[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>

arch/s390/include/asm/ccwdev.h

@@ -208,6 +208,8 @@ extern void ccw_device_get_id(struct ccw_device *, struct ccw_dev_id *);
 extern struct ccw_device *ccw_device_probe_console(void);
 extern int ccw_device_force_console(void);
 
+int ccw_device_siosl(struct ccw_device *);
+
 // FIXME: these have to go
 extern int _ccw_device_get_subchannel_number(struct ccw_device *);
 

drivers/s390/cio/chsc.c

@@ -29,6 +29,7 @@
 #include "chsc.h"
 
 static void *sei_page;
+static DEFINE_SPINLOCK(siosl_lock);
 static DEFINE_SPINLOCK(sda_lock);
 
 /**
@@ -48,6 +49,7 @@ int chsc_error_from_response(int response)
 	case 0x0007:
 	case 0x0008:
 	case 0x000a:
+	case 0x0104:
 		return -EINVAL;
 	case 0x0004:
 		return -EOPNOTSUPP;
@@ -974,3 +976,49 @@ int chsc_sstpi(void *page, void *result, size_t size)
 	return (rr->response.code == 0x0001) ? 0 : -EIO;
 }
 
+static struct {
+	struct chsc_header request;
+	u32 word1;
+	struct subchannel_id sid;
+	u32 word3;
+	struct chsc_header response;
+	u32 word[11];
+} __attribute__ ((packed)) siosl_area __attribute__ ((__aligned__(PAGE_SIZE)));
+
+int chsc_siosl(struct subchannel_id schid)
+{
+	unsigned long flags;
+	int ccode;
+	int rc;
+
+	spin_lock_irqsave(&siosl_lock, flags);
+	memset(&siosl_area, 0, sizeof(siosl_area));
+	siosl_area.request.length = 0x0010;
+	siosl_area.request.code = 0x0046;
+	siosl_area.word1 = 0x80000000;
+	siosl_area.sid = schid;
+
+	ccode = chsc(&siosl_area);
+	if (ccode > 0) {
+		if (ccode == 3)
+			rc = -ENODEV;
+		else
+			rc = -EBUSY;
+		CIO_MSG_EVENT(2, "chsc: chsc failed for 0.%x.%04x (ccode=%d)\n",
+			      schid.ssid, schid.sch_no, ccode);
+		goto out;
+	}
+	rc = chsc_error_from_response(siosl_area.response.code);
+	if (rc)
+		CIO_MSG_EVENT(2, "chsc: siosl failed for 0.%x.%04x (rc=%04x)\n",
+			      schid.ssid, schid.sch_no,
+			      siosl_area.response.code);
+	else
+		CIO_MSG_EVENT(4, "chsc: siosl succeeded for 0.%x.%04x\n",
+			      schid.ssid, schid.sch_no);
+out:
+	spin_unlock_irqrestore(&siosl_lock, flags);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(chsc_siosl);

drivers/s390/cio/chsc.h

@@ -80,4 +80,6 @@ int chsc_get_channel_measurement_chars(struct channel_path *chp);
 
 int chsc_error_from_response(int response);
 
+int chsc_siosl(struct subchannel_id schid);
+
 #endif

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);