net: hns3: add cond_resched() to hns3 ring buffer init process

Currently hns3 ring buffer init process would hold cpu too long with big
Tx/Rx ring depth. This could cause soft lockup.

So this patch adds cond_resched() to the process. Then cpu can break to
run other tasks instead of busy looping.

Fixes: a723fb8 ("net: hns3: refine for set ring parameters")
Signed-off-by: Jie Wang <[email protected]>
Signed-off-by: Jijie Shao <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Jie Wang

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

@@ -3535,6 +3535,9 @@ static int hns3_alloc_ring_buffers(struct hns3_enet_ring *ring)
 		ret = hns3_alloc_and_attach_buffer(ring, i);
 		if (ret)
 			goto out_buffer_fail;
+
+		if (!(i % HNS3_RESCHED_BD_NUM))
+			cond_resched();
 	}
 
 	return 0;
@@ -5107,6 +5110,7 @@ int hns3_init_all_ring(struct hns3_nic_priv *priv)
 		}
 
 		u64_stats_init(&priv->ring[i].syncp);
+		cond_resched();
 	}
 
 	return 0;

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

@@ -214,6 +214,8 @@ enum hns3_nic_state {
 #define HNS3_CQ_MODE_EQE			1U
 #define HNS3_CQ_MODE_CQE			0U
 
+#define HNS3_RESCHED_BD_NUM			1024
+
 enum hns3_pkt_l2t_type {
 	HNS3_L2_TYPE_UNICAST,
 	HNS3_L2_TYPE_MULTICAST,