i386/linux/linux-2.3.21/drivers/net/eql.c

   1 /*
   2  * Equalizer Load-balancer for serial network interfaces.
   3  *
   4  * (c) Copyright 1995 Simon "Guru Aleph-Null" Janes
   5  * NCM: Network and Communications Management, Inc.
   6  *
   7  *
   8  *      This software may be used and distributed according to the terms
   9  *      of the GNU Public License, incorporated herein by reference.
  10  *
  11  * The author may be reached as simon@ncm.com, or C/O
  12  *    NCM
  13  *    Attn: Simon Janes
  14  *    6803 Whittier Ave
  15  *    McLean VA 22101
  16  *    Phone: 1-703-847-0040 ext 103
  17  */
  18
  19 static const char *version =
  20         "Equalizer1996: $Revision: 1.2.1 $ $Date: 1996/09/22 13:52:00 $ Simon Janes (simon@ncm.com)\n";
  21
  22 /*
  23  * Sources:
  24  *   skeleton.c by Donald Becker.
  25  * Inspirations:
  26  *   The Harried and Overworked Alan Cox
  27  * Conspiracies:
  28  *   The Alan Cox and Mike McLagan plot to get someone else to do the code,
  29  *   which turned out to be me.
  30  */
  31
  32 /*
  33  * $Log: eql.c,v $
  34  * Revision 1.2  1996/04/11 17:51:52  guru
  35  * Added one-line eql_remove_slave patch.
  36  *
  37  * Revision 1.1  1996/04/11 17:44:17  guru
  38  * Initial revision
  39  *
  40  * Revision 3.13  1996/01/21  15:17:18  alan
  41  * tx_queue_len changes.
  42  * reformatted.
  43  *
  44  * Revision 3.12  1995/03/22  21:07:51  anarchy
  45  * Added suser() checks on configuration.
  46  * Moved header file.
  47  *
  48  * Revision 3.11  1995/01/19  23:14:31  guru
  49  *                    slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
  50  *                      (priority_Bps) + bytes_queued * 8;
  51  *
  52  * Revision 3.10  1995/01/19  23:07:53  guru
  53  * back to
  54  *                    slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
  55  *                      (priority_Bps) + bytes_queued;
  56  *
  57  * Revision 3.9  1995/01/19  22:38:20  guru
  58  *                    slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
  59  *                      (priority_Bps) + bytes_queued * 4;
  60  *
  61  * Revision 3.8  1995/01/19  22:30:55  guru
  62  *       slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
  63  *                      (priority_Bps) + bytes_queued * 2;
  64  *
  65  * Revision 3.7  1995/01/19  21:52:35  guru
  66  * printk's trimmed out.
  67  *
  68  * Revision 3.6  1995/01/19  21:49:56  guru
  69  * This is working pretty well. I gained 1 K/s in speed.. now it's just
  70  * robustness and printk's to be diked out.
  71  *
  72  * Revision 3.5  1995/01/18  22:29:59  guru
  73  * still crashes the kernel when the lock_wait thing is woken up.
  74  *
  75  * Revision 3.4  1995/01/18  21:59:47  guru
  76  * Broken set-bit locking snapshot
  77  *
  78  * Revision 3.3  1995/01/17  22:09:18  guru
  79  * infinite sleep in a lock somewhere..
  80  *
  81  * Revision 3.2  1995/01/15  16:46:06  guru
  82  * Log trimmed of non-pertinent 1.x branch messages
  83  *
  84  * Revision 3.1  1995/01/15  14:41:45  guru
  85  * New Scheduler and timer stuff...
  86  *
  87  * Revision 1.15  1995/01/15  14:29:02  guru
  88  * Will make 1.14 (now 1.15) the 3.0 branch, and the 1.12 the 2.0 branch, the one
  89  * with the dumber scheduler
  90  *
  91  * Revision 1.14  1995/01/15  02:37:08  guru
  92  * shock.. the kept-new-versions could have zonked working
  93  * stuff.. shudder
  94  *
  95  * Revision 1.13  1995/01/15  02:36:31  guru
  96  * big changes
  97  *
  98  *      scheduler was torn out and replaced with something smarter
  99  *
 100  *      global names not prefixed with eql_ were renamed to protect
 101  *      against namespace collisions
 102  *
 103  *      a few more abstract interfaces were added to facilitate any
 104  *      potential change of datastructure.  the driver is still using
 105  *      a linked list of slaves.  going to a heap would be a bit of
 106  *      an overkill.
 107  *
 108  *      this compiles fine with no warnings.
 109  *
 110  *      the locking mechanism and timer stuff must be written however,
 111  *      this version will not work otherwise
 112  *
 113  */
 114
 115 #include <linux/module.h>
 116
 117 #include <linux/kernel.h>
 118 #include <linux/sched.h>
 119 #include <linux/types.h>
 120 #include <linux/fcntl.h>
 121 #include <linux/interrupt.h>
 122 #include <linux/ptrace.h>
 123 #include <linux/ioport.h>
 124 #include <linux/in.h>
 125 #include <linux/malloc.h>
 126 #include <linux/string.h>
 127 #include <asm/system.h>
 128 #include <asm/bitops.h>
 129 #include <asm/io.h>
 130 #include <asm/dma.h>
 131 #include <asm/uaccess.h>
 132 #include <linux/errno.h>
 133 #include <linux/init.h>
 134
 135 #include <linux/netdevice.h>
 136 #include <linux/if.h>
 137 #include <linux/if_arp.h>
 138 #include <linux/timer.h>
 139
 140 #include <linux/if_eql.h>
 141
 142 #ifndef EQL_DEBUG
 143 /* #undef EQL_DEBUG      -* print nothing at all, not even a boot-banner */
 144 /* #define EQL_DEBUG 1   -* print only the boot-banner */
 145 /* #define EQL_DEBUG 5   -* print major function entries */
 146 /* #define EQL_DEBUG 20  -* print subfunction entries */
 147 /* #define EQL_DEBUG 50  -* print utility entries */
 148 /* #define EQL_DEBUG 100 -* print voluminous function entries */
 149 #define EQL_DEBUG 1
 150 #endif
 151 static unsigned int eql_debug = EQL_DEBUG;
 152
 153 int        eql_init(struct net_device *dev); /*  */
 154 static int eql_open(struct net_device *dev); /*  */
 155 static int eql_close(struct net_device *dev); /*  */
 156 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd); /*  */
 157 static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev); /*  */
 158
 159 static struct net_device_stats *eql_get_stats(struct net_device *dev); /*  */
 160
 161 /* ioctl() handlers
 162    ---------------- */
 163 static int eql_enslave(struct net_device *dev,  slaving_request_t *srq); /*  */
 164 static int eql_emancipate(struct net_device *dev, slaving_request_t *srq); /*  */
 165
 166 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t *sc); /*  */
 167 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t *sc); /*  */
 168
 169 static int eql_g_master_cfg(struct net_device *dev, master_config_t *mc); /*  */
 170 static int eql_s_master_cfg(struct net_device *dev, master_config_t *mc); /*  */
 171
 172 static inline int eql_is_slave(struct net_device *dev); /*  */
 173 static inline int eql_is_master(struct net_device *dev); /*  */
 174
 175 static slave_t *eql_new_slave(void); /*  */
 176 static void eql_delete_slave(slave_t *slave); /*  */
 177
 178 /* static long eql_slave_priority(slave_t *slave); -*  */
 179 static inline int eql_number_slaves(slave_queue_t *queue); /*  */
 180
 181 static inline int eql_is_empty(slave_queue_t *queue); /*  */
 182 static inline int eql_is_full(slave_queue_t *queue); /*  */
 183
 184 static slave_queue_t *eql_new_slave_queue(struct net_device *dev); /*  */
 185 static void eql_delete_slave_queue(slave_queue_t *queue); /*  */
 186
 187 static int eql_insert_slave(slave_queue_t *queue, slave_t *slave); /*  */
 188 static slave_t *eql_remove_slave(slave_queue_t *queue, slave_t *slave); /*  */
 189
 190 /* static int eql_insert_slave_dev(slave_queue_t *queue, struct net_device *dev); -*  */
 191 static int eql_remove_slave_dev(slave_queue_t *queue, struct net_device *dev); /*  */
 192
 193 static inline struct net_device *eql_best_slave_dev(slave_queue_t *queue); /*  */
 194 static inline slave_t *eql_best_slave(slave_queue_t *queue); /*  */
 195 static inline slave_t *eql_first_slave(slave_queue_t *queue); /*  */
 196 static inline slave_t *eql_next_slave(slave_queue_t *queue, slave_t *slave); /*  */
 197
 198 static inline void eql_set_best_slave(slave_queue_t *queue, slave_t *slave); /*  */
 199 static inline void eql_schedule_slaves(slave_queue_t *queue); /*  */
 200
 201 static slave_t *eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev); /*  */
 202
 203 /* static inline eql_lock_slave_queue(slave_queue_t *queue); -*  */
 204 /* static inline eql_unlock_slave_queue(slave_queue_t *queue); -*  */
 205
 206 static void eql_timer(unsigned long param);     /*  */
 207 \f
 208 /* struct net_device * interface functions
 209    ---------------------------------------------------------
 210    */
 211
 212 int __init eql_init(struct net_device *dev)
 213 {
 214         static unsigned version_printed = 0;
 215         /* static unsigned num_masters     = 0; */
 216         equalizer_t *eql = 0;
 217
 218         if ( version_printed++ == 0 && eql_debug > 0)
 219                 printk(version);
 220         /*
 221          *      Initialize the device structure.
 222          */
 223         dev->priv = kmalloc (sizeof (equalizer_t), GFP_KERNEL);
 224         if (dev->priv == NULL)
 225                 return -ENOMEM;
 226         memset (dev->priv, 0, sizeof (equalizer_t));
 227         eql = (equalizer_t *) dev->priv;
 228
 229         eql->stats = kmalloc (sizeof (struct net_device_stats), GFP_KERNEL);
 230         if (eql->stats == NULL)
 231         {
 232                 kfree(dev->priv);
 233                 dev->priv = NULL;
 234                 return -ENOMEM;
 235         }
 236         memset (eql->stats, 0, sizeof (struct net_device_stats));
 237
 238         init_timer (&eql->timer);
 239         eql->timer.data         = (unsigned long) dev->priv;
 240         eql->timer.expires      = jiffies+EQL_DEFAULT_RESCHED_IVAL;
 241         eql->timer.function     = &eql_timer;
 242         eql->timer_on           = 0;
 243
 244         dev->open               = eql_open;
 245         dev->stop               = eql_close;
 246         dev->do_ioctl           = eql_ioctl;
 247         dev->hard_start_xmit    = eql_slave_xmit;
 248         dev->get_stats          = eql_get_stats;
 249
 250         /*
 251          *      Fill in the fields of the device structure with
 252          *      eql-generic values.
 253          */
 254
 255         dev_init_buffers(dev);
 256
 257         /*
 258          *      Now we undo some of the things that eth_setup does
 259          *      that we don't like
 260          */
 261
 262         dev->mtu                = EQL_DEFAULT_MTU;      /* set to 576 in eql.h */
 263         dev->flags              = IFF_MASTER;
 264
 265         dev->type               = ARPHRD_SLIP;
 266         dev->tx_queue_len       = 5;            /* Hands them off fast */
 267
 268         return 0;
 269 }
 270
 271 static int eql_open(struct net_device *dev)
 272 {
 273         equalizer_t *eql = (equalizer_t *) dev->priv;
 274         slave_queue_t *new_queue;
 275
 276 #ifdef EQL_DEBUG
 277         if (eql_debug >= 5)
 278                 printk ("%s: open\n", dev->name);
 279 #endif
 280
 281         printk ("%s: remember to turn off Van-Jacobson compression on your slave devices.\n", dev->name);
 282
 283         new_queue = eql_new_slave_queue (dev);
 284
 285         if (new_queue != 0)
 286         {
 287                 new_queue->master_dev = dev;
 288                 eql->queue = new_queue;
 289                 eql->queue->lock = 0;
 290                 eql->min_slaves = 1;
 291                 eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
 292
 293                 printk ("%s: adding timer\n", dev->name);
 294                 eql->timer_on = 1;
 295                 add_timer (&eql->timer);
 296
 297                 MOD_INC_USE_COUNT;
 298                 return 0;
 299         }
 300         return 1;
 301 }
 302
 303
 304 static int eql_close(struct net_device *dev)
 305 {
 306         equalizer_t *eql = (equalizer_t *) dev->priv;
 307
 308 #ifdef EQL_DEBUG
 309         if ( eql_debug >= 5)
 310                 printk ("%s: close\n", dev->name);
 311 #endif
 312         /*
 313          *      The timer has to be stopped first before we start hacking away
 314          *      at the data structure it scans every so often...
 315          */
 316
 317 #ifdef EQL_DEBUG
 318         printk ("%s: stopping timer\n", dev->name);
 319 #endif
 320         eql->timer_on = 0;
 321         del_timer (&eql->timer);
 322
 323         eql_delete_slave_queue (eql->queue);
 324
 325         MOD_DEC_USE_COUNT;
 326         return 0;
 327 }
 328
 329
 330 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 331 {
 332         if(cmd!=EQL_GETMASTRCFG && cmd!=EQL_GETSLAVECFG &&
 333            !capable(CAP_NET_ADMIN))
 334                 return -EPERM;
 335         switch (cmd)
 336         {
 337                 case EQL_ENSLAVE:
 338                         return eql_enslave (dev, (slaving_request_t *) ifr->ifr_data);
 339                 case EQL_EMANCIPATE:
 340                         return eql_emancipate (dev, (slaving_request_t *) ifr->ifr_data);
 341                 case EQL_GETSLAVECFG:
 342                         return eql_g_slave_cfg (dev, (slave_config_t *) ifr->ifr_data);
 343                 case EQL_SETSLAVECFG:
 344                         return eql_s_slave_cfg (dev, (slave_config_t *) ifr->ifr_data);
 345                 case EQL_GETMASTRCFG:
 346                         return eql_g_master_cfg (dev, (master_config_t *) ifr->ifr_data);
 347                 case EQL_SETMASTRCFG:
 348                         return eql_s_master_cfg (dev, (master_config_t *) ifr->ifr_data);
 349                 default:
 350                         return -EOPNOTSUPP;
 351         }
 352 }
 353
 354
 355 static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
 356 {
 357         equalizer_t *eql = (equalizer_t *) dev->priv;
 358         struct net_device *slave_dev = 0;
 359         slave_t *slave;
 360
 361         if (skb == NULL)
 362                 return 0;
 363
 364         eql_schedule_slaves (eql->queue);
 365
 366         slave = eql_best_slave (eql->queue);
 367         slave_dev = slave ? slave->dev : 0;
 368
 369         if ( slave_dev != 0 )
 370         {
 371 #ifdef EQL_DEBUG
 372                 if (eql_debug >= 100)
 373                         printk ("%s: %d slaves xmitng %d B %s\n",
 374                                 dev->name, eql_number_slaves (eql->queue), skb->len,
 375                                 slave_dev->name);
 376 #endif
 377                 skb->dev = slave_dev;
 378                 skb->priority = 1;
 379                 dev_queue_xmit (skb);
 380                 eql->stats->tx_packets++;
 381                 slave->bytes_queued += skb->len;
 382         }
 383         else
 384         {
 385                 /*
 386                  *      The alternative for this is the return 1 and have
 387                  *      dev_queue_xmit just queue it up on the eql's queue.
 388                  */
 389
 390                 eql->stats->tx_dropped++;
 391                 dev_kfree_skb(skb);
 392         }
 393         return 0;
 394 }
 395
 396
 397 static struct net_device_stats * eql_get_stats(struct net_device *dev)
 398 {
 399         equalizer_t *eql = (equalizer_t *) dev->priv;
 400         return eql->stats;
 401 }
 402
 403 /*
 404  *      Private ioctl functions
 405  */
 406
 407 static int eql_enslave(struct net_device *dev, slaving_request_t *srqp)
 408 {
 409         struct net_device *master_dev;
 410         struct net_device *slave_dev;
 411         slaving_request_t srq;
 412         int err;
 413
 414         err = copy_from_user(&srq, srqp, sizeof (slaving_request_t));
 415         if (err)
 416           {
 417 #ifdef EQL_DEBUG
 418         if (eql_debug >= 20)
 419                 printk ("EQL enslave: error detected by copy_from_user\n");
 420 #endif
 421                 return err;
 422           }
 423
 424 #ifdef EQL_DEBUG
 425         if (eql_debug >= 20)
 426                 printk ("%s: enslave '%s' %ld bps\n", dev->name,
 427                         srq.slave_name, srq.priority);
 428 #endif
 429         master_dev = dev;               /* for "clarity" */
 430         slave_dev  = __dev_get_by_name (srq.slave_name);
 431
 432         if (master_dev != 0 && slave_dev != 0)
 433         {
 434                 if ((master_dev->flags & IFF_UP) == IFF_UP)
 435                 {
 436                         /*slave is not a master & not already a slave:*/
 437                         if (! eql_is_master (slave_dev)  &&
 438                             ! eql_is_slave (slave_dev) )
 439                         {
 440                                 slave_t *s = eql_new_slave ();
 441                                 equalizer_t *eql =
 442                                         (equalizer_t *) master_dev->priv;
 443                                 s->dev = slave_dev;
 444                                 s->priority = srq.priority;
 445                                 s->priority_bps = srq.priority;
 446                                 s->priority_Bps = srq.priority / 8;
 447                                 slave_dev->flags |= IFF_SLAVE;
 448                                 eql_insert_slave (eql->queue, s);
 449                                 return 0;
 450                         }
 451 #ifdef EQL_DEBUG
 452                         else if (eql_debug >= 20)
 453                                 printk ("EQL enslave: slave is master or slave is already slave\n");
 454 #endif
 455                 }
 456 #ifdef EQL_DEBUG
 457                 else if (eql_debug >= 20)
 458                         printk ("EQL enslave: master device not up!\n");
 459 #endif
 460         }
 461 #ifdef EQL_DEBUG
 462         else if (eql_debug >= 20)
 463                 printk ("EQL enslave: master or slave are NULL");
 464 #endif
 465         return -EINVAL;
 466 }
 467
 468 static int eql_emancipate(struct net_device *dev, slaving_request_t *srqp)
 469 {
 470         struct net_device *master_dev;
 471         struct net_device *slave_dev;
 472         slaving_request_t srq;
 473         int err;
 474
 475         err = copy_from_user(&srq, srqp, sizeof (slaving_request_t));
 476         if (err)
 477                 return err;
 478
 479 #ifdef EQL_DEBUG
 480         if (eql_debug >= 20)
 481                 printk ("%s: emancipate `%s`\n", dev->name, srq.slave_name);
 482 #endif
 483         master_dev = dev;               /* for "clarity" */
 484         slave_dev  = __dev_get_by_name (srq.slave_name);
 485
 486         if ( eql_is_slave (slave_dev) ) /* really is a slave */
 487         {
 488                 equalizer_t *eql = (equalizer_t *) master_dev->priv;
 489                 slave_dev->flags = slave_dev->flags & ~IFF_SLAVE;
 490                 eql_remove_slave_dev (eql->queue, slave_dev);
 491                 return 0;
 492         }
 493         return -EINVAL;
 494 }
 495
 496
 497 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t *scp)
 498 {
 499         slave_t *slave;
 500         equalizer_t *eql;
 501         struct net_device *slave_dev;
 502         slave_config_t sc;
 503         int err;
 504
 505         err = copy_from_user (&sc, scp, sizeof (slave_config_t));
 506         if (err)
 507                 return err;
 508
 509 #ifdef EQL_DEBUG
 510         if (eql_debug >= 20)
 511                 printk ("%s: get config for slave `%s'\n", dev->name, sc.slave_name);
 512 #endif
 513         eql = (equalizer_t *) dev->priv;
 514         slave_dev = __dev_get_by_name (sc.slave_name);
 515
 516         if ( eql_is_slave (slave_dev) )
 517         {
 518                 slave = eql_find_slave_dev (eql->queue,  slave_dev);
 519                 if (slave != 0)
 520                 {
 521                         sc.priority = slave->priority;
 522                         err = verify_area(VERIFY_WRITE, (void *)scp, sizeof (slave_config_t));
 523                         if (err)
 524                                 return err;
 525                         copy_to_user (scp, &sc, sizeof (slave_config_t));
 526                         return 0;
 527                 }
 528         }
 529         return -EINVAL;
 530 }
 531
 532
 533 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t *scp)
 534 {
 535         slave_t *slave;
 536         equalizer_t *eql;
 537         struct net_device *slave_dev;
 538         slave_config_t sc;
 539         int err;
 540
 541         err = copy_from_user (&sc, scp, sizeof (slave_config_t));
 542         if (err)
 543                 return err;
 544
 545 #ifdef EQL_DEBUG
 546         if (eql_debug >= 20)
 547                 printk ("%s: set config for slave `%s'\n", dev->name, sc.slave_name);
 548 #endif
 549
 550
 551         eql = (equalizer_t *) dev->priv;
 552         slave_dev = __dev_get_by_name (sc.slave_name);
 553
 554         if ( eql_is_slave (slave_dev) )
 555         {
 556                 slave = eql_find_slave_dev (eql->queue, slave_dev);
 557                 if (slave != 0)
 558                 {
 559                         slave->priority = sc.priority;
 560                         slave->priority_bps = sc.priority;
 561                         slave->priority_Bps = sc.priority / 8;
 562                         return 0;
 563                 }
 564         }
 565         return -EINVAL;
 566 }
 567
 568
 569 static int eql_g_master_cfg(struct net_device *dev, master_config_t *mcp)
 570 {
 571         equalizer_t *eql;
 572         master_config_t mc;
 573
 574 #if EQL_DEBUG
 575         if (eql_debug >= 20)
 576                 printk ("%s: get master config\n", dev->name);
 577 #endif
 578
 579         if ( eql_is_master (dev) )
 580         {
 581                 int err;
 582                 eql = (equalizer_t *) dev->priv;
 583                 mc.max_slaves = eql->max_slaves;
 584                 mc.min_slaves = eql->min_slaves;
 585                 err = copy_to_user (mcp, &mc, sizeof (master_config_t));
 586                 if (err)
 587                         return err;
 588                 return 0;
 589         }
 590         return -EINVAL;
 591 }
 592
 593
 594 static int eql_s_master_cfg(struct net_device *dev, master_config_t *mcp)
 595 {
 596         equalizer_t *eql;
 597         master_config_t mc;
 598         int err;
 599
 600         err = copy_from_user (&mc, mcp, sizeof (master_config_t));
 601         if (err)
 602                 return err;
 603 #if EQL_DEBUG
 604         if (eql_debug >= 20)
 605                 printk ("%s: set master config\n", dev->name);
 606 #endif
 607         if ( eql_is_master (dev) )
 608         {
 609                 eql = (equalizer_t *) dev->priv;
 610                 eql->max_slaves = mc.max_slaves;
 611                 eql->min_slaves = mc.min_slaves;
 612                 return 0;
 613         }
 614         return -EINVAL;
 615 }
 616
 617 /*
 618  *      Private device support functions
 619  */
 620
 621 static inline int eql_is_slave(struct net_device *dev)
 622 {
 623         if (dev)
 624         {
 625                 if ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
 626                         return 1;
 627         }
 628         return 0;
 629 }
 630
 631
 632 static inline int eql_is_master(struct net_device *dev)
 633 {
 634         if (dev)
 635         {
 636                 if ((dev->flags & IFF_MASTER) == IFF_MASTER)
 637                 return 1;
 638         }
 639         return 0;
 640 }
 641
 642
 643 static slave_t *eql_new_slave(void)
 644 {
 645         slave_t *slave;
 646
 647         slave = (slave_t *) kmalloc (sizeof (slave_t), GFP_KERNEL);
 648         if (slave)
 649         {
 650                 memset(slave, 0, sizeof (slave_t));
 651                 return slave;
 652         }
 653         return 0;
 654 }
 655
 656
 657 static void eql_delete_slave(slave_t *slave)
 658 {
 659         kfree (slave);
 660 }
 661
 662
 663 #if 0                           /* not currently used, will be used
 664                                    when we really use a priority queue */
 665 static long slave_Bps(slave_t *slave)
 666 {
 667         return (slave->priority_Bps);
 668 }
 669
 670 static long slave_bps(slave_t *slave)
 671 {
 672         return (slave->priority_bps);
 673 }
 674
 675 #endif
 676
 677 static inline int eql_number_slaves(slave_queue_t *queue)
 678 {
 679         return queue->num_slaves;
 680 }
 681
 682 static inline int eql_is_empty(slave_queue_t *queue)
 683 {
 684         if (eql_number_slaves (queue) == 0)
 685                 return 1;
 686         return 0;
 687 }
 688
 689 static inline int eql_is_full(slave_queue_t *queue)
 690 {
 691         equalizer_t *eql = (equalizer_t *) queue->master_dev->priv;
 692
 693         if (eql_number_slaves (queue) == eql->max_slaves)
 694                 return 1;
 695         return 0;
 696 }
 697
 698 static slave_queue_t *eql_new_slave_queue(struct net_device *dev)
 699 {
 700         slave_queue_t *queue;
 701         slave_t *head_slave;
 702         slave_t *tail_slave;
 703
 704         queue = (slave_queue_t *) kmalloc (sizeof (slave_queue_t), GFP_KERNEL);
 705         if (queue == NULL)
 706                 return 0;
 707         memset (queue, 0, sizeof (slave_queue_t));
 708         head_slave = eql_new_slave ();
 709         tail_slave = eql_new_slave ();
 710
 711         if ( head_slave != 0 &&
 712                 tail_slave != 0 )
 713         {
 714                 head_slave->next = tail_slave;
 715                 tail_slave->next = 0;
 716                 queue->head = head_slave;
 717                 queue->num_slaves = 0;
 718                 queue->master_dev = dev;
 719         }
 720         else
 721         {
 722                 if (head_slave)
 723                         kfree(head_slave);
 724                 if (tail_slave)
 725                         kfree(tail_slave);
 726                 kfree (queue);
 727                 return 0;
 728         }
 729         return queue;
 730 }
 731
 732
 733 static void eql_delete_slave_queue(slave_queue_t *queue)
 734 {
 735         slave_t *zapped;
 736         /*
 737          *      This should only be called when there isn't a
 738          *      timer running that scans the data periodically..
 739          *      dev_close stops the timer...
 740          */
 741
 742         while ( ! eql_is_empty (queue) )
 743         {
 744                 zapped = eql_remove_slave (queue, queue->head->next);
 745                 eql_delete_slave (zapped);
 746         }
 747         kfree (queue->head->next);
 748         kfree (queue->head);
 749         kfree (queue);
 750 }
 751
 752 static int eql_insert_slave(slave_queue_t *queue, slave_t *slave)
 753 {
 754         cli ();
 755
 756         if ( ! eql_is_full (queue) )
 757         {
 758                 slave_t *duplicate_slave = 0;
 759                 duplicate_slave = eql_find_slave_dev (queue, slave->dev);
 760                 if (duplicate_slave != 0)
 761                 {
 762 /*                        printk ("%s: found a duplicate, killing it and replacing\n",
 763                                   queue->master_dev->name); */
 764                         eql_delete_slave (eql_remove_slave (queue, duplicate_slave));
 765                 }
 766                 slave->next = queue->head->next;
 767                 queue->head->next = slave;
 768                 queue->num_slaves++;
 769                 sti ();
 770                 return 0;
 771         }
 772         sti ();
 773         return 1;
 774 }
 775
 776
 777 static slave_t *eql_remove_slave(slave_queue_t *queue, slave_t *slave)
 778 {
 779         slave_t *prev;
 780         slave_t *curr;
 781
 782         cli ();
 783
 784         prev = queue->head;
 785         curr = queue->head->next;
 786         while (curr != slave &&
 787                 curr->dev != 0 )
 788         {
 789 /*              printk ("%s: remove_slave; searching...\n", queue->master_dev->name); */
 790                 prev = curr;
 791                 curr = curr->next;
 792         }
 793
 794         if (curr == slave)
 795         {
 796                 prev->next = curr->next;
 797                 queue->num_slaves--;
 798                 curr->dev->flags = curr->dev->flags & ~IFF_SLAVE;
 799                 sti();
 800                 return curr;
 801         }
 802         sti ();
 803         return 0;                       /* not found */
 804 }
 805
 806
 807 static int eql_remove_slave_dev(slave_queue_t *queue, struct net_device *dev)
 808 {
 809         slave_t *prev;
 810         slave_t *curr;
 811         slave_t *target;
 812
 813         target = eql_find_slave_dev (queue, dev);
 814
 815         if (target != 0)
 816         {
 817                 cli ();
 818                 prev = queue->head;
 819                 curr = prev->next;
 820                 while (curr != target)
 821                 {
 822                         prev = curr;
 823                         curr = curr->next;
 824                 }
 825                 prev->next = curr->next;
 826                 queue->num_slaves--;
 827                 sti ();
 828                 eql_delete_slave (curr);
 829                 return 0;
 830         }
 831         return 1;
 832 }
 833
 834
 835 static inline struct net_device *eql_best_slave_dev(slave_queue_t *queue)
 836 {
 837         if (queue->best_slave != 0)
 838         {
 839                 if (queue->best_slave->dev != 0)
 840                         return queue->best_slave->dev;
 841                 else
 842                         return 0;
 843         }
 844         else
 845                 return 0;
 846 }
 847
 848
 849 static inline slave_t *eql_best_slave(slave_queue_t *queue)
 850 {
 851         return queue->best_slave;
 852 }
 853
 854 static inline void eql_schedule_slaves(slave_queue_t *queue)
 855 {
 856         struct net_device *master_dev = queue->master_dev;
 857         slave_t *best_slave = 0;
 858         slave_t *slave_corpse = 0;
 859
 860 #ifdef EQL_DEBUG
 861         if (eql_debug >= 100)
 862                 printk ("%s: schedule %d slaves\n",
 863                         master_dev->name, eql_number_slaves (queue));
 864 #endif
 865         if ( eql_is_empty (queue) )
 866         {
 867                 /*
 868                  *      No slaves to play with
 869                  */
 870                 eql_set_best_slave (queue, (slave_t *) 0);
 871                 return;
 872         }
 873         else
 874         {
 875                 /*
 876                  *      Make a pass to set the best slave
 877                  */
 878                 unsigned long best_load = (unsigned long) ULONG_MAX;
 879                 slave_t *slave = 0;
 880                 int i;
 881
 882                 cli ();
 883                 for (i = 1, slave = eql_first_slave (queue);
 884                         i <= eql_number_slaves (queue);
 885                         i++, slave = eql_next_slave (queue, slave))
 886                 {
 887                         /*
 888                          *      Go through the slave list once, updating best_slave
 889                          *      whenever a new best_load is found, whenever a dead
 890                          *      slave is found, it is marked to be pulled out of the
 891                          *      queue
 892                          */
 893
 894                         unsigned long slave_load;
 895                         unsigned long bytes_queued;
 896                         unsigned long priority_Bps;
 897
 898                         if (slave != 0)
 899                         {
 900                                 bytes_queued = slave->bytes_queued;
 901                                 priority_Bps = slave->priority_Bps;
 902                                 if ( slave->dev != 0)
 903                                 {
 904                                         if ((slave->dev->flags & IFF_UP) == IFF_UP )
 905                                         {
 906                                                 slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
 907                                                         (priority_Bps) + bytes_queued * 8;
 908
 909                                                 if (slave_load < best_load)
 910                                                 {
 911                                                         best_load = slave_load;
 912                                                         best_slave = slave;
 913                                                 }
 914                                         }
 915                                         else            /* we found a dead slave */
 916                                         {
 917                                                 /*
 918                                                  *      We only bury one slave at a time, if more than
 919                                                  *      one slave dies, we will bury him on the next
 920                                                  *      reschedule. slaves don't die all at once that
 921                                                  *      much anyway
 922                                                  */
 923                                                 slave_corpse = slave;
 924                                         }
 925                                 }
 926                         }
 927                 } /* for */
 928                 sti ();
 929                 eql_set_best_slave (queue, best_slave);
 930         } /* else */
 931         if (slave_corpse != 0)
 932         {
 933                 printk ("eql: scheduler found dead slave, burying...\n");
 934                 eql_delete_slave (eql_remove_slave (queue, slave_corpse));
 935         }
 936         return;
 937 }
 938
 939
 940 static slave_t * eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
 941 {
 942         slave_t *slave = 0;
 943         slave = eql_first_slave(queue);
 944
 945         while (slave != 0 && slave->dev != dev && slave != 0)
 946         {
 947 #if 0
 948                 if (slave->dev != 0)
 949                         printk ("eql: find_slave_dev; looked at '%s'...\n", slave->dev->name);
 950                 else
 951                         printk ("eql: find_slave_dev; looked at nothing...\n");
 952 #endif
 953                 slave = slave->next;
 954         }
 955         return slave;
 956 }
 957 \f
 958
 959 static inline slave_t *eql_first_slave(slave_queue_t *queue)
 960 {
 961         return queue->head->next;
 962 }
 963
 964
 965 static inline slave_t *eql_next_slave(slave_queue_t *queue, slave_t *slave)
 966 {
 967         return slave->next;
 968 }
 969
 970 static inline void eql_set_best_slave(slave_queue_t *queue, slave_t *slave)
 971 {
 972         queue->best_slave = slave;
 973 }
 974
 975 static void eql_timer(unsigned long param)
 976 {
 977         equalizer_t *eql = (equalizer_t *) param;
 978         slave_t *slave;
 979         slave_t *slave_corpse = 0;
 980         int i;
 981
 982         if ( ! eql_is_empty (eql->queue) )
 983         {
 984                 cli ();
 985                 for (i = 1, slave = eql_first_slave (eql->queue);
 986                         i <= eql_number_slaves (eql->queue);
 987                         i++, slave = eql_next_slave (eql->queue, slave))
 988                 {
 989                         if (slave != 0)
 990                         {
 991                                 if ((slave->dev->flags & IFF_UP) == IFF_UP )
 992                                 {
 993                                         slave->bytes_queued -= slave->priority_Bps;
 994                                         if (slave->bytes_queued < 0)
 995                                                 slave->bytes_queued = 0;
 996                                 }
 997                                 else
 998                                         slave_corpse = slave;
 999                         }
1000                 }
1001                 sti ();
1002                 if (slave_corpse != 0)
1003                 {
1004                         printk ("eql: timer found dead slave, burying...\n");
1005                         eql_delete_slave (eql_remove_slave (eql->queue, slave_corpse));
1006                 }
1007         }
1008
1009         if (eql->timer_on != 0)
1010         {
1011                 eql->timer.expires = jiffies+EQL_DEFAULT_RESCHED_IVAL;
1012                 add_timer (&eql->timer);
1013         }
1014 }
1015
1016 #ifdef MODULE
1017 static struct net_device dev_eql =
1018 {
1019         "eql", 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL, eql_init
1020 };
1021
1022 int init_module(void)
1023 {
1024         if (register_netdev(&dev_eql) != 0) {
1025                 printk("eql: register_netdev() returned non-zero.\n");
1026                 return -EIO;
1027         }
1028         return 0;
1029 }
1030
1031 void cleanup_module(void)
1032 {
1033         unregister_netdev(&dev_eql);
1034 }
1035 #endif /* MODULE */
1036
1037 /*
1038  * Local Variables:
1039  * compile-command: "gcc -D__KERNEL__ -I/usr/src/linux/net/inet -Wall -Wstrict-prototypes -O6 -m486 -c eql.c"
1040  * version-control: t
1041  * kept-new-versions: 20
1042  * End:
1043  */