IB/core: Fix unable to change lifespan entry for hw_counters

This patch fixes the case where 'lifespan' entry of the hw_counters
is not writable. Currently write callback is not exposed for for
the hw_counters sysfs operation. Due to this, modifying lifespan
value results into permission denied error in below example.

echo 10 > /sys/class/infiniband/mlx5_0/ports/1/hw_counters/lifespan
-bash: /sys/class/infiniband/mlx5_0/ports/1/hw_counters/lifespan:
Permission denied

This patch adds the hook to modify any attribute which implements
store() operation.

Merge-monkey: Aron Silverton <[email protected]>
Merge-monkey-notes:
  The commit title and commit message body were updated to match the
  upstream commit which more accurately describes the code change.
  A reference to the upstream commit this fixes was also added.

Orabug: 26761264
MlnxSF: 00384047
Upstream_status: done
issue: 1124008
Change-Id: Ieeb30eb65a80e9afab4a0a53bac6edc4a6e6ee73
Fixes: b40f475 ("IB/core: Make device counter infrastructure dynamic")
Signed-off-by: Parav Pandit <[email protected]>
Signed-off-by: Aron Silverton <[email protected]>
Reviewed-by: Håkon Bugge <[email protected]>

Signed-off-by: Somasundaram Krishnasamy <[email protected]>

Author: paravmellanox

drivers/infiniband/core/sysfs.c

@@ -108,8 +108,22 @@ static ssize_t port_attr_show(struct kobject *kobj,
 	return port_attr->show(p, port_attr, buf);
 }
 
+static ssize_t port_attr_store(struct kobject *kobj,
+			       struct attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct port_attribute *port_attr =
+		container_of(attr, struct port_attribute, attr);
+	struct ib_port *p = container_of(kobj, struct ib_port, kobj);
+
+	if (!port_attr->store)
+		return -EIO;
+	return port_attr->store(p, port_attr, buf, count);
+}
+
 static const struct sysfs_ops port_sysfs_ops = {
-	.show = port_attr_show
+	.show =		port_attr_show,
+	.store =	port_attr_store
 };
 
 static ssize_t gid_attr_show(struct kobject *kobj,