RDMA/ocrdma: Depend on async link events from CNA
Recently Dough Ledford reported a deadlock happening
between ocrdma-load sequence and NetworkManager service
issuing "open" on be2net interface.
The deadlock happens when any be2net hook (e.g. open/close) is called
in parallel to insmod ocrdma.ko.
A. be2net is sending administrative open/close event to ocrdma holding
device_list_mutex. It does this from ndo_open/ndo_stop hooks of be2net.
So sequence of locks is rtnl_lock---> device_list lock
B. When new ocrdma roce device gets registered, infiniband stack now
takes rtnl_lock in ib_register_device() in GID initialization routines.
So sequence of locks in this path is device_list lock ---> rtnl_lock.
This improper locking sequence causes deadlock.
With this patch we stop using administrative open and close events
injected by be2net driver. These events were used to dispatch PORT_ACTIVE
and PORT_ERROR events to the IB-stack. This patch implements a logic
to receive async-link-events generated from CNA whenever link-state-change
is detected. Now on, these async-events will be used to dispatch
PORT_ACTIVE and PORT_ERROR events to IB-stack.
Depending on async-events from CNA removes the need to hold device-list-mutex
and thus breaks the busy-wait scenario.
Reported-by: Doug Ledford <dledford@redhat.com>
CC: Sathya Perla <sathya.perla@avagotech.com>
Signed-off-by: Padmanabh Ratnakar <padmanabh.ratnakar@avagotech.com>
Signed-off-by: Selvin Xavier <selvin.xavier@avagotech.com>
Signed-off-by: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/hw/ocrdma/ocrdma.h b/drivers/infiniband/hw/ocrdma/ocrdma.h
index ae80590..040bb8b 100644
--- a/drivers/infiniband/hw/ocrdma/ocrdma.h
+++ b/drivers/infiniband/hw/ocrdma/ocrdma.h
@@ -232,6 +232,10 @@
u16 interface_type;
};
+enum ocrdma_flags {
+ OCRDMA_FLAGS_LINK_STATUS_INIT = 0x01
+};
+
struct ocrdma_dev {
struct ib_device ibdev;
struct ocrdma_dev_attr attr;
@@ -287,6 +291,7 @@
atomic_t update_sl;
u16 pvid;
u32 asic_id;
+ u32 flags;
ulong last_stats_time;
struct mutex stats_lock; /* provide synch for debugfs operations */
@@ -591,4 +596,9 @@
(state & OCRDMA_STATE_FLAG_SYNC);
}
+static inline u8 ocrdma_get_ae_link_state(u32 ae_state)
+{
+ return ((ae_state & OCRDMA_AE_LSC_LS_MASK) >> OCRDMA_AE_LSC_LS_SHIFT);
+}
+
#endif