/*	$NetBSD: mappedcopy.c,v 1.26 2011/02/08 20:20:16 rmind Exp $	*/

/*
 * XXX This doesn't work yet.  Soon.  --thorpej@NetBSD.org
 */

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1982, 1986, 1990, 1993
 *	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.
 *
 * 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 $Hdr: vm_machdep.c 1.21 91/04/06$
 *
 *	@(#)vm_machdep.c	8.6 (Berkeley) 1/12/94
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: mappedcopy.c,v 1.26 2011/02/08 20:20:16 rmind Exp $");

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

#include <uvm/uvm_extern.h>

#include <machine/cpu.h>

#ifdef DEBUG
#define	MDB_COPYIN	0x01
#define	MDB_COPYOUT	0x02
int	mappedcopydebug = 0;

int	mappedcopyincount;
int	mappedcopyoutcount;
#endif

/*
 * This turns off mappedcopy by default.  Ports initialize the
 * threshold in initcpu().
 */
u_int	mappedcopysize = -1;

static void *caddr1 = 0;

int
mappedcopyin(void *f, void *t, size_t count)
{
	void *fromp = f, *top = t;
	vaddr_t kva;
	paddr_t upa;
	register size_t len;
	int off, alignable;
	pmap_t upmap;
#define CADDR1 caddr1

#ifdef DEBUG
	if (mappedcopydebug & MDB_COPYIN)
		printf("mappedcopyin(%p, %p, %lu), pid %d\n",
		    fromp, top, (u_long)count, curproc->p_pid);
	mappedcopyincount++;
#endif

	if (CADDR1 == 0)
		CADDR1 = (void *) uvm_km_alloc(kernel_map, PAGE_SIZE, 0,
		    UVM_KMF_VAONLY);

	kva = (vaddr_t)CADDR1;
	off = (int)((u_long)fromp & PAGE_MASK);
	alignable = (off == ((u_long)top & PAGE_MASK));
	upmap = vm_map_pmap(&curproc->p_vmspace->vm_map);
	while (count > 0) {
		/*
		 * First access of a page, use fubyte to make sure
		 * page is faulted in and read access allowed.
		 */
		if (fubyte(fromp) == -1)
			return EFAULT;
		/*
		 * Map in the page and memcpy data in from it
		 */
		if (pmap_extract(upmap, trunc_page((vaddr_t)fromp), &upa)
		    == false)
			panic("mappedcopyin: null page frame");
		len = min(count, (PAGE_SIZE - off));
		pmap_enter(pmap_kernel(), kva, upa,
		    VM_PROT_READ, VM_PROT_READ | PMAP_WIRED);
		pmap_update(pmap_kernel());
		if (len == PAGE_SIZE && alignable && off == 0)
			copypage((void *)kva, top);
		else
			memcpy(top, (void *)(kva + off), len);
		fromp += len;
		top += len;
		count -= len;
		off = 0;
	}
	pmap_remove(pmap_kernel(), kva, kva + PAGE_SIZE);
	pmap_update(pmap_kernel());
	return 0;
#undef CADDR1
}

int
mappedcopyout(void *f, void *t, size_t count)
{
	void *fromp = f, *top = t;
	vaddr_t kva;
	paddr_t upa;
	size_t len;
	int off, alignable;
	pmap_t upmap;
#define CADDR2 caddr1

#ifdef DEBUG
	if (mappedcopydebug & MDB_COPYOUT)
		printf("mappedcopyout(%p, %p, %lu), pid %d\n",
		    fromp, top, (u_long)count, curproc->p_pid);
	mappedcopyoutcount++;
#endif

	if (CADDR2 == 0)
		CADDR2 = (void *) uvm_km_alloc(kernel_map, PAGE_SIZE, 0,
		    UVM_KMF_VAONLY);

	kva = (vaddr_t) CADDR2;
	off = (int)((u_long)top & PAGE_MASK);
	alignable = (off == ((u_long)fromp & PAGE_MASK));
	upmap = vm_map_pmap(&curproc->p_vmspace->vm_map);
	while (count > 0) {
		/*
		 * First access of a page, use subyte to make sure
		 * page is faulted in and write access allowed.
		 */
		if (subyte(top, *((char *)fromp)) == -1)
			return EFAULT;
		/*
		 * Map in the page and memcpy data out to it
		 */
		if (pmap_extract(upmap, trunc_page((vaddr_t)top), &upa)
		    == false)
			panic("mappedcopyout: null page frame");
		len = min(count, (PAGE_SIZE - off));
		pmap_enter(pmap_kernel(), kva, upa,
		    VM_PROT_READ|VM_PROT_WRITE,
		    VM_PROT_READ|VM_PROT_WRITE|PMAP_WIRED);
		pmap_update(pmap_kernel());
		if (len == PAGE_SIZE && alignable && off == 0)
			copypage(fromp, (void *)kva);
		else
			memcpy((void *)(kva + off), fromp, len);
		fromp += len;
		top += len;
		count -= len;
		off = 0;
	}
	pmap_remove(pmap_kernel(), kva, kva + PAGE_SIZE);
	pmap_update(pmap_kernel());
	return 0;
#undef CADDR2
}