RDMA/cxgb4: Use a mutex for QP and EP state transitions

Move the connection setup/teardown paths to the workq thread removing
spin lock/irq disable requirements for these paths.  This allows calls
down to the LLD for EP and QP state transition actions to be atomic
with respect to processing CPL messages coming up from the HW.
Namely, calls to rdma_init() and rdma_fini() can now be called with
the mutex held avoiding many race conditions with the abort path.

The QP spinlock is still used but only to manipulate the qp state.  This
allows the fastpaths, poll, post_send, and pos_recv, to run in the
irq context.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
index 1c269223945e..16032cdb4337 100644
--- a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
+++ b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
@@ -46,6 +46,7 @@
 #include <linux/timer.h>
 #include <linux/io.h>
 #include <linux/kfifo.h>
+#include <linux/mutex.h>
 
 #include <asm/byteorder.h>
 
@@ -353,6 +354,7 @@ struct c4iw_qp {
 	struct c4iw_qp_attributes attr;
 	struct t4_wq wq;
 	spinlock_t lock;
+	struct mutex mutex;
 	atomic_t refcnt;
 	wait_queue_head_t wait;
 	struct timer_list timer;
@@ -605,7 +607,7 @@ struct c4iw_ep_common {
 	struct c4iw_dev *dev;
 	enum c4iw_ep_state state;
 	struct kref kref;
-	spinlock_t lock;
+	struct mutex mutex;
 	struct sockaddr_in local_addr;
 	struct sockaddr_in remote_addr;
 	struct c4iw_wr_wait wr_wait;