sysfs.h revision 270710
1169691Skan/*- 2169691Skan * Copyright (c) 2010 Isilon Systems, Inc. 3169691Skan * Copyright (c) 2010 iX Systems, Inc. 4169691Skan * Copyright (c) 2010 Panasas, Inc. 5169691Skan * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd. 6169691Skan * All rights reserved. 7169691Skan * 8169691Skan * Redistribution and use in source and binary forms, with or without 9169691Skan * modification, are permitted provided that the following conditions 10169691Skan * are met: 11169691Skan * 1. Redistributions of source code must retain the above copyright 12169691Skan * notice unmodified, this list of conditions, and the following 13169691Skan * disclaimer. 14169691Skan * 2. Redistributions in binary form must reproduce the above copyright 15169691Skan * notice, this list of conditions and the following disclaimer in the 16169691Skan * documentation and/or other materials provided with the distribution. 17169691Skan * 18169691Skan * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19169691Skan * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20169691Skan * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21169691Skan * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22169691Skan * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23169691Skan * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24169691Skan * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25169691Skan * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26169691Skan * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27169691Skan * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28169691Skan */ 29169691Skan 30169691Skan#ifndef _LINUX_SYSFS_H_ 31169691Skan#define _LINUX_SYSFS_H_ 32169691Skan 33169691Skan#include <sys/sysctl.h> 34169691Skan 35169691Skanstruct attribute { 36169691Skan const char *name; 37169691Skan struct module *owner; 38169691Skan mode_t mode; 39169691Skan}; 40169691Skan 41169691Skanstruct sysfs_ops { 42169691Skan ssize_t (*show)(struct kobject *, struct attribute *, char *); 43169691Skan ssize_t (*store)(struct kobject *, struct attribute *, const char *, 44169691Skan size_t); 45169691Skan}; 46169691Skan 47169691Skanstruct attribute_group { 48169691Skan const char *name; 49169691Skan mode_t (*is_visible)(struct kobject *, 50169691Skan struct attribute *, int); 51169691Skan struct attribute **attrs; 52169691Skan}; 53169691Skan 54169691Skan#define __ATTR(_name, _mode, _show, _store) { \ 55169691Skan .attr = { .name = __stringify(_name), .mode = _mode }, \ 56169691Skan .show = _show, .store = _store, \ 57169691Skan} 58169691Skan 59169691Skan#define __ATTR_RO(_name) { \ 60169691Skan .attr = { .name = __stringify(_name), .mode = 0444 }, \ 61169691Skan .show = _name##_show, \ 62169691Skan} 63169691Skan 64169691Skan#define __ATTR_NULL { .attr = { .name = NULL } } 65169691Skan 66169691Skan/* 67169691Skan * Handle our generic '\0' terminated 'C' string. 68169691Skan * Two cases: 69169691Skan * a variable string: point arg1 at it, arg2 is max length. 70169691Skan * a constant string: point arg1 at it, arg2 is zero. 71169691Skan */ 72169691Skan 73169691Skanstatic inline int 74169691Skansysctl_handle_attr(SYSCTL_HANDLER_ARGS) 75169691Skan{ 76169691Skan struct kobject *kobj; 77169691Skan struct attribute *attr; 78169691Skan const struct sysfs_ops *ops; 79169691Skan char *buf; 80169691Skan int error; 81169691Skan ssize_t len; 82169691Skan 83169691Skan kobj = arg1; 84169691Skan attr = (struct attribute *)arg2; 85169691Skan if (kobj->ktype == NULL || kobj->ktype->sysfs_ops == NULL) 86169691Skan return (ENODEV); 87169691Skan buf = (char *)get_zeroed_page(GFP_KERNEL); 88169691Skan if (buf == NULL) 89169691Skan return (ENOMEM); 90169691Skan ops = kobj->ktype->sysfs_ops; 91169691Skan if (ops->show) { 92169691Skan len = ops->show(kobj, attr, buf); 93169691Skan /* 94169691Skan * It's valid to not have a 'show' so just return an 95169691Skan * empty string. 96169691Skan */ 97169691Skan if (len < 0) { 98169691Skan error = -len; 99169691Skan if (error != EIO) 100169691Skan goto out; 101169691Skan buf[0] = '\0'; 102169691Skan } else if (len) { 103169691Skan len--; 104169691Skan if (len >= PAGE_SIZE) 105169691Skan len = PAGE_SIZE - 1; 106169691Skan /* Trim trailing newline. */ 107169691Skan buf[len] = '\0'; 108169691Skan } 109169691Skan } 110169691Skan 111169691Skan /* Leave one trailing byte to append a newline. */ 112169691Skan error = sysctl_handle_string(oidp, buf, PAGE_SIZE - 1, req); 113169691Skan if (error != 0 || req->newptr == NULL || ops->store == NULL) 114169691Skan goto out; 115169691Skan len = strlcat(buf, "\n", PAGE_SIZE); 116169691Skan KASSERT(len < PAGE_SIZE, ("new attribute truncated")); 117169691Skan len = ops->store(kobj, attr, buf, len); 118169691Skan if (len < 0) 119169691Skan error = -len; 120169691Skanout: 121169691Skan free_page((unsigned long)buf); 122169691Skan 123169691Skan return (error); 124169691Skan} 125169691Skan 126169691Skanstatic inline int 127169691Skansysfs_create_file(struct kobject *kobj, const struct attribute *attr) 128169691Skan{ 129169691Skan 130169691Skan sysctl_add_oid(NULL, SYSCTL_CHILDREN(kobj->oidp), OID_AUTO, 131169691Skan attr->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, kobj, 132169691Skan (uintptr_t)attr, sysctl_handle_attr, "A", ""); 133169691Skan 134169691Skan return (0); 135169691Skan} 136169691Skan 137169691Skanstatic inline void 138169691Skansysfs_remove_file(struct kobject *kobj, const struct attribute *attr) 139169691Skan{ 140169691Skan 141169691Skan if (kobj->oidp) 142169691Skan sysctl_remove_name(kobj->oidp, attr->name, 1, 1); 143169691Skan} 144169691Skan 145169691Skanstatic inline void 146169691Skansysfs_remove_group(struct kobject *kobj, const struct attribute_group *grp) 147169691Skan{ 148169691Skan 149169691Skan if (kobj->oidp) 150169691Skan sysctl_remove_name(kobj->oidp, grp->name, 1, 1); 151169691Skan} 152169691Skan 153169691Skanstatic inline int 154169691Skansysfs_create_group(struct kobject *kobj, const struct attribute_group *grp) 155169691Skan{ 156169691Skan struct attribute **attr; 157169691Skan struct sysctl_oid *oidp; 158169691Skan 159169691Skan oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->oidp), 160169691Skan OID_AUTO, grp->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, grp->name); 161169691Skan for (attr = grp->attrs; *attr != NULL; attr++) { 162169691Skan sysctl_add_oid(NULL, SYSCTL_CHILDREN(oidp), OID_AUTO, 163169691Skan (*attr)->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, 164169691Skan kobj, (uintptr_t)*attr, sysctl_handle_attr, "A", ""); 165169691Skan } 166169691Skan 167169691Skan return (0); 168169691Skan} 169169691Skan 170169691Skanstatic inline int 171169691Skansysfs_create_dir(struct kobject *kobj) 172169691Skan{ 173169691Skan 174169691Skan kobj->oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->parent->oidp), 175169691Skan OID_AUTO, kobj->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, kobj->name); 176169691Skan 177169691Skan return (0); 178169691Skan} 179169691Skan 180169691Skanstatic inline void 181169691Skansysfs_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