s390: add scm notification

Detect an scm change notification in store event information.
Update affected scm devices and notify their drivers.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 49 insertions, 1 deletions

diff --git a/drivers/s390/cio/scm.c b/drivers/s390/cio/scm.c
index 874b64a4bf26..aa4476e92050 100644
--- a/drivers/s390/cio/scm.c
+++ b/drivers/s390/cio/scm.c
@@ -196,6 +196,47 @@ static void scmdev_setup(struct scm_device *scmdev, struct sale *sale,
         spin_lock_init(&scmdev->lock);
 }
 
+/*
+ * Check for state-changes, notify the driver and userspace.
+ */
+static void scmdev_update(struct scm_device *scmdev, struct sale *sale)
+{
+        struct scm_driver *scmdrv;
+        bool changed;
+
+        device_lock(&scmdev->dev);
+        changed = scmdev->attrs.rank != sale->rank ||
+                  scmdev->attrs.oper_state != sale->op_state;
+        scmdev->attrs.rank = sale->rank;
+        scmdev->attrs.oper_state = sale->op_state;
+        if (!scmdev->dev.driver)
+                goto out;
+        scmdrv = to_scm_drv(scmdev->dev.driver);
+        if (changed && scmdrv->notify)
+                scmdrv->notify(scmdev);
+out:
+        device_unlock(&scmdev->dev);
+        if (changed)
+                kobject_uevent(&scmdev->dev.kobj, KOBJ_CHANGE);
+}
+
+static int check_address(struct device *dev, void *data)
+{
+        struct scm_device *scmdev = to_scm_dev(dev);
+        struct sale *sale = data;
+
+        return scmdev->address == sale->sa;
+}
+
+static struct scm_device *scmdev_find(struct sale *sale)
+{
+        struct device *dev;
+
+        dev = bus_find_device(&scm_bus_type, NULL, sale, check_address);
+
+        return dev ? to_scm_dev(dev) : NULL;
+}
+
 static int scm_add(struct chsc_scm_info *scm_info, size_t num)
 {
         struct sale *sale, *scmal = scm_info->scmal;
@@ -203,6 +244,13 @@ static int scm_add(struct chsc_scm_info *scm_info, size_t num)
         int ret;
 
         for (sale = scmal; sale < scmal + num; sale++) {
+                scmdev = scmdev_find(sale);
+                if (scmdev) {
+                        scmdev_update(scmdev, sale);
+                        /* Release reference from scm_find(). */
+                        put_device(&scmdev->dev);
+                        continue;
+                }
                 scmdev = kzalloc(sizeof(*scmdev), GFP_KERNEL);
                 if (!scmdev)
                         return -ENODEV;
@@ -218,7 +266,7 @@ static int scm_add(struct chsc_scm_info *scm_info, size_t num)
         return 0;
 }
 
-static int scm_update_information(void)
+int scm_update_information(void)
 {
         struct chsc_scm_info *scm_info;
         u64 token = 0;