NetBSD/sys/dev/md.c

517 lines
12 KiB
C

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