[Qemu-devel] [RFC Patch 10/12] IXGBEVF: Add lock to protect tx/rx ring operation

[Lan Tianyu <tianyu.lan@intel.com>]

Ring shifting during restoring VF function maybe race with original
ring operation(transmit/receive package). This patch is to add tx/rx
lock to protect ring related data.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
---
 drivers/net/ethernet/intel/ixgbevf/ixgbevf.h      |  2 ++
 drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 28 ++++++++++++++++++++---
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
index 6eab402e..3a748c8 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
@@ -448,6 +448,8 @@ struct ixgbevf_adapter {
 
 	spinlock_t mbx_lock;
 	unsigned long last_reset;
+	spinlock_t mg_rx_lock;
+	spinlock_t mg_tx_lock;
 };
 
 enum ixbgevf_state_t {
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 15ec361..04b6ce7 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -227,8 +227,10 @@ static u64 ixgbevf_get_tx_completed(struct ixgbevf_ring *ring)
 
 int ixgbevf_tx_ring_shift(struct ixgbevf_ring *r, u32 head)
 {
+	struct ixgbevf_adapter *adapter = netdev_priv(r->netdev);
 	struct ixgbevf_tx_buffer *tx_buffer = NULL;
 	static union ixgbevf_desc *tx_desc = NULL;
+	unsigned long flags;
 
 	tx_buffer = vmalloc(sizeof(struct ixgbevf_tx_buffer) * (r->count));
 	if (!tx_buffer)
@@ -238,6 +240,7 @@ int ixgbevf_tx_ring_shift(struct ixgbevf_ring *r, u32 head)
 	if (!tx_desc)
 		return -ENOMEM;
 
+	spin_lock_irqsave(&adapter->mg_tx_lock, flags);
 	memcpy(tx_desc, r->desc, sizeof(union ixgbevf_desc) * r->count);
 	memcpy(r->desc, &tx_desc[head], sizeof(union ixgbevf_desc) * (r->count - head));
 	memcpy(&r->desc[r->count - head], tx_desc, sizeof(union ixgbevf_desc) * head);
@@ -256,6 +259,8 @@ int ixgbevf_tx_ring_shift(struct ixgbevf_ring *r, u32 head)
 	else
 		r->next_to_use += (r->count - head);
 
+	spin_unlock_irqrestore(&adapter->mg_tx_lock, flags);
+
 	vfree(tx_buffer);
 	vfree(tx_desc);
 	return 0;
@@ -263,8 +268,10 @@ int ixgbevf_tx_ring_shift(struct ixgbevf_ring *r, u32 head)
 
 int ixgbevf_rx_ring_shift(struct ixgbevf_ring *r, u32 head)
 {
+	struct ixgbevf_adapter *adapter = netdev_priv(r->netdev);
 	struct ixgbevf_rx_buffer *rx_buffer = NULL;
 	static union ixgbevf_desc *rx_desc = NULL;
+	unsigned long flags;	
 
 	rx_buffer = vmalloc(sizeof(struct ixgbevf_rx_buffer) * (r->count));
 	if (!rx_buffer)
@@ -274,6 +281,7 @@ int ixgbevf_rx_ring_shift(struct ixgbevf_ring *r, u32 head)
 	if (!rx_desc)
 		return -ENOMEM;
 
+	spin_lock_irqsave(&adapter->mg_rx_lock, flags);
 	memcpy(rx_desc, r->desc, sizeof(union ixgbevf_desc) * (r->count));
 	memcpy(r->desc, &rx_desc[head], sizeof(union ixgbevf_desc) * (r->count - head));
 	memcpy(&r->desc[r->count - head], rx_desc, sizeof(union ixgbevf_desc) * head);
@@ -291,6 +299,7 @@ int ixgbevf_rx_ring_shift(struct ixgbevf_ring *r, u32 head)
 		r->next_to_use -= head;
 	else
 		r->next_to_use += (r->count - head);
+	spin_unlock_irqrestore(&adapter->mg_rx_lock, flags);
 
 	vfree(rx_buffer);
 	vfree(rx_desc);
@@ -377,6 +386,8 @@ static bool ixgbevf_clean_tx_irq(struct ixgbevf_q_vector *q_vector,
 	if (test_bit(__IXGBEVF_DOWN, &adapter->state))
 		return true;
 
+	spin_lock(&adapter->mg_tx_lock);
+	i = tx_ring->next_to_clean;
 	tx_buffer = &tx_ring->tx_buffer_info[i];
 	tx_desc = IXGBEVF_TX_DESC(tx_ring, i);
 	i -= tx_ring->count;
@@ -471,6 +482,8 @@ static bool ixgbevf_clean_tx_irq(struct ixgbevf_q_vector *q_vector,
 	q_vector->tx.total_bytes += total_bytes;
 	q_vector->tx.total_packets += total_packets;
 
+	spin_unlock(&adapter->mg_tx_lock);
+
 	if (check_for_tx_hang(tx_ring) && ixgbevf_check_tx_hang(tx_ring)) {
 		struct ixgbe_hw *hw = &adapter->hw;
 		union ixgbe_adv_tx_desc *eop_desc;
@@ -999,10 +1012,12 @@ static int ixgbevf_clean_rx_irq(struct ixgbevf_q_vector *q_vector,
 				struct ixgbevf_ring *rx_ring,
 				int budget)
 {
+	struct ixgbevf_adapter *adapter = netdev_priv(rx_ring->netdev);
 	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
 	u16 cleaned_count = ixgbevf_desc_unused(rx_ring);
 	struct sk_buff *skb = rx_ring->skb;
 
+	spin_lock(&adapter->mg_rx_lock);
 	while (likely(total_rx_packets < budget)) {
 		union ixgbe_adv_rx_desc *rx_desc;
 
@@ -1078,6 +1093,7 @@ static int ixgbevf_clean_rx_irq(struct ixgbevf_q_vector *q_vector,
 	q_vector->rx.total_packets += total_rx_packets;
 	q_vector->rx.total_bytes += total_rx_bytes;
 
+	spin_unlock(&adapter->mg_rx_lock);
 	return total_rx_packets;
 }
 
@@ -3572,14 +3588,17 @@ static void ixgbevf_tx_map(struct ixgbevf_ring *tx_ring,
 	struct ixgbevf_tx_buffer *tx_buffer;
 	union ixgbe_adv_tx_desc *tx_desc;
 	struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0];
+	struct ixgbevf_adapter *adapter = netdev_priv(tx_ring->netdev);
 	unsigned int data_len = skb->data_len;
 	unsigned int size = skb_headlen(skb);
 	unsigned int paylen = skb->len - hdr_len;
+	unsigned long flags;
 	u32 tx_flags = first->tx_flags;
 	__le32 cmd_type;
-	u16 i = tx_ring->next_to_use;
-	u16 start;
+	u16 i, start;     
 
+	spin_lock_irqsave(&adapter->mg_tx_lock, flags);
+	i = tx_ring->next_to_use;
 	tx_desc = IXGBEVF_TX_DESC(tx_ring, i);
 
 	ixgbevf_tx_olinfo_status(tx_desc, tx_flags, paylen);
@@ -3673,7 +3692,7 @@ static void ixgbevf_tx_map(struct ixgbevf_ring *tx_ring,
 
 	/* notify HW of packet */
 	ixgbevf_write_tail(tx_ring, i);
-
+	spin_unlock_irqrestore(&adapter->mg_tx_lock, flags);
 	return;
 dma_error:
 	dev_err(tx_ring->dev, "TX DMA map failed\n");
@@ -3690,6 +3709,7 @@ dma_error:
 	}
 
 	tx_ring->next_to_use = i;
+	spin_unlock_irqrestore(&adapter->mg_tx_lock, flags);
 }
 
 static int __ixgbevf_maybe_stop_tx(struct ixgbevf_ring *tx_ring, int size)
@@ -4188,6 +4208,8 @@ static int ixgbevf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		break;
 	}
 
+	spin_lock_init(&adapter->mg_tx_lock);
+	spin_lock_init(&adapter->mg_rx_lock);
 	return 0;
 
 err_register:
-- 
1.8.4.rc0.1.g8f6a3e5.dirty