[dpdk-stable] [PATCH 1/4] lpm: fix vector lookup for Arm

[Ruifeng Wang]

rte_lpm_lookupx4 could return wrong next hop when more than 256 tbl8
groups are created. This is caused by incorrect type casting of tbl8
group index that been stored in tbl24 entry. The casting caused group
index truncation and hence wrong tbl8 group been searched.

Issue fixed by applying proper mask to tbl24 entry to get tbl8 group index.

Fixes: cbc2f1dccfba ("lpm/arm: support NEON")
Cc: jerinj at marvell.com
Cc: stable at dpdk.org

Signed-off-by: Ruifeng Wang <ruifeng.wang at arm.com>
---
 lib/librte_lpm/rte_lpm_neon.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/librte_lpm/rte_lpm_neon.h b/lib/librte_lpm/rte_lpm_neon.h
index 6c131d312..4642a866f 100644
--- a/lib/librte_lpm/rte_lpm_neon.h
+++ b/lib/librte_lpm/rte_lpm_neon.h
@@ -81,28 +81,28 @@ rte_lpm_lookupx4(const struct rte_lpm *lpm, xmm_t ip, uint32_t hop[4],
 	if (unlikely((pt & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
 			RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
 		i8.u32[0] = i8.u32[0] +
-			(uint8_t)tbl[0] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
+			(tbl[0] & 0x00FFFFFF) * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
 		ptbl = (const uint32_t *)&lpm->tbl8[i8.u32[0]];
 		tbl[0] = *ptbl;
 	}
 	if (unlikely((pt >> 32 & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
 			RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
 		i8.u32[1] = i8.u32[1] +
-			(uint8_t)tbl[1] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
+			(tbl[1] & 0x00FFFFFF) * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
 		ptbl = (const uint32_t *)&lpm->tbl8[i8.u32[1]];
 		tbl[1] = *ptbl;
 	}
 	if (unlikely((pt2 & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
 			RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
 		i8.u32[2] = i8.u32[2] +
-			(uint8_t)tbl[2] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
+			(tbl[2] & 0x00FFFFFF) * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
 		ptbl = (const uint32_t *)&lpm->tbl8[i8.u32[2]];
 		tbl[2] = *ptbl;
 	}
 	if (unlikely((pt2 >> 32 & RTE_LPM_VALID_EXT_ENTRY_BITMASK) ==
 			RTE_LPM_VALID_EXT_ENTRY_BITMASK)) {
 		i8.u32[3] = i8.u32[3] +
-			(uint8_t)tbl[3] * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
+			(tbl[3] & 0x00FFFFFF) * RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
 		ptbl = (const uint32_t *)&lpm->tbl8[i8.u32[3]];
 		tbl[3] = *ptbl;
 	}
-- 
2.25.1