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 30#ifndef _LINUX_SYSFS_H_ 31#define _LINUX_SYSFS_H_ 32 33#include <sys/sysctl.h> 34 35struct attribute { 36 const char *name; 37 struct module *owner; 38 mode_t mode; 39}; 40 41struct sysfs_ops { 42 ssize_t (*show)(struct kobject *, struct attribute *, char *); 43 ssize_t (*store)(struct kobject *, struct attribute *, const char *, 44 size_t); 45}; 46 47struct attribute_group { 48 const char *name; 49 mode_t (*is_visible)(struct kobject *, 50 struct attribute *, int); 51 struct attribute **attrs; 52}; 53 54#define __ATTR(_name, _mode, _show, _store) { \ 55 .attr = { .name = __stringify(_name), .mode = _mode }, \ 56 .show = _show, .store = _store, \ 57} 58 59#define __ATTR_RO(_name) { \ 60 .attr = { .name = __stringify(_name), .mode = 0444 }, \ 61 .show = _name##_show, \ 62} 63 64#define __ATTR_NULL { .attr = { .name = NULL } } 65 66/* 67 * Handle our generic '\0' terminated 'C' string. 68 * Two cases: 69 * a variable string: point arg1 at it, arg2 is max length. 70 * a constant string: point arg1 at it, arg2 is zero. 71 */ 72 73static inline int 74sysctl_handle_attr(SYSCTL_HANDLER_ARGS) 75{ 76 struct kobject *kobj; 77 struct attribute *attr; 78 const struct sysfs_ops *ops; 79 char *buf; 80 int error; 81 ssize_t len; 82 83 kobj = arg1; 84 attr = (struct attribute *)arg2; 85 if (kobj->ktype == NULL || kobj->ktype->sysfs_ops == NULL) 86 return (ENODEV); 87 buf = (char *)get_zeroed_page(GFP_KERNEL); 88 if (buf == NULL) 89 return (ENOMEM); 90 ops = kobj->ktype->sysfs_ops; 91 if (ops->show) { 92 len = ops->show(kobj, attr, buf); 93 /* 94 * It's valid to not have a 'show' so just return an 95 * empty string. 96 */ 97 if (len < 0) { 98 error = -len; 99 if (error != EIO) 100 goto out; 101 buf[0] = '\0'; 102 } else if (len) { 103 len--; 104 if (len >= PAGE_SIZE) 105 len = PAGE_SIZE - 1; 106 /* Trim trailing newline. */ 107 buf[len] = '\0'; 108 } 109 } 110 111 /* Leave one trailing byte to append a newline. */ 112 error = sysctl_handle_string(oidp, buf, PAGE_SIZE - 1, req); 113 if (error != 0 || req->newptr == NULL || ops->store == NULL) 114 goto out; 115 len = strlcat(buf, "\n", PAGE_SIZE); 116 KASSERT(len < PAGE_SIZE, ("new attribute truncated")); 117 len = ops->store(kobj, attr, buf, len); 118 if (len < 0) 119 error = -len; 120out: 121 free_page((unsigned long)buf); 122 123 return (error); 124} 125 126static inline int 127sysfs_create_file(struct kobject *kobj, const struct attribute *attr) 128{ 129 130 sysctl_add_oid(NULL, SYSCTL_CHILDREN(kobj->oidp), OID_AUTO, 131 attr->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, kobj, 132 (uintptr_t)attr, sysctl_handle_attr, "A", ""); 133 134 return (0); 135} 136 137static inline void 138sysfs_remove_file(struct kobject *kobj, const struct attribute *attr) 139{ 140 141 if (kobj->oidp) 142 sysctl_remove_name(kobj->oidp, attr->name, 1, 1); 143} 144 145static inline void 146sysfs_remove_group(struct kobject *kobj, const struct attribute_group *grp) 147{ 148 149 if (kobj->oidp) 150 sysctl_remove_name(kobj->oidp, grp->name, 1, 1); 151} 152 153static inline int 154sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp) 155{ 156 struct attribute **attr; 157 struct sysctl_oid *oidp; 158 159 oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->oidp), 160 OID_AUTO, grp->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, grp->name); 161 for (attr = grp->attrs; *attr != NULL; attr++) { 162 sysctl_add_oid(NULL, SYSCTL_CHILDREN(oidp), OID_AUTO, 163 (*attr)->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, 164 kobj, (uintptr_t)*attr, sysctl_handle_attr, "A", ""); 165 } 166 167 return (0); 168} 169 170static inline int 171sysfs_create_dir(struct kobject *kobj) 172{ 173 174 kobj->oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->parent->oidp), 175 OID_AUTO, kobj->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, kobj->name); 176 177 return (0); 178} 179 180static inline void 181sysfs_remove_dir(struct kobject *kobj) 182{ 183 184 if (kobj->oidp == NULL) 185 return; 186 sysctl_remove_oid(kobj->oidp, 1, 1); 187} 188 189#define sysfs_attr_init(attr) do {} while(0) 190 191#endif /* _LINUX_SYSFS_H_ */ 192