1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice unmodified, this list of conditions, and the following 13 * disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 #ifndef _LINUXKPI_LINUX_SYSFS_H_ 30 #define _LINUXKPI_LINUX_SYSFS_H_ 31 32 #include <sys/types.h> 33 #include <sys/sysctl.h> 34 #include <sys/errno.h> 35 36 #include <linux/kobject.h> 37 #include <linux/stringify.h> 38 #include <linux/mm.h> 39 40 struct sysfs_ops { 41 ssize_t (*show)(struct kobject *, struct attribute *, char *); 42 ssize_t (*store)(struct kobject *, struct attribute *, const char *, 43 size_t); 44 }; 45 46 struct attribute_group { 47 const char *name; 48 mode_t (*is_visible)(struct kobject *, 49 struct attribute *, int); 50 struct attribute **attrs; 51 }; 52 53 #define __ATTR(_name, _mode, _show, _store) { \ 54 .attr = { .name = __stringify(_name), .mode = _mode }, \ 55 .show = _show, .store = _store, \ 56 } 57 #define __ATTR_RO(_name) { \ 58 .attr = { .name = __stringify(_name), .mode = 0444 }, \ 59 .show = _name##_show, \ 60 } 61 #define __ATTR_WO(_name) __ATTR(_name, 0200, NULL, _name##_store) 62 #define __ATTR_RW(_name) __ATTR(_name, 0644, _name##_show, _name##_store) 63 #define __ATTR_NULL { .attr = { .name = NULL } } 64 65 #define ATTRIBUTE_GROUPS(_name) \ 66 static struct attribute_group _name##_group = { \ 67 .name = __stringify(_name), \ 68 .attrs = _name##_attrs, \ 69 }; \ 70 static const struct attribute_group *_name##_groups[] = { \ 71 &_name##_group, \ 72 NULL, \ 73 } 74 75 /* 76 * Handle our generic '\0' terminated 'C' string. 77 * Two cases: 78 * a variable string: point arg1 at it, arg2 is max length. 79 * a constant string: point arg1 at it, arg2 is zero. 80 */ 81 82 static inline int 83 sysctl_handle_attr(SYSCTL_HANDLER_ARGS) 84 { 85 struct kobject *kobj; 86 struct attribute *attr; 87 const struct sysfs_ops *ops; 88 char *buf; 89 int error; 90 ssize_t len; 91 92 kobj = arg1; 93 attr = (struct attribute *)(intptr_t)arg2; 94 if (kobj->ktype == NULL || kobj->ktype->sysfs_ops == NULL) 95 return (ENODEV); 96 buf = (char *)get_zeroed_page(GFP_KERNEL); 97 if (buf == NULL) 98 return (ENOMEM); 99 ops = kobj->ktype->sysfs_ops; 100 if (ops->show) { 101 len = ops->show(kobj, attr, buf); 102 /* 103 * It's valid to not have a 'show' so just return an 104 * empty string. 105 */ 106 if (len < 0) { 107 error = -len; 108 if (error != EIO) 109 goto out; 110 buf[0] = '\0'; 111 } else if (len) { 112 len--; 113 if (len >= PAGE_SIZE) 114 len = PAGE_SIZE - 1; 115 /* Trim trailing newline. */ 116 buf[len] = '\0'; 117 } 118 } 119 120 /* Leave one trailing byte to append a newline. */ 121 error = sysctl_handle_string(oidp, buf, PAGE_SIZE - 1, req); 122 if (error != 0 || req->newptr == NULL || ops->store == NULL) 123 goto out; 124 len = strlcat(buf, "\n", PAGE_SIZE); 125 KASSERT(len < PAGE_SIZE, ("new attribute truncated")); 126 len = ops->store(kobj, attr, buf, len); 127 if (len < 0) 128 error = -len; 129 out: 130 free_page((unsigned long)buf); 131 132 return (error); 133 } 134 135 static inline int 136 sysfs_create_file(struct kobject *kobj, const struct attribute *attr) 137 { 138 struct sysctl_oid *oid; 139 140 oid = SYSCTL_ADD_OID(NULL, SYSCTL_CHILDREN(kobj->oidp), OID_AUTO, 141 attr->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, kobj, 142 (uintptr_t)attr, sysctl_handle_attr, "A", ""); 143 if (!oid) { 144 return (-ENOMEM); 145 } 146 147 return (0); 148 } 149 150 static inline void 151 sysfs_remove_file(struct kobject *kobj, const struct attribute *attr) 152 { 153 154 if (kobj->oidp) 155 sysctl_remove_name(kobj->oidp, attr->name, 1, 1); 156 } 157 158 static inline int 159 sysfs_create_link(struct kobject *kobj __unused, 160 struct kobject *target __unused, const char *name __unused) 161 { 162 /* TODO */ 163 164 return (0); 165 } 166 167 static inline void 168 sysfs_remove_link(struct kobject *kobj, const char *name) 169 { 170 /* TODO (along with sysfs_create_link) */ 171 } 172 173 static inline int 174 sysfs_create_files(struct kobject *kobj, const struct attribute * const *attrs) 175 { 176 int error = 0; 177 int i; 178 179 for (i = 0; attrs[i] && !error; i++) 180 error = sysfs_create_file(kobj, attrs[i]); 181 while (error && --i >= 0) 182 sysfs_remove_file(kobj, attrs[i]); 183 184 return (error); 185 } 186 187 static inline void 188 sysfs_remove_files(struct kobject *kobj, const struct attribute * const *attrs) 189 { 190 int i; 191 192 for (i = 0; attrs[i]; i++) 193 sysfs_remove_file(kobj, attrs[i]); 194 } 195 196 static inline int 197 sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp) 198 { 199 struct attribute **attr; 200 struct sysctl_oid *oidp; 201 202 /* Don't create the group node if grp->name is undefined. */ 203 if (grp->name) 204 oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->oidp), 205 OID_AUTO, grp->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, grp->name); 206 else 207 oidp = kobj->oidp; 208 for (attr = grp->attrs; *attr != NULL; attr++) { 209 SYSCTL_ADD_OID(NULL, SYSCTL_CHILDREN(oidp), OID_AUTO, 210 (*attr)->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, 211 kobj, (uintptr_t)*attr, sysctl_handle_attr, "A", ""); 212 } 213 214 return (0); 215 } 216 217 static inline void 218 sysfs_remove_group(struct kobject *kobj, const struct attribute_group *grp) 219 { 220 221 if (kobj->oidp) 222 sysctl_remove_name(kobj->oidp, grp->name, 1, 1); 223 } 224 225 static inline int 226 sysfs_create_groups(struct kobject *kobj, const struct attribute_group **grps) 227 { 228 int error = 0; 229 int i; 230 231 if (grps == NULL) 232 goto done; 233 for (i = 0; grps[i] && !error; i++) 234 error = sysfs_create_group(kobj, grps[i]); 235 while (error && --i >= 0) 236 sysfs_remove_group(kobj, grps[i]); 237 done: 238 return (error); 239 } 240 241 static inline void 242 sysfs_remove_groups(struct kobject *kobj, const struct attribute_group **grps) 243 { 244 int i; 245 246 if (grps == NULL) 247 return; 248 for (i = 0; grps[i]; i++) 249 sysfs_remove_group(kobj, grps[i]); 250 } 251 252 static inline int 253 sysfs_merge_group(struct kobject *kobj, const struct attribute_group *grp) 254 { 255 256 /* Really expected behavior is to return failure if group exists. */ 257 return (sysfs_create_group(kobj, grp)); 258 } 259 260 static inline void 261 sysfs_unmerge_group(struct kobject *kobj, const struct attribute_group *grp) 262 { 263 struct attribute **attr; 264 struct sysctl_oid *oidp; 265 266 SYSCTL_FOREACH(oidp, SYSCTL_CHILDREN(kobj->oidp)) { 267 if (strcmp(oidp->oid_name, grp->name) != 0) 268 continue; 269 for (attr = grp->attrs; *attr != NULL; attr++) { 270 sysctl_remove_name(oidp, (*attr)->name, 1, 1); 271 } 272 } 273 } 274 275 static inline int 276 sysfs_create_dir(struct kobject *kobj) 277 { 278 struct sysctl_oid *oid; 279 280 oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->parent->oidp), 281 OID_AUTO, kobj->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, kobj->name); 282 if (!oid) { 283 return (-ENOMEM); 284 } 285 kobj->oidp = oid; 286 287 return (0); 288 } 289 290 static inline void 291 sysfs_remove_dir(struct kobject *kobj) 292 { 293 294 if (kobj->oidp == NULL) 295 return; 296 sysctl_remove_oid(kobj->oidp, 1, 1); 297 } 298 299 static inline bool 300 sysfs_streq(const char *s1, const char *s2) 301 { 302 int l1, l2; 303 304 l1 = strlen(s1); 305 l2 = strlen(s2); 306 307 if (l1 != 0 && s1[l1-1] == '\n') 308 l1--; 309 if (l2 != 0 && s2[l2-1] == '\n') 310 l2--; 311 312 return (l1 == l2 && strncmp(s1, s2, l1) == 0); 313 } 314 315 static inline int 316 sysfs_emit(char *buf, const char *fmt, ...) 317 { 318 va_list args; 319 int i; 320 321 if (!buf || offset_in_page(buf)) { 322 pr_warn("invalid sysfs_emit: buf:%p\n", buf); 323 return (0); 324 } 325 326 va_start(args, fmt); 327 i = vscnprintf(buf, PAGE_SIZE, fmt, args); 328 va_end(args); 329 330 return (i); 331 } 332 333 static inline int 334 sysfs_emit_at(char *buf, int at, const char *fmt, ...) 335 { 336 va_list args; 337 int i; 338 339 if (!buf || offset_in_page(buf) || at < 0 || at >= PAGE_SIZE) { 340 pr_warn("invalid sysfs_emit: buf:%p at:%d\n", buf, at); 341 return (0); 342 } 343 344 va_start(args, fmt); 345 i = vscnprintf(buf + at, PAGE_SIZE - at, fmt, args); 346 va_end(args); 347 348 return (i); 349 } 350 351 #define sysfs_attr_init(attr) do {} while(0) 352 353 #endif /* _LINUXKPI_LINUX_SYSFS_H_ */ 354