/*-
 * 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 $Hdr: mem.c 1.13 89/10/08$
 */

#include <sys/cdefs.h>
/*
 * 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/vm_param.h>
#include <vm/vm_page.h>
#include <vm/vm_phys.h>
#include <vm/vm_dumpset.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>

#include <machine/memdev.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, PAGE_SIZE, v,
                            VM_MEMATTR_DEFAULT);
                        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);
}

int
memioctl_md(struct cdev *dev __unused, u_long cmd __unused,
    caddr_t data __unused, int flags __unused, struct thread *td __unused)
{
        return (ENOTTY);
}