4 files changed, 434 insertions, 0 deletions

diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index f04d4a484d53..73431d4aa6ef 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -205,6 +205,18 @@ config NET_SCH_DRR
 
           If unsure, say N.
 
+config NET_SCH_MQPRIO
+        tristate "Multi-queue priority scheduler (MQPRIO)"
+        help
+          Say Y here if you want to use the Multi-queue Priority scheduler.
+          This scheduler allows QOS to be offloaded on NICs that have support
+          for offloading QOS schedulers.
+
+          To compile this driver as a module, choose M here: the module will
+          be called sch_mqprio.
+
+          If unsure, say N.
+
 config NET_SCH_INGRESS
         tristate "Ingress Qdisc"
         depends on NET_CLS_ACT
diff --git a/net/sched/Makefile b/net/sched/Makefile
index 960f5dba6304..26ce681a2c60 100644
--- a/net/sched/Makefile
+++ b/net/sched/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_NET_SCH_MULTIQ)	+= sch_multiq.o
 obj-$(CONFIG_NET_SCH_ATM)       += sch_atm.o
 obj-$(CONFIG_NET_SCH_NETEM)     += sch_netem.o
 obj-$(CONFIG_NET_SCH_DRR)       += sch_drr.o
+obj-$(CONFIG_NET_SCH_MQPRIO)    += sch_mqprio.o
 obj-$(CONFIG_NET_CLS_U32)       += cls_u32.o
 obj-$(CONFIG_NET_CLS_ROUTE4)    += cls_route.o
 obj-$(CONFIG_NET_CLS_FW)        += cls_fw.o
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 34dc598440a2..723b27849a50 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -540,6 +540,7 @@ struct Qdisc_ops pfifo_fast_ops __read_mostly = {
         .dump           =       pfifo_fast_dump,
         .owner          =       THIS_MODULE,
 };
+EXPORT_SYMBOL(pfifo_fast_ops);
 
 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
                           struct Qdisc_ops *ops)
@@ -674,6 +675,7 @@ struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
 
         return oqdisc;
 }
+EXPORT_SYMBOL(dev_graft_qdisc);
 
 static void attach_one_default_qdisc(struct net_device *dev,
                                      struct netdev_queue *dev_queue,
@@ -761,6 +763,7 @@ void dev_activate(struct net_device *dev)
                 dev_watchdog_up(dev);
         }
 }
+EXPORT_SYMBOL(dev_activate);
 
 static void dev_deactivate_queue(struct net_device *dev,
                                  struct netdev_queue *dev_queue,
@@ -840,6 +843,7 @@ void dev_deactivate(struct net_device *dev)
         list_add(&dev->unreg_list, &single);
         dev_deactivate_many(&single);
 }
+EXPORT_SYMBOL(dev_deactivate);
 
 static void dev_init_scheduler_queue(struct net_device *dev,
                                      struct netdev_queue *dev_queue,
diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
new file mode 100644
index 000000000000..8620c65f480a
--- /dev/null
+++ b/net/sched/sch_mqprio.c
@@ -0,0 +1,417 @@
+/*
+ * net/sched/sch_mqprio.c
+ *
+ * Copyright (c) 2010 John Fastabend <john.r.fastabend@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/skbuff.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+#include <net/sch_generic.h>
+
+struct mqprio_sched {
+        struct Qdisc            **qdiscs;
+        int hw_owned;
+};
+
+static void mqprio_destroy(struct Qdisc *sch)
+{
+        struct net_device *dev = qdisc_dev(sch);
+        struct mqprio_sched *priv = qdisc_priv(sch);
+        unsigned int ntx;
+
+        if (!priv->qdiscs)
+                return;
+
+        for (ntx = 0; ntx < dev->num_tx_queues && priv->qdiscs[ntx]; ntx++)
+                qdisc_destroy(priv->qdiscs[ntx]);
+
+        if (priv->hw_owned && dev->netdev_ops->ndo_setup_tc)
+                dev->netdev_ops->ndo_setup_tc(dev, 0);
+        else
+                netdev_set_num_tc(dev, 0);
+
+        kfree(priv->qdiscs);
+}
+
+static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt)
+{
+        int i, j;
+
+        /* Verify num_tc is not out of max range */
+        if (qopt->num_tc > TC_MAX_QUEUE)
+                return -EINVAL;
+
+        /* Verify priority mapping uses valid tcs */
+        for (i = 0; i < TC_BITMASK + 1; i++) {
+                if (qopt->prio_tc_map[i] >= qopt->num_tc)
+                        return -EINVAL;
+        }
+
+        /* net_device does not support requested operation */
+        if (qopt->hw && !dev->netdev_ops->ndo_setup_tc)
+                return -EINVAL;
+
+        /* if hw owned qcount and qoffset are taken from LLD so
+         * no reason to verify them here
+         */
+        if (qopt->hw)
+                return 0;
+
+        for (i = 0; i < qopt->num_tc; i++) {
+                unsigned int last = qopt->offset[i] + qopt->count[i];
+
+                /* Verify the queue count is in tx range being equal to the
+                 * real_num_tx_queues indicates the last queue is in use.
+                 */
+                if (qopt->offset[i] >= dev->real_num_tx_queues ||
+                    !qopt->count[i] ||
+                    last > dev->real_num_tx_queues)
+                        return -EINVAL;
+
+                /* Verify that the offset and counts do not overlap */
+                for (j = i + 1; j < qopt->num_tc; j++) {
+                        if (last > qopt->offset[j])
+                                return -EINVAL;
+                }
+        }
+
+        return 0;
+}
+
+static int mqprio_init(struct Qdisc *sch, struct nlattr *opt)
+{
+        struct net_device *dev = qdisc_dev(sch);
+        struct mqprio_sched *priv = qdisc_priv(sch);
+        struct netdev_queue *dev_queue;
+        struct Qdisc *qdisc;
+        int i, err = -EOPNOTSUPP;
+        struct tc_mqprio_qopt *qopt = NULL;
+
+        BUILD_BUG_ON(TC_MAX_QUEUE != TC_QOPT_MAX_QUEUE);
+        BUILD_BUG_ON(TC_BITMASK != TC_QOPT_BITMASK);
+
+        if (sch->parent != TC_H_ROOT)
+                return -EOPNOTSUPP;
+
+        if (!netif_is_multiqueue(dev))
+                return -EOPNOTSUPP;
+
+        if (nla_len(opt) < sizeof(*qopt))
+                return -EINVAL;
+
+        qopt = nla_data(opt);
+        if (mqprio_parse_opt(dev, qopt))
+                return -EINVAL;
+
+        /* pre-allocate qdisc, attachment can't fail */
+        priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]),
+                               GFP_KERNEL);
+        if (priv->qdiscs == NULL) {
+                err = -ENOMEM;
+                goto err;
+        }
+
+        for (i = 0; i < dev->num_tx_queues; i++) {
+                dev_queue = netdev_get_tx_queue(dev, i);
+                qdisc = qdisc_create_dflt(dev_queue, &pfifo_fast_ops,
+                                          TC_H_MAKE(TC_H_MAJ(sch->handle),
+                                                    TC_H_MIN(i + 1)));
+                if (qdisc == NULL) {
+                        err = -ENOMEM;
+                        goto err;
+                }
+                qdisc->flags |= TCQ_F_CAN_BYPASS;
+                priv->qdiscs[i] = qdisc;
+        }
+
+        /* If the mqprio options indicate that hardware should own
+         * the queue mapping then run ndo_setup_tc otherwise use the
+         * supplied and verified mapping
+         */
+        if (qopt->hw) {
+                priv->hw_owned = 1;
+                err = dev->netdev_ops->ndo_setup_tc(dev, qopt->num_tc);
+                if (err)
+                        goto err;
+        } else {
+                netdev_set_num_tc(dev, qopt->num_tc);
+                for (i = 0; i < qopt->num_tc; i++)
+                        netdev_set_tc_queue(dev, i,
+                                            qopt->count[i], qopt->offset[i]);
+        }
+
+        /* Always use supplied priority mappings */
+        for (i = 0; i < TC_BITMASK + 1; i++)
+                netdev_set_prio_tc_map(dev, i, qopt->prio_tc_map[i]);
+
+        sch->flags |= TCQ_F_MQROOT;
+        return 0;
+
+err:
+        mqprio_destroy(sch);
+        return err;
+}
+
+static void mqprio_attach(struct Qdisc *sch)
+{
+        struct net_device *dev = qdisc_dev(sch);
+        struct mqprio_sched *priv = qdisc_priv(sch);
+        struct Qdisc *qdisc;
+        unsigned int ntx;
+
+        /* Attach underlying qdisc */
+        for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
+                qdisc = priv->qdiscs[ntx];
+                qdisc = dev_graft_qdisc(qdisc->dev_queue, qdisc);
+                if (qdisc)
+                        qdisc_destroy(qdisc);
+        }
+        kfree(priv->qdiscs);
+        priv->qdiscs = NULL;
+}
+
+static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch,
+                                             unsigned long cl)
+{
+        struct net_device *dev = qdisc_dev(sch);
+        unsigned long ntx = cl - 1 - netdev_get_num_tc(dev);
+
+        if (ntx >= dev->num_tx_queues)
+                return NULL;
+        return netdev_get_tx_queue(dev, ntx);
+}
+
+static int mqprio_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
+                    struct Qdisc **old)
+{
+        struct net_device *dev = qdisc_dev(sch);
+        struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
+
+        if (!dev_queue)
+                return -EINVAL;
+
+        if (dev->flags & IFF_UP)
+                dev_deactivate(dev);
+
+        *old = dev_graft_qdisc(dev_queue, new);
+
+        if (dev->flags & IFF_UP)
+                dev_activate(dev);
+
+        return 0;
+}
+
+static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+        struct net_device *dev = qdisc_dev(sch);
+        struct mqprio_sched *priv = qdisc_priv(sch);
+        unsigned char *b = skb_tail_pointer(skb);
+        struct tc_mqprio_qopt opt;
+        struct Qdisc *qdisc;
+        unsigned int i;
+
+        sch->q.qlen = 0;
+        memset(&sch->bstats, 0, sizeof(sch->bstats));
+        memset(&sch->qstats, 0, sizeof(sch->qstats));
+
+        for (i = 0; i < dev->num_tx_queues; i++) {
+                qdisc = netdev_get_tx_queue(dev, i)->qdisc;
+                spin_lock_bh(qdisc_lock(qdisc));
+                sch->q.qlen             += qdisc->q.qlen;
+                sch->bstats.bytes       += qdisc->bstats.bytes;
+                sch->bstats.packets     += qdisc->bstats.packets;
+                sch->qstats.qlen        += qdisc->qstats.qlen;
+                sch->qstats.backlog     += qdisc->qstats.backlog;
+                sch->qstats.drops       += qdisc->qstats.drops;
+                sch->qstats.requeues    += qdisc->qstats.requeues;
+                sch->qstats.overlimits  += qdisc->qstats.overlimits;
+                spin_unlock_bh(qdisc_lock(qdisc));
+        }
+
+        opt.num_tc = netdev_get_num_tc(dev);
+        memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map));
+        opt.hw = priv->hw_owned;
+
+        for (i = 0; i < netdev_get_num_tc(dev); i++) {
+                opt.count[i] = dev->tc_to_txq[i].count;
+                opt.offset[i] = dev->tc_to_txq[i].offset;
+        }
+
+        NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
+
+        return skb->len;
+nla_put_failure:
+        nlmsg_trim(skb, b);
+        return -1;
+}
+
+static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl)
+{
+        struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
+
+        if (!dev_queue)
+                return NULL;
+
+        return dev_queue->qdisc_sleeping;
+}
+
+static unsigned long mqprio_get(struct Qdisc *sch, u32 classid)
+{
+        struct net_device *dev = qdisc_dev(sch);
+        unsigned int ntx = TC_H_MIN(classid);
+
+        if (ntx > dev->num_tx_queues + netdev_get_num_tc(dev))
+                return 0;
+        return ntx;
+}
+
+static void mqprio_put(struct Qdisc *sch, unsigned long cl)
+{
+}
+
+static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl,
+                         struct sk_buff *skb, struct tcmsg *tcm)
+{
+        struct net_device *dev = qdisc_dev(sch);
+
+        if (cl <= netdev_get_num_tc(dev)) {
+                tcm->tcm_parent = TC_H_ROOT;
+                tcm->tcm_info = 0;
+        } else {
+                int i;
+                struct netdev_queue *dev_queue;
+
+                dev_queue = mqprio_queue_get(sch, cl);
+                tcm->tcm_parent = 0;
+                for (i = 0; i < netdev_get_num_tc(dev); i++) {
+                        struct netdev_tc_txq tc = dev->tc_to_txq[i];
+                        int q_idx = cl - netdev_get_num_tc(dev);
+
+                        if (q_idx > tc.offset &&
+                            q_idx <= tc.offset + tc.count) {
+                                tcm->tcm_parent =
+                                        TC_H_MAKE(TC_H_MAJ(sch->handle),
+                                                  TC_H_MIN(i + 1));
+                                break;
+                        }
+                }
+                tcm->tcm_info = dev_queue->qdisc_sleeping->handle;
+        }
+        tcm->tcm_handle |= TC_H_MIN(cl);
+        return 0;
+}
+
+static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
+                               struct gnet_dump *d)
+{
+        struct net_device *dev = qdisc_dev(sch);
+
+        if (cl <= netdev_get_num_tc(dev)) {
+                int i;
+                struct Qdisc *qdisc;
+                struct gnet_stats_queue qstats = {0};
+                struct gnet_stats_basic_packed bstats = {0};
+                struct netdev_tc_txq tc = dev->tc_to_txq[cl - 1];
+
+                /* Drop lock here it will be reclaimed before touching
+                 * statistics this is required because the d->lock we
+                 * hold here is the look on dev_queue->qdisc_sleeping
+                 * also acquired below.
+                 */
+                spin_unlock_bh(d->lock);
+
+                for (i = tc.offset; i < tc.offset + tc.count; i++) {
+                        qdisc = netdev_get_tx_queue(dev, i)->qdisc;
+                        spin_lock_bh(qdisc_lock(qdisc));
+                        bstats.bytes      += qdisc->bstats.bytes;
+                        bstats.packets    += qdisc->bstats.packets;
+                        qstats.qlen       += qdisc->qstats.qlen;
+                        qstats.backlog    += qdisc->qstats.backlog;
+                        qstats.drops      += qdisc->qstats.drops;
+                        qstats.requeues   += qdisc->qstats.requeues;
+                        qstats.overlimits += qdisc->qstats.overlimits;
+                        spin_unlock_bh(qdisc_lock(qdisc));
+                }
+                /* Reclaim root sleeping lock before completing stats */
+                spin_lock_bh(d->lock);
+                if (gnet_stats_copy_basic(d, &bstats) < 0 ||
+                    gnet_stats_copy_queue(d, &qstats) < 0)
+                        return -1;
+        } else {
+                struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
+
+                sch = dev_queue->qdisc_sleeping;
+                sch->qstats.qlen = sch->q.qlen;
+                if (gnet_stats_copy_basic(d, &sch->bstats) < 0 ||
+                    gnet_stats_copy_queue(d, &sch->qstats) < 0)
+                        return -1;
+        }
+        return 0;
+}
+
+static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+{
+        struct net_device *dev = qdisc_dev(sch);
+        unsigned long ntx;
+
+        if (arg->stop)
+                return;
+
+        /* Walk hierarchy with a virtual class per tc */
+        arg->count = arg->skip;
+        for (ntx = arg->skip;
+             ntx < dev->num_tx_queues + netdev_get_num_tc(dev);
+             ntx++) {
+                if (arg->fn(sch, ntx + 1, arg) < 0) {
+                        arg->stop = 1;
+                        break;
+                }
+                arg->count++;
+        }
+}
+
+static const struct Qdisc_class_ops mqprio_class_ops = {
+        .graft          = mqprio_graft,
+        .leaf           = mqprio_leaf,
+        .get            = mqprio_get,
+        .put            = mqprio_put,
+        .walk           = mqprio_walk,
+        .dump           = mqprio_dump_class,
+        .dump_stats     = mqprio_dump_class_stats,
+};
+
+struct Qdisc_ops mqprio_qdisc_ops __read_mostly = {
+        .cl_ops         = &mqprio_class_ops,
+        .id             = "mqprio",
+        .priv_size      = sizeof(struct mqprio_sched),
+        .init           = mqprio_init,
+        .destroy        = mqprio_destroy,
+        .attach         = mqprio_attach,
+        .dump           = mqprio_dump,
+        .owner          = THIS_MODULE,
+};
+
+static int __init mqprio_module_init(void)
+{
+        return register_qdisc(&mqprio_qdisc_ops);
+}
+
+static void __exit mqprio_module_exit(void)
+{
+        unregister_qdisc(&mqprio_qdisc_ops);
+}
+
+module_init(mqprio_module_init);
+module_exit(mqprio_module_exit);
+
+MODULE_LICENSE("GPL");