ethdev: add mbuf fast free Tx offload

PMDs which expose this offload cap supports optimization for fast release
of mbufs following successful Tx.
Such optimization requires that per queue, all mbufs come from the same
mempool and has refcnt = 1.

Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>

diff --git a/doc/guides/nics/features.rst b/doc/guides/nics/features.rst
index 17745da..6538470 100644 (file)
--- a/doc/guides/nics/features.rst
+++ b/doc/guides/nics/features.rst
@@ -628,6 +628,15 @@ Supports packet type parsing and returns a list of supported types.
 
 .. _nic_features_timesync:
 
+Mbuf fast free
+--------------
+
+Supports optimization for fast release of mbufs following successful Tx.
+Requires that per queue, all mbufs come from the same mempool and has refcnt = 1.
+
+* **[uses]       rte_eth_txconf,rte_eth_txmode**: ``offloads:DEV_TX_OFFLOAD_MBUF_FAST_FREE``.
+* **[provides]   rte_eth_dev_info**: ``tx_offload_capa,tx_queue_offload_capa:DEV_TX_OFFLOAD_MBUF_FAST_FREE``.
+
 Timesync
 --------
 

diff --git a/doc/guides/nics/features/default.ini b/doc/guides/nics/features/default.ini
index 5424306..9a59901 100644 (file)
--- a/doc/guides/nics/features/default.ini
+++ b/doc/guides/nics/features/default.ini
@@ -75,3 +75,4 @@ x86-64               =
 Usage doc            =
 Design doc           =
 Perf doc             =
+Mbuf fast free       =

diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
index 856a54a..59756dd 100644 (file)
--- a/lib/librte_ether/rte_ethdev.c
+++ b/lib/librte_ether/rte_ethdev.c
@@ -1232,6 +1232,9 @@ rte_eth_convert_txq_flags(const uint32_t txq_flags, uint64_t *tx_offloads)
                offloads |= DEV_TX_OFFLOAD_UDP_CKSUM;
        if (!(txq_flags & ETH_TXQ_FLAGS_NOXSUMTCP))
                offloads |= DEV_TX_OFFLOAD_TCP_CKSUM;
+       if ((txq_flags & ETH_TXQ_FLAGS_NOREFCOUNT) &&
+           (txq_flags & ETH_TXQ_FLAGS_NOMULTMEMP))
+               offloads |= DEV_TX_OFFLOAD_MBUF_FAST_FREE;
 
        *tx_offloads = offloads;
 }
@@ -1254,6 +1257,8 @@ rte_eth_convert_txq_offloads(const uint64_t tx_offloads, uint32_t *txq_flags)
                flags |= ETH_TXQ_FLAGS_NOXSUMUDP;
        if (!(tx_offloads & DEV_TX_OFFLOAD_TCP_CKSUM))
                flags |= ETH_TXQ_FLAGS_NOXSUMTCP;
+       if (tx_offloads & DEV_TX_OFFLOAD_MBUF_FAST_FREE)
+               flags |= (ETH_TXQ_FLAGS_NOREFCOUNT | ETH_TXQ_FLAGS_NOMULTMEMP);
 
        *txq_flags = flags;
 }

diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
index da91f87..78de045 100644 (file)
--- a/lib/librte_ether/rte_ethdev.h
+++ b/lib/librte_ether/rte_ethdev.h
@@ -991,6 +991,11 @@ struct rte_eth_conf {
  */
 #define DEV_TX_OFFLOAD_MULTI_SEGS      0x00008000
 /**< Device supports multi segment send. */
+#define DEV_TX_OFFLOAD_MBUF_FAST_FREE  0x00010000
+/**< Device supports optimization for fast release of mbufs.
+ *   When set application must guarantee that per-queue all mbufs comes from
+ *   the same mempool and has refcnt = 1.
+ */
 
 struct rte_pci_device;