[dpdk-dev,1/2] mbuf: fix Tx checksum offload API doc
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Commit Message
When introducing rte_eth_tx_prepare(), the constraints on checksum
pre-filling for Tx offloads were relaxed because implemented in
the PMDs with rte_net_intel_cksum_flags_prepare() helper.
As a consequence, these old requirements are removed for:
- PKT_TX_OUTER_IP_CKSUM
- PKT_TX_IP_CKSUM
- PKT_TX_[L4]_CKSUM
- PKT_TX_TCP_SEG
Not sure SCTP offload is properly implemented though.
A reference to rte_eth_tx_prepare() is added in rte_eth_tx_burst() doc.
Fixes: 4fb7e803eb1a ("ethdev: add Tx preparation")
Cc: tomaszx.kulasek@intel.com
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
---
lib/librte_ether/rte_ethdev.h | 3 +++
lib/librte_mbuf/rte_mbuf.h | 16 +++-------------
2 files changed, 6 insertions(+), 13 deletions(-)
Comments
On Fri, Apr 20, 2018 at 02:13:23AM +0200, Thomas Monjalon wrote:
> When introducing rte_eth_tx_prepare(), the constraints on checksum
> pre-filling for Tx offloads were relaxed because implemented in
> the PMDs with rte_net_intel_cksum_flags_prepare() helper.
> As a consequence, these old requirements are removed for:
> - PKT_TX_OUTER_IP_CKSUM
> - PKT_TX_IP_CKSUM
> - PKT_TX_[L4]_CKSUM
> - PKT_TX_TCP_SEG
>
> Not sure SCTP offload is properly implemented though.
>
> A reference to rte_eth_tx_prepare() is added in rte_eth_tx_burst() doc.
>
> Fixes: 4fb7e803eb1a ("ethdev: add Tx preparation")
> Cc: tomaszx.kulasek@intel.com
>
> Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
> @@ -288,10 +280,8 @@ extern "C" {
>
> /**
> * Offload the IP checksum of an external header in the hardware. The
> - * flag PKT_TX_OUTER_IPV4 should also be set by the application, alto ugh
> - * a PMD will only check PKT_TX_IP_CKSUM. The IP checksum field in the
> - * packet must be set to 0.
> - * - set the outer IP checksum field in the packet to 0
> + * flag PKT_TX_OUTER_IPV4 should also be set by the application, altough
> + * a PMD will only check PKT_TX_OUTER_IP_CKSUM.
> * - fill the mbuf offload information: outer_l2_len, outer_l3_len
> */
> #define PKT_TX_OUTER_IP_CKSUM (1ULL << 58)
Nice catch (PKT_TX_IP_CKSUM -> PKT_TX_OUTER_IP_CKSUM).
It could eventually deserve also a:
Fixes: 609dd68ef14f ("mbuf: enhance the API documentation of offload flags")
Thanks
Olivier
@@ -3911,6 +3911,9 @@ static inline int rte_eth_tx_descriptor_status(uint16_t port_id,
* invoke this function concurrently on the same tx queue without SW lock.
* @see rte_eth_dev_info_get, struct rte_eth_txconf::txq_flags
*
+ * @see rte_eth_tx_prepare to perform some prior checks or adjustments
+ * for offloads.
+ *
* @param port_id
* The port identifier of the Ethernet device.
* @param queue_id
@@ -226,12 +226,8 @@ extern "C" {
* - set the PKT_TX_TCP_SEG flag in mbuf->ol_flags (this flag implies
* PKT_TX_TCP_CKSUM)
* - set the flag PKT_TX_IPV4 or PKT_TX_IPV6
- * - if it's IPv4, set the PKT_TX_IP_CKSUM flag and write the IP checksum
- * to 0 in the packet
+ * - if it's IPv4, set the PKT_TX_IP_CKSUM flag
* - fill the mbuf offload information: l2_len, l3_len, l4_len, tso_segsz
- * - calculate the pseudo header checksum without taking ip_len in account,
- * and set it in the TCP header. Refer to rte_ipv4_phdr_cksum() and
- * rte_ipv6_phdr_cksum() that can be used as helpers.
*/
#define PKT_TX_TCP_SEG (1ULL << 50)
@@ -244,9 +240,6 @@ extern "C" {
* - fill l2_len and l3_len in mbuf
* - set the flags PKT_TX_TCP_CKSUM, PKT_TX_SCTP_CKSUM or PKT_TX_UDP_CKSUM
* - set the flag PKT_TX_IPV4 or PKT_TX_IPV6
- * - calculate the pseudo header checksum and set it in the L4 header (only
- * for TCP or UDP). See rte_ipv4_phdr_cksum() and rte_ipv6_phdr_cksum().
- * For SCTP, set the crc field to 0.
*/
#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. */
@@ -258,7 +251,6 @@ extern "C" {
* Offload the IP checksum in the hardware. The flag PKT_TX_IPV4 should
* also be set by the application, although a PMD will only check
* PKT_TX_IP_CKSUM.
- * - set the IP checksum field in the packet to 0
* - fill the mbuf offload information: l2_len, l3_len
*/
#define PKT_TX_IP_CKSUM (1ULL << 54)
@@ -288,10 +280,8 @@ extern "C" {
/**
* Offload the IP checksum of an external header in the hardware. The
- * flag PKT_TX_OUTER_IPV4 should also be set by the application, alto ugh
- * a PMD will only check PKT_TX_IP_CKSUM. The IP checksum field in the
- * packet must be set to 0.
- * - set the outer IP checksum field in the packet to 0
+ * flag PKT_TX_OUTER_IPV4 should also be set by the application, altough
+ * a PMD will only check PKT_TX_OUTER_IP_CKSUM.
* - fill the mbuf offload information: outer_l2_len, outer_l3_len
*/
#define PKT_TX_OUTER_IP_CKSUM (1ULL << 58)