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 #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;
  44         spinlock_t lock;
  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         netif_trans_update(dev);
 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
 158 hysdn_tx_netack(hysdn_card *card)
 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         skb_put_data(skb, 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 *
 218 hysdn_tx_netget(hysdn_card *card)
 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_set_mac_address    = eth_mac_addr,
 236         .ndo_validate_addr      = eth_validate_addr,
 237 };
 238
 239
 240 /*****************************************************************************/
 241 /* hysdn_net_create creates a new net device for the given card. If a device */
 242 /* already exists, it will be deleted and created a new one. The return value */
 243 /* 0 announces success, else a negative error code will be returned.         */
 244 /*****************************************************************************/
 245 int
 246 hysdn_net_create(hysdn_card *card)
 247 {
 248         struct net_device *dev;
 249         int i;
 250         struct net_local *lp;
 251
 252         if (!card) {
 253                 printk(KERN_WARNING "No card-pt in hysdn_net_create!\n");
 254                 return (-ENOMEM);
 255         }
 256         hysdn_net_release(card);        /* release an existing net device */
 257
 258         dev = alloc_etherdev(sizeof(struct net_local));
 259         if (!dev) {
 260                 printk(KERN_WARNING "HYSDN: unable to allocate mem\n");
 261                 return (-ENOMEM);
 262         }
 263
 264         lp = netdev_priv(dev);
 265         lp->dev = dev;
 266
 267         dev->netdev_ops = &hysdn_netdev_ops;
 268         spin_lock_init(&((struct net_local *) dev)->lock);
 269
 270         /* initialise necessary or informing fields */
 271         dev->base_addr = card->iobase;  /* IO address */
 272         dev->irq = card->irq;   /* irq */
 273
 274         dev->netdev_ops = &hysdn_netdev_ops;
 275         if ((i = register_netdev(dev))) {
 276                 printk(KERN_WARNING "HYSDN: unable to create network device\n");
 277                 free_netdev(dev);
 278                 return (i);
 279         }
 280         dev->ml_priv = card;    /* remember pointer to own data structure */
 281         card->netif = dev;      /* setup the local pointer */
 282
 283         if (card->debug_flags & LOG_NET_INIT)
 284                 hysdn_addlog(card, "network device created");
 285         return (0);             /* and return success */
 286 }                               /* hysdn_net_create */
 287
 288 /***************************************************************************/
 289 /* hysdn_net_release deletes the net device for the given card. The return */
 290 /* value 0 announces success, else a negative error code will be returned. */
 291 /***************************************************************************/
 292 int
 293 hysdn_net_release(hysdn_card *card)
 294 {
 295         struct net_device *dev = card->netif;
 296
 297         if (!dev)
 298                 return (0);     /* non existing */
 299
 300         card->netif = NULL;     /* clear out pointer */
 301         net_close(dev);
 302
 303         flush_tx_buffers((struct net_local *) dev);     /* empty buffers */
 304
 305         unregister_netdev(dev); /* release the device */
 306         free_netdev(dev);       /* release the memory allocated */
 307         if (card->debug_flags & LOG_NET_INIT)
 308                 hysdn_addlog(card, "network device deleted");
 309
 310         return (0);             /* always successful */
 311 }                               /* hysdn_net_release */
 312
 313 /*****************************************************************************/
 314 /* hysdn_net_getname returns a pointer to the name of the network interface. */
 315 /* if the interface is not existing, a "-" is returned.                      */
 316 /*****************************************************************************/
 317 char *
 318 hysdn_net_getname(hysdn_card *card)
 319 {
 320         struct net_device *dev = card->netif;
 321
 322         if (!dev)
 323                 return ("-");   /* non existing */
 324
 325         return (dev->name);
 326 }                               /* hysdn_net_getname */