xen: introduce xenbus_read_unsigned()

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@suse.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>

diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index 22f7cd711c5792e25eac035f0aa138c9992d9bd9..99dfdfae42c6d1605a2d3276363a8251ad30876e 100644 (file)
--- 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 32b944b7cebd1eab42e78b6a3e56ec4a9ce5f693..271ba62503c7e5fe23abc3a9628d556bad65e606 100644 (file)
--- 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,