[dpdk-dev] [PATCHv2 5/5] ixgbe: remove awkward typecasts from ixgbe SSE PMD
Konstantin Ananyev
konstantin.ananyev at intel.com
Fri Jul 24 15:58:15 CEST 2015
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.
v2 changes:
- fix remaining wrong typecast.
Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
Signed-off-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
---
drivers/net/ixgbe/ixgbe_rxtx.h | 5 ++++-
drivers/net/ixgbe/ixgbe_rxtx_vec.c | 22 ++++++++++------------
2 files changed, 14 insertions(+), 13 deletions(-)
diff --git a/drivers/net/ixgbe/ixgbe_rxtx.h b/drivers/net/ixgbe/ixgbe_rxtx.h
index befdc3a..1557438 100644
--- 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
--- 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;
--
1.8.3.1
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