From c277b34c1b3b787d4b89bb4d0663c1871effbe55 Mon Sep 17 00:00:00 2001 From: Yongseok Koh Date: Mon, 14 Jan 2019 13:16:21 -0800 Subject: [PATCH] mbuf: add function returning buffer address This patch introduces two new functions - rte_mbuf_buf_addr() and rte_mbuf_data_addr_default(). rte_mbuf_buf_addr() reutrns the buffer address of given mbuf which comes after mbuf structure and private data. rte_mbuf_data_addr_default() returns the default address of mbuf data taking the headroom into account. Signed-off-by: Yongseok Koh Acked-by: Olivier Matz Reviewed-by: David Marchand --- lib/librte_mbuf/rte_mbuf.h | 54 +++++++++++++++++++++++++++++++++++++- 1 file changed, 53 insertions(+), 1 deletion(-) diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h index b0a5a38211..d716294751 100644 --- a/lib/librte_mbuf/rte_mbuf.h +++ b/lib/librte_mbuf/rte_mbuf.h @@ -791,7 +791,55 @@ rte_mbuf_from_indirect(struct rte_mbuf *mi) } /** - * Return the buffer address embedded in the given mbuf. + * Return address of buffer embedded in the given mbuf. + * + * The return value shall be same as mb->buf_addr if the mbuf is already + * initialized and direct. However, this API is useful if mempool of the + * mbuf is already known because it doesn't need to access mbuf contents in + * order to get the mempool pointer. + * + * @warning + * @b EXPERIMENTAL: This API may change without prior notice. + * This will be used by rte_mbuf_to_baddr() which has redundant code once + * experimental tag is removed. + * + * @param mb + * The pointer to the mbuf. + * @param mp + * The pointer to the mempool of the mbuf. + * @return + * The pointer of the mbuf buffer. + */ +static inline char * __rte_experimental +rte_mbuf_buf_addr(struct rte_mbuf *mb, struct rte_mempool *mp) +{ + return (char *)mb + sizeof(*mb) + rte_pktmbuf_priv_size(mp); +} + +/** + * Return the default address of the beginning of the mbuf data. + * + * @warning + * @b EXPERIMENTAL: This API may change without prior notice. + * + * @param mb + * The pointer to the mbuf. + * @return + * The pointer of the beginning of the mbuf data. + */ +static inline char * __rte_experimental +rte_mbuf_data_addr_default(struct rte_mbuf *mb) +{ + return rte_mbuf_buf_addr(mb, mb->pool) + RTE_PKTMBUF_HEADROOM; +} + +/** + * Return address of buffer embedded in the given mbuf. + * + * @note: Accessing mempool pointer of a mbuf is expensive because the + * pointer is stored in the 2nd cache line of mbuf. If mempool is known, it + * is better not to reference the mempool pointer in mbuf but calling + * rte_mbuf_buf_addr() would be more efficient. * * @param md * The pointer to the mbuf. @@ -801,9 +849,13 @@ rte_mbuf_from_indirect(struct rte_mbuf *mi) static inline char * rte_mbuf_to_baddr(struct rte_mbuf *md) { +#ifdef ALLOW_EXPERIMENTAL_API + return rte_mbuf_buf_addr(md, md->pool); +#else char *buffer_addr; buffer_addr = (char *)md + sizeof(*md) + rte_pktmbuf_priv_size(md->pool); return buffer_addr; +#endif } /** -- 2.20.1