netdev - [net 10/11] net/mlx5e: Fix no rewrite fields with the same match

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Date:   Fri, 17 May 2019 20:20:01 +0000
From:   Saeed Mahameed <saeedm@...lanox.com>
To:     "David S. Miller" <davem@...emloft.net>
CC:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        Eli Britstein <elibr@...lanox.com>,
        Roi Dayan <roid@...lanox.com>,
        Saeed Mahameed <saeedm@...lanox.com>
Subject: [net 10/11] net/mlx5e: Fix no rewrite fields with the same match

From: Eli Britstein <elibr@...lanox.com>

With commit 27c11b6b844c ("net/mlx5e: Do not rewrite fields with the
same match") there are no rewrites if the rewrite value is the same as
the matched value. However, if the field is not matched, the rewrite is
also wrongly skipped. Fix it.

Fixes: 27c11b6b844c ("net/mlx5e: Do not rewrite fields with the same match")
Signed-off-by: Eli Britstein <elibr@...lanox.com>
Reviewed-by: Roi Dayan <roid@...lanox.com>
Signed-off-by: Saeed Mahameed <saeedm@...lanox.com>
---
 .../net/ethernet/mellanox/mlx5/core/en_tc.c   | 22 ++++++++++++++-----
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 542354b5eb4d..4722ac70f0a9 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -1916,6 +1916,19 @@ struct mlx5_fields {
 		 offsetof(struct pedit_headers, field) + (off), \
 		 MLX5_BYTE_OFF(fte_match_set_lyr_2_4, match_field)}
 
+/* masked values are the same and there are no rewrites that do not have a
+ * match.
+ */
+#define SAME_VAL_MASK(type, valp, maskp, matchvalp, matchmaskp) ({ \
+	type matchmaskx = *(type *)(matchmaskp); \
+	type matchvalx = *(type *)(matchvalp); \
+	type maskx = *(type *)(maskp); \
+	type valx = *(type *)(valp); \
+	\
+	(valx & maskx) == (matchvalx & matchmaskx) && !(maskx & (maskx ^ \
+								 matchmaskx)); \
+})
+
 static bool cmp_val_mask(void *valp, void *maskp, void *matchvalp,
 			 void *matchmaskp, int size)
 {
@@ -1923,16 +1936,13 @@ static bool cmp_val_mask(void *valp, void *maskp, void *matchvalp,
 
 	switch (size) {
 	case sizeof(u8):
-		same = ((*(u8 *)valp) & (*(u8 *)maskp)) ==
-		       ((*(u8 *)matchvalp) & (*(u8 *)matchmaskp));
+		same = SAME_VAL_MASK(u8, valp, maskp, matchvalp, matchmaskp);
 		break;
 	case sizeof(u16):
-		same = ((*(u16 *)valp) & (*(u16 *)maskp)) ==
-		       ((*(u16 *)matchvalp) & (*(u16 *)matchmaskp));
+		same = SAME_VAL_MASK(u16, valp, maskp, matchvalp, matchmaskp);
 		break;
 	case sizeof(u32):
-		same = ((*(u32 *)valp) & (*(u32 *)maskp)) ==
-		       ((*(u32 *)matchvalp) & (*(u32 *)matchmaskp));
+		same = SAME_VAL_MASK(u32, valp, maskp, matchvalp, matchmaskp);
 		break;
 	}
 
-- 
2.21.0