diff options
Diffstat (limited to 'drivers/xen/grant-table.c')
| -rw-r--r-- | drivers/xen/grant-table.c | 10 |
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; } |