powerpc/eeh: atomic_dec_if_positive() to update passthru count

No need to have two atomic opertions (update and fetch/check) when
decreasing PE's number of passed devices as one atomic operation
is enough.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Gavin Shan 2015-08-27 15:58:27 +10:00 committed by Michael Ellerman
parent 2e1a2556eb
commit 54f9a64a36

View file

@ -1412,8 +1412,7 @@ void eeh_dev_release(struct pci_dev *pdev)
goto out;
/* Decrease PE's pass through count */
atomic_dec(&edev->pe->pass_dev_cnt);
WARN_ON(atomic_read(&edev->pe->pass_dev_cnt) < 0);
WARN_ON(atomic_dec_if_positive(&edev->pe->pass_dev_cnt) < 0);
eeh_pe_change_owner(edev->pe);
out:
mutex_unlock(&eeh_dev_mutex);