/*- * 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. * 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. * * from: Utah $Hdr: mem.c 1.13 89/10/08$ * from: @(#)mem.c 7.2 (Berkeley) 5/9/91 */ #include __FBSDID("$FreeBSD$"); /* * Memory special file */ #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"); static struct sx memsxlock; SX_SYSINIT(memsxlockinit, &memsxlock, "/dev/mem lock"); /* ARGSUSED */ int memrw(struct cdev *dev, struct uio *uio, int flags) { int o; u_int c = 0; vm_paddr_t pa; struct iovec *iov; int error = 0; vm_offset_t addr; /* XXX UPS Why ? */ GIANT_REQUIRED; if (dev2unit(dev) != CDEV_MINOR_MEM && dev2unit(dev) != CDEV_MINOR_KMEM) return EIO; if (dev2unit(dev) == CDEV_MINOR_KMEM && uio->uio_resid > 0) { if (uio->uio_offset < (vm_offset_t)VADDR(PTDPTDI, 0)) return (EFAULT); if (!kernacc((caddr_t)(int)uio->uio_offset, uio->uio_resid, uio->uio_rw == UIO_READ ? VM_PROT_READ : VM_PROT_WRITE)) return (EFAULT); } 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; } if (dev2unit(dev) == CDEV_MINOR_MEM) { pa = uio->uio_offset; pa &= ~PAGE_MASK; } else { /* * Extract the physical page since the mapping may * change at any time. This avoids panics on page * fault in this case but will cause reading/writing * to the wrong page. * Hopefully an application will notice the wrong * data on read access and refrain from writing. * This should be replaced by a special uiomove * type function that just returns an error if there * is a page fault on a kernel page. */ addr = trunc_page(uio->uio_offset); pa = pmap_extract(kernel_pmap, addr); if (pa == 0) return EFAULT; } /* * XXX UPS This should just use sf_buf_alloc. * Unfortunately sf_buf_alloc needs a vm_page * and we may want to look at memory not covered * by the page array. */ sx_xlock(&memsxlock); pmap_kenter((vm_offset_t)ptvmmap, pa); pmap_invalidate_page(kernel_pmap,(vm_offset_t)ptvmmap); o = (int)uio->uio_offset & PAGE_MASK; c = PAGE_SIZE - o; c = min(c, (u_int)iov->iov_len); error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio); pmap_qremove((vm_offset_t)ptvmmap, 1); sx_xunlock(&memsxlock); } 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) *paddr = offset; else if (dev2unit(dev) == CDEV_MINOR_KMEM) *paddr = vtophys(offset); /* else panic! */ return (0); } /* * Operations for changing memory attributes. * * This is basically just an ioctl shim for mem_range_attr_get * and mem_range_attr_set. */ /* ARGSUSED */ int memioctl(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); }