On 16-02-17 12:17 AM, John Fastabend wrote:
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.
This one i have comments on.
Signed-off-by: John Fastabend <john.r.fastab...@intel.com>
---
include/linux/netdevice.h | 6 ++-
include/net/pkt_cls.h | 34 +++++++++++++++
net/sched/cls_u32.c | 99 ++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 136 insertions(+), 3 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index e396060..47671ce0 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -779,17 +779,21 @@ 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..59789ca 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -358,4 +358,38 @@ 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;
+};
Swapping sel and fshift would give better struct alignment.
+struct tc_cls_u32_hnode {
+ u32 handle;
+ u32 prio;
+ unsigned int divisor;
+};
Assuming in the future "prio" would be moved to something that is more
generic classifier specific?
+enum tc_clsu32_command {
+ TC_CLSU32_NEW_KNODE,
+ TC_CLSU32_REPLACE_KNODE,
+ TC_CLSU32_DELETE_KNODE,
+ TC_CLSU32_NEW_HNODE,
+ TC_CLSU32_REPLACE_HNODE,
+ TC_CLSU32_DELETE_HNODE,
+};
+
It seems to me commands should be generic which speak
Netlinkism. A REPLACE is just a flag to NEW. You dont need
a NEW_XXX for every object. switchdev got this right.
If you use cmd + flags then you can have all kinds of
netlink semantics that relay user intent from user space. Example:
Exclusivity where user says "create if it doesnt exist but dont replace
if it does".
At minimal add "flags" there.
Maybe not this release - but it makes sense to move "command" into
tc_to_netdev; a u16 cmd + u16 flags.
+struct tc_cls_u32_offload {
+ /* knode values */
+ enum tc_clsu32_command 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..d54bc94 100644
+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;
TC_CLSU32_REPLACE_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_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
{
struct tc_u_knode *n;
@@ -434,6 +522,7 @@ 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);
}
}
@@ -454,6 +543,7 @@ static int u32_destroy_hnode(struct tcf_proto *tp, struct
tc_u_hnode *ht)
phn;
hn = &phn->next, phn = rtnl_dereference(*hn)) {
if (phn == ht) {
+ u32_clear_hw_hnode(tp, ht);
RCU_INIT_POINTER(*hn, ht->next);
kfree_rcu(ht, rcu);
return 0;
@@ -540,8 +630,10 @@ 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);
+ }
You are unconditionally calling the _hw_ api. For someone not using _hw_
offloads, there are a few more instructions. Maybe just do the
dev->netdev_ops->ndo_setup_tc first?
And to Or's point: How do i distinguish s/w from h/w?
cheers,
jamal
