Hi,
Reading through the patch, I found some minor typos below.
On Sat, Aug 27, 2016 at 12:11 AM, John Fastabend
<john.fastab...@gmail.com> wrote:
> From: Alexei Starovoitov <a...@fb.com>
>
> This patch adds initial support for XDP on e1000 driver. Note e1000
> driver does not support page recycling in general which could be
> added as a further improvement. However for XDP_DROP and XDP_XMIT
I think you mean XDP_PASS instead of XDP_XMIT?
> the xdp code paths will recycle pages.
>
> This patch includes the rcu_read_lock/rcu_read_unlock pair noted by
> Brenden Blanco in another pending patch.
>
> net/mlx4_en: protect ring->xdp_prog with rcu_read_lock
>
> CC: William Tu <u9012...@gmail.com>
> Signed-off-by: Alexei Starovoitov <a...@kernel.org>
> Signed-off-by: John Fastabend <john.r.fastab...@intel.com>
> ---
> drivers/net/ethernet/intel/e1000/e1000.h | 1
> drivers/net/ethernet/intel/e1000/e1000_main.c | 168
> ++++++++++++++++++++++++-
> 2 files changed, 165 insertions(+), 4 deletions(-)
>
> +static void e1000_xmit_raw_frame(struct e1000_rx_buffer *rx_buffer_info,
> + unsigned int len,
> + struct net_device *netdev,
> + struct e1000_adapter *adapter)
> +{
> + struct netdev_queue *txq = netdev_get_tx_queue(netdev, 0);
> + struct e1000_hw *hw = &adapter->hw;
> + struct e1000_tx_ring *tx_ring;
> +
> + if (len > E1000_MAX_DATA_PER_TXD)
> + return;
> +
> + /* e1000 only support a single txq at the moment so the queue is being
> + * shared with stack. To support this requires locking to ensure the
> + * stack and XPD are not running at the same time. Devices would
> + * multiple queues should allocate a separate queue space.
> + */
XPD --> XDP
Devices would --> with?
> + HARD_TX_LOCK(netdev, txq, smp_processor_id());
> +
> + tx_ring = adapter->tx_ring;
> +
> + if (E1000_DESC_UNUSED(tx_ring) < 2)
> + return;
> +
> + e1000_tx_map_rxpage(tx_ring, rx_buffer_info, len);
> +
> + e1000_tx_queue(adapter, tx_ring, 0/*tx_flags*/, 1);
> +
> + writel(tx_ring->next_to_use, hw->hw_addr + tx_ring->tdt);
> + mmiowb();
> +
> + HARD_TX_UNLOCK(netdev, txq);
> +}
> +
> #define NUM_REGS 38 /* 1 based count */
> static void e1000_regdump(struct e1000_adapter *adapter)
> {
> @@ -4142,6 +4240,22 @@ static struct sk_buff *e1000_alloc_rx_skb(struct
> e1000_adapter *adapter,
> return skb;
> }
>
> +static inline int e1000_call_bpf(struct bpf_prog *prog, void *data,
> + unsigned int length)
> +{
> + struct xdp_buff xdp;
> + int ret;
> +
> + xdp.data = data;
> + xdp.data_end = data + length;
> +
> + rcu_read_lock();
> + ret = BPF_PROG_RUN(prog, (void *)&xdp);
> + rcu_read_unlock();
> +
> + return ret;
> +}
> +
> /**
> * e1000_clean_jumbo_rx_irq - Send received data up the network stack; legacy
> * @adapter: board private structure
> @@ -4160,12 +4274,15 @@ static bool e1000_clean_jumbo_rx_irq(struct
> e1000_adapter *adapter,
> struct pci_dev *pdev = adapter->pdev;
> struct e1000_rx_desc *rx_desc, *next_rxd;
> struct e1000_rx_buffer *buffer_info, *next_buffer;
> + struct bpf_prog *prog;
> u32 length;
> unsigned int i;
> int cleaned_count = 0;
> bool cleaned = false;
> unsigned int total_rx_bytes = 0, total_rx_packets = 0;
>
> + rcu_read_lock(); /* rcu lock needed here to protect xdp programs */
> + prog = READ_ONCE(adapter->prog);
If having rcu_read_lock() here, do we still need another in e1000_call_bpf()?
> i = rx_ring->next_to_clean;
> rx_desc = E1000_RX_DESC(*rx_ring, i);
> buffer_info = &rx_ring->buffer_info[i];
> @@ -4188,15 +4305,57 @@ static bool e1000_clean_jumbo_rx_irq(struct
> e1000_adapter *adapter,
> prefetch(next_rxd);
>
> next_buffer = &rx_ring->buffer_info[i];
> -
> cleaned = true;
> cleaned_count++;
> + length = le16_to_cpu(rx_desc->length);
> +
> + if (prog) {
> + struct page *p = buffer_info->rxbuf.page;
> + dma_addr_t dma = buffer_info->dma;
> + int act;
> +
> + if (unlikely(!(status & E1000_RXD_STAT_EOP))) {
> + /* attached bpf disallows larger than page
> + * packets, so this is hw error or corruption
> + */
> + pr_info_once("%s buggy !eop\n", netdev->name);
> + break;
> + }
> + if (unlikely(rx_ring->rx_skb_top)) {
> + pr_info_once("%s ring resizing bug\n",
> + netdev->name);
> + break;
>
