xen/grant-table: add gnttab_try_end_foreign_access()

[linux-2.6-microblaze.git] / drivers / xen / grant-table.c

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 3729bea..1b82e7a 100644 (file)
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -435,11 +435,21 @@ static void gnttab_add_deferred(grant_ref_t ref, bool readonly,
               what, ref, page ? page_to_pfn(page) : -1);
 }
 
+int gnttab_try_end_foreign_access(grant_ref_t ref)
+{
+       int ret = _gnttab_end_foreign_access_ref(ref, 0);
+
+       if (ret)
+               put_free_entry(ref);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(gnttab_try_end_foreign_access);
+
 void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
                               unsigned long page)
 {
-       if (gnttab_end_foreign_access_ref(ref, readonly)) {
-               put_free_entry(ref);
+       if (gnttab_try_end_foreign_access(ref)) {
                if (page != 0)
                        put_page(virt_to_page(page));
        } else