Lockdep found the following potential deadlock between mcast_lock and
n_mcast_grps_lock: mcast_lock is taken from both interrupt context and
process context, so spin_lock_irqsave() must be used to take it.
n_mcast_grps_lock is only taken from process context, so at first it
seems safe to take it with plain spin_lock(); however, it also nests
inside mcast_lock, and hence we could deadlock:
cpu A cpu B
ipath_mcast_add():
spin_lock_irq(&mcast_lock);
ipath_mcast_detach():
spin_lock(&n_mcast_grps_lock);
<enter interrupt>
ipath_mcast_find():
spin_lock_irqsave(&mcast_lock);
spin_lock(&n_mcast_grps_lock);
Fix this by using spin_lock_irq() to take n_mcast_grps_lock.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
These limits are somewhat artificial in that we don't actually have any
device limits. However, the verbs layer expects that such limits exist
and are enforced, so we make up arbitrary (but sensible) limits.
Signed-off-by: Robert Walsh <robert.walsh@qlogic.com>
Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Cc: "Michael S. Tsirkin" <mst@mellanox.co.il>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The ipath_verbs.c file implements the driver-specific components of the
kernel's Infiniband verbs layer.
Signed-off-by: Bryan O'Sullivan <bos@pathscale.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
