drivers/net/macmace.c

   1 /*
   2  *      Driver for the Macintosh 68K onboard MACE controller with PSC
   3  *      driven DMA. The MACE driver code is derived from mace.c. The
   4  *      Mac68k theory of operation is courtesy of the MacBSD wizards.
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License
   8  *      as published by the Free Software Foundation; either version
   9  *      2 of the License, or (at your option) any later version.
  10  *
  11  *      Copyright (C) 1996 Paul Mackerras.
  12  *      Copyright (C) 1998 Alan Cox <alan@redhat.com>
  13  *
  14  *      Modified heavily by Joshua M. Thompson based on Dave Huang's NetBSD driver
  15  */
  16
  17
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/netdevice.h>
  21 #include <linux/etherdevice.h>
  22 #include <linux/delay.h>
  23 #include <linux/string.h>
  24 #include <linux/crc32.h>
  25 #include <asm/io.h>
  26 #include <asm/pgtable.h>
  27 #include <asm/irq.h>
  28 #include <asm/macintosh.h>
  29 #include <asm/macints.h>
  30 #include <asm/mac_psc.h>
  31 #include <asm/page.h>
  32 #include "mace.h"
  33
  34 #define N_TX_RING       1
  35 #define N_RX_RING       8
  36 #define N_RX_PAGES      ((N_RX_RING * 0x0800 + PAGE_SIZE - 1) / PAGE_SIZE)
  37 #define TX_TIMEOUT      HZ
  38
  39 /* Bits in transmit DMA status */
  40 #define TX_DMA_ERR      0x80
  41
  42 /* The MACE is simply wired down on a Mac68K box */
  43
  44 #define MACE_BASE       (void *)(0x50F1C000)
  45 #define MACE_PROM       (void *)(0x50F08001)
  46
  47 struct mace_data {
  48         volatile struct mace *mace;
  49         volatile unsigned char *tx_ring;
  50         volatile unsigned char *tx_ring_phys;
  51         volatile unsigned char *rx_ring;
  52         volatile unsigned char *rx_ring_phys;
  53         int dma_intr;
  54         struct net_device_stats stats;
  55         int rx_slot, rx_tail;
  56         int tx_slot, tx_sloti, tx_count;
  57 };
  58
  59 struct mace_frame {
  60         u16     len;
  61         u16     status;
  62         u16     rntpc;
  63         u16     rcvcc;
  64         u32     pad1;
  65         u32     pad2;
  66         u8      data[1];
  67         /* And frame continues.. */
  68 };
  69
  70 #define PRIV_BYTES      sizeof(struct mace_data)
  71
  72 extern void psc_debug_dump(void);
  73
  74 static int mace_open(struct net_device *dev);
  75 static int mace_close(struct net_device *dev);
  76 static int mace_xmit_start(struct sk_buff *skb, struct net_device *dev);
  77 static struct net_device_stats *mace_stats(struct net_device *dev);
  78 static void mace_set_multicast(struct net_device *dev);
  79 static int mace_set_address(struct net_device *dev, void *addr);
  80 static irqreturn_t mace_interrupt(int irq, void *dev_id, struct pt_regs *regs);
  81 static irqreturn_t mace_dma_intr(int irq, void *dev_id, struct pt_regs *regs);
  82 static void mace_tx_timeout(struct net_device *dev);
  83
  84 /* Bit-reverse one byte of an ethernet hardware address. */
  85
  86 static int bitrev(int b)
  87 {
  88         int d = 0, i;
  89
  90         for (i = 0; i < 8; ++i, b >>= 1) {
  91                 d = (d << 1) | (b & 1);
  92         }
  93
  94         return d;
  95 }
  96
  97 /*
  98  * Load a receive DMA channel with a base address and ring length
  99  */
 100
 101 static void mace_load_rxdma_base(struct net_device *dev, int set)
 102 {
 103         struct mace_data *mp = (struct mace_data *) dev->priv;
 104
 105         psc_write_word(PSC_ENETRD_CMD + set, 0x0100);
 106         psc_write_long(PSC_ENETRD_ADDR + set, (u32) mp->rx_ring_phys);
 107         psc_write_long(PSC_ENETRD_LEN + set, N_RX_RING);
 108         psc_write_word(PSC_ENETRD_CMD + set, 0x9800);
 109         mp->rx_tail = 0;
 110 }
 111
 112 /*
 113  * Reset the receive DMA subsystem
 114  */
 115
 116 static void mace_rxdma_reset(struct net_device *dev)
 117 {
 118         struct mace_data *mp = (struct mace_data *) dev->priv;
 119         volatile struct mace *mace = mp->mace;
 120         u8 maccc = mace->maccc;
 121
 122         mace->maccc = maccc & ~ENRCV;
 123
 124         psc_write_word(PSC_ENETRD_CTL, 0x8800);
 125         mace_load_rxdma_base(dev, 0x00);
 126         psc_write_word(PSC_ENETRD_CTL, 0x0400);
 127
 128         psc_write_word(PSC_ENETRD_CTL, 0x8800);
 129         mace_load_rxdma_base(dev, 0x10);
 130         psc_write_word(PSC_ENETRD_CTL, 0x0400);
 131
 132         mace->maccc = maccc;
 133         mp->rx_slot = 0;
 134
 135         psc_write_word(PSC_ENETRD_CMD + PSC_SET0, 0x9800);
 136         psc_write_word(PSC_ENETRD_CMD + PSC_SET1, 0x9800);
 137 }
 138
 139 /*
 140  * Reset the transmit DMA subsystem
 141  */
 142
 143 static void mace_txdma_reset(struct net_device *dev)
 144 {
 145         struct mace_data *mp = (struct mace_data *) dev->priv;
 146         volatile struct mace *mace = mp->mace;
 147         u8 maccc;
 148
 149         psc_write_word(PSC_ENETWR_CTL, 0x8800);
 150
 151         maccc = mace->maccc;
 152         mace->maccc = maccc & ~ENXMT;
 153
 154         mp->tx_slot = mp->tx_sloti = 0;
 155         mp->tx_count = N_TX_RING;
 156
 157         psc_write_word(PSC_ENETWR_CTL, 0x0400);
 158         mace->maccc = maccc;
 159 }
 160
 161 /*
 162  * Disable DMA
 163  */
 164
 165 static void mace_dma_off(struct net_device *dev)
 166 {
 167         psc_write_word(PSC_ENETRD_CTL, 0x8800);
 168         psc_write_word(PSC_ENETRD_CTL, 0x1000);
 169         psc_write_word(PSC_ENETRD_CMD + PSC_SET0, 0x1100);
 170         psc_write_word(PSC_ENETRD_CMD + PSC_SET1, 0x1100);
 171
 172         psc_write_word(PSC_ENETWR_CTL, 0x8800);
 173         psc_write_word(PSC_ENETWR_CTL, 0x1000);
 174         psc_write_word(PSC_ENETWR_CMD + PSC_SET0, 0x1100);
 175         psc_write_word(PSC_ENETWR_CMD + PSC_SET1, 0x1100);
 176 }
 177
 178 /*
 179  * Not really much of a probe. The hardware table tells us if this
 180  * model of Macintrash has a MACE (AV macintoshes)
 181  */
 182
 183 struct net_device *mace_probe(int unit)
 184 {
 185         int j;
 186         struct mace_data *mp;
 187         unsigned char *addr;
 188         struct net_device *dev;
 189         unsigned char checksum = 0;
 190         static int found = 0;
 191         int err;
 192
 193         if (found || macintosh_config->ether_type != MAC_ETHER_MACE)
 194                 return ERR_PTR(-ENODEV);
 195
 196         found = 1;      /* prevent 'finding' one on every device probe */
 197
 198         dev = alloc_etherdev(PRIV_BYTES);
 199         if (!dev)
 200                 return ERR_PTR(-ENOMEM);
 201
 202         if (unit >= 0)
 203                 sprintf(dev->name, "eth%d", unit);
 204
 205         mp = (struct mace_data *) dev->priv;
 206         dev->base_addr = (u32)MACE_BASE;
 207         mp->mace = (volatile struct mace *) MACE_BASE;
 208
 209         dev->irq = IRQ_MAC_MACE;
 210         mp->dma_intr = IRQ_MAC_MACE_DMA;
 211
 212         /*
 213          * The PROM contains 8 bytes which total 0xFF when XOR'd
 214          * together. Due to the usual peculiar apple brain damage
 215          * the bytes are spaced out in a strange boundary and the
 216          * bits are reversed.
 217          */
 218
 219         addr = (void *)MACE_PROM;
 220
 221         for (j = 0; j < 6; ++j) {
 222                 u8 v=bitrev(addr[j<<4]);
 223                 checksum ^= v;
 224                 dev->dev_addr[j] = v;
 225         }
 226         for (; j < 8; ++j) {
 227                 checksum ^= bitrev(addr[j<<4]);
 228         }
 229
 230         if (checksum != 0xFF) {
 231                 free_netdev(dev);
 232                 return ERR_PTR(-ENODEV);
 233         }
 234
 235         memset(&mp->stats, 0, sizeof(mp->stats));
 236
 237         dev->open               = mace_open;
 238         dev->stop               = mace_close;
 239         dev->hard_start_xmit    = mace_xmit_start;
 240         dev->tx_timeout         = mace_tx_timeout;
 241         dev->watchdog_timeo     = TX_TIMEOUT;
 242         dev->get_stats          = mace_stats;
 243         dev->set_multicast_list = mace_set_multicast;
 244         dev->set_mac_address    = mace_set_address;
 245
 246         printk(KERN_INFO "%s: 68K MACE, hardware address %.2X", dev->name, dev->dev_addr[0]);
 247         for (j = 1 ; j < 6 ; j++) printk(":%.2X", dev->dev_addr[j]);
 248         printk("\n");
 249
 250         err = register_netdev(dev);
 251         if (!err)
 252                 return dev;
 253
 254         free_netdev(dev);
 255         return ERR_PTR(err);
 256 }
 257
 258 /*
 259  * Load the address on a mace controller.
 260  */
 261
 262 static int mace_set_address(struct net_device *dev, void *addr)
 263 {
 264         unsigned char *p = addr;
 265         struct mace_data *mp = (struct mace_data *) dev->priv;
 266         volatile struct mace *mb = mp->mace;
 267         int i;
 268         unsigned long flags;
 269         u8 maccc;
 270
 271         local_irq_save(flags);
 272
 273         maccc = mb->maccc;
 274
 275         /* load up the hardware address */
 276         mb->iac = ADDRCHG | PHYADDR;
 277         while ((mb->iac & ADDRCHG) != 0);
 278
 279         for (i = 0; i < 6; ++i) {
 280                 mb->padr = dev->dev_addr[i] = p[i];
 281         }
 282
 283         mb->maccc = maccc;
 284         local_irq_restore(flags);
 285
 286         return 0;
 287 }
 288
 289 /*
 290  * Open the Macintosh MACE. Most of this is playing with the DMA
 291  * engine. The ethernet chip is quite friendly.
 292  */
 293
 294 static int mace_open(struct net_device *dev)
 295 {
 296         struct mace_data *mp = (struct mace_data *) dev->priv;
 297         volatile struct mace *mb = mp->mace;
 298 #if 0
 299         int i;
 300
 301         i = 200;
 302         while (--i) {
 303                 mb->biucc = SWRST;
 304                 if (mb->biucc & SWRST) {
 305                         udelay(10);
 306                         continue;
 307                 }
 308                 break;
 309         }
 310         if (!i) {
 311                 printk(KERN_ERR "%s: software reset failed!!\n", dev->name);
 312                 return -EAGAIN;
 313         }
 314 #endif
 315
 316         mb->biucc = XMTSP_64;
 317         mb->fifocc = XMTFW_16 | RCVFW_64 | XMTFWU | RCVFWU | XMTBRST | RCVBRST;
 318         mb->xmtfc = AUTO_PAD_XMIT;
 319         mb->plscc = PORTSEL_AUI;
 320         /* mb->utr = RTRD; */
 321
 322         if (request_irq(dev->irq, mace_interrupt, 0, dev->name, dev)) {
 323                 printk(KERN_ERR "%s: can't get irq %d\n", dev->name, dev->irq);
 324                 return -EAGAIN;
 325         }
 326         if (request_irq(mp->dma_intr, mace_dma_intr, 0, dev->name, dev)) {
 327                 printk(KERN_ERR "%s: can't get irq %d\n", dev->name, mp->dma_intr);
 328                 free_irq(dev->irq, dev);
 329                 return -EAGAIN;
 330         }
 331
 332         /* Allocate the DMA ring buffers */
 333
 334         mp->rx_ring = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, N_RX_PAGES);
 335         mp->tx_ring = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, 0);
 336
 337         if (mp->tx_ring==NULL || mp->rx_ring==NULL) {
 338                 if (mp->rx_ring) free_pages((u32) mp->rx_ring, N_RX_PAGES);
 339                 if (mp->tx_ring) free_pages((u32) mp->tx_ring, 0);
 340                 free_irq(dev->irq, dev);
 341                 free_irq(mp->dma_intr, dev);
 342                 printk(KERN_ERR "%s: unable to allocate DMA buffers\n", dev->name);
 343                 return -ENOMEM;
 344         }
 345
 346         mp->rx_ring_phys = (unsigned char *) virt_to_bus((void *)mp->rx_ring);
 347         mp->tx_ring_phys = (unsigned char *) virt_to_bus((void *)mp->tx_ring);
 348
 349         /* We want the Rx buffer to be uncached and the Tx buffer to be writethrough */
 350
 351         kernel_set_cachemode((void *)mp->rx_ring, N_RX_PAGES * PAGE_SIZE, IOMAP_NOCACHE_NONSER);
 352         kernel_set_cachemode((void *)mp->tx_ring, PAGE_SIZE, IOMAP_WRITETHROUGH);
 353
 354         mace_dma_off(dev);
 355
 356         /* Not sure what these do */
 357
 358         psc_write_word(PSC_ENETWR_CTL, 0x9000);
 359         psc_write_word(PSC_ENETRD_CTL, 0x9000);
 360         psc_write_word(PSC_ENETWR_CTL, 0x0400);
 361         psc_write_word(PSC_ENETRD_CTL, 0x0400);
 362
 363 #if 0
 364         /* load up the hardware address */
 365
 366         mb->iac = ADDRCHG | PHYADDR;
 367
 368         while ((mb->iac & ADDRCHG) != 0);
 369
 370         for (i = 0; i < 6; ++i)
 371                 mb->padr = dev->dev_addr[i];
 372
 373         /* clear the multicast filter */
 374         mb->iac = ADDRCHG | LOGADDR;
 375
 376         while ((mb->iac & ADDRCHG) != 0);
 377
 378         for (i = 0; i < 8; ++i)
 379                 mb->ladrf = 0;
 380
 381         mb->plscc = PORTSEL_GPSI + ENPLSIO;
 382
 383         mb->maccc = ENXMT | ENRCV;
 384         mb->imr = RCVINT;
 385 #endif
 386
 387         mace_rxdma_reset(dev);
 388         mace_txdma_reset(dev);
 389
 390         return 0;
 391 }
 392
 393 /*
 394  * Shut down the mace and its interrupt channel
 395  */
 396
 397 static int mace_close(struct net_device *dev)
 398 {
 399         struct mace_data *mp = (struct mace_data *) dev->priv;
 400         volatile struct mace *mb = mp->mace;
 401
 402         mb->maccc = 0;          /* disable rx and tx     */
 403         mb->imr = 0xFF;         /* disable all irqs      */
 404         mace_dma_off(dev);      /* disable rx and tx dma */
 405
 406         free_irq(dev->irq, dev);
 407         free_irq(IRQ_MAC_MACE_DMA, dev);
 408
 409         free_pages((u32) mp->rx_ring, N_RX_PAGES);
 410         free_pages((u32) mp->tx_ring, 0);
 411
 412         return 0;
 413 }
 414
 415 /*
 416  * Transmit a frame
 417  */
 418
 419 static int mace_xmit_start(struct sk_buff *skb, struct net_device *dev)
 420 {
 421         struct mace_data *mp = (struct mace_data *) dev->priv;
 422
 423         /* Stop the queue if the buffer is full */
 424
 425         if (!mp->tx_count) {
 426                 netif_stop_queue(dev);
 427                 return 1;
 428         }
 429         mp->tx_count--;
 430
 431         mp->stats.tx_packets++;
 432         mp->stats.tx_bytes += skb->len;
 433
 434         /* We need to copy into our xmit buffer to take care of alignment and caching issues */
 435
 436         memcpy((void *) mp->tx_ring, skb->data, skb->len);
 437
 438         /* load the Tx DMA and fire it off */
 439
 440         psc_write_long(PSC_ENETWR_ADDR + mp->tx_slot, (u32)  mp->tx_ring_phys);
 441         psc_write_long(PSC_ENETWR_LEN + mp->tx_slot, skb->len);
 442         psc_write_word(PSC_ENETWR_CMD + mp->tx_slot, 0x9800);
 443
 444         mp->tx_slot ^= 0x10;
 445
 446         dev_kfree_skb(skb);
 447
 448         return 0;
 449 }
 450
 451 static struct net_device_stats *mace_stats(struct net_device *dev)
 452 {
 453         struct mace_data *p = (struct mace_data *) dev->priv;
 454         return &p->stats;
 455 }
 456
 457 static void mace_set_multicast(struct net_device *dev)
 458 {
 459         struct mace_data *mp = (struct mace_data *) dev->priv;
 460         volatile struct mace *mb = mp->mace;
 461         int i, j;
 462         u32 crc;
 463         u8 maccc;
 464
 465         maccc = mb->maccc;
 466         mb->maccc &= ~PROM;
 467
 468         if (dev->flags & IFF_PROMISC) {
 469                 mb->maccc |= PROM;
 470         } else {
 471                 unsigned char multicast_filter[8];
 472                 struct dev_mc_list *dmi = dev->mc_list;
 473
 474                 if (dev->flags & IFF_ALLMULTI) {
 475                         for (i = 0; i < 8; i++) {
 476                                 multicast_filter[i] = 0xFF;
 477                         }
 478                 } else {
 479                         for (i = 0; i < 8; i++)
 480                                 multicast_filter[i] = 0;
 481                         for (i = 0; i < dev->mc_count; i++) {
 482                                 crc = ether_crc_le(6, dmi->dmi_addr);
 483                                 j = crc >> 26;  /* bit number in multicast_filter */
 484                                 multicast_filter[j >> 3] |= 1 << (j & 7);
 485                                 dmi = dmi->next;
 486                         }
 487                 }
 488
 489                 mb->iac = ADDRCHG | LOGADDR;
 490                 while (mb->iac & ADDRCHG);
 491
 492                 for (i = 0; i < 8; ++i) {
 493                         mb->ladrf = multicast_filter[i];
 494                 }
 495         }
 496
 497         mb->maccc = maccc;
 498 }
 499
 500 /*
 501  * Miscellaneous interrupts are handled here. We may end up
 502  * having to bash the chip on the head for bad errors
 503  */
 504
 505 static void mace_handle_misc_intrs(struct mace_data *mp, int intr)
 506 {
 507         volatile struct mace *mb = mp->mace;
 508         static int mace_babbles, mace_jabbers;
 509
 510         if (intr & MPCO) {
 511                 mp->stats.rx_missed_errors += 256;
 512         }
 513         mp->stats.rx_missed_errors += mb->mpc;  /* reading clears it */
 514
 515         if (intr & RNTPCO) {
 516                 mp->stats.rx_length_errors += 256;
 517         }
 518         mp->stats.rx_length_errors += mb->rntpc;        /* reading clears it */
 519
 520         if (intr & CERR) {
 521                 ++mp->stats.tx_heartbeat_errors;
 522         }
 523         if (intr & BABBLE) {
 524                 if (mace_babbles++ < 4) {
 525                         printk(KERN_DEBUG "mace: babbling transmitter\n");
 526                 }
 527         }
 528         if (intr & JABBER) {
 529                 if (mace_jabbers++ < 4) {
 530                         printk(KERN_DEBUG "mace: jabbering transceiver\n");
 531                 }
 532         }
 533 }
 534
 535 /*
 536  *      A transmit error has occurred. (We kick the transmit side from
 537  *      the DMA completion)
 538  */
 539
 540 static void mace_xmit_error(struct net_device *dev)
 541 {
 542         struct mace_data *mp = (struct mace_data *) dev->priv;
 543         volatile struct mace *mb = mp->mace;
 544         u8 xmtfs, xmtrc;
 545
 546         xmtfs = mb->xmtfs;
 547         xmtrc = mb->xmtrc;
 548
 549         if (xmtfs & XMTSV) {
 550                 if (xmtfs & UFLO) {
 551                         printk("%s: DMA underrun.\n", dev->name);
 552                         mp->stats.tx_errors++;
 553                         mp->stats.tx_fifo_errors++;
 554                         mace_txdma_reset(dev);
 555                 }
 556                 if (xmtfs & RTRY) {
 557                         mp->stats.collisions++;
 558                 }
 559         }
 560 }
 561
 562 /*
 563  *      A receive interrupt occurred.
 564  */
 565
 566 static void mace_recv_interrupt(struct net_device *dev)
 567 {
 568 /*      struct mace_data *mp = (struct mace_data *) dev->priv; */
 569 //      volatile struct mace *mb = mp->mace;
 570 }
 571
 572 /*
 573  * Process the chip interrupt
 574  */
 575
 576 static irqreturn_t mace_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 577 {
 578         struct net_device *dev = (struct net_device *) dev_id;
 579         struct mace_data *mp = (struct mace_data *) dev->priv;
 580         volatile struct mace *mb = mp->mace;
 581         u8 ir;
 582
 583         ir = mb->ir;
 584         mace_handle_misc_intrs(mp, ir);
 585
 586         if (ir & XMTINT) {
 587                 mace_xmit_error(dev);
 588         }
 589         if (ir & RCVINT) {
 590                 mace_recv_interrupt(dev);
 591         }
 592         return IRQ_HANDLED;
 593 }
 594
 595 static void mace_tx_timeout(struct net_device *dev)
 596 {
 597 /*      struct mace_data *mp = (struct mace_data *) dev->priv; */
 598 //      volatile struct mace *mb = mp->mace;
 599 }
 600
 601 /*
 602  * Handle a newly arrived frame
 603  */
 604
 605 static void mace_dma_rx_frame(struct net_device *dev, struct mace_frame *mf)
 606 {
 607         struct mace_data *mp = (struct mace_data *) dev->priv;
 608         struct sk_buff *skb;
 609
 610         if (mf->status & RS_OFLO) {
 611                 printk("%s: fifo overflow.\n", dev->name);
 612                 mp->stats.rx_errors++;
 613                 mp->stats.rx_fifo_errors++;
 614         }
 615         if (mf->status&(RS_CLSN|RS_FRAMERR|RS_FCSERR))
 616                 mp->stats.rx_errors++;
 617
 618         if (mf->status&RS_CLSN) {
 619                 mp->stats.collisions++;
 620         }
 621         if (mf->status&RS_FRAMERR) {
 622                 mp->stats.rx_frame_errors++;
 623         }
 624         if (mf->status&RS_FCSERR) {
 625                 mp->stats.rx_crc_errors++;
 626         }
 627
 628         skb = dev_alloc_skb(mf->len+2);
 629         if (!skb) {
 630                 mp->stats.rx_dropped++;
 631                 return;
 632         }
 633         skb_reserve(skb,2);
 634         memcpy(skb_put(skb, mf->len), mf->data, mf->len);
 635
 636         skb->dev = dev;
 637         skb->protocol = eth_type_trans(skb, dev);
 638         netif_rx(skb);
 639         dev->last_rx = jiffies;
 640         mp->stats.rx_packets++;
 641         mp->stats.rx_bytes += mf->len;
 642 }
 643
 644 /*
 645  * The PSC has passed us a DMA interrupt event.
 646  */
 647
 648 static irqreturn_t mace_dma_intr(int irq, void *dev_id, struct pt_regs *regs)
 649 {
 650         struct net_device *dev = (struct net_device *) dev_id;
 651         struct mace_data *mp = (struct mace_data *) dev->priv;
 652         int left, head;
 653         u16 status;
 654         u32 baka;
 655
 656         /* Not sure what this does */
 657
 658         while ((baka = psc_read_long(PSC_MYSTERY)) != psc_read_long(PSC_MYSTERY));
 659         if (!(baka & 0x60000000)) return IRQ_NONE;
 660
 661         /*
 662          * Process the read queue
 663          */
 664
 665         status = psc_read_word(PSC_ENETRD_CTL);
 666
 667         if (status & 0x2000) {
 668                 mace_rxdma_reset(dev);
 669         } else if (status & 0x0100) {
 670                 psc_write_word(PSC_ENETRD_CMD + mp->rx_slot, 0x1100);
 671
 672                 left = psc_read_long(PSC_ENETRD_LEN + mp->rx_slot);
 673                 head = N_RX_RING - left;
 674
 675                 /* Loop through the ring buffer and process new packages */
 676
 677                 while (mp->rx_tail < head) {
 678                         mace_dma_rx_frame(dev, (struct mace_frame *) (mp->rx_ring + (mp->rx_tail * 0x0800)));
 679                         mp->rx_tail++;
 680                 }
 681
 682                 /* If we're out of buffers in this ring then switch to */
 683                 /* the other set, otherwise just reactivate this one.  */
 684
 685                 if (!left) {
 686                         mace_load_rxdma_base(dev, mp->rx_slot);
 687                         mp->rx_slot ^= 0x10;
 688                 } else {
 689                         psc_write_word(PSC_ENETRD_CMD + mp->rx_slot, 0x9800);
 690                 }
 691         }
 692
 693         /*
 694          * Process the write queue
 695          */
 696
 697         status = psc_read_word(PSC_ENETWR_CTL);
 698
 699         if (status & 0x2000) {
 700                 mace_txdma_reset(dev);
 701         } else if (status & 0x0100) {
 702                 psc_write_word(PSC_ENETWR_CMD + mp->tx_sloti, 0x0100);
 703                 mp->tx_sloti ^= 0x10;
 704                 mp->tx_count++;
 705                 netif_wake_queue(dev);
 706         }
 707         return IRQ_HANDLED;
 708 }
 709
 710 MODULE_LICENSE("GPL");