[S390] cio: CHSC SIOSL Support

A Linux interface for the CHSC command
store-I/O-operation-status-and-initiate-logging (SIOSL).
Model-dependent logging within the channel subsystem can be invoked
via a helper function or a writable subchannel device attribute.

Signed-off-by: Michael Ernst <mernst@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 6d229f3523a0..75acec3b2d6b 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -36,6 +36,7 @@
 #include "ioasm.h"
 #include "io_sch.h"
 #include "blacklist.h"
+#include "chsc.h"
 
 static struct timer_list recovery_timer;
 static DEFINE_SPINLOCK(recovery_lock);
@@ -598,6 +599,25 @@ available_show (struct device *dev, struct device_attribute *attr, char *buf)
         }
 }
 
+static ssize_t
+initiate_logging(struct device *dev, struct device_attribute *attr,
+                 const char *buf, size_t count)
+{
+        struct subchannel *sch = to_subchannel(dev);
+        int rc;
+
+        rc = chsc_siosl(sch->schid);
+        if (rc < 0) {
+                pr_warning("Logging for subchannel 0.%x.%04x failed with "
+                           "errno=%d\n",
+                           sch->schid.ssid, sch->schid.sch_no, rc);
+                return rc;
+        }
+        pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
+                  sch->schid.ssid, sch->schid.sch_no);
+        return count;
+}
+
 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
@@ -605,10 +625,12 @@ static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 static DEVICE_ATTR(online, 0644, online_show, online_store);
 static DEVICE_ATTR(availability, 0444, available_show, NULL);
+static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
 
 static struct attribute *io_subchannel_attrs[] = {
         &dev_attr_chpids.attr,
         &dev_attr_pimpampom.attr,
+        &dev_attr_logging.attr,
         NULL,
 };
 
@@ -2036,6 +2058,21 @@ void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
         }
 }
 
+/**
+ * ccw_device_siosl() - initiate logging
+ * @cdev: ccw device
+ *
+ * This function is used to invoke model-dependent logging within the channel
+ * subsystem.
+ */
+int ccw_device_siosl(struct ccw_device *cdev)
+{
+        struct subchannel *sch = to_subchannel(cdev->dev.parent);
+
+        return chsc_siosl(sch->schid);
+}
+EXPORT_SYMBOL_GPL(ccw_device_siosl);
+
 MODULE_LICENSE("GPL");
 EXPORT_SYMBOL(ccw_device_set_online);
 EXPORT_SYMBOL(ccw_device_set_offline);