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| author | Juergen Gross <jgross@suse.com> | 2020-10-22 11:49:06 +0200 |
|---|---|---|
| committer | Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2020-10-23 12:41:25 +0200 |
| commit | eabe741782d5a52ce884dba4bab8825f977ab1eb (patch) | |
| tree | 9caef07843681e1d53942f7ca1c813a9671eea33 /drivers | |
| parent | xen/events: only register debug interrupt for 2-level events (diff) | |
| download | linux-eabe741782d5a52ce884dba4bab8825f977ab1eb.tar.xz linux-eabe741782d5a52ce884dba4bab8825f977ab1eb.zip | |
xen/events: unmask a fifo event channel only if it was masked
Unmasking an event channel with fifo events channels being used can
require a hypercall to be made, so try to avoid that by checking
whether the event channel was really masked.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Link: https://lore.kernel.org/r/20201022094907.28560-5-jgross@suse.com
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/xen/events/events_fifo.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/xen/events/events_fifo.c b/drivers/xen/events/events_fifo.c index 243e7b6d7b96..b234f1766810 100644 --- a/drivers/xen/events/events_fifo.c +++ b/drivers/xen/events/events_fifo.c @@ -237,6 +237,9 @@ static bool clear_masked_cond(volatile event_word_t *word) w = *word; do { + if (!(w & (1 << EVTCHN_FIFO_MASKED))) + return true; + if (w & (1 << EVTCHN_FIFO_PENDING)) return false; |