[dpdk-dev] [PATCH] doc: update the snow3g library information

[Pablo de Lara <pablo.de.lara.guarch@intel.com>]

A new process to request the libsso library required by the SNOW3G PMD
has been put in place, through a website, replacing the previous email method.
This commit updates the SNOW3G documentation, to reflect this change.

Since the library does not support newer gcc versions, the documentation
also contains a patch to make the library work with gcc > 5.0.

Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
---
 doc/guides/cryptodevs/snow3g.rst | 41 ++++++++++++++++++++++++++++++++--------
 1 file changed, 33 insertions(+), 8 deletions(-)

diff --git a/doc/guides/cryptodevs/snow3g.rst b/doc/guides/cryptodevs/snow3g.rst
index b4c53dc..7e38d20 100644
--- a/doc/guides/cryptodevs/snow3g.rst
+++ b/doc/guides/cryptodevs/snow3g.rst
@@ -57,15 +57,40 @@ Limitations
 Installation
 ------------
 
-To build DPDK with the SNOW3G_PMD the user is required to get
-the export controlled libsso library, sending a request to
-`DPDKUser_software_access@intel.com`, and compile it
-on their user system before building DPDK:
+To build DPDK with the SNOW3G_PMD the user is required to download
+the export controlled ``libsso`` library, by requesting it from
+`<https://networkbuilders.intel.com/network-technologies/dpdk>`_,
+and compiling it on their system before building DPDK::
 
-.. code-block:: console
+   make -f Makefile_snow3g
 
-	make -f Makefile_snow3g
+**Note**: If using a gcc version higher than 5.0, and compilation fails, apply the following patch:
 
-The environmental variable LIBSSO_PATH must be exported with the path
+.. code-block:: diff
+
+   /libsso/src/snow3g/sso_snow3g.c
+
+   static inline void ClockFSM_4(sso_snow3gKeyState4_t *pCtx, __m128i *data)
+   {
+       __m128i F, R;
+   -    uint32_t K, L;
+   +    uint32_t K;
+   +    /* Declare unused if SNOW3G_WSM/SNB are defined */
+   +    uint32_t L __attribute__ ((unused)) = 0;
+
+        F = _mm_add_epi32(pCtx->LFSR_X[15], pCtx->FSM_X[0]);
+        R = _mm_xor_si128(pCtx->LFSR_X[5], pCtx->FSM_X[2]);
+
+   /libsso/include/sso_snow3g_internal.h
+
+   -inline void ClockFSM_1(sso_snow3gKeyState1_t *pCtx, uint32_t *data);
+   -inline void ClockLFSR_1(sso_snow3gKeyState1_t *pCtx);
+   -inline void sso_snow3gStateInitialize_1(sso_snow3gKeyState1_t * pCtx, sso_snow3g_key_schedule_t *pKeySched, uint8_t *pIV);
+   +void ClockFSM_1(sso_snow3gKeyState1_t *pCtx, uint32_t *data);
+   +void ClockLFSR_1(sso_snow3gKeyState1_t *pCtx);
+   +void sso_snow3gStateInitialize_1(sso_snow3gKeyState1_t * pCtx, sso_snow3g_key_schedule_t *pKeySched, uint8_t *pIV);
+
+
+The environmental variable ``LIBSSO_PATH`` must be exported with the path
 where you extracted and built the libsso library and finally set
-CONFIG_RTE_LIBRTE_PMD_SNOW3G=y in config/common_base.
+``CONFIG_RTE_LIBRTE_PMD_SNOW3G=y`` in ``config/common_base``.
-- 
2.5.5