xref: /linux/arch/loongarch/kvm/intc/pch_pic.c (revision d5ffba0f254d29a13908d4510762b31d4247a94c)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2024 Loongson Technology Corporation Limited
4  */
5 
6 #include <asm/kvm_eiointc.h>
7 #include <asm/kvm_pch_pic.h>
8 #include <asm/kvm_vcpu.h>
9 #include <linux/count_zeros.h>
10 
11 /* update the isr according to irq level and route irq to eiointc */
12 static void pch_pic_update_irq(struct loongarch_pch_pic *s, int irq, int level)
13 {
14 	u64 mask = BIT(irq);
15 
16 	/*
17 	 * set isr and route irq to eiointc and
18 	 * the route table is in htmsi_vector[]
19 	 */
20 	if (level) {
21 		if (mask & s->irr & ~s->mask) {
22 			s->isr |= mask;
23 			irq = s->htmsi_vector[irq];
24 			eiointc_set_irq(s->kvm->arch.eiointc, irq, level);
25 		}
26 	} else {
27 		if (mask & s->isr & ~s->irr) {
28 			s->isr &= ~mask;
29 			irq = s->htmsi_vector[irq];
30 			eiointc_set_irq(s->kvm->arch.eiointc, irq, level);
31 		}
32 	}
33 }
34 
35 /* update batch irqs, the irq_mask is a bitmap of irqs */
36 static void pch_pic_update_batch_irqs(struct loongarch_pch_pic *s, u64 irq_mask, int level)
37 {
38 	int irq, bits;
39 
40 	/* find each irq by irqs bitmap and update each irq */
41 	bits = sizeof(irq_mask) * 8;
42 	irq = find_first_bit((void *)&irq_mask, bits);
43 	while (irq < bits) {
44 		pch_pic_update_irq(s, irq, level);
45 		bitmap_clear((void *)&irq_mask, irq, 1);
46 		irq = find_first_bit((void *)&irq_mask, bits);
47 	}
48 }
49 
50 /* called when a irq is triggered in pch pic */
51 void pch_pic_set_irq(struct loongarch_pch_pic *s, int irq, int level)
52 {
53 	u64 mask = BIT(irq);
54 
55 	spin_lock(&s->lock);
56 	if (level)
57 		s->irr |= mask; /* set irr */
58 	else {
59 		/*
60 		 * In edge triggered mode, 0 does not mean to clear irq
61 		 * The irr register variable is cleared when cpu writes to the
62 		 * PCH_PIC_CLEAR_START address area
63 		 */
64 		if (s->edge & mask) {
65 			spin_unlock(&s->lock);
66 			return;
67 		}
68 		s->irr &= ~mask;
69 	}
70 	pch_pic_update_irq(s, irq, level);
71 	spin_unlock(&s->lock);
72 }
73 
74 /* msi irq handler */
75 void pch_msi_set_irq(struct kvm *kvm, int irq, int level)
76 {
77 	eiointc_set_irq(kvm->arch.eiointc, irq, level);
78 }
79 
80 /*
81  * pch pic register is 64-bit, but it is accessed by 32-bit,
82  * so we use high to get whether low or high 32 bits we want
83  * to read.
84  */
85 static u32 pch_pic_read_reg(u64 *s, int high)
86 {
87 	u64 val = *s;
88 
89 	/* read the high 32 bits when high is 1 */
90 	return high ? (u32)(val >> 32) : (u32)val;
91 }
92 
93 /*
94  * pch pic register is 64-bit, but it is accessed by 32-bit,
95  * so we use high to get whether low or high 32 bits we want
96  * to write.
97  */
98 static u32 pch_pic_write_reg(u64 *s, int high, u32 v)
99 {
100 	u64 val = *s, data = v;
101 
102 	if (high) {
103 		/*
104 		 * Clear val high 32 bits
105 		 * Write the high 32 bits when the high is 1
106 		 */
107 		*s = (val << 32 >> 32) | (data << 32);
108 		val >>= 32;
109 	} else
110 		/*
111 		 * Clear val low 32 bits
112 		 * Write the low 32 bits when the high is 0
113 		 */
114 		*s = (val >> 32 << 32) | v;
115 
116 	return (u32)val;
117 }
118 
119 static int loongarch_pch_pic_read(struct loongarch_pch_pic *s, gpa_t addr, int len, void *val)
120 {
121 	int offset, index, ret = 0;
122 	u32 data = 0;
123 	u64 int_id = 0;
124 
125 	offset = addr - s->pch_pic_base;
126 
127 	spin_lock(&s->lock);
128 	switch (offset) {
129 	case PCH_PIC_INT_ID_START ... PCH_PIC_INT_ID_END:
130 		/* int id version */
131 		int_id |= (u64)PCH_PIC_INT_ID_VER << 32;
132 		/* irq number */
133 		int_id |= (u64)31 << (32 + 16);
134 		/* int id value */
135 		int_id |= PCH_PIC_INT_ID_VAL;
136 		*(u64 *)val = int_id;
137 		break;
138 	case PCH_PIC_MASK_START ... PCH_PIC_MASK_END:
139 		offset -= PCH_PIC_MASK_START;
140 		index = offset >> 2;
141 		/* read mask reg */
142 		data = pch_pic_read_reg(&s->mask, index);
143 		*(u32 *)val = data;
144 		break;
145 	case PCH_PIC_HTMSI_EN_START ... PCH_PIC_HTMSI_EN_END:
146 		offset -= PCH_PIC_HTMSI_EN_START;
147 		index = offset >> 2;
148 		/* read htmsi enable reg */
149 		data = pch_pic_read_reg(&s->htmsi_en, index);
150 		*(u32 *)val = data;
151 		break;
152 	case PCH_PIC_EDGE_START ... PCH_PIC_EDGE_END:
153 		offset -= PCH_PIC_EDGE_START;
154 		index = offset >> 2;
155 		/* read edge enable reg */
156 		data = pch_pic_read_reg(&s->edge, index);
157 		*(u32 *)val = data;
158 		break;
159 	case PCH_PIC_AUTO_CTRL0_START ... PCH_PIC_AUTO_CTRL0_END:
160 	case PCH_PIC_AUTO_CTRL1_START ... PCH_PIC_AUTO_CTRL1_END:
161 		/* we only use default mode: fixed interrupt distribution mode */
162 		*(u32 *)val = 0;
163 		break;
164 	case PCH_PIC_ROUTE_ENTRY_START ... PCH_PIC_ROUTE_ENTRY_END:
165 		/* only route to int0: eiointc */
166 		*(u8 *)val = 1;
167 		break;
168 	case PCH_PIC_HTMSI_VEC_START ... PCH_PIC_HTMSI_VEC_END:
169 		offset -= PCH_PIC_HTMSI_VEC_START;
170 		/* read htmsi vector */
171 		data = s->htmsi_vector[offset];
172 		*(u8 *)val = data;
173 		break;
174 	case PCH_PIC_POLARITY_START ... PCH_PIC_POLARITY_END:
175 		/* we only use defalut value 0: high level triggered */
176 		*(u32 *)val = 0;
177 		break;
178 	default:
179 		ret = -EINVAL;
180 	}
181 	spin_unlock(&s->lock);
182 
183 	return ret;
184 }
185 
186 static int kvm_pch_pic_read(struct kvm_vcpu *vcpu,
187 			struct kvm_io_device *dev,
188 			gpa_t addr, int len, void *val)
189 {
190 	int ret;
191 	struct loongarch_pch_pic *s = vcpu->kvm->arch.pch_pic;
192 
193 	if (!s) {
194 		kvm_err("%s: pch pic irqchip not valid!\n", __func__);
195 		return -EINVAL;
196 	}
197 
198 	if (addr & (len - 1)) {
199 		kvm_err("%s: pch pic not aligned addr %llx len %d\n", __func__, addr, len);
200 		return -EINVAL;
201 	}
202 
203 	/* statistics of pch pic reading */
204 	vcpu->stat.pch_pic_read_exits++;
205 	ret = loongarch_pch_pic_read(s, addr, len, val);
206 
207 	return ret;
208 }
209 
210 static int loongarch_pch_pic_write(struct loongarch_pch_pic *s, gpa_t addr,
211 					int len, const void *val)
212 {
213 	int ret;
214 	u32 old, data, offset, index;
215 	u64 irq;
216 
217 	ret = 0;
218 	data = *(u32 *)val;
219 	offset = addr - s->pch_pic_base;
220 
221 	spin_lock(&s->lock);
222 	switch (offset) {
223 	case PCH_PIC_MASK_START ... PCH_PIC_MASK_END:
224 		offset -= PCH_PIC_MASK_START;
225 		/* get whether high or low 32 bits we want to write */
226 		index = offset >> 2;
227 		old = pch_pic_write_reg(&s->mask, index, data);
228 		/* enable irq when mask value change to 0 */
229 		irq = (old & ~data) << (32 * index);
230 		pch_pic_update_batch_irqs(s, irq, 1);
231 		/* disable irq when mask value change to 1 */
232 		irq = (~old & data) << (32 * index);
233 		pch_pic_update_batch_irqs(s, irq, 0);
234 		break;
235 	case PCH_PIC_HTMSI_EN_START ... PCH_PIC_HTMSI_EN_END:
236 		offset -= PCH_PIC_HTMSI_EN_START;
237 		index = offset >> 2;
238 		pch_pic_write_reg(&s->htmsi_en, index, data);
239 		break;
240 	case PCH_PIC_EDGE_START ... PCH_PIC_EDGE_END:
241 		offset -= PCH_PIC_EDGE_START;
242 		index = offset >> 2;
243 		/* 1: edge triggered, 0: level triggered */
244 		pch_pic_write_reg(&s->edge, index, data);
245 		break;
246 	case PCH_PIC_CLEAR_START ... PCH_PIC_CLEAR_END:
247 		offset -= PCH_PIC_CLEAR_START;
248 		index = offset >> 2;
249 		/* write 1 to clear edge irq */
250 		old = pch_pic_read_reg(&s->irr, index);
251 		/*
252 		 * get the irq bitmap which is edge triggered and
253 		 * already set and to be cleared
254 		 */
255 		irq = old & pch_pic_read_reg(&s->edge, index) & data;
256 		/* write irr to the new state where irqs have been cleared */
257 		pch_pic_write_reg(&s->irr, index, old & ~irq);
258 		/* update cleared irqs */
259 		pch_pic_update_batch_irqs(s, irq, 0);
260 		break;
261 	case PCH_PIC_AUTO_CTRL0_START ... PCH_PIC_AUTO_CTRL0_END:
262 		offset -= PCH_PIC_AUTO_CTRL0_START;
263 		index = offset >> 2;
264 		/* we only use default mode: fixed interrupt distribution mode */
265 		pch_pic_write_reg(&s->auto_ctrl0, index, 0);
266 		break;
267 	case PCH_PIC_AUTO_CTRL1_START ... PCH_PIC_AUTO_CTRL1_END:
268 		offset -= PCH_PIC_AUTO_CTRL1_START;
269 		index = offset >> 2;
270 		/* we only use default mode: fixed interrupt distribution mode */
271 		pch_pic_write_reg(&s->auto_ctrl1, index, 0);
272 		break;
273 	case PCH_PIC_ROUTE_ENTRY_START ... PCH_PIC_ROUTE_ENTRY_END:
274 		offset -= PCH_PIC_ROUTE_ENTRY_START;
275 		/* only route to int0: eiointc */
276 		s->route_entry[offset] = 1;
277 		break;
278 	case PCH_PIC_HTMSI_VEC_START ... PCH_PIC_HTMSI_VEC_END:
279 		/* route table to eiointc */
280 		offset -= PCH_PIC_HTMSI_VEC_START;
281 		s->htmsi_vector[offset] = (u8)data;
282 		break;
283 	case PCH_PIC_POLARITY_START ... PCH_PIC_POLARITY_END:
284 		offset -= PCH_PIC_POLARITY_START;
285 		index = offset >> 2;
286 		/* we only use defalut value 0: high level triggered */
287 		pch_pic_write_reg(&s->polarity, index, 0);
288 		break;
289 	default:
290 		ret = -EINVAL;
291 		break;
292 	}
293 	spin_unlock(&s->lock);
294 
295 	return ret;
296 }
297 
298 static int kvm_pch_pic_write(struct kvm_vcpu *vcpu,
299 			struct kvm_io_device *dev,
300 			gpa_t addr, int len, const void *val)
301 {
302 	int ret;
303 	struct loongarch_pch_pic *s = vcpu->kvm->arch.pch_pic;
304 
305 	if (!s) {
306 		kvm_err("%s: pch pic irqchip not valid!\n", __func__);
307 		return -EINVAL;
308 	}
309 
310 	if (addr & (len - 1)) {
311 		kvm_err("%s: pch pic not aligned addr %llx len %d\n", __func__, addr, len);
312 		return -EINVAL;
313 	}
314 
315 	/* statistics of pch pic writing */
316 	vcpu->stat.pch_pic_write_exits++;
317 	ret = loongarch_pch_pic_write(s, addr, len, val);
318 
319 	return ret;
320 }
321 
322 static const struct kvm_io_device_ops kvm_pch_pic_ops = {
323 	.read	= kvm_pch_pic_read,
324 	.write	= kvm_pch_pic_write,
325 };
326 
327 static int kvm_pch_pic_init(struct kvm_device *dev, u64 addr)
328 {
329 	int ret;
330 	struct kvm *kvm = dev->kvm;
331 	struct kvm_io_device *device;
332 	struct loongarch_pch_pic *s = dev->kvm->arch.pch_pic;
333 
334 	s->pch_pic_base = addr;
335 	device = &s->device;
336 	/* init device by pch pic writing and reading ops */
337 	kvm_iodevice_init(device, &kvm_pch_pic_ops);
338 	mutex_lock(&kvm->slots_lock);
339 	/* register pch pic device */
340 	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, addr, PCH_PIC_SIZE, device);
341 	mutex_unlock(&kvm->slots_lock);
342 
343 	return (ret < 0) ? -EFAULT : 0;
344 }
345 
346 /* used by user space to get or set pch pic registers */
347 static int kvm_pch_pic_regs_access(struct kvm_device *dev,
348 				struct kvm_device_attr *attr,
349 				bool is_write)
350 {
351 	int addr, offset, len = 8, ret = 0;
352 	void __user *data;
353 	void *p = NULL;
354 	struct loongarch_pch_pic *s;
355 
356 	s = dev->kvm->arch.pch_pic;
357 	addr = attr->attr;
358 	data = (void __user *)attr->addr;
359 
360 	/* get pointer to pch pic register by addr */
361 	switch (addr) {
362 	case PCH_PIC_MASK_START:
363 		p = &s->mask;
364 		break;
365 	case PCH_PIC_HTMSI_EN_START:
366 		p = &s->htmsi_en;
367 		break;
368 	case PCH_PIC_EDGE_START:
369 		p = &s->edge;
370 		break;
371 	case PCH_PIC_AUTO_CTRL0_START:
372 		p = &s->auto_ctrl0;
373 		break;
374 	case PCH_PIC_AUTO_CTRL1_START:
375 		p = &s->auto_ctrl1;
376 		break;
377 	case PCH_PIC_ROUTE_ENTRY_START ... PCH_PIC_ROUTE_ENTRY_END:
378 		offset = addr - PCH_PIC_ROUTE_ENTRY_START;
379 		p = &s->route_entry[offset];
380 		len = 1;
381 		break;
382 	case PCH_PIC_HTMSI_VEC_START ... PCH_PIC_HTMSI_VEC_END:
383 		offset = addr - PCH_PIC_HTMSI_VEC_START;
384 		p = &s->htmsi_vector[offset];
385 		len = 1;
386 		break;
387 	case PCH_PIC_INT_IRR_START:
388 		p = &s->irr;
389 		break;
390 	case PCH_PIC_INT_ISR_START:
391 		p = &s->isr;
392 		break;
393 	case PCH_PIC_POLARITY_START:
394 		p = &s->polarity;
395 		break;
396 	default:
397 		return -EINVAL;
398 	}
399 
400 	spin_lock(&s->lock);
401 	/* write or read value according to is_write */
402 	if (is_write) {
403 		if (copy_from_user(p, data, len))
404 			ret = -EFAULT;
405 	} else {
406 		if (copy_to_user(data, p, len))
407 			ret = -EFAULT;
408 	}
409 	spin_unlock(&s->lock);
410 
411 	return ret;
412 }
413 
414 static int kvm_pch_pic_get_attr(struct kvm_device *dev,
415 				struct kvm_device_attr *attr)
416 {
417 	switch (attr->group) {
418 	case KVM_DEV_LOONGARCH_PCH_PIC_GRP_REGS:
419 		return kvm_pch_pic_regs_access(dev, attr, false);
420 	default:
421 		return -EINVAL;
422 	}
423 }
424 
425 static int kvm_pch_pic_set_attr(struct kvm_device *dev,
426 				struct kvm_device_attr *attr)
427 {
428 	u64 addr;
429 	void __user *uaddr = (void __user *)(long)attr->addr;
430 
431 	switch (attr->group) {
432 	case KVM_DEV_LOONGARCH_PCH_PIC_GRP_CTRL:
433 		switch (attr->attr) {
434 		case KVM_DEV_LOONGARCH_PCH_PIC_CTRL_INIT:
435 			if (copy_from_user(&addr, uaddr, sizeof(addr)))
436 				return -EFAULT;
437 
438 			if (!dev->kvm->arch.pch_pic) {
439 				kvm_err("%s: please create pch_pic irqchip first!\n", __func__);
440 				return -ENODEV;
441 			}
442 
443 			return kvm_pch_pic_init(dev, addr);
444 		default:
445 			kvm_err("%s: unknown group (%d) attr (%lld)\n", __func__, attr->group,
446 					attr->attr);
447 			return -EINVAL;
448 		}
449 	case KVM_DEV_LOONGARCH_PCH_PIC_GRP_REGS:
450 		return kvm_pch_pic_regs_access(dev, attr, true);
451 	default:
452 		return -EINVAL;
453 	}
454 }
455 
456 static int kvm_setup_default_irq_routing(struct kvm *kvm)
457 {
458 	int i, ret;
459 	u32 nr = KVM_IRQCHIP_NUM_PINS;
460 	struct kvm_irq_routing_entry *entries;
461 
462 	entries = kcalloc(nr, sizeof(*entries), GFP_KERNEL);
463 	if (!entries)
464 		return -ENOMEM;
465 
466 	for (i = 0; i < nr; i++) {
467 		entries[i].gsi = i;
468 		entries[i].type = KVM_IRQ_ROUTING_IRQCHIP;
469 		entries[i].u.irqchip.irqchip = 0;
470 		entries[i].u.irqchip.pin = i;
471 	}
472 	ret = kvm_set_irq_routing(kvm, entries, nr, 0);
473 	kfree(entries);
474 
475 	return ret;
476 }
477 
478 static int kvm_pch_pic_create(struct kvm_device *dev, u32 type)
479 {
480 	int ret;
481 	struct kvm *kvm = dev->kvm;
482 	struct loongarch_pch_pic *s;
483 
484 	/* pch pic should not has been created */
485 	if (kvm->arch.pch_pic)
486 		return -EINVAL;
487 
488 	ret = kvm_setup_default_irq_routing(kvm);
489 	if (ret)
490 		return -ENOMEM;
491 
492 	s = kzalloc(sizeof(struct loongarch_pch_pic), GFP_KERNEL);
493 	if (!s)
494 		return -ENOMEM;
495 
496 	spin_lock_init(&s->lock);
497 	s->kvm = kvm;
498 	kvm->arch.pch_pic = s;
499 
500 	return 0;
501 }
502 
503 static void kvm_pch_pic_destroy(struct kvm_device *dev)
504 {
505 	struct kvm *kvm;
506 	struct loongarch_pch_pic *s;
507 
508 	if (!dev || !dev->kvm || !dev->kvm->arch.pch_pic)
509 		return;
510 
511 	kvm = dev->kvm;
512 	s = kvm->arch.pch_pic;
513 	/* unregister pch pic device and free it's memory */
514 	kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &s->device);
515 	kfree(s);
516 }
517 
518 static struct kvm_device_ops kvm_pch_pic_dev_ops = {
519 	.name = "kvm-loongarch-pch-pic",
520 	.create = kvm_pch_pic_create,
521 	.destroy = kvm_pch_pic_destroy,
522 	.set_attr = kvm_pch_pic_set_attr,
523 	.get_attr = kvm_pch_pic_get_attr,
524 };
525 
526 int kvm_loongarch_register_pch_pic_device(void)
527 {
528 	return kvm_register_device_ops(&kvm_pch_pic_dev_ops, KVM_DEV_TYPE_LOONGARCH_PCHPIC);
529 }
530