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/*
* 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];
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_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_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 enclosure_show_components(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 struct device_attribute enclosure_attrs[] = {
__ATTR(components, S_IRUGO, enclosure_show_components, NULL),
__ATTR_NULL
};
static struct class enclosure_class = {
.name = "enclosure",
.owner = THIS_MODULE,
.dev_release = enclosure_release,
.dev_attrs = enclosure_attrs,
};
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
};
static struct attribute_group enclosure_group = {
.attrs = enclosure_component_attrs,
};
static const struct attribute_group *enclosure_groups[] = {
&enclosure_group,
NULL
};
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");