sfc: insert default MAE rules to connect VFs to representors

Default rules are low-priority switching rules which the hardware uses
 in the absence of higher-priority rules.  Each representor requires a
 corresponding rule matching traffic from its representee VF and
 delivering to the PF (where a check on INGRESS_MPORT in
 __ef100_rx_packet() will direct it to the representor).  No rule is
 required in the reverse direction, because representor TX uses a TX
 override descriptor to bypass the MAE and deliver directly to the VF.
Since inserting any rule into the MAE disables the firmware's own
 default rules, also insert a pair of rules to connect the PF to the
 physical network port and vice-versa.

Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 183 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sfc/tc.c b/drivers/net/ethernet/sfc/tc.c
new file mode 100644
index 000000000000..0fb01f73c56e
--- /dev/null
+++ b/drivers/net/ethernet/sfc/tc.c
@@ -0,0 +1,183 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/****************************************************************************
+ * Driver for Solarflare network controllers and boards
+ * Copyright 2019 Solarflare Communications Inc.
+ * Copyright 2020-2022 Xilinx Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation, incorporated herein by reference.
+ */
+
+#include "tc.h"
+#include "mae.h"
+#include "ef100_rep.h"
+
+static void efx_tc_free_action_set(struct efx_nic *efx,
+				   struct efx_tc_action_set *act, bool in_hw)
+{
+	/* Failure paths calling this on the 'running action' set in_hw=false,
+	 * because if the alloc had succeeded we'd've put it in acts.list and
+	 * not still have it in act.
+	 */
+	if (in_hw) {
+		efx_mae_free_action_set(efx, act->fw_id);
+		/* in_hw is true iff we are on an acts.list; make sure to
+		 * remove ourselves from that list before we are freed.
+		 */
+		list_del(&act->list);
+	}
+	kfree(act);
+}
+
+static void efx_tc_free_action_set_list(struct efx_nic *efx,
+					struct efx_tc_action_set_list *acts,
+					bool in_hw)
+{
+	struct efx_tc_action_set *act, *next;
+
+	/* Failure paths set in_hw=false, because usually the acts didn't get
+	 * to efx_mae_alloc_action_set_list(); if they did, the failure tree
+	 * has a separate efx_mae_free_action_set_list() before calling us.
+	 */
+	if (in_hw)
+		efx_mae_free_action_set_list(efx, acts);
+	/* Any act that's on the list will be in_hw even if the list isn't */
+	list_for_each_entry_safe(act, next, &acts->list, list)
+		efx_tc_free_action_set(efx, act, true);
+	/* Don't kfree, as acts is embedded inside a struct efx_tc_flow_rule */
+}
+
+static void efx_tc_delete_rule(struct efx_nic *efx, struct efx_tc_flow_rule *rule)
+{
+	efx_mae_delete_rule(efx, rule->fw_id);
+
+	/* Release entries in subsidiary tables */
+	efx_tc_free_action_set_list(efx, &rule->acts, true);
+	rule->fw_id = MC_CMD_MAE_ACTION_RULE_INSERT_OUT_ACTION_RULE_ID_NULL;
+}
+
+static int efx_tc_configure_default_rule(struct efx_nic *efx, u32 ing_port,
+					 u32 eg_port, struct efx_tc_flow_rule *rule)
+{
+	struct efx_tc_action_set_list *acts = &rule->acts;
+	struct efx_tc_match *match = &rule->match;
+	struct efx_tc_action_set *act;
+	int rc;
+
+	match->value.ingress_port = ing_port;
+	match->mask.ingress_port = ~0;
+	act = kzalloc(sizeof(*act), GFP_KERNEL);
+	if (!act)
+		return -ENOMEM;
+	act->deliver = 1;
+	act->dest_mport = eg_port;
+	rc = efx_mae_alloc_action_set(efx, act);
+	if (rc)
+		goto fail1;
+	EFX_WARN_ON_PARANOID(!list_empty(&acts->list));
+	list_add_tail(&act->list, &acts->list);
+	rc = efx_mae_alloc_action_set_list(efx, acts);
+	if (rc)
+		goto fail2;
+	rc = efx_mae_insert_rule(efx, match, EFX_TC_PRIO_DFLT,
+				 acts->fw_id, &rule->fw_id);
+	if (rc)
+		goto fail3;
+	return 0;
+fail3:
+	efx_mae_free_action_set_list(efx, acts);
+fail2:
+	list_del(&act->list);
+	efx_mae_free_action_set(efx, act->fw_id);
+fail1:
+	kfree(act);
+	return rc;
+}
+
+static int efx_tc_configure_default_rule_pf(struct efx_nic *efx)
+{
+	struct efx_tc_flow_rule *rule = &efx->tc->dflt.pf;
+	u32 ing_port, eg_port;
+
+	efx_mae_mport_uplink(efx, &ing_port);
+	efx_mae_mport_wire(efx, &eg_port);
+	return efx_tc_configure_default_rule(efx, ing_port, eg_port, rule);
+}
+
+static int efx_tc_configure_default_rule_wire(struct efx_nic *efx)
+{
+	struct efx_tc_flow_rule *rule = &efx->tc->dflt.wire;
+	u32 ing_port, eg_port;
+
+	efx_mae_mport_wire(efx, &ing_port);
+	efx_mae_mport_uplink(efx, &eg_port);
+	return efx_tc_configure_default_rule(efx, ing_port, eg_port, rule);
+}
+
+int efx_tc_configure_default_rule_rep(struct efx_rep *efv)
+{
+	struct efx_tc_flow_rule *rule = &efv->dflt;
+	struct efx_nic *efx = efv->parent;
+	u32 ing_port, eg_port;
+
+	efx_mae_mport_mport(efx, efv->mport, &ing_port);
+	efx_mae_mport_uplink(efx, &eg_port);
+	return efx_tc_configure_default_rule(efx, ing_port, eg_port, rule);
+}
+
+void efx_tc_deconfigure_default_rule(struct efx_nic *efx,
+				     struct efx_tc_flow_rule *rule)
+{
+	if (rule->fw_id != MC_CMD_MAE_ACTION_RULE_INSERT_OUT_ACTION_RULE_ID_NULL)
+		efx_tc_delete_rule(efx, rule);
+	rule->fw_id = MC_CMD_MAE_ACTION_RULE_INSERT_OUT_ACTION_RULE_ID_NULL;
+}
+
+int efx_init_tc(struct efx_nic *efx)
+{
+	int rc;
+
+	rc = efx_tc_configure_default_rule_pf(efx);
+	if (rc)
+		return rc;
+	return efx_tc_configure_default_rule_wire(efx);
+}
+
+void efx_fini_tc(struct efx_nic *efx)
+{
+	/* We can get called even if efx_init_struct_tc() failed */
+	if (!efx->tc)
+		return;
+	efx_tc_deconfigure_default_rule(efx, &efx->tc->dflt.pf);
+	efx_tc_deconfigure_default_rule(efx, &efx->tc->dflt.wire);
+}
+
+int efx_init_struct_tc(struct efx_nic *efx)
+{
+	if (efx->type->is_vf)
+		return 0;
+
+	efx->tc = kzalloc(sizeof(*efx->tc), GFP_KERNEL);
+	if (!efx->tc)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&efx->tc->dflt.pf.acts.list);
+	efx->tc->dflt.pf.fw_id = MC_CMD_MAE_ACTION_RULE_INSERT_OUT_ACTION_RULE_ID_NULL;
+	INIT_LIST_HEAD(&efx->tc->dflt.wire.acts.list);
+	efx->tc->dflt.wire.fw_id = MC_CMD_MAE_ACTION_RULE_INSERT_OUT_ACTION_RULE_ID_NULL;
+	return 0;
+}
+
+void efx_fini_struct_tc(struct efx_nic *efx)
+{
+	if (!efx->tc)
+		return;
+
+	EFX_WARN_ON_PARANOID(efx->tc->dflt.pf.fw_id !=
+			     MC_CMD_MAE_ACTION_RULE_INSERT_OUT_ACTION_RULE_ID_NULL);
+	EFX_WARN_ON_PARANOID(efx->tc->dflt.wire.fw_id !=
+			     MC_CMD_MAE_ACTION_RULE_INSERT_OUT_ACTION_RULE_ID_NULL);
+	kfree(efx->tc);
+	efx->tc = NULL;
+}