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 * $FreeBSD$ 30 */ 31 #ifndef _LINUXKPI_LINUX_SYSFS_H_ 32 #define _LINUXKPI_LINUX_SYSFS_H_ 33 34 #include <sys/types.h> 35 #include <sys/sysctl.h> 36 #include <sys/errno.h> 37 38 #include <linux/kobject.h> 39 #include <linux/stringify.h> 40 #include <linux/mm.h> 41 42 struct sysfs_ops { 43 ssize_t (*show)(struct kobject *, struct attribute *, char *); 44 ssize_t (*store)(struct kobject *, struct attribute *, const char *, 45 size_t); 46 }; 47 48 struct attribute_group { 49 const char *name; 50 mode_t (*is_visible)(struct kobject *, 51 struct attribute *, int); 52 struct attribute **attrs; 53 }; 54 55 #define __ATTR(_name, _mode, _show, _store) { \ 56 .attr = { .name = __stringify(_name), .mode = _mode }, \ 57 .show = _show, .store = _store, \ 58 } 59 #define __ATTR_RO(_name) __ATTR(_name, 0444, _name##_show, NULL) 60 #define __ATTR_WO(_name) __ATTR(_name, 0200, NULL, _name##_store) 61 #define __ATTR_RW(_name) __ATTR(_name, 0644, _name##_show, _name##_store) 62 #define __ATTR_NULL { .attr = { .name = NULL } } 63 64 #define ATTRIBUTE_GROUPS(_name) \ 65 static struct attribute_group _name##_group = { \ 66 .name = __stringify(_name), \ 67 .attrs = _name##_attrs, \ 68 }; \ 69 static const struct attribute_group *_name##_groups[] = { \ 70 &_name##_group, \ 71 NULL, \ 72 } 73 74 /* 75 * Handle our generic '\0' terminated 'C' string. 76 * Two cases: 77 * a variable string: point arg1 at it, arg2 is max length. 78 * a constant string: point arg1 at it, arg2 is zero. 79 */ 80 81 static inline int 82 sysctl_handle_attr(SYSCTL_HANDLER_ARGS) 83 { 84 struct kobject *kobj; 85 struct attribute *attr; 86 const struct sysfs_ops *ops; 87 char *buf; 88 int error; 89 ssize_t len; 90 91 kobj = arg1; 92 attr = (struct attribute *)(intptr_t)arg2; 93 if (kobj->ktype == NULL || kobj->ktype->sysfs_ops == NULL) 94 return (ENODEV); 95 buf = (char *)get_zeroed_page(GFP_KERNEL); 96 if (buf == NULL) 97 return (ENOMEM); 98 ops = kobj->ktype->sysfs_ops; 99 if (ops->show) { 100 len = ops->show(kobj, attr, buf); 101 /* 102 * It's valid to not have a 'show' so just return an 103 * empty string. 104 */ 105 if (len < 0) { 106 error = -len; 107 if (error != EIO) 108 goto out; 109 buf[0] = '\0'; 110 } else if (len) { 111 len--; 112 if (len >= PAGE_SIZE) 113 len = PAGE_SIZE - 1; 114 /* Trim trailing newline. */ 115 buf[len] = '\0'; 116 } 117 } 118 119 /* Leave one trailing byte to append a newline. */ 120 error = sysctl_handle_string(oidp, buf, PAGE_SIZE - 1, req); 121 if (error != 0 || req->newptr == NULL || ops->store == NULL) 122 goto out; 123 len = strlcat(buf, "\n", PAGE_SIZE); 124 KASSERT(len < PAGE_SIZE, ("new attribute truncated")); 125 len = ops->store(kobj, attr, buf, len); 126 if (len < 0) 127 error = -len; 128 out: 129 free_page((unsigned long)buf); 130 131 return (error); 132 } 133 134 static inline int 135 sysfs_create_file(struct kobject *kobj, const struct attribute *attr) 136 { 137 struct sysctl_oid *oid; 138 139 oid = SYSCTL_ADD_OID(NULL, SYSCTL_CHILDREN(kobj->oidp), OID_AUTO, 140 attr->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, kobj, 141 (uintptr_t)attr, sysctl_handle_attr, "A", ""); 142 if (!oid) { 143 return (-ENOMEM); 144 } 145 146 return (0); 147 } 148 149 static inline void 150 sysfs_remove_file(struct kobject *kobj, const struct attribute *attr) 151 { 152 153 if (kobj->oidp) 154 sysctl_remove_name(kobj->oidp, attr->name, 1, 1); 155 } 156 157 static inline int 158 sysfs_create_files(struct kobject *kobj, const struct attribute * const *attrs) 159 { 160 int error = 0; 161 int i; 162 163 for (i = 0; attrs[i] && !error; i++) 164 error = sysfs_create_file(kobj, attrs[i]); 165 while (error && --i >= 0) 166 sysfs_remove_file(kobj, attrs[i]); 167 168 return (error); 169 } 170 171 static inline void 172 sysfs_remove_files(struct kobject *kobj, const struct attribute * const *attrs) 173 { 174 int i; 175 176 for (i = 0; attrs[i]; i++) 177 sysfs_remove_file(kobj, attrs[i]); 178 } 179 180 static inline int 181 sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp) 182 { 183 struct attribute **attr; 184 struct sysctl_oid *oidp; 185 186 /* Don't create the group node if grp->name is undefined. */ 187 if (grp->name) 188 oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->oidp), 189 OID_AUTO, grp->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, grp->name); 190 else 191 oidp = kobj->oidp; 192 for (attr = grp->attrs; *attr != NULL; attr++) { 193 SYSCTL_ADD_OID(NULL, SYSCTL_CHILDREN(oidp), OID_AUTO, 194 (*attr)->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, 195 kobj, (uintptr_t)*attr, sysctl_handle_attr, "A", ""); 196 } 197 198 return (0); 199 } 200 201 static inline void 202 sysfs_remove_group(struct kobject *kobj, const struct attribute_group *grp) 203 { 204 205 if (kobj->oidp) 206 sysctl_remove_name(kobj->oidp, grp->name, 1, 1); 207 } 208 209 static inline int 210 sysfs_create_groups(struct kobject *kobj, const struct attribute_group **grps) 211 { 212 int error = 0; 213 int i; 214 215 if (grps == NULL) 216 goto done; 217 for (i = 0; grps[i] && !error; i++) 218 error = sysfs_create_group(kobj, grps[i]); 219 while (error && --i >= 0) 220 sysfs_remove_group(kobj, grps[i]); 221 done: 222 return (error); 223 } 224 225 static inline void 226 sysfs_remove_groups(struct kobject *kobj, const struct attribute_group **grps) 227 { 228 int i; 229 230 if (grps == NULL) 231 return; 232 for (i = 0; grps[i]; i++) 233 sysfs_remove_group(kobj, grps[i]); 234 } 235 236 static inline int 237 sysfs_merge_group(struct kobject *kobj, const struct attribute_group *grp) 238 { 239 240 /* Really expected behavior is to return failure if group exists. */ 241 return (sysfs_create_group(kobj, grp)); 242 } 243 244 static inline void 245 sysfs_unmerge_group(struct kobject *kobj, const struct attribute_group *grp) 246 { 247 struct attribute **attr; 248 struct sysctl_oid *oidp; 249 250 SYSCTL_FOREACH(oidp, SYSCTL_CHILDREN(kobj->oidp)) { 251 if (strcmp(oidp->oid_name, grp->name) != 0) 252 continue; 253 for (attr = grp->attrs; *attr != NULL; attr++) { 254 sysctl_remove_name(oidp, (*attr)->name, 1, 1); 255 } 256 } 257 } 258 259 static inline int 260 sysfs_create_dir(struct kobject *kobj) 261 { 262 struct sysctl_oid *oid; 263 264 oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->parent->oidp), 265 OID_AUTO, kobj->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, kobj->name); 266 if (!oid) { 267 return (-ENOMEM); 268 } 269 kobj->oidp = oid; 270 271 return (0); 272 } 273 274 static inline void 275 sysfs_remove_dir(struct kobject *kobj) 276 { 277 278 if (kobj->oidp == NULL) 279 return; 280 sysctl_remove_oid(kobj->oidp, 1, 1); 281 } 282 283 static inline bool 284 sysfs_streq(const char *s1, const char *s2) 285 { 286 int l1, l2; 287 288 l1 = strlen(s1); 289 l2 = strlen(s2); 290 291 if (l1 != 0 && s1[l1-1] == '\n') 292 l1--; 293 if (l2 != 0 && s2[l2-1] == '\n') 294 l2--; 295 296 return (l1 == l2 && strncmp(s1, s2, l1) == 0); 297 } 298 299 static inline int 300 sysfs_emit(char *buf, const char *fmt, ...) 301 { 302 va_list args; 303 int i; 304 305 if (!buf || offset_in_page(buf)) { 306 pr_warn("invalid sysfs_emit: buf:%p\n", buf); 307 return (0); 308 } 309 310 va_start(args, fmt); 311 i = vscnprintf(buf, PAGE_SIZE, fmt, args); 312 va_end(args); 313 314 return (i); 315 } 316 317 static inline int 318 sysfs_emit_at(char *buf, int at, const char *fmt, ...) 319 { 320 va_list args; 321 int i; 322 323 if (!buf || offset_in_page(buf) || at < 0 || at >= PAGE_SIZE) { 324 pr_warn("invalid sysfs_emit: buf:%p at:%d\n", buf, at); 325 return (0); 326 } 327 328 va_start(args, fmt); 329 i = vscnprintf(buf + at, PAGE_SIZE - at, fmt, args); 330 va_end(args); 331 332 return (i); 333 } 334 335 #define sysfs_attr_init(attr) do {} while(0) 336 337 #endif /* _LINUXKPI_LINUX_SYSFS_H_ */ 338