cxgb4: DB Drop Recovery for RDMA and LLD queues
recover LLD EQs for DB drop interrupts. This includes adding a new
db_lock, a spin lock disabling BH too, used by the recovery thread and
the ring_tx_db() paths to allow db drop recovery.
Clean up initial DB avoidance code.
Add read_eq_indices() - this allows the LLD to use the PCIe mw to
efficiently read hw eq contexts.
Add cxgb4_sync_txq_pidx() - called by iw_cxgb4 to sync up the sw/hw
pidx value.
Add flush_eq_cache() and cxgb4_flush_eq_cache(). This allows iw_cxgb4
to flush the sge eq context cache before beginning db drop recovery.
Add module parameter, dbfoifo_int_thresh, to allow tuning the db
interrupt threshold value.
Add dbfifo_int_thresh to cxgb4_lld_info so iw_cxgb4 knows the threshold.
Add module parameter, dbfoifo_drain_delay, to allow tuning the amount
of time delay between DB FULL and EMPTY upcalls to iw_cxgb4.
Signed-off-by: Vipul Pandya <vipul@chelsio.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c
index 234c157..e111d97 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c
@@ -767,8 +767,13 @@
static inline void ring_tx_db(struct adapter *adap, struct sge_txq *q, int n)
{
wmb(); /* write descriptors before telling HW */
- t4_write_reg(adap, MYPF_REG(SGE_PF_KDOORBELL),
- QID(q->cntxt_id) | PIDX(n));
+ spin_lock(&q->db_lock);
+ if (!q->db_disabled) {
+ t4_write_reg(adap, MYPF_REG(A_SGE_PF_KDOORBELL),
+ V_QID(q->cntxt_id) | V_PIDX(n));
+ }
+ q->db_pidx = q->pidx;
+ spin_unlock(&q->db_lock);
}
/**
@@ -2081,6 +2086,7 @@
q->stops = q->restarts = 0;
q->stat = (void *)&q->desc[q->size];
q->cntxt_id = id;
+ spin_lock_init(&q->db_lock);
adap->sge.egr_map[id - adap->sge.egr_start] = q;
}
@@ -2415,9 +2421,15 @@
RXPKTCPLMODE |
(STAT_LEN == 128 ? EGRSTATUSPAGESIZE : 0));
+ /*
+ * Set up to drop DOORBELL writes when the DOORBELL FIFO overflows
+ * and generate an interrupt when this occurs so we can recover.
+ */
t4_set_reg_field(adap, A_SGE_DBFIFO_STATUS,
- V_HP_INT_THRESH(5) | V_LP_INT_THRESH(5),
- V_HP_INT_THRESH(5) | V_LP_INT_THRESH(5));
+ V_HP_INT_THRESH(M_HP_INT_THRESH) |
+ V_LP_INT_THRESH(M_LP_INT_THRESH),
+ V_HP_INT_THRESH(dbfifo_int_thresh) |
+ V_LP_INT_THRESH(dbfifo_int_thresh));
t4_set_reg_field(adap, A_SGE_DOORBELL_CONTROL, F_ENABLE_DROP,
F_ENABLE_DROP);