/*-
 * 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/kernel.h>
#include <sys/lock.h>
#include <sys/ioccom.h>
#include <sys/malloc.h>
#include <sys/memrange.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/msgbuf.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
#include <sys/uio.h>

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

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

#include <machine/memdev.h>

static void ppc_mrinit(struct mem_range_softc *);
static int ppc_mrset(struct mem_range_softc *, struct mem_range_desc *, int *);

MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");

static struct mem_range_ops ppc_mem_range_ops = {
        ppc_mrinit,
        ppc_mrset,
        NULL,
        NULL
};
struct mem_range_softc mem_range_softc = {
        &ppc_mem_range_ops,
        0, 0, NULL
}; 

/* ARGSUSED */
int
memrw(struct cdev *dev, struct uio *uio, int flags)
{
        struct iovec *iov;
        int error = 0;
        vm_offset_t va, eva, off, v;
        vm_prot_t prot;
        struct vm_page m;
        vm_page_t marr;
        vm_size_t cnt;
        ssize_t orig_resid;

        cnt = 0;
        error = 0;
        orig_resid = uio->uio_resid;

        while (uio->uio_resid > 0 && !error) {
                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) {
                        v = uio->uio_offset;

kmem_direct_mapped:     off = v & PAGE_MASK;
                        cnt = PAGE_SIZE - ((vm_offset_t)iov->iov_base &
                            PAGE_MASK);
                        cnt = min(cnt, PAGE_SIZE - off);
                        cnt = min(cnt, iov->iov_len);

                        if (mem_valid(v, cnt)) {
                                error = EFAULT;
                                break;
                        }

                        if (hw_direct_map && !pmap_dev_direct_mapped(v, cnt)) {
                                error = uiomove(PHYS_TO_DMAP(v), cnt, uio);
                        } else {
                                m.phys_addr = trunc_page(v);
                                marr = &m;
                                error = uiomove_fromphys(&marr, off, cnt, uio);
                        }
                }
                else if (dev2unit(dev) == CDEV_MINOR_KMEM) {
                        va = uio->uio_offset;

                        if (hw_direct_map &&
                            ((va < VM_MIN_KERNEL_ADDRESS) || (va > virtual_end))) {
                                v = DMAP_TO_PHYS(va);
                                goto kmem_direct_mapped;
                        }

                        va = trunc_page(uio->uio_offset);
                        eva = round_page(uio->uio_offset
                            + iov->iov_len);

                        /* 
                         * Make sure that all the pages are currently resident
                         * so that we don't create any zero-fill pages.
                         */

                        for (; va < eva; va += PAGE_SIZE) {
                                if (pmap_extract(kernel_pmap, va) == 0) {
                                        error = EFAULT;
                                        break;
                                }
                        }
                        if (error != 0)
                                break;

                        prot = (uio->uio_rw == UIO_READ)
                            ? VM_PROT_READ : VM_PROT_WRITE;

                        va = uio->uio_offset;
                        if (((va >= VM_MIN_KERNEL_ADDRESS) && (va <= virtual_end)) &&
                            !kernacc((void *) va, iov->iov_len, prot)) {
                                error = EFAULT;
                                break;
                        }

                        error = uiomove((void *)va, iov->iov_len, uio);
                }
        }
        /*
         * Don't return error if any byte was written.  Read and write
         * can return error only if no i/o was performed.
         */
        if (uio->uio_resid != orig_resid)
                error = 0;
        return (error);
}

/*
 * allow user processes to MMAP some memory sections
 * instead of going through read/write
 */
int
memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
    int prot, vm_memattr_t *memattr)
{
        int i;

        if (dev2unit(dev) == CDEV_MINOR_MEM)
                *paddr = offset;
        else
                return (EFAULT);

        for (i = 0; i < mem_range_softc.mr_ndesc; i++) {
                if (!(mem_range_softc.mr_desc[i].mr_flags & MDF_ACTIVE))
                        continue;

                if (offset >= mem_range_softc.mr_desc[i].mr_base &&
                    offset < mem_range_softc.mr_desc[i].mr_base +
                    mem_range_softc.mr_desc[i].mr_len) {
                        switch (mem_range_softc.mr_desc[i].mr_flags &
                            MDF_ATTRMASK) {
                        case MDF_WRITEBACK:
                                *memattr = VM_MEMATTR_WRITE_BACK;
                                break;
                        case MDF_WRITECOMBINE:
                                *memattr = VM_MEMATTR_WRITE_COMBINING;
                                break;
                        case MDF_UNCACHEABLE:
                                *memattr = VM_MEMATTR_UNCACHEABLE;
                                break;
                        case MDF_WRITETHROUGH:
                                *memattr = VM_MEMATTR_WRITE_THROUGH;
                                break;
                        }

                        break;
                }
        }

        return (0);
}

static void
ppc_mrinit(struct mem_range_softc *sc)
{
        sc->mr_cap = 0;
        sc->mr_ndesc = 8; /* XXX: Should be dynamically expandable */
        sc->mr_desc = malloc(sc->mr_ndesc * sizeof(struct mem_range_desc),
            M_MEMDESC, M_WAITOK | M_ZERO);
}

static int
ppc_mrset(struct mem_range_softc *sc, struct mem_range_desc *desc, int *arg)
{
        int i;

        switch(*arg) {
        case MEMRANGE_SET_UPDATE:
                for (i = 0; i < sc->mr_ndesc; i++) {
                        if (!sc->mr_desc[i].mr_len) {
                                sc->mr_desc[i] = *desc;
                                sc->mr_desc[i].mr_flags |= MDF_ACTIVE;
                                return (0);
                        }
                        if (sc->mr_desc[i].mr_base == desc->mr_base &&
                            sc->mr_desc[i].mr_len == desc->mr_len)
                                return (EEXIST);
                }
                return (ENOSPC);
        case MEMRANGE_SET_REMOVE:
                for (i = 0; i < sc->mr_ndesc; i++)
                        if (sc->mr_desc[i].mr_base == desc->mr_base &&
                            sc->mr_desc[i].mr_len == desc->mr_len) {
                                bzero(&sc->mr_desc[i], sizeof(sc->mr_desc[i]));
                                return (0);
                        }
                return (ENOENT);
        default:
                return (EOPNOTSUPP);
        }

        return (0);
}

/*
 * Operations for changing memory attributes.
 *
 * This is basically just an ioctl shim for mem_range_attr_get
 * and mem_range_attr_set.
 */
int 
memioctl_md(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
    struct thread *td)
{
        int nd, error = 0;
        struct mem_range_op *mo = (struct mem_range_op *)data;
        struct mem_range_desc *md;

        /* is this for us? */
        if ((cmd != MEMRANGE_GET) &&
            (cmd != MEMRANGE_SET))
                return (ENOTTY);

        /* any chance we can handle this? */
        if (mem_range_softc.mr_op == NULL)
                return (EOPNOTSUPP);

        /* do we have any descriptors? */
        if (mem_range_softc.mr_ndesc == 0)
                return (ENXIO);

        switch (cmd) {
        case MEMRANGE_GET:
                nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
                if (nd > 0) {
                        md = (struct mem_range_desc *)
                                malloc(nd * sizeof(struct mem_range_desc),
                                       M_MEMDESC, M_WAITOK);
                        error = mem_range_attr_get(md, &nd);
                        if (!error)
                                error = copyout(md, mo->mo_desc, 
                                        nd * sizeof(struct mem_range_desc));
                        free(md, M_MEMDESC);
                }
                else
                        nd = mem_range_softc.mr_ndesc;
                mo->mo_arg[0] = nd;
                break;
                
        case MEMRANGE_SET:
                md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc),
                                                    M_MEMDESC, M_WAITOK);
                error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
                /* clamp description string */
                md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
                if (error == 0)
                        error = mem_range_attr_set(md, &mo->mo_arg[0]);
                free(md, M_MEMDESC);
                break;
        }
        return (error);
}