1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * vDPA bridge driver for modern virtio-pci device
4  *
5  * Copyright (c) 2020, Red Hat Inc. All rights reserved.
6  * Author: Jason Wang <jasowang@redhat.com>
7  *
8  * Based on virtio_pci_modern.c.
9  */
10 
11 #include <linux/interrupt.h>
12 #include <linux/module.h>
13 #include <linux/pci.h>
14 #include <linux/vdpa.h>
15 #include <linux/virtio.h>
16 #include <linux/virtio_config.h>
17 #include <linux/virtio_ring.h>
18 #include <linux/virtio_pci.h>
19 #include <linux/virtio_pci_modern.h>
20 
21 #define VP_VDPA_QUEUE_MAX 256
22 #define VP_VDPA_DRIVER_NAME "vp_vdpa"
23 #define VP_VDPA_NAME_SIZE 256
24 
25 struct vp_vring {
26 	void __iomem *notify;
27 	char msix_name[VP_VDPA_NAME_SIZE];
28 	struct vdpa_callback cb;
29 	resource_size_t notify_pa;
30 	int irq;
31 };
32 
33 struct vp_vdpa {
34 	struct vdpa_device vdpa;
35 	struct virtio_pci_modern_device mdev;
36 	struct vp_vring *vring;
37 	struct vdpa_callback config_cb;
38 	char msix_name[VP_VDPA_NAME_SIZE];
39 	int config_irq;
40 	int queues;
41 	int vectors;
42 };
43 
44 static struct vp_vdpa *vdpa_to_vp(struct vdpa_device *vdpa)
45 {
46 	return container_of(vdpa, struct vp_vdpa, vdpa);
47 }
48 
49 static struct virtio_pci_modern_device *vdpa_to_mdev(struct vdpa_device *vdpa)
50 {
51 	struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
52 
53 	return &vp_vdpa->mdev;
54 }
55 
56 static u64 vp_vdpa_get_device_features(struct vdpa_device *vdpa)
57 {
58 	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
59 
60 	return vp_modern_get_features(mdev);
61 }
62 
63 static int vp_vdpa_set_driver_features(struct vdpa_device *vdpa, u64 features)
64 {
65 	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
66 
67 	vp_modern_set_features(mdev, features);
68 
69 	return 0;
70 }
71 
72 static u64 vp_vdpa_get_driver_features(struct vdpa_device *vdpa)
73 {
74 	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
75 
76 	return vp_modern_get_driver_features(mdev);
77 }
78 
79 static u8 vp_vdpa_get_status(struct vdpa_device *vdpa)
80 {
81 	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
82 
83 	return vp_modern_get_status(mdev);
84 }
85 
86 static int vp_vdpa_get_vq_irq(struct vdpa_device *vdpa, u16 idx)
87 {
88 	struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
89 	int irq = vp_vdpa->vring[idx].irq;
90 
91 	if (irq == VIRTIO_MSI_NO_VECTOR)
92 		return -EINVAL;
93 
94 	return irq;
95 }
96 
97 static void vp_vdpa_free_irq(struct vp_vdpa *vp_vdpa)
98 {
99 	struct virtio_pci_modern_device *mdev = &vp_vdpa->mdev;
100 	struct pci_dev *pdev = mdev->pci_dev;
101 	int i;
102 
103 	for (i = 0; i < vp_vdpa->queues; i++) {
104 		if (vp_vdpa->vring[i].irq != VIRTIO_MSI_NO_VECTOR) {
105 			vp_modern_queue_vector(mdev, i, VIRTIO_MSI_NO_VECTOR);
106 			devm_free_irq(&pdev->dev, vp_vdpa->vring[i].irq,
107 				      &vp_vdpa->vring[i]);
108 			vp_vdpa->vring[i].irq = VIRTIO_MSI_NO_VECTOR;
109 		}
110 	}
111 
112 	if (vp_vdpa->config_irq != VIRTIO_MSI_NO_VECTOR) {
113 		vp_modern_config_vector(mdev, VIRTIO_MSI_NO_VECTOR);
114 		devm_free_irq(&pdev->dev, vp_vdpa->config_irq, vp_vdpa);
115 		vp_vdpa->config_irq = VIRTIO_MSI_NO_VECTOR;
116 	}
117 
118 	if (vp_vdpa->vectors) {
119 		pci_free_irq_vectors(pdev);
120 		vp_vdpa->vectors = 0;
121 	}
122 }
123 
124 static irqreturn_t vp_vdpa_vq_handler(int irq, void *arg)
125 {
126 	struct vp_vring *vring = arg;
127 
128 	if (vring->cb.callback)
129 		return vring->cb.callback(vring->cb.private);
130 
131 	return IRQ_HANDLED;
132 }
133 
134 static irqreturn_t vp_vdpa_config_handler(int irq, void *arg)
135 {
136 	struct vp_vdpa *vp_vdpa = arg;
137 
138 	if (vp_vdpa->config_cb.callback)
139 		return vp_vdpa->config_cb.callback(vp_vdpa->config_cb.private);
140 
141 	return IRQ_HANDLED;
142 }
143 
144 static int vp_vdpa_request_irq(struct vp_vdpa *vp_vdpa)
145 {
146 	struct virtio_pci_modern_device *mdev = &vp_vdpa->mdev;
147 	struct pci_dev *pdev = mdev->pci_dev;
148 	int i, ret, irq;
149 	int queues = vp_vdpa->queues;
150 	int vectors = queues + 1;
151 
152 	ret = pci_alloc_irq_vectors(pdev, vectors, vectors, PCI_IRQ_MSIX);
153 	if (ret != vectors) {
154 		dev_err(&pdev->dev,
155 			"vp_vdpa: fail to allocate irq vectors want %d but %d\n",
156 			vectors, ret);
157 		return ret;
158 	}
159 
160 	vp_vdpa->vectors = vectors;
161 
162 	for (i = 0; i < queues; i++) {
163 		snprintf(vp_vdpa->vring[i].msix_name, VP_VDPA_NAME_SIZE,
164 			"vp-vdpa[%s]-%d\n", pci_name(pdev), i);
165 		irq = pci_irq_vector(pdev, i);
166 		ret = devm_request_irq(&pdev->dev, irq,
167 				       vp_vdpa_vq_handler,
168 				       0, vp_vdpa->vring[i].msix_name,
169 				       &vp_vdpa->vring[i]);
170 		if (ret) {
171 			dev_err(&pdev->dev,
172 				"vp_vdpa: fail to request irq for vq %d\n", i);
173 			goto err;
174 		}
175 		vp_modern_queue_vector(mdev, i, i);
176 		vp_vdpa->vring[i].irq = irq;
177 	}
178 
179 	snprintf(vp_vdpa->msix_name, VP_VDPA_NAME_SIZE, "vp-vdpa[%s]-config\n",
180 		 pci_name(pdev));
181 	irq = pci_irq_vector(pdev, queues);
182 	ret = devm_request_irq(&pdev->dev, irq,	vp_vdpa_config_handler, 0,
183 			       vp_vdpa->msix_name, vp_vdpa);
184 	if (ret) {
185 		dev_err(&pdev->dev,
186 			"vp_vdpa: fail to request irq for vq %d\n", i);
187 			goto err;
188 	}
189 	vp_modern_config_vector(mdev, queues);
190 	vp_vdpa->config_irq = irq;
191 
192 	return 0;
193 err:
194 	vp_vdpa_free_irq(vp_vdpa);
195 	return ret;
196 }
197 
198 static void vp_vdpa_set_status(struct vdpa_device *vdpa, u8 status)
199 {
200 	struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
201 	struct virtio_pci_modern_device *mdev = &vp_vdpa->mdev;
202 	u8 s = vp_vdpa_get_status(vdpa);
203 
204 	if (status & VIRTIO_CONFIG_S_DRIVER_OK &&
205 	    !(s & VIRTIO_CONFIG_S_DRIVER_OK)) {
206 		vp_vdpa_request_irq(vp_vdpa);
207 	}
208 
209 	vp_modern_set_status(mdev, status);
210 }
211 
212 static int vp_vdpa_reset(struct vdpa_device *vdpa)
213 {
214 	struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
215 	struct virtio_pci_modern_device *mdev = &vp_vdpa->mdev;
216 	u8 s = vp_vdpa_get_status(vdpa);
217 
218 	vp_modern_set_status(mdev, 0);
219 
220 	if (s & VIRTIO_CONFIG_S_DRIVER_OK)
221 		vp_vdpa_free_irq(vp_vdpa);
222 
223 	return 0;
224 }
225 
226 static u16 vp_vdpa_get_vq_num_max(struct vdpa_device *vdpa)
227 {
228 	return VP_VDPA_QUEUE_MAX;
229 }
230 
231 static int vp_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 qid,
232 				struct vdpa_vq_state *state)
233 {
234 	/* Note that this is not supported by virtio specification, so
235 	 * we return -EOPNOTSUPP here. This means we can't support live
236 	 * migration, vhost device start/stop.
237 	 */
238 	return -EOPNOTSUPP;
239 }
240 
241 static int vp_vdpa_set_vq_state_split(struct vdpa_device *vdpa,
242 				      const struct vdpa_vq_state *state)
243 {
244 	const struct vdpa_vq_state_split *split = &state->split;
245 
246 	if (split->avail_index == 0)
247 		return 0;
248 
249 	return -EOPNOTSUPP;
250 }
251 
252 static int vp_vdpa_set_vq_state_packed(struct vdpa_device *vdpa,
253 				       const struct vdpa_vq_state *state)
254 {
255 	const struct vdpa_vq_state_packed *packed = &state->packed;
256 
257 	if (packed->last_avail_counter == 1 &&
258 	    packed->last_avail_idx == 0 &&
259 	    packed->last_used_counter == 1 &&
260 	    packed->last_used_idx == 0)
261 		return 0;
262 
263 	return -EOPNOTSUPP;
264 }
265 
266 static int vp_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 qid,
267 				const struct vdpa_vq_state *state)
268 {
269 	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
270 
271 	/* Note that this is not supported by virtio specification.
272 	 * But if the state is by chance equal to the device initial
273 	 * state, we can let it go.
274 	 */
275 	if ((vp_modern_get_status(mdev) & VIRTIO_CONFIG_S_FEATURES_OK) &&
276 	    !vp_modern_get_queue_enable(mdev, qid)) {
277 		if (vp_modern_get_driver_features(mdev) &
278 		    BIT_ULL(VIRTIO_F_RING_PACKED))
279 			return vp_vdpa_set_vq_state_packed(vdpa, state);
280 		else
281 			return vp_vdpa_set_vq_state_split(vdpa,	state);
282 	}
283 
284 	return -EOPNOTSUPP;
285 }
286 
287 static void vp_vdpa_set_vq_cb(struct vdpa_device *vdpa, u16 qid,
288 			      struct vdpa_callback *cb)
289 {
290 	struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
291 
292 	vp_vdpa->vring[qid].cb = *cb;
293 }
294 
295 static void vp_vdpa_set_vq_ready(struct vdpa_device *vdpa,
296 				 u16 qid, bool ready)
297 {
298 	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
299 
300 	vp_modern_set_queue_enable(mdev, qid, ready);
301 }
302 
303 static bool vp_vdpa_get_vq_ready(struct vdpa_device *vdpa, u16 qid)
304 {
305 	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
306 
307 	return vp_modern_get_queue_enable(mdev, qid);
308 }
309 
310 static void vp_vdpa_set_vq_num(struct vdpa_device *vdpa, u16 qid,
311 			       u32 num)
312 {
313 	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
314 
315 	vp_modern_set_queue_size(mdev, qid, num);
316 }
317 
318 static int vp_vdpa_set_vq_address(struct vdpa_device *vdpa, u16 qid,
319 				  u64 desc_area, u64 driver_area,
320 				  u64 device_area)
321 {
322 	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
323 
324 	vp_modern_queue_address(mdev, qid, desc_area,
325 				driver_area, device_area);
326 
327 	return 0;
328 }
329 
330 static void vp_vdpa_kick_vq(struct vdpa_device *vdpa, u16 qid)
331 {
332 	struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
333 
334 	vp_iowrite16(qid, vp_vdpa->vring[qid].notify);
335 }
336 
337 static u32 vp_vdpa_get_generation(struct vdpa_device *vdpa)
338 {
339 	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
340 
341 	return vp_modern_generation(mdev);
342 }
343 
344 static u32 vp_vdpa_get_device_id(struct vdpa_device *vdpa)
345 {
346 	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
347 
348 	return mdev->id.device;
349 }
350 
351 static u32 vp_vdpa_get_vendor_id(struct vdpa_device *vdpa)
352 {
353 	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
354 
355 	return mdev->id.vendor;
356 }
357 
358 static u32 vp_vdpa_get_vq_align(struct vdpa_device *vdpa)
359 {
360 	return PAGE_SIZE;
361 }
362 
363 static size_t vp_vdpa_get_config_size(struct vdpa_device *vdpa)
364 {
365 	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
366 
367 	return mdev->device_len;
368 }
369 
370 static void vp_vdpa_get_config(struct vdpa_device *vdpa,
371 			       unsigned int offset,
372 			       void *buf, unsigned int len)
373 {
374 	struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
375 	struct virtio_pci_modern_device *mdev = &vp_vdpa->mdev;
376 	u8 old, new;
377 	u8 *p;
378 	int i;
379 
380 	do {
381 		old = vp_ioread8(&mdev->common->config_generation);
382 		p = buf;
383 		for (i = 0; i < len; i++)
384 			*p++ = vp_ioread8(mdev->device + offset + i);
385 
386 		new = vp_ioread8(&mdev->common->config_generation);
387 	} while (old != new);
388 }
389 
390 static void vp_vdpa_set_config(struct vdpa_device *vdpa,
391 			       unsigned int offset, const void *buf,
392 			       unsigned int len)
393 {
394 	struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
395 	struct virtio_pci_modern_device *mdev = &vp_vdpa->mdev;
396 	const u8 *p = buf;
397 	int i;
398 
399 	for (i = 0; i < len; i++)
400 		vp_iowrite8(*p++, mdev->device + offset + i);
401 }
402 
403 static void vp_vdpa_set_config_cb(struct vdpa_device *vdpa,
404 				  struct vdpa_callback *cb)
405 {
406 	struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
407 
408 	vp_vdpa->config_cb = *cb;
409 }
410 
411 static struct vdpa_notification_area
412 vp_vdpa_get_vq_notification(struct vdpa_device *vdpa, u16 qid)
413 {
414 	struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
415 	struct virtio_pci_modern_device *mdev = &vp_vdpa->mdev;
416 	struct vdpa_notification_area notify;
417 
418 	notify.addr = vp_vdpa->vring[qid].notify_pa;
419 	notify.size = mdev->notify_offset_multiplier;
420 
421 	return notify;
422 }
423 
424 static const struct vdpa_config_ops vp_vdpa_ops = {
425 	.get_device_features = vp_vdpa_get_device_features,
426 	.set_driver_features = vp_vdpa_set_driver_features,
427 	.get_driver_features = vp_vdpa_get_driver_features,
428 	.get_status	= vp_vdpa_get_status,
429 	.set_status	= vp_vdpa_set_status,
430 	.reset		= vp_vdpa_reset,
431 	.get_vq_num_max	= vp_vdpa_get_vq_num_max,
432 	.get_vq_state	= vp_vdpa_get_vq_state,
433 	.get_vq_notification = vp_vdpa_get_vq_notification,
434 	.set_vq_state	= vp_vdpa_set_vq_state,
435 	.set_vq_cb	= vp_vdpa_set_vq_cb,
436 	.set_vq_ready	= vp_vdpa_set_vq_ready,
437 	.get_vq_ready	= vp_vdpa_get_vq_ready,
438 	.set_vq_num	= vp_vdpa_set_vq_num,
439 	.set_vq_address	= vp_vdpa_set_vq_address,
440 	.kick_vq	= vp_vdpa_kick_vq,
441 	.get_generation	= vp_vdpa_get_generation,
442 	.get_device_id	= vp_vdpa_get_device_id,
443 	.get_vendor_id	= vp_vdpa_get_vendor_id,
444 	.get_vq_align	= vp_vdpa_get_vq_align,
445 	.get_config_size = vp_vdpa_get_config_size,
446 	.get_config	= vp_vdpa_get_config,
447 	.set_config	= vp_vdpa_set_config,
448 	.set_config_cb  = vp_vdpa_set_config_cb,
449 	.get_vq_irq	= vp_vdpa_get_vq_irq,
450 };
451 
452 static void vp_vdpa_free_irq_vectors(void *data)
453 {
454 	pci_free_irq_vectors(data);
455 }
456 
457 static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
458 {
459 	struct virtio_pci_modern_device *mdev;
460 	struct device *dev = &pdev->dev;
461 	struct vp_vdpa *vp_vdpa;
462 	int ret, i;
463 
464 	ret = pcim_enable_device(pdev);
465 	if (ret)
466 		return ret;
467 
468 	vp_vdpa = vdpa_alloc_device(struct vp_vdpa, vdpa,
469 				    dev, &vp_vdpa_ops, NULL, false);
470 	if (IS_ERR(vp_vdpa)) {
471 		dev_err(dev, "vp_vdpa: Failed to allocate vDPA structure\n");
472 		return PTR_ERR(vp_vdpa);
473 	}
474 
475 	mdev = &vp_vdpa->mdev;
476 	mdev->pci_dev = pdev;
477 
478 	ret = vp_modern_probe(mdev);
479 	if (ret) {
480 		dev_err(&pdev->dev, "Failed to probe modern PCI device\n");
481 		goto err;
482 	}
483 
484 	pci_set_master(pdev);
485 	pci_set_drvdata(pdev, vp_vdpa);
486 
487 	vp_vdpa->vdpa.dma_dev = &pdev->dev;
488 	vp_vdpa->queues = vp_modern_get_num_queues(mdev);
489 
490 	ret = devm_add_action_or_reset(dev, vp_vdpa_free_irq_vectors, pdev);
491 	if (ret) {
492 		dev_err(&pdev->dev,
493 			"Failed for adding devres for freeing irq vectors\n");
494 		goto err;
495 	}
496 
497 	vp_vdpa->vring = devm_kcalloc(&pdev->dev, vp_vdpa->queues,
498 				      sizeof(*vp_vdpa->vring),
499 				      GFP_KERNEL);
500 	if (!vp_vdpa->vring) {
501 		ret = -ENOMEM;
502 		dev_err(&pdev->dev, "Fail to allocate virtqueues\n");
503 		goto err;
504 	}
505 
506 	for (i = 0; i < vp_vdpa->queues; i++) {
507 		vp_vdpa->vring[i].irq = VIRTIO_MSI_NO_VECTOR;
508 		vp_vdpa->vring[i].notify =
509 			vp_modern_map_vq_notify(mdev, i,
510 						&vp_vdpa->vring[i].notify_pa);
511 		if (!vp_vdpa->vring[i].notify) {
512 			ret = -EINVAL;
513 			dev_warn(&pdev->dev, "Fail to map vq notify %d\n", i);
514 			goto err;
515 		}
516 	}
517 	vp_vdpa->config_irq = VIRTIO_MSI_NO_VECTOR;
518 
519 	ret = vdpa_register_device(&vp_vdpa->vdpa, vp_vdpa->queues);
520 	if (ret) {
521 		dev_err(&pdev->dev, "Failed to register to vdpa bus\n");
522 		goto err;
523 	}
524 
525 	return 0;
526 
527 err:
528 	put_device(&vp_vdpa->vdpa.dev);
529 	return ret;
530 }
531 
532 static void vp_vdpa_remove(struct pci_dev *pdev)
533 {
534 	struct vp_vdpa *vp_vdpa = pci_get_drvdata(pdev);
535 
536 	vdpa_unregister_device(&vp_vdpa->vdpa);
537 	vp_modern_remove(&vp_vdpa->mdev);
538 }
539 
540 static struct pci_driver vp_vdpa_driver = {
541 	.name		= "vp-vdpa",
542 	.id_table	= NULL, /* only dynamic ids */
543 	.probe		= vp_vdpa_probe,
544 	.remove		= vp_vdpa_remove,
545 };
546 
547 module_pci_driver(vp_vdpa_driver);
548 
549 MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
550 MODULE_DESCRIPTION("vp-vdpa");
551 MODULE_LICENSE("GPL");
552 MODULE_VERSION("1");
553