1 /*
2 * 8253/8254 interval timer emulation
3 *
4 * Copyright (c) 2003-2004 Fabrice Bellard
5 * Copyright (c) 2006 Intel Corporation
6 * Copyright (c) 2007 Keir Fraser, XenSource Inc
7 * Copyright (c) 2008 Intel Corporation
8 * Copyright 2009 Red Hat, Inc. and/or its affiliates.
9 *
10 * Permission is hereby granted, free of charge, to any person obtaining a copy
11 * of this software and associated documentation files (the "Software"), to deal
12 * in the Software without restriction, including without limitation the rights
13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14 * copies of the Software, and to permit persons to whom the Software is
15 * furnished to do so, subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26 * THE SOFTWARE.
27 *
28 * Authors:
29 * Sheng Yang <sheng.yang@intel.com>
30 * Based on QEMU and Xen.
31 */
32
33 #define pr_fmt(fmt) "pit: " fmt
34
35 #include <linux/kvm_host.h>
36 #include <linux/slab.h>
37 #include <linux/workqueue.h>
38
39 #include "irq.h"
40 #include "i8254.h"
41
42 #ifndef CONFIG_X86_64
43 #define mod_64(x, y) ((x) - (y) * div64_u64(x, y))
44 #else
45 #define mod_64(x, y) ((x) % (y))
46 #endif
47
48 #define RW_STATE_LSB 1
49 #define RW_STATE_MSB 2
50 #define RW_STATE_WORD0 3
51 #define RW_STATE_WORD1 4
52
53 /* Compute with 96 bit intermediate result: (a*b)/c */
muldiv64(u64 a,u32 b,u32 c)54 static u64 muldiv64(u64 a, u32 b, u32 c)
55 {
56 union {
57 u64 ll;
58 struct {
59 u32 low, high;
60 } l;
61 } u, res;
62 u64 rl, rh;
63
64 u.ll = a;
65 rl = (u64)u.l.low * (u64)b;
66 rh = (u64)u.l.high * (u64)b;
67 rh += (rl >> 32);
68 res.l.high = div64_u64(rh, c);
69 res.l.low = div64_u64(((mod_64(rh, c) << 32) + (rl & 0xffffffff)), c);
70 return res.ll;
71 }
72
pit_set_gate(struct kvm * kvm,int channel,u32 val)73 static void pit_set_gate(struct kvm *kvm, int channel, u32 val)
74 {
75 struct kvm_kpit_channel_state *c =
76 &kvm->arch.vpit->pit_state.channels[channel];
77
78 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
79
80 switch (c->mode) {
81 default:
82 case 0:
83 case 4:
84 /* XXX: just disable/enable counting */
85 break;
86 case 1:
87 case 2:
88 case 3:
89 case 5:
90 /* Restart counting on rising edge. */
91 if (c->gate < val)
92 c->count_load_time = ktime_get();
93 break;
94 }
95
96 c->gate = val;
97 }
98
pit_get_gate(struct kvm * kvm,int channel)99 static int pit_get_gate(struct kvm *kvm, int channel)
100 {
101 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
102
103 return kvm->arch.vpit->pit_state.channels[channel].gate;
104 }
105
__kpit_elapsed(struct kvm * kvm)106 static s64 __kpit_elapsed(struct kvm *kvm)
107 {
108 s64 elapsed;
109 ktime_t remaining;
110 struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
111
112 if (!ps->pit_timer.period)
113 return 0;
114
115 /*
116 * The Counter does not stop when it reaches zero. In
117 * Modes 0, 1, 4, and 5 the Counter ``wraps around'' to
118 * the highest count, either FFFF hex for binary counting
119 * or 9999 for BCD counting, and continues counting.
120 * Modes 2 and 3 are periodic; the Counter reloads
121 * itself with the initial count and continues counting
122 * from there.
123 */
124 remaining = hrtimer_get_remaining(&ps->pit_timer.timer);
125 elapsed = ps->pit_timer.period - ktime_to_ns(remaining);
126 elapsed = mod_64(elapsed, ps->pit_timer.period);
127
128 return elapsed;
129 }
130
kpit_elapsed(struct kvm * kvm,struct kvm_kpit_channel_state * c,int channel)131 static s64 kpit_elapsed(struct kvm *kvm, struct kvm_kpit_channel_state *c,
132 int channel)
133 {
134 if (channel == 0)
135 return __kpit_elapsed(kvm);
136
137 return ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time));
138 }
139
pit_get_count(struct kvm * kvm,int channel)140 static int pit_get_count(struct kvm *kvm, int channel)
141 {
142 struct kvm_kpit_channel_state *c =
143 &kvm->arch.vpit->pit_state.channels[channel];
144 s64 d, t;
145 int counter;
146
147 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
148
149 t = kpit_elapsed(kvm, c, channel);
150 d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
151
152 switch (c->mode) {
153 case 0:
154 case 1:
155 case 4:
156 case 5:
157 counter = (c->count - d) & 0xffff;
158 break;
159 case 3:
160 /* XXX: may be incorrect for odd counts */
161 counter = c->count - (mod_64((2 * d), c->count));
162 break;
163 default:
164 counter = c->count - mod_64(d, c->count);
165 break;
166 }
167 return counter;
168 }
169
pit_get_out(struct kvm * kvm,int channel)170 static int pit_get_out(struct kvm *kvm, int channel)
171 {
172 struct kvm_kpit_channel_state *c =
173 &kvm->arch.vpit->pit_state.channels[channel];
174 s64 d, t;
175 int out;
176
177 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
178
179 t = kpit_elapsed(kvm, c, channel);
180 d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
181
182 switch (c->mode) {
183 default:
184 case 0:
185 out = (d >= c->count);
186 break;
187 case 1:
188 out = (d < c->count);
189 break;
190 case 2:
191 out = ((mod_64(d, c->count) == 0) && (d != 0));
192 break;
193 case 3:
194 out = (mod_64(d, c->count) < ((c->count + 1) >> 1));
195 break;
196 case 4:
197 case 5:
198 out = (d == c->count);
199 break;
200 }
201
202 return out;
203 }
204
pit_latch_count(struct kvm * kvm,int channel)205 static void pit_latch_count(struct kvm *kvm, int channel)
206 {
207 struct kvm_kpit_channel_state *c =
208 &kvm->arch.vpit->pit_state.channels[channel];
209
210 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
211
212 if (!c->count_latched) {
213 c->latched_count = pit_get_count(kvm, channel);
214 c->count_latched = c->rw_mode;
215 }
216 }
217
pit_latch_status(struct kvm * kvm,int channel)218 static void pit_latch_status(struct kvm *kvm, int channel)
219 {
220 struct kvm_kpit_channel_state *c =
221 &kvm->arch.vpit->pit_state.channels[channel];
222
223 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
224
225 if (!c->status_latched) {
226 /* TODO: Return NULL COUNT (bit 6). */
227 c->status = ((pit_get_out(kvm, channel) << 7) |
228 (c->rw_mode << 4) |
229 (c->mode << 1) |
230 c->bcd);
231 c->status_latched = 1;
232 }
233 }
234
kvm_pit_ack_irq(struct kvm_irq_ack_notifier * kian)235 static void kvm_pit_ack_irq(struct kvm_irq_ack_notifier *kian)
236 {
237 struct kvm_kpit_state *ps = container_of(kian, struct kvm_kpit_state,
238 irq_ack_notifier);
239 int value;
240
241 spin_lock(&ps->inject_lock);
242 value = atomic_dec_return(&ps->pit_timer.pending);
243 if (value < 0)
244 /* spurious acks can be generated if, for example, the
245 * PIC is being reset. Handle it gracefully here
246 */
247 atomic_inc(&ps->pit_timer.pending);
248 else if (value > 0)
249 /* in this case, we had multiple outstanding pit interrupts
250 * that we needed to inject. Reinject
251 */
252 queue_work(ps->pit->wq, &ps->pit->expired);
253 ps->irq_ack = 1;
254 spin_unlock(&ps->inject_lock);
255 }
256
__kvm_migrate_pit_timer(struct kvm_vcpu * vcpu)257 void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu)
258 {
259 struct kvm_pit *pit = vcpu->kvm->arch.vpit;
260 struct hrtimer *timer;
261
262 if (!kvm_vcpu_is_bsp(vcpu) || !pit)
263 return;
264
265 timer = &pit->pit_state.pit_timer.timer;
266 if (hrtimer_cancel(timer))
267 hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
268 }
269
destroy_pit_timer(struct kvm_pit * pit)270 static void destroy_pit_timer(struct kvm_pit *pit)
271 {
272 hrtimer_cancel(&pit->pit_state.pit_timer.timer);
273 cancel_work_sync(&pit->expired);
274 }
275
kpit_is_periodic(struct kvm_timer * ktimer)276 static bool kpit_is_periodic(struct kvm_timer *ktimer)
277 {
278 struct kvm_kpit_state *ps = container_of(ktimer, struct kvm_kpit_state,
279 pit_timer);
280 return ps->is_periodic;
281 }
282
283 static struct kvm_timer_ops kpit_ops = {
284 .is_periodic = kpit_is_periodic,
285 };
286
pit_do_work(struct work_struct * work)287 static void pit_do_work(struct work_struct *work)
288 {
289 struct kvm_pit *pit = container_of(work, struct kvm_pit, expired);
290 struct kvm *kvm = pit->kvm;
291 struct kvm_vcpu *vcpu;
292 int i;
293 struct kvm_kpit_state *ps = &pit->pit_state;
294 int inject = 0;
295
296 /* Try to inject pending interrupts when
297 * last one has been acked.
298 */
299 spin_lock(&ps->inject_lock);
300 if (ps->irq_ack) {
301 ps->irq_ack = 0;
302 inject = 1;
303 }
304 spin_unlock(&ps->inject_lock);
305 if (inject) {
306 kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1);
307 kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0);
308
309 /*
310 * Provides NMI watchdog support via Virtual Wire mode.
311 * The route is: PIT -> PIC -> LVT0 in NMI mode.
312 *
313 * Note: Our Virtual Wire implementation is simplified, only
314 * propagating PIT interrupts to all VCPUs when they have set
315 * LVT0 to NMI delivery. Other PIC interrupts are just sent to
316 * VCPU0, and only if its LVT0 is in EXTINT mode.
317 */
318 if (kvm->arch.vapics_in_nmi_mode > 0)
319 kvm_for_each_vcpu(i, vcpu, kvm)
320 kvm_apic_nmi_wd_deliver(vcpu);
321 }
322 }
323
pit_timer_fn(struct hrtimer * data)324 static enum hrtimer_restart pit_timer_fn(struct hrtimer *data)
325 {
326 struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);
327 struct kvm_pit *pt = ktimer->kvm->arch.vpit;
328
329 if (ktimer->reinject || !atomic_read(&ktimer->pending)) {
330 atomic_inc(&ktimer->pending);
331 queue_work(pt->wq, &pt->expired);
332 }
333
334 if (ktimer->t_ops->is_periodic(ktimer)) {
335 hrtimer_add_expires_ns(&ktimer->timer, ktimer->period);
336 return HRTIMER_RESTART;
337 } else
338 return HRTIMER_NORESTART;
339 }
340
create_pit_timer(struct kvm * kvm,u32 val,int is_period)341 static void create_pit_timer(struct kvm *kvm, u32 val, int is_period)
342 {
343 struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
344 struct kvm_timer *pt = &ps->pit_timer;
345 s64 interval;
346
347 if (!irqchip_in_kernel(kvm) || ps->flags & KVM_PIT_FLAGS_HPET_LEGACY)
348 return;
349
350 interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ);
351
352 pr_debug("create pit timer, interval is %llu nsec\n", interval);
353
354 /* TODO The new value only affected after the retriggered */
355 hrtimer_cancel(&pt->timer);
356 cancel_work_sync(&ps->pit->expired);
357 pt->period = interval;
358 ps->is_periodic = is_period;
359
360 pt->timer.function = pit_timer_fn;
361 pt->t_ops = &kpit_ops;
362 pt->kvm = ps->pit->kvm;
363
364 atomic_set(&pt->pending, 0);
365 ps->irq_ack = 1;
366
367 hrtimer_start(&pt->timer, ktime_add_ns(ktime_get(), interval),
368 HRTIMER_MODE_ABS);
369 }
370
pit_load_count(struct kvm * kvm,int channel,u32 val)371 static void pit_load_count(struct kvm *kvm, int channel, u32 val)
372 {
373 struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
374
375 WARN_ON(!mutex_is_locked(&ps->lock));
376
377 pr_debug("load_count val is %d, channel is %d\n", val, channel);
378
379 /*
380 * The largest possible initial count is 0; this is equivalent
381 * to 216 for binary counting and 104 for BCD counting.
382 */
383 if (val == 0)
384 val = 0x10000;
385
386 ps->channels[channel].count = val;
387
388 if (channel != 0) {
389 ps->channels[channel].count_load_time = ktime_get();
390 return;
391 }
392
393 /* Two types of timer
394 * mode 1 is one shot, mode 2 is period, otherwise del timer */
395 switch (ps->channels[0].mode) {
396 case 0:
397 case 1:
398 /* FIXME: enhance mode 4 precision */
399 case 4:
400 create_pit_timer(kvm, val, 0);
401 break;
402 case 2:
403 case 3:
404 create_pit_timer(kvm, val, 1);
405 break;
406 default:
407 destroy_pit_timer(kvm->arch.vpit);
408 }
409 }
410
kvm_pit_load_count(struct kvm * kvm,int channel,u32 val,int hpet_legacy_start)411 void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_start)
412 {
413 u8 saved_mode;
414 if (hpet_legacy_start) {
415 /* save existing mode for later reenablement */
416 saved_mode = kvm->arch.vpit->pit_state.channels[0].mode;
417 kvm->arch.vpit->pit_state.channels[0].mode = 0xff; /* disable timer */
418 pit_load_count(kvm, channel, val);
419 kvm->arch.vpit->pit_state.channels[0].mode = saved_mode;
420 } else {
421 pit_load_count(kvm, channel, val);
422 }
423 }
424
dev_to_pit(struct kvm_io_device * dev)425 static inline struct kvm_pit *dev_to_pit(struct kvm_io_device *dev)
426 {
427 return container_of(dev, struct kvm_pit, dev);
428 }
429
speaker_to_pit(struct kvm_io_device * dev)430 static inline struct kvm_pit *speaker_to_pit(struct kvm_io_device *dev)
431 {
432 return container_of(dev, struct kvm_pit, speaker_dev);
433 }
434
pit_in_range(gpa_t addr)435 static inline int pit_in_range(gpa_t addr)
436 {
437 return ((addr >= KVM_PIT_BASE_ADDRESS) &&
438 (addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH));
439 }
440
pit_ioport_write(struct kvm_io_device * this,gpa_t addr,int len,const void * data)441 static int pit_ioport_write(struct kvm_io_device *this,
442 gpa_t addr, int len, const void *data)
443 {
444 struct kvm_pit *pit = dev_to_pit(this);
445 struct kvm_kpit_state *pit_state = &pit->pit_state;
446 struct kvm *kvm = pit->kvm;
447 int channel, access;
448 struct kvm_kpit_channel_state *s;
449 u32 val = *(u32 *) data;
450 if (!pit_in_range(addr))
451 return -EOPNOTSUPP;
452
453 val &= 0xff;
454 addr &= KVM_PIT_CHANNEL_MASK;
455
456 mutex_lock(&pit_state->lock);
457
458 if (val != 0)
459 pr_debug("write addr is 0x%x, len is %d, val is 0x%x\n",
460 (unsigned int)addr, len, val);
461
462 if (addr == 3) {
463 channel = val >> 6;
464 if (channel == 3) {
465 /* Read-Back Command. */
466 for (channel = 0; channel < 3; channel++) {
467 s = &pit_state->channels[channel];
468 if (val & (2 << channel)) {
469 if (!(val & 0x20))
470 pit_latch_count(kvm, channel);
471 if (!(val & 0x10))
472 pit_latch_status(kvm, channel);
473 }
474 }
475 } else {
476 /* Select Counter <channel>. */
477 s = &pit_state->channels[channel];
478 access = (val >> 4) & KVM_PIT_CHANNEL_MASK;
479 if (access == 0) {
480 pit_latch_count(kvm, channel);
481 } else {
482 s->rw_mode = access;
483 s->read_state = access;
484 s->write_state = access;
485 s->mode = (val >> 1) & 7;
486 if (s->mode > 5)
487 s->mode -= 4;
488 s->bcd = val & 1;
489 }
490 }
491 } else {
492 /* Write Count. */
493 s = &pit_state->channels[addr];
494 switch (s->write_state) {
495 default:
496 case RW_STATE_LSB:
497 pit_load_count(kvm, addr, val);
498 break;
499 case RW_STATE_MSB:
500 pit_load_count(kvm, addr, val << 8);
501 break;
502 case RW_STATE_WORD0:
503 s->write_latch = val;
504 s->write_state = RW_STATE_WORD1;
505 break;
506 case RW_STATE_WORD1:
507 pit_load_count(kvm, addr, s->write_latch | (val << 8));
508 s->write_state = RW_STATE_WORD0;
509 break;
510 }
511 }
512
513 mutex_unlock(&pit_state->lock);
514 return 0;
515 }
516
pit_ioport_read(struct kvm_io_device * this,gpa_t addr,int len,void * data)517 static int pit_ioport_read(struct kvm_io_device *this,
518 gpa_t addr, int len, void *data)
519 {
520 struct kvm_pit *pit = dev_to_pit(this);
521 struct kvm_kpit_state *pit_state = &pit->pit_state;
522 struct kvm *kvm = pit->kvm;
523 int ret, count;
524 struct kvm_kpit_channel_state *s;
525 if (!pit_in_range(addr))
526 return -EOPNOTSUPP;
527
528 addr &= KVM_PIT_CHANNEL_MASK;
529 if (addr == 3)
530 return 0;
531
532 s = &pit_state->channels[addr];
533
534 mutex_lock(&pit_state->lock);
535
536 if (s->status_latched) {
537 s->status_latched = 0;
538 ret = s->status;
539 } else if (s->count_latched) {
540 switch (s->count_latched) {
541 default:
542 case RW_STATE_LSB:
543 ret = s->latched_count & 0xff;
544 s->count_latched = 0;
545 break;
546 case RW_STATE_MSB:
547 ret = s->latched_count >> 8;
548 s->count_latched = 0;
549 break;
550 case RW_STATE_WORD0:
551 ret = s->latched_count & 0xff;
552 s->count_latched = RW_STATE_MSB;
553 break;
554 }
555 } else {
556 switch (s->read_state) {
557 default:
558 case RW_STATE_LSB:
559 count = pit_get_count(kvm, addr);
560 ret = count & 0xff;
561 break;
562 case RW_STATE_MSB:
563 count = pit_get_count(kvm, addr);
564 ret = (count >> 8) & 0xff;
565 break;
566 case RW_STATE_WORD0:
567 count = pit_get_count(kvm, addr);
568 ret = count & 0xff;
569 s->read_state = RW_STATE_WORD1;
570 break;
571 case RW_STATE_WORD1:
572 count = pit_get_count(kvm, addr);
573 ret = (count >> 8) & 0xff;
574 s->read_state = RW_STATE_WORD0;
575 break;
576 }
577 }
578
579 if (len > sizeof(ret))
580 len = sizeof(ret);
581 memcpy(data, (char *)&ret, len);
582
583 mutex_unlock(&pit_state->lock);
584 return 0;
585 }
586
speaker_ioport_write(struct kvm_io_device * this,gpa_t addr,int len,const void * data)587 static int speaker_ioport_write(struct kvm_io_device *this,
588 gpa_t addr, int len, const void *data)
589 {
590 struct kvm_pit *pit = speaker_to_pit(this);
591 struct kvm_kpit_state *pit_state = &pit->pit_state;
592 struct kvm *kvm = pit->kvm;
593 u32 val = *(u32 *) data;
594 if (addr != KVM_SPEAKER_BASE_ADDRESS)
595 return -EOPNOTSUPP;
596
597 mutex_lock(&pit_state->lock);
598 pit_state->speaker_data_on = (val >> 1) & 1;
599 pit_set_gate(kvm, 2, val & 1);
600 mutex_unlock(&pit_state->lock);
601 return 0;
602 }
603
speaker_ioport_read(struct kvm_io_device * this,gpa_t addr,int len,void * data)604 static int speaker_ioport_read(struct kvm_io_device *this,
605 gpa_t addr, int len, void *data)
606 {
607 struct kvm_pit *pit = speaker_to_pit(this);
608 struct kvm_kpit_state *pit_state = &pit->pit_state;
609 struct kvm *kvm = pit->kvm;
610 unsigned int refresh_clock;
611 int ret;
612 if (addr != KVM_SPEAKER_BASE_ADDRESS)
613 return -EOPNOTSUPP;
614
615 /* Refresh clock toggles at about 15us. We approximate as 2^14ns. */
616 refresh_clock = ((unsigned int)ktime_to_ns(ktime_get()) >> 14) & 1;
617
618 mutex_lock(&pit_state->lock);
619 ret = ((pit_state->speaker_data_on << 1) | pit_get_gate(kvm, 2) |
620 (pit_get_out(kvm, 2) << 5) | (refresh_clock << 4));
621 if (len > sizeof(ret))
622 len = sizeof(ret);
623 memcpy(data, (char *)&ret, len);
624 mutex_unlock(&pit_state->lock);
625 return 0;
626 }
627
kvm_pit_reset(struct kvm_pit * pit)628 void kvm_pit_reset(struct kvm_pit *pit)
629 {
630 int i;
631 struct kvm_kpit_channel_state *c;
632
633 mutex_lock(&pit->pit_state.lock);
634 pit->pit_state.flags = 0;
635 for (i = 0; i < 3; i++) {
636 c = &pit->pit_state.channels[i];
637 c->mode = 0xff;
638 c->gate = (i != 2);
639 pit_load_count(pit->kvm, i, 0);
640 }
641 mutex_unlock(&pit->pit_state.lock);
642
643 atomic_set(&pit->pit_state.pit_timer.pending, 0);
644 pit->pit_state.irq_ack = 1;
645 }
646
pit_mask_notifer(struct kvm_irq_mask_notifier * kimn,bool mask)647 static void pit_mask_notifer(struct kvm_irq_mask_notifier *kimn, bool mask)
648 {
649 struct kvm_pit *pit = container_of(kimn, struct kvm_pit, mask_notifier);
650
651 if (!mask) {
652 atomic_set(&pit->pit_state.pit_timer.pending, 0);
653 pit->pit_state.irq_ack = 1;
654 }
655 }
656
657 static const struct kvm_io_device_ops pit_dev_ops = {
658 .read = pit_ioport_read,
659 .write = pit_ioport_write,
660 };
661
662 static const struct kvm_io_device_ops speaker_dev_ops = {
663 .read = speaker_ioport_read,
664 .write = speaker_ioport_write,
665 };
666
667 /* Caller must hold slots_lock */
kvm_create_pit(struct kvm * kvm,u32 flags)668 struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags)
669 {
670 struct kvm_pit *pit;
671 struct kvm_kpit_state *pit_state;
672 int ret;
673
674 pit = kzalloc(sizeof(struct kvm_pit), GFP_KERNEL);
675 if (!pit)
676 return NULL;
677
678 pit->irq_source_id = kvm_request_irq_source_id(kvm);
679 if (pit->irq_source_id < 0) {
680 kfree(pit);
681 return NULL;
682 }
683
684 mutex_init(&pit->pit_state.lock);
685 mutex_lock(&pit->pit_state.lock);
686 spin_lock_init(&pit->pit_state.inject_lock);
687
688 pit->wq = create_singlethread_workqueue("kvm-pit-wq");
689 if (!pit->wq) {
690 mutex_unlock(&pit->pit_state.lock);
691 kvm_free_irq_source_id(kvm, pit->irq_source_id);
692 kfree(pit);
693 return NULL;
694 }
695 INIT_WORK(&pit->expired, pit_do_work);
696
697 kvm->arch.vpit = pit;
698 pit->kvm = kvm;
699
700 pit_state = &pit->pit_state;
701 pit_state->pit = pit;
702 hrtimer_init(&pit_state->pit_timer.timer,
703 CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
704 pit_state->irq_ack_notifier.gsi = 0;
705 pit_state->irq_ack_notifier.irq_acked = kvm_pit_ack_irq;
706 kvm_register_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier);
707 pit_state->pit_timer.reinject = true;
708 mutex_unlock(&pit->pit_state.lock);
709
710 kvm_pit_reset(pit);
711
712 pit->mask_notifier.func = pit_mask_notifer;
713 kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier);
714
715 kvm_iodevice_init(&pit->dev, &pit_dev_ops);
716 ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, KVM_PIT_BASE_ADDRESS,
717 KVM_PIT_MEM_LENGTH, &pit->dev);
718 if (ret < 0)
719 goto fail;
720
721 if (flags & KVM_PIT_SPEAKER_DUMMY) {
722 kvm_iodevice_init(&pit->speaker_dev, &speaker_dev_ops);
723 ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS,
724 KVM_SPEAKER_BASE_ADDRESS, 4,
725 &pit->speaker_dev);
726 if (ret < 0)
727 goto fail_unregister;
728 }
729
730 return pit;
731
732 fail_unregister:
733 kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &pit->dev);
734
735 fail:
736 kvm_unregister_irq_mask_notifier(kvm, 0, &pit->mask_notifier);
737 kvm_unregister_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier);
738 kvm_free_irq_source_id(kvm, pit->irq_source_id);
739 destroy_workqueue(pit->wq);
740 kfree(pit);
741 return NULL;
742 }
743
kvm_free_pit(struct kvm * kvm)744 void kvm_free_pit(struct kvm *kvm)
745 {
746 struct hrtimer *timer;
747
748 if (kvm->arch.vpit) {
749 kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &kvm->arch.vpit->dev);
750 kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS,
751 &kvm->arch.vpit->speaker_dev);
752 kvm_unregister_irq_mask_notifier(kvm, 0,
753 &kvm->arch.vpit->mask_notifier);
754 kvm_unregister_irq_ack_notifier(kvm,
755 &kvm->arch.vpit->pit_state.irq_ack_notifier);
756 mutex_lock(&kvm->arch.vpit->pit_state.lock);
757 timer = &kvm->arch.vpit->pit_state.pit_timer.timer;
758 hrtimer_cancel(timer);
759 cancel_work_sync(&kvm->arch.vpit->expired);
760 kvm_free_irq_source_id(kvm, kvm->arch.vpit->irq_source_id);
761 mutex_unlock(&kvm->arch.vpit->pit_state.lock);
762 destroy_workqueue(kvm->arch.vpit->wq);
763 kfree(kvm->arch.vpit);
764 }
765 }
766