init4 = val & 1;
294: if (val & 0x02)
295: hw_error("single mode not supported");
296: if (val & 0x08)
297: hw_error("level sensitive irq not supported");
298: } else if (val & 0x08) {
299: if (val & 0x04)
300: s->poll = 1;
301: if (val & 0x02)
302: s->read_reg_select = val & 1;
303: if (val & 0x40)
304: s->special_mask = (val >> 5) & 1;
305: } else {
306: cmd = val >> 5;
307: switch(cmd) {
308: case 0:
309: case 4:
310: s->rotate_on_auto_eoi = cmd >> 2;
311: break;
312: case 1: /* end of interrupt */
313: case 5:
314: priority = get_priority(s, s->isr);
315: if (priority != 8) {
316: irq = (priority + s->priority_add) & 7;
317: s->isr &= ~(1 << irq);
318: if (cmd == 5)
319: s->priority_add = (irq + 1) & 7;
320: pic_update_irq(s->pics_state);
321: }
322: break;
323: case 3:
324: irq = val & 7;
325: s->isr &= ~(1 << irq);
326: pic_update_irq(s->pics_state);
327: break;
328: case 6:
329: s->priority_add = (val + 1) & 7;
330: pic_update_irq(s->pics_state);
331: break;
332: case 7:
333: irq = val & 7;
334: s->isr &= ~(1 << irq);
335: s->priority_add = (irq + 1) & 7;
336: pic_update_irq(s->pics_state);
337: break;
338: default:
339: /* no operation */
340: break;
341: }
342: }
343: } else {
344: switch(s->init_state) {
345: case 0:
346: /* normal mode */
347: s->imr = val;
348: pic_update_irq(s->pics_state);
349: break;
350: case 1:
351: s->irq_base = val & 0xf8;
352: s->init_state = 2;
353: break;
354: case 2:
355: if (s->init4) {
356: s->init_state = 3;
357: } else {
358: s->init_state = 0;
359: }
360: break;
361: case 3:
362: s->special_fully_nested_mode = (val >> 4) & 1;
363: s->auto_eoi = (val >> 1) & 1;
364: s->init_state = 0;
365: break;
366: }
367: }
368: }
369:
370: static uint32_t pic_poll_read (PicState *s, uint32_t addr1)
371: {
372: int ret;
373:
374: ret = pic_get_irq(s);
375: if (ret >= 0) {
376: if (addr1 >> 7) {
377: s->pics_state->pics[0].isr &= ~(1 << 2);
378: s->pics_state->pics[0].irr &= ~(1 << 2);
379: }
380: s->irr &= ~(1 << ret);
381: s->isr &= ~(1 << ret);
382: if (addr1 >> 7 || ret != 2)
383: pic_update_irq(s->pics_state);
384: } else {
385: ret = 0x07;
386: pic_update_irq(s->pics_state);
387: }
388:
389: return ret;
390: }
391:
392: static uint32_t pic_ioport_read(void *opaque, uint32_t addr1)
393: {
394: PicState *s = opaque;
395: unsigned int addr;
396: int ret;
397:
398: addr = addr1;
399: addr &= 1;
400: if (s->poll) {
401: ret = pic_poll_read(s, addr1);
402: s->poll = 0;
403: } else {
404: if (addr == 0) {
405: if (s->read_reg_select)
406: ret = s->isr;
407: else
408: ret = s->irr;
409: } else {
410: ret = s->imr;
411: }
412: }
413: #ifdef DEBUG_PIC
414: printf("pic_read: addr=0x%02x val=0x%02x\n", addr1, ret);
415: #endif
416: return ret;
417: }
418:
419: /* memory mapped interrupt status */
420: /* XXX: may be the same than pic_read_irq() */
421: uint32_t pic_intack_read(PicState2 *s)
422: {
423: int ret;
424:
425: ret = pic_poll_read(&s->pics[0], 0x00);
426: if (ret == 2)
427: ret = pic_poll_read(&s->pics[1], 0x80) + 8;
428: /* Prepare for ISR read */
429: s->pics[0].read_reg_select = 1;
430:
431: return ret;
432: }
433:
434: static void elcr_ioport_write(void *opaque, uint32_t addr, uint32_t val)
435: {
436: PicState *s = opaque;
437: s->elcr = val & s->elcr_mask;
438: }
439:
440: static uint32_t elcr_ioport_read(void *opaque, uint32_t addr1)
441: {
442: PicState *s = opaque;
443: return s->elcr;
444: }
445:
446: static void pic_save(QEMUFile *f, void *opaque)
447: {
448: PicState *s = opaque;
449:
450: qemu_put_8s(f, &s->last_irr);
451: qemu_put_8s(f, &s->irr);
452: qemu_put_8s(f, &s->imr);
453: qemu_put_8s(f, &s->isr);
454: qemu_put_8s(f, &s->priority_add);
455: qemu_put_8s(f, &s->irq_base);
456: qemu_put_8s(f, &s->read_reg_select);
457: qemu_put_8s(f, &s->poll);
458: qemu_put_8s(f, &s->special_mask);
459: qemu_put_8s(f, &s->init_state);
460: qemu_put_8s(f, &s->auto_eoi);
461: qemu_put_8s(f, &s->rotate_on_auto_eoi);
462: qemu_put_8s(f, &s->special_fully_nested_mode);
463: qemu_put_8s(f, &s->init4);
464: qemu_put_8s(f, &s->elcr);
465: }
466:
467: static int pic_load(QEMUFile *f, void *opaque, int version_id)
468: {
469: PicState *s = opaque;
470:
471: if (version_id != 1)
472: return -EINVAL;
473:
474: qemu_get_8s(f, &s->last_irr);
475: qemu_get_8s(f, &s->irr);
476: qemu_get_8s(f, &s->imr);
477: qemu_get_8s(f, &s->isr);
478: qemu_get_8s(f, &s->priority_add);
479: qemu_get_8s(f, &s->irq_base);
480: qemu_get_8s(f, &s->read_reg_select);
481: qemu_get_8s(f, &s->poll);
482: qemu_get_8s(f, &s->special_mask);
483: qemu_get_8s(f, &s->init_state);
484: qemu_get_8s(f, &s->auto_eoi);
485: qemu_get_8s(f, &s->rotate_on_auto_eoi);
486: qemu_get_8s(f, &s->special_fully_nested_mode);
487: qemu_get_8s(f, &s->init4);
488: qemu_get_8s(f, &s->elcr);
489: return 0;
490: }
491:
492: /* XXX: add generic master/slave system */
493: static void pic_init1(int io_addr, int elcr_addr, PicState *s)
494: {
495: register_ioport_write(io_addr, 2, 1, pic_ioport_write, s);
496: register_ioport_read(io_addr, 2, 1, pic_ioport_read, s);
497: if (elcr_addr >= 0) {
498: register_ioport_write(elcr_addr, 1, 1, elcr_ioport_write, s);
499: register_ioport_read(elcr_addr, 1, 1, elcr_ioport_read, s);
500: }
501: register_savevm("i8259", io_addr, 1, pic_save, pic_load, s);
502: qemu_register_reset(pic_reset, s);
503: }
504:
505: void pic_info(void)
506: {
507: int i;
508: PicState *s;
509:
510: if (!isa_pic)
511: return;
512:
513: for(i=0;i<2;i++) {
514: s = &isa_pic->pics[i];
515: term_printf("pic%d: irr=%02x imr=%02x isr=%02x hprio=%d irq_base=%02x rr_sel=%d elcr=%02x fnm=%d\n",
516: i, s->irr, s->imr, s->isr, s->priority_add,
517: s->irq_base, s->read_reg_select, s->elcr,
518: s->special_fully_nested_mode);
519: }
520: }
521:
522: void irq_info(void)
523: {
524: #ifndef DEBUG_IRQ_COUNT
525: term_printf("irq statistic code not compiled.\n");
526: #else
527: int i;
528: int64_t count;
529:
530: term_printf("IRQ statistics:\n");
531: for (i = 0; i < 16; i++) {
532: count = irq_count[i];
533: if (count > 0)
1.1.1.3 ! root 534: term_printf("%2d: %" PRId64 "\n", i, count);
1.1 root 535: }
536: #endif
537: }
538:
539: PicState2 *pic_init(IRQRequestFunc *irq_request, void *irq_request_opaque)
540: {
541: PicState2 *s;
542: s = qemu_mallocz(sizeof(PicState2));
543: if (!s)
544: return NULL;
545: pic_init1(0x20, 0x4d0, &s->pics[0]);
546: pic_init1(0xa0, 0x4d1, &s->pics[1]);
547: s->pics[0].elcr_mask = 0xf8;
548: s->pics[1].elcr_mask = 0xde;
549: s->irq_request = irq_request;
550: s->irq_request_opaque = irq_request_opaque;
551: s->pics[0].pics_state = s;
552: s->pics[1].pics_state = s;
553: return s;
554: }
555:
556: void pic_set_alt_irq_func(PicState2 *s, SetIRQFunc *alt_irq_func,
557: void *alt_irq_opaque)
558: {
559: s->alt_irq_func = alt_irq_func;
560: s->alt_irq_opaque = alt_irq_opaque;
561: }
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