sfc: add MAE table machinery for conntrack table

Access to the connection tracking table in EF100 hardware is through
 a "generic" table mechanism, whereby a firmware call at probe time
 gives the driver a description of the field widths and offsets, so
 that the driver can then construct key and response bitstrings at
 runtime.
Probe the NIC for this information and populate the needed metadata
 into a new meta_ct field of struct efx_tc_state.

Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 250 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sfc/mae.c b/drivers/net/ethernet/sfc/mae.c
index 0cab508f2f9d..33ae2c852b44 100644
--- a/drivers/net/ethernet/sfc/mae.c
+++ b/drivers/net/ethernet/sfc/mae.c
@@ -227,6 +227,256 @@ void efx_mae_counters_grant_credits(struct work_struct *work)
 		rx_queue->granted_count += credits;
 }
 
+static int efx_mae_table_get_desc(struct efx_nic *efx,
+				  struct efx_tc_table_desc *desc,
+				  u32 table_id)
+{
+	MCDI_DECLARE_BUF(outbuf, MC_CMD_TABLE_DESCRIPTOR_OUT_LEN(16));
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_TABLE_DESCRIPTOR_IN_LEN);
+	unsigned int offset = 0, i;
+	size_t outlen;
+	int rc;
+
+	memset(desc, 0, sizeof(*desc));
+
+	MCDI_SET_DWORD(inbuf, TABLE_DESCRIPTOR_IN_TABLE_ID, table_id);
+more:
+	MCDI_SET_DWORD(inbuf, TABLE_DESCRIPTOR_IN_FIRST_FIELDS_INDEX, offset);
+	rc = efx_mcdi_rpc(efx, MC_CMD_TABLE_DESCRIPTOR, inbuf, sizeof(inbuf),
+			  outbuf, sizeof(outbuf), &outlen);
+	if (rc)
+		goto fail;
+	if (outlen < MC_CMD_TABLE_DESCRIPTOR_OUT_LEN(1)) {
+		rc = -EIO;
+		goto fail;
+	}
+	if (!offset) { /* first iteration: get metadata */
+		desc->type = MCDI_WORD(outbuf, TABLE_DESCRIPTOR_OUT_TYPE);
+		desc->key_width = MCDI_WORD(outbuf, TABLE_DESCRIPTOR_OUT_KEY_WIDTH);
+		desc->resp_width = MCDI_WORD(outbuf, TABLE_DESCRIPTOR_OUT_RESP_WIDTH);
+		desc->n_keys = MCDI_WORD(outbuf, TABLE_DESCRIPTOR_OUT_N_KEY_FIELDS);
+		desc->n_resps = MCDI_WORD(outbuf, TABLE_DESCRIPTOR_OUT_N_RESP_FIELDS);
+		desc->n_prios = MCDI_WORD(outbuf, TABLE_DESCRIPTOR_OUT_N_PRIORITIES);
+		desc->flags = MCDI_BYTE(outbuf, TABLE_DESCRIPTOR_OUT_FLAGS);
+		rc = -EOPNOTSUPP;
+		if (desc->flags)
+			goto fail;
+		desc->scheme = MCDI_BYTE(outbuf, TABLE_DESCRIPTOR_OUT_SCHEME);
+		if (desc->scheme)
+			goto fail;
+		rc = -ENOMEM;
+		desc->keys = kcalloc(desc->n_keys,
+				     sizeof(struct efx_tc_table_field_fmt),
+				     GFP_KERNEL);
+		if (!desc->keys)
+			goto fail;
+		desc->resps = kcalloc(desc->n_resps,
+				      sizeof(struct efx_tc_table_field_fmt),
+				      GFP_KERNEL);
+		if (!desc->resps)
+			goto fail;
+	}
+	/* FW could have returned more than the 16 field_descrs we
+	 * made room for in our outbuf
+	 */
+	outlen = min(outlen, sizeof(outbuf));
+	for (i = 0; i + offset < desc->n_keys + desc->n_resps; i++) {
+		struct efx_tc_table_field_fmt *field;
+		MCDI_DECLARE_STRUCT_PTR(fdesc);
+
+		if (outlen < MC_CMD_TABLE_DESCRIPTOR_OUT_LEN(i + 1)) {
+			offset += i;
+			goto more;
+		}
+		if (i + offset < desc->n_keys)
+			field = desc->keys + i + offset;
+		else
+			field = desc->resps + (i + offset - desc->n_keys);
+		fdesc = MCDI_ARRAY_STRUCT_PTR(outbuf,
+					      TABLE_DESCRIPTOR_OUT_FIELDS, i);
+		field->field_id = MCDI_STRUCT_WORD(fdesc,
+						   TABLE_FIELD_DESCR_FIELD_ID);
+		field->lbn = MCDI_STRUCT_WORD(fdesc, TABLE_FIELD_DESCR_LBN);
+		field->width = MCDI_STRUCT_WORD(fdesc, TABLE_FIELD_DESCR_WIDTH);
+		field->masking = MCDI_STRUCT_BYTE(fdesc, TABLE_FIELD_DESCR_MASK_TYPE);
+		field->scheme = MCDI_STRUCT_BYTE(fdesc, TABLE_FIELD_DESCR_SCHEME);
+	}
+	return 0;
+
+fail:
+	kfree(desc->keys);
+	kfree(desc->resps);
+	return rc;
+}
+
+static int efx_mae_table_hook_find(u16 n_fields,
+				   struct efx_tc_table_field_fmt *fields,
+				   u16 field_id)
+{
+	unsigned int i;
+
+	for (i = 0; i < n_fields; i++) {
+		if (fields[i].field_id == field_id)
+			return i;
+	}
+	return -EPROTO;
+}
+
+#define TABLE_FIND_KEY(_desc, _id)	\
+	efx_mae_table_hook_find((_desc)->n_keys, (_desc)->keys, _id)
+#define TABLE_FIND_RESP(_desc, _id)	\
+	efx_mae_table_hook_find((_desc)->n_resps, (_desc)->resps, _id)
+
+#define TABLE_HOOK_KEY(_meta, _name, _mcdi_name)	({			\
+	int _rc = TABLE_FIND_KEY(&_meta->desc, TABLE_FIELD_ID_##_mcdi_name);	\
+										\
+	if (_rc > U8_MAX)							\
+		_rc = -EOPNOTSUPP;						\
+	if (_rc >= 0) {								\
+		_meta->keys._name##_idx = _rc;					\
+		_rc = 0;							\
+	}									\
+	_rc;									\
+})
+#define TABLE_HOOK_RESP(_meta, _name, _mcdi_name)	({			\
+	int _rc = TABLE_FIND_RESP(&_meta->desc, TABLE_FIELD_ID_##_mcdi_name);	\
+										\
+	if (_rc > U8_MAX)							\
+		_rc = -EOPNOTSUPP;						\
+	if (_rc >= 0) {								\
+		_meta->resps._name##_idx = _rc;					\
+		_rc = 0;							\
+	}									\
+	_rc;									\
+})
+
+static int efx_mae_table_hook_ct(struct efx_nic *efx,
+				 struct efx_tc_table_ct *meta_ct)
+{
+	int rc;
+
+	rc = TABLE_HOOK_KEY(meta_ct, eth_proto, ETHER_TYPE);
+	if (rc)
+		return rc;
+	rc = TABLE_HOOK_KEY(meta_ct, ip_proto, IP_PROTO);
+	if (rc)
+		return rc;
+	rc = TABLE_HOOK_KEY(meta_ct, src_ip, SRC_IP);
+	if (rc)
+		return rc;
+	rc = TABLE_HOOK_KEY(meta_ct, dst_ip, DST_IP);
+	if (rc)
+		return rc;
+	rc = TABLE_HOOK_KEY(meta_ct, l4_sport, SRC_PORT);
+	if (rc)
+		return rc;
+	rc = TABLE_HOOK_KEY(meta_ct, l4_dport, DST_PORT);
+	if (rc)
+		return rc;
+	rc = TABLE_HOOK_KEY(meta_ct, zone, DOMAIN);
+	if (rc)
+		return rc;
+	rc = TABLE_HOOK_RESP(meta_ct, dnat, NAT_DIR);
+	if (rc)
+		return rc;
+	rc = TABLE_HOOK_RESP(meta_ct, nat_ip, NAT_IP);
+	if (rc)
+		return rc;
+	rc = TABLE_HOOK_RESP(meta_ct, l4_natport, NAT_PORT);
+	if (rc)
+		return rc;
+	rc = TABLE_HOOK_RESP(meta_ct, mark, CT_MARK);
+	if (rc)
+		return rc;
+	rc = TABLE_HOOK_RESP(meta_ct, counter_id, COUNTER_ID);
+	if (rc)
+		return rc;
+	meta_ct->hooked = true;
+	return 0;
+}
+
+static void efx_mae_table_free_desc(struct efx_tc_table_desc *desc)
+{
+	kfree(desc->keys);
+	kfree(desc->resps);
+	memset(desc, 0, sizeof(*desc));
+}
+
+static bool efx_mae_check_table_exists(struct efx_nic *efx, u32 tbl_req)
+{
+	MCDI_DECLARE_BUF(outbuf, MC_CMD_TABLE_LIST_OUT_LEN(16));
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_TABLE_LIST_IN_LEN);
+	u32 tbl_id, tbl_total, tbl_cnt, pos = 0;
+	size_t outlen, msg_max;
+	bool ct_tbl = false;
+	int rc, idx;
+
+	msg_max = sizeof(outbuf);
+	efx->tc->meta_ct.hooked = false;
+more:
+	memset(outbuf, 0, sizeof(*outbuf));
+	MCDI_SET_DWORD(inbuf, TABLE_LIST_IN_FIRST_TABLE_ID_INDEX, pos);
+	rc = efx_mcdi_rpc(efx, MC_CMD_TABLE_LIST, inbuf, sizeof(inbuf), outbuf,
+			  msg_max, &outlen);
+	if (rc)
+		return false;
+
+	if (outlen < MC_CMD_TABLE_LIST_OUT_LEN(1))
+		return false;
+
+	tbl_total = MCDI_DWORD(outbuf, TABLE_LIST_OUT_N_TABLES);
+	tbl_cnt = MC_CMD_TABLE_LIST_OUT_TABLE_ID_NUM(min(outlen, msg_max));
+
+	for (idx = 0; idx < tbl_cnt; idx++) {
+		tbl_id = MCDI_ARRAY_DWORD(outbuf, TABLE_LIST_OUT_TABLE_ID, idx);
+		if (tbl_id == tbl_req) {
+			ct_tbl = true;
+			break;
+		}
+	}
+
+	pos += tbl_cnt;
+	if (!ct_tbl && pos < tbl_total)
+		goto more;
+
+	return ct_tbl;
+}
+
+int efx_mae_get_tables(struct efx_nic *efx)
+{
+	int rc;
+
+	efx->tc->meta_ct.hooked = false;
+	if (efx_mae_check_table_exists(efx, TABLE_ID_CONNTRACK_TABLE)) {
+		rc = efx_mae_table_get_desc(efx, &efx->tc->meta_ct.desc,
+					    TABLE_ID_CONNTRACK_TABLE);
+		if (rc) {
+			pci_info(efx->pci_dev,
+				 "FW does not support conntrack desc rc %d\n",
+				 rc);
+			return 0;
+		}
+
+		rc = efx_mae_table_hook_ct(efx, &efx->tc->meta_ct);
+		if (rc) {
+			pci_info(efx->pci_dev,
+				 "FW does not support conntrack hook rc %d\n",
+				 rc);
+			return 0;
+		}
+	} else {
+		pci_info(efx->pci_dev,
+			 "FW does not support conntrack table\n");
+	}
+	return 0;
+}
+
+void efx_mae_free_tables(struct efx_nic *efx)
+{
+	efx_mae_table_free_desc(&efx->tc->meta_ct.desc);
+	efx->tc->meta_ct.hooked = false;
+}
+
 static int efx_mae_get_basic_caps(struct efx_nic *efx, struct mae_caps *caps)
 {
 	MCDI_DECLARE_BUF(outbuf, MC_CMD_MAE_GET_CAPS_OUT_LEN);