[PATCH RFC bpf-next 31/52] net, gro: expose some GRO API to use outside of NAPI

Alexander Lobakin
2022-06-28T19:54:32Z

Make several functions global to be able to use GRO without a NAPI
instance. This includes init, cleanup, receive functions, as well
as a couple inlines to start and stop the deferred flush timer.
Taking into account already global gro_flush(), it is now fully
possible to maintain a GRO node without an aux NAPI entity.

Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
---
include/net/gro.h | 18 +++++++++++++++
net/core/dev.c | 45 ++++++-------------------------------
net/core/gro.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 82 insertions(+), 38 deletions(-)

diff --git a/include/net/gro.h b/include/net/gro.h
index 75211ebd8765..539f931e736f 100644
--- a/include/net/gro.h
+++ b/include/net/gro.h
@@ -421,6 +421,7 @@ static inline __wsum ip6_gro_compute_pseudo(struct sk_buff *skb, int proto)
}

int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb);
+void gro_receive_skb_list(struct gro_node *gro, struct list_head *list);
void __gro_flush(struct gro_node *gro, bool flush_old);

static inline void gro_flush(struct gro_node *gro, bool flush_old)
@@ -458,5 +459,22 @@ static inline void gro_normal_one(struct gro_node *gro, struct sk_buff *skb,
gro_normal_list(gro);
}

+static inline void gro_timer_start(struct gro_node *gro, u64 timeout_ns)
+{
+ if (!timeout_ns)
+ return;
+
+ hrtimer_start(&gro->timer, ns_to_ktime(timeout_ns),
+ HRTIMER_MODE_REL_PINNED);
+}
+
+static inline void gro_timer_cancel(struct gro_node *gro)
+{
+ hrtimer_cancel(&gro->timer);
+}
+
+void gro_init(struct gro_node *gro,
+ enum hrtimer_restart (*timer_cb)(struct hrtimer *timer));
+void gro_cleanup(struct gro_node *gro);

#endif /* _NET_IPV6_GRO_H */
diff --git a/net/core/dev.c b/net/core/dev.c
index 8b334aa974c2..62bf6ee00741 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5812,9 +5812,8 @@ bool napi_complete_done(struct napi_struct *n, int work_done)
return false;
}

- if (timeout)
- hrtimer_start(&n->gro.timer, ns_to_ktime(timeout),
- HRTIMER_MODE_REL_PINNED);
+ gro_timer_start(&n->gro, timeout);
+
return ret;
}
EXPORT_SYMBOL(napi_complete_done);
@@ -5876,7 +5875,7 @@ static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool
napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
timeout = READ_ONCE(napi->dev->gro_flush_timeout);
if (napi->defer_hard_irqs_count && timeout) {
- hrtimer_start(&napi->gro.timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
+ gro_timer_start(&napi->gro, timeout);
skip_schedule = true;
}
}
@@ -6025,17 +6024,6 @@ static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
return HRTIMER_NORESTART;
}

-static void init_gro_hash(struct napi_struct *napi)
-{
- int i;
-
- for (i = 0; i < GRO_HASH_BUCKETS; i++) {
- INIT_LIST_HEAD(&napi->gro.hash[i].list);
- napi->gro.hash[i].count = 0;
- }
- napi->gro.bitmask = 0;
-}
-
int dev_set_threaded(struct net_device *dev, bool threaded)
{
struct napi_struct *napi;
@@ -6105,12 +6093,8 @@ void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,

INIT_LIST_HEAD(&napi->poll_list);
INIT_HLIST_NODE(&napi->napi_hash_node);
- hrtimer_init(&napi->gro.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
- napi->gro.timer.function = napi_watchdog;
- init_gro_hash(napi);
+ gro_init(&napi->gro, napi_watchdog);
napi->skb = NULL;
- INIT_LIST_HEAD(&napi->gro.rx_list);
- napi->gro.rx_count = 0;
napi->poll = poll;
if (weight > NAPI_POLL_WEIGHT)
netdev_err_once(dev, "%s() called with weight %d\n", __func__,
@@ -6155,8 +6139,7 @@ void napi_disable(struct napi_struct *n)
break;
}

- hrtimer_cancel(&n->gro.timer);
-
+ gro_timer_cancel(&n->gro);
clear_bit(NAPI_STATE_DISABLE, &n->state);
}
EXPORT_SYMBOL(napi_disable);
@@ -6183,19 +6166,6 @@ void napi_enable(struct napi_struct *n)
}
EXPORT_SYMBOL(napi_enable);

-static void flush_gro_hash(struct napi_struct *napi)
-{
- int i;
-
- for (i = 0; i < GRO_HASH_BUCKETS; i++) {
- struct sk_buff *skb, *n;
-
- list_for_each_entry_safe(skb, n, &napi->gro.hash[i].list, list)
- kfree_skb(skb);
- napi->gro.hash[i].count = 0;
- }
-}
-
/* Must be called in process context */
void __netif_napi_del(struct napi_struct *napi)
{
@@ -6206,8 +6176,7 @@ void __netif_napi_del(struct napi_struct *napi)
list_del_rcu(&napi->dev_list);
napi_free_frags(napi);

- flush_gro_hash(napi);
- napi->gro.bitmask = 0;
+ gro_cleanup(&napi->gro);

if (napi->thread) {
kthread_stop(napi->thread);
@@ -10627,7 +10596,7 @@ static int __init net_dev_init(void)
INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd);
spin_lock_init(&sd->defer_lock);

- init_gro_hash(&sd->backlog);
+ gro_init(&sd->backlog.gro, NULL);
sd->backlog.poll = process_backlog;
sd->backlog.weight = weight_p;
}
diff --git a/net/core/gro.c b/net/core/gro.c
index 67fd587a87c9..424c812abe79 100644
--- a/net/core/gro.c
+++ b/net/core/gro.c
@@ -624,6 +624,18 @@ static gro_result_t gro_skb_finish(struct gro_node *gro, struct sk_buff *skb,
return ret;
}

+void gro_receive_skb_list(struct gro_node *gro, struct list_head *list)
+{
+ struct sk_buff *skb, *tmp;
+
+ list_for_each_entry_safe(skb, tmp, list, list) {
+ skb_list_del_init(skb);
+
+ skb_gro_reset_offset(skb, 0);
+ gro_skb_finish(gro, skb, dev_gro_receive(gro, skb));
+ }
+}
+
gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
{
struct gro_node *gro = &napi->gro;
@@ -792,3 +804,48 @@ __sum16 __skb_gro_checksum_complete(struct sk_buff *skb)
return sum;
}
EXPORT_SYMBOL(__skb_gro_checksum_complete);
+
+void gro_init(struct gro_node *gro,
+ enum hrtimer_restart (*timer_cb)(struct hrtimer *))
+{
+ u32 i;
+
+ for (i = 0; i < GRO_HASH_BUCKETS; i++) {
+ INIT_LIST_HEAD(&gro->hash[i].list);
+ gro->hash[i].count = 0;
+ }
+
+ gro->bitmask = 0;
+
+ INIT_LIST_HEAD(&gro->rx_list);
+ gro->rx_count = 0;
+
+ if (!timer_cb)
+ return;
+
+ hrtimer_init(&gro->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
+ gro->timer.function = timer_cb;
+}
+
+void gro_cleanup(struct gro_node *gro)
+{
+ struct sk_buff *skb, *n;
+ u32 i;
+
+ gro_timer_cancel(gro);
+ memset(&gro->timer, 0, sizeof(gro->timer));
+
+ for (i = 0; i < GRO_HASH_BUCKETS; i++) {
+ list_for_each_entry_safe(skb, n, &gro->hash[i].list, list)
+ kfree_skb(skb);
+
+ gro->hash[i].count = 0;
+ }
+
+ gro->bitmask = 0;
+
+ list_for_each_entry_safe(skb, n, &gro->rx_list, list)
+ kfree_skb(skb);
+
+ gro->rx_count = 0;
+}
--
2.36.1