From: Konstantin Ananyev <konstantin.anan...@huawei.com>

../drivers/net/ice/ice_rxtx.c:1871:29: warning: variable length array used 
[-Wvla]

Here VLA is used as a temp array for mbufs that will be used as a split
RX data buffers.
As at any given time only one thread can do RX from particular queue,
at rx_queue_setup() we can allocate extra space for that array, and then
safely use it at RX fast-path.

Signed-off-by: Konstantin Ananyev <konstantin.anan...@huawei.com>
---
 drivers/net/ice/ice_rxtx.c | 18 ++++++++++++------
 drivers/net/ice/ice_rxtx.h |  2 ++
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ice/ice_rxtx.c b/drivers/net/ice/ice_rxtx.c
index 95a2db3432..6395a3b50a 100644
--- a/drivers/net/ice/ice_rxtx.c
+++ b/drivers/net/ice/ice_rxtx.c
@@ -1171,7 +1171,7 @@ ice_rx_queue_setup(struct rte_eth_dev *dev,
        struct ice_vsi *vsi = pf->main_vsi;
        struct ice_rx_queue *rxq;
        const struct rte_memzone *rz;
-       uint32_t ring_size;
+       uint32_t ring_size, tlen;
        uint16_t len;
        int use_def_burst_func = 1;
        uint64_t offloads;
@@ -1279,9 +1279,14 @@ ice_rx_queue_setup(struct rte_eth_dev *dev,
        /* always reserve more for bulk alloc */
        len = (uint16_t)(nb_desc + ICE_RX_MAX_BURST);
 
+       /* allocate extra entries for SW split buffer */
+       tlen = ((rxq->offloads & RTE_ETH_RX_OFFLOAD_BUFFER_SPLIT) != 0) ?
+               rxq->rx_free_thresh : 0;
+       tlen += len;
+
        /* Allocate the software ring. */
        rxq->sw_ring = rte_zmalloc_socket(NULL,
-                                         sizeof(struct ice_rx_entry) * len,
+                                         sizeof(struct ice_rx_entry) * tlen,
                                          RTE_CACHE_LINE_SIZE,
                                          socket_id);
        if (!rxq->sw_ring) {
@@ -1290,6 +1295,8 @@ ice_rx_queue_setup(struct rte_eth_dev *dev,
                return -ENOMEM;
        }
 
+       rxq->sw_split_buf = (tlen == len) ? NULL : rxq->sw_ring + len;
+
        ice_reset_rx_queue(rxq);
        rxq->q_set = true;
        dev->data->rx_queues[queue_idx] = rxq;
@@ -1868,7 +1875,6 @@ ice_rx_alloc_bufs(struct ice_rx_queue *rxq)
        uint64_t dma_addr;
        int diag, diag_pay;
        uint64_t pay_addr;
-       struct rte_mbuf *mbufs_pay[rxq->rx_free_thresh];
 
        /* Allocate buffers in bulk */
        alloc_idx = (uint16_t)(rxq->rx_free_trigger -
@@ -1883,7 +1889,7 @@ ice_rx_alloc_bufs(struct ice_rx_queue *rxq)
 
        if (rxq->offloads & RTE_ETH_RX_OFFLOAD_BUFFER_SPLIT) {
                diag_pay = rte_mempool_get_bulk(rxq->rxseg[1].mp,
-                               (void *)mbufs_pay, rxq->rx_free_thresh);
+                               (void *)rxq->sw_split_buf, rxq->rx_free_thresh);
                if (unlikely(diag_pay != 0)) {
                        PMD_RX_LOG(ERR, "Failed to get payload mbufs in bulk");
                        return -ENOMEM;
@@ -1908,8 +1914,8 @@ ice_rx_alloc_bufs(struct ice_rx_queue *rxq)
                        rxdp[i].read.hdr_addr = 0;
                        rxdp[i].read.pkt_addr = dma_addr;
                } else {
-                       mb->next = mbufs_pay[i];
-                       pay_addr = 
rte_cpu_to_le_64(rte_mbuf_data_iova_default(mbufs_pay[i]));
+                       mb->next = rxq->sw_split_buf[i].mbuf;
+                       pay_addr = 
rte_cpu_to_le_64(rte_mbuf_data_iova_default(mb->next));
                        rxdp[i].read.hdr_addr = dma_addr;
                        rxdp[i].read.pkt_addr = pay_addr;
                }
diff --git a/drivers/net/ice/ice_rxtx.h b/drivers/net/ice/ice_rxtx.h
index f7276cfc9f..d0f0b6c1d2 100644
--- a/drivers/net/ice/ice_rxtx.h
+++ b/drivers/net/ice/ice_rxtx.h
@@ -139,6 +139,8 @@ struct ice_rx_queue {
        uint32_t hw_time_high; /* high 32 bits of timestamp */
        uint32_t hw_time_low; /* low 32 bits of timestamp */
        uint64_t hw_time_update; /* SW time of HW record updating */
+       struct ice_rx_entry *sw_split_buf;
+       /* address of temp buffer for RX split mbufs */
        struct rte_eth_rxseg_split rxseg[ICE_RX_MAX_NSEG];
        uint32_t rxseg_nb;
        bool ts_enable; /* if rxq timestamp is enabled */
-- 
2.35.3

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