arm/arm64: KVM: Enforce unconditional flush to PoC when mapping to stage-2
[firefly-linux-kernel-4.4.55.git] / arch / x86 / kvm / i8259.c
1 /*
2  * 8259 interrupt controller emulation
3  *
4  * Copyright (c) 2003-2004 Fabrice Bellard
5  * Copyright (c) 2007 Intel Corporation
6  * Copyright 2009 Red Hat, Inc. and/or its affiliates.
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to deal
10  * in the Software without restriction, including without limitation the rights
11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12  * copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24  * THE SOFTWARE.
25  * Authors:
26  *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
27  *   Port from Qemu.
28  */
29 #include <linux/mm.h>
30 #include <linux/slab.h>
31 #include <linux/bitops.h>
32 #include "irq.h"
33
34 #include <linux/kvm_host.h>
35 #include "trace.h"
36
37 #define pr_pic_unimpl(fmt, ...) \
38         pr_err_ratelimited("kvm: pic: " fmt, ## __VA_ARGS__)
39
40 static void pic_irq_request(struct kvm *kvm, int level);
41
42 static void pic_lock(struct kvm_pic *s)
43         __acquires(&s->lock)
44 {
45         spin_lock(&s->lock);
46 }
47
48 static void pic_unlock(struct kvm_pic *s)
49         __releases(&s->lock)
50 {
51         bool wakeup = s->wakeup_needed;
52         struct kvm_vcpu *vcpu, *found = NULL;
53         int i;
54
55         s->wakeup_needed = false;
56
57         spin_unlock(&s->lock);
58
59         if (wakeup) {
60                 kvm_for_each_vcpu(i, vcpu, s->kvm) {
61                         if (kvm_apic_accept_pic_intr(vcpu)) {
62                                 found = vcpu;
63                                 break;
64                         }
65                 }
66
67                 if (!found)
68                         return;
69
70                 kvm_make_request(KVM_REQ_EVENT, found);
71                 kvm_vcpu_kick(found);
72         }
73 }
74
75 static void pic_clear_isr(struct kvm_kpic_state *s, int irq)
76 {
77         s->isr &= ~(1 << irq);
78         if (s != &s->pics_state->pics[0])
79                 irq += 8;
80         /*
81          * We are dropping lock while calling ack notifiers since ack
82          * notifier callbacks for assigned devices call into PIC recursively.
83          * Other interrupt may be delivered to PIC while lock is dropped but
84          * it should be safe since PIC state is already updated at this stage.
85          */
86         pic_unlock(s->pics_state);
87         kvm_notify_acked_irq(s->pics_state->kvm, SELECT_PIC(irq), irq);
88         pic_lock(s->pics_state);
89 }
90
91 /*
92  * set irq level. If an edge is detected, then the IRR is set to 1
93  */
94 static inline int pic_set_irq1(struct kvm_kpic_state *s, int irq, int level)
95 {
96         int mask, ret = 1;
97         mask = 1 << irq;
98         if (s->elcr & mask)     /* level triggered */
99                 if (level) {
100                         ret = !(s->irr & mask);
101                         s->irr |= mask;
102                         s->last_irr |= mask;
103                 } else {
104                         s->irr &= ~mask;
105                         s->last_irr &= ~mask;
106                 }
107         else    /* edge triggered */
108                 if (level) {
109                         if ((s->last_irr & mask) == 0) {
110                                 ret = !(s->irr & mask);
111                                 s->irr |= mask;
112                         }
113                         s->last_irr |= mask;
114                 } else
115                         s->last_irr &= ~mask;
116
117         return (s->imr & mask) ? -1 : ret;
118 }
119
120 /*
121  * return the highest priority found in mask (highest = smallest
122  * number). Return 8 if no irq
123  */
124 static inline int get_priority(struct kvm_kpic_state *s, int mask)
125 {
126         int priority;
127         if (mask == 0)
128                 return 8;
129         priority = 0;
130         while ((mask & (1 << ((priority + s->priority_add) & 7))) == 0)
131                 priority++;
132         return priority;
133 }
134
135 /*
136  * return the pic wanted interrupt. return -1 if none
137  */
138 static int pic_get_irq(struct kvm_kpic_state *s)
139 {
140         int mask, cur_priority, priority;
141
142         mask = s->irr & ~s->imr;
143         priority = get_priority(s, mask);
144         if (priority == 8)
145                 return -1;
146         /*
147          * compute current priority. If special fully nested mode on the
148          * master, the IRQ coming from the slave is not taken into account
149          * for the priority computation.
150          */
151         mask = s->isr;
152         if (s->special_fully_nested_mode && s == &s->pics_state->pics[0])
153                 mask &= ~(1 << 2);
154         cur_priority = get_priority(s, mask);
155         if (priority < cur_priority)
156                 /*
157                  * higher priority found: an irq should be generated
158                  */
159                 return (priority + s->priority_add) & 7;
160         else
161                 return -1;
162 }
163
164 /*
165  * raise irq to CPU if necessary. must be called every time the active
166  * irq may change
167  */
168 static void pic_update_irq(struct kvm_pic *s)
169 {
170         int irq2, irq;
171
172         irq2 = pic_get_irq(&s->pics[1]);
173         if (irq2 >= 0) {
174                 /*
175                  * if irq request by slave pic, signal master PIC
176                  */
177                 pic_set_irq1(&s->pics[0], 2, 1);
178                 pic_set_irq1(&s->pics[0], 2, 0);
179         }
180         irq = pic_get_irq(&s->pics[0]);
181         pic_irq_request(s->kvm, irq >= 0);
182 }
183
184 void kvm_pic_update_irq(struct kvm_pic *s)
185 {
186         pic_lock(s);
187         pic_update_irq(s);
188         pic_unlock(s);
189 }
190
191 int kvm_pic_set_irq(struct kvm_pic *s, int irq, int irq_source_id, int level)
192 {
193         int ret, irq_level;
194
195         BUG_ON(irq < 0 || irq >= PIC_NUM_PINS);
196
197         pic_lock(s);
198         irq_level = __kvm_irq_line_state(&s->irq_states[irq],
199                                          irq_source_id, level);
200         ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
201         pic_update_irq(s);
202         trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
203                               s->pics[irq >> 3].imr, ret == 0);
204         pic_unlock(s);
205
206         return ret;
207 }
208
209 void kvm_pic_clear_all(struct kvm_pic *s, int irq_source_id)
210 {
211         int i;
212
213         pic_lock(s);
214         for (i = 0; i < PIC_NUM_PINS; i++)
215                 __clear_bit(irq_source_id, &s->irq_states[i]);
216         pic_unlock(s);
217 }
218
219 /*
220  * acknowledge interrupt 'irq'
221  */
222 static inline void pic_intack(struct kvm_kpic_state *s, int irq)
223 {
224         s->isr |= 1 << irq;
225         /*
226          * We don't clear a level sensitive interrupt here
227          */
228         if (!(s->elcr & (1 << irq)))
229                 s->irr &= ~(1 << irq);
230
231         if (s->auto_eoi) {
232                 if (s->rotate_on_auto_eoi)
233                         s->priority_add = (irq + 1) & 7;
234                 pic_clear_isr(s, irq);
235         }
236
237 }
238
239 int kvm_pic_read_irq(struct kvm *kvm)
240 {
241         int irq, irq2, intno;
242         struct kvm_pic *s = pic_irqchip(kvm);
243
244         s->output = 0;
245
246         pic_lock(s);
247         irq = pic_get_irq(&s->pics[0]);
248         if (irq >= 0) {
249                 pic_intack(&s->pics[0], irq);
250                 if (irq == 2) {
251                         irq2 = pic_get_irq(&s->pics[1]);
252                         if (irq2 >= 0)
253                                 pic_intack(&s->pics[1], irq2);
254                         else
255                                 /*
256                                  * spurious IRQ on slave controller
257                                  */
258                                 irq2 = 7;
259                         intno = s->pics[1].irq_base + irq2;
260                         irq = irq2 + 8;
261                 } else
262                         intno = s->pics[0].irq_base + irq;
263         } else {
264                 /*
265                  * spurious IRQ on host controller
266                  */
267                 irq = 7;
268                 intno = s->pics[0].irq_base + irq;
269         }
270         pic_update_irq(s);
271         pic_unlock(s);
272
273         return intno;
274 }
275
276 void kvm_pic_reset(struct kvm_kpic_state *s)
277 {
278         int irq, i;
279         struct kvm_vcpu *vcpu;
280         u8 edge_irr = s->irr & ~s->elcr;
281         bool found = false;
282
283         s->last_irr = 0;
284         s->irr &= s->elcr;
285         s->imr = 0;
286         s->priority_add = 0;
287         s->special_mask = 0;
288         s->read_reg_select = 0;
289         if (!s->init4) {
290                 s->special_fully_nested_mode = 0;
291                 s->auto_eoi = 0;
292         }
293         s->init_state = 1;
294
295         kvm_for_each_vcpu(i, vcpu, s->pics_state->kvm)
296                 if (kvm_apic_accept_pic_intr(vcpu)) {
297                         found = true;
298                         break;
299                 }
300
301
302         if (!found)
303                 return;
304
305         for (irq = 0; irq < PIC_NUM_PINS/2; irq++)
306                 if (edge_irr & (1 << irq))
307                         pic_clear_isr(s, irq);
308 }
309
310 static void pic_ioport_write(void *opaque, u32 addr, u32 val)
311 {
312         struct kvm_kpic_state *s = opaque;
313         int priority, cmd, irq;
314
315         addr &= 1;
316         if (addr == 0) {
317                 if (val & 0x10) {
318                         s->init4 = val & 1;
319                         if (val & 0x02)
320                                 pr_pic_unimpl("single mode not supported");
321                         if (val & 0x08)
322                                 pr_pic_unimpl(
323                                                 "level sensitive irq not supported");
324                         kvm_pic_reset(s);
325                 } else if (val & 0x08) {
326                         if (val & 0x04)
327                                 s->poll = 1;
328                         if (val & 0x02)
329                                 s->read_reg_select = val & 1;
330                         if (val & 0x40)
331                                 s->special_mask = (val >> 5) & 1;
332                 } else {
333                         cmd = val >> 5;
334                         switch (cmd) {
335                         case 0:
336                         case 4:
337                                 s->rotate_on_auto_eoi = cmd >> 2;
338                                 break;
339                         case 1: /* end of interrupt */
340                         case 5:
341                                 priority = get_priority(s, s->isr);
342                                 if (priority != 8) {
343                                         irq = (priority + s->priority_add) & 7;
344                                         if (cmd == 5)
345                                                 s->priority_add = (irq + 1) & 7;
346                                         pic_clear_isr(s, irq);
347                                         pic_update_irq(s->pics_state);
348                                 }
349                                 break;
350                         case 3:
351                                 irq = val & 7;
352                                 pic_clear_isr(s, irq);
353                                 pic_update_irq(s->pics_state);
354                                 break;
355                         case 6:
356                                 s->priority_add = (val + 1) & 7;
357                                 pic_update_irq(s->pics_state);
358                                 break;
359                         case 7:
360                                 irq = val & 7;
361                                 s->priority_add = (irq + 1) & 7;
362                                 pic_clear_isr(s, irq);
363                                 pic_update_irq(s->pics_state);
364                                 break;
365                         default:
366                                 break;  /* no operation */
367                         }
368                 }
369         } else
370                 switch (s->init_state) {
371                 case 0: { /* normal mode */
372                         u8 imr_diff = s->imr ^ val,
373                                 off = (s == &s->pics_state->pics[0]) ? 0 : 8;
374                         s->imr = val;
375                         for (irq = 0; irq < PIC_NUM_PINS/2; irq++)
376                                 if (imr_diff & (1 << irq))
377                                         kvm_fire_mask_notifiers(
378                                                 s->pics_state->kvm,
379                                                 SELECT_PIC(irq + off),
380                                                 irq + off,
381                                                 !!(s->imr & (1 << irq)));
382                         pic_update_irq(s->pics_state);
383                         break;
384                 }
385                 case 1:
386                         s->irq_base = val & 0xf8;
387                         s->init_state = 2;
388                         break;
389                 case 2:
390                         if (s->init4)
391                                 s->init_state = 3;
392                         else
393                                 s->init_state = 0;
394                         break;
395                 case 3:
396                         s->special_fully_nested_mode = (val >> 4) & 1;
397                         s->auto_eoi = (val >> 1) & 1;
398                         s->init_state = 0;
399                         break;
400                 }
401 }
402
403 static u32 pic_poll_read(struct kvm_kpic_state *s, u32 addr1)
404 {
405         int ret;
406
407         ret = pic_get_irq(s);
408         if (ret >= 0) {
409                 if (addr1 >> 7) {
410                         s->pics_state->pics[0].isr &= ~(1 << 2);
411                         s->pics_state->pics[0].irr &= ~(1 << 2);
412                 }
413                 s->irr &= ~(1 << ret);
414                 pic_clear_isr(s, ret);
415                 if (addr1 >> 7 || ret != 2)
416                         pic_update_irq(s->pics_state);
417         } else {
418                 ret = 0x07;
419                 pic_update_irq(s->pics_state);
420         }
421
422         return ret;
423 }
424
425 static u32 pic_ioport_read(void *opaque, u32 addr1)
426 {
427         struct kvm_kpic_state *s = opaque;
428         unsigned int addr;
429         int ret;
430
431         addr = addr1;
432         addr &= 1;
433         if (s->poll) {
434                 ret = pic_poll_read(s, addr1);
435                 s->poll = 0;
436         } else
437                 if (addr == 0)
438                         if (s->read_reg_select)
439                                 ret = s->isr;
440                         else
441                                 ret = s->irr;
442                 else
443                         ret = s->imr;
444         return ret;
445 }
446
447 static void elcr_ioport_write(void *opaque, u32 addr, u32 val)
448 {
449         struct kvm_kpic_state *s = opaque;
450         s->elcr = val & s->elcr_mask;
451 }
452
453 static u32 elcr_ioport_read(void *opaque, u32 addr1)
454 {
455         struct kvm_kpic_state *s = opaque;
456         return s->elcr;
457 }
458
459 static int picdev_in_range(gpa_t addr)
460 {
461         switch (addr) {
462         case 0x20:
463         case 0x21:
464         case 0xa0:
465         case 0xa1:
466         case 0x4d0:
467         case 0x4d1:
468                 return 1;
469         default:
470                 return 0;
471         }
472 }
473
474 static int picdev_write(struct kvm_pic *s,
475                          gpa_t addr, int len, const void *val)
476 {
477         unsigned char data = *(unsigned char *)val;
478         if (!picdev_in_range(addr))
479                 return -EOPNOTSUPP;
480
481         if (len != 1) {
482                 pr_pic_unimpl("non byte write\n");
483                 return 0;
484         }
485         pic_lock(s);
486         switch (addr) {
487         case 0x20:
488         case 0x21:
489         case 0xa0:
490         case 0xa1:
491                 pic_ioport_write(&s->pics[addr >> 7], addr, data);
492                 break;
493         case 0x4d0:
494         case 0x4d1:
495                 elcr_ioport_write(&s->pics[addr & 1], addr, data);
496                 break;
497         }
498         pic_unlock(s);
499         return 0;
500 }
501
502 static int picdev_read(struct kvm_pic *s,
503                        gpa_t addr, int len, void *val)
504 {
505         unsigned char data = 0;
506         if (!picdev_in_range(addr))
507                 return -EOPNOTSUPP;
508
509         if (len != 1) {
510                 memset(val, 0, len);
511                 pr_pic_unimpl("non byte read\n");
512                 return 0;
513         }
514         pic_lock(s);
515         switch (addr) {
516         case 0x20:
517         case 0x21:
518         case 0xa0:
519         case 0xa1:
520                 data = pic_ioport_read(&s->pics[addr >> 7], addr);
521                 break;
522         case 0x4d0:
523         case 0x4d1:
524                 data = elcr_ioport_read(&s->pics[addr & 1], addr);
525                 break;
526         }
527         *(unsigned char *)val = data;
528         pic_unlock(s);
529         return 0;
530 }
531
532 static int picdev_master_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
533                                gpa_t addr, int len, const void *val)
534 {
535         return picdev_write(container_of(dev, struct kvm_pic, dev_master),
536                             addr, len, val);
537 }
538
539 static int picdev_master_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
540                               gpa_t addr, int len, void *val)
541 {
542         return picdev_read(container_of(dev, struct kvm_pic, dev_master),
543                             addr, len, val);
544 }
545
546 static int picdev_slave_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
547                               gpa_t addr, int len, const void *val)
548 {
549         return picdev_write(container_of(dev, struct kvm_pic, dev_slave),
550                             addr, len, val);
551 }
552
553 static int picdev_slave_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
554                              gpa_t addr, int len, void *val)
555 {
556         return picdev_read(container_of(dev, struct kvm_pic, dev_slave),
557                             addr, len, val);
558 }
559
560 static int picdev_eclr_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
561                              gpa_t addr, int len, const void *val)
562 {
563         return picdev_write(container_of(dev, struct kvm_pic, dev_eclr),
564                             addr, len, val);
565 }
566
567 static int picdev_eclr_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
568                             gpa_t addr, int len, void *val)
569 {
570         return picdev_read(container_of(dev, struct kvm_pic, dev_eclr),
571                             addr, len, val);
572 }
573
574 /*
575  * callback when PIC0 irq status changed
576  */
577 static void pic_irq_request(struct kvm *kvm, int level)
578 {
579         struct kvm_pic *s = pic_irqchip(kvm);
580
581         if (!s->output)
582                 s->wakeup_needed = true;
583         s->output = level;
584 }
585
586 static const struct kvm_io_device_ops picdev_master_ops = {
587         .read     = picdev_master_read,
588         .write    = picdev_master_write,
589 };
590
591 static const struct kvm_io_device_ops picdev_slave_ops = {
592         .read     = picdev_slave_read,
593         .write    = picdev_slave_write,
594 };
595
596 static const struct kvm_io_device_ops picdev_eclr_ops = {
597         .read     = picdev_eclr_read,
598         .write    = picdev_eclr_write,
599 };
600
601 struct kvm_pic *kvm_create_pic(struct kvm *kvm)
602 {
603         struct kvm_pic *s;
604         int ret;
605
606         s = kzalloc(sizeof(struct kvm_pic), GFP_KERNEL);
607         if (!s)
608                 return NULL;
609         spin_lock_init(&s->lock);
610         s->kvm = kvm;
611         s->pics[0].elcr_mask = 0xf8;
612         s->pics[1].elcr_mask = 0xde;
613         s->pics[0].pics_state = s;
614         s->pics[1].pics_state = s;
615
616         /*
617          * Initialize PIO device
618          */
619         kvm_iodevice_init(&s->dev_master, &picdev_master_ops);
620         kvm_iodevice_init(&s->dev_slave, &picdev_slave_ops);
621         kvm_iodevice_init(&s->dev_eclr, &picdev_eclr_ops);
622         mutex_lock(&kvm->slots_lock);
623         ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, 0x20, 2,
624                                       &s->dev_master);
625         if (ret < 0)
626                 goto fail_unlock;
627
628         ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, 0xa0, 2, &s->dev_slave);
629         if (ret < 0)
630                 goto fail_unreg_2;
631
632         ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, 0x4d0, 2, &s->dev_eclr);
633         if (ret < 0)
634                 goto fail_unreg_1;
635
636         mutex_unlock(&kvm->slots_lock);
637
638         return s;
639
640 fail_unreg_1:
641         kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &s->dev_slave);
642
643 fail_unreg_2:
644         kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &s->dev_master);
645
646 fail_unlock:
647         mutex_unlock(&kvm->slots_lock);
648
649         kfree(s);
650
651         return NULL;
652 }
653
654 void kvm_destroy_pic(struct kvm_pic *vpic)
655 {
656         kvm_io_bus_unregister_dev(vpic->kvm, KVM_PIO_BUS, &vpic->dev_master);
657         kvm_io_bus_unregister_dev(vpic->kvm, KVM_PIO_BUS, &vpic->dev_slave);
658         kvm_io_bus_unregister_dev(vpic->kvm, KVM_PIO_BUS, &vpic->dev_eclr);
659         kfree(vpic);
660 }