From: Stefan Raspl <raspl@linux.ibm.com>
Subject: s390/cio: add util_string sysfs attribute
Patch-mainline: v4.17-rc1
Git-commit: b9dd652499d645707dda2b835a905455e3718157
References: FATE#325698, LTC#167867, bsc#1113481

Summary:     net/smc: Add support for SMC-D
Description: Add support for SMC-D to the existing AF_SMC address family.
             Also includes the ISM device driver as required by SMC-D.

Upstream-Description:

             s390/cio: add util_string sysfs attribute

             Export utility strings as a chpid's binary sysfs attribute.

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

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/s390/cio/chp.c |   23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

--- a/drivers/s390/cio/chp.c
+++ b/drivers/s390/cio/chp.c
@@ -383,6 +383,28 @@ static ssize_t chp_chid_external_show(st
 }
 static DEVICE_ATTR(chid_external, 0444, chp_chid_external_show, NULL);
 
+static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
+				struct bin_attribute *attr, char *buf,
+				loff_t off, size_t count)
+{
+	struct channel_path *chp = to_channelpath(kobj_to_dev(kobj));
+	ssize_t rc;
+
+	mutex_lock(&chp->lock);
+	rc = memory_read_from_buffer(buf, count, &off, chp->desc_fmt3.util_str,
+				     sizeof(chp->desc_fmt3.util_str));
+	mutex_unlock(&chp->lock);
+
+	return rc;
+}
+static BIN_ATTR_RO(util_string,
+		   sizeof(((struct channel_path_desc_fmt3 *)0)->util_str));
+
+static struct bin_attribute *chp_bin_attrs[] = {
+	&bin_attr_util_string,
+	NULL,
+};
+
 static struct attribute *chp_attrs[] = {
 	&dev_attr_status.attr,
 	&dev_attr_configure.attr,
@@ -395,6 +417,7 @@ static struct attribute *chp_attrs[] = {
 };
 static struct attribute_group chp_attr_group = {
 	.attrs = chp_attrs,
+	.bin_attrs = chp_bin_attrs,
 };
 static const struct attribute_group *chp_attr_groups[] = {
 	&chp_attr_group,