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/sysctl.h> 35 36 struct attribute { 37 const char *name; 38 struct module *owner; 39 mode_t mode; 40 }; 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 60 #define __ATTR_RO(_name) { \ 61 .attr = { .name = __stringify(_name), .mode = 0444 }, \ 62 .show = _name##_show, \ 63 } 64 65 #define __ATTR_NULL { .attr = { .name = NULL } } 66 67 /* 68 * Handle our generic '\0' terminated 'C' string. 69 * Two cases: 70 * a variable string: point arg1 at it, arg2 is max length. 71 * a constant string: point arg1 at it, arg2 is zero. 72 */ 73 74 static inline int 75 sysctl_handle_attr(SYSCTL_HANDLER_ARGS) 76 { 77 struct kobject *kobj; 78 struct attribute *attr; 79 const struct sysfs_ops *ops; 80 char *buf; 81 int error; 82 ssize_t len; 83 84 kobj = arg1; 85 attr = (struct attribute *)arg2; 86 if (kobj->ktype == NULL || kobj->ktype->sysfs_ops == NULL) 87 return (ENODEV); 88 buf = (char *)get_zeroed_page(GFP_KERNEL); 89 if (buf == NULL) 90 return (ENOMEM); 91 ops = kobj->ktype->sysfs_ops; 92 if (ops->show) { 93 len = ops->show(kobj, attr, buf); 94 /* 95 * It's valid to not have a 'show' so just return an 96 * empty string. 97 */ 98 if (len < 0) { 99 error = -len; 100 if (error != EIO) 101 goto out; 102 buf[0] = '\0'; 103 } else if (len) { 104 len--; 105 if (len >= PAGE_SIZE) 106 len = PAGE_SIZE - 1; 107 /* Trim trailing newline. */ 108 buf[len] = '\0'; 109 } 110 } 111 112 /* Leave one trailing byte to append a newline. */ 113 error = sysctl_handle_string(oidp, buf, PAGE_SIZE - 1, req); 114 if (error != 0 || req->newptr == NULL || ops->store == NULL) 115 goto out; 116 len = strlcat(buf, "\n", PAGE_SIZE); 117 KASSERT(len < PAGE_SIZE, ("new attribute truncated")); 118 len = ops->store(kobj, attr, buf, len); 119 if (len < 0) 120 error = -len; 121 out: 122 free_page((unsigned long)buf); 123 124 return (error); 125 } 126 127 static inline int 128 sysfs_create_file(struct kobject *kobj, const struct attribute *attr) 129 { 130 131 sysctl_add_oid(NULL, SYSCTL_CHILDREN(kobj->oidp), OID_AUTO, 132 attr->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, kobj, 133 (uintptr_t)attr, sysctl_handle_attr, "A", ""); 134 135 return (0); 136 } 137 138 static inline void 139 sysfs_remove_file(struct kobject *kobj, const struct attribute *attr) 140 { 141 142 if (kobj->oidp) 143 sysctl_remove_name(kobj->oidp, attr->name, 1, 1); 144 } 145 146 static inline void 147 sysfs_remove_group(struct kobject *kobj, const struct attribute_group *grp) 148 { 149 150 if (kobj->oidp) 151 sysctl_remove_name(kobj->oidp, grp->name, 1, 1); 152 } 153 154 static inline int 155 sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp) 156 { 157 struct attribute **attr; 158 struct sysctl_oid *oidp; 159 160 oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->oidp), 161 OID_AUTO, grp->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, grp->name); 162 for (attr = grp->attrs; *attr != NULL; attr++) { 163 sysctl_add_oid(NULL, SYSCTL_CHILDREN(oidp), OID_AUTO, 164 (*attr)->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, 165 kobj, (uintptr_t)*attr, sysctl_handle_attr, "A", ""); 166 } 167 168 return (0); 169 } 170 171 static inline int 172 sysfs_create_dir(struct kobject *kobj) 173 { 174 175 kobj->oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->parent->oidp), 176 OID_AUTO, kobj->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, kobj->name); 177 178 return (0); 179 } 180 181 static inline void 182 sysfs_remove_dir(struct kobject *kobj) 183 { 184 185 if (kobj->oidp == NULL) 186 return; 187 sysctl_remove_oid(kobj->oidp, 1, 1); 188 } 189 190 #define sysfs_attr_init(attr) do {} while(0) 191 192 #endif /* _LINUX_SYSFS_H_ */ 193