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