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