Subject: [PATCH RFC,net-next 02/10] net/mlx5e: allow two independent packet edit actions

From: Pablo Neira Ayuso <[email-masked]>
Date: Tue, 25 Sep 2018 21:19:53 +0200

Although the packet edit infrastructure allows an arbitrary number of
packet mangling in the same action, it is still possible to define a
rule with two or more packet edit instances. This would result in the
last packet mangling action being applied to the mlx5e driver.

This patch adds pedit_headers_action struct that annotates the headers
mangling configuration that is used to configure hardware. Then,
alloc_tc_pedit_action() is called to populate the mlx5e hardware
intermediate representation once all actions have been parsed.

Signed-off-by: Pablo Neira Ayuso <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 77 +++++++++++++++++--------
 1 file changed, 54 insertions(+), 23 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index c9d541944a14..5139e63daa74 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -1600,6 +1600,12 @@ struct pedit_headers {
 	struct udphdr  udp;
 };
 
+struct pedit_headers_action {
+	struct pedit_headers	vals;
+	struct pedit_headers	masks;
+	u32			pedits;
+};
+
 static int pedit_header_offsets[] = {
 	[TCA_PEDIT_KEY_EX_HDR_TYPE_ETH] = offsetof(struct pedit_headers, eth),
 	[TCA_PEDIT_KEY_EX_HDR_TYPE_IP4] = offsetof(struct pedit_headers, ip4),
@@ -1611,16 +1617,15 @@ static int pedit_header_offsets[] = {
 #define pedit_header(_ph, _htype) ((void *)(_ph) + pedit_header_offsets[_htype])
 
 static int set_pedit_val(u8 hdr_type, u32 mask, u32 val, u32 offset,
-			 struct pedit_headers *masks,
-			 struct pedit_headers *vals)
+			 struct pedit_headers_action *hdrs)
 {
 	u32 *curr_pmask, *curr_pval;
 
 	if (hdr_type >= __PEDIT_HDR_TYPE_MAX)
 		goto out_err;
 
-	curr_pmask = (u32 *)(pedit_header(masks, hdr_type) + offset);
-	curr_pval  = (u32 *)(pedit_header(vals, hdr_type) + offset);
+	curr_pmask = (u32 *)(pedit_header(&hdrs->masks, hdr_type) + offset);
+	curr_pval  = (u32 *)(pedit_header(&hdrs->vals, hdr_type) + offset);
 
 	if (*curr_pmask & mask)  /* disallow acting twice on the same location */
 		goto out_err;
@@ -1676,8 +1681,7 @@ static struct mlx5_fields fields[] = {
  * max from the SW pedit action. On success, it says how many HW actions were
  * actually parsed.
  */
-static int offload_pedit_fields(struct pedit_headers *masks,
-				struct pedit_headers *vals,
+static int offload_pedit_fields(struct pedit_headers_action *hdrs,
 				struct mlx5e_tc_flow_parse_attr *parse_attr)
 {
 	struct pedit_headers *set_masks, *add_masks, *set_vals, *add_vals;
@@ -1691,10 +1695,10 @@ static int offload_pedit_fields(struct pedit_headers *masks,
 	__be16 mask_be16;
 	void *action;
 
-	set_masks = &masks[TCA_PEDIT_KEY_EX_CMD_SET];
-	add_masks = &masks[TCA_PEDIT_KEY_EX_CMD_ADD];
-	set_vals = &vals[TCA_PEDIT_KEY_EX_CMD_SET];
-	add_vals = &vals[TCA_PEDIT_KEY_EX_CMD_ADD];
+	set_masks = &hdrs[TCA_PEDIT_KEY_EX_CMD_SET].masks;
+	add_masks = &hdrs[TCA_PEDIT_KEY_EX_CMD_ADD].masks;
+	set_vals = &hdrs[TCA_PEDIT_KEY_EX_CMD_SET].vals;
+	add_vals = &hdrs[TCA_PEDIT_KEY_EX_CMD_ADD].vals;
 
 	action_size = MLX5_UN_SZ_BYTES(set_action_in_add_action_in_auto);
 	action = parse_attr->mod_hdr_actions;
@@ -1784,12 +1788,12 @@ static int offload_pedit_fields(struct pedit_headers *masks,
 }
 
 static int alloc_mod_hdr_actions(struct mlx5e_priv *priv,
-				 const struct tc_action *a, int namespace,
+				 u32 pedits, int namespace,
 				 struct mlx5e_tc_flow_parse_attr *parse_attr)
 {
 	int nkeys, action_size, max_actions;
 
-	nkeys = tcf_pedit_nkeys(a);
+	nkeys = pedits;
 	action_size = MLX5_UN_SZ_BYTES(set_action_in_add_action_in_auto);
 
 	if (namespace == MLX5_FLOW_NAMESPACE_FDB) /* FDB offloading */
@@ -1812,17 +1816,15 @@ static const struct pedit_headers zero_masks = {};
 
 static int parse_tc_pedit_action(struct mlx5e_priv *priv,
 				 const struct tc_action *a, int namespace,
-				 struct mlx5e_tc_flow_parse_attr *parse_attr)
+				 struct mlx5e_tc_flow_parse_attr *parse_attr,
+				 struct pedit_headers_action *hdrs)
 {
-	struct pedit_headers masks[__PEDIT_CMD_MAX], vals[__PEDIT_CMD_MAX], *cmd_masks;
 	int nkeys, i, err = -EOPNOTSUPP;
 	u32 mask, val, offset;
 	u8 cmd, htype;
 
 	nkeys = tcf_pedit_nkeys(a);
-
-	memset(masks, 0, sizeof(struct pedit_headers) * __PEDIT_CMD_MAX);
-	memset(vals,  0, sizeof(struct pedit_headers) * __PEDIT_CMD_MAX);
+	hdrs->pedits += nkeys;
 
 	for (i = 0; i < nkeys; i++) {
 		htype = tcf_pedit_htype(a, i);
@@ -1843,21 +1845,34 @@ static int parse_tc_pedit_action(struct mlx5e_priv *priv,
 		val = tcf_pedit_val(a, i);
 		offset = tcf_pedit_offset(a, i);
 
-		err = set_pedit_val(htype, ~mask, val, offset, &masks[cmd], &vals[cmd]);
+		err = set_pedit_val(htype, ~mask, val, offset, &hdrs[cmd]);
 		if (err)
 			goto out_err;
 	}
 
-	err = alloc_mod_hdr_actions(priv, a, namespace, parse_attr);
+	return 0;
+out_err:
+	return err;
+}
+
+static int alloc_tc_pedit_action(struct mlx5e_priv *priv, int namespace,
+				 struct mlx5e_tc_flow_parse_attr *parse_attr,
+				 struct pedit_headers_action *hdrs)
+{
+	struct pedit_headers *cmd_masks;
+	int err;
+	u8 cmd;
+
+	err = alloc_mod_hdr_actions(priv, hdrs->pedits, namespace, parse_attr);
 	if (err)
 		goto out_err;
 
-	err = offload_pedit_fields(masks, vals, parse_attr);
+	err = offload_pedit_fields(hdrs, parse_attr);
 	if (err < 0)
 		goto out_dealloc_parsed_actions;
 
 	for (cmd = 0; cmd < __PEDIT_CMD_MAX; cmd++) {
-		cmd_masks = &masks[cmd];
+		cmd_masks = &hdrs[cmd].masks;
 		if (memcmp(cmd_masks, &zero_masks, sizeof(zero_masks))) {
 			netdev_warn(priv->netdev, "attempt to offload an unsupported field (cmd %d)\n", cmd);
 			print_hex_dump(KERN_WARNING, "mask: ", DUMP_PREFIX_ADDRESS,
@@ -1984,6 +1999,7 @@ static int parse_tc_nic_actions(struct mlx5e_priv *priv, struct tcf_exts *exts,
 				struct mlx5e_tc_flow_parse_attr *parse_attr,
 				struct mlx5e_tc_flow *flow)
 {
+	struct pedit_headers_action hdrs[__PEDIT_CMD_MAX] = {};
 	struct mlx5_nic_flow_attr *attr = flow->nic_attr;
 	const struct tc_action *a;
 	LIST_HEAD(actions);
@@ -2006,7 +2022,7 @@ static int parse_tc_nic_actions(struct mlx5e_priv *priv, struct tcf_exts *exts,
 
 		if (is_tcf_pedit(a)) {
 			err = parse_tc_pedit_action(priv, a, MLX5_FLOW_NAMESPACE_KERNEL,
-						    parse_attr);
+						    parse_attr, hdrs);
 			if (err)
 				return err;
 
@@ -2057,6 +2073,13 @@ static int parse_tc_nic_actions(struct mlx5e_priv *priv, struct tcf_exts *exts,
 		return -EINVAL;
 	}
 
+	if (hdrs->pedits) {
+		err = alloc_tc_pedit_action(priv, MLX5_FLOW_NAMESPACE_KERNEL,
+					    parse_attr, hdrs);
+		if (err)
+			return err;
+	}
+
 	attr->action = action;
 	if (!actions_match_supported(priv, exts, parse_attr, flow))
 		return -EOPNOTSUPP;
@@ -2593,6 +2616,7 @@ static int parse_tc_fdb_actions(struct mlx5e_priv *priv, struct tcf_exts *exts,
 				struct mlx5e_tc_flow_parse_attr *parse_attr,
 				struct mlx5e_tc_flow *flow)
 {
+	struct pedit_headers_action hdrs[__PEDIT_CMD_MAX] = {};
 	struct mlx5_esw_flow_attr *attr = flow->esw_attr;
 	struct mlx5e_rep_priv *rpriv = priv->ppriv;
 	struct ip_tunnel_info *info = NULL;
@@ -2617,7 +2641,7 @@ static int parse_tc_fdb_actions(struct mlx5e_priv *priv, struct tcf_exts *exts,
 
 		if (is_tcf_pedit(a)) {
 			err = parse_tc_pedit_action(priv, a, MLX5_FLOW_NAMESPACE_FDB,
-						    parse_attr);
+						    parse_attr, hdrs);
 			if (err)
 				return err;
 
@@ -2699,6 +2723,13 @@ static int parse_tc_fdb_actions(struct mlx5e_priv *priv, struct tcf_exts *exts,
 		return -EINVAL;
 	}
 
+	if (hdrs->pedits) {
+		err = alloc_tc_pedit_action(priv, MLX5_FLOW_NAMESPACE_KERNEL,
+					    parse_attr, hdrs);
+		if (err)
+			return err;
+	}
+
 	attr->action = action;
 	if (!actions_match_supported(priv, exts, parse_attr, flow))
 		return -EOPNOTSUPP;
-- 
2.11.0