drivers/isdn/hysdn/hysdn_net.c

   1 /* $Id: hysdn_net.c,v 1.8 2000/11/13 22:51:47 kai Exp $
   2
   3  * Linux driver for HYSDN cards, net (ethernet type) handling routines.
   4  *
   5  * written by Werner Cornelius (werner@titro.de) for Hypercope GmbH
   6  *
   7  * Copyright 1999  by Werner Cornelius (werner@titro.de)
   8  *
   9  * This net module has been inspired by the skeleton driver from
  10  * Donald Becker (becker@CESDIS.gsfc.nasa.gov)
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  *
  26  */
  27
  28 #define __NO_VERSION__
  29 #include <linux/module.h>
  30 #include <linux/version.h>
  31 #include <linux/signal.h>
  32 #include <linux/kernel.h>
  33 #include <linux/netdevice.h>
  34 #include <linux/etherdevice.h>
  35 #include <linux/skbuff.h>
  36 #include <linux/inetdevice.h>
  37
  38 #include "hysdn_defs.h"
  39
  40 /* store the actual version for log reporting */
  41 char *hysdn_net_revision = "$Revision: 1.8 $";
  42
  43 #define MAX_SKB_BUFFERS 20      /* number of buffers for keeping TX-data */
  44
  45 /****************************************************************************/
  46 /* structure containing the complete network data. The structure is aligned */
  47 /* in a way that both, the device and statistics are kept inside it.        */
  48 /* for proper access, the device structure MUST be the first var/struct     */
  49 /* inside the definition.                                                   */
  50 /****************************************************************************/
  51 struct net_local {
  52         struct net_device netdev;       /* the network device */
  53         struct net_device_stats stats;
  54         /* additional vars may be added here */
  55         char dev_name[9];       /* our own device name */
  56
  57         /* Tx control lock.  This protects the transmit buffer ring
  58          * state along with the "tx full" state of the driver.  This
  59          * means all netif_queue flow control actions are protected
  60          * by this lock as well.
  61          */
  62         spinlock_t lock;
  63         struct sk_buff *skbs[MAX_SKB_BUFFERS];  /* pointers to tx-skbs */
  64         int in_idx, out_idx;    /* indexes to buffer ring */
  65         int sk_count;           /* number of buffers currently in ring */
  66
  67         int is_open;            /* flag controlling module locking */
  68 };                              /* net_local */
  69
  70
  71 /*****************************************************/
  72 /* Get the current statistics for this card.         */
  73 /* This may be called with the card open or closed ! */
  74 /*****************************************************/
  75 static struct net_device_stats *
  76 net_get_stats(struct net_device *dev)
  77 {
  78         return (&((struct net_local *) dev)->stats);
  79 }                               /* net_device_stats */
  80
  81 /*********************************************************************/
  82 /* Open/initialize the board. This is called (in the current kernel) */
  83 /* sometime after booting when the 'ifconfig' program is run.        */
  84 /* This routine should set everything up anew at each open, even     */
  85 /* registers that "should" only need to be set once at boot, so that */
  86 /* there is non-reboot way to recover if something goes wrong.       */
  87 /*********************************************************************/
  88 static int
  89 net_open(struct net_device *dev)
  90 {
  91         struct in_device *in_dev;
  92         hysdn_card *card = dev->priv;
  93         int i;
  94
  95         if (!((struct net_local *) dev)->is_open)
  96                 MOD_INC_USE_COUNT;      /* increment only if interface is actually down */
  97         ((struct net_local *) dev)->is_open = 1;        /* device actually open */
  98
  99         netif_start_queue(dev); /* start tx-queueing */
 100
 101         /* Fill in the MAC-level header (if not already set) */
 102         if (!card->mac_addr[0]) {
 103                 for (i = 0; i < ETH_ALEN - sizeof(ulong); i++)
 104                         dev->dev_addr[i] = 0xfc;
 105                 if ((in_dev = dev->ip_ptr) != NULL) {
 106                         struct in_ifaddr *ifa = in_dev->ifa_list;
 107                         if (ifa != NULL)
 108                                 memcpy(dev->dev_addr + (ETH_ALEN - sizeof(ulong)), &ifa->ifa_local, sizeof(ulong));
 109                 }
 110         } else
 111                 memcpy(dev->dev_addr, card->mac_addr, ETH_ALEN);
 112
 113         return (0);
 114 }                               /* net_open */
 115
 116 /*******************************************/
 117 /* flush the currently occupied tx-buffers */
 118 /* must only be called when device closed  */
 119 /*******************************************/
 120 static void
 121 flush_tx_buffers(struct net_local *nl)
 122 {
 123
 124         while (nl->sk_count) {
 125                 dev_kfree_skb(nl->skbs[nl->out_idx++]);         /* free skb */
 126                 if (nl->out_idx >= MAX_SKB_BUFFERS)
 127                         nl->out_idx = 0;        /* wrap around */
 128                 nl->sk_count--;
 129         }
 130 }                               /* flush_tx_buffers */
 131
 132
 133 /*********************************************************************/
 134 /* close/decativate the device. The device is not removed, but only  */
 135 /* deactivated.                                                      */
 136 /*********************************************************************/
 137 static int
 138 net_close(struct net_device *dev)
 139 {
 140
 141         netif_stop_queue(dev);  /* disable queueing */
 142
 143         if (((struct net_local *) dev)->is_open)
 144                 MOD_DEC_USE_COUNT;      /* adjust module counter */
 145         ((struct net_local *) dev)->is_open = 0;
 146         flush_tx_buffers((struct net_local *) dev);
 147
 148         return (0);             /* success */
 149 }                               /* net_close */
 150
 151 /************************************/
 152 /* send a packet on this interface. */
 153 /* new style for kernel >= 2.3.33   */
 154 /************************************/
 155 static int
 156 net_send_packet(struct sk_buff *skb, struct net_device *dev)
 157 {
 158         struct net_local *lp = (struct net_local *) dev;
 159
 160         spin_lock_irq(&lp->lock);
 161
 162         lp->skbs[lp->in_idx++] = skb;   /* add to buffer list */
 163         if (lp->in_idx >= MAX_SKB_BUFFERS)
 164                 lp->in_idx = 0; /* wrap around */
 165         lp->sk_count++;         /* adjust counter */
 166         dev->trans_start = jiffies;
 167
 168         /* If we just used up the very last entry in the
 169          * TX ring on this device, tell the queueing
 170          * layer to send no more.
 171          */
 172         if (lp->sk_count >= MAX_SKB_BUFFERS)
 173                 netif_stop_queue(dev);
 174
 175         /* When the TX completion hw interrupt arrives, this
 176          * is when the transmit statistics are updated.
 177          */
 178
 179         spin_unlock_irq(&lp->lock);
 180
 181         if (lp->sk_count <= 3) {
 182                 queue_task(&((hysdn_card *) dev->priv)->irq_queue, &tq_immediate);
 183                 mark_bh(IMMEDIATE_BH);
 184         }
 185         return (0);             /* success */
 186 }                               /* net_send_packet */
 187
 188
 189
 190 /***********************************************************************/
 191 /* acknowlegde a packet send. The network layer will be informed about */
 192 /* completion                                                          */
 193 /***********************************************************************/
 194 void
 195 hysdn_tx_netack(hysdn_card * card)
 196 {
 197         struct net_local *lp = card->netif;
 198
 199         if (!lp)
 200                 return;         /* non existing device */
 201
 202
 203         if (!lp->sk_count)
 204                 return;         /* error condition */
 205
 206         lp->stats.tx_packets++;
 207         lp->stats.tx_bytes += lp->skbs[lp->out_idx]->len;
 208
 209         dev_kfree_skb(lp->skbs[lp->out_idx++]);         /* free skb */
 210         if (lp->out_idx >= MAX_SKB_BUFFERS)
 211                 lp->out_idx = 0;        /* wrap around */
 212
 213         if (lp->sk_count-- == MAX_SKB_BUFFERS)  /* dec usage count */
 214                 netif_start_queue((struct net_device *) lp);
 215 }                               /* hysdn_tx_netack */
 216
 217 /*****************************************************/
 218 /* we got a packet from the network, go and queue it */
 219 /*****************************************************/
 220 void
 221 hysdn_rx_netpkt(hysdn_card * card, uchar * buf, word len)
 222 {
 223         struct net_local *lp = card->netif;
 224         struct sk_buff *skb;
 225
 226         if (!lp)
 227                 return;         /* non existing device */
 228
 229         lp->stats.rx_bytes += len;
 230
 231         skb = dev_alloc_skb(len);
 232         if (skb == NULL) {
 233                 printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n",
 234                        lp->netdev.name);
 235                 lp->stats.rx_dropped++;
 236                 return;
 237         }
 238         skb->dev = &lp->netdev;
 239
 240         /* copy the data */
 241         memcpy(skb_put(skb, len), buf, len);
 242
 243         /* determine the used protocol */
 244         skb->protocol = eth_type_trans(skb, &lp->netdev);
 245
 246         netif_rx(skb);
 247         lp->stats.rx_packets++; /* adjust packet count */
 248
 249 }                               /* hysdn_rx_netpkt */
 250
 251 /*****************************************************/
 252 /* return the pointer to a network packet to be send */
 253 /*****************************************************/
 254 struct sk_buff *
 255 hysdn_tx_netget(hysdn_card * card)
 256 {
 257         struct net_local *lp = card->netif;
 258
 259         if (!lp)
 260                 return (NULL);  /* non existing device */
 261
 262         if (!lp->sk_count)
 263                 return (NULL);  /* nothing available */
 264
 265         return (lp->skbs[lp->out_idx]);         /* next packet to send */
 266 }                               /* hysdn_tx_netget */
 267
 268
 269 /*******************************************/
 270 /* init function called by register device */
 271 /*******************************************/
 272 static int
 273 net_init(struct net_device *dev)
 274 {
 275         /* setup the function table */
 276         dev->open = net_open;
 277         dev->stop = net_close;
 278         dev->hard_start_xmit = net_send_packet;
 279         dev->get_stats = net_get_stats;
 280
 281         /* Fill in the fields of the device structure with ethernet values. */
 282         ether_setup(dev);
 283
 284         return (0);             /* success */
 285 }                               /* net_init */
 286
 287 /*****************************************************************************/
 288 /* hysdn_net_create creates a new net device for the given card. If a device */
 289 /* already exists, it will be deleted and created a new one. The return value */
 290 /* 0 announces success, else a negative error code will be returned.         */
 291 /*****************************************************************************/
 292 int
 293 hysdn_net_create(hysdn_card * card)
 294 {
 295         struct net_device *dev;
 296         int i;
 297         if(!card) {
 298                 printk(KERN_WARNING "No card-pt in hysdn_net_create!\n");
 299                 return (-ENOMEM);
 300         }
 301         hysdn_net_release(card);        /* release an existing net device */
 302         if ((dev = kmalloc(sizeof(struct net_local), GFP_KERNEL)) == NULL) {
 303                 printk(KERN_WARNING "HYSDN: unable to allocate mem\n");
 304                 if (card->debug_flags & LOG_NET_INIT)
 305                         return (-ENOMEM);
 306         }
 307         memset(dev, 0, sizeof(struct net_local));       /* clean the structure */
 308
 309         spin_lock_init(&((struct net_local *) dev)->lock);
 310
 311         /* initialise necessary or informing fields */
 312         dev->base_addr = card->iobase;  /* IO address */
 313         dev->irq = card->irq;   /* irq */
 314         dev->init = net_init;   /* the init function of the device */
 315         if(dev->name) {
 316                 strcpy(dev->name, ((struct net_local *) dev)->dev_name);
 317         }
 318         if ((i = register_netdev(dev))) {
 319                 printk(KERN_WARNING "HYSDN: unable to create network device\n");
 320                 kfree(dev);
 321                 return (i);
 322         }
 323         dev->priv = card;       /* remember pointer to own data structure */
 324         card->netif = dev;      /* setup the local pointer */
 325
 326         if (card->debug_flags & LOG_NET_INIT)
 327                 hysdn_addlog(card, "network device created");
 328         return (0);             /* and return success */
 329 }                               /* hysdn_net_create */
 330
 331 /***************************************************************************/
 332 /* hysdn_net_release deletes the net device for the given card. The return */
 333 /* value 0 announces success, else a negative error code will be returned. */
 334 /***************************************************************************/
 335 int
 336 hysdn_net_release(hysdn_card * card)
 337 {
 338         struct net_device *dev = card->netif;
 339
 340         if (!dev)
 341                 return (0);     /* non existing */
 342
 343         card->netif = NULL;     /* clear out pointer */
 344         dev->stop(dev);         /* close the device */
 345
 346         flush_tx_buffers((struct net_local *) dev);     /* empty buffers */
 347
 348         unregister_netdev(dev); /* release the device */
 349         kfree(dev);             /* release the memory allocated */
 350         if (card->debug_flags & LOG_NET_INIT)
 351                 hysdn_addlog(card, "network device deleted");
 352
 353         return (0);             /* always successfull */
 354 }                               /* hysdn_net_release */
 355
 356 /*****************************************************************************/
 357 /* hysdn_net_getname returns a pointer to the name of the network interface. */
 358 /* if the interface is not existing, a "-" is returned.                      */
 359 /*****************************************************************************/
 360 char *
 361 hysdn_net_getname(hysdn_card * card)
 362 {
 363         struct net_device *dev = card->netif;
 364
 365         if (!dev)
 366                 return ("-");   /* non existing */
 367
 368         return (dev->name);
 369 }                               /* hysdn_net_getname */