Reserve XDP_PACKET_HEADROOM for packet and enable bpf_xdp_adjust_head()
support. This patch only affects the code path when XDP is active.
After testing, the tx_dropped counter is incremented if the xdp_prog sends
more than wire MTU.
Signed-off-by: Martin KaFai Lau <ka...@fb.com>
---
drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 8 ++------
drivers/net/ethernet/mellanox/mlx4/en_rx.c | 24 ++++++++++++++++++------
drivers/net/ethernet/mellanox/mlx4/en_tx.c | 9 +++++----
drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 3 ++-
4 files changed, 27 insertions(+), 17 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index c97d25b06444..bcd955339058 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -51,7 +51,8 @@
#include "mlx4_en.h"
#include "en_port.h"
-#define MLX4_EN_MAX_XDP_MTU ((int)(PAGE_SIZE - ETH_HLEN - (2 * VLAN_HLEN)))
+#define MLX4_EN_MAX_XDP_MTU ((int)(PAGE_SIZE - ETH_HLEN - (2 * VLAN_HLEN) - \
+ XDP_PACKET_HEADROOM))
int mlx4_en_setup_tc(struct net_device *dev, u8 up)
{
@@ -2700,11 +2701,6 @@ static int mlx4_xdp_set(struct net_device *dev, struct
bpf_prog *prog)
int err;
int i;
- if (prog && prog->xdp_adjust_head) {
- en_err(priv, "Does not support bpf_xdp_adjust_head()\n");
- return -EOPNOTSUPP;
- }
-
xdp_ring_num = prog ? priv->rx_ring_num : 0;
/* No need to reconfigure buffers when simply swapping the
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 23e9d04d1ef4..3c37e216bbf3 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -96,7 +96,6 @@ static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
struct mlx4_en_rx_alloc page_alloc[MLX4_EN_MAX_RX_FRAGS];
const struct mlx4_en_frag_info *frag_info;
struct page *page;
- dma_addr_t dma;
int i;
for (i = 0; i < priv->num_frags; i++) {
@@ -115,9 +114,10 @@ static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
for (i = 0; i < priv->num_frags; i++) {
frags[i] = ring_alloc[i];
- dma = ring_alloc[i].dma + ring_alloc[i].page_offset;
+ frags[i].page_offset += priv->frag_info[i].rx_headroom;
+ rx_desc->data[i].addr = cpu_to_be64(frags[i].dma +
+ frags[i].page_offset);
ring_alloc[i] = page_alloc[i];
- rx_desc->data[i].addr = cpu_to_be64(dma);
}
return 0;
@@ -250,7 +250,8 @@ static int mlx4_en_prepare_rx_desc(struct mlx4_en_priv
*priv,
if (ring->page_cache.index > 0) {
frags[0] = ring->page_cache.buf[--ring->page_cache.index];
- rx_desc->data[0].addr = cpu_to_be64(frags[0].dma);
+ rx_desc->data[0].addr = cpu_to_be64(frags[0].dma +
+ frags[0].page_offset);
return 0;
}
@@ -889,6 +890,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct
mlx4_en_cq *cq, int bud
if (xdp_prog) {
struct xdp_buff xdp;
dma_addr_t dma;
+ void *orig_data;
u32 act;
dma = be64_to_cpu(rx_desc->data[0].addr);
@@ -896,11 +898,19 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct
mlx4_en_cq *cq, int bud
priv->frag_info[0].frag_size,
DMA_FROM_DEVICE);
- xdp.data = page_address(frags[0].page) +
- frags[0].page_offset;
+ xdp.data_hard_start = page_address(frags[0].page);
+ xdp.data = xdp.data_hard_start + frags[0].page_offset;
xdp.data_end = xdp.data + length;
+ orig_data = xdp.data;
act = bpf_prog_run_xdp(xdp_prog, &xdp);
+
+ if (xdp.data != orig_data) {
+ length = xdp.data_end - xdp.data;
+ frags[0].page_offset = xdp.data -
+ xdp.data_hard_start;
+ }
+
switch (act) {
case XDP_PASS:
break;
@@ -1180,6 +1190,7 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
*/
priv->frag_info[0].frag_stride = PAGE_SIZE;
priv->frag_info[0].dma_dir = PCI_DMA_BIDIRECTIONAL;
+ priv->frag_info[0].rx_headroom = XDP_PACKET_HEADROOM;
i = 1;
} else {
int buf_size = 0;
@@ -1194,6 +1205,7 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
ALIGN(priv->frag_info[i].frag_size,
SMP_CACHE_BYTES);
priv->frag_info[i].dma_dir = PCI_DMA_FROMDEVICE;
+ priv->frag_info[i].rx_headroom = 0;
buf_size += priv->frag_info[i].frag_size;
i++;
}
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index 4b597dca5c52..5886ad78058f 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -354,7 +354,7 @@ u32 mlx4_en_recycle_tx_desc(struct mlx4_en_priv *priv,
struct mlx4_en_rx_alloc frame = {
.page = tx_info->page,
.dma = tx_info->map0_dma,
- .page_offset = 0,
+ .page_offset = XDP_PACKET_HEADROOM,
.page_size = PAGE_SIZE,
};
@@ -1132,7 +1132,7 @@ netdev_tx_t mlx4_en_xmit_frame(struct mlx4_en_rx_ring
*rx_ring,
tx_info->page = frame->page;
frame->page = NULL;
tx_info->map0_dma = dma;
- tx_info->map0_byte_count = length;
+ tx_info->map0_byte_count = PAGE_SIZE;
tx_info->nr_txbb = nr_txbb;
tx_info->nr_bytes = max_t(unsigned int, length, ETH_ZLEN);
tx_info->data_offset = (void *)data - (void *)tx_desc;
@@ -1141,9 +1141,10 @@ netdev_tx_t mlx4_en_xmit_frame(struct mlx4_en_rx_ring
*rx_ring,
tx_info->linear = 1;
tx_info->inl = 0;
- dma_sync_single_for_device(priv->ddev, dma, length, PCI_DMA_TODEVICE);
+ dma_sync_single_range_for_device(priv->ddev, dma, frame->page_offset,
+ length, PCI_DMA_TODEVICE);
- data->addr = cpu_to_be64(dma);
+ data->addr = cpu_to_be64(dma + frame->page_offset);
data->lkey = ring->mr_key;
dma_wmb();
data->byte_count = cpu_to_be32(length);
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 20a936428f4a..ba1c6cd0cc79 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -475,7 +475,8 @@ struct mlx4_en_frag_info {
u16 frag_prefix_size;
u32 frag_stride;
enum dma_data_direction dma_dir;
- int order;
+ u16 order;
+ u16 rx_headroom;
};
#ifdef CONFIG_MLX4_EN_DCB
--
2.5.1
