[S390] dasd: tunable missing interrupt handler

This feature provides a user interface to specify the timeout for
missing interrupts for standard I/O operations.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/block/dasd_devmap.c

@@ -1083,6 +1083,49 @@ dasd_eer_store(struct device *dev, struct device_attribute *attr,
 
 static DEVICE_ATTR(eer_enabled, 0644, dasd_eer_show, dasd_eer_store);
 
+/*
+ * expiration time for default requests
+ */
+static ssize_t
+dasd_expires_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dasd_device *device;
+	int len;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+	len = snprintf(buf, PAGE_SIZE, "%lu\n", device->default_expires);
+	dasd_put_device(device);
+	return len;
+}
+
+static ssize_t
+dasd_expires_store(struct device *dev, struct device_attribute *attr,
+	       const char *buf, size_t count)
+{
+	struct dasd_device *device;
+	unsigned long val;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+
+	if ((strict_strtoul(buf, 10, &val) != 0) ||
+	    (val > DASD_EXPIRES_MAX) || val == 0) {
+		dasd_put_device(device);
+		return -EINVAL;
+	}
+
+	if (val)
+		device->default_expires = val;
+
+	dasd_put_device(device);
+	return count;
+}
+
+static DEVICE_ATTR(expires, 0644, dasd_expires_show, dasd_expires_store);
+
 static struct attribute * dasd_attrs[] = {
 	&dev_attr_readonly.attr,
 	&dev_attr_discipline.attr,
@@ -1094,6 +1137,7 @@ static struct attribute * dasd_attrs[] = {
 	&dev_attr_eer_enabled.attr,
 	&dev_attr_erplog.attr,
 	&dev_attr_failfast.attr,
+	&dev_attr_expires.attr,
 	NULL,
 };
 

drivers/s390/block/dasd_diag.c

@@ -43,7 +43,7 @@ MODULE_LICENSE("GPL");
 			   sizeof(struct dasd_diag_req)) / \
 		           sizeof(struct dasd_diag_bio)) / 2)
 #define DIAG_MAX_RETRIES	32
-#define DIAG_TIMEOUT		50 * HZ
+#define DIAG_TIMEOUT		50
 
 static struct dasd_discipline dasd_diag_discipline;
 
@@ -360,6 +360,8 @@ dasd_diag_check_device(struct dasd_device *device)
 		goto out;
 	}
 
+	device->default_expires = DIAG_TIMEOUT;
+
 	/* Figure out position of label block */
 	switch (private->rdc_data.vdev_class) {
 	case DEV_CLASS_FBA:
@@ -563,7 +565,7 @@ static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev,
 	cqr->startdev = memdev;
 	cqr->memdev = memdev;
 	cqr->block = block;
-	cqr->expires = DIAG_TIMEOUT;
+	cqr->expires = memdev->default_expires * HZ;
 	cqr->status = DASD_CQR_FILLED;
 	return cqr;
 }

drivers/s390/block/dasd_eckd.c

@@ -1115,8 +1115,9 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
 	struct dasd_eckd_private *private;
 	struct dasd_block *block;
 	struct dasd_uid temp_uid;
-	int is_known, rc;
+	int is_known, rc, i;
 	int readonly;
+	unsigned long value;
 
 	if (!ccw_device_is_pathgroup(device->cdev)) {
 		dev_warn(&device->cdev->dev,
@@ -1151,6 +1152,18 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
 	if (rc)
 		goto out_err1;
 
+	/* set default timeout */
+	device->default_expires = DASD_EXPIRES;
+	if (private->gneq) {
+		value = 1;
+		for (i = 0; i < private->gneq->timeout.value; i++)
+			value = 10 * value;
+		value = value * private->gneq->timeout.number;
+		/* do not accept useless values */
+		if (value != 0 && value <= DASD_EXPIRES_MAX)
+			device->default_expires = value;
+	}
+
 	/* Generate device unique id */
 	rc = dasd_eckd_generate_uid(device);
 	if (rc)
@@ -1981,7 +1994,7 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_single(
 	cqr->startdev = startdev;
 	cqr->memdev = startdev;
 	cqr->block = block;
-	cqr->expires = 5 * 60 * HZ;	/* 5 minutes */
+	cqr->expires = startdev->default_expires * HZ;	/* default 5 minutes */
 	cqr->lpm = private->path_data.ppm;
 	cqr->retries = 256;
 	cqr->buildclk = get_clock();
@@ -2158,7 +2171,7 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_track(
 	cqr->startdev = startdev;
 	cqr->memdev = startdev;
 	cqr->block = block;
-	cqr->expires = 5 * 60 * HZ;	/* 5 minutes */
+	cqr->expires = startdev->default_expires * HZ;	/* default 5 minutes */
 	cqr->lpm = private->path_data.ppm;
 	cqr->retries = 256;
 	cqr->buildclk = get_clock();
@@ -2406,7 +2419,7 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_tpm_track(
 	cqr->startdev = startdev;
 	cqr->memdev = startdev;
 	cqr->block = block;
-	cqr->expires = 5 * 60 * HZ;	/* 5 minutes */
+	cqr->expires = startdev->default_expires * HZ;	/* default 5 minutes */
 	cqr->lpm = private->path_data.ppm;
 	cqr->retries = 256;
 	cqr->buildclk = get_clock();

drivers/s390/block/dasd_eckd.h

@@ -320,7 +320,12 @@ struct dasd_gneq {
 		__u8 identifier:2;
 		__u8 reserved:6;
 	} __attribute__ ((packed)) flags;
-	__u8 reserved[7];
+	__u8 reserved[5];
+	struct {
+		__u8 value:2;
+		__u8 number:6;
+	} __attribute__ ((packed)) timeout;
+	__u8 reserved3;
 	__u16 subsystemID;
 	__u8 reserved2[22];
 } __attribute__ ((packed));

drivers/s390/block/dasd_fba.c

@@ -163,6 +163,8 @@ dasd_fba_check_characteristics(struct dasd_device *device)
 		return rc;
 	}
 
+	device->default_expires = DASD_EXPIRES;
+
 	readonly = dasd_device_is_ro(device);
 	if (readonly)
 		set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
@@ -370,7 +372,7 @@ static struct dasd_ccw_req *dasd_fba_build_cp(struct dasd_device * memdev,
 	cqr->startdev = memdev;
 	cqr->memdev = memdev;
 	cqr->block = block;
-	cqr->expires = 5 * 60 * HZ;	/* 5 minutes */
+	cqr->expires = memdev->default_expires * HZ;	/* default 5 minutes */
 	cqr->retries = 32;
 	cqr->buildclk = get_clock();
 	cqr->status = DASD_CQR_FILLED;

drivers/s390/block/dasd_int.h

@@ -186,7 +186,7 @@ struct dasd_ccw_req {
 
 	/* ... and how */
 	unsigned long starttime;	/* jiffies time of request start */
-	int expires;			/* expiration period in jiffies */
+	unsigned long expires;		/* expiration period in jiffies */
 	char lpm;			/* logical path mask */
 	void *data;			/* pointer to data area */
 
@@ -224,6 +224,9 @@ struct dasd_ccw_req {
 #define DASD_CQR_CLEARED	0x84	/* request was cleared */
 #define DASD_CQR_SUCCESS	0x85	/* request was successful */
 
+/* default expiration time*/
+#define DASD_EXPIRES	  300
+#define DASD_EXPIRES_MAX  40000000
 
 /* per dasd_ccw_req flags */
 #define DASD_CQR_FLAGS_USE_ERP   0	/* use ERP for this request */
@@ -404,6 +407,9 @@ struct dasd_device {
 
 	/* hook for alias management */
 	struct list_head alias_list;
+
+	/* default expiration time in s */
+	unsigned long default_expires;
 };
 
 struct dasd_block {