517 lines
12 KiB
C
517 lines
12 KiB
C
/* $NetBSD: md.c,v 1.48 2007/03/04 06:01:42 christos Exp $ */
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/*
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* Copyright (c) 1995 Gordon W. Ross, Leo Weppelman.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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* 4. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by
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* Gordon W. Ross and Leo Weppelman.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* This implements a general-purpose memory-disk.
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* See md.h for notes on the config types.
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*
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* Note that this driver provides the same functionality
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* as the MFS filesystem hack, but this is better because
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* you can use this for any filesystem type you'd like!
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*
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* Credit for most of the kmem ramdisk code goes to:
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* Leo Weppelman (atari) and Phil Nelson (pc532)
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* Credit for the ideas behind the "user space memory" code goes
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* to the authors of the MFS implementation.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: md.c,v 1.48 2007/03/04 06:01:42 christos Exp $");
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#include "opt_md.h"
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/malloc.h>
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#include <sys/systm.h>
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#include <sys/buf.h>
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#include <sys/bufq.h>
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#include <sys/device.h>
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#include <sys/disk.h>
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#include <sys/proc.h>
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#include <sys/conf.h>
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#include <sys/disklabel.h>
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#include <uvm/uvm_extern.h>
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#include <dev/md.h>
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/*
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* By default, include the user-space functionality.
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* Use `options MEMORY_DISK_SERVER=0' to turn it off.
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*/
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#ifndef MEMORY_DISK_SERVER
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#define MEMORY_DISK_SERVER 1
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#endif /* MEMORY_DISK_SERVER */
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/*
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* We should use the raw partition for ioctl.
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*/
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#define MD_MAX_UNITS 0x10
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#define MD_UNIT(unit) DISKUNIT(unit)
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/* autoconfig stuff... */
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struct md_softc {
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struct device sc_dev; /* REQUIRED first entry */
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struct disk sc_dkdev; /* hook for generic disk handling */
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struct md_conf sc_md;
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struct bufq_state *sc_buflist;
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};
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/* shorthand for fields in sc_md: */
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#define sc_addr sc_md.md_addr
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#define sc_size sc_md.md_size
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#define sc_type sc_md.md_type
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void mdattach(int);
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static void md_attach(struct device *, struct device *, void *);
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static dev_type_open(mdopen);
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static dev_type_close(mdclose);
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static dev_type_read(mdread);
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static dev_type_write(mdwrite);
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static dev_type_ioctl(mdioctl);
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static dev_type_strategy(mdstrategy);
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static dev_type_size(mdsize);
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const struct bdevsw md_bdevsw = {
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mdopen, mdclose, mdstrategy, mdioctl, nodump, mdsize, D_DISK
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};
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const struct cdevsw md_cdevsw = {
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mdopen, mdclose, mdread, mdwrite, mdioctl,
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nostop, notty, nopoll, nommap, nokqfilter, D_DISK
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};
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static struct dkdriver mddkdriver = { mdstrategy, NULL };
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static int ramdisk_ndevs;
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static void *ramdisk_devs[MD_MAX_UNITS];
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/*
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* This is called if we are configured as a pseudo-device
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*/
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void
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mdattach(int n)
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{
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struct md_softc *sc;
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int i;
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#ifdef DIAGNOSTIC
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if (ramdisk_ndevs) {
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aprint_error("ramdisk: multiple attach calls?\n");
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return;
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}
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#endif
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/* XXX: Are we supposed to provide a default? */
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if (n <= 1)
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n = 1;
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if (n > MD_MAX_UNITS)
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n = MD_MAX_UNITS;
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ramdisk_ndevs = n;
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/* Attach as if by autoconfig. */
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for (i = 0; i < n; i++) {
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sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT|M_ZERO);
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if (!sc) {
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aprint_error("ramdisk: malloc for attach failed!\n");
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return;
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}
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ramdisk_devs[i] = sc;
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sc->sc_dev.dv_unit = i;
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snprintf(sc->sc_dev.dv_xname, sizeof(sc->sc_dev.dv_xname),
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"md%d", i);
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md_attach(NULL, &sc->sc_dev, NULL);
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}
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}
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static void
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md_attach(struct device *parent, struct device *self,
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void *aux)
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{
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struct md_softc *sc = (struct md_softc *)self;
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bufq_alloc(&sc->sc_buflist, "fcfs", 0);
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/* XXX - Could accept aux info here to set the config. */
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#ifdef MEMORY_DISK_HOOKS
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/*
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* This external function might setup a pre-loaded disk.
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* All it would need to do is setup the md_conf struct.
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* See sys/dev/md_root.c for an example.
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*/
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md_attach_hook(device_unit(&sc->sc_dev), &sc->sc_md);
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#endif
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/*
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* Initialize and attach the disk structure.
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*/
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sc->sc_dkdev.dk_driver = &mddkdriver;
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sc->sc_dkdev.dk_name = sc->sc_dev.dv_xname;
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disk_attach(&sc->sc_dkdev);
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}
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/*
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* operational routines:
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* open, close, read, write, strategy,
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* ioctl, dump, size
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*/
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#if MEMORY_DISK_SERVER
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static int md_server_loop(struct md_softc *sc);
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static int md_ioctl_server(struct md_softc *sc, struct md_conf *umd,
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struct lwp *l);
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#endif /* MEMORY_DISK_SERVER */
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static int md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd,
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struct lwp *l);
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static int
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mdsize(dev_t dev)
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{
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int unit;
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struct md_softc *sc;
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unit = MD_UNIT(dev);
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if (unit >= ramdisk_ndevs)
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return 0;
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sc = ramdisk_devs[unit];
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if (sc == NULL)
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return 0;
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if (sc->sc_type == MD_UNCONFIGURED)
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return 0;
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return (sc->sc_size >> DEV_BSHIFT);
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}
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static int
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mdopen(dev_t dev, int flag, int fmt, struct lwp *l)
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{
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int unit;
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struct md_softc *sc;
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unit = MD_UNIT(dev);
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if (unit >= ramdisk_ndevs)
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return ENXIO;
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sc = ramdisk_devs[unit];
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if (sc == NULL)
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return ENXIO;
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/*
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* The raw partition is used for ioctl to configure.
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*/
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if (DISKPART(dev) == RAW_PART)
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return 0;
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#ifdef MEMORY_DISK_HOOKS
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/* Call the open hook to allow loading the device. */
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md_open_hook(unit, &sc->sc_md);
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#endif
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/*
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* This is a normal, "slave" device, so
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* enforce initialized.
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*/
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if (sc->sc_type == MD_UNCONFIGURED)
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return ENXIO;
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return 0;
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}
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static int
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mdclose(dev_t dev, int flag, int fmt, struct lwp *l)
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{
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int unit;
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unit = MD_UNIT(dev);
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if (unit >= ramdisk_ndevs)
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return ENXIO;
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return 0;
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}
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static int
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mdread(dev_t dev, struct uio *uio, int flags)
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{
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int unit;
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struct md_softc *sc;
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unit = MD_UNIT(dev);
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if (unit >= ramdisk_ndevs)
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return ENXIO;
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sc = ramdisk_devs[unit];
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if (sc->sc_type == MD_UNCONFIGURED)
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return ENXIO;
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return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio));
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}
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static int
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mdwrite(dev_t dev, struct uio *uio, int flags)
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{
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int unit;
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struct md_softc *sc;
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unit = MD_UNIT(dev);
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if (unit >= ramdisk_ndevs)
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return ENXIO;
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sc = ramdisk_devs[unit];
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if (sc->sc_type == MD_UNCONFIGURED)
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return ENXIO;
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return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio));
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}
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/*
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* Handle I/O requests, either directly, or
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* by passing them to the server process.
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*/
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static void
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mdstrategy(struct buf *bp)
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{
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int unit;
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struct md_softc *sc;
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void * addr;
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size_t off, xfer;
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unit = MD_UNIT(bp->b_dev);
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sc = ramdisk_devs[unit];
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if (sc->sc_type == MD_UNCONFIGURED) {
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bp->b_error = ENXIO;
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bp->b_flags |= B_ERROR;
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goto done;
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}
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switch (sc->sc_type) {
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#if MEMORY_DISK_SERVER
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case MD_UMEM_SERVER:
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/* Just add this job to the server's queue. */
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BUFQ_PUT(sc->sc_buflist, bp);
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wakeup((void *)sc);
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/* see md_server_loop() */
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/* no biodone in this case */
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return;
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#endif /* MEMORY_DISK_SERVER */
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case MD_KMEM_FIXED:
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case MD_KMEM_ALLOCATED:
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/* These are in kernel space. Access directly. */
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bp->b_resid = bp->b_bcount;
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off = (bp->b_blkno << DEV_BSHIFT);
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if (off >= sc->sc_size) {
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if (bp->b_flags & B_READ)
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break; /* EOF */
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goto set_eio;
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}
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xfer = bp->b_resid;
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if (xfer > (sc->sc_size - off))
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xfer = (sc->sc_size - off);
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addr = (char *)sc->sc_addr + off;
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if (bp->b_flags & B_READ)
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memcpy(bp->b_data, addr, xfer);
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else
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memcpy(addr, bp->b_data, xfer);
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bp->b_resid -= xfer;
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break;
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default:
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bp->b_resid = bp->b_bcount;
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set_eio:
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bp->b_error = EIO;
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bp->b_flags |= B_ERROR;
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break;
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}
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done:
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biodone(bp);
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}
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static int
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mdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
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{
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int unit;
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struct md_softc *sc;
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struct md_conf *umd;
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unit = MD_UNIT(dev);
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sc = ramdisk_devs[unit];
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/* If this is not the raw partition, punt! */
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if (DISKPART(dev) != RAW_PART)
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return ENOTTY;
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umd = (struct md_conf *)data;
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switch (cmd) {
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case MD_GETCONF:
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*umd = sc->sc_md;
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return 0;
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case MD_SETCONF:
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/* Can only set it once. */
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if (sc->sc_type != MD_UNCONFIGURED)
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break;
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switch (umd->md_type) {
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case MD_KMEM_ALLOCATED:
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return md_ioctl_kalloc(sc, umd, l);
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#if MEMORY_DISK_SERVER
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case MD_UMEM_SERVER:
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return md_ioctl_server(sc, umd, l);
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#endif /* MEMORY_DISK_SERVER */
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default:
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break;
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}
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break;
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}
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return EINVAL;
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}
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/*
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* Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED)
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* Just allocate some kernel memory and return.
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*/
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static int
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md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd,
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struct lwp *l)
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{
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vaddr_t addr;
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vsize_t size;
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/* Sanity check the size. */
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size = umd->md_size;
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addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_WIRED|UVM_KMF_ZERO);
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if (!addr)
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return ENOMEM;
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/* This unit is now configured. */
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sc->sc_addr = (void *)addr; /* kernel space */
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sc->sc_size = (size_t)size;
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sc->sc_type = MD_KMEM_ALLOCATED;
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return 0;
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}
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#if MEMORY_DISK_SERVER
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/*
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* Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER)
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* Set config, then become the I/O server for this unit.
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*/
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static int
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md_ioctl_server(struct md_softc *sc, struct md_conf *umd,
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struct lwp *l)
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{
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vaddr_t end;
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int error;
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/* Sanity check addr, size. */
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end = (vaddr_t) ((char *)umd->md_addr + umd->md_size);
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if ((end >= VM_MAXUSER_ADDRESS) ||
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(end < ((vaddr_t) umd->md_addr)) )
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return EINVAL;
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/* This unit is now configured. */
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sc->sc_addr = umd->md_addr; /* user space */
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sc->sc_size = umd->md_size;
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sc->sc_type = MD_UMEM_SERVER;
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/* Become the server daemon */
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error = md_server_loop(sc);
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/* This server is now going away! */
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sc->sc_type = MD_UNCONFIGURED;
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sc->sc_addr = 0;
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sc->sc_size = 0;
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return (error);
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}
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static int md_sleep_pri = PWAIT | PCATCH;
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static int
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md_server_loop(struct md_softc *sc)
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{
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struct buf *bp;
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void *addr; /* user space address */
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size_t off; /* offset into "device" */
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size_t xfer; /* amount to transfer */
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int error;
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for (;;) {
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/* Wait for some work to arrive. */
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while ((bp = BUFQ_GET(sc->sc_buflist)) == NULL) {
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error = tsleep((void *)sc, md_sleep_pri, "md_idle", 0);
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if (error)
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return error;
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}
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/* Do the transfer to/from user space. */
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error = 0;
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bp->b_resid = bp->b_bcount;
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off = (bp->b_blkno << DEV_BSHIFT);
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if (off >= sc->sc_size) {
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if (bp->b_flags & B_READ)
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goto done; /* EOF (not an error) */
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error = EIO;
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goto done;
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}
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xfer = bp->b_resid;
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if (xfer > (sc->sc_size - off))
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xfer = (sc->sc_size - off);
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addr = (char *)sc->sc_addr + off;
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if (bp->b_flags & B_READ)
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error = copyin(addr, bp->b_data, xfer);
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else
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error = copyout(bp->b_data, addr, xfer);
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if (!error)
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bp->b_resid -= xfer;
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done:
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if (error) {
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bp->b_error = error;
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bp->b_flags |= B_ERROR;
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}
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biodone(bp);
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}
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}
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#endif /* MEMORY_DISK_SERVER */
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