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 */ 39 40 #include <sys/cdefs.h> 41 /* 42 * Memory special file 43 */ 44 45 #include <sys/param.h> 46 #include <sys/conf.h> 47 #include <sys/fcntl.h> 48 #include <sys/ioccom.h> 49 #include <sys/kernel.h> 50 #include <sys/lock.h> 51 #include <sys/malloc.h> 52 #include <sys/memrange.h> 53 #include <sys/module.h> 54 #include <sys/mutex.h> 55 #include <sys/proc.h> 56 #include <sys/signalvar.h> 57 #include <sys/systm.h> 58 #include <sys/uio.h> 59 60 #include <machine/md_var.h> 61 #include <machine/specialreg.h> 62 #include <machine/vmparam.h> 63 64 #include <vm/vm.h> 65 #include <vm/pmap.h> 66 #include <vm/vm_extern.h> 67 68 #include <machine/memdev.h> 69 70 /* 71 * Used in /dev/mem drivers and elsewhere 72 */ 73 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 74 75 /* ARGSUSED */ 76 int 77 memrw(struct cdev *dev, struct uio *uio, int flags) 78 { 79 struct iovec *iov; 80 void *p; 81 ssize_t orig_resid; 82 u_long v, vd; 83 u_int c; 84 int error; 85 86 error = 0; 87 orig_resid = uio->uio_resid; 88 while (uio->uio_resid > 0 && error == 0) { 89 iov = uio->uio_iov; 90 if (iov->iov_len == 0) { 91 uio->uio_iov++; 92 uio->uio_iovcnt--; 93 if (uio->uio_iovcnt < 0) 94 panic("memrw"); 95 continue; 96 } 97 v = uio->uio_offset; 98 c = ulmin(iov->iov_len, PAGE_SIZE - (u_int)(v & PAGE_MASK)); 99 100 switch (dev2unit(dev)) { 101 case CDEV_MINOR_KMEM: 102 /* 103 * Since c is clamped to be less or equal than 104 * PAGE_SIZE, the uiomove() call does not 105 * access past the end of the direct map. 106 */ 107 if (v >= DMAP_MIN_ADDRESS && 108 v < DMAP_MIN_ADDRESS + dmaplimit) { 109 error = uiomove((void *)v, c, uio); 110 break; 111 } 112 113 if (!kernacc((void *)v, c, uio->uio_rw == UIO_READ ? 114 VM_PROT_READ : VM_PROT_WRITE)) { 115 error = EFAULT; 116 break; 117 } 118 119 /* 120 * If the extracted address is not accessible 121 * through the direct map, then we make a 122 * private (uncached) mapping because we can't 123 * depend on the existing kernel mapping 124 * remaining valid until the completion of 125 * uiomove(). 126 * 127 * XXX We cannot provide access to the 128 * physical page 0 mapped into KVA. 129 */ 130 v = pmap_extract(kernel_pmap, v); 131 if (v == 0) { 132 error = EFAULT; 133 break; 134 } 135 /* FALLTHROUGH */ 136 case CDEV_MINOR_MEM: 137 if (v < dmaplimit) { 138 vd = PHYS_TO_DMAP(v); 139 error = uiomove((void *)vd, c, uio); 140 break; 141 } 142 if (v > cpu_getmaxphyaddr()) { 143 error = EFAULT; 144 break; 145 } 146 p = pmap_mapdev(v, PAGE_SIZE); 147 error = uiomove(p, c, uio); 148 pmap_unmapdev(p, PAGE_SIZE); 149 break; 150 } 151 } 152 /* 153 * Don't return error if any byte was written. Read and write 154 * can return error only if no i/o was performed. 155 */ 156 if (uio->uio_resid != orig_resid) 157 error = 0; 158 return (error); 159 } 160 161 /* 162 * allow user processes to MMAP some memory sections 163 * instead of going through read/write 164 */ 165 /* ARGSUSED */ 166 int 167 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, 168 int prot __unused, vm_memattr_t *memattr __unused) 169 { 170 if (dev2unit(dev) == CDEV_MINOR_MEM) { 171 if (offset > cpu_getmaxphyaddr()) 172 return (-1); 173 *paddr = offset; 174 return (0); 175 } 176 return (-1); 177 } 178 179 /* 180 * Operations for changing memory attributes. 181 * 182 * This is basically just an ioctl shim for mem_range_attr_get 183 * and mem_range_attr_set. 184 */ 185 int 186 memioctl_md(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags, 187 struct thread *td) 188 { 189 int nd, error = 0; 190 struct mem_range_op *mo = (struct mem_range_op *)data; 191 struct mem_range_desc *md; 192 193 /* is this for us? */ 194 if ((cmd != MEMRANGE_GET) && 195 (cmd != MEMRANGE_SET)) 196 return (ENOTTY); 197 198 /* any chance we can handle this? */ 199 if (mem_range_softc.mr_op == NULL) 200 return (EOPNOTSUPP); 201 202 /* do we have any descriptors? */ 203 if (mem_range_softc.mr_ndesc == 0) 204 return (ENXIO); 205 206 switch (cmd) { 207 case MEMRANGE_GET: 208 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 209 if (nd > 0) { 210 md = (struct mem_range_desc *) 211 malloc(nd * sizeof(struct mem_range_desc), 212 M_MEMDESC, M_WAITOK); 213 error = mem_range_attr_get(md, &nd); 214 if (!error) 215 error = copyout(md, mo->mo_desc, 216 nd * sizeof(struct mem_range_desc)); 217 free(md, M_MEMDESC); 218 } 219 else 220 nd = mem_range_softc.mr_ndesc; 221 mo->mo_arg[0] = nd; 222 break; 223 224 case MEMRANGE_SET: 225 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), 226 M_MEMDESC, M_WAITOK); 227 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 228 /* clamp description string */ 229 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 230 if (error == 0) 231 error = mem_range_attr_set(md, &mo->mo_arg[0]); 232 free(md, M_MEMDESC); 233 break; 234 } 235 return (error); 236 } 237