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/version.h>
  18 #include <linux/signal.h>
  19 #include <linux/kernel.h>
  20 #include <linux/netdevice.h>
  21 #include <linux/etherdevice.h>
  22 #include <linux/skbuff.h>
  23 #include <linux/inetdevice.h>
  24
  25 #include "hysdn_defs.h"
  26
  27 unsigned int hynet_enable = 0xffffffff;
  28 MODULE_PARM(hynet_enable, "i");
  29
  30 /* store the actual version for log reporting */
  31 char *hysdn_net_revision = "$Revision: 1.8.6.4 $";
  32
  33 #define MAX_SKB_BUFFERS 20      /* number of buffers for keeping TX-data */
  34
  35 /****************************************************************************/
  36 /* structure containing the complete network data. The structure is aligned */
  37 /* in a way that both, the device and statistics are kept inside it.        */
  38 /* for proper access, the device structure MUST be the first var/struct     */
  39 /* inside the definition.                                                   */
  40 /****************************************************************************/
  41 struct net_local {
  42         struct net_device netdev;       /* the network device */
  43         struct net_device_stats stats;
  44         /* additional vars may be added here */
  45         char dev_name[9];       /* our own device name */
  46
  47         /* Tx control lock.  This protects the transmit buffer ring
  48          * state along with the "tx full" state of the driver.  This
  49          * means all netif_queue flow control actions are protected
  50          * by this lock as well.
  51          */
  52         spinlock_t lock;
  53         struct sk_buff *skbs[MAX_SKB_BUFFERS];  /* pointers to tx-skbs */
  54         int in_idx, out_idx;    /* indexes to buffer ring */
  55         int sk_count;           /* number of buffers currently in ring */
  56 };                              /* net_local */
  57
  58
  59 /*****************************************************/
  60 /* Get the current statistics for this card.         */
  61 /* This may be called with the card open or closed ! */
  62 /*****************************************************/
  63 static struct net_device_stats *
  64 net_get_stats(struct net_device *dev)
  65 {
  66         return (&((struct net_local *) dev)->stats);
  67 }                               /* net_device_stats */
  68
  69 /*********************************************************************/
  70 /* Open/initialize the board. This is called (in the current kernel) */
  71 /* sometime after booting when the 'ifconfig' program is run.        */
  72 /* This routine should set everything up anew at each open, even     */
  73 /* registers that "should" only need to be set once at boot, so that */
  74 /* there is non-reboot way to recover if something goes wrong.       */
  75 /*********************************************************************/
  76 static int
  77 net_open(struct net_device *dev)
  78 {
  79         struct in_device *in_dev;
  80         hysdn_card *card = dev->priv;
  81         int i;
  82
  83         netif_start_queue(dev); /* start tx-queueing */
  84
  85         /* Fill in the MAC-level header (if not already set) */
  86         if (!card->mac_addr[0]) {
  87                 for (i = 0; i < ETH_ALEN - sizeof(ulong); i++)
  88                         dev->dev_addr[i] = 0xfc;
  89                 if ((in_dev = dev->ip_ptr) != NULL) {
  90                         struct in_ifaddr *ifa = in_dev->ifa_list;
  91                         if (ifa != NULL)
  92                                 memcpy(dev->dev_addr + (ETH_ALEN - sizeof(ulong)), &ifa->ifa_local, sizeof(ulong));
  93                 }
  94         } else
  95                 memcpy(dev->dev_addr, card->mac_addr, ETH_ALEN);
  96
  97         return (0);
  98 }                               /* net_open */
  99
 100 /*******************************************/
 101 /* flush the currently occupied tx-buffers */
 102 /* must only be called when device closed  */
 103 /*******************************************/
 104 static void
 105 flush_tx_buffers(struct net_local *nl)
 106 {
 107
 108         while (nl->sk_count) {
 109                 dev_kfree_skb(nl->skbs[nl->out_idx++]);         /* free skb */
 110                 if (nl->out_idx >= MAX_SKB_BUFFERS)
 111                         nl->out_idx = 0;        /* wrap around */
 112                 nl->sk_count--;
 113         }
 114 }                               /* flush_tx_buffers */
 115
 116
 117 /*********************************************************************/
 118 /* close/decativate the device. The device is not removed, but only  */
 119 /* deactivated.                                                      */
 120 /*********************************************************************/
 121 static int
 122 net_close(struct net_device *dev)
 123 {
 124
 125         netif_stop_queue(dev);  /* disable queueing */
 126
 127         flush_tx_buffers((struct net_local *) dev);
 128
 129         return (0);             /* success */
 130 }                               /* net_close */
 131
 132 /************************************/
 133 /* send a packet on this interface. */
 134 /* new style for kernel >= 2.3.33   */
 135 /************************************/
 136 static int
 137 net_send_packet(struct sk_buff *skb, struct net_device *dev)
 138 {
 139         struct net_local *lp = (struct net_local *) dev;
 140
 141         spin_lock_irq(&lp->lock);
 142
 143         lp->skbs[lp->in_idx++] = skb;   /* add to buffer list */
 144         if (lp->in_idx >= MAX_SKB_BUFFERS)
 145                 lp->in_idx = 0; /* wrap around */
 146         lp->sk_count++;         /* adjust counter */
 147         dev->trans_start = jiffies;
 148
 149         /* If we just used up the very last entry in the
 150          * TX ring on this device, tell the queueing
 151          * layer to send no more.
 152          */
 153         if (lp->sk_count >= MAX_SKB_BUFFERS)
 154                 netif_stop_queue(dev);
 155
 156         /* When the TX completion hw interrupt arrives, this
 157          * is when the transmit statistics are updated.
 158          */
 159
 160         spin_unlock_irq(&lp->lock);
 161
 162         if (lp->sk_count <= 3) {
 163                 schedule_work(&((hysdn_card *) dev->priv)->irq_queue);
 164         }
 165         return (0);             /* success */
 166 }                               /* net_send_packet */
 167
 168
 169
 170 /***********************************************************************/
 171 /* acknowlegde a packet send. The network layer will be informed about */
 172 /* completion                                                          */
 173 /***********************************************************************/
 174 void
 175 hysdn_tx_netack(hysdn_card * card)
 176 {
 177         struct net_local *lp = card->netif;
 178
 179         if (!lp)
 180                 return;         /* non existing device */
 181
 182
 183         if (!lp->sk_count)
 184                 return;         /* error condition */
 185
 186         lp->stats.tx_packets++;
 187         lp->stats.tx_bytes += lp->skbs[lp->out_idx]->len;
 188
 189         dev_kfree_skb(lp->skbs[lp->out_idx++]);         /* free skb */
 190         if (lp->out_idx >= MAX_SKB_BUFFERS)
 191                 lp->out_idx = 0;        /* wrap around */
 192
 193         if (lp->sk_count-- == MAX_SKB_BUFFERS)  /* dec usage count */
 194                 netif_start_queue((struct net_device *) lp);
 195 }                               /* hysdn_tx_netack */
 196
 197 /*****************************************************/
 198 /* we got a packet from the network, go and queue it */
 199 /*****************************************************/
 200 void
 201 hysdn_rx_netpkt(hysdn_card * card, uchar * buf, word len)
 202 {
 203         struct net_local *lp = card->netif;
 204         struct sk_buff *skb;
 205
 206         if (!lp)
 207                 return;         /* non existing device */
 208
 209         lp->stats.rx_bytes += len;
 210
 211         skb = dev_alloc_skb(len);
 212         if (skb == NULL) {
 213                 printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n",
 214                        lp->netdev.name);
 215                 lp->stats.rx_dropped++;
 216                 return;
 217         }
 218         skb->dev = &lp->netdev;
 219
 220         /* copy the data */
 221         memcpy(skb_put(skb, len), buf, len);
 222
 223         /* determine the used protocol */
 224         skb->protocol = eth_type_trans(skb, &lp->netdev);
 225
 226         netif_rx(skb);
 227         lp->stats.rx_packets++; /* adjust packet count */
 228
 229 }                               /* hysdn_rx_netpkt */
 230
 231 /*****************************************************/
 232 /* return the pointer to a network packet to be send */
 233 /*****************************************************/
 234 struct sk_buff *
 235 hysdn_tx_netget(hysdn_card * card)
 236 {
 237         struct net_local *lp = card->netif;
 238
 239         if (!lp)
 240                 return (NULL);  /* non existing device */
 241
 242         if (!lp->sk_count)
 243                 return (NULL);  /* nothing available */
 244
 245         return (lp->skbs[lp->out_idx]);         /* next packet to send */
 246 }                               /* hysdn_tx_netget */
 247
 248
 249 /*******************************************/
 250 /* init function called by register device */
 251 /*******************************************/
 252 static int
 253 net_init(struct net_device *dev)
 254 {
 255         /* setup the function table */
 256         dev->open = net_open;
 257         dev->stop = net_close;
 258         dev->hard_start_xmit = net_send_packet;
 259         dev->get_stats = net_get_stats;
 260
 261         /* Fill in the fields of the device structure with ethernet values. */
 262         ether_setup(dev);
 263
 264         return (0);             /* success */
 265 }                               /* net_init */
 266
 267 /*****************************************************************************/
 268 /* hysdn_net_create creates a new net device for the given card. If a device */
 269 /* already exists, it will be deleted and created a new one. The return value */
 270 /* 0 announces success, else a negative error code will be returned.         */
 271 /*****************************************************************************/
 272 int
 273 hysdn_net_create(hysdn_card * card)
 274 {
 275         struct net_device *dev;
 276         int i;
 277         if(!card) {
 278                 printk(KERN_WARNING "No card-pt in hysdn_net_create!\n");
 279                 return (-ENOMEM);
 280         }
 281         hysdn_net_release(card);        /* release an existing net device */
 282         if ((dev = kmalloc(sizeof(struct net_local), GFP_KERNEL)) == NULL) {
 283                 printk(KERN_WARNING "HYSDN: unable to allocate mem\n");
 284                 return (-ENOMEM);
 285         }
 286         memset(dev, 0, sizeof(struct net_local));       /* clean the structure */
 287
 288         spin_lock_init(&((struct net_local *) dev)->lock);
 289
 290         /* initialise necessary or informing fields */
 291         dev->base_addr = card->iobase;  /* IO address */
 292         dev->irq = card->irq;   /* irq */
 293         dev->init = net_init;   /* the init function of the device */
 294         if(dev->name) {
 295                 strcpy(dev->name, ((struct net_local *) dev)->dev_name);
 296         }
 297         if ((i = register_netdev(dev))) {
 298                 printk(KERN_WARNING "HYSDN: unable to create network device\n");
 299                 kfree(dev);
 300                 return (i);
 301         }
 302         dev->priv = card;       /* remember pointer to own data structure */
 303         card->netif = dev;      /* setup the local pointer */
 304
 305         if (card->debug_flags & LOG_NET_INIT)
 306                 hysdn_addlog(card, "network device created");
 307         return (0);             /* and return success */
 308 }                               /* hysdn_net_create */
 309
 310 /***************************************************************************/
 311 /* hysdn_net_release deletes the net device for the given card. The return */
 312 /* value 0 announces success, else a negative error code will be returned. */
 313 /***************************************************************************/
 314 int
 315 hysdn_net_release(hysdn_card * card)
 316 {
 317         struct net_device *dev = card->netif;
 318
 319         if (!dev)
 320                 return (0);     /* non existing */
 321
 322         card->netif = NULL;     /* clear out pointer */
 323         dev->stop(dev);         /* close the device */
 324
 325         flush_tx_buffers((struct net_local *) dev);     /* empty buffers */
 326
 327         unregister_netdev(dev); /* release the device */
 328         free_netdev(dev);       /* release the memory allocated */
 329         if (card->debug_flags & LOG_NET_INIT)
 330                 hysdn_addlog(card, "network device deleted");
 331
 332         return (0);             /* always successful */
 333 }                               /* hysdn_net_release */
 334
 335 /*****************************************************************************/
 336 /* hysdn_net_getname returns a pointer to the name of the network interface. */
 337 /* if the interface is not existing, a "-" is returned.                      */
 338 /*****************************************************************************/
 339 char *
 340 hysdn_net_getname(hysdn_card * card)
 341 {
 342         struct net_device *dev = card->netif;
 343
 344         if (!dev)
 345                 return ("-");   /* non existing */
 346
 347         return (dev->name);
 348 }                               /* hysdn_net_getname */