[dpdk-dev] [PATCH v2 3/4] lpm: fix vector lookup for ppc64

[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: d2cc7959342b ("lpm: add AltiVec for ppc64")
Cc: gowrishankar.m at linux.vnet.ibm.com
Cc: stable at dpdk.org

Signed-off-by: Ruifeng Wang <ruifeng.wang at arm.com>
Tested-by: David Christensen <drc at linux.vnet.ibm.com>
Acked-by: Vladimir Medvedkin <vladimir.medvedkin at intel.com>
---
 lib/librte_lpm/rte_lpm_altivec.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/librte_lpm/rte_lpm_altivec.h b/lib/librte_lpm/rte_lpm_altivec.h
index 228c41b38..4fbc1b595 100644
--- a/lib/librte_lpm/rte_lpm_altivec.h
+++ b/lib/librte_lpm/rte_lpm_altivec.h
@@ -88,28 +88,28 @@ 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