/*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1988 University of Utah. * Copyright (c) 1982, 1986, 1990 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, and code derived from software contributed to * Berkeley by William Jolitz. * * 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. * * from: Utah $Hdr: mem.c 1.13 89/10/08$ */ #include /* * Memory special file */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Used in /dev/mem drivers and elsewhere */ MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); /* ARGSUSED */ int memrw(struct cdev *dev, struct uio *uio, int flags) { struct iovec *iov; void *p; ssize_t orig_resid; u_long v, vd; u_int c; int error; error = 0; orig_resid = uio->uio_resid; 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("memrw"); continue; } v = uio->uio_offset; c = ulmin(iov->iov_len, PAGE_SIZE - (u_int)(v & PAGE_MASK)); switch (dev2unit(dev)) { case CDEV_MINOR_KMEM: /* * Since c is clamped to be less or equal than * PAGE_SIZE, the uiomove() call does not * access past the end of the direct map. */ if (v >= DMAP_MIN_ADDRESS && v < DMAP_MIN_ADDRESS + dmaplimit) { error = uiomove((void *)v, c, uio); break; } if (!kernacc((void *)v, c, uio->uio_rw == UIO_READ ? VM_PROT_READ : VM_PROT_WRITE)) { error = EFAULT; break; } /* * If the extracted address is not accessible * through the direct map, then we make a * private (uncached) mapping because we can't * depend on the existing kernel mapping * remaining valid until the completion of * uiomove(). * * XXX We cannot provide access to the * physical page 0 mapped into KVA. */ v = pmap_extract(kernel_pmap, v); if (v == 0) { error = EFAULT; break; } /* FALLTHROUGH */ case CDEV_MINOR_MEM: if (v < dmaplimit) { vd = PHYS_TO_DMAP(v); error = uiomove((void *)vd, c, uio); break; } if (v > cpu_getmaxphyaddr()) { error = EFAULT; break; } p = pmap_mapdev(v, PAGE_SIZE); error = uiomove(p, c, uio); pmap_unmapdev(p, PAGE_SIZE); break; } } /* * Don't return error if any byte was written. Read and write * can return error only if no i/o was performed. */ if (uio->uio_resid != orig_resid) error = 0; return (error); } /* * allow user processes to MMAP some memory sections * instead of going through read/write */ /* ARGSUSED */ int memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int prot __unused, vm_memattr_t *memattr __unused) { if (dev2unit(dev) == CDEV_MINOR_MEM) { if (offset > cpu_getmaxphyaddr()) return (-1); *paddr = offset; return (0); } return (-1); } /* * Operations for changing memory attributes. * * This is basically just an ioctl shim for mem_range_attr_get * and mem_range_attr_set. */ int memioctl_md(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags, struct thread *td) { 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 = (struct mem_range_desc *) malloc(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); } else nd = mem_range_softc.mr_ndesc; mo->mo_arg[0] = nd; break; case MEMRANGE_SET: md = (struct mem_range_desc *)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); break; } return (error); }