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path: root/drivers/xen/xenbus/xenbus_xs.c
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Diffstat (limited to 'drivers/xen/xenbus/xenbus_xs.c')
-rw-r--r--drivers/xen/xenbus/xenbus_xs.c22
1 files changed, 18 insertions, 4 deletions
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index 22f7cd711c57..6afb993c5809 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, ...)
@@ -672,7 +687,7 @@ static bool xen_strict_xenbus_quirk(void)
}
static void xs_reset_watches(void)
{
- int err, supported = 0;
+ int err;
if (!xen_hvm_domain() || xen_initial_domain())
return;
@@ -680,9 +695,8 @@ static void xs_reset_watches(void)
if (xen_strict_xenbus_quirk())
return;
- err = xenbus_scanf(XBT_NIL, "control",
- "platform-feature-xs_reset_watches", "%d", &supported);
- if (err != 1 || !supported)
+ if (!xenbus_read_unsigned("control",
+ "platform-feature-xs_reset_watches", 0))
return;
err = xs_error(xs_single(XBT_NIL, XS_RESET_WATCHES, "", NULL));