ixgbe: remove awkward typecasts

The vector/SSE pmd used a different element type for the tx queue sw_ring
entries. This led to lots of typecasts in the code which required specific
use of bracketing, leading to subtle errors.
For example, in the original code:
	txe = (struct ixgbe_tx_entry_v *)&txq->sw_ring[i];
instead needs to be written as:
	txe = &((struct ixgbe_tx_entry_v *)txq->sw_ring)[i];

We can eliminate this problem, by having two software ring pointers in the
structure for the two different element types.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>

diff --git a/drivers/net/ixgbe/ixgbe_rxtx.h b/drivers/net/ixgbe/ixgbe_rxtx.h
index befdc3a..1557438 100644 (file)
--- a/drivers/net/ixgbe/ixgbe_rxtx.h
+++ b/drivers/net/ixgbe/ixgbe_rxtx.h
@@ -193,7 +193,10 @@ struct ixgbe_tx_queue {
        /** TX ring virtual address. */
        volatile union ixgbe_adv_tx_desc *tx_ring;
        uint64_t            tx_ring_phys_addr; /**< TX ring DMA address. */
-       struct ixgbe_tx_entry *sw_ring;      /**< virtual address of SW ring. */
+       union {
+               struct ixgbe_tx_entry *sw_ring; /**< address of SW ring for scalar PMD. */
+               struct ixgbe_tx_entry_v *sw_ring_v; /**< address of SW ring for vector PMD */
+       };
        volatile uint32_t   *tdt_reg_addr; /**< Address of TDT register. */
        uint16_t            nb_tx_desc;    /**< number of TX descriptors. */
        uint16_t            tx_tail;       /**< current value of TDT reg. */

diff --git a/drivers/net/ixgbe/ixgbe_rxtx_vec.c b/drivers/net/ixgbe/ixgbe_rxtx_vec.c
index d3da31d..9c5390e 100644 (file)
--- a/drivers/net/ixgbe/ixgbe_rxtx_vec.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx_vec.c
@@ -608,8 +608,7 @@ ixgbe_tx_free_bufs(struct ixgbe_tx_queue *txq)
         * first buffer to free from S/W ring is at index
         * tx_next_dd - (tx_rs_thresh-1)
         */
-       txep = &((struct ixgbe_tx_entry_v *)txq->sw_ring)[txq->tx_next_dd -
-                       (n - 1)];
+       txep = &txq->sw_ring_v[txq->tx_next_dd - (n - 1)];
        m = __rte_pktmbuf_prefree_seg(txep[0].mbuf);
        if (likely(m != NULL)) {
                free[0] = m;
@@ -678,7 +677,7 @@ ixgbe_xmit_pkts_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
 
        tx_id = txq->tx_tail;
        txdp = &txq->tx_ring[tx_id];
-       txep = &((struct ixgbe_tx_entry_v *)txq->sw_ring)[tx_id];
+       txep = &txq->sw_ring_v[tx_id];
 
        txq->nb_tx_free = (uint16_t)(txq->nb_tx_free - nb_pkts);
 
@@ -699,7 +698,7 @@ ixgbe_xmit_pkts_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
 
                /* avoid reach the end of ring */
                txdp = &(txq->tx_ring[tx_id]);
-               txep = &(((struct ixgbe_tx_entry_v *)txq->sw_ring)[tx_id]);
+               txep = &txq->sw_ring_v[tx_id];
        }
 
        tx_backlog_entry(txep, tx_pkts, nb_commit);
@@ -735,14 +734,14 @@ ixgbe_tx_queue_release_mbufs_vec(struct ixgbe_tx_queue *txq)
        for (i = txq->tx_next_dd - (txq->tx_rs_thresh - 1);
             i != txq->tx_tail;
             i = (i + 1) & max_desc) {
-               txe = &((struct ixgbe_tx_entry_v *)txq->sw_ring)[i];
+               txe = &txq->sw_ring_v[i];
                rte_pktmbuf_free_seg(txe->mbuf);
        }
        txq->nb_tx_free = max_desc;
 
        /* reset tx_entry */
        for (i = 0; i < txq->nb_tx_desc; i++) {
-               txe = (struct ixgbe_tx_entry_v *)&txq->sw_ring[i];
+               txe = &txq->sw_ring_v[i];
                txe->mbuf = NULL;
        }
 }
@@ -772,8 +771,8 @@ ixgbe_tx_free_swring(struct ixgbe_tx_queue *txq)
                return;
 
        if (txq->sw_ring != NULL) {
-               rte_free((struct ixgbe_rx_entry *)txq->sw_ring - 1);
-               txq->sw_ring = NULL;
+               rte_free(txq->sw_ring_v - 1);
+               txq->sw_ring_v = NULL;
        }
 }
 
@@ -781,7 +780,7 @@ static void __attribute__((cold))
 ixgbe_reset_tx_queue(struct ixgbe_tx_queue *txq)
 {
        static const union ixgbe_adv_tx_desc zeroed_desc = {{0}};
-       struct ixgbe_tx_entry_v *txe = (struct ixgbe_tx_entry_v *)txq->sw_ring;
+       struct ixgbe_tx_entry_v *txe = txq->sw_ring_v;
        uint16_t i;
 
        /* Zero out HW ring memory */
@@ -838,12 +837,11 @@ ixgbe_rxq_vec_setup(struct ixgbe_rx_queue *rxq)
 int __attribute__((cold))
 ixgbe_txq_vec_setup(struct ixgbe_tx_queue *txq)
 {
-       if (txq->sw_ring == NULL)
+       if (txq->sw_ring_v == NULL)
                return -1;
 
        /* leave the first one for overflow */
-       txq->sw_ring = (struct ixgbe_tx_entry *)
-               ((struct ixgbe_tx_entry_v *)txq->sw_ring + 1);
+       txq->sw_ring_v = txq->sw_ring_v + 1;
        txq->ops = &vec_txq_ops;
 
        return 0;