[PATCH net v2 1/4] octeon_ep: Relocate counter updates before NAPI

[Vimlesh Kumar]

Relocate IQ/OQ IN/OUT_CNTS updates to occur before NAPI completion,
and replace napi_complete with napi_complete_done.

Moving the IQ/OQ counter updates before napi_complete_done ensures
1. Counter registers are updated before re-enabling interrupts.
2. Prevents a race where new packets arrive but counters aren't properly
   synchronized.
napi_complete_done (vs napi_complete) allows for better
interrupt coalescing.

Fixes: 37d79d0596062 ("octeon_ep: add Tx/Rx processing and interrupt support")
Signed-off-by: Sathesh Edara <sedara@xxxxxxxxxxx>
Signed-off-by: Shinas Rasheed <srasheed@xxxxxxxxxxx>
Signed-off-by: Vimlesh Kumar <vimleshk@xxxxxxxxxxx>
---
 .../ethernet/marvell/octeon_ep/octep_main.c   | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
index bcea3fc26a8c..a93c3c9994c2 100644
--- a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
+++ b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
@@ -555,12 +555,12 @@ static void octep_clean_irqs(struct octep_device *oct)
 }
 
 /**
- * octep_enable_ioq_irq() - Enable MSI-x interrupt of a Tx/Rx queue.
+ * octep_update_pkt() - Update IQ/OQ IN/OUT_CNT registers.
  *
  * @iq: Octeon Tx queue data structure.
  * @oq: Octeon Rx queue data structure.
  */
-static void octep_enable_ioq_irq(struct octep_iq *iq, struct octep_oq *oq)
+static void octep_update_pkt(struct octep_iq *iq, struct octep_oq *oq)
 {
 	u32 pkts_pend = oq->pkts_pending;
 
@@ -576,7 +576,17 @@ static void octep_enable_ioq_irq(struct octep_iq *iq, struct octep_oq *oq)
 	}
 
 	/* Flush the previous wrties before writing to RESEND bit */
-	wmb();
+	smp_wmb();
+}
+
+/**
+ * octep_enable_ioq_irq() - Enable MSI-x interrupt of a Tx/Rx queue.
+ *
+ * @iq: Octeon Tx queue data structure.
+ * @oq: Octeon Rx queue data structure.
+ */
+static void octep_enable_ioq_irq(struct octep_iq *iq, struct octep_oq *oq)
+{
 	writeq(1UL << OCTEP_OQ_INTR_RESEND_BIT, oq->pkts_sent_reg);
 	writeq(1UL << OCTEP_IQ_INTR_RESEND_BIT, iq->inst_cnt_reg);
 }
@@ -602,7 +612,8 @@ static int octep_napi_poll(struct napi_struct *napi, int budget)
 	if (tx_pending || rx_done >= budget)
 		return budget;
 
-	napi_complete(napi);
+	octep_update_pkt(ioq_vector->iq, ioq_vector->oq);
+	napi_complete_done(napi, rx_done);
 	octep_enable_ioq_irq(ioq_vector->iq, ioq_vector->oq);
 	return rx_done;
 }
-- 
2.47.3