/* $NetBSD: md.c,v 1.1.2.1 1995/11/17 23:34:25 gwr 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-puspose RAM-disk.
* See ramdisk.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 RAM" code goes
* to the authors of the MFS implementation.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/device.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
/* Don't want all those other VM headers... */
extern vm_offset_t kmem_alloc __P((vm_map_t, vm_size_t));
#include <dev/ramdisk.h>
/*
* By default, include the user-space functionality.
* Use: option RAMDISK_SERVER=0 to turn it off.
*/
#ifndef RAMDISK_SERVER
#define RAMDISK_SERVER 1
#endif
/*
* XXX: the "control" unit is (base unit + 16).
* We should just use the cdev as the "control", but
* that interferes with the security stuff preventing
* simulatneous use of raw and block devices.
*
* XXX Assumption: 16 RAM-disks are enough!
*/
#define RD_IS_CTRL(unit) (unit & 0x10)
#define RD_UNIT(unit) (unit & 0xF)
/*
* XXX - This is just for a sanity check. Only
* applies to kernel-space RAM disk allocations.
*/
#define RD_KMEM_MAX_SIZE 0x100000 /* 1MB */
/* autoconfig stuff... */
struct rd_softc {
struct device sc_dev; /* REQUIRED first entry */
struct rd_conf sc_rd;
struct buf *sc_buflist;
int sc_flags;
};
/* shorthand for fields in sc_rd: */
#define sc_addr sc_rd.rd_addr
#define sc_size sc_rd.rd_size
#define sc_type sc_rd.rd_type
/* flags */
#define RD_ISOPEN 0x01
#define RD_SERVED 0x02
static int rd_match (struct device *, void *self, void *);
static void rd_attach(struct device *, struct device *self, void *);
struct cfdriver rdcd = {
NULL, "rd", rd_match, rd_attach,
DV_DULL, sizeof(struct rd_softc), NULL, 0 };
static int
rd_match(parent, self, aux)
struct device *parent;
void *self;
void *aux;
{
return(1);
}
static void
rd_attach(parent, self, aux)
struct device *parent, *self;
void *aux;
{
struct rd_softc *sc = (struct rd_softc *)self;
/* XXX - Could accept aux info here to set the config. */
#ifdef RAMDISK_HOOKS
/*
* This external function might setup a pre-loaded disk.
* All it would need to do is setup the rd_conf struct.
* See sys/arch/sun3/dev/rd_root.c for an example.
*/
rd_attach_hook(sc->sc_dev.dv_unit, &sc->sc_rd);
#endif
printf("\n");
}
/*
* operational routines:
* open, close, read, write, strategy,
* ioctl, dump, size
*/
void rdstrategy __P((struct buf *bp));
#if RAMDISK_SERVER
static int rd_server_loop __P((struct rd_softc *sc));
static int rd_ioctl_server __P((struct rd_softc *sc,
struct rd_conf *urd, struct proc *proc));
#endif
int rddump(dev, blkno, va, size)
dev_t dev;
daddr_t blkno;
caddr_t va;
size_t size;
{
return ENODEV;
}
int rdsize(dev_t dev)
{
int unit;
struct rd_softc *sc;
/* Disallow control units. */
unit = minor(dev);
if (unit >= rdcd.cd_ndevs)
return 0;
sc = rdcd.cd_devs[unit];
if (sc == NULL)
return 0;
if (sc->sc_type == RD_UNCONFIGURED)
return 0;
return (sc->sc_size >> DEV_BSHIFT);
}
int rdopen(dev, flag, fmt, proc)
dev_t dev;
int flag, fmt;
struct proc *proc;
{
int md, unit;
struct rd_softc *sc;
md = minor(dev);
unit = RD_UNIT(md);
if (unit >= rdcd.cd_ndevs)
return ENXIO;
sc = rdcd.cd_devs[unit];
if (sc == NULL)
return ENXIO;
/*
* The control device is not exclusive, and can
* open uninitialized units (so you can setconf).
*/
if (RD_IS_CTRL(md))
return 0;
#ifdef RAMDISK_HOOKS
/* Call the open hook to allow loading the device. */
rd_open_hook(unit, &sc->sc_rd);
#endif
/*
* This is a normal, "slave" device, so
* enforce initialized, exclusive open.
*/
if (sc->sc_type == RD_UNCONFIGURED)
return ENXIO;
if (sc->sc_flags & RD_ISOPEN)
return EBUSY;
return 0;
}
int rdclose(dev, flag, fmt, proc)
dev_t dev;
int flag, fmt;
struct proc *proc;
{
int md, unit;
struct rd_softc *sc;
md = minor(dev);
unit = RD_UNIT(md);
sc = rdcd.cd_devs[unit];
if (RD_IS_CTRL(md))
return 0;
/* Normal device. */
sc->sc_flags = 0;
return 0;
}
int
rdread(dev, uio)
dev_t dev;
struct uio *uio;
{
return (physio(rdstrategy, NULL, dev, B_READ, minphys, uio));
}
int
rdwrite(dev, uio)
dev_t dev;
struct uio *uio;
{
return (physio(rdstrategy, NULL, dev, B_WRITE, minphys, uio));
}
/*
* Handle I/O requests, either directly, or
* by passing them to the server process.
*/
void
rdstrategy(bp)
struct buf *bp;
{
int md, unit;
struct rd_softc *sc;
caddr_t addr;
size_t off, xfer;
md = minor(bp->b_dev);
unit = RD_UNIT(md);
sc = rdcd.cd_devs[unit];
switch (sc->sc_type) {
#if RAMDISK_SERVER
case RD_UMEM_SERVER:
/* Just add this job to the server's queue. */
bp->b_actf = sc->sc_buflist;
sc->sc_buflist = bp;
if (bp->b_actf == NULL) {
/* server queue was empty. */
wakeup((caddr_t)sc);
/* see rd_server_loop() */
}
/* no biodone in this case */
return;
#endif /* RAMDISK_SERVER */
case RD_KMEM_FIXED:
case RD_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 = sc->sc_addr + off;
if (bp->b_flags & B_READ)
bcopy(addr, bp->b_data, xfer);
else
bcopy(bp->b_data, addr, 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;
}
biodone(bp);
}
int
rdioctl(dev, cmd, data, flag, proc)
dev_t dev;
u_long cmd;
int flag;
caddr_t data;
struct proc *proc;
{
int md, unit;
struct rd_softc *sc;
struct rd_conf *urd;
md = minor(dev);
unit = RD_UNIT(md);
sc = rdcd.cd_devs[unit];
/* If this is not the control device, punt! */
if (RD_IS_CTRL(md) == 0)
return ENOTTY;
urd = (struct rd_conf *)data;
switch (cmd) {
case RD_GETCONF:
*urd = sc->sc_rd;
return 0;
case RD_SETCONF:
/* Can only set it once. */
if (sc->sc_type != RD_UNCONFIGURED)
break;
switch (urd->rd_type) {
case RD_KMEM_ALLOCATED:
return rd_ioctl_kalloc(sc, urd, proc);
#if RAMDISK_SERVER
case RD_UMEM_SERVER:
return rd_ioctl_server(sc, urd, proc);
#endif
default:
break;
}
break;
}
return EINVAL;
}
/*
* Handle ioctl RD_SETCONF for (sc_type == RD_KMEM_ALLOCATED)
* Just allocate some kernel memory and return.
*/
int
rd_ioctl_kalloc(sc, urd, proc)
struct rd_softc *sc;
struct rd_conf *urd;
struct proc *proc;
{
vm_offset_t addr;
vm_size_t size;
/* Sanity check the size. */
size = urd->rd_size;
if (size > RD_KMEM_MAX_SIZE)
return EINVAL;
addr = kmem_alloc(kernel_map, size);
if (!addr)
return ENOMEM;
/* This unit is now configured. */
sc->sc_addr = (caddr_t)addr; /* kernel space */
sc->sc_size = (size_t)size;
sc->sc_type = RD_KMEM_ALLOCATED;
return 0;
}
#if RAMDISK_SERVER
/*
* Handle ioctl RD_SETCONF for (sc_type == RD_UMEM_SERVER)
* Set config, then become the I/O server for this unit.
*/
int
rd_ioctl_server(sc, urd, proc)
struct rd_softc *sc;
struct rd_conf *urd;
struct proc *proc;
{
vm_offset_t end;
int error;
/* Sanity check addr, size. */
end = (vm_offset_t) (urd->rd_addr + urd->rd_size);
if ((end >= VM_MAXUSER_ADDRESS) ||
(end < ((vm_offset_t) urd->rd_addr)) )
return EINVAL;
/* This unit is now configured. */
sc->sc_addr = urd->rd_addr; /* user space */
sc->sc_size = urd->rd_size;
sc->sc_type = RD_UMEM_SERVER;
/* Become the server daemon */
error = rd_server_loop(sc);
/* This server is now going away! */
sc->sc_type = RD_UNCONFIGURED;
sc->sc_addr = 0;
sc->sc_size = 0;
return (error);
}
int rd_sleep_pri = PWAIT | PCATCH;
static int
rd_server_loop(sc)
struct rd_softc *sc;
{
struct buf *bp;
caddr_t 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 (sc->sc_buflist == NULL) {
error = tsleep((caddr_t)sc, rd_sleep_pri, "rd_idle", 0);
if (error)
return error;
}
/* Unlink buf from head of list. */
bp = sc->sc_buflist;
sc->sc_buflist = bp->b_actf;
bp->b_actf = NULL;
/* 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 = 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 /* RAMDISK_SERVER */
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