/* $OpenBSD: mem.c,v 1.39 2024/12/30 02:46:00 guenther 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. 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. * * @(#)mem.c 8.3 (Berkeley) 1/12/94 */ /* * Memory special file */ #include #include #include #include #include #include #include #include #include #include #include caddr_t zeropage; extern int start, end, etext; /* open counter for aperture */ #ifdef APERTURE static int ap_open_count = 0; extern int allowaperture; #define VGA_START 0xA0000 #define BIOS_END 0xFFFFF #endif #ifdef MTRR struct mem_range_softc mem_range_softc; int mem_ioctl(dev_t, u_long, caddr_t, int, struct proc *); int mem_range_attr_get(struct mem_range_desc *, int *); int mem_range_attr_set(struct mem_range_desc *, int *); #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); } int mmrw(dev_t dev, struct uio *uio, int flags) { extern vaddr_t kern_end; vaddr_t v; size_t c; struct iovec *iov; int error = 0; 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)) { /* minor device 0 is physical memory */ case 0: v = PMAP_DIRECT_MAP(uio->uio_offset); error = uiomove((caddr_t)v, uio->uio_resid, uio); continue; /* minor device 1 is kernel memory */ case 1: v = uio->uio_offset; c = ulmin(iov->iov_len, MAXPHYS); if (v >= (vaddr_t)&start && v < kern_end - c) { if (v < (vaddr_t)&etext - c && uio->uio_rw == UIO_WRITE) return EFAULT; } else if ((!uvm_kernacc((caddr_t)v, c, uio->uio_rw == UIO_READ ? B_READ : B_WRITE)) && (v < PMAP_DIRECT_BASE || v > PMAP_DIRECT_END - c)) return (EFAULT); error = uiomove((caddr_t)v, c, uio); continue; /* minor device 2 is /dev/null */ case 2: if (uio->uio_rw == UIO_WRITE) uio->uio_resid = 0; return (0); /* minor device 12 is /dev/zero */ case 12: if (uio->uio_rw == UIO_WRITE) { c = iov->iov_len; break; } 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); continue; default: return (ENXIO); } iov->iov_base += c; iov->iov_len -= c; uio->uio_offset += c; uio->uio_resid -= c; } return (error); } paddr_t mmmmap(dev_t dev, off_t off, int prot) { struct proc *p = curproc; /* XXX */ switch (minor(dev)) { /* minor device 0 is physical memory */ case 0: if (suser(p) != 0 && amd64_pa_used(off)) return -1; return off; #ifdef APERTURE /* minor device 4 is aperture driver */ case 4: /* Check if a write combining mapping is requested. */ if (off >= MEMRANGE_WC_RANGE) off = (off - MEMRANGE_WC_RANGE) | PMAP_WC; switch (allowaperture) { case 1: /* Allow mapping of the VGA framebuffer & BIOS only */ if ((off >= VGA_START && off <= BIOS_END) || !amd64_pa_used(off)) return off; else return -1; case 2: case 3: /* Allow mapping of the whole 1st megabyte for x86emu */ if (off <= BIOS_END || !amd64_pa_used(off)) return off; else return -1; default: return -1; } #endif default: return -1; } } 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; } #ifdef MTRR switch (minor(dev)) { case 0: case 4: return mem_ioctl(dev, cmd, data, flags, p); } #endif return (ENOTTY); } #ifdef MTRR /* * Operations for changing memory attributes. * * This is basically just an ioctl shim for mem_range_attr_get * and mem_range_attr_set. */ int mem_ioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p) { int nd, error = 0; struct mem_range_op *mo = (struct mem_range_op *)data; struct mem_range_desc *md; /* is this for us? */ if ((cmd != MEMRANGE_GET) && (cmd != MEMRANGE_SET)) return (ENOTTY); /* any chance we can handle this? */ if (mem_range_softc.mr_op == NULL) return (EOPNOTSUPP); /* do we have any descriptors? */ if (mem_range_softc.mr_ndesc == 0) return (ENXIO); switch (cmd) { case MEMRANGE_GET: nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); if (nd > 0) { md = mallocarray(nd, sizeof(struct mem_range_desc), M_MEMDESC, M_WAITOK); error = mem_range_attr_get(md, &nd); if (!error) error = copyout(md, mo->mo_desc, nd * sizeof(struct mem_range_desc)); free(md, M_MEMDESC, nd * sizeof(struct mem_range_desc)); } else { nd = mem_range_softc.mr_ndesc; } mo->mo_arg[0] = nd; break; case MEMRANGE_SET: md = malloc(sizeof(struct mem_range_desc), M_MEMDESC, M_WAITOK); error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); /* clamp description string */ md->mr_owner[sizeof(md->mr_owner) - 1] = 0; if (error == 0) error = mem_range_attr_set(md, &mo->mo_arg[0]); free(md, M_MEMDESC, sizeof(struct mem_range_desc)); break; } return (error); } /* * Implementation-neutral, kernel-callable functions for manipulating * memory range attributes. */ int mem_range_attr_get(struct mem_range_desc *mrd, int *arg) { /* can we handle this? */ if (mem_range_softc.mr_op == NULL) return (EOPNOTSUPP); if (*arg == 0) { *arg = mem_range_softc.mr_ndesc; } else { memcpy(mrd, mem_range_softc.mr_desc, (*arg) * sizeof(struct mem_range_desc)); } return (0); } int mem_range_attr_set(struct mem_range_desc *mrd, int *arg) { /* can we handle this? */ if (mem_range_softc.mr_op == NULL) return (EOPNOTSUPP); return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg)); } #endif /* MTRR */