[net-next PATCH 3/7] net: sched: add cls_u32 offload hooks for netdevs

John Fastabend
2016-02-03T09:28:54Z

This patch allows netdev drivers to consume cls_u32 offloads via
the ndo_setup_tc ndo op.

This works aligns with how network drivers have been doing qdisc
offloads for mqprio.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
---
include/linux/netdevice.h | 6 +++-
include/net/pkt_cls.h | 33 ++++++++++++++++++++
net/sched/cls_u32.c | 73 ++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 109 insertions(+), 3 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 9090ff7..861ce67 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -778,17 +778,21 @@ static inline bool netdev_phys_item_id_same(struct netdev_phys_item_id *a,
typedef u16 (*select_queue_fallback_t)(struct net_device *dev,
struct sk_buff *skb);

-/* This structure holds attributes of qdisc and classifiers
+/* These structures hold the attributes of qdisc and classifiers
* that are being passed to the netdevice through the setup_tc op.
*/
enum {
TC_SETUP_MQPRIO,
+ TC_SETUP_CLSU32,
};

+struct tc_cls_u32_offload;
+
struct tc_to_netdev {
unsigned int type;
union {
u8 tc;
+ struct tc_cls_u32_offload *cls_u32;
};
};

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index bc49967..0bd12cd 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -358,4 +358,37 @@ tcf_match_indev(struct sk_buff *skb, int ifindex)
}
#endif /* CONFIG_NET_CLS_IND */

+struct tc_cls_u32_knode {
+ struct tcf_exts *exts;
+ u8 fshift;
+ u32 handle;
+ u32 val;
+ u32 mask;
+ u32 link_handle;
+ struct tc_u32_sel *sel;
+};
+
+struct tc_cls_u32_hnode {
+ u32 handle;
+ u32 prio;
+ unsigned int divisor;
+};
+
+enum {
+ TC_CLSU32_NEW_KNODE,
+ TC_CLSU32_REPLACE_KNODE,
+ TC_CLSU32_DELETE_KNODE,
+ TC_CLSU32_NEW_HNODE,
+ TC_CLSU32_REPLACE_HNODE,
+};
+
+struct tc_cls_u32_offload {
+ /* knode values */
+ int command;
+ union {
+ struct tc_cls_u32_knode knode;
+ struct tc_cls_u32_hnode hnode;
+ };
+};
+
#endif
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 4fbb674..dfaaf29 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -43,6 +43,7 @@
#include <net/netlink.h>
#include <net/act_api.h>
#include <net/pkt_cls.h>
+#include <linux/netdevice.h>

struct tc_u_knode {
struct tc_u_knode __rcu *next;
@@ -424,6 +425,68 @@ static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
return 0;
}

+static void u32_remove_hw_knode(struct tcf_proto *tp, u32 handle)
+{
+ struct net_device *dev = tp->q->dev_queue->dev;
+ struct tc_cls_u32_offload u32_offload = {0};
+ struct tc_to_netdev offload;
+
+ offload.type = TC_SETUP_CLSU32;
+ offload.cls_u32 = &u32_offload;
+
+ if (dev->netdev_ops->ndo_setup_tc) {
+ offload.cls_u32->command = TC_CLSU32_DELETE_KNODE;
+ offload.cls_u32->knode.handle = handle;
+ dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
+ tp->protocol, &offload);
+ }
+}
+
+static void u32_replace_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h)
+{
+ struct net_device *dev = tp->q->dev_queue->dev;
+ struct tc_cls_u32_offload u32_offload = {0};
+ struct tc_to_netdev offload;
+
+ offload.type = TC_SETUP_CLSU32;
+ offload.cls_u32 = &u32_offload;
+
+ if (dev->netdev_ops->ndo_setup_tc) {
+ offload.cls_u32->command = TC_CLSU32_NEW_HNODE;
+ offload.cls_u32->hnode.divisor = h->divisor;
+ offload.cls_u32->hnode.handle = h->handle;
+ offload.cls_u32->hnode.prio = h->prio;
+
+ dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
+ tp->protocol, &offload);
+ }
+}
+
+static void u32_replace_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n)
+{
+ struct net_device *dev = tp->q->dev_queue->dev;
+ struct tc_cls_u32_offload u32_offload = {0};
+ struct tc_to_netdev offload;
+
+ offload.type = TC_SETUP_CLSU32;
+ offload.cls_u32 = &u32_offload;
+
+ if (dev->netdev_ops->ndo_setup_tc) {
+ offload.cls_u32->command = TC_CLSU32_REPLACE_KNODE;
+ offload.cls_u32->knode.handle = n->handle;
+ offload.cls_u32->knode.fshift = n->fshift;
+ offload.cls_u32->knode.val = n->val;
+ offload.cls_u32->knode.mask = n->mask;
+ offload.cls_u32->knode.sel = &n->sel;
+ offload.cls_u32->knode.exts = &n->exts;
+ if (n->ht_down)
+ offload.cls_u32->knode.link_handle = n->ht_down->handle;
+
+ dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
+ tp->protocol, &offload);
+ }
+}
+
static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
{
struct tc_u_knode *n;
@@ -434,6 +497,7 @@ static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
RCU_INIT_POINTER(ht->ht[h],
rtnl_dereference(n->next));
tcf_unbind_filter(tp, &n->res);
+ u32_remove_hw_knode(tp, n->handle);
call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
}
}
@@ -540,8 +604,10 @@ static int u32_delete(struct tcf_proto *tp, unsigned long arg)
if (ht == NULL)
return 0;

- if (TC_U32_KEY(ht->handle))
+ if (TC_U32_KEY(ht->handle)) {
+ u32_remove_hw_knode(tp, ht->handle);
return u32_delete_key(tp, (struct tc_u_knode *)ht);
+ }

if (root_ht == ht)
return -EINVAL;
@@ -769,6 +835,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
u32_replace_knode(tp, tp_c, new);
tcf_unbind_filter(tp, &n->res);
call_rcu(&n->rcu, u32_delete_key_rcu);
+ u32_replace_hw_knode(tp, new);
return 0;
}

@@ -795,6 +862,8 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
RCU_INIT_POINTER(ht->next, tp_c->hlist);
rcu_assign_pointer(tp_c->hlist, ht);
*arg = (unsigned long)ht;
+
+ u32_replace_hw_hnode(tp, ht);
return 0;
}

@@ -877,7 +946,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,

RCU_INIT_POINTER(n->next, pins);
rcu_assign_pointer(*ins, n);
-
+ u32_replace_hw_knode(tp, n);
*arg = (unsigned long)n;
return 0;
}