subr_hash.c revision 32286
1/* 2 * Copyright (c) 1982, 1986, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94 39 * $Id: kern_subr.c,v 1.14 1997/12/19 09:03:23 dyson Exp $ 40 */ 41 42#include <sys/param.h> 43#include <sys/systm.h> 44#include <sys/proc.h> 45#include <sys/malloc.h> 46#include <sys/lock.h> 47 48#include <vm/vm.h> 49#include <vm/vm_prot.h> 50#include <vm/vm_page.h> 51#include <vm/vm_map.h> 52 53int 54uiomove(cp, n, uio) 55 register caddr_t cp; 56 register int n; 57 register struct uio *uio; 58{ 59 register struct iovec *iov; 60 u_int cnt; 61 int error; 62 63#ifdef DIAGNOSTIC 64 if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE) 65 panic("uiomove: mode"); 66 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 67 panic("uiomove proc"); 68#endif 69 while (n > 0 && uio->uio_resid) { 70 iov = uio->uio_iov; 71 cnt = iov->iov_len; 72 if (cnt == 0) { 73 uio->uio_iov++; 74 uio->uio_iovcnt--; 75 continue; 76 } 77 if (cnt > n) 78 cnt = n; 79 80 switch (uio->uio_segflg) { 81 82 case UIO_USERSPACE: 83 case UIO_USERISPACE: 84 if (uio->uio_rw == UIO_READ) 85 error = copyout(cp, iov->iov_base, cnt); 86 else 87 error = copyin(iov->iov_base, cp, cnt); 88 if (error) 89 return (error); 90 break; 91 92 case UIO_SYSSPACE: 93 if (uio->uio_rw == UIO_READ) 94 bcopy((caddr_t)cp, iov->iov_base, cnt); 95 else 96 bcopy(iov->iov_base, (caddr_t)cp, cnt); 97 break; 98 case UIO_NOCOPY: 99 break; 100 } 101 iov->iov_base += cnt; 102 iov->iov_len -= cnt; 103 uio->uio_resid -= cnt; 104 uio->uio_offset += cnt; 105 cp += cnt; 106 n -= cnt; 107 } 108 return (0); 109} 110 111int 112uiomoveco(cp, n, uio, obj) 113 caddr_t cp; 114 int n; 115 struct uio *uio; 116 struct vm_object *obj; 117{ 118 struct iovec *iov; 119 u_int cnt; 120 int error; 121 122#ifdef DIAGNOSTIC 123 if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE) 124 panic("uiomove: mode"); 125 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 126 panic("uiomove proc"); 127#endif 128 while (n > 0 && uio->uio_resid) { 129 iov = uio->uio_iov; 130 cnt = iov->iov_len; 131 if (cnt == 0) { 132 uio->uio_iov++; 133 uio->uio_iovcnt--; 134 continue; 135 } 136 if (cnt > n) 137 cnt = n; 138 139 switch (uio->uio_segflg) { 140 141 case UIO_USERSPACE: 142 case UIO_USERISPACE: 143 if (uio->uio_rw == UIO_READ) { 144 if (((cnt & PAGE_MASK) == 0) && 145 ((((int) iov->iov_base) & PAGE_MASK) == 0) && 146 ((uio->uio_offset & PAGE_MASK) == 0) && 147 ((((int) cp) & PAGE_MASK) == 0)) { 148 error = vm_uiomove(&curproc->p_vmspace->vm_map, obj, 149 uio->uio_offset, cnt, 150 (vm_offset_t) iov->iov_base, NULL); 151 } else { 152 error = copyout(cp, iov->iov_base, cnt); 153 } 154 } else { 155 error = copyin(iov->iov_base, cp, cnt); 156 } 157 if (error) 158 return (error); 159 break; 160 161 case UIO_SYSSPACE: 162 if (uio->uio_rw == UIO_READ) 163 bcopy((caddr_t)cp, iov->iov_base, cnt); 164 else 165 bcopy(iov->iov_base, (caddr_t)cp, cnt); 166 break; 167 case UIO_NOCOPY: 168 break; 169 } 170 iov->iov_base += cnt; 171 iov->iov_len -= cnt; 172 uio->uio_resid -= cnt; 173 uio->uio_offset += cnt; 174 cp += cnt; 175 n -= cnt; 176 } 177 return (0); 178} 179 180int 181uioread(n, uio, obj, nread) 182 int n; 183 struct uio *uio; 184 struct vm_object *obj; 185 int *nread; 186{ 187 int npagesmoved; 188 struct iovec *iov; 189 u_int cnt, tcnt; 190 int error; 191 192 *nread = 0; 193 error = 0; 194 195 while (n > 0 && uio->uio_resid) { 196 iov = uio->uio_iov; 197 cnt = iov->iov_len; 198 if (cnt == 0) { 199 uio->uio_iov++; 200 uio->uio_iovcnt--; 201 continue; 202 } 203 if (cnt > n) 204 cnt = n; 205 206 if ((uio->uio_segflg == UIO_USERSPACE) && 207 ((((int) iov->iov_base) & PAGE_MASK) == 0) && 208 ((uio->uio_offset & PAGE_MASK) == 0) ) { 209 210 if (cnt < PAGE_SIZE) 211 break; 212 213 cnt &= ~PAGE_MASK; 214 215 error = vm_uiomove(&curproc->p_vmspace->vm_map, obj, 216 uio->uio_offset, cnt, 217 (vm_offset_t) iov->iov_base, &npagesmoved); 218 219 if (npagesmoved == 0) 220 break; 221 222 tcnt = npagesmoved * PAGE_SIZE; 223 if (tcnt != cnt) { 224 cnt = tcnt; 225 } 226 227 if (error) 228 break; 229 230 iov->iov_base += cnt; 231 iov->iov_len -= cnt; 232 uio->uio_resid -= cnt; 233 uio->uio_offset += cnt; 234 *nread += cnt; 235 n -= cnt; 236 } else { 237 break; 238 } 239 } 240 return error; 241} 242 243/* 244 * Give next character to user as result of read. 245 */ 246int 247ureadc(c, uio) 248 register int c; 249 register struct uio *uio; 250{ 251 register struct iovec *iov; 252 253again: 254 if (uio->uio_iovcnt == 0 || uio->uio_resid == 0) 255 panic("ureadc"); 256 iov = uio->uio_iov; 257 if (iov->iov_len == 0) { 258 uio->uio_iovcnt--; 259 uio->uio_iov++; 260 goto again; 261 } 262 switch (uio->uio_segflg) { 263 264 case UIO_USERSPACE: 265 if (subyte(iov->iov_base, c) < 0) 266 return (EFAULT); 267 break; 268 269 case UIO_SYSSPACE: 270 *iov->iov_base = c; 271 break; 272 273 case UIO_USERISPACE: 274 if (suibyte(iov->iov_base, c) < 0) 275 return (EFAULT); 276 break; 277 case UIO_NOCOPY: 278 break; 279 } 280 iov->iov_base++; 281 iov->iov_len--; 282 uio->uio_resid--; 283 uio->uio_offset++; 284 return (0); 285} 286 287#ifdef vax /* unused except by ct.c, other oddities XXX */ 288/* 289 * Get next character written in by user from uio. 290 */ 291int 292uwritec(uio) 293 struct uio *uio; 294{ 295 register struct iovec *iov; 296 register int c; 297 298 if (uio->uio_resid <= 0) 299 return (-1); 300again: 301 if (uio->uio_iovcnt <= 0) 302 panic("uwritec"); 303 iov = uio->uio_iov; 304 if (iov->iov_len == 0) { 305 uio->uio_iov++; 306 if (--uio->uio_iovcnt == 0) 307 return (-1); 308 goto again; 309 } 310 switch (uio->uio_segflg) { 311 312 case UIO_USERSPACE: 313 c = fubyte(iov->iov_base); 314 break; 315 316 case UIO_SYSSPACE: 317 c = *(u_char *) iov->iov_base; 318 break; 319 320 case UIO_USERISPACE: 321 c = fuibyte(iov->iov_base); 322 break; 323 } 324 if (c < 0) 325 return (-1); 326 iov->iov_base++; 327 iov->iov_len--; 328 uio->uio_resid--; 329 uio->uio_offset++; 330 return (c); 331} 332#endif /* vax */ 333 334/* 335 * General routine to allocate a hash table. 336 */ 337void * 338hashinit(elements, type, hashmask) 339 int elements; 340 struct malloc_type *type; 341 u_long *hashmask; 342{ 343 long hashsize; 344 LIST_HEAD(generic, generic) *hashtbl; 345 int i; 346 347 if (elements <= 0) 348 panic("hashinit: bad elements"); 349 for (hashsize = 1; hashsize <= elements; hashsize <<= 1) 350 continue; 351 hashsize >>= 1; 352 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK); 353 for (i = 0; i < hashsize; i++) 354 LIST_INIT(&hashtbl[i]); 355 *hashmask = hashsize - 1; 356 return (hashtbl); 357} 358 359static int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 2039, 360 2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 6653, 361 7159, 7673, 8191, 12281, 16381, 24571, 32749 }; 362#define NPRIMES (sizeof(primes) / sizeof(primes[0])) 363 364/* 365 * General routine to allocate a prime number sized hash table. 366 */ 367void * 368phashinit(elements, type, nentries) 369 int elements; 370 struct malloc_type *type; 371 u_long *nentries; 372{ 373 long hashsize; 374 LIST_HEAD(generic, generic) *hashtbl; 375 int i; 376 377 if (elements <= 0) 378 panic("phashinit: bad elements"); 379 for (i = 1, hashsize = primes[1]; hashsize <= elements;) { 380 i++; 381 if (i == NPRIMES) 382 break; 383 hashsize = primes[i]; 384 } 385 hashsize = primes[i - 1]; 386 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK); 387 for (i = 0; i < hashsize; i++) 388 LIST_INIT(&hashtbl[i]); 389 *nentries = hashsize; 390 return (hashtbl); 391} 392