/* $OpenBSD: mem.c,v 1.27 2024/12/30 02:46:00 guenther Exp $ */ /* $NetBSD: mem.c,v 1.11 2003/10/16 12:02:58 jdolecek Exp $ */ /* * 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. */ /* * Copyright (c) 1988 University of Utah. * * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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. */ /* * Memory special file */ #include <sys/param.h> #include <sys/buf.h> #include <sys/filio.h> #include <sys/systm.h> #include <sys/uio.h> #include <sys/malloc.h> #include <sys/rwlock.h> #include <sys/atomic.h> #include <arm/conf.h> #include <uvm/uvm_extern.h> extern char *memhook; /* poor name! */ caddr_t zeropage; /* open counter for aperture */ #ifdef APERTURE static int ap_open_count = 0; extern int allowaperture; #endif int mmopen(dev_t dev, int flag, int mode, struct proc *p) { extern int allowkmem; switch (minor(dev)) { case 0: case 1: if ((int)atomic_load_int(&securelevel) <= 0 || atomic_load_int(&allowkmem)) break; return (EPERM); case 2: case 12: break; #ifdef APERTURE case 4: if (suser(p) != 0 || !allowaperture) return (EPERM); /* authorize only one simultaneous open() unless * allowaperture=3 */ if (ap_open_count > 0 && allowaperture < 3) return (EPERM); ap_open_count++; break; #endif default: return (ENXIO); } return (0); } int mmclose(dev_t dev, int flag, int mode, struct proc *p) { #ifdef APERTURE if (minor(dev) == 4) ap_open_count = 0; #endif return (0); } static struct rwlock physlock = RWLOCK_INITIALIZER("mmrw"); int mmrw(dev_t dev, struct uio *uio, int flags) { vaddr_t o, v; size_t c; struct iovec *iov; int error = 0; vm_prot_t prot; if (minor(dev) == 0) { /* lock against other uses of shared vmmap */ error = rw_enter(&physlock, RW_WRITE | RW_INTR); if (error) return (error); } while (uio->uio_resid > 0 && error == 0) { 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)) { case 0: v = uio->uio_offset; prot = uio->uio_rw == UIO_READ ? PROT_READ : PROT_WRITE; pmap_enter(pmap_kernel(), (vaddr_t)memhook, trunc_page(v), prot, prot|PMAP_WIRED); pmap_update(pmap_kernel()); o = uio->uio_offset & PGOFSET; c = ulmin(uio->uio_resid, PAGE_SIZE - o); error = uiomove((caddr_t)memhook + o, c, uio); pmap_remove(pmap_kernel(), (vaddr_t)memhook, (vaddr_t)memhook + PAGE_SIZE); pmap_update(pmap_kernel()); break; case 1: v = uio->uio_offset; c = ulmin(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; case 2: if (uio->uio_rw == UIO_WRITE) uio->uio_resid = 0; return (0); case 12: if (uio->uio_rw == UIO_WRITE) { uio->uio_resid = 0; return (0); } if (zeropage == NULL) zeropage = malloc(PAGE_SIZE, M_TEMP, M_WAITOK | M_ZERO); c = ulmin(iov->iov_len, PAGE_SIZE); error = uiomove(zeropage, c, uio); break; default: return (ENXIO); } } if (minor(dev) == 0) { rw_exit(&physlock); } return (error); } paddr_t mmmmap(dev_t dev, off_t off, int prot) { struct proc *p = curproc; /* XXX */ /* * /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(). */ if (minor(dev) != 0) return (-1); /* minor device 0 is physical memory */ if ((paddr_t)off >= ptoa((paddr_t)physmem) && suser(p) != 0) return -1; return off; } int mmioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p) { switch (cmd) { case FIOASYNC: /* handled by fd layer */ return 0; } return (ENOTTY); }
