/* $NetBSD: vm_machdep.c,v 1.5 2018/01/24 09:04:45 skrll Exp $ */

/*-
 * Copyright (c) 2007 Jared D. McNeill <jmcneill@invisible.ca>
 * 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 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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.5 2018/01/24 09:04:45 skrll Exp $");

#include <sys/param.h>
#include <sys/buf.h>
#include <sys/proc.h>

#include <uvm/uvm_extern.h>


/*
 * Map a user I/O request into kernel virtual address space.
 * Note: the pages are already locked by uvm_vslock(), so we
 * do not need to pass an access_type to pmap_enter().
 */
/* This code was originally stolen from the alpha port. */

int
vmapbuf(struct buf *bp, vsize_t len)
{
        vaddr_t faddr, taddr, off;
        paddr_t pa;
        struct proc *p;
        vm_prot_t prot;

        if ((bp->b_flags & B_PHYS) == 0)
                panic("vmapbuf");
        p = bp->b_proc;
        bp->b_saveaddr = bp->b_data;
        faddr = trunc_page((vaddr_t)bp->b_data);
        off = (vaddr_t)bp->b_data - faddr;
        len = round_page(off + len);
        taddr = uvm_km_alloc(phys_map, len, 0, UVM_KMF_VAONLY | UVM_KMF_WAITVA);
        bp->b_data = (void *)(taddr + off);
        len = atop(len);
        prot = bp->b_flags & B_READ ? VM_PROT_READ | VM_PROT_WRITE :
                                      VM_PROT_READ;
        while (len--) {
                if (pmap_extract(vm_map_pmap(&p->p_vmspace->vm_map), faddr,
                    &pa) == false)
                        panic("vmapbuf: null page frame");
                pmap_enter(vm_map_pmap(phys_map), taddr, trunc_page(pa),
                    prot, prot | PMAP_WIRED);
                faddr += PAGE_SIZE;
                taddr += PAGE_SIZE;
        }
        pmap_update(vm_map_pmap(phys_map));

        return 0;
}

/*
 * Unmap a previously-mapped user I/O request.
 */
void
vunmapbuf(struct buf *bp, vsize_t len)
{
        vaddr_t addr, off;

        if ((bp->b_flags & B_PHYS) == 0)
                panic("vunmapbuf");
        addr = trunc_page((vaddr_t)bp->b_data);
        off = (vaddr_t)bp->b_data - addr;
        len = round_page(off + len);
        pmap_remove(vm_map_pmap(phys_map), addr, addr + len);
        pmap_update(vm_map_pmap(phys_map));
        uvm_km_free(phys_map, addr, len, UVM_KMF_VAONLY);
        bp->b_data = bp->b_saveaddr;
        bp->b_saveaddr = NULL;
}