midway.c

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/*
 * en_b2sz: convert a DMA burst code to its byte size
 */

STATIC INLINE int en_b2sz(b)

int b;

{
  switch (b) {
    case MIDDMA_WORD:   return(1*4);
    case MIDDMA_2WMAYBE:
    case MIDDMA_2WORD:  return(2*4);
    case MIDDMA_4WMAYBE:
    case MIDDMA_4WORD:  return(4*4);
    case MIDDMA_8WMAYBE:
    case MIDDMA_8WORD:  return(8*4);
    case MIDDMA_16WMAYBE:
    case MIDDMA_16WORD: return(16*4);
    default: panic("en_b2sz");
  }
  return(0);
}


/*
 * en_sz2b: convert a burst size (bytes) to DMA burst code
 */

STATIC INLINE int en_sz2b(sz)

int sz;

{
  switch (sz) {
    case 1*4:  return(MIDDMA_WORD);
    case 2*4:  return(MIDDMA_2WORD);
    case 4*4:  return(MIDDMA_4WORD);
    case 8*4:  return(MIDDMA_8WORD);
    case 16*4: return(MIDDMA_16WORD);
    default: panic("en_sz2b");
  }
  return(0);
}


/*
 * en_dqneed: calculate number of DTQ/DRQ's needed for a buffer
 */

STATIC INLINE int en_dqneed(sc, data, len, tx)

struct en_softc *sc;
caddr_t data;
u_int len, tx;

{
  int result, needalign, sz;

#if !defined(MIDWAY_ENIONLY)
#if !defined(MIDWAY_ADPONLY)
    if (sc->is_adaptec)
#endif /* !MIDWAY_ADPONLY */
      return(1);	/* adaptec can DMA anything in one go */
#endif
    
#if !defined(MIDWAY_ADPONLY)
    result = 0;
    if (len < EN_MINDMA) {
      if (!tx)			/* XXX: conservative */
        return(1);		/* will copy/DMA_JK */
    }

    if (tx) {			/* byte burst? */
      needalign = (((uintptr_t) (void *) data) % sizeof(u_int32_t));
      if (needalign) {
        result++;
        sz = min(len, sizeof(u_int32_t) - needalign);
        len -= sz;
        data += sz;
      }
    }

    if (sc->alburst && len) {
      needalign = (((uintptr_t) (void *) data) & sc->bestburstmask);
      if (needalign) {
	result++;		/* alburst */
        sz = min(len, sc->bestburstlen - needalign);
        len -= sz;
      }
    }

    if (len >= sc->bestburstlen) {
      sz = len / sc->bestburstlen;
      sz = sz * sc->bestburstlen;
      len -= sz;
      result++;			/* best shot */
    }
    
    if (len) {
      result++;			/* clean up */
      if (tx && (len % sizeof(u_int32_t)) != 0)
        result++;		/* byte cleanup */
    }

    return(result);
#endif	/* !MIDWAY_ADPONLY */
}


/*
 * en_mget: get an mbuf chain that can hold totlen bytes and return it
 * (for recv)   [based on am7990_get from if_le and ieget from if_ie]
 * after this call the sum of all the m_len's in the chain will be totlen.
 */

STATIC INLINE struct mbuf *en_mget(sc, totlen, drqneed)

struct en_softc *sc;
u_int totlen, *drqneed;

{
  struct mbuf *m;
  struct mbuf *top, **mp;
  *drqneed = 0;

  MGETHDR(m, M_DONTWAIT, MT_DATA);
  if (m == NULL)
    return(NULL);
  m->m_pkthdr.rcvif = &sc->enif;
  m->m_pkthdr.len = totlen;
  m->m_len = MHLEN;
  top = NULL;
  mp = &top;
  
  /* if (top != NULL) then we've already got 1 mbuf on the chain */
  while (totlen > 0) {
    if (top) {
      MGET(m, M_DONTWAIT, MT_DATA);
      if (!m) {
	m_freem(top);	
	return(NULL);	/* out of mbufs */
      }
      m->m_len = MLEN;
    }
    if (totlen >= MINCLSIZE) {
      MCLGET(m, M_DONTWAIT);
      if ((m->m_flags & M_EXT) == 0) {
	m_free(m);
	m_freem(top);
	return(NULL);	  /* out of mbuf clusters */
      }
      m->m_len = MCLBYTES;
    }
    m->m_len = min(totlen, m->m_len);
    totlen -= m->m_len;
    *mp = m;
    mp = &m->m_next;

    *drqneed += en_dqneed(sc, m->m_data, m->m_len, 0);

  }
  return(top);
}

/***********************************************************************/

/*
 * autoconfig stuff
 */

void en_attach(sc)

struct en_softc *sc;

{
  struct ifnet *ifp = &sc->enif;
  int sz;
  u_int32_t reg, lcv, check, ptr, sav, midvloc;

  /*
   * probe card to determine memory size.   the stupid ENI card always
   * reports to PCI that it needs 4MB of space (2MB regs and 2MB RAM).
   * if it has less than 2MB RAM the addresses wrap in the RAM address space.
   * (i.e. on a 512KB card addresses 0x3ffffc, 0x37fffc, and 0x2ffffc
   * are aliases for 0x27fffc  [note that RAM starts at offset 0x200000]).
   */

  if (sc->en_busreset)
    sc->en_busreset(sc);
  EN_WRITE(sc, MID_RESID, 0x0);	/* reset card before touching RAM */
  for (lcv = MID_PROBEOFF; lcv <= MID_MAXOFF ; lcv += MID_PROBSIZE) {
    EN_WRITE(sc, lcv, lcv);	/* data[address] = address */
    for (check = MID_PROBEOFF ; check < lcv ; check += MID_PROBSIZE) {
      reg = EN_READ(sc, check);
      if (reg != check) {		/* found an alias! */
	goto done_probe;		/* and quit */
      }
    }
  }
done_probe:
  lcv -= MID_PROBSIZE;			/* take one step back */
  sc->en_obmemsz = (lcv + 4) - MID_RAMOFF;

  /*
   * determine the largest DMA burst supported
   */

  en_dmaprobe(sc);

  /*
   * "hello world"
   */

  if (sc->en_busreset)
    sc->en_busreset(sc);
  EN_WRITE(sc, MID_RESID, 0x0);		/* reset */
  for (lcv = MID_RAMOFF ; lcv < MID_RAMOFF + sc->en_obmemsz ; lcv += 4)
    EN_WRITE(sc, lcv, 0);	/* zero memory */

  reg = EN_READ(sc, MID_RESID);

  printf("%s: ATM midway v%d, board IDs %d.%d, %s%s%s, %ldKB on-board RAM\n",
	sc->sc_dev.dv_xname, MID_VER(reg), MID_MID(reg), MID_DID(reg), 
	(MID_IS_SABRE(reg)) ? "sabre controller, " : "",
	(MID_IS_SUNI(reg)) ? "SUNI" : "Utopia",
	(!MID_IS_SUNI(reg) && MID_IS_UPIPE(reg)) ? " (pipelined)" : "",
	(long)(sc->en_obmemsz / 1024));

  if (sc->is_adaptec) {
    if (sc->bestburstlen == 64 && sc->alburst == 0)
      printf("%s: passed 64 byte DMA test\n", sc->sc_dev.dv_xname);
    else
      printf("%s: FAILED DMA TEST: burst=%d, alburst=%d\n", 
	    sc->sc_dev.dv_xname, sc->bestburstlen, sc->alburst);
  } else {
    printf("%s: maximum DMA burst length = %d bytes%s\n", sc->sc_dev.dv_xname,
	  sc->bestburstlen, (sc->alburst) ? " (must align)" : "");
  }

  /*
   * link into network subsystem and prepare card
   */

#if defined(__NetBSD__) || defined(__OpenBSD__)
  bcopy(sc->sc_dev.dv_xname, sc->enif.if_xname, IFNAMSIZ);
#endif
  sc->enif.if_softc = sc;
  ifp->if_flags = IFF_SIMPLEX|IFF_NOTRAILERS;
  ifp->if_ioctl = en_ioctl;
  ifp->if_output = atm_output;
  ifp->if_start = en_start;

  /*
   * init softc
   */

  for (lcv = 0 ; lcv < MID_N_VC ; lcv++) {
    sc->rxvc2slot[lcv] = RX_NONE;
    sc->txspeed[lcv] = 0;	/* full */
    sc->txvc2slot[lcv] = 0;	/* full speed == slot 0 */
  }

  sz = sc->en_obmemsz - (MID_BUFOFF - MID_RAMOFF);
  ptr = sav = MID_BUFOFF;
  ptr = roundup(ptr, EN_TXSZ * 1024);	/* align */
  sz = sz - (ptr - sav);
  if (EN_TXSZ*1024 * EN_NTX > sz) {
    printf("%s: EN_NTX/EN_TXSZ too big\n", sc->sc_dev.dv_xname);
    return;
  }
  for (lcv = 0 ; lcv < EN_NTX ; lcv++) {
    sc->txslot[lcv].mbsize = 0;
    sc->txslot[lcv].start = ptr;
    ptr += (EN_TXSZ * 1024);
    sz -= (EN_TXSZ * 1024);
    sc->txslot[lcv].stop = ptr;
    sc->txslot[lcv].nref = 0;
    bzero(&sc->txslot[lcv].indma, sizeof(sc->txslot[lcv].indma));
    bzero(&sc->txslot[lcv].q, sizeof(sc->txslot[lcv].q));
#ifdef EN_DEBUG
    printf("%s: tx%d: start 0x%x, stop 0x%x\n", sc->sc_dev.dv_xname, lcv,
		sc->txslot[lcv].start, sc->txslot[lcv].stop);
#endif
  }

  sav = ptr;
  ptr = roundup(ptr, EN_RXSZ * 1024);	/* align */
  sz = sz - (ptr - sav);
  sc->en_nrx = sz / (EN_RXSZ * 1024);
  if (sc->en_nrx <= 0) {
    printf("%s: EN_NTX/EN_TXSZ/EN_RXSZ too big\n", sc->sc_dev.dv_xname);
    return;
  }

  /* 
   * ensure that there is always one VC slot on the service list free
   * so that we can tell the difference between a full and empty list.
   */
  if (sc->en_nrx >= MID_N_VC)
    sc->en_nrx = MID_N_VC - 1;

  for (lcv = 0 ; lcv < sc->en_nrx ; lcv++) {
    sc->rxslot[lcv].rxhand = NULL;
    sc->rxslot[lcv].oth_flags = ENOTHER_FREE;
    bzero(&sc->rxslot[lcv].indma, sizeof(sc->rxslot[lcv].indma));
    bzero(&sc->rxslot[lcv].q, sizeof(sc->rxslot[lcv].q));
    midvloc = sc->rxslot[lcv].start = ptr;
    ptr += (EN_RXSZ * 1024);
    sz -= (EN_RXSZ * 1024);
    sc->rxslot[lcv].stop = ptr;
    midvloc = midvloc - MID_RAMOFF;
    midvloc = (midvloc & ~((EN_RXSZ*1024) - 1)) >> 2; /* mask, cvt to words */
    midvloc = midvloc >> MIDV_LOCTOPSHFT;  /* we only want the top 11 bits */
    midvloc = (midvloc & MIDV_LOCMASK) << MIDV_LOCSHIFT;
    sc->rxslot[lcv].mode = midvloc | 
	(en_k2sz(EN_RXSZ) << MIDV_SZSHIFT) | MIDV_TRASH;

#ifdef EN_DEBUG
    printf("%s: rx%d: start 0x%x, stop 0x%x, mode 0x%x\n", sc->sc_dev.dv_xname,
	lcv, sc->rxslot[lcv].start, sc->rxslot[lcv].stop, sc->rxslot[lcv].mode);
#endif
  }

#ifdef EN_STAT
  sc->vtrash = sc->otrash = sc->mfix = sc->txmbovr = sc->dmaovr = 0;
  sc->txoutspace = sc->txdtqout = sc->launch = sc->lheader = sc->ltail = 0;
  sc->hwpull = sc->swadd = sc->rxqnotus = sc->rxqus = sc->rxoutboth = 0;
  sc->rxdrqout = sc->ttrash = sc->rxmbufout = sc->mfixfail = 0;
  sc->headbyte = sc->tailbyte = sc->tailflush = 0;
#endif
  sc->need_drqs = sc->need_dtqs = 0;

  printf("%s: %d %dKB receive buffers, %d %dKB transmit buffers allocated\n",
	sc->sc_dev.dv_xname, sc->en_nrx, EN_RXSZ, EN_NTX, EN_TXSZ);

  printf("%s: End Station Identifier (mac address) %6D\n",
	 sc->sc_dev.dv_xname, sc->macaddr, ":");

  /*
   * final commit
   */

  if_attach(ifp);
  atm_ifattach(ifp); 

#if NBPFILTER > 0 
  BPFATTACH(ifp, DLT_ATM_RFC1483, sizeof(struct atmllc));
#endif
}


/*
 * en_dmaprobe: helper function for en_attach.
 *
 * see how the card handles DMA by running a few DMA tests.   we need
 * to figure out the largest number of bytes we can DMA in one burst
 * ("bestburstlen"), and if the starting address for a burst needs to
 * be aligned on any sort of boundary or not ("alburst").
 *
 * typical findings:
 * sparc1: bestburstlen=4, alburst=0 (ick, broken DMA!)
 * sparc2: bestburstlen=64, alburst=1
 * p166:   bestburstlen=64, alburst=0 
 */

#if 1 /* __FreeBSD__ */
#define NBURSTS	3	/* number of bursts to use for dmaprobe */
#define BOUNDARY 1024	/* test misaligned dma crossing the bounday.
			   should be n * 64.  at least 64*(NBURSTS+1).
			   dell P6 with EDO DRAM has 1K bounday problem */
#endif

STATIC void en_dmaprobe(sc)

struct en_softc *sc;

{
#ifdef NBURSTS
  /* be careful. kernel stack is only 8K */
  u_int8_t buffer[BOUNDARY * 2 + 64 * (NBURSTS + 1)]; 
#else
  u_int32_t srcbuf[64], dstbuf[64];
#endif
  u_int8_t *sp, *dp;
  int bestalgn, bestnotalgn, lcv, try;

  sc->alburst = 0;

#ifdef NBURSTS
  /* setup src and dst buf at the end of the boundary */
  sp = (u_int8_t *)roundup((uintptr_t)(void *)buffer, 64);
  while (((uintptr_t)(void *)sp & (BOUNDARY - 1)) != (BOUNDARY - 64))
      sp += 64;
  dp = sp + BOUNDARY;

  /*
   * we can't dma across page boundary so that, if buf is at a page
   * boundary, move it to the next page.  but still either src or dst
   * will be at the boundary, which should be ok.
   */
  if ((((uintptr_t)(void *)sp + 64) & PAGE_MASK) == 0)
      sp += 64;
  if ((((uintptr_t)(void *)dp + 64) & PAGE_MASK) == 0)
      dp += 64;
#else /* !NBURSTS */
  sp = (u_int8_t *) srcbuf;
  while ((((unsigned long) sp) % MIDDMA_MAXBURST) != 0)
    sp += 4;
  dp = (u_int8_t *) dstbuf;
  while ((((unsigned long) dp) % MIDDMA_MAXBURST) != 0)
    dp += 4;
#endif /* !NBURSTS */

  bestalgn = bestnotalgn = en_dmaprobe_doit(sc, sp, dp, 0);

  for (lcv = 4 ; lcv < MIDDMA_MAXBURST ; lcv += 4) {
    try = en_dmaprobe_doit(sc, sp+lcv, dp+lcv, 0);
#ifdef NBURSTS
    if (try < bestnotalgn) {
      bestnotalgn = try;
      break;
    }
#else
    if (try < bestnotalgn)
      bestnotalgn = try;
#endif
  }

  if (bestalgn != bestnotalgn) 		/* need bursts aligned */
    sc->alburst = 1;

  sc->bestburstlen = bestalgn;
  sc->bestburstshift = en_log2(bestalgn);
  sc->bestburstmask = sc->bestburstlen - 1; /* must be power of 2 */
  sc->bestburstcode = en_sz2b(bestalgn);

#if 1 /* __FreeBSD__ */
  /*
   * correct pci chipsets should be able to handle misaligned-64-byte DMA.
   * but there are too many broken chipsets around.  we try to work around
   * by finding the best workable dma size, but still some broken machines
   * exhibit the problem later. so warn it here.
   */
  if (bestalgn != 64 || sc->alburst != 0) {
    printf("%s: WARNING: DMA test detects a broken PCI chipset!\n", 
	   sc->sc_dev.dv_xname);
    printf("     trying to work around the problem...  but if this doesn't\n");
    printf("     work for you, you'd better switch to a newer motherboard.\n");
  }
#endif /* 1 */
    return;
}


/*
 * en_dmaprobe_doit: do actual testing
 */

int
en_dmaprobe_doit(sc, sp, dp, wmtry)

struct en_softc *sc;
u_int8_t *sp, *dp;
int wmtry;

{
  int lcv, retval = 4, cnt, count;
  u_int32_t reg, bcode, midvloc;

  /*
   * set up a 1k buffer at MID_BUFOFF
   */

  if (sc->en_busreset)
    sc->en_busreset(sc);