Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
NetBSD/sys/dev/md.c

719 lines
16 KiB
C
Raw Blame History

/* $NetBSD: md.c,v 1.80 2018/03/03 19:26:12 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.
*
* 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 1.80 2018/03/03 19:26:12 christos Exp $");
#ifdef _KERNEL_OPT
#include "opt_md.h"
#else
#define MEMORY_DISK_SERVER 1
#endif
#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/stat.h>
#include <sys/proc.h>
#include <sys/conf.h>
#include <sys/disklabel.h>
#include <uvm/uvm_extern.h>
#include <dev/md.h>
#include "ioconf.h"
/*
* The user-space functionality is included by default.
* Use `options MEMORY_DISK_SERVER=0' to turn it off.
*/
#ifndef MEMORY_DISK_SERVER
#error MEMORY_DISK_SERVER should be defined by opt_md.h
#endif /* MEMORY_DISK_SERVER */
/*
* We should use the raw partition for ioctl.
*/
#define MD_UNIT(unit) DISKUNIT(unit)
/* autoconfig stuff... */
struct md_softc {
device_t sc_dev; /* Self. */
struct disk sc_dkdev; /* hook for generic disk handling */
struct md_conf sc_md;
kmutex_t sc_lock; /* Protect self. */
kcondvar_t sc_cv; /* Wait here for work. */
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
static void md_attach(device_t, device_t, void *);
static int md_detach(device_t, int);
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 = {
.d_open = mdopen,
.d_close = mdclose,
.d_strategy = mdstrategy,
.d_ioctl = mdioctl,
.d_dump = nodump,
.d_psize = mdsize,
.d_discard = nodiscard,
.d_flag = D_DISK | D_MPSAFE
};
const struct cdevsw md_cdevsw = {
.d_open = mdopen,
.d_close = mdclose,
.d_read = mdread,
.d_write = mdwrite,
.d_ioctl = mdioctl,
.d_stop = nostop,
.d_tty = notty,
.d_poll = nopoll,
.d_mmap = nommap,
.d_kqfilter = nokqfilter,
.d_discard = nodiscard,
.d_flag = D_DISK
};
static struct dkdriver mddkdriver = {
.d_strategy = mdstrategy
};
CFATTACH_DECL3_NEW(md, sizeof(struct md_softc),
0, md_attach, md_detach, NULL, NULL, NULL, DVF_DETACH_SHUTDOWN);
static kmutex_t md_device_lock; /* Protect unit creation / deletion. */
extern size_t md_root_size;
static void md_set_disklabel(struct md_softc *);
/*
* This is called if we are configured as a pseudo-device
*/
void
mdattach(int n)
{
mutex_init(&md_device_lock, MUTEX_DEFAULT, IPL_NONE);
if (config_cfattach_attach(md_cd.cd_name, &md_ca)) {
aprint_error("%s: cfattach_attach failed\n", md_cd.cd_name);
return;
}
}
static void
md_attach(device_t parent, device_t self, void *aux)
{
struct md_softc *sc = device_private(self);
sc->sc_dev = self;
sc->sc_type = MD_UNCONFIGURED;
mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE);
cv_init(&sc->sc_cv, "mdidle");
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(self), &sc->sc_md);
#endif
/*
* Initialize and attach the disk structure.
*/
disk_init(&sc->sc_dkdev, device_xname(self), &mddkdriver);
disk_attach(&sc->sc_dkdev);
if (sc->sc_type != MD_UNCONFIGURED)
md_set_disklabel(sc);
if (!pmf_device_register(self, NULL, NULL))
aprint_error_dev(self, "couldn't establish power handler\n");
}
static int
md_detach(device_t self, int flags)
{
struct md_softc *sc = device_private(self);
int rc;
rc = 0;
mutex_enter(&sc->sc_dkdev.dk_openlock);
if (sc->sc_dkdev.dk_openmask == 0 && sc->sc_type == MD_UNCONFIGURED)
; /* nothing to do */
else if ((flags & DETACH_FORCE) == 0)
rc = EBUSY;
mutex_exit(&sc->sc_dkdev.dk_openlock);
if (rc != 0)
return rc;
pmf_device_deregister(self);
disk_detach(&sc->sc_dkdev);
disk_destroy(&sc->sc_dkdev);
bufq_free(sc->sc_buflist);
mutex_destroy(&sc->sc_lock);
cv_destroy(&sc->sc_cv);
return 0;
}
/*
* 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)
{
struct md_softc *sc;
int res;
sc = device_lookup_private(&md_cd, MD_UNIT(dev));
if (sc == NULL)
return 0;
mutex_enter(&sc->sc_lock);
if (sc->sc_type == MD_UNCONFIGURED)
res = 0;
else
res = sc->sc_size >> DEV_BSHIFT;
mutex_exit(&sc->sc_lock);
return res;
}
static int
mdopen(dev_t dev, int flag, int fmt, struct lwp *l)
{
int unit;
int part = DISKPART(dev);
int pmask = 1 << part;
cfdata_t cf;
struct md_softc *sc;
struct disk *dk;
#ifdef MEMORY_DISK_HOOKS
bool configured;
#endif
mutex_enter(&md_device_lock);
unit = MD_UNIT(dev);
sc = device_lookup_private(&md_cd, unit);
if (sc == NULL) {
if (part != RAW_PART) {
mutex_exit(&md_device_lock);
return ENXIO;
}
cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK);
cf->cf_name = md_cd.cd_name;
cf->cf_atname = md_cd.cd_name;
cf->cf_unit = unit;
cf->cf_fstate = FSTATE_STAR;
sc = device_private(config_attach_pseudo(cf));
if (sc == NULL) {
mutex_exit(&md_device_lock);
return ENOMEM;
}
}
dk = &sc->sc_dkdev;
/*
* The raw partition is used for ioctl to configure.
*/
if (part == RAW_PART)
goto ok;
#ifdef MEMORY_DISK_HOOKS
/* Call the open hook to allow loading the device. */
configured = (sc->sc_type != MD_UNCONFIGURED);
md_open_hook(unit, &sc->sc_md);
/* initialize disklabel if the device is configured in open hook */
if (!configured && sc->sc_type != MD_UNCONFIGURED)
md_set_disklabel(sc);
#endif
/*
* This is a normal, "slave" device, so
* enforce initialized.
*/
if (sc->sc_type == MD_UNCONFIGURED) {
mutex_exit(&md_device_lock);
return ENXIO;
}
ok:
/* XXX duplicates code in dk_open(). Call dk_open(), instead? */
mutex_enter(&dk->dk_openlock);
/* Mark our unit as open. */
switch (fmt) {
case S_IFCHR:
dk->dk_copenmask |= pmask;
break;
case S_IFBLK:
dk->dk_bopenmask |= pmask;
break;
}
dk->dk_openmask = dk->dk_copenmask | dk->dk_bopenmask;
mutex_exit(&dk->dk_openlock);
mutex_exit(&md_device_lock);
return 0;
}
static int
mdclose(dev_t dev, int flag, int fmt, struct lwp *l)
{
int part = DISKPART(dev);
int pmask = 1 << part;
int error;
cfdata_t cf;
struct md_softc *sc;
struct disk *dk;
sc = device_lookup_private(&md_cd, MD_UNIT(dev));
if (sc == NULL)
return ENXIO;
dk = &sc->sc_dkdev;
mutex_enter(&dk->dk_openlock);
switch (fmt) {
case S_IFCHR:
dk->dk_copenmask &= ~pmask;
break;
case S_IFBLK:
dk->dk_bopenmask &= ~pmask;
break;
}
dk->dk_openmask = dk->dk_copenmask | dk->dk_bopenmask;
if (dk->dk_openmask != 0) {
mutex_exit(&dk->dk_openlock);
return 0;
}
mutex_exit(&dk->dk_openlock);
mutex_enter(&md_device_lock);
cf = device_cfdata(sc->sc_dev);
error = config_detach(sc->sc_dev, DETACH_QUIET);
if (! error)
free(cf, M_DEVBUF);
mutex_exit(&md_device_lock);
return error;
}
static int
mdread(dev_t dev, struct uio *uio, int flags)
{
struct md_softc *sc;
sc = device_lookup_private(&md_cd, MD_UNIT(dev));
if (sc == NULL || 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)
{
struct md_softc *sc;
sc = device_lookup_private(&md_cd, MD_UNIT(dev));
if (sc == NULL || 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)
{
struct md_softc *sc;
void * addr;
size_t off, xfer;
bool is_read;
sc = device_lookup_private(&md_cd, MD_UNIT(bp->b_dev));
if (sc == NULL || sc->sc_type == MD_UNCONFIGURED) {
bp->b_error = ENXIO;
goto done;
}
mutex_enter(&sc->sc_lock);
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);
cv_signal(&sc->sc_cv);
mutex_exit(&sc->sc_lock);
/* 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. */
is_read = ((bp->b_flags & B_READ) == B_READ);
bp->b_resid = bp->b_bcount;
off = (bp->b_blkno << DEV_BSHIFT);
if (off >= sc->sc_size) {
if (is_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;
disk_busy(&sc->sc_dkdev);
if (is_read)
memcpy(bp->b_data, addr, xfer);
else
memcpy(addr, bp->b_data, xfer);
disk_unbusy(&sc->sc_dkdev, xfer, is_read);
bp->b_resid -= xfer;
break;
default:
bp->b_resid = bp->b_bcount;
set_eio:
bp->b_error = EIO;
break;
}
mutex_exit(&sc->sc_lock);
done:
biodone(bp);
}
static int
mdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
struct md_softc *sc;
struct md_conf *umd;
int error;
if ((sc = device_lookup_private(&md_cd, MD_UNIT(dev))) == NULL)
return ENXIO;
mutex_enter(&sc->sc_lock);
if (sc->sc_type != MD_UNCONFIGURED) {
error = disk_ioctl(&sc->sc_dkdev, dev, cmd, data, flag, l);
if (error != EPASSTHROUGH) {
mutex_exit(&sc->sc_lock);
return 0;
}
}
/* If this is not the raw partition, punt! */
if (DISKPART(dev) != RAW_PART) {
mutex_exit(&sc->sc_lock);
return ENOTTY;
}
umd = (struct md_conf *)data;
error = EINVAL;
switch (cmd) {
case MD_GETCONF:
*umd = sc->sc_md;
error = 0;
break;
case MD_SETCONF:
/* Can only set it once. */
if (sc->sc_type != MD_UNCONFIGURED)
break;
switch (umd->md_type) {
case MD_KMEM_ALLOCATED:
error = md_ioctl_kalloc(sc, umd, l);
break;
#if MEMORY_DISK_SERVER
case MD_UMEM_SERVER:
error = md_ioctl_server(sc, umd, l);
break;
#endif /* MEMORY_DISK_SERVER */
default:
break;
}
break;
}
mutex_exit(&sc->sc_lock);
return error;
}
static void
md_set_disklabel(struct md_softc *sc)
{
struct disk_geom *dg = &sc->sc_dkdev.dk_geom;
struct disklabel *lp = sc->sc_dkdev.dk_label;
struct partition *pp;
memset(lp, 0, sizeof(*lp));
lp->d_secsize = DEV_BSIZE;
lp->d_secperunit = sc->sc_size / DEV_BSIZE;
if (lp->d_secperunit >= (32*64)) {
lp->d_nsectors = 32;
lp->d_ntracks = 64;
lp->d_ncylinders = lp->d_secperunit / (32*64);
} else {
lp->d_nsectors = 1;
lp->d_ntracks = 1;
lp->d_ncylinders = lp->d_secperunit;
}
lp->d_secpercyl = lp->d_ntracks*lp->d_nsectors;
strncpy(lp->d_typename, md_cd.cd_name, sizeof(lp->d_typename));
lp->d_type = DKTYPE_MD;
strncpy(lp->d_packname, "fictitious", sizeof(lp->d_packname));
lp->d_rpm = 3600;
lp->d_interleave = 1;
lp->d_flags = 0;
pp = &lp->d_partitions[0];
pp->p_offset = 0;
pp->p_size = lp->d_secperunit;
pp->p_fstype = FS_BSDFFS;
pp = &lp->d_partitions[RAW_PART];
pp->p_offset = 0;
pp->p_size = lp->d_secperunit;
pp->p_fstype = FS_UNUSED;
lp->d_npartitions = RAW_PART+1;
lp->d_magic = DISKMAGIC;
lp->d_magic2 = DISKMAGIC;
lp->d_checksum = dkcksum(lp);
memset(dg, 0, sizeof(*dg));
dg->dg_secsize = lp->d_secsize;
dg->dg_secperunit = lp->d_secperunit;
dg->dg_nsectors = lp->d_nsectors;
dg->dg_ntracks = lp->d_ntracks = 64;;
dg->dg_ncylinders = lp->d_ncylinders;
disk_set_info(sc->sc_dev, &sc->sc_dkdev, NULL);
}
/*
* 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;
mutex_exit(&sc->sc_lock);
/* Sanity check the size. */
size = umd->md_size;
addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_WIRED|UVM_KMF_ZERO);
mutex_enter(&sc->sc_lock);
if (!addr)
return ENOMEM;
/* If another thread beat us to configure this unit: fail. */
if (sc->sc_type != MD_UNCONFIGURED) {
uvm_km_free(kernel_map, addr, size, UVM_KMF_WIRED);
return EINVAL;
}
/* This unit is now configured. */
sc->sc_addr = (void *)addr; /* kernel space */
sc->sc_size = (size_t)size;
sc->sc_type = MD_KMEM_ALLOCATED;
md_set_disklabel(sc);
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;
KASSERT(mutex_owned(&sc->sc_lock));
/* Sanity check addr, size. */
end = (vaddr_t) ((char *)umd->md_addr + umd->md_size);
if (
#ifndef _RUMPKERNEL
/*
* On some architectures (e.g. powerpc) rump kernel provides
* "safe" low defaults which make this test fail since malloc
* does return higher addresses than the "safe" default.
*/
(end >= VM_MAXUSER_ADDRESS) ||
#endif
(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;
md_set_disklabel(sc);
/* 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_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;
bool is_read;
KASSERT(mutex_owned(&sc->sc_lock));
for (;;) {
/* Wait for some work to arrive. */
while ((bp = bufq_get(sc->sc_buflist)) == NULL) {
error = cv_wait_sig(&sc->sc_cv, &sc->sc_lock);
if (error)
return error;
}
/* Do the transfer to/from user space. */
mutex_exit(&sc->sc_lock);
error = 0;
is_read = ((bp->b_flags & B_READ) == B_READ);
bp->b_resid = bp->b_bcount;
off = (bp->b_blkno << DEV_BSHIFT);
if (off >= sc->sc_size) {
if (is_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;
disk_busy(&sc->sc_dkdev);
if (is_read)
error = copyin(addr, bp->b_data, xfer);
else
error = copyout(bp->b_data, addr, xfer);
disk_unbusy(&sc->sc_dkdev, (error ? 0 : xfer), is_read);
if (!error)
bp->b_resid -= xfer;
done:
if (error) {
bp->b_error = error;
}
biodone(bp);
mutex_enter(&sc->sc_lock);
}
}
#endif /* MEMORY_DISK_SERVER */
Reference in New Issue View Git Blame Copy Permalink