[PATCH v3 3/4] hash: implement RSS hash key generation API

[Vladimir Medvedkin]

This patch implements Toeplitz hash key generation function using the new
polynomial generation function.

Signed-off-by: Vladimir Medvedkin <vladimir.medved...@intel.com>
---
 lib/hash/rte_thash.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/lib/hash/rte_thash.c b/lib/hash/rte_thash.c
index 5c3d246657..80fcfe866f 100644
--- a/lib/hash/rte_thash.c
+++ b/lib/hash/rte_thash.c
@@ -803,11 +803,24 @@ int
 rte_thash_gen_key(uint8_t *key, size_t key_len, size_t reta_sz_log,
        uint32_t entropy_start, size_t entropy_sz)
 {
-       RTE_SET_USED(key);
-       RTE_SET_USED(key_len);
-       RTE_SET_USED(reta_sz_log);
-       RTE_SET_USED(entropy_start);
-       RTE_SET_USED(entropy_sz);
+       size_t i, end, start;
+
+       /* define lfsr sequence range*/
+       end = entropy_start + entropy_sz + TOEPLITZ_HASH_LEN - 1;
+       start = end - (entropy_sz + reta_sz_log - 1);
+
+       if ((key == NULL) || (key_len * CHAR_BIT < entropy_start + entropy_sz) 
||
+                       (entropy_sz < reta_sz_log) || (reta_sz_log > 
TOEPLITZ_HASH_LEN))
+               return -EINVAL;
+
+       struct thash_lfsr *lfsr = alloc_lfsr(reta_sz_log);
+       if (lfsr == NULL)
+               return -ENOMEM;
+
+       for (i = start; i < end; i++)
+               set_bit(key, get_bit_lfsr(lfsr), i);
+
+       free_lfsr(lfsr);
 
        return 0;
 }
-- 
2.43.0