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 _LINUX_SYSFS_H_ 32 #define _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 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) __ATTR(_name, 0444, _name##_show, NULL) 58 #define __ATTR_WO(_name) __ATTR(_name, 0200, NULL, _name##_store) 59 #define __ATTR_RW(_name) __ATTR(_name, 0644, _name##_show, _name##_store) 60 61 #define __ATTR_NULL { .attr = { .name = NULL } } 62 63 #define ATTRIBUTE_GROUPS(_name) \ 64 static struct attribute_group _name##_group = { \ 65 .attrs = _name##_attrs, \ 66 }; \ 67 static struct attribute_group *_name##_groups[] = { \ 68 &_name##_group, \ 69 NULL, \ 70 }; 71 72 /* 73 * Handle our generic '\0' terminated 'C' string. 74 * Two cases: 75 * a variable string: point arg1 at it, arg2 is max length. 76 * a constant string: point arg1 at it, arg2 is zero. 77 */ 78 79 static inline int 80 sysctl_handle_attr(SYSCTL_HANDLER_ARGS) 81 { 82 struct kobject *kobj; 83 struct attribute *attr; 84 const struct sysfs_ops *ops; 85 char *buf; 86 int error; 87 ssize_t len; 88 89 kobj = arg1; 90 attr = (struct attribute *)(intptr_t)arg2; 91 if (kobj->ktype == NULL || kobj->ktype->sysfs_ops == NULL) 92 return (ENODEV); 93 buf = (char *)get_zeroed_page(GFP_KERNEL); 94 if (buf == NULL) 95 return (ENOMEM); 96 ops = kobj->ktype->sysfs_ops; 97 if (ops->show) { 98 len = ops->show(kobj, attr, buf); 99 /* 100 * It's valid to not have a 'show' so just return an 101 * empty string. 102 */ 103 if (len < 0) { 104 error = -len; 105 if (error != EIO) 106 goto out; 107 buf[0] = '\0'; 108 } else if (len) { 109 len--; 110 if (len >= PAGE_SIZE) 111 len = PAGE_SIZE - 1; 112 /* Trim trailing newline. */ 113 buf[len] = '\0'; 114 } 115 } 116 117 /* Leave one trailing byte to append a newline. */ 118 error = sysctl_handle_string(oidp, buf, PAGE_SIZE - 1, req); 119 if (error != 0 || req->newptr == NULL || ops->store == NULL) 120 goto out; 121 len = strlcat(buf, "\n", PAGE_SIZE); 122 KASSERT(len < PAGE_SIZE, ("new attribute truncated")); 123 len = ops->store(kobj, attr, buf, len); 124 if (len < 0) 125 error = -len; 126 out: 127 free_page((unsigned long)buf); 128 129 return (error); 130 } 131 132 static inline int 133 sysfs_create_file(struct kobject *kobj, const struct attribute *attr) 134 { 135 struct sysctl_oid *oid; 136 137 oid = SYSCTL_ADD_OID(NULL, SYSCTL_CHILDREN(kobj->oidp), OID_AUTO, 138 attr->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, kobj, 139 (uintptr_t)attr, sysctl_handle_attr, "A", ""); 140 if (!oid) { 141 return (-ENOMEM); 142 } 143 144 return (0); 145 } 146 147 static inline void 148 sysfs_remove_file(struct kobject *kobj, const struct attribute *attr) 149 { 150 151 if (kobj->oidp) 152 sysctl_remove_name(kobj->oidp, attr->name, 1, 1); 153 } 154 155 static inline int 156 sysfs_create_files(struct kobject *kobj, const struct attribute * const *attrs) 157 { 158 int error = 0; 159 int i; 160 161 for (i = 0; attrs[i] && !error; i++) 162 error = sysfs_create_file(kobj, attrs[i]); 163 while (error && --i >= 0) 164 sysfs_remove_file(kobj, attrs[i]); 165 166 return (error); 167 } 168 169 static inline void 170 sysfs_remove_files(struct kobject *kobj, const struct attribute * const *attrs) 171 { 172 int i; 173 174 for (i = 0; attrs[i]; i++) 175 sysfs_remove_file(kobj, attrs[i]); 176 } 177 178 static inline void 179 sysfs_remove_group(struct kobject *kobj, const struct attribute_group *grp) 180 { 181 182 if (kobj->oidp) 183 sysctl_remove_name(kobj->oidp, grp->name, 1, 1); 184 } 185 186 static inline int 187 sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp) 188 { 189 struct attribute **attr; 190 struct sysctl_oid *oidp; 191 192 oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->oidp), 193 OID_AUTO, grp->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, grp->name); 194 for (attr = grp->attrs; *attr != NULL; attr++) { 195 SYSCTL_ADD_OID(NULL, SYSCTL_CHILDREN(oidp), OID_AUTO, 196 (*attr)->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, 197 kobj, (uintptr_t)*attr, sysctl_handle_attr, "A", ""); 198 } 199 200 return (0); 201 } 202 203 static inline int 204 sysfs_create_dir(struct kobject *kobj) 205 { 206 struct sysctl_oid *oid; 207 208 oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->parent->oidp), 209 OID_AUTO, kobj->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, kobj->name); 210 if (!oid) { 211 return (-ENOMEM); 212 } 213 kobj->oidp = oid; 214 215 return (0); 216 } 217 218 static inline void 219 sysfs_remove_dir(struct kobject *kobj) 220 { 221 222 if (kobj->oidp == NULL) 223 return; 224 sysctl_remove_oid(kobj->oidp, 1, 1); 225 } 226 227 #define sysfs_attr_init(attr) do {} while(0) 228 229 #endif /* _LINUX_SYSFS_H_ */ 230