From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= <bjorn.topel@intel.com>
Date: Tue, 28 Aug 2018 14:44:32 +0200
Subject: i40e: add AF_XDP zero-copy Rx support
MIME-Version: 1.0
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Patch-mainline: v4.20-rc1
Git-commit: 0a714186d3c0f7c563a03537f98716457c1f5ae0
References: bsc#1111981 FATE#326312 FATE#326313
This patch adds zero-copy Rx support for AF_XDP sockets. Instead of
allocating buffers of type MEM_TYPE_PAGE_SHARED, the Rx frames are
allocated as MEM_TYPE_ZERO_COPY when AF_XDP is enabled for a certain
queue.
All AF_XDP specific functions are added to a new file, i40e_xsk.c.
Note that when AF_XDP zero-copy is enabled, the XDP action XDP_PASS
will allocate a new buffer and copy the zero-copy frame prior passing
it to the kernel stack.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/intel/i40e/Makefile | 3
drivers/net/ethernet/intel/i40e/i40e.h | 19
drivers/net/ethernet/intel/i40e/i40e_main.c | 53 ++
drivers/net/ethernet/intel/i40e/i40e_txrx.c | 9
drivers/net/ethernet/intel/i40e/i40e_txrx.h | 20
drivers/net/ethernet/intel/i40e/i40e_xsk.c | 661 ++++++++++++++++++++++++++++
drivers/net/ethernet/intel/i40e/i40e_xsk.h | 21
7 files changed, 775 insertions(+), 11 deletions(-)
create mode 100644 drivers/net/ethernet/intel/i40e/i40e_xsk.c
create mode 100644 drivers/net/ethernet/intel/i40e/i40e_xsk.h
--- a/drivers/net/ethernet/intel/i40e/Makefile
+++ b/drivers/net/ethernet/intel/i40e/Makefile
@@ -45,6 +45,7 @@ i40e-objs := i40e_main.o \
i40e_txrx.o \
i40e_ptp.o \
i40e_client.o \
- i40e_virtchnl_pf.o
+ i40e_virtchnl_pf.o \
+ i40e_xsk.o
i40e-$(CONFIG_I40E_DCB) += i40e_dcb.o i40e_dcb_nl.o
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -809,6 +809,11 @@ struct i40e_vsi {
/* VSI specific handlers */
irqreturn_t (*irq_handler)(int irq, void *data);
+
+ /* AF_XDP zero-copy */
+ struct xdp_umem **xsk_umems;
+ u16 num_xsk_umems_used;
+ u16 num_xsk_umems;
} ____cacheline_internodealigned_in_smp;
struct i40e_netdev_priv {
@@ -1113,6 +1118,20 @@ static inline bool i40e_enabled_xdp_vsi(
return !!vsi->xdp_prog;
}
+static inline struct xdp_umem *i40e_xsk_umem(struct i40e_ring *ring)
+{
+ bool xdp_on = i40e_enabled_xdp_vsi(ring->vsi);
+ int qid = ring->queue_index;
+
+ if (ring_is_xdp(ring))
+ qid -= ring->vsi->alloc_queue_pairs;
+
+ if (!ring->vsi->xsk_umems || !ring->vsi->xsk_umems[qid] || !xdp_on)
+ return NULL;
+
+ return ring->vsi->xsk_umems[qid];
+}
+
int i40e_create_queue_channel(struct i40e_vsi *vsi, struct i40e_channel *ch);
int i40e_set_bw_limit(struct i40e_vsi *vsi, u16 seid, u64 max_tx_rate);
int i40e_add_del_cloud_filter(struct i40e_vsi *vsi,
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -32,7 +32,9 @@
/* Local includes */
#include "i40e.h"
#include "i40e_diag.h"
+#include "i40e_xsk.h"
#include <net/udp_tunnel.h>
+#include <net/xdp_sock.h>
/* All i40e tracepoints are defined by the include below, which
* must be included exactly once across the whole kernel with
* CREATE_TRACE_POINTS defined
@@ -3206,13 +3208,46 @@ static int i40e_configure_rx_ring(struct
struct i40e_hw *hw = &vsi->back->hw;
struct i40e_hmc_obj_rxq rx_ctx;
i40e_status err = 0;
+ bool ok;
+ int ret;
bitmap_zero(ring->state, __I40E_RING_STATE_NBITS);
/* clear the context structure first */
memset(&rx_ctx, 0, sizeof(rx_ctx));
- ring->rx_buf_len = vsi->rx_buf_len;
+ if (ring->vsi->type == I40E_VSI_MAIN)
+ xdp_rxq_info_unreg_mem_model(&ring->xdp_rxq);
+
+ ring->xsk_umem = i40e_xsk_umem(ring);
+ if (ring->xsk_umem) {
+ ring->rx_buf_len = ring->xsk_umem->chunk_size_nohr -
+ XDP_PACKET_HEADROOM;
+ /* For AF_XDP ZC, we disallow packets to span on
+ * multiple buffers, thus letting us skip that
+ * handling in the fast-path.
+ */
+ chain_len = 1;
+ ring->zca.free = i40e_zca_free;
+ ret = xdp_rxq_info_reg_mem_model(&ring->xdp_rxq,
+ MEM_TYPE_ZERO_COPY,
+ &ring->zca);
+ if (ret)
+ return ret;
+ dev_info(&vsi->back->pdev->dev,
+ "Registered XDP mem model MEM_TYPE_ZERO_COPY on Rx ring %d\n",
+ ring->queue_index);
+
+ } else {
+ ring->rx_buf_len = vsi->rx_buf_len;
+ if (ring->vsi->type == I40E_VSI_MAIN) {
+ ret = xdp_rxq_info_reg_mem_model(&ring->xdp_rxq,
+ MEM_TYPE_PAGE_SHARED,
+ NULL);
+ if (ret)
+ return ret;
+ }
+ }
rx_ctx.dbuff = DIV_ROUND_UP(ring->rx_buf_len,
BIT_ULL(I40E_RXQ_CTX_DBUFF_SHIFT));
@@ -3268,7 +3303,15 @@ static int i40e_configure_rx_ring(struct
ring->tail = hw->hw_addr + I40E_QRX_TAIL(pf_q);
writel(0, ring->tail);
- i40e_alloc_rx_buffers(ring, I40E_DESC_UNUSED(ring));
+ ok = ring->xsk_umem ?
+ i40e_alloc_rx_buffers_zc(ring, I40E_DESC_UNUSED(ring)) :
+ !i40e_alloc_rx_buffers(ring, I40E_DESC_UNUSED(ring));
+ if (!ok) {
+ dev_info(&vsi->back->pdev->dev,
+ "Failed allocate some buffers on %sRx ring %d (pf_q %d)\n",
+ ring->xsk_umem ? "UMEM enabled " : "",
+ ring->queue_index, pf_q);
+ }
return 0;
}
@@ -12140,6 +12183,12 @@ static int i40e_xdp(struct net_device *d
case XDP_QUERY_PROG:
xdp->prog_id = vsi->xdp_prog ? vsi->xdp_prog->aux->id : 0;
return 0;
+ case XDP_QUERY_XSK_UMEM:
+ return i40e_xsk_umem_query(vsi, &xdp->xsk.umem,
+ xdp->xsk.queue_id);
+ case XDP_SETUP_XSK_UMEM:
+ return i40e_xsk_umem_setup(vsi, xdp->xsk.umem,
+ xdp->xsk.queue_id);
default:
return -EINVAL;
}
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -32,6 +32,7 @@
#include "i40e_trace.h"
#include "i40e_prototype.h"
#include "i40e_txrx_common.h"
+#include "i40e_xsk.h"
static inline __le64 build_ctob(u32 td_cmd, u32 td_offset, unsigned int size,
u32 td_tag)
@@ -1403,6 +1404,9 @@ void i40e_clean_rx_ring(struct i40e_ring
rx_ring->skb = NULL;
}
+ if (rx_ring->xsk_umem)
+ goto skip_free;
+
/* Free all the Rx ring sk_buffs */
for (i = 0; i < rx_ring->count; i++) {
struct i40e_rx_buffer *rx_bi = &rx_ring->rx_bi[i];
@@ -1431,6 +1435,7 @@ void i40e_clean_rx_ring(struct i40e_ring
rx_bi->page_offset = 0;
}
+skip_free:
bi_size = sizeof(struct i40e_rx_buffer) * rx_ring->count;
memset(rx_ring->rx_bi, 0, bi_size);
@@ -2664,7 +2669,9 @@ int i40e_napi_poll(struct napi_struct *n
budget_per_ring = max(budget/q_vector->num_ringpairs, 1);
i40e_for_each_ring(ring, q_vector->rx) {
- int cleaned = i40e_clean_rx_irq(ring, budget_per_ring);
+ int cleaned = ring->xsk_umem ?
+ i40e_clean_rx_irq_zc(ring, budget_per_ring) :
+ i40e_clean_rx_irq(ring, budget_per_ring);
work_done += cleaned;
/* if we clean as many as budgeted, we must not be done */
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -319,13 +319,17 @@ struct i40e_tx_buffer {
struct i40e_rx_buffer {
dma_addr_t dma;
- struct page *page;
-#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
- __u32 page_offset;
-#else
- __u16 page_offset;
-#endif
- __u16 pagecnt_bias;
+ union {
+ struct {
+ struct page *page;
+ __u32 page_offset;
+ __u16 pagecnt_bias;
+ };
+ struct {
+ void *addr;
+ u64 handle;
+ };
+ };
};
struct i40e_queue_stats {
@@ -437,6 +441,8 @@ struct i40e_ring {
struct i40e_channel *ch;
struct xdp_rxq_info xdp_rxq;
+ struct xdp_umem *xsk_umem;
+ struct zero_copy_allocator zca; /* ZC allocator anchor */
} ____cacheline_internodealigned_in_smp;
static inline bool ring_uses_build_skb(struct i40e_ring *ring)
--- /dev/null
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -0,0 +1,661 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2018 Intel Corporation. */
+
+#include <linux/bpf_trace.h>
+#include <net/xdp_sock.h>
+#include <net/xdp.h>
+
+#include "i40e.h"
+#include "i40e_txrx_common.h"
+#include "i40e_xsk.h"
+
+/**
+ * i40e_alloc_xsk_umems - Allocate an array to store per ring UMEMs
+ * @vsi: Current VSI
+ *
+ * Returns 0 on success, <0 on failure
+ **/
+static int i40e_alloc_xsk_umems(struct i40e_vsi *vsi)
+{
+ if (vsi->xsk_umems)
+ return 0;
+
+ vsi->num_xsk_umems_used = 0;
+ vsi->num_xsk_umems = vsi->alloc_queue_pairs;
+ vsi->xsk_umems = kcalloc(vsi->num_xsk_umems, sizeof(*vsi->xsk_umems),
+ GFP_KERNEL);
+ if (!vsi->xsk_umems) {
+ vsi->num_xsk_umems = 0;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+/**
+ * i40e_add_xsk_umem - Store an UMEM for a certain ring/qid
+ * @vsi: Current VSI
+ * @umem: UMEM to store
+ * @qid: Ring/qid to associate with the UMEM
+ *
+ * Returns 0 on success, <0 on failure
+ **/
+static int i40e_add_xsk_umem(struct i40e_vsi *vsi, struct xdp_umem *umem,
+ u16 qid)
+{
+ int err;
+
+ err = i40e_alloc_xsk_umems(vsi);
+ if (err)
+ return err;
+
+ vsi->xsk_umems[qid] = umem;
+ vsi->num_xsk_umems_used++;
+
+ return 0;
+}
+
+/**
+ * i40e_remove_xsk_umem - Remove an UMEM for a certain ring/qid
+ * @vsi: Current VSI
+ * @qid: Ring/qid associated with the UMEM
+ **/
+static void i40e_remove_xsk_umem(struct i40e_vsi *vsi, u16 qid)
+{
+ vsi->xsk_umems[qid] = NULL;
+ vsi->num_xsk_umems_used--;
+
+ if (vsi->num_xsk_umems == 0) {
+ kfree(vsi->xsk_umems);
+ vsi->xsk_umems = NULL;
+ vsi->num_xsk_umems = 0;
+ }
+}
+
+/**
+ * i40e_xsk_umem_dma_map - DMA maps all UMEM memory for the netdev
+ * @vsi: Current VSI
+ * @umem: UMEM to DMA map
+ *
+ * Returns 0 on success, <0 on failure
+ **/
+static int i40e_xsk_umem_dma_map(struct i40e_vsi *vsi, struct xdp_umem *umem)
+{
+ struct i40e_pf *pf = vsi->back;
+ struct device *dev;
+ unsigned int i, j;
+ dma_addr_t dma;
+
+ dev = &pf->pdev->dev;
+ for (i = 0; i < umem->npgs; i++) {
+ dma = dma_map_page_attrs(dev, umem->pgs[i], 0, PAGE_SIZE,
+ DMA_BIDIRECTIONAL, I40E_RX_DMA_ATTR);
+ if (dma_mapping_error(dev, dma))
+ goto out_unmap;
+
+ umem->pages[i].dma = dma;
+ }
+
+ return 0;
+
+out_unmap:
+ for (j = 0; j < i; j++) {
+ dma_unmap_page_attrs(dev, umem->pages[i].dma, PAGE_SIZE,
+ DMA_BIDIRECTIONAL, I40E_RX_DMA_ATTR);
+ umem->pages[i].dma = 0;
+ }
+
+ return -1;
+}
+
+/**
+ * i40e_xsk_umem_dma_unmap - DMA unmaps all UMEM memory for the netdev
+ * @vsi: Current VSI
+ * @umem: UMEM to DMA map
+ **/
+static void i40e_xsk_umem_dma_unmap(struct i40e_vsi *vsi, struct xdp_umem *umem)
+{
+ struct i40e_pf *pf = vsi->back;
+ struct device *dev;
+ unsigned int i;
+
+ dev = &pf->pdev->dev;
+
+ for (i = 0; i < umem->npgs; i++) {
+ dma_unmap_page_attrs(dev, umem->pages[i].dma, PAGE_SIZE,
+ DMA_BIDIRECTIONAL, I40E_RX_DMA_ATTR);
+
+ umem->pages[i].dma = 0;
+ }
+}
+
+/**
+ * i40e_xsk_umem_enable - Enable/associate an UMEM to a certain ring/qid
+ * @vsi: Current VSI
+ * @umem: UMEM
+ * @qid: Rx ring to associate UMEM to
+ *
+ * Returns 0 on success, <0 on failure
+ **/
+static int i40e_xsk_umem_enable(struct i40e_vsi *vsi, struct xdp_umem *umem,
+ u16 qid)
+{
+ bool if_running;
+ int err;
+
+ if (vsi->type != I40E_VSI_MAIN)
+ return -EINVAL;
+
+ if (qid >= vsi->num_queue_pairs)
+ return -EINVAL;
+
+ if (vsi->xsk_umems) {
+ if (qid >= vsi->num_xsk_umems)
+ return -EINVAL;
+ if (vsi->xsk_umems[qid])
+ return -EBUSY;
+ }
+
+ err = i40e_xsk_umem_dma_map(vsi, umem);
+ if (err)
+ return err;
+
+ if_running = netif_running(vsi->netdev) && i40e_enabled_xdp_vsi(vsi);
+
+ if (if_running) {
+ err = i40e_queue_pair_disable(vsi, qid);
+ if (err)
+ return err;
+ }
+
+ err = i40e_add_xsk_umem(vsi, umem, qid);
+ if (err)
+ return err;
+
+ if (if_running) {
+ err = i40e_queue_pair_enable(vsi, qid);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+/**
+ * i40e_xsk_umem_disable - Diassociate an UMEM from a certain ring/qid
+ * @vsi: Current VSI
+ * @qid: Rx ring to associate UMEM to
+ *
+ * Returns 0 on success, <0 on failure
+ **/
+static int i40e_xsk_umem_disable(struct i40e_vsi *vsi, u16 qid)
+{
+ bool if_running;
+ int err;
+
+ if (!vsi->xsk_umems || qid >= vsi->num_xsk_umems ||
+ !vsi->xsk_umems[qid])
+ return -EINVAL;
+
+ if_running = netif_running(vsi->netdev) && i40e_enabled_xdp_vsi(vsi);
+
+ if (if_running) {
+ err = i40e_queue_pair_disable(vsi, qid);
+ if (err)
+ return err;
+ }
+
+ i40e_xsk_umem_dma_unmap(vsi, vsi->xsk_umems[qid]);
+ i40e_remove_xsk_umem(vsi, qid);
+
+ if (if_running) {
+ err = i40e_queue_pair_enable(vsi, qid);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+/**
+ * i40e_xsk_umem_query - Queries a certain ring/qid for its UMEM
+ * @vsi: Current VSI
+ * @umem: UMEM associated to the ring, if any
+ * @qid: Rx ring to associate UMEM to
+ *
+ * This function will store, if any, the UMEM associated to certain ring.
+ *
+ * Returns 0 on success, <0 on failure
+ **/
+int i40e_xsk_umem_query(struct i40e_vsi *vsi, struct xdp_umem **umem,
+ u16 qid)
+{
+ if (vsi->type != I40E_VSI_MAIN)
+ return -EINVAL;
+
+ if (qid >= vsi->num_queue_pairs)
+ return -EINVAL;
+
+ if (vsi->xsk_umems) {
+ if (qid >= vsi->num_xsk_umems)
+ return -EINVAL;
+ *umem = vsi->xsk_umems[qid];
+ return 0;
+ }
+
+ *umem = NULL;
+ return 0;
+}
+
+/**
+ * i40e_xsk_umem_query - Queries a certain ring/qid for its UMEM
+ * @vsi: Current VSI
+ * @umem: UMEM to enable/associate to a ring, or NULL to disable
+ * @qid: Rx ring to (dis)associate UMEM (from)to
+ *
+ * This function enables or disables an UMEM to a certain ring.
+ *
+ * Returns 0 on success, <0 on failure
+ **/
+int i40e_xsk_umem_setup(struct i40e_vsi *vsi, struct xdp_umem *umem,
+ u16 qid)
+{
+ return umem ? i40e_xsk_umem_enable(vsi, umem, qid) :
+ i40e_xsk_umem_disable(vsi, qid);
+}
+
+/**
+ * i40e_run_xdp_zc - Executes an XDP program on an xdp_buff
+ * @rx_ring: Rx ring
+ * @xdp: xdp_buff used as input to the XDP program
+ *
+ * This function enables or disables an UMEM to a certain ring.
+ *
+ * Returns any of I40E_XDP_{PASS, CONSUMED, TX, REDIR}
+ **/
+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;
+
+ rcu_read_lock();
+ /* NB! xdp_prog will always be !NULL, due to the fact that
+ * this path is enabled by setting an XDP program.
+ */
+ xdp_prog = READ_ONCE(rx_ring->xdp_prog);
+ act = bpf_prog_run_xdp(xdp_prog, xdp);
+ xdp->handle += xdp->data - xdp->data_hard_start;
+ 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);
+ break;
+ case XDP_REDIRECT:
+ err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
+ result = !err ? I40E_XDP_REDIR : I40E_XDP_CONSUMED;
+ break;
+ default:
+ bpf_warn_invalid_xdp_action(act);
+ case XDP_ABORTED:
+ trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
+ /* fallthrough -- handle aborts by dropping packet */
+ case XDP_DROP:
+ result = I40E_XDP_CONSUMED;
+ break;
+ }
+ rcu_read_unlock();
+ return result;
+}
+
+/**
+ * i40e_alloc_buffer_zc - Allocates an i40e_rx_buffer
+ * @rx_ring: Rx ring
+ * @bi: Rx buffer to populate
+ *
+ * This function allocates an Rx buffer. The buffer can come from fill
+ * queue, or via the recycle queue (next_to_alloc).
+ *
+ * Returns true for a successful allocation, false otherwise
+ **/
+static bool i40e_alloc_buffer_zc(struct i40e_ring *rx_ring,
+ struct i40e_rx_buffer *bi)
+{
+ struct xdp_umem *umem = rx_ring->xsk_umem;
+ void *addr = bi->addr;
+ u64 handle, hr;
+
+ if (addr) {
+ rx_ring->rx_stats.page_reuse_count++;
+ return true;
+ }
+
+ if (!xsk_umem_peek_addr(umem, &handle)) {
+ rx_ring->rx_stats.alloc_page_failed++;
+ return false;
+ }
+
+ hr = umem->headroom + XDP_PACKET_HEADROOM;
+
+ bi->dma = xdp_umem_get_dma(umem, handle);
+ bi->dma += hr;
+
+ bi->addr = xdp_umem_get_data(umem, handle);
+ bi->addr += hr;
+
+ bi->handle = handle + umem->headroom;
+
+ xsk_umem_discard_addr(umem);
+ return true;
+}
+
+/**
+ * i40e_alloc_rx_buffers_zc - Allocates a number of Rx buffers
+ * @rx_ring: Rx ring
+ * @count: The number of buffers to allocate
+ *
+ * This function allocates a number of Rx buffers and places them on
+ * the Rx ring.
+ *
+ * Returns true for a successful allocation, false otherwise
+ **/
+bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count)
+{
+ u16 ntu = rx_ring->next_to_use;
+ union i40e_rx_desc *rx_desc;
+ struct i40e_rx_buffer *bi;
+ bool ok = true;
+
+ rx_desc = I40E_RX_DESC(rx_ring, ntu);
+ bi = &rx_ring->rx_bi[ntu];
+ do {
+ if (!i40e_alloc_buffer_zc(rx_ring, bi)) {
+ ok = false;
+ goto no_buffers;
+ }
+
+ dma_sync_single_range_for_device(rx_ring->dev, bi->dma, 0,
+ rx_ring->rx_buf_len,
+ DMA_BIDIRECTIONAL);
+
+ rx_desc->read.pkt_addr = cpu_to_le64(bi->dma);
+
+ rx_desc++;
+ bi++;
+ ntu++;
+
+ if (unlikely(ntu == rx_ring->count)) {
+ rx_desc = I40E_RX_DESC(rx_ring, 0);
+ bi = rx_ring->rx_bi;
+ ntu = 0;
+ }
+
+ rx_desc->wb.qword1.status_error_len = 0;
+ count--;
+ } while (count);
+
+no_buffers:
+ if (rx_ring->next_to_use != ntu)
+ i40e_release_rx_desc(rx_ring, ntu);
+
+ return ok;
+}
+
+/**
+ * i40e_get_rx_buffer_zc - Return the current Rx buffer
+ * @rx_ring: Rx ring
+ * @size: The size of the rx buffer (read from descriptor)
+ *
+ * This function returns the current, received Rx buffer, and also
+ * does DMA synchronization. the Rx ring.
+ *
+ * Returns the received Rx buffer
+ **/
+static struct i40e_rx_buffer *i40e_get_rx_buffer_zc(struct i40e_ring *rx_ring,
+ const unsigned int size)
+{
+ struct i40e_rx_buffer *bi;
+
+ bi = &rx_ring->rx_bi[rx_ring->next_to_clean];
+
+ /* we are reusing so sync this buffer for CPU use */
+ dma_sync_single_range_for_cpu(rx_ring->dev,
+ bi->dma, 0,
+ size,
+ DMA_BIDIRECTIONAL);
+
+ return bi;
+}
+
+/**
+ * i40e_reuse_rx_buffer_zc - Recycle an Rx buffer
+ * @rx_ring: Rx ring
+ * @old_bi: The Rx buffer to recycle
+ *
+ * This function recycles a finished Rx buffer, and places it on the
+ * recycle queue (next_to_alloc).
+ **/
+static void i40e_reuse_rx_buffer_zc(struct i40e_ring *rx_ring,
+ struct i40e_rx_buffer *old_bi)
+{
+ struct i40e_rx_buffer *new_bi = &rx_ring->rx_bi[rx_ring->next_to_alloc];
+ unsigned long mask = (unsigned long)rx_ring->xsk_umem->props.chunk_mask;
+ u64 hr = rx_ring->xsk_umem->headroom + XDP_PACKET_HEADROOM;
+ u16 nta = rx_ring->next_to_alloc;
+
+ /* update, and store next to alloc */
+ nta++;
+ rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0;
+
+ /* transfer page from old buffer to new buffer */
+ new_bi->dma = old_bi->dma & mask;
+ new_bi->dma += hr;
+
+ new_bi->addr = (void *)((unsigned long)old_bi->addr & mask);
+ new_bi->addr += hr;
+
+ new_bi->handle = old_bi->handle & mask;
+ new_bi->handle += rx_ring->xsk_umem->headroom;
+
+ old_bi->addr = NULL;
+}
+
+/**
+ * i40e_zca_free - Free callback for MEM_TYPE_ZERO_COPY allocations
+ * @alloc: Zero-copy allocator
+ * @handle: Buffer handle
+ **/
+void i40e_zca_free(struct zero_copy_allocator *alloc, unsigned long handle)
+{
+ struct i40e_rx_buffer *bi;
+ struct i40e_ring *rx_ring;
+ u64 hr, mask;
+ u16 nta;
+
+ rx_ring = container_of(alloc, struct i40e_ring, zca);
+ hr = rx_ring->xsk_umem->headroom + XDP_PACKET_HEADROOM;
+ mask = rx_ring->xsk_umem->props.chunk_mask;
+
+ nta = rx_ring->next_to_alloc;
+ bi = &rx_ring->rx_bi[nta];
+
+ nta++;
+ rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0;
+
+ handle &= mask;
+
+ bi->dma = xdp_umem_get_dma(rx_ring->xsk_umem, handle);
+ bi->dma += hr;
+
+ bi->addr = xdp_umem_get_data(rx_ring->xsk_umem, handle);
+ bi->addr += hr;
+
+ bi->handle = (u64)handle + rx_ring->xsk_umem->headroom;
+}
+
+/**
+ * i40e_construct_skb_zc - Create skbufff from zero-copy Rx buffer
+ * @rx_ring: Rx ring
+ * @bi: Rx buffer
+ * @xdp: xdp_buff
+ *
+ * This functions allocates a new skb from a zero-copy Rx buffer.
+ *
+ * Returns the skb, or NULL on failure.
+ **/
+static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring,
+ struct i40e_rx_buffer *bi,
+ struct xdp_buff *xdp)
+{
+ unsigned int metasize = xdp->data - xdp->data_meta;
+ unsigned int datasize = xdp->data_end - xdp->data;
+ struct sk_buff *skb;
+
+ /* allocate a skb to store the frags */
+ skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
+ xdp->data_end - xdp->data_hard_start,
+ GFP_ATOMIC | __GFP_NOWARN);
+ if (unlikely(!skb))
+ return NULL;
+
+ skb_reserve(skb, xdp->data - xdp->data_hard_start);
+ memcpy(__skb_put(skb, datasize), xdp->data, datasize);
+ if (metasize)
+ skb_metadata_set(skb, metasize);
+
+ i40e_reuse_rx_buffer_zc(rx_ring, bi);
+ return skb;
+}
+
+/**
+ * i40e_inc_ntc: Advance the next_to_clean index
+ * @rx_ring: Rx ring
+ **/
+static void i40e_inc_ntc(struct i40e_ring *rx_ring)
+{
+ u32 ntc = rx_ring->next_to_clean + 1;
+
+ ntc = (ntc < rx_ring->count) ? ntc : 0;
+ rx_ring->next_to_clean = ntc;
+ prefetch(I40E_RX_DESC(rx_ring, ntc));
+}
+
+/**
+ * i40e_clean_rx_irq_zc - Consumes Rx packets from the hardware ring
+ * @rx_ring: Rx ring
+ * @budget: NAPI budget
+ *
+ * Returns amount of work completed
+ **/
+int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
+{
+ unsigned int total_rx_bytes = 0, total_rx_packets = 0;
+ u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
+ unsigned int xdp_res, xdp_xmit = 0;
+ bool failure = false;
+ struct sk_buff *skb;
+ struct xdp_buff xdp;
+
+ xdp.rxq = &rx_ring->xdp_rxq;
+
+ while (likely(total_rx_packets < (unsigned int)budget)) {
+ struct i40e_rx_buffer *bi;
+ union i40e_rx_desc *rx_desc;
+ unsigned int size;
+ u16 vlan_tag;
+ u8 rx_ptype;
+ u64 qword;
+
+ if (cleaned_count >= I40E_RX_BUFFER_WRITE) {
+ failure = failure ||
+ !i40e_alloc_rx_buffers_zc(rx_ring,
+ cleaned_count);
+ cleaned_count = 0;
+ }
+
+ rx_desc = I40E_RX_DESC(rx_ring, rx_ring->next_to_clean);
+ qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
+
+ /* This memory barrier is needed to keep us from reading
+ * any other fields out of the rx_desc until we have
+ * verified the descriptor has been written back.
+ */
+ dma_rmb();
+
+ bi = i40e_clean_programming_status(rx_ring, rx_desc,
+ qword);
+ if (unlikely(bi)) {
+ i40e_reuse_rx_buffer_zc(rx_ring, bi);
+ cleaned_count++;
+ continue;
+ }
+
+ size = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>
+ I40E_RXD_QW1_LENGTH_PBUF_SHIFT;
+ if (!size)
+ break;
+
+ bi = i40e_get_rx_buffer_zc(rx_ring, size);
+ xdp.data = bi->addr;
+ xdp.data_meta = xdp.data;
+ xdp.data_hard_start = xdp.data - XDP_PACKET_HEADROOM;
+ xdp.data_end = xdp.data + size;
+ xdp.handle = bi->handle;
+
+ xdp_res = i40e_run_xdp_zc(rx_ring, &xdp);
+ if (xdp_res) {
+ if (xdp_res & (I40E_XDP_TX | I40E_XDP_REDIR)) {
+ xdp_xmit |= xdp_res;
+ bi->addr = NULL;
+ } else {
+ i40e_reuse_rx_buffer_zc(rx_ring, bi);
+ }
+
+ total_rx_bytes += size;
+ total_rx_packets++;
+
+ cleaned_count++;
+ i40e_inc_ntc(rx_ring);
+ continue;
+ }
+
+ /* XDP_PASS path */
+
+ /* NB! We are not checking for errors using
+ * i40e_test_staterr with
+ * BIT(I40E_RXD_QW1_ERROR_SHIFT). This is due to that
+ * SBP is *not* set in PRT_SBPVSI (default not set).
+ */
+ skb = i40e_construct_skb_zc(rx_ring, bi, &xdp);
+ if (!skb) {
+ rx_ring->rx_stats.alloc_buff_failed++;
+ break;
+ }
+
+ cleaned_count++;
+ i40e_inc_ntc(rx_ring);
+
+ if (eth_skb_pad(skb))
+ continue;
+
+ total_rx_bytes += skb->len;
+ total_rx_packets++;
+
+ qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
+ rx_ptype = (qword & I40E_RXD_QW1_PTYPE_MASK) >>
+ I40E_RXD_QW1_PTYPE_SHIFT;
+ i40e_process_skb_fields(rx_ring, rx_desc, skb, rx_ptype);
+
+ vlan_tag = (qword & BIT(I40E_RX_DESC_STATUS_L2TAG1P_SHIFT)) ?
+ le16_to_cpu(rx_desc->wb.qword0.lo_dword.l2tag1) : 0;
+ i40e_receive_skb(rx_ring, skb, vlan_tag);
+ }
+
+ i40e_finalize_xdp_rx(rx_ring, xdp_xmit);
+ i40e_update_rx_stats(rx_ring, total_rx_bytes, total_rx_packets);
+ return failure ? budget : (int)total_rx_packets;
+}
+
--- /dev/null
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright(c) 2018 Intel Corporation. */
+
+#ifndef _I40E_XSK_H_
+#define _I40E_XSK_H_
+
+struct i40e_vsi;
+struct xdp_umem;
+struct zero_copy_allocator;
+
+int i40e_queue_pair_disable(struct i40e_vsi *vsi, int queue_pair);
+int i40e_queue_pair_enable(struct i40e_vsi *vsi, int queue_pair);
+int i40e_xsk_umem_query(struct i40e_vsi *vsi, struct xdp_umem **umem,
+ u16 qid);
+int i40e_xsk_umem_setup(struct i40e_vsi *vsi, struct xdp_umem *umem,
+ u16 qid);
+void i40e_zca_free(struct zero_copy_allocator *alloc, unsigned long handle);
+bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 cleaned_count);
+int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget);
+
+#endif /* _I40E_XSK_H_ */