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. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * Utah $Hdr: mem.c 1.13 89/10/08$ 40 * @(#)mem.c 7.2 (Berkeley) 5/9/91 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 /* 47 * Memory special file 48 */ 49 50 #include <sys/param.h> 51 #include <sys/conf.h> 52 #include <sys/fcntl.h> 53 #include <sys/ioccom.h> 54 #include <sys/kernel.h> 55 #include <sys/lock.h> 56 #include <sys/malloc.h> 57 #include <sys/memrange.h> 58 #include <sys/mutex.h> 59 #include <sys/proc.h> 60 #include <sys/signalvar.h> 61 #include <sys/systm.h> 62 #include <sys/uio.h> 63 64 #include <machine/db_machdep.h> 65 #include <machine/frame.h> 66 #include <machine/psl.h> 67 #include <machine/specialreg.h> 68 #include <machine/vmparam.h> 69 70 #include <vm/vm.h> 71 #include <vm/pmap.h> 72 #include <vm/vm_extern.h> 73 74 static dev_t memdev, kmemdev, iodev; 75 76 static d_open_t mmopen; 77 static d_close_t mmclose; 78 static d_read_t mmrw; 79 static d_ioctl_t mmioctl; 80 static d_mmap_t memmmap; 81 82 #define CDEV_MAJOR 2 83 static struct cdevsw mem_cdevsw = { 84 .d_open = mmopen, 85 .d_close = mmclose, 86 .d_read = mmrw, 87 .d_write = mmrw, 88 .d_ioctl = mmioctl, 89 .d_mmap = memmmap, 90 .d_name = "mem", 91 .d_maj = CDEV_MAJOR, 92 .d_flags = D_MEM, 93 }; 94 95 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 96 97 struct mem_range_softc mem_range_softc; 98 99 static int 100 mmclose(dev_t dev, int flags, int fmt, struct thread *td) 101 { 102 switch (minor(dev)) { 103 case 14: 104 td->td_frame->tf_rflags &= ~PSL_IOPL; 105 } 106 return (0); 107 } 108 109 static int 110 mmopen(dev_t dev, int flags, int fmt, struct thread *td) 111 { 112 int error; 113 114 switch (minor(dev)) { 115 case 0: 116 case 1: 117 if (flags & FWRITE) { 118 error = securelevel_gt(td->td_ucred, 0); 119 if (error != 0) 120 return (error); 121 } 122 break; 123 case 14: 124 error = suser(td); 125 if (error != 0) 126 return (error); 127 error = securelevel_gt(td->td_ucred, 0); 128 if (error != 0) 129 return (error); 130 td->td_frame->tf_rflags |= PSL_IOPL; 131 break; 132 } 133 return (0); 134 } 135 136 /*ARGSUSED*/ 137 static int 138 mmrw(dev_t dev, struct uio *uio, int flags) 139 { 140 int o; 141 u_long c = 0, v; 142 struct iovec *iov; 143 int error = 0; 144 vm_offset_t addr, eaddr; 145 146 GIANT_REQUIRED; 147 148 while (uio->uio_resid > 0 && error == 0) { 149 iov = uio->uio_iov; 150 if (iov->iov_len == 0) { 151 uio->uio_iov++; 152 uio->uio_iovcnt--; 153 if (uio->uio_iovcnt < 0) 154 panic("mmrw"); 155 continue; 156 } 157 switch (minor(dev)) { 158 159 /* minor device 0 is physical memory */ 160 case 0: 161 v = uio->uio_offset; 162 kmemphys: 163 o = v & PAGE_MASK; 164 c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o)); 165 error = uiomove((void *)PHYS_TO_DMAP(v), (int)c, uio); 166 continue; 167 168 /* minor device 1 is kernel memory */ 169 case 1: 170 v = uio->uio_offset; 171 172 if (v >= DMAP_MIN_ADDRESS && v < DMAP_MAX_ADDRESS) { 173 v = DMAP_TO_PHYS(v); 174 goto kmemphys; 175 } 176 177 c = iov->iov_len; 178 /* 179 * Make sure that all of the pages are currently resident so 180 * that we don't create any zero-fill pages. 181 */ 182 addr = trunc_page(v); 183 eaddr = round_page(v + c); 184 185 if (addr < (vm_offset_t)KERNBASE) 186 return (EFAULT); 187 for (; addr < eaddr; addr += PAGE_SIZE) 188 if (pmap_extract(kernel_pmap, addr) == 0) 189 return (EFAULT); 190 191 if (!kernacc((caddr_t)(long)v, c, 192 uio->uio_rw == UIO_READ ? 193 VM_PROT_READ : VM_PROT_WRITE)) 194 return (EFAULT); 195 196 error = uiomove((caddr_t)(long)v, (int)c, uio); 197 continue; 198 199 default: 200 return (ENODEV); 201 } 202 203 if (error) 204 break; 205 iov->iov_base = (char *)iov->iov_base + c; 206 iov->iov_len -= c; 207 uio->uio_offset += c; 208 uio->uio_resid -= c; 209 } 210 return (error); 211 } 212 213 /*******************************************************\ 214 * allow user processes to MMAP some memory sections * 215 * instead of going through read/write * 216 \*******************************************************/ 217 static int 218 memmmap(dev_t dev, vm_offset_t offset, vm_paddr_t *paddr, int prot) 219 { 220 switch (minor(dev)) 221 { 222 223 /* minor device 0 is physical memory */ 224 case 0: 225 *paddr = offset; 226 break; 227 228 /* minor device 1 is kernel memory */ 229 case 1: 230 *paddr = vtophys(offset); 231 break; 232 233 default: 234 return (-1); 235 } 236 return (0); 237 } 238 239 /* 240 * Operations for changing memory attributes. 241 * 242 * This is basically just an ioctl shim for mem_range_attr_get 243 * and mem_range_attr_set. 244 */ 245 static int 246 mmioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td) 247 { 248 int nd, error = 0; 249 struct mem_range_op *mo = (struct mem_range_op *)data; 250 struct mem_range_desc *md; 251 252 /* is this for us? */ 253 if ((cmd != MEMRANGE_GET) && 254 (cmd != MEMRANGE_SET)) 255 return (ENOTTY); 256 257 /* any chance we can handle this? */ 258 if (mem_range_softc.mr_op == NULL) 259 return (EOPNOTSUPP); 260 261 /* do we have any descriptors? */ 262 if (mem_range_softc.mr_ndesc == 0) 263 return (ENXIO); 264 265 switch (cmd) { 266 case MEMRANGE_GET: 267 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 268 if (nd > 0) { 269 md = (struct mem_range_desc *) 270 malloc(nd * sizeof(struct mem_range_desc), 271 M_MEMDESC, M_WAITOK); 272 error = mem_range_attr_get(md, &nd); 273 if (!error) 274 error = copyout(md, mo->mo_desc, 275 nd * sizeof(struct mem_range_desc)); 276 free(md, M_MEMDESC); 277 } 278 else 279 nd = mem_range_softc.mr_ndesc; 280 mo->mo_arg[0] = nd; 281 break; 282 283 case MEMRANGE_SET: 284 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), 285 M_MEMDESC, M_WAITOK); 286 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 287 /* clamp description string */ 288 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 289 if (error == 0) 290 error = mem_range_attr_set(md, &mo->mo_arg[0]); 291 free(md, M_MEMDESC); 292 break; 293 } 294 return (error); 295 } 296 297 /* 298 * Implementation-neutral, kernel-callable functions for manipulating 299 * memory range attributes. 300 */ 301 int 302 mem_range_attr_get(struct mem_range_desc *mrd, int *arg) 303 { 304 /* can we handle this? */ 305 if (mem_range_softc.mr_op == NULL) 306 return (EOPNOTSUPP); 307 308 if (*arg == 0) 309 *arg = mem_range_softc.mr_ndesc; 310 else 311 bcopy(mem_range_softc.mr_desc, mrd, 312 (*arg) * sizeof(struct mem_range_desc)); 313 return (0); 314 } 315 316 int 317 mem_range_attr_set(struct mem_range_desc *mrd, int *arg) 318 { 319 /* can we handle this? */ 320 if (mem_range_softc.mr_op == NULL) 321 return (EOPNOTSUPP); 322 323 return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg)); 324 } 325 326 static int 327 mem_modevent(module_t mod, int type, void *data) 328 { 329 switch(type) { 330 case MOD_LOAD: 331 if (bootverbose) 332 printf("mem: <memory & I/O>\n"); 333 /* Initialise memory range handling */ 334 if (mem_range_softc.mr_op != NULL) 335 mem_range_softc.mr_op->init(&mem_range_softc); 336 337 memdev = make_dev(&mem_cdevsw, 0, UID_ROOT, GID_KMEM, 338 0640, "mem"); 339 kmemdev = make_dev(&mem_cdevsw, 1, UID_ROOT, GID_KMEM, 340 0640, "kmem"); 341 iodev = make_dev(&mem_cdevsw, 14, UID_ROOT, GID_WHEEL, 342 0600, "io"); 343 return (0); 344 345 case MOD_UNLOAD: 346 destroy_dev(memdev); 347 destroy_dev(kmemdev); 348 destroy_dev(iodev); 349 return (0); 350 351 case MOD_SHUTDOWN: 352 return (0); 353 354 default: 355 return (EOPNOTSUPP); 356 } 357 } 358 359 DEV_MODULE(mem, mem_modevent, NULL); 360