/* $OpenBSD: ramdisk.c,v 1.44 2008/08/22 03:12:37 deraadt Exp $ */ /* $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-purpose 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 #include #include #include /* * By default, include the user-space functionality. * Use: option RAMDISK_SERVER=0 to turn it off. */ #if !defined(RAMDISK_SERVER) && !defined(SMALL_KERNEL) #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 * simultaneous use of raw and block devices. * * XXX Assumption: 16 RAM-disks are enough! */ #define RD_MAX_UNITS 0x10 #define RD_IS_CTRL(dev) (DISKPART(dev) == RAW_PART) /* autoconfig stuff... */ struct rd_softc { struct device sc_dev; /* REQUIRED first entry */ struct disk sc_dk; /* hook for generic disk handling */ struct rd_conf sc_rd; #if RAMDISK_SERVER struct buf *sc_buflist; #endif }; /* 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 void rdattach(int); void rd_attach(struct device *, struct device *, void *); void rdgetdisklabel(dev_t, struct rd_softc *, struct disklabel *, int); /* * 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_DISK }; /* * Here we define a cfattach structure for inserting any new rd device into the * device tree. This is needed by some archs that look for bootable devices in * there. */ int rd_probe(struct device *, void *, void *); int rd_detach(struct device *, int); int rd_activate(struct device *, enum devact); struct cfattach rd_ca = { sizeof(struct rd_softc), rd_probe, rd_attach, rd_detach, rd_activate }; void rdstrategy(struct buf *bp); struct dkdriver rddkdriver = { rdstrategy }; int ramdisk_ndevs; void *ramdisk_devs[RD_MAX_UNITS]; /* * This is called if we are configured as a pseudo-device */ void rdattach(int n) { struct rd_softc *sc; struct cfdata *cf; 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. */ cf = malloc(sizeof(struct cfdata), M_DEVBUF, M_NOWAIT | M_ZERO); if (cf == NULL) { printf("WARNING: no memory for cfdata struct\n"); return; } cf->cf_attach = &rd_ca; cf->cf_driver = &rd_cd; for (i = 0; i < n; i++) { sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK | M_ZERO); if (snprintf(sc->sc_dev.dv_xname, sizeof(sc->sc_dev.dv_xname), "rd%d", i) >= sizeof(sc->sc_dev.dv_xname)) { printf("rdattach: device name too long\n"); free(sc, M_DEVBUF); return; } ramdisk_devs[i] = sc; sc->sc_dev.dv_unit = i; sc->sc_dev.dv_class = DV_DISK; sc->sc_dev.dv_parent = NULL; sc->sc_dev.dv_cfdata = cf; TAILQ_INSERT_TAIL(&alldevs, &sc->sc_dev, dv_list); device_ref(&sc->sc_dev); rd_attach(NULL, &sc->sc_dev, NULL); } } void rd_attach(struct device *parent, struct device *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_dk.dk_driver = &rddkdriver; sc->sc_dk.dk_name = sc->sc_dev.dv_xname; disk_attach(&sc->sc_dk); } /* * operational routines: * open, close, read, write, strategy, * ioctl, dump, size */ #if RAMDISK_SERVER int rd_server_loop(struct rd_softc *sc); int rd_ioctl_server(struct rd_softc *sc, struct rd_conf *urd, struct proc *proc); #endif int rd_ioctl_kalloc(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_t dev, daddr64_t blkno, caddr_t va, size_t size) { return (ENODEV); } daddr64_t rdsize(dev_t dev) { int part, unit; struct rd_softc *sc; /* Disallow control units. */ unit = DISKUNIT(dev); if (unit >= ramdisk_ndevs) return (0); sc = ramdisk_devs[unit]; if (sc == NULL) return (0); if (sc->sc_type == RD_UNCONFIGURED) return (0); rdgetdisklabel(dev, sc, sc->sc_dk.dk_label, 0); part = DISKPART(dev); if (part >= sc->sc_dk.dk_label->d_npartitions) return (0); return (DL_GETPSIZE(&sc->sc_dk.dk_label->d_partitions[part]) * (sc->sc_dk.dk_label->d_secsize / DEV_BSIZE)); } int rdopen(dev_t dev, int flag, int fmt, struct proc *proc) { int unit; struct rd_softc *sc; unit = DISKUNIT(dev); 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(dev)) 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); /* * Make sure we have read the disklabel. */ rdgetdisklabel(dev, sc, sc->sc_dk.dk_label, 0); return (0); } int rdclose(dev_t dev, int flag, int fmt, struct proc *proc) { return (0); } int rdread(dev_t dev, struct uio *uio, int flags) { return (physio(rdstrategy, NULL, dev, B_READ, minphys, uio)); } int rdwrite(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(struct buf *bp) { int unit, s; struct rd_softc *sc; caddr_t addr; size_t off, xfer; unit = DISKUNIT(bp->b_dev); sc = ramdisk_devs[unit]; /* Sort rogue requests out */ if (sc == NULL || bp->b_blkno < 0 || (bp->b_bcount % sc->sc_dk.dk_label->d_secsize) != 0) { bp->b_error = EINVAL; goto bad; } /* Do not write on "no trespassing" areas... */ if (bounds_check_with_label(bp, sc->sc_dk.dk_label, 1) <= 0) goto bad; 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); xfer = bp->b_bcount; 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_error = EIO; bad: bp->b_flags |= B_ERROR; bp->b_resid = bp->b_bcount; break; } s = splbio(); biodone(bp); splx(s); } int rdioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *proc) { struct disklabel *lp; struct rd_softc *sc; struct rd_conf *urd; int unit = DISKUNIT(dev), error; sc = ramdisk_devs[unit]; urd = (struct rd_conf *)data; switch (cmd) { case DIOCRLDINFO: if (sc->sc_type == RD_UNCONFIGURED) break; lp = malloc(sizeof(*lp), M_TEMP, M_WAITOK); rdgetdisklabel(dev, sc, lp, 0); bcopy(lp, sc->sc_dk.dk_label, sizeof(*lp)); free(lp, M_TEMP); return (0); case DIOCGPDINFO: if (sc->sc_type == RD_UNCONFIGURED) break; rdgetdisklabel(dev, sc, (struct disklabel *)data, 1); return (0); case DIOCGDINFO: if (sc->sc_type == RD_UNCONFIGURED) break; *(struct disklabel *)data = *(sc->sc_dk.dk_label); return (0); case DIOCGPART: ((struct partinfo *)data)->disklab = sc->sc_dk.dk_label; ((struct partinfo *)data)->part = &sc->sc_dk.dk_label->d_partitions[DISKPART(dev)]; return (0); case DIOCWDINFO: case DIOCSDINFO: if (sc->sc_type == RD_UNCONFIGURED) break; if ((flag & FWRITE) == 0) return (EBADF); error = setdisklabel(sc->sc_dk.dk_label, (struct disklabel *)data, /*sd->sc_dk.dk_openmask : */0); if (error == 0) { if (cmd == DIOCWDINFO) error = writedisklabel(DISKLABELDEV(dev), rdstrategy, sc->sc_dk.dk_label); } return (error); case DIOCWLABEL: if (sc->sc_type == RD_UNCONFIGURED) break; if ((flag & FWRITE) == 0) return (EBADF); return (0); case RD_GETCONF: /* If this is not the control device, punt! */ if (RD_IS_CTRL(dev) == 0) break; *urd = sc->sc_rd; return (0); case RD_SETCONF: /* If this is not the control device, punt! */ if (RD_IS_CTRL(dev) == 0) break; /* 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; default: return (ENOTTY); } return (EINVAL); } void rdgetdisklabel(dev_t dev, struct rd_softc *sc, struct disklabel *lp, int spoofonly) { bzero(lp, sizeof(struct disklabel)); lp->d_secsize = DEV_BSIZE; lp->d_ntracks = 1; lp->d_nsectors = sc->sc_size >> DEV_BSHIFT; lp->d_ncylinders = 1; lp->d_secpercyl = lp->d_nsectors; if (lp->d_secpercyl == 0) { lp->d_secpercyl = 100; /* as long as it's not 0 - readdisklabel divides by it (?) */ } strncpy(lp->d_typename, "RAM disk", sizeof(lp->d_typename)); lp->d_type = DTYPE_SCSI; strncpy(lp->d_packname, "fictitious", sizeof(lp->d_packname)); DL_SETDSIZE(lp, lp->d_nsectors); lp->d_rpm = 3600; lp->d_interleave = 1; lp->d_version = 1; lp->d_magic = DISKMAGIC; lp->d_magic2 = DISKMAGIC; lp->d_checksum = dkcksum(lp); /* * Call the generic disklabel extraction routine */ readdisklabel(DISKLABELDEV(dev), rdstrategy, lp, spoofonly); } /* * Handle ioctl RD_SETCONF for (sc_type == RD_KMEM_ALLOCATED) * Just allocate some kernel memory and return. */ int rd_ioctl_kalloc(struct rd_softc *sc, struct rd_conf *urd, struct proc *proc) { vaddr_t addr; vsize_t size; /* Sanity check the size. */ size = urd->rd_size; addr = uvm_km_zalloc(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); } int rd_probe(struct device *parent, void *match_, void *aux) { return (0); } int rd_detach(struct device *self, int flags) { return (0); } int rd_activate(struct device *self, enum devact act) { 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(struct rd_softc *sc, struct rd_conf *urd, struct proc *proc) { vaddr_t end; int error; /* Sanity check addr, size. */ end = (vaddr_t) (urd->rd_addr + urd->rd_size); if ((end >= VM_MAXUSER_ADDRESS) || (end < ((vaddr_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; int rd_server_loop(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, s; 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; } s = splbio(); biodone(bp); splx(s); } } #endif /* RAMDISK_SERVER */