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path: root/drivers/s390/cio/ccwgroup.c
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Diffstat (limited to 'drivers/s390/cio/ccwgroup.c')
-rw-r--r--drivers/s390/cio/ccwgroup.c482
1 files changed, 482 insertions, 0 deletions
diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
new file mode 100644
index 00000000000..21a75ee28b8
--- /dev/null
+++ b/drivers/s390/cio/ccwgroup.c
@@ -0,0 +1,482 @@
+/*
+ * drivers/s390/cio/ccwgroup.c
+ * bus driver for ccwgroup
+ * $Revision: 1.29 $
+ *
+ * Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
+ * IBM Corporation
+ * Author(s): Arnd Bergmann (arndb@de.ibm.com)
+ * Cornelia Huck (cohuck@de.ibm.com)
+ */
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/ctype.h>
+#include <linux/dcache.h>
+
+#include <asm/semaphore.h>
+#include <asm/ccwdev.h>
+#include <asm/ccwgroup.h>
+
+/* 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
+ * one of its functions, namely the translation of single subchannels
+ * to devices that use multiple subchannels.
+ */
+
+/* a device matches a driver if all its slave devices match the same
+ * entry of the driver */
+static int
+ccwgroup_bus_match (struct device * dev, struct device_driver * drv)
+{
+ struct ccwgroup_device *gdev;
+ struct ccwgroup_driver *gdrv;
+
+ gdev = container_of(dev, struct ccwgroup_device, dev);
+ gdrv = container_of(drv, struct ccwgroup_driver, driver);
+
+ if (gdev->creator_id == gdrv->driver_id)
+ return 1;
+
+ return 0;
+}
+static int
+ccwgroup_hotplug (struct device *dev, char **envp, int num_envp, char *buffer,
+ int buffer_size)
+{
+ /* TODO */
+ return 0;
+}
+
+static struct bus_type ccwgroup_bus_type = {
+ .name = "ccwgroup",
+ .match = ccwgroup_bus_match,
+ .hotplug = ccwgroup_hotplug,
+};
+
+static inline void
+__ccwgroup_remove_symlinks(struct ccwgroup_device *gdev)
+{
+ int i;
+ char str[8];
+
+ for (i = 0; i < gdev->count; i++) {
+ sprintf(str, "cdev%d", i);
+ sysfs_remove_link(&gdev->dev.kobj, str);
+ sysfs_remove_link(&gdev->cdev[i]->dev.kobj, "group_device");
+ }
+
+}
+
+/*
+ * Provide an 'ungroup' attribute so the user can remove group devices no
+ * longer needed or accidentially created. Saves memory :)
+ */
+static ssize_t
+ccwgroup_ungroup_store(struct device *dev, const char *buf, size_t count)
+{
+ struct ccwgroup_device *gdev;
+
+ gdev = to_ccwgroupdev(dev);
+
+ if (gdev->state != CCWGROUP_OFFLINE)
+ return -EINVAL;
+
+ __ccwgroup_remove_symlinks(gdev);
+ device_unregister(dev);
+
+ return count;
+}
+
+static DEVICE_ATTR(ungroup, 0200, NULL, ccwgroup_ungroup_store);
+
+static void
+ccwgroup_release (struct device *dev)
+{
+ struct ccwgroup_device *gdev;
+ int i;
+
+ gdev = to_ccwgroupdev(dev);
+
+ for (i = 0; i < gdev->count; i++) {
+ gdev->cdev[i]->dev.driver_data = NULL;
+ put_device(&gdev->cdev[i]->dev);
+ }
+ kfree(gdev);
+}
+
+static inline int
+__ccwgroup_create_symlinks(struct ccwgroup_device *gdev)
+{
+ char str[8];
+ int i, rc;
+
+ for (i = 0; i < gdev->count; i++) {
+ rc = sysfs_create_link(&gdev->cdev[i]->dev.kobj, &gdev->dev.kobj,
+ "group_device");
+ if (rc) {
+ for (--i; i >= 0; i--)
+ sysfs_remove_link(&gdev->cdev[i]->dev.kobj,
+ "group_device");
+ return rc;
+ }
+ }
+ for (i = 0; i < gdev->count; i++) {
+ sprintf(str, "cdev%d", i);
+ rc = sysfs_create_link(&gdev->dev.kobj, &gdev->cdev[i]->dev.kobj,
+ str);
+ if (rc) {
+ for (--i; i >= 0; i--) {
+ sprintf(str, "cdev%d", i);
+ sysfs_remove_link(&gdev->dev.kobj, str);
+ }
+ for (i = 0; i < gdev->count; i++)
+ sysfs_remove_link(&gdev->cdev[i]->dev.kobj,
+ "group_device");
+ return rc;
+ }
+ }
+ 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.
+ */
+int
+ccwgroup_create(struct device *root,
+ unsigned int creator_id,
+ struct ccw_driver *cdrv,
+ int argc, char *argv[])
+{
+ struct ccwgroup_device *gdev;
+ int i;
+ int rc;
+ int del_drvdata;
+
+ if (argc > 256) /* disallow dumb users */
+ return -EINVAL;
+
+ gdev = kmalloc(sizeof(*gdev) + argc*sizeof(gdev->cdev[0]), GFP_KERNEL);
+ if (!gdev)
+ return -ENOMEM;
+
+ memset(gdev, 0, sizeof(*gdev) + argc*sizeof(gdev->cdev[0]));
+ atomic_set(&gdev->onoff, 0);
+
+ del_drvdata = 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 */
+ if (!gdev->cdev[i]
+ || gdev->cdev[i]->id.driver_info !=
+ gdev->cdev[0]->id.driver_info) {
+ rc = -EINVAL;
+ goto free_dev;
+ }
+ /* Don't allow a device to belong to more than one group. */
+ if (gdev->cdev[i]->dev.driver_data) {
+ rc = -EINVAL;
+ goto free_dev;
+ }
+ }
+ for (i = 0; i < argc; i++)
+ gdev->cdev[i]->dev.driver_data = gdev;
+ del_drvdata = 1;
+
+ gdev->creator_id = creator_id;
+ gdev->count = argc;
+ gdev->dev = (struct device ) {
+ .bus = &ccwgroup_bus_type,
+ .parent = root,
+ .release = ccwgroup_release,
+ };
+
+ snprintf (gdev->dev.bus_id, BUS_ID_SIZE, "%s",
+ gdev->cdev[0]->dev.bus_id);
+
+ rc = device_register(&gdev->dev);
+
+ if (rc)
+ goto free_dev;
+ get_device(&gdev->dev);
+ rc = device_create_file(&gdev->dev, &dev_attr_ungroup);
+
+ if (rc) {
+ device_unregister(&gdev->dev);
+ goto error;
+ }
+
+ rc = __ccwgroup_create_symlinks(gdev);
+ if (!rc) {
+ 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++)
+ if (gdev->cdev[i]) {
+ put_device(&gdev->cdev[i]->dev);
+ gdev->cdev[i]->dev.driver_data = NULL;
+ }
+ put_device(&gdev->dev);
+ return rc;
+free_dev:
+ for (i = 0; i < argc; i++)
+ if (gdev->cdev[i]) {
+ put_device(&gdev->cdev[i]->dev);
+ if (del_drvdata)
+ gdev->cdev[i]->dev.driver_data = NULL;
+ }
+ kfree(gdev);
+ return rc;
+}
+
+static int __init
+init_ccwgroup (void)
+{
+ return bus_register (&ccwgroup_bus_type);
+}
+
+static void __exit
+cleanup_ccwgroup (void)
+{
+ bus_unregister (&ccwgroup_bus_type);
+}
+
+module_init(init_ccwgroup);
+module_exit(cleanup_ccwgroup);
+
+/************************** driver stuff ******************************/
+
+static int
+ccwgroup_set_online(struct ccwgroup_device *gdev)
+{
+ struct ccwgroup_driver *gdrv;
+ int ret;
+
+ if (atomic_compare_and_swap(0, 1, &gdev->onoff))
+ return -EAGAIN;
+ if (gdev->state == CCWGROUP_ONLINE) {
+ ret = 0;
+ goto out;
+ }
+ if (!gdev->dev.driver) {
+ ret = -EINVAL;
+ goto out;
+ }
+ gdrv = to_ccwgroupdrv (gdev->dev.driver);
+ if ((ret = gdrv->set_online(gdev)))
+ goto out;
+
+ gdev->state = CCWGROUP_ONLINE;
+ out:
+ atomic_set(&gdev->onoff, 0);
+ return ret;
+}
+
+static int
+ccwgroup_set_offline(struct ccwgroup_device *gdev)
+{
+ struct ccwgroup_driver *gdrv;
+ int ret;
+
+ if (atomic_compare_and_swap(0, 1, &gdev->onoff))
+ return -EAGAIN;
+ if (gdev->state == CCWGROUP_OFFLINE) {
+ ret = 0;
+ goto out;
+ }
+ if (!gdev->dev.driver) {
+ ret = -EINVAL;
+ goto out;
+ }
+ gdrv = to_ccwgroupdrv (gdev->dev.driver);
+ if ((ret = gdrv->set_offline(gdev)))
+ goto out;
+
+ gdev->state = CCWGROUP_OFFLINE;
+ out:
+ atomic_set(&gdev->onoff, 0);
+ return ret;
+}
+
+static ssize_t
+ccwgroup_online_store (struct device *dev, const char *buf, size_t count)
+{
+ struct ccwgroup_device *gdev;
+ struct ccwgroup_driver *gdrv;
+ unsigned int value;
+ int ret;
+
+ gdev = to_ccwgroupdev(dev);
+ if (!dev->driver)
+ return count;
+
+ gdrv = to_ccwgroupdrv (gdev->dev.driver);
+ if (!try_module_get(gdrv->owner))
+ return -EINVAL;
+
+ value = simple_strtoul(buf, 0, 0);
+ ret = count;
+ if (value == 1)
+ ccwgroup_set_online(gdev);
+ else if (value == 0)
+ ccwgroup_set_offline(gdev);
+ else
+ ret = -EINVAL;
+ module_put(gdrv->owner);
+ return ret;
+}
+
+static ssize_t
+ccwgroup_online_show (struct device *dev, char *buf)
+{
+ int online;
+
+ online = (to_ccwgroupdev(dev)->state == CCWGROUP_ONLINE);
+
+ return sprintf(buf, online ? "1\n" : "0\n");
+}
+
+static DEVICE_ATTR(online, 0644, ccwgroup_online_show, ccwgroup_online_store);
+
+static int
+ccwgroup_probe (struct device *dev)
+{
+ struct ccwgroup_device *gdev;
+ struct ccwgroup_driver *gdrv;
+
+ int ret;
+
+ gdev = to_ccwgroupdev(dev);
+ gdrv = to_ccwgroupdrv(dev->driver);
+
+ 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);
+
+ return ret;
+}
+
+static int
+ccwgroup_remove (struct device *dev)
+{
+ struct ccwgroup_device *gdev;
+ struct ccwgroup_driver *gdrv;
+
+ gdev = to_ccwgroupdev(dev);
+ gdrv = to_ccwgroupdrv(dev->driver);
+
+ pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id);
+
+ device_remove_file(dev, &dev_attr_online);
+
+ if (gdrv && gdrv->remove)
+ gdrv->remove(gdev);
+ return 0;
+}
+
+int
+ccwgroup_driver_register (struct ccwgroup_driver *cdriver)
+{
+ /* register our new driver with the core */
+ cdriver->driver = (struct device_driver) {
+ .bus = &ccwgroup_bus_type,
+ .name = cdriver->name,
+ .probe = ccwgroup_probe,
+ .remove = ccwgroup_remove,
+ };
+
+ return driver_register(&cdriver->driver);
+}
+
+static inline struct device *
+__get_next_ccwgroup_device(struct device_driver *drv)
+{
+ struct device *dev, *d;
+
+ down_read(&drv->bus->subsys.rwsem);
+ dev = NULL;
+ list_for_each_entry(d, &drv->devices, driver_list) {
+ dev = get_device(d);
+ if (dev)
+ break;
+ }
+ up_read(&drv->bus->subsys.rwsem);
+ return dev;
+}
+
+void
+ccwgroup_driver_unregister (struct ccwgroup_driver *cdriver)
+{
+ struct device *dev;
+
+ /* We don't want ccwgroup devices to live longer than their driver. */
+ get_driver(&cdriver->driver);
+ while ((dev = __get_next_ccwgroup_device(&cdriver->driver))) {
+ __ccwgroup_remove_symlinks(to_ccwgroupdev(dev));
+ device_unregister(dev);
+ put_device(dev);
+ };
+ put_driver(&cdriver->driver);
+ driver_unregister(&cdriver->driver);
+}
+
+int
+ccwgroup_probe_ccwdev(struct ccw_device *cdev)
+{
+ return 0;
+}
+
+static inline 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;
+ if (get_device(&gdev->dev)) {
+ if (!list_empty(&gdev->dev.node))
+ return gdev;
+ put_device(&gdev->dev);
+ }
+ return NULL;
+ }
+ return NULL;
+}
+
+void
+ccwgroup_remove_ccwdev(struct ccw_device *cdev)
+{
+ struct ccwgroup_device *gdev;
+
+ /* Ignore offlining errors, device is gone anyway. */
+ ccw_device_set_offline(cdev);
+ /* If one of its devices is gone, the whole group is done for. */
+ gdev = __ccwgroup_get_gdev_by_cdev(cdev);
+ if (gdev) {
+ __ccwgroup_remove_symlinks(gdev);
+ device_unregister(&gdev->dev);
+ 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);