net/mlx5e: Bit sized fields rewrite support

This patch doesn't change any functionality, but is a pre-step for
adding support for rewriting of bit-sized fields, like DSCP and ECN
in IPv4 header, similar fields in IPv6, etc.

Signed-off-by: Dmytro Linkin <dmitrolin@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

1 files changed, 62 insertions, 60 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 8c4bce940bfb..67b73a00f8fa 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -2238,13 +2238,14 @@ out_err:
 
 struct mlx5_fields {
 	u8  field;
-	u8  size;
+	u8  field_bsize;
+	u32 field_mask;
 	u32 offset;
 	u32 match_offset;
 };
 
-#define OFFLOAD(fw_field, size, field, off, match_field) \
-		{MLX5_ACTION_IN_FIELD_OUT_ ## fw_field, size, \
+#define OFFLOAD(fw_field, field_bsize, field_mask, field, off, match_field) \
+		{MLX5_ACTION_IN_FIELD_OUT_ ## fw_field, field_bsize, field_mask, \
 		 offsetof(struct pedit_headers, field) + (off), \
 		 MLX5_BYTE_OFF(fte_match_set_lyr_2_4, match_field)}
 
@@ -2262,18 +2263,18 @@ struct mlx5_fields {
 })
 
 static bool cmp_val_mask(void *valp, void *maskp, void *matchvalp,
-			 void *matchmaskp, int size)
+			 void *matchmaskp, u8 bsize)
 {
 	bool same = false;
 
-	switch (size) {
-	case sizeof(u8):
+	switch (bsize) {
+	case 8:
 		same = SAME_VAL_MASK(u8, valp, maskp, matchvalp, matchmaskp);
 		break;
-	case sizeof(u16):
+	case 16:
 		same = SAME_VAL_MASK(u16, valp, maskp, matchvalp, matchmaskp);
 		break;
-	case sizeof(u32):
+	case 32:
 		same = SAME_VAL_MASK(u32, valp, maskp, matchvalp, matchmaskp);
 		break;
 	}
@@ -2282,41 +2283,42 @@ static bool cmp_val_mask(void *valp, void *maskp, void *matchvalp,
 }
 
 static struct mlx5_fields fields[] = {
-	OFFLOAD(DMAC_47_16, 4, eth.h_dest[0], 0, dmac_47_16),
-	OFFLOAD(DMAC_15_0,  2, eth.h_dest[4], 0, dmac_15_0),
-	OFFLOAD(SMAC_47_16, 4, eth.h_source[0], 0, smac_47_16),
-	OFFLOAD(SMAC_15_0,  2, eth.h_source[4], 0, smac_15_0),
-	OFFLOAD(ETHERTYPE,  2, eth.h_proto, 0, ethertype),
-	OFFLOAD(FIRST_VID,  2, vlan.h_vlan_TCI, 0, first_vid),
-
-	OFFLOAD(IP_TTL, 1, ip4.ttl,   0, ttl_hoplimit),
-	OFFLOAD(SIPV4,  4, ip4.saddr, 0, src_ipv4_src_ipv6.ipv4_layout.ipv4),
-	OFFLOAD(DIPV4,  4, ip4.daddr, 0, dst_ipv4_dst_ipv6.ipv4_layout.ipv4),
-
-	OFFLOAD(SIPV6_127_96, 4, ip6.saddr.s6_addr32[0], 0,
+	OFFLOAD(DMAC_47_16, 32, U32_MAX, eth.h_dest[0], 0, dmac_47_16),
+	OFFLOAD(DMAC_15_0,  16, U16_MAX, eth.h_dest[4], 0, dmac_15_0),
+	OFFLOAD(SMAC_47_16, 32, U32_MAX, eth.h_source[0], 0, smac_47_16),
+	OFFLOAD(SMAC_15_0,  16, U16_MAX, eth.h_source[4], 0, smac_15_0),
+	OFFLOAD(ETHERTYPE,  16, U16_MAX, eth.h_proto, 0, ethertype),
+	OFFLOAD(FIRST_VID,  16, U16_MAX, vlan.h_vlan_TCI, 0, first_vid),
+
+	OFFLOAD(IP_TTL,  8,  U8_MAX, ip4.ttl,   0, ttl_hoplimit),
+	OFFLOAD(SIPV4,  32, U32_MAX, ip4.saddr, 0, src_ipv4_src_ipv6.ipv4_layout.ipv4),
+	OFFLOAD(DIPV4,  32, U32_MAX, ip4.daddr, 0, dst_ipv4_dst_ipv6.ipv4_layout.ipv4),
+
+	OFFLOAD(SIPV6_127_96, 32, U32_MAX, ip6.saddr.s6_addr32[0], 0,
 		src_ipv4_src_ipv6.ipv6_layout.ipv6[0]),
-	OFFLOAD(SIPV6_95_64,  4, ip6.saddr.s6_addr32[1], 0,
+	OFFLOAD(SIPV6_95_64,  32, U32_MAX, ip6.saddr.s6_addr32[1], 0,
 		src_ipv4_src_ipv6.ipv6_layout.ipv6[4]),
-	OFFLOAD(SIPV6_63_32,  4, ip6.saddr.s6_addr32[2], 0,
+	OFFLOAD(SIPV6_63_32,  32, U32_MAX, ip6.saddr.s6_addr32[2], 0,
 		src_ipv4_src_ipv6.ipv6_layout.ipv6[8]),
-	OFFLOAD(SIPV6_31_0,   4, ip6.saddr.s6_addr32[3], 0,
+	OFFLOAD(SIPV6_31_0,   32, U32_MAX, ip6.saddr.s6_addr32[3], 0,
 		src_ipv4_src_ipv6.ipv6_layout.ipv6[12]),
-	OFFLOAD(DIPV6_127_96, 4, ip6.daddr.s6_addr32[0], 0,
+	OFFLOAD(DIPV6_127_96, 32, U32_MAX, ip6.daddr.s6_addr32[0], 0,
 		dst_ipv4_dst_ipv6.ipv6_layout.ipv6[0]),
-	OFFLOAD(DIPV6_95_64,  4, ip6.daddr.s6_addr32[1], 0,
+	OFFLOAD(DIPV6_95_64,  32, U32_MAX, ip6.daddr.s6_addr32[1], 0,
 		dst_ipv4_dst_ipv6.ipv6_layout.ipv6[4]),
-	OFFLOAD(DIPV6_63_32,  4, ip6.daddr.s6_addr32[2], 0,
+	OFFLOAD(DIPV6_63_32,  32, U32_MAX, ip6.daddr.s6_addr32[2], 0,
 		dst_ipv4_dst_ipv6.ipv6_layout.ipv6[8]),
-	OFFLOAD(DIPV6_31_0,   4, ip6.daddr.s6_addr32[3], 0,
+	OFFLOAD(DIPV6_31_0,   32, U32_MAX, ip6.daddr.s6_addr32[3], 0,
 		dst_ipv4_dst_ipv6.ipv6_layout.ipv6[12]),
-	OFFLOAD(IPV6_HOPLIMIT, 1, ip6.hop_limit, 0, ttl_hoplimit),
+	OFFLOAD(IPV6_HOPLIMIT, 8,  U8_MAX, ip6.hop_limit, 0, ttl_hoplimit),
 
-	OFFLOAD(TCP_SPORT, 2, tcp.source,  0, tcp_sport),
-	OFFLOAD(TCP_DPORT, 2, tcp.dest,    0, tcp_dport),
-	OFFLOAD(TCP_FLAGS, 1, tcp.ack_seq, 5, tcp_flags),
+	OFFLOAD(TCP_SPORT, 16, U16_MAX, tcp.source,  0, tcp_sport),
+	OFFLOAD(TCP_DPORT, 16, U16_MAX, tcp.dest,    0, tcp_dport),
+	/* in linux iphdr tcp_flags is 8 bits long */
+	OFFLOAD(TCP_FLAGS,  8,  U8_MAX, tcp.ack_seq, 5, tcp_flags),
 
-	OFFLOAD(UDP_SPORT, 2, udp.source, 0, udp_sport),
-	OFFLOAD(UDP_DPORT, 2, udp.dest,   0, udp_dport),
+	OFFLOAD(UDP_SPORT, 16, U16_MAX, udp.source, 0, udp_sport),
+	OFFLOAD(UDP_DPORT, 16, U16_MAX, udp.dest,   0, udp_dport),
 };
 
 /* On input attr->max_mod_hdr_actions tells how many HW actions can be parsed at
@@ -2329,19 +2331,17 @@ static int offload_pedit_fields(struct pedit_headers_action *hdrs,
 				struct netlink_ext_ack *extack)
 {
 	struct pedit_headers *set_masks, *add_masks, *set_vals, *add_vals;
-	void *headers_c = get_match_headers_criteria(*action_flags,
-						     &parse_attr->spec);
-	void *headers_v = get_match_headers_value(*action_flags,
-						  &parse_attr->spec);
 	int i, action_size, nactions, max_actions, first, last, next_z;
-	void *s_masks_p, *a_masks_p, *vals_p;
+	void *headers_c, *headers_v, *action, *vals_p;
+	u32 *s_masks_p, *a_masks_p, s_mask, a_mask;
 	struct mlx5_fields *f;
-	u8 cmd, field_bsize;
-	u32 s_mask, a_mask;
 	unsigned long mask;
 	__be32 mask_be32;
 	__be16 mask_be16;
-	void *action;
+	u8 cmd;
+
+	headers_c = get_match_headers_criteria(*action_flags, &parse_attr->spec);
+	headers_v = get_match_headers_value(*action_flags, &parse_attr->spec);
 
 	set_masks = &hdrs[0].masks;
 	add_masks = &hdrs[1].masks;
@@ -2366,8 +2366,8 @@ static int offload_pedit_fields(struct pedit_headers_action *hdrs,
 		s_masks_p = (void *)set_masks + f->offset;
 		a_masks_p = (void *)add_masks + f->offset;
 
-		memcpy(&s_mask, s_masks_p, f->size);
-		memcpy(&a_mask, a_masks_p, f->size);
+		s_mask = *s_masks_p & f->field_mask;
+		a_mask = *a_masks_p & f->field_mask;
 
 		if (!s_mask && !a_mask) /* nothing to offload here */
 			continue;
@@ -2396,38 +2396,34 @@ static int offload_pedit_fields(struct pedit_headers_action *hdrs,
 			vals_p = (void *)set_vals + f->offset;
 			/* don't rewrite if we have a match on the same value */
 			if (cmp_val_mask(vals_p, s_masks_p, match_val,
-					 match_mask, f->size))
+					 match_mask, f->field_bsize))
 				skip = true;
 			/* clear to denote we consumed this field */
-			memset(s_masks_p, 0, f->size);
+			*s_masks_p &= ~f->field_mask;
 		} else {
-			u32 zero = 0;
-
 			cmd  = MLX5_ACTION_TYPE_ADD;
 			mask = a_mask;
 			vals_p = (void *)add_vals + f->offset;
 			/* add 0 is no change */
-			if (!memcmp(vals_p, &zero, f->size))
+			if ((*(u32 *)vals_p & f->field_mask) == 0)
 				skip = true;
 			/* clear to denote we consumed this field */
-			memset(a_masks_p, 0, f->size);
+			*a_masks_p &= ~f->field_mask;
 		}
 		if (skip)
 			continue;
 
-		field_bsize = f->size * BITS_PER_BYTE;
-
-		if (field_bsize == 32) {
+		if (f->field_bsize == 32) {
 			mask_be32 = *(__be32 *)&mask;
 			mask = (__force unsigned long)cpu_to_le32(be32_to_cpu(mask_be32));
-		} else if (field_bsize == 16) {
+		} else if (f->field_bsize == 16) {
 			mask_be16 = *(__be16 *)&mask;
 			mask = (__force unsigned long)cpu_to_le16(be16_to_cpu(mask_be16));
 		}
 
-		first = find_first_bit(&mask, field_bsize);
-		next_z = find_next_zero_bit(&mask, field_bsize, first);
-		last  = find_last_bit(&mask, field_bsize);
+		first = find_first_bit(&mask, f->field_bsize);
+		next_z = find_next_zero_bit(&mask, f->field_bsize, first);
+		last  = find_last_bit(&mask, f->field_bsize);
 		if (first < next_z && next_z < last) {
 			NL_SET_ERR_MSG_MOD(extack,
 					   "rewrite of few sub-fields isn't supported");
@@ -2440,16 +2436,22 @@ static int offload_pedit_fields(struct pedit_headers_action *hdrs,
 		MLX5_SET(set_action_in, action, field, f->field);
 
 		if (cmd == MLX5_ACTION_TYPE_SET) {
-			MLX5_SET(set_action_in, action, offset, first);
+			int start;
+
+			/* if field is bit sized it can start not from first bit */
+			start = find_first_bit((unsigned long *)&f->field_mask,
+					       f->field_bsize);
+
+			MLX5_SET(set_action_in, action, offset, first - start);
 			/* length is num of bits to be written, zero means length of 32 */
 			MLX5_SET(set_action_in, action, length, (last - first + 1));
 		}
 
-		if (field_bsize == 32)
+		if (f->field_bsize == 32)
 			MLX5_SET(set_action_in, action, data, ntohl(*(__be32 *)vals_p) >> first);
-		else if (field_bsize == 16)
+		else if (f->field_bsize == 16)
 			MLX5_SET(set_action_in, action, data, ntohs(*(__be16 *)vals_p) >> first);
-		else if (field_bsize == 8)
+		else if (f->field_bsize == 8)
 			MLX5_SET(set_action_in, action, data, *(u8 *)vals_p >> first);
 
 		action += action_size;