net/hns3: fix HW exception for unbalanced Rx/Tx queues

For kupeng 930, there are 3 registers to control the enable
status of a TQP(i.e. task queue pair, include a txq and a rxq).
One of them controls whether the TQP is enabled, and the other
two controls whether the rxq and txq are enabled. The registers
used to control the enabled status of the rxq and txq are enabled
by default. Therefore, after the TQP is enabled, the rxq and txq
are enabled by default.

Currently, when the number of rxq is not equal to the number of txq, the
unused rxqs or txqs are not disabled by driver, so these unused queues
will be enabled in this situation.  And the related HW rings have not
been initialized which could lead to a hardware exception.

This patch fix it by disable these unused queues during enable the TQPs.

Fixes: fa29fe45a7b4 ("net/hns3: support queue start and stop")
Cc: stable@dpdk.org
Signed-off-by: Chengchang Tang <tangchengchang@huawei.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>

diff --git a/drivers/net/hns3/hns3_rxtx.c b/drivers/net/hns3/hns3_rxtx.c
index c76e635..88d3bab 100644 (file)
--- a/drivers/net/hns3/hns3_rxtx.c
+++ b/drivers/net/hns3/hns3_rxtx.c
@@ -353,6 +353,19 @@ hns3_update_all_queues_pvid_proc_en(struct hns3_hw *hw)
        }
 }
 
+static void
+hns3_stop_unused_queue(void *tqp_base, enum hns3_ring_type queue_type)
+{
+       uint32_t reg_offset;
+       uint32_t reg;
+
+       reg_offset = queue_type == HNS3_RING_TYPE_TX ?
+                                  HNS3_RING_TX_EN_REG : HNS3_RING_RX_EN_REG;
+       reg = hns3_read_reg(tqp_base, reg_offset);
+       reg &= ~BIT(HNS3_RING_EN_B);
+       hns3_write_reg(tqp_base, reg_offset, reg);
+}
+
 void
 hns3_enable_all_queues(struct hns3_hw *hw, bool en)
 {
@@ -368,16 +381,22 @@ hns3_enable_all_queues(struct hns3_hw *hw, bool en)
                if (hns3_dev_indep_txrx_supported(hw)) {
                        rxq = i < nb_rx_q ? hw->data->rx_queues[i] : NULL;
                        txq = i < nb_tx_q ? hw->data->tx_queues[i] : NULL;
+
+                       tqp_base = (void *)((char *)hw->io_base +
+                                       hns3_get_tqp_reg_offset(i));
                        /*
-                        * After initialization, rxq and txq won't be NULL at
-                        * the same time.
+                        * If queue struct is not initialized, it means the
+                        * related HW ring has not been initialized yet.
+                        * So, these queues should be disabled before enable
+                        * the tqps to avoid a HW exception since the queues
+                        * are enabled by default.
                         */
-                       if (rxq != NULL)
-                               tqp_base = rxq->io_base;
-                       else if (txq != NULL)
-                               tqp_base = txq->io_base;
-                       else
-                               return;
+                       if (rxq == NULL)
+                               hns3_stop_unused_queue(tqp_base,
+                                                       HNS3_RING_TYPE_RX);
+                       if (txq == NULL)
+                               hns3_stop_unused_queue(tqp_base,
+                                                       HNS3_RING_TYPE_TX);
                } else {
                        rxq = i < nb_rx_q ? hw->data->rx_queues[i] :
                              hw->fkq_data.rx_queues[i - nb_rx_q];