diff options
| author | Anjali Singhai <anjali.singhai@intel.com> | 2015-02-21 06:42:35 +0000 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2015-02-26 04:53:58 -0800 |
| commit | 71da61976ec18fb57b3ba9a1dd846b747cc7c884 (patch) | |
| tree | 9de12ed2f5e134a02805d09f26c11b9295bd4438 /drivers/net/ethernet/intel/i40evf | |
| parent | b67a03357cab0ccb91d641fead6f167c697a24cb (diff) | |
i40e: Fix TSO with more than 8 frags per segment issue
The hardware has some limitations the driver needs to adhere to,
that we found in extended testing.
1) no more than 8 descriptors per packet on the wire
2) no header can span more than 3 descriptors
If one of these events occurs, the hardware will generate an internal
error and freeze the Tx queue.
This patch linearizes the skb to avoid these situations.
Change-ID: I37dab7d3966e14895a9663ec4d0aaa8eb0d9e115
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Tested-by: Jim Young <james.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net/ethernet/intel/i40evf')
| -rw-r--r-- | drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 65 | ||||
| -rw-r--r-- | drivers/net/ethernet/intel/i40evf/i40e_txrx.h | 1 |
2 files changed, 66 insertions, 0 deletions
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c index 29004382f462..1320a433b8ed 100644 --- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c @@ -1380,6 +1380,67 @@ static void i40e_create_tx_ctx(struct i40e_ring *tx_ring, context_desc->type_cmd_tso_mss = cpu_to_le64(cd_type_cmd_tso_mss); } + /** + * i40e_chk_linearize - Check if there are more than 8 fragments per packet + * @skb: send buffer + * @tx_flags: collected send information + * @hdr_len: size of the packet header + * + * Note: Our HW can't scatter-gather more than 8 fragments to build + * a packet on the wire and so we need to figure out the cases where we + * need to linearize the skb. + **/ +static bool i40e_chk_linearize(struct sk_buff *skb, u32 tx_flags, + const u8 hdr_len) +{ + struct skb_frag_struct *frag; + bool linearize = false; + unsigned int size = 0; + u16 num_frags; + u16 gso_segs; + + num_frags = skb_shinfo(skb)->nr_frags; + gso_segs = skb_shinfo(skb)->gso_segs; + + if (tx_flags & (I40E_TX_FLAGS_TSO | I40E_TX_FLAGS_FSO)) { + u16 j = 1; + + if (num_frags < (I40E_MAX_BUFFER_TXD)) + goto linearize_chk_done; + /* try the simple math, if we have too many frags per segment */ + if (DIV_ROUND_UP((num_frags + gso_segs), gso_segs) > + I40E_MAX_BUFFER_TXD) { + linearize = true; + goto linearize_chk_done; + } + frag = &skb_shinfo(skb)->frags[0]; + size = hdr_len; + /* we might still have more fragments per segment */ + do { + size += skb_frag_size(frag); + frag++; j++; + if (j == I40E_MAX_BUFFER_TXD) { + if (size < skb_shinfo(skb)->gso_size) { + linearize = true; + break; + } + j = 1; + size -= skb_shinfo(skb)->gso_size; + if (size) + j++; + size += hdr_len; + } + num_frags--; + } while (num_frags); + } else { + if (num_frags >= I40E_MAX_BUFFER_TXD) + linearize = true; + } + +linearize_chk_done: + return linearize; +} + /** * i40e_tx_map - Build the Tx descriptor * @tx_ring: ring to send buffer on @@ -1654,6 +1715,10 @@ static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb, else if (tso) tx_flags |= I40E_TX_FLAGS_TSO; + if (i40e_chk_linearize(skb, tx_flags, hdr_len)) + if (skb_linearize(skb)) + goto out_drop; + skb_tx_timestamp(skb); /* always enable CRC insertion offload */ diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h index 4e15903b2b6d..c950a038237c 100644 --- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h +++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h @@ -112,6 +112,7 @@ enum i40e_dyn_idx_t { #define i40e_rx_desc i40e_32byte_rx_desc +#define I40E_MAX_BUFFER_TXD 8 #define I40E_MIN_TX_LEN 17 #define I40E_MAX_DATA_PER_TXD 8192 |