/* $OpenBSD: mem.c,v 1.21 2006/04/13 14:41:08 brad Exp $ */ /* $NetBSD: mem.c,v 1.26 2000/03/29 03:48:20 simonb Exp $ */ /* * Copyright (c) 1988 University of Utah. * Copyright (c) 1982, 1986, 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department. * * 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. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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. * * @(#)mem.c 8.3 (Berkeley) 1/12/94 */ /* * Memory special file */ #include #include #include #include #include #include #include #include #include #include #define mmread mmrw #define mmwrite mmrw cdev_decl(mm); caddr_t zeropage; /* open counter for aperture */ #ifdef APERTURE static int ap_open_count = 0; static pid_t ap_open_pid = -1; extern int allowaperture; #endif /*ARGSUSED*/ int mmopen(dev, flag, mode, p) dev_t dev; int flag, mode; struct proc *p; { switch (minor(dev)) { case 0: case 1: case 2: return (0); #ifdef APERTURE case 4: if (suser(p, 0) != 0 || !allowaperture) return (EPERM); /* authorize only one simultaneous open() from the same pid */ if (ap_open_count > 0 && p->p_pid != ap_open_pid) return(EPERM); ap_open_count++; ap_open_pid = p->p_pid; return (0); #endif case 12: return (0); default: return (ENXIO); } } /*ARGSUSED*/ int mmclose(dev, flag, mode, p) dev_t dev; int flag, mode; struct proc *p; { #ifdef APERTURE if (minor(dev) == 4) { ap_open_count--; ap_open_pid = -1; } #endif return (0); } /*ARGSUSED*/ int mmrw(dev, uio, flags) dev_t dev; struct uio *uio; int flags; { register vaddr_t o, v; register int c; register struct iovec *iov; int error = 0, rw; extern int msgbufmapped; while (uio->uio_resid > 0 && !error) { iov = uio->uio_iov; if (iov->iov_len == 0) { uio->uio_iov++; uio->uio_iovcnt--; if (uio->uio_iovcnt < 0) panic("mmrw"); continue; } switch (minor(dev)) { /* minor device 0 is physical memory */ case 0: v = uio->uio_offset; kmemphys: if (v >= ALPHA_K0SEG_TO_PHYS((vaddr_t)msgbufp)) { if (msgbufmapped == 0) { printf("Message Buf not Mapped\n"); error = EFAULT; break; } } /* Allow reads only in RAM. */ rw = (uio->uio_rw == UIO_READ) ? PROT_READ : PROT_WRITE; if ((alpha_pa_access(v) & rw) != rw) { error = EFAULT; break; } o = uio->uio_offset & PGOFSET; c = min(uio->uio_resid, (int)(PAGE_SIZE - o)); error = uiomove((caddr_t)ALPHA_PHYS_TO_K0SEG(v), c, uio); break; /* minor device 1 is kernel memory */ case 1: v = uio->uio_offset; if (v >= ALPHA_K0SEG_BASE && v <= ALPHA_K0SEG_END) { v = ALPHA_K0SEG_TO_PHYS(v); goto kmemphys; } c = min(iov->iov_len, MAXPHYS); if (!uvm_kernacc((caddr_t)v, c, uio->uio_rw == UIO_READ ? B_READ : B_WRITE)) return (EFAULT); error = uiomove((caddr_t)v, c, uio); break; /* minor device 2 is EOF/rathole */ case 2: if (uio->uio_rw == UIO_WRITE) uio->uio_resid = 0; return (0); /* minor device 12 (/dev/zero) is source of nulls on read, rathole on write */ case 12: if (uio->uio_rw == UIO_WRITE) { uio->uio_resid = 0; return (0); } /* * On the first call, allocate and zero a page * of memory for use with /dev/zero. */ if (zeropage == NULL) { zeropage = (caddr_t) malloc(PAGE_SIZE, M_TEMP, M_WAITOK); bzero(zeropage, PAGE_SIZE); } c = min(iov->iov_len, PAGE_SIZE); error = uiomove(zeropage, c, uio); break; default: return (ENXIO); } } return (error); } paddr_t mmmmap(dev, off, prot) dev_t dev; off_t off; int prot; { switch (minor(dev)) { case 0: /* * /dev/mem is the only one that makes sense through this * interface. For /dev/kmem any physaddr we return here * could be transient and hence incorrect or invalid at * a later time. /dev/null just doesn't make any sense * and /dev/zero is a hack that is handled via the default * pager in mmap(). */ /* * Allow access only in RAM. */ if ((prot & alpha_pa_access(atop(off))) != prot) return (-1); return (atop(off)); #ifdef APERTURE case 4: /* minor device 4 is aperture driver */ switch (allowaperture) { case 1: if ((prot & alpha_pa_access(atop(off))) != prot) return (-1); return atop(off); default: return -1; } #endif default: return -1; } } int mmioctl(dev, cmd, data, flags, p) dev_t dev; u_long cmd; caddr_t data; int flags; struct proc *p; { return (EOPNOTSUPP); }