[dpdk-dev,1/4] net/ixgbe: add compile-time checks to vector driver
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Commit Message
The vector PMD is very sensitive to the layout of the mbuf, especially on
the RX path. Add in some compile-time checks to make sure the mbuf layout
assumptions are valid, and to provide hints to anyone changing the mbuf
where things may need to be updated.
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
@@ -87,6 +87,8 @@ ixgbe_rxq_rearm(struct ixgbe_rx_queue *rxq)
mb1 = rxep[1].mbuf;
/* load buf_addr(lo 64bit) and buf_physaddr(hi 64bit) */
+ RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, buf_physaddr) !=
+ offsetof(struct rte_mbuf, buf_addr) + 8);
vaddr0 = _mm_loadu_si128((__m128i *)&(mb0->buf_addr));
vaddr1 = _mm_loadu_si128((__m128i *)&(mb1->buf_addr));
@@ -234,6 +236,11 @@ desc_to_olflags_v(__m128i descs[4], __m128i mbuf_init, uint8_t vlan_flags,
#endif /* RTE_MACHINE_CPUFLAG_SSE4_2 */
+ /* write the rearm data and the olflags in one write */
+ RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, ol_flags) !=
+ offsetof(struct rte_mbuf, rearm_data) + 8);
+ RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, rearm_data) !=
+ RTE_ALIGN(offsetof(struct rte_mbuf, rearm_data), 16));
_mm_store_si128((__m128i *)&rx_pkts[0]->rearm_data, rearm0);
_mm_store_si128((__m128i *)&rx_pkts[1]->rearm_data, rearm1);
_mm_store_si128((__m128i *)&rx_pkts[2]->rearm_data, rearm2);
@@ -266,6 +273,15 @@ _recv_raw_pkts_vec(struct ixgbe_rx_queue *rxq, struct rte_mbuf **rx_pkts,
-rxq->crc_len, /* sub crc on pkt_len */
0, 0 /* ignore pkt_type field */
);
+ /*
+ * compile-time check the above crc_adjust layout is correct.
+ * NOTE: the first field (lowest address) is given last in set_epi16
+ * call above.
+ */
+ RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, pkt_len) !=
+ offsetof(struct rte_mbuf, rx_descriptor_fields1) + 4);
+ RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, data_len) !=
+ offsetof(struct rte_mbuf, rx_descriptor_fields1) + 8);
__m128i dd_check, eop_check;
__m128i mbuf_init;
uint8_t vlan_flags;
@@ -312,6 +328,19 @@ _recv_raw_pkts_vec(struct ixgbe_rx_queue *rxq, struct rte_mbuf **rx_pkts,
0xFF, 0xFF, /* skip 32 bit pkt_type */
0xFF, 0xFF
);
+ /*
+ * Compile-time verify the shuffle mask
+ * NOTE: some field positions already verified above, but duplicated
+ * here for completeness in case of future modifications.
+ */
+ RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, pkt_len) !=
+ offsetof(struct rte_mbuf, rx_descriptor_fields1) + 4);
+ RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, data_len) !=
+ offsetof(struct rte_mbuf, rx_descriptor_fields1) + 8);
+ RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, vlan_tci) !=
+ offsetof(struct rte_mbuf, rx_descriptor_fields1) + 10);
+ RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, hash) !=
+ offsetof(struct rte_mbuf, rx_descriptor_fields1) + 12);
mbuf_init = _mm_set_epi64x(0, rxq->mbuf_initializer);