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

[Lan Tianyu]

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 <address@hidden>
---
 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