[PATCH] mbuf: add mbuf physical address field to dynamic field

[Shijith Thotton]

If all devices are configured to run in IOVA mode as VA, physical
address field of mbuf (buf_iova) won't be used. In such cases, buf_iova
space is free to use as a dynamic field. So a new dynamic field member
(dynfield2) is added in mbuf structure to make use of that space.

A new mbuf flag RTE_MBUF_F_DYNFIELD2 is introduced to help identify the
mbuf that can use dynfield2.

Signed-off-by: Shijith Thotton <sthotton at marvell.com>
---
 lib/mbuf/rte_mbuf.c      |  8 ++++++++
 lib/mbuf/rte_mbuf.h      | 16 +++++++++++++---
 lib/mbuf/rte_mbuf_core.h | 29 ++++++++++++++++++++++-------
 lib/mbuf/rte_mbuf_dyn.c  |  3 +++
 4 files changed, 46 insertions(+), 10 deletions(-)

diff --git a/lib/mbuf/rte_mbuf.c b/lib/mbuf/rte_mbuf.c
index a2307cebe6..718b4505c4 100644
--- a/lib/mbuf/rte_mbuf.c
+++ b/lib/mbuf/rte_mbuf.c
@@ -101,6 +101,10 @@ rte_pktmbuf_init(struct rte_mempool *mp,
 	m->port = RTE_MBUF_PORT_INVALID;
 	rte_mbuf_refcnt_set(m, 1);
 	m->next = NULL;
+
+	/* enable dynfield2 if IOVA mode is VA */
+	if (rte_eal_iova_mode() == RTE_IOVA_VA)
+		m->ol_flags = RTE_MBUF_F_DYNFIELD2;
 }
 
 /*
@@ -206,6 +210,10 @@ __rte_pktmbuf_init_extmem(struct rte_mempool *mp,
 	rte_mbuf_refcnt_set(m, 1);
 	m->next = NULL;
 
+	/* enable dynfield2 if IOVA mode is VA */
+	if (rte_eal_iova_mode() == RTE_IOVA_VA)
+		m->ol_flags |= RTE_MBUF_F_DYNFIELD2;
+
 	/* init external buffer shared info items */
 	shinfo = RTE_PTR_ADD(m, mbuf_size);
 	m->shinfo = shinfo;
diff --git a/lib/mbuf/rte_mbuf.h b/lib/mbuf/rte_mbuf.h
index 9811e8c760..59485f04ed 100644
--- a/lib/mbuf/rte_mbuf.h
+++ b/lib/mbuf/rte_mbuf.h
@@ -1056,9 +1056,11 @@ rte_pktmbuf_attach_extbuf(struct rte_mbuf *m, void *buf_addr,
 	RTE_ASSERT(shinfo->free_cb != NULL);
 
 	m->buf_addr = buf_addr;
-	m->buf_iova = buf_iova;
 	m->buf_len = buf_len;
 
+	if (!RTE_MBUF_HAS_DYNFIELD2(m))
+		m->buf_iova = buf_iova;
+
 	m->data_len = 0;
 	m->data_off = 0;
 
@@ -1087,6 +1089,10 @@ static inline void
 rte_mbuf_dynfield_copy(struct rte_mbuf *mdst, const struct rte_mbuf *msrc)
 {
 	memcpy(&mdst->dynfield1, msrc->dynfield1, sizeof(mdst->dynfield1));
+
+	if (RTE_MBUF_HAS_DYNFIELD2(mdst))
+		memcpy(&mdst->dynfield2, &msrc->dynfield2,
+		       sizeof(mdst->dynfield2));
 }
 
 /* internal */
@@ -1143,10 +1149,12 @@ static inline void rte_pktmbuf_attach(struct rte_mbuf *mi, struct rte_mbuf *m)
 
 	mi->data_off = m->data_off;
 	mi->data_len = m->data_len;
-	mi->buf_iova = m->buf_iova;
 	mi->buf_addr = m->buf_addr;
 	mi->buf_len = m->buf_len;
 
+	if (!RTE_MBUF_HAS_DYNFIELD2(mi))
+		mi->buf_iova = m->buf_iova;
+
 	mi->next = NULL;
 	mi->pkt_len = mi->data_len;
 	mi->nb_segs = 1;
@@ -1245,11 +1253,13 @@ static inline void rte_pktmbuf_detach(struct rte_mbuf *m)
 
 	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;
+
+	if (!RTE_MBUF_HAS_DYNFIELD2(m))
+		m->buf_iova = rte_mempool_virt2iova(m) + mbuf_size;
 }
 
 /**
diff --git a/lib/mbuf/rte_mbuf_core.h b/lib/mbuf/rte_mbuf_core.h
index 3d6ddd6773..a549e36464 100644
--- a/lib/mbuf/rte_mbuf_core.h
+++ b/lib/mbuf/rte_mbuf_core.h
@@ -504,6 +504,8 @@ extern "C" {
 #define RTE_MBUF_F_INDIRECT    (1ULL << 62) /**< Indirect attached mbuf */
 #define IND_ATTACHED_MBUF RTE_DEPRECATED(IND_ATTACHED_MBUF) RTE_MBUF_F_INDIRECT
 
+#define RTE_MBUF_F_DYNFIELD2	(1ULL << 63) /**< dynfield2 mbuf field enabled */
+
 /** Alignment constraint of mbuf private area. */
 #define RTE_MBUF_PRIV_ALIGN 8
 
@@ -579,13 +581,18 @@ struct rte_mbuf {
 	RTE_MARKER cacheline0;
 
 	void *buf_addr;           /**< Virtual address of segment buffer. */
-	/**
-	 * Physical address of segment buffer.
-	 * Force alignment to 8-bytes, so as to ensure we have the exact
-	 * same mbuf cacheline0 layout for 32-bit and 64-bit. This makes
-	 * working on vector drivers easier.
-	 */
-	rte_iova_t buf_iova __rte_aligned(sizeof(rte_iova_t));
+	RTE_STD_C11
+	union {
+		/**
+		 * Physical address of segment buffer if IOVA mode is not VA.
+		 * Force alignment to 8-bytes, so as to ensure we have the exact
+		 * same mbuf cacheline0 layout for 32-bit and 64-bit. This makes
+		 * working on vector drivers easier.
+		 */
+		rte_iova_t buf_iova __rte_aligned(sizeof(rte_iova_t));
+		/* Reserved for dynamic field if IOVA mode is VA. */
+		uint64_t dynfield2;
+	};
 
 	/* next 8 bytes are initialised on RX descriptor rearm */
 	RTE_MARKER64 rearm_data;
@@ -803,6 +810,14 @@ struct rte_mbuf_ext_shared_info {
 #define RTE_MBUF_DIRECT(mb) \
 	(!((mb)->ol_flags & (RTE_MBUF_F_INDIRECT | RTE_MBUF_F_EXTERNAL)))
 
+/**
+ *
+ * Retrurns TRUE if given mbuf has dynfield2 field enabled, or FALSE otherwise.
+ *
+ * dynfield2 field can be enabled if IOVA mode is configured as VA.
+ */
+#define RTE_MBUF_HAS_DYNFIELD2(mb) (!!((mb)->ol_flags & RTE_MBUF_F_DYNFIELD2))
+
 /** Uninitialized or unspecified port. */
 #define RTE_MBUF_PORT_INVALID UINT16_MAX
 /** For backwards compatibility. */
diff --git a/lib/mbuf/rte_mbuf_dyn.c b/lib/mbuf/rte_mbuf_dyn.c
index 4ae79383b5..7bfe50e0e2 100644
--- a/lib/mbuf/rte_mbuf_dyn.c
+++ b/lib/mbuf/rte_mbuf_dyn.c
@@ -127,7 +127,10 @@ init_shared_mem(void)
 		 * rte_mbuf_dynfield_copy().
 		 */
 		memset(shm, 0, sizeof(*shm));
+
 		mark_free(dynfield1);
+		if (rte_eal_iova_mode() == RTE_IOVA_VA)
+			mark_free(dynfield2);
 
 		/* init free_flags */
 		for (mask = RTE_MBUF_F_FIRST_FREE; mask <= RTE_MBUF_F_LAST_FREE; mask <<= 1)
-- 
2.25.1