summaryrefslogtreecommitdiffstats
path: root/drivers/xen/grant-table.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/xen/grant-table.c')
-rw-r--r--drivers/xen/grant-table.c10
1 files changed, 4 insertions, 6 deletions
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 35659bf707..04a6b470b1 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -427,16 +427,14 @@ EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access);
static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref)
{
- u16 flags, nflags;
- u16 *pflags;
+ u16 *pflags = &gnttab_shared.v1[ref].flags;
+ u16 flags;
- pflags = &gnttab_shared.v1[ref].flags;
- nflags = *pflags;
+ flags = *pflags;
do {
- flags = nflags;
if (flags & (GTF_reading|GTF_writing))
return 0;
- } while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags);
+ } while (!sync_try_cmpxchg(pflags, &flags, 0));
return 1;
}