nfp: abm: keep track of all RED thresholds

Instead of writing the threshold out when Qdisc is configured
and not remembering it move to a scheme where we remember all
thresholds.  When configuration changes parse the offloaded
Qdiscs and set thresholds appropriately.

This will help future extensions.
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/ctrl.c

@@ -71,35 +71,37 @@ nfp_abm_ctrl_stat_all(struct nfp_abm_link *alink, const struct nfp_rtsym *sym,
 	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)

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

@@ -2,6 +2,7 @@
 /* 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>
@@ -399,6 +400,7 @@ 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) {
@@ -425,15 +427,28 @@ 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);
@@ -445,6 +460,10 @@ 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;
@@ -458,6 +477,8 @@ 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

@@ -20,6 +20,11 @@ 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 +33,11 @@ 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;
@@ -64,11 +74,13 @@ struct nfp_alink_xstats {
 /**
  * struct nfp_red_qdisc - representation of single RED Qdisc
  * @handle:	handle of currently offloaded RED Qdisc
+ * @threshold:	marking threshold of this Qdisc
  * @stats:	statistics from last refresh
  * @xstats:	base of extended statistics
  */
 struct nfp_red_qdisc {
 	u32 handle;
+	u32 threshold;
 	struct nfp_alink_stats stats;
 	struct nfp_alink_xstats xstats;
 };
@@ -102,8 +114,8 @@ 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);

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

@@ -7,25 +7,73 @@
 
 #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
+static void
+nfp_abm_offload_compile_red(struct nfp_abm_link *alink,
+			    struct nfp_red_qdisc *qdisc, unsigned int queue)
+{
+	if (!qdisc->handle)
+		return;
+
+	nfp_abm_ctrl_set_q_lvl(alink, queue, qdisc->threshold);
+}
+
+static void nfp_abm_offload_compile_one(struct nfp_abm_link *alink)
+{
+	unsigned int i;
+	bool is_mq;
+
+	is_mq = alink->num_qdiscs > 1;
+
+	for (i = 0; i < alink->total_queues; i++) {
+		struct nfp_red_qdisc *next;
+
+		if (is_mq && !alink->red_qdiscs[i].handle)
+			continue;
+
+		next = is_mq ? &alink->red_qdiscs[i] : &alink->red_qdiscs[0];
+		nfp_abm_offload_compile_red(alink, next, i);
+	}
+}
+
+static void nfp_abm_offload_update(struct nfp_abm *abm)
+{
+	struct nfp_abm_link *alink = NULL;
+	struct nfp_pf *pf = abm->app->pf;
+	struct nfp_net *nn;
+	size_t i;
+
+	/* Mark all thresholds as unconfigured */
+	__bitmap_set(abm->threshold_undef, 0, abm->num_thresholds);
+
+	/* Configure all offloads */
+	list_for_each_entry(nn, &pf->vnics, vnic_list) {
+		alink = nn->app_priv;
+		nfp_abm_offload_compile_one(alink);
+	}
+
+	/* 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);
+}
+
+static void
 __nfp_abm_reset_root(struct net_device *netdev, struct nfp_abm_link *alink,
 		     u32 handle, unsigned int qs, u32 init_val)
 {
 	struct nfp_port *port = nfp_port_from_netdev(netdev);
-	int ret;
 
-	ret = nfp_abm_ctrl_set_all_q_lvls(alink, 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;
-
-	return ret;
 }
 
 static void
@@ -66,12 +114,12 @@ nfp_abm_red_destroy(struct net_device *netdev, struct nfp_abm_link *alink,
 	if (i == alink->num_qdiscs)
 		return;
 
-	if (alink->parent == TC_H_ROOT) {
+	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);
+	else
 		memset(&alink->red_qdiscs[i], 0, sizeof(*alink->red_qdiscs));
-	}
+
+	nfp_abm_offload_update(alink->abm);
 }
 
 static bool
@@ -121,29 +169,19 @@ nfp_abm_red_replace(struct net_device *netdev, struct nfp_abm_link *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;
+		nfp_abm_offload_update(alink->abm);
 		return 0;
 	}
 
 	if (opt->parent == TC_H_ROOT) {
 		i = 0;
-		err = __nfp_abm_reset_root(netdev, alink, TC_H_ROOT, 1,
-					   opt->set.min);
+		__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 {
 		return -EINVAL;
 	}
-	/* Set the handle to try full clean up, in case IO failed */
 	alink->red_qdiscs[i].handle = opt->handle;
-	if (err)
-		goto err_destroy;
 
 	if (opt->parent == TC_H_ROOT)
 		err = nfp_abm_ctrl_read_stats(alink,
@@ -163,9 +201,12 @@ nfp_abm_red_replace(struct net_device *netdev, struct nfp_abm_link *alink,
 	if (err)
 		goto err_destroy;
 
+	alink->red_qdiscs[i].threshold = opt->set.min;
 	alink->red_qdiscs[i].stats.backlog_pkts = 0;
 	alink->red_qdiscs[i].stats.backlog_bytes = 0;
 
+	nfp_abm_offload_update(alink->abm);
+
 	return 0;
 err_destroy:
 	/* If the qdisc keeps on living, but we can't offload undo changes */
@@ -292,10 +333,13 @@ int nfp_abm_setup_tc_mq(struct net_device *netdev, struct nfp_abm_link *alink,
 	case TC_MQ_CREATE:
 		nfp_abm_reset_root(netdev, alink, opt->handle,
 				   alink->total_queues);
+		nfp_abm_offload_update(alink->abm);
 		return 0;
 	case TC_MQ_DESTROY:
-		if (opt->handle == alink->parent)
+		if (opt->handle == alink->parent) {
 			nfp_abm_reset_root(netdev, alink, TC_H_ROOT, 0);
+			nfp_abm_offload_update(alink->abm);
+		}
 		return 0;
 	case TC_MQ_STATS:
 		return nfp_abm_mq_stats(alink, opt);