mlxsw: spectrum: acl: Implement delta for ERP

Allow ERP sharing for multiple mask. Do it by properly implementing
delta_create() objagg object. Use the computed delta info for inserting
rules in A-TCAM.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 187 insertions, 6 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c
index bfd0c8a6cabf..d9a4b7e8434b 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c
@@ -29,6 +29,8 @@ struct mlxsw_sp_acl_erp_core {
 
 struct mlxsw_sp_acl_erp_key {
 	char mask[MLXSW_REG_PTCEX_FLEX_KEY_BLOCKS_LEN];
+#define __MASK_LEN 0x38
+#define __MASK_IDX(i) (__MASK_LEN - (i) - 1)
 	bool ctcam;
 };
 
@@ -58,6 +60,7 @@ struct mlxsw_sp_acl_erp_table {
 	unsigned int num_atcam_erps;
 	unsigned int num_max_atcam_erps;
 	unsigned int num_ctcam_erps;
+	unsigned int num_deltas;
 	struct objagg *objagg;
 };
 
@@ -629,7 +632,7 @@ __mlxsw_sp_acl_erp_table_other_inc(struct mlxsw_sp_acl_erp_table *erp_table,
 {
 	int err;
 
-	/* If there are C-TCAM eRPs in use we need to transition
+	/* If there are C-TCAM eRP or deltas in use we need to transition
 	 * the region to use eRP table, if it is not already done
 	 */
 	if (erp_table->ops != &erp_two_masks_ops &&
@@ -639,7 +642,7 @@ __mlxsw_sp_acl_erp_table_other_inc(struct mlxsw_sp_acl_erp_table *erp_table,
 			return err;
 	}
 
-	/* When C-TCAM is used, the eRP table must be used */
+	/* When C-TCAM or deltas are used, the eRP table must be used */
 	if (erp_table->ops != &erp_multiple_masks_ops)
 		erp_table->ops = &erp_multiple_masks_ops;
 
@@ -654,17 +657,23 @@ static int mlxsw_sp_acl_erp_ctcam_inc(struct mlxsw_sp_acl_erp_table *erp_table)
 						  &erp_table->num_ctcam_erps);
 }
 
+static int mlxsw_sp_acl_erp_delta_inc(struct mlxsw_sp_acl_erp_table *erp_table)
+{
+	return __mlxsw_sp_acl_erp_table_other_inc(erp_table,
+						  &erp_table->num_deltas);
+}
+
 static void
 __mlxsw_sp_acl_erp_table_other_dec(struct mlxsw_sp_acl_erp_table *erp_table,
 				   unsigned int *dec_num)
 {
 	(*dec_num)--;
 
-	/* If there are no C-TCAM eRPs in use, the state we
+	/* If there are no C-TCAM eRP or deltas in use, the state we
 	 * transition to depends on the number of A-TCAM eRPs currently
 	 * in use.
 	 */
-	if (erp_table->num_ctcam_erps > 0)
+	if (erp_table->num_ctcam_erps > 0 || erp_table->num_deltas > 0)
 		return;
 
 	switch (erp_table->num_atcam_erps) {
@@ -706,6 +715,12 @@ static void mlxsw_sp_acl_erp_ctcam_dec(struct mlxsw_sp_acl_erp_table *erp_table)
 					   &erp_table->num_ctcam_erps);
 }
 
+static void mlxsw_sp_acl_erp_delta_dec(struct mlxsw_sp_acl_erp_table *erp_table)
+{
+	__mlxsw_sp_acl_erp_table_other_dec(erp_table,
+					   &erp_table->num_deltas);
+}
+
 static struct mlxsw_sp_acl_erp *
 mlxsw_sp_acl_erp_ctcam_mask_create(struct mlxsw_sp_acl_erp_table *erp_table,
 				   struct mlxsw_sp_acl_erp_key *key)
@@ -813,7 +828,8 @@ mlxsw_sp_acl_erp_mask_destroy(struct mlxsw_sp_acl_erp_table *erp_table,
 	mlxsw_sp_acl_erp_index_put(erp_table, erp->index);
 	mlxsw_sp_acl_erp_generic_destroy(erp);
 
-	if (erp_table->num_atcam_erps == 2 && erp_table->num_ctcam_erps == 0)
+	if (erp_table->num_atcam_erps == 2 && erp_table->num_ctcam_erps == 0 &&
+	    erp_table->num_deltas == 0)
 		erp_table->ops = &erp_two_masks_ops;
 }
 
@@ -961,14 +977,179 @@ u8 mlxsw_sp_acl_erp_mask_erp_id(const struct mlxsw_sp_acl_erp_mask *erp_mask)
 	return erp->id;
 }
 
+struct mlxsw_sp_acl_erp_delta {
+	struct mlxsw_sp_acl_erp_key key;
+	u16 start;
+	u8 mask;
+};
+
+u16 mlxsw_sp_acl_erp_delta_start(const struct mlxsw_sp_acl_erp_delta *delta)
+{
+	return delta->start;
+}
+
+u8 mlxsw_sp_acl_erp_delta_mask(const struct mlxsw_sp_acl_erp_delta *delta)
+{
+	return delta->mask;
+}
+
+u8 mlxsw_sp_acl_erp_delta_value(const struct mlxsw_sp_acl_erp_delta *delta,
+				const char *enc_key)
+{
+	u16 start = delta->start;
+	u8 mask = delta->mask;
+	u16 tmp;
+
+	if (!mask)
+		return 0;
+
+	tmp = (unsigned char) enc_key[__MASK_IDX(start / 8)];
+	if (start / 8 + 1 < __MASK_LEN)
+		tmp |= (unsigned char) enc_key[__MASK_IDX(start / 8 + 1)] << 8;
+	tmp >>= start % 8;
+	tmp &= mask;
+	return tmp;
+}
+
+void mlxsw_sp_acl_erp_delta_clear(const struct mlxsw_sp_acl_erp_delta *delta,
+				  const char *enc_key)
+{
+	u16 start = delta->start;
+	u8 mask = delta->mask;
+	unsigned char *byte;
+	u16 tmp;
+
+	tmp = mask;
+	tmp <<= start % 8;
+	tmp = ~tmp;
+
+	byte = (unsigned char *) &enc_key[__MASK_IDX(start / 8)];
+	*byte &= tmp & 0xff;
+	if (start / 8 + 1 < __MASK_LEN) {
+		byte = (unsigned char *) &enc_key[__MASK_IDX(start / 8 + 1)];
+		*byte &= (tmp >> 8) & 0xff;
+	}
+}
+
+static const struct mlxsw_sp_acl_erp_delta
+mlxsw_sp_acl_erp_delta_default = {};
+
+const struct mlxsw_sp_acl_erp_delta *
+mlxsw_sp_acl_erp_delta(const struct mlxsw_sp_acl_erp_mask *erp_mask)
+{
+	struct objagg_obj *objagg_obj = (struct objagg_obj *) erp_mask;
+	const struct mlxsw_sp_acl_erp_delta *delta;
+
+	delta = objagg_obj_delta_priv(objagg_obj);
+	if (!delta)
+		delta = &mlxsw_sp_acl_erp_delta_default;
+	return delta;
+}
+
+static int
+mlxsw_sp_acl_erp_delta_fill(const struct mlxsw_sp_acl_erp_key *parent_key,
+			    const struct mlxsw_sp_acl_erp_key *key,
+			    u16 *delta_start, u8 *delta_mask)
+{
+	int offset = 0;
+	int si = -1;
+	u16 pmask;
+	u16 mask;
+	int i;
+
+	/* The difference between 2 masks can be up to 8 consecutive bits. */
+	for (i = 0; i < __MASK_LEN; i++) {
+		if (parent_key->mask[__MASK_IDX(i)] == key->mask[__MASK_IDX(i)])
+			continue;
+		if (si == -1)
+			si = i;
+		else if (si != i - 1)
+			return -EINVAL;
+	}
+	if (si == -1) {
+		/* The masks are the same, this cannot happen.
+		 * That means the caller is broken.
+		 */
+		WARN_ON(1);
+		*delta_start = 0;
+		*delta_mask = 0;
+		return 0;
+	}
+	pmask = (unsigned char) parent_key->mask[__MASK_IDX(si)];
+	mask = (unsigned char) key->mask[__MASK_IDX(si)];
+	if (si + 1 < __MASK_LEN) {
+		pmask |= (unsigned char) parent_key->mask[__MASK_IDX(si + 1)] << 8;
+		mask |= (unsigned char) key->mask[__MASK_IDX(si + 1)] << 8;
+	}
+
+	if ((pmask ^ mask) & pmask)
+		return -EINVAL;
+	mask &= ~pmask;
+	while (!(mask & (1 << offset)))
+		offset++;
+	while (!(mask & 1))
+		mask >>= 1;
+	if (mask & 0xff00)
+		return -EINVAL;
+
+	*delta_start = si * 8 + offset;
+	*delta_mask = mask;
+
+	return 0;
+}
+
 static void *mlxsw_sp_acl_erp_delta_create(void *priv, void *parent_obj,
 					   void *obj)
 {
-	return ERR_PTR(-EOPNOTSUPP);
+	struct mlxsw_sp_acl_erp_key *parent_key = parent_obj;
+	struct mlxsw_sp_acl_atcam_region *aregion = priv;
+	struct mlxsw_sp_acl_erp_table *erp_table = aregion->erp_table;
+	struct mlxsw_sp_acl_erp_key *key = obj;
+	struct mlxsw_sp_acl_erp_delta *delta;
+	u16 delta_start;
+	u8 delta_mask;
+	int err;
+
+	if (parent_key->ctcam || key->ctcam)
+		return ERR_PTR(-EINVAL);
+	err = mlxsw_sp_acl_erp_delta_fill(parent_key, key,
+					  &delta_start, &delta_mask);
+	if (err)
+		return ERR_PTR(-EINVAL);
+
+	delta = kzalloc(sizeof(*delta), GFP_KERNEL);
+	if (!delta)
+		return ERR_PTR(-ENOMEM);
+	delta->start = delta_start;
+	delta->mask = delta_mask;
+
+	err = mlxsw_sp_acl_erp_delta_inc(erp_table);
+	if (err)
+		goto err_erp_delta_inc;
+
+	memcpy(&delta->key, key, sizeof(*key));
+	err = mlxsw_sp_acl_erp_master_mask_set(erp_table, &delta->key);
+	if (err)
+		goto err_master_mask_set;
+
+	return delta;
+
+err_master_mask_set:
+	mlxsw_sp_acl_erp_delta_dec(erp_table);
+err_erp_delta_inc:
+	kfree(delta);
+	return ERR_PTR(err);
 }
 
 static void mlxsw_sp_acl_erp_delta_destroy(void *priv, void *delta_priv)
 {
+	struct mlxsw_sp_acl_erp_delta *delta = delta_priv;
+	struct mlxsw_sp_acl_atcam_region *aregion = priv;
+	struct mlxsw_sp_acl_erp_table *erp_table = aregion->erp_table;
+
+	mlxsw_sp_acl_erp_master_mask_clear(erp_table, &delta->key);
+	mlxsw_sp_acl_erp_delta_dec(erp_table);
+	kfree(delta);
 }
 
 static void *mlxsw_sp_acl_erp_root_create(void *priv, void *obj)