Merge branch 'sfc-tc-offload'

Edward Cree says:

====================
sfc: bare bones TC offload

This series begins the work of supporting TC flower offload on EF100 NICs.
This is the absolute minimum viable TC implementation to get traffic to
 VFs and allow them to be tested; it supports no match fields besides
 ingress port, no actions besides mirred and drop, and no stats.
More matches, actions, and counters will be added in subsequent patches.

Changed in v2:
 - Add missing 'static' on declarations (kernel test robot, sparse)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 429 insertions, 1 deletions

diff --git a/drivers/net/ethernet/sfc/tc.c b/drivers/net/ethernet/sfc/tc.c
index 0c0aeb91f500..3478860d4023 100644
--- a/drivers/net/ethernet/sfc/tc.c
+++ b/drivers/net/ethernet/sfc/tc.c
@@ -9,11 +9,60 @@
  * by the Free Software Foundation, incorporated herein by reference.
  */
 
+#include <net/pkt_cls.h>
 #include "tc.h"
+#include "tc_bindings.h"
 #include "mae.h"
 #include "ef100_rep.h"
 #include "efx.h"
 
+#define EFX_EFV_PF	NULL
+/* Look up the representor information (efv) for a device.
+ * May return NULL for the PF (us), or an error pointer for a device that
+ * isn't supported as a TC offload endpoint
+ */
+static struct efx_rep *efx_tc_flower_lookup_efv(struct efx_nic *efx,
+						struct net_device *dev)
+{
+	struct efx_rep *efv;
+
+	if (!dev)
+		return ERR_PTR(-EOPNOTSUPP);
+	/* Is it us (the PF)? */
+	if (dev == efx->net_dev)
+		return EFX_EFV_PF;
+	/* Is it an efx vfrep at all? */
+	if (dev->netdev_ops != &efx_ef100_rep_netdev_ops)
+		return ERR_PTR(-EOPNOTSUPP);
+	/* Is it ours?  We don't support TC rules that include another
+	 * EF100's netdevices (not even on another port of the same NIC).
+	 */
+	efv = netdev_priv(dev);
+	if (efv->parent != efx)
+		return ERR_PTR(-EOPNOTSUPP);
+	return efv;
+}
+
+/* Convert a driver-internal vport ID into an external device (wire or VF) */
+static s64 efx_tc_flower_external_mport(struct efx_nic *efx, struct efx_rep *efv)
+{
+	u32 mport;
+
+	if (IS_ERR(efv))
+		return PTR_ERR(efv);
+	if (!efv) /* device is PF (us) */
+		efx_mae_mport_wire(efx, &mport);
+	else /* device is repr */
+		efx_mae_mport_mport(efx, efv->mport, &mport);
+	return mport;
+}
+
+static const struct rhashtable_params efx_tc_match_action_ht_params = {
+	.key_len	= sizeof(unsigned long),
+	.key_offset	= offsetof(struct efx_tc_flow_rule, cookie),
+	.head_offset	= offsetof(struct efx_tc_flow_rule, linkage),
+};
+
 static void efx_tc_free_action_set(struct efx_nic *efx,
 				   struct efx_tc_action_set *act, bool in_hw)
 {
@@ -58,6 +107,333 @@ static void efx_tc_delete_rule(struct efx_nic *efx, struct efx_tc_flow_rule *rul
 	rule->fw_id = MC_CMD_MAE_ACTION_RULE_INSERT_OUT_ACTION_RULE_ID_NULL;
 }
 
+static void efx_tc_flow_free(void *ptr, void *arg)
+{
+	struct efx_tc_flow_rule *rule = ptr;
+	struct efx_nic *efx = arg;
+
+	netif_err(efx, drv, efx->net_dev,
+		  "tc rule %lx still present at teardown, removing\n",
+		  rule->cookie);
+
+	efx_mae_delete_rule(efx, rule->fw_id);
+
+	/* Release entries in subsidiary tables */
+	efx_tc_free_action_set_list(efx, &rule->acts, true);
+
+	kfree(rule);
+}
+
+static int efx_tc_flower_parse_match(struct efx_nic *efx,
+				     struct flow_rule *rule,
+				     struct efx_tc_match *match,
+				     struct netlink_ext_ack *extack)
+{
+	struct flow_dissector *dissector = rule->match.dissector;
+
+	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_CONTROL)) {
+		struct flow_match_control fm;
+
+		flow_rule_match_control(rule, &fm);
+
+		if (fm.mask->flags) {
+			efx_tc_err(efx, "Unsupported match on control.flags %#x\n",
+				   fm.mask->flags);
+			NL_SET_ERR_MSG_MOD(extack, "Unsupported match on control.flags");
+			return -EOPNOTSUPP;
+		}
+	}
+	if (dissector->used_keys &
+	    ~(BIT(FLOW_DISSECTOR_KEY_CONTROL) |
+	      BIT(FLOW_DISSECTOR_KEY_BASIC))) {
+		efx_tc_err(efx, "Unsupported flower keys %#x\n", dissector->used_keys);
+		NL_SET_ERR_MSG_MOD(extack, "Unsupported flower keys encountered");
+		return -EOPNOTSUPP;
+	}
+
+	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_BASIC)) {
+		struct flow_match_basic fm;
+
+		flow_rule_match_basic(rule, &fm);
+		if (fm.mask->n_proto) {
+			EFX_TC_ERR_MSG(efx, extack, "Unsupported eth_proto match\n");
+			return -EOPNOTSUPP;
+		}
+		if (fm.mask->ip_proto) {
+			EFX_TC_ERR_MSG(efx, extack, "Unsupported ip_proto match\n");
+			return -EOPNOTSUPP;
+		}
+	}
+
+	return 0;
+}
+
+static int efx_tc_flower_replace(struct efx_nic *efx,
+				 struct net_device *net_dev,
+				 struct flow_cls_offload *tc,
+				 struct efx_rep *efv)
+{
+	struct flow_rule *fr = flow_cls_offload_flow_rule(tc);
+	struct netlink_ext_ack *extack = tc->common.extack;
+	struct efx_tc_flow_rule *rule = NULL, *old;
+	struct efx_tc_action_set *act = NULL;
+	const struct flow_action_entry *fa;
+	struct efx_rep *from_efv, *to_efv;
+	struct efx_tc_match match;
+	s64 rc;
+	int i;
+
+	if (!tc_can_offload_extack(efx->net_dev, extack))
+		return -EOPNOTSUPP;
+	if (WARN_ON(!efx->tc))
+		return -ENETDOWN;
+	if (WARN_ON(!efx->tc->up))
+		return -ENETDOWN;
+
+	from_efv = efx_tc_flower_lookup_efv(efx, net_dev);
+	if (IS_ERR(from_efv)) {
+		/* Might be a tunnel decap rule from an indirect block.
+		 * Support for those not implemented yet.
+		 */
+		return -EOPNOTSUPP;
+	}
+
+	if (efv != from_efv) {
+		/* can't happen */
+		efx_tc_err(efx, "for %s efv is %snull but from_efv is %snull\n",
+			   netdev_name(net_dev), efv ? "non-" : "",
+			   from_efv ? "non-" : "");
+		if (efv)
+			NL_SET_ERR_MSG_MOD(extack, "vfrep filter has PF net_dev (can't happen)");
+		else
+			NL_SET_ERR_MSG_MOD(extack, "PF filter has vfrep net_dev (can't happen)");
+		return -EINVAL;
+	}
+
+	/* Parse match */
+	memset(&match, 0, sizeof(match));
+	rc = efx_tc_flower_external_mport(efx, from_efv);
+	if (rc < 0) {
+		EFX_TC_ERR_MSG(efx, extack, "Failed to identify ingress m-port");
+		return rc;
+	}
+	match.value.ingress_port = rc;
+	match.mask.ingress_port = ~0;
+	rc = efx_tc_flower_parse_match(efx, fr, &match, extack);
+	if (rc)
+		return rc;
+
+	if (tc->common.chain_index) {
+		EFX_TC_ERR_MSG(efx, extack, "No support for nonzero chain_index");
+		return -EOPNOTSUPP;
+	}
+	match.mask.recirc_id = 0xff;
+
+	rc = efx_mae_match_check_caps(efx, &match.mask, extack);
+	if (rc)
+		return rc;
+
+	rule = kzalloc(sizeof(*rule), GFP_USER);
+	if (!rule)
+		return -ENOMEM;
+	INIT_LIST_HEAD(&rule->acts.list);
+	rule->cookie = tc->cookie;
+	old = rhashtable_lookup_get_insert_fast(&efx->tc->match_action_ht,
+						&rule->linkage,
+						efx_tc_match_action_ht_params);
+	if (old) {
+		netif_dbg(efx, drv, efx->net_dev,
+			  "Already offloaded rule (cookie %lx)\n", tc->cookie);
+		rc = -EEXIST;
+		NL_SET_ERR_MSG_MOD(extack, "Rule already offloaded");
+		goto release;
+	}
+
+	/* Parse actions */
+	act = kzalloc(sizeof(*act), GFP_USER);
+	if (!act) {
+		rc = -ENOMEM;
+		goto release;
+	}
+
+	flow_action_for_each(i, fa, &fr->action) {
+		struct efx_tc_action_set save;
+
+		if (!act) {
+			/* more actions after a non-pipe action */
+			EFX_TC_ERR_MSG(efx, extack, "Action follows non-pipe action");
+			rc = -EINVAL;
+			goto release;
+		}
+
+		switch (fa->id) {
+		case FLOW_ACTION_DROP:
+			rc = efx_mae_alloc_action_set(efx, act);
+			if (rc) {
+				EFX_TC_ERR_MSG(efx, extack, "Failed to write action set to hw (drop)");
+				goto release;
+			}
+			list_add_tail(&act->list, &rule->acts.list);
+			act = NULL; /* end of the line */
+			break;
+		case FLOW_ACTION_REDIRECT:
+		case FLOW_ACTION_MIRRED:
+			save = *act;
+			to_efv = efx_tc_flower_lookup_efv(efx, fa->dev);
+			if (IS_ERR(to_efv)) {
+				EFX_TC_ERR_MSG(efx, extack, "Mirred egress device not on switch");
+				rc = PTR_ERR(to_efv);
+				goto release;
+			}
+			rc = efx_tc_flower_external_mport(efx, to_efv);
+			if (rc < 0) {
+				EFX_TC_ERR_MSG(efx, extack, "Failed to identify egress m-port");
+				goto release;
+			}
+			act->dest_mport = rc;
+			act->deliver = 1;
+			rc = efx_mae_alloc_action_set(efx, act);
+			if (rc) {
+				EFX_TC_ERR_MSG(efx, extack, "Failed to write action set to hw (mirred)");
+				goto release;
+			}
+			list_add_tail(&act->list, &rule->acts.list);
+			act = NULL;
+			if (fa->id == FLOW_ACTION_REDIRECT)
+				break; /* end of the line */
+			/* Mirror, so continue on with saved act */
+			act = kzalloc(sizeof(*act), GFP_USER);
+			if (!act) {
+				rc = -ENOMEM;
+				goto release;
+			}
+			*act = save;
+			break;
+		default:
+			efx_tc_err(efx, "Unhandled action %u\n", fa->id);
+			rc = -EOPNOTSUPP;
+			NL_SET_ERR_MSG_MOD(extack, "Unsupported action");
+			goto release;
+		}
+	}
+
+	if (act) {
+		/* Not shot/redirected, so deliver to default dest */
+		if (from_efv == EFX_EFV_PF)
+			/* Rule applies to traffic from the wire,
+			 * and default dest is thus the PF
+			 */
+			efx_mae_mport_uplink(efx, &act->dest_mport);
+		else
+			/* Representor, so rule applies to traffic from
+			 * representee, and default dest is thus the rep.
+			 * All reps use the same mport for delivery
+			 */
+			efx_mae_mport_mport(efx, efx->tc->reps_mport_id,
+					    &act->dest_mport);
+		act->deliver = 1;
+		rc = efx_mae_alloc_action_set(efx, act);
+		if (rc) {
+			EFX_TC_ERR_MSG(efx, extack, "Failed to write action set to hw (deliver)");
+			goto release;
+		}
+		list_add_tail(&act->list, &rule->acts.list);
+		act = NULL; /* Prevent double-free in error path */
+	}
+
+	netif_dbg(efx, drv, efx->net_dev,
+		  "Successfully parsed filter (cookie %lx)\n",
+		  tc->cookie);
+
+	rule->match = match;
+
+	rc = efx_mae_alloc_action_set_list(efx, &rule->acts);
+	if (rc) {
+		EFX_TC_ERR_MSG(efx, extack, "Failed to write action set list to hw");
+		goto release;
+	}
+	rc = efx_mae_insert_rule(efx, &rule->match, EFX_TC_PRIO_TC,
+				 rule->acts.fw_id, &rule->fw_id);
+	if (rc) {
+		EFX_TC_ERR_MSG(efx, extack, "Failed to insert rule in hw");
+		goto release_acts;
+	}
+	return 0;
+
+release_acts:
+	efx_mae_free_action_set_list(efx, &rule->acts);
+release:
+	/* We failed to insert the rule, so free up any entries we created in
+	 * subsidiary tables.
+	 */
+	if (act)
+		efx_tc_free_action_set(efx, act, false);
+	if (rule) {
+		rhashtable_remove_fast(&efx->tc->match_action_ht,
+				       &rule->linkage,
+				       efx_tc_match_action_ht_params);
+		efx_tc_free_action_set_list(efx, &rule->acts, false);
+	}
+	kfree(rule);
+	return rc;
+}
+
+static int efx_tc_flower_destroy(struct efx_nic *efx,
+				 struct net_device *net_dev,
+				 struct flow_cls_offload *tc)
+{
+	struct netlink_ext_ack *extack = tc->common.extack;
+	struct efx_tc_flow_rule *rule;
+
+	rule = rhashtable_lookup_fast(&efx->tc->match_action_ht, &tc->cookie,
+				      efx_tc_match_action_ht_params);
+	if (!rule) {
+		/* Only log a message if we're the ingress device.  Otherwise
+		 * it's a foreign filter and we might just not have been
+		 * interested (e.g. we might not have been the egress device
+		 * either).
+		 */
+		if (!IS_ERR(efx_tc_flower_lookup_efv(efx, net_dev)))
+			netif_warn(efx, drv, efx->net_dev,
+				   "Filter %lx not found to remove\n", tc->cookie);
+		NL_SET_ERR_MSG_MOD(extack, "Flow cookie not found in offloaded rules");
+		return -ENOENT;
+	}
+
+	/* Remove it from HW */
+	efx_tc_delete_rule(efx, rule);
+	/* Delete it from SW */
+	rhashtable_remove_fast(&efx->tc->match_action_ht, &rule->linkage,
+			       efx_tc_match_action_ht_params);
+	netif_dbg(efx, drv, efx->net_dev, "Removed filter %lx\n", rule->cookie);
+	kfree(rule);
+	return 0;
+}
+
+int efx_tc_flower(struct efx_nic *efx, struct net_device *net_dev,
+		  struct flow_cls_offload *tc, struct efx_rep *efv)
+{
+	int rc;
+
+	if (!efx->tc)
+		return -EOPNOTSUPP;
+
+	mutex_lock(&efx->tc->mutex);
+	switch (tc->command) {
+	case FLOW_CLS_REPLACE:
+		rc = efx_tc_flower_replace(efx, net_dev, tc, efv);
+		break;
+	case FLOW_CLS_DESTROY:
+		rc = efx_tc_flower_destroy(efx, net_dev, tc);
+		break;
+	default:
+		rc = -EOPNOTSUPP;
+		break;
+	}
+	mutex_unlock(&efx->tc->mutex);
+	return rc;
+}
+
 static int efx_tc_configure_default_rule(struct efx_nic *efx, u32 ing_port,
 					 u32 eg_port, struct efx_tc_flow_rule *rule)
 {
@@ -201,13 +577,37 @@ int efx_init_tc(struct efx_nic *efx)
 {
 	int rc;
 
+	rc = efx_mae_get_caps(efx, efx->tc->caps);
+	if (rc)
+		return rc;
+	if (efx->tc->caps->match_field_count > MAE_NUM_FIELDS)
+		/* Firmware supports some match fields the driver doesn't know
+		 * about.  Not fatal, unless any of those fields are required
+		 * (MAE_FIELD_SUPPORTED_MATCH_ALWAYS) but if so we don't know.
+		 */
+		netif_warn(efx, probe, efx->net_dev,
+			   "FW reports additional match fields %u\n",
+			   efx->tc->caps->match_field_count);
+	if (efx->tc->caps->action_prios < EFX_TC_PRIO__NUM) {
+		netif_err(efx, probe, efx->net_dev,
+			  "Too few action prios supported (have %u, need %u)\n",
+			  efx->tc->caps->action_prios, EFX_TC_PRIO__NUM);
+		return -EIO;
+	}
 	rc = efx_tc_configure_default_rule_pf(efx);
 	if (rc)
 		return rc;
 	rc = efx_tc_configure_default_rule_wire(efx);
 	if (rc)
 		return rc;
-	return efx_tc_configure_rep_mport(efx);
+	rc = efx_tc_configure_rep_mport(efx);
+	if (rc)
+		return rc;
+	efx->tc->up = true;
+	rc = flow_indr_dev_register(efx_tc_indr_setup_cb, efx);
+	if (rc)
+		return rc;
+	return 0;
 }
 
 void efx_fini_tc(struct efx_nic *efx)
@@ -215,20 +615,35 @@ void efx_fini_tc(struct efx_nic *efx)
 	/* We can get called even if efx_init_struct_tc() failed */
 	if (!efx->tc)
 		return;
+	if (efx->tc->up)
+		flow_indr_dev_unregister(efx_tc_indr_setup_cb, efx, efx_tc_block_unbind);
 	efx_tc_deconfigure_rep_mport(efx);
 	efx_tc_deconfigure_default_rule(efx, &efx->tc->dflt.pf);
 	efx_tc_deconfigure_default_rule(efx, &efx->tc->dflt.wire);
+	efx->tc->up = false;
 }
 
 int efx_init_struct_tc(struct efx_nic *efx)
 {
+	int rc;
+
 	if (efx->type->is_vf)
 		return 0;
 
 	efx->tc = kzalloc(sizeof(*efx->tc), GFP_KERNEL);
 	if (!efx->tc)
 		return -ENOMEM;
+	efx->tc->caps = kzalloc(sizeof(struct mae_caps), GFP_KERNEL);
+	if (!efx->tc->caps) {
+		rc = -ENOMEM;
+		goto fail_alloc_caps;
+	}
+	INIT_LIST_HEAD(&efx->tc->block_list);
 
+	mutex_init(&efx->tc->mutex);
+	rc = rhashtable_init(&efx->tc->match_action_ht, &efx_tc_match_action_ht_params);
+	if (rc < 0)
+		goto fail_match_action_ht;
 	efx->tc->reps_filter_uc = -1;
 	efx->tc->reps_filter_mc = -1;
 	INIT_LIST_HEAD(&efx->tc->dflt.pf.acts.list);
@@ -236,6 +651,13 @@ int efx_init_struct_tc(struct efx_nic *efx)
 	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;
+fail_match_action_ht:
+	mutex_destroy(&efx->tc->mutex);
+	kfree(efx->tc->caps);
+fail_alloc_caps:
+	kfree(efx->tc);
+	efx->tc = NULL;
+	return rc;
 }
 
 void efx_fini_struct_tc(struct efx_nic *efx)
@@ -243,10 +665,16 @@ void efx_fini_struct_tc(struct efx_nic *efx)
 	if (!efx->tc)
 		return;
 
+	mutex_lock(&efx->tc->mutex);
 	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);
+	rhashtable_free_and_destroy(&efx->tc->match_action_ht, efx_tc_flow_free,
+				    efx);
+	mutex_unlock(&efx->tc->mutex);
+	mutex_destroy(&efx->tc->mutex);
+	kfree(efx->tc->caps);
 	kfree(efx->tc);
 	efx->tc = NULL;
 }