/*
- * drivers/s390/cio/ccwgroup.c
* bus driver for ccwgroup
*
- * Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
- * IBM Corporation
- * Author(s): Arnd Bergmann (arndb@de.ibm.com)
- * Cornelia Huck (cornelia.huck@de.ibm.com)
+ * Copyright IBM Corp. 2002, 2009
+ *
+ * Author(s): Arnd Bergmann (arndb@de.ibm.com)
+ * Cornelia Huck (cornelia.huck@de.ibm.com)
*/
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/ctype.h>
#include <linux/dcache.h>
-#include <asm/semaphore.h>
#include <asm/ccwdev.h>
#include <asm/ccwgroup.h>
+#define CCW_BUS_ID_SIZE 20
+
/* In Linux 2.4, we had a channel device layer called "chandev"
* that did all sorts of obscure stuff for networking devices.
* This is another driver that serves as a replacement for just
struct ccwgroup_device *gdev;
struct ccwgroup_driver *gdrv;
- gdev = container_of(dev, struct ccwgroup_device, dev);
- gdrv = container_of(drv, struct ccwgroup_driver, driver);
+ gdev = to_ccwgroupdev(dev);
+ gdrv = to_ccwgroupdrv(drv);
if (gdev->creator_id == gdrv->driver_id)
return 1;
return 0;
}
static int
-ccwgroup_uevent (struct device *dev, char **envp, int num_envp, char *buffer,
- int buffer_size)
+ccwgroup_uevent (struct device *dev, struct kobj_uevent_env *env)
{
/* TODO */
return 0;
static struct bus_type ccwgroup_bus_type;
-static inline void
+static void
__ccwgroup_remove_symlinks(struct ccwgroup_device *gdev)
{
int i;
* Provide an 'ungroup' attribute so the user can remove group devices no
* longer needed or accidentially created. Saves memory :)
*/
+static void ccwgroup_ungroup_callback(struct device *dev)
+{
+ struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
+
+ mutex_lock(&gdev->reg_mutex);
+ if (device_is_registered(&gdev->dev)) {
+ __ccwgroup_remove_symlinks(gdev);
+ device_unregister(dev);
+ }
+ mutex_unlock(&gdev->reg_mutex);
+}
+
static ssize_t
ccwgroup_ungroup_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
struct ccwgroup_device *gdev;
+ int rc;
gdev = to_ccwgroupdev(dev);
- if (gdev->state != CCWGROUP_OFFLINE)
- return -EINVAL;
-
- __ccwgroup_remove_symlinks(gdev);
- device_unregister(dev);
-
+ /* Prevent concurrent online/offline processing and ungrouping. */
+ if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0)
+ return -EAGAIN;
+ if (gdev->state != CCWGROUP_OFFLINE) {
+ rc = -EINVAL;
+ goto out;
+ }
+ /* Note that we cannot unregister the device from one of its
+ * attribute methods, so we have to use this roundabout approach.
+ */
+ rc = device_schedule_callback(dev, ccwgroup_ungroup_callback);
+out:
+ if (rc) {
+ if (rc != -EAGAIN)
+ /* Release onoff "lock" when ungrouping failed. */
+ atomic_set(&gdev->onoff, 0);
+ return rc;
+ }
return count;
}
gdev = to_ccwgroupdev(dev);
for (i = 0; i < gdev->count; i++) {
- gdev->cdev[i]->dev.driver_data = NULL;
- put_device(&gdev->cdev[i]->dev);
+ if (gdev->cdev[i]) {
+ if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev)
+ dev_set_drvdata(&gdev->cdev[i]->dev, NULL);
+ put_device(&gdev->cdev[i]->dev);
+ }
}
kfree(gdev);
}
-static inline int
+static int
__ccwgroup_create_symlinks(struct ccwgroup_device *gdev)
{
char str[8];
return 0;
}
-/*
- * try to add a new ccwgroup device for one driver
- * argc and argv[] are a list of bus_id's of devices
- * belonging to the driver.
+static int __get_next_bus_id(const char **buf, char *bus_id)
+{
+ int rc, len;
+ char *start, *end;
+
+ start = (char *)*buf;
+ end = strchr(start, ',');
+ if (!end) {
+ /* Last entry. Strip trailing newline, if applicable. */
+ end = strchr(start, '\n');
+ if (end)
+ *end = '\0';
+ len = strlen(start) + 1;
+ } else {
+ len = end - start + 1;
+ end++;
+ }
+ if (len < CCW_BUS_ID_SIZE) {
+ strlcpy(bus_id, start, len);
+ rc = 0;
+ } else
+ rc = -EINVAL;
+ *buf = end;
+ return rc;
+}
+
+static int __is_valid_bus_id(char bus_id[CCW_BUS_ID_SIZE])
+{
+ int cssid, ssid, devno;
+
+ /* Must be of form %x.%x.%04x */
+ if (sscanf(bus_id, "%x.%1x.%04x", &cssid, &ssid, &devno) != 3)
+ return 0;
+ return 1;
+}
+
+/**
+ * ccwgroup_create_from_string() - create and register a ccw group device
+ * @root: parent device for the new device
+ * @creator_id: identifier of creating driver
+ * @cdrv: ccw driver of slave devices
+ * @num_devices: number of slave devices
+ * @buf: buffer containing comma separated bus ids of slave devices
+ *
+ * Create and register a new ccw group device as a child of @root. Slave
+ * devices are obtained from the list of bus ids given in @buf and must all
+ * belong to @cdrv.
+ * Returns:
+ * %0 on success and an error code on failure.
+ * Context:
+ * non-atomic
*/
-int
-ccwgroup_create(struct device *root,
- unsigned int creator_id,
- struct ccw_driver *cdrv,
- int argc, char *argv[])
+int ccwgroup_create_from_string(struct device *root, unsigned int creator_id,
+ struct ccw_driver *cdrv, int num_devices,
+ const char *buf)
{
struct ccwgroup_device *gdev;
- int i;
- int rc;
+ int rc, i;
+ char tmp_bus_id[CCW_BUS_ID_SIZE];
+ const char *curr_buf;
- if (argc > 256) /* disallow dumb users */
- return -EINVAL;
-
- gdev = kzalloc(sizeof(*gdev) + argc*sizeof(gdev->cdev[0]), GFP_KERNEL);
+ gdev = kzalloc(sizeof(*gdev) + num_devices * sizeof(gdev->cdev[0]),
+ GFP_KERNEL);
if (!gdev)
return -ENOMEM;
atomic_set(&gdev->onoff, 0);
-
- for (i = 0; i < argc; i++) {
- gdev->cdev[i] = get_ccwdev_by_busid(cdrv, argv[i]);
-
- /* all devices have to be of the same type in
- * order to be grouped */
+ mutex_init(&gdev->reg_mutex);
+ mutex_lock(&gdev->reg_mutex);
+ gdev->creator_id = creator_id;
+ gdev->count = num_devices;
+ gdev->dev.bus = &ccwgroup_bus_type;
+ gdev->dev.parent = root;
+ gdev->dev.release = ccwgroup_release;
+ device_initialize(&gdev->dev);
+
+ curr_buf = buf;
+ for (i = 0; i < num_devices && curr_buf; i++) {
+ rc = __get_next_bus_id(&curr_buf, tmp_bus_id);
+ if (rc != 0)
+ goto error;
+ if (!__is_valid_bus_id(tmp_bus_id)) {
+ rc = -EINVAL;
+ goto error;
+ }
+ gdev->cdev[i] = get_ccwdev_by_busid(cdrv, tmp_bus_id);
+ /*
+ * All devices have to be of the same type in
+ * order to be grouped.
+ */
if (!gdev->cdev[i]
|| gdev->cdev[i]->id.driver_info !=
gdev->cdev[0]->id.driver_info) {
rc = -EINVAL;
- goto free_dev;
+ goto error;
}
/* Don't allow a device to belong to more than one group. */
- if (gdev->cdev[i]->dev.driver_data) {
+ if (dev_get_drvdata(&gdev->cdev[i]->dev)) {
rc = -EINVAL;
- goto free_dev;
+ goto error;
}
- gdev->cdev[i]->dev.driver_data = gdev;
+ dev_set_drvdata(&gdev->cdev[i]->dev, gdev);
+ }
+ /* Check for sufficient number of bus ids. */
+ if (i < num_devices && !curr_buf) {
+ rc = -EINVAL;
+ goto error;
+ }
+ /* Check for trailing stuff. */
+ if (i == num_devices && strlen(curr_buf) > 0) {
+ rc = -EINVAL;
+ goto error;
}
- gdev->creator_id = creator_id;
- gdev->count = argc;
- gdev->dev.bus = &ccwgroup_bus_type;
- gdev->dev.parent = root;
- gdev->dev.release = ccwgroup_release;
-
- snprintf (gdev->dev.bus_id, BUS_ID_SIZE, "%s",
- gdev->cdev[0]->dev.bus_id);
+ dev_set_name(&gdev->dev, "%s", dev_name(&gdev->cdev[0]->dev));
- rc = device_register(&gdev->dev);
-
+ rc = device_add(&gdev->dev);
if (rc)
- goto free_dev;
+ goto error;
get_device(&gdev->dev);
rc = device_create_file(&gdev->dev, &dev_attr_ungroup);
rc = __ccwgroup_create_symlinks(gdev);
if (!rc) {
+ mutex_unlock(&gdev->reg_mutex);
put_device(&gdev->dev);
return 0;
}
device_remove_file(&gdev->dev, &dev_attr_ungroup);
device_unregister(&gdev->dev);
error:
- for (i = 0; i < argc; i++)
+ for (i = 0; i < num_devices; i++)
if (gdev->cdev[i]) {
+ if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev)
+ dev_set_drvdata(&gdev->cdev[i]->dev, NULL);
put_device(&gdev->cdev[i]->dev);
- gdev->cdev[i]->dev.driver_data = NULL;
+ gdev->cdev[i] = NULL;
}
+ mutex_unlock(&gdev->reg_mutex);
put_device(&gdev->dev);
return rc;
-free_dev:
- for (i = 0; i < argc; i++)
- if (gdev->cdev[i]) {
- if (gdev->cdev[i]->dev.driver_data == gdev)
- gdev->cdev[i]->dev.driver_data = NULL;
- put_device(&gdev->cdev[i]->dev);
- }
- kfree(gdev);
- return rc;
}
+EXPORT_SYMBOL(ccwgroup_create_from_string);
+
+static int ccwgroup_notifier(struct notifier_block *nb, unsigned long action,
+ void *data);
-static int __init
-init_ccwgroup (void)
+static struct notifier_block ccwgroup_nb = {
+ .notifier_call = ccwgroup_notifier
+};
+
+static int __init init_ccwgroup(void)
{
- return bus_register (&ccwgroup_bus_type);
+ int ret;
+
+ ret = bus_register(&ccwgroup_bus_type);
+ if (ret)
+ return ret;
+
+ ret = bus_register_notifier(&ccwgroup_bus_type, &ccwgroup_nb);
+ if (ret)
+ bus_unregister(&ccwgroup_bus_type);
+
+ return ret;
}
-static void __exit
-cleanup_ccwgroup (void)
+static void __exit cleanup_ccwgroup(void)
{
- bus_unregister (&ccwgroup_bus_type);
+ bus_unregister_notifier(&ccwgroup_bus_type, &ccwgroup_nb);
+ bus_unregister(&ccwgroup_bus_type);
}
module_init(init_ccwgroup);
{
struct ccwgroup_device *gdev;
struct ccwgroup_driver *gdrv;
- unsigned int value;
+ unsigned long value;
int ret;
- gdev = to_ccwgroupdev(dev);
if (!dev->driver)
- return count;
+ return -ENODEV;
+
+ gdev = to_ccwgroupdev(dev);
+ gdrv = to_ccwgroupdrv(dev->driver);
- gdrv = to_ccwgroupdrv (gdev->dev.driver);
if (!try_module_get(gdrv->owner))
return -EINVAL;
- value = simple_strtoul(buf, NULL, 0);
- ret = count;
+ ret = strict_strtoul(buf, 0, &value);
+ if (ret)
+ goto out;
+
if (value == 1)
- ccwgroup_set_online(gdev);
+ ret = ccwgroup_set_online(gdev);
else if (value == 0)
- ccwgroup_set_offline(gdev);
+ ret = ccwgroup_set_offline(gdev);
else
ret = -EINVAL;
+out:
module_put(gdrv->owner);
- return ret;
+ return (ret == 0) ? count : ret;
}
static ssize_t
if ((ret = device_create_file(dev, &dev_attr_online)))
return ret;
- pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id);
ret = gdrv->probe ? gdrv->probe(gdev) : -ENODEV;
if (ret)
device_remove_file(dev, &dev_attr_online);
struct ccwgroup_device *gdev;
struct ccwgroup_driver *gdrv;
- gdev = to_ccwgroupdev(dev);
- gdrv = to_ccwgroupdrv(dev->driver);
+ device_remove_file(dev, &dev_attr_online);
+ device_remove_file(dev, &dev_attr_ungroup);
- pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id);
+ if (!dev->driver)
+ return 0;
- device_remove_file(dev, &dev_attr_online);
+ gdev = to_ccwgroupdev(dev);
+ gdrv = to_ccwgroupdrv(dev->driver);
- if (gdrv && gdrv->remove)
+ if (gdrv->remove)
gdrv->remove(gdev);
+
return 0;
}
+static void ccwgroup_shutdown(struct device *dev)
+{
+ struct ccwgroup_device *gdev;
+ struct ccwgroup_driver *gdrv;
+
+ if (!dev->driver)
+ return;
+
+ gdev = to_ccwgroupdev(dev);
+ gdrv = to_ccwgroupdrv(dev->driver);
+
+ if (gdrv->shutdown)
+ gdrv->shutdown(gdev);
+}
+
+static int ccwgroup_pm_prepare(struct device *dev)
+{
+ struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
+ struct ccwgroup_driver *gdrv = to_ccwgroupdrv(gdev->dev.driver);
+
+ /* Fail while device is being set online/offline. */
+ if (atomic_read(&gdev->onoff))
+ return -EAGAIN;
+
+ if (!gdev->dev.driver || gdev->state != CCWGROUP_ONLINE)
+ return 0;
+
+ return gdrv->prepare ? gdrv->prepare(gdev) : 0;
+}
+
+static void ccwgroup_pm_complete(struct device *dev)
+{
+ struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
+ struct ccwgroup_driver *gdrv = to_ccwgroupdrv(dev->driver);
+
+ if (!gdev->dev.driver || gdev->state != CCWGROUP_ONLINE)
+ return;
+
+ if (gdrv->complete)
+ gdrv->complete(gdev);
+}
+
+static int ccwgroup_pm_freeze(struct device *dev)
+{
+ struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
+ struct ccwgroup_driver *gdrv = to_ccwgroupdrv(gdev->dev.driver);
+
+ if (!gdev->dev.driver || gdev->state != CCWGROUP_ONLINE)
+ return 0;
+
+ return gdrv->freeze ? gdrv->freeze(gdev) : 0;
+}
+
+static int ccwgroup_pm_thaw(struct device *dev)
+{
+ struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
+ struct ccwgroup_driver *gdrv = to_ccwgroupdrv(gdev->dev.driver);
+
+ if (!gdev->dev.driver || gdev->state != CCWGROUP_ONLINE)
+ return 0;
+
+ return gdrv->thaw ? gdrv->thaw(gdev) : 0;
+}
+
+static int ccwgroup_pm_restore(struct device *dev)
+{
+ struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
+ struct ccwgroup_driver *gdrv = to_ccwgroupdrv(gdev->dev.driver);
+
+ if (!gdev->dev.driver || gdev->state != CCWGROUP_ONLINE)
+ return 0;
+
+ return gdrv->restore ? gdrv->restore(gdev) : 0;
+}
+
+static const struct dev_pm_ops ccwgroup_pm_ops = {
+ .prepare = ccwgroup_pm_prepare,
+ .complete = ccwgroup_pm_complete,
+ .freeze = ccwgroup_pm_freeze,
+ .thaw = ccwgroup_pm_thaw,
+ .restore = ccwgroup_pm_restore,
+};
+
static struct bus_type ccwgroup_bus_type = {
.name = "ccwgroup",
.match = ccwgroup_bus_match,
.uevent = ccwgroup_uevent,
.probe = ccwgroup_probe,
.remove = ccwgroup_remove,
+ .shutdown = ccwgroup_shutdown,
+ .pm = &ccwgroup_pm_ops,
};
-int
-ccwgroup_driver_register (struct ccwgroup_driver *cdriver)
+
+static int ccwgroup_notifier(struct notifier_block *nb, unsigned long action,
+ void *data)
+{
+ struct device *dev = data;
+
+ if (action == BUS_NOTIFY_UNBIND_DRIVER)
+ device_schedule_callback(dev, ccwgroup_ungroup_callback);
+
+ return NOTIFY_OK;
+}
+
+
+/**
+ * ccwgroup_driver_register() - register a ccw group driver
+ * @cdriver: driver to be registered
+ *
+ * This function is mainly a wrapper around driver_register().
+ */
+int ccwgroup_driver_register(struct ccwgroup_driver *cdriver)
{
/* register our new driver with the core */
cdriver->driver.bus = &ccwgroup_bus_type;
cdriver->driver.name = cdriver->name;
+ cdriver->driver.owner = cdriver->owner;
return driver_register(&cdriver->driver);
}
return 1;
}
-void
-ccwgroup_driver_unregister (struct ccwgroup_driver *cdriver)
+/**
+ * ccwgroup_driver_unregister() - deregister a ccw group driver
+ * @cdriver: driver to be deregistered
+ *
+ * This function is mainly a wrapper around driver_unregister().
+ */
+void ccwgroup_driver_unregister(struct ccwgroup_driver *cdriver)
{
struct device *dev;
get_driver(&cdriver->driver);
while ((dev = driver_find_device(&cdriver->driver, NULL, NULL,
__ccwgroup_match_all))) {
- __ccwgroup_remove_symlinks(to_ccwgroupdev(dev));
+ struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
+
+ mutex_lock(&gdev->reg_mutex);
+ __ccwgroup_remove_symlinks(gdev);
device_unregister(dev);
+ mutex_unlock(&gdev->reg_mutex);
put_device(dev);
}
put_driver(&cdriver->driver);
driver_unregister(&cdriver->driver);
}
-int
-ccwgroup_probe_ccwdev(struct ccw_device *cdev)
+/**
+ * ccwgroup_probe_ccwdev() - probe function for slave devices
+ * @cdev: ccw device to be probed
+ *
+ * This is a dummy probe function for ccw devices that are slave devices in
+ * a ccw group device.
+ * Returns:
+ * always %0
+ */
+int ccwgroup_probe_ccwdev(struct ccw_device *cdev)
{
return 0;
}
-static inline struct ccwgroup_device *
+static struct ccwgroup_device *
__ccwgroup_get_gdev_by_cdev(struct ccw_device *cdev)
{
struct ccwgroup_device *gdev;
- if (cdev->dev.driver_data) {
- gdev = (struct ccwgroup_device *)cdev->dev.driver_data;
+ gdev = dev_get_drvdata(&cdev->dev);
+ if (gdev) {
if (get_device(&gdev->dev)) {
+ mutex_lock(&gdev->reg_mutex);
if (device_is_registered(&gdev->dev))
return gdev;
+ mutex_unlock(&gdev->reg_mutex);
put_device(&gdev->dev);
}
return NULL;
return NULL;
}
-void
-ccwgroup_remove_ccwdev(struct ccw_device *cdev)
+/**
+ * ccwgroup_remove_ccwdev() - remove function for slave devices
+ * @cdev: ccw device to be removed
+ *
+ * This is a remove function for ccw devices that are slave devices in a ccw
+ * group device. It sets the ccw device offline and also deregisters the
+ * embedding ccw group device.
+ */
+void ccwgroup_remove_ccwdev(struct ccw_device *cdev)
{
struct ccwgroup_device *gdev;
if (gdev) {
__ccwgroup_remove_symlinks(gdev);
device_unregister(&gdev->dev);
+ mutex_unlock(&gdev->reg_mutex);
put_device(&gdev->dev);
}
}
MODULE_LICENSE("GPL");
EXPORT_SYMBOL(ccwgroup_driver_register);
EXPORT_SYMBOL(ccwgroup_driver_unregister);
-EXPORT_SYMBOL(ccwgroup_create);
EXPORT_SYMBOL(ccwgroup_probe_ccwdev);
EXPORT_SYMBOL(ccwgroup_remove_ccwdev);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff