1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1988 University of Utah. 5 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the Systems Programming Group of the University of Utah Computer 10 * Science Department, and code derived from software contributed to 11 * Berkeley by William Jolitz. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * from: Utah $Hdr: mem.c 1.13 89/10/08$ 38 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 /* 45 * Memory special file 46 */ 47 48 #include <sys/param.h> 49 #include <sys/conf.h> 50 #include <sys/fcntl.h> 51 #include <sys/ioccom.h> 52 #include <sys/kernel.h> 53 #include <sys/lock.h> 54 #include <sys/malloc.h> 55 #include <sys/memrange.h> 56 #include <sys/module.h> 57 #include <sys/mutex.h> 58 #include <sys/proc.h> 59 #include <sys/signalvar.h> 60 #include <sys/systm.h> 61 #include <sys/uio.h> 62 63 #include <machine/md_var.h> 64 #include <machine/specialreg.h> 65 #include <machine/vmparam.h> 66 67 #include <vm/vm.h> 68 #include <vm/pmap.h> 69 #include <vm/vm_extern.h> 70 71 #include <machine/memdev.h> 72 73 /* 74 * Used in /dev/mem drivers and elsewhere 75 */ 76 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 77 78 /* ARGSUSED */ 79 int 80 memrw(struct cdev *dev, struct uio *uio, int flags) 81 { 82 struct iovec *iov; 83 void *p; 84 ssize_t orig_resid; 85 u_long v, vd; 86 u_int c; 87 int error; 88 89 error = 0; 90 orig_resid = uio->uio_resid; 91 while (uio->uio_resid > 0 && error == 0) { 92 iov = uio->uio_iov; 93 if (iov->iov_len == 0) { 94 uio->uio_iov++; 95 uio->uio_iovcnt--; 96 if (uio->uio_iovcnt < 0) 97 panic("memrw"); 98 continue; 99 } 100 v = uio->uio_offset; 101 c = ulmin(iov->iov_len, PAGE_SIZE - (u_int)(v & PAGE_MASK)); 102 103 switch (dev2unit(dev)) { 104 case CDEV_MINOR_KMEM: 105 /* 106 * Since c is clamped to be less or equal than 107 * PAGE_SIZE, the uiomove() call does not 108 * access past the end of the direct map. 109 */ 110 if (v >= DMAP_MIN_ADDRESS && 111 v < DMAP_MIN_ADDRESS + dmaplimit) { 112 error = uiomove((void *)v, c, uio); 113 break; 114 } 115 116 if (!kernacc((void *)v, c, uio->uio_rw == UIO_READ ? 117 VM_PROT_READ : VM_PROT_WRITE)) { 118 error = EFAULT; 119 break; 120 } 121 122 /* 123 * If the extracted address is not accessible 124 * through the direct map, then we make a 125 * private (uncached) mapping because we can't 126 * depend on the existing kernel mapping 127 * remaining valid until the completion of 128 * uiomove(). 129 * 130 * XXX We cannot provide access to the 131 * physical page 0 mapped into KVA. 132 */ 133 v = pmap_extract(kernel_pmap, v); 134 if (v == 0) { 135 error = EFAULT; 136 break; 137 } 138 /* FALLTHROUGH */ 139 case CDEV_MINOR_MEM: 140 if (v < dmaplimit) { 141 vd = PHYS_TO_DMAP(v); 142 error = uiomove((void *)vd, c, uio); 143 break; 144 } 145 if (v > cpu_getmaxphyaddr()) { 146 error = EFAULT; 147 break; 148 } 149 p = pmap_mapdev(v, PAGE_SIZE); 150 error = uiomove(p, c, uio); 151 pmap_unmapdev((vm_offset_t)p, PAGE_SIZE); 152 break; 153 } 154 } 155 /* 156 * Don't return error if any byte was written. Read and write 157 * can return error only if no i/o was performed. 158 */ 159 if (uio->uio_resid != orig_resid) 160 error = 0; 161 return (error); 162 } 163 164 /* 165 * allow user processes to MMAP some memory sections 166 * instead of going through read/write 167 */ 168 /* ARGSUSED */ 169 int 170 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, 171 int prot __unused, vm_memattr_t *memattr __unused) 172 { 173 if (dev2unit(dev) == CDEV_MINOR_MEM) { 174 if (offset > cpu_getmaxphyaddr()) 175 return (-1); 176 *paddr = offset; 177 return (0); 178 } 179 return (-1); 180 } 181 182 /* 183 * Operations for changing memory attributes. 184 * 185 * This is basically just an ioctl shim for mem_range_attr_get 186 * and mem_range_attr_set. 187 */ 188 /* ARGSUSED */ 189 int 190 memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags, 191 struct thread *td) 192 { 193 int nd, error = 0; 194 struct mem_range_op *mo = (struct mem_range_op *)data; 195 struct mem_range_desc *md; 196 197 /* is this for us? */ 198 if ((cmd != MEMRANGE_GET) && 199 (cmd != MEMRANGE_SET)) 200 return (ENOTTY); 201 202 /* any chance we can handle this? */ 203 if (mem_range_softc.mr_op == NULL) 204 return (EOPNOTSUPP); 205 206 /* do we have any descriptors? */ 207 if (mem_range_softc.mr_ndesc == 0) 208 return (ENXIO); 209 210 switch (cmd) { 211 case MEMRANGE_GET: 212 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 213 if (nd > 0) { 214 md = (struct mem_range_desc *) 215 malloc(nd * sizeof(struct mem_range_desc), 216 M_MEMDESC, M_WAITOK); 217 error = mem_range_attr_get(md, &nd); 218 if (!error) 219 error = copyout(md, mo->mo_desc, 220 nd * sizeof(struct mem_range_desc)); 221 free(md, M_MEMDESC); 222 } 223 else 224 nd = mem_range_softc.mr_ndesc; 225 mo->mo_arg[0] = nd; 226 break; 227 228 case MEMRANGE_SET: 229 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), 230 M_MEMDESC, M_WAITOK); 231 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 232 /* clamp description string */ 233 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 234 if (error == 0) 235 error = mem_range_attr_set(md, &mo->mo_arg[0]); 236 free(md, M_MEMDESC); 237 break; 238 } 239 return (error); 240 } 241