/*	$OpenBSD: syscall.c,v 1.28 2023/12/13 15:57:22 miod 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];

	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);
}