NetBSD-5.0.2/sys/arch/acorn26/acorn26/mem.c

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/*	$NetBSD: mem.c,v 1.10 2007/03/05 16:39:21 he Exp $	*/

/*
 * 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.
 */
/*
 * Copyright (c) 1988 University of Utah.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 */

/*
 * Memory special file
 */

#include "opt_compat_netbsd.h"

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: mem.c,v 1.10 2007/03/05 16:39:21 he Exp $");

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/buf.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/fcntl.h>

#include <machine/cpu.h>
#include <machine/memcreg.h>

#include <uvm/uvm_extern.h>

void *zeropage;
int physlock;

dev_type_read(mmrw);
dev_type_ioctl(mmioctl);
dev_type_mmap(mmmmap);

const struct cdevsw mem_cdevsw = {
	nullopen, nullclose, mmrw, mmrw, mmioctl,
	nostop, notty, nopoll, mmmmap, nokqfilter,
};

/*ARGSUSED*/
int
mmrw(dev, uio, flags)
	dev_t dev;
	struct uio *uio;
	int flags;
{
	register vm_offset_t v;
	register int c;
	register struct iovec *iov;
	int error = 0;

	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("mmrw");
			continue;
		}
		switch (minor(dev)) {

		case DEV_MEM:
			/*
			 * On arm26, there's no need to map in the
			 * relevant page, as we've got physical memory
			 * mapped in at another address and can just
			 * use that.
			 */
			v = uio->uio_offset;
			c = min(iov->iov_len, MAXPHYS);
			/* XXX Should use pmap_find(). */
			if (v < 0 ||
			    (char *)v + c > 
			    		(char*)MEMC_PHYS_BASE + ptoa(physmem))
				return EFAULT;
			error = uiomove((char*)MEMC_PHYS_BASE + uio->uio_offset,
					uio->uio_resid, uio);
			continue;

		case DEV_KMEM:
			v = uio->uio_offset;
			c = min(iov->iov_len, MAXPHYS);
			/* Allow reading from physically mapped space. */
			if (((void *)v >= MEMC_PHYS_BASE &&
			     (char *)v + c <
			     	(char*)MEMC_PHYS_BASE + ptoa(physmem)) ||
			    uvm_kernacc((void *)v, c,
					uio->uio_rw == UIO_READ ?
					B_READ : B_WRITE))
				error = uiomove((void *)v, c, uio);
			else
				return (EFAULT);
			break;

		case DEV_NULL:
			if (uio->uio_rw == UIO_WRITE)
				uio->uio_resid = 0;
			return (0);

#ifdef COMPAT_16
		case _DEV_ZERO_oARM:
#endif
		case DEV_ZERO:
			if (uio->uio_rw == UIO_WRITE) {
				uio->uio_resid = 0;
				return (0);
			}
			if (zeropage == NULL) {
				zeropage = (void *)
				    malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
				bzero(zeropage, PAGE_SIZE);
			}
			c = min(iov->iov_len, PAGE_SIZE);
			error = uiomove(zeropage, c, uio);
			break;

		default:
			return (ENXIO);
		}
	}
	if (minor(dev) == DEV_MEM) {
/*unlock:*/
		if (physlock > 1)
			wakeup((void *)&physlock);
		physlock = 0;
	}
	return (error);
}

paddr_t
mmmmap(dev, off, prot)
	dev_t dev;
	off_t off;
	int prot;
{
	int ppn;

	/*
	 * /dev/mem is the only one that makes sense through this
	 * interface.  For /dev/kmem any physaddr we return here
	 * could be transient and hence incorrect or invalid at
	 * a later time.  /dev/null just doesn't make any sense
	 * and /dev/zero is a hack that is handled via the default
	 * pager in mmap().
	 */
	if (minor(dev) != DEV_MEM)
		return (-1);

	/* minor device 0 is physical memory */

	/* XXX This may botch our cacheing assumptions.  Do we care? */
	ppn = atop(off);
	if (ppn >= 0 && ppn < physmem)
		return ppn;
	return -1;
}