1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2021 Western Digital Corporation or its affiliates.
4 * Copyright (C) 2022 Ventana Micro Systems Inc.
5 *
6 * Authors:
7 *	Anup Patel <apatel@ventanamicro.com>
8 */
9
10#include <linux/kvm_host.h>
11#include <linux/math.h>
12#include <linux/spinlock.h>
13#include <linux/swab.h>
14#include <kvm/iodev.h>
15#include <asm/kvm_aia_aplic.h>
16
17struct aplic_irq {
18	raw_spinlock_t lock;
19	u32 sourcecfg;
20	u32 state;
21#define APLIC_IRQ_STATE_PENDING		BIT(0)
22#define APLIC_IRQ_STATE_ENABLED		BIT(1)
23#define APLIC_IRQ_STATE_ENPEND		(APLIC_IRQ_STATE_PENDING | \
24					 APLIC_IRQ_STATE_ENABLED)
25#define APLIC_IRQ_STATE_INPUT		BIT(8)
26	u32 target;
27};
28
29struct aplic {
30	struct kvm_io_device iodev;
31
32	u32 domaincfg;
33	u32 genmsi;
34
35	u32 nr_irqs;
36	u32 nr_words;
37	struct aplic_irq *irqs;
38};
39
40static u32 aplic_read_sourcecfg(struct aplic *aplic, u32 irq)
41{
42	u32 ret;
43	unsigned long flags;
44	struct aplic_irq *irqd;
45
46	if (!irq || aplic->nr_irqs <= irq)
47		return 0;
48	irqd = &aplic->irqs[irq];
49
50	raw_spin_lock_irqsave(&irqd->lock, flags);
51	ret = irqd->sourcecfg;
52	raw_spin_unlock_irqrestore(&irqd->lock, flags);
53
54	return ret;
55}
56
57static void aplic_write_sourcecfg(struct aplic *aplic, u32 irq, u32 val)
58{
59	unsigned long flags;
60	struct aplic_irq *irqd;
61
62	if (!irq || aplic->nr_irqs <= irq)
63		return;
64	irqd = &aplic->irqs[irq];
65
66	if (val & APLIC_SOURCECFG_D)
67		val = 0;
68	else
69		val &= APLIC_SOURCECFG_SM_MASK;
70
71	raw_spin_lock_irqsave(&irqd->lock, flags);
72	irqd->sourcecfg = val;
73	raw_spin_unlock_irqrestore(&irqd->lock, flags);
74}
75
76static u32 aplic_read_target(struct aplic *aplic, u32 irq)
77{
78	u32 ret;
79	unsigned long flags;
80	struct aplic_irq *irqd;
81
82	if (!irq || aplic->nr_irqs <= irq)
83		return 0;
84	irqd = &aplic->irqs[irq];
85
86	raw_spin_lock_irqsave(&irqd->lock, flags);
87	ret = irqd->target;
88	raw_spin_unlock_irqrestore(&irqd->lock, flags);
89
90	return ret;
91}
92
93static void aplic_write_target(struct aplic *aplic, u32 irq, u32 val)
94{
95	unsigned long flags;
96	struct aplic_irq *irqd;
97
98	if (!irq || aplic->nr_irqs <= irq)
99		return;
100	irqd = &aplic->irqs[irq];
101
102	val &= APLIC_TARGET_EIID_MASK |
103	       (APLIC_TARGET_HART_IDX_MASK << APLIC_TARGET_HART_IDX_SHIFT) |
104	       (APLIC_TARGET_GUEST_IDX_MASK << APLIC_TARGET_GUEST_IDX_SHIFT);
105
106	raw_spin_lock_irqsave(&irqd->lock, flags);
107	irqd->target = val;
108	raw_spin_unlock_irqrestore(&irqd->lock, flags);
109}
110
111static bool aplic_read_pending(struct aplic *aplic, u32 irq)
112{
113	bool ret;
114	unsigned long flags;
115	struct aplic_irq *irqd;
116
117	if (!irq || aplic->nr_irqs <= irq)
118		return false;
119	irqd = &aplic->irqs[irq];
120
121	raw_spin_lock_irqsave(&irqd->lock, flags);
122	ret = (irqd->state & APLIC_IRQ_STATE_PENDING) ? true : false;
123	raw_spin_unlock_irqrestore(&irqd->lock, flags);
124
125	return ret;
126}
127
128static void aplic_write_pending(struct aplic *aplic, u32 irq, bool pending)
129{
130	unsigned long flags, sm;
131	struct aplic_irq *irqd;
132
133	if (!irq || aplic->nr_irqs <= irq)
134		return;
135	irqd = &aplic->irqs[irq];
136
137	raw_spin_lock_irqsave(&irqd->lock, flags);
138
139	sm = irqd->sourcecfg & APLIC_SOURCECFG_SM_MASK;
140	if (!pending &&
141	    ((sm == APLIC_SOURCECFG_SM_LEVEL_HIGH) ||
142	     (sm == APLIC_SOURCECFG_SM_LEVEL_LOW)))
143		goto skip_write_pending;
144
145	if (pending)
146		irqd->state |= APLIC_IRQ_STATE_PENDING;
147	else
148		irqd->state &= ~APLIC_IRQ_STATE_PENDING;
149
150skip_write_pending:
151	raw_spin_unlock_irqrestore(&irqd->lock, flags);
152}
153
154static bool aplic_read_enabled(struct aplic *aplic, u32 irq)
155{
156	bool ret;
157	unsigned long flags;
158	struct aplic_irq *irqd;
159
160	if (!irq || aplic->nr_irqs <= irq)
161		return false;
162	irqd = &aplic->irqs[irq];
163
164	raw_spin_lock_irqsave(&irqd->lock, flags);
165	ret = (irqd->state & APLIC_IRQ_STATE_ENABLED) ? true : false;
166	raw_spin_unlock_irqrestore(&irqd->lock, flags);
167
168	return ret;
169}
170
171static void aplic_write_enabled(struct aplic *aplic, u32 irq, bool enabled)
172{
173	unsigned long flags;
174	struct aplic_irq *irqd;
175
176	if (!irq || aplic->nr_irqs <= irq)
177		return;
178	irqd = &aplic->irqs[irq];
179
180	raw_spin_lock_irqsave(&irqd->lock, flags);
181	if (enabled)
182		irqd->state |= APLIC_IRQ_STATE_ENABLED;
183	else
184		irqd->state &= ~APLIC_IRQ_STATE_ENABLED;
185	raw_spin_unlock_irqrestore(&irqd->lock, flags);
186}
187
188static bool aplic_read_input(struct aplic *aplic, u32 irq)
189{
190	bool ret;
191	unsigned long flags;
192	struct aplic_irq *irqd;
193
194	if (!irq || aplic->nr_irqs <= irq)
195		return false;
196	irqd = &aplic->irqs[irq];
197
198	raw_spin_lock_irqsave(&irqd->lock, flags);
199	ret = (irqd->state & APLIC_IRQ_STATE_INPUT) ? true : false;
200	raw_spin_unlock_irqrestore(&irqd->lock, flags);
201
202	return ret;
203}
204
205static void aplic_inject_msi(struct kvm *kvm, u32 irq, u32 target)
206{
207	u32 hart_idx, guest_idx, eiid;
208
209	hart_idx = target >> APLIC_TARGET_HART_IDX_SHIFT;
210	hart_idx &= APLIC_TARGET_HART_IDX_MASK;
211	guest_idx = target >> APLIC_TARGET_GUEST_IDX_SHIFT;
212	guest_idx &= APLIC_TARGET_GUEST_IDX_MASK;
213	eiid = target & APLIC_TARGET_EIID_MASK;
214	kvm_riscv_aia_inject_msi_by_id(kvm, hart_idx, guest_idx, eiid);
215}
216
217static void aplic_update_irq_range(struct kvm *kvm, u32 first, u32 last)
218{
219	bool inject;
220	u32 irq, target;
221	unsigned long flags;
222	struct aplic_irq *irqd;
223	struct aplic *aplic = kvm->arch.aia.aplic_state;
224
225	if (!(aplic->domaincfg & APLIC_DOMAINCFG_IE))
226		return;
227
228	for (irq = first; irq <= last; irq++) {
229		if (!irq || aplic->nr_irqs <= irq)
230			continue;
231		irqd = &aplic->irqs[irq];
232
233		raw_spin_lock_irqsave(&irqd->lock, flags);
234
235		inject = false;
236		target = irqd->target;
237		if ((irqd->state & APLIC_IRQ_STATE_ENPEND) ==
238		    APLIC_IRQ_STATE_ENPEND) {
239			irqd->state &= ~APLIC_IRQ_STATE_PENDING;
240			inject = true;
241		}
242
243		raw_spin_unlock_irqrestore(&irqd->lock, flags);
244
245		if (inject)
246			aplic_inject_msi(kvm, irq, target);
247	}
248}
249
250int kvm_riscv_aia_aplic_inject(struct kvm *kvm, u32 source, bool level)
251{
252	u32 target;
253	bool inject = false, ie;
254	unsigned long flags;
255	struct aplic_irq *irqd;
256	struct aplic *aplic = kvm->arch.aia.aplic_state;
257
258	if (!aplic || !source || (aplic->nr_irqs <= source))
259		return -ENODEV;
260	irqd = &aplic->irqs[source];
261	ie = (aplic->domaincfg & APLIC_DOMAINCFG_IE) ? true : false;
262
263	raw_spin_lock_irqsave(&irqd->lock, flags);
264
265	if (irqd->sourcecfg & APLIC_SOURCECFG_D)
266		goto skip_unlock;
267
268	switch (irqd->sourcecfg & APLIC_SOURCECFG_SM_MASK) {
269	case APLIC_SOURCECFG_SM_EDGE_RISE:
270		if (level && !(irqd->state & APLIC_IRQ_STATE_INPUT) &&
271		    !(irqd->state & APLIC_IRQ_STATE_PENDING))
272			irqd->state |= APLIC_IRQ_STATE_PENDING;
273		break;
274	case APLIC_SOURCECFG_SM_EDGE_FALL:
275		if (!level && (irqd->state & APLIC_IRQ_STATE_INPUT) &&
276		    !(irqd->state & APLIC_IRQ_STATE_PENDING))
277			irqd->state |= APLIC_IRQ_STATE_PENDING;
278		break;
279	case APLIC_SOURCECFG_SM_LEVEL_HIGH:
280		if (level && !(irqd->state & APLIC_IRQ_STATE_PENDING))
281			irqd->state |= APLIC_IRQ_STATE_PENDING;
282		break;
283	case APLIC_SOURCECFG_SM_LEVEL_LOW:
284		if (!level && !(irqd->state & APLIC_IRQ_STATE_PENDING))
285			irqd->state |= APLIC_IRQ_STATE_PENDING;
286		break;
287	}
288
289	if (level)
290		irqd->state |= APLIC_IRQ_STATE_INPUT;
291	else
292		irqd->state &= ~APLIC_IRQ_STATE_INPUT;
293
294	target = irqd->target;
295	if (ie && ((irqd->state & APLIC_IRQ_STATE_ENPEND) ==
296		   APLIC_IRQ_STATE_ENPEND)) {
297		irqd->state &= ~APLIC_IRQ_STATE_PENDING;
298		inject = true;
299	}
300
301skip_unlock:
302	raw_spin_unlock_irqrestore(&irqd->lock, flags);
303
304	if (inject)
305		aplic_inject_msi(kvm, source, target);
306
307	return 0;
308}
309
310static u32 aplic_read_input_word(struct aplic *aplic, u32 word)
311{
312	u32 i, ret = 0;
313
314	for (i = 0; i < 32; i++)
315		ret |= aplic_read_input(aplic, word * 32 + i) ? BIT(i) : 0;
316
317	return ret;
318}
319
320static u32 aplic_read_pending_word(struct aplic *aplic, u32 word)
321{
322	u32 i, ret = 0;
323
324	for (i = 0; i < 32; i++)
325		ret |= aplic_read_pending(aplic, word * 32 + i) ? BIT(i) : 0;
326
327	return ret;
328}
329
330static void aplic_write_pending_word(struct aplic *aplic, u32 word,
331				     u32 val, bool pending)
332{
333	u32 i;
334
335	for (i = 0; i < 32; i++) {
336		if (val & BIT(i))
337			aplic_write_pending(aplic, word * 32 + i, pending);
338	}
339}
340
341static u32 aplic_read_enabled_word(struct aplic *aplic, u32 word)
342{
343	u32 i, ret = 0;
344
345	for (i = 0; i < 32; i++)
346		ret |= aplic_read_enabled(aplic, word * 32 + i) ? BIT(i) : 0;
347
348	return ret;
349}
350
351static void aplic_write_enabled_word(struct aplic *aplic, u32 word,
352				     u32 val, bool enabled)
353{
354	u32 i;
355
356	for (i = 0; i < 32; i++) {
357		if (val & BIT(i))
358			aplic_write_enabled(aplic, word * 32 + i, enabled);
359	}
360}
361
362static int aplic_mmio_read_offset(struct kvm *kvm, gpa_t off, u32 *val32)
363{
364	u32 i;
365	struct aplic *aplic = kvm->arch.aia.aplic_state;
366
367	if ((off & 0x3) != 0)
368		return -EOPNOTSUPP;
369
370	if (off == APLIC_DOMAINCFG) {
371		*val32 = APLIC_DOMAINCFG_RDONLY |
372			 aplic->domaincfg | APLIC_DOMAINCFG_DM;
373	} else if ((off >= APLIC_SOURCECFG_BASE) &&
374		 (off < (APLIC_SOURCECFG_BASE + (aplic->nr_irqs - 1) * 4))) {
375		i = ((off - APLIC_SOURCECFG_BASE) >> 2) + 1;
376		*val32 = aplic_read_sourcecfg(aplic, i);
377	} else if ((off >= APLIC_SETIP_BASE) &&
378		   (off < (APLIC_SETIP_BASE + aplic->nr_words * 4))) {
379		i = (off - APLIC_SETIP_BASE) >> 2;
380		*val32 = aplic_read_pending_word(aplic, i);
381	} else if (off == APLIC_SETIPNUM) {
382		*val32 = 0;
383	} else if ((off >= APLIC_CLRIP_BASE) &&
384		   (off < (APLIC_CLRIP_BASE + aplic->nr_words * 4))) {
385		i = (off - APLIC_CLRIP_BASE) >> 2;
386		*val32 = aplic_read_input_word(aplic, i);
387	} else if (off == APLIC_CLRIPNUM) {
388		*val32 = 0;
389	} else if ((off >= APLIC_SETIE_BASE) &&
390		   (off < (APLIC_SETIE_BASE + aplic->nr_words * 4))) {
391		i = (off - APLIC_SETIE_BASE) >> 2;
392		*val32 = aplic_read_enabled_word(aplic, i);
393	} else if (off == APLIC_SETIENUM) {
394		*val32 = 0;
395	} else if ((off >= APLIC_CLRIE_BASE) &&
396		   (off < (APLIC_CLRIE_BASE + aplic->nr_words * 4))) {
397		*val32 = 0;
398	} else if (off == APLIC_CLRIENUM) {
399		*val32 = 0;
400	} else if (off == APLIC_SETIPNUM_LE) {
401		*val32 = 0;
402	} else if (off == APLIC_SETIPNUM_BE) {
403		*val32 = 0;
404	} else if (off == APLIC_GENMSI) {
405		*val32 = aplic->genmsi;
406	} else if ((off >= APLIC_TARGET_BASE) &&
407		   (off < (APLIC_TARGET_BASE + (aplic->nr_irqs - 1) * 4))) {
408		i = ((off - APLIC_TARGET_BASE) >> 2) + 1;
409		*val32 = aplic_read_target(aplic, i);
410	} else
411		return -ENODEV;
412
413	return 0;
414}
415
416static int aplic_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
417			   gpa_t addr, int len, void *val)
418{
419	if (len != 4)
420		return -EOPNOTSUPP;
421
422	return aplic_mmio_read_offset(vcpu->kvm,
423				      addr - vcpu->kvm->arch.aia.aplic_addr,
424				      val);
425}
426
427static int aplic_mmio_write_offset(struct kvm *kvm, gpa_t off, u32 val32)
428{
429	u32 i;
430	struct aplic *aplic = kvm->arch.aia.aplic_state;
431
432	if ((off & 0x3) != 0)
433		return -EOPNOTSUPP;
434
435	if (off == APLIC_DOMAINCFG) {
436		/* Only IE bit writeable */
437		aplic->domaincfg = val32 & APLIC_DOMAINCFG_IE;
438	} else if ((off >= APLIC_SOURCECFG_BASE) &&
439		 (off < (APLIC_SOURCECFG_BASE + (aplic->nr_irqs - 1) * 4))) {
440		i = ((off - APLIC_SOURCECFG_BASE) >> 2) + 1;
441		aplic_write_sourcecfg(aplic, i, val32);
442	} else if ((off >= APLIC_SETIP_BASE) &&
443		   (off < (APLIC_SETIP_BASE + aplic->nr_words * 4))) {
444		i = (off - APLIC_SETIP_BASE) >> 2;
445		aplic_write_pending_word(aplic, i, val32, true);
446	} else if (off == APLIC_SETIPNUM) {
447		aplic_write_pending(aplic, val32, true);
448	} else if ((off >= APLIC_CLRIP_BASE) &&
449		   (off < (APLIC_CLRIP_BASE + aplic->nr_words * 4))) {
450		i = (off - APLIC_CLRIP_BASE) >> 2;
451		aplic_write_pending_word(aplic, i, val32, false);
452	} else if (off == APLIC_CLRIPNUM) {
453		aplic_write_pending(aplic, val32, false);
454	} else if ((off >= APLIC_SETIE_BASE) &&
455		   (off < (APLIC_SETIE_BASE + aplic->nr_words * 4))) {
456		i = (off - APLIC_SETIE_BASE) >> 2;
457		aplic_write_enabled_word(aplic, i, val32, true);
458	} else if (off == APLIC_SETIENUM) {
459		aplic_write_enabled(aplic, val32, true);
460	} else if ((off >= APLIC_CLRIE_BASE) &&
461		   (off < (APLIC_CLRIE_BASE + aplic->nr_words * 4))) {
462		i = (off - APLIC_CLRIE_BASE) >> 2;
463		aplic_write_enabled_word(aplic, i, val32, false);
464	} else if (off == APLIC_CLRIENUM) {
465		aplic_write_enabled(aplic, val32, false);
466	} else if (off == APLIC_SETIPNUM_LE) {
467		aplic_write_pending(aplic, val32, true);
468	} else if (off == APLIC_SETIPNUM_BE) {
469		aplic_write_pending(aplic, __swab32(val32), true);
470	} else if (off == APLIC_GENMSI) {
471		aplic->genmsi = val32 & ~(APLIC_TARGET_GUEST_IDX_MASK <<
472					  APLIC_TARGET_GUEST_IDX_SHIFT);
473		kvm_riscv_aia_inject_msi_by_id(kvm,
474				val32 >> APLIC_TARGET_HART_IDX_SHIFT, 0,
475				val32 & APLIC_TARGET_EIID_MASK);
476	} else if ((off >= APLIC_TARGET_BASE) &&
477		   (off < (APLIC_TARGET_BASE + (aplic->nr_irqs - 1) * 4))) {
478		i = ((off - APLIC_TARGET_BASE) >> 2) + 1;
479		aplic_write_target(aplic, i, val32);
480	} else
481		return -ENODEV;
482
483	aplic_update_irq_range(kvm, 1, aplic->nr_irqs - 1);
484
485	return 0;
486}
487
488static int aplic_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
489			    gpa_t addr, int len, const void *val)
490{
491	if (len != 4)
492		return -EOPNOTSUPP;
493
494	return aplic_mmio_write_offset(vcpu->kvm,
495				       addr - vcpu->kvm->arch.aia.aplic_addr,
496				       *((const u32 *)val));
497}
498
499static struct kvm_io_device_ops aplic_iodoev_ops = {
500	.read = aplic_mmio_read,
501	.write = aplic_mmio_write,
502};
503
504int kvm_riscv_aia_aplic_set_attr(struct kvm *kvm, unsigned long type, u32 v)
505{
506	int rc;
507
508	if (!kvm->arch.aia.aplic_state)
509		return -ENODEV;
510
511	rc = aplic_mmio_write_offset(kvm, type, v);
512	if (rc)
513		return rc;
514
515	return 0;
516}
517
518int kvm_riscv_aia_aplic_get_attr(struct kvm *kvm, unsigned long type, u32 *v)
519{
520	int rc;
521
522	if (!kvm->arch.aia.aplic_state)
523		return -ENODEV;
524
525	rc = aplic_mmio_read_offset(kvm, type, v);
526	if (rc)
527		return rc;
528
529	return 0;
530}
531
532int kvm_riscv_aia_aplic_has_attr(struct kvm *kvm, unsigned long type)
533{
534	int rc;
535	u32 val;
536
537	if (!kvm->arch.aia.aplic_state)
538		return -ENODEV;
539
540	rc = aplic_mmio_read_offset(kvm, type, &val);
541	if (rc)
542		return rc;
543
544	return 0;
545}
546
547int kvm_riscv_aia_aplic_init(struct kvm *kvm)
548{
549	int i, ret = 0;
550	struct aplic *aplic;
551
552	/* Do nothing if we have zero sources */
553	if (!kvm->arch.aia.nr_sources)
554		return 0;
555
556	/* Allocate APLIC global state */
557	aplic = kzalloc(sizeof(*aplic), GFP_KERNEL);
558	if (!aplic)
559		return -ENOMEM;
560	kvm->arch.aia.aplic_state = aplic;
561
562	/* Setup APLIC IRQs */
563	aplic->nr_irqs = kvm->arch.aia.nr_sources + 1;
564	aplic->nr_words = DIV_ROUND_UP(aplic->nr_irqs, 32);
565	aplic->irqs = kcalloc(aplic->nr_irqs,
566			      sizeof(*aplic->irqs), GFP_KERNEL);
567	if (!aplic->irqs) {
568		ret = -ENOMEM;
569		goto fail_free_aplic;
570	}
571	for (i = 0; i < aplic->nr_irqs; i++)
572		raw_spin_lock_init(&aplic->irqs[i].lock);
573
574	/* Setup IO device */
575	kvm_iodevice_init(&aplic->iodev, &aplic_iodoev_ops);
576	mutex_lock(&kvm->slots_lock);
577	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS,
578				      kvm->arch.aia.aplic_addr,
579				      KVM_DEV_RISCV_APLIC_SIZE,
580				      &aplic->iodev);
581	mutex_unlock(&kvm->slots_lock);
582	if (ret)
583		goto fail_free_aplic_irqs;
584
585	/* Setup default IRQ routing */
586	ret = kvm_riscv_setup_default_irq_routing(kvm, aplic->nr_irqs);
587	if (ret)
588		goto fail_unreg_iodev;
589
590	return 0;
591
592fail_unreg_iodev:
593	mutex_lock(&kvm->slots_lock);
594	kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &aplic->iodev);
595	mutex_unlock(&kvm->slots_lock);
596fail_free_aplic_irqs:
597	kfree(aplic->irqs);
598fail_free_aplic:
599	kvm->arch.aia.aplic_state = NULL;
600	kfree(aplic);
601	return ret;
602}
603
604void kvm_riscv_aia_aplic_cleanup(struct kvm *kvm)
605{
606	struct aplic *aplic = kvm->arch.aia.aplic_state;
607
608	if (!aplic)
609		return;
610
611	mutex_lock(&kvm->slots_lock);
612	kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &aplic->iodev);
613	mutex_unlock(&kvm->slots_lock);
614
615	kfree(aplic->irqs);
616
617	kvm->arch.aia.aplic_state = NULL;
618	kfree(aplic);
619}
620