[PATCH v6 20/23] mbuf: remove and stop using rte marker fields

[Tyler Retzlaff]

RTE_MARKER typedefs are a GCC extension unsupported by MSVC. Remove
RTE_MARKER fields from rte_mbuf struct.

Maintain alignment of fields after removed cacheline1 marker by placing
C11 alignas(RTE_CACHE_LINE_MIN_SIZE).

Update implementation of rte_mbuf_prefetch_part1() and
rte_mbuf_prefetch_part2() inline functions calculate pointer for
prefetch of cachline0 and cachline1 without using removed markers.

Update static_assert of rte_mbuf struct fields to reference data_off and
packet_type fields that occupy the original offsets of the marker
fields.

Signed-off-by: Tyler Retzlaff <roretzla at linux.microsoft.com>
---
 doc/guides/rel_notes/release_24_03.rst |  9 ++++++++
 lib/mbuf/rte_mbuf.h                    |  4 ++--
 lib/mbuf/rte_mbuf_core.h               | 39 +++++++++++++---------------------
 3 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/doc/guides/rel_notes/release_24_03.rst b/doc/guides/rel_notes/release_24_03.rst
index 879bb49..67750f2 100644
--- a/doc/guides/rel_notes/release_24_03.rst
+++ b/doc/guides/rel_notes/release_24_03.rst
@@ -156,6 +156,15 @@ Removed Items
   The application reserved statically defined logtypes ``RTE_LOGTYPE_USER1..RTE_LOGTYPE_USER8``
   are still defined.
 
+* mbuf: ``RTE_MARKER`` fields ``cacheline0`` ``cacheline1``
+  ``rx_descriptor_fields1`` and ``RTE_MARKER64`` field ``rearm_data``
+  have been removed from ``struct rte_mbuf``.
+  Prefetch of ``cacheline0`` and ``cacheline1`` may be achieved through
+  ``rte_mbuf_prefetch_part1()`` and ``rte_mbuf_prefetch_part2()`` inline
+  functions respectively.
+  Access to ``rearm_data`` and ``rx_descriptor_fields1`` should be
+  through new inline functions ``rte_mbuf_rearm_data()`` and
+  ``rte_mbuf_rx_descriptor_fields1()`` respectively.
 
 API Changes
 -----------
diff --git a/lib/mbuf/rte_mbuf.h b/lib/mbuf/rte_mbuf.h
index aa7495b..61cda20 100644
--- a/lib/mbuf/rte_mbuf.h
+++ b/lib/mbuf/rte_mbuf.h
@@ -108,7 +108,7 @@
 static inline void
 rte_mbuf_prefetch_part1(struct rte_mbuf *m)
 {
-	rte_prefetch0(&m->cacheline0);
+	rte_prefetch0(m);
 }
 
 /**
@@ -126,7 +126,7 @@
 rte_mbuf_prefetch_part2(struct rte_mbuf *m)
 {
 #if RTE_CACHE_LINE_SIZE == 64
-	rte_prefetch0(&m->cacheline1);
+	rte_prefetch0(RTE_PTR_ADD(m, RTE_CACHE_LINE_MIN_SIZE));
 #else
 	RTE_SET_USED(m);
 #endif
diff --git a/lib/mbuf/rte_mbuf_core.h b/lib/mbuf/rte_mbuf_core.h
index 36551c2..4e06f15 100644
--- a/lib/mbuf/rte_mbuf_core.h
+++ b/lib/mbuf/rte_mbuf_core.h
@@ -18,6 +18,7 @@
 
 #include <assert.h>
 #include <stddef.h>
+#include <stdalign.h>
 #include <stdint.h>
 
 #include <rte_common.h>
@@ -467,8 +468,6 @@ enum {
  * The generic rte_mbuf, containing a packet mbuf.
  */
 struct rte_mbuf {
-	RTE_MARKER cacheline0;
-
 	void *buf_addr;           /**< Virtual address of segment buffer. */
 #if RTE_IOVA_IN_MBUF
 	/**
@@ -495,7 +494,6 @@ struct rte_mbuf {
 	 * To obtain a pointer to rearm_data use the rte_mbuf_rearm_data()
 	 * accessor instead of directly referencing through the data_off field.
 	 */
-	RTE_MARKER64 rearm_data;
 	uint16_t data_off;
 
 	/**
@@ -522,8 +520,6 @@ struct rte_mbuf {
 	uint64_t ol_flags;        /**< Offload features. */
 
 	/* remaining bytes are set on RX when pulling packet from descriptor */
-	RTE_MARKER rx_descriptor_fields1;
-
 	/*
 	 * The packet type, which is the combination of outer/inner L2, L3, L4
 	 * and tunnel types. The packet_type is about data really present in the
@@ -607,8 +603,7 @@ struct rte_mbuf {
 	struct rte_mempool *pool; /**< Pool from which mbuf was allocated. */
 
 	/* second cache line - fields only used in slow path or on TX */
-	RTE_MARKER cacheline1 __rte_cache_min_aligned;
-
+	alignas(RTE_CACHE_LINE_MIN_SIZE)
 #if RTE_IOVA_IN_MBUF
 	/**
 	 * Next segment of scattered packet. Must be NULL in the last
@@ -677,35 +672,31 @@ struct rte_mbuf {
 } __rte_cache_aligned;
 
 static_assert(!(offsetof(struct rte_mbuf, ol_flags) !=
-	offsetof(struct rte_mbuf, rearm_data) + 8), "ol_flags");
-static_assert(!(offsetof(struct rte_mbuf, rearm_data) !=
-	RTE_ALIGN(offsetof(struct rte_mbuf, rearm_data), 16)), "rearm_data");
+	offsetof(struct rte_mbuf, data_off) + 8), "ol_flags");
 static_assert(!(offsetof(struct rte_mbuf, data_off) !=
-	offsetof(struct rte_mbuf, rearm_data)), "data_off");
-static_assert(!(offsetof(struct rte_mbuf, data_off) <
-	offsetof(struct rte_mbuf, rearm_data)), "data_off");
+	RTE_ALIGN(offsetof(struct rte_mbuf, data_off), 16)), "data_off");
 static_assert(!(offsetof(struct rte_mbuf, refcnt) <
-	offsetof(struct rte_mbuf, rearm_data)), "refcnt");
+	offsetof(struct rte_mbuf, data_off)), "refcnt");
 static_assert(!(offsetof(struct rte_mbuf, nb_segs) <
-	offsetof(struct rte_mbuf, rearm_data)), "nb_segs");
+	offsetof(struct rte_mbuf, data_off)), "nb_segs");
 static_assert(!(offsetof(struct rte_mbuf, port) <
-	offsetof(struct rte_mbuf, rearm_data)), "port");
+	offsetof(struct rte_mbuf, data_off)), "port");
 static_assert(!(offsetof(struct rte_mbuf, data_off) -
-	offsetof(struct rte_mbuf, rearm_data) > 6), "data_off");
+	offsetof(struct rte_mbuf, data_off) > 6), "data_off");
 static_assert(!(offsetof(struct rte_mbuf, refcnt) -
-	offsetof(struct rte_mbuf, rearm_data) > 6), "refcnt");
+	offsetof(struct rte_mbuf, data_off) > 6), "refcnt");
 static_assert(!(offsetof(struct rte_mbuf, nb_segs) -
-	offsetof(struct rte_mbuf, rearm_data) > 6), "nb_segs");
+	offsetof(struct rte_mbuf, data_off) > 6), "nb_segs");
 static_assert(!(offsetof(struct rte_mbuf, port) -
-	offsetof(struct rte_mbuf, rearm_data) > 6), "port");
+	offsetof(struct rte_mbuf, data_off) > 6), "port");
 static_assert(!(offsetof(struct rte_mbuf, pkt_len) !=
-	offsetof(struct rte_mbuf, rx_descriptor_fields1) + 4), "pkt_len");
+	offsetof(struct rte_mbuf, packet_type) + 4), "pkt_len");
 static_assert(!(offsetof(struct rte_mbuf, data_len) !=
-	offsetof(struct rte_mbuf, rx_descriptor_fields1) + 8), "data_len");
+	offsetof(struct rte_mbuf, packet_type) + 8), "data_len");
 static_assert(!(offsetof(struct rte_mbuf, vlan_tci) !=
-	offsetof(struct rte_mbuf, rx_descriptor_fields1) + 10), "vlan_tci");
+	offsetof(struct rte_mbuf, packet_type) + 10), "vlan_tci");
 static_assert(!(offsetof(struct rte_mbuf, hash) !=
-	offsetof(struct rte_mbuf, rx_descriptor_fields1) + 12), "hash");
+	offsetof(struct rte_mbuf, packet_type) + 12), "hash");
 
 /**
  * Function typedef of callback to free externally attached buffer.
-- 
1.8.3.1