Merge branch 'nfp-abm-track-all-Qdiscs'

Jakub Kicinski says:

====================
nfp: abm: track all Qdiscs

Our Qdisc offload so far has been very simplistic.  We held
and array of marking thresholds and statistics sized to the
number of PF queues.  This was sufficient since the only
configuration we supported was single layer of RED Qdiscs
(on top of MQ or not, but MQ isn't really about queuing).

As we move to add more Qdiscs it's time to actually try to
track the full Qdisc hierarchy.  This allows us to make sure
our offloaded configuration reflects the SW path better.
We add graft notifications to MQ and RED (PRIO already sends
them) to allow drivers offloading those to learn how Qdiscs
are linked.  MQ graft gives us the obvious advantage of being
able to track when Qdiscs are shared or moved.  It seems
unlikely HW would offload RED's child Qdiscs but since the
behaviour would change based on linked child we should
stop offloading REDs with modified child.  RED will also
handle the child differently during reconfig when limit
parameter is set - so we have to inform the drivers about
the limit, and have them reset the child state when
appropriate.

The NFP driver will now allocate a structure to track each
Qdisc and link it to its children.  We will also maintain
a shadow copy of threshold settings - to save device writes
and make it easier to apply defaults when config is
re-evaluated.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -50,56 +50,37 @@ nfp_abm_ctrl_stat(struct nfp_abm_link *alink, const struct nfp_rtsym *sym,
 	return 0;
 }
 
-static int
-nfp_abm_ctrl_stat_all(struct nfp_abm_link *alink, const struct nfp_rtsym *sym,
-		      unsigned int stride, unsigned int offset, bool is_u64,
-		      u64 *res)
-{
-	u64 val, sum = 0;
-	unsigned int i;
-	int err;
-
-	for (i = 0; i < alink->vnic->max_rx_rings; i++) {
-		err = nfp_abm_ctrl_stat(alink, sym, stride, offset, i,
-					is_u64, &val);
-		if (err)
-			return err;
-		sum += val;
-	}
-
-	*res = sum;
-	return 0;
-}
-
-int nfp_abm_ctrl_set_q_lvl(struct nfp_abm_link *alink, unsigned int i, u32 val)
+int __nfp_abm_ctrl_set_q_lvl(struct nfp_abm *abm, unsigned int id, u32 val)
 {
-	struct nfp_cpp *cpp = alink->abm->app->cpp;
+	struct nfp_cpp *cpp = abm->app->cpp;
 	u64 sym_offset;
 	int err;
 
-	sym_offset = (alink->queue_base + i) * NFP_QLVL_STRIDE + NFP_QLVL_THRS;
-	err = __nfp_rtsym_writel(cpp, alink->abm->q_lvls, 4, 0,
-				 sym_offset, val);
+	__clear_bit(id, abm->threshold_undef);
+	if (abm->thresholds[id] == val)
+		return 0;
+
+	sym_offset = id * NFP_QLVL_STRIDE + NFP_QLVL_THRS;
+	err = __nfp_rtsym_writel(cpp, abm->q_lvls, 4, 0, sym_offset, val);
 	if (err) {
-		nfp_err(cpp, "RED offload setting level failed on vNIC %d queue %d\n",
-			alink->id, i);
+		nfp_err(cpp,
+			"RED offload setting level failed on subqueue %d\n",
+			id);
 		return err;
 	}
 
+	abm->thresholds[id] = val;
 	return 0;
 }
 
-int nfp_abm_ctrl_set_all_q_lvls(struct nfp_abm_link *alink, u32 val)
+int nfp_abm_ctrl_set_q_lvl(struct nfp_abm_link *alink, unsigned int queue,
+			   u32 val)
 {
-	int i, err;
+	unsigned int threshold;
 
-	for (i = 0; i < alink->vnic->max_rx_rings; i++) {
-		err = nfp_abm_ctrl_set_q_lvl(alink, i, val);
-		if (err)
-			return err;
-	}
+	threshold = alink->queue_base + queue;
 
-	return 0;
+	return __nfp_abm_ctrl_set_q_lvl(alink->abm, threshold, val);
 }
 
 u64 nfp_abm_ctrl_stat_non_sto(struct nfp_abm_link *alink, unsigned int i)
@@ -153,42 +134,6 @@ int nfp_abm_ctrl_read_q_stats(struct nfp_abm_link *alink, unsigned int i,
 				 i, true, &stats->overlimits);
 }
 
-int nfp_abm_ctrl_read_stats(struct nfp_abm_link *alink,
-			    struct nfp_alink_stats *stats)
-{
-	u64 pkts = 0, bytes = 0;
-	int i, err;
-
-	for (i = 0; i < alink->vnic->max_rx_rings; i++) {
-		pkts += nn_readq(alink->vnic, NFP_NET_CFG_RXR_STATS(i));
-		bytes += nn_readq(alink->vnic, NFP_NET_CFG_RXR_STATS(i) + 8);
-	}
-	stats->tx_pkts = pkts;
-	stats->tx_bytes = bytes;
-
-	err = nfp_abm_ctrl_stat_all(alink, alink->abm->q_lvls,
-				    NFP_QLVL_STRIDE, NFP_QLVL_BLOG_BYTES,
-				    false, &stats->backlog_bytes);
-	if (err)
-		return err;
-
-	err = nfp_abm_ctrl_stat_all(alink, alink->abm->q_lvls,
-				    NFP_QLVL_STRIDE, NFP_QLVL_BLOG_PKTS,
-				    false, &stats->backlog_pkts);
-	if (err)
-		return err;
-
-	err = nfp_abm_ctrl_stat_all(alink, alink->abm->qm_stats,
-				    NFP_QMSTAT_STRIDE, NFP_QMSTAT_DROP,
-				    true, &stats->drops);
-	if (err)
-		return err;
-
-	return nfp_abm_ctrl_stat_all(alink, alink->abm->qm_stats,
-				     NFP_QMSTAT_STRIDE, NFP_QMSTAT_ECN,
-				     true, &stats->overlimits);
-}
-
 int nfp_abm_ctrl_read_q_xstats(struct nfp_abm_link *alink, unsigned int i,
 			       struct nfp_alink_xstats *xstats)
 {
@@ -205,22 +150,6 @@ int nfp_abm_ctrl_read_q_xstats(struct nfp_abm_link *alink, unsigned int i,
 				 i, true, &xstats->ecn_marked);
 }
 
-int nfp_abm_ctrl_read_xstats(struct nfp_abm_link *alink,
-			     struct nfp_alink_xstats *xstats)
-{
-	int err;
-
-	err = nfp_abm_ctrl_stat_all(alink, alink->abm->qm_stats,
-				    NFP_QMSTAT_STRIDE, NFP_QMSTAT_DROP,
-				    true, &xstats->pdrop);
-	if (err)
-		return err;
-
-	return nfp_abm_ctrl_stat_all(alink, alink->abm->qm_stats,
-				     NFP_QMSTAT_STRIDE, NFP_QMSTAT_ECN,
-				     true, &xstats->ecn_marked);
-}
-
 int nfp_abm_ctrl_qm_enable(struct nfp_abm *abm)
 {
 	return nfp_mbox_cmd(abm->app->pf, NFP_MBOX_PCIE_ABM_ENABLE,

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

@@ -2,10 +2,12 @@
 /* Copyright (C) 2018 Netronome Systems, Inc. */
 
 #include <linux/bitfield.h>
+#include <linux/bitmap.h>
 #include <linux/etherdevice.h>
 #include <linux/lockdep.h>
 #include <linux/netdevice.h>
 #include <linux/rcupdate.h>
+#include <linux/rtnetlink.h>
 #include <linux/slab.h>
 
 #include "../nfpcore/nfp.h"
@@ -36,6 +38,8 @@ nfp_abm_setup_tc(struct nfp_app *app, struct net_device *netdev,
 		return -EOPNOTSUPP;
 
 	switch (type) {
+	case TC_SETUP_ROOT_QDISC:
+		return nfp_abm_setup_root(netdev, repr->app_priv, type_data);
 	case TC_SETUP_QDISC_MQ:
 		return nfp_abm_setup_tc_mq(netdev, repr->app_priv, type_data);
 	case TC_SETUP_QDISC_RED:
@@ -307,31 +311,23 @@ nfp_abm_vnic_alloc(struct nfp_app *app, struct nfp_net *nn, unsigned int id)
 	alink->abm = abm;
 	alink->vnic = nn;
 	alink->id = id;
-	alink->parent = TC_H_ROOT;
 	alink->total_queues = alink->vnic->max_rx_rings;
-	alink->qdiscs = kvcalloc(alink->total_queues, sizeof(*alink->qdiscs),
-				 GFP_KERNEL);
-	if (!alink->qdiscs) {
-		err = -ENOMEM;
-		goto err_free_alink;
-	}
 
 	/* This is a multi-host app, make sure MAC/PHY is up, but don't
 	 * make the MAC/PHY state follow the state of any of the ports.
 	 */
 	err = nfp_eth_set_configured(app->cpp, eth_port->index, true);
 	if (err < 0)
-		goto err_free_qdiscs;
+		goto err_free_alink;
 
 	netif_keep_dst(nn->dp.netdev);
 
 	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;
 
-err_free_qdiscs:
-	kvfree(alink->qdiscs);
 err_free_alink:
 	kfree(alink);
 	return err;
@@ -342,7 +338,7 @@ 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);
-	kvfree(alink->qdiscs);
+	WARN(!radix_tree_empty(&alink->qdiscs), "left over qdiscs\n");
 	kfree(alink);
 }
 
@@ -398,6 +394,7 @@ static int nfp_abm_init(struct nfp_app *app)
 	struct nfp_pf *pf = app->pf;
 	struct nfp_reprs *reprs;
 	struct nfp_abm *abm;
+	unsigned int i;
 	int err;
 
 	if (!pf->eth_tbl) {
@@ -424,15 +421,28 @@ static int nfp_abm_init(struct nfp_app *app)
 	if (err)
 		goto err_free_abm;
 
+	err = -ENOMEM;
+	abm->num_thresholds = NFP_NET_MAX_RX_RINGS;
+	abm->threshold_undef = bitmap_zalloc(abm->num_thresholds, GFP_KERNEL);
+	if (!abm->threshold_undef)
+		goto err_free_abm;
+
+	abm->thresholds = kvcalloc(abm->num_thresholds,
+				   sizeof(*abm->thresholds), GFP_KERNEL);
+	if (!abm->thresholds)
+		goto err_free_thresh_umap;
+	for (i = 0; i < NFP_NET_MAX_RX_RINGS; i++)
+		__nfp_abm_ctrl_set_q_lvl(abm, i, NFP_ABM_LVL_INFINITY);
+
 	/* We start in legacy mode, make sure advanced queuing is disabled */
 	err = nfp_abm_ctrl_qm_disable(abm);
 	if (err)
-		goto err_free_abm;
+		goto err_free_thresh;
 
 	err = -ENOMEM;
 	reprs = nfp_reprs_alloc(pf->max_data_vnics);
 	if (!reprs)
-		goto err_free_abm;
+		goto err_free_thresh;
 	RCU_INIT_POINTER(app->reprs[NFP_REPR_TYPE_PHYS_PORT], reprs);
 
 	reprs = nfp_reprs_alloc(pf->max_data_vnics);
@@ -444,6 +454,10 @@ static int nfp_abm_init(struct nfp_app *app)
 
 err_free_phys:
 	nfp_reprs_clean_and_free_by_type(app, NFP_REPR_TYPE_PHYS_PORT);
+err_free_thresh:
+	kvfree(abm->thresholds);
+err_free_thresh_umap:
+	bitmap_free(abm->threshold_undef);
 err_free_abm:
 	kfree(abm);
 	app->priv = NULL;
@@ -457,6 +471,8 @@ static void nfp_abm_clean(struct nfp_app *app)
 	nfp_abm_eswitch_clean_up(abm);
 	nfp_reprs_clean_and_free_by_type(app, NFP_REPR_TYPE_PF);
 	nfp_reprs_clean_and_free_by_type(app, NFP_REPR_TYPE_PHYS_PORT);
+	bitmap_free(abm->threshold_undef);
+	kvfree(abm->thresholds);
 	kfree(abm);
 	app->priv = NULL;
 }

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

@@ -5,9 +5,15 @@
 #define __NFP_ABM_H__ 1
 
 #include <linux/bits.h>
+#include <linux/radix-tree.h>
 #include <net/devlink.h>
 #include <net/pkt_cls.h>
 
+/* Dump of 64 PRIOs and 256 REDs seems to take 850us on Xeon v4 @ 2.20GHz;
+ * 2.5ms / 400Hz seems more than sufficient for stats resolution.
+ */
+#define NFP_ABM_STATS_REFRESH_IVAL	(2500 * 1000) /* ns */
+
 #define NFP_ABM_LVL_INFINITY		S32_MAX
 
 struct nfp_app;
@@ -20,6 +26,11 @@ struct nfp_net;
  * struct nfp_abm - ABM NIC app structure
  * @app:	back pointer to nfp_app
  * @pf_id:	ID of our PF link
+ *
+ * @thresholds:		current threshold configuration
+ * @threshold_undef:	bitmap of thresholds which have not been set
+ * @num_thresholds:	number of @thresholds and bits in @threshold_undef
+ *
  * @eswitch_mode:	devlink eswitch mode, advanced functions only visible
  *			in switchdev mode
  * @q_lvls:	queue level control area
@@ -28,6 +39,11 @@ struct nfp_net;
 struct nfp_abm {
 	struct nfp_app *app;
 	unsigned int pf_id;
+
+	u32 *thresholds;
+	unsigned long *threshold_undef;
+	size_t num_thresholds;
+
 	enum devlink_eswitch_mode eswitch_mode;
 	const struct nfp_rtsym *q_lvls;
 	const struct nfp_rtsym *qm_stats;
@@ -61,16 +77,67 @@ struct nfp_alink_xstats {
 	u64 pdrop;
 };
 
+enum nfp_qdisc_type {
+	NFP_QDISC_NONE = 0,
+	NFP_QDISC_MQ,
+	NFP_QDISC_RED,
+};
+
+#define NFP_QDISC_UNTRACKED	((struct nfp_qdisc *)1UL)
+
 /**
- * struct nfp_red_qdisc - representation of single RED Qdisc
- * @handle:	handle of currently offloaded RED Qdisc
- * @stats:	statistics from last refresh
- * @xstats:	base of extended statistics
+ * 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)
+ * @use_cnt:		number of attachment points in the hierarchy
+ * @num_children:	current size of the @children array
+ * @children:		pointers to children
+ *
+ * @params_ok:		parameters of this Qdisc are OK for offload
+ * @offload_mark:	offload refresh state - selected for offload
+ * @offloaded:		Qdisc is currently offloaded to the HW
+ *
+ * @mq:			MQ Qdisc specific parameters and state
+ * @mq.stats:		current stats of the MQ Qdisc
+ * @mq.prev_stats:	previously reported @mq.stats
+ *
+ * @red:		RED Qdisc specific parameters and state
+ * @red.threshold:	ECN marking threshold
+ * @red.stats:		current stats of the RED Qdisc
+ * @red.prev_stats:	previously reported @red.stats
+ * @red.xstats:		extended stats for RED - current
+ * @red.prev_xstats:	extended stats for RED - previously reported
  */
-struct nfp_red_qdisc {
+struct nfp_qdisc {
+	struct net_device *netdev;
+	enum nfp_qdisc_type type;
 	u32 handle;
-	struct nfp_alink_stats stats;
-	struct nfp_alink_xstats xstats;
+	u32 parent_handle;
+	unsigned int use_cnt;
+	unsigned int num_children;
+	struct nfp_qdisc **children;
+
+	bool params_ok;
+	bool offload_mark;
+	bool offloaded;
+
+	union {
+		/* NFP_QDISC_MQ */
+		struct {
+			struct nfp_alink_stats stats;
+			struct nfp_alink_stats prev_stats;
+		} mq;
+		/* TC_SETUP_QDISC_RED */
+		struct {
+			u32 threshold;
+			struct nfp_alink_stats stats;
+			struct nfp_alink_stats prev_stats;
+			struct nfp_alink_xstats xstats;
+			struct nfp_alink_xstats prev_xstats;
+		} red;
+	};
 };
 
 /**
@@ -80,9 +147,11 @@ struct nfp_red_qdisc {
  * @id:		id of the data vNIC
  * @queue_base:	id of base to host queue within PCIe (not QC idx)
  * @total_queues:	number of PF queues
- * @parent:	handle of expected parent, i.e. handle of MQ, or TC_H_ROOT
- * @num_qdiscs:	number of currently used qdiscs
- * @qdiscs:	array of qdiscs
+ *
+ * @last_stats_update:	ktime of last stats update
+ *
+ * @root_qdisc:	pointer to the current root of the Qdisc hierarchy
+ * @qdiscs:	all qdiscs recorded by major part of the handle
  */
 struct nfp_abm_link {
 	struct nfp_abm *abm;
@@ -90,11 +159,16 @@ struct nfp_abm_link {
 	unsigned int id;
 	unsigned int queue_base;
 	unsigned int total_queues;
-	u32 parent;
-	unsigned int num_qdiscs;
-	struct nfp_red_qdisc *qdiscs;
+
+	u64 last_stats_update;
+
+	struct nfp_qdisc *root_qdisc;
+	struct radix_tree_root qdiscs;
 };
 
+void nfp_abm_qdisc_offload_update(struct nfp_abm_link *alink);
+int nfp_abm_setup_root(struct net_device *netdev, struct nfp_abm_link *alink,
+		       struct tc_root_qopt_offload *opt);
 int nfp_abm_setup_tc_red(struct net_device *netdev, struct nfp_abm_link *alink,
 			 struct tc_red_qopt_offload *opt);
 int nfp_abm_setup_tc_mq(struct net_device *netdev, struct nfp_abm_link *alink,
@@ -102,15 +176,11 @@ int nfp_abm_setup_tc_mq(struct net_device *netdev, struct nfp_abm_link *alink,
 
 void nfp_abm_ctrl_read_params(struct nfp_abm_link *alink);
 int nfp_abm_ctrl_find_addrs(struct nfp_abm *abm);
-int nfp_abm_ctrl_set_all_q_lvls(struct nfp_abm_link *alink, u32 val);
-int nfp_abm_ctrl_set_q_lvl(struct nfp_abm_link *alink, unsigned int i,
+int __nfp_abm_ctrl_set_q_lvl(struct nfp_abm *abm, unsigned int id, u32 val);
+int nfp_abm_ctrl_set_q_lvl(struct nfp_abm_link *alink, unsigned int queue,
 			   u32 val);
-int nfp_abm_ctrl_read_stats(struct nfp_abm_link *alink,
-			    struct nfp_alink_stats *stats);
 int nfp_abm_ctrl_read_q_stats(struct nfp_abm_link *alink, unsigned int i,
 			      struct nfp_alink_stats *stats);
-int nfp_abm_ctrl_read_xstats(struct nfp_abm_link *alink,
-			     struct nfp_alink_xstats *xstats);
 int nfp_abm_ctrl_read_q_xstats(struct nfp_abm_link *alink, unsigned int i,
 			       struct nfp_alink_xstats *xstats);
 u64 nfp_abm_ctrl_stat_non_sto(struct nfp_abm_link *alink, unsigned int i);

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

 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
 /* Copyright (C) 2018 Netronome Systems, Inc. */
 
+#include <linux/rtnetlink.h>
 #include <net/pkt_cls.h>
 #include <net/pkt_sched.h>
 #include <net/red.h>
 
 #include "../nfpcore/nfp_cpp.h"
 #include "../nfp_app.h"
+#include "../nfp_main.h"
+#include "../nfp_net.h"
 #include "../nfp_port.h"
 #include "main.h"
 
-static int
-__nfp_abm_reset_root(struct net_device *netdev, struct nfp_abm_link *alink,
-		     u32 handle, unsigned int qs, u32 init_val)
+static bool nfp_abm_qdisc_is_red(struct nfp_qdisc *qdisc)
 {
-	struct nfp_port *port = nfp_port_from_netdev(netdev);
-	int ret;
+	return qdisc->type == NFP_QDISC_RED;
+}
 
-	ret = nfp_abm_ctrl_set_all_q_lvls(alink, init_val);
-	memset(alink->qdiscs, 0, sizeof(*alink->qdiscs) * alink->num_qdiscs);
+static bool nfp_abm_qdisc_child_valid(struct nfp_qdisc *qdisc, unsigned int id)
+{
+	return qdisc->children[id] &&
+	       qdisc->children[id] != NFP_QDISC_UNTRACKED;
+}
 
-	alink->parent = handle;
-	alink->num_qdiscs = qs;
-	port->tc_offload_cnt = qs;
+static void *nfp_abm_qdisc_tree_deref_slot(void __rcu **slot)
+{
+	return rtnl_dereference(*slot);
+}
 
-	return ret;
+static void
+nfp_abm_stats_propagate(struct nfp_alink_stats *parent,
+			struct nfp_alink_stats *child)
+{
+	parent->tx_pkts		+= child->tx_pkts;
+	parent->tx_bytes	+= child->tx_bytes;
+	parent->backlog_pkts	+= child->backlog_pkts;
+	parent->backlog_bytes	+= child->backlog_bytes;
+	parent->overlimits	+= child->overlimits;
+	parent->drops		+= child->drops;
 }
 
 static void
-nfp_abm_reset_root(struct net_device *netdev, struct nfp_abm_link *alink,
-		   u32 handle, unsigned int qs)
+nfp_abm_stats_update_red(struct nfp_abm_link *alink, struct nfp_qdisc *qdisc,
+			 unsigned int queue)
 {
-	__nfp_abm_reset_root(netdev, alink, handle, qs, NFP_ABM_LVL_INFINITY);
+	struct nfp_cpp *cpp = alink->abm->app->cpp;
+	int err;
+
+	if (!qdisc->offloaded)
+		return;
+
+	err = nfp_abm_ctrl_read_q_stats(alink, queue, &qdisc->red.stats);
+	if (err)
+		nfp_err(cpp, "RED stats (%d) read failed with error %d\n",
+			queue, err);
+
+	err = nfp_abm_ctrl_read_q_xstats(alink, queue, &qdisc->red.xstats);
+	if (err)
+		nfp_err(cpp, "RED xstats (%d) read failed with error %d\n",
+			queue, err);
 }
 
-static int
-nfp_abm_red_find(struct nfp_abm_link *alink, struct tc_red_qopt_offload *opt)
+static void
+nfp_abm_stats_update_mq(struct nfp_abm_link *alink, struct nfp_qdisc *qdisc)
 {
-	unsigned int i = TC_H_MIN(opt->parent) - 1;
+	unsigned int i;
 
-	if (opt->parent == TC_H_ROOT)
-		i = 0;
-	else if (TC_H_MAJ(alink->parent) == TC_H_MAJ(opt->parent))
-		i = TC_H_MIN(opt->parent) - 1;
-	else
-		return -EOPNOTSUPP;
+	if (qdisc->type != NFP_QDISC_MQ)
+		return;
 
-	if (i >= alink->num_qdiscs || opt->handle != alink->qdiscs[i].handle)
-		return -EOPNOTSUPP;
+	for (i = 0; i < alink->total_queues; i++)
+		if (nfp_abm_qdisc_child_valid(qdisc, i))
+			nfp_abm_stats_update_red(alink, qdisc->children[i], i);
+}
 
-	return i;
+static void __nfp_abm_stats_update(struct nfp_abm_link *alink, u64 time_now)
+{
+	alink->last_stats_update = time_now;
+	if (alink->root_qdisc)
+		nfp_abm_stats_update_mq(alink, alink->root_qdisc);
+}
+
+static void nfp_abm_stats_update(struct nfp_abm_link *alink)
+{
+	u64 now;
+
+	/* Limit the frequency of updates - stats of non-leaf qdiscs are a sum
+	 * of all their leafs, so we would read the same stat multiple times
+	 * for every dump.
+	 */
+	now = ktime_get();
+	if (now - alink->last_stats_update < NFP_ABM_STATS_REFRESH_IVAL)
+		return;
+
+	__nfp_abm_stats_update(alink, now);
 }
 
 static void
-nfp_abm_red_destroy(struct net_device *netdev, struct nfp_abm_link *alink,
-		    u32 handle)
+nfp_abm_qdisc_unlink_children(struct nfp_qdisc *qdisc,
+			      unsigned int start, unsigned int end)
 {
 	unsigned int i;
 
-	for (i = 0; i < alink->num_qdiscs; i++)
-		if (handle == alink->qdiscs[i].handle)
-			break;
-	if (i == alink->num_qdiscs)
+	for (i = start; i < end; i++)
+		if (nfp_abm_qdisc_child_valid(qdisc, i)) {
+			qdisc->children[i]->use_cnt--;
+			qdisc->children[i] = NULL;
+		}
+}
+
+static void
+nfp_abm_qdisc_offload_stop(struct nfp_abm_link *alink, struct nfp_qdisc *qdisc)
+{
+	/* Don't complain when qdisc is getting unlinked */
+	if (qdisc->use_cnt)
+		nfp_warn(alink->abm->app->cpp, "Offload of '%08x' stopped\n",
+			 qdisc->handle);
+
+	if (!nfp_abm_qdisc_is_red(qdisc))
 		return;
 
-	if (alink->parent == TC_H_ROOT) {
-		nfp_abm_reset_root(netdev, alink, TC_H_ROOT, 0);
-	} else {
-		nfp_abm_ctrl_set_q_lvl(alink, i, NFP_ABM_LVL_INFINITY);
-		memset(&alink->qdiscs[i], 0, sizeof(*alink->qdiscs));
+	qdisc->red.stats.backlog_pkts = 0;
+	qdisc->red.stats.backlog_bytes = 0;
+}
+
+static int
+__nfp_abm_stats_init(struct nfp_abm_link *alink,
+		     unsigned int queue, struct nfp_alink_stats *prev_stats,
+		     struct nfp_alink_xstats *prev_xstats)
+{
+	u64 backlog_pkts, backlog_bytes;
+	int err;
+
+	/* Don't touch the backlog, backlog can only be reset after it has
+	 * been reported back to the tc qdisc stats.
+	 */
+	backlog_pkts = prev_stats->backlog_pkts;
+	backlog_bytes = prev_stats->backlog_bytes;
+
+	err = nfp_abm_ctrl_read_q_stats(alink, queue, prev_stats);
+	if (err) {
+		nfp_err(alink->abm->app->cpp,
+			"RED stats init (%d) failed with error %d\n",
+			queue, err);
+		return err;
 	}
+
+	err = nfp_abm_ctrl_read_q_xstats(alink, queue, prev_xstats);
+	if (err) {
+		nfp_err(alink->abm->app->cpp,
+			"RED xstats init (%d) failed with error %d\n",
+			queue, err);
+		return err;
+	}
+
+	prev_stats->backlog_pkts = backlog_pkts;
+	prev_stats->backlog_bytes = backlog_bytes;
+	return 0;
 }
 
-static bool
-nfp_abm_red_check_params(struct nfp_abm_link *alink,
-			 struct tc_red_qopt_offload *opt)
+static int
+nfp_abm_stats_init(struct nfp_abm_link *alink, struct nfp_qdisc *qdisc,
+		   unsigned int queue)
 {
-	struct nfp_cpp *cpp = alink->abm->app->cpp;
+	return __nfp_abm_stats_init(alink, queue,
+				    &qdisc->red.prev_stats,
+				    &qdisc->red.prev_xstats);
+}
 
-	if (!opt->set.is_ecn) {
-		nfp_warn(cpp, "RED offload failed - drop is not supported (ECN option required) (p:%08x h:%08x)\n",
-			 opt->parent, opt->handle);
-		return false;
+static void
+nfp_abm_offload_compile_red(struct nfp_abm_link *alink, struct nfp_qdisc *qdisc,
+			    unsigned int queue)
+{
+	qdisc->offload_mark = qdisc->type == NFP_QDISC_RED &&
+			      qdisc->params_ok &&
+			      qdisc->use_cnt == 1 &&
+			      !qdisc->children[0];
+
+	/* If we are starting offload init prev_stats */
+	if (qdisc->offload_mark && !qdisc->offloaded)
+		if (nfp_abm_stats_init(alink, qdisc, queue))
+			qdisc->offload_mark = false;
+
+	if (!qdisc->offload_mark)
+		return;
+
+	nfp_abm_ctrl_set_q_lvl(alink, queue, qdisc->red.threshold);
+}
+
+static void
+nfp_abm_offload_compile_mq(struct nfp_abm_link *alink, struct nfp_qdisc *qdisc)
+{
+	unsigned int i;
+
+	qdisc->offload_mark = qdisc->type == NFP_QDISC_MQ;
+	if (!qdisc->offload_mark)
+		return;
+
+	for (i = 0; i < alink->total_queues; i++) {
+		struct nfp_qdisc *child = qdisc->children[i];
+
+		if (!nfp_abm_qdisc_child_valid(qdisc, i))
+			continue;
+
+		nfp_abm_offload_compile_red(alink, child, i);
 	}
-	if (opt->set.is_harddrop) {
-		nfp_warn(cpp, "RED offload failed - harddrop is not supported (p:%08x h:%08x)\n",
-			 opt->parent, opt->handle);
-		return false;
+}
+
+void nfp_abm_qdisc_offload_update(struct nfp_abm_link *alink)
+{
+	struct nfp_abm *abm = alink->abm;
+	struct radix_tree_iter iter;
+	struct nfp_qdisc *qdisc;
+	void __rcu **slot;
+	size_t i;
+
+	/* Mark all thresholds as unconfigured */
+	__bitmap_set(abm->threshold_undef,
+		     alink->queue_base, alink->total_queues);
+
+	/* Clear offload marks */
+	radix_tree_for_each_slot(slot, &alink->qdiscs, &iter, 0) {
+		qdisc = nfp_abm_qdisc_tree_deref_slot(slot);
+		qdisc->offload_mark = false;
 	}
-	if (opt->set.min != opt->set.max) {
-		nfp_warn(cpp, "RED offload failed - unsupported min/max parameters (p:%08x h:%08x)\n",
-			 opt->parent, opt->handle);
-		return false;
+
+	if (alink->root_qdisc)
+		nfp_abm_offload_compile_mq(alink, alink->root_qdisc);
+
+	/* Refresh offload status */
+	radix_tree_for_each_slot(slot, &alink->qdiscs, &iter, 0) {
+		qdisc = nfp_abm_qdisc_tree_deref_slot(slot);
+		if (!qdisc->offload_mark && qdisc->offloaded)
+			nfp_abm_qdisc_offload_stop(alink, qdisc);
+		qdisc->offloaded = qdisc->offload_mark;
 	}
-	if (opt->set.min > NFP_ABM_LVL_INFINITY) {
-		nfp_warn(cpp, "RED offload failed - threshold too large %d > %d (p:%08x h:%08x)\n",
-			 opt->set.min, NFP_ABM_LVL_INFINITY, opt->parent,
-			 opt->handle);
-		return false;
+
+	/* Reset the unconfigured thresholds */
+	for (i = 0; i < abm->num_thresholds; i++)
+		if (test_bit(i, abm->threshold_undef))
+			__nfp_abm_ctrl_set_q_lvl(abm, i, NFP_ABM_LVL_INFINITY);
+
+	__nfp_abm_stats_update(alink, ktime_get());
+}
+
+static void
+nfp_abm_qdisc_clear_mq(struct net_device *netdev, struct nfp_abm_link *alink,
+		       struct nfp_qdisc *qdisc)
+{
+	struct radix_tree_iter iter;
+	unsigned int mq_refs = 0;
+	void __rcu **slot;
+
+	if (!qdisc->use_cnt)
+		return;
+	/* MQ doesn't notify well on destruction, we need special handling of
+	 * MQ's children.
+	 */
+	if (qdisc->type == NFP_QDISC_MQ &&
+	    qdisc == alink->root_qdisc &&
+	    netdev->reg_state == NETREG_UNREGISTERING)
+		return;
+
+	/* Count refs held by MQ instances and clear pointers */
+	radix_tree_for_each_slot(slot, &alink->qdiscs, &iter, 0) {
+		struct nfp_qdisc *mq = nfp_abm_qdisc_tree_deref_slot(slot);
+		unsigned int i;
+
+		if (mq->type != NFP_QDISC_MQ || mq->netdev != netdev)
+			continue;
+		for (i = 0; i < mq->num_children; i++)
+			if (mq->children[i] == qdisc) {
+				mq->children[i] = NULL;
+				mq_refs++;
+			}
 	}
 
-	return true;
+	WARN(qdisc->use_cnt != mq_refs, "non-zero qdisc use count: %d (- %d)\n",
+	     qdisc->use_cnt, mq_refs);
+}
+
+static void
+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;
+	nfp_abm_qdisc_clear_mq(netdev, alink, qdisc);
+	WARN_ON(radix_tree_delete(&alink->qdiscs,
+				  TC_H_MAJ(qdisc->handle)) != qdisc);
+
+	kfree(qdisc->children);
+	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,
+		    unsigned int children)
+{
+	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->children = kcalloc(children, sizeof(void *), GFP_KERNEL);
+	if (!qdisc->children)
+		goto err_free_qdisc;
+
+	qdisc->netdev = netdev;
+	qdisc->type = type;
+	qdisc->parent_handle = parent_handle;
+	qdisc->handle = handle;
+	qdisc->num_children = children;
+
+	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_child_tbl;
+	}
+
+	port->tc_offload_cnt++;
+	return qdisc;
+
+err_free_child_tbl:
+	kfree(qdisc->children);
+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_red_replace(struct net_device *netdev, struct nfp_abm_link *alink,
-		    struct tc_red_qopt_offload *opt)
+nfp_abm_qdisc_replace(struct net_device *netdev, struct nfp_abm_link *alink,
+		      enum nfp_qdisc_type type, u32 parent_handle, u32 handle,
+		      unsigned int children, struct nfp_qdisc **qdisc)
+{
+	*qdisc = nfp_abm_qdisc_find(alink, handle);
+	if (*qdisc) {
+		if (WARN_ON((*qdisc)->type != type))
+			return -EINVAL;
+		return 1;
+	}
+
+	*qdisc = nfp_abm_qdisc_alloc(netdev, alink, type, parent_handle, handle,
+				     children);
+	return *qdisc ? 0 : -ENOMEM;
+}
+
+static void
+nfp_abm_qdisc_destroy(struct net_device *netdev, struct nfp_abm_link *alink,
+		      u32 handle)
 {
-	bool existing;
-	int i, err;
+	struct nfp_qdisc *qdisc;
 
-	i = nfp_abm_red_find(alink, opt);
-	existing = i >= 0;
+	qdisc = nfp_abm_qdisc_find(alink, handle);
+	if (!qdisc)
+		return;
+
+	/* We don't get TC_SETUP_ROOT_QDISC w/ MQ when netdev is unregistered */
+	if (alink->root_qdisc == qdisc)
+		qdisc->use_cnt--;
 
-	if (!nfp_abm_red_check_params(alink, opt)) {
-		err = -EINVAL;
-		goto err_destroy;
+	nfp_abm_qdisc_unlink_children(qdisc, 0, qdisc->num_children);
+	nfp_abm_qdisc_free(netdev, alink, qdisc);
+
+	if (alink->root_qdisc == qdisc) {
+		alink->root_qdisc = NULL;
+		/* Only root change matters, other changes are acted upon on
+		 * the graft notification.
+		 */
+		nfp_abm_qdisc_offload_update(alink);
 	}
+}
 
-	if (existing) {
-		if (alink->parent == TC_H_ROOT)
-			err = nfp_abm_ctrl_set_all_q_lvls(alink, opt->set.min);
-		else
-			err = nfp_abm_ctrl_set_q_lvl(alink, i, opt->set.min);
-		if (err)
-			goto err_destroy;
+static int
+nfp_abm_qdisc_graft(struct nfp_abm_link *alink, u32 handle, u32 child_handle,
+		    unsigned int id)
+{
+	struct nfp_qdisc *parent, *child;
+
+	parent = nfp_abm_qdisc_find(alink, handle);
+	if (!parent)
 		return 0;
-	}
 
-	if (opt->parent == TC_H_ROOT) {
-		i = 0;
-		err = __nfp_abm_reset_root(netdev, alink, TC_H_ROOT, 1,
-					   opt->set.min);
-	} else if (TC_H_MAJ(alink->parent) == TC_H_MAJ(opt->parent)) {
-		i = TC_H_MIN(opt->parent) - 1;
-		err = nfp_abm_ctrl_set_q_lvl(alink, i, opt->set.min);
-	} else {
+	if (WARN(id >= parent->num_children,
+		 "graft child out of bound %d >= %d\n",
+		 id, parent->num_children))
 		return -EINVAL;
-	}
-	/* Set the handle to try full clean up, in case IO failed */
-	alink->qdiscs[i].handle = opt->handle;
-	if (err)
-		goto err_destroy;
 
-	if (opt->parent == TC_H_ROOT)
-		err = nfp_abm_ctrl_read_stats(alink, &alink->qdiscs[i].stats);
-	else
-		err = nfp_abm_ctrl_read_q_stats(alink, i,
-						&alink->qdiscs[i].stats);
-	if (err)
-		goto err_destroy;
+	nfp_abm_qdisc_unlink_children(parent, id, id + 1);
 
-	if (opt->parent == TC_H_ROOT)
-		err = nfp_abm_ctrl_read_xstats(alink,
-					       &alink->qdiscs[i].xstats);
+	child = nfp_abm_qdisc_find(alink, child_handle);
+	if (child)
+		child->use_cnt++;
 	else
-		err = nfp_abm_ctrl_read_q_xstats(alink, i,
-						 &alink->qdiscs[i].xstats);
-	if (err)
-		goto err_destroy;
+		child = NFP_QDISC_UNTRACKED;
+	parent->children[id] = child;
 
-	alink->qdiscs[i].stats.backlog_pkts = 0;
-	alink->qdiscs[i].stats.backlog_bytes = 0;
+	nfp_abm_qdisc_offload_update(alink);
 
 	return 0;
-err_destroy:
-	/* If the qdisc keeps on living, but we can't offload undo changes */
-	if (existing) {
-		opt->set.qstats->qlen -= alink->qdiscs[i].stats.backlog_pkts;
-		opt->set.qstats->backlog -=
-			alink->qdiscs[i].stats.backlog_bytes;
-	}
-	nfp_abm_red_destroy(netdev, alink, opt->handle);
-
-	return err;
 }
 
 static void
-nfp_abm_update_stats(struct nfp_alink_stats *new, struct nfp_alink_stats *old,
-		     struct tc_qopt_offload_stats *stats)
+nfp_abm_stats_calculate(struct nfp_alink_stats *new,
+			struct nfp_alink_stats *old,
+			struct gnet_stats_basic_packed *bstats,
+			struct gnet_stats_queue *qstats)
 {
-	_bstats_update(stats->bstats, new->tx_bytes - old->tx_bytes,
+	_bstats_update(bstats, new->tx_bytes - old->tx_bytes,
 		       new->tx_pkts - old->tx_pkts);
-	stats->qstats->qlen += new->backlog_pkts - old->backlog_pkts;
-	stats->qstats->backlog += new->backlog_bytes - old->backlog_bytes;
-	stats->qstats->overlimits += new->overlimits - old->overlimits;
-	stats->qstats->drops += new->drops - old->drops;
+	qstats->qlen += new->backlog_pkts - old->backlog_pkts;
+	qstats->backlog += new->backlog_bytes - old->backlog_bytes;
+	qstats->overlimits += new->overlimits - old->overlimits;
+	qstats->drops += new->drops - old->drops;
+}
+
+static void
+nfp_abm_stats_red_calculate(struct nfp_alink_xstats *new,
+			    struct nfp_alink_xstats *old,
+			    struct red_stats *stats)
+{
+	stats->forced_mark += new->ecn_marked - old->ecn_marked;
+	stats->pdrop += new->pdrop - old->pdrop;
 }
 
 static int
-nfp_abm_red_stats(struct nfp_abm_link *alink, struct tc_red_qopt_offload *opt)
+nfp_abm_red_xstats(struct nfp_abm_link *alink, struct tc_red_qopt_offload *opt)
 {
-	struct nfp_alink_stats *prev_stats;
-	struct nfp_alink_stats stats;
-	int i, err;
+	struct nfp_qdisc *qdisc;
 
-	i = nfp_abm_red_find(alink, opt);
-	if (i < 0)
-		return i;
-	prev_stats = &alink->qdiscs[i].stats;
+	nfp_abm_stats_update(alink);
 
-	if (alink->parent == TC_H_ROOT)
-		err = nfp_abm_ctrl_read_stats(alink, &stats);
-	else
-		err = nfp_abm_ctrl_read_q_stats(alink, i, &stats);
-	if (err)
-		return err;
+	qdisc = nfp_abm_qdisc_find(alink, opt->handle);
+	if (!qdisc || !qdisc->offloaded)
+		return -EOPNOTSUPP;
 
-	nfp_abm_update_stats(&stats, prev_stats, &opt->stats);
+	nfp_abm_stats_red_calculate(&qdisc->red.xstats,
+				    &qdisc->red.prev_xstats,
+				    opt->xstats);
+	qdisc->red.prev_xstats = qdisc->red.xstats;
+	return 0;
+}
 
-	*prev_stats = stats;
+static int
+nfp_abm_red_stats(struct nfp_abm_link *alink, u32 handle,
+		  struct tc_qopt_offload_stats *stats)
+{
+	struct nfp_qdisc *qdisc;
 
-	return 0;
+	nfp_abm_stats_update(alink);
+
+	qdisc = nfp_abm_qdisc_find(alink, handle);
+	if (!qdisc)
+		return -EOPNOTSUPP;
+	/* If the qdisc offload has stopped we may need to adjust the backlog
+	 * counters back so carry on even if qdisc is not currently offloaded.
+	 */
+
+	nfp_abm_stats_calculate(&qdisc->red.stats,
+				&qdisc->red.prev_stats,
+				stats->bstats, stats->qstats);
+	qdisc->red.prev_stats = qdisc->red.stats;
+
+	return qdisc->offloaded ? 0 : -EOPNOTSUPP;
+}
+
+static bool
+nfp_abm_red_check_params(struct nfp_abm_link *alink,
+			 struct tc_red_qopt_offload *opt)
+{
+	struct nfp_cpp *cpp = alink->abm->app->cpp;
+
+	if (!opt->set.is_ecn) {
+		nfp_warn(cpp, "RED offload failed - drop is not supported (ECN option required) (p:%08x h:%08x)\n",
+			 opt->parent, opt->handle);
+		return false;
+	}
+	if (opt->set.is_harddrop) {
+		nfp_warn(cpp, "RED offload failed - harddrop is not supported (p:%08x h:%08x)\n",
+			 opt->parent, opt->handle);
+		return false;
+	}
+	if (opt->set.min != opt->set.max) {
+		nfp_warn(cpp, "RED offload failed - unsupported min/max parameters (p:%08x h:%08x)\n",
+			 opt->parent, opt->handle);
+		return false;
+	}
+	if (opt->set.min > NFP_ABM_LVL_INFINITY) {
+		nfp_warn(cpp, "RED offload failed - threshold too large %d > %d (p:%08x h:%08x)\n",
+			 opt->set.min, NFP_ABM_LVL_INFINITY, opt->parent,
+			 opt->handle);
+		return false;
+	}
+
+	return true;
 }
 
 static int
-nfp_abm_red_xstats(struct nfp_abm_link *alink, struct tc_red_qopt_offload *opt)
+nfp_abm_red_replace(struct net_device *netdev, struct nfp_abm_link *alink,
+		    struct tc_red_qopt_offload *opt)
 {
-	struct nfp_alink_xstats *prev_xstats;
-	struct nfp_alink_xstats xstats;
-	int i, err;
+	struct nfp_qdisc *qdisc;
+	int ret;
 
-	i = nfp_abm_red_find(alink, opt);
-	if (i < 0)
-		return i;
-	prev_xstats = &alink->qdiscs[i].xstats;
+	ret = nfp_abm_qdisc_replace(netdev, alink, NFP_QDISC_RED, opt->parent,
+				    opt->handle, 1, &qdisc);
+	if (ret < 0)
+		return ret;
 
-	if (alink->parent == TC_H_ROOT)
-		err = nfp_abm_ctrl_read_xstats(alink, &xstats);
-	else
-		err = nfp_abm_ctrl_read_q_xstats(alink, i, &xstats);
-	if (err)
-		return err;
+	/* If limit != 0 child gets reset */
+	if (opt->set.limit) {
+		if (nfp_abm_qdisc_child_valid(qdisc, 0))
+			qdisc->children[0]->use_cnt--;
+		qdisc->children[0] = NULL;
+	} else {
+		/* Qdisc was just allocated without a limit will use noop_qdisc,
+		 * i.e. a block hole.
+		 */
+		if (!ret)
+			qdisc->children[0] = NFP_QDISC_UNTRACKED;
+	}
 
-	opt->xstats->forced_mark += xstats.ecn_marked - prev_xstats->ecn_marked;
-	opt->xstats->pdrop += xstats.pdrop - prev_xstats->pdrop;
+	qdisc->params_ok = nfp_abm_red_check_params(alink, opt);
+	if (qdisc->params_ok)
+		qdisc->red.threshold = opt->set.min;
 
-	*prev_xstats = xstats;
+	if (qdisc->use_cnt == 1)
+		nfp_abm_qdisc_offload_update(alink);
 
 	return 0;
 }
@@ -248,37 +554,76 @@ int nfp_abm_setup_tc_red(struct net_device *netdev, struct nfp_abm_link *alink,
 	case TC_RED_REPLACE:
 		return nfp_abm_red_replace(netdev, alink, opt);
 	case TC_RED_DESTROY:
-		nfp_abm_red_destroy(netdev, alink, opt->handle);
+		nfp_abm_qdisc_destroy(netdev, alink, opt->handle);
 		return 0;
 	case TC_RED_STATS:
-		return nfp_abm_red_stats(alink, opt);
+		return nfp_abm_red_stats(alink, opt->handle, &opt->stats);
 	case TC_RED_XSTATS:
 		return nfp_abm_red_xstats(alink, opt);
+	case TC_RED_GRAFT:
+		return nfp_abm_qdisc_graft(alink, opt->handle,
+					   opt->child_handle, 0);
 	default:
 		return -EOPNOTSUPP;
 	}
 }
 
 static int
-nfp_abm_mq_stats(struct nfp_abm_link *alink, struct tc_mq_qopt_offload *opt)
+nfp_abm_mq_create(struct net_device *netdev, struct nfp_abm_link *alink,
+		  struct tc_mq_qopt_offload *opt)
 {
-	struct nfp_alink_stats stats;
+	struct nfp_qdisc *qdisc;
+	int ret;
+
+	ret = nfp_abm_qdisc_replace(netdev, alink, NFP_QDISC_MQ,
+				    TC_H_ROOT, opt->handle, alink->total_queues,
+				    &qdisc);
+	if (ret < 0)
+		return ret;
+
+	qdisc->params_ok = true;
+	qdisc->offloaded = true;
+	nfp_abm_qdisc_offload_update(alink);
+	return 0;
+}
+
+static int
+nfp_abm_mq_stats(struct nfp_abm_link *alink, u32 handle,
+		 struct tc_qopt_offload_stats *stats)
+{
+	struct nfp_qdisc *qdisc, *red;
 	unsigned int i;
-	int err;
 
-	for (i = 0; i < alink->num_qdiscs; i++) {
-		if (alink->qdiscs[i].handle == TC_H_UNSPEC)
+	qdisc = nfp_abm_qdisc_find(alink, handle);
+	if (!qdisc)
+		return -EOPNOTSUPP;
+
+	nfp_abm_stats_update(alink);
+
+	/* MQ stats are summed over the children in the core, so we need
+	 * to add up the unreported child values.
+	 */
+	memset(&qdisc->mq.stats, 0, sizeof(qdisc->mq.stats));
+	memset(&qdisc->mq.prev_stats, 0, sizeof(qdisc->mq.prev_stats));
+
+	for (i = 0; i < qdisc->num_children; i++) {
+		if (!nfp_abm_qdisc_child_valid(qdisc, i))
 			continue;
 
-		err = nfp_abm_ctrl_read_q_stats(alink, i, &stats);
-		if (err)
-			return err;
+		if (!nfp_abm_qdisc_is_red(qdisc->children[i]))
+			continue;
+		red = qdisc->children[i];
 
-		nfp_abm_update_stats(&stats, &alink->qdiscs[i].stats,
-				     &opt->stats);
+		nfp_abm_stats_propagate(&qdisc->mq.stats,
+					&red->red.stats);
+		nfp_abm_stats_propagate(&qdisc->mq.prev_stats,
+					&red->red.prev_stats);
 	}
 
-	return 0;
+	nfp_abm_stats_calculate(&qdisc->mq.stats, &qdisc->mq.prev_stats,
+				stats->bstats, stats->qstats);
+
+	return qdisc->offloaded ? 0 : -EOPNOTSUPP;
 }
 
 int nfp_abm_setup_tc_mq(struct net_device *netdev, struct nfp_abm_link *alink,
@@ -286,16 +631,33 @@ int nfp_abm_setup_tc_mq(struct net_device *netdev, struct nfp_abm_link *alink,
 {
 	switch (opt->command) {
 	case TC_MQ_CREATE:
-		nfp_abm_reset_root(netdev, alink, opt->handle,
-				   alink->total_queues);
-		return 0;
+		return nfp_abm_mq_create(netdev, alink, opt);
 	case TC_MQ_DESTROY:
-		if (opt->handle == alink->parent)
-			nfp_abm_reset_root(netdev, alink, TC_H_ROOT, 0);
+		nfp_abm_qdisc_destroy(netdev, alink, opt->handle);
 		return 0;
 	case TC_MQ_STATS:
-		return nfp_abm_mq_stats(alink, opt);
+		return nfp_abm_mq_stats(alink, opt->handle, &opt->stats);
+	case TC_MQ_GRAFT:
+		return nfp_abm_qdisc_graft(alink, opt->handle,
+					   opt->graft_params.child_handle,
+					   opt->graft_params.queue);
 	default:
 		return -EOPNOTSUPP;
 	}
 }
+
+int nfp_abm_setup_root(struct net_device *netdev, struct nfp_abm_link *alink,
+		       struct tc_root_qopt_offload *opt)
+{
+	if (opt->ingress)
+		return -EOPNOTSUPP;
+	if (alink->root_qdisc)
+		alink->root_qdisc->use_cnt--;
+	alink->root_qdisc = nfp_abm_qdisc_find(alink, opt->handle);
+	if (alink->root_qdisc)
+		alink->root_qdisc->use_cnt++;
+
+	nfp_abm_qdisc_offload_update(alink);
+
+	return 0;
+}

include/linux/netdevice.h

@@ -845,6 +845,7 @@ enum tc_setup_type {
 	TC_SETUP_QDISC_PRIO,
 	TC_SETUP_QDISC_MQ,
 	TC_SETUP_QDISC_ETF,
+	TC_SETUP_ROOT_QDISC,
 };
 
 /* These structures hold the attributes of bpf state that are being passed

include/net/pkt_cls.h

@@ -821,12 +821,21 @@ enum tc_mq_command {
 	TC_MQ_CREATE,
 	TC_MQ_DESTROY,
 	TC_MQ_STATS,
+	TC_MQ_GRAFT,
+};
+
+struct tc_mq_opt_offload_graft_params {
+	unsigned long queue;
+	u32 child_handle;
 };
 
 struct tc_mq_qopt_offload {
 	enum tc_mq_command command;
 	u32 handle;
-	struct tc_qopt_offload_stats stats;
+	union {
+		struct tc_qopt_offload_stats stats;
+		struct tc_mq_opt_offload_graft_params graft_params;
+	};
 };
 
 enum tc_red_command {
@@ -834,12 +843,14 @@ enum tc_red_command {
 	TC_RED_DESTROY,
 	TC_RED_STATS,
 	TC_RED_XSTATS,
+	TC_RED_GRAFT,
 };
 
 struct tc_red_qopt_offload_params {
 	u32 min;
 	u32 max;
 	u32 probability;
+	u32 limit;
 	bool is_ecn;
 	bool is_harddrop;
 	struct gnet_stats_queue *qstats;
@@ -853,6 +864,7 @@ struct tc_red_qopt_offload {
 		struct tc_red_qopt_offload_params set;
 		struct tc_qopt_offload_stats stats;
 		struct red_stats *xstats;
+		u32 child_handle;
 	};
 };
 
@@ -889,4 +901,14 @@ struct tc_prio_qopt_offload {
 	};
 };
 
+enum tc_root_command {
+	TC_ROOT_GRAFT,
+};
+
+struct tc_root_qopt_offload {
+	enum tc_root_command command;
+	u32 handle;
+	bool ingress;
+};
+
 #endif

net/sched/sch_api.c

@@ -860,6 +860,21 @@ void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
 }
 EXPORT_SYMBOL(qdisc_offload_graft_helper);
 
+static void qdisc_offload_graft_root(struct net_device *dev,
+				     struct Qdisc *new, struct Qdisc *old,
+				     struct netlink_ext_ack *extack)
+{
+	struct tc_root_qopt_offload graft_offload = {
+		.command	= TC_ROOT_GRAFT,
+		.handle		= new ? new->handle : 0,
+		.ingress	= (new && new->flags & TCQ_F_INGRESS) ||
+				  (old && old->flags & TCQ_F_INGRESS),
+	};
+
+	qdisc_offload_graft_helper(dev, NULL, new, old,
+				   TC_SETUP_ROOT_QDISC, &graft_offload, extack);
+}
+
 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
 			 u32 portid, u32 seq, u16 flags, int event)
 {
@@ -1026,6 +1041,8 @@ static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
 		if (dev->flags & IFF_UP)
 			dev_deactivate(dev);
 
+		qdisc_offload_graft_root(dev, new, old, extack);
+
 		if (new && new->ops->attach)
 			goto skip;
 

net/sched/sch_mq.c

@@ -193,6 +193,7 @@ static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
 		    struct Qdisc **old, struct netlink_ext_ack *extack)
 {
 	struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
+	struct tc_mq_qopt_offload graft_offload;
 	struct net_device *dev = qdisc_dev(sch);
 
 	if (dev->flags & IFF_UP)
@@ -203,6 +204,14 @@ static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
 		new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
 	if (dev->flags & IFF_UP)
 		dev_activate(dev);
+
+	graft_offload.handle = sch->handle;
+	graft_offload.graft_params.queue = cl - 1;
+	graft_offload.graft_params.child_handle = new ? new->handle : 0;
+	graft_offload.command = TC_MQ_GRAFT;
+
+	qdisc_offload_graft_helper(qdisc_dev(sch), sch, new, *old,
+				   TC_SETUP_QDISC_MQ, &graft_offload, extack);
 	return 0;
 }
 

net/sched/sch_red.c

@@ -166,6 +166,7 @@ static int red_offload(struct Qdisc *sch, bool enable)
 		opt.set.min = q->parms.qth_min >> q->parms.Wlog;
 		opt.set.max = q->parms.qth_max >> q->parms.Wlog;
 		opt.set.probability = q->parms.max_P;
+		opt.set.limit = q->limit;
 		opt.set.is_ecn = red_use_ecn(q);
 		opt.set.is_harddrop = red_use_harddrop(q);
 		opt.set.qstats = &sch->qstats;
@@ -367,6 +368,21 @@ static int red_dump_class(struct Qdisc *sch, unsigned long cl,
 	return 0;
 }
 
+static void red_graft_offload(struct Qdisc *sch,
+			      struct Qdisc *new, struct Qdisc *old,
+			      struct netlink_ext_ack *extack)
+{
+	struct tc_red_qopt_offload graft_offload = {
+		.handle		= sch->handle,
+		.parent		= sch->parent,
+		.child_handle	= new->handle,
+		.command	= TC_RED_GRAFT,
+	};
+
+	qdisc_offload_graft_helper(qdisc_dev(sch), sch, new, old,
+				   TC_SETUP_QDISC_RED, &graft_offload, extack);
+}
+
 static int red_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
 		     struct Qdisc **old, struct netlink_ext_ack *extack)
 {
@@ -376,6 +392,8 @@ static int red_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
 		new = &noop_qdisc;
 
 	*old = qdisc_replace(sch, new, &q->qdisc);
+
+	red_graft_offload(sch, new, *old, extack);
 	return 0;
 }