[SCSI] enclosure: add support for enclosure services

The enclosure misc device is really just a library providing sysfs
support for physical enclosure devices and their components.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 484 insertions, 0 deletions

diff --git a/drivers/misc/enclosure.c b/drivers/misc/enclosure.c
new file mode 100644
index 000000000000..6fcb0e96adf4
--- /dev/null
+++ b/drivers/misc/enclosure.c
@@ -0,0 +1,484 @@
+/*
+ * 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>
+
+static LIST_HEAD(container_list);
+static DEFINE_MUTEX(container_list_lock);
+static struct class enclosure_class;
+static struct class enclosure_component_class;
+
+/**
+ * enclosure_find - find an enclosure given a device
+ * @dev:        the device to find for
+ *
+ * Looks through the list of registered enclosures to see
+ * if it can find a match for a device.  Returns NULL if no
+ * enclosure is found. Obtains a reference to the enclosure class
+ * device which must be released with class_device_put().
+ */
+struct enclosure_device *enclosure_find(struct device *dev)
+{
+        struct enclosure_device *edev = NULL;
+
+        mutex_lock(&container_list_lock);
+        list_for_each_entry(edev, &container_list, node) {
+                if (edev->cdev.dev == dev) {
+                        class_device_get(&edev->cdev);
+                        mutex_unlock(&container_list_lock);
+                        return edev;
+                }
+        }
+        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->cdev.class = &enclosure_class;
+        edev->cdev.dev = get_device(dev);
+        edev->cb = cb;
+        snprintf(edev->cdev.class_id, BUS_ID_SIZE, "%s", name);
+        err = class_device_register(&edev->cdev);
+        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->cdev.dev);
+        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)
+                        class_device_unregister(&edev->component[i].cdev);
+
+        /* prevent any callbacks into service user */
+        edev->cb = &enclosure_null_callbacks;
+        class_device_unregister(&edev->cdev);
+}
+EXPORT_SYMBOL_GPL(enclosure_unregister);
+
+static void enclosure_release(struct class_device *cdev)
+{
+        struct enclosure_device *edev = to_enclosure_device(cdev);
+
+        put_device(cdev->dev);
+        kfree(edev);
+}
+
+static void enclosure_component_release(struct class_device *cdev)
+{
+        if (cdev->dev)
+                put_device(cdev->dev);
+        class_device_put(cdev->parent);
+}
+
+/**
+ * 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 class_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 = class_device_get(&edev->cdev);
+        cdev->class = &enclosure_component_class;
+        if (name)
+                snprintf(cdev->class_id, BUS_ID_SIZE, "%s", name);
+        else
+                snprintf(cdev->class_id, BUS_ID_SIZE, "%u", number);
+
+        err = class_device_register(cdev);
+        if (err)
+                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 class_device *cdev;
+
+        if (!edev || component >= edev->components)
+                return -EINVAL;
+
+        cdev = &edev->component[component].cdev;
+
+        class_device_del(cdev);
+        if (cdev->dev)
+                put_device(cdev->dev);
+        cdev->dev = get_device(dev);
+        return class_device_add(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, int component)
+{
+        struct class_device *cdev;
+
+        if (!edev || component >= edev->components)
+                return -EINVAL;
+
+        cdev = &edev->component[component].cdev;
+
+        class_device_del(cdev);
+        if (cdev->dev)
+                put_device(cdev->dev);
+        cdev->dev = NULL;
+        return class_device_add(cdev);
+}
+EXPORT_SYMBOL_GPL(enclosure_remove_device);
+
+/*
+ * sysfs pieces below
+ */
+
+static ssize_t enclosure_show_components(struct class_device *cdev, char *buf)
+{
+        struct enclosure_device *edev = to_enclosure_device(cdev);
+
+        return snprintf(buf, 40, "%d\n", edev->components);
+}
+
+static struct class_device_attribute enclosure_attrs[] = {
+        __ATTR(components, S_IRUGO, enclosure_show_components, NULL),
+        __ATTR_NULL
+};
+
+static struct class enclosure_class = {
+        .name                   = "enclosure",
+        .owner                  = THIS_MODULE,
+        .release                = enclosure_release,
+        .class_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",
+};
+
+static const char *const enclosure_type [] = {
+        [ENCLOSURE_COMPONENT_DEVICE] = "device",
+        [ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device",
+};
+
+static ssize_t get_component_fault(struct class_device *cdev, 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 class_device *cdev, 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 class_device *cdev, 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 class_device *cdev, 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 class_device *cdev, 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 class_device *cdev, 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 class_device *cdev, 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 class_device *cdev, 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 class_device *cdev, char *buf)
+{
+        struct enclosure_component *ecomp = to_enclosure_component(cdev);
+
+        return snprintf(buf, 40, "%s\n", enclosure_type[ecomp->type]);
+}
+
+
+static struct class_device_attribute enclosure_component_attrs[] = {
+        __ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault,
+               set_component_fault),
+        __ATTR(status, S_IRUGO | S_IWUSR, get_component_status,
+               set_component_status),
+        __ATTR(active, S_IRUGO | S_IWUSR, get_component_active,
+               set_component_active),
+        __ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate,
+               set_component_locate),
+        __ATTR(type, S_IRUGO, get_component_type, NULL),
+        __ATTR_NULL
+};
+
+static struct class enclosure_component_class =  {
+        .name                   = "enclosure_component",
+        .owner                  = THIS_MODULE,
+        .class_dev_attrs        = enclosure_component_attrs,
+        .release                = enclosure_component_release,
+};
+
+static int __init enclosure_init(void)
+{
+        int err;
+
+        err = class_register(&enclosure_class);
+        if (err)
+                return err;
+        err = class_register(&enclosure_component_class);
+        if (err)
+                goto err_out;
+
+        return 0;
+ err_out:
+        class_unregister(&enclosure_class);
+
+        return err;
+}
+
+static void __exit enclosure_exit(void)
+{
+        class_unregister(&enclosure_component_class);
+        class_unregister(&enclosure_class);
+}
+
+module_init(enclosure_init);
+module_exit(enclosure_exit);
+
+MODULE_AUTHOR("James Bottomley");
+MODULE_DESCRIPTION("Enclosure Services");
+MODULE_LICENSE("GPL v2");