/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department, and code derived from software contributed to
 * Berkeley by William Jolitz.
 *
 * 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. 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.
 *
 *	from: Utah $Hdr: mem.c 1.13 89/10/08$
 *	from: @(#)mem.c	7.2 (Berkeley) 5/9/91
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: releng/12.0/sys/arm/arm/mem.c 326023 2017-11-20 19:43:44Z pfg $");

/*
 * Memory special file
 */

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/ioccom.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/memrange.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/sx.h>
#include <sys/systm.h>
#include <sys/uio.h>

#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>

#include <machine/memdev.h>
#include <machine/vmparam.h>

/*
 * Used in /dev/mem drivers and elsewhere
 */
MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");

struct mem_range_softc mem_range_softc;

static struct sx tmppt_lock;
SX_SYSINIT(tmppt, &tmppt_lock, "mem4map");

/* ARGSUSED */
int
memrw(struct cdev *dev, struct uio *uio, int flags)
{
	int o;
	u_int c = 0, v;
	struct iovec *iov;
	int error = 0;
	vm_offset_t addr, eaddr;

	while (uio->uio_resid > 0 && error == 0) {
		iov = uio->uio_iov;
		if (iov->iov_len == 0) {
			uio->uio_iov++;
			uio->uio_iovcnt--;
			if (uio->uio_iovcnt < 0)
				panic("memrw");
			continue;
		}
		if (dev2unit(dev) == CDEV_MINOR_MEM) {
			int i;
			int address_valid = 0;

			v = uio->uio_offset;
			v &= ~PAGE_MASK;
			for (i = 0; dump_avail[i] || dump_avail[i + 1];
			i += 2) {
				if (v >= dump_avail[i] &&
				    v < dump_avail[i + 1]) {
					address_valid = 1;
					break;
				}
			}
			if (!address_valid)
				return (EINVAL);
			sx_xlock(&tmppt_lock);
			pmap_kenter((vm_offset_t)_tmppt, v);
#if __ARM_ARCH >= 6
			pmap_tlb_flush(kernel_pmap, (vm_offset_t)_tmppt);
#endif
			o = (int)uio->uio_offset & PAGE_MASK;
			c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK));
			c = min(c, (u_int)(PAGE_SIZE - o));
			c = min(c, (u_int)iov->iov_len);
			error = uiomove((caddr_t)&_tmppt[o], (int)c, uio);
			pmap_qremove((vm_offset_t)_tmppt, 1);
			sx_xunlock(&tmppt_lock);
			continue;
		}
		else if (dev2unit(dev) == CDEV_MINOR_KMEM) {
			c = iov->iov_len;

			/*
			 * Make sure that all of the pages are currently
			 * resident so that we don't create any zero-fill
			 * pages.
			 */
			addr = trunc_page(uio->uio_offset);
			eaddr = round_page(uio->uio_offset + c);

			for (; addr < eaddr; addr += PAGE_SIZE)
				if (pmap_extract(kernel_pmap, addr) == 0)
					return (EFAULT);
			if (!kernacc((caddr_t)(int)uio->uio_offset, c,
			    uio->uio_rw == UIO_READ ?
			    VM_PROT_READ : VM_PROT_WRITE))
					return (EFAULT);
			error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio);
			continue;
		}
		/* else panic! */
	}
	return (error);
}

/*
 * allow user processes to MMAP some memory sections
 * instead of going through read/write
 */
/* ARGSUSED */

int
memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
    int prot __unused, vm_memattr_t *memattr __unused)
{
	if (dev2unit(dev) == CDEV_MINOR_MEM) {
		*paddr = offset;
		return (0);
	}
	return (-1);
}
