/*      $OpenBSD: emul.c,v 1.28 2024/03/29 21:14:31 miod Exp $  */
/*      $NetBSD: emul.c,v 1.8 2001/06/29 23:58:40 eeh Exp $     */

/*-
 * Copyright (c) 1997, 2001 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/malloc.h>
#include <machine/reg.h>
#include <machine/instr.h>
#include <machine/cpu.h>
#include <machine/psl.h>
#include <uvm/uvm_extern.h>

#ifdef DEBUG_EMUL
# define DPRINTF(a) printf a
#else
# define DPRINTF(a)
#endif

void swap_quad(int64_t *);

#define SIGN_EXT13(v)   (((int64_t)(v) << 51) >> 51)

void
swap_quad(int64_t *p)
{
        int64_t t;

        t = htole64(p[0]);
        p[0] = htole64(p[1]);
        p[1] = t;
}

/*
 * emulate STQF, STQFA, LDQF, and LDQFA
 */
int
emul_qf(int32_t insv, struct proc *p, union sigval sv, struct trapframe *tf)
{
        extern const struct fpstate initfpstate;
        struct fpstate *fs = p->p_md.md_fpstate;
        int64_t addr, buf[2];
        union instr ins;
        int freg, isload, err;
        u_int8_t asi;

        ins.i_int = insv;
        freg = ins.i_op3.i_rd & ~1;
        freg |= (ins.i_op3.i_rd & 1) << 5;

        if (ins.i_op3.i_op3 == IOP3_LDQF || ins.i_op3.i_op3 == IOP3_LDQFA)
                isload = 1;
        else
                isload = 0;

        if (ins.i_op3.i_op3 == IOP3_STQF || ins.i_op3.i_op3 == IOP3_LDQF)
                asi = ASI_PRIMARY;
        else if (ins.i_loadstore.i_i)
                asi = (tf->tf_tstate & TSTATE_ASI) >> TSTATE_ASI_SHIFT;
        else
                asi = ins.i_asi.i_asi;

        addr = tf->tf_global[ins.i_asi.i_rs1];
        if (ins.i_loadstore.i_i)
                addr += SIGN_EXT13(ins.i_simm13.i_simm13);
        else
                addr += tf->tf_global[ins.i_asi.i_rs2];

        if (asi < ASI_PRIMARY) {
                /* privileged asi */
                trapsignal(p, SIGILL, 0, ILL_PRVOPC, sv);
                return (0);
        }
        if (asi > ASI_SECONDARY_NOFAULT_LITTLE ||
            (asi > ASI_SECONDARY_NOFAULT && asi < ASI_PRIMARY_LITTLE)) {
                /* architecturally undefined user ASI's */
                goto segv;
        }

        if ((freg & 3) != 0) {
                /* only valid for %fN where N % 4 = 0 */
                trapsignal(p, SIGILL, 0, ILL_ILLOPN, sv);
                return (0);
        }

        if ((addr & 3) != 0) {
                /* request is not aligned */
                trapsignal(p, SIGBUS, 0, BUS_ADRALN, sv);
                return (0);
        }

        fs = p->p_md.md_fpstate;
        if (fs == NULL) {
                KERNEL_LOCK();
                /* don't currently have an fpu context, get one */
                fs = malloc(sizeof(*fs), M_SUBPROC, M_WAITOK);
                *fs = initfpstate;
                p->p_md.md_fpstate = fs;
                KERNEL_UNLOCK();
        } else
                fpusave_proc(p, 1);

        /* Ok, try to do the actual operation (finally) */
        if (isload) {
                err = copyin((caddr_t)addr, buf, sizeof(buf));
                if (err != 0 && (asi & 2) == 0)
                        goto segv;
                if (err == 0) {
                        if (asi & 8)
                                swap_quad(buf);
                        bcopy(buf, &fs->fs_regs[freg], sizeof(buf));
                }
        } else {
                bcopy(&fs->fs_regs[freg], buf, sizeof(buf));
                if (asi & 8)
                        swap_quad(buf);
                if (copyout(buf, (caddr_t)addr, sizeof(buf)) && (asi & 2) == 0)
                        goto segv;
        }

        return (1);

segv:
        trapsignal(p, SIGSEGV, isload ? PROT_READ : PROT_WRITE,
            SEGV_MAPERR, sv);
        return (0);
}

int
emul_popc(int32_t insv, struct proc *p, union sigval sv, struct trapframe *tf)
{
        u_int64_t val, ret = 0;
        union instr ins;

        ins.i_int = insv;
        if (ins.i_simm13.i_i == 0)
                val = tf->tf_global[ins.i_asi.i_rs2];
        else
                val = SIGN_EXT13(ins.i_simm13.i_simm13);

        for (; val != 0; val >>= 1)
                ret += val & 1;

        tf->tf_global[ins.i_asi.i_rd] = ret;
        return (1);
}