diff options
Diffstat (limited to 'drivers/xen/events/events_fifo.c')
| -rw-r--r-- | drivers/xen/events/events_fifo.c | 26 |
1 files changed, 12 insertions, 14 deletions
diff --git a/drivers/xen/events/events_fifo.c b/drivers/xen/events/events_fifo.c index ad9fe51d3fb3..655775db7caf 100644 --- a/drivers/xen/events/events_fifo.c +++ b/drivers/xen/events/events_fifo.c @@ -226,21 +226,20 @@ static bool evtchn_fifo_is_masked(evtchn_port_t port) */ static bool clear_masked_cond(volatile event_word_t *word) { - event_word_t new, old, w; + event_word_t new, old; - w = *word; + old = *word; do { - if (!(w & (1 << EVTCHN_FIFO_MASKED))) + if (!(old & (1 << EVTCHN_FIFO_MASKED))) return true; - if (w & (1 << EVTCHN_FIFO_PENDING)) + if (old & (1 << EVTCHN_FIFO_PENDING)) return false; - old = w & ~(1 << EVTCHN_FIFO_BUSY); + old = old & ~(1 << EVTCHN_FIFO_BUSY); new = old & ~(1 << EVTCHN_FIFO_MASKED); - w = sync_cmpxchg(word, old, new); - } while (w != old); + } while (!sync_try_cmpxchg(word, &old, new)); return true; } @@ -259,17 +258,16 @@ static void evtchn_fifo_unmask(evtchn_port_t port) static uint32_t clear_linked(volatile event_word_t *word) { - event_word_t new, old, w; + event_word_t new, old; - w = *word; + old = *word; do { - old = w; - new = (w & ~((1 << EVTCHN_FIFO_LINKED) - | EVTCHN_FIFO_LINK_MASK)); - } while ((w = sync_cmpxchg(word, old, new)) != old); + new = (old & ~((1 << EVTCHN_FIFO_LINKED) + | EVTCHN_FIFO_LINK_MASK)); + } while (!sync_try_cmpxchg(word, &old, new)); - return w & EVTCHN_FIFO_LINK_MASK; + return old & EVTCHN_FIFO_LINK_MASK; } static void consume_one_event(unsigned cpu, struct evtchn_loop_ctrl *ctrl, |