/* $NetBSD: ramdisk.c,v 1.8 1996/04/12 08:30:09 leo 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 #include #include #include #include #include #include #include #include #include #include /* Don't want all those other VM headers... */ extern vm_offset_t kmem_alloc __P((vm_map_t, vm_size_t)); #include /* * 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_MAX_UNITS 0x10 #define RD_IS_CTRL(unit) (unit & 0x10) #define RD_UNIT(unit) (unit & 0xF) /* autoconfig stuff... */ struct rd_softc { struct device sc_dev; /* REQUIRED first entry */ struct disk sc_dkdev; /* hook for generic disk handling */ 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 void rdattach __P((int)); static void rd_attach __P((struct device *, struct device *, void *)); /* * Some ports (like i386) use a swapgeneric that wants to * snoop around in this rd_cd structure. It is preserved * (for now) to remain compatible with such practice. * XXX - that practice is questionable... */ struct cfdriver rd_cd = { NULL, "rd", DV_DULL, NULL, 0 }; void rdstrategy __P((struct buf *bp)); struct dkdriver rddkdriver = { rdstrategy }; static int ramdisk_ndevs; static void *ramdisk_devs[RD_MAX_UNITS]; /* * This is called if we are configured as a pseudo-device */ void rdattach(n) int n; { struct rd_softc *sc; int i; #ifdef DIAGNOSTIC if (ramdisk_ndevs) { printf("ramdisk: multiple attach calls?\n"); return; } #endif /* XXX: Are we supposed to provide a default? */ if (n <= 1) n = 1; if (n > RD_MAX_UNITS) n = RD_MAX_UNITS; ramdisk_ndevs = n; /* XXX: Fake-up rd_cd (see above) */ rd_cd.cd_ndevs = ramdisk_ndevs; rd_cd.cd_devs = ramdisk_devs; /* Attach as if by autoconfig. */ for (i = 0; i < n; i++) { sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK); if (!sc) { printf("ramdisk: malloc for attach failed!\n"); return; } bzero((caddr_t)sc, sizeof(*sc)); ramdisk_devs[i] = sc; sc->sc_dev.dv_unit = i; sprintf(sc->sc_dev.dv_xname, "rd%d", i); rd_attach(NULL, &sc->sc_dev, NULL); } } 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 /* * Initialize and attach the disk structure. */ sc->sc_dkdev.dk_driver = &rddkdriver; 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 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 static int rd_ioctl_kalloc __P((struct rd_softc *sc, struct rd_conf *urd, struct proc *proc)); dev_type_open(rdopen); dev_type_close(rdclose); dev_type_read(rdread); dev_type_write(rdwrite); dev_type_ioctl(rdioctl); dev_type_size(rdsize); dev_type_dump(rddump); 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 >= ramdisk_ndevs) return 0; sc = ramdisk_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 >= ramdisk_ndevs) return ENXIO; sc = ramdisk_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 = ramdisk_devs[unit]; if (RD_IS_CTRL(md)) return 0; /* Normal device. */ sc->sc_flags = 0; return 0; } int rdread(dev, uio, flags) dev_t dev; struct uio *uio; int flags; { return (physio(rdstrategy, NULL, dev, B_READ, minphys, uio)); } int rdwrite(dev, uio, flags) dev_t dev; struct uio *uio; int flags; { 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 = ramdisk_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 = ramdisk_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. */ static 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; 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. */ static 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 */