1 /* $OpenBSD: mem.c,v 1.10 2024/12/30 02:46:00 guenther Exp $ */ 2 /* $NetBSD: mem.c,v 1.11 2003/10/16 12:02:58 jdolecek Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1990, 1993 6 * The Regents of the University of California. 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. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 /* 37 * Copyright (c) 1988 University of Utah. 38 * 39 * This code is derived from software contributed to Berkeley by 40 * the Systems Programming Group of the University of Utah Computer 41 * Science Department. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 3. All advertising materials mentioning features or use of this software 52 * must display the following acknowledgement: 53 * This product includes software developed by the University of 54 * California, Berkeley and its contributors. 55 * 4. Neither the name of the University nor the names of its contributors 56 * may be used to endorse or promote products derived from this software 57 * without specific prior written permission. 58 * 59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 62 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 69 * SUCH DAMAGE. 70 */ 71 72 /* 73 * Memory special file 74 */ 75 76 #include <sys/param.h> 77 #include <sys/conf.h> 78 #include <sys/buf.h> 79 #include <sys/filio.h> 80 #include <sys/systm.h> 81 #include <sys/uio.h> 82 #include <sys/malloc.h> 83 #include <sys/proc.h> 84 #include <sys/fcntl.h> 85 #include <sys/rwlock.h> 86 #include <sys/atomic.h> 87 88 #include <machine/cpu.h> 89 #include <arm64/conf.h> 90 91 #include <uvm/uvm_extern.h> 92 93 caddr_t zeropage; 94 95 /* open counter for aperture */ 96 #ifdef APERTURE 97 static int ap_open_count = 0; 98 extern int allowaperture; 99 #endif 100 101 static struct rwlock physlock = RWLOCK_INITIALIZER("mmrw"); 102 103 int 104 mmopen(dev_t dev, int flag, int mode, struct proc *p) 105 { 106 extern int allowkmem; 107 108 switch (minor(dev)) { 109 case 0: 110 case 1: 111 if ((int)atomic_load_int(&securelevel) <= 0 || 112 atomic_load_int(&allowkmem)) 113 break; 114 return (EPERM); 115 case 2: 116 case 12: 117 break; 118 #ifdef APERTURE 119 case 4: 120 if (suser(p) != 0 || !allowaperture) 121 return (EPERM); 122 123 /* authorize only one simultaneous open() unless 124 * allowaperture=3 */ 125 if (ap_open_count > 0 && allowaperture < 3) 126 return (EPERM); 127 ap_open_count++; 128 break; 129 #endif 130 default: 131 return (ENXIO); 132 } 133 return (0); 134 } 135 136 int 137 mmclose(dev_t dev, int flag, int mode, struct proc *p) 138 { 139 #ifdef APERTURE 140 if (minor(dev) == 4) 141 ap_open_count = 0; 142 #endif 143 return (0); 144 } 145 146 int 147 mmrw(dev_t dev, struct uio *uio, int flags) 148 { 149 vaddr_t o, v; 150 size_t c; 151 struct iovec *iov; 152 int error = 0; 153 vm_prot_t prot; 154 extern caddr_t vmmap; 155 156 if (minor(dev) == 0) { 157 /* lock against other uses of shared vmmap */ 158 error = rw_enter(&physlock, RW_WRITE | RW_INTR); 159 if (error) 160 return (error); 161 } 162 while (uio->uio_resid > 0 && error == 0) { 163 iov = uio->uio_iov; 164 if (iov->iov_len == 0) { 165 uio->uio_iov++; 166 uio->uio_iovcnt--; 167 if (uio->uio_iovcnt < 0) 168 panic("mmrw"); 169 continue; 170 } 171 switch (minor(dev)) { 172 173 case 0: 174 v = uio->uio_offset; 175 prot = uio->uio_rw == UIO_READ ? PROT_READ : 176 PROT_WRITE; 177 pmap_enter(pmap_kernel(), (vaddr_t)vmmap, 178 trunc_page(v), prot, prot|PMAP_WIRED); 179 pmap_update(pmap_kernel()); 180 o = uio->uio_offset & PGOFSET; 181 c = ulmin(uio->uio_resid, PAGE_SIZE - o); 182 error = uiomove((caddr_t)vmmap + o, c, uio); 183 pmap_remove(pmap_kernel(), (vaddr_t)vmmap, 184 (vaddr_t)vmmap + PAGE_SIZE); 185 pmap_update(pmap_kernel()); 186 break; 187 188 case 1: 189 v = uio->uio_offset; 190 c = ulmin(iov->iov_len, MAXPHYS); 191 if (!uvm_kernacc((caddr_t)v, c, 192 uio->uio_rw == UIO_READ ? B_READ : B_WRITE)) 193 return (EFAULT); 194 error = uiomove((caddr_t)v, c, uio); 195 break; 196 197 case 2: 198 if (uio->uio_rw == UIO_WRITE) 199 uio->uio_resid = 0; 200 return (0); 201 202 case 12: 203 if (uio->uio_rw == UIO_WRITE) { 204 uio->uio_resid = 0; 205 return (0); 206 } 207 if (zeropage == NULL) 208 zeropage = malloc(PAGE_SIZE, M_TEMP, 209 M_WAITOK | M_ZERO); 210 c = ulmin(iov->iov_len, PAGE_SIZE); 211 error = uiomove(zeropage, c, uio); 212 break; 213 214 default: 215 return (ENXIO); 216 } 217 } 218 if (minor(dev) == 0) { 219 rw_exit(&physlock); 220 } 221 return (error); 222 } 223 224 paddr_t 225 mmmmap(dev_t dev, off_t off, int prot) 226 { 227 struct proc *p = curproc; /* XXX */ 228 229 /* 230 * /dev/mem is the only one that makes sense through this 231 * interface. For /dev/kmem any physaddr we return here 232 * could be transient and hence incorrect or invalid at 233 * a later time. /dev/null just doesn't make any sense 234 * and /dev/zero is a hack that is handled via the default 235 * pager in mmap(). 236 */ 237 if (minor(dev) != 0) 238 return (-1); 239 240 /* minor device 0 is physical memory */ 241 242 if ((paddr_t)off >= ptoa((paddr_t)physmem) && 243 suser(p) != 0) 244 return -1; 245 return off; 246 } 247 248 int 249 mmioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p) 250 { 251 switch (cmd) { 252 case FIOASYNC: 253 /* handled by fd layer */ 254 return 0; 255 } 256 257 return (ENOTTY); 258 } 259