1 /* $Id: hysdn_net.c,v 1.8.6.4 2001/09/23 22:24:54 kai Exp $
2 *
3 * Linux driver for HYSDN cards, net (ethernet type) handling routines.
4 *
5 * Author Werner Cornelius (werner@titro.de) for Hypercope GmbH
6 * Copyright 1999 by Werner Cornelius (werner@titro.de)
7 *
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
10 *
11 * This net module has been inspired by the skeleton driver from
12 * Donald Becker (becker@CESDIS.gsfc.nasa.gov)
13 *
14 */
15
16 #include <linux/module.h>
17 #include <linux/signal.h>
18 #include <linux/kernel.h>
19 #include <linux/netdevice.h>
20 #include <linux/etherdevice.h>
21 #include <linux/skbuff.h>
22 #include <linux/inetdevice.h>
23
24 #include "hysdn_defs.h"
25
26 unsigned int hynet_enable = 0xffffffff;
27 module_param(hynet_enable, uint, 0);
28
29 /* store the actual version for log reporting */
30 char *hysdn_net_revision = "$Revision: 1.8.6.4 $";
31
32 #define MAX_SKB_BUFFERS 20 /* number of buffers for keeping TX-data */
33
34 /****************************************************************************/
35 /* structure containing the complete network data. The structure is aligned */
36 /* in a way that both, the device and statistics are kept inside it. */
37 /* for proper access, the device structure MUST be the first var/struct */
38 /* inside the definition. */
39 /****************************************************************************/
40 struct net_local {
41 /* Tx control lock. This protects the transmit buffer ring
42 * state along with the "tx full" state of the driver. This
43 * means all netif_queue flow control actions are protected
44 * by this lock as well.
45 */
46 struct net_device *dev;
47 spinlock_t lock;
48 struct sk_buff *skbs[MAX_SKB_BUFFERS]; /* pointers to tx-skbs */
49 int in_idx, out_idx; /* indexes to buffer ring */
50 int sk_count; /* number of buffers currently in ring */
51 }; /* net_local */
52
53
54
55 /*********************************************************************/
56 /* Open/initialize the board. This is called (in the current kernel) */
57 /* sometime after booting when the 'ifconfig' program is run. */
58 /* This routine should set everything up anew at each open, even */
59 /* registers that "should" only need to be set once at boot, so that */
60 /* there is non-reboot way to recover if something goes wrong. */
61 /*********************************************************************/
62 static int
63 net_open(struct net_device *dev)
64 {
65 struct in_device *in_dev;
66 hysdn_card *card = dev->ml_priv;
67 int i;
68
69 netif_start_queue(dev); /* start tx-queueing */
70
71 /* Fill in the MAC-level header (if not already set) */
72 if (!card->mac_addr[0]) {
73 for (i = 0; i < ETH_ALEN; i++)
74 dev->dev_addr[i] = 0xfc;
75 if ((in_dev = dev->ip_ptr) != NULL) {
76 struct in_ifaddr *ifa = in_dev->ifa_list;
77 if (ifa != NULL)
78 memcpy(dev->dev_addr + (ETH_ALEN - sizeof(ifa->ifa_local)), &ifa->ifa_local, sizeof(ifa->ifa_local));
79 }
80 } else
81 memcpy(dev->dev_addr, card->mac_addr, ETH_ALEN);
82
83 return (0);
84 } /* net_open */
85
86 /*******************************************/
87 /* flush the currently occupied tx-buffers */
88 /* must only be called when device closed */
89 /*******************************************/
90 static void
91 flush_tx_buffers(struct net_local *nl)
92 {
93
94 while (nl->sk_count) {
95 dev_kfree_skb(nl->skbs[nl->out_idx++]); /* free skb */
96 if (nl->out_idx >= MAX_SKB_BUFFERS)
97 nl->out_idx = 0; /* wrap around */
98 nl->sk_count--;
99 }
100 } /* flush_tx_buffers */
101
102
103 /*********************************************************************/
104 /* close/decativate the device. The device is not removed, but only */
105 /* deactivated. */
106 /*********************************************************************/
107 static int
108 net_close(struct net_device *dev)
109 {
110
111 netif_stop_queue(dev); /* disable queueing */
112
113 flush_tx_buffers((struct net_local *) dev);
114
115 return (0); /* success */
116 } /* net_close */
117
118 /************************************/
119 /* send a packet on this interface. */
120 /* new style for kernel >= 2.3.33 */
121 /************************************/
122 static int
123 net_send_packet(struct sk_buff *skb, struct net_device *dev)
124 {
125 struct net_local *lp = (struct net_local *) dev;
126
127 spin_lock_irq(&lp->lock);
128
129 lp->skbs[lp->in_idx++] = skb; /* add to buffer list */
130 if (lp->in_idx >= MAX_SKB_BUFFERS)
131 lp->in_idx = 0; /* wrap around */
132 lp->sk_count++; /* adjust counter */
133 dev->trans_start = jiffies;
134
135 /* If we just used up the very last entry in the
136 * TX ring on this device, tell the queueing
137 * layer to send no more.
138 */
139 if (lp->sk_count >= MAX_SKB_BUFFERS)
140 netif_stop_queue(dev);
141
142 /* When the TX completion hw interrupt arrives, this
143 * is when the transmit statistics are updated.
144 */
145
146 spin_unlock_irq(&lp->lock);
147
148 if (lp->sk_count <= 3) {
149 schedule_work(&((hysdn_card *) dev->ml_priv)->irq_queue);
150 }
151 return (0); /* success */
152 } /* net_send_packet */
153
154
155
156 /***********************************************************************/
157 /* acknowlegde a packet send. The network layer will be informed about */
158 /* completion */
159 /***********************************************************************/
160 void
161 hysdn_tx_netack(hysdn_card * card)
162 {
163 struct net_local *lp = card->netif;
164
165 if (!lp)
166 return; /* non existing device */
167
168
169 if (!lp->sk_count)
170 return; /* error condition */
171
172 lp->dev->stats.tx_packets++;
173 lp->dev->stats.tx_bytes += lp->skbs[lp->out_idx]->len;
174
175 dev_kfree_skb(lp->skbs[lp->out_idx++]); /* free skb */
176 if (lp->out_idx >= MAX_SKB_BUFFERS)
177 lp->out_idx = 0; /* wrap around */
178
179 if (lp->sk_count-- == MAX_SKB_BUFFERS) /* dec usage count */
180 netif_start_queue((struct net_device *) lp);
181 } /* hysdn_tx_netack */
182
183 /*****************************************************/
184 /* we got a packet from the network, go and queue it */
185 /*****************************************************/
186 void
187 hysdn_rx_netpkt(hysdn_card * card, unsigned char *buf, unsigned short len)
188 {
189 struct net_local *lp = card->netif;
190 struct net_device *dev = lp->dev;
191 struct sk_buff *skb;
192
193 if (!lp)
194 return; /* non existing device */
195
196 dev->stats.rx_bytes += len;
197
198 skb = dev_alloc_skb(len);
199 if (skb == NULL) {
200 printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n",
201 dev->name);
202 dev->stats.rx_dropped++;
203 return;
204 }
205 /* copy the data */
206 memcpy(skb_put(skb, len), buf, len);
207
208 /* determine the used protocol */
209 skb->protocol = eth_type_trans(skb, dev);
210
211 dev->stats.rx_packets++; /* adjust packet count */
212
213 netif_rx(skb);
214 } /* hysdn_rx_netpkt */
215
216 /*****************************************************/
217 /* return the pointer to a network packet to be send */
218 /*****************************************************/
219 struct sk_buff *
220 hysdn_tx_netget(hysdn_card * card)
221 {
222 struct net_local *lp = card->netif;
223
224 if (!lp)
225 return (NULL); /* non existing device */
226
227 if (!lp->sk_count)
228 return (NULL); /* nothing available */
229
230 return (lp->skbs[lp->out_idx]); /* next packet to send */
231 } /* hysdn_tx_netget */
232
233 static const struct net_device_ops hysdn_netdev_ops = {
234 .ndo_open = net_open,
235 .ndo_stop = net_close,
236 .ndo_start_xmit = net_send_packet,
237 .ndo_change_mtu = eth_change_mtu,
238 .ndo_set_mac_address = eth_mac_addr,
239 .ndo_validate_addr = eth_validate_addr,
240 };
241
242
243 /*****************************************************************************/
244 /* hysdn_net_create creates a new net device for the given card. If a device */
245 /* already exists, it will be deleted and created a new one. The return value */
246 /* 0 announces success, else a negative error code will be returned. */
247 /*****************************************************************************/
248 int
249 hysdn_net_create(hysdn_card * card)
250 {
251 struct net_device *dev;
252 int i;
253 struct net_local *lp;
254
255 if(!card) {
256 printk(KERN_WARNING "No card-pt in hysdn_net_create!\n");
257 return (-ENOMEM);
258 }
259 hysdn_net_release(card); /* release an existing net device */
260
261 dev = alloc_etherdev(sizeof(struct net_local));
262 if (!dev) {
263 printk(KERN_WARNING "HYSDN: unable to allocate mem\n");
264 return (-ENOMEM);
265 }
266
267 lp = netdev_priv(dev);
268 lp->dev = dev;
269
270 dev->netdev_ops = &hysdn_netdev_ops;
271 spin_lock_init(&((struct net_local *) dev)->lock);
272
273 /* initialise necessary or informing fields */
274 dev->base_addr = card->iobase; /* IO address */
275 dev->irq = card->irq; /* irq */
276
277 dev->netdev_ops = &hysdn_netdev_ops;
278 if ((i = register_netdev(dev))) {
279 printk(KERN_WARNING "HYSDN: unable to create network device\n");
280 free_netdev(dev);
281 return (i);
282 }
283 dev->ml_priv = card; /* remember pointer to own data structure */
284 card->netif = dev; /* setup the local pointer */
285
286 if (card->debug_flags & LOG_NET_INIT)
287 hysdn_addlog(card, "network device created");
288 return (0); /* and return success */
289 } /* hysdn_net_create */
290
291 /***************************************************************************/
292 /* hysdn_net_release deletes the net device for the given card. The return */
293 /* value 0 announces success, else a negative error code will be returned. */
294 /***************************************************************************/
295 int
296 hysdn_net_release(hysdn_card * card)
297 {
298 struct net_device *dev = card->netif;
299
300 if (!dev)
301 return (0); /* non existing */
302
303 card->netif = NULL; /* clear out pointer */
304 net_close(dev);
305
306 flush_tx_buffers((struct net_local *) dev); /* empty buffers */
307
308 unregister_netdev(dev); /* release the device */
309 free_netdev(dev); /* release the memory allocated */
310 if (card->debug_flags & LOG_NET_INIT)
311 hysdn_addlog(card, "network device deleted");
312
313 return (0); /* always successful */
314 } /* hysdn_net_release */
315
316 /*****************************************************************************/
317 /* hysdn_net_getname returns a pointer to the name of the network interface. */
318 /* if the interface is not existing, a "-" is returned. */
319 /*****************************************************************************/
320 char *
321 hysdn_net_getname(hysdn_card * card)
322 {
323 struct net_device *dev = card->netif;
324
325 if (!dev)
326 return ("-"); /* non existing */
327
328 return (dev->name);
329 } /* hysdn_net_getname */
330
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