[S390] cio: Avoid machine check vs. not operational races.

[linux-block.git] / drivers / s390 / cio / device.c

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index e44d92eac8e9e8f80fb0f4c57f05b096bb3c494d..39f02b48e4c7dbf46ac7cf8defe35d9cbb257f38 100644 (file)
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -21,6 +21,7 @@
 #include <asm/ccwdev.h>
 #include <asm/cio.h>
 #include <asm/param.h>         /* HZ */
+#include <asm/cmb.h>
 
 #include "cio.h"
 #include "cio_debug.h"
@@ -357,8 +358,18 @@ ccw_device_remove_disconnected(struct ccw_device *cdev)
                              cdev->private->dev_id.devno);
 }
 
-int
-ccw_device_set_offline(struct ccw_device *cdev)
+/**
+ * ccw_device_set_offline() - disable a ccw device for I/O
+ * @cdev: target ccw device
+ *
+ * This function calls the driver's set_offline() function for @cdev, if
+ * given, and then disables @cdev.
+ * Returns:
+ *   %0 on success and a negative error value on failure.
+ * Context:
+ *  enabled, ccw device lock not held
+ */
+int ccw_device_set_offline(struct ccw_device *cdev)
 {
        int ret;
 
@@ -396,8 +407,19 @@ ccw_device_set_offline(struct ccw_device *cdev)
        return ret;
 }
 
-int
-ccw_device_set_online(struct ccw_device *cdev)
+/**
+ * ccw_device_set_online() - enable a ccw device for I/O
+ * @cdev: target ccw device
+ *
+ * This function first enables @cdev and then calls the driver's set_online()
+ * function for @cdev, if given. If set_online() returns an error, @cdev is
+ * disabled again.
+ * Returns:
+ *   %0 on success and a negative error value on failure.
+ * Context:
+ *  enabled, ccw device lock not held
+ */
+int ccw_device_set_online(struct ccw_device *cdev)
 {
        int ret;
 
@@ -947,8 +969,7 @@ out:
                wake_up(&ccw_device_init_wq);
 }
 
-void
-ccw_device_call_sch_unregister(struct work_struct *work)
+static void ccw_device_call_sch_unregister(struct work_struct *work)
 {
        struct ccw_device_private *priv;
        struct ccw_device *cdev;
@@ -1101,6 +1122,7 @@ io_subchannel_probe (struct subchannel *sch)
                 * device, e.g. the console.
                 */
                cdev = sch->dev.driver_data;
+               cdev->dev.groups = ccwdev_attr_groups;
                device_initialize(&cdev->dev);
                ccw_device_register(cdev);
                /*
@@ -1326,8 +1348,19 @@ __ccwdev_check_busid(struct device *dev, void *id)
 }
 
 
-struct ccw_device *
-get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
+/**
+ * get_ccwdev_by_busid() - obtain device from a bus id
+ * @cdrv: driver the device is owned by
+ * @bus_id: bus id of the device to be searched
+ *
+ * This function searches all devices owned by @cdrv for a device with a bus
+ * id matching @bus_id.
+ * Returns:
+ *  If a match is found, its reference count of the found device is increased
+ *  and it is returned; else %NULL is returned.
+ */
+struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
+                                      const char *bus_id)
 {
        struct device *dev;
        struct device_driver *drv;
@@ -1401,16 +1434,34 @@ ccw_device_remove (struct device *dev)
        return 0;
 }
 
+static void ccw_device_shutdown(struct device *dev)
+{
+       struct ccw_device *cdev;
+
+       cdev = to_ccwdev(dev);
+       if (cdev->drv && cdev->drv->shutdown)
+               cdev->drv->shutdown(cdev);
+       disable_cmf(cdev);
+}
+
 struct bus_type ccw_bus_type = {
        .name   = "ccw",
        .match  = ccw_bus_match,
        .uevent = ccw_uevent,
        .probe  = ccw_device_probe,
        .remove = ccw_device_remove,
+       .shutdown = ccw_device_shutdown,
 };
 
-int
-ccw_driver_register (struct ccw_driver *cdriver)
+/**
+ * ccw_driver_register() - register a ccw driver
+ * @cdriver: driver to be registered
+ *
+ * This function is mainly a wrapper around driver_register().
+ * Returns:
+ *   %0 on success and a negative error value on failure.
+ */
+int ccw_driver_register(struct ccw_driver *cdriver)
 {
        struct device_driver *drv = &cdriver->driver;
 
@@ -1420,8 +1471,13 @@ ccw_driver_register (struct ccw_driver *cdriver)
        return driver_register(drv);
 }
 
-void
-ccw_driver_unregister (struct ccw_driver *cdriver)
+/**
+ * ccw_driver_unregister() - deregister a ccw driver
+ * @cdriver: driver to be deregistered
+ *
+ * This function is mainly a wrapper around driver_unregister().
+ */
+void ccw_driver_unregister(struct ccw_driver *cdriver)
 {
        driver_unregister(&cdriver->driver);
 }