cxgb4: add FLOWC based QoS offload

Rework SCHED API to allow offloading TC-MQPRIO QoS configuration.
The existing QUEUE based rate limiting throttles all queues sharing
a traffic class, to the specified max rate limit value. So, if
multiple queues share a traffic class, then all the queues get
the aggregate specified max rate limit.

So, introduce the new FLOWC based rate limiting, where multiple
queues can share a traffic class with each queue getting its own
individual specified max rate limit.

For example, if 2 queues are bound to class 0, which is rate limited
to 1 Gbps, then 2 queues using QUEUE based rate limiting, get the
aggregate output of 1 Gbps only. In FLOWC based rate limiting, each
queue gets its own output of max 1 Gbps each; i.e. 2 queues * 1 Gbps
rate limit = 2 Gbps.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 183 insertions, 46 deletions

diff --git a/drivers/net/ethernet/chelsio/cxgb4/sched.c b/drivers/net/ethernet/chelsio/cxgb4/sched.c
index 60218dc676a8..0a98c4dbb36b 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/sched.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/sched.c
@@ -92,45 +92,69 @@ static int t4_sched_bind_unbind_op(struct port_info *pi, void *arg,
 
 		pf = adap->pf;
 		vf = 0;
+
+		err = t4_set_params(adap, adap->mbox, pf, vf, 1,
+				    &fw_param, &fw_class);
+		break;
+	}
+	case SCHED_FLOWC: {
+		struct sched_flowc_entry *fe;
+
+		fe = (struct sched_flowc_entry *)arg;
+
+		fw_class = bind ? fe->param.class : FW_SCHED_CLS_NONE;
+		err = cxgb4_ethofld_send_flowc(adap->port[pi->port_id],
+					       fe->param.tid, fw_class);
 		break;
 	}
 	default:
 		err = -ENOTSUPP;
-		goto out;
+		break;
 	}
 
-	err = t4_set_params(adap, adap->mbox, pf, vf, 1, &fw_param, &fw_class);
-
-out:
 	return err;
 }
 
-static struct sched_class *t4_sched_queue_lookup(struct port_info *pi,
-						 const unsigned int qid,
-						 int *index)
+static void *t4_sched_entry_lookup(struct port_info *pi,
+				   enum sched_bind_type type,
+				   const u32 val)
 {
 	struct sched_table *s = pi->sched_tbl;
 	struct sched_class *e, *end;
-	struct sched_class *found = NULL;
-	int i;
+	void *found = NULL;
 
-	/* Look for a class with matching bound queue parameters */
+	/* Look for an entry with matching @val */
 	end = &s->tab[s->sched_size];
 	for (e = &s->tab[0]; e != end; ++e) {
-		struct sched_queue_entry *qe;
-
-		i = 0;
-		if (e->state == SCHED_STATE_UNUSED)
+		if (e->state == SCHED_STATE_UNUSED ||
+		    e->bind_type != type)
 			continue;
 
-		list_for_each_entry(qe, &e->queue_list, list) {
-			if (qe->cntxt_id == qid) {
-				found = e;
-				if (index)
-					*index = i;
-				break;
+		switch (type) {
+		case SCHED_QUEUE: {
+			struct sched_queue_entry *qe;
+
+			list_for_each_entry(qe, &e->entry_list, list) {
+				if (qe->cntxt_id == val) {
+					found = qe;
+					break;
+				}
 			}
-			i++;
+			break;
+		}
+		case SCHED_FLOWC: {
+			struct sched_flowc_entry *fe;
+
+			list_for_each_entry(fe, &e->entry_list, list) {
+				if (fe->param.tid == val) {
+					found = fe;
+					break;
+				}
+			}
+			break;
+		}
+		default:
+			return NULL;
 		}
 
 		if (found)
@@ -142,35 +166,26 @@ static struct sched_class *t4_sched_queue_lookup(struct port_info *pi,
 
 static int t4_sched_queue_unbind(struct port_info *pi, struct ch_sched_queue *p)
 {
-	struct adapter *adap = pi->adapter;
-	struct sched_class *e;
 	struct sched_queue_entry *qe = NULL;
+	struct adapter *adap = pi->adapter;
 	struct sge_eth_txq *txq;
-	unsigned int qid;
-	int index = -1;
+	struct sched_class *e;
 	int err = 0;
 
 	if (p->queue < 0 || p->queue >= pi->nqsets)
 		return -ERANGE;
 
 	txq = &adap->sge.ethtxq[pi->first_qset + p->queue];
-	qid = txq->q.cntxt_id;
-
-	/* Find the existing class that the queue is bound to */
-	e = t4_sched_queue_lookup(pi, qid, &index);
-	if (e && index >= 0) {
-		int i = 0;
 
-		list_for_each_entry(qe, &e->queue_list, list) {
-			if (i == index)
-				break;
-			i++;
-		}
+	/* Find the existing entry that the queue is bound to */
+	qe = t4_sched_entry_lookup(pi, SCHED_QUEUE, txq->q.cntxt_id);
+	if (qe) {
 		err = t4_sched_bind_unbind_op(pi, (void *)qe, SCHED_QUEUE,
 					      false);
 		if (err)
 			return err;
 
+		e = &pi->sched_tbl->tab[qe->param.class];
 		list_del(&qe->list);
 		kvfree(qe);
 		if (atomic_dec_and_test(&e->refcnt)) {
@@ -183,11 +198,11 @@ static int t4_sched_queue_unbind(struct port_info *pi, struct ch_sched_queue *p)
 
 static int t4_sched_queue_bind(struct port_info *pi, struct ch_sched_queue *p)
 {
-	struct adapter *adap = pi->adapter;
 	struct sched_table *s = pi->sched_tbl;
-	struct sched_class *e;
 	struct sched_queue_entry *qe = NULL;
+	struct adapter *adap = pi->adapter;
 	struct sge_eth_txq *txq;
+	struct sched_class *e;
 	unsigned int qid;
 	int err = 0;
 
@@ -215,7 +230,8 @@ static int t4_sched_queue_bind(struct port_info *pi, struct ch_sched_queue *p)
 	if (err)
 		goto out_err;
 
-	list_add_tail(&qe->list, &e->queue_list);
+	list_add_tail(&qe->list, &e->entry_list);
+	e->bind_type = SCHED_QUEUE;
 	atomic_inc(&e->refcnt);
 	return err;
 
@@ -224,6 +240,73 @@ out_err:
 	return err;
 }
 
+static int t4_sched_flowc_unbind(struct port_info *pi, struct ch_sched_flowc *p)
+{
+	struct sched_flowc_entry *fe = NULL;
+	struct adapter *adap = pi->adapter;
+	struct sched_class *e;
+	int err = 0;
+
+	if (p->tid < 0 || p->tid >= adap->tids.neotids)
+		return -ERANGE;
+
+	/* Find the existing entry that the flowc is bound to */
+	fe = t4_sched_entry_lookup(pi, SCHED_FLOWC, p->tid);
+	if (fe) {
+		err = t4_sched_bind_unbind_op(pi, (void *)fe, SCHED_FLOWC,
+					      false);
+		if (err)
+			return err;
+
+		e = &pi->sched_tbl->tab[fe->param.class];
+		list_del(&fe->list);
+		kvfree(fe);
+		if (atomic_dec_and_test(&e->refcnt)) {
+			e->state = SCHED_STATE_UNUSED;
+			memset(&e->info, 0, sizeof(e->info));
+		}
+	}
+	return err;
+}
+
+static int t4_sched_flowc_bind(struct port_info *pi, struct ch_sched_flowc *p)
+{
+	struct sched_table *s = pi->sched_tbl;
+	struct sched_flowc_entry *fe = NULL;
+	struct adapter *adap = pi->adapter;
+	struct sched_class *e;
+	int err = 0;
+
+	if (p->tid < 0 || p->tid >= adap->tids.neotids)
+		return -ERANGE;
+
+	fe = kvzalloc(sizeof(*fe), GFP_KERNEL);
+	if (!fe)
+		return -ENOMEM;
+
+	/* Unbind flowc from any existing class */
+	err = t4_sched_flowc_unbind(pi, p);
+	if (err)
+		goto out_err;
+
+	/* Bind flowc to specified class */
+	memcpy(&fe->param, p, sizeof(fe->param));
+
+	e = &s->tab[fe->param.class];
+	err = t4_sched_bind_unbind_op(pi, (void *)fe, SCHED_FLOWC, true);
+	if (err)
+		goto out_err;
+
+	list_add_tail(&fe->list, &e->entry_list);
+	e->bind_type = SCHED_FLOWC;
+	atomic_inc(&e->refcnt);
+	return err;
+
+out_err:
+	kvfree(fe);
+	return err;
+}
+
 static void t4_sched_class_unbind_all(struct port_info *pi,
 				      struct sched_class *e,
 				      enum sched_bind_type type)
@@ -235,10 +318,17 @@ static void t4_sched_class_unbind_all(struct port_info *pi,
 	case SCHED_QUEUE: {
 		struct sched_queue_entry *qe;
 
-		list_for_each_entry(qe, &e->queue_list, list)
+		list_for_each_entry(qe, &e->entry_list, list)
 			t4_sched_queue_unbind(pi, &qe->param);
 		break;
 	}
+	case SCHED_FLOWC: {
+		struct sched_flowc_entry *fe;
+
+		list_for_each_entry(fe, &e->entry_list, list)
+			t4_sched_flowc_unbind(pi, &fe->param);
+		break;
+	}
 	default:
 		break;
 	}
@@ -262,6 +352,15 @@ static int t4_sched_class_bind_unbind_op(struct port_info *pi, void *arg,
 			err = t4_sched_queue_unbind(pi, qe);
 		break;
 	}
+	case SCHED_FLOWC: {
+		struct ch_sched_flowc *fe = (struct ch_sched_flowc *)arg;
+
+		if (bind)
+			err = t4_sched_flowc_bind(pi, fe);
+		else
+			err = t4_sched_flowc_unbind(pi, fe);
+		break;
+	}
 	default:
 		err = -ENOTSUPP;
 		break;
@@ -299,6 +398,12 @@ int cxgb4_sched_class_bind(struct net_device *dev, void *arg,
 		class_id = qe->class;
 		break;
 	}
+	case SCHED_FLOWC: {
+		struct ch_sched_flowc *fe = (struct ch_sched_flowc *)arg;
+
+		class_id = fe->class;
+		break;
+	}
 	default:
 		return -ENOTSUPP;
 	}
@@ -340,6 +445,12 @@ int cxgb4_sched_class_unbind(struct net_device *dev, void *arg,
 		class_id = qe->class;
 		break;
 	}
+	case SCHED_FLOWC: {
+		struct ch_sched_flowc *fe = (struct ch_sched_flowc *)arg;
+
+		class_id = fe->class;
+		break;
+	}
 	default:
 		return -ENOTSUPP;
 	}
@@ -355,10 +466,13 @@ static struct sched_class *t4_sched_class_lookup(struct port_info *pi,
 						const struct ch_sched_params *p)
 {
 	struct sched_table *s = pi->sched_tbl;
-	struct sched_class *e, *end;
 	struct sched_class *found = NULL;
+	struct sched_class *e, *end;
 
-	if (!p) {
+	/* Only allow tc to be shared among SCHED_FLOWC types. For
+	 * other types, always allocate a new tc.
+	 */
+	if (!p || p->u.params.mode != SCHED_CLASS_MODE_FLOW) {
 		/* Get any available unused class */
 		end = &s->tab[s->sched_size];
 		for (e = &s->tab[0]; e != end; ++e) {
@@ -467,9 +581,32 @@ struct sched_class *cxgb4_sched_class_alloc(struct net_device *dev,
 	return t4_sched_class_alloc(pi, p);
 }
 
-static void t4_sched_class_free(struct port_info *pi, struct sched_class *e)
+/**
+ * cxgb4_sched_class_free - free a scheduling class
+ * @dev: net_device pointer
+ * @e: scheduling class
+ *
+ * Frees a scheduling class if there are no users.
+ */
+void cxgb4_sched_class_free(struct net_device *dev, u8 classid)
+{
+	struct port_info *pi = netdev2pinfo(dev);
+	struct sched_table *s = pi->sched_tbl;
+	struct sched_class *e;
+
+	e = &s->tab[classid];
+	if (!atomic_read(&e->refcnt)) {
+		e->state = SCHED_STATE_UNUSED;
+		memset(&e->info, 0, sizeof(e->info));
+	}
+}
+
+static void t4_sched_class_free(struct net_device *dev, struct sched_class *e)
 {
-	t4_sched_class_unbind_all(pi, e, SCHED_QUEUE);
+	struct port_info *pi = netdev2pinfo(dev);
+
+	t4_sched_class_unbind_all(pi, e, e->bind_type);
+	cxgb4_sched_class_free(dev, e->idx);
 }
 
 struct sched_table *t4_init_sched(unsigned int sched_size)
@@ -487,7 +624,7 @@ struct sched_table *t4_init_sched(unsigned int sched_size)
 		memset(&s->tab[i], 0, sizeof(struct sched_class));
 		s->tab[i].idx = i;
 		s->tab[i].state = SCHED_STATE_UNUSED;
-		INIT_LIST_HEAD(&s->tab[i].queue_list);
+		INIT_LIST_HEAD(&s->tab[i].entry_list);
 		atomic_set(&s->tab[i].refcnt, 0);
 	}
 	return s;
@@ -510,7 +647,7 @@ void t4_cleanup_sched(struct adapter *adap)
 
 			e = &s->tab[i];
 			if (e->state == SCHED_STATE_ACTIVE)
-				t4_sched_class_free(pi, e);
+				t4_sched_class_free(adap->port[j], e);
 		}
 		kvfree(s);
 	}