drivers/net/sgiseeq.c

   1 /* $Id: sgiseeq.c,v 1.9 1998/10/14 23:40:46 ralf Exp $
   2  *
   3  * sgiseeq.c: Seeq8003 ethernet driver for SGI machines.
   4  *
   5  * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
   6  */
   7 #include <linux/kernel.h>
   8 #include <linux/sched.h>
   9 #include <linux/types.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/ptrace.h>
  12 #include <linux/ioport.h>
  13 #include <linux/in.h>
  14 #include <linux/malloc.h>
  15 #include <linux/string.h>
  16 #include <linux/delay.h>
  17
  18 #include <asm/io.h>
  19 #include <asm/segment.h>
  20 #include <asm/system.h>
  21 #include <asm/bitops.h>
  22 #include <asm/page.h>
  23 #include <asm/pgtable.h>
  24 #include <linux/errno.h>
  25 #include <asm/byteorder.h>
  26
  27 #include <linux/socket.h>
  28 #include <linux/route.h>
  29
  30 #include <linux/netdevice.h>
  31 #include <linux/etherdevice.h>
  32 #include <linux/skbuff.h>
  33
  34 #include <asm/sgihpc.h>
  35 #include <asm/sgialib.h>
  36
  37 #include "sgiseeq.h"
  38
  39 static char *version =
  40         "sgiseeq.c: David S. Miller (dm@engr.sgi.com)\n";
  41
  42 static char *sgiseeqstr = "SGI Seeq8003";
  43
  44 /* If you want speed, you do something silly, it always has worked
  45  * for me.  So, with that in mind, I've decided to make this driver
  46  * look completely like a stupid Lance from a driver architecture
  47  * perspective.  Only difference is that here our "ring buffer" looks
  48  * and acts like a real Lance one does but is layed out like how the
  49  * HPC DMA and the Seeq want it to.  You'd be surprised how a stupid
  50  * idea like this can pay off in performance, not to mention making
  51  * this driver 2,000 times easier to write. ;-)
  52  */
  53
  54 /* Tune these if we tend to run out often etc. */
  55 #define SEEQ_RX_BUFFERS  16
  56 #define SEEQ_TX_BUFFERS  16
  57
  58 #define PKT_BUF_SZ       1584
  59
  60 #define NEXT_RX(i)  (((i) + 1) & (SEEQ_RX_BUFFERS - 1))
  61 #define NEXT_TX(i)  (((i) + 1) & (SEEQ_TX_BUFFERS - 1))
  62 #define PREV_RX(i)  (((i) - 1) & (SEEQ_RX_BUFFERS - 1))
  63 #define PREV_TX(i)  (((i) - 1) & (SEEQ_TX_BUFFERS - 1))
  64
  65 #define TX_BUFFS_AVAIL(sp) ((sp->tx_old <= sp->tx_new) ? \
  66                             sp->tx_old + (SEEQ_TX_BUFFERS - 1) - sp->tx_new : \
  67                             sp->tx_old - sp->tx_new - 1)
  68
  69 #define DEBUG
  70
  71 struct sgiseeq_rx_desc {
  72         struct hpc_dma_desc rdma;
  73         unsigned long buf_vaddr;
  74 };
  75
  76 struct sgiseeq_tx_desc {
  77         struct hpc_dma_desc tdma;
  78         unsigned long buf_vaddr;
  79 };
  80
  81 /* Warning: This structure is layed out in a certain way because
  82  *          HPC dma descriptors must be 8-byte aligned.  So don't
  83  *          touch this without some care.
  84  */
  85 struct sgiseeq_init_block { /* Note the name ;-) */
  86         /* Ptrs to the descriptors in KSEG1 uncached space. */
  87         struct sgiseeq_rx_desc *rx_desc;
  88         struct sgiseeq_tx_desc *tx_desc;
  89         unsigned long _padding[30]; /* Pad out to largest cache line size. */
  90
  91         struct sgiseeq_rx_desc rxvector[SEEQ_RX_BUFFERS];
  92         struct sgiseeq_tx_desc txvector[SEEQ_TX_BUFFERS];
  93 };
  94
  95 struct sgiseeq_private {
  96         volatile struct sgiseeq_init_block srings;
  97         char *name;
  98         volatile struct hpc3_ethregs *hregs;
  99         volatile struct sgiseeq_regs *sregs;
 100
 101         /* Ring entry counters. */
 102         unsigned int rx_new, tx_new;
 103         unsigned int rx_old, tx_old;
 104
 105         int is_edlc;
 106         unsigned char control;
 107         unsigned char mode;
 108
 109         struct enet_statistics stats;
 110 };
 111
 112 static inline void hpc3_eth_reset(volatile struct hpc3_ethregs *hregs)
 113 {
 114         hregs->rx_reset = (HPC3_ERXRST_CRESET | HPC3_ERXRST_CLRIRQ);
 115         udelay(20);
 116         hregs->rx_reset = 0;
 117 }
 118
 119 static inline void reset_hpc3_and_seeq(volatile struct hpc3_ethregs *hregs,
 120                                        volatile struct sgiseeq_regs *sregs)
 121 {
 122         hregs->rx_ctrl = hregs->tx_ctrl = 0;
 123         hpc3_eth_reset(hregs);
 124 }
 125
 126 #define RSTAT_GO_BITS (SEEQ_RCMD_IGOOD | SEEQ_RCMD_IEOF | SEEQ_RCMD_ISHORT | \
 127                        SEEQ_RCMD_IDRIB | SEEQ_RCMD_ICRC)
 128
 129 static inline void seeq_go(struct sgiseeq_private *sp,
 130                            volatile struct hpc3_ethregs *hregs,
 131                            volatile struct sgiseeq_regs *sregs)
 132 {
 133         sregs->rstat = sp->mode | RSTAT_GO_BITS;
 134         hregs->rx_ctrl = HPC3_ERXCTRL_ACTIVE;
 135 }
 136
 137 static inline void seeq_load_eaddr(struct net_device *dev,
 138                                    volatile struct sgiseeq_regs *sregs)
 139 {
 140         int i;
 141
 142         sregs->tstat = SEEQ_TCMD_RB0;
 143         for(i = 0; i < 6; i++)
 144                 sregs->rw.eth_addr[i] = dev->dev_addr[i];
 145 }
 146
 147 #define TCNTINFO_INIT (HPCDMA_EOX | HPCDMA_ETXD)
 148 #define RCNTCFG_INIT  (HPCDMA_OWN | HPCDMA_EORP | HPCDMA_XIE)
 149 #define RCNTINFO_INIT (RCNTCFG_INIT | (PKT_BUF_SZ & HPCDMA_BCNT))
 150
 151 static void seeq_init_ring(struct net_device *dev)
 152 {
 153         struct sgiseeq_private *sp = (struct sgiseeq_private *) dev->priv;
 154         volatile struct sgiseeq_init_block *ib = &sp->srings;
 155         int i;
 156
 157         dev->tbusy = 1;
 158         sp->rx_new = sp->tx_new = 0;
 159         sp->rx_old = sp->tx_old = 0;
 160
 161         seeq_load_eaddr(dev, sp->sregs);
 162
 163         /* XXX for now just accept packets directly to us
 164          * XXX and ether-broadcast.  Will do multicast and
 165          * XXX promiscuous mode later. -davem
 166          */
 167         sp->mode = SEEQ_RCMD_RBCAST;
 168
 169         /* Setup tx ring. */
 170         for(i = 0; i < SEEQ_TX_BUFFERS; i++) {
 171                 if(!ib->tx_desc[i].tdma.pbuf) {
 172                         unsigned long buffer;
 173
 174                         buffer = (unsigned long) kmalloc(PKT_BUF_SZ, GFP_KERNEL);
 175                         ib->tx_desc[i].buf_vaddr = KSEG1ADDR(buffer);
 176                         ib->tx_desc[i].tdma.pbuf = PHYSADDR(buffer);
 177 //                      flush_cache_all();
 178                 }
 179                 ib->tx_desc[i].tdma.cntinfo = (TCNTINFO_INIT);
 180         }
 181
 182         /* And now the rx ring. */
 183         for(i = 0; i < SEEQ_RX_BUFFERS; i++) {
 184                 if(!ib->rx_desc[i].rdma.pbuf) {
 185                         unsigned long buffer;
 186
 187                         buffer = (unsigned long) kmalloc(PKT_BUF_SZ, GFP_KERNEL);
 188                         ib->rx_desc[i].buf_vaddr = KSEG1ADDR(buffer);
 189                         ib->rx_desc[i].rdma.pbuf = PHYSADDR(buffer);
 190 //                      flush_cache_all();
 191                 }
 192                 ib->rx_desc[i].rdma.cntinfo = (RCNTINFO_INIT);
 193         }
 194         ib->rx_desc[i - 1].rdma.cntinfo |= (HPCDMA_EOR);
 195 }
 196
 197 #ifdef DEBUG
 198 static struct sgiseeq_private *gpriv;
 199 static struct net_device *gdev;
 200
 201 void sgiseeq_dump_rings(void)
 202 {
 203         static int once = 0;
 204         struct sgiseeq_rx_desc *r = gpriv->srings.rx_desc;
 205         struct sgiseeq_tx_desc *t = gpriv->srings.tx_desc;
 206         volatile struct hpc3_ethregs *hregs = gpriv->hregs;
 207         int i;
 208
 209         if(once)
 210                 return;
 211         once++;
 212         printk("RING DUMP:\n");
 213         for(i = 0; i < SEEQ_RX_BUFFERS; i++) {
 214                 printk("RX [%d]: @(%p) [%08lx,%08lx,%08lx] ",
 215                        i, (&r[i]), r[i].rdma.pbuf, r[i].rdma.cntinfo,
 216                        r[i].rdma.pnext);
 217                 i += 1;
 218                 printk("-- [%d]: @(%p) [%08lx,%08lx,%08lx]\n",
 219                        i, (&r[i]), r[i].rdma.pbuf, r[i].rdma.cntinfo,
 220                        r[i].rdma.pnext);
 221         }
 222         for(i = 0; i < SEEQ_TX_BUFFERS; i++) {
 223                 printk("TX [%d]: @(%p) [%08lx,%08lx,%08lx] ",
 224                        i, (&t[i]), t[i].tdma.pbuf, t[i].tdma.cntinfo,
 225                        t[i].tdma.pnext);
 226                 i += 1;
 227                 printk("-- [%d]: @(%p) [%08lx,%08lx,%08lx]\n",
 228                        i, (&t[i]), t[i].tdma.pbuf, t[i].tdma.cntinfo,
 229                        t[i].tdma.pnext);
 230         }
 231         printk("INFO: [rx_new = %d rx_old=%d] [tx_new = %d tx_old = %d]\n",
 232                gpriv->rx_new, gpriv->rx_old, gpriv->tx_new, gpriv->tx_old);
 233         printk("RREGS: rx_cbptr[%08lx] rx_ndptr[%08lx] rx_ctrl[%08lx]\n",
 234                hregs->rx_cbptr, hregs->rx_ndptr, hregs->rx_ctrl);
 235         printk("TREGS: tx_cbptr[%08lx] tx_ndptr[%08lx] tx_ctrl[%08lx]\n",
 236                hregs->tx_cbptr, hregs->tx_ndptr, hregs->tx_ctrl);
 237 }
 238 #endif
 239
 240 #define TSTAT_INIT_SEEQ (SEEQ_TCMD_IPT|SEEQ_TCMD_I16|SEEQ_TCMD_IC|SEEQ_TCMD_IUF)
 241 #define TSTAT_INIT_EDLC ((TSTAT_INIT_SEEQ) | SEEQ_TCMD_RB2)
 242 #define RDMACFG_INIT    (HPC3_ERXDCFG_FRXDC | HPC3_ERXDCFG_FEOP | HPC3_ERXDCFG_FIRQ)
 243
 244 static void init_seeq(struct net_device *dev, struct sgiseeq_private *sp,
 245                       volatile struct sgiseeq_regs *sregs)
 246 {
 247         volatile struct hpc3_ethregs *hregs = sp->hregs;
 248
 249         reset_hpc3_and_seeq(hregs, sregs);
 250         seeq_init_ring(dev);
 251
 252         /* Setup to field the proper interrupt types. */
 253         if(sp->is_edlc) {
 254                 sregs->tstat = (TSTAT_INIT_EDLC);
 255                 sregs->rw.wregs.control = sp->control;
 256                 sregs->rw.wregs.frame_gap = 0;
 257         } else {
 258                 sregs->tstat = (TSTAT_INIT_SEEQ);
 259         }
 260
 261         hregs->rx_dconfig |= RDMACFG_INIT;
 262
 263         hregs->rx_ndptr = PHYSADDR(&sp->srings.rx_desc[0]);
 264         hregs->tx_ndptr = PHYSADDR(&sp->srings.tx_desc[0]);
 265
 266         seeq_go(sp, hregs, sregs);
 267 }
 268
 269 static inline void record_rx_errors(struct sgiseeq_private *sp,
 270                                     unsigned char status)
 271 {
 272         if(status & SEEQ_RSTAT_OVERF ||
 273            status & SEEQ_RSTAT_SFRAME)
 274                 sp->stats.rx_over_errors++;
 275         if(status & SEEQ_RSTAT_CERROR)
 276                 sp->stats.rx_crc_errors++;
 277         if(status & SEEQ_RSTAT_DERROR)
 278                 sp->stats.rx_frame_errors++;
 279         if(status & SEEQ_RSTAT_REOF)
 280                 sp->stats.rx_errors++;
 281 }
 282
 283 static inline void rx_maybe_restart(struct sgiseeq_private *sp,
 284                                     volatile struct hpc3_ethregs *hregs,
 285                                     volatile struct sgiseeq_regs *sregs)
 286 {
 287         if(!(hregs->rx_ctrl & HPC3_ERXCTRL_ACTIVE)) {
 288                 hregs->rx_ndptr = PHYSADDR(&sp->srings.rx_desc[sp->rx_new]);
 289                 seeq_go(sp, hregs, sregs);
 290         }
 291 }
 292
 293 #define for_each_rx(rd, sp) for((rd) = &(sp)->srings.rx_desc[(sp)->rx_new]; \
 294                                 !((rd)->rdma.cntinfo & HPCDMA_OWN); \
 295                                 (rd) = &(sp)->srings.rx_desc[(sp)->rx_new])
 296
 297 static inline void sgiseeq_rx(struct net_device *dev, struct sgiseeq_private *sp,
 298                               volatile struct hpc3_ethregs *hregs,
 299                               volatile struct sgiseeq_regs *sregs)
 300 {
 301         struct sgiseeq_rx_desc *rd;
 302         struct sk_buff *skb = 0;
 303         unsigned char pkt_status;
 304         unsigned char *pkt_pointer = 0;
 305         int len = 0;
 306         unsigned int orig_end = PREV_RX(sp->rx_new);
 307
 308         /* Service every received packet. */
 309         for_each_rx(rd, sp) {
 310                 len = (PKT_BUF_SZ - (rd->rdma.cntinfo & HPCDMA_BCNT) - 3);
 311                 pkt_pointer = (unsigned char *)rd->buf_vaddr;
 312                 pkt_status = pkt_pointer[len + 2];
 313
 314                 if(pkt_status & SEEQ_RSTAT_FIG) {
 315                         /* Packet is OK. */
 316                         skb = dev_alloc_skb(len + 2);
 317
 318                         if(skb) {
 319                                 skb->dev = dev;
 320                                 skb_reserve(skb, 2);
 321                                 skb_put(skb, len);
 322
 323                                 /* Copy out of kseg1 to avoid silly cache flush. */
 324                                 eth_copy_and_sum(skb, pkt_pointer + 2, len, 0);
 325                                 skb->protocol = eth_type_trans(skb, dev);
 326                                 netif_rx(skb);
 327                                 sp->stats.rx_packets++;
 328                         } else {
 329                                 printk ("%s: Memory squeeze, deferring packet.\n",
 330                                         dev->name);
 331                                 sp->stats.rx_dropped++;
 332                         }
 333                 } else {
 334                         record_rx_errors(sp, pkt_status);
 335                 }
 336
 337                 /* Return the entry to the ring pool. */
 338                 rd->rdma.cntinfo = (RCNTINFO_INIT);
 339                 sp->rx_new = NEXT_RX(sp->rx_new);
 340         }
 341         sp->srings.rx_desc[orig_end].rdma.cntinfo &= ~(HPCDMA_EOR);
 342         sp->srings.rx_desc[PREV_RX(sp->rx_new)].rdma.cntinfo |= HPCDMA_EOR;
 343         rx_maybe_restart(sp, hregs, sregs);
 344 }
 345
 346 static inline void tx_maybe_reset_collisions(struct sgiseeq_private *sp,
 347                                              volatile struct sgiseeq_regs *sregs)
 348 {
 349         if(sp->is_edlc) {
 350                 sregs->rw.wregs.control = sp->control & ~(SEEQ_CTRL_XCNT);
 351                 sregs->rw.wregs.control = sp->control;
 352         }
 353 }
 354
 355 static inline void kick_tx(struct sgiseeq_tx_desc *td,
 356                            volatile struct hpc3_ethregs *hregs)
 357 {
 358         /* If the HPC aint doin nothin, and there are more packets
 359          * with ETXD cleared and XIU set we must make very certain
 360          * that we restart the HPC else we risk locking up the
 361          * adapter.  The following code is only safe iff the HPCDMA
 362          * is not active!
 363          */
 364         while((td->tdma.cntinfo & (HPCDMA_XIU | HPCDMA_ETXD)) ==
 365               (HPCDMA_XIU | HPCDMA_ETXD))
 366                 td = (struct sgiseeq_tx_desc *)
 367                         KSEG1ADDR(td->tdma.pnext);
 368         if(td->tdma.cntinfo & HPCDMA_XIU) {
 369                 hregs->tx_ndptr = PHYSADDR(td);
 370                 hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
 371         }
 372 }
 373
 374 static inline void sgiseeq_tx(struct net_device *dev, struct sgiseeq_private *sp,
 375                               volatile struct hpc3_ethregs *hregs,
 376                               volatile struct sgiseeq_regs *sregs)
 377 {
 378         struct sgiseeq_tx_desc *td;
 379         unsigned long status = hregs->tx_ctrl;
 380         int j;
 381
 382         tx_maybe_reset_collisions(sp, sregs);
 383
 384         if(!(status & (HPC3_ETXCTRL_ACTIVE | SEEQ_TSTAT_PTRANS))) {
 385                 /* Oops, HPC detected some sort of error. */
 386                 if(status & SEEQ_TSTAT_R16)
 387                         sp->stats.tx_aborted_errors++;
 388                 if(status & SEEQ_TSTAT_UFLOW)
 389                         sp->stats.tx_fifo_errors++;
 390                 if(status & SEEQ_TSTAT_LCLS)
 391                         sp->stats.collisions++;
 392         }
 393
 394         /* Ack 'em... */
 395         for(j = sp->tx_old; j != sp->tx_new; j = NEXT_TX(j)) {
 396                 td = &sp->srings.tx_desc[j];
 397
 398                 if(!(td->tdma.cntinfo & (HPCDMA_XIU)))
 399                         break;
 400                 if(!(td->tdma.cntinfo & (HPCDMA_ETXD))) {
 401                         if(!(status & HPC3_ETXCTRL_ACTIVE)) {
 402                                 hregs->tx_ndptr = PHYSADDR(td);
 403                                 hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
 404                         }
 405                         break;
 406                 }
 407                 sp->stats.tx_packets++;
 408                 sp->tx_old = NEXT_TX(sp->tx_old);
 409                 td->tdma.cntinfo &= ~(HPCDMA_XIU | HPCDMA_XIE);
 410                 td->tdma.cntinfo |= HPCDMA_EOX;
 411         }
 412 }
 413
 414 static inline void tx_maybe_unbusy(struct sgiseeq_private *sp,
 415                                    struct net_device *dev)
 416 {
 417         if((TX_BUFFS_AVAIL(sp) >= 0) && dev->tbusy) {
 418                 dev->tbusy = 0;
 419                 mark_bh(NET_BH);
 420         }
 421 }
 422
 423 static void sgiseeq_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 424 {
 425         struct net_device *dev = (struct net_device *) dev_id;
 426         struct sgiseeq_private *sp = (struct sgiseeq_private *) dev->priv;
 427         volatile struct hpc3_ethregs *hregs = sp->hregs;
 428         volatile struct sgiseeq_regs *sregs = sp->sregs;
 429
 430         /* Ack the IRQ and set software state. */
 431         hregs->rx_reset = HPC3_ERXRST_CLRIRQ;
 432         dev->interrupt = 1;
 433
 434         /* Always check for received packets. */
 435         sgiseeq_rx(dev, sp, hregs, sregs);
 436
 437         /* Only check for tx acks iff we have something queued. */
 438         if(sp->tx_old != sp->tx_new)
 439                 sgiseeq_tx(dev, sp, hregs, sregs);
 440
 441         tx_maybe_unbusy(sp, dev);
 442         dev->interrupt = 0;
 443 }
 444
 445 static int sgiseeq_open(struct net_device *dev)
 446 {
 447         struct sgiseeq_private *sp = (struct sgiseeq_private *)dev->priv;
 448         volatile struct sgiseeq_regs *sregs = sp->sregs;
 449         unsigned long flags;
 450
 451         save_flags(flags); cli();
 452         if(request_irq(dev->irq, sgiseeq_interrupt, 0, sgiseeqstr, (void *) dev)) {
 453                 printk("Seeq8003: Can't get irq %d\n", dev->irq);
 454                 restore_flags(flags);
 455                 return -EAGAIN;
 456         }
 457
 458         init_seeq(dev, sp, sregs);
 459
 460         dev->tbusy = 0;
 461         dev->interrupt = 0;
 462         dev->start = 1;
 463         restore_flags(flags);
 464         return 0;
 465 }
 466
 467 static int sgiseeq_close(struct net_device *dev)
 468 {
 469         struct sgiseeq_private *sp = (struct sgiseeq_private *) dev->priv;
 470         volatile struct sgiseeq_regs *sregs = sp->sregs;
 471
 472         dev->start = 0;
 473         dev->tbusy = 1;
 474
 475         /* Shutdown the Seeq. */
 476         reset_hpc3_and_seeq(sp->hregs, sregs);
 477
 478         free_irq(dev->irq, dev);
 479
 480         return 0;
 481 }
 482
 483 static inline int sgiseeq_reset(struct net_device *dev)
 484 {
 485         struct sgiseeq_private *sp = (struct sgiseeq_private *) dev->priv;
 486         volatile struct sgiseeq_regs *sregs = sp->sregs;
 487
 488         init_seeq(dev, sp, sregs);
 489
 490         dev->trans_start = jiffies;
 491         dev->interrupt = 0;
 492         dev->start = 1;
 493         dev->tbusy = 0;
 494
 495         return 0;
 496 }
 497
 498 void sgiseeq_my_reset(void)
 499 {
 500         printk("RESET!\n");
 501         sgiseeq_reset(gdev);
 502 }
 503
 504 static inline int verify_tx(struct sgiseeq_private *sp,
 505                             struct net_device *dev,
 506                             struct sk_buff *skb)
 507 {
 508         /* Are we bolixed? */
 509         if(dev->tbusy) {
 510                 int tickssofar = jiffies - dev->trans_start;
 511                 if (tickssofar < 20)
 512                         return 1;
 513
 514                 printk("%s: transmit timed out, ticks=%d resetting\n",
 515                        dev->name, tickssofar);
 516                 sgiseeq_reset(dev);
 517                 return 0;
 518         }
 519         /* Are we getting in someone else's way? */
 520         if(test_and_set_bit(0, (void *) &dev->tbusy) != 0) {
 521                 printk("%s: Transmitter access conflict.\n", dev->name);
 522                 return -1;
 523         }
 524
 525         /* Can we even send anything? */
 526         if(!TX_BUFFS_AVAIL(sp))
 527                 return -1;
 528
 529         return 0;
 530 }
 531
 532 static int sgiseeq_start_xmit(struct sk_buff *skb, struct net_device *dev)
 533 {
 534         struct sgiseeq_private *sp = (struct sgiseeq_private *) dev->priv;
 535         volatile struct hpc3_ethregs *hregs = sp->hregs;
 536         unsigned long flags;
 537         struct sgiseeq_tx_desc *td;
 538         int skblen, len, entry;
 539
 540         if(verify_tx(sp, dev, skb))
 541                 return -1; /* Yeee... */
 542
 543         save_flags(flags); cli();
 544
 545         /* Setup... */
 546         skblen = skb->len;
 547         len = (skblen <= ETH_ZLEN) ? ETH_ZLEN : skblen;
 548         entry = sp->tx_new;
 549         td = &sp->srings.tx_desc[entry];
 550
 551         /* Create entry.  There are so many races with adding a new
 552          * descriptor to the chain:
 553          * 1) Assume that the HPC is off processing a DMA chain while
 554          *    we are changing all of the following.
 555          * 2) Do no allow the HPC to look at a new descriptor until
 556          *    we have completely set up it's state.  This means, do
 557          *    not clear HPCDMA_EOX in the current last descritptor
 558          *    until the one we are adding looks consistant and could
 559          *    be processes right now.
 560          * 3) The tx interrupt code must notice when we've added a new
 561          *    entry and the HPC got to the end of the chain before we
 562          *    added this new entry and restarted it.
 563          */
 564         memcpy((char *)td->buf_vaddr, skb->data, skblen);
 565         td->tdma.cntinfo = ((len) & HPCDMA_BCNT) |
 566                 (HPCDMA_XIU | HPCDMA_EOXP | HPCDMA_XIE | HPCDMA_EOX);
 567         if(sp->tx_old != sp->tx_new) {
 568                 struct sgiseeq_tx_desc *backend;
 569
 570                 backend = &sp->srings.tx_desc[PREV_TX(sp->tx_new)];
 571                 backend->tdma.cntinfo &= ~(HPCDMA_EOX);
 572         }
 573         sp->tx_new = NEXT_TX(sp->tx_new); /* Advance. */
 574
 575         /* Maybe kick the HPC back into motion. */
 576         if(!(hregs->tx_ctrl & HPC3_ETXCTRL_ACTIVE))
 577                 kick_tx(&sp->srings.tx_desc[sp->tx_old], hregs);
 578
 579         dev->trans_start = jiffies;
 580         dev_kfree_skb(skb);
 581
 582         if(TX_BUFFS_AVAIL(sp))
 583                 dev->tbusy = 0;
 584         restore_flags(flags);
 585         return 0;
 586 }
 587
 588 static struct enet_statistics *sgiseeq_get_stats(struct net_device *dev)
 589 {
 590         struct sgiseeq_private *sp = (struct sgiseeq_private *) dev->priv;
 591
 592         return &sp->stats;
 593 }
 594
 595 static void sgiseeq_set_multicast(struct net_device *dev)
 596 {
 597 }
 598
 599 static inline void setup_tx_ring(struct sgiseeq_tx_desc *buf, int nbufs)
 600 {
 601         int i = 0;
 602
 603         while(i < (nbufs - 1)) {
 604                 buf[i].tdma.pnext = PHYSADDR(&buf[i + 1]);
 605                 buf[i].tdma.pbuf = 0;
 606                 i++;
 607         }
 608         buf[i].tdma.pnext = PHYSADDR(&buf[0]);
 609 }
 610
 611 static inline void setup_rx_ring(struct sgiseeq_rx_desc *buf, int nbufs)
 612 {
 613         int i = 0;
 614
 615         while(i < (nbufs - 1)) {
 616                 buf[i].rdma.pnext = PHYSADDR(&buf[i + 1]);
 617                 buf[i].rdma.pbuf = 0;
 618                 i++;
 619         }
 620         buf[i].rdma.pbuf = 0;
 621         buf[i].rdma.pnext = PHYSADDR(&buf[0]);
 622 }
 623
 624 static char onboard_eth_addr[6];
 625
 626 #define ALIGNED(x)  ((((unsigned long)(x)) + 0xf) & ~(0xf))
 627
 628 int sgiseeq_init(struct net_device *dev, struct sgiseeq_regs *sregs,
 629                  struct hpc3_ethregs *hregs, int irq)
 630 {
 631         static unsigned version_printed = 0;
 632         int i;
 633         struct sgiseeq_private *sp;
 634
 635         if(dev == NULL) {
 636                 dev = init_etherdev(0, sizeof(struct sgiseeq_private));
 637         } else {
 638                 dev->priv = (struct sgiseeq_private *) get_free_page(GFP_KERNEL);
 639                 if(dev->priv == NULL)
 640                         return -ENOMEM;
 641         }
 642
 643         if(!version_printed++)
 644                 printk(version);
 645
 646         printk("%s: SGI Seeq8003 ", dev->name);
 647
 648         for(i = 0; i < 6; i++)
 649                 printk("%2.2x%c",
 650                        dev->dev_addr[i] = onboard_eth_addr[i],
 651                        i == 5 ? ' ': ':');
 652
 653         printk("\n");
 654
 655         sp = (struct sgiseeq_private *) dev->priv;
 656 #ifdef DEBUG
 657         gpriv = sp;
 658         gdev = dev;
 659 #endif
 660         memset((char *)dev->priv, 0, sizeof(struct sgiseeq_private));
 661         sp->sregs = sregs;
 662         sp->hregs = hregs;
 663         sp->name = sgiseeqstr;
 664
 665         sp->srings.rx_desc = (struct sgiseeq_rx_desc *)
 666                              (KSEG1ADDR(ALIGNED(&sp->srings.rxvector[0])));
 667         dma_cache_wback_inv((unsigned long)&sp->srings.rxvector,
 668                             sizeof(sp->srings.rxvector));
 669         sp->srings.tx_desc = (struct sgiseeq_tx_desc *)
 670                              (KSEG1ADDR(ALIGNED(&sp->srings.txvector[0])));
 671         dma_cache_wback_inv((unsigned long)&sp->srings.txvector,
 672                             sizeof(sp->srings.txvector));
 673
 674         /* A couple calculations now, saves many cycles later. */
 675         setup_rx_ring(sp->srings.rx_desc, SEEQ_RX_BUFFERS);
 676         setup_tx_ring(sp->srings.tx_desc, SEEQ_TX_BUFFERS);
 677
 678         /* Reset the chip. */
 679         hpc3_eth_reset((volatile struct hpc3_ethregs *) hregs);
 680
 681         sp->is_edlc = !(sregs->rw.rregs.collision_tx[0] & 0xff);
 682         if(sp->is_edlc) {
 683                 sp->control = (SEEQ_CTRL_XCNT | SEEQ_CTRL_ACCNT |
 684                                SEEQ_CTRL_SFLAG | SEEQ_CTRL_ESHORT |
 685                                SEEQ_CTRL_ENCARR);
 686         }
 687
 688         dev->open                 = sgiseeq_open;
 689         dev->stop                 = sgiseeq_close;
 690         dev->hard_start_xmit      = sgiseeq_start_xmit;
 691         dev->get_stats            = sgiseeq_get_stats;
 692         dev->set_multicast_list   = sgiseeq_set_multicast;
 693         dev->irq                  = irq;
 694         dev->dma                  = 0;
 695         ether_setup(dev);
 696
 697         return 0;
 698 }
 699
 700 static inline unsigned char str2hexnum(unsigned char c)
 701 {
 702         if(c >= '0' && c <= '9')
 703                 return c - '0';
 704         if(c >= 'a' && c <= 'f')
 705                 return c - 'a' + 10;
 706         return 0; /* foo */
 707 }
 708
 709 static inline void str2eaddr(unsigned char *ea, unsigned char *str)
 710 {
 711         int i;
 712
 713         for(i = 0; i < 6; i++) {
 714                 unsigned char num;
 715
 716                 if(*str == ':')
 717                         str++;
 718                 num = str2hexnum(*str++) << 4;
 719                 num |= (str2hexnum(*str++));
 720                 ea[i] = num;
 721         }
 722 }
 723
 724 int sgiseeq_probe(struct net_device *dev)
 725 {
 726         static int initialized;
 727         char *ep;
 728
 729         if (initialized)        /* Already initialized? */
 730                 return 0;
 731         initialized++;
 732
 733         /* First get the ethernet address of the onboard
 734          * interface from ARCS.
 735          * (This is fragile; PROM doesn't like running from cache.)
 736          */
 737         ep = romvec->get_evar("eaddr");
 738         str2eaddr(onboard_eth_addr, ep);
 739         return sgiseeq_init(dev,
 740                             (struct sgiseeq_regs *) (KSEG1ADDR(0x1fbd4000)),
 741                             &hpc3c0->ethregs, 3);
 742 }