vatpic.c revision 268891 
1/*-
2 * Copyright (c) 2014 Tycho Nightingale <tycho.nightingale@pluribusnetworks.com>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/10/sys/amd64/vmm/io/vatpic.c 268891 2014-07-19 22:06:46Z jhb $");
29
30#include <sys/param.h>
31#include <sys/types.h>
32#include <sys/queue.h>
33#include <sys/cpuset.h>
34#include <sys/kernel.h>
35#include <sys/lock.h>
36#include <sys/malloc.h>
37#include <sys/mutex.h>
38#include <sys/systm.h>
39
40#include <x86/apicreg.h>
41#include <dev/ic/i8259.h>
42
43#include <machine/vmm.h>
44
45#include "vmm_ktr.h"
46#include "vmm_lapic.h"
47#include "vioapic.h"
48#include "vatpic.h"
49
50static MALLOC_DEFINE(M_VATPIC, "atpic", "bhyve virtual atpic (8259)");
51
52#define	VATPIC_LOCK(vatpic)		mtx_lock_spin(&((vatpic)->mtx))
53#define	VATPIC_UNLOCK(vatpic)		mtx_unlock_spin(&((vatpic)->mtx))
54#define	VATPIC_LOCKED(vatpic)		mtx_owned(&((vatpic)->mtx))
55
56enum irqstate {
57	IRQSTATE_ASSERT,
58	IRQSTATE_DEASSERT,
59	IRQSTATE_PULSE
60};
61
62struct atpic {
63	bool		ready;
64	int		icw_num;
65	int		rd_cmd_reg;
66
67	bool		aeoi;
68	bool		poll;
69	bool		rotate;
70	bool		sfn;		/* special fully-nested mode */
71
72	int		irq_base;
73	uint8_t		request;	/* Interrupt Request Register (IIR) */
74	uint8_t		service;	/* Interrupt Service (ISR) */
75	uint8_t		mask;		/* Interrupt Mask Register (IMR) */
76
77	int		acnt[8];	/* sum of pin asserts and deasserts */
78	int		priority;	/* current pin priority */
79
80	bool		intr_raised;
81};
82
83struct vatpic {
84	struct vm	*vm;
85	struct mtx	mtx;
86	struct atpic	atpic[2];
87	uint8_t		elc[2];
88};
89
90#define	VATPIC_CTR0(vatpic, fmt)					\
91	VM_CTR0((vatpic)->vm, fmt)
92
93#define	VATPIC_CTR1(vatpic, fmt, a1)					\
94	VM_CTR1((vatpic)->vm, fmt, a1)
95
96#define	VATPIC_CTR2(vatpic, fmt, a1, a2)				\
97	VM_CTR2((vatpic)->vm, fmt, a1, a2)
98
99#define	VATPIC_CTR3(vatpic, fmt, a1, a2, a3)				\
100	VM_CTR3((vatpic)->vm, fmt, a1, a2, a3)
101
102#define	VATPIC_CTR4(vatpic, fmt, a1, a2, a3, a4)			\
103	VM_CTR4((vatpic)->vm, fmt, a1, a2, a3, a4)
104
105static void vatpic_set_pinstate(struct vatpic *vatpic, int pin, bool newstate);
106
107static __inline int
108vatpic_get_highest_isrpin(struct atpic *atpic)
109{
110	int bit, pin;
111	int i;
112
113	for (i = 0; i <= 7; i++) {
114		pin = ((i + 7 - atpic->priority) & 0x7);
115                bit = (1 << pin);
116
117		if (atpic->service & bit)
118			return (pin);
119	}
120
121	return (-1);
122}
123
124static __inline int
125vatpic_get_highest_irrpin(struct atpic *atpic)
126{
127	int serviced;
128	int bit, pin;
129	int i, j;
130
131	/*
132	 * In 'Special Fully-Nested Mode' when an interrupt request from
133	 * a slave is in service, the slave is not locked out from the
134	 * master's priority logic.
135	 */
136	serviced = atpic->service;
137	if (atpic->sfn)
138		serviced &= ~(1 << 2);
139
140	for (i = 0; i <= 7; i++) {
141		pin = ((i + 7 - atpic->priority) & 0x7);
142		bit = (1 << pin);
143		if (serviced & bit)
144			break;
145	}
146
147	for (j = 0; j < i; j++) {
148		pin = ((j + 7 - atpic->priority) & 0x7);
149		bit = (1 << pin);
150		if (atpic->request & bit && (~atpic->mask & bit))
151			return (pin);
152	}
153
154	return (-1);
155}
156
157static void
158vatpic_notify_intr(struct vatpic *vatpic)
159{
160	struct atpic *atpic;
161	int pin;
162
163	KASSERT(VATPIC_LOCKED(vatpic), ("vatpic_notify_intr not locked"));
164
165	/*
166	 * First check the slave.
167	 */
168	atpic = &vatpic->atpic[1];
169	if (!atpic->intr_raised &&
170	    (pin = vatpic_get_highest_irrpin(atpic)) != -1) {
171		VATPIC_CTR4(vatpic, "atpic slave notify pin = %d "
172		    "(imr 0x%x irr 0x%x isr 0x%x)", pin,
173		    atpic->mask, atpic->request, atpic->service);
174
175		/*
176		 * Cascade the request from the slave to the master.
177		 */
178		atpic->intr_raised = true;
179		vatpic_set_pinstate(vatpic, 2, true);
180		vatpic_set_pinstate(vatpic, 2, false);
181	} else {
182		VATPIC_CTR3(vatpic, "atpic slave no eligible interrupts "
183		    "(imr 0x%x irr 0x%x isr 0x%x)",
184		    atpic->mask, atpic->request, atpic->service);
185	}
186
187	/*
188	 * Then check the master.
189	 */
190	atpic = &vatpic->atpic[0];
191	if (!atpic->intr_raised &&
192	    (pin = vatpic_get_highest_irrpin(atpic)) != -1) {
193		VATPIC_CTR4(vatpic, "atpic master notify pin = %d "
194		    "(imr 0x%x irr 0x%x isr 0x%x)", pin,
195		    atpic->mask, atpic->request, atpic->service);
196
197		/*
198		 * PIC interrupts are routed to both the Local APIC
199		 * and the I/O APIC to support operation in 1 of 3
200		 * modes.
201		 *
202		 * 1. Legacy PIC Mode: the PIC effectively bypasses
203		 * all APIC components.  In mode '1' the local APIC is
204		 * disabled and LINT0 is reconfigured as INTR to
205		 * deliver the PIC interrupt directly to the CPU.
206		 *
207		 * 2. Virtual Wire Mode: the APIC is treated as a
208		 * virtual wire which delivers interrupts from the PIC
209		 * to the CPU.  In mode '2' LINT0 is programmed as
210		 * ExtINT to indicate that the PIC is the source of
211		 * the interrupt.
212		 *
213		 * 3. Symmetric I/O Mode: PIC interrupts are fielded
214		 * by the I/O APIC and delivered to the appropriate
215		 * CPU.  In mode '3' the I/O APIC input 0 is
216		 * programmed as ExtINT to indicate that the PIC is
217		 * the source of the interrupt.
218		 */
219		atpic->intr_raised = true;
220		lapic_set_local_intr(vatpic->vm, -1, APIC_LVT_LINT0);
221		vioapic_pulse_irq(vatpic->vm, 0);
222	} else {
223		VATPIC_CTR3(vatpic, "atpic master no eligible interrupts "
224		    "(imr 0x%x irr 0x%x isr 0x%x)",
225		    atpic->mask, atpic->request, atpic->service);
226	}
227}
228
229static int
230vatpic_icw1(struct vatpic *vatpic, struct atpic *atpic, uint8_t val)
231{
232	VATPIC_CTR1(vatpic, "atpic icw1 0x%x", val);
233
234	atpic->ready = false;
235
236	atpic->icw_num = 1;
237	atpic->mask = 0;
238	atpic->priority = 0;
239	atpic->rd_cmd_reg = 0;
240
241	if ((val & ICW1_SNGL) != 0) {
242		VATPIC_CTR0(vatpic, "vatpic cascade mode required");
243		return (-1);
244	}
245
246	if ((val & ICW1_IC4) == 0) {
247		VATPIC_CTR0(vatpic, "vatpic icw4 required");
248		return (-1);
249	}
250
251	atpic->icw_num++;
252
253	return (0);
254}
255
256static int
257vatpic_icw2(struct vatpic *vatpic, struct atpic *atpic, uint8_t val)
258{
259	VATPIC_CTR1(vatpic, "atpic icw2 0x%x", val);
260
261	atpic->irq_base = val & 0xf8;
262
263	atpic->icw_num++;
264
265	return (0);
266}
267
268static int
269vatpic_icw3(struct vatpic *vatpic, struct atpic *atpic, uint8_t val)
270{
271	VATPIC_CTR1(vatpic, "atpic icw3 0x%x", val);
272
273	atpic->icw_num++;
274
275	return (0);
276}
277
278static int
279vatpic_icw4(struct vatpic *vatpic, struct atpic *atpic, uint8_t val)
280{
281	VATPIC_CTR1(vatpic, "atpic icw4 0x%x", val);
282
283	if ((val & ICW4_8086) == 0) {
284		VATPIC_CTR0(vatpic, "vatpic microprocessor mode required");
285		return (-1);
286	}
287
288	if ((val & ICW4_AEOI) != 0)
289		atpic->aeoi = true;
290
291	atpic->icw_num = 0;
292	atpic->ready = true;
293
294	return (0);
295}
296
297static int
298vatpic_ocw1(struct vatpic *vatpic, struct atpic *atpic, uint8_t val)
299{
300	VATPIC_CTR1(vatpic, "atpic ocw1 0x%x", val);
301
302	atpic->mask = val & 0xff;
303
304	return (0);
305}
306
307static int
308vatpic_ocw2(struct vatpic *vatpic, struct atpic *atpic, uint8_t val)
309{
310	VATPIC_CTR1(vatpic, "atpic ocw2 0x%x", val);
311
312	atpic->rotate = ((val & OCW2_R) != 0);
313
314	if ((val & OCW2_EOI) != 0) {
315		int isr_bit;
316
317		if ((val & OCW2_SL) != 0) {
318			/* specific EOI */
319			isr_bit = val & 0x7;
320		} else {
321			/* non-specific EOI */
322			isr_bit = vatpic_get_highest_isrpin(atpic);
323		}
324
325		if (isr_bit != -1) {
326			atpic->service &= ~(1 << isr_bit);
327
328			if (atpic->rotate)
329				atpic->priority = isr_bit;
330		}
331	} else if ((val & OCW2_SL) != 0 && atpic->rotate == true) {
332		/* specific priority */
333		atpic->priority = val & 0x7;
334	}
335
336	return (0);
337}
338
339static int
340vatpic_ocw3(struct vatpic *vatpic, struct atpic *atpic, uint8_t val)
341{
342	VATPIC_CTR1(vatpic, "atpic ocw3 0x%x", val);
343
344	atpic->poll = ((val & OCW3_P) != 0);
345
346	if (val & OCW3_RR) {
347		/* read register command */
348		atpic->rd_cmd_reg = val & OCW3_RIS;
349	}
350
351	return (0);
352}
353
354static void
355vatpic_set_pinstate(struct vatpic *vatpic, int pin, bool newstate)
356{
357	struct atpic *atpic;
358	int oldcnt, newcnt;
359	bool level;
360
361	KASSERT(pin >= 0 && pin < 16,
362	    ("vatpic_set_pinstate: invalid pin number %d", pin));
363	KASSERT(VATPIC_LOCKED(vatpic),
364	    ("vatpic_set_pinstate: vatpic is not locked"));
365
366	atpic = &vatpic->atpic[pin >> 3];
367
368	oldcnt = atpic->acnt[pin & 0x7];
369	if (newstate)
370		atpic->acnt[pin & 0x7]++;
371	else
372		atpic->acnt[pin & 0x7]--;
373	newcnt = atpic->acnt[pin & 0x7];
374
375	if (newcnt < 0) {
376		VATPIC_CTR2(vatpic, "atpic pin%d: bad acnt %d", pin, newcnt);
377	}
378
379	level = ((vatpic->elc[pin >> 3] & (1 << (pin & 0x7))) != 0);
380
381	if ((oldcnt == 0 && newcnt == 1) || (newcnt > 0 && level == true)) {
382		/* rising edge or level */
383		VATPIC_CTR1(vatpic, "atpic pin%d: asserted", pin);
384		atpic->request |= (1 << (pin & 0x7));
385	} else if (oldcnt == 1 && newcnt == 0) {
386		/* falling edge */
387		VATPIC_CTR1(vatpic, "atpic pin%d: deasserted", pin);
388	} else {
389		VATPIC_CTR3(vatpic, "atpic pin%d: %s, ignored, acnt %d",
390		    pin, newstate ? "asserted" : "deasserted", newcnt);
391	}
392
393	vatpic_notify_intr(vatpic);
394}
395
396static int
397vatpic_set_irqstate(struct vm *vm, int irq, enum irqstate irqstate)
398{
399	struct vatpic *vatpic;
400	struct atpic *atpic;
401
402	if (irq < 0 || irq > 15)
403		return (EINVAL);
404
405	vatpic = vm_atpic(vm);
406	atpic = &vatpic->atpic[irq >> 3];
407
408	if (atpic->ready == false)
409		return (0);
410
411	VATPIC_LOCK(vatpic);
412	switch (irqstate) {
413	case IRQSTATE_ASSERT:
414		vatpic_set_pinstate(vatpic, irq, true);
415		break;
416	case IRQSTATE_DEASSERT:
417		vatpic_set_pinstate(vatpic, irq, false);
418		break;
419	case IRQSTATE_PULSE:
420		vatpic_set_pinstate(vatpic, irq, true);
421		vatpic_set_pinstate(vatpic, irq, false);
422		break;
423	default:
424		panic("vatpic_set_irqstate: invalid irqstate %d", irqstate);
425	}
426	VATPIC_UNLOCK(vatpic);
427
428	return (0);
429}
430
431int
432vatpic_assert_irq(struct vm *vm, int irq)
433{
434	return (vatpic_set_irqstate(vm, irq, IRQSTATE_ASSERT));
435}
436
437int
438vatpic_deassert_irq(struct vm *vm, int irq)
439{
440	return (vatpic_set_irqstate(vm, irq, IRQSTATE_DEASSERT));
441}
442
443int
444vatpic_pulse_irq(struct vm *vm, int irq)
445{
446	return (vatpic_set_irqstate(vm, irq, IRQSTATE_PULSE));
447}
448
449void
450vatpic_pending_intr(struct vm *vm, int *vecptr)
451{
452	struct vatpic *vatpic;
453	struct atpic *atpic;
454	int pin;
455
456	vatpic = vm_atpic(vm);
457
458	atpic = &vatpic->atpic[0];
459
460	VATPIC_LOCK(vatpic);
461
462	pin = vatpic_get_highest_irrpin(atpic);
463	if (pin == -1)
464		pin = 7;
465	if (pin == 2) {
466		atpic = &vatpic->atpic[1];
467		pin = vatpic_get_highest_irrpin(atpic);
468	}
469
470	*vecptr = atpic->irq_base + pin;
471
472	VATPIC_UNLOCK(vatpic);
473}
474
475static void
476vatpic_pin_accepted(struct atpic *atpic, int pin)
477{
478	atpic->intr_raised = false;
479
480	if (atpic->acnt[pin] == 0)
481		atpic->request &= ~(1 << pin);
482
483	if (atpic->aeoi == true) {
484		if (atpic->rotate == true)
485			atpic->priority = pin;
486	} else {
487		atpic->service |= (1 << pin);
488	}
489}
490
491void
492vatpic_intr_accepted(struct vm *vm, int vector)
493{
494	struct vatpic *vatpic;
495	int pin;
496
497	vatpic = vm_atpic(vm);
498
499	VATPIC_LOCK(vatpic);
500
501	pin = vector & 0x7;
502
503	if ((vector & ~0x7) == vatpic->atpic[1].irq_base) {
504		vatpic_pin_accepted(&vatpic->atpic[1], pin);
505		/*
506		 * If this vector originated from the slave,
507		 * accept the cascaded interrupt too.
508		 */
509		vatpic_pin_accepted(&vatpic->atpic[0], 2);
510	} else {
511		vatpic_pin_accepted(&vatpic->atpic[0], pin);
512	}
513
514	vatpic_notify_intr(vatpic);
515
516	VATPIC_UNLOCK(vatpic);
517}
518
519static int
520vatpic_read(struct vatpic *vatpic, struct atpic *atpic, bool in, int port,
521	    int bytes, uint32_t *eax)
522{
523	VATPIC_LOCK(vatpic);
524
525	if (atpic->poll) {
526		VATPIC_CTR0(vatpic, "vatpic polled mode not supported");
527		VATPIC_UNLOCK(vatpic);
528		return (-1);
529	} else {
530		if (port & ICU_IMR_OFFSET) {
531			/* read interrrupt mask register */
532			*eax = atpic->mask;
533		} else {
534			if (atpic->rd_cmd_reg == OCW3_RIS) {
535				/* read interrupt service register */
536				*eax = atpic->service;
537			} else {
538				/* read interrupt request register */
539				*eax = atpic->request;
540			}
541		}
542	}
543
544	VATPIC_UNLOCK(vatpic);
545
546	return (0);
547
548}
549
550static int
551vatpic_write(struct vatpic *vatpic, struct atpic *atpic, bool in, int port,
552    int bytes, uint32_t *eax)
553{
554	int error;
555	uint8_t val;
556
557	error = 0;
558	val = *eax;
559
560	VATPIC_LOCK(vatpic);
561
562	if (port & ICU_IMR_OFFSET) {
563		if (atpic->ready) {
564			error = vatpic_ocw1(vatpic, atpic, val);
565		} else {
566			switch (atpic->icw_num) {
567			case 2:
568				error = vatpic_icw2(vatpic, atpic, val);
569				break;
570			case 3:
571				error = vatpic_icw3(vatpic, atpic, val);
572				break;
573			case 4:
574				error = vatpic_icw4(vatpic, atpic, val);
575				break;
576			}
577		}
578	} else {
579		if (val & (1 << 4))
580			error = vatpic_icw1(vatpic, atpic, val);
581
582		if (atpic->ready) {
583			if (val & (1 << 3))
584				error = vatpic_ocw3(vatpic, atpic, val);
585			else
586				error = vatpic_ocw2(vatpic, atpic, val);
587		}
588	}
589
590	if (atpic->ready)
591		vatpic_notify_intr(vatpic);
592
593	VATPIC_UNLOCK(vatpic);
594
595	return (error);
596}
597
598int
599vatpic_master_handler(void *vm, int vcpuid, bool in, int port, int bytes,
600    uint32_t *eax)
601{
602	struct vatpic *vatpic;
603	struct atpic *atpic;
604
605	vatpic = vm_atpic(vm);
606	atpic = &vatpic->atpic[0];
607
608	if (bytes != 1)
609		return (-1);
610
611	if (in) {
612		return (vatpic_read(vatpic, atpic, in, port, bytes, eax));
613	}
614
615	return (vatpic_write(vatpic, atpic, in, port, bytes, eax));
616}
617
618int
619vatpic_slave_handler(void *vm, int vcpuid, bool in, int port, int bytes,
620    uint32_t *eax)
621{
622	struct vatpic *vatpic;
623	struct atpic *atpic;
624
625	vatpic = vm_atpic(vm);
626	atpic = &vatpic->atpic[1];
627
628	if (bytes != 1)
629		return (-1);
630
631	if (in) {
632		return (vatpic_read(vatpic, atpic, in, port, bytes, eax));
633	}
634
635	return (vatpic_write(vatpic, atpic, in, port, bytes, eax));
636}
637
638int
639vatpic_elc_handler(void *vm, int vcpuid, bool in, int port, int bytes,
640    uint32_t *eax)
641{
642	struct vatpic *vatpic;
643	bool is_master;
644
645	vatpic = vm_atpic(vm);
646	is_master = (port == IO_ELCR1);
647
648	if (bytes != 1)
649		return (-1);
650
651	VATPIC_LOCK(vatpic);
652
653	if (in) {
654		if (is_master)
655			*eax = vatpic->elc[0];
656		else
657			*eax = vatpic->elc[1];
658	} else {
659		/*
660		 * For the master PIC the cascade channel (IRQ2), the
661		 * heart beat timer (IRQ0), and the keyboard
662		 * controller (IRQ1) cannot be programmed for level
663		 * mode.
664		 *
665		 * For the slave PIC the real time clock (IRQ8) and
666		 * the floating point error interrupt (IRQ13) cannot
667		 * be programmed for level mode.
668		 */
669		if (is_master)
670			vatpic->elc[0] = (*eax & 0xf8);
671		else
672			vatpic->elc[1] = (*eax & 0xde);
673	}
674
675	VATPIC_UNLOCK(vatpic);
676
677	return (0);
678}
679
680struct vatpic *
681vatpic_init(struct vm *vm)
682{
683	struct vatpic *vatpic;
684
685	vatpic = malloc(sizeof(struct vatpic), M_VATPIC, M_WAITOK | M_ZERO);
686	vatpic->vm = vm;
687
688	mtx_init(&vatpic->mtx, "vatpic lock", NULL, MTX_SPIN);
689
690	return (vatpic);
691}
692
693void
694vatpic_cleanup(struct vatpic *vatpic)
695{
696	free(vatpic, M_VATPIC);
697}
698