1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
4 * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
5 */
6
7 #include <common.h>
8 #include <dm.h>
9 #include <net.h>
10 #include <virtio_types.h>
11 #include <virtio.h>
12 #include <virtio_ring.h>
13 #include "virtio_net.h"
14
15 /* Amount of buffers to keep in the RX virtqueue */
16 #define VIRTIO_NET_NUM_RX_BUFS 32
17
18 /*
19 * This value comes from the VirtIO spec: 1500 for maximum packet size,
20 * 14 for the Ethernet header, 12 for virtio_net_hdr. In total 1526 bytes.
21 */
22 #define VIRTIO_NET_RX_BUF_SIZE 1526
23
24 struct virtio_net_priv {
25 union {
26 struct virtqueue *vqs[2];
27 struct {
28 struct virtqueue *rx_vq;
29 struct virtqueue *tx_vq;
30 };
31 };
32
33 char rx_buff[VIRTIO_NET_NUM_RX_BUFS][VIRTIO_NET_RX_BUF_SIZE];
34 bool rx_running;
35 int net_hdr_len;
36 };
37
38 /*
39 * For simplicity, the driver only negotiates the VIRTIO_NET_F_MAC feature.
40 * For the VIRTIO_NET_F_STATUS feature, we don't negotiate it, hence per spec
41 * we should assume the link is always active.
42 */
43 static const u32 feature[] = {
44 VIRTIO_NET_F_MAC
45 };
46
47 static const u32 feature_legacy[] = {
48 VIRTIO_NET_F_MAC
49 };
50
virtio_net_start(struct udevice * dev)51 static int virtio_net_start(struct udevice *dev)
52 {
53 struct virtio_net_priv *priv = dev_get_priv(dev);
54 struct virtio_sg sg;
55 struct virtio_sg *sgs[] = { &sg };
56 int i;
57
58 if (!priv->rx_running) {
59 /* receive buffer length is always 1526 */
60 sg.length = VIRTIO_NET_RX_BUF_SIZE;
61
62 /* setup the receive buffer address */
63 for (i = 0; i < VIRTIO_NET_NUM_RX_BUFS; i++) {
64 sg.addr = priv->rx_buff[i];
65 virtqueue_add(priv->rx_vq, sgs, 0, 1);
66 }
67
68 virtqueue_kick(priv->rx_vq);
69
70 /* setup the receive queue only once */
71 priv->rx_running = true;
72 }
73
74 return 0;
75 }
76
virtio_net_send(struct udevice * dev,void * packet,int length)77 static int virtio_net_send(struct udevice *dev, void *packet, int length)
78 {
79 struct virtio_net_priv *priv = dev_get_priv(dev);
80 struct virtio_net_hdr hdr;
81 struct virtio_net_hdr_v1 hdr_v1;
82 struct virtio_sg hdr_sg;
83 struct virtio_sg data_sg = { packet, length };
84 struct virtio_sg *sgs[] = { &hdr_sg, &data_sg };
85 int ret;
86
87 if (priv->net_hdr_len == sizeof(struct virtio_net_hdr))
88 hdr_sg.addr = &hdr;
89 else
90 hdr_sg.addr = &hdr_v1;
91 hdr_sg.length = priv->net_hdr_len;
92
93 memset(hdr_sg.addr, 0, priv->net_hdr_len);
94
95 ret = virtqueue_add(priv->tx_vq, sgs, 2, 0);
96 if (ret)
97 return ret;
98
99 virtqueue_kick(priv->tx_vq);
100
101 while (1) {
102 if (virtqueue_get_buf(priv->tx_vq, NULL))
103 break;
104 }
105
106 return 0;
107 }
108
virtio_net_recv(struct udevice * dev,int flags,uchar ** packetp)109 static int virtio_net_recv(struct udevice *dev, int flags, uchar **packetp)
110 {
111 struct virtio_net_priv *priv = dev_get_priv(dev);
112 unsigned int len;
113 void *buf;
114
115 buf = virtqueue_get_buf(priv->rx_vq, &len);
116 if (!buf)
117 return -EAGAIN;
118
119 *packetp = buf + priv->net_hdr_len;
120 return len - priv->net_hdr_len;
121 }
122
virtio_net_free_pkt(struct udevice * dev,uchar * packet,int length)123 static int virtio_net_free_pkt(struct udevice *dev, uchar *packet, int length)
124 {
125 struct virtio_net_priv *priv = dev_get_priv(dev);
126 void *buf = packet - priv->net_hdr_len;
127 struct virtio_sg sg = { buf, VIRTIO_NET_RX_BUF_SIZE };
128 struct virtio_sg *sgs[] = { &sg };
129
130 /* Put the buffer back to the rx ring */
131 virtqueue_add(priv->rx_vq, sgs, 0, 1);
132
133 return 0;
134 }
135
virtio_net_stop(struct udevice * dev)136 static void virtio_net_stop(struct udevice *dev)
137 {
138 /*
139 * There is no way to stop the queue from running, unless we issue
140 * a reset to the virtio device, and re-do the queue initialization
141 * from the beginning.
142 */
143 }
144
virtio_net_write_hwaddr(struct udevice * dev)145 static int virtio_net_write_hwaddr(struct udevice *dev)
146 {
147 struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent);
148 struct eth_pdata *pdata = dev_get_platdata(dev);
149 int i;
150
151 /*
152 * v1.0 compliant device's MAC address is set through control channel,
153 * which we don't support for now.
154 */
155 if (!uc_priv->legacy)
156 return -ENOSYS;
157
158 for (i = 0; i < sizeof(pdata->enetaddr); i++) {
159 virtio_cwrite8(dev,
160 offsetof(struct virtio_net_config, mac) + i,
161 pdata->enetaddr[i]);
162 }
163
164 return 0;
165 }
166
virtio_net_read_rom_hwaddr(struct udevice * dev)167 static int virtio_net_read_rom_hwaddr(struct udevice *dev)
168 {
169 struct eth_pdata *pdata = dev_get_platdata(dev);
170
171 if (!pdata)
172 return -ENOSYS;
173
174 if (virtio_has_feature(dev, VIRTIO_NET_F_MAC)) {
175 virtio_cread_bytes(dev,
176 offsetof(struct virtio_net_config, mac),
177 pdata->enetaddr, sizeof(pdata->enetaddr));
178 }
179
180 return 0;
181 }
182
virtio_net_bind(struct udevice * dev)183 static int virtio_net_bind(struct udevice *dev)
184 {
185 struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent);
186
187 /* Indicate what driver features we support */
188 virtio_driver_features_init(uc_priv, feature, ARRAY_SIZE(feature),
189 feature_legacy, ARRAY_SIZE(feature_legacy));
190
191 return 0;
192 }
193
virtio_net_probe(struct udevice * dev)194 static int virtio_net_probe(struct udevice *dev)
195 {
196 struct virtio_net_priv *priv = dev_get_priv(dev);
197 struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent);
198 int ret;
199
200 ret = virtio_find_vqs(dev, 2, priv->vqs);
201 if (ret < 0)
202 return ret;
203
204 /*
205 * For v1.0 compliant device, it always assumes the member
206 * 'num_buffers' exists in the struct virtio_net_hdr while
207 * the legacy driver only presented 'num_buffers' when
208 * VIRTIO_NET_F_MRG_RXBUF was negotiated. Without that feature
209 * the structure was 2 bytes shorter.
210 */
211 if (uc_priv->legacy)
212 priv->net_hdr_len = sizeof(struct virtio_net_hdr);
213 else
214 priv->net_hdr_len = sizeof(struct virtio_net_hdr_v1);
215
216 return 0;
217 }
218
219 static const struct eth_ops virtio_net_ops = {
220 .start = virtio_net_start,
221 .send = virtio_net_send,
222 .recv = virtio_net_recv,
223 .free_pkt = virtio_net_free_pkt,
224 .stop = virtio_net_stop,
225 .write_hwaddr = virtio_net_write_hwaddr,
226 .read_rom_hwaddr = virtio_net_read_rom_hwaddr,
227 };
228
229 U_BOOT_DRIVER(virtio_net) = {
230 .name = VIRTIO_NET_DRV_NAME,
231 .id = UCLASS_ETH,
232 .bind = virtio_net_bind,
233 .probe = virtio_net_probe,
234 .remove = virtio_reset,
235 .ops = &virtio_net_ops,
236 .priv_auto_alloc_size = sizeof(struct virtio_net_priv),
237 .platdata_auto_alloc_size = sizeof(struct eth_pdata),
238 .flags = DM_FLAG_ACTIVE_DMA,
239 };
240