/*-
 * Copyright (c) 2011 Advanced Computing Technologies LLC
 * Written by: John H. Baldwin <jhb@FreeBSD.org>
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 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.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/*
 * Simple driver to demonstrate the d_mmap() method by exporting a read-only
 * uncacheable mapping of the local APIC.
 */

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/mman.h>
#include <sys/module.h>
#include <sys/systm.h>
#include <vm/vm.h>
#include <machine/intr_machdep.h>
#include <machine/apicvar.h>

static d_mmap_t		lapicdev_mmap;

static struct cdevsw lapicdev_cdevsw = {
	.d_version =	D_VERSION,
	.d_mmap =	lapicdev_mmap,
	.d_name =	"lapicdev",
};

static int
lapicdev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
    int nprot, vm_memattr_t *memattr)
{
	/* Local APIC is only a single page. */
	if (offset != 0)
		return (EINVAL);

	/* Only read mappings are permitted. */
	if (nprot != PROT_READ)
		return (EINVAL);

	*paddr = lapic_paddr;
	*memattr = VM_MEMATTR_UNCACHEABLE;
	return (0);
}

static int
lapicdev_modevent(module_t mod, int type, void *arg)
{
	static struct cdev *lapicdev;

	switch (type) {
	case MOD_LOAD:
		lapicdev = make_dev(&lapicdev_cdevsw, 0, UID_ROOT, GID_WHEEL,
		    0400, "lapic");
		if (lapicdev == NULL) {
			printf("lapicdev: Failed to create /dev/lapic\n");
			return (ENXIO);
		}
		break;
	case MOD_UNLOAD:
		if (lapicdev != NULL)
			destroy_dev(lapicdev);
		break;
	case MOD_SHUTDOWN:
		break;
	default:
		return (EOPNOTSUPP);
	}
	return (0);
}

DEV_MODULE(lapicdev, lapicdev_modevent, NULL);