nfp: abm: track all offload-enabled qdiscs

Allocate an object corresponding to any offloaded qdisc we are
informed about by the kernel.  Not only the qdiscs we have a
chance of offloading.

The count of created objects will be used to decide whether
the ethtool TC offload can be disabled, since otherwise we may
miss destroy commands.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/abm/main.c

@@ -329,6 +329,7 @@ nfp_abm_vnic_alloc(struct nfp_app *app, struct nfp_net *nn, unsigned int id)
 
 	nfp_abm_vnic_set_mac(app->pf, abm, nn, id);
 	nfp_abm_ctrl_read_params(alink);
+	INIT_RADIX_TREE(&alink->qdiscs, GFP_KERNEL);
 
 	return 0;
 
@@ -344,6 +345,7 @@ static void nfp_abm_vnic_free(struct nfp_app *app, struct nfp_net *nn)
 	struct nfp_abm_link *alink = nn->app_priv;
 
 	nfp_abm_kill_reprs(alink->abm, alink);
+	WARN(!radix_tree_empty(&alink->qdiscs), "left over qdiscs\n");
 	kvfree(alink->red_qdiscs);
 	kfree(alink);
 }

drivers/net/ethernet/netronome/nfp/abm/main.h

@@ -5,6 +5,7 @@
 #define __NFP_ABM_H__ 1
 
 #include <linux/bits.h>
+#include <linux/radix-tree.h>
 #include <net/devlink.h>
 #include <net/pkt_cls.h>
 
@@ -71,6 +72,26 @@ struct nfp_alink_xstats {
 	u64 pdrop;
 };
 
+enum nfp_qdisc_type {
+	NFP_QDISC_NONE = 0,
+	NFP_QDISC_MQ,
+	NFP_QDISC_RED,
+};
+
+/**
+ * struct nfp_qdisc - tracked TC Qdisc
+ * @netdev:		netdev on which Qdisc was created
+ * @type:		Qdisc type
+ * @handle:		handle of this Qdisc
+ * @parent_handle:	handle of the parent (unreliable if Qdisc was grafted)
+ */
+struct nfp_qdisc {
+	struct net_device *netdev;
+	enum nfp_qdisc_type type;
+	u32 handle;
+	u32 parent_handle;
+};
+
 /**
  * struct nfp_red_qdisc - representation of single RED Qdisc
  * @handle:	handle of currently offloaded RED Qdisc
@@ -95,6 +116,7 @@ struct nfp_red_qdisc {
  * @parent:	handle of expected parent, i.e. handle of MQ, or TC_H_ROOT
  * @num_qdiscs:	number of currently used qdiscs
  * @red_qdiscs:	array of qdiscs
+ * @qdiscs:	all qdiscs recorded by major part of the handle
  */
 struct nfp_abm_link {
 	struct nfp_abm *abm;
@@ -105,6 +127,7 @@ struct nfp_abm_link {
 	u32 parent;
 	unsigned int num_qdiscs;
 	struct nfp_red_qdisc *red_qdiscs;
+	struct radix_tree_root qdiscs;
 };
 
 int nfp_abm_setup_tc_red(struct net_device *netdev, struct nfp_abm_link *alink,

drivers/net/ethernet/netronome/nfp/abm/qdisc.c

@@ -63,17 +63,97 @@ static void nfp_abm_offload_update(struct nfp_abm *abm)
 }
 
 static void
-__nfp_abm_reset_root(struct net_device *netdev, struct nfp_abm_link *alink,
-		     u32 handle, unsigned int qs, u32 init_val)
+nfp_abm_qdisc_free(struct net_device *netdev, struct nfp_abm_link *alink,
+		   struct nfp_qdisc *qdisc)
 {
 	struct nfp_port *port = nfp_port_from_netdev(netdev);
 
+	if (!qdisc)
+		return;
+	WARN_ON(radix_tree_delete(&alink->qdiscs,
+				  TC_H_MAJ(qdisc->handle)) != qdisc);
+	kfree(qdisc);
+
+	port->tc_offload_cnt--;
+}
+
+static struct nfp_qdisc *
+nfp_abm_qdisc_alloc(struct net_device *netdev, struct nfp_abm_link *alink,
+		    enum nfp_qdisc_type type, u32 parent_handle, u32 handle)
+{
+	struct nfp_port *port = nfp_port_from_netdev(netdev);
+	struct nfp_qdisc *qdisc;
+	int err;
+
+	qdisc = kzalloc(sizeof(*qdisc), GFP_KERNEL);
+	if (!qdisc)
+		return NULL;
+
+	qdisc->netdev = netdev;
+	qdisc->type = type;
+	qdisc->parent_handle = parent_handle;
+	qdisc->handle = handle;
+
+	err = radix_tree_insert(&alink->qdiscs, TC_H_MAJ(qdisc->handle), qdisc);
+	if (err) {
+		nfp_err(alink->abm->app->cpp,
+			"Qdisc insertion into radix tree failed: %d\n", err);
+		goto err_free_qdisc;
+	}
+
+	port->tc_offload_cnt++;
+	return qdisc;
+
+err_free_qdisc:
+	kfree(qdisc);
+	return NULL;
+}
+
+static struct nfp_qdisc *
+nfp_abm_qdisc_find(struct nfp_abm_link *alink, u32 handle)
+{
+	return radix_tree_lookup(&alink->qdiscs, TC_H_MAJ(handle));
+}
+
+static int
+nfp_abm_qdisc_replace(struct net_device *netdev, struct nfp_abm_link *alink,
+		      enum nfp_qdisc_type type, u32 parent_handle, u32 handle,
+		      struct nfp_qdisc **qdisc)
+{
+	*qdisc = nfp_abm_qdisc_find(alink, handle);
+	if (*qdisc) {
+		if (WARN_ON((*qdisc)->type != type))
+			return -EINVAL;
+		return 0;
+	}
+
+	*qdisc = nfp_abm_qdisc_alloc(netdev, alink, type, parent_handle,
+				     handle);
+	return *qdisc ? 0 : -ENOMEM;
+}
+
+static void
+nfp_abm_qdisc_destroy(struct net_device *netdev, struct nfp_abm_link *alink,
+		      u32 handle)
+{
+	struct nfp_qdisc *qdisc;
+
+	qdisc = nfp_abm_qdisc_find(alink, handle);
+	if (!qdisc)
+		return;
+
+	nfp_abm_qdisc_free(netdev, alink, qdisc);
+}
+
+static void
+__nfp_abm_reset_root(struct net_device *netdev, struct nfp_abm_link *alink,
+		     u32 handle, unsigned int qs, u32 init_val)
+{
 	memset(alink->red_qdiscs, 0,
 	       sizeof(*alink->red_qdiscs) * alink->num_qdiscs);
 
 	alink->parent = handle;
 	alink->num_qdiscs = qs;
-	port->tc_offload_cnt = qs;
 }
 
 static void
@@ -108,6 +188,8 @@ nfp_abm_red_destroy(struct net_device *netdev, struct nfp_abm_link *alink,
 {
 	unsigned int i;
 
+	nfp_abm_qdisc_destroy(netdev, alink, handle);
+
 	for (i = 0; i < alink->num_qdiscs; i++)
 		if (handle == alink->red_qdiscs[i].handle)
 			break;
@@ -157,12 +239,22 @@ static int
 nfp_abm_red_replace(struct net_device *netdev, struct nfp_abm_link *alink,
 		    struct tc_red_qopt_offload *opt)
 {
+	struct nfp_qdisc *qdisc;
 	bool existing;
 	int i, err;
+	int ret;
+
+	ret = nfp_abm_qdisc_replace(netdev, alink, NFP_QDISC_RED, opt->parent,
+				    opt->handle, &qdisc);
 
 	i = nfp_abm_red_find(alink, opt);
 	existing = i >= 0;
 
+	if (ret) {
+		err = ret;
+		goto err_destroy;
+	}
+
 	if (!nfp_abm_red_check_params(alink, opt)) {
 		err = -EINVAL;
 		goto err_destroy;
@@ -326,6 +418,16 @@ nfp_abm_mq_stats(struct nfp_abm_link *alink, struct tc_mq_qopt_offload *opt)
 	return 0;
 }
 
+static int
+nfp_abm_mq_create(struct net_device *netdev, struct nfp_abm_link *alink,
+		  struct tc_mq_qopt_offload *opt)
+{
+	struct nfp_qdisc *qdisc;
+
+	return nfp_abm_qdisc_replace(netdev, alink, NFP_QDISC_MQ,
+				     TC_H_ROOT, opt->handle, &qdisc);
+}
+
 int nfp_abm_setup_tc_mq(struct net_device *netdev, struct nfp_abm_link *alink,
 			struct tc_mq_qopt_offload *opt)
 {
@@ -334,8 +436,9 @@ int nfp_abm_setup_tc_mq(struct net_device *netdev, struct nfp_abm_link *alink,
 		nfp_abm_reset_root(netdev, alink, opt->handle,
 				   alink->total_queues);
 		nfp_abm_offload_update(alink->abm);
-		return 0;
+		return nfp_abm_mq_create(netdev, alink, opt);
 	case TC_MQ_DESTROY:
+		nfp_abm_qdisc_destroy(netdev, alink, opt->handle);
 		if (opt->handle == alink->parent) {
 			nfp_abm_reset_root(netdev, alink, TC_H_ROOT, 0);
 			nfp_abm_offload_update(alink->abm);