subr_hints.c revision 229272
1/*- 2 * Copyright (c) 2000,2001 Peter Wemm <peter@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: head/sys/kern/subr_hints.c 229272 2012-01-02 12:12:10Z ed $"); 29 30#include <sys/param.h> 31#include <sys/lock.h> 32#include <sys/mutex.h> 33#include <sys/systm.h> 34#include <sys/bus.h> 35 36/* 37 * Access functions for device resources. 38 */ 39 40static int checkmethod = 1; 41static int use_kenv; 42static char *hintp; 43 44/* 45 * Evil wildcarding resource string lookup. 46 * This walks the supplied env string table and returns a match. 47 * The start point can be remembered for incremental searches. 48 */ 49static int 50res_find(int *line, int *startln, 51 const char *name, int *unit, const char *resname, const char *value, 52 const char **ret_name, int *ret_namelen, int *ret_unit, 53 const char **ret_resname, int *ret_resnamelen, const char **ret_value) 54{ 55 int n = 0, hit, i = 0; 56 char r_name[32]; 57 int r_unit; 58 char r_resname[32]; 59 char r_value[128]; 60 const char *s, *cp; 61 char *p; 62 63 if (checkmethod) { 64 hintp = NULL; 65 66 switch (hintmode) { 67 case 0: /* loader hints in environment only */ 68 break; 69 case 1: /* static hints only */ 70 hintp = static_hints; 71 checkmethod = 0; 72 break; 73 case 2: /* fallback mode */ 74 if (dynamic_kenv) { 75 mtx_lock(&kenv_lock); 76 cp = kenvp[0]; 77 for (i = 0; cp != NULL; cp = kenvp[++i]) { 78 if (!strncmp(cp, "hint.", 5)) { 79 use_kenv = 1; 80 checkmethod = 0; 81 break; 82 } 83 } 84 mtx_unlock(&kenv_lock); 85 } else { 86 cp = kern_envp; 87 while (cp) { 88 if (strncmp(cp, "hint.", 5) == 0) { 89 cp = NULL; 90 hintp = kern_envp; 91 break; 92 } 93 while (*cp != '\0') 94 cp++; 95 cp++; 96 if (*cp == '\0') { 97 cp = NULL; 98 hintp = static_hints; 99 break; 100 } 101 } 102 } 103 break; 104 default: 105 break; 106 } 107 if (hintp == NULL) { 108 if (dynamic_kenv) { 109 use_kenv = 1; 110 checkmethod = 0; 111 } else 112 hintp = kern_envp; 113 } 114 } 115 116 if (use_kenv) { 117 mtx_lock(&kenv_lock); 118 i = 0; 119 cp = kenvp[0]; 120 if (cp == NULL) { 121 mtx_unlock(&kenv_lock); 122 return (ENOENT); 123 } 124 } else 125 cp = hintp; 126 while (cp) { 127 hit = 1; 128 (*line)++; 129 if (strncmp(cp, "hint.", 5) != 0) 130 hit = 0; 131 else 132 n = sscanf(cp, "hint.%32[^.].%d.%32[^=]=%128s", 133 r_name, &r_unit, r_resname, r_value); 134 if (hit && n != 4) { 135 printf("CONFIG: invalid hint '%s'\n", cp); 136 p = strchr(cp, 'h'); 137 *p = 'H'; 138 hit = 0; 139 } 140 if (hit && startln && *startln >= 0 && *line < *startln) 141 hit = 0; 142 if (hit && name && strcmp(name, r_name) != 0) 143 hit = 0; 144 if (hit && unit && *unit != r_unit) 145 hit = 0; 146 if (hit && resname && strcmp(resname, r_resname) != 0) 147 hit = 0; 148 if (hit && value && strcmp(value, r_value) != 0) 149 hit = 0; 150 if (hit) 151 break; 152 if (use_kenv) { 153 cp = kenvp[++i]; 154 if (cp == NULL) 155 break; 156 } else { 157 while (*cp != '\0') 158 cp++; 159 cp++; 160 if (*cp == '\0') { 161 cp = NULL; 162 break; 163 } 164 } 165 } 166 if (use_kenv) 167 mtx_unlock(&kenv_lock); 168 if (cp == NULL) 169 return ENOENT; 170 171 s = cp; 172 /* This is a bit of a hack, but at least is reentrant */ 173 /* Note that it returns some !unterminated! strings. */ 174 s = strchr(s, '.') + 1; /* start of device */ 175 if (ret_name) 176 *ret_name = s; 177 s = strchr(s, '.') + 1; /* start of unit */ 178 if (ret_namelen && ret_name) 179 *ret_namelen = s - *ret_name - 1; /* device length */ 180 if (ret_unit) 181 *ret_unit = r_unit; 182 s = strchr(s, '.') + 1; /* start of resname */ 183 if (ret_resname) 184 *ret_resname = s; 185 s = strchr(s, '=') + 1; /* start of value */ 186 if (ret_resnamelen && ret_resname) 187 *ret_resnamelen = s - *ret_resname - 1; /* value len */ 188 if (ret_value) 189 *ret_value = s; 190 if (startln) /* line number for anchor */ 191 *startln = *line + 1; 192 return 0; 193} 194 195/* 196 * Search all the data sources for matches to our query. We look for 197 * dynamic hints first as overrides for static or fallback hints. 198 */ 199static int 200resource_find(int *line, int *startln, 201 const char *name, int *unit, const char *resname, const char *value, 202 const char **ret_name, int *ret_namelen, int *ret_unit, 203 const char **ret_resname, int *ret_resnamelen, const char **ret_value) 204{ 205 int i; 206 int un; 207 208 *line = 0; 209 210 /* Search for exact unit matches first */ 211 i = res_find(line, startln, name, unit, resname, value, 212 ret_name, ret_namelen, ret_unit, ret_resname, ret_resnamelen, 213 ret_value); 214 if (i == 0) 215 return 0; 216 if (unit == NULL) 217 return ENOENT; 218 /* If we are still here, search for wildcard matches */ 219 un = -1; 220 i = res_find(line, startln, name, &un, resname, value, 221 ret_name, ret_namelen, ret_unit, ret_resname, ret_resnamelen, 222 ret_value); 223 if (i == 0) 224 return 0; 225 return ENOENT; 226} 227 228int 229resource_int_value(const char *name, int unit, const char *resname, int *result) 230{ 231 int error; 232 const char *str; 233 char *op; 234 unsigned long val; 235 int line; 236 237 line = 0; 238 error = resource_find(&line, NULL, name, &unit, resname, NULL, 239 NULL, NULL, NULL, NULL, NULL, &str); 240 if (error) 241 return error; 242 if (*str == '\0') 243 return EFTYPE; 244 val = strtoul(str, &op, 0); 245 if (*op != '\0') 246 return EFTYPE; 247 *result = val; 248 return 0; 249} 250 251int 252resource_long_value(const char *name, int unit, const char *resname, 253 long *result) 254{ 255 int error; 256 const char *str; 257 char *op; 258 unsigned long val; 259 int line; 260 261 line = 0; 262 error = resource_find(&line, NULL, name, &unit, resname, NULL, 263 NULL, NULL, NULL, NULL, NULL, &str); 264 if (error) 265 return error; 266 if (*str == '\0') 267 return EFTYPE; 268 val = strtoul(str, &op, 0); 269 if (*op != '\0') 270 return EFTYPE; 271 *result = val; 272 return 0; 273} 274 275int 276resource_string_value(const char *name, int unit, const char *resname, 277 const char **result) 278{ 279 int error; 280 const char *str; 281 int line; 282 283 line = 0; 284 error = resource_find(&line, NULL, name, &unit, resname, NULL, 285 NULL, NULL, NULL, NULL, NULL, &str); 286 if (error) 287 return error; 288 *result = str; 289 return 0; 290} 291 292/* 293 * This is a bit nasty, but allows us to not modify the env strings. 294 */ 295static const char * 296resource_string_copy(const char *s, int len) 297{ 298 static char stringbuf[256]; 299 static int offset = 0; 300 const char *ret; 301 302 if (len == 0) 303 len = strlen(s); 304 if (len > 255) 305 return NULL; 306 if ((offset + len + 1) > 255) 307 offset = 0; 308 bcopy(s, &stringbuf[offset], len); 309 stringbuf[offset + len] = '\0'; 310 ret = &stringbuf[offset]; 311 offset += len + 1; 312 return ret; 313} 314 315/* 316 * err = resource_find_match(&anchor, &name, &unit, resname, value) 317 * Iteratively fetch a list of devices wired "at" something 318 * res and value are restrictions. eg: "at", "scbus0". 319 * For practical purposes, res = required, value = optional. 320 * *name and *unit are set. 321 * set *anchor to zero before starting. 322 */ 323int 324resource_find_match(int *anchor, const char **name, int *unit, 325 const char *resname, const char *value) 326{ 327 const char *found_name; 328 int found_namelen; 329 int found_unit; 330 int ret; 331 int newln; 332 333 newln = *anchor; 334 ret = resource_find(anchor, &newln, NULL, NULL, resname, value, 335 &found_name, &found_namelen, &found_unit, NULL, NULL, NULL); 336 if (ret == 0) { 337 *name = resource_string_copy(found_name, found_namelen); 338 *unit = found_unit; 339 } 340 *anchor = newln; 341 return ret; 342} 343 344 345/* 346 * err = resource_find_dev(&anchor, name, &unit, res, value); 347 * Iterate through a list of devices, returning their unit numbers. 348 * res and value are optional restrictions. eg: "at", "scbus0". 349 * *unit is set to the value. 350 * set *anchor to zero before starting. 351 */ 352int 353resource_find_dev(int *anchor, const char *name, int *unit, 354 const char *resname, const char *value) 355{ 356 int found_unit; 357 int newln; 358 int ret; 359 360 newln = *anchor; 361 ret = resource_find(anchor, &newln, name, NULL, resname, value, 362 NULL, NULL, &found_unit, NULL, NULL, NULL); 363 if (ret == 0) { 364 *unit = found_unit; 365 } 366 *anchor = newln; 367 return ret; 368} 369 370/* 371 * Check to see if a device is disabled via a disabled hint. 372 */ 373int 374resource_disabled(const char *name, int unit) 375{ 376 int error, value; 377 378 error = resource_int_value(name, unit, "disabled", &value); 379 if (error) 380 return (0); 381 return (value); 382} 383