In ascpoll, return revents, not 0.

[FreeBSD/FreeBSD.git] / sys / i386 / isa / if_wl.c

/* $FreeBSD$ */
/* 
 * 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 all copyright 
 *    notices, this list of conditions and the following disclaimer.
 * 2. The names of the authors may not be used to endorse or promote products
 *    derived from this software withough specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``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 AUTHORS 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.
 * 
 */
/*
 * if_wl.c - original MACH, then BSDI ISA wavelan driver
 *      ported to mach by Anders Klemets
 *      to BSDI by Robert Morris
 *      to FreeBSD by Jim Binkley
 *      to FreeBSD 2.2+ by Michael Smith
 *
 * 2.2 update:
 * Changed interface to match 2.1-2.2 differences.
 * Implement IRQ selection logic in wlprobe()
 * Implement PSA updating.
 * Pruned heading comments for relevance.
 * Ripped out all the 'interface counters' cruft.
 * Cut the missing-interrupt timer back to 100ms.
 * 2.2.1 update:
 * now supports all multicast mode (mrouted will work),
 *      but unfortunately must do that by going into promiscuous mode
 * NWID sysctl added so that normally promiscuous mode is NWID-specific
 *      but can be made NWID-inspecific
 *                      7/14/97 jrb
 *
 * Work done:
 * Ported to FreeBSD, got promiscuous mode working with bpfs,
 * and rewired timer routine.  The i82586 will hang occasionally on output 
 * and the watchdog timer will kick it if so and log an entry.
 * 2 second timeout there.  Apparently the chip loses an interrupt.
 * Code borrowed from if_ie.c for watchdog timer.
 *
 * The wavelan card is a 2mbit radio modem that emulates ethernet;
 * i.e., it uses MAC addresses.  This should not be a surprise since
 * it uses an ethernet controller as a major hw item.
 * It can broadcast, unicast or apparently multicast in a base cell 
 * using a omni-directional antennae that is 
 * about 800 feet around the base cell barring walls and metal.  
 * With directional antennae, it can be used point to point over a mile
 * or so apparently (haven't tried that).
 *
 * There are ISA and pcmcia versions (not supported by this code).
 * The ISA card has an Intel 82586 lan controller on it.  It consists
 * of 2 pieces of hw, the lan controller (intel) and a radio-modem.
 * The latter has an extra set of controller registers that has nothing
 * to do with the i82586 and allows setting and monitoring of radio
 * signal strength, etc.  There is a nvram area called the PSA that
 * contains a number of setup variables including the IRQ and so-called
 * NWID or Network ID.  The NWID must be set the same for all radio
 * cards to communicate (unless you are using the ATT/NCR roaming feature
 * with their access points.  There is no support for that here. Roaming
 * involves a link-layer beacon sent out from the access points.  End
 * stations monitor the signal strength and only use the strongest
 * access point).  This driver assumes that the base ISA port, IRQ, 
 * and NWID are first set in nvram via the dos-side "instconf.exe" utility 
 * supplied with the card. This driver takes the ISA port from 
 * the kernel configuration setup, and then determines the IRQ either 
 * from the kernel config (if an explicit IRQ is set) or from the 
 * PSA on the card if not.
 * The hw also magically just uses the IRQ set in the nvram.
 * The NWID is used magically as well by the radio-modem
 * to determine which packets to keep or throw out.  
 *
 * sample config:
 *
 * device wl0 at isa? port 0x300 net irq ?
 *
 * Ifdefs:
 * 1. WLDEBUG. (off) - if turned on enables IFF_DEBUG set via ifconfig debug
 * 2. MULTICAST (on) - turned on and works up to and including mrouted
 * 3. WLCACHE (off) -  define to turn on a signal strength 
 * (and other metric) cache that is indexed by sender MAC address.  
 * Apps can read this out to learn the remote signal strength of a 
 * sender.  Note that it has a switch so that it only stores 
 * broadcast/multicast senders but it could be set to store unicast 
 * too only.  Size is hardwired in if_wl_wavelan.h
 *
 * one further note: promiscuous mode is a curious thing.  In this driver,
 * promiscuous mode apparently CAN catch ALL packets and ignore the NWID
 * setting.  This is probably more useful in a sense (for snoopers) if
 * you are interested in all traffic as opposed to if you are interested
 * in just your own.  There is a driver specific sysctl to turn promiscuous
 * from just promiscuous to wildly promiscuous...
 *
 * This driver also knows how to load the synthesizers in the 2.4 Gz
 * ISA Half-card, Product number 847647476 (USA/FCC IEEE Channel set).
 * This product consists of a "mothercard" that contains the 82586,
 * NVRAM that holds the PSA, and the ISA-buss interface custom ASIC. 
 * The radio transceiver is a "daughtercard" called the WaveMODEM which
 * connects to the mothercard through two single-inline connectors: a
 * 20-pin connector provides DC-power and modem signals, and a 3-pin
 * connector which exports the antenna connection. The code herein
 * loads the receive and transmit synthesizers and the corresponding
 * transmitter output power value from an EEPROM controlled through
 * additional registers via the MMC. The EEPROM address selected
 * are those whose values are preset by the DOS utility programs
 * provided with the product, and this provides compatible operation
 * with the DOS Packet Driver software. A future modification will
 * add the necessary functionality to this driver and to the wlconfig
 * utility to completely replace the DOS Configuration Utilities.
 * The 2.4 Gz WaveMODEM is described in document number 407-024692/E,
 * and is available through Lucent Technologies OEM supply channels.
 * --RAB 1997/06/08.
 */

#define MULTICAST  1

/* 
 *      Olivetti PC586 Mach Ethernet driver v1.0
 *      Copyright Ing. C. Olivetti & C. S.p.A. 1988, 1989
 *      All rights reserved.
 *
 */ 

/*
  Copyright 1988, 1989 by Olivetti Advanced Technology Center, Inc.,
Cupertino, California.

                All Rights Reserved

  Permission to use, copy, modify, and distribute this software and
its documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appears in all
copies and that both the copyright notice and this permission notice
appear in supporting documentation, and that the name of Olivetti
not be used in advertising or publicity pertaining to distribution
of the software without specific, written prior permission.

  OLIVETTI DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
IN NO EVENT SHALL OLIVETTI BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUR OF OR IN CONNECTION
WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

/*
  Copyright 1988, 1989 by Intel Corporation, Santa Clara, California.

                All Rights Reserved

Permission to use, copy, modify, and distribute this software and
its documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appears in all
copies and that both the copyright notice and this permission notice
appear in supporting documentation, and that the name of Intel
not be used in advertising or publicity pertaining to distribution
of the software without specific, written prior permission.

INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

/*
 * NOTE:
 *              by rvb:
 *  1.  The best book on the 82586 is:
 *              LAN Components User's Manual by Intel
 *      The copy I found was dated 1984.  This really tells you
 *      what the state machines are doing
 *  2.  In the current design, we only do one write at a time,
 *      though the hardware is capable of chaining and possibly
 *      even batching.  The problem is that we only make one
 *      transmit buffer available in sram space.
 */

#include "wl.h"
#include "opt_wavelan.h"
#include "opt_inet.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/bus.h>

#include <sys/sysctl.h>

#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_dl.h>

#ifdef INET
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/if_ether.h>
#endif

#include <net/bpf.h>


#include <i386/isa/isa_device.h>

#include <i386/isa/ic/if_wl_i82586.h>   /* Definitions for the Intel chip */

/* was 1000 in original, fed to DELAY(x) */
#define DELAYCONST      1000
#include <i386/isa/if_wl.h>
#include <machine/if_wl_wavelan.h>

#ifndef COMPAT_OLDISA
#error "The wl device requires the old isa compatibility shims"
#endif

static char     t_packet[ETHERMTU + sizeof(struct ether_header) + sizeof(long)];

struct wl_softc{ 
    struct      arpcom  wl_ac;                  /* Ethernet common part */
#define wl_if   wl_ac.ac_if                     /* network visible interface */
#define wl_addr wl_ac.ac_enaddr                 /* hardware address */
    u_char      psa[0x40];
    u_char      nwid[2];        /* current radio modem nwid */
    short       base;
    short       unit;
    int         flags;
    int         tbusy;          /* flag to determine if xmit is busy */
    u_short     begin_fd;
    u_short     end_fd;
    u_short     end_rbd;
    u_short     hacr;           /* latest host adapter CR command */
    short       mode;
    u_char      chan24;         /* 2.4 Gz: channel number/EEPROM Area # */
    u_short     freq24;         /* 2.4 Gz: resulting frequency  */
    struct      callout_handle watchdog_ch;
#ifdef WLCACHE
    int         w_sigitems;     /* number of cached entries */
    /*  array of cache entries */
    struct w_sigcache w_sigcache[ MAXCACHEITEMS ];            
    int w_nextcache;            /* next free cache entry */    
    int w_wrapindex;            /* next "free" cache entry */
#endif
};
static struct wl_softc wl_softc[NWL];

#define WLSOFTC(unit) ((struct wl_softc *)(&wl_softc[unit]))

static int      wlprobe(struct isa_device *);
static int      wlattach(struct isa_device *);

struct isa_driver wldriver = {
        INTR_TYPE_NET,
        wlprobe,
        wlattach,
        "wl",
        0
};
COMPAT_ISA_DRIVER(wl, wldriver);

/*
 * XXX  The Wavelan appears to be prone to dropping stuff if you talk to
 * it too fast.  This disgusting hack inserts a delay after each packet
 * is queued which helps avoid this behaviour on fast systems.
 */
static int      wl_xmit_delay = 250;
SYSCTL_INT(_machdep, OID_AUTO, wl_xmit_delay, CTLFLAG_RW, &wl_xmit_delay, 0, "");

/* 
 * not XXX, but ZZZ (bizarre).
 * promiscuous mode can be toggled to ignore NWIDs.  By default,
 * it does not.  Caution should be exercised about combining
 * this mode with IFF_ALLMULTI which puts this driver in
 * promiscuous mode.
 */
static int      wl_ignore_nwid = 0;
SYSCTL_INT(_machdep, OID_AUTO, wl_ignore_nwid, CTLFLAG_RW, &wl_ignore_nwid, 0, "");

/*
 * Emit diagnostics about transmission problems
 */
static int      xmt_watch = 0;
SYSCTL_INT(_machdep, OID_AUTO, wl_xmit_watch, CTLFLAG_RW, &xmt_watch, 0, "");

/*
 * Collect SNR statistics
 */
static int      gathersnr = 0;
SYSCTL_INT(_machdep, OID_AUTO, wl_gather_snr, CTLFLAG_RW, &gathersnr, 0, "");

static void     wlstart(struct ifnet *ifp);
static void     wlinit(void *xsc);
static int      wlioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
static timeout_t wlwatchdog;
static ointhand2_t wlintr;
static void     wlxmt(int unt, struct mbuf *m);
static int      wldiag(int unt); 
static int      wlconfig(int unit); 
static int      wlcmd(int unit, char *str);
static void     wlmmcstat(int unit);
static u_short  wlbldru(int unit);
static u_short  wlmmcread(u_int base, u_short reg);
static void     wlinitmmc(int unit);
static int      wlhwrst(int unit);
static void     wlrustrt(int unit);
static void     wlbldcu(int unit);
static int      wlack(int unit);
static int      wlread(int unit, u_short fd_p);
static void     getsnr(int unit);
static void     wlrcv(int unit);
static int      wlrequeue(int unit, u_short fd_p);
static void     wlsftwsleaze(u_short *countp, u_char **mb_pp, struct mbuf **tm_pp, int unit);
static void     wlhdwsleaze(u_short *countp, u_char **mb_pp, struct mbuf **tm_pp, int unit);
static void     wltbd(int unit);
static void     wlgetpsa(int base, u_char *buf);
static void     wlsetpsa(int unit);
static u_short  wlpsacrc(u_char *buf);
static void     wldump(int unit);
#ifdef WLCACHE
static void     wl_cache_store(int, int, struct ether_header *, struct mbuf *);
static void     wl_cache_zero(int unit);
#endif
#ifdef MULTICAST
# if defined(__FreeBSD__) && __FreeBSD_version < 300000
static int      check_allmulti(int unit);
# endif
#endif

/* array for maping irq numbers to values for the irq parameter register */
static int irqvals[16] = { 
    0, 0, 0, 0x01, 0x02, 0x04, 0, 0x08, 0, 0, 0x10, 0x20, 0x40, 0, 0, 0x80 
};
/* mask of valid IRQs */
#define WL_IRQS (IRQ3|IRQ4|IRQ5|IRQ7|IRQ10|IRQ11|IRQ12|IRQ15)

/*
 * wlprobe:
 *
 *      This function "probes" or checks for the WaveLAN board on the bus to
 *      see if it is there.  As far as I can tell, the best break between this
 *      routine and the attach code is to simply determine whether the board
 *      is configured in properly.  Currently my approach to this is to write
 *      and read a word from the SRAM on the board being probed.  If the word
 *      comes back properly then we assume the board is there.  The config
 *      code expects to see a successful return from the probe routine before
 *      attach will be called.
 *
 * input        : address device is mapped to, and unit # being checked
 * output       : a '1' is returned if the board exists, and a 0 otherwise
 *
 */
static int
wlprobe(struct isa_device *id)
{
    struct wl_softc     *sc = &wl_softc[id->id_unit];   
    register short      base = id->id_iobase;
    char                *str = "wl%d: board out of range [0..%d]\n";
    u_char              inbuf[100];
    unsigned long       oldpri;
    int                 irq;

    /* TBD. not true.
     * regular CMD() will not work, since no softc yet 
     */
#define PCMD(base, hacr) outw((base), (hacr))

    oldpri = splimp();
    PCMD(base, HACR_RESET);                     /* reset the board */
    DELAY(DELAYCONST);                          /* >> 4 clocks at 6MHz */
    PCMD(base, HACR_RESET);                     /* reset the board */
    DELAY(DELAYCONST);                          /* >> 4 clocks at 6MHz */
    splx(oldpri);

    /* clear reset command and set PIO#1 in autoincrement mode */
    PCMD(base, HACR_DEFAULT);
    PCMD(base, HACR_DEFAULT);
    outw(PIOR1(base), 0);                       /* go to beginning of RAM */
    outsw(PIOP1(base), str, strlen(str)/2+1);   /* write string */
    
    outw(PIOR1(base), 0);                       /* rewind */
    insw(PIOP1(base), inbuf, strlen(str)/2+1);  /* read result */
    
    if (bcmp(str, inbuf, strlen(str)))
        return(0);

    sc->chan24 = 0;                             /* 2.4 Gz: config channel */
    sc->freq24 = 0;                             /* 2.4 Gz: frequency    */

    /* read the PSA from the board into temporary storage */
    wlgetpsa(base, inbuf);
    
    /* We read the IRQ value from the PSA on the board. */
    for (irq = 15; irq >= 0; irq--)
        if (irqvals[irq] == inbuf[WLPSA_IRQNO])
            break;
    if ((irq == 0) || (irqvals[irq] == 0)){
        printf("wl%d: PSA corrupt (invalid IRQ value)\n", id->id_unit);
        id->id_irq = 0;                         /* no interrupt */
    } else {
        /*
         * If the IRQ requested by the PSA is already claimed by another
         * device, the board won't work, but the user can still access the
         * driver to change the IRQ.
         */
        id->id_irq = (1<<irq);                  /* use IRQ from PSA */
    }
    return(16);
}


/*
 * wlattach:
 *
 *      This function attaches a WaveLAN board to the "system".  The rest of
 *      runtime structures are initialized here (this routine is called after
 *      a successful probe of the board).  Once the ethernet address is read
 *      and stored, the board's ifnet structure is attached and readied.
 *
 * input        : isa_dev structure setup in autoconfig
 * output       : board structs and ifnet is setup
 *
 */
static int
wlattach(struct isa_device *id)
{
    struct wl_softc     *sc = (struct wl_softc *) &wl_softc[id->id_unit];
    register short      base = id->id_iobase;
    int                 i,j;
    u_char              unit = id->id_unit;
    register struct ifnet       *ifp = &sc->wl_if;

#ifdef WLDEBUG
    printf("wlattach: base %x, unit %d\n", base, unit);
#endif
    id->id_ointr = wlintr;
    sc->base = base;
    sc->unit = unit;
    sc->flags = 0;
    sc->mode = 0;
    sc->hacr = HACR_RESET;
    callout_handle_init(&sc->watchdog_ch);
    CMD(unit);                          /* reset the board */
    DELAY(DELAYCONST);                  /* >> 4 clocks at 6MHz */
        
    /* clear reset command and set PIO#2 in parameter access mode */
    sc->hacr = (HACR_DEFAULT & ~HACR_16BITS);
    CMD(unit);

    /* Read the PSA from the board for our later reference */
    wlgetpsa(base, sc->psa);

    /* fetch NWID */
    sc->nwid[0] = sc->psa[WLPSA_NWID];
    sc->nwid[1] = sc->psa[WLPSA_NWID+1];
    
    /* fetch MAC address - decide which one first */
    if (sc->psa[WLPSA_MACSEL] & 1) {
        j = WLPSA_LOCALMAC;
    } else {
        j = WLPSA_UNIMAC;
    }
    for(i=0; i < WAVELAN_ADDR_SIZE; ++i) {
        sc->wl_addr[i] = sc->psa[j + i];
    }

    /* enter normal 16 bit mode operation */
    sc->hacr = HACR_DEFAULT;
    CMD(unit);

    wlinitmmc(unit);
    outw(PIOR1(base), OFFSET_SCB + 8);  /* address of scb_crcerrs */
    outw(PIOP1(base), 0);                       /* clear scb_crcerrs */
    outw(PIOP1(base), 0);                       /* clear scb_alnerrs */
    outw(PIOP1(base), 0);                       /* clear scb_rscerrs */
    outw(PIOP1(base), 0);                       /* clear scb_ovrnerrs */

    bzero(ifp, sizeof(ifp));
    ifp->if_softc = sc;
    ifp->if_unit = id->id_unit;
    ifp->if_mtu = WAVELAN_MTU;
    ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX;
#ifdef    WLDEBUG
    ifp->if_flags |= IFF_DEBUG;
#endif
#if     MULTICAST
    ifp->if_flags |= IFF_MULTICAST;
#endif  /* MULTICAST */
    ifp->if_name = "wl";
    ifp->if_unit = unit;
    ifp->if_init = wlinit;
    ifp->if_output = ether_output;
    ifp->if_start = wlstart;
    ifp->if_ioctl = wlioctl;
    ifp->if_timer = 0;   /* paranoia */
    /* no entries
       ifp->if_watchdog
       ifp->if_done
       ifp->if_reset
       */
    ether_ifattach(ifp, ETHER_BPF_SUPPORTED);

    bcopy(&sc->wl_addr[0], sc->wl_ac.ac_enaddr, WAVELAN_ADDR_SIZE);
    printf("%s%d: address %6D, NWID 0x%02x%02x", ifp->if_name, ifp->if_unit,
           sc->wl_ac.ac_enaddr, ":", sc->nwid[0], sc->nwid[1]);
    if (sc->freq24) 
        printf(", Freq %d MHz",sc->freq24);             /* 2.4 Gz       */
    printf("\n");                                       /* 2.4 Gz       */


    if (bootverbose)
        wldump(unit);
    return(1);
}

/*
 * Print out interesting information about the 82596.
 */
static void
wldump(int unit)
{
    register struct wl_softc *sp = WLSOFTC(unit);
    int         base = sp->base;
    int         i;
        
    printf("hasr %04x\n", inw(HASR(base)));
        
    printf("scb at %04x:\n ", OFFSET_SCB);
    outw(PIOR1(base), OFFSET_SCB);
    for(i = 0; i < 8; i++)
        printf("%04x ", inw(PIOP1(base)));
    printf("\n");
        
    printf("cu at %04x:\n ", OFFSET_CU);
    outw(PIOR1(base), OFFSET_CU);
    for(i = 0; i < 8; i++)
        printf("%04x ", inw(PIOP1(base)));
    printf("\n");
        
    printf("tbd at %04x:\n ", OFFSET_TBD);
    outw(PIOR1(base), OFFSET_TBD);
    for(i = 0; i < 4; i++)
        printf("%04x ", inw(PIOP1(base)));
    printf("\n");
}

/* Initialize the Modem Management Controller */
static void
wlinitmmc(int unit)
{
    register struct wl_softc *sp = WLSOFTC(unit);
    int         base = sp->base;
    int         configured;
    int         mode = sp->mode;
    int         i;                              /* 2.4 Gz               */
        
    /* enter 8 bit operation */
    sp->hacr = (HACR_DEFAULT & ~HACR_16BITS);
    CMD(unit);

    configured = sp->psa[WLPSA_CONFIGURED] & 1;
        
    /*
     * Set default modem control parameters.  Taken from NCR document
     *  407-0024326 Rev. A 
     */
    MMC_WRITE(MMC_JABBER_ENABLE, 0x01);
    MMC_WRITE(MMC_ANTEN_SEL, 0x02);
    MMC_WRITE(MMC_IFS, 0x20);
    MMC_WRITE(MMC_MOD_DELAY, 0x04);
    MMC_WRITE(MMC_JAM_TIME, 0x38);
    MMC_WRITE(MMC_DECAY_PRM, 0x00);             /* obsolete ? */
    MMC_WRITE(MMC_DECAY_UPDAT_PRM, 0x00);
    if (!configured) {
        MMC_WRITE(MMC_LOOPT_SEL, 0x00);
        if (sp->psa[WLPSA_COMPATNO] & 1) {
            MMC_WRITE(MMC_THR_PRE_SET, 0x01);   /* 0x04 for AT and 0x01 for MCA */
        } else {
            MMC_WRITE(MMC_THR_PRE_SET, 0x04);   /* 0x04 for AT and 0x01 for MCA */
        }
        MMC_WRITE(MMC_QUALITY_THR, 0x03);
    } else {
        /* use configuration defaults from parameter storage area */
        if (sp->psa[WLPSA_NWIDENABLE] & 1) {
            if ((mode & (MOD_PROM | MOD_ENAL)) && wl_ignore_nwid) {
                MMC_WRITE(MMC_LOOPT_SEL, 0x40);
            } else {
                MMC_WRITE(MMC_LOOPT_SEL, 0x00);
            }
        } else {
            MMC_WRITE(MMC_LOOPT_SEL, 0x40);     /* disable network id check */
        }
        MMC_WRITE(MMC_THR_PRE_SET, sp->psa[WLPSA_THRESH]);
        MMC_WRITE(MMC_QUALITY_THR, sp->psa[WLPSA_QUALTHRESH]);
    }
    MMC_WRITE(MMC_FREEZE, 0x00);
    MMC_WRITE(MMC_ENCR_ENABLE, 0x00);

    MMC_WRITE(MMC_NETW_ID_L,sp->nwid[1]);       /* set NWID */
    MMC_WRITE(MMC_NETW_ID_H,sp->nwid[0]);

    /* enter normal 16 bit mode operation */
    sp->hacr = HACR_DEFAULT;
    CMD(unit);
    CMD(unit);                                  /* virtualpc1 needs this! */

    if (sp->psa[WLPSA_COMPATNO]==               /* 2.4 Gz: half-card ver     */
                WLPSA_COMPATNO_WL24B) {         /* 2.4 Gz                    */
        i=sp->chan24<<4;                        /* 2.4 Gz: position ch #     */
        MMC_WRITE(MMC_EEADDR,i+0x0f);           /* 2.4 Gz: named ch, wc=16   */
        MMC_WRITE(MMC_EECTRL,MMC_EECTRL_DWLD+   /* 2.4 Gz: Download Synths   */
                        MMC_EECTRL_EEOP_READ);  /* 2.4 Gz: Read EEPROM       */
        for (i=0; i<1000; ++i) {                /* 2.4 Gz: wait for download */
            DELAY(40);                          /* 2.4 Gz             */
            if ((wlmmcread(base,MMC_EECTRLstat) /* 2.4 Gz: check DWLD and    */
                &(MMC_EECTRLstat_DWLD           /* 2.4 Gz:       EEBUSY      */
                 +MMC_EECTRLstat_EEBUSY))==0)   /* 2.4 Gz:                   */
                break;                          /* 2.4 Gz: download finished */
        }                                       /* 2.4 Gz                    */
        if (i==1000) printf("wl: synth load failed\n"); /* 2.4 Gz       */
        MMC_WRITE(MMC_EEADDR,0x61);             /* 2.4 Gz: default pwr, wc=2 */
        MMC_WRITE(MMC_EECTRL,MMC_EECTRL_DWLD+   /* 2.4 Gz: Download Xmit Pwr */
                        MMC_EECTRL_EEOP_READ);  /* 2.4 Gz: Read EEPROM       */
        for (i=0; i<1000; ++i) {                /* 2.4 Gz: wait for download */
            DELAY(40);                          /* 2.4 Gz             */
            if ((wlmmcread(base,MMC_EECTRLstat) /* 2.4 Gz: check DWLD and    */
                &(MMC_EECTRLstat_DWLD           /* 2.4 Gz:       EEBUSY      */
                 +MMC_EECTRLstat_EEBUSY))==0)   /* 2.4 Gz:                   */
                break;                          /* 2.4 Gz: download finished */
        }                                       /* 2.4 Gz                    */
        if (i==1000) printf("wl: xmit pwr load failed\n"); /* 2.4 Gz         */
        MMC_WRITE(MMC_ANALCTRL,                 /* 2.4 Gz: EXT ant+polarity  */
                        MMC_ANALCTRL_ANTPOL +   /* 2.4 Gz:                   */
                        MMC_ANALCTRL_EXTANT);   /* 2.4 Gz:                   */
        i=sp->chan24<<4;                        /* 2.4 Gz: position ch #     */
        MMC_WRITE(MMC_EEADDR,i);                /* 2.4 Gz: get frequency     */
        MMC_WRITE(MMC_EECTRL,                   /* 2.4 Gz: EEPROM read      */
                        MMC_EECTRL_EEOP_READ);  /* 2.4 Gz:                  */
        DELAY(40);                              /* 2.4 Gz                    */
        i = wlmmcread(base,MMC_EEDATALrv)       /* 2.4 Gz: freq val          */
          + (wlmmcread(base,MMC_EEDATAHrv)<<8); /* 2.4 Gz                    */
        sp->freq24 = (i>>6)+2400;               /* 2.4 Gz: save real freq    */
    }
}

/*
 * wlinit:
 *
 *      Another routine that interfaces the "if" layer to this driver.  
 *      Simply resets the structures that are used by "upper layers".  
 *      As well as calling wlhwrst that does reset the WaveLAN board.
 *
 * input        : softc pointer for this interface
 * output       : structures (if structs) and board are reset
 *
 */     
static void
wlinit(void *xsc)
{
    register struct wl_softc *sc = xsc;
    struct ifnet        *ifp = &sc->wl_if;
    int                 stat;
    u_long              oldpri;

#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        printf("wl%d: entered wlinit()\n",sc->unit);
#endif
#if defined(__FreeBSD__) && __FreeBSD_version >= 300000
    if (TAILQ_FIRST(&ifp->if_addrhead) == (struct ifaddr *)0) {
#else
    if (ifp->if_addrlist == (struct ifaddr *)0) {
#endif
        return;
    }
    oldpri = splimp();
    if ((stat = wlhwrst(sc->unit)) == TRUE) {
        sc->wl_if.if_flags |= IFF_RUNNING;   /* same as DSF_RUNNING */
        /* 
         * OACTIVE is used by upper-level routines
         * and must be set
         */
        sc->wl_if.if_flags &= ~IFF_OACTIVE;  /* same as tbusy below */
                
        sc->flags |= DSF_RUNNING;
        sc->tbusy = 0;
        untimeout(wlwatchdog, sc, sc->watchdog_ch);
                
        wlstart(ifp);
    } else {
        printf("wl%d init(): trouble resetting board.\n", sc->unit);
    }
    splx(oldpri);
}

/*
 * wlhwrst:
 *
 *      This routine resets the WaveLAN board that corresponds to the 
 *      board number passed in.
 *
 * input        : board number to do a hardware reset
 * output       : board is reset
 *
 */
static int
wlhwrst(int unit)
{
    register struct wl_softc    *sc = WLSOFTC(unit);

#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        printf("wl%d: entered wlhwrst()\n",unit);
#endif
    sc->hacr = HACR_RESET;
    CMD(unit);                  /* reset the board */
        
    /* clear reset command and set PIO#1 in autoincrement mode */
    sc->hacr = HACR_DEFAULT;
    CMD(unit);

#ifdef  WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        wlmmcstat(unit);        /* Display MMC registers */
#endif  /* WLDEBUG */
    wlbldcu(unit);              /* set up command unit structures */
    
    if (wldiag(unit) == 0)
        return(0);
    
    if (wlconfig(unit) == 0)
            return(0);
    /* 
     * insert code for loopback test here
     */
    wlrustrt(unit);             /* start receive unit */

    /* enable interrupts */
    sc->hacr = (HACR_DEFAULT | HACR_INTRON);
    CMD(unit);
    
    return(1);
}

/*
 * wlbldcu:
 *
 *      This function builds up the command unit structures.  It inits
 *      the scp, iscp, scb, cb, tbd, and tbuf.
 *
 */
static void
wlbldcu(int unit)
{
    register struct wl_softc *sc = WLSOFTC(unit);
    short               base = sc->base;
    scp_t               scp;
    iscp_t              iscp;
    scb_t               scb;
    ac_t                cb;
    tbd_t               tbd;
    int         i;

    bzero(&scp, sizeof(scp));
    scp.scp_sysbus = 0;
    scp.scp_iscp = OFFSET_ISCP;
    scp.scp_iscp_base = 0;
    outw(PIOR1(base), OFFSET_SCP);
    outsw(PIOP1(base), &scp, sizeof(scp_t)/2);

    bzero(&iscp, sizeof(iscp));
    iscp.iscp_busy = 1;
    iscp.iscp_scb_offset = OFFSET_SCB;
    iscp.iscp_scb = 0;
    iscp.iscp_scb_base = 0;
    outw(PIOR1(base), OFFSET_ISCP);
    outsw(PIOP1(base), &iscp, sizeof(iscp_t)/2);

    scb.scb_status = 0;
    scb.scb_command = SCB_RESET;
    scb.scb_cbl_offset = OFFSET_CU;
    scb.scb_rfa_offset = OFFSET_RU;
    scb.scb_crcerrs = 0;
    scb.scb_alnerrs = 0;
    scb.scb_rscerrs = 0;
    scb.scb_ovrnerrs = 0;
    outw(PIOR1(base), OFFSET_SCB);
    outsw(PIOP1(base), &scb, sizeof(scb_t)/2);

    SET_CHAN_ATTN(unit);

    outw(PIOR0(base), OFFSET_ISCP + 0); /* address of iscp_busy */
    for (i = 1000000; inw(PIOP0(base)) && (i-- > 0); );
    if (i <= 0) printf("wl%d bldcu(): iscp_busy timeout.\n", unit);
    outw(PIOR0(base), OFFSET_SCB + 0);  /* address of scb_status */
    for (i = STATUS_TRIES; i-- > 0; ) {
        if (inw(PIOP0(base)) == (SCB_SW_CX|SCB_SW_CNA)) 
            break;
    }
    if (i <= 0)
        printf("wl%d bldcu(): not ready after reset.\n", unit);
    wlack(unit);

    cb.ac_status = 0;
    cb.ac_command = AC_CW_EL;           /* NOP */
    cb.ac_link_offset = OFFSET_CU;
    outw(PIOR1(base), OFFSET_CU);
    outsw(PIOP1(base), &cb, 6/2);

    tbd.act_count = 0;
    tbd.next_tbd_offset = I82586NULL;
    tbd.buffer_addr = 0;
    tbd.buffer_base = 0;
    outw(PIOR1(base), OFFSET_TBD);
    outsw(PIOP1(base), &tbd, sizeof(tbd_t)/2);
}

/*
 * wlstart:
 *
 *      send a packet
 *
 * input        : board number
 * output       : stuff sent to board if any there
 *
 */
static void
wlstart(struct ifnet *ifp)
{
    int                         unit = ifp->if_unit;
    struct mbuf                 *m;
    register struct wl_softc    *sc = WLSOFTC(unit);
    short                       base = sc->base;
    int                         scb_status, cu_status, scb_command;

#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        printf("wl%d: entered wlstart()\n",unit);
#endif

    outw(PIOR1(base), OFFSET_CU);
    cu_status = inw(PIOP1(base));
    outw(PIOR0(base),OFFSET_SCB + 0);   /* scb_status */
    scb_status = inw(PIOP0(base));
    outw(PIOR0(base), OFFSET_SCB + 2);
    scb_command = inw(PIOP0(base));

    /*
     * don't need OACTIVE check as tbusy here checks to see
     * if we are already busy 
     */
    if (sc->tbusy) {
        if((scb_status & 0x0700) == SCB_CUS_IDLE &&
           (cu_status & AC_SW_B) == 0){
            sc->tbusy = 0;
            untimeout(wlwatchdog, sc, sc->watchdog_ch);
            sc->wl_ac.ac_if.if_flags &= ~IFF_OACTIVE;
            /*
             * This is probably just a race.  The xmt'r is just
             * became idle but WE have masked interrupts so ...
             */
#ifdef WLDEBUG
            printf("wl%d: CU idle, scb %04x %04x cu %04x\n",
                   unit, scb_status, scb_command, cu_status);
#endif 
            if (xmt_watch) printf("!!");
        } else {
            return;     /* genuinely still busy */
        }
    } else if((scb_status & 0x0700) == SCB_CUS_ACTV ||
              (cu_status & AC_SW_B)){
#ifdef WLDEBUG
        printf("wl%d: CU unexpectedly busy; scb %04x cu %04x\n",
               unit, scb_status, cu_status);
#endif
        if (xmt_watch) printf("wl%d: busy?!",unit);
        return;         /* hey, why are we busy? */
    }

    /* get ourselves some data */
    ifp = &(sc->wl_if);
    IF_DEQUEUE(&ifp->if_snd, m);
    if (m != (struct mbuf *)0) {
        /* let BPF see it before we commit it */
        if (ifp->if_bpf) {
            bpf_mtap(ifp, m);
        }
        sc->tbusy++;
        /* set the watchdog timer so that if the board
         * fails to interrupt we will restart
         */
        /* try 10 ticks, not very long */
        sc->watchdog_ch = timeout(wlwatchdog, sc, 10);
        sc->wl_ac.ac_if.if_flags |= IFF_OACTIVE;
        sc->wl_if.if_opackets++;
        wlxmt(unit, m);
    } else {
        sc->wl_ac.ac_if.if_flags &= ~IFF_OACTIVE;
    }
    return;
}

/*
 * wlread:
 *
 *      This routine does the actual copy of data (including ethernet header
 *      structure) from the WaveLAN to an mbuf chain that will be passed up
 *      to the "if" (network interface) layer.  NOTE:  we currently
 *      don't handle trailer protocols, so if that is needed, it will
 *      (at least in part) be added here.  For simplicities sake, this
 *      routine copies the receive buffers from the board into a local (stack)
 *      buffer until the frame has been copied from the board.  Once in
 *      the local buffer, the contents are copied to an mbuf chain that
 *      is then enqueued onto the appropriate "if" queue.
 *
 * input        : board number, and an frame descriptor address
 * output       : the packet is put into an mbuf chain, and passed up
 * assumes      : if any errors occur, packet is "dropped on the floor"
 *
 */
static int
wlread(int unit, u_short fd_p)
{
    register struct wl_softc    *sc = WLSOFTC(unit);
    register struct ifnet       *ifp = &sc->wl_if;
    short                       base = sc->base;
    fd_t                        fd;
    struct ether_header         eh;
    struct mbuf                 *m, *tm;
    rbd_t                       rbd;
    u_char                      *mb_p;
    u_short                     mlen, len, clen;
    u_short                     bytes_in_msg, bytes_in_mbuf, bytes;


#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        printf("wl%d: entered wlread()\n",unit);
#endif
    if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
        printf("wl%d read(): board is not running.\n", ifp->if_unit);
        sc->hacr &= ~HACR_INTRON;
        CMD(unit);              /* turn off interrupts */
    }
    /* read ether_header info out of device memory. doesn't
     * go into mbuf.  goes directly into eh structure
     */
    len = sizeof(struct ether_header);  /* 14 bytes */
    outw(PIOR1(base), fd_p);
    insw(PIOP1(base), &fd, (sizeof(fd_t) - len)/2);
    insw(PIOP1(base), &eh, (len-2)/2);
    eh.ether_type = ntohs(inw(PIOP1(base)));
#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG) {
        printf("wlread: rcv packet, type is %x\n", eh.ether_type);
    }
#endif 
    /*
     * WARNING.  above is done now in ether_input, above may be
     * useful for debug. jrb
     */
    eh.ether_type = htons(eh.ether_type);

    if (fd.rbd_offset == I82586NULL) {
        printf("wl%d read(): Invalid buffer\n", unit);
        if (wlhwrst(unit) != TRUE) {
            printf("wl%d read(): hwrst trouble.\n", unit);
        }
        return 0;
    }

    outw(PIOR1(base), fd.rbd_offset);
    insw(PIOP1(base), &rbd, sizeof(rbd_t)/2);
    bytes_in_msg = rbd.status & RBD_SW_COUNT;
    MGETHDR(m, M_DONTWAIT, MT_DATA);
    tm = m;
    if (m == (struct mbuf *)0) {
        /*
         * not only do we want to return, we need to drop the packet on
         * the floor to clear the interrupt.
         *
         */
        if (wlhwrst(unit) != TRUE) {
            sc->hacr &= ~HACR_INTRON;
            CMD(unit);          /* turn off interrupts */
            printf("wl%d read(): hwrst trouble.\n", unit);
        }
        return 0;
    }
    m->m_next = (struct mbuf *) 0;
    m->m_pkthdr.rcvif = ifp;
    m->m_pkthdr.len = 0; /* don't know this yet */
    m->m_len = MHLEN;

    /* always use a cluster. jrb 
     */
    MCLGET(m, M_DONTWAIT);
    if (m->m_flags & M_EXT) {
        m->m_len = MCLBYTES;
    }
    else {
        m_freem(m);
        if (wlhwrst(unit) != TRUE) {
            sc->hacr &= ~HACR_INTRON;
            CMD(unit);          /* turn off interrupts */
            printf("wl%d read(): hwrst trouble.\n", unit);
        }
        return 0;
    }

    mlen = 0;
    clen = mlen;
    bytes_in_mbuf = m->m_len;
    mb_p = mtod(tm, u_char *);
    bytes = min(bytes_in_mbuf, bytes_in_msg);
    for (;;) {
        if (bytes & 1) {
            len = bytes + 1;
        } else {
            len = bytes;
        }
        outw(PIOR1(base), rbd.buffer_addr);
        insw(PIOP1(base), mb_p, len/2);
        clen += bytes;
        mlen += bytes;

        if (!(bytes_in_mbuf -= bytes)) {
            MGET(tm->m_next, M_DONTWAIT, MT_DATA);
            tm = tm->m_next;
            if (tm == (struct mbuf *)0) {
                m_freem(m);
                printf("wl%d read(): No mbuf nth\n", unit);
                if (wlhwrst(unit) != TRUE) {
                    sc->hacr &= ~HACR_INTRON;
                    CMD(unit);  /* turn off interrupts */
                    printf("wl%d read(): hwrst trouble.\n", unit);
                }
                return 0;
            }
            mlen = 0;
            tm->m_len = MLEN;
            bytes_in_mbuf = MLEN;
            mb_p = mtod(tm, u_char *);
        } else {
            mb_p += bytes;
        }

        if (!(bytes_in_msg  -= bytes)) {
            if (rbd.status & RBD_SW_EOF ||
                rbd.next_rbd_offset == I82586NULL) {
                tm->m_len = mlen;
                break;
            } else {
                outw(PIOR1(base), rbd.next_rbd_offset);
                insw(PIOP1(base), &rbd, sizeof(rbd_t)/2);
                bytes_in_msg = rbd.status & RBD_SW_COUNT;
            }
        } else {
            rbd.buffer_addr += bytes;
        }

        bytes = min(bytes_in_mbuf, bytes_in_msg);
    }

    m->m_pkthdr.len = clen;

    /*
     * If hw is in promiscuous mode (note that I said hardware, not if
     * IFF_PROMISC is set in ifnet flags), then if this is a unicast
     * packet and the MAC dst is not us, drop it.  This check in normally
     * inside ether_input(), but IFF_MULTI causes hw promisc without
     * a bpf listener, so this is wrong.
     *          Greg Troxel <gdt@ir.bbn.com>, 1998-08-07
     */
    /*
     * TBD: also discard packets where NWID does not match.
     * However, there does not appear to be a way to read the nwid
     * for a received packet.  -gdt 1998-08-07
     */
    if (
#ifdef WL_USE_IFNET_PROMISC_CHECK /* not defined */
        (sc->wl_ac.ac_if.if_flags & (IFF_PROMISC|IFF_ALLMULTI))
#else
        /* hw is in promisc mode if this is true */
        (sc->mode & (MOD_PROM | MOD_ENAL))
#endif
        &&
        (eh.ether_dhost[0] & 1) == 0 && /* !mcast and !bcast */
        bcmp(eh.ether_dhost, sc->wl_ac.ac_enaddr,
             sizeof(eh.ether_dhost)) != 0 ) {
      m_freem(m);
      return 1;
    }

#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        printf("wl%d: wlrecv %d bytes\n", unit, clen);
#endif

#ifdef WLCACHE
    wl_cache_store(unit, base, &eh, m);
#endif

    /*
     * received packet is now in a chain of mbuf's.  next step is
     * to pass the packet upwards.
     *
     */
    ether_input(&sc->wl_if, &eh, m);
    return 1;
}

/*
 * wlioctl:
 *
 *      This routine processes an ioctl request from the "if" layer
 *      above.
 *
 * input        : pointer the appropriate "if" struct, command, and data
 * output       : based on command appropriate action is taken on the
 *                WaveLAN board(s) or related structures
 * return       : error is returned containing exit conditions
 *
 */
static int
wlioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
    register struct ifreq       *ifr = (struct ifreq *)data;
    int                         unit = ifp->if_unit;
    register struct wl_softc    *sc = WLSOFTC(unit);
    short               base = sc->base;
    short               mode = 0;
    int                 opri, error = 0;
    struct proc         *p = curproc;   /* XXX */
    int                 irq, irqval, i, isroot, size;
    caddr_t             up;
    char *              cpt;
        

#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        printf("wl%d: entered wlioctl()\n",unit);
#endif
    opri = splimp();
    switch (cmd) {
    case SIOCSIFADDR:
    case SIOCGIFADDR:
    case SIOCSIFMTU:
        error = ether_ioctl(ifp, cmd, data);
        break;

    case SIOCSIFFLAGS:
        if (ifp->if_flags & IFF_ALLMULTI) {
            mode |= MOD_ENAL;
        }
        if (ifp->if_flags & IFF_PROMISC) {
            mode |= MOD_PROM;
        }
        if(ifp->if_flags & IFF_LINK0) {
            mode |= MOD_PROM;
        }
        /*
         * force a complete reset if the recieve multicast/
         * promiscuous mode changes so that these take 
         * effect immediately.
         *
         */
        if (sc->mode != mode) {
            sc->mode = mode;
            if (sc->flags & DSF_RUNNING) {
                sc->flags &= ~DSF_RUNNING;
                wlinit(sc);
            }
        }
        /* if interface is marked DOWN and still running then
         * stop it.
         */
        if ((ifp->if_flags & IFF_UP) == 0 && sc->flags & DSF_RUNNING) {
            printf("wl%d ioctl(): board is not running\n", unit);
            sc->flags &= ~DSF_RUNNING;
            sc->hacr &= ~HACR_INTRON;
            CMD(unit);            /* turn off interrupts */
        } 
        /* else if interface is UP and RUNNING, start it
                */
        else if (ifp->if_flags & IFF_UP && (sc->flags & DSF_RUNNING) == 0) {
            wlinit(sc);
        }
  
        /* if WLDEBUG set on interface, then printf rf-modem regs
        */
        if(ifp->if_flags & IFF_DEBUG)
            wlmmcstat(unit);
        break;
#if     MULTICAST
    case SIOCADDMULTI:
    case SIOCDELMULTI:

#if defined(__FreeBSD__) && __FreeBSD_version < 300000
        if (cmd == SIOCADDMULTI) {
            error = ether_addmulti(ifr, &sc->wl_ac);
        }
        else {
            error = ether_delmulti(ifr, &sc->wl_ac);
        }

        /* see if we should be in all multicast mode
         * note that 82586 cannot do that, must simulate with
         * promiscuous mode
         */
        if ( check_allmulti(unit)) {
                ifp->if_flags |=  IFF_ALLMULTI;
                sc->mode |= MOD_ENAL;
                sc->flags &= ~DSF_RUNNING;
                wlinit(sc);
                error = 0;
                break;
        }

        if (error == ENETRESET) {
            if(sc->flags & DSF_RUNNING) {
                sc->flags &= ~DSF_RUNNING;
                wlinit(sc);
            }
            error = 0;
        }
#else
        wlinit(sc);
#endif
        break;
#endif  /* MULTICAST */

    /* DEVICE SPECIFIC */


        /* copy the PSA out to the caller */
    case SIOCGWLPSA:
        /* pointer to buffer in user space */
        up = (void *)ifr->ifr_data;
        /* work out if they're root */
        isroot = (suser(p) == 0);
        
        for (i = 0; i < 0x40; i++) {
            /* don't hand the DES key out to non-root users */
            if ((i > WLPSA_DESKEY) && (i < (WLPSA_DESKEY + 8)) && !isroot)
                continue;
            if (subyte((up + i), sc->psa[i]))
                return(EFAULT);
        }
        break;


        /* copy the PSA in from the caller; we only copy _some_ values */
    case SIOCSWLPSA:
        /* root only */
        if ((error = suser(p)))
            break;
        error = EINVAL; /* assume the worst */
        /* pointer to buffer in user space containing data */
        up = (void *)ifr->ifr_data;
        
        /* check validity of input range */
        for (i = 0; i < 0x40; i++)
            if (fubyte(up + i) < 0)
                return(EFAULT);

        /* check IRQ value */
        irqval = fubyte(up+WLPSA_IRQNO);
        for (irq = 15; irq >= 0; irq--)
            if(irqvals[irq] == irqval)
                break;
        if (irq == 0)                   /* oops */
            break;
        /* new IRQ */
        sc->psa[WLPSA_IRQNO] = irqval;

        /* local MAC */
        for (i = 0; i < 6; i++)
            sc->psa[WLPSA_LOCALMAC+i] = fubyte(up+WLPSA_LOCALMAC+i);
                
        /* MAC select */        
        sc->psa[WLPSA_MACSEL] = fubyte(up+WLPSA_MACSEL);
        
        /* default nwid */
        sc->psa[WLPSA_NWID] = fubyte(up+WLPSA_NWID);
        sc->psa[WLPSA_NWID+1] = fubyte(up+WLPSA_NWID+1);

        error = 0;
        wlsetpsa(unit);         /* update the PSA */
        break;


        /* get the current NWID out of the sc since we stored it there */
    case SIOCGWLCNWID:
        ifr->ifr_data = (caddr_t) (sc->nwid[0] << 8 | sc->nwid[1]);
        break;


        /*
         * change the nwid dynamically.  This
         * ONLY changes the radio modem and does not
         * change the PSA.
         *
         * 2 steps:
         *      1. save in softc "soft registers"
         *      2. save in radio modem (MMC)
         */
    case SIOCSWLCNWID:
        /* root only */
        if ((error = suser(p)))
            break;
        if (!(ifp->if_flags & IFF_UP)) {
            error = EIO;        /* only allowed while up */
        } else {
            /* 
             * soft c nwid shadows radio modem setting
             */
            sc->nwid[0] = (int)ifr->ifr_data >> 8;
            sc->nwid[1] = (int)ifr->ifr_data & 0xff;
            MMC_WRITE(MMC_NETW_ID_L,sc->nwid[1]);
            MMC_WRITE(MMC_NETW_ID_H,sc->nwid[0]);
        }
        break;

        /* copy the EEPROM in 2.4 Gz WaveMODEM  out to the caller */
    case SIOCGWLEEPROM:
        /* root only */
        if ((error = suser(p)))
            break;
        /* pointer to buffer in user space */
        up = (void *)ifr->ifr_data;
        
        for (i=0x00; i<0x80; ++i) {             /* 2.4 Gz: size of EEPROM   */
            MMC_WRITE(MMC_EEADDR,i);            /* 2.4 Gz: get frequency    */
            MMC_WRITE(MMC_EECTRL,               /* 2.4 Gz: EEPROM read      */
                        MMC_EECTRL_EEOP_READ);  /* 2.4 Gz:                  */
            DELAY(40);                          /* 2.4 Gz                   */
            if (subyte(up + 2*i  ,              /* 2.4 Gz: pass low byte of */
                 wlmmcread(base,MMC_EEDATALrv)) /* 2.4 Gz: EEPROM word      */
               ) return(EFAULT);                /* 2.4 Gz:                  */
            if (subyte(up + 2*i+1,              /* 2.4 Gz: pass hi byte of  */
                 wlmmcread(base,MMC_EEDATALrv)) /* 2.4 Gz: EEPROM word      */
               ) return(EFAULT);                /* 2.4 Gz:                  */
        }
        break;

#ifdef WLCACHE
        /* zero (Delete) the wl cache */
    case SIOCDWLCACHE:
        /* root only */
        if ((error = suser(p)))
            break;
        wl_cache_zero(unit);
        break;

        /* read out the number of used cache elements */
    case SIOCGWLCITEM:
        ifr->ifr_data = (caddr_t) sc->w_sigitems;
        break;

        /* read out the wl cache */
    case SIOCGWLCACHE:
        /* pointer to buffer in user space */
        up = (void *)ifr->ifr_data;
        cpt = (char *) &sc->w_sigcache[0];
        size = sc->w_sigitems * sizeof(struct w_sigcache);
        
        for (i = 0; i < size; i++) {
            if (subyte((up + i), *cpt++))
                return(EFAULT);
        }
        break;
#endif

    default:
        error = EINVAL;
    }
    splx(opri);
    return (error);
}

/*
 * wlwatchdog():
 *
 * Called if the timer set in wlstart expires before an interrupt is received
 * from the wavelan.   It seems to lose interrupts sometimes.
 * The watchdog routine gets called if the transmitter failed to interrupt
 *
 * input        : which board is timing out
 * output       : board reset 
 *
 */
static void
wlwatchdog(void *vsc)
{
    struct wl_softc *sc = vsc;
    int unit = sc->unit;

    log(LOG_ERR, "wl%d: wavelan device timeout on xmit\n", unit);
    sc->wl_ac.ac_if.if_oerrors++;
    wlinit(sc);
}

/*
 * wlintr:
 *
 *      This function is the interrupt handler for the WaveLAN
 *      board.  This routine will be called whenever either a packet
 *      is received, or a packet has successfully been transfered and
 *      the unit is ready to transmit another packet.
 *
 * input        : board number that interrupted
 * output       : either a packet is received, or a packet is transfered
 *
 */
static void
wlintr(unit)
int unit;
{
    register struct wl_softc *sc = &wl_softc[unit];
    short               base = sc->base;
    int                 ac_status;
    u_short             int_type, int_type1;

#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        printf("wl%d: wlintr() called\n",unit);
#endif

    if((int_type = inw(HASR(base))) & HASR_MMC_INTR) {
        /* handle interrupt from the modem management controler */
        /* This will clear the interrupt condition */ 
        (void) wlmmcread(base,MMC_DCE_STATUS); /* ignored for now */
    }

    if(!(int_type & HASR_INTR)){        /* return if no interrupt from 82586 */
        /* commented out. jrb.  it happens when reinit occurs
           printf("wlintr: int_type %x, dump follows\n", int_type);
           wldump(unit);
           */
        return;
    }

    if (gathersnr)
        getsnr(unit);
    for(;;) {
        outw(PIOR0(base), OFFSET_SCB + 0);      /* get scb status */
        int_type = (inw(PIOP0(base)) & SCB_SW_INT);
        if (int_type == 0)                      /* no interrupts left */
            break;

        int_type1 = wlack(unit);                /* acknowledge interrupt(s) */
        /* make sure no bits disappeared (others may appear) */
        if ((int_type & int_type1) != int_type)
            printf("wlack() int bits disappeared : %04x != int_type %04x\n",
                   int_type1, int_type);
        int_type = int_type1;                   /* go with the new status */
        /* 
         * incoming packet
         */
        if (int_type & SCB_SW_FR) {
            sc->wl_if.if_ipackets++;
            wlrcv(unit);
        }
        /*
         * receiver not ready
         */
        if (int_type & SCB_SW_RNR) {
            sc->wl_if.if_ierrors++;
#ifdef  WLDEBUG
            if (sc->wl_if.if_flags & IFF_DEBUG)
                printf("wl%d intr(): receiver overrun! begin_fd = %x\n",
                       unit, sc->begin_fd);
#endif
            wlrustrt(unit);
        }
        /*
         * CU not ready
         */
        if (int_type & SCB_SW_CNA) {
            /*
             * At present, we don't care about CNA's.  We
             * believe they are a side effect of XMT.
             */
        }
        if (int_type & SCB_SW_CX) {
            /*
             * At present, we only request Interrupt for
             * XMT.
             */
            outw(PIOR1(base), OFFSET_CU);       /* get command status */
            ac_status = inw(PIOP1(base));

            if (xmt_watch) {                    /* report some anomalies */

                if (sc->tbusy == 0) {
                    printf("wl%d: xmt intr but not busy, CU %04x\n",
                           unit, ac_status);
                }
                if (ac_status == 0) {
                    printf("wl%d: xmt intr but ac_status == 0\n", unit);
                }
                if (ac_status & AC_SW_A) {
                    printf("wl%d: xmt aborted\n",unit);
                }
#ifdef  notdef
                if (ac_status & TC_CARRIER) {
                    printf("wl%d: no carrier\n", unit);
                }
#endif  /* notdef */
                if (ac_status & TC_CLS) {
                    printf("wl%d: no CTS\n", unit);
                }
                if (ac_status & TC_DMA) {
                    printf("wl%d: DMA underrun\n", unit);
                }
                if (ac_status & TC_DEFER) {
                    printf("wl%d: xmt deferred\n",unit);
                }
                if (ac_status & TC_SQE) {
                    printf("wl%d: heart beat\n", unit);
                }
                if (ac_status & TC_COLLISION) {
                    printf("wl%d: too many collisions\n", unit);
                }
            }
            /* if the transmit actually failed, or returned some status */
            if ((!(ac_status & AC_SW_OK)) || (ac_status & 0xfff)) {
                if (ac_status & (TC_COLLISION | TC_CLS | TC_DMA)) {
                    sc->wl_if.if_oerrors++;
                }
                /* count collisions */
                sc->wl_if.if_collisions += (ac_status & 0xf);
                /* if TC_COLLISION set and collision count zero, 16 collisions */
                if ((ac_status & 0x20) == 0x20) {
                    sc->wl_if.if_collisions += 0x10;
                }
            }
            sc->tbusy = 0;
            untimeout(wlwatchdog, sc, sc->watchdog_ch);
            sc->wl_ac.ac_if.if_flags &= ~IFF_OACTIVE;
            wlstart(&(sc->wl_if));
        }
    }
    return;
}

/*
 * wlrcv:
 *
 *      This routine is called by the interrupt handler to initiate a
 *      packet transfer from the board to the "if" layer above this
 *      driver.  This routine checks if a buffer has been successfully
 *      received by the WaveLAN.  If so, the routine wlread is called
 *      to do the actual transfer of the board data (including the
 *      ethernet header) into a packet (consisting of an mbuf chain).
 *
 * input        : number of the board to check
 * output       : if a packet is available, it is "sent up"
 *
 */
static void
wlrcv(int unit)
{
    register struct wl_softc *sc = WLSOFTC(unit);
    short       base = sc->base;
    u_short     fd_p, status, offset, link_offset;

#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        printf("wl%d: entered wlrcv()\n",unit);
#endif
    for (fd_p = sc->begin_fd; fd_p != I82586NULL; fd_p = sc->begin_fd) {

        outw(PIOR0(base), fd_p + 0);    /* address of status */
        status = inw(PIOP0(base));
        outw(PIOR1(base), fd_p + 4);    /* address of link_offset */
        link_offset = inw(PIOP1(base));
        offset = inw(PIOP1(base));      /* rbd_offset */
        if (status == 0xffff || offset == 0xffff /*I82586NULL*/) {
            if (wlhwrst(unit) != TRUE)
                printf("wl%d rcv(): hwrst ffff trouble.\n", unit);
            return;
        } else if (status & AC_SW_C) {
            if (status == (RFD_DONE|RFD_RSC)) {
                /* lost one */
#ifdef  WLDEBUG
                if (sc->wl_if.if_flags & IFF_DEBUG)
                    printf("wl%d RCV: RSC %x\n", unit, status);
#endif
                sc->wl_if.if_ierrors++;
            } else if (!(status & RFD_OK)) {
                printf("wl%d RCV: !OK %x\n", unit, status);
                sc->wl_if.if_ierrors++;
            } else if (status & 0xfff) {        /* can't happen */
                printf("wl%d RCV: ERRs %x\n", unit, status);
                sc->wl_if.if_ierrors++;
            } else if (!wlread(unit, fd_p))
                return;

            if (!wlrequeue(unit, fd_p)) {
                /* abort on chain error */
                if (wlhwrst(unit) != TRUE)
                    printf("wl%d rcv(): hwrst trouble.\n", unit);
                return;
            }
            sc->begin_fd = link_offset;
        } else {
            break;
        }
    }
    return;
}

/*
 * wlrequeue:
 *
 *      This routine puts rbd's used in the last receive back onto the
 *      free list for the next receive.
 *
 */
static int
wlrequeue(int unit, u_short fd_p)
{
    register struct wl_softc *sc = WLSOFTC(unit);
    short               base = sc->base;
    fd_t                fd;
    u_short             l_rbdp, f_rbdp, rbd_offset;

    outw(PIOR0(base), fd_p + 6);
    rbd_offset = inw(PIOP0(base));
    if ((f_rbdp = rbd_offset) != I82586NULL) {
        l_rbdp = f_rbdp;
        for(;;) {
            outw(PIOR0(base), l_rbdp + 0);      /* address of status */
            if(inw(PIOP0(base)) & RBD_SW_EOF)
                break;
            outw(PIOP0(base), 0);
            outw(PIOR0(base), l_rbdp + 2);      /* next_rbd_offset */
            if((l_rbdp = inw(PIOP0(base))) == I82586NULL)
                break;
        }
        outw(PIOP0(base), 0);
        outw(PIOR0(base), l_rbdp + 2);          /* next_rbd_offset */
        outw(PIOP0(base), I82586NULL);
        outw(PIOR0(base), l_rbdp + 8);          /* address of size */
        outw(PIOP0(base), inw(PIOP0(base)) | AC_CW_EL);
        outw(PIOR0(base), sc->end_rbd + 2);
        outw(PIOP0(base), f_rbdp);              /* end_rbd->next_rbd_offset */
        outw(PIOR0(base), sc->end_rbd + 8);     /* size */
        outw(PIOP0(base), inw(PIOP0(base)) & ~AC_CW_EL);
        sc->end_rbd = l_rbdp;
    }

    fd.status = 0;
    fd.command = AC_CW_EL;
    fd.link_offset = I82586NULL;
    fd.rbd_offset = I82586NULL;
    outw(PIOR1(base), fd_p);
    outsw(PIOP1(base), &fd, 8/2);
    
    outw(PIOR1(base), sc->end_fd + 2);  /* addr of command */
    outw(PIOP1(base), 0);               /* command = 0 */
    outw(PIOP1(base), fd_p);            /* end_fd->link_offset = fd_p */
    sc->end_fd = fd_p;

    return 1;
}

#ifdef  WLDEBUG
static int xmt_debug = 0;
#endif  /* WLDEBUG */

/*
 * wlxmt:
 *
 *      This routine fills in the appropriate registers and memory
 *      locations on the WaveLAN board and starts the board off on
 *      the transmit.
 *
 * input        : board number of interest, and a pointer to the mbuf
 * output       : board memory and registers are set for xfer and attention
 *
 */
static void
wlxmt(int unit, struct mbuf *m)
{
    register struct wl_softc *sc = WLSOFTC(unit);
    register u_short            xmtdata_p = OFFSET_TBUF;
    register u_short            xmtshort_p;
    struct      mbuf                    *tm_p = m;
    register struct ether_header        *eh_p = mtod(m, struct ether_header *);
    u_char                              *mb_p = mtod(m, u_char *) + sizeof(struct ether_header);
    u_short                             count = m->m_len - sizeof(struct ether_header);
    ac_t                                cb;
    u_short                             tbd_p = OFFSET_TBD;
    u_short                             len, clen = 0;
    short                               base = sc->base;
    int                                 spin;
        
#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        printf("wl%d: entered wlxmt()\n",unit);
#endif

    cb.ac_status = 0;
    cb.ac_command = (AC_CW_EL|AC_TRANSMIT|AC_CW_I);
    cb.ac_link_offset = I82586NULL;
    outw(PIOR1(base), OFFSET_CU);
    outsw(PIOP1(base), &cb, 6/2);
    outw(PIOP1(base), OFFSET_TBD);      /* cb.cmd.transmit.tbd_offset */
    outsw(PIOP1(base), eh_p->ether_dhost, WAVELAN_ADDR_SIZE/2);
    outw(PIOP1(base), eh_p->ether_type);

#ifdef  WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG) {
        if (xmt_debug) {
            printf("XMT    mbuf: L%d @%p ", count, (void *)mb_p);
            printf("ether type %x\n", eh_p->ether_type);
        }
    }
#endif  /* WLDEBUG */
    outw(PIOR0(base), OFFSET_TBD);
    outw(PIOP0(base), 0);               /* act_count */
    outw(PIOR1(base), OFFSET_TBD + 4);
    outw(PIOP1(base), xmtdata_p);       /* buffer_addr */
    outw(PIOP1(base), 0);               /* buffer_base */
    for (;;) {
        if (count) {
            if (clen + count > WAVELAN_MTU)
                break;
            if (count & 1)
                len = count + 1;
            else
                len = count;
            outw(PIOR1(base), xmtdata_p);
            outsw(PIOP1(base), mb_p, len/2);
            clen += count;
            outw(PIOR0(base), tbd_p);  /* address of act_count */
            outw(PIOP0(base), inw(PIOP0(base)) + count);
            xmtdata_p += len;
            if ((tm_p = tm_p->m_next) == (struct mbuf *)0)
                break;
            if (count & 1) {
                /* go to the next descriptor */
                outw(PIOR0(base), tbd_p + 2);
                tbd_p += sizeof (tbd_t);
                outw(PIOP0(base), tbd_p); /* next_tbd_offset */
                outw(PIOR0(base), tbd_p);
                outw(PIOP0(base), 0);   /* act_count */
                outw(PIOR1(base), tbd_p + 4);
                outw(PIOP1(base), xmtdata_p); /* buffer_addr */
                outw(PIOP1(base), 0);         /* buffer_base */
                /* at the end -> coallesce remaining mbufs */
                if (tbd_p == OFFSET_TBD + (N_TBD-1) * sizeof (tbd_t)) {
                    wlsftwsleaze(&count, &mb_p, &tm_p, unit);
                    continue;
                }
                /* next mbuf short -> coallesce as needed */
                if ( (tm_p->m_next == (struct mbuf *) 0) ||
#define HDW_THRESHOLD 55
                     tm_p->m_len > HDW_THRESHOLD)
                    /* ok */;
                else {
                    wlhdwsleaze(&count, &mb_p, &tm_p, unit);
                    continue;
                }
            }
        } else if ((tm_p = tm_p->m_next) == (struct mbuf *)0)
            break;
        count = tm_p->m_len;
        mb_p = mtod(tm_p, u_char *);
#ifdef  WLDEBUG
        if (sc->wl_if.if_flags & IFF_DEBUG)
            if (xmt_debug)
                printf("mbuf+ L%d @%p ", count, (void *)mb_p);
#endif  /* WLDEBUG */
    }
#ifdef  WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        if (xmt_debug)
            printf("CLEN = %d\n", clen);
#endif  /* WLDEBUG */
    outw(PIOR0(base), tbd_p);
    if (clen < ETHERMIN) {
        outw(PIOP0(base), inw(PIOP0(base)) + ETHERMIN - clen);
        outw(PIOR1(base), xmtdata_p);
        for (xmtshort_p = xmtdata_p; clen < ETHERMIN; clen += 2)
            outw(PIOP1(base), 0);
    }   
    outw(PIOP0(base), inw(PIOP0(base)) | TBD_SW_EOF);
    outw(PIOR0(base), tbd_p + 2);
    outw(PIOP0(base), I82586NULL);
#ifdef  WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG) {
        if (xmt_debug) {
            wltbd(unit);
            printf("\n");
        }
    }
#endif  /* WLDEBUG */

    outw(PIOR0(base), OFFSET_SCB + 2);  /* address of scb_command */
    /* 
     * wait for 586 to clear previous command, complain if it takes
     * too long
     */
    for (spin = 1;;spin = (spin + 1) % 10000) {
        if (inw(PIOP0(base)) == 0) {            /* it's done, we can go */
            break;
        }
        if ((spin == 0) && xmt_watch) {         /* not waking up, and we care */
                printf("wl%d: slow accepting xmit\n",unit);
        }
    }
    outw(PIOP0(base), SCB_CU_STRT);             /* new command */
    SET_CHAN_ATTN(unit);
    
    m_freem(m);

    /* XXX 
     * Pause to avoid transmit overrun problems.
     * The required delay tends to vary with platform type, and may be
     * related to interrupt loss.
     */
    if (wl_xmit_delay) {
        DELAY(wl_xmit_delay);
    }
    return;
}

/*
 * wlbldru:
 *
 *      This function builds the linear linked lists of fd's and
 *      rbd's.  Based on page 4-32 of 1986 Intel microcom handbook.
 *
 */
static u_short
wlbldru(int unit)
{
    register struct wl_softc *sc = WLSOFTC(unit);
    short       base = sc->base;
    fd_t        fd;
    rbd_t       rbd;
    u_short     fd_p = OFFSET_RU;
    u_short     rbd_p = OFFSET_RBD;
    int         i;

    sc->begin_fd = fd_p;
    for(i = 0; i < N_FD; i++) {
        fd.status = 0;
        fd.command = 0;
        fd.link_offset = fd_p + sizeof(fd_t);
        fd.rbd_offset = I82586NULL;
        outw(PIOR1(base), fd_p);
        outsw(PIOP1(base), &fd, 8/2);
        fd_p = fd.link_offset;
    }
    fd_p -= sizeof(fd_t);
    sc->end_fd = fd_p;
    outw(PIOR1(base), fd_p + 2);
    outw(PIOP1(base), AC_CW_EL);        /* command */
    outw(PIOP1(base), I82586NULL);      /* link_offset */
    fd_p = OFFSET_RU;
    
    outw(PIOR0(base), fd_p + 6);        /* address of rbd_offset */
    outw(PIOP0(base), rbd_p);
    outw(PIOR1(base), rbd_p);
    for(i = 0; i < N_RBD; i++) {
        rbd.status = 0;
        rbd.buffer_addr = rbd_p + sizeof(rbd_t) + 2;
        rbd.buffer_base = 0;
        rbd.size = RCVBUFSIZE;
        if (i != N_RBD-1) {
            rbd_p += sizeof(ru_t);
            rbd.next_rbd_offset = rbd_p;
        } else {
            rbd.next_rbd_offset = I82586NULL;
            rbd.size |= AC_CW_EL;
            sc->end_rbd = rbd_p;
        }
        outsw(PIOP1(base), &rbd, sizeof(rbd_t)/2);
        outw(PIOR1(base), rbd_p);
    }
    return sc->begin_fd;
}

/*
 * wlrustrt:
 *
 *      This routine starts the receive unit running.  First checks if the
 *      board is actually ready, then the board is instructed to receive
 *      packets again.
 *
 */
static void
wlrustrt(int unit)
{
    register struct wl_softc *sc = WLSOFTC(unit);
    short               base = sc->base;
    u_short             rfa;

#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        printf("wl%d: entered wlrustrt()\n",unit);
#endif
    outw(PIOR0(base), OFFSET_SCB);
    if (inw(PIOP0(base)) & SCB_RUS_READY){
        printf("wlrustrt: RUS_READY\n");
        return;
    }

    outw(PIOR0(base), OFFSET_SCB + 2);
    outw(PIOP0(base), SCB_RU_STRT);             /* command */
    rfa = wlbldru(unit);
    outw(PIOR0(base), OFFSET_SCB + 6);  /* address of scb_rfa_offset */
    outw(PIOP0(base), rfa);

    SET_CHAN_ATTN(unit);
    return;
}

/*
 * wldiag:
 *
 *      This routine does a 586 op-code number 7, and obtains the
 *      diagnose status for the WaveLAN.
 *
 */
static int
wldiag(int unit)
{
    register struct wl_softc *sc = WLSOFTC(unit);
    short               base = sc->base;
    short status;

#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        printf("wl%d: entered wldiag()\n",unit);
#endif
    outw(PIOR0(base), OFFSET_SCB);
    status = inw(PIOP0(base));
    if (status & SCB_SW_INT) {
                /* state is 2000 which seems ok
                   printf("wl%d diag(): unexpected initial state %\n",
                   unit, inw(PIOP0(base)));
                */
        wlack(unit);
    }
    outw(PIOR1(base), OFFSET_CU);
    outw(PIOP1(base), 0);                       /* ac_status */
    outw(PIOP1(base), AC_DIAGNOSE|AC_CW_EL);/* ac_command */
    if(wlcmd(unit, "diag()") == 0)
        return 0;
    outw(PIOR0(base), OFFSET_CU);
    if (inw(PIOP0(base)) & 0x0800) {
        printf("wl%d: i82586 Self Test failed!\n", unit);
        return 0;
    }
    return TRUE;
}

/*
 * wlconfig:
 *
 *      This routine does a standard config of the WaveLAN board.
 *
 */
static int
wlconfig(int unit)
{
    configure_t configure;
    register struct wl_softc *sc = WLSOFTC(unit);
    short               base = sc->base;

#if     MULTICAST
#if defined(__FreeBSD__) && __FreeBSD_version >= 300000
    struct ifmultiaddr *ifma;
    u_char *addrp;
#else
    struct ether_multi *enm;
    struct ether_multistep step;
#endif
    int cnt = 0;
#endif  /* MULTICAST */

#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        printf("wl%d: entered wlconfig()\n",unit);
#endif
    outw(PIOR0(base), OFFSET_SCB);
    if (inw(PIOP0(base)) & SCB_SW_INT) {
        /*
          printf("wl%d config(): unexpected initial state %x\n",
          unit, inw(PIOP0(base)));
          */
    }
    wlack(unit);

    outw(PIOR1(base), OFFSET_CU);
    outw(PIOP1(base), 0);                               /* ac_status */
    outw(PIOP1(base), AC_CONFIGURE|AC_CW_EL);   /* ac_command */

/* jrb hack */
    configure.fifolim_bytecnt   = 0x080c;
    configure.addrlen_mode      = 0x0600;
    configure.linprio_interframe        = 0x2060;
    configure.slot_time         = 0xf200;
    configure.hardware          = 0x0008;       /* tx even w/o CD */
    configure.min_frame_len     = 0x0040;
#if 0
    /* This is the configuration block suggested by Marc Meertens
     * <mmeerten@obelix.utrecht.NCR.COM> in an e-mail message to John
     * Ioannidis on 10 Nov 92.
     */
    configure.fifolim_bytecnt   = 0x040c;
    configure.addrlen_mode      = 0x0600;
    configure.linprio_interframe        = 0x2060;
    configure.slot_time         = 0xf000;
    configure.hardware          = 0x0008;       /* tx even w/o CD */
    configure.min_frame_len     = 0x0040;
#else
    /*
     * below is the default board configuration from p2-28 from 586 book
     */
    configure.fifolim_bytecnt   = 0x080c;
    configure.addrlen_mode      = 0x2600;
    configure.linprio_interframe        = 0x7820;       /* IFS=120, ACS=2 */
    configure.slot_time         = 0xf00c;       /* slottime=12    */
    configure.hardware          = 0x0008;       /* tx even w/o CD */
    configure.min_frame_len     = 0x0040;
#endif
    if(sc->mode & (MOD_PROM | MOD_ENAL)) {
        configure.hardware |= 1;
    }
    outw(PIOR1(base), OFFSET_CU + 6);
    outsw(PIOP1(base), &configure, sizeof(configure_t)/2);

    if(wlcmd(unit, "config()-configure") == 0)
        return 0;
#if     MULTICAST
    outw(PIOR1(base), OFFSET_CU);
    outw(PIOP1(base), 0);                               /* ac_status */
    outw(PIOP1(base), AC_MCSETUP|AC_CW_EL);             /* ac_command */
    outw(PIOR1(base), OFFSET_CU + 8);
#if defined(__FreeBSD__) && __FreeBSD_version >= 300000
    TAILQ_FOREACH(ifma, &sc->wl_if.if_multiaddrs, ifma_link) {
        if (ifma->ifma_addr->sa_family != AF_LINK)
            continue;
        
        addrp = LLADDR((struct sockaddr_dl *)ifma->ifma_addr);
        outw(PIOP1(base), addrp[0] + (addrp[1] << 8));
        outw(PIOP1(base), addrp[2] + (addrp[3] << 8));
        outw(PIOP1(base), addrp[4] + (addrp[5] << 8));
        ++cnt;
    }
#else
    ETHER_FIRST_MULTI(step, &sc->wl_ac, enm);
    while (enm != NULL) {
        unsigned int lo, hi;
        /* break if setting a multicast range, else we would crash */
        if (bcmp(enm->enm_addrlo, enm->enm_addrhi, 6) != 0) {
                break;
        }
        lo = (enm->enm_addrlo[3] << 16) + (enm->enm_addrlo[4] << 8)
            + enm->enm_addrlo[5];
        hi = (enm->enm_addrhi[3] << 16) + (enm->enm_addrhi[4] << 8)
            + enm->enm_addrhi[5];
        while(lo <= hi) {
            outw(PIOP1(base),enm->enm_addrlo[0] +
                 (enm->enm_addrlo[1] << 8));
            outw(PIOP1(base),enm->enm_addrlo[2] +
                 ((lo >> 8) & 0xff00));
            outw(PIOP1(base), ((lo >> 8) & 0xff) +
                 ((lo << 8) & 0xff00));
/* #define MCASTDEBUG */
#ifdef MCASTDEBUG
printf("mcast_addr[%d,%d,%d] %x %x %x %x %x %x\n", lo, hi, cnt,
                enm->enm_addrlo[0],
                enm->enm_addrlo[1],
                enm->enm_addrlo[2],
                enm->enm_addrlo[3],
                enm->enm_addrlo[4],
                enm->enm_addrlo[5]);
#endif
            ++cnt;
            ++lo;
        }
        ETHER_NEXT_MULTI(step, enm);
    }
#endif
    outw(PIOR1(base), OFFSET_CU + 6);           /* mc-cnt */
    outw(PIOP1(base), cnt * WAVELAN_ADDR_SIZE);
    if(wlcmd(unit, "config()-mcaddress") == 0)
        return 0;
#endif  /* MULTICAST */

    outw(PIOR1(base), OFFSET_CU);
    outw(PIOP1(base), 0);                               /* ac_status */
    outw(PIOP1(base), AC_IASETUP|AC_CW_EL);             /* ac_command */
    outw(PIOR1(base), OFFSET_CU + 6);
    outsw(PIOP1(base), sc->wl_addr, WAVELAN_ADDR_SIZE/2);

    if(wlcmd(unit, "config()-address") == 0)
        return(0);

    wlinitmmc(unit);

    return(1);
}

/*
 * wlcmd:
 *
 * Set channel attention bit and busy wait until command has
 * completed. Then acknowledge the command completion.
 */
static int
wlcmd(int unit, char *str)
{
    register struct wl_softc *sc = WLSOFTC(unit);
    short       base = sc->base;
    int i;
        
    outw(PIOR0(base), OFFSET_SCB + 2);  /* address of scb_command */
    outw(PIOP0(base), SCB_CU_STRT);
    
    SET_CHAN_ATTN(unit);
    
    outw(PIOR0(base), OFFSET_CU);
    for(i = 0; i < 0xffff; i++)
        if (inw(PIOP0(base)) & AC_SW_C)
            break;
    if (i == 0xffff || !(inw(PIOP0(base)) & AC_SW_OK)) {
        printf("wl%d: %s failed; status = %d, inw = %x, outw = %x\n",
               unit, str, inw(PIOP0(base)) & AC_SW_OK, inw(PIOP0(base)), inw(PIOR0(base)));
        outw(PIOR0(base), OFFSET_SCB);
        printf("scb_status %x\n", inw(PIOP0(base)));
        outw(PIOR0(base), OFFSET_SCB+2);
        printf("scb_command %x\n", inw(PIOP0(base)));
        outw(PIOR0(base), OFFSET_SCB+4);
        printf("scb_cbl %x\n", inw(PIOP0(base)));
        outw(PIOR0(base), OFFSET_CU+2);
        printf("cu_cmd %x\n", inw(PIOP0(base)));
        return(0);
    }

    outw(PIOR0(base), OFFSET_SCB);
    if ((inw(PIOP0(base)) & SCB_SW_INT) && (inw(PIOP0(base)) != SCB_SW_CNA)) {
        /*
          printf("wl%d %s: unexpected final state %x\n",
          unit, str, inw(PIOP0(base)));
          */
    }
    wlack(unit);
    return(TRUE);
}       

/*
 * wlack: if the 82596 wants attention because it has finished
 * sending or receiving a packet, acknowledge its desire and
 * return bits indicating the kind of attention. wlack() returns
 * these bits so that the caller can service exactly the
 * conditions that wlack() acknowledged.
 */
static int
wlack(int unit)
{
    int i;
    register u_short cmd;
    register struct wl_softc *sc = WLSOFTC(unit);
    short base = sc->base;

    outw(PIOR1(base), OFFSET_SCB);
    if(!(cmd = (inw(PIOP1(base)) & SCB_SW_INT)))
        return(0);
#ifdef WLDEBUG
    if (sc->wl_if.if_flags & IFF_DEBUG)
        printf("wl%d: doing a wlack()\n",unit);
#endif
    outw(PIOP1(base), cmd);
    SET_CHAN_ATTN(unit);
    outw(PIOR0(base), OFFSET_SCB + 2);  /* address of scb_command */
    for (i = 1000000; inw(PIOP0(base)) && (i-- > 0); );
    if (i < 1)
        printf("wl%d wlack(): board not accepting command.\n", unit);
    return(cmd);
}

static void
wltbd(int unit)
{
    register struct wl_softc *sc = WLSOFTC(unit);
    short               base = sc->base;
    u_short             tbd_p = OFFSET_TBD;
    tbd_t               tbd;
    int                 i = 0;
    int                 sum = 0;

    for (;;) {
        outw(PIOR1(base), tbd_p);
        insw(PIOP1(base), &tbd, sizeof(tbd_t)/2);
        sum += (tbd.act_count & ~TBD_SW_EOF);
        printf("%d: addr %x, count %d (%d), next %x, base %x\n",
               i++, tbd.buffer_addr,
               (tbd.act_count & ~TBD_SW_EOF), sum,
               tbd.next_tbd_offset, tbd.buffer_base);
        if (tbd.act_count & TBD_SW_EOF)
            break;
        tbd_p = tbd.next_tbd_offset;
    }
}

static void
wlhdwsleaze(u_short *countp, u_char **mb_pp, struct mbuf **tm_pp, int unit)
{
    struct mbuf *tm_p = *tm_pp;
    u_char              *mb_p = *mb_pp;
    u_short             count = 0;
    u_char              *cp;
    int         len;

    /*
     * can we get a run that will be coallesced or
     * that terminates before breaking
     */
    do {
        count += tm_p->m_len;
        if (tm_p->m_len & 1)
            break;
    } while ((tm_p = tm_p->m_next) != (struct mbuf *)0);
    if ( (tm_p == (struct mbuf *)0) ||
         count > HDW_THRESHOLD) {
        *countp = (*tm_pp)->m_len;
        *mb_pp = mtod((*tm_pp), u_char *);
        return;
    }

    /* we need to copy */
    tm_p = *tm_pp;
    mb_p = *mb_pp;
    count = 0;
    cp = (u_char *) t_packet;
    for (;;) {
        bcopy(mtod(tm_p, u_char *), cp, len = tm_p->m_len);
        count += len;
        if (count > HDW_THRESHOLD)
                        break;
        cp += len;
        if (tm_p->m_next == (struct mbuf *)0)
            break;
        tm_p = tm_p->m_next;
    }
    *countp = count;
    *mb_pp = (u_char *) t_packet;
    *tm_pp = tm_p;
    return;
}


static void
wlsftwsleaze(u_short *countp, u_char **mb_pp, struct mbuf **tm_pp, int unit)
{
    struct mbuf *tm_p = *tm_pp;
    u_short             count = 0;
    u_char              *cp = (u_char *) t_packet;
    int                 len;

    /* we need to copy */
    for (;;) {
        bcopy(mtod(tm_p, u_char *), cp, len = tm_p->m_len);
        count += len;
        cp += len;
        if (tm_p->m_next == (struct mbuf *)0)
            break;
        tm_p = tm_p->m_next;
    }

    *countp = count;
    *mb_pp = (u_char *) t_packet;
    *tm_pp = tm_p;
    return;
}

static void
wlmmcstat(int unit)
{
    register struct wl_softc *sc = WLSOFTC(unit);
    short       base = sc->base;
    u_short tmp;

    printf("wl%d: DCE_STATUS: 0x%x, ", unit,
           wlmmcread(base,MMC_DCE_STATUS) & 0x0f);
    tmp = wlmmcread(base,MMC_CORRECT_NWID_H) << 8;
    tmp |= wlmmcread(base,MMC_CORRECT_NWID_L);
    printf("Correct NWID's: %d, ", tmp);
    tmp = wlmmcread(base,MMC_WRONG_NWID_H) << 8;
    tmp |= wlmmcread(base,MMC_WRONG_NWID_L);
    printf("Wrong NWID's: %d\n", tmp);
    printf("THR_PRE_SET: 0x%x, ", wlmmcread(base,MMC_THR_PRE_SET));
    printf("SIGNAL_LVL: %d, SILENCE_LVL: %d\n", 
           wlmmcread(base,MMC_SIGNAL_LVL),
           wlmmcread(base,MMC_SILENCE_LVL));
    printf("SIGN_QUAL: 0x%x, NETW_ID: %x:%x, DES: %d\n",
           wlmmcread(base,MMC_SIGN_QUAL),
           wlmmcread(base,MMC_NETW_ID_H),
           wlmmcread(base,MMC_NETW_ID_L),
           wlmmcread(base,MMC_DES_AVAIL));
}

static u_short
wlmmcread(u_int base, u_short reg)
{
    while(inw(HASR(base)) & HASR_MMC_BUSY) ;
    outw(MMCR(base),reg << 1);
    while(inw(HASR(base)) & HASR_MMC_BUSY) ;
    return (u_short)inw(MMCR(base)) >> 8;
}

static void
getsnr(int unit)
{
    MMC_WRITE(MMC_FREEZE,1);
    /* 
     * SNR retrieval procedure :
     *
     * read signal level : wlmmcread(base, MMC_SIGNAL_LVL);
     * read silence level : wlmmcread(base, MMC_SILENCE_LVL);
     */
    MMC_WRITE(MMC_FREEZE,0);
    /*
     * SNR is signal:silence ratio.
     */
}

/*
** wlgetpsa
**
** Reads the psa for the wavelan at (base) into (buf)
*/
static void
wlgetpsa(int base, u_char *buf)
{
    int i;

    PCMD(base, HACR_DEFAULT & ~HACR_16BITS);
    PCMD(base, HACR_DEFAULT & ~HACR_16BITS);

    for (i = 0; i < 0x40; i++) {
        outw(PIOR2(base), i);
        buf[i] = inb(PIOP2(base));
    }
    PCMD(base, HACR_DEFAULT);
    PCMD(base, HACR_DEFAULT);
}

/*
** wlsetpsa
**
** Writes the psa for wavelan (unit) from the softc back to the
** board.  Updates the CRC and sets the CRC OK flag.
**
** Do not call this when the board is operating, as it doesn't 
** preserve the hacr.
*/
static void
wlsetpsa(int unit)
{
    register struct wl_softc *sc = WLSOFTC(unit);
    short       base = sc->base;
    int         i, oldpri;
    u_short     crc;

    crc = wlpsacrc(sc->psa);    /* calculate CRC of PSA */
    sc->psa[WLPSA_CRCLOW] = crc & 0xff;
    sc->psa[WLPSA_CRCHIGH] = (crc >> 8) & 0xff;
    sc->psa[WLPSA_CRCOK] = 0x55;        /* default to 'bad' until programming complete */

    oldpri = splimp();          /* ick, long pause */
    
    PCMD(base, HACR_DEFAULT & ~HACR_16BITS);
    PCMD(base, HACR_DEFAULT & ~HACR_16BITS);
    
    for (i = 0; i < 0x40; i++) {
        DELAY(DELAYCONST);
        outw(PIOR2(base),i);  /* write param memory */
        DELAY(DELAYCONST);
        outb(PIOP2(base), sc->psa[i]);
    }
    DELAY(DELAYCONST);
    outw(PIOR2(base),WLPSA_CRCOK);  /* update CRC flag*/
    DELAY(DELAYCONST);
    sc->psa[WLPSA_CRCOK] = 0xaa;        /* OK now */
    outb(PIOP2(base), 0xaa);    /* all OK */
    DELAY(DELAYCONST);
    
    PCMD(base, HACR_DEFAULT);
    PCMD(base, HACR_DEFAULT);
    
    splx(oldpri);
}

/* 
** CRC routine provided by Christopher Giordano <cgiordan@gdeb.com>,
** from original code by Tomi Mikkonen (tomitm@remedy.fi)
*/

static u_int crc16_table[16] = { 
    0x0000, 0xCC01, 0xD801, 0x1400,
    0xF001, 0x3C00, 0x2800, 0xE401,
    0xA001, 0x6C00, 0x7800, 0xB401,
    0x5000, 0x9C01, 0x8801, 0x4400 
};

static u_short
wlpsacrc(u_char *buf)
{
    u_short     crc = 0;
    int         i, r1;
    
    for (i = 0; i < 0x3d; i++, buf++) {
        /* lower 4 bits */
        r1 = crc16_table[crc & 0xF];
        crc = (crc >> 4) & 0x0FFF;
        crc = crc ^ r1 ^ crc16_table[*buf & 0xF];
        
        /* upper 4 bits */
        r1 = crc16_table[crc & 0xF];
        crc = (crc >> 4) & 0x0FFF;
        crc = crc ^ r1 ^ crc16_table[(*buf >> 4) & 0xF];
    }
    return(crc);
}
#ifdef WLCACHE

/*
 * wl_cache_store
 *
 * take input packet and cache various radio hw characteristics
 * indexed by MAC address.
 *
 * Some things to think about:
 *      note that no space is malloced. 
 *      We might hash the mac address if the cache were bigger.
 *      It is not clear that the cache is big enough.
 *              It is also not clear how big it should be.
 *      The cache is IP-specific.  We don't care about that as
 *              we want it to be IP-specific.
 *      The last N recv. packets are saved.  This will tend
 *              to reward agents and mobile hosts that beacon.
 *              That is probably fine for mobile ip.
 */

/* globals for wavelan signal strength cache */
/* this should go into softc structure above. 
*/

/* set true if you want to limit cache items to broadcast/mcast 
 * only packets (not unicast)
 */
static int wl_cache_mcastonly = 1;
SYSCTL_INT(_machdep, OID_AUTO, wl_cache_mcastonly, CTLFLAG_RW, 
        &wl_cache_mcastonly, 0, "");

/* set true if you want to limit cache items to IP packets only
*/
static int wl_cache_iponly = 1;
SYSCTL_INT(_machdep, OID_AUTO, wl_cache_iponly, CTLFLAG_RW, 
        &wl_cache_iponly, 0, "");

/* zero out the cache
*/
static void
wl_cache_zero(int unit)
{
        register struct wl_softc        *sc = WLSOFTC(unit);

        bzero(&sc->w_sigcache[0], sizeof(struct w_sigcache) * MAXCACHEITEMS);
        sc->w_sigitems = 0;
        sc->w_nextcache = 0;
        sc->w_wrapindex = 0;
}

/* store hw signal info in cache.
 * index is MAC address, but an ip src gets stored too
 * There are two filters here controllable via sysctl:
 *      throw out unicast (on by default, but can be turned off)
 *      throw out non-ip (on by default, but can be turned off)
 */
static
void wl_cache_store (int unit, int base, struct ether_header *eh,
                     struct mbuf *m)
{
        struct ip *ip = NULL;   /* Avoid GCC warning */
        int i;
        int signal, silence;
        int w_insertcache;   /* computed index for cache entry storage */
        register struct wl_softc *sc = WLSOFTC(unit);
        int ipflag = wl_cache_iponly;

        /* filters:
         * 1. ip only
         * 2. configurable filter to throw out unicast packets,
         * keep multicast only.
         */
 
#ifdef INET
        /* reject if not IP packet
        */
        if ( wl_cache_iponly && (ntohs(eh->ether_type) != 0x800)) {
                return;
        }

        /* check if broadcast or multicast packet.  we toss
         * unicast packets
         */
        if (wl_cache_mcastonly && ((eh->ether_dhost[0] & 1) == 0)) {
                return;
        }

        /* find the ip header.  we want to store the ip_src
         * address.  use the mtod macro(in mbuf.h) 
         * to typecast m to struct ip *
         */
        if (ipflag) {
                ip = mtod(m, struct ip *);
        }
        
        /* do a linear search for a matching MAC address 
         * in the cache table
         * . MAC address is 6 bytes,
         * . var w_nextcache holds total number of entries already cached
         */
        for(i = 0; i < sc->w_nextcache; i++) {
                if (! bcmp(eh->ether_shost, sc->w_sigcache[i].macsrc,  6 )) {
                        /* Match!,
                         * so we already have this entry,
                         * update the data, and LRU age
                         */
                        break;  
                }
        }

        /* did we find a matching mac address?
         * if yes, then overwrite a previously existing cache entry
         */
        if (i <  sc->w_nextcache )   {
                w_insertcache = i; 
        }
        /* else, have a new address entry,so
         * add this new entry,
         * if table full, then we need to replace entry
         */
        else    {                          

                /* check for space in cache table 
                 * note: w_nextcache also holds number of entries
                 * added in the cache table 
                 */
                if ( sc->w_nextcache < MAXCACHEITEMS ) {
                        w_insertcache = sc->w_nextcache;
                        sc->w_nextcache++;                 
                        sc->w_sigitems = sc->w_nextcache;
                }
                /* no space found, so simply wrap with wrap index
                 * and "zap" the next entry
                 */
                else {
                        if (sc->w_wrapindex == MAXCACHEITEMS) {
                                sc->w_wrapindex = 0;
                        }
                        w_insertcache = sc->w_wrapindex++;
                }
        }

        /* invariant: w_insertcache now points at some slot
         * in cache.
         */
        if (w_insertcache < 0 || w_insertcache >= MAXCACHEITEMS) {
                log(LOG_ERR, 
                        "wl_cache_store, bad index: %d of [0..%d], gross cache error\n",
                        w_insertcache, MAXCACHEITEMS);
                return;
        }

        /*  store items in cache
         *  .ipsrc
         *  .macsrc
         *  .signal (0..63) ,silence (0..63) ,quality (0..15)
         */
        if (ipflag) {
                sc->w_sigcache[w_insertcache].ipsrc = ip->ip_src.s_addr;
        }
        bcopy( eh->ether_shost, sc->w_sigcache[w_insertcache].macsrc,  6);
        signal = sc->w_sigcache[w_insertcache].signal  = wlmmcread(base, MMC_SIGNAL_LVL) & 0x3f;
        silence = sc->w_sigcache[w_insertcache].silence = wlmmcread(base, MMC_SILENCE_LVL) & 0x3f;
        sc->w_sigcache[w_insertcache].quality = wlmmcread(base, MMC_SIGN_QUAL) & 0x0f;
        if (signal > 0)
                sc->w_sigcache[w_insertcache].snr = 
                        signal - silence;
        else
                sc->w_sigcache[w_insertcache].snr = 0;
#endif /* INET */

}
#endif /* WLCACHE */

/*
 * determine if in all multicast mode or not
 * 
 * returns: 1 if IFF_ALLMULTI should be set
 *          else 0
 */
#ifdef MULTICAST

#if defined(__FreeBSD__) && __FreeBSD_version < 300000  /* not required */
static int
check_allmulti(int unit)
{
    register struct wl_softc *sc = WLSOFTC(unit);
    short  base = sc->base;
    struct ether_multi *enm;
    struct ether_multistep step;

    ETHER_FIRST_MULTI(step, &sc->wl_ac, enm);
    while (enm != NULL) {
        unsigned int lo, hi;
#ifdef MDEBUG
                printf("enm_addrlo %x:%x:%x:%x:%x:%x\n", enm->enm_addrlo[0], enm->enm_addrlo[1],
                enm->enm_addrlo[2], enm->enm_addrlo[3], enm->enm_addrlo[4],
                enm->enm_addrlo[5]);
                printf("enm_addrhi %x:%x:%x:%x:%x:%x\n", enm->enm_addrhi[0], enm->enm_addrhi[1],
                enm->enm_addrhi[2], enm->enm_addrhi[3], enm->enm_addrhi[4],
                enm->enm_addrhi[5]);
#endif
        if (bcmp(enm->enm_addrlo, enm->enm_addrhi, 6) != 0) {
                return(1);
        }
        ETHER_NEXT_MULTI(step, enm);
    }
    return(0);
}
#endif
#endif