1 /*- 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department, and code derived from software contributed to 9 * Berkeley by William Jolitz. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * from: Utah $Hdr: mem.c 1.13 89/10/08$ 36 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 /* 43 * Memory special file 44 */ 45 46 #include <sys/param.h> 47 #include <sys/conf.h> 48 #include <sys/fcntl.h> 49 #include <sys/ioccom.h> 50 #include <sys/kernel.h> 51 #include <sys/lock.h> 52 #include <sys/malloc.h> 53 #include <sys/memrange.h> 54 #include <sys/module.h> 55 #include <sys/mutex.h> 56 #include <sys/proc.h> 57 #include <sys/signalvar.h> 58 #include <sys/sx.h> 59 #include <sys/systm.h> 60 #include <sys/uio.h> 61 62 #include <vm/vm.h> 63 #include <vm/pmap.h> 64 #include <vm/vm_extern.h> 65 66 #include <machine/memdev.h> 67 #include <machine/vmparam.h> 68 69 /* 70 * Used in /dev/mem drivers and elsewhere 71 */ 72 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 73 74 struct mem_range_softc mem_range_softc; 75 76 static struct sx tmppt_lock; 77 SX_SYSINIT(tmppt, &tmppt_lock, "mem4map"); 78 79 /* ARGSUSED */ 80 int 81 memrw(struct cdev *dev, struct uio *uio, int flags) 82 { 83 int o; 84 u_int c = 0, v; 85 struct iovec *iov; 86 int error = 0; 87 vm_offset_t addr, eaddr; 88 89 while (uio->uio_resid > 0 && error == 0) { 90 iov = uio->uio_iov; 91 if (iov->iov_len == 0) { 92 uio->uio_iov++; 93 uio->uio_iovcnt--; 94 if (uio->uio_iovcnt < 0) 95 panic("memrw"); 96 continue; 97 } 98 if (dev2unit(dev) == CDEV_MINOR_MEM) { 99 int i; 100 int address_valid = 0; 101 102 v = uio->uio_offset; 103 v &= ~PAGE_MASK; 104 for (i = 0; dump_avail[i] || dump_avail[i + 1]; 105 i += 2) { 106 if (v >= dump_avail[i] && 107 v < dump_avail[i + 1]) { 108 address_valid = 1; 109 break; 110 } 111 } 112 if (!address_valid) 113 return (EINVAL); 114 sx_xlock(&tmppt_lock); 115 pmap_kenter((vm_offset_t)_tmppt, v); 116 #if __ARM_ARCH >= 6 117 pmap_tlb_flush(kernel_pmap, (vm_offset_t)_tmppt); 118 #endif 119 o = (int)uio->uio_offset & PAGE_MASK; 120 c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK)); 121 c = min(c, (u_int)(PAGE_SIZE - o)); 122 c = min(c, (u_int)iov->iov_len); 123 error = uiomove((caddr_t)&_tmppt[o], (int)c, uio); 124 pmap_qremove((vm_offset_t)_tmppt, 1); 125 sx_xunlock(&tmppt_lock); 126 continue; 127 } 128 else if (dev2unit(dev) == CDEV_MINOR_KMEM) { 129 c = iov->iov_len; 130 131 /* 132 * Make sure that all of the pages are currently 133 * resident so that we don't create any zero-fill 134 * pages. 135 */ 136 addr = trunc_page(uio->uio_offset); 137 eaddr = round_page(uio->uio_offset + c); 138 139 for (; addr < eaddr; addr += PAGE_SIZE) 140 if (pmap_extract(kernel_pmap, addr) == 0) 141 return (EFAULT); 142 if (!kernacc((caddr_t)(int)uio->uio_offset, c, 143 uio->uio_rw == UIO_READ ? 144 VM_PROT_READ : VM_PROT_WRITE)) 145 return (EFAULT); 146 error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio); 147 continue; 148 } 149 /* else panic! */ 150 } 151 return (error); 152 } 153 154 /* 155 * allow user processes to MMAP some memory sections 156 * instead of going through read/write 157 */ 158 /* ARGSUSED */ 159 160 int 161 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, 162 int prot __unused, vm_memattr_t *memattr __unused) 163 { 164 if (dev2unit(dev) == CDEV_MINOR_MEM) { 165 *paddr = offset; 166 return (0); 167 } 168 return (-1); 169 } 170