/* * Enclosure Services * * Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com> * **----------------------------------------------------------------------------- ** ** This program is free software; you can redistribute it and/or ** modify it under the terms of the GNU General Public License ** version 2 as published by the Free Software Foundation. ** ** This program is distributed in the hope that it will be useful, ** but WITHOUT ANY WARRANTY; without even the implied warranty of ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ** GNU General Public License for more details. ** ** You should have received a copy of the GNU General Public License ** along with this program; if not, write to the Free Software ** Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. ** **----------------------------------------------------------------------------- */ #include <linux/device.h> #include <linux/enclosure.h> #include <linux/err.h> #include <linux/list.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/slab.h> static LIST_HEAD(container_list); static DEFINE_MUTEX(container_list_lock); static struct class enclosure_class; /** * enclosure_find - find an enclosure given a parent device * @dev: the parent to match against * @start: Optional enclosure device to start from (NULL if none) * * Looks through the list of registered enclosures to find all those * with @dev as a parent. Returns NULL if no enclosure is * found. @start can be used as a starting point to obtain multiple * enclosures per parent (should begin with NULL and then be set to * each returned enclosure device). Obtains a reference to the * enclosure class device which must be released with device_put(). * If @start is not NULL, a reference must be taken on it which is * released before returning (this allows a loop through all * enclosures to exit with only the reference on the enclosure of * interest held). Note that the @dev may correspond to the actual * device housing the enclosure, in which case no iteration via @start * is required. */ struct enclosure_device *enclosure_find(struct device *dev, struct enclosure_device *start) { struct enclosure_device *edev; mutex_lock(&container_list_lock); edev = list_prepare_entry(start, &container_list, node); if (start) put_device(&start->edev); list_for_each_entry_continue(edev, &container_list, node) { struct device *parent = edev->edev.parent; /* parent might not be immediate, so iterate up to * the root of the tree if necessary */ while (parent) { if (parent == dev) { get_device(&edev->edev); mutex_unlock(&container_list_lock); return edev; } parent = parent->parent; } } mutex_unlock(&container_list_lock); return NULL; } EXPORT_SYMBOL_GPL(enclosure_find); /** * enclosure_for_each_device - calls a function for each enclosure * @fn: the function to call * @data: the data to pass to each call * * Loops over all the enclosures calling the function. * * Note, this function uses a mutex which will be held across calls to * @fn, so it must have non atomic context, and @fn may (although it * should not) sleep or otherwise cause the mutex to be held for * indefinite periods */ int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *), void *data) { int error = 0; struct enclosure_device *edev; mutex_lock(&container_list_lock); list_for_each_entry(edev, &container_list, node) { error = fn(edev, data); if (error) break; } mutex_unlock(&container_list_lock); return error; } EXPORT_SYMBOL_GPL(enclosure_for_each_device); /** * enclosure_register - register device as an enclosure * * @dev: device containing the enclosure * @components: number of components in the enclosure * * This sets up the device for being an enclosure. Note that @dev does * not have to be a dedicated enclosure device. It may be some other type * of device that additionally responds to enclosure services */ struct enclosure_device * enclosure_register(struct device *dev, const char *name, int components, struct enclosure_component_callbacks *cb) { struct enclosure_device *edev = kzalloc(sizeof(struct enclosure_device) + sizeof(struct enclosure_component)*components, GFP_KERNEL); int err, i; BUG_ON(!cb); if (!edev) return ERR_PTR(-ENOMEM); edev->components = components; edev->edev.class = &enclosure_class; edev->edev.parent = get_device(dev); edev->cb = cb; dev_set_name(&edev->edev, "%s", name); err = device_register(&edev->edev); if (err) goto err; for (i = 0; i < components; i++) edev->component[i].number = -1; mutex_lock(&container_list_lock); list_add_tail(&edev->node, &container_list); mutex_unlock(&container_list_lock); return edev; err: put_device(edev->edev.parent); kfree(edev); return ERR_PTR(err); } EXPORT_SYMBOL_GPL(enclosure_register); static struct enclosure_component_callbacks enclosure_null_callbacks; /** * enclosure_unregister - remove an enclosure * * @edev: the registered enclosure to remove; */ void enclosure_unregister(struct enclosure_device *edev) { int i; mutex_lock(&container_list_lock); list_del(&edev->node); mutex_unlock(&container_list_lock); for (i = 0; i < edev->components; i++) if (edev->component[i].number != -1) device_unregister(&edev->component[i].cdev); /* prevent any callbacks into service user */ edev->cb = &enclosure_null_callbacks; device_unregister(&edev->edev); } EXPORT_SYMBOL_GPL(enclosure_unregister); #define ENCLOSURE_NAME_SIZE 64 static void enclosure_link_name(struct enclosure_component *cdev, char *name) { strcpy(name, "enclosure_device:"); strcat(name, dev_name(&cdev->cdev)); } static void enclosure_remove_links(struct enclosure_component *cdev) { char name[ENCLOSURE_NAME_SIZE]; /* * In odd circumstances, like multipath devices, something else may * already have removed the links, so check for this condition first. */ if (!cdev->dev->kobj.sd) return; enclosure_link_name(cdev, name); sysfs_remove_link(&cdev->dev->kobj, name); sysfs_remove_link(&cdev->cdev.kobj, "device"); } static int enclosure_add_links(struct enclosure_component *cdev) { int error; char name[ENCLOSURE_NAME_SIZE]; error = sysfs_create_link(&cdev->cdev.kobj, &cdev->dev->kobj, "device"); if (error) return error; enclosure_link_name(cdev, name); error = sysfs_create_link(&cdev->dev->kobj, &cdev->cdev.kobj, name); if (error) sysfs_remove_link(&cdev->cdev.kobj, "device"); return error; } static void enclosure_release(struct device *cdev) { struct enclosure_device *edev = to_enclosure_device(cdev); put_device(cdev->parent); kfree(edev); } static void enclosure_component_release(struct device *dev) { struct enclosure_component *cdev = to_enclosure_component(dev); if (cdev->dev) { enclosure_remove_links(cdev); put_device(cdev->dev); } put_device(dev->parent); } static const struct attribute_group *enclosure_component_groups[]; /** * enclosure_component_register - add a particular component to an enclosure * @edev: the enclosure to add the component * @num: the device number * @type: the type of component being added * @name: an optional name to appear in sysfs (leave NULL if none) * * Registers the component. The name is optional for enclosures that * give their components a unique name. If not, leave the field NULL * and a name will be assigned. * * Returns a pointer to the enclosure component or an error. */ struct enclosure_component * enclosure_component_register(struct enclosure_device *edev, unsigned int number, enum enclosure_component_type type, const char *name) { struct enclosure_component *ecomp; struct device *cdev; int err; if (number >= edev->components) return ERR_PTR(-EINVAL); ecomp = &edev->component[number]; if (ecomp->number != -1) return ERR_PTR(-EINVAL); ecomp->type = type; ecomp->number = number; cdev = &ecomp->cdev; cdev->parent = get_device(&edev->edev); if (name && name[0]) dev_set_name(cdev, "%s", name); else dev_set_name(cdev, "%u", number); cdev->release = enclosure_component_release; cdev->groups = enclosure_component_groups; err = device_register(cdev); if (err) { ecomp->number = -1; put_device(cdev); return ERR_PTR(err); } return ecomp; } EXPORT_SYMBOL_GPL(enclosure_component_register); /** * enclosure_add_device - add a device as being part of an enclosure * @edev: the enclosure device being added to. * @num: the number of the component * @dev: the device being added * * Declares a real device to reside in slot (or identifier) @num of an * enclosure. This will cause the relevant sysfs links to appear. * This function may also be used to change a device associated with * an enclosure without having to call enclosure_remove_device() in * between. * * Returns zero on success or an error. */ int enclosure_add_device(struct enclosure_device *edev, int component, struct device *dev) { struct enclosure_component *cdev; if (!edev || component >= edev->components) return -EINVAL; cdev = &edev->component[component]; if (cdev->dev == dev) return -EEXIST; if (cdev->dev) enclosure_remove_links(cdev); put_device(cdev->dev); cdev->dev = get_device(dev); return enclosure_add_links(cdev); } EXPORT_SYMBOL_GPL(enclosure_add_device); /** * enclosure_remove_device - remove a device from an enclosure * @edev: the enclosure device * @num: the number of the component to remove * * Returns zero on success or an error. * */ int enclosure_remove_device(struct enclosure_device *edev, struct device *dev) { struct enclosure_component *cdev; int i; if (!edev || !dev) return -EINVAL; for (i = 0; i < edev->components; i++) { cdev = &edev->component[i]; if (cdev->dev == dev) { enclosure_remove_links(cdev); device_del(&cdev->cdev); put_device(dev); cdev->dev = NULL; return device_add(&cdev->cdev); } } return -ENODEV; } EXPORT_SYMBOL_GPL(enclosure_remove_device); /* * sysfs pieces below */ static ssize_t components_show(struct device *cdev, struct device_attribute *attr, char *buf) { struct enclosure_device *edev = to_enclosure_device(cdev); return snprintf(buf, 40, "%d\n", edev->components); } static DEVICE_ATTR_RO(components); static struct attribute *enclosure_class_attrs[] = { &dev_attr_components.attr, NULL, }; ATTRIBUTE_GROUPS(enclosure_class); static struct class enclosure_class = { .name = "enclosure", .owner = THIS_MODULE, .dev_release = enclosure_release, .dev_groups = enclosure_class_groups, }; static const char *const enclosure_status [] = { [ENCLOSURE_STATUS_UNSUPPORTED] = "unsupported", [ENCLOSURE_STATUS_OK] = "OK", [ENCLOSURE_STATUS_CRITICAL] = "critical", [ENCLOSURE_STATUS_NON_CRITICAL] = "non-critical", [ENCLOSURE_STATUS_UNRECOVERABLE] = "unrecoverable", [ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed", [ENCLOSURE_STATUS_UNKNOWN] = "unknown", [ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable", [ENCLOSURE_STATUS_MAX] = NULL, }; static const char *const enclosure_type [] = { [ENCLOSURE_COMPONENT_DEVICE] = "device", [ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device", }; static ssize_t get_component_fault(struct device *cdev, struct device_attribute *attr, char *buf) { struct enclosure_device *edev = to_enclosure_device(cdev->parent); struct enclosure_component *ecomp = to_enclosure_component(cdev); if (edev->cb->get_fault) edev->cb->get_fault(edev, ecomp); return snprintf(buf, 40, "%d\n", ecomp->fault); } static ssize_t set_component_fault(struct device *cdev, struct device_attribute *attr, const char *buf, size_t count) { struct enclosure_device *edev = to_enclosure_device(cdev->parent); struct enclosure_component *ecomp = to_enclosure_component(cdev); int val = simple_strtoul(buf, NULL, 0); if (edev->cb->set_fault) edev->cb->set_fault(edev, ecomp, val); return count; } static ssize_t get_component_status(struct device *cdev, struct device_attribute *attr,char *buf) { struct enclosure_device *edev = to_enclosure_device(cdev->parent); struct enclosure_component *ecomp = to_enclosure_component(cdev); if (edev->cb->get_status) edev->cb->get_status(edev, ecomp); return snprintf(buf, 40, "%s\n", enclosure_status[ecomp->status]); } static ssize_t set_component_status(struct device *cdev, struct device_attribute *attr, const char *buf, size_t count) { struct enclosure_device *edev = to_enclosure_device(cdev->parent); struct enclosure_component *ecomp = to_enclosure_component(cdev); int i; for (i = 0; enclosure_status[i]; i++) { if (strncmp(buf, enclosure_status[i], strlen(enclosure_status[i])) == 0 && (buf[strlen(enclosure_status[i])] == '\n' || buf[strlen(enclosure_status[i])] == '\0')) break; } if (enclosure_status[i] && edev->cb->set_status) { edev->cb->set_status(edev, ecomp, i); return count; } else return -EINVAL; } static ssize_t get_component_active(struct device *cdev, struct device_attribute *attr, char *buf) { struct enclosure_device *edev = to_enclosure_device(cdev->parent); struct enclosure_component *ecomp = to_enclosure_component(cdev); if (edev->cb->get_active) edev->cb->get_active(edev, ecomp); return snprintf(buf, 40, "%d\n", ecomp->active); } static ssize_t set_component_active(struct device *cdev, struct device_attribute *attr, const char *buf, size_t count) { struct enclosure_device *edev = to_enclosure_device(cdev->parent); struct enclosure_component *ecomp = to_enclosure_component(cdev); int val = simple_strtoul(buf, NULL, 0); if (edev->cb->set_active) edev->cb->set_active(edev, ecomp, val); return count; } static ssize_t get_component_locate(struct device *cdev, struct device_attribute *attr, char *buf) { struct enclosure_device *edev = to_enclosure_device(cdev->parent); struct enclosure_component *ecomp = to_enclosure_component(cdev); if (edev->cb->get_locate) edev->cb->get_locate(edev, ecomp); return snprintf(buf, 40, "%d\n", ecomp->locate); } static ssize_t set_component_locate(struct device *cdev, struct device_attribute *attr, const char *buf, size_t count) { struct enclosure_device *edev = to_enclosure_device(cdev->parent); struct enclosure_component *ecomp = to_enclosure_component(cdev); int val = simple_strtoul(buf, NULL, 0); if (edev->cb->set_locate) edev->cb->set_locate(edev, ecomp, val); return count; } static ssize_t get_component_type(struct device *cdev, struct device_attribute *attr, char *buf) { struct enclosure_component *ecomp = to_enclosure_component(cdev); return snprintf(buf, 40, "%s\n", enclosure_type[ecomp->type]); } static DEVICE_ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault, set_component_fault); static DEVICE_ATTR(status, S_IRUGO | S_IWUSR, get_component_status, set_component_status); static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, get_component_active, set_component_active); static DEVICE_ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate, set_component_locate); static DEVICE_ATTR(type, S_IRUGO, get_component_type, NULL); static struct attribute *enclosure_component_attrs[] = { &dev_attr_fault.attr, &dev_attr_status.attr, &dev_attr_active.attr, &dev_attr_locate.attr, &dev_attr_type.attr, NULL }; ATTRIBUTE_GROUPS(enclosure_component); static int __init enclosure_init(void) { int err; err = class_register(&enclosure_class); if (err) return err; return 0; } static void __exit enclosure_exit(void) { class_unregister(&enclosure_class); } module_init(enclosure_init); module_exit(enclosure_exit); MODULE_AUTHOR("James Bottomley"); MODULE_DESCRIPTION("Enclosure Services"); MODULE_LICENSE("GPL v2");