/* $NetBSD: md.c,v 1.54 2008/06/13 19:55:26 cegger 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 __KERNEL_RCSID(0, "$NetBSD: md.c,v 1.54 2008/06/13 19:55:26 cegger Exp $"); #include "opt_md.h" #include #include #include #include #include #include #include #include #include #include #include #include #include /* * 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; /* 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(device_t, device_t, 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 }; extern struct cfdriver md_cd; CFATTACH_DECL_NEW(md, sizeof(struct md_softc), 0, md_attach, 0, NULL); /* * This is called if we are configured as a pseudo-device */ void mdattach(int n) { int i; cfdata_t cf; if (config_cfattach_attach("md", &md_ca)) { printf("md: cfattach_attach failed\n"); return; } /* XXX: Are we supposed to provide a default? */ if (n <= 1) n = 1; /* Attach as if by autoconfig. */ for (i = 0; i < n; i++) { cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK); cf->cf_name = "md"; cf->cf_atname = "md"; cf->cf_unit = i; cf->cf_fstate = FSTATE_NOTFOUND; (void)config_attach_pseudo(cf); } } static void md_attach(device_t parent, device_t self, void *aux) { struct md_softc *sc = device_private(self); sc->sc_dev = 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(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); } /* * 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; sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 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); sc = device_lookup_private(&md_cd, 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) { return 0; } 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->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->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; sc = device_lookup_private(&md_cd, MD_UNIT(bp->b_dev)); if (sc->sc_type == MD_UNCONFIGURED) { bp->b_error = ENXIO; 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; break; } 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; sc = device_lookup_private(&md_cd, MD_UNIT(dev)); /* 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; } biodone(bp); } } #endif /* MEMORY_DISK_SERVER */