net/sfc: support changing the number of transmit queues

Fixes: a8ad8cf83f01 ("net/sfc: provide basic stubs for Tx subsystem")
Cc: stable@dpdk.org
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
Reviewed-by: Andy Moreton <amoreton@solarflare.com>

diff --git a/drivers/net/sfc/sfc_tx.c b/drivers/net/sfc/sfc_tx.c
index 1605eaa..b8581d1 100644 (file)
--- a/drivers/net/sfc/sfc_tx.c
+++ b/drivers/net/sfc/sfc_tx.c
@@ -289,14 +289,37 @@ sfc_tx_check_mode(struct sfc_adapter *sa, const struct rte_eth_txmode *txmode)
        return rc;
 }
 
+/**
+ * Destroy excess queues that are no longer needed after reconfiguration
+ * or complete close.
+ */
+static void
+sfc_tx_fini_queues(struct sfc_adapter *sa, unsigned int nb_tx_queues)
+{
+       int sw_index;
+
+       SFC_ASSERT(nb_tx_queues <= sa->txq_count);
+
+       sw_index = sa->txq_count;
+       while (--sw_index >= (int)nb_tx_queues) {
+               if (sa->txq_info[sw_index].txq != NULL)
+                       sfc_tx_qfini(sa, sw_index);
+       }
+
+       sa->txq_count = nb_tx_queues;
+}
+
 int
 sfc_tx_configure(struct sfc_adapter *sa)
 {
        const efx_nic_cfg_t *encp = efx_nic_cfg_get(sa->nic);
        const struct rte_eth_conf *dev_conf = &sa->eth_dev->data->dev_conf;
-       unsigned int sw_index;
+       const unsigned int nb_tx_queues = sa->eth_dev->data->nb_tx_queues;
        int rc = 0;
 
+       sfc_log_init(sa, "nb_tx_queues=%u (old %u)",
+                    nb_tx_queues, sa->txq_count);
+
        /*
         * The datapath implementation assumes absence of boundary
         * limits on Tx DMA descriptors. Addition of these checks on
@@ -311,28 +334,49 @@ sfc_tx_configure(struct sfc_adapter *sa)
        if (rc != 0)
                goto fail_check_mode;
 
-       sa->txq_count = sa->eth_dev->data->nb_tx_queues;
+       if (nb_tx_queues == sa->txq_count)
+               goto done;
 
-       sa->txq_info = rte_calloc_socket("sfc-txqs", sa->txq_count,
-                                        sizeof(sa->txq_info[0]), 0,
-                                        sa->socket_id);
-       if (sa->txq_info == NULL)
-               goto fail_txqs_alloc;
+       if (sa->txq_info == NULL) {
+               sa->txq_info = rte_calloc_socket("sfc-txqs", nb_tx_queues,
+                                                sizeof(sa->txq_info[0]), 0,
+                                                sa->socket_id);
+               if (sa->txq_info == NULL)
+                       goto fail_txqs_alloc;
+       } else {
+               struct sfc_txq_info *new_txq_info;
+
+               if (nb_tx_queues < sa->txq_count)
+                       sfc_tx_fini_queues(sa, nb_tx_queues);
+
+               new_txq_info =
+                       rte_realloc(sa->txq_info,
+                                   nb_tx_queues * sizeof(sa->txq_info[0]), 0);
+               if (new_txq_info == NULL && nb_tx_queues > 0)
+                       goto fail_txqs_realloc;
+
+               sa->txq_info = new_txq_info;
+               if (nb_tx_queues > sa->txq_count)
+                       memset(&sa->txq_info[sa->txq_count], 0,
+                              (nb_tx_queues - sa->txq_count) *
+                              sizeof(sa->txq_info[0]));
+       }
 
-       for (sw_index = 0; sw_index < sa->txq_count; ++sw_index) {
-               rc = sfc_tx_qinit_info(sa, sw_index);
+       while (sa->txq_count < nb_tx_queues) {
+               rc = sfc_tx_qinit_info(sa, sa->txq_count);
                if (rc != 0)
                        goto fail_tx_qinit_info;
+
+               sa->txq_count++;
        }
 
+done:
        return 0;
 
 fail_tx_qinit_info:
-       rte_free(sa->txq_info);
-       sa->txq_info = NULL;
-
+fail_txqs_realloc:
 fail_txqs_alloc:
-       sa->txq_count = 0;
+       sfc_tx_close(sa);
 
 fail_check_mode:
 fail_tx_dma_desc_boundary:
@@ -343,17 +387,10 @@ fail_tx_dma_desc_boundary:
 void
 sfc_tx_close(struct sfc_adapter *sa)
 {
-       int sw_index;
-
-       sw_index = sa->txq_count;
-       while (--sw_index >= 0) {
-               if (sa->txq_info[sw_index].txq != NULL)
-                       sfc_tx_qfini(sa, sw_index);
-       }
+       sfc_tx_fini_queues(sa, 0);
 
        rte_free(sa->txq_info);
        sa->txq_info = NULL;
-       sa->txq_count = 0;
 }
 
 int