KVM: Rename VCPU_MP_STATE_* to KVM_MP_STATE_*
[linux-2.6.git] / arch / x86 / kvm / i8254.c
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  *
9  * Permission is hereby granted, free of charge, to any person obtaining a copy
10  * of this software and associated documentation files (the "Software"), to deal
11  * in the Software without restriction, including without limitation the rights
12  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13  * copies of the Software, and to permit persons to whom the Software is
14  * furnished to do so, subject to the following conditions:
15  *
16  * The above copyright notice and this permission notice shall be included in
17  * all copies or substantial portions of the Software.
18  *
19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25  * THE SOFTWARE.
26  *
27  * Authors:
28  *   Sheng Yang <sheng.yang@intel.com>
29  *   Based on QEMU and Xen.
30  */
31
32 #include <linux/kvm_host.h>
33
34 #include "irq.h"
35 #include "i8254.h"
36
37 #ifndef CONFIG_X86_64
38 #define mod_64(x, y) ((x) - (y) * div64_64(x, y))
39 #else
40 #define mod_64(x, y) ((x) % (y))
41 #endif
42
43 #define RW_STATE_LSB 1
44 #define RW_STATE_MSB 2
45 #define RW_STATE_WORD0 3
46 #define RW_STATE_WORD1 4
47
48 /* Compute with 96 bit intermediate result: (a*b)/c */
49 static u64 muldiv64(u64 a, u32 b, u32 c)
50 {
51         union {
52                 u64 ll;
53                 struct {
54                         u32 low, high;
55                 } l;
56         } u, res;
57         u64 rl, rh;
58
59         u.ll = a;
60         rl = (u64)u.l.low * (u64)b;
61         rh = (u64)u.l.high * (u64)b;
62         rh += (rl >> 32);
63         res.l.high = div64_64(rh, c);
64         res.l.low = div64_64(((mod_64(rh, c) << 32) + (rl & 0xffffffff)), c);
65         return res.ll;
66 }
67
68 static void pit_set_gate(struct kvm *kvm, int channel, u32 val)
69 {
70         struct kvm_kpit_channel_state *c =
71                 &kvm->arch.vpit->pit_state.channels[channel];
72
73         WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
74
75         switch (c->mode) {
76         default:
77         case 0:
78         case 4:
79                 /* XXX: just disable/enable counting */
80                 break;
81         case 1:
82         case 2:
83         case 3:
84         case 5:
85                 /* Restart counting on rising edge. */
86                 if (c->gate < val)
87                         c->count_load_time = ktime_get();
88                 break;
89         }
90
91         c->gate = val;
92 }
93
94 int pit_get_gate(struct kvm *kvm, int channel)
95 {
96         WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
97
98         return kvm->arch.vpit->pit_state.channels[channel].gate;
99 }
100
101 static int pit_get_count(struct kvm *kvm, int channel)
102 {
103         struct kvm_kpit_channel_state *c =
104                 &kvm->arch.vpit->pit_state.channels[channel];
105         s64 d, t;
106         int counter;
107
108         WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
109
110         t = ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time));
111         d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
112
113         switch (c->mode) {
114         case 0:
115         case 1:
116         case 4:
117         case 5:
118                 counter = (c->count - d) & 0xffff;
119                 break;
120         case 3:
121                 /* XXX: may be incorrect for odd counts */
122                 counter = c->count - (mod_64((2 * d), c->count));
123                 break;
124         default:
125                 counter = c->count - mod_64(d, c->count);
126                 break;
127         }
128         return counter;
129 }
130
131 static int pit_get_out(struct kvm *kvm, int channel)
132 {
133         struct kvm_kpit_channel_state *c =
134                 &kvm->arch.vpit->pit_state.channels[channel];
135         s64 d, t;
136         int out;
137
138         WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
139
140         t = ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time));
141         d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
142
143         switch (c->mode) {
144         default:
145         case 0:
146                 out = (d >= c->count);
147                 break;
148         case 1:
149                 out = (d < c->count);
150                 break;
151         case 2:
152                 out = ((mod_64(d, c->count) == 0) && (d != 0));
153                 break;
154         case 3:
155                 out = (mod_64(d, c->count) < ((c->count + 1) >> 1));
156                 break;
157         case 4:
158         case 5:
159                 out = (d == c->count);
160                 break;
161         }
162
163         return out;
164 }
165
166 static void pit_latch_count(struct kvm *kvm, int channel)
167 {
168         struct kvm_kpit_channel_state *c =
169                 &kvm->arch.vpit->pit_state.channels[channel];
170
171         WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
172
173         if (!c->count_latched) {
174                 c->latched_count = pit_get_count(kvm, channel);
175                 c->count_latched = c->rw_mode;
176         }
177 }
178
179 static void pit_latch_status(struct kvm *kvm, int channel)
180 {
181         struct kvm_kpit_channel_state *c =
182                 &kvm->arch.vpit->pit_state.channels[channel];
183
184         WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
185
186         if (!c->status_latched) {
187                 /* TODO: Return NULL COUNT (bit 6). */
188                 c->status = ((pit_get_out(kvm, channel) << 7) |
189                                 (c->rw_mode << 4) |
190                                 (c->mode << 1) |
191                                 c->bcd);
192                 c->status_latched = 1;
193         }
194 }
195
196 int __pit_timer_fn(struct kvm_kpit_state *ps)
197 {
198         struct kvm_vcpu *vcpu0 = ps->pit->kvm->vcpus[0];
199         struct kvm_kpit_timer *pt = &ps->pit_timer;
200
201         atomic_inc(&pt->pending);
202         smp_mb__after_atomic_inc();
203         /* FIXME: handle case where the guest is in guest mode */
204         if (vcpu0 && waitqueue_active(&vcpu0->wq)) {
205                 vcpu0->arch.mp_state = KVM_MP_STATE_RUNNABLE;
206                 wake_up_interruptible(&vcpu0->wq);
207         }
208
209         pt->timer.expires = ktime_add_ns(pt->timer.expires, pt->period);
210         pt->scheduled = ktime_to_ns(pt->timer.expires);
211
212         return (pt->period == 0 ? 0 : 1);
213 }
214
215 int pit_has_pending_timer(struct kvm_vcpu *vcpu)
216 {
217         struct kvm_pit *pit = vcpu->kvm->arch.vpit;
218
219         if (pit && vcpu->vcpu_id == 0)
220                 return atomic_read(&pit->pit_state.pit_timer.pending);
221
222         return 0;
223 }
224
225 static enum hrtimer_restart pit_timer_fn(struct hrtimer *data)
226 {
227         struct kvm_kpit_state *ps;
228         int restart_timer = 0;
229
230         ps = container_of(data, struct kvm_kpit_state, pit_timer.timer);
231
232         restart_timer = __pit_timer_fn(ps);
233
234         if (restart_timer)
235                 return HRTIMER_RESTART;
236         else
237                 return HRTIMER_NORESTART;
238 }
239
240 static void destroy_pit_timer(struct kvm_kpit_timer *pt)
241 {
242         pr_debug("pit: execute del timer!\n");
243         hrtimer_cancel(&pt->timer);
244 }
245
246 static void create_pit_timer(struct kvm_kpit_timer *pt, u32 val, int is_period)
247 {
248         s64 interval;
249
250         interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ);
251
252         pr_debug("pit: create pit timer, interval is %llu nsec\n", interval);
253
254         /* TODO The new value only affected after the retriggered */
255         hrtimer_cancel(&pt->timer);
256         pt->period = (is_period == 0) ? 0 : interval;
257         pt->timer.function = pit_timer_fn;
258         atomic_set(&pt->pending, 0);
259
260         hrtimer_start(&pt->timer, ktime_add_ns(ktime_get(), interval),
261                       HRTIMER_MODE_ABS);
262 }
263
264 static void pit_load_count(struct kvm *kvm, int channel, u32 val)
265 {
266         struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
267
268         WARN_ON(!mutex_is_locked(&ps->lock));
269
270         pr_debug("pit: load_count val is %d, channel is %d\n", val, channel);
271
272         /*
273          * Though spec said the state of 8254 is undefined after power-up,
274          * seems some tricky OS like Windows XP depends on IRQ0 interrupt
275          * when booting up.
276          * So here setting initialize rate for it, and not a specific number
277          */
278         if (val == 0)
279                 val = 0x10000;
280
281         ps->channels[channel].count_load_time = ktime_get();
282         ps->channels[channel].count = val;
283
284         if (channel != 0)
285                 return;
286
287         /* Two types of timer
288          * mode 1 is one shot, mode 2 is period, otherwise del timer */
289         switch (ps->channels[0].mode) {
290         case 1:
291                 create_pit_timer(&ps->pit_timer, val, 0);
292                 break;
293         case 2:
294                 create_pit_timer(&ps->pit_timer, val, 1);
295                 break;
296         default:
297                 destroy_pit_timer(&ps->pit_timer);
298         }
299 }
300
301 void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val)
302 {
303         mutex_lock(&kvm->arch.vpit->pit_state.lock);
304         pit_load_count(kvm, channel, val);
305         mutex_unlock(&kvm->arch.vpit->pit_state.lock);
306 }
307
308 static void pit_ioport_write(struct kvm_io_device *this,
309                              gpa_t addr, int len, const void *data)
310 {
311         struct kvm_pit *pit = (struct kvm_pit *)this->private;
312         struct kvm_kpit_state *pit_state = &pit->pit_state;
313         struct kvm *kvm = pit->kvm;
314         int channel, access;
315         struct kvm_kpit_channel_state *s;
316         u32 val = *(u32 *) data;
317
318         val  &= 0xff;
319         addr &= KVM_PIT_CHANNEL_MASK;
320
321         mutex_lock(&pit_state->lock);
322
323         if (val != 0)
324                 pr_debug("pit: write addr is 0x%x, len is %d, val is 0x%x\n",
325                           (unsigned int)addr, len, val);
326
327         if (addr == 3) {
328                 channel = val >> 6;
329                 if (channel == 3) {
330                         /* Read-Back Command. */
331                         for (channel = 0; channel < 3; channel++) {
332                                 s = &pit_state->channels[channel];
333                                 if (val & (2 << channel)) {
334                                         if (!(val & 0x20))
335                                                 pit_latch_count(kvm, channel);
336                                         if (!(val & 0x10))
337                                                 pit_latch_status(kvm, channel);
338                                 }
339                         }
340                 } else {
341                         /* Select Counter <channel>. */
342                         s = &pit_state->channels[channel];
343                         access = (val >> 4) & KVM_PIT_CHANNEL_MASK;
344                         if (access == 0) {
345                                 pit_latch_count(kvm, channel);
346                         } else {
347                                 s->rw_mode = access;
348                                 s->read_state = access;
349                                 s->write_state = access;
350                                 s->mode = (val >> 1) & 7;
351                                 if (s->mode > 5)
352                                         s->mode -= 4;
353                                 s->bcd = val & 1;
354                         }
355                 }
356         } else {
357                 /* Write Count. */
358                 s = &pit_state->channels[addr];
359                 switch (s->write_state) {
360                 default:
361                 case RW_STATE_LSB:
362                         pit_load_count(kvm, addr, val);
363                         break;
364                 case RW_STATE_MSB:
365                         pit_load_count(kvm, addr, val << 8);
366                         break;
367                 case RW_STATE_WORD0:
368                         s->write_latch = val;
369                         s->write_state = RW_STATE_WORD1;
370                         break;
371                 case RW_STATE_WORD1:
372                         pit_load_count(kvm, addr, s->write_latch | (val << 8));
373                         s->write_state = RW_STATE_WORD0;
374                         break;
375                 }
376         }
377
378         mutex_unlock(&pit_state->lock);
379 }
380
381 static void pit_ioport_read(struct kvm_io_device *this,
382                             gpa_t addr, int len, void *data)
383 {
384         struct kvm_pit *pit = (struct kvm_pit *)this->private;
385         struct kvm_kpit_state *pit_state = &pit->pit_state;
386         struct kvm *kvm = pit->kvm;
387         int ret, count;
388         struct kvm_kpit_channel_state *s;
389
390         addr &= KVM_PIT_CHANNEL_MASK;
391         s = &pit_state->channels[addr];
392
393         mutex_lock(&pit_state->lock);
394
395         if (s->status_latched) {
396                 s->status_latched = 0;
397                 ret = s->status;
398         } else if (s->count_latched) {
399                 switch (s->count_latched) {
400                 default:
401                 case RW_STATE_LSB:
402                         ret = s->latched_count & 0xff;
403                         s->count_latched = 0;
404                         break;
405                 case RW_STATE_MSB:
406                         ret = s->latched_count >> 8;
407                         s->count_latched = 0;
408                         break;
409                 case RW_STATE_WORD0:
410                         ret = s->latched_count & 0xff;
411                         s->count_latched = RW_STATE_MSB;
412                         break;
413                 }
414         } else {
415                 switch (s->read_state) {
416                 default:
417                 case RW_STATE_LSB:
418                         count = pit_get_count(kvm, addr);
419                         ret = count & 0xff;
420                         break;
421                 case RW_STATE_MSB:
422                         count = pit_get_count(kvm, addr);
423                         ret = (count >> 8) & 0xff;
424                         break;
425                 case RW_STATE_WORD0:
426                         count = pit_get_count(kvm, addr);
427                         ret = count & 0xff;
428                         s->read_state = RW_STATE_WORD1;
429                         break;
430                 case RW_STATE_WORD1:
431                         count = pit_get_count(kvm, addr);
432                         ret = (count >> 8) & 0xff;
433                         s->read_state = RW_STATE_WORD0;
434                         break;
435                 }
436         }
437
438         if (len > sizeof(ret))
439                 len = sizeof(ret);
440         memcpy(data, (char *)&ret, len);
441
442         mutex_unlock(&pit_state->lock);
443 }
444
445 static int pit_in_range(struct kvm_io_device *this, gpa_t addr)
446 {
447         return ((addr >= KVM_PIT_BASE_ADDRESS) &&
448                 (addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH));
449 }
450
451 static void speaker_ioport_write(struct kvm_io_device *this,
452                                  gpa_t addr, int len, const void *data)
453 {
454         struct kvm_pit *pit = (struct kvm_pit *)this->private;
455         struct kvm_kpit_state *pit_state = &pit->pit_state;
456         struct kvm *kvm = pit->kvm;
457         u32 val = *(u32 *) data;
458
459         mutex_lock(&pit_state->lock);
460         pit_state->speaker_data_on = (val >> 1) & 1;
461         pit_set_gate(kvm, 2, val & 1);
462         mutex_unlock(&pit_state->lock);
463 }
464
465 static void speaker_ioport_read(struct kvm_io_device *this,
466                                 gpa_t addr, int len, void *data)
467 {
468         struct kvm_pit *pit = (struct kvm_pit *)this->private;
469         struct kvm_kpit_state *pit_state = &pit->pit_state;
470         struct kvm *kvm = pit->kvm;
471         unsigned int refresh_clock;
472         int ret;
473
474         /* Refresh clock toggles at about 15us. We approximate as 2^14ns. */
475         refresh_clock = ((unsigned int)ktime_to_ns(ktime_get()) >> 14) & 1;
476
477         mutex_lock(&pit_state->lock);
478         ret = ((pit_state->speaker_data_on << 1) | pit_get_gate(kvm, 2) |
479                 (pit_get_out(kvm, 2) << 5) | (refresh_clock << 4));
480         if (len > sizeof(ret))
481                 len = sizeof(ret);
482         memcpy(data, (char *)&ret, len);
483         mutex_unlock(&pit_state->lock);
484 }
485
486 static int speaker_in_range(struct kvm_io_device *this, gpa_t addr)
487 {
488         return (addr == KVM_SPEAKER_BASE_ADDRESS);
489 }
490
491 void kvm_pit_reset(struct kvm_pit *pit)
492 {
493         int i;
494         struct kvm_kpit_channel_state *c;
495
496         mutex_lock(&pit->pit_state.lock);
497         for (i = 0; i < 3; i++) {
498                 c = &pit->pit_state.channels[i];
499                 c->mode = 0xff;
500                 c->gate = (i != 2);
501                 pit_load_count(pit->kvm, i, 0);
502         }
503         mutex_unlock(&pit->pit_state.lock);
504
505         atomic_set(&pit->pit_state.pit_timer.pending, 0);
506         pit->pit_state.inject_pending = 1;
507 }
508
509 struct kvm_pit *kvm_create_pit(struct kvm *kvm)
510 {
511         struct kvm_pit *pit;
512         struct kvm_kpit_state *pit_state;
513
514         pit = kzalloc(sizeof(struct kvm_pit), GFP_KERNEL);
515         if (!pit)
516                 return NULL;
517
518         mutex_init(&pit->pit_state.lock);
519         mutex_lock(&pit->pit_state.lock);
520
521         /* Initialize PIO device */
522         pit->dev.read = pit_ioport_read;
523         pit->dev.write = pit_ioport_write;
524         pit->dev.in_range = pit_in_range;
525         pit->dev.private = pit;
526         kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev);
527
528         pit->speaker_dev.read = speaker_ioport_read;
529         pit->speaker_dev.write = speaker_ioport_write;
530         pit->speaker_dev.in_range = speaker_in_range;
531         pit->speaker_dev.private = pit;
532         kvm_io_bus_register_dev(&kvm->pio_bus, &pit->speaker_dev);
533
534         kvm->arch.vpit = pit;
535         pit->kvm = kvm;
536
537         pit_state = &pit->pit_state;
538         pit_state->pit = pit;
539         hrtimer_init(&pit_state->pit_timer.timer,
540                      CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
541         mutex_unlock(&pit->pit_state.lock);
542
543         kvm_pit_reset(pit);
544
545         return pit;
546 }
547
548 void kvm_free_pit(struct kvm *kvm)
549 {
550         struct hrtimer *timer;
551
552         if (kvm->arch.vpit) {
553                 mutex_lock(&kvm->arch.vpit->pit_state.lock);
554                 timer = &kvm->arch.vpit->pit_state.pit_timer.timer;
555                 hrtimer_cancel(timer);
556                 mutex_unlock(&kvm->arch.vpit->pit_state.lock);
557                 kfree(kvm->arch.vpit);
558         }
559 }
560
561 void __inject_pit_timer_intr(struct kvm *kvm)
562 {
563         mutex_lock(&kvm->lock);
564         kvm_ioapic_set_irq(kvm->arch.vioapic, 0, 1);
565         kvm_ioapic_set_irq(kvm->arch.vioapic, 0, 0);
566         kvm_pic_set_irq(pic_irqchip(kvm), 0, 1);
567         kvm_pic_set_irq(pic_irqchip(kvm), 0, 0);
568         mutex_unlock(&kvm->lock);
569 }
570
571 void kvm_inject_pit_timer_irqs(struct kvm_vcpu *vcpu)
572 {
573         struct kvm_pit *pit = vcpu->kvm->arch.vpit;
574         struct kvm *kvm = vcpu->kvm;
575         struct kvm_kpit_state *ps;
576
577         if (vcpu && pit) {
578                 ps = &pit->pit_state;
579
580                 /* Try to inject pending interrupts when:
581                  * 1. Pending exists
582                  * 2. Last interrupt was accepted or waited for too long time*/
583                 if (atomic_read(&ps->pit_timer.pending) &&
584                     (ps->inject_pending ||
585                     (jiffies - ps->last_injected_time
586                                 >= KVM_MAX_PIT_INTR_INTERVAL))) {
587                         ps->inject_pending = 0;
588                         __inject_pit_timer_intr(kvm);
589                         ps->last_injected_time = jiffies;
590                 }
591         }
592 }
593
594 void kvm_pit_timer_intr_post(struct kvm_vcpu *vcpu, int vec)
595 {
596         struct kvm_arch *arch = &vcpu->kvm->arch;
597         struct kvm_kpit_state *ps;
598
599         if (vcpu && arch->vpit) {
600                 ps = &arch->vpit->pit_state;
601                 if (atomic_read(&ps->pit_timer.pending) &&
602                 (((arch->vpic->pics[0].imr & 1) == 0 &&
603                   arch->vpic->pics[0].irq_base == vec) ||
604                   (arch->vioapic->redirtbl[0].fields.vector == vec &&
605                   arch->vioapic->redirtbl[0].fields.mask != 1))) {
606                         ps->inject_pending = 1;
607                         atomic_dec(&ps->pit_timer.pending);
608                         ps->channels[0].count_load_time = ktime_get();
609                 }
610         }
611 }