/*      $OpenBSD: syscall.c,v 1.29 2026/03/08 17:07:31 deraadt Exp $    */
/*      $NetBSD: syscall.c,v 1.24 2003/11/14 19:03:17 scw Exp $ */

/*-
 * Copyright (c) 2000, 2003 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Charles M. Hannum.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Copyright (c) 1994-1998 Mark Brinicombe.
 * Copyright (c) 1994 Brini.
 * All rights reserved.
 *
 * This code is derived from software written for Brini by Mark Brinicombe
 *
 * 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 Mark Brinicombe
 *      for the NetBSD Project.
 * 4. The name of the company nor the name of the author may be used to
 *    endorse or promote products derived from this software without specific
 *    prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 * syscall entry handling
 *
 * Created      : 09/11/94
 */

#include <sys/param.h>

#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/syscall.h>
#include <sys/syscall_mi.h>

#include <uvm/uvm_extern.h>

#include <machine/cpu.h>
#include <machine/frame.h>
#include <machine/pcb.h>
#include <arm/vfp.h>

#define MAXARGS 8

void
swi_handler(trapframe_t *frame)
{
        struct proc *p = curproc;
        const struct sysent *callp = sysent;
        int code, error;
        u_int nap = 4, nargs;
        register_t *ap, *args, copyargs[MAXARGS], rval[2];

        atomic_inc_int(&uvmexp.syscalls);

        /* Before enabling interrupts, save FPU state */
        vfp_save();

        enable_interrupts(PSR_I);

        p->p_addr->u_pcb.pcb_tf = frame;

        /* Skip over speculation-blocking barrier. */
        frame->tf_pc += 8;

        ap = &frame->tf_r0;

        code = frame->tf_r12;
        // XXX out of range stays on syscall0, which we assume is enosys
        if (code > 0 && code < SYS_MAXSYSCALL)
                callp += code;

        nargs = callp->sy_argsize / sizeof(register_t);
        if (nargs <= nap) {
                args = ap;
        } else {
                KASSERT(nargs <= MAXARGS);
                memcpy(copyargs, ap, nap * sizeof(register_t));
                if ((error = copyin((void *)frame->tf_usr_sp, copyargs + nap,
                    (nargs - nap) * sizeof(register_t))))
                        goto bad;
                args = copyargs;
        }

        rval[0] = 0;
        rval[1] = frame->tf_r1;

        error = mi_syscall(p, code, callp, args, rval);

        switch (error) {
        case 0:
                frame->tf_r0 = rval[0];
                frame->tf_r1 = rval[1];
                frame->tf_spsr &= ~PSR_C;       /* carry bit */
                break;
        case ERESTART:
                /*
                 * Reconstruct the pc to point at the swi.
                 */
                frame->tf_pc -= 12;
                break;
        case EJUSTRETURN:
                /* nothing to do */
                break;
        default:
        bad:
                frame->tf_r0 = error;
                frame->tf_spsr |= PSR_C;        /* carry bit */
                break;
        }

        mi_syscall_return(p, code, error, rval);
}

void
child_return(void *arg)
{
        struct proc *p = arg;
        struct trapframe *frame = p->p_addr->u_pcb.pcb_tf;

        frame->tf_r0 = 0;
        frame->tf_spsr &= ~PSR_C;       /* carry bit */

        KERNEL_UNLOCK();

        mi_child_return(p);
}