[PATCH 01/12] xen: introduce xenbus_read_unsigned()

[Juergen Gross]

There are multiple instances of code reading an optional unsigned
parameter from Xenstore via xenbus_scanf(). Instead of repeating the
same code over and over add a service function doing the job.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
 drivers/xen/xenbus/xenbus_xs.c | 15 +++++++++++++++
 include/xen/xenbus.h           |  4 ++++
 2 files changed, 19 insertions(+)

diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index 22f7cd7..99dfdfa 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -559,6 +559,21 @@ int xenbus_scanf(struct xenbus_transaction t,
 }
 EXPORT_SYMBOL_GPL(xenbus_scanf);
 
+/* Read an (optional) unsigned value. */
+unsigned int xenbus_read_unsigned(const char *dir, const char *node,
+				  unsigned int default_val)
+{
+	unsigned int val;
+	int ret;
+
+	ret = xenbus_scanf(XBT_NIL, dir, node, "%u", &val);
+	if (ret <= 0)
+		val = default_val;
+
+	return val;
+}
+EXPORT_SYMBOL_GPL(xenbus_read_unsigned);
+
 /* Single printf and write: returns -errno or 0. */
 int xenbus_printf(struct xenbus_transaction t,
 		  const char *dir, const char *node, const char *fmt, ...)
diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h
index 32b944b..271ba62 100644
--- a/include/xen/xenbus.h
+++ b/include/xen/xenbus.h
@@ -151,6 +151,10 @@ __scanf(4, 5)
 int xenbus_scanf(struct xenbus_transaction t,
 		 const char *dir, const char *node, const char *fmt, ...);
 
+/* Read an (optional) unsigned value. */
+unsigned int xenbus_read_unsigned(const char *dir, const char *node,
+				  unsigned int default_val);
+
 /* Single printf and write: returns -errno or 0. */
 __printf(4, 5)
 int xenbus_printf(struct xenbus_transaction t,
-- 
2.6.6