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 u16 eni_vdpa_get_vq_size(struct vdpa_device *vdpa, u16 qid)
258{
259	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
260
261	return vp_legacy_get_queue_size(ldev, qid);
262}
263
264static int eni_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 qid,
265				struct vdpa_vq_state *state)
266{
267	return -EOPNOTSUPP;
268}
269
270static int eni_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 qid,
271				 const struct vdpa_vq_state *state)
272{
273	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
274	const struct vdpa_vq_state_split *split = &state->split;
275
276	/* ENI is build upon virtio-pci specfication which not support
277	 * to set state of virtqueue. But if the state is equal to the
278	 * device initial state by chance, we can let it go.
279	 */
280	if (!vp_legacy_get_queue_enable(ldev, qid)
281	    && split->avail_index == 0)
282		return 0;
283
284	return -EOPNOTSUPP;
285}
286
287
288static void eni_vdpa_set_vq_cb(struct vdpa_device *vdpa, u16 qid,
289			       struct vdpa_callback *cb)
290{
291	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
292
293	eni_vdpa->vring[qid].cb = *cb;
294}
295
296static void eni_vdpa_set_vq_ready(struct vdpa_device *vdpa, u16 qid,
297				  bool ready)
298{
299	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
300
301	/* ENI is a legacy virtio-pci device. This is not supported
302	 * by specification. But we can disable virtqueue by setting
303	 * address to 0.
304	 */
305	if (!ready)
306		vp_legacy_set_queue_address(ldev, qid, 0);
307}
308
309static bool eni_vdpa_get_vq_ready(struct vdpa_device *vdpa, u16 qid)
310{
311	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
312
313	return vp_legacy_get_queue_enable(ldev, qid);
314}
315
316static void eni_vdpa_set_vq_num(struct vdpa_device *vdpa, u16 qid,
317			       u32 num)
318{
319	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
320	struct pci_dev *pdev = ldev->pci_dev;
321	u16 n = vp_legacy_get_queue_size(ldev, qid);
322
323	/* ENI is a legacy virtio-pci device which not allow to change
324	 * virtqueue size. Just report a error if someone tries to
325	 * change it.
326	 */
327	if (num != n)
328		ENI_ERR(pdev,
329			"not support to set vq %u fixed num %u to %u\n",
330			qid, n, num);
331}
332
333static int eni_vdpa_set_vq_address(struct vdpa_device *vdpa, u16 qid,
334				   u64 desc_area, u64 driver_area,
335				   u64 device_area)
336{
337	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
338	u32 pfn = desc_area >> VIRTIO_PCI_QUEUE_ADDR_SHIFT;
339
340	vp_legacy_set_queue_address(ldev, qid, pfn);
341
342	return 0;
343}
344
345static void eni_vdpa_kick_vq(struct vdpa_device *vdpa, u16 qid)
346{
347	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
348
349	iowrite16(qid, eni_vdpa->vring[qid].notify);
350}
351
352static u32 eni_vdpa_get_device_id(struct vdpa_device *vdpa)
353{
354	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
355
356	return ldev->id.device;
357}
358
359static u32 eni_vdpa_get_vendor_id(struct vdpa_device *vdpa)
360{
361	struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
362
363	return ldev->id.vendor;
364}
365
366static u32 eni_vdpa_get_vq_align(struct vdpa_device *vdpa)
367{
368	return VIRTIO_PCI_VRING_ALIGN;
369}
370
371static size_t eni_vdpa_get_config_size(struct vdpa_device *vdpa)
372{
373	return sizeof(struct virtio_net_config);
374}
375
376
377static void eni_vdpa_get_config(struct vdpa_device *vdpa,
378				unsigned int offset,
379				void *buf, unsigned int len)
380{
381	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
382	struct virtio_pci_legacy_device *ldev = &eni_vdpa->ldev;
383	void __iomem *ioaddr = ldev->ioaddr +
384		VIRTIO_PCI_CONFIG_OFF(eni_vdpa->vectors) +
385		offset;
386	u8 *p = buf;
387	int i;
388
389	for (i = 0; i < len; i++)
390		*p++ = ioread8(ioaddr + i);
391}
392
393static void eni_vdpa_set_config(struct vdpa_device *vdpa,
394				unsigned int offset, const void *buf,
395				unsigned int len)
396{
397	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
398	struct virtio_pci_legacy_device *ldev = &eni_vdpa->ldev;
399	void __iomem *ioaddr = ldev->ioaddr +
400		VIRTIO_PCI_CONFIG_OFF(eni_vdpa->vectors) +
401		offset;
402	const u8 *p = buf;
403	int i;
404
405	for (i = 0; i < len; i++)
406		iowrite8(*p++, ioaddr + i);
407}
408
409static void eni_vdpa_set_config_cb(struct vdpa_device *vdpa,
410				   struct vdpa_callback *cb)
411{
412	struct eni_vdpa *eni_vdpa = vdpa_to_eni(vdpa);
413
414	eni_vdpa->config_cb = *cb;
415}
416
417static const struct vdpa_config_ops eni_vdpa_ops = {
418	.get_device_features = eni_vdpa_get_device_features,
419	.set_driver_features = eni_vdpa_set_driver_features,
420	.get_driver_features = eni_vdpa_get_driver_features,
421	.get_status	= eni_vdpa_get_status,
422	.set_status	= eni_vdpa_set_status,
423	.reset		= eni_vdpa_reset,
424	.get_vq_num_max	= eni_vdpa_get_vq_num_max,
425	.get_vq_num_min	= eni_vdpa_get_vq_num_min,
426	.get_vq_size	= eni_vdpa_get_vq_size,
427	.get_vq_state	= eni_vdpa_get_vq_state,
428	.set_vq_state	= eni_vdpa_set_vq_state,
429	.set_vq_cb	= eni_vdpa_set_vq_cb,
430	.set_vq_ready	= eni_vdpa_set_vq_ready,
431	.get_vq_ready	= eni_vdpa_get_vq_ready,
432	.set_vq_num	= eni_vdpa_set_vq_num,
433	.set_vq_address	= eni_vdpa_set_vq_address,
434	.kick_vq	= eni_vdpa_kick_vq,
435	.get_device_id	= eni_vdpa_get_device_id,
436	.get_vendor_id	= eni_vdpa_get_vendor_id,
437	.get_vq_align	= eni_vdpa_get_vq_align,
438	.get_config_size = eni_vdpa_get_config_size,
439	.get_config	= eni_vdpa_get_config,
440	.set_config	= eni_vdpa_set_config,
441	.set_config_cb  = eni_vdpa_set_config_cb,
442	.get_vq_irq	= eni_vdpa_get_vq_irq,
443};
444
445
446static u16 eni_vdpa_get_num_queues(struct eni_vdpa *eni_vdpa)
447{
448	struct virtio_pci_legacy_device *ldev = &eni_vdpa->ldev;
449	u32 features = vp_legacy_get_features(ldev);
450	u16 num = 2;
451
452	if (features & BIT_ULL(VIRTIO_NET_F_MQ)) {
453		__virtio16 max_virtqueue_pairs;
454
455		eni_vdpa_get_config(&eni_vdpa->vdpa,
456			offsetof(struct virtio_net_config, max_virtqueue_pairs),
457			&max_virtqueue_pairs,
458			sizeof(max_virtqueue_pairs));
459		num = 2 * __virtio16_to_cpu(virtio_legacy_is_little_endian(),
460				max_virtqueue_pairs);
461	}
462
463	if (features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ))
464		num += 1;
465
466	return num;
467}
468
469static int eni_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
470{
471	struct device *dev = &pdev->dev;
472	struct eni_vdpa *eni_vdpa;
473	struct virtio_pci_legacy_device *ldev;
474	int ret, i;
475
476	ret = pcim_enable_device(pdev);
477	if (ret)
478		return ret;
479
480	eni_vdpa = vdpa_alloc_device(struct eni_vdpa, vdpa,
481				     dev, &eni_vdpa_ops, 1, 1, NULL, false);
482	if (IS_ERR(eni_vdpa)) {
483		ENI_ERR(pdev, "failed to allocate vDPA structure\n");
484		return PTR_ERR(eni_vdpa);
485	}
486
487	ldev = &eni_vdpa->ldev;
488	ldev->pci_dev = pdev;
489
490	ret = vp_legacy_probe(ldev);
491	if (ret) {
492		ENI_ERR(pdev, "failed to probe legacy PCI device\n");
493		goto err;
494	}
495
496	pci_set_master(pdev);
497	pci_set_drvdata(pdev, eni_vdpa);
498
499	eni_vdpa->vdpa.dma_dev = &pdev->dev;
500	eni_vdpa->queues = eni_vdpa_get_num_queues(eni_vdpa);
501
502	eni_vdpa->vring = devm_kcalloc(&pdev->dev, eni_vdpa->queues,
503				      sizeof(*eni_vdpa->vring),
504				      GFP_KERNEL);
505	if (!eni_vdpa->vring) {
506		ret = -ENOMEM;
507		ENI_ERR(pdev, "failed to allocate virtqueues\n");
508		goto err_remove_vp_legacy;
509	}
510
511	for (i = 0; i < eni_vdpa->queues; i++) {
512		eni_vdpa->vring[i].irq = VIRTIO_MSI_NO_VECTOR;
513		eni_vdpa->vring[i].notify = ldev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
514	}
515	eni_vdpa->config_irq = VIRTIO_MSI_NO_VECTOR;
516
517	ret = vdpa_register_device(&eni_vdpa->vdpa, eni_vdpa->queues);
518	if (ret) {
519		ENI_ERR(pdev, "failed to register to vdpa bus\n");
520		goto err_remove_vp_legacy;
521	}
522
523	return 0;
524
525err_remove_vp_legacy:
526	vp_legacy_remove(&eni_vdpa->ldev);
527err:
528	put_device(&eni_vdpa->vdpa.dev);
529	return ret;
530}
531
532static void eni_vdpa_remove(struct pci_dev *pdev)
533{
534	struct eni_vdpa *eni_vdpa = pci_get_drvdata(pdev);
535
536	vdpa_unregister_device(&eni_vdpa->vdpa);
537	vp_legacy_remove(&eni_vdpa->ldev);
538}
539
540static struct pci_device_id eni_pci_ids[] = {
541	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_REDHAT_QUMRANET,
542			 VIRTIO_TRANS_ID_NET,
543			 PCI_SUBVENDOR_ID_REDHAT_QUMRANET,
544			 VIRTIO_ID_NET) },
545	{ 0 },
546};
547
548static struct pci_driver eni_vdpa_driver = {
549	.name		= "alibaba-eni-vdpa",
550	.id_table	= eni_pci_ids,
551	.probe		= eni_vdpa_probe,
552	.remove		= eni_vdpa_remove,
553};
554
555module_pci_driver(eni_vdpa_driver);
556
557MODULE_AUTHOR("Wu Zongyong <wuzongyong@linux.alibaba.com>");
558MODULE_DESCRIPTION("Alibaba ENI vDPA driver");
559MODULE_LICENSE("GPL v2");
560