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>
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