1 /* virtio-net.c - etherboot driver for virtio network interface
2 *
3 * (c) Copyright 2008 Bull S.A.S.
4 *
5 * Author: Laurent Vivier <Laurent.Vivier@bull.net>
6 *
7 * some parts from Linux Virtio PCI driver
8 *
9 * Copyright IBM Corp. 2007
10 * Authors: Anthony Liguori <aliguori@us.ibm.com>
11 *
12 * some parts from Linux Virtio Ring
13 *
14 * Copyright Rusty Russell IBM Corporation 2007
15 *
16 * This work is licensed under the terms of the GNU GPL, version 2 or later.
17 * See the COPYING file in the top-level directory.
18 *
19 *
20 */
21
22 #include "etherboot.h"
23 #include "nic.h"
24 #include "gpxe/virtio-ring.h"
25 #include "gpxe/virtio-pci.h"
26 #include "virtio-net.h"
27
28 #define BUG() do { \
29 printf("BUG: failure at %s:%d/%s()!\n", \
30 __FILE__, __LINE__, __FUNCTION__); \
31 while(1); \
32 } while (0)
33 #define BUG_ON(condition) do { if (condition) BUG(); } while (0)
34
35 /* Ethernet header */
36
37 struct eth_hdr {
38 unsigned char dst_addr[ETH_ALEN];
39 unsigned char src_addr[ETH_ALEN];
40 unsigned short type;
41 };
42
43 struct eth_frame {
44 struct eth_hdr hdr;
45 unsigned char data[ETH_FRAME_LEN];
46 };
47
48 /* TX: virtio header and eth buffer */
49
50 static struct virtio_net_hdr tx_virtio_hdr;
51 static struct eth_frame tx_eth_frame;
52
53 /* RX: virtio headers and buffers */
54
55 #define RX_BUF_NB 6
56 static struct virtio_net_hdr rx_hdr[RX_BUF_NB];
57 static unsigned char rx_buffer[RX_BUF_NB][ETH_FRAME_LEN];
58
59 /* virtio queues and vrings */
60
61 enum {
62 RX_INDEX = 0,
63 TX_INDEX,
64 QUEUE_NB
65 };
66
67 static struct vring_virtqueue virtqueue[QUEUE_NB];
68
69 /*
70 * virtnet_disable
71 *
72 * Turn off ethernet interface
73 *
74 */
75
virtnet_disable(struct nic * nic)76 static void virtnet_disable(struct nic *nic)
77 {
78 int i;
79
80 for (i = 0; i < QUEUE_NB; i++) {
81 vring_disable_cb(&virtqueue[i]);
82 vp_del_vq(nic->ioaddr, i);
83 }
84 vp_reset(nic->ioaddr);
85 }
86
87 /*
88 * virtnet_poll
89 *
90 * Wait for a frame
91 *
92 * return true if there is a packet ready to read
93 *
94 * nic->packet should contain data on return
95 * nic->packetlen should contain length of data
96 *
97 */
virtnet_poll(struct nic * nic,int retrieve)98 static int virtnet_poll(struct nic *nic, int retrieve)
99 {
100 unsigned int len;
101 u16 token;
102 struct virtio_net_hdr *hdr;
103 struct vring_list list[2];
104
105 if (!vring_more_used(&virtqueue[RX_INDEX]))
106 return 0;
107
108 if (!retrieve)
109 return 1;
110
111 token = vring_get_buf(&virtqueue[RX_INDEX], &len);
112
113 BUG_ON(len > sizeof(struct virtio_net_hdr) + ETH_FRAME_LEN);
114
115 hdr = &rx_hdr[token]; /* FIXME: check flags */
116 len -= sizeof(struct virtio_net_hdr);
117
118 nic->packetlen = len;
119 memcpy(nic->packet, (char *)rx_buffer[token], nic->packetlen);
120
121 /* add buffer to desc */
122
123 list[0].addr = (char*)&rx_hdr[token];
124 list[0].length = sizeof(struct virtio_net_hdr);
125 list[1].addr = (char*)&rx_buffer[token];
126 list[1].length = ETH_FRAME_LEN;
127
128 vring_add_buf(&virtqueue[RX_INDEX], list, 0, 2, token, 0);
129 vring_kick(nic->ioaddr, &virtqueue[RX_INDEX], 1);
130
131 return 1;
132 }
133
134 /*
135 *
136 * virtnet_transmit
137 *
138 * Transmit a frame
139 *
140 */
141
virtnet_transmit(struct nic * nic,const char * destaddr,unsigned int type,unsigned int len,const char * data)142 static void virtnet_transmit(struct nic *nic, const char *destaddr,
143 unsigned int type, unsigned int len, const char *data)
144 {
145 struct vring_list list[2];
146
147 /*
148 * from http://www.etherboot.org/wiki/dev/devmanual :
149 * "You do not need more than one transmit buffer."
150 */
151
152 /* FIXME: initialize header according to vp_get_features() */
153
154 tx_virtio_hdr.flags = 0;
155 tx_virtio_hdr.csum_offset = 0;
156 tx_virtio_hdr.csum_start = 0;
157 tx_virtio_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
158 tx_virtio_hdr.gso_size = 0;
159 tx_virtio_hdr.hdr_len = 0;
160
161 /* add ethernet frame into vring */
162
163 BUG_ON(len > sizeof(tx_eth_frame.data));
164
165 memcpy(tx_eth_frame.hdr.dst_addr, destaddr, ETH_ALEN);
166 memcpy(tx_eth_frame.hdr.src_addr, nic->node_addr, ETH_ALEN);
167 tx_eth_frame.hdr.type = htons(type);
168 memcpy(tx_eth_frame.data, data, len);
169
170 list[0].addr = (char*)&tx_virtio_hdr;
171 list[0].length = sizeof(struct virtio_net_hdr);
172 list[1].addr = (char*)&tx_eth_frame;
173 list[1].length = ETH_FRAME_LEN;
174
175 vring_add_buf(&virtqueue[TX_INDEX], list, 2, 0, 0, 0);
176
177 vring_kick(nic->ioaddr, &virtqueue[TX_INDEX], 1);
178
179 /*
180 * http://www.etherboot.org/wiki/dev/devmanual
181 *
182 * "You should ensure the packet is fully transmitted
183 * before returning from this routine"
184 */
185
186 while (!vring_more_used(&virtqueue[TX_INDEX])) {
187 mb();
188 udelay(10);
189 }
190
191 /* free desc */
192
193 (void)vring_get_buf(&virtqueue[TX_INDEX], NULL);
194 }
195
virtnet_irq(struct nic * nic __unused,irq_action_t action)196 static void virtnet_irq(struct nic *nic __unused, irq_action_t action)
197 {
198 switch ( action ) {
199 case DISABLE :
200 vring_disable_cb(&virtqueue[RX_INDEX]);
201 vring_disable_cb(&virtqueue[TX_INDEX]);
202 break;
203 case ENABLE :
204 vring_enable_cb(&virtqueue[RX_INDEX]);
205 vring_enable_cb(&virtqueue[TX_INDEX]);
206 break;
207 case FORCE :
208 break;
209 }
210 }
211
provide_buffers(struct nic * nic)212 static void provide_buffers(struct nic *nic)
213 {
214 int i;
215 struct vring_list list[2];
216
217 for (i = 0; i < RX_BUF_NB; i++) {
218 list[0].addr = (char*)&rx_hdr[i];
219 list[0].length = sizeof(struct virtio_net_hdr);
220 list[1].addr = (char*)&rx_buffer[i];
221 list[1].length = ETH_FRAME_LEN;
222 vring_add_buf(&virtqueue[RX_INDEX], list, 0, 2, i, i);
223 }
224
225 /* nofify */
226
227 vring_kick(nic->ioaddr, &virtqueue[RX_INDEX], i);
228 }
229
230 static struct nic_operations virtnet_operations = {
231 .connect = dummy_connect,
232 .poll = virtnet_poll,
233 .transmit = virtnet_transmit,
234 .irq = virtnet_irq,
235 };
236
237 /*
238 * virtnet_probe
239 *
240 * Look for a virtio network adapter
241 *
242 */
243
virtnet_probe(struct nic * nic,struct pci_device * pci)244 static int virtnet_probe(struct nic *nic, struct pci_device *pci)
245 {
246 u32 features;
247 int i;
248
249 /* Mask the bit that says "this is an io addr" */
250
251 nic->ioaddr = pci->ioaddr & ~3;
252
253 /* Copy IRQ from PCI information */
254
255 nic->irqno = pci->irq;
256
257 printf("I/O address 0x%08x, IRQ #%d\n", nic->ioaddr, nic->irqno);
258
259 adjust_pci_device(pci);
260
261 vp_reset(nic->ioaddr);
262
263 features = vp_get_features(nic->ioaddr);
264 if (features & (1 << VIRTIO_NET_F_MAC)) {
265 vp_get(nic->ioaddr, offsetof(struct virtio_net_config, mac),
266 nic->node_addr, ETH_ALEN);
267 printf("MAC address ");
268 for (i = 0; i < ETH_ALEN; i++) {
269 printf("%02x%c", nic->node_addr[i],
270 (i == ETH_ALEN - 1) ? '\n' : ':');
271 }
272 }
273
274 /* initialize emit/receive queue */
275
276 for (i = 0; i < QUEUE_NB; i++) {
277 virtqueue[i].free_head = 0;
278 virtqueue[i].last_used_idx = 0;
279 memset((char*)&virtqueue[i].queue, 0, sizeof(virtqueue[i].queue));
280 if (vp_find_vq(nic->ioaddr, i, &virtqueue[i]) == -1)
281 printf("Cannot register queue #%d\n", i);
282 }
283
284 /* provide some receive buffers */
285
286 provide_buffers(nic);
287
288 /* define NIC interface */
289
290 nic->nic_op = &virtnet_operations;
291
292 /* driver is ready */
293
294 vp_set_features(nic->ioaddr, features & (1 << VIRTIO_NET_F_MAC));
295 vp_set_status(nic->ioaddr, VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK);
296
297 return 1;
298 }
299
300 static struct pci_device_id virtnet_nics[] = {
301 PCI_ROM(0x1af4, 0x1000, "virtio-net", "Virtio Network Interface", 0),
302 };
303
304 PCI_DRIVER ( virtnet_driver, virtnet_nics, PCI_NO_CLASS );
305
306 DRIVER ( "VIRTIO-NET", nic_driver, pci_driver, virtnet_driver,
307 virtnet_probe, virtnet_disable );
308