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authorThomas Falcon <tlfalcon@linux.vnet.ibm.com>2017-03-05 12:18:41 -0600
committerDavid S. Miller <davem@davemloft.net>2017-03-07 14:14:30 -0800
commit142c0ac445792c492579cb01f1cfd4e32e6dfcce (patch)
tree656a3545ab1f3070a77f5bf7fbca80bd400871d9
parent6c4dc75c251721f517e9daeb5370ea606b5b35ce (diff)
downloadlinux-142c0ac445792c492579cb01f1cfd4e32e6dfcce.tar.bz2
ibmvnic: Fix overflowing firmware/hardware TX queue
Use a counter to track the number of outstanding transmissions sent that have not received completions. If the counter reaches the maximum number of queue entries, stop transmissions on that queue. As we receive more completions from firmware, wake the queue once the counter reaches an acceptable level. This patch prevents hardware/firmware TX queue from filling up and and generating errors. Since incorporating this fix, internal testing has reported that these firmware errors have stopped. Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/ibm/ibmvnic.c27
-rw-r--r--drivers/net/ethernet/ibm/ibmvnic.h1
2 files changed, 27 insertions, 1 deletions
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 9198e6bd5160..0e87b83f25e2 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -705,6 +705,7 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
u8 *hdrs = (u8 *)&adapter->tx_rx_desc_req;
struct device *dev = &adapter->vdev->dev;
struct ibmvnic_tx_buff *tx_buff = NULL;
+ struct ibmvnic_sub_crq_queue *tx_scrq;
struct ibmvnic_tx_pool *tx_pool;
unsigned int tx_send_failed = 0;
unsigned int tx_map_failed = 0;
@@ -724,6 +725,7 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
int ret = 0;
tx_pool = &adapter->tx_pool[queue_num];
+ tx_scrq = adapter->tx_scrq[queue_num];
txq = netdev_get_tx_queue(netdev, skb_get_queue_mapping(skb));
handle_array = (u64 *)((u8 *)(adapter->login_rsp_buf) +
be32_to_cpu(adapter->login_rsp_buf->
@@ -826,6 +828,14 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
ret = NETDEV_TX_BUSY;
goto out;
}
+
+ atomic_inc(&tx_scrq->used);
+
+ if (atomic_read(&tx_scrq->used) >= adapter->req_tx_entries_per_subcrq) {
+ netdev_info(netdev, "Stopping queue %d\n", queue_num);
+ netif_stop_subqueue(netdev, queue_num);
+ }
+
tx_packets++;
tx_bytes += skb->len;
txq->trans_start = jiffies;
@@ -1213,6 +1223,7 @@ static struct ibmvnic_sub_crq_queue *init_sub_crq_queue(struct ibmvnic_adapter
scrq->adapter = adapter;
scrq->size = 4 * PAGE_SIZE / sizeof(*scrq->msgs);
scrq->cur = 0;
+ atomic_set(&scrq->used, 0);
scrq->rx_skb_top = NULL;
spin_lock_init(&scrq->lock);
@@ -1355,8 +1366,22 @@ restart_loop:
DMA_TO_DEVICE);
}
- if (txbuff->last_frag)
+ if (txbuff->last_frag) {
+ atomic_dec(&scrq->used);
+
+ if (atomic_read(&scrq->used) <=
+ (adapter->req_tx_entries_per_subcrq / 2) &&
+ netif_subqueue_stopped(adapter->netdev,
+ txbuff->skb)) {
+ netif_wake_subqueue(adapter->netdev,
+ scrq->pool_index);
+ netdev_dbg(adapter->netdev,
+ "Started queue %d\n",
+ scrq->pool_index);
+ }
+
dev_kfree_skb_any(txbuff->skb);
+ }
adapter->tx_pool[pool].free_map[adapter->tx_pool[pool].
producer_index] = index;
diff --git a/drivers/net/ethernet/ibm/ibmvnic.h b/drivers/net/ethernet/ibm/ibmvnic.h
index 422824f1f42a..1993b42666f7 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.h
+++ b/drivers/net/ethernet/ibm/ibmvnic.h
@@ -863,6 +863,7 @@ struct ibmvnic_sub_crq_queue {
spinlock_t lock;
struct sk_buff *rx_skb_top;
struct ibmvnic_adapter *adapter;
+ atomic_t used;
};
struct ibmvnic_long_term_buff {