[dpdk-dev] [PATCH 3/8] net/octeontx: add fast mbuf free support

Harman Kalra hkalra at marvell.com
Mon Mar 16 10:33:39 CET 2020


This patch adds capability to fast release of mbuf
following successful transmission.

Signed-off-by: Harman Kalra <hkalra at marvell.com>
---
 drivers/net/octeontx/octeontx_ethdev.c |  4 +-
 drivers/net/octeontx/octeontx_ethdev.h |  1 +
 drivers/net/octeontx/octeontx_rxtx.c   |  9 +--
 drivers/net/octeontx/octeontx_rxtx.h   | 93 ++++++++++++++++++++++++--
 4 files changed, 98 insertions(+), 9 deletions(-)

diff --git a/drivers/net/octeontx/octeontx_ethdev.c b/drivers/net/octeontx/octeontx_ethdev.c
index d6adbbc93..97b4298fe 100644
--- a/drivers/net/octeontx/octeontx_ethdev.c
+++ b/drivers/net/octeontx/octeontx_ethdev.c
@@ -267,7 +267,9 @@ octeontx_tx_offload_flags(struct rte_eth_dev *eth_dev)
 	struct octeontx_nic *nic = octeontx_pmd_priv(eth_dev);
 	uint16_t flags = 0;
 
-	/* Created function for supoorting future offloads */
+	if (!(nic->tx_offloads & DEV_TX_OFFLOAD_MBUF_FAST_FREE))
+		flags |= OCCTX_TX_OFFLOAD_MBUF_NOFF_F;
+
 	if (nic->tx_offloads & DEV_TX_OFFLOAD_MULTI_SEGS)
 		flags |= OCCTX_TX_MULTI_SEG_F;
 
diff --git a/drivers/net/octeontx/octeontx_ethdev.h b/drivers/net/octeontx/octeontx_ethdev.h
index 06223e6e7..1abe1703b 100644
--- a/drivers/net/octeontx/octeontx_ethdev.h
+++ b/drivers/net/octeontx/octeontx_ethdev.h
@@ -34,6 +34,7 @@
 					 DEV_RX_OFFLOAD_JUMBO_FRAME)
 
 #define OCTEONTX_TX_OFFLOADS		(DEV_TX_OFFLOAD_MT_LOCKFREE    |  \
+					 DEV_TX_OFFLOAD_MBUF_FAST_FREE |  \
 					 DEV_TX_OFFLOAD_MULTI_SEGS)
 
 static inline struct octeontx_nic *
diff --git a/drivers/net/octeontx/octeontx_rxtx.c b/drivers/net/octeontx/octeontx_rxtx.c
index 3de88e187..c817f7179 100644
--- a/drivers/net/octeontx/octeontx_rxtx.c
+++ b/drivers/net/octeontx/octeontx_rxtx.c
@@ -41,7 +41,7 @@ octeontx_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 	return count; /* return number of pkts received */
 }
 
-#define T(name, f1, sz, flags)					\
+#define T(name, f1, f0, sz, flags)					\
 static uint16_t __rte_noinline	__hot					\
 octeontx_xmit_pkts_ ##name(void *tx_queue,				\
 			struct rte_mbuf **tx_pkts, uint16_t pkts)	\
@@ -60,14 +60,15 @@ octeontx_set_tx_function(struct rte_eth_dev *dev)
 {
 	struct octeontx_nic *nic = octeontx_pmd_priv(dev);
 
-	const eth_tx_burst_t tx_burst_func[2] = {
-#define T(name, f0, sz, flags)			\
-	[f0] =  octeontx_xmit_pkts_ ##name,
+	const eth_tx_burst_t tx_burst_func[2][2] = {
+#define T(name, f1, f0, sz, flags)			\
+	[f1][f0] =  octeontx_xmit_pkts_ ##name,
 
 OCCTX_TX_FASTPATH_MODES
 #undef T
 	};
 
 	dev->tx_pkt_burst = tx_burst_func
+		[!!(nic->tx_offload_flags & OCCTX_TX_OFFLOAD_MBUF_NOFF_F)]
 		[!!(nic->tx_offload_flags & OCCTX_TX_MULTI_SEG_F)];
 }
diff --git a/drivers/net/octeontx/octeontx_rxtx.h b/drivers/net/octeontx/octeontx_rxtx.h
index 6182cd8ee..2383a8eb6 100644
--- a/drivers/net/octeontx/octeontx_rxtx.h
+++ b/drivers/net/octeontx/octeontx_rxtx.h
@@ -22,6 +22,7 @@
 #define OCCTX_RX_MULTI_SEG_F		BIT(15)
 
 #define OCCTX_TX_OFFLOAD_NONE		(0)
+#define OCCTX_TX_OFFLOAD_MBUF_NOFF_F	BIT(3)
 
 #define OCCTX_TX_MULTI_SEG_F		BIT(15)
 /* Packet type table */
@@ -114,9 +115,75 @@ ptype_table[PTYPE_SIZE][PTYPE_SIZE][PTYPE_SIZE] = {
 };
 
 
+static __rte_always_inline uint64_t
+octeontx_pktmbuf_detach(struct rte_mbuf *m)
+{
+	struct rte_mempool *mp = m->pool;
+	uint32_t mbuf_size, buf_len;
+	struct rte_mbuf *md;
+	uint16_t priv_size;
+	uint16_t refcount;
+
+	/* Update refcount of direct mbuf */
+	md = rte_mbuf_from_indirect(m);
+	refcount = rte_mbuf_refcnt_update(md, -1);
+
+	priv_size = rte_pktmbuf_priv_size(mp);
+	mbuf_size = (uint32_t)(sizeof(struct rte_mbuf) + priv_size);
+	buf_len = rte_pktmbuf_data_room_size(mp);
+
+	m->priv_size = priv_size;
+	m->buf_addr = (char *)m + mbuf_size;
+	m->buf_iova = rte_mempool_virt2iova(m) + mbuf_size;
+	m->buf_len = (uint16_t)buf_len;
+	rte_pktmbuf_reset_headroom(m);
+	m->data_len = 0;
+	m->ol_flags = 0;
+	m->next = NULL;
+	m->nb_segs = 1;
+
+	/* Now indirect mbuf is safe to free */
+	rte_pktmbuf_free(m);
+
+	if (refcount == 0) {
+		rte_mbuf_refcnt_set(md, 1);
+		md->data_len = 0;
+		md->ol_flags = 0;
+		md->next = NULL;
+		md->nb_segs = 1;
+		return 0;
+	} else {
+		return 1;
+	}
+}
+
+static __rte_always_inline uint64_t
+octeontx_prefree_seg(struct rte_mbuf *m)
+{
+	if (likely(rte_mbuf_refcnt_read(m) == 1)) {
+		if (!RTE_MBUF_DIRECT(m))
+			return octeontx_pktmbuf_detach(m);
+
+		m->next = NULL;
+		m->nb_segs = 1;
+		return 0;
+	} else if (rte_mbuf_refcnt_update(m, -1) == 0) {
+		if (!RTE_MBUF_DIRECT(m))
+			return octeontx_pktmbuf_detach(m);
+
+		rte_mbuf_refcnt_set(m, 1);
+		m->next = NULL;
+		m->nb_segs = 1;
+		return 0;
+	}
+
+	/* Mbuf is having refcount more than 1 so need not to be freed */
+	return 1;
+}
+
 static __rte_always_inline uint16_t
 __octeontx_xmit_prepare(struct rte_mbuf *tx_pkt, uint64_t *cmd_buf,
-			const uint16_t flag __rte_unused)
+			const uint16_t flag)
 {
 	uint16_t gaura_id, nb_desc = 0;
 
@@ -124,6 +191,13 @@ __octeontx_xmit_prepare(struct rte_mbuf *tx_pkt, uint64_t *cmd_buf,
 	cmd_buf[nb_desc++] = tx_pkt->data_len & 0xffff;
 	cmd_buf[nb_desc++] = 0x0;
 
+	/* SEND_HDR[DF] bit controls if buffer is to be freed or
+	 * not, as SG_DESC[I] and SEND_HDR[II] are clear.
+	 */
+	if (flag & OCCTX_TX_OFFLOAD_MBUF_NOFF_F)
+		cmd_buf[0] |= (octeontx_prefree_seg(tx_pkt) <<
+			       58);
+
 	/* Mark mempool object as "put" since it is freed by PKO */
 	if (!(cmd_buf[0] & (1ULL << 58)))
 		__mempool_check_cookies(tx_pkt->pool, (void **)&tx_pkt,
@@ -144,7 +218,7 @@ __octeontx_xmit_prepare(struct rte_mbuf *tx_pkt, uint64_t *cmd_buf,
 
 static __rte_always_inline uint16_t
 __octeontx_xmit_mseg_prepare(struct rte_mbuf *tx_pkt, uint64_t *cmd_buf,
-			const uint16_t flag __rte_unused)
+			const uint16_t flag)
 {
 	uint16_t nb_segs, nb_desc = 0;
 	uint16_t gaura_id, len = 0;
@@ -169,6 +243,14 @@ __octeontx_xmit_mseg_prepare(struct rte_mbuf *tx_pkt, uint64_t *cmd_buf,
 				   PKO_SEND_GATHER_GAUAR((long)gaura_id) |
 				   tx_pkt->data_len;
 
+		/* SG_DESC[I] bit controls if buffer is to be freed or
+		 * not, as SEND_HDR[DF] and SEND_HDR[II] are clear.
+		 */
+		if (flag & OCCTX_TX_OFFLOAD_MBUF_NOFF_F) {
+			cmd_buf[nb_desc] |=
+			     (octeontx_prefree_seg(tx_pkt) << 57);
+		}
+
 		/* Mark mempool object as "put" since it is freed by
 		 * PKO.
 		 */
@@ -222,10 +304,13 @@ __octeontx_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 uint16_t
 octeontx_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
 
+#define NOFF_F       OCCTX_TX_OFFLOAD_MBUF_NOFF_F
 #define MULT_F       OCCTX_TX_MULTI_SEG_F
 /* [NOFF] [MULTI_SEG] */
 #define OCCTX_TX_FASTPATH_MODES						      \
-T(no_offload,				0,	4,   OCCTX_TX_OFFLOAD_NONE)   \
-T(mseg,					1,	14,  MULT_F)		      \
+T(no_offload,				0, 0,	4,   OCCTX_TX_OFFLOAD_NONE)   \
+T(mseg,					0, 1,	14,  MULT_F)		      \
+T(noff,					1, 0,	4,   NOFF_F)		      \
+T(noff_mseg,				1, 1,	14,  NOFF_F | MULT_F)
 
  #endif /* __OCTEONTX_RXTX_H__ */
-- 
2.18.0



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