[PATCH net-next v3 7/7] net: lan966x: Add support for XDP_REDIRECT

Horatiu Vultur
2022-11-21T21:25:41Z

Extend lan966x XDP support with the action XDP_REDIRECT. This is similar
with the XDP_TX, so a lot of functionality can be reused.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
.../ethernet/microchip/lan966x/lan966x_fdma.c | 83 +++++++++++++++----
.../ethernet/microchip/lan966x/lan966x_main.c | 1 +
.../ethernet/microchip/lan966x/lan966x_main.h | 10 ++-
.../ethernet/microchip/lan966x/lan966x_xdp.c | 31 ++++++-
4 files changed, 109 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index b14fdb8e15e22..81dc27d8f8963 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0+

#include <linux/bpf.h>
+#include <linux/filter.h>

#include "lan966x_main.h"

@@ -391,11 +392,14 @@ static void lan966x_fdma_tx_clear_buf(struct lan966x *lan966x, int weight)
{
struct lan966x_tx *tx = &lan966x->tx;
struct lan966x_tx_dcb_buf *dcb_buf;
+ struct xdp_frame_bulk bq;
struct lan966x_db *db;
unsigned long flags;
bool clear = false;
int i;

+ xdp_frame_bulk_init(&bq);
+
spin_lock_irqsave(&lan966x->tx_lock, flags);
for (i = 0; i < FDMA_DCB_MAX; ++i) {
dcb_buf = &tx->dcbs_buf[i];
@@ -421,12 +425,24 @@ static void lan966x_fdma_tx_clear_buf(struct lan966x *lan966x, int weight)
dev_kfree_skb_any(dcb_buf->skb);
}

- if (dcb_buf->xdpf)
- xdp_return_frame_rx_napi(dcb_buf->xdpf);
+ if (dcb_buf->xdpf) {
+ if (dcb_buf->xdp_ndo)
+ dma_unmap_single(lan966x->dev,
+ dcb_buf->dma_addr,
+ dcb_buf->len,
+ DMA_TO_DEVICE);
+
+ if (dcb_buf->xdp_ndo)
+ xdp_return_frame_bulk(dcb_buf->xdpf, &bq);
+ else
+ xdp_return_frame_rx_napi(dcb_buf->xdpf);
+ }

clear = true;
}

+ xdp_flush_frame_bulk(&bq);
+
if (clear)
lan966x_fdma_wakeup_netdev(lan966x);

@@ -533,6 +549,7 @@ static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
int dcb_reload = rx->dcb_index;
struct lan966x_rx_dcb *old_dcb;
struct lan966x_db *db;
+ bool redirect = false;
struct sk_buff *skb;
struct page *page;
int counter = 0;
@@ -558,6 +575,10 @@ static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
case FDMA_TX:
lan966x_fdma_rx_advance_dcb(rx);
continue;
+ case FDMA_REDIRECT:
+ lan966x_fdma_rx_advance_dcb(rx);
+ redirect = true;
+ continue;
case FDMA_DROP:
lan966x_fdma_rx_free_page(rx);
lan966x_fdma_rx_advance_dcb(rx);
@@ -594,6 +615,9 @@ static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
if (counter < weight && napi_complete_done(napi, counter))
lan_wr(0xff, lan966x, FDMA_INTR_DB_ENA);

+ if (redirect)
+ xdp_do_flush();
+
return counter;
}

@@ -681,7 +705,8 @@ static void lan966x_fdma_tx_start(struct lan966x_tx *tx, int next_to_use)

int lan966x_fdma_xmit_xdpf(struct lan966x_port *port,
struct xdp_frame *xdpf,
- struct page *page)
+ struct page *page,
+ bool dma_map)
{
struct lan966x *lan966x = port->lan966x;
struct lan966x_tx_dcb_buf *next_dcb_buf;
@@ -702,24 +727,53 @@ int lan966x_fdma_xmit_xdpf(struct lan966x_port *port,
}

/* Generate new IFH */
- ifh = page_address(page) + XDP_PACKET_HEADROOM;
- memset(ifh, 0x0, sizeof(__be32) * IFH_LEN);
- lan966x_ifh_set_bypass(ifh, 1);
- lan966x_ifh_set_port(ifh, BIT_ULL(port->chip_port));
+ if (dma_map) {
+ if (xdpf->headroom < IFH_LEN_BYTES) {
+ ret = NETDEV_TX_OK;
+ goto out;
+ }

- dma_addr = page_pool_get_dma_addr(page);
- dma_sync_single_for_device(lan966x->dev, dma_addr + XDP_PACKET_HEADROOM,
- xdpf->len + IFH_LEN_BYTES,
- DMA_TO_DEVICE);
+ ifh = xdpf->data - IFH_LEN_BYTES;
+ memset(ifh, 0x0, sizeof(__be32) * IFH_LEN);
+ lan966x_ifh_set_bypass(ifh, 1);
+ lan966x_ifh_set_port(ifh, BIT_ULL(port->chip_port));
+
+ dma_addr = dma_map_single(lan966x->dev,
+ xdpf->data - IFH_LEN_BYTES,
+ xdpf->len + IFH_LEN_BYTES,
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(lan966x->dev, dma_addr)) {
+ ret = NETDEV_TX_OK;
+ goto out;
+ }

- /* Setup next dcb */
- lan966x_fdma_tx_setup_dcb(tx, next_to_use, xdpf->len + IFH_LEN_BYTES,
- dma_addr + XDP_PACKET_HEADROOM);
+ /* Setup next dcb */
+ lan966x_fdma_tx_setup_dcb(tx, next_to_use,
+ xdpf->len + IFH_LEN_BYTES,
+ dma_addr);
+ } else {
+ ifh = page_address(page) + XDP_PACKET_HEADROOM;
+ memset(ifh, 0x0, sizeof(__be32) * IFH_LEN);
+ lan966x_ifh_set_bypass(ifh, 1);
+ lan966x_ifh_set_port(ifh, BIT_ULL(port->chip_port));
+
+ dma_addr = page_pool_get_dma_addr(page);
+ dma_sync_single_for_device(lan966x->dev,
+ dma_addr + XDP_PACKET_HEADROOM,
+ xdpf->len + IFH_LEN_BYTES,
+ DMA_TO_DEVICE);
+
+ /* Setup next dcb */
+ lan966x_fdma_tx_setup_dcb(tx, next_to_use,
+ xdpf->len + IFH_LEN_BYTES,
+ dma_addr + XDP_PACKET_HEADROOM);
+ }

/* Fill up the buffer */
next_dcb_buf = &tx->dcbs_buf[next_to_use];
next_dcb_buf->skb = NULL;
next_dcb_buf->xdpf = xdpf;
+ next_dcb_buf->xdp_ndo = dma_map;
next_dcb_buf->len = xdpf->len + IFH_LEN_BYTES;
next_dcb_buf->dma_addr = dma_addr;
next_dcb_buf->used = true;
@@ -792,6 +846,7 @@ int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
next_dcb_buf = &tx->dcbs_buf[next_to_use];
next_dcb_buf->skb = skb;
next_dcb_buf->xdpf = NULL;
+ next_dcb_buf->xdp_ndo = false;
next_dcb_buf->len = skb->len;
next_dcb_buf->dma_addr = dma_addr;
next_dcb_buf->used = true;
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index 0b7707306da26..0aed244826d39 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -469,6 +469,7 @@ static const struct net_device_ops lan966x_port_netdev_ops = {
.ndo_eth_ioctl = lan966x_port_ioctl,
.ndo_setup_tc = lan966x_tc_setup,
.ndo_bpf = lan966x_xdp,
+ .ndo_xdp_xmit = lan966x_xdp_xmit,
};

bool lan966x_netdevice_check(const struct net_device *dev)
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
index e303a12daf88a..ed4adeae553d3 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
@@ -106,12 +106,14 @@ enum macaccess_entry_type {
* FDMA_ERROR, something went wrong, stop getting more frames
* FDMA_DROP, frame is dropped, but continue to get more frames
* FDMA_TX, frame is given to TX, but continue to get more frames
+ * FDMA_REDIRECT, frame is given to TX, but continue to get more frames
*/
enum lan966x_fdma_action {
FDMA_PASS = 0,
FDMA_ERROR,
FDMA_DROP,
FDMA_TX,
+ FDMA_REDIRECT,
};

struct lan966x_port;
@@ -178,6 +180,7 @@ struct lan966x_tx_dcb_buf {
struct net_device *dev;
struct sk_buff *skb;
struct xdp_frame *xdpf;
+ bool xdp_ndo;
int len;
dma_addr_t dma_addr;
bool used;
@@ -467,7 +470,8 @@ int lan966x_ptp_gettime64(struct ptp_clock_info *ptp, struct timespec64 *ts);
int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev);
int lan966x_fdma_xmit_xdpf(struct lan966x_port *port,
struct xdp_frame *frame,
- struct page *page);
+ struct page *page,
+ bool dma_map);
int lan966x_fdma_change_mtu(struct lan966x *lan966x);
void lan966x_fdma_netdev_init(struct lan966x *lan966x, struct net_device *dev);
void lan966x_fdma_netdev_deinit(struct lan966x *lan966x, struct net_device *dev);
@@ -565,6 +569,10 @@ int lan966x_xdp(struct net_device *dev, struct netdev_bpf *xdp);
int lan966x_xdp_run(struct lan966x_port *port,
struct page *page,
u32 data_len);
+int lan966x_xdp_xmit(struct net_device *dev,
+ int n,
+ struct xdp_frame **frames,
+ u32 flags);
bool lan966x_xdp_present(struct lan966x *lan966x);
static inline bool lan966x_xdp_port_present(struct lan966x_port *port)
{
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
index 5fd2f3b01e179..9f363316115ae 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
@@ -50,6 +50,30 @@ int lan966x_xdp(struct net_device *dev, struct netdev_bpf *xdp)
}
}

+int lan966x_xdp_xmit(struct net_device *dev,
+ int n,
+ struct xdp_frame **frames,
+ u32 flags)
+{
+ struct lan966x_port *port = netdev_priv(dev);
+ int i, nxmit = 0;
+
+ for (i = 0; i < n; ++i) {
+ struct xdp_frame *xdpf = frames[i];
+ int err;
+
+ err = lan966x_fdma_xmit_xdpf(port, xdpf,
+ virt_to_head_page(xdpf->data),
+ true);
+ if (err)
+ break;
+
+ nxmit++;
+ }
+
+ return nxmit;
+}
+
int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len)
{
struct bpf_prog *xdp_prog = port->xdp_prog;
@@ -72,8 +96,13 @@ int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len)
if (!xdpf)
return FDMA_DROP;

- return lan966x_fdma_xmit_xdpf(port, xdpf, page) ?
+ return lan966x_fdma_xmit_xdpf(port, xdpf, page, false) ?
FDMA_DROP : FDMA_TX;
+ case XDP_REDIRECT:
+ if (xdp_do_redirect(port->dev, &xdp, xdp_prog))
+ return FDMA_DROP;
+
+ return FDMA_REDIRECT;
default:
bpf_warn_invalid_xdp_action(port->dev, xdp_prog, act);
fallthrough;
--
2.38.0