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