RDMA/cxgb4: DB Drop Recovery for RDMA and LLD queues

Add module option db_fc_threshold which is the count of active QPs
that trigger automatic db flow control mode.  Automatically transition
to/from flow control mode when the active qp count crosses
db_fc_theshold.

Add more db debugfs stats

On DB DROP event from the LLD, recover all the iwarp queues.

Signed-off-by: Vipul Pandya <vipul@chelsio.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/cxgb4/t4.h b/drivers/infiniband/hw/cxgb4/t4.h
index c0221eec8817..16f26ab29302 100644
--- a/drivers/infiniband/hw/cxgb4/t4.h
+++ b/drivers/infiniband/hw/cxgb4/t4.h
@@ -62,6 +62,10 @@ struct t4_status_page {
 	__be16 pidx;
 	u8 qp_err;	/* flit 1 - sw owns */
 	u8 db_off;
+	u8 pad;
+	u16 host_wq_pidx;
+	u16 host_cidx;
+	u16 host_pidx;
 };
 
 #define T4_EQ_ENTRY_SIZE 64
@@ -375,6 +379,16 @@ static inline void t4_rq_consume(struct t4_wq *wq)
 		wq->rq.cidx = 0;
 }
 
+static inline u16 t4_rq_host_wq_pidx(struct t4_wq *wq)
+{
+	return wq->rq.queue[wq->rq.size].status.host_wq_pidx;
+}
+
+static inline u16 t4_rq_wq_size(struct t4_wq *wq)
+{
+		return wq->rq.size * T4_RQ_NUM_SLOTS;
+}
+
 static inline int t4_sq_onchip(struct t4_sq *sq)
 {
 	return sq->flags & T4_SQ_ONCHIP;
@@ -412,6 +426,16 @@ static inline void t4_sq_consume(struct t4_wq *wq)
 		wq->sq.cidx = 0;
 }
 
+static inline u16 t4_sq_host_wq_pidx(struct t4_wq *wq)
+{
+	return wq->sq.queue[wq->sq.size].status.host_wq_pidx;
+}
+
+static inline u16 t4_sq_wq_size(struct t4_wq *wq)
+{
+		return wq->sq.size * T4_SQ_NUM_SLOTS;
+}
+
 static inline void t4_ring_sq_db(struct t4_wq *wq, u16 inc)
 {
 	wmb();