1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * vDPA bridge driver for Alibaba ENI(Elastic Network Interface)
4 *
5 * Copyright (c) 2021, Alibaba Inc. All rights reserved.
6 * Author: Wu Zongyong <wuzongyong@linux.alibaba.com>
7 *
8 */
9
10#include "linux/bits.h"
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_legacy.h>
20#include <uapi/linux/virtio_net.h>
21
22#define ENI_MSIX_NAME_SIZE 256
23
24#define ENI_ERR(pdev, fmt, ...)	\
25	dev_err(&pdev->dev, "%s"fmt, "eni_vdpa: ", ##__VA_ARGS__)
26#define ENI_DBG(pdev, fmt, ...)	\
27	dev_dbg(&pdev->dev, "%s"fmt, "eni_vdpa: ", ##__VA_ARGS__)
28#define ENI_INFO(pdev, fmt, ...) \
29	dev_info(&pdev->dev, "%s"fmt, "eni_vdpa: ", ##__VA_ARGS__)
30
31struct eni_vring {
32	void __iomem *notify;
33	char msix_name[ENI_MSIX_NAME_SIZE];
34	struct vdpa_callback cb;
35	int irq;
36};
37
38struct eni_vdpa {
39	struct vdpa_device vdpa;
40	struct virtio_pci_legacy_device ldev;
41	struct eni_vring *vring;
42	struct vdpa_callback config_cb;
43	char msix_name[ENI_MSIX_NAME_SIZE];
44	int config_irq;
45	int queues;
46	int vectors;
47};
48
49static struct eni_vdpa *vdpa_to_eni(struct vdpa_device *vdpa)
50{
51	return container_of(vdpa, struct eni_vdpa, vdpa);
52}
53
54static struct virtio_pci_legacy_device *vdpa_to_ldev(struct vdpa_device *vdpa)
55{
56	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
57
58	return &eni_vdpa->ldev;
59}
60
61static u64 eni_vdpa_get_device_features(struct vdpa_device *vdpa)
62{
63	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
64	u64 features = vp_legacy_get_features(ldev);
65
66	features |= BIT_ULL(VIRTIO_F_ACCESS_PLATFORM);
67	features |= BIT_ULL(VIRTIO_F_ORDER_PLATFORM);
68
69	return features;
70}
71
72static int eni_vdpa_set_driver_features(struct vdpa_device *vdpa, u64 features)
73{
74	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
75
76	if (!(features & BIT_ULL(VIRTIO_NET_F_MRG_RXBUF)) && features) {
77		ENI_ERR(ldev->pci_dev,
78			"VIRTIO_NET_F_MRG_RXBUF is not negotiated\n");
79		return -EINVAL;
80	}
81
82	vp_legacy_set_features(ldev, (u32)features);
83
84	return 0;
85}
86
87static u64 eni_vdpa_get_driver_features(struct vdpa_device *vdpa)
88{
89	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
90
91	return vp_legacy_get_driver_features(ldev);
92}
93
94static u8 eni_vdpa_get_status(struct vdpa_device *vdpa)
95{
96	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
97
98	return vp_legacy_get_status(ldev);
99}
100
101static int eni_vdpa_get_vq_irq(struct vdpa_device *vdpa, u16 idx)
102{
103	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
104	int irq = eni_vdpa->vring[idx].irq;
105
106	if (irq == VIRTIO_MSI_NO_VECTOR)
107		return -EINVAL;
108
109	return irq;
110}
111
112static void eni_vdpa_free_irq(struct eni_vdpa *eni_vdpa)
113{
114	struct virtio_pci_legacy_device *ldev = &eni_vdpa->ldev;
115	struct pci_dev *pdev = ldev->pci_dev;
116	int i;
117
118	for (i = 0; i < eni_vdpa->queues; i++) {
119		if (eni_vdpa->vring[i].irq != VIRTIO_MSI_NO_VECTOR) {
120			vp_legacy_queue_vector(ldev, i, VIRTIO_MSI_NO_VECTOR);
121			devm_free_irq(&pdev->dev, eni_vdpa->vring[i].irq,
122				      &eni_vdpa->vring[i]);
123			eni_vdpa->vring[i].irq = VIRTIO_MSI_NO_VECTOR;
124		}
125	}
126
127	if (eni_vdpa->config_irq != VIRTIO_MSI_NO_VECTOR) {
128		vp_legacy_config_vector(ldev, VIRTIO_MSI_NO_VECTOR);
129		devm_free_irq(&pdev->dev, eni_vdpa->config_irq, eni_vdpa);
130		eni_vdpa->config_irq = VIRTIO_MSI_NO_VECTOR;
131	}
132
133	if (eni_vdpa->vectors) {
134		pci_free_irq_vectors(pdev);
135		eni_vdpa->vectors = 0;
136	}
137}
138
139static irqreturn_t eni_vdpa_vq_handler(int irq, void *arg)
140{
141	struct eni_vring *vring = arg;
142
143	if (vring->cb.callback)
144		return vring->cb.callback(vring->cb.private);
145
146	return IRQ_HANDLED;
147}
148
149static irqreturn_t eni_vdpa_config_handler(int irq, void *arg)
150{
151	struct eni_vdpa *eni_vdpa = arg;
152
153	if (eni_vdpa->config_cb.callback)
154		return eni_vdpa->config_cb.callback(eni_vdpa->config_cb.private);
155
156	return IRQ_HANDLED;
157}
158
159static int eni_vdpa_request_irq(struct eni_vdpa *eni_vdpa)
160{
161	struct virtio_pci_legacy_device *ldev = &eni_vdpa->ldev;
162	struct pci_dev *pdev = ldev->pci_dev;
163	int i, ret, irq;
164	int queues = eni_vdpa->queues;
165	int vectors = queues + 1;
166
167	ret = pci_alloc_irq_vectors(pdev, vectors, vectors, PCI_IRQ_MSIX);
168	if (ret != vectors) {
169		ENI_ERR(pdev,
170			"failed to allocate irq vectors want %d but %d\n",
171			vectors, ret);
172		return ret;
173	}
174
175	eni_vdpa->vectors = vectors;
176
177	for (i = 0; i < queues; i++) {
178		snprintf(eni_vdpa->vring[i].msix_name, ENI_MSIX_NAME_SIZE,
179			 "eni-vdpa[%s]-%d\n", pci_name(pdev), i);
180		irq = pci_irq_vector(pdev, i);
181		ret = devm_request_irq(&pdev->dev, irq,
182				       eni_vdpa_vq_handler,
183				       0, eni_vdpa->vring[i].msix_name,
184				       &eni_vdpa->vring[i]);
185		if (ret) {
186			ENI_ERR(pdev, "failed to request irq for vq %d\n", i);
187			goto err;
188		}
189		vp_legacy_queue_vector(ldev, i, i);
190		eni_vdpa->vring[i].irq = irq;
191	}
192
193	snprintf(eni_vdpa->msix_name, ENI_MSIX_NAME_SIZE, "eni-vdpa[%s]-config\n",
194		 pci_name(pdev));
195	irq = pci_irq_vector(pdev, queues);
196	ret = devm_request_irq(&pdev->dev, irq, eni_vdpa_config_handler, 0,
197			       eni_vdpa->msix_name, eni_vdpa);
198	if (ret) {
199		ENI_ERR(pdev, "failed to request irq for config vq %d\n", i);
200		goto err;
201	}
202	vp_legacy_config_vector(ldev, queues);
203	eni_vdpa->config_irq = irq;
204
205	return 0;
206err:
207	eni_vdpa_free_irq(eni_vdpa);
208	return ret;
209}
210
211static void eni_vdpa_set_status(struct vdpa_device *vdpa, u8 status)
212{
213	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
214	struct virtio_pci_legacy_device *ldev = &eni_vdpa->ldev;
215	u8 s = eni_vdpa_get_status(vdpa);
216
217	if (status & VIRTIO_CONFIG_S_DRIVER_OK &&
218	    !(s & VIRTIO_CONFIG_S_DRIVER_OK)) {
219		eni_vdpa_request_irq(eni_vdpa);
220	}
221
222	vp_legacy_set_status(ldev, status);
223
224	if (!(status & VIRTIO_CONFIG_S_DRIVER_OK) &&
225	    (s & VIRTIO_CONFIG_S_DRIVER_OK))
226		eni_vdpa_free_irq(eni_vdpa);
227}
228
229static int eni_vdpa_reset(struct vdpa_device *vdpa)
230{
231	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
232	struct virtio_pci_legacy_device *ldev = &eni_vdpa->ldev;
233	u8 s = eni_vdpa_get_status(vdpa);
234
235	vp_legacy_set_status(ldev, 0);
236
237	if (s & VIRTIO_CONFIG_S_DRIVER_OK)
238		eni_vdpa_free_irq(eni_vdpa);
239
240	return 0;
241}
242
243static u16 eni_vdpa_get_vq_num_max(struct vdpa_device *vdpa)
244{
245	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
246
247	return vp_legacy_get_queue_size(ldev, 0);
248}
249
250static u16 eni_vdpa_get_vq_num_min(struct vdpa_device *vdpa)
251{
252	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
253
254	return vp_legacy_get_queue_size(ldev, 0);
255}
256
257static int eni_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 qid,
258				struct vdpa_vq_state *state)
259{
260	return -EOPNOTSUPP;
261}
262
263static int eni_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 qid,
264				 const struct vdpa_vq_state *state)
265{
266	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
267	const struct vdpa_vq_state_split *split = &state->split;
268
269	/* ENI is build upon virtio-pci specfication which not support
270	 * to set state of virtqueue. But if the state is equal to the
271	 * device initial state by chance, we can let it go.
272	 */
273	if (!vp_legacy_get_queue_enable(ldev, qid)
274	    && split->avail_index == 0)
275		return 0;
276
277	return -EOPNOTSUPP;
278}
279
280
281static void eni_vdpa_set_vq_cb(struct vdpa_device *vdpa, u16 qid,
282			       struct vdpa_callback *cb)
283{
284	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
285
286	eni_vdpa->vring[qid].cb = *cb;
287}
288
289static void eni_vdpa_set_vq_ready(struct vdpa_device *vdpa, u16 qid,
290				  bool ready)
291{
292	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
293
294	/* ENI is a legacy virtio-pci device. This is not supported
295	 * by specification. But we can disable virtqueue by setting
296	 * address to 0.
297	 */
298	if (!ready)
299		vp_legacy_set_queue_address(ldev, qid, 0);
300}
301
302static bool eni_vdpa_get_vq_ready(struct vdpa_device *vdpa, u16 qid)
303{
304	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
305
306	return vp_legacy_get_queue_enable(ldev, qid);
307}
308
309static void eni_vdpa_set_vq_num(struct vdpa_device *vdpa, u16 qid,
310			       u32 num)
311{
312	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
313	struct pci_dev *pdev = ldev->pci_dev;
314	u16 n = vp_legacy_get_queue_size(ldev, qid);
315
316	/* ENI is a legacy virtio-pci device which not allow to change
317	 * virtqueue size. Just report a error if someone tries to
318	 * change it.
319	 */
320	if (num != n)
321		ENI_ERR(pdev,
322			"not support to set vq %u fixed num %u to %u\n",
323			qid, n, num);
324}
325
326static int eni_vdpa_set_vq_address(struct vdpa_device *vdpa, u16 qid,
327				   u64 desc_area, u64 driver_area,
328				   u64 device_area)
329{
330	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
331	u32 pfn = desc_area >> VIRTIO_PCI_QUEUE_ADDR_SHIFT;
332
333	vp_legacy_set_queue_address(ldev, qid, pfn);
334
335	return 0;
336}
337
338static void eni_vdpa_kick_vq(struct vdpa_device *vdpa, u16 qid)
339{
340	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
341
342	iowrite16(qid, eni_vdpa->vring[qid].notify);
343}
344
345static u32 eni_vdpa_get_device_id(struct vdpa_device *vdpa)
346{
347	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
348
349	return ldev->id.device;
350}
351
352static u32 eni_vdpa_get_vendor_id(struct vdpa_device *vdpa)
353{
354	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
355
356	return ldev->id.vendor;
357}
358
359static u32 eni_vdpa_get_vq_align(struct vdpa_device *vdpa)
360{
361	return VIRTIO_PCI_VRING_ALIGN;
362}
363
364static size_t eni_vdpa_get_config_size(struct vdpa_device *vdpa)
365{
366	return sizeof(struct virtio_net_config);
367}
368
369
370static void eni_vdpa_get_config(struct vdpa_device *vdpa,
371				unsigned int offset,
372				void *buf, unsigned int len)
373{
374	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
375	struct virtio_pci_legacy_device *ldev = &eni_vdpa->ldev;
376	void __iomem *ioaddr = ldev->ioaddr +
377		VIRTIO_PCI_CONFIG_OFF(eni_vdpa->vectors) +
378		offset;
379	u8 *p = buf;
380	int i;
381
382	for (i = 0; i < len; i++)
383		*p++ = ioread8(ioaddr + i);
384}
385
386static void eni_vdpa_set_config(struct vdpa_device *vdpa,
387				unsigned int offset, const void *buf,
388				unsigned int len)
389{
390	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
391	struct virtio_pci_legacy_device *ldev = &eni_vdpa->ldev;
392	void __iomem *ioaddr = ldev->ioaddr +
393		VIRTIO_PCI_CONFIG_OFF(eni_vdpa->vectors) +
394		offset;
395	const u8 *p = buf;
396	int i;
397
398	for (i = 0; i < len; i++)
399		iowrite8(*p++, ioaddr + i);
400}
401
402static void eni_vdpa_set_config_cb(struct vdpa_device *vdpa,
403				   struct vdpa_callback *cb)
404{
405	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
406
407	eni_vdpa->config_cb = *cb;
408}
409
410static const struct vdpa_config_ops eni_vdpa_ops = {
411	.get_device_features = eni_vdpa_get_device_features,
412	.set_driver_features = eni_vdpa_set_driver_features,
413	.get_driver_features = eni_vdpa_get_driver_features,
414	.get_status	= eni_vdpa_get_status,
415	.set_status	= eni_vdpa_set_status,
416	.reset		= eni_vdpa_reset,
417	.get_vq_num_max	= eni_vdpa_get_vq_num_max,
418	.get_vq_num_min	= eni_vdpa_get_vq_num_min,
419	.get_vq_state	= eni_vdpa_get_vq_state,
420	.set_vq_state	= eni_vdpa_set_vq_state,
421	.set_vq_cb	= eni_vdpa_set_vq_cb,
422	.set_vq_ready	= eni_vdpa_set_vq_ready,
423	.get_vq_ready	= eni_vdpa_get_vq_ready,
424	.set_vq_num	= eni_vdpa_set_vq_num,
425	.set_vq_address	= eni_vdpa_set_vq_address,
426	.kick_vq	= eni_vdpa_kick_vq,
427	.get_device_id	= eni_vdpa_get_device_id,
428	.get_vendor_id	= eni_vdpa_get_vendor_id,
429	.get_vq_align	= eni_vdpa_get_vq_align,
430	.get_config_size = eni_vdpa_get_config_size,
431	.get_config	= eni_vdpa_get_config,
432	.set_config	= eni_vdpa_set_config,
433	.set_config_cb  = eni_vdpa_set_config_cb,
434	.get_vq_irq	= eni_vdpa_get_vq_irq,
435};
436
437
438static u16 eni_vdpa_get_num_queues(struct eni_vdpa *eni_vdpa)
439{
440	struct virtio_pci_legacy_device *ldev = &eni_vdpa->ldev;
441	u32 features = vp_legacy_get_features(ldev);
442	u16 num = 2;
443
444	if (features & BIT_ULL(VIRTIO_NET_F_MQ)) {
445		__virtio16 max_virtqueue_pairs;
446
447		eni_vdpa_get_config(&eni_vdpa->vdpa,
448			offsetof(struct virtio_net_config, max_virtqueue_pairs),
449			&max_virtqueue_pairs,
450			sizeof(max_virtqueue_pairs));
451		num = 2 * __virtio16_to_cpu(virtio_legacy_is_little_endian(),
452				max_virtqueue_pairs);
453	}
454
455	if (features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ))
456		num += 1;
457
458	return num;
459}
460
461static int eni_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
462{
463	struct device *dev = &pdev->dev;
464	struct eni_vdpa *eni_vdpa;
465	struct virtio_pci_legacy_device *ldev;
466	int ret, i;
467
468	ret = pcim_enable_device(pdev);
469	if (ret)
470		return ret;
471
472	eni_vdpa = vdpa_alloc_device(struct eni_vdpa, vdpa,
473				     dev, &eni_vdpa_ops, 1, 1, NULL, false);
474	if (IS_ERR(eni_vdpa)) {
475		ENI_ERR(pdev, "failed to allocate vDPA structure\n");
476		return PTR_ERR(eni_vdpa);
477	}
478
479	ldev = &eni_vdpa->ldev;
480	ldev->pci_dev = pdev;
481
482	ret = vp_legacy_probe(ldev);
483	if (ret) {
484		ENI_ERR(pdev, "failed to probe legacy PCI device\n");
485		goto err;
486	}
487
488	pci_set_master(pdev);
489	pci_set_drvdata(pdev, eni_vdpa);
490
491	eni_vdpa->vdpa.dma_dev = &pdev->dev;
492	eni_vdpa->queues = eni_vdpa_get_num_queues(eni_vdpa);
493
494	eni_vdpa->vring = devm_kcalloc(&pdev->dev, eni_vdpa->queues,
495				      sizeof(*eni_vdpa->vring),
496				      GFP_KERNEL);
497	if (!eni_vdpa->vring) {
498		ret = -ENOMEM;
499		ENI_ERR(pdev, "failed to allocate virtqueues\n");
500		goto err_remove_vp_legacy;
501	}
502
503	for (i = 0; i < eni_vdpa->queues; i++) {
504		eni_vdpa->vring[i].irq = VIRTIO_MSI_NO_VECTOR;
505		eni_vdpa->vring[i].notify = ldev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
506	}
507	eni_vdpa->config_irq = VIRTIO_MSI_NO_VECTOR;
508
509	ret = vdpa_register_device(&eni_vdpa->vdpa, eni_vdpa->queues);
510	if (ret) {
511		ENI_ERR(pdev, "failed to register to vdpa bus\n");
512		goto err_remove_vp_legacy;
513	}
514
515	return 0;
516
517err_remove_vp_legacy:
518	vp_legacy_remove(&eni_vdpa->ldev);
519err:
520	put_device(&eni_vdpa->vdpa.dev);
521	return ret;
522}
523
524static void eni_vdpa_remove(struct pci_dev *pdev)
525{
526	struct eni_vdpa *eni_vdpa = pci_get_drvdata(pdev);
527
528	vdpa_unregister_device(&eni_vdpa->vdpa);
529	vp_legacy_remove(&eni_vdpa->ldev);
530}
531
532static struct pci_device_id eni_pci_ids[] = {
533	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_REDHAT_QUMRANET,
534			 VIRTIO_TRANS_ID_NET,
535			 PCI_SUBVENDOR_ID_REDHAT_QUMRANET,
536			 VIRTIO_ID_NET) },
537	{ 0 },
538};
539
540static struct pci_driver eni_vdpa_driver = {
541	.name		= "alibaba-eni-vdpa",
542	.id_table	= eni_pci_ids,
543	.probe		= eni_vdpa_probe,
544	.remove		= eni_vdpa_remove,
545};
546
547module_pci_driver(eni_vdpa_driver);
548
549MODULE_AUTHOR("Wu Zongyong <wuzongyong@linux.alibaba.com>");
550MODULE_DESCRIPTION("Alibaba ENI vDPA driver");
551MODULE_LICENSE("GPL v2");
552