[PATCH net-next v2 1/5] net: lan966x: Add XDP_PACKET_HEADROOM

Horatiu Vultur
2022-11-15T21:40:30Z

Update the page_pool params to allocate XDP_PACKET_HEADROOM space as
headroom for all received frames.
This is needed for when the XDP_TX and XDP_REDIRECT are implemented.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
.../ethernet/microchip/lan966x/lan966x_fdma.c | 16 +++++++++++-----
.../net/ethernet/microchip/lan966x/lan966x_xdp.c | 3 ++-
2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index 5fbbd479cfb06..3055124b4dd79 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -1,5 +1,7 @@
// SPDX-License-Identifier: GPL-2.0+

+#include <linux/bpf.h>
+
#include "lan966x_main.h"

static int lan966x_fdma_channel_active(struct lan966x *lan966x)
@@ -16,7 +18,7 @@ static struct page *lan966x_fdma_rx_alloc_page(struct lan966x_rx *rx,
if (unlikely(!page))
return NULL;

- db->dataptr = page_pool_get_dma_addr(page);
+ db->dataptr = page_pool_get_dma_addr(page) + XDP_PACKET_HEADROOM;

return page;
}
@@ -72,7 +74,7 @@ static int lan966x_fdma_rx_alloc_page_pool(struct lan966x_rx *rx)
.nid = NUMA_NO_NODE,
.dev = lan966x->dev,
.dma_dir = DMA_FROM_DEVICE,
- .offset = 0,
+ .offset = XDP_PACKET_HEADROOM,
.max_len = rx->max_mtu -
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
};
@@ -432,11 +434,13 @@ static int lan966x_fdma_rx_check_frame(struct lan966x_rx *rx, u64 *src_port)
if (unlikely(!page))
return FDMA_ERROR;

- dma_sync_single_for_cpu(lan966x->dev, (dma_addr_t)db->dataptr,
+ dma_sync_single_for_cpu(lan966x->dev,
+ (dma_addr_t)db->dataptr + XDP_PACKET_HEADROOM,
FDMA_DCB_STATUS_BLOCKL(db->status),
DMA_FROM_DEVICE);

- lan966x_ifh_get_src_port(page_address(page), src_port);
+ lan966x_ifh_get_src_port(page_address(page) + XDP_PACKET_HEADROOM,
+ src_port);
if (WARN_ON(*src_port >= lan966x->num_phys_ports))
return FDMA_ERROR;

@@ -466,6 +470,7 @@ static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx,

skb_mark_for_recycle(skb);

+ skb_reserve(skb, XDP_PACKET_HEADROOM);
skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status));

lan966x_ifh_get_timestamp(skb->data, &timestamp);
@@ -786,7 +791,8 @@ static int lan966x_fdma_get_max_frame(struct lan966x *lan966x)
return lan966x_fdma_get_max_mtu(lan966x) +
IFH_LEN_BYTES +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +
- VLAN_HLEN * 2;
+ VLAN_HLEN * 2 +
+ XDP_PACKET_HEADROOM;
}

int lan966x_fdma_change_mtu(struct lan966x *lan966x)
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
index e77d9f2aad2b4..8ebde1eb6a09c 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
@@ -44,7 +44,8 @@ int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len)

xdp_init_buff(&xdp, PAGE_SIZE << lan966x->rx.page_order,
&port->xdp_rxq);
- xdp_prepare_buff(&xdp, page_address(page), IFH_LEN_BYTES,
+ xdp_prepare_buff(&xdp, page_address(page),
+ IFH_LEN_BYTES + XDP_PACKET_HEADROOM,
data_len - IFH_LEN_BYTES, false);
act = bpf_prog_run_xdp(xdp_prog, &xdp);
switch (act) {
--
2.38.0