Commit d5d5e019 authored by Yunsheng Lin's avatar Yunsheng Lin Committed by David S. Miller
Browse files

net: hns3: add handling for xmit skb with recursive fraglist 



Currently hns3 driver only handle the xmit skb with one level of
fraglist skb, add handling for multi level by calling hns3_tx_bd_num()
recursively when calculating bd num and calling hns3_fill_skb_to_desc()
recursively when filling tx desc.

When the skb has a fraglist level of 24, the skb is simply dropped and
stats.max_recursion_level is added to record the error. Move the stat
handling from hns3_nic_net_xmit() to hns3_nic_maybe_stop_tx() in order
to handle different error stat and add the 'max_recursion_level' and
'hw_limitation' stat.

Note that the max recursive level as 24 is chose according to below:
commit 48a1df65 ("skbuff: return -EMSGSIZE in skb_to_sgvec to
prevent overflow").

And that we are not able to find a testcase to verify the recursive
fraglist case, so Fixes tag is not provided.

Reported-by: default avatarBarry Song <song.bao.hua@hisilicon.com>
Signed-off-by: default avatarYunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: default avatarHuazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8fa86551

drivers/net/ethernet/hisilicon/hns3/hns3_enet.c

+74 −41
Original line number Diff line number Diff line
@@ -1275,30 +1275,29 @@ static unsigned int hns3_skb_bd_num(struct sk_buff *skb, unsigned int *bd_size, 
}



static unsigned int hns3_tx_bd_num(struct sk_buff *skb, unsigned int *bd_size,

				   u8 max_non_tso_bd_num)

				   u8 max_non_tso_bd_num, unsigned int bd_num,

				   unsigned int recursion_level)

{

#define HNS3_MAX_RECURSION_LEVEL	24



	struct sk_buff *frag_skb;

	unsigned int bd_num = 0;



	/* If the total len is within the max bd limit */

	if (likely(skb->len <= HNS3_MAX_BD_SIZE && !skb_has_frag_list(skb) &&

	if (likely(skb->len <= HNS3_MAX_BD_SIZE && !recursion_level &&

		   !skb_has_frag_list(skb) &&

		   skb_shinfo(skb)->nr_frags < max_non_tso_bd_num))

		return skb_shinfo(skb)->nr_frags + 1U;



	/* The below case will always be linearized, return

	 * HNS3_MAX_BD_NUM_TSO + 1U to make sure it is linearized.

	 */

	if (unlikely(skb->len > HNS3_MAX_TSO_SIZE ||

		     (!skb_is_gso(skb) && skb->len >

		      HNS3_MAX_NON_TSO_SIZE(max_non_tso_bd_num))))

		return HNS3_MAX_TSO_BD_NUM + 1U;

	if (unlikely(recursion_level >= HNS3_MAX_RECURSION_LEVEL))

		return UINT_MAX;



	bd_num = hns3_skb_bd_num(skb, bd_size, bd_num);

	if (!skb_has_frag_list(skb) || bd_num > HNS3_MAX_TSO_BD_NUM)

		return bd_num;



	skb_walk_frags(skb, frag_skb) {

		bd_num = hns3_skb_bd_num(frag_skb, bd_size, bd_num);

		bd_num = hns3_tx_bd_num(frag_skb, bd_size, max_non_tso_bd_num,

					bd_num, recursion_level + 1);

		if (bd_num > HNS3_MAX_TSO_BD_NUM)

			return bd_num;

	}
@@ -1358,6 +1357,43 @@ void hns3_shinfo_pack(struct skb_shared_info *shinfo, __u32 *size) 
		size[i] = skb_frag_size(&shinfo->frags[i]);

}



static int hns3_skb_linearize(struct hns3_enet_ring *ring,

			      struct sk_buff *skb,

			      u8 max_non_tso_bd_num,

			      unsigned int bd_num)

{

	/* 'bd_num == UINT_MAX' means the skb' fraglist has a

	 * recursion level of over HNS3_MAX_RECURSION_LEVEL.

	 */

	if (bd_num == UINT_MAX) {

		u64_stats_update_begin(&ring->syncp);

		ring->stats.over_max_recursion++;

		u64_stats_update_end(&ring->syncp);

		return -ENOMEM;

	}



	/* The skb->len has exceeded the hw limitation, linearization

	 * will not help.

	 */

	if (skb->len > HNS3_MAX_TSO_SIZE ||

	    (!skb_is_gso(skb) && skb->len >

	     HNS3_MAX_NON_TSO_SIZE(max_non_tso_bd_num))) {

		u64_stats_update_begin(&ring->syncp);

		ring->stats.hw_limitation++;

		u64_stats_update_end(&ring->syncp);

		return -ENOMEM;

	}



	if (__skb_linearize(skb)) {

		u64_stats_update_begin(&ring->syncp);

		ring->stats.sw_err_cnt++;

		u64_stats_update_end(&ring->syncp);

		return -ENOMEM;

	}



	return 0;

}



static int hns3_nic_maybe_stop_tx(struct hns3_enet_ring *ring,

				  struct net_device *netdev,

				  struct sk_buff *skb)
@@ -1367,7 +1403,7 @@ static int hns3_nic_maybe_stop_tx(struct hns3_enet_ring *ring, 
	unsigned int bd_size[HNS3_MAX_TSO_BD_NUM + 1U];

	unsigned int bd_num;



	bd_num = hns3_tx_bd_num(skb, bd_size, max_non_tso_bd_num);

	bd_num = hns3_tx_bd_num(skb, bd_size, max_non_tso_bd_num, 0, 0);

	if (unlikely(bd_num > max_non_tso_bd_num)) {

		if (bd_num <= HNS3_MAX_TSO_BD_NUM && skb_is_gso(skb) &&

		    !hns3_skb_need_linearized(skb, bd_size, bd_num,
@@ -1376,16 +1412,11 @@ static int hns3_nic_maybe_stop_tx(struct hns3_enet_ring *ring, 
			goto out;

		}



		if (__skb_linearize(skb))

		if (hns3_skb_linearize(ring, skb, max_non_tso_bd_num,

				       bd_num))

			return -ENOMEM;



		bd_num = hns3_tx_bd_count(skb->len);

		if ((skb_is_gso(skb) && bd_num > HNS3_MAX_TSO_BD_NUM) ||

		    (!skb_is_gso(skb) &&

		     bd_num > max_non_tso_bd_num)) {

			trace_hns3_over_max_bd(skb);

			return -ENOMEM;

		}



		u64_stats_update_begin(&ring->syncp);

		ring->stats.tx_copy++;
@@ -1409,6 +1440,10 @@ static int hns3_nic_maybe_stop_tx(struct hns3_enet_ring *ring, 
		return bd_num;

	}



	u64_stats_update_begin(&ring->syncp);

	ring->stats.tx_busy++;

	u64_stats_update_end(&ring->syncp);



	return -EBUSY;

}
@@ -1456,6 +1491,7 @@ static int hns3_fill_skb_to_desc(struct hns3_enet_ring *ring, 
				 struct sk_buff *skb, enum hns_desc_type type)

{

	unsigned int size = skb_headlen(skb);

	struct sk_buff *frag_skb;

	int i, ret, bd_num = 0;



	if (size) {
@@ -1480,6 +1516,15 @@ static int hns3_fill_skb_to_desc(struct hns3_enet_ring *ring, 
		bd_num += ret;

	}



	skb_walk_frags(skb, frag_skb) {

		ret = hns3_fill_skb_to_desc(ring, frag_skb,

					    DESC_TYPE_FRAGLIST_SKB);

		if (unlikely(ret < 0))

			return ret;



		bd_num += ret;

	}



	return bd_num;

}
@@ -1510,8 +1555,6 @@ netdev_tx_t hns3_nic_net_xmit(struct sk_buff *skb, struct net_device *netdev) 
	struct hns3_enet_ring *ring = &priv->ring[skb->queue_mapping];

	struct netdev_queue *dev_queue;

	int pre_ntu, next_to_use_head;

	struct sk_buff *frag_skb;

	int bd_num = 0;

	bool doorbell;

	int ret;
@@ -1527,15 +1570,8 @@ netdev_tx_t hns3_nic_net_xmit(struct sk_buff *skb, struct net_device *netdev) 
	ret = hns3_nic_maybe_stop_tx(ring, netdev, skb);

	if (unlikely(ret <= 0)) {

		if (ret == -EBUSY) {

			u64_stats_update_begin(&ring->syncp);

			ring->stats.tx_busy++;

			u64_stats_update_end(&ring->syncp);

			hns3_tx_doorbell(ring, 0, true);

			return NETDEV_TX_BUSY;

		} else if (ret == -ENOMEM) {

			u64_stats_update_begin(&ring->syncp);

			ring->stats.sw_err_cnt++;

			u64_stats_update_end(&ring->syncp);

		}



		hns3_rl_err(netdev, "xmit error: %d!\n", ret);
@@ -1548,21 +1584,14 @@ netdev_tx_t hns3_nic_net_xmit(struct sk_buff *skb, struct net_device *netdev) 
	if (unlikely(ret < 0))

		goto fill_err;



	/* 'ret < 0' means filling error, 'ret == 0' means skb->len is

	 * zero, which is unlikely, and 'ret > 0' means how many tx desc

	 * need to be notified to the hw.

	 */

	ret = hns3_fill_skb_to_desc(ring, skb, DESC_TYPE_SKB);

	if (unlikely(ret < 0))

		goto fill_err;



	bd_num += ret;



	skb_walk_frags(skb, frag_skb) {

		ret = hns3_fill_skb_to_desc(ring, frag_skb,

					    DESC_TYPE_FRAGLIST_SKB);

		if (unlikely(ret < 0))

	if (unlikely(ret <= 0))

		goto fill_err;



		bd_num += ret;

	}



	pre_ntu = ring->next_to_use ? (ring->next_to_use - 1) :

					(ring->desc_num - 1);

	ring->desc[pre_ntu].tx.bdtp_fe_sc_vld_ra_ri |=
@@ -1573,7 +1602,7 @@ netdev_tx_t hns3_nic_net_xmit(struct sk_buff *skb, struct net_device *netdev) 
	dev_queue = netdev_get_tx_queue(netdev, ring->queue_index);

	doorbell = __netdev_tx_sent_queue(dev_queue, skb->len,

					  netdev_xmit_more());

	hns3_tx_doorbell(ring, bd_num, doorbell);

	hns3_tx_doorbell(ring, ret, doorbell);



	return NETDEV_TX_OK;
@@ -1745,11 +1774,15 @@ static void hns3_nic_get_stats64(struct net_device *netdev, 
			tx_drop += ring->stats.tx_l4_proto_err;

			tx_drop += ring->stats.tx_l2l3l4_err;

			tx_drop += ring->stats.tx_tso_err;

			tx_drop += ring->stats.over_max_recursion;

			tx_drop += ring->stats.hw_limitation;

			tx_errors += ring->stats.sw_err_cnt;

			tx_errors += ring->stats.tx_vlan_err;

			tx_errors += ring->stats.tx_l4_proto_err;

			tx_errors += ring->stats.tx_l2l3l4_err;

			tx_errors += ring->stats.tx_tso_err;

			tx_errors += ring->stats.over_max_recursion;

			tx_errors += ring->stats.hw_limitation;

		} while (u64_stats_fetch_retry_irq(&ring->syncp, start));



		/* fetch the rx stats */

drivers/net/ethernet/hisilicon/hns3/hns3_enet.h

+2 −0
Original line number Diff line number Diff line
@@ -376,6 +376,8 @@ struct ring_stats { 
			u64 tx_l4_proto_err;

			u64 tx_l2l3l4_err;

			u64 tx_tso_err;

			u64 over_max_recursion;

			u64 hw_limitation;

		};

		struct {

			u64 rx_pkts;

drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c

+2 −0
Original line number Diff line number Diff line
@@ -44,6 +44,8 @@ static const struct hns3_stats hns3_txq_stats[] = { 
	HNS3_TQP_STAT("l4_proto_err", tx_l4_proto_err),

	HNS3_TQP_STAT("l2l3l4_err", tx_l2l3l4_err),

	HNS3_TQP_STAT("tso_err", tx_tso_err),

	HNS3_TQP_STAT("over_max_recursion", over_max_recursion),

	HNS3_TQP_STAT("hw_limitation", hw_limitation),

};



#define HNS3_TXQ_STATS_COUNT ARRAY_SIZE(hns3_txq_stats)