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Message-ID: <20190417195853.2819390-1-jonathan.lemon@gmail.com>
Date: Wed, 17 Apr 2019 12:58:53 -0700
From: Jonathan Lemon <jonathan.lemon@...il.com>
To: <netdev@...r.kernel.org>
CC: <bjorn.topel@...il.com>, <magnus.karlsson@...el.com>,
<kernel-team@...com>
Subject: [PATCH RFC] xdp: Support zero-copy XDP_TX from AF_XDP sockets.
When the XDP program attached to a zero-copy AF_XDP socket returns XDP_TX,
queue the umem frame on the XDP TX ring, and arrange for it to be released
via the ZCA free routine, which should place it back onto the reuseq.
Signed-off-by: Jonathan Lemon <jonathan.lemon@...il.com>
---
drivers/net/ethernet/intel/i40e/i40e_txrx.h | 1 +
drivers/net/ethernet/intel/i40e/i40e_xsk.c | 52 +++++++++++++++++++--
include/net/xdp.h | 20 ++++++--
3 files changed, 65 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index 100e92d2982f..3e7954277737 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -274,6 +274,7 @@ static inline unsigned int i40e_txd_use_count(unsigned int size)
#define I40E_TX_FLAGS_TSYN BIT(8)
#define I40E_TX_FLAGS_FD_SB BIT(9)
#define I40E_TX_FLAGS_UDP_TUNNEL BIT(10)
+#define I40E_TX_FLAGS_ZC_FRAME BIT(11)
#define I40E_TX_FLAGS_VLAN_MASK 0xffff0000
#define I40E_TX_FLAGS_VLAN_PRIO_MASK 0xe0000000
#define I40E_TX_FLAGS_VLAN_PRIO_SHIFT 29
diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index d2e212d007c3..16a31c57906a 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -188,7 +188,6 @@ int i40e_xsk_umem_setup(struct i40e_vsi *vsi, struct xdp_umem *umem,
static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp)
{
int err, result = I40E_XDP_PASS;
- struct i40e_ring *xdp_ring;
struct bpf_prog *xdp_prog;
u32 act;
@@ -202,9 +201,8 @@ static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp)
switch (act) {
case XDP_PASS:
break;
- case XDP_TX:
- xdp_ring = rx_ring->vsi->xdp_rings[rx_ring->queue_index];
- result = i40e_xmit_xdp_tx_ring(xdp, xdp_ring);
+ case XDP_TX
+ result = i40e_xmit_rcvd_zc(rx_ring, xdp);
break;
case XDP_REDIRECT:
err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
@@ -623,6 +621,48 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
return failure ? budget : (int)total_rx_packets;
}
+static int i40e_xmit_rcvd_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp)
+{
+ struct i40e_ring *xdp_ring;
+ struct i40e_tx_desc *tx_desc;
+ struct i40e_tx_buffer *tx_bi;
+ struct xdp_frame *xdpf;
+ dma_addr_t dma;
+
+ xdp_ring = rx_ring->vsi->xdp_rings[rx_ring->queue_index];
+
+ if (!unlikely(I40E_DESC_UNUSED(xdp_ring))) {
+ xdp_ring->tx_stats.tx_busy++;
+ return I40E_XDP_CONSUMED;
+ }
+ xpdf = convert_to_xdp_frame_keep_zc(xdp);
+ if (unlikely(!xpdf)
+ return I40E_XDP_CONSUMED;
+ xpdf->handle = xdp->handle;
+
+ dma = xdp_umem_get_dma(rx_ring->xsk_umem, xdp->handle);
+ tx_bi = &xdp_ring->tx_bi[xdp_ring->next_to_use];
+ tx_bi->bytecount = xpdf->len;
+ tx_bi->gso_segs = 1;
+ tx_bi->xdpf = xdpf;
+ tx_bi->tx_flags = I40E_TX_FLAGS_ZC_FRAME;
+
+ tx_desc = I40E_TX_DESC(xdp_ring, xdp_ring->next_to_use);
+ tx_desc->buffer_addr = cpu_to_le64(dma);
+ tx_desc->cmd_type_offset_bsz = build_ctob(I40E_TX_DESC_CMD_ICRC |
+ I40E_TX_DESC_CMD_EOP,
+ 0, xpdf->len, 0);
+ smp_wmb();
+
+ xdp_ring->next_to_use++;
+ if (xdp_ring->next_to_use == xdp_ring->count)
+ xdp_ring->next_to_use = 0;
+
+ tx_bi->next_to_watch = tx_desc;
+
+ return I40E_XDP_TX;
+}
+
/**
* i40e_xmit_zc - Performs zero-copy Tx AF_XDP
* @xdp_ring: XDP Tx ring
@@ -689,6 +729,10 @@ static void i40e_clean_xdp_tx_buffer(struct i40e_ring *tx_ring,
struct i40e_tx_buffer *tx_bi)
{
xdp_return_frame(tx_bi->xdpf);
+ if (tx_bi->tx_flags & I40E_TX_FLAGS_ZC_FRAME) {
+ tx_bi->tx_flags = 0;
+ return;
+ }
dma_unmap_single(tx_ring->dev,
dma_unmap_addr(tx_bi, dma),
dma_unmap_len(tx_bi, len), DMA_TO_DEVICE);
diff --git a/include/net/xdp.h b/include/net/xdp.h
index 0f25b3675c5c..191359c5ebdd 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -82,6 +82,7 @@ struct xdp_frame {
*/
struct xdp_mem_info mem;
struct net_device *dev_rx; /* used by cpumap */
+ unsigned long handle;
};
/* Clear kernel pointers in xdp_frame */
@@ -95,15 +96,12 @@ struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp);
/* Convert xdp_buff to xdp_frame */
static inline
-struct xdp_frame *convert_to_xdp_frame(struct xdp_buff *xdp)
+struct xdp_frame *__convert_to_xdp_frame(struct xdp_buff *xdp)
{
struct xdp_frame *xdp_frame;
int metasize;
int headroom;
- if (xdp->rxq->mem.type == MEM_TYPE_ZERO_COPY)
- return xdp_convert_zc_to_xdp_frame(xdp);
-
/* Assure headroom is available for storing info */
headroom = xdp->data - xdp->data_hard_start;
metasize = xdp->data - xdp->data_meta;
@@ -125,6 +123,20 @@ struct xdp_frame *convert_to_xdp_frame(struct xdp_buff *xdp)
return xdp_frame;
}
+static inline
+struct xdp_frame *convert_to_xdp_frame(struct xdp_buff *xdp)
+{
+ if (xdp->rxq->mem.type == MEM_TYPE_ZERO_COPY)
+ return xdp_convert_zc_to_xdp_frame(xdp);
+ return __convert_to_xdp_frame(xdp);
+}
+
+static inline
+struct xdp_frame *convert_to_xdp_frame_keep_zc(struct xdp_buff *xdp)
+{
+ return __convert_to_xdp_frame(xdp);
+}
+
void xdp_return_frame(struct xdp_frame *xdpf);
void xdp_return_frame_rx_napi(struct xdp_frame *xdpf);
void xdp_return_buff(struct xdp_buff *xdp);
--
2.17.1
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