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 /* 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/systm.h> 59 #include <sys/uio.h> 60 61 #include <machine/md_var.h> 62 #include <machine/specialreg.h> 63 #include <machine/vmparam.h> 64 65 #include <vm/vm.h> 66 #include <vm/pmap.h> 67 #include <vm/vm_extern.h> 68 69 #include <machine/memdev.h> 70 71 /* 72 * Used in /dev/mem drivers and elsewhere 73 */ 74 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 75 76 /* ARGSUSED */ 77 int 78 memrw(struct cdev *dev, struct uio *uio, int flags) 79 { 80 struct iovec *iov; 81 void *p; 82 ssize_t orig_resid; 83 u_long v, vd; 84 u_int c; 85 int error; 86 87 error = 0; 88 orig_resid = uio->uio_resid; 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 v = uio->uio_offset; 99 c = ulmin(iov->iov_len, PAGE_SIZE - (u_int)(v & PAGE_MASK)); 100 101 switch (dev2unit(dev)) { 102 case CDEV_MINOR_KMEM: 103 /* 104 * Since c is clamped to be less or equal than 105 * PAGE_SIZE, the uiomove() call does not 106 * access past the end of the direct map. 107 */ 108 if (v >= DMAP_MIN_ADDRESS && 109 v < DMAP_MIN_ADDRESS + dmaplimit) { 110 error = uiomove((void *)v, c, uio); 111 break; 112 } 113 114 if (!kernacc((void *)v, c, uio->uio_rw == UIO_READ ? 115 VM_PROT_READ : VM_PROT_WRITE)) { 116 error = EFAULT; 117 break; 118 } 119 120 /* 121 * If the extracted address is not accessible 122 * through the direct map, then we make a 123 * private (uncached) mapping because we can't 124 * depend on the existing kernel mapping 125 * remaining valid until the completion of 126 * uiomove(). 127 * 128 * XXX We cannot provide access to the 129 * physical page 0 mapped into KVA. 130 */ 131 v = pmap_extract(kernel_pmap, v); 132 if (v == 0) { 133 error = EFAULT; 134 break; 135 } 136 /* FALLTHROUGH */ 137 case CDEV_MINOR_MEM: 138 if (v < dmaplimit) { 139 vd = PHYS_TO_DMAP(v); 140 error = uiomove((void *)vd, c, uio); 141 break; 142 } 143 if (v > cpu_getmaxphyaddr()) { 144 error = EFAULT; 145 break; 146 } 147 p = pmap_mapdev(v, PAGE_SIZE); 148 error = uiomove(p, c, uio); 149 pmap_unmapdev(p, PAGE_SIZE); 150 break; 151 } 152 } 153 /* 154 * Don't return error if any byte was written. Read and write 155 * can return error only if no i/o was performed. 156 */ 157 if (uio->uio_resid != orig_resid) 158 error = 0; 159 return (error); 160 } 161 162 /* 163 * allow user processes to MMAP some memory sections 164 * instead of going through read/write 165 */ 166 /* ARGSUSED */ 167 int 168 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, 169 int prot __unused, vm_memattr_t *memattr __unused) 170 { 171 if (dev2unit(dev) == CDEV_MINOR_MEM) { 172 if (offset > cpu_getmaxphyaddr()) 173 return (-1); 174 *paddr = offset; 175 return (0); 176 } 177 return (-1); 178 } 179 180 /* 181 * Operations for changing memory attributes. 182 * 183 * This is basically just an ioctl shim for mem_range_attr_get 184 * and mem_range_attr_set. 185 */ 186 int 187 memioctl_md(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags, 188 struct thread *td) 189 { 190 int nd, error = 0; 191 struct mem_range_op *mo = (struct mem_range_op *)data; 192 struct mem_range_desc *md; 193 194 /* is this for us? */ 195 if ((cmd != MEMRANGE_GET) && 196 (cmd != MEMRANGE_SET)) 197 return (ENOTTY); 198 199 /* any chance we can handle this? */ 200 if (mem_range_softc.mr_op == NULL) 201 return (EOPNOTSUPP); 202 203 /* do we have any descriptors? */ 204 if (mem_range_softc.mr_ndesc == 0) 205 return (ENXIO); 206 207 switch (cmd) { 208 case MEMRANGE_GET: 209 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 210 if (nd > 0) { 211 md = (struct mem_range_desc *) 212 malloc(nd * sizeof(struct mem_range_desc), 213 M_MEMDESC, M_WAITOK); 214 error = mem_range_attr_get(md, &nd); 215 if (!error) 216 error = copyout(md, mo->mo_desc, 217 nd * sizeof(struct mem_range_desc)); 218 free(md, M_MEMDESC); 219 } 220 else 221 nd = mem_range_softc.mr_ndesc; 222 mo->mo_arg[0] = nd; 223 break; 224 225 case MEMRANGE_SET: 226 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), 227 M_MEMDESC, M_WAITOK); 228 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 229 /* clamp description string */ 230 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 231 if (error == 0) 232 error = mem_range_attr_set(md, &mo->mo_arg[0]); 233 free(md, M_MEMDESC); 234 break; 235 } 236 return (error); 237 } 238