This patch adds documentation for the new optimized Toeplitz hash implementation using GFNI.
Signed-off-by: Vladimir Medvedkin <vladimir.medved...@intel.com> --- doc/guides/prog_guide/toeplitz_hash_lib.rst | 37 +++++++++++++++++++++++++---- doc/guides/rel_notes/release_21_11.rst | 4 ++++ 2 files changed, 37 insertions(+), 4 deletions(-) diff --git a/doc/guides/prog_guide/toeplitz_hash_lib.rst b/doc/guides/prog_guide/toeplitz_hash_lib.rst index f916857..88b152e 100644 --- a/doc/guides/prog_guide/toeplitz_hash_lib.rst +++ b/doc/guides/prog_guide/toeplitz_hash_lib.rst @@ -19,24 +19,53 @@ to calculate the RSS hash sum to spread the traffic among the queues. Toeplitz hash function API -------------------------- -There are two functions that provide calculation of the Toeplitz hash sum: +There are four functions that provide calculation of the Toeplitz hash sum: * ``rte_softrss()`` * ``rte_softrss_be()`` +* ``rte_thash_gfni()`` +* ``rte_thash_gfni_x2()`` -Both of these functions take the parameters: +First two functions are scalar implementation and take the parameters: * A pointer to the tuple, containing fields extracted from the packet. * A length of this tuple counted in double words. * A pointer to the RSS hash key corresponding to the one installed on the NIC. -Both functions expect the tuple to be in "host" byte order -and a multiple of 4 bytes in length. +Both of above mentioned _softrss_ functions expect the tuple to be in +"host" byte order and a multiple of 4 bytes in length. The ``rte_softrss()`` function expects the ``rss_key`` to be exactly the same as the one installed on the NIC. The ``rte_softrss_be`` function is a faster implementation, but it expects ``rss_key`` to be converted to the host byte order. +The last two functions are vectorized implementations using +Galois Fields New Instructions. Could be used if ``rte_thash_gfni_supported`` is true. +They expect the tuple to be in network byte order. + +``rte_thash_gfni()`` calculates the hash value for a single tuple, and +``rte_thash_gfni_x2()`` calculates for a two independent tuples in one go. + +``rte_thash_gfni()`` takes the parameters: + +* A pointer to the matrices derived from the RSS hash key using ``rte_thash_complete_matrix()``. +* A pointer to the tuple. +* A length of the tuple in bytes. + +``rte_thash_gfni_x2()`` takes the parameters: + +* A pointer to the matrices derived from the RSS hash key using ``rte_thash_complete_matrix()``. +* Two tuple pointers. +* A length of the longest tuple in bytes. +* Two pointers on the ``uint32_t`` to write results to. + +``rte_thash_complete_matrix()`` is a function that calculates matrices required by +GFNI implementations from the RSS hash key. It takes the parameters: + +* A pointer to the memory where the matrices will be written. +* A pointer to the RSS hash key. +* Length of the RSS hash key in bytes. + Predictable RSS --------------- diff --git a/doc/guides/rel_notes/release_21_11.rst b/doc/guides/rel_notes/release_21_11.rst index a0ad309..d6f39fb 100644 --- a/doc/guides/rel_notes/release_21_11.rst +++ b/doc/guides/rel_notes/release_21_11.rst @@ -240,6 +240,10 @@ New Features * Added tests to verify tunnel header verification in IPsec inbound. * Added tests to verify inner checksum. +* **Added optimized Toeplitz hash implementation.** + + Added optimized Toeplitz hash implementation using Galois Fields New Instructions. + Removed Items ------------- -- 2.7.4
