diff options
Diffstat (limited to 'drivers/net/ethernet/intel/i40e/i40e_txrx.c')
| -rw-r--r-- | drivers/net/ethernet/intel/i40e/i40e_txrx.c | 46 |
1 files changed, 40 insertions, 6 deletions
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 88666adb0743..079c6b2bafc3 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -619,6 +619,20 @@ static bool i40e_check_tx_hang(struct i40e_ring *tx_ring) } /** + * i40e_get_head - Retrieve head from head writeback + * @tx_ring: tx ring to fetch head of + * + * Returns value of Tx ring head based on value stored + * in head write-back location + **/ +static inline u32 i40e_get_head(struct i40e_ring *tx_ring) +{ + void *head = (struct i40e_tx_desc *)tx_ring->desc + tx_ring->count; + + return le32_to_cpu(*(volatile __le32 *)head); +} + +/** * i40e_clean_tx_irq - Reclaim resources after transmit completes * @tx_ring: tx ring to clean * @budget: how many cleans we're allowed @@ -629,6 +643,7 @@ static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget) { u16 i = tx_ring->next_to_clean; struct i40e_tx_buffer *tx_buf; + struct i40e_tx_desc *tx_head; struct i40e_tx_desc *tx_desc; unsigned int total_packets = 0; unsigned int total_bytes = 0; @@ -637,6 +652,8 @@ static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget) tx_desc = I40E_TX_DESC(tx_ring, i); i -= tx_ring->count; + tx_head = I40E_TX_DESC(tx_ring, i40e_get_head(tx_ring)); + do { struct i40e_tx_desc *eop_desc = tx_buf->next_to_watch; @@ -647,9 +664,8 @@ static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget) /* prevent any other reads prior to eop_desc */ read_barrier_depends(); - /* if the descriptor isn't done, no work yet to do */ - if (!(eop_desc->cmd_type_offset_bsz & - cpu_to_le64(I40E_TX_DESC_DTYPE_DESC_DONE))) + /* we have caught up to head, no work left to do */ + if (tx_head == tx_desc) break; /* clear next_to_watch to prevent false hangs */ @@ -905,6 +921,10 @@ int i40e_setup_tx_descriptors(struct i40e_ring *tx_ring) /* round up to nearest 4K */ tx_ring->size = tx_ring->count * sizeof(struct i40e_tx_desc); + /* add u32 for head writeback, align after this takes care of + * guaranteeing this is at least one cache line in size + */ + tx_ring->size += sizeof(u32); tx_ring->size = ALIGN(tx_ring->size, 4096); tx_ring->desc = dma_alloc_coherent(dev, tx_ring->size, &tx_ring->dma, GFP_KERNEL); @@ -2042,9 +2062,23 @@ static void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb, tx_bi = &tx_ring->tx_bi[i]; } - tx_desc->cmd_type_offset_bsz = - build_ctob(td_cmd, td_offset, size, td_tag) | - cpu_to_le64((u64)I40E_TXD_CMD << I40E_TXD_QW1_CMD_SHIFT); + /* Place RS bit on last descriptor of any packet that spans across the + * 4th descriptor (WB_STRIDE aka 0x3) in a 64B cacheline. + */ +#define WB_STRIDE 0x3 + if (((i & WB_STRIDE) != WB_STRIDE) && + (first <= &tx_ring->tx_bi[i]) && + (first >= &tx_ring->tx_bi[i & ~WB_STRIDE])) { + tx_desc->cmd_type_offset_bsz = + build_ctob(td_cmd, td_offset, size, td_tag) | + cpu_to_le64((u64)I40E_TX_DESC_CMD_EOP << + I40E_TXD_QW1_CMD_SHIFT); + } else { + tx_desc->cmd_type_offset_bsz = + build_ctob(td_cmd, td_offset, size, td_tag) | + cpu_to_le64((u64)I40E_TXD_CMD << + I40E_TXD_QW1_CMD_SHIFT); + } netdev_tx_sent_queue(netdev_get_tx_queue(tx_ring->netdev, tx_ring->queue_index), |
