net: mvpp2: fix parsing fragmentation detection

Parsing fragmentation detection failed due to wrong configured
parser TCAM entry's. Some traffic was marked as fragmented in RX
descriptor, even it wasn't IP fragmented. The hardware also failed to
calculate checksums which lead to use software checksum and caused
performance degradation.

Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375 network unit")
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Stefan Chulski <stefanc@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvpp2.c

@@ -676,6 +676,7 @@ enum mvpp2_tag_type {
 #define MVPP2_PRS_RI_L3_MCAST			BIT(15)
 #define MVPP2_PRS_RI_L3_BCAST			(BIT(15) | BIT(16))
 #define MVPP2_PRS_RI_IP_FRAG_MASK		0x20000
+#define MVPP2_PRS_RI_IP_FRAG_TRUE		BIT(17)
 #define MVPP2_PRS_RI_UDF3_MASK			0x300000
 #define MVPP2_PRS_RI_UDF3_RX_SPECIAL		BIT(21)
 #define MVPP2_PRS_RI_L4_PROTO_MASK		0x1c00000
@@ -2315,7 +2316,7 @@ static int mvpp2_prs_ip4_proto(struct mvpp2 *priv, unsigned short proto,
 	    (proto != IPPROTO_IGMP))
 		return -EINVAL;
 
-	/* Fragmented packet */
+	/* Not fragmented packet */
 	tid = mvpp2_prs_tcam_first_free(priv, MVPP2_PE_FIRST_FREE_TID,
 					MVPP2_PE_LAST_FREE_TID);
 	if (tid < 0)
@@ -2334,8 +2335,12 @@ static int mvpp2_prs_ip4_proto(struct mvpp2 *priv, unsigned short proto,
 				  MVPP2_PRS_SRAM_OP_SEL_UDF_ADD);
 	mvpp2_prs_sram_ai_update(&pe, MVPP2_PRS_IPV4_DIP_AI_BIT,
 				 MVPP2_PRS_IPV4_DIP_AI_BIT);
-	mvpp2_prs_sram_ri_update(&pe, ri | MVPP2_PRS_RI_IP_FRAG_MASK,
-				 ri_mask | MVPP2_PRS_RI_IP_FRAG_MASK);
+	mvpp2_prs_sram_ri_update(&pe, ri, ri_mask | MVPP2_PRS_RI_IP_FRAG_MASK);
+
+	mvpp2_prs_tcam_data_byte_set(&pe, 2, 0x00,
+				     MVPP2_PRS_TCAM_PROTO_MASK_L);
+	mvpp2_prs_tcam_data_byte_set(&pe, 3, 0x00,
+				     MVPP2_PRS_TCAM_PROTO_MASK);
 
 	mvpp2_prs_tcam_data_byte_set(&pe, 5, proto, MVPP2_PRS_TCAM_PROTO_MASK);
 	mvpp2_prs_tcam_ai_update(&pe, 0, MVPP2_PRS_IPV4_DIP_AI_BIT);
@@ -2346,7 +2351,7 @@ static int mvpp2_prs_ip4_proto(struct mvpp2 *priv, unsigned short proto,
 	mvpp2_prs_shadow_set(priv, pe.index, MVPP2_PRS_LU_IP4);
 	mvpp2_prs_hw_write(priv, &pe);
 
-	/* Not fragmented packet */
+	/* Fragmented packet */
 	tid = mvpp2_prs_tcam_first_free(priv, MVPP2_PE_FIRST_FREE_TID,
 					MVPP2_PE_LAST_FREE_TID);
 	if (tid < 0)
@@ -2358,8 +2363,11 @@ static int mvpp2_prs_ip4_proto(struct mvpp2 *priv, unsigned short proto,
 	pe.sram.word[MVPP2_PRS_SRAM_RI_CTRL_WORD] = 0x0;
 	mvpp2_prs_sram_ri_update(&pe, ri, ri_mask);
 
-	mvpp2_prs_tcam_data_byte_set(&pe, 2, 0x00, MVPP2_PRS_TCAM_PROTO_MASK_L);
-	mvpp2_prs_tcam_data_byte_set(&pe, 3, 0x00, MVPP2_PRS_TCAM_PROTO_MASK);
+	mvpp2_prs_sram_ri_update(&pe, ri | MVPP2_PRS_RI_IP_FRAG_TRUE,
+				 ri_mask | MVPP2_PRS_RI_IP_FRAG_MASK);
+
+	mvpp2_prs_tcam_data_byte_set(&pe, 2, 0x00, 0x0);
+	mvpp2_prs_tcam_data_byte_set(&pe, 3, 0x00, 0x0);
 
 	/* Update shadow table and hw entry */
 	mvpp2_prs_shadow_set(priv, pe.index, MVPP2_PRS_LU_IP4);