+static int e1000_xdp_set(struct net_device *netdev, struct bpf_prog *prog)
+{
+ struct e1000_adapter *adapter = netdev_priv(netdev);
+ struct bpf_prog *old_prog;
+
+ old_prog = xchg(&adapter->prog, prog);
+ if (old_prog) {
+ synchronize_net();
+ bpf_prog_put(old_prog);
+ }
+
+ if (netif_running(netdev))
+ e1000_reinit_locked(adapter);
+ else
+ e1000_reset(adapter);
+ return 0;
+}
To this function, is it better to use "static void
e1000_xdp_set(struct net_device *netdev, struct bpf_prog *prog)"?
since it is always to return 0.
On Sat, Sep 10, 2016 at 5:29 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 XDP_DROP case will recycle.
> XDP_TX and XDP_PASS do not support recycling yet.
>
> I tested this patch running e1000 in a VM using KVM over a tap
> device.
>
> 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 | 2
> drivers/net/ethernet/intel/e1000/e1000_main.c | 171
> +++++++++++++++++++++++++
> 2 files changed, 170 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/e1000/e1000.h
> b/drivers/net/ethernet/intel/e1000/e1000.h
> index d7bdea7..5cf8a0a 100644
> --- a/drivers/net/ethernet/intel/e1000/e1000.h
> +++ b/drivers/net/ethernet/intel/e1000/e1000.h
> @@ -150,6 +150,7 @@ struct e1000_adapter;
> */
> struct e1000_tx_buffer {
> struct sk_buff *skb;
> + struct page *page;
> dma_addr_t dma;
> unsigned long time_stamp;
> u16 length;
> @@ -279,6 +280,7 @@ struct e1000_adapter {
> struct e1000_rx_ring *rx_ring,
> int cleaned_count);
> struct e1000_rx_ring *rx_ring; /* One per active queue */
> + struct bpf_prog *prog;
> struct napi_struct napi;
>
> int num_tx_queues;
> diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c
> b/drivers/net/ethernet/intel/e1000/e1000_main.c
> index f42129d..91d5c87 100644
> --- a/drivers/net/ethernet/intel/e1000/e1000_main.c
> +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
> @@ -32,6 +32,7 @@
> #include <linux/prefetch.h>
> #include <linux/bitops.h>
> #include <linux/if_vlan.h>
> +#include <linux/bpf.h>
>
> char e1000_driver_name[] = "e1000";
> static char e1000_driver_string[] = "Intel(R) PRO/1000 Network Driver";
> @@ -842,6 +843,44 @@ static int e1000_set_features(struct net_device *netdev,
> return 0;
> }
>
> +static int e1000_xdp_set(struct net_device *netdev, struct bpf_prog *prog)
> +{
> + struct e1000_adapter *adapter = netdev_priv(netdev);
> + struct bpf_prog *old_prog;
> +
> + old_prog = xchg(&adapter->prog, prog);
> + if (old_prog) {
> + synchronize_net();
> + bpf_prog_put(old_prog);
> + }
> +
> + if (netif_running(netdev))
> + e1000_reinit_locked(adapter);
> + else
> + e1000_reset(adapter);
> + return 0;
> +}
> +
> +static bool e1000_xdp_attached(struct net_device *dev)
> +{
> + struct e1000_adapter *priv = netdev_priv(dev);
> +
> + return !!priv->prog;
> +}
> +
> +static int e1000_xdp(struct net_device *dev, struct netdev_xdp *xdp)
> +{
> + switch (xdp->command) {
> + case XDP_SETUP_PROG:
> + return e1000_xdp_set(dev, xdp->prog);
> + case XDP_QUERY_PROG:
> + xdp->prog_attached = e1000_xdp_attached(dev);
> + return 0;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> static const struct net_device_ops e1000_netdev_ops = {
> .ndo_open = e1000_open,
> .ndo_stop = e1000_close,
> @@ -860,6 +899,7 @@ static const struct net_device_ops e1000_netdev_ops = {
> #endif
> .ndo_fix_features = e1000_fix_features,
> .ndo_set_features = e1000_set_features,
> + .ndo_xdp = e1000_xdp,
> };
>
> /**
> @@ -1276,6 +1316,9 @@ static void e1000_remove(struct pci_dev *pdev)
> e1000_down_and_stop(adapter);
> e1000_release_manageability(adapter);
>
> + if (adapter->prog)
> + bpf_prog_put(adapter->prog);
> +
> unregister_netdev(netdev);
>
> e1000_phy_hw_reset(hw);
> @@ -1859,7 +1902,7 @@ static void e1000_configure_rx(struct e1000_adapter
> *adapter)
> struct e1000_hw *hw = &adapter->hw;
> u32 rdlen, rctl, rxcsum;
>
> - if (adapter->netdev->mtu > ETH_DATA_LEN) {
> + if (adapter->netdev->mtu > ETH_DATA_LEN || adapter->prog) {
> rdlen = adapter->rx_ring[0].count *
> sizeof(struct e1000_rx_desc);
> adapter->clean_rx = e1000_clean_jumbo_rx_irq;
> @@ -1973,6 +2016,11 @@ e1000_unmap_and_free_tx_resource(struct e1000_adapter
> *adapter,
> dev_kfree_skb_any(buffer_info->skb);
> buffer_info->skb = NULL;
> }
> + if (buffer_info->page) {
> + put_page(buffer_info->page);
> + buffer_info->page = NULL;
> + }
> +
> buffer_info->time_stamp = 0;
> /* buffer_info must be completely set up in the transmit path */
> }
> @@ -3298,6 +3346,63 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff
> *skb,
> return NETDEV_TX_OK;
> }
>
> +static void e1000_tx_map_rxpage(struct e1000_tx_ring *tx_ring,
> + struct e1000_rx_buffer *rx_buffer_info,
> + unsigned int len)
> +{
> + struct e1000_tx_buffer *buffer_info;
> + unsigned int i = tx_ring->next_to_use;
> +
> + buffer_info = &tx_ring->buffer_info[i];
> +
> + buffer_info->length = len;
> + buffer_info->time_stamp = jiffies;
> + buffer_info->mapped_as_page = false;
> + buffer_info->dma = rx_buffer_info->dma;
> + buffer_info->next_to_watch = i;
> + buffer_info->page = rx_buffer_info->rxbuf.page;
> +
> + tx_ring->buffer_info[i].skb = NULL;
> + tx_ring->buffer_info[i].segs = 1;
> + tx_ring->buffer_info[i].bytecount = len;
> + tx_ring->buffer_info[i].next_to_watch = i;
> +}
> +
> +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 XDP are not running at the same time. Devices with
> + * multiple queues should allocate a separate queue space.
> + */
> + HARD_TX_LOCK(netdev, txq, smp_processor_id());
> +
> + tx_ring = adapter->tx_ring;
> +
> + if (E1000_DESC_UNUSED(tx_ring) < 2) {
> + HARD_TX_UNLOCK(netdev, txq);
> + 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 +4247,19 @@ 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;
> + ret = BPF_PROG_RUN(prog, (void *)&xdp);
> +
> + return ret;
> +}
> +
> /**
> * e1000_clean_jumbo_rx_irq - Send received data up the network stack; legacy
> * @adapter: board private structure
> @@ -4160,12 +4278,15 @@ 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);
> i = rx_ring->next_to_clean;
> rx_desc = E1000_RX_DESC(*rx_ring, i);
> buffer_info = &rx_ring->buffer_info[i];
> @@ -4191,12 +4312,55 @@ static bool e1000_clean_jumbo_rx_irq(struct
> e1000_adapter *adapter,
>
> 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;
> + }
> + dma_sync_single_for_cpu(&pdev->dev, dma,
> + length, DMA_FROM_DEVICE);
> + act = e1000_call_bpf(prog, page_address(p), length);
> + switch (act) {
> + case XDP_PASS:
> + break;
> + case XDP_TX:
> + dma_sync_single_for_device(&pdev->dev,
> + dma,
> + length,
> + DMA_TO_DEVICE);
> + e1000_xmit_raw_frame(buffer_info, length,
> + netdev, adapter);
> + buffer_info->rxbuf.page = NULL;
> + case XDP_DROP:
> + default:
> + /* re-use mapped page. keep buffer_info->dma
> + * as-is, so that e1000_alloc_jumbo_rx_buffers
> + * only needs to put it back into rx ring
> + */
> + total_rx_bytes += length;
> + total_rx_packets++;
> + goto next_desc;
> + }
> + }
> +
> dma_unmap_page(&pdev->dev, buffer_info->dma,
> adapter->rx_buffer_len, DMA_FROM_DEVICE);
> buffer_info->dma = 0;
>
> - length = le16_to_cpu(rx_desc->length);
> -
> /* errors is only valid for DD + EOP descriptors */
> if (unlikely((status & E1000_RXD_STAT_EOP) &&
> (rx_desc->errors & E1000_RXD_ERR_FRAME_ERR_MASK))) {
> @@ -4330,6 +4494,7 @@ next_desc:
> rx_desc = next_rxd;
> buffer_info = next_buffer;
> }
> + rcu_read_unlock();
> rx_ring->next_to_clean = i;
>
> cleaned_count = E1000_DESC_UNUSED(rx_ring);
>
