drivers/isdn/hysdn/hysdn_net.c

   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 netdev_tx_t
 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 NETDEV_TX_OK;    /* 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 */