/*      $NetBSD: if_vr.c,v 1.138 2024/06/29 12:11:12 riastradh Exp $    */

/*-
* Copyright (c) 1998, 1999 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

/*
* Copyright (c) 1997, 1998
*      Bill Paul <[email protected]>.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by Bill Paul.
* 4. Neither the name of the author nor the names of any co-contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*
*      $FreeBSD: if_vr.c,v 1.7 1999/01/10 18:51:49 wpaul Exp $
*/

/*
* VIA Rhine fast ethernet PCI NIC driver
*
* Supports various network adapters based on the VIA Rhine
* and Rhine II PCI controllers, including the D-Link DFE530TX.
* Datasheets are available at http://www.via.com.tw.
*
* Written by Bill Paul <[email protected]>
* Electrical Engineering Department
* Columbia University, New York City
*/

/*
* The VIA Rhine controllers are similar in some respects to the
* the DEC tulip chips, except less complicated. The controller
* uses an MII bus and an external physical layer interface. The
* receiver has a one entry perfect filter and a 64-bit hash table
* multicast filter. Transmit and receive descriptors are similar
* to the tulip.
*
* The Rhine has a serious flaw in its transmit DMA mechanism:
* transmit buffers must be longword aligned. Unfortunately,
* the kernel doesn't guarantee that mbufs will be filled in starting
* at longword boundaries, so we have to do a buffer copy before
* transmission.
*
* Apparently, the receive DMA mechanism also has the same flaw.  This
* means that on systems with struct alignment requirements, incoming
* frames must be copied to a new buffer which shifts the data forward
* 2 bytes so that the payload is aligned on a 4-byte boundary.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_vr.c,v 1.138 2024/06/29 12:11:12 riastradh Exp $");



#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/device.h>

#include <sys/rndsource.h>

#include <net/if.h>
#include <net/if_arp.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#include <net/if_ether.h>

#include <net/bpf.h>

#include <sys/bus.h>
#include <sys/intr.h>
#include <machine/endian.h>

#include <dev/mii/mii.h>
#include <dev/mii/miivar.h>
#include <dev/mii/mii_bitbang.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>
#include <dev/pci/pcidevs.h>

#include <dev/pci/if_vrreg.h>

#define VR_USEIOSPACE

/*
* Various supported device vendors/types and their names.
*/
static const struct device_compatible_entry compat_data[] = {
       { .id = PCI_ID_CODE(PCI_VENDOR_VIATECH,
               PCI_PRODUCT_VIATECH_VT3043) },

       { .id = PCI_ID_CODE(PCI_VENDOR_VIATECH,
               PCI_PRODUCT_VIATECH_VT6102) },

       { .id = PCI_ID_CODE(PCI_VENDOR_VIATECH,
               PCI_PRODUCT_VIATECH_VT6105) },

       { .id = PCI_ID_CODE(PCI_VENDOR_VIATECH,
               PCI_PRODUCT_VIATECH_VT6105M) },

       { .id = PCI_ID_CODE(PCI_VENDOR_VIATECH,
               PCI_PRODUCT_VIATECH_VT86C100A) },

       PCI_COMPAT_EOL
};

/*
* Transmit descriptor list size.
*/
#define VR_NTXDESC              64
#define VR_NTXDESC_MASK         (VR_NTXDESC - 1)
#define VR_NEXTTX(x)            (((x) + 1) & VR_NTXDESC_MASK)

/*
* Receive descriptor list size.
*/
#define VR_NRXDESC              64
#define VR_NRXDESC_MASK         (VR_NRXDESC - 1)
#define VR_NEXTRX(x)            (((x) + 1) & VR_NRXDESC_MASK)

/*
* Control data structures that are DMA'd to the Rhine chip.  We allocate
* them in a single clump that maps to a single DMA segment to make several
* things easier.
*
* Note that since we always copy outgoing packets to aligned transmit
* buffers, we can reduce the transmit descriptors to one per packet.
*/
struct vr_control_data {
       struct vr_desc          vr_txdescs[VR_NTXDESC];
       struct vr_desc          vr_rxdescs[VR_NRXDESC];
};

#define VR_CDOFF(x)             offsetof(struct vr_control_data, x)
#define VR_CDTXOFF(x)           VR_CDOFF(vr_txdescs[(x)])
#define VR_CDRXOFF(x)           VR_CDOFF(vr_rxdescs[(x)])

/*
* Software state of transmit and receive descriptors.
*/
struct vr_descsoft {
       struct mbuf             *ds_mbuf;       /* head of mbuf chain */
       bus_dmamap_t            ds_dmamap;      /* our DMA map */
};

struct vr_softc {
       device_t                vr_dev;
       void                    *vr_ih;         /* interrupt cookie */
       bus_space_tag_t         vr_bst;         /* bus space tag */
       bus_space_handle_t      vr_bsh;         /* bus space handle */
       bus_dma_tag_t           vr_dmat;        /* bus DMA tag */
       pci_chipset_tag_t       vr_pc;          /* PCI chipset info */
       pcitag_t                vr_tag;         /* PCI tag */
       struct ethercom         vr_ec;          /* Ethernet common info */
       uint8_t                 vr_enaddr[ETHER_ADDR_LEN];
       struct mii_data         vr_mii;         /* MII/media info */

       pcireg_t                vr_id;          /* vendor/product ID */
       uint8_t                 vr_revid;       /* Rhine chip revision */

       callout_t               vr_tick_ch;     /* tick callout */

       bus_dmamap_t            vr_cddmamap;    /* control data DMA map */
#define vr_cddma        vr_cddmamap->dm_segs[0].ds_addr

       /*
        * Software state for transmit and receive descriptors.
        */
       struct vr_descsoft      vr_txsoft[VR_NTXDESC];
       struct vr_descsoft      vr_rxsoft[VR_NRXDESC];

       /*
        * Control data structures.
        */
       struct vr_control_data  *vr_control_data;

       int     vr_txpending;           /* number of TX requests pending */
       int     vr_txdirty;             /* first dirty TX descriptor */
       int     vr_txlast;              /* last used TX descriptor */

       int     vr_rxptr;               /* next ready RX descriptor */

       uint32_t        vr_save_iobase;
       uint32_t        vr_save_membase;
       uint32_t        vr_save_irq;

       bool            vr_link;
       int             vr_flags;
#define VR_F_RESTART    0x1             /* restart on next tick */
       u_short         vr_if_flags;

       krndsource_t rnd_source;        /* random source */
};

#define VR_CDTXADDR(sc, x)      ((sc)->vr_cddma + VR_CDTXOFF((x)))
#define VR_CDRXADDR(sc, x)      ((sc)->vr_cddma + VR_CDRXOFF((x)))

#define VR_CDTX(sc, x)          (&(sc)->vr_control_data->vr_txdescs[(x)])
#define VR_CDRX(sc, x)          (&(sc)->vr_control_data->vr_rxdescs[(x)])

#define VR_DSTX(sc, x)          (&(sc)->vr_txsoft[(x)])
#define VR_DSRX(sc, x)          (&(sc)->vr_rxsoft[(x)])

#define VR_CDTXSYNC(sc, x, ops)                                         \
       bus_dmamap_sync((sc)->vr_dmat, (sc)->vr_cddmamap,               \
           VR_CDTXOFF((x)), sizeof(struct vr_desc), (ops))

#define VR_CDRXSYNC(sc, x, ops)                                         \
       bus_dmamap_sync((sc)->vr_dmat, (sc)->vr_cddmamap,               \
           VR_CDRXOFF((x)), sizeof(struct vr_desc), (ops))

/*
* Note we rely on MCLBYTES being a power of two below.
*/
#define VR_INIT_RXDESC(sc, i)                                           \
do {                                                                    \
       struct vr_desc *__d = VR_CDRX((sc), (i));                       \
       struct vr_descsoft *__ds = VR_DSRX((sc), (i));                  \
                                                                       \
       __d->vr_next = htole32(VR_CDRXADDR((sc), VR_NEXTRX((i))));      \
       __d->vr_data = htole32(__ds->ds_dmamap->dm_segs[0].ds_addr);    \
       __d->vr_ctl = htole32(VR_RXCTL_CHAIN | VR_RXCTL_RX_INTR |       \
           ((MCLBYTES - 1) & VR_RXCTL_BUFLEN));                        \
       __d->vr_status = htole32(VR_RXSTAT_FIRSTFRAG |                  \
           VR_RXSTAT_LASTFRAG | VR_RXSTAT_OWN);                        \
       VR_CDRXSYNC((sc), (i), BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE); \
} while (/* CONSTCOND */ 0)

/*
* register space access macros
*/
#define CSR_WRITE_4(sc, reg, val)                                       \
       bus_space_write_4(sc->vr_bst, sc->vr_bsh, reg, val)
#define CSR_WRITE_2(sc, reg, val)                                       \
       bus_space_write_2(sc->vr_bst, sc->vr_bsh, reg, val)
#define CSR_WRITE_1(sc, reg, val)                                       \
       bus_space_write_1(sc->vr_bst, sc->vr_bsh, reg, val)

#define CSR_READ_4(sc, reg)                                             \
       bus_space_read_4(sc->vr_bst, sc->vr_bsh, reg)
#define CSR_READ_2(sc, reg)                                             \
       bus_space_read_2(sc->vr_bst, sc->vr_bsh, reg)
#define CSR_READ_1(sc, reg)                                             \
       bus_space_read_1(sc->vr_bst, sc->vr_bsh, reg)

#define VR_TIMEOUT              1000

static int      vr_add_rxbuf(struct vr_softc *, int);

static void     vr_rxeof(struct vr_softc *);
static void     vr_rxeoc(struct vr_softc *);
static void     vr_txeof(struct vr_softc *);
static int      vr_intr(void *);
static void     vr_start(struct ifnet *);
static int      vr_ioctl(struct ifnet *, u_long, void *);
static int      vr_init(struct ifnet *);
static void     vr_stop(struct ifnet *, int);
static void     vr_rxdrain(struct vr_softc *);
static void     vr_watchdog(struct ifnet *);
static void     vr_tick(void *);

static int      vr_mii_readreg(device_t, int, int, uint16_t *);
static int      vr_mii_writereg(device_t, int, int, uint16_t);
static void     vr_mii_statchg(struct ifnet *);

static void     vr_setmulti(struct vr_softc *);
static void     vr_reset(struct vr_softc *);
static int      vr_restore_state(pci_chipset_tag_t, pcitag_t, device_t,
   pcireg_t);
static bool     vr_resume(device_t, const pmf_qual_t *);

int     vr_copy_small = 0;

#define VR_SETBIT(sc, reg, x)                           \
       CSR_WRITE_1(sc, reg,                            \
           CSR_READ_1(sc, reg) | (x))

#define VR_CLRBIT(sc, reg, x)                           \
       CSR_WRITE_1(sc, reg,                            \
           CSR_READ_1(sc, reg) & ~(x))

#define VR_SETBIT16(sc, reg, x)                         \
       CSR_WRITE_2(sc, reg,                            \
           CSR_READ_2(sc, reg) | (x))

#define VR_CLRBIT16(sc, reg, x)                         \
       CSR_WRITE_2(sc, reg,                            \
           CSR_READ_2(sc, reg) & ~(x))

#define VR_SETBIT32(sc, reg, x)                         \
       CSR_WRITE_4(sc, reg,                            \
           CSR_READ_4(sc, reg) | (x))

#define VR_CLRBIT32(sc, reg, x)                         \
       CSR_WRITE_4(sc, reg,                            \
           CSR_READ_4(sc, reg) & ~(x))

/*
* MII bit-bang glue.
*/
static uint32_t vr_mii_bitbang_read(device_t);
static void     vr_mii_bitbang_write(device_t, uint32_t);

static const struct mii_bitbang_ops vr_mii_bitbang_ops = {
       vr_mii_bitbang_read,
       vr_mii_bitbang_write,
       {
               VR_MIICMD_DATAOUT,      /* MII_BIT_MDO */
               VR_MIICMD_DATAIN,       /* MII_BIT_MDI */
               VR_MIICMD_CLK,          /* MII_BIT_MDC */
               VR_MIICMD_DIR,          /* MII_BIT_DIR_HOST_PHY */
               0,                      /* MII_BIT_DIR_PHY_HOST */
       }
};

static uint32_t
vr_mii_bitbang_read(device_t self)
{
       struct vr_softc *sc = device_private(self);

       return (CSR_READ_1(sc, VR_MIICMD));
}

static void
vr_mii_bitbang_write(device_t self, uint32_t val)
{
       struct vr_softc *sc = device_private(self);

       CSR_WRITE_1(sc, VR_MIICMD, (val & 0xff) | VR_MIICMD_DIRECTPGM);
}

/*
* Read an PHY register through the MII.
*/
static int
vr_mii_readreg(device_t self, int phy, int reg, uint16_t *val)
{
       struct vr_softc *sc = device_private(self);

       CSR_WRITE_1(sc, VR_MIICMD, VR_MIICMD_DIRECTPGM);
       return (mii_bitbang_readreg(self, &vr_mii_bitbang_ops, phy, reg, val));
}

/*
* Write to a PHY register through the MII.
*/
static int
vr_mii_writereg(device_t self, int phy, int reg, uint16_t val)
{
       struct vr_softc *sc = device_private(self);

       CSR_WRITE_1(sc, VR_MIICMD, VR_MIICMD_DIRECTPGM);
       return mii_bitbang_writereg(self, &vr_mii_bitbang_ops, phy, reg, val);
}

static void
vr_mii_statchg(struct ifnet *ifp)
{
       struct vr_softc *sc = ifp->if_softc;
       int i;

       /*
        * In order to fiddle with the 'full-duplex' bit in the netconfig
        * register, we first have to put the transmit and/or receive logic
        * in the idle state.
        */
       if ((sc->vr_mii.mii_media_status & IFM_ACTIVE) &&
           IFM_SUBTYPE(sc->vr_mii.mii_media_active) != IFM_NONE) {
               sc->vr_link = true;

               if (CSR_READ_2(sc, VR_COMMAND) & (VR_CMD_TX_ON | VR_CMD_RX_ON))
                       VR_CLRBIT16(sc, VR_COMMAND,
                           (VR_CMD_TX_ON | VR_CMD_RX_ON));

               if (sc->vr_mii.mii_media_active & IFM_FDX)
                       VR_SETBIT16(sc, VR_COMMAND, VR_CMD_FULLDUPLEX);
               else
                       VR_CLRBIT16(sc, VR_COMMAND, VR_CMD_FULLDUPLEX);

               VR_SETBIT16(sc, VR_COMMAND, VR_CMD_TX_ON | VR_CMD_RX_ON);
       } else {
               sc->vr_link = false;
               VR_CLRBIT16(sc, VR_COMMAND, VR_CMD_TX_ON | VR_CMD_RX_ON);
               for (i = VR_TIMEOUT; i > 0; i--) {
                       delay(10);
                       if (!(CSR_READ_2(sc, VR_COMMAND) &
                           (VR_CMD_TX_ON | VR_CMD_RX_ON)))
                               break;
               }
               if (i == 0) {
#ifdef VR_DEBUG
                       aprint_error_dev(sc->vr_dev, "rx shutdown error!\n");
#endif
                       sc->vr_flags |= VR_F_RESTART;
               }
       }
}

#define vr_calchash(addr) \
       (ether_crc32_be((addr), ETHER_ADDR_LEN) >> 26)

/*
* Program the 64-bit multicast hash filter.
*/
static void
vr_setmulti(struct vr_softc *sc)
{
       struct ethercom *ec = &sc->vr_ec;
       struct ifnet *ifp = &ec->ec_if;
       int h = 0;
       uint32_t hashes[2] = { 0, 0 };
       struct ether_multistep step;
       struct ether_multi *enm;
       int mcnt = 0;
       uint8_t rxfilt;

       rxfilt = CSR_READ_1(sc, VR_RXCFG);

       if (ifp->if_flags & IFF_PROMISC) {
allmulti:
               ifp->if_flags |= IFF_ALLMULTI;
               rxfilt |= VR_RXCFG_RX_MULTI;
               CSR_WRITE_1(sc, VR_RXCFG, rxfilt);
               CSR_WRITE_4(sc, VR_MAR0, 0xFFFFFFFF);
               CSR_WRITE_4(sc, VR_MAR1, 0xFFFFFFFF);
               return;
       }

       /* first, zot all the existing hash bits */
       CSR_WRITE_4(sc, VR_MAR0, 0);
       CSR_WRITE_4(sc, VR_MAR1, 0);

       /* now program new ones */
       ETHER_LOCK(ec);
       ETHER_FIRST_MULTI(step, ec, enm);
       while (enm != NULL) {
               if (memcmp(enm->enm_addrlo, enm->enm_addrhi,
                   ETHER_ADDR_LEN) != 0) {
                       ETHER_UNLOCK(ec);
                       goto allmulti;
               }

               h = vr_calchash(enm->enm_addrlo);

               if (h < 32)
                       hashes[0] |= (1 << h);
               else
                       hashes[1] |= (1 << (h - 32));
               ETHER_NEXT_MULTI(step, enm);
               mcnt++;
       }
       ETHER_UNLOCK(ec);

       ifp->if_flags &= ~IFF_ALLMULTI;

       if (mcnt)
               rxfilt |= VR_RXCFG_RX_MULTI;
       else
               rxfilt &= ~VR_RXCFG_RX_MULTI;

       CSR_WRITE_4(sc, VR_MAR0, hashes[0]);
       CSR_WRITE_4(sc, VR_MAR1, hashes[1]);
       CSR_WRITE_1(sc, VR_RXCFG, rxfilt);
}

static void
vr_reset(struct vr_softc *sc)
{
       int i;

       VR_SETBIT16(sc, VR_COMMAND, VR_CMD_RESET);

       for (i = 0; i < VR_TIMEOUT; i++) {
               DELAY(10);
               if (!(CSR_READ_2(sc, VR_COMMAND) & VR_CMD_RESET))
                       break;
       }
       if (i == VR_TIMEOUT) {
               if (sc->vr_revid < REV_ID_VT3065_A) {
                       aprint_error_dev(sc->vr_dev,
                           "reset never completed!\n");
               } else {
                       /* Use newer force reset command */
                       aprint_normal_dev(sc->vr_dev,
                           "using force reset command.\n");
                       VR_SETBIT(sc, VR_MISC_CR1, VR_MISCCR1_FORSRST);
               }
       }

       /* Wait a little while for the chip to get its brains in order. */
       DELAY(1000);
}

/*
* Initialize an RX descriptor and attach an MBUF cluster.
* Note: the length fields are only 11 bits wide, which means the
* largest size we can specify is 2047. This is important because
* MCLBYTES is 2048, so we have to subtract one otherwise we'll
* overflow the field and make a mess.
*/
static int
vr_add_rxbuf(struct vr_softc *sc, int i)
{
       struct vr_descsoft *ds = VR_DSRX(sc, i);
       struct mbuf *m_new;
       int error;

       MGETHDR(m_new, M_DONTWAIT, MT_DATA);
       if (m_new == NULL)
               return (ENOBUFS);

       MCLGET(m_new, M_DONTWAIT);
       if ((m_new->m_flags & M_EXT) == 0) {
               m_freem(m_new);
               return (ENOBUFS);
       }

       if (ds->ds_mbuf != NULL)
               bus_dmamap_unload(sc->vr_dmat, ds->ds_dmamap);

       ds->ds_mbuf = m_new;

       error = bus_dmamap_load(sc->vr_dmat, ds->ds_dmamap,
           m_new->m_ext.ext_buf, m_new->m_ext.ext_size, NULL,
           BUS_DMA_READ | BUS_DMA_NOWAIT);
       if (error) {
               aprint_error_dev(sc->vr_dev,
                   "unable to load rx DMA map %d, error = %d\n", i, error);
               panic("vr_add_rxbuf");          /* XXX */
       }

       bus_dmamap_sync(sc->vr_dmat, ds->ds_dmamap, 0,
           ds->ds_dmamap->dm_mapsize, BUS_DMASYNC_PREREAD);

       VR_INIT_RXDESC(sc, i);

       return (0);
}

/*
* A frame has been uploaded: pass the resulting mbuf chain up to
* the higher level protocols.
*/
static void
vr_rxeof(struct vr_softc *sc)
{
       struct mbuf *m;
       struct ifnet *ifp;
       struct vr_desc *d;
       struct vr_descsoft *ds;
       int i, total_len;
       uint32_t rxstat;

       ifp = &sc->vr_ec.ec_if;

       for (i = sc->vr_rxptr;; i = VR_NEXTRX(i)) {
               d = VR_CDRX(sc, i);
               ds = VR_DSRX(sc, i);

               VR_CDRXSYNC(sc, i,
                   BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);

               rxstat = le32toh(d->vr_status);

               if (rxstat & VR_RXSTAT_OWN) {
                       /*
                        * We have processed all of the receive buffers.
                        */
                       break;
               }

               /*
                * If an error occurs, update stats, clear the
                * status word and leave the mbuf cluster in place:
                * it should simply get re-used next time this descriptor
                * comes up in the ring.
                */
               if (rxstat & VR_RXSTAT_RXERR) {
                       const char *errstr;

                       if_statinc(ifp, if_ierrors);
                       switch (rxstat & 0x000000FF) {
                       case VR_RXSTAT_CRCERR:
                               errstr = "crc error";
                               break;
                       case VR_RXSTAT_FRAMEALIGNERR:
                               errstr = "frame alignment error";
                               break;
                       case VR_RXSTAT_FIFOOFLOW:
                               errstr = "FIFO overflow";
                               break;
                       case VR_RXSTAT_GIANT:
                               errstr = "received giant packet";
                               break;
                       case VR_RXSTAT_RUNT:
                               errstr = "received runt packet";
                               break;
                       case VR_RXSTAT_BUSERR:
                               errstr = "system bus error";
                               break;
                       case VR_RXSTAT_BUFFERR:
                               errstr = "rx buffer error";
                               break;
                       default:
                               errstr = "unknown rx error";
                               break;
                       }
                       aprint_error_dev(sc->vr_dev, "receive error: %s\n",
                           errstr);

                       VR_INIT_RXDESC(sc, i);

                       continue;
               } else if (!(rxstat & VR_RXSTAT_FIRSTFRAG) ||
                          !(rxstat & VR_RXSTAT_LASTFRAG)) {
                       /*
                        * This driver expects to receive whole packets every
                        * time.  In case we receive a fragment that is not
                        * a complete packet, we discard it.
                        */
                       if_statinc(ifp, if_ierrors);

                       aprint_error_dev(sc->vr_dev,
                           "receive error: incomplete frame; "
                           "size = %d, status = 0x%x\n",
                           VR_RXBYTES(le32toh(d->vr_status)), rxstat);

                       VR_INIT_RXDESC(sc, i);

                       continue;
               }

               bus_dmamap_sync(sc->vr_dmat, ds->ds_dmamap, 0,
                   ds->ds_dmamap->dm_mapsize, BUS_DMASYNC_POSTREAD);

               /* No errors; receive the packet. */
               total_len = VR_RXBYTES(le32toh(d->vr_status));
#ifdef DIAGNOSTIC
               if (total_len == 0) {
                       /*
                        * If we receive a zero-length packet, we probably
                        * missed to handle an error condition above.
                        * Discard it to avoid a later crash.
                        */
                       if_statinc(ifp, if_ierrors);

                       aprint_error_dev(sc->vr_dev,
                           "receive error: zero-length packet; "
                           "status = 0x%x\n", rxstat);

                       VR_INIT_RXDESC(sc, i);

                       continue;
               }
#endif

               /*
                * The Rhine chip includes the CRC with every packet.
                * Trim it off here.
                */
               total_len -= ETHER_CRC_LEN;

#ifdef __NO_STRICT_ALIGNMENT
               /*
                * If the packet is small enough to fit in a
                * single header mbuf, allocate one and copy
                * the data into it.  This greatly reduces
                * memory consumption when we receive lots
                * of small packets.
                *
                * Otherwise, we add a new buffer to the receive
                * chain.  If this fails, we drop the packet and
                * recycle the old buffer.
                */
               if (vr_copy_small != 0 && total_len <= MHLEN) {
                       MGETHDR(m, M_DONTWAIT, MT_DATA);
                       if (m == NULL)
                               goto dropit;
                       memcpy(mtod(m, void *),
                           mtod(ds->ds_mbuf, void *), total_len);
                       VR_INIT_RXDESC(sc, i);
                       bus_dmamap_sync(sc->vr_dmat, ds->ds_dmamap, 0,
                           ds->ds_dmamap->dm_mapsize,
                           BUS_DMASYNC_PREREAD);
               } else {
                       m = ds->ds_mbuf;
                       if (vr_add_rxbuf(sc, i) == ENOBUFS) {
dropit:
                               if_statinc(ifp, if_ierrors);
                               VR_INIT_RXDESC(sc, i);
                               bus_dmamap_sync(sc->vr_dmat,
                                   ds->ds_dmamap, 0,
                                   ds->ds_dmamap->dm_mapsize,
                                   BUS_DMASYNC_PREREAD);
                               continue;
                       }
               }
#else
               /*
                * The Rhine's packet buffers must be 4-byte aligned.
                * But this means that the data after the Ethernet header
                * is misaligned.  We must allocate a new buffer and
                * copy the data, shifted forward 2 bytes.
                */
               MGETHDR(m, M_DONTWAIT, MT_DATA);
               if (m == NULL) {
dropit:
                       if_statinc(ifp, if_ierrors);
                       VR_INIT_RXDESC(sc, i);
                       bus_dmamap_sync(sc->vr_dmat, ds->ds_dmamap, 0,
                           ds->ds_dmamap->dm_mapsize, BUS_DMASYNC_PREREAD);
                       continue;
               }
               if (total_len > (MHLEN - 2)) {
                       MCLGET(m, M_DONTWAIT);
                       if ((m->m_flags & M_EXT) == 0) {
                               m_freem(m);
                               goto dropit;
                       }
               }
               m->m_data += 2;

               /*
                * Note that we use clusters for incoming frames, so the
                * buffer is virtually contiguous.
                */
               memcpy(mtod(m, void *), mtod(ds->ds_mbuf, void *),
                   total_len);

               /* Allow the receive descriptor to continue using its mbuf. */
               VR_INIT_RXDESC(sc, i);
               bus_dmamap_sync(sc->vr_dmat, ds->ds_dmamap, 0,
                   ds->ds_dmamap->dm_mapsize, BUS_DMASYNC_PREREAD);
#endif /* __NO_STRICT_ALIGNMENT */

               m_set_rcvif(m, ifp);
               m->m_pkthdr.len = m->m_len = total_len;
               /* Pass it on. */
               if_percpuq_enqueue(ifp->if_percpuq, m);
       }

       /* Update the receive pointer. */
       sc->vr_rxptr = i;
}

void
vr_rxeoc(struct vr_softc *sc)
{
       struct ifnet *ifp;
       int i;

       ifp = &sc->vr_ec.ec_if;

       if_statinc(ifp, if_ierrors);

       VR_CLRBIT16(sc, VR_COMMAND, VR_CMD_RX_ON);
       for (i = 0; i < VR_TIMEOUT; i++) {
               DELAY(10);
               if ((CSR_READ_2(sc, VR_COMMAND) & VR_CMD_RX_ON) == 0)
                       break;
       }
       if (i == VR_TIMEOUT) {
               /* XXX need reset? */
               aprint_error_dev(sc->vr_dev, "RX shutdown never completed\n");
       }

       vr_rxeof(sc);

       CSR_WRITE_4(sc, VR_RXADDR, VR_CDRXADDR(sc, sc->vr_rxptr));
       VR_SETBIT16(sc, VR_COMMAND, VR_CMD_RX_ON);
       VR_SETBIT16(sc, VR_COMMAND, VR_CMD_RX_GO);
}

/*
* A frame was downloaded to the chip. It's safe for us to clean up
* the list buffers.
*/
static void
vr_txeof(struct vr_softc *sc)
{
       struct ifnet *ifp = &sc->vr_ec.ec_if;
       struct vr_desc *d;
       struct vr_descsoft *ds;
       uint32_t txstat;
       int i, j;

       /*
        * Go through our tx list and free mbufs for those
        * frames that have been transmitted.
        */
       for (i = sc->vr_txdirty; sc->vr_txpending != 0;
            i = VR_NEXTTX(i), sc->vr_txpending--) {
               d = VR_CDTX(sc, i);
               ds = VR_DSTX(sc, i);

               VR_CDTXSYNC(sc, i,
                   BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);

               txstat = le32toh(d->vr_status);

               if (txstat & (VR_TXSTAT_ABRT | VR_TXSTAT_UDF)) {
                       VR_CLRBIT16(sc, VR_COMMAND, VR_CMD_TX_ON);
                       for (j = 0; j < VR_TIMEOUT; j++) {
                               DELAY(10);
                               if ((CSR_READ_2(sc, VR_COMMAND) &
                                   VR_CMD_TX_ON) == 0)
                                       break;
                       }
                       if (j == VR_TIMEOUT) {
                               /* XXX need reset? */
                               aprint_error_dev(sc->vr_dev,
                                   "TX shutdown never completed\n");
                       }
                       d->vr_status = htole32(VR_TXSTAT_OWN);
                       CSR_WRITE_4(sc, VR_TXADDR, VR_CDTXADDR(sc, i));
                       break;
               }

               if (txstat & VR_TXSTAT_OWN)
                       break;

               bus_dmamap_sync(sc->vr_dmat, ds->ds_dmamap,
                   0, ds->ds_dmamap->dm_mapsize, BUS_DMASYNC_POSTWRITE);
               bus_dmamap_unload(sc->vr_dmat, ds->ds_dmamap);
               m_freem(ds->ds_mbuf);
               ds->ds_mbuf = NULL;

               net_stat_ref_t nsr = IF_STAT_GETREF(ifp);
               if (txstat & VR_TXSTAT_ERRSUM) {
                       if_statinc_ref(ifp, nsr, if_oerrors);
                       if (txstat & VR_TXSTAT_DEFER)
                               if_statinc_ref(ifp, nsr, if_collisions);
                       if (txstat & VR_TXSTAT_LATECOLL)
                               if_statinc_ref(ifp, nsr, if_collisions);
               }

               if_statadd_ref(ifp, nsr, if_collisions,
                   (txstat & VR_TXSTAT_COLLCNT) >> 3);
               if_statinc_ref(ifp, nsr, if_opackets);
               IF_STAT_PUTREF(ifp);
       }

       /* Update the dirty transmit buffer pointer. */
       sc->vr_txdirty = i;

       /*
        * Cancel the watchdog timer if there are no pending
        * transmissions.
        */
       if (sc->vr_txpending == 0)
               ifp->if_timer = 0;
}

static int
vr_intr(void *arg)
{
       struct vr_softc *sc;
       struct ifnet *ifp;
       uint16_t status;
       int handled = 0, dotx = 0;

       sc = arg;
       ifp = &sc->vr_ec.ec_if;

       /* Suppress unwanted interrupts. */
       if ((ifp->if_flags & IFF_UP) == 0) {
               vr_stop(ifp, 1);
               return (0);
       }

       /* Disable interrupts. */
       CSR_WRITE_2(sc, VR_IMR, 0x0000);

       for (;;) {
               status = CSR_READ_2(sc, VR_ISR);
               if (status)
                       CSR_WRITE_2(sc, VR_ISR, status);

               if ((status & VR_INTRS) == 0)
                       break;

               handled = 1;

               rnd_add_uint32(&sc->rnd_source, status);

               if (status & VR_ISR_RX_OK)
                       vr_rxeof(sc);

               if (status & VR_ISR_RX_DROPPED) {
                       aprint_error_dev(sc->vr_dev, "rx packet lost\n");
                       if_statinc(ifp, if_ierrors);
               }

               if (status &
                   (VR_ISR_RX_ERR | VR_ISR_RX_NOBUF | VR_ISR_RX_OFLOW))
                       vr_rxeoc(sc);


               if (status & (VR_ISR_BUSERR | VR_ISR_TX_UNDERRUN)) {
                       if (status & VR_ISR_BUSERR)
                               aprint_error_dev(sc->vr_dev, "PCI bus error\n");
                       if (status & VR_ISR_TX_UNDERRUN)
                               aprint_error_dev(sc->vr_dev,
                                   "transmit underrun\n");
                       /* vr_init() calls vr_start() */
                       dotx = 0;
                       (void)vr_init(ifp);

               }

               if (status & VR_ISR_TX_OK) {
                       dotx = 1;
                       vr_txeof(sc);
               }

               if (status &
                   (VR_ISR_TX_ABRT | VR_ISR_TX_ABRT2 | VR_ISR_TX_UDFI)) {
                       if (status & (VR_ISR_TX_ABRT | VR_ISR_TX_ABRT2))
                               aprint_error_dev(sc->vr_dev,
                                   "transmit aborted\n");
                       if (status & VR_ISR_TX_UDFI)
                               aprint_error_dev(sc->vr_dev,
                                   "transmit underflow\n");
                       if_statinc(ifp, if_oerrors);
                       dotx = 1;
                       vr_txeof(sc);
                       if (sc->vr_txpending) {
                               VR_SETBIT16(sc, VR_COMMAND, VR_CMD_TX_ON);
                               VR_SETBIT16(sc, VR_COMMAND, VR_CMD_TX_GO);
                       }
               }
       }

       /* Re-enable interrupts. */
       CSR_WRITE_2(sc, VR_IMR, VR_INTRS);

       if (dotx)
               if_schedule_deferred_start(ifp);

       return (handled);
}

/*
* Main transmit routine. To avoid having to do mbuf copies, we put pointers
* to the mbuf data regions directly in the transmit lists. We also save a
* copy of the pointers since the transmit list fragment pointers are
* physical addresses.
*/
static void
vr_start(struct ifnet *ifp)
{
       struct vr_softc *sc = ifp->if_softc;
       struct mbuf *m0, *m;
       struct vr_desc *d;
       struct vr_descsoft *ds;
       int error, firsttx, nexttx, opending;

       if ((ifp->if_flags & IFF_RUNNING) == 0)
               return;
       if (sc->vr_link == false)
               return;

       /*
        * Remember the previous txpending and the first transmit
        * descriptor we use.
        */
       opending = sc->vr_txpending;
       firsttx = VR_NEXTTX(sc->vr_txlast);

       /*
        * Loop through the send queue, setting up transmit descriptors
        * until we drain the queue, or use up all available transmit
        * descriptors.
        */
       while (sc->vr_txpending < VR_NTXDESC) {
               /*
                * Grab a packet off the queue.
                */
               IFQ_POLL(&ifp->if_snd, m0);
               if (m0 == NULL)
                       break;
               m = NULL;

               /*
                * Get the next available transmit descriptor.
                */
               nexttx = VR_NEXTTX(sc->vr_txlast);
               d = VR_CDTX(sc, nexttx);
               ds = VR_DSTX(sc, nexttx);

               /*
                * Load the DMA map.  If this fails, the packet didn't
                * fit in one DMA segment, and we need to copy.  Note,
                * the packet must also be aligned.
                * if the packet is too small, copy it too, so we're sure
                * we have enough room for the pad buffer.
                */
               if ((mtod(m0, uintptr_t) & 3) != 0 ||
                   m0->m_pkthdr.len < VR_MIN_FRAMELEN ||
                   bus_dmamap_load_mbuf(sc->vr_dmat, ds->ds_dmamap, m0,
                    BUS_DMA_WRITE | BUS_DMA_NOWAIT) != 0) {
                       MGETHDR(m, M_DONTWAIT, MT_DATA);
                       if (m == NULL) {
                               aprint_error_dev(sc->vr_dev,
                                   "unable to allocate Tx mbuf\n");
                               break;
                       }
                       if (m0->m_pkthdr.len > MHLEN) {
                               MCLGET(m, M_DONTWAIT);
                               if ((m->m_flags & M_EXT) == 0) {
                                       aprint_error_dev(sc->vr_dev,
                                           "unable to allocate Tx cluster\n");
                                       m_freem(m);
                                       break;
                               }
                       }
                       m_copydata(m0, 0, m0->m_pkthdr.len, mtod(m, void *));
                       m->m_pkthdr.len = m->m_len = m0->m_pkthdr.len;
                       /*
                        * The Rhine doesn't auto-pad, so we have to do this
                        * ourselves.
                        */
                       if (m0->m_pkthdr.len < VR_MIN_FRAMELEN) {
                               memset(mtod(m, char *) + m0->m_pkthdr.len,
                                   0, VR_MIN_FRAMELEN - m0->m_pkthdr.len);
                               m->m_pkthdr.len = m->m_len = VR_MIN_FRAMELEN;
                       }
                       error = bus_dmamap_load_mbuf(sc->vr_dmat,
                           ds->ds_dmamap, m, BUS_DMA_WRITE | BUS_DMA_NOWAIT);
                       if (error) {
                               m_freem(m);
                               aprint_error_dev(sc->vr_dev, "unable to load "
                                   "Tx buffer, error = %d\n", error);
                               break;
                       }
               }

               IFQ_DEQUEUE(&ifp->if_snd, m0);
               if (m != NULL) {
                       m_freem(m0);
                       m0 = m;
               }

               /* Sync the DMA map. */
               bus_dmamap_sync(sc->vr_dmat, ds->ds_dmamap, 0,
                   ds->ds_dmamap->dm_mapsize, BUS_DMASYNC_PREWRITE);

               /*
                * Store a pointer to the packet so we can free it later.
                */
               ds->ds_mbuf = m0;

               /*
                * If there's a BPF listener, bounce a copy of this frame
                * to him.
                */
               bpf_mtap(ifp, m0, BPF_D_OUT);

               /*
                * Fill in the transmit descriptor.
                */
               d->vr_data = htole32(ds->ds_dmamap->dm_segs[0].ds_addr);
               d->vr_ctl = htole32(m0->m_pkthdr.len);
               d->vr_ctl |= htole32(VR_TXCTL_FIRSTFRAG | VR_TXCTL_LASTFRAG);

               /*
                * If this is the first descriptor we're enqueuing,
                * don't give it to the Rhine yet.  That could cause
                * a race condition.  We'll do it below.
                */
               if (nexttx == firsttx)
                       d->vr_status = 0;
               else
                       d->vr_status = htole32(VR_TXSTAT_OWN);

               VR_CDTXSYNC(sc, nexttx,
                   BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);

               /* Advance the tx pointer. */
               sc->vr_txpending++;
               sc->vr_txlast = nexttx;
       }

       if (sc->vr_txpending != opending) {
               /*
                * We enqueued packets.  If the transmitter was idle,
                * reset the txdirty pointer.
                */
               if (opending == 0)
                       sc->vr_txdirty = firsttx;

               /*
                * Cause a transmit interrupt to happen on the
                * last packet we enqueued.
                */
               VR_CDTX(sc, sc->vr_txlast)->vr_ctl |= htole32(VR_TXCTL_FINT);
               VR_CDTXSYNC(sc, sc->vr_txlast,
                   BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);

               /*
                * The entire packet chain is set up.  Give the
                * first descriptor to the Rhine now.
                */
               VR_CDTX(sc, firsttx)->vr_status = htole32(VR_TXSTAT_OWN);
               VR_CDTXSYNC(sc, firsttx,
                   BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);

               /* Start the transmitter. */
               VR_SETBIT16(sc, VR_COMMAND, VR_CMD_TX_GO);

               /* Set the watchdog timer in case the chip flakes out. */
               ifp->if_timer = 5;
       }
}

/*
* Initialize the interface.  Must be called at splnet.
*/
static int
vr_init(struct ifnet *ifp)
{
       struct vr_softc *sc = ifp->if_softc;
       struct vr_desc *d;
       struct vr_descsoft *ds;
       int i, error = 0;

       /* Cancel pending I/O. */
       vr_stop(ifp, 0);

       /* Reset the Rhine to a known state. */
       vr_reset(sc);

       /* set DMA length in BCR0 and BCR1 */
       VR_CLRBIT(sc, VR_BCR0, VR_BCR0_DMA_LENGTH);
       VR_SETBIT(sc, VR_BCR0, VR_BCR0_DMA_STORENFWD);

       VR_CLRBIT(sc, VR_BCR0, VR_BCR0_RX_THRESH);
       VR_SETBIT(sc, VR_BCR0, VR_BCR0_RXTH_128BYTES);

       VR_CLRBIT(sc, VR_BCR1, VR_BCR1_TX_THRESH);
       VR_SETBIT(sc, VR_BCR1, VR_BCR1_TXTH_STORENFWD);

       /* set DMA threshold length in RXCFG and TXCFG */
       VR_CLRBIT(sc, VR_RXCFG, VR_RXCFG_RX_THRESH);
       VR_SETBIT(sc, VR_RXCFG, VR_RXTHRESH_128BYTES);

       VR_CLRBIT(sc, VR_TXCFG, VR_TXCFG_TX_THRESH);
       VR_SETBIT(sc, VR_TXCFG, VR_TXTHRESH_STORENFWD);

       /*
        * Initialize the transmit descriptor ring.  txlast is initialized
        * to the end of the list so that it will wrap around to the first
        * descriptor when the first packet is transmitted.
        */
       for (i = 0; i < VR_NTXDESC; i++) {
               d = VR_CDTX(sc, i);
               memset(d, 0, sizeof(struct vr_desc));
               d->vr_next = htole32(VR_CDTXADDR(sc, VR_NEXTTX(i)));
               VR_CDTXSYNC(sc, i, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
       }
       sc->vr_txpending = 0;
       sc->vr_txdirty = 0;
       sc->vr_txlast = VR_NTXDESC - 1;

       /*
        * Initialize the receive descriptor ring.
        */
       for (i = 0; i < VR_NRXDESC; i++) {
               ds = VR_DSRX(sc, i);
               if (ds->ds_mbuf == NULL) {
                       if ((error = vr_add_rxbuf(sc, i)) != 0) {
                               aprint_error_dev(sc->vr_dev,
                                   "unable to allocate or map rx buffer %d, "
                                   "error = %d\n", i, error);
                               /*
                                * XXX Should attempt to run with fewer receive
                                * XXX buffers instead of just failing.
                                */
                               vr_rxdrain(sc);
                               goto out;
                       }
               } else
                       VR_INIT_RXDESC(sc, i);
       }
       sc->vr_rxptr = 0;

       /* If we want promiscuous mode, set the allframes bit. */
       if (ifp->if_flags & IFF_PROMISC)
               VR_SETBIT(sc, VR_RXCFG, VR_RXCFG_RX_PROMISC);
       else
               VR_CLRBIT(sc, VR_RXCFG, VR_RXCFG_RX_PROMISC);

       /* Set capture broadcast bit to capture broadcast frames. */
       if (ifp->if_flags & IFF_BROADCAST)
               VR_SETBIT(sc, VR_RXCFG, VR_RXCFG_RX_BROAD);
       else
               VR_CLRBIT(sc, VR_RXCFG, VR_RXCFG_RX_BROAD);

       /* Program the multicast filter, if necessary. */
       vr_setmulti(sc);

       /* Give the transmit and receive rings to the Rhine. */
       CSR_WRITE_4(sc, VR_RXADDR, VR_CDRXADDR(sc, sc->vr_rxptr));
       CSR_WRITE_4(sc, VR_TXADDR, VR_CDTXADDR(sc, VR_NEXTTX(sc->vr_txlast)));

       /* Set current media. */
       sc->vr_link = true;
       if ((error = ether_mediachange(ifp)) != 0)
               goto out;

       /* Enable receiver and transmitter. */
       CSR_WRITE_2(sc, VR_COMMAND, VR_CMD_TX_NOPOLL | VR_CMD_START |
                                   VR_CMD_TX_ON | VR_CMD_RX_ON |
                                   VR_CMD_RX_GO);

       /* Enable interrupts. */
       CSR_WRITE_2(sc, VR_ISR, 0xFFFF);
       CSR_WRITE_2(sc, VR_IMR, VR_INTRS);

       ifp->if_flags |= IFF_RUNNING;

       /* Start one second timer. */
       callout_schedule(&sc->vr_tick_ch, hz);

       /* Attempt to start output on the interface. */
       vr_start(ifp);

out:
       if (error)
               aprint_error_dev(sc->vr_dev, "interface not running\n");
       return (error);
}

static int
vr_ioctl(struct ifnet *ifp, u_long command, void *data)
{
       struct vr_softc *sc = ifp->if_softc;
       int s, error = 0;

       s = splnet();

       switch (command) {
       case SIOCSIFFLAGS:
               if ((error = ifioctl_common(ifp, command, data)) != 0)
                       break;

               switch (ifp->if_flags & (IFF_UP | IFF_RUNNING)) {
               case IFF_RUNNING:
                       vr_stop(ifp, 1);
                       break;
               case IFF_UP:
                       vr_init(ifp);
                       break;
               case IFF_UP | IFF_RUNNING:
                       if ((ifp->if_flags ^ sc->vr_if_flags) == IFF_PROMISC)
                               vr_setmulti(sc);
                       else
                               vr_init(ifp);
                       break;
               }
               sc->vr_if_flags = ifp->if_flags;
               break;
       default:
               if ((error = ether_ioctl(ifp, command, data)) != ENETRESET)
                       break;
               error = 0;
               if (command == SIOCADDMULTI || command == SIOCDELMULTI)
                       vr_setmulti(sc);
       }
       splx(s);

       return error;
}

static void
vr_watchdog(struct ifnet *ifp)
{
       struct vr_softc *sc = ifp->if_softc;

       aprint_error_dev(sc->vr_dev, "device timeout\n");
       if_statinc(ifp, if_oerrors);

       (void) vr_init(ifp);
}

/*
* One second timer, used to tick MII.
*/
static void
vr_tick(void *arg)
{
       struct vr_softc *sc = arg;
       int s;

       s = splnet();
       if (sc->vr_flags & VR_F_RESTART) {
               aprint_normal_dev(sc->vr_dev, "restarting\n");
               vr_init(&sc->vr_ec.ec_if);
               sc->vr_flags &= ~VR_F_RESTART;
       }
       mii_tick(&sc->vr_mii);
       splx(s);

       callout_schedule(&sc->vr_tick_ch, hz);
}

/*
* Drain the receive queue.
*/
static void
vr_rxdrain(struct vr_softc *sc)
{
       struct vr_descsoft *ds;
       int i;

       for (i = 0; i < VR_NRXDESC; i++) {
               ds = VR_DSRX(sc, i);
               if (ds->ds_mbuf != NULL) {
                       bus_dmamap_unload(sc->vr_dmat, ds->ds_dmamap);
                       m_freem(ds->ds_mbuf);
                       ds->ds_mbuf = NULL;
               }
       }
}

/*
* Stop the adapter and free any mbufs allocated to the
* transmit lists.
*/
static void
vr_stop(struct ifnet *ifp, int disable)
{
       struct vr_softc *sc = ifp->if_softc;
       struct vr_descsoft *ds;
       int i;

       /* Cancel one second timer. */
       callout_stop(&sc->vr_tick_ch);

       /* Down the MII. */
       mii_down(&sc->vr_mii);

       ifp = &sc->vr_ec.ec_if;
       ifp->if_timer = 0;

       VR_SETBIT16(sc, VR_COMMAND, VR_CMD_STOP);
       VR_CLRBIT16(sc, VR_COMMAND, (VR_CMD_RX_ON | VR_CMD_TX_ON));
       CSR_WRITE_2(sc, VR_IMR, 0x0000);
       CSR_WRITE_4(sc, VR_TXADDR, 0x00000000);
       CSR_WRITE_4(sc, VR_RXADDR, 0x00000000);

       /*
        * Release any queued transmit buffers.
        */
       for (i = 0; i < VR_NTXDESC; i++) {
               ds = VR_DSTX(sc, i);
               if (ds->ds_mbuf != NULL) {
                       bus_dmamap_unload(sc->vr_dmat, ds->ds_dmamap);
                       m_freem(ds->ds_mbuf);
                       ds->ds_mbuf = NULL;
               }
       }

       /*
        * Mark the interface down and cancel the watchdog timer.
        */
       ifp->if_flags &= ~IFF_RUNNING;
       ifp->if_timer = 0;

       if (disable)
               vr_rxdrain(sc);
}

static int      vr_probe(device_t, cfdata_t, void *);
static void     vr_attach(device_t, device_t, void *);
static bool     vr_shutdown(device_t, int);

CFATTACH_DECL_NEW(vr, sizeof (struct vr_softc),
   vr_probe, vr_attach, NULL, NULL);

static int
vr_probe(device_t parent, cfdata_t match, void *aux)
{
       struct pci_attach_args *pa = (struct pci_attach_args *)aux;

       return pci_compatible_match(pa, compat_data);
}

/*
* Stop all chip I/O so that the kernel's probe routines don't
* get confused by errant DMAs when rebooting.
*/
static bool
vr_shutdown(device_t self, int howto)
{
       struct vr_softc *sc = device_private(self);

       vr_stop(&sc->vr_ec.ec_if, 1);

       return true;
}

/*
* Attach the interface. Allocate softc structures, do ifmedia
* setup and ethernet/BPF attach.
*/
static void
vr_attach(device_t parent, device_t self, void *aux)
{
       struct vr_softc *sc = device_private(self);
       struct pci_attach_args *pa = (struct pci_attach_args *) aux;
       bus_dma_segment_t seg;
       uint32_t reg;
       struct ifnet *ifp;
       struct mii_data * const mii = &sc->vr_mii;
       uint8_t eaddr[ETHER_ADDR_LEN], mac;
       int i, rseg, error;
       char intrbuf[PCI_INTRSTR_LEN];

#define PCI_CONF_WRITE(r, v)    pci_conf_write(sc->vr_pc, sc->vr_tag, (r), (v))
#define PCI_CONF_READ(r)        pci_conf_read(sc->vr_pc, sc->vr_tag, (r))

       sc->vr_dev = self;
       sc->vr_pc = pa->pa_pc;
       sc->vr_tag = pa->pa_tag;
       sc->vr_id = pa->pa_id;
       callout_init(&sc->vr_tick_ch, 0);
       callout_setfunc(&sc->vr_tick_ch, vr_tick, sc);

       pci_aprint_devinfo(pa, NULL);

       /*
        * Handle power management nonsense.
        */

       sc->vr_save_iobase = PCI_CONF_READ(VR_PCI_LOIO);
       sc->vr_save_membase = PCI_CONF_READ(VR_PCI_LOMEM);
       sc->vr_save_irq = PCI_CONF_READ(PCI_INTERRUPT_REG);

       /* power up chip */
       if ((error = pci_activate(pa->pa_pc, pa->pa_tag, self,
           vr_restore_state)) && error != EOPNOTSUPP) {
               aprint_error_dev(self, "cannot activate %d\n", error);
               return;
       }

       /* Make sure bus mastering is enabled. */
       reg = PCI_CONF_READ(PCI_COMMAND_STATUS_REG);
       reg |= PCI_COMMAND_MASTER_ENABLE;
       PCI_CONF_WRITE(PCI_COMMAND_STATUS_REG, reg);

       /* Get revision */
       sc->vr_revid = PCI_REVISION(pa->pa_class);

       /*
        * Map control/status registers.
        */
       {
               bus_space_tag_t iot, memt;
               bus_space_handle_t ioh, memh;
               int ioh_valid, memh_valid;
               pci_intr_handle_t intrhandle;
               const char *intrstr;

               ioh_valid = (pci_mapreg_map(pa, VR_PCI_LOIO,
                       PCI_MAPREG_TYPE_IO, 0,
                       &iot, &ioh, NULL, NULL) == 0);
               memh_valid = (pci_mapreg_map(pa, VR_PCI_LOMEM,
                       PCI_MAPREG_TYPE_MEM |
                       PCI_MAPREG_MEM_TYPE_32BIT,
                       0, &memt, &memh, NULL, NULL) == 0);
#if defined(VR_USEIOSPACE)
               if (ioh_valid) {
                       sc->vr_bst = iot;
                       sc->vr_bsh = ioh;
               } else if (memh_valid) {
                       sc->vr_bst = memt;
                       sc->vr_bsh = memh;
               }
#else
               if (memh_valid) {
                       sc->vr_bst = memt;
                       sc->vr_bsh = memh;
               } else if (ioh_valid) {
                       sc->vr_bst = iot;
                       sc->vr_bsh = ioh;
               }
#endif
               else {
                       aprint_error_dev(self,
                           "unable to map device registers\n");
                       return;
               }

               /* Allocate interrupt */
               if (pci_intr_map(pa, &intrhandle)) {
                       aprint_error_dev(self, "couldn't map interrupt\n");
                       return;
               }
               intrstr = pci_intr_string(pa->pa_pc, intrhandle, intrbuf,
                   sizeof(intrbuf));
               sc->vr_ih = pci_intr_establish_xname(pa->pa_pc, intrhandle,
                   IPL_NET, vr_intr, sc, device_xname(self));
               if (sc->vr_ih == NULL) {
                       aprint_error_dev(self, "couldn't establish interrupt");
                       if (intrstr != NULL)
                               aprint_error(" at %s", intrstr);
                       aprint_error("\n");
                       return;
               }
               aprint_normal_dev(self, "interrupting at %s\n", intrstr);
       }

       /*
        * Windows may put the chip in suspend mode when it
        * shuts down. Be sure to kick it in the head to wake it
        * up again.
        *
        * Don't touch this register on VT3043 since it causes
        * kernel MCHK trap on macppc.
        * (Note some VT86C100A chip returns a product ID of VT3043)
        */
       if (PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_VIATECH_VT3043)
               VR_CLRBIT(sc, VR_STICKHW, (VR_STICKHW_DS0 | VR_STICKHW_DS1));

       /* Reset the adapter. */
       vr_reset(sc);

       /*
        * Get station address. The way the Rhine chips work,
        * you're not allowed to directly access the EEPROM once
        * they've been programmed a special way. Consequently,
        * we need to read the node address from the PAR registers.
        *
        * XXXSCW: On the Rhine III, setting VR_EECSR_LOAD forces a reload
        *         of the *whole* EEPROM, not just the MAC address. This is
        *         pretty pointless since the chip does this automatically
        *         at powerup/reset.
        *         I suspect the same thing applies to the other Rhine
        *         variants, but in the absence of a data sheet for those
        *         (and the lack of anyone else noticing the problems this
        *         causes) I'm going to retain the old behaviour for the
        *         other parts.
        *         In some cases, the chip really does startup without having
        *         read the EEPROM (kern/34812). To handle this case, we force
        *         a reload if we see an all-zeroes MAC address.
        */
       for (mac = 0, i = 0; i < ETHER_ADDR_LEN; i++)
               mac |= (eaddr[i] = CSR_READ_1(sc, VR_PAR0 + i));

       if (mac == 0 || (PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_VIATECH_VT6105 &&
           PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_VIATECH_VT6102)) {
               VR_SETBIT(sc, VR_EECSR, VR_EECSR_LOAD);
               DELAY(200);
               for (i = 0; i < ETHER_ADDR_LEN; i++)
                       eaddr[i] = CSR_READ_1(sc, VR_PAR0 + i);
       }

       /*
        * A Rhine chip was detected. Inform the world.
        */
       aprint_normal_dev(self, "Ethernet address %s\n", ether_sprintf(eaddr));

       memcpy(sc->vr_enaddr, eaddr, ETHER_ADDR_LEN);

       sc->vr_dmat = pa->pa_dmat;

       /*
        * Allocate the control data structures, and create and load
        * the DMA map for it.
        */
       if ((error = bus_dmamem_alloc(sc->vr_dmat,
           sizeof(struct vr_control_data), PAGE_SIZE, 0, &seg, 1, &rseg,
           0)) != 0) {
               aprint_error_dev(self,
                   "unable to allocate control data, error = %d\n", error);
               goto fail_0;
       }

       if ((error = bus_dmamem_map(sc->vr_dmat, &seg, rseg,
           sizeof(struct vr_control_data), (void **)&sc->vr_control_data,
           BUS_DMA_COHERENT)) != 0) {
               aprint_error_dev(self,
                   "unable to map control data, error = %d\n", error);
               goto fail_1;
       }

       if ((error = bus_dmamap_create(sc->vr_dmat,
           sizeof(struct vr_control_data), 1,
           sizeof(struct vr_control_data), 0, 0,
           &sc->vr_cddmamap)) != 0) {
               aprint_error_dev(self,
                   "unable to create control data DMA map, error = %d\n",
                   error);
               goto fail_2;
       }

       if ((error = bus_dmamap_load(sc->vr_dmat, sc->vr_cddmamap,
           sc->vr_control_data, sizeof(struct vr_control_data), NULL,
           0)) != 0) {
               aprint_error_dev(self,
                   "unable to load control data DMA map, error = %d\n",
                   error);
               goto fail_3;
       }

       /*
        * Create the transmit buffer DMA maps.
        */
       for (i = 0; i < VR_NTXDESC; i++) {
               if ((error = bus_dmamap_create(sc->vr_dmat, MCLBYTES,
                   1, MCLBYTES, 0, 0,
                   &VR_DSTX(sc, i)->ds_dmamap)) != 0) {
                       aprint_error_dev(self,
                           "unable to create tx DMA map %d, error = %d\n", i,
                           error);
                       goto fail_4;
               }
       }

       /*
        * Create the receive buffer DMA maps.
        */
       for (i = 0; i < VR_NRXDESC; i++) {
               if ((error = bus_dmamap_create(sc->vr_dmat, MCLBYTES, 1,
                   MCLBYTES, 0, 0,
                   &VR_DSRX(sc, i)->ds_dmamap)) != 0) {
                       aprint_error_dev(self,
                           "unable to create rx DMA map %d, error = %d\n", i,
                           error);
                       goto fail_5;
               }
               VR_DSRX(sc, i)->ds_mbuf = NULL;
       }

       ifp = &sc->vr_ec.ec_if;
       ifp->if_softc = sc;
       ifp->if_mtu = ETHERMTU;
       ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
       ifp->if_ioctl = vr_ioctl;
       ifp->if_start = vr_start;
       ifp->if_watchdog = vr_watchdog;
       ifp->if_init = vr_init;
       ifp->if_stop = vr_stop;
       IFQ_SET_READY(&ifp->if_snd);

       strlcpy(ifp->if_xname, device_xname(self), IFNAMSIZ);

       /*
        * Initialize MII/media info.
        */
       mii->mii_ifp = ifp;
       mii->mii_readreg = vr_mii_readreg;
       mii->mii_writereg = vr_mii_writereg;
       mii->mii_statchg = vr_mii_statchg;

       sc->vr_ec.ec_mii = mii;
       ifmedia_init(&mii->mii_media, IFM_IMASK, ether_mediachange,
               ether_mediastatus);
       mii_attach(self, mii, 0xffffffff, MII_PHY_ANY,
           MII_OFFSET_ANY, MIIF_FORCEANEG);
       if (LIST_FIRST(&sc->vr_mii.mii_phys) == NULL) {
               ifmedia_add(&mii->mii_media, IFM_ETHER | IFM_NONE, 0, NULL);
               ifmedia_set(&mii->mii_media, IFM_ETHER | IFM_NONE);
       } else
               ifmedia_set(&mii->mii_media, IFM_ETHER | IFM_AUTO);

       sc->vr_ec.ec_capabilities |= ETHERCAP_VLAN_MTU;

       /*
        * Call MI attach routines.
        */
       if_attach(ifp);
       if_deferred_start_init(ifp, NULL);
       ether_ifattach(ifp, sc->vr_enaddr);

       rnd_attach_source(&sc->rnd_source, device_xname(self),
           RND_TYPE_NET, RND_FLAG_DEFAULT);

       if (pmf_device_register1(self, NULL, vr_resume, vr_shutdown))
               pmf_class_network_register(self, ifp);
       else
               aprint_error_dev(self, "couldn't establish power handler\n");

       return;

fail_5:
       for (i = 0; i < VR_NRXDESC; i++) {
               if (sc->vr_rxsoft[i].ds_dmamap != NULL)
                       bus_dmamap_destroy(sc->vr_dmat,
                           sc->vr_rxsoft[i].ds_dmamap);
       }
fail_4:
       for (i = 0; i < VR_NTXDESC; i++) {
               if (sc->vr_txsoft[i].ds_dmamap != NULL)
                       bus_dmamap_destroy(sc->vr_dmat,
                           sc->vr_txsoft[i].ds_dmamap);
       }
       bus_dmamap_unload(sc->vr_dmat, sc->vr_cddmamap);
fail_3:
       bus_dmamap_destroy(sc->vr_dmat, sc->vr_cddmamap);
fail_2:
       bus_dmamem_unmap(sc->vr_dmat, (void *)sc->vr_control_data,
           sizeof(struct vr_control_data));
fail_1:
       bus_dmamem_free(sc->vr_dmat, &seg, rseg);
fail_0:
       return;
}

static int
vr_restore_state(pci_chipset_tag_t pc, pcitag_t tag, device_t self,
   pcireg_t state)
{
       struct vr_softc *sc = device_private(self);
       int error;

       if (state == PCI_PMCSR_STATE_D0)
               return 0;
       if ((error = pci_set_powerstate(pc, tag, PCI_PMCSR_STATE_D0)))
               return error;

       /* Restore PCI config data. */
       PCI_CONF_WRITE(VR_PCI_LOIO, sc->vr_save_iobase);
       PCI_CONF_WRITE(VR_PCI_LOMEM, sc->vr_save_membase);
       PCI_CONF_WRITE(PCI_INTERRUPT_REG, sc->vr_save_irq);
       return 0;
}

static bool
vr_resume(device_t self, const pmf_qual_t *qual)
{
       struct vr_softc *sc = device_private(self);

       if (PCI_PRODUCT(sc->vr_id) != PCI_PRODUCT_VIATECH_VT3043)
               VR_CLRBIT(sc, VR_STICKHW, (VR_STICKHW_DS0 | VR_STICKHW_DS1));

       return true;
}