cxgb4: add support for tx traffic scheduling classes

Add support to create tx traffic scheduling classes with specified
scheduling parameters.  Return an existing class if a match is found
with same scheduling parameters.

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

1 files changed, 235 insertions, 0 deletions

diff --git a/drivers/net/ethernet/chelsio/cxgb4/sched.c b/drivers/net/ethernet/chelsio/cxgb4/sched.c
new file mode 100644
index 000000000000..6158daf685c2
--- /dev/null
+++ b/drivers/net/ethernet/chelsio/cxgb4/sched.c
@@ -0,0 +1,235 @@
+/*
+ * This file is part of the Chelsio T4 Ethernet driver for Linux.
+ *
+ * Copyright (c) 2016 Chelsio Communications, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+
+#include "cxgb4.h"
+#include "sched.h"
+
+/* Spinlock must be held by caller */
+static int t4_sched_class_fw_cmd(struct port_info *pi,
+				 struct ch_sched_params *p,
+				 enum sched_fw_ops op)
+{
+	struct adapter *adap = pi->adapter;
+	struct sched_table *s = pi->sched_tbl;
+	struct sched_class *e;
+	int err = 0;
+
+	e = &s->tab[p->u.params.class];
+	switch (op) {
+	case SCHED_FW_OP_ADD:
+		err = t4_sched_params(adap, p->type,
+				      p->u.params.level, p->u.params.mode,
+				      p->u.params.rateunit,
+				      p->u.params.ratemode,
+				      p->u.params.channel, e->idx,
+				      p->u.params.minrate, p->u.params.maxrate,
+				      p->u.params.weight, p->u.params.pktsize);
+		break;
+	default:
+		err = -ENOTSUPP;
+		break;
+	}
+
+	return err;
+}
+
+/* If @p is NULL, fetch any available unused class */
+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;
+
+	if (!p) {
+		/* Get any available unused class */
+		end = &s->tab[s->sched_size];
+		for (e = &s->tab[0]; e != end; ++e) {
+			if (e->state == SCHED_STATE_UNUSED) {
+				found = e;
+				break;
+			}
+		}
+	} else {
+		/* Look for a class with matching scheduling parameters */
+		struct ch_sched_params info;
+		struct ch_sched_params tp;
+
+		memset(&info, 0, sizeof(info));
+		memset(&tp, 0, sizeof(tp));
+
+		memcpy(&tp, p, sizeof(tp));
+		/* Don't try to match class parameter */
+		tp.u.params.class = SCHED_CLS_NONE;
+
+		end = &s->tab[s->sched_size];
+		for (e = &s->tab[0]; e != end; ++e) {
+			if (e->state == SCHED_STATE_UNUSED)
+				continue;
+
+			memset(&info, 0, sizeof(info));
+			memcpy(&info, &e->info, sizeof(info));
+			/* Don't try to match class parameter */
+			info.u.params.class = SCHED_CLS_NONE;
+
+			if ((info.type == tp.type) &&
+			    (!memcmp(&info.u.params, &tp.u.params,
+				     sizeof(info.u.params)))) {
+				found = e;
+				break;
+			}
+		}
+	}
+
+	return found;
+}
+
+static struct sched_class *t4_sched_class_alloc(struct port_info *pi,
+						struct ch_sched_params *p)
+{
+	struct sched_table *s = pi->sched_tbl;
+	struct sched_class *e;
+	u8 class_id;
+	int err;
+
+	if (!p)
+		return NULL;
+
+	class_id = p->u.params.class;
+
+	/* Only accept search for existing class with matching params
+	 * or allocation of new class with specified params
+	 */
+	if (class_id != SCHED_CLS_NONE)
+		return NULL;
+
+	write_lock(&s->rw_lock);
+	/* See if there's an exisiting class with same
+	 * requested sched params
+	 */
+	e = t4_sched_class_lookup(pi, p);
+	if (!e) {
+		struct ch_sched_params np;
+
+		/* Fetch any available unused class */
+		e = t4_sched_class_lookup(pi, NULL);
+		if (!e)
+			goto out;
+
+		memset(&np, 0, sizeof(np));
+		memcpy(&np, p, sizeof(np));
+		np.u.params.class = e->idx;
+
+		spin_lock(&e->lock);
+		/* New class */
+		err = t4_sched_class_fw_cmd(pi, &np, SCHED_FW_OP_ADD);
+		if (err) {
+			spin_unlock(&e->lock);
+			e = NULL;
+			goto out;
+		}
+		memcpy(&e->info, &np, sizeof(e->info));
+		atomic_set(&e->refcnt, 0);
+		e->state = SCHED_STATE_ACTIVE;
+		spin_unlock(&e->lock);
+	}
+
+out:
+	write_unlock(&s->rw_lock);
+	return e;
+}
+
+/**
+ * cxgb4_sched_class_alloc - allocate a scheduling class
+ * @dev: net_device pointer
+ * @p: new scheduling class to create.
+ *
+ * Returns pointer to the scheduling class created.  If @p is NULL, then
+ * it allocates and returns any available unused scheduling class. If a
+ * scheduling class with matching @p is found, then the matching class is
+ * returned.
+ */
+struct sched_class *cxgb4_sched_class_alloc(struct net_device *dev,
+					    struct ch_sched_params *p)
+{
+	struct port_info *pi = netdev2pinfo(dev);
+	u8 class_id;
+
+	if (!can_sched(dev))
+		return NULL;
+
+	class_id = p->u.params.class;
+	if (!valid_class_id(dev, class_id))
+		return NULL;
+
+	return t4_sched_class_alloc(pi, p);
+}
+
+struct sched_table *t4_init_sched(unsigned int sched_size)
+{
+	struct sched_table *s;
+	unsigned int i;
+
+	s = t4_alloc_mem(sizeof(*s) + sched_size * sizeof(struct sched_class));
+	if (!s)
+		return NULL;
+
+	s->sched_size = sched_size;
+	rwlock_init(&s->rw_lock);
+
+	for (i = 0; i < s->sched_size; i++) {
+		memset(&s->tab[i], 0, sizeof(struct sched_class));
+		s->tab[i].idx = i;
+		s->tab[i].state = SCHED_STATE_UNUSED;
+		spin_lock_init(&s->tab[i].lock);
+		atomic_set(&s->tab[i].refcnt, 0);
+	}
+	return s;
+}
+
+void t4_cleanup_sched(struct adapter *adap)
+{
+	struct sched_table *s;
+	unsigned int i;
+
+	for_each_port(adap, i) {
+		struct port_info *pi = netdev2pinfo(adap->port[i]);
+
+		s = pi->sched_tbl;
+		t4_free_mem(s);
+	}
+}