usr/src/sys.386bsd/i386/isa/npx.c

/*-
 * Copyright (c) 1990 William Jolitz.
 * Copyright (c) 1991 The Regents of the University of California.
 * 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 the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *      @(#)npx.c       7.2 (Berkeley) 5/12/91
 */
static char rcsid[] = "$Header: /usr/bill/working/sys/i386/isa/RCS/npx.c,v 1.2 92/01/21 14:34:27 william Exp $";
#include "npx.h"
#if NNPX > 0

#include "param.h"
#include "systm.h"
#include "conf.h"
#include "file.h"
#include "proc.h"
#include "machine/cpu.h"
#include "machine/pcb.h"
#include "machine/trap.h"
#include "ioctl.h"
#include "machine/specialreg.h"
#include "i386/isa/isa_device.h"
#include "icu.h"
/*
 * 387 and 287 Numeric Coprocessor Extension (NPX) Driver.
 */

int     npxprobe(), npxattach(), npxintr();
struct  isa_driver npxdriver = {
        npxprobe, npxattach, "npx",
};

struct proc *npxproc;   /* process who owns device, otherwise zero */
struct pcb *npxpcb;     /* owners context structure */
int npxexists;
extern long npx0mask;

/*
 * Probe routine - look device, otherwise set emulator bit
 */
npxprobe(dvp)
        struct isa_device *dvp;
{       static status, control;

#ifdef lint
        npxintr();
#endif

        /* insure EM bit off */
        load_cr0(rcr0() & ~CR0_EM);     /* stop emulating */
        asm("   fninit ");      /* put device in known state */

        /* check for a proper status of zero */
        status = 0x5a5a;
        asm ("  fnstsw  %0 " : "=m" (status) : "m" (status) );

        if ((status&0xff) == 0) {

                /* good, now check for a proper control word */
                asm ("  fnstcw %0 " : "=m" (status) : "m" (status));

                if ((status&0x103f) == 0x3f) {
                        /* then we have a numeric coprocessor */
                /* XXX should force an exception here to generate an intr */
                        return (1);
                }
        }

        /* insure EM bit on */
        load_cr0(rcr0() | CR0_EM);      /* start emulating */
        return (0);
}

/*
 * Attach routine - announce which it is, and wire into system
 */
npxattach(dvp)
        struct isa_device *dvp;
{

        npxinit(__INITIAL_NPXCW__);
        npxexists++;
        npx0mask = dvp->id_irq;
}

/*
 * Initialize floating point unit.
 */
npxinit(control) {
        static short wd;

        if (npxexists == 0) return;


        wd = control;
        wd = 0x272;
        load_cr0(rcr0() & ~CR0_EM);     /* stop emulating */
        asm ("  fninit");
        asm("   fldcw %0" : : "g" (wd));
        if (curpcb) {
                asm("   fnsave %0 " : : "g" (curpcb->pcb_savefpu) );
                curpcb->pcb_flags |= FP_NEEDSRESTORE;
        }
        load_cr0(rcr0() | CR0_EM);      /* start emulating */
        outb(0xb1,0);           /* reset processor */
}

/*
 * Load floating point context and record ownership to suite
 */
npxload() {

        if (npxproc) panic ("npxload");
        npxproc = curproc;
        npxpcb = curpcb;
        asm("   frstor %0 " : : "g" (curpcb->pcb_savefpu) );
}

/*
 * Unload floating point context and relinquish ownership
 */
npxunload() {

        if (npxproc == 0) panic ("npxunload");
        asm("   fsave %0 " : : "g" (npxpcb->pcb_savefpu) );
        npxproc = 0 ;
}

/*
 * Record information needed in processing an exception and clear status word
 */
npxintr(frame) struct intrframe frame; {
        int code;
static status;

        outb(0xf0,0);           /* reset processor */
/*pg("npxintr");*/

        asm ("  fnstsw  %0 " : "=m" (status) : "m" (status) );
        /* sync state in process context structure, in advance of debugger/process looking for it */
        if (npxproc == 0 || npxexists == 0) panic ("npxintr");
        asm ("  fnsave %0 " : : "g" (npxpcb->pcb_savefpu) );

#ifdef notyet
        /* encode the appropriate code for detailed information on this exception */
        code = ???;
#else
        code = 0;       /* XXX */
#endif

/*if((pg("status %x", status) & 0x7f) == 't') {*/
        /* pass exception to process, which may not be the current one */
        if (npxproc == curproc) {
                /* Q: what if in an interrupt, or in trap processing? */
                if (ISPL(frame.if_cs) == SEL_UPL) {
                        curproc->p_regs = (int *)&frame.if_es;
                        curpcb->pcb_flags |= FM_TRAP;   /* used by sendsig */
                } /* else printf("*");*/
                trapsignal(curproc, SIGFPE, code);
                curpcb->pcb_flags &= ~FM_TRAP;  /* used by sendsig */
        } else {
                /* printf("P");*/
                psignal(npxproc, SIGFPE);
        }
/*}*/

        /* clear the exception so we can catch others like it */
        asm ("  fnclex");
}

/*
 * Implement device not available (DNA) exception
 */
npxdna() {
/*pg("npxdna");*/


        if (npxexists == 0) return(0);
        load_cr0(rcr0() & ~CR0_EM);     /* stop emulating */
        if (curpcb->pcb_flags & FP_NEEDSRESTORE)
                asm("   frstor %0 " : : "g" (curpcb->pcb_savefpu));
        curpcb->pcb_flags |= FP_WASUSED | FP_NEEDSSAVE;
        curpcb->pcb_flags &= ~FP_NEEDSRESTORE;
        npxproc = curproc;
        npxpcb = curpcb;
        return (1);
}
#endif