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 * from: Utah $Hdr: mem.c 1.13 89/10/08$ 40 * from: @(#)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_version = D_VERSION, 85 .d_open = mmopen, 86 .d_close = mmclose, 87 .d_read = mmrw, 88 .d_write = mmrw, 89 .d_ioctl = mmioctl, 90 .d_mmap = memmmap, 91 .d_name = "mem", 92 .d_maj = CDEV_MAJOR, 93 .d_flags = D_MEM | D_NEEDGIANT, 94 }; 95 96 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 97 98 struct mem_range_softc mem_range_softc; 99 100 static int 101 mmclose(dev_t dev, int flags, int fmt, struct thread *td) 102 { 103 switch (minor(dev)) { 104 case 14: 105 td->td_frame->tf_rflags &= ~PSL_IOPL; 106 } 107 return (0); 108 } 109 110 static int 111 mmopen(dev_t dev, int flags, int fmt, struct thread *td) 112 { 113 int error; 114 115 switch (minor(dev)) { 116 case 0: 117 case 1: 118 if (flags & FWRITE) { 119 error = securelevel_gt(td->td_ucred, 0); 120 if (error != 0) 121 return (error); 122 } 123 break; 124 case 14: 125 error = suser(td); 126 if (error != 0) 127 return (error); 128 error = securelevel_gt(td->td_ucred, 0); 129 if (error != 0) 130 return (error); 131 td->td_frame->tf_rflags |= PSL_IOPL; 132 break; 133 } 134 return (0); 135 } 136 137 /*ARGSUSED*/ 138 static int 139 mmrw(dev_t dev, struct uio *uio, int flags) 140 { 141 int o; 142 u_long c = 0, v; 143 struct iovec *iov; 144 int error = 0; 145 vm_offset_t addr, eaddr; 146 147 GIANT_REQUIRED; 148 149 while (uio->uio_resid > 0 && error == 0) { 150 iov = uio->uio_iov; 151 if (iov->iov_len == 0) { 152 uio->uio_iov++; 153 uio->uio_iovcnt--; 154 if (uio->uio_iovcnt < 0) 155 panic("mmrw"); 156 continue; 157 } 158 switch (minor(dev)) { 159 160 /* minor device 0 is physical memory */ 161 case 0: 162 v = uio->uio_offset; 163 kmemphys: 164 o = v & PAGE_MASK; 165 c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o)); 166 error = uiomove((void *)PHYS_TO_DMAP(v), (int)c, uio); 167 continue; 168 169 /* minor device 1 is kernel memory */ 170 case 1: 171 v = uio->uio_offset; 172 173 if (v >= DMAP_MIN_ADDRESS && v < DMAP_MAX_ADDRESS) { 174 v = DMAP_TO_PHYS(v); 175 goto kmemphys; 176 } 177 178 c = iov->iov_len; 179 180 /* 181 * Make sure that all of the pages are currently resident so 182 * that we don't create any zero-fill pages. 183 */ 184 addr = trunc_page(v); 185 eaddr = round_page(v + c); 186 187 if (addr < (vm_offset_t)KERNBASE) 188 return (EFAULT); 189 for (; addr < eaddr; addr += PAGE_SIZE) 190 if (pmap_extract(kernel_pmap, addr) == 0) 191 return (EFAULT); 192 193 if (!kernacc((caddr_t)(long)v, c, 194 uio->uio_rw == UIO_READ ? 195 VM_PROT_READ : VM_PROT_WRITE)) 196 return (EFAULT); 197 198 error = uiomove((caddr_t)(long)v, (int)c, uio); 199 continue; 200 201 default: 202 return (ENODEV); 203 } 204 205 if (error) 206 break; 207 iov->iov_base = (char *)iov->iov_base + c; 208 iov->iov_len -= c; 209 uio->uio_offset += c; 210 uio->uio_resid -= c; 211 } 212 return (error); 213 } 214 215 /*******************************************************\ 216 * allow user processes to MMAP some memory sections * 217 * instead of going through read/write * 218 \*******************************************************/ 219 static int 220 memmmap(dev_t dev, vm_offset_t offset, vm_paddr_t *paddr, int prot) 221 { 222 switch (minor(dev)) 223 { 224 225 /* minor device 0 is physical memory */ 226 case 0: 227 *paddr = offset; 228 break; 229 230 /* minor device 1 is kernel memory */ 231 case 1: 232 *paddr = vtophys(offset); 233 break; 234 235 default: 236 return (-1); 237 } 238 return (0); 239 } 240 241 /* 242 * Operations for changing memory attributes. 243 * 244 * This is basically just an ioctl shim for mem_range_attr_get 245 * and mem_range_attr_set. 246 */ 247 static int 248 mmioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td) 249 { 250 int nd, error = 0; 251 struct mem_range_op *mo = (struct mem_range_op *)data; 252 struct mem_range_desc *md; 253 254 /* is this for us? */ 255 if ((cmd != MEMRANGE_GET) && 256 (cmd != MEMRANGE_SET)) 257 return (ENOTTY); 258 259 /* any chance we can handle this? */ 260 if (mem_range_softc.mr_op == NULL) 261 return (EOPNOTSUPP); 262 263 /* do we have any descriptors? */ 264 if (mem_range_softc.mr_ndesc == 0) 265 return (ENXIO); 266 267 switch (cmd) { 268 case MEMRANGE_GET: 269 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 270 if (nd > 0) { 271 md = (struct mem_range_desc *) 272 malloc(nd * sizeof(struct mem_range_desc), 273 M_MEMDESC, M_WAITOK); 274 error = mem_range_attr_get(md, &nd); 275 if (!error) 276 error = copyout(md, mo->mo_desc, 277 nd * sizeof(struct mem_range_desc)); 278 free(md, M_MEMDESC); 279 } 280 else 281 nd = mem_range_softc.mr_ndesc; 282 mo->mo_arg[0] = nd; 283 break; 284 285 case MEMRANGE_SET: 286 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), 287 M_MEMDESC, M_WAITOK); 288 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 289 /* clamp description string */ 290 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 291 if (error == 0) 292 error = mem_range_attr_set(md, &mo->mo_arg[0]); 293 free(md, M_MEMDESC); 294 break; 295 } 296 return (error); 297 } 298 299 /* 300 * Implementation-neutral, kernel-callable functions for manipulating 301 * memory range attributes. 302 */ 303 int 304 mem_range_attr_get(struct mem_range_desc *mrd, int *arg) 305 { 306 /* can we handle this? */ 307 if (mem_range_softc.mr_op == NULL) 308 return (EOPNOTSUPP); 309 310 if (*arg == 0) 311 *arg = mem_range_softc.mr_ndesc; 312 else 313 bcopy(mem_range_softc.mr_desc, mrd, 314 (*arg) * sizeof(struct mem_range_desc)); 315 return (0); 316 } 317 318 int 319 mem_range_attr_set(struct mem_range_desc *mrd, int *arg) 320 { 321 /* can we handle this? */ 322 if (mem_range_softc.mr_op == NULL) 323 return (EOPNOTSUPP); 324 325 return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg)); 326 } 327 328 #ifdef SMP 329 void 330 mem_range_AP_init(void) 331 { 332 if (mem_range_softc.mr_op && mem_range_softc.mr_op->initAP) 333 (mem_range_softc.mr_op->initAP(&mem_range_softc)); 334 } 335 #endif 336 337 static int 338 mem_modevent(module_t mod, int type, void *data) 339 { 340 switch(type) { 341 case MOD_LOAD: 342 if (bootverbose) 343 printf("mem: <memory & I/O>\n"); 344 /* Initialise memory range handling */ 345 if (mem_range_softc.mr_op != NULL) 346 mem_range_softc.mr_op->init(&mem_range_softc); 347 348 memdev = make_dev(&mem_cdevsw, 0, UID_ROOT, GID_KMEM, 349 0640, "mem"); 350 kmemdev = make_dev(&mem_cdevsw, 1, UID_ROOT, GID_KMEM, 351 0640, "kmem"); 352 iodev = make_dev(&mem_cdevsw, 14, UID_ROOT, GID_WHEEL, 353 0600, "io"); 354 return (0); 355 356 case MOD_UNLOAD: 357 destroy_dev(memdev); 358 destroy_dev(kmemdev); 359 destroy_dev(iodev); 360 return (0); 361 362 case MOD_SHUTDOWN: 363 return (0); 364 365 default: 366 return (EOPNOTSUPP); 367 } 368 } 369 370 DEV_MODULE(mem, mem_modevent, NULL); 371