[PATCH v3 1/3] ethdev: introduce maximum Rx buffer size

[Huisong Li <lihuisong@huawei.com>]

The "min_rx_bufsize" in struct rte_eth_dev_info stands for the minimum
Rx buffer size supported by hardware. Actually, some engines also have
the maximum Rx buffer specification, like, hns3. If mbuf data room size
in mempool is greater then the maximum Rx buffer size supported by HW,
the data size application used in each mbuf is just as much as the maximum
Rx buffer size supported by HW instead of the whole data room size.

So introduce maximum Rx buffer size which is not enforced just to
report user to avoid memory waste. In addition, fix the comment for
the "min_rx_bufsize" to make it be more specific.

Signed-off-by: Huisong Li <lihuisong@huawei.com>
Acked-by: Chengwen Feng <fengchengwen@huawei.com>
Acked-by: Morten Brørup <mb@smartsharesystems.com>
---
 lib/ethdev/rte_ethdev.c |  7 +++++++
 lib/ethdev/rte_ethdev.h | 10 +++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
index 9dabcb5ae2..eb657a984e 100644
--- a/lib/ethdev/rte_ethdev.c
+++ b/lib/ethdev/rte_ethdev.c
@@ -2112,6 +2112,7 @@ rte_eth_rx_queue_setup(uint16_t port_id, uint16_t rx_queue_id,
 	struct rte_eth_dev *dev;
 	struct rte_eth_dev_info dev_info;
 	struct rte_eth_rxconf local_conf;
+	uint32_t vld_bufsize;
 
 	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
 	dev = &rte_eth_devices[port_id];
@@ -2158,6 +2159,11 @@ rte_eth_rx_queue_setup(uint16_t port_id, uint16_t rx_queue_id,
 			return ret;
 
 		mbp_buf_size = rte_pktmbuf_data_room_size(mp);
+		vld_bufsize = mbp_buf_size - RTE_PKTMBUF_HEADROOM;
+		if (vld_bufsize > dev_info.max_rx_bufsize)
+			RTE_ETHDEV_LOG(INFO,
+				"Ethdev port_id=%u, the data size application used in each mbuf is just %u instead of the whole data room(%u).\n",
+				port_id, dev_info.max_rx_bufsize, vld_bufsize);
 	} else if (rx_conf != NULL && rx_conf->rx_nseg > 0) {
 		const struct rte_eth_rxseg_split *rx_seg;
 		uint16_t n_seg;
@@ -3757,6 +3763,7 @@ rte_eth_dev_info_get(uint16_t port_id, struct rte_eth_dev_info *dev_info)
 	dev_info->min_mtu = RTE_ETHER_MIN_LEN - RTE_ETHER_HDR_LEN -
 		RTE_ETHER_CRC_LEN;
 	dev_info->max_mtu = UINT16_MAX;
+	dev_info->max_rx_bufsize = UINT32_MAX;
 
 	if (*dev->dev_ops->dev_infos_get == NULL)
 		return -ENOTSUP;
diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
index 2fd3cd808d..b8f5dcae00 100644
--- a/lib/ethdev/rte_ethdev.h
+++ b/lib/ethdev/rte_ethdev.h
@@ -1723,7 +1723,15 @@ struct rte_eth_dev_info {
 	uint16_t min_mtu;	/**< Minimum MTU allowed */
 	uint16_t max_mtu;	/**< Maximum MTU allowed */
 	const uint32_t *dev_flags; /**< Device flags */
-	uint32_t min_rx_bufsize; /**< Minimum size of Rx buffer. */
+	/** Minimum Rx buffer size per descriptor supported by HW. */
+	uint32_t min_rx_bufsize;
+	/**
+	 * Maximum Rx buffer size per descriptor supported by HW.
+	 * The value is not enforced, information only to application to
+	 * optimize mbuf size. Its value is UINT32_MAX when not specified
+	 * by the driver.
+	 */
+	uint32_t max_rx_bufsize;
 	uint32_t max_rx_pktlen; /**< Maximum configurable length of Rx pkt. */
 	/** Maximum configurable size of LRO aggregated packet. */
 	uint32_t max_lro_pkt_size;
-- 
2.33.0