[dpdk-dev] [PATCH 1/3] mbuf: move TX flags to group them near end of field

[Bruce Richardson]

This patch takes the existing TX flags defined for the mbuf and shifts
each uniquely defined one left so that additional RX flags can be
defined without having RX and TX flags mixed together. Under the new
scheme, RX flags start at bit 0 and work left, TX flags start at bit 55
and work right, and bits 56-63 are reserved for generic mbuf use, not
for offloads.

Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
---
 lib/librte_mbuf/rte_mbuf.h | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index 1c6e115..7aa507e 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -68,6 +68,12 @@ extern "C" {
 /*
  * Packet Offload Features Flags. It also carry packet type information.
  * Critical resources. Both rx/tx shared these bits. Be cautious on any change
+ *
+ * - RX flags start at bit position zero, and get added to the left of previous
+ *   flags.
+ * - The most-significant 8 bits are reserved for generic mbuf flags
+ * - TX flags therefore start at bit position 55 (i.e. 63-8), and new flags get
+ *   added to the right of the previously defined flags
  */
 #define PKT_RX_VLAN_PKT      0x0001 /**< RX packet is a 802.1q VLAN packet. */
 #define PKT_RX_RSS_HASH      0x0002 /**< RX packet with RSS hash result. */
@@ -86,26 +92,27 @@ extern "C" {
 #define PKT_RX_IEEE1588_PTP  0x0200 /**< RX IEEE1588 L2 Ethernet PT Packet. */
 #define PKT_RX_IEEE1588_TMST 0x0400 /**< RX IEEE1588 L2/L4 timestamped packet.*/
 
-#define PKT_TX_VLAN_PKT      0x0800 /**< TX packet is a 802.1q VLAN packet. */
-#define PKT_TX_IP_CKSUM      0x1000 /**< IP cksum of TX pkt. computed by NIC. */
-#define PKT_TX_IPV4_CSUM     0x1000 /**< Alias of PKT_TX_IP_CKSUM. */
+#define PKT_TX_VLAN_PKT      (1ULL << 55) /**< TX packet is a 802.1q VLAN packet. */
+#define PKT_TX_IP_CKSUM      (1ULL << 54) /**< IP cksum of TX pkt. computed by NIC. */
+#define PKT_TX_IPV4_CSUM     PKT_TX_IP_CKSUM /**< Alias of PKT_TX_IP_CKSUM. */
 #define PKT_TX_IPV4          PKT_RX_IPV4_HDR /**< IPv4 with no IP checksum offload. */
 #define PKT_TX_IPV6          PKT_RX_IPV6_HDR /**< IPv6 packet */
 
 /*
- * Bit 14~13 used for L4 packet type with checksum enabled.
+ * Bits 52+53 used for L4 packet type with checksum enabled.
  *     00: Reserved
  *     01: TCP checksum
  *     10: SCTP checksum
  *     11: UDP checksum
  */
-#define PKT_TX_L4_MASK       0x6000 /**< Mask bits for L4 checksum offload request. */
-#define PKT_TX_L4_NO_CKSUM   0x0000 /**< Disable L4 cksum of TX pkt. */
-#define PKT_TX_TCP_CKSUM     0x2000 /**< TCP cksum of TX pkt. computed by NIC. */
-#define PKT_TX_SCTP_CKSUM    0x4000 /**< SCTP cksum of TX pkt. computed by NIC. */
-#define PKT_TX_UDP_CKSUM     0x6000 /**< UDP cksum of TX pkt. computed by NIC. */
-/* Bit 15 */
-#define PKT_TX_IEEE1588_TMST 0x8000 /**< TX IEEE1588 packet to timestamp. */
+#define PKT_TX_L4_NO_CKSUM   (0ULL << 52) /**< Disable L4 cksum of TX pkt. */
+#define PKT_TX_TCP_CKSUM     (1ULL << 52) /**< TCP cksum of TX pkt. computed by NIC. */
+#define PKT_TX_SCTP_CKSUM    (2ULL << 52) /**< SCTP cksum of TX pkt. computed by NIC. */
+#define PKT_TX_UDP_CKSUM     (3ULL << 52) /**< UDP cksum of TX pkt. computed by NIC. */
+#define PKT_TX_L4_MASK       (3ULL << 52) /**< Mask for L4 cksum offload request. */
+
+/* Bit 51 - IEEE1588*/
+#define PKT_TX_IEEE1588_TMST (1ULL << 51) /**< TX IEEE1588 packet to timestamp. */
 
 /* Use final bit of flags to indicate a control mbuf */
 #define CTRL_MBUF_FLAG       (1ULL << 63)
-- 
1.9.3