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 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * from: Utah $Hdr: mem.c 1.13 89/10/08$ 36 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 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/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/db_machdep.h> 61 #include <machine/frame.h> 62 #include <machine/psl.h> 63 #include <machine/specialreg.h> 64 #include <machine/vmparam.h> 65 66 #include <vm/vm.h> 67 #include <vm/pmap.h> 68 #include <vm/vm_extern.h> 69 70 static dev_t memdev, kmemdev, iodev; 71 72 static d_open_t mmopen; 73 static d_close_t mmclose; 74 static d_read_t mmrw; 75 static d_ioctl_t mmioctl; 76 static d_mmap_t memmmap; 77 78 #define CDEV_MAJOR 2 79 static struct cdevsw mem_cdevsw = { 80 .d_version = D_VERSION, 81 .d_open = mmopen, 82 .d_close = mmclose, 83 .d_read = mmrw, 84 .d_write = mmrw, 85 .d_ioctl = mmioctl, 86 .d_mmap = memmmap, 87 .d_name = "mem", 88 .d_maj = CDEV_MAJOR, 89 .d_flags = D_MEM | D_NEEDGIANT, 90 }; 91 92 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 93 94 struct mem_range_softc mem_range_softc; 95 96 static int 97 mmclose(dev_t dev, int flags, int fmt, struct thread *td) 98 { 99 switch (minor(dev)) { 100 case 14: 101 td->td_frame->tf_rflags &= ~PSL_IOPL; 102 } 103 return (0); 104 } 105 106 static int 107 mmopen(dev_t dev, int flags, int fmt, struct thread *td) 108 { 109 int error; 110 111 switch (minor(dev)) { 112 case 0: 113 case 1: 114 if (flags & FWRITE) { 115 error = securelevel_gt(td->td_ucred, 0); 116 if (error != 0) 117 return (error); 118 } 119 break; 120 case 14: 121 error = suser(td); 122 if (error != 0) 123 return (error); 124 error = securelevel_gt(td->td_ucred, 0); 125 if (error != 0) 126 return (error); 127 td->td_frame->tf_rflags |= PSL_IOPL; 128 break; 129 } 130 return (0); 131 } 132 133 /*ARGSUSED*/ 134 static int 135 mmrw(dev_t dev, struct uio *uio, int flags) 136 { 137 int o; 138 u_long c = 0, v; 139 struct iovec *iov; 140 int error = 0; 141 vm_offset_t addr, eaddr; 142 143 GIANT_REQUIRED; 144 145 while (uio->uio_resid > 0 && error == 0) { 146 iov = uio->uio_iov; 147 if (iov->iov_len == 0) { 148 uio->uio_iov++; 149 uio->uio_iovcnt--; 150 if (uio->uio_iovcnt < 0) 151 panic("mmrw"); 152 continue; 153 } 154 switch (minor(dev)) { 155 156 /* minor device 0 is physical memory */ 157 case 0: 158 v = uio->uio_offset; 159 kmemphys: 160 o = v & PAGE_MASK; 161 c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o)); 162 error = uiomove((void *)PHYS_TO_DMAP(v), (int)c, uio); 163 continue; 164 165 /* minor device 1 is kernel memory */ 166 case 1: 167 v = uio->uio_offset; 168 169 if (v >= DMAP_MIN_ADDRESS && v < DMAP_MAX_ADDRESS) { 170 v = DMAP_TO_PHYS(v); 171 goto kmemphys; 172 } 173 174 c = iov->iov_len; 175 176 /* 177 * Make sure that all of the pages are currently resident so 178 * that we don't create any zero-fill pages. 179 */ 180 addr = trunc_page(v); 181 eaddr = round_page(v + c); 182 183 if (addr < (vm_offset_t)KERNBASE) 184 return (EFAULT); 185 for (; addr < eaddr; addr += PAGE_SIZE) 186 if (pmap_extract(kernel_pmap, addr) == 0) 187 return (EFAULT); 188 189 if (!kernacc((caddr_t)(long)v, c, 190 uio->uio_rw == UIO_READ ? 191 VM_PROT_READ : VM_PROT_WRITE)) 192 return (EFAULT); 193 194 error = uiomove((caddr_t)(long)v, (int)c, uio); 195 continue; 196 197 default: 198 return (ENODEV); 199 } 200 201 if (error) 202 break; 203 iov->iov_base = (char *)iov->iov_base + c; 204 iov->iov_len -= c; 205 uio->uio_offset += c; 206 uio->uio_resid -= c; 207 } 208 return (error); 209 } 210 211 /*******************************************************\ 212 * allow user processes to MMAP some memory sections * 213 * instead of going through read/write * 214 \*******************************************************/ 215 static int 216 memmmap(dev_t dev, vm_offset_t offset, vm_paddr_t *paddr, int prot) 217 { 218 switch (minor(dev)) 219 { 220 221 /* minor device 0 is physical memory */ 222 case 0: 223 *paddr = offset; 224 break; 225 226 /* minor device 1 is kernel memory */ 227 case 1: 228 *paddr = vtophys(offset); 229 break; 230 231 default: 232 return (-1); 233 } 234 return (0); 235 } 236 237 /* 238 * Operations for changing memory attributes. 239 * 240 * This is basically just an ioctl shim for mem_range_attr_get 241 * and mem_range_attr_set. 242 */ 243 static int 244 mmioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td) 245 { 246 int nd, error = 0; 247 struct mem_range_op *mo = (struct mem_range_op *)data; 248 struct mem_range_desc *md; 249 250 /* is this for us? */ 251 if ((cmd != MEMRANGE_GET) && 252 (cmd != MEMRANGE_SET)) 253 return (ENOTTY); 254 255 /* any chance we can handle this? */ 256 if (mem_range_softc.mr_op == NULL) 257 return (EOPNOTSUPP); 258 259 /* do we have any descriptors? */ 260 if (mem_range_softc.mr_ndesc == 0) 261 return (ENXIO); 262 263 switch (cmd) { 264 case MEMRANGE_GET: 265 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 266 if (nd > 0) { 267 md = (struct mem_range_desc *) 268 malloc(nd * sizeof(struct mem_range_desc), 269 M_MEMDESC, M_WAITOK); 270 error = mem_range_attr_get(md, &nd); 271 if (!error) 272 error = copyout(md, mo->mo_desc, 273 nd * sizeof(struct mem_range_desc)); 274 free(md, M_MEMDESC); 275 } 276 else 277 nd = mem_range_softc.mr_ndesc; 278 mo->mo_arg[0] = nd; 279 break; 280 281 case MEMRANGE_SET: 282 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), 283 M_MEMDESC, M_WAITOK); 284 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 285 /* clamp description string */ 286 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 287 if (error == 0) 288 error = mem_range_attr_set(md, &mo->mo_arg[0]); 289 free(md, M_MEMDESC); 290 break; 291 } 292 return (error); 293 } 294 295 /* 296 * Implementation-neutral, kernel-callable functions for manipulating 297 * memory range attributes. 298 */ 299 int 300 mem_range_attr_get(struct mem_range_desc *mrd, int *arg) 301 { 302 /* can we handle this? */ 303 if (mem_range_softc.mr_op == NULL) 304 return (EOPNOTSUPP); 305 306 if (*arg == 0) 307 *arg = mem_range_softc.mr_ndesc; 308 else 309 bcopy(mem_range_softc.mr_desc, mrd, 310 (*arg) * sizeof(struct mem_range_desc)); 311 return (0); 312 } 313 314 int 315 mem_range_attr_set(struct mem_range_desc *mrd, int *arg) 316 { 317 /* can we handle this? */ 318 if (mem_range_softc.mr_op == NULL) 319 return (EOPNOTSUPP); 320 321 return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg)); 322 } 323 324 #ifdef SMP 325 void 326 mem_range_AP_init(void) 327 { 328 if (mem_range_softc.mr_op && mem_range_softc.mr_op->initAP) 329 (mem_range_softc.mr_op->initAP(&mem_range_softc)); 330 } 331 #endif 332 333 static int 334 mem_modevent(module_t mod, int type, void *data) 335 { 336 switch(type) { 337 case MOD_LOAD: 338 if (bootverbose) 339 printf("mem: <memory & I/O>\n"); 340 /* Initialise memory range handling */ 341 if (mem_range_softc.mr_op != NULL) 342 mem_range_softc.mr_op->init(&mem_range_softc); 343 344 memdev = make_dev(&mem_cdevsw, 0, UID_ROOT, GID_KMEM, 345 0640, "mem"); 346 kmemdev = make_dev(&mem_cdevsw, 1, UID_ROOT, GID_KMEM, 347 0640, "kmem"); 348 iodev = make_dev(&mem_cdevsw, 14, UID_ROOT, GID_WHEEL, 349 0600, "io"); 350 return (0); 351 352 case MOD_UNLOAD: 353 destroy_dev(memdev); 354 destroy_dev(kmemdev); 355 destroy_dev(iodev); 356 return (0); 357 358 case MOD_SHUTDOWN: 359 return (0); 360 361 default: 362 return (EOPNOTSUPP); 363 } 364 } 365 366 DEV_MODULE(mem, mem_modevent, NULL); 367