Resguardo inicial

linux-7.2.3/drivers/net/ethernet/intel/libeth/Kconfig

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Copyright (C) 2024-2025 Intel Corporation
+
+config LIBETH
+	tristate "Common Ethernet library (libeth)" if COMPILE_TEST
+	select PAGE_POOL
+	help
+	  libeth is a common library containing routines shared between several
+	  drivers, but not yet promoted to the generic kernel API.
+
+config LIBETH_XDP
+	tristate "Common XDP library (libeth_xdp)" if COMPILE_TEST
+	select LIBETH
+	help
+	  XDP and XSk helpers based on libeth hotpath management.

linux-7.2.3/drivers/net/ethernet/intel/libeth/Makefile

@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Copyright (C) 2024-2025 Intel Corporation
+
+obj-$(CONFIG_LIBETH)		+= libeth.o
+
+libeth-y			:= rx.o
+libeth-y			+= tx.o
+
+obj-$(CONFIG_LIBETH_XDP)	+= libeth_xdp.o
+
+libeth_xdp-y			+= xdp.o
+libeth_xdp-y			+= xsk.o

linux-7.2.3/drivers/net/ethernet/intel/libeth/priv.h

@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (C) 2025 Intel Corporation */
+
+#ifndef __LIBETH_PRIV_H
+#define __LIBETH_PRIV_H
+
+#include <linux/types.h>
+
+/* XDP */
+
+enum xdp_action;
+struct libeth_xdp_buff;
+struct libeth_xdp_tx_frame;
+struct skb_shared_info;
+struct xdp_frame_bulk;
+
+extern const struct xsk_tx_metadata_ops libeth_xsktmo_slow;
+
+void libeth_xsk_tx_return_bulk(const struct libeth_xdp_tx_frame *bq,
+			       u32 count);
+u32 libeth_xsk_prog_exception(struct libeth_xdp_buff *xdp, enum xdp_action act,
+			      int ret);
+
+struct libeth_xdp_ops {
+	void	(*bulk)(const struct skb_shared_info *sinfo,
+			struct xdp_frame_bulk *bq, bool frags);
+	void	(*xsk)(struct libeth_xdp_buff *xdp);
+};
+
+void libeth_attach_xdp(const struct libeth_xdp_ops *ops);
+
+static inline void libeth_detach_xdp(void)
+{
+	libeth_attach_xdp(NULL);
+}
+
+#endif /* __LIBETH_PRIV_H */

linux-7.2.3/drivers/net/ethernet/intel/libeth/rx.c

@@ -0,0 +1,273 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2024-2025 Intel Corporation */
+
+#define DEFAULT_SYMBOL_NAMESPACE	"LIBETH"
+
+#include <linux/export.h>
+
+#include <net/libeth/rx.h>
+
+/* Rx buffer management */
+
+/**
+ * libeth_rx_hw_len_mtu - get the actual buffer size to be passed to HW
+ * @pp: &page_pool_params of the netdev to calculate the size for
+ * @max_len: maximum buffer size for a single descriptor
+ *
+ * Return: HW-writeable length per one buffer to pass it to the HW accounting:
+ * MTU the @dev has, HW required alignment, minimum and maximum allowed values,
+ * and system's page size.
+ */
+static u32 libeth_rx_hw_len_mtu(const struct page_pool_params *pp, u32 max_len)
+{
+	u32 len;
+
+	len = READ_ONCE(pp->netdev->mtu) + LIBETH_RX_LL_LEN;
+	len = ALIGN(len, LIBETH_RX_BUF_STRIDE);
+	len = min3(len, ALIGN_DOWN(max_len ? : U32_MAX, LIBETH_RX_BUF_STRIDE),
+		   pp->max_len);
+
+	return len;
+}
+
+/**
+ * libeth_rx_hw_len_truesize - get the short buffer size to be passed to HW
+ * @pp: &page_pool_params of the netdev to calculate the size for
+ * @max_len: maximum buffer size for a single descriptor
+ * @truesize: desired truesize for the buffers
+ *
+ * Return: HW-writeable length per one buffer to pass it to the HW ignoring the
+ * MTU and closest to the passed truesize. Can be used for "short" buffer
+ * queues to fragment pages more efficiently.
+ */
+static u32 libeth_rx_hw_len_truesize(const struct page_pool_params *pp,
+				     u32 max_len, u32 truesize)
+{
+	u32 min, len;
+
+	min = SKB_HEAD_ALIGN(pp->offset + LIBETH_RX_BUF_STRIDE);
+	truesize = clamp(roundup_pow_of_two(truesize), roundup_pow_of_two(min),
+			 PAGE_SIZE << LIBETH_RX_PAGE_ORDER);
+
+	len = SKB_WITH_OVERHEAD(truesize - pp->offset);
+	len = ALIGN_DOWN(len, LIBETH_RX_BUF_STRIDE) ? : LIBETH_RX_BUF_STRIDE;
+	len = min3(len, ALIGN_DOWN(max_len ? : U32_MAX, LIBETH_RX_BUF_STRIDE),
+		   pp->max_len);
+
+	return len;
+}
+
+/**
+ * libeth_rx_page_pool_params - calculate params with the stack overhead
+ * @fq: buffer queue to calculate the size for
+ * @pp: &page_pool_params of the netdev
+ *
+ * Set the PP params to will all needed stack overhead (headroom, tailroom) and
+ * both the HW buffer length and the truesize for all types of buffers. For
+ * "short" buffers, truesize never exceeds the "wanted" one; for the rest,
+ * it can be up to the page size.
+ *
+ * Return: true on success, false on invalid input params.
+ */
+static bool libeth_rx_page_pool_params(struct libeth_fq *fq,
+				       struct page_pool_params *pp)
+{
+	pp->offset = fq->xdp ? LIBETH_XDP_HEADROOM : LIBETH_SKB_HEADROOM;
+	/* HW-writeable / syncable length per one page */
+	pp->max_len = LIBETH_RX_PAGE_LEN(pp->offset);
+
+	/* HW-writeable length per buffer */
+	switch (fq->type) {
+	case LIBETH_FQE_MTU:
+		fq->buf_len = libeth_rx_hw_len_mtu(pp, fq->buf_len);
+		break;
+	case LIBETH_FQE_SHORT:
+		fq->buf_len = libeth_rx_hw_len_truesize(pp, fq->buf_len,
+							fq->truesize);
+		break;
+	case LIBETH_FQE_HDR:
+		fq->buf_len = ALIGN(LIBETH_MAX_HEAD, LIBETH_RX_BUF_STRIDE);
+		break;
+	default:
+		return false;
+	}
+
+	/* Buffer size to allocate */
+	fq->truesize = roundup_pow_of_two(SKB_HEAD_ALIGN(pp->offset +
+							 fq->buf_len));
+
+	return true;
+}
+
+/**
+ * libeth_rx_page_pool_params_zc - calculate params without the stack overhead
+ * @fq: buffer queue to calculate the size for
+ * @pp: &page_pool_params of the netdev
+ *
+ * Set the PP params to exclude the stack overhead and both the buffer length
+ * and the truesize, which are equal for the data buffers. Note that this
+ * requires separate header buffers to be always active and account the
+ * overhead.
+ * With the MTU == ``PAGE_SIZE``, this allows the kernel to enable the zerocopy
+ * mode.
+ *
+ * Return: true on success, false on invalid input params.
+ */
+static bool libeth_rx_page_pool_params_zc(struct libeth_fq *fq,
+					  struct page_pool_params *pp)
+{
+	u32 mtu, max;
+
+	pp->offset = 0;
+	pp->max_len = PAGE_SIZE << LIBETH_RX_PAGE_ORDER;
+
+	switch (fq->type) {
+	case LIBETH_FQE_MTU:
+		mtu = READ_ONCE(pp->netdev->mtu);
+		break;
+	case LIBETH_FQE_SHORT:
+		mtu = fq->truesize;
+		break;
+	default:
+		return false;
+	}
+
+	mtu = roundup_pow_of_two(mtu);
+	max = min(rounddown_pow_of_two(fq->buf_len ? : U32_MAX),
+		  pp->max_len);
+
+	fq->buf_len = clamp(mtu, LIBETH_RX_BUF_STRIDE, max);
+	fq->truesize = fq->buf_len;
+
+	return true;
+}
+
+/**
+ * libeth_rx_fq_create - create a PP with the default libeth settings
+ * @fq: buffer queue struct to fill
+ * @napi: &napi_struct covering this PP (no usage outside its poll loops)
+ *
+ * Return: %0 on success, -%errno on failure.
+ */
+int libeth_rx_fq_create(struct libeth_fq *fq, struct napi_struct *napi)
+{
+	struct page_pool_params pp = {
+		.flags		= PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV,
+		.order		= LIBETH_RX_PAGE_ORDER,
+		.pool_size	= fq->count,
+		.nid		= fq->nid,
+		.dev		= napi->dev->dev.parent,
+		.netdev		= napi->dev,
+		.napi		= napi,
+	};
+	struct libeth_fqe *fqes;
+	struct page_pool *pool;
+	int ret;
+
+	pp.dma_dir = fq->xdp ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE;
+
+	if (!fq->hsplit)
+		ret = libeth_rx_page_pool_params(fq, &pp);
+	else
+		ret = libeth_rx_page_pool_params_zc(fq, &pp);
+	if (!ret)
+		return -EINVAL;
+
+	pool = page_pool_create(&pp);
+	if (IS_ERR(pool))
+		return PTR_ERR(pool);
+
+	fqes = kvcalloc_node(fq->count, sizeof(*fqes), GFP_KERNEL, fq->nid);
+	if (!fqes) {
+		ret = -ENOMEM;
+		goto err_buf;
+	}
+
+	ret = xdp_reg_page_pool(pool);
+	if (ret)
+		goto err_mem;
+
+	fq->fqes = fqes;
+	fq->pp = pool;
+
+	return 0;
+
+err_mem:
+	kvfree(fqes);
+err_buf:
+	page_pool_destroy(pool);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(libeth_rx_fq_create);
+
+/**
+ * libeth_rx_fq_destroy - destroy a &page_pool created by libeth
+ * @fq: buffer queue to process
+ */
+void libeth_rx_fq_destroy(struct libeth_fq *fq)
+{
+	xdp_unreg_page_pool(fq->pp);
+	kvfree(fq->fqes);
+	page_pool_destroy(fq->pp);
+}
+EXPORT_SYMBOL_GPL(libeth_rx_fq_destroy);
+
+/**
+ * libeth_rx_recycle_slow - recycle libeth netmem
+ * @netmem: network memory to recycle
+ *
+ * To be used on exceptions or rare cases not requiring fast inline recycling.
+ */
+void __cold libeth_rx_recycle_slow(netmem_ref netmem)
+{
+	page_pool_put_full_netmem(netmem_get_pp(netmem), netmem, false);
+}
+EXPORT_SYMBOL_GPL(libeth_rx_recycle_slow);
+
+/* Converting abstract packet type numbers into a software structure with
+ * the packet parameters to do O(1) lookup on Rx.
+ */
+
+static const u16 libeth_rx_pt_xdp_oip[] = {
+	[LIBETH_RX_PT_OUTER_L2]		= XDP_RSS_TYPE_NONE,
+	[LIBETH_RX_PT_OUTER_IPV4]	= XDP_RSS_L3_IPV4,
+	[LIBETH_RX_PT_OUTER_IPV6]	= XDP_RSS_L3_IPV6,
+};
+
+static const u16 libeth_rx_pt_xdp_iprot[] = {
+	[LIBETH_RX_PT_INNER_NONE]	= XDP_RSS_TYPE_NONE,
+	[LIBETH_RX_PT_INNER_UDP]	= XDP_RSS_L4_UDP,
+	[LIBETH_RX_PT_INNER_TCP]	= XDP_RSS_L4_TCP,
+	[LIBETH_RX_PT_INNER_SCTP]	= XDP_RSS_L4_SCTP,
+	[LIBETH_RX_PT_INNER_ICMP]	= XDP_RSS_L4_ICMP,
+	[LIBETH_RX_PT_INNER_TIMESYNC]	= XDP_RSS_TYPE_NONE,
+};
+
+static const u16 libeth_rx_pt_xdp_pl[] = {
+	[LIBETH_RX_PT_PAYLOAD_NONE]	= XDP_RSS_TYPE_NONE,
+	[LIBETH_RX_PT_PAYLOAD_L2]	= XDP_RSS_TYPE_NONE,
+	[LIBETH_RX_PT_PAYLOAD_L3]	= XDP_RSS_TYPE_NONE,
+	[LIBETH_RX_PT_PAYLOAD_L4]	= XDP_RSS_L4,
+};
+
+/**
+ * libeth_rx_pt_gen_hash_type - generate an XDP RSS hash type for a PT
+ * @pt: PT structure to evaluate
+ *
+ * Generates ```hash_type``` field with XDP RSS type values from the parsed
+ * packet parameters if they're obtained dynamically at runtime.
+ */
+void libeth_rx_pt_gen_hash_type(struct libeth_rx_pt *pt)
+{
+	pt->hash_type = 0;
+	pt->hash_type |= libeth_rx_pt_xdp_oip[pt->outer_ip];
+	pt->hash_type |= libeth_rx_pt_xdp_iprot[pt->inner_prot];
+	pt->hash_type |= libeth_rx_pt_xdp_pl[pt->payload_layer];
+}
+EXPORT_SYMBOL_GPL(libeth_rx_pt_gen_hash_type);
+
+/* Module */
+
+MODULE_DESCRIPTION("Common Ethernet library");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/net/ethernet/intel/libeth/tx.c

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2025 Intel Corporation */
+
+#define DEFAULT_SYMBOL_NAMESPACE	"LIBETH"
+
+#include <net/libeth/xdp.h>
+
+#include "priv.h"
+
+/* Tx buffer completion */
+
+DEFINE_STATIC_CALL_NULL(bulk, libeth_xdp_return_buff_bulk);
+DEFINE_STATIC_CALL_NULL(xsk, libeth_xsk_buff_free_slow);
+
+/**
+ * libeth_tx_complete_any - perform Tx completion for one SQE of any type
+ * @sqe: Tx buffer to complete
+ * @cp: polling params
+ *
+ * Can be used to complete both regular and XDP SQEs, for example when
+ * destroying queues.
+ * When libeth_xdp is not loaded, XDPSQEs won't be handled.
+ */
+void libeth_tx_complete_any(struct libeth_sqe *sqe, struct libeth_cq_pp *cp)
+{
+	if (sqe->type >= __LIBETH_SQE_XDP_START)
+		__libeth_xdp_complete_tx(sqe, cp, static_call(bulk),
+					 static_call(xsk));
+	else
+		libeth_tx_complete(sqe, cp);
+}
+EXPORT_SYMBOL_GPL(libeth_tx_complete_any);
+
+/* Module */
+
+void libeth_attach_xdp(const struct libeth_xdp_ops *ops)
+{
+	static_call_update(bulk, ops ? ops->bulk : NULL);
+	static_call_update(xsk, ops ? ops->xsk : NULL);
+}
+EXPORT_SYMBOL_GPL(libeth_attach_xdp);

linux-7.2.3/drivers/net/ethernet/intel/libeth/xdp.c

@@ -0,0 +1,451 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2025 Intel Corporation */
+
+#define DEFAULT_SYMBOL_NAMESPACE	"LIBETH_XDP"
+
+#include <linux/export.h>
+
+#include <net/libeth/xdp.h>
+
+#include "priv.h"
+
+/* XDPSQ sharing */
+
+DEFINE_STATIC_KEY_FALSE(libeth_xdpsq_share);
+EXPORT_SYMBOL_GPL(libeth_xdpsq_share);
+
+void __libeth_xdpsq_get(struct libeth_xdpsq_lock *lock,
+			const struct net_device *dev)
+{
+	bool warn;
+
+	spin_lock_init(&lock->lock);
+	lock->share = true;
+
+	warn = !static_key_enabled(&libeth_xdpsq_share);
+	static_branch_inc(&libeth_xdpsq_share);
+
+	if (warn && net_ratelimit())
+		netdev_warn(dev, "XDPSQ sharing enabled, possible XDP Tx slowdown\n");
+}
+EXPORT_SYMBOL_GPL(__libeth_xdpsq_get);
+
+void __libeth_xdpsq_put(struct libeth_xdpsq_lock *lock,
+			const struct net_device *dev)
+{
+	static_branch_dec(&libeth_xdpsq_share);
+
+	if (!static_key_enabled(&libeth_xdpsq_share) && net_ratelimit())
+		netdev_notice(dev, "XDPSQ sharing disabled\n");
+
+	lock->share = false;
+}
+EXPORT_SYMBOL_GPL(__libeth_xdpsq_put);
+
+void __acquires(&lock->lock)
+__libeth_xdpsq_lock(struct libeth_xdpsq_lock *lock)
+{
+	spin_lock(&lock->lock);
+}
+EXPORT_SYMBOL_GPL(__libeth_xdpsq_lock);
+
+void __releases(&lock->lock)
+__libeth_xdpsq_unlock(struct libeth_xdpsq_lock *lock)
+{
+	spin_unlock(&lock->lock);
+}
+EXPORT_SYMBOL_GPL(__libeth_xdpsq_unlock);
+
+/* XDPSQ clean-up timers */
+
+/**
+ * libeth_xdpsq_init_timer - initialize an XDPSQ clean-up timer
+ * @timer: timer to initialize
+ * @xdpsq: queue this timer belongs to
+ * @lock: corresponding XDPSQ lock
+ * @poll: queue polling/completion function
+ *
+ * XDPSQ clean-up timers must be set up before using at the queue configuration
+ * time. Set the required pointers and the cleaning callback.
+ */
+void libeth_xdpsq_init_timer(struct libeth_xdpsq_timer *timer, void *xdpsq,
+			     struct libeth_xdpsq_lock *lock,
+			     void (*poll)(struct work_struct *work))
+{
+	timer->xdpsq = xdpsq;
+	timer->lock = lock;
+
+	INIT_DELAYED_WORK(&timer->dwork, poll);
+}
+EXPORT_SYMBOL_GPL(libeth_xdpsq_init_timer);
+
+/* ``XDP_TX`` bulking */
+
+static void __cold
+libeth_xdp_tx_return_one(const struct libeth_xdp_tx_frame *frm)
+{
+	if (frm->len_fl & LIBETH_XDP_TX_MULTI)
+		libeth_xdp_return_frags(frm->data + frm->soff, true);
+
+	libeth_xdp_return_va(frm->data, true);
+}
+
+static void __cold
+libeth_xdp_tx_return_bulk(const struct libeth_xdp_tx_frame *bq, u32 count)
+{
+	for (u32 i = 0; i < count; i++) {
+		const struct libeth_xdp_tx_frame *frm = &bq[i];
+
+		if (!(frm->len_fl & LIBETH_XDP_TX_FIRST))
+			continue;
+
+		libeth_xdp_tx_return_one(frm);
+	}
+}
+
+static void __cold libeth_trace_xdp_exception(const struct net_device *dev,
+					      const struct bpf_prog *prog,
+					      u32 act)
+{
+	trace_xdp_exception(dev, prog, act);
+}
+
+/**
+ * libeth_xdp_tx_exception - handle Tx exceptions of XDP frames
+ * @bq: XDP Tx frame bulk
+ * @sent: number of frames sent successfully (from this bulk)
+ * @flags: internal libeth_xdp flags (XSk, .ndo_xdp_xmit etc.)
+ *
+ * Cold helper used by __libeth_xdp_tx_flush_bulk(), do not call directly.
+ * Reports XDP Tx exceptions, frees the frames that won't be sent or adjust
+ * the Tx bulk to try again later.
+ */
+void __cold libeth_xdp_tx_exception(struct libeth_xdp_tx_bulk *bq, u32 sent,
+				    u32 flags)
+{
+	const struct libeth_xdp_tx_frame *pos = &bq->bulk[sent];
+	u32 left = bq->count - sent;
+
+	if (!(flags & LIBETH_XDP_TX_NDO))
+		libeth_trace_xdp_exception(bq->dev, bq->prog, XDP_TX);
+
+	if (!(flags & LIBETH_XDP_TX_DROP)) {
+		memmove(bq->bulk, pos, left * sizeof(*bq->bulk));
+		bq->count = left;
+
+		return;
+	}
+
+	if (flags & LIBETH_XDP_TX_XSK)
+		libeth_xsk_tx_return_bulk(pos, left);
+	else if (!(flags & LIBETH_XDP_TX_NDO))
+		libeth_xdp_tx_return_bulk(pos, left);
+	else
+		libeth_xdp_xmit_return_bulk(pos, left, bq->dev);
+
+	bq->count = 0;
+}
+EXPORT_SYMBOL_GPL(libeth_xdp_tx_exception);
+
+/* .ndo_xdp_xmit() implementation */
+
+u32 __cold libeth_xdp_xmit_return_bulk(const struct libeth_xdp_tx_frame *bq,
+				       u32 count, const struct net_device *dev)
+{
+	u32 n = 0;
+
+	for (u32 i = 0; i < count; i++) {
+		const struct libeth_xdp_tx_frame *frm = &bq[i];
+		dma_addr_t dma;
+
+		if (frm->flags & LIBETH_XDP_TX_FIRST)
+			dma = *libeth_xdp_xmit_frame_dma(frm->xdpf);
+		else
+			dma = dma_unmap_addr(frm, dma);
+
+		dma_unmap_page(dev->dev.parent, dma, dma_unmap_len(frm, len),
+			       DMA_TO_DEVICE);
+
+		/* Actual xdp_frames are freed by the core */
+		n += !!(frm->flags & LIBETH_XDP_TX_FIRST);
+	}
+
+	return n;
+}
+EXPORT_SYMBOL_GPL(libeth_xdp_xmit_return_bulk);
+
+/* Rx polling path */
+
+/**
+ * libeth_xdp_load_stash - recreate an &xdp_buff from libeth_xdp buffer stash
+ * @dst: target &libeth_xdp_buff to initialize
+ * @src: source stash
+ *
+ * External helper used by libeth_xdp_init_buff(), do not call directly.
+ * Recreate an onstack &libeth_xdp_buff using the stash saved earlier.
+ * The only field untouched (rxq) is initialized later in the
+ * abovementioned function.
+ */
+void libeth_xdp_load_stash(struct libeth_xdp_buff *dst,
+			   const struct libeth_xdp_buff_stash *src)
+{
+	dst->data = src->data;
+	dst->base.data_end = src->data + src->len;
+	dst->base.data_meta = src->data;
+	dst->base.data_hard_start = src->data - src->headroom;
+
+	dst->base.frame_sz = src->frame_sz;
+	dst->base.flags = src->flags;
+}
+EXPORT_SYMBOL_GPL(libeth_xdp_load_stash);
+
+/**
+ * libeth_xdp_save_stash - convert &xdp_buff to a libeth_xdp buffer stash
+ * @dst: target &libeth_xdp_buff_stash to initialize
+ * @src: source XDP buffer
+ *
+ * External helper used by libeth_xdp_save_buff(), do not call directly.
+ * Use the fields from the passed XDP buffer to initialize the stash on the
+ * queue, so that a partially received frame can be finished later during
+ * the next NAPI poll.
+ */
+void libeth_xdp_save_stash(struct libeth_xdp_buff_stash *dst,
+			   const struct libeth_xdp_buff *src)
+{
+	dst->data = src->data;
+	dst->headroom = src->data - src->base.data_hard_start;
+	dst->len = src->base.data_end - src->data;
+
+	dst->frame_sz = src->base.frame_sz;
+	dst->flags = src->base.flags;
+
+	WARN_ON_ONCE(dst->flags != src->base.flags);
+}
+EXPORT_SYMBOL_GPL(libeth_xdp_save_stash);
+
+void __libeth_xdp_return_stash(struct libeth_xdp_buff_stash *stash)
+{
+	LIBETH_XDP_ONSTACK_BUFF(xdp);
+
+	libeth_xdp_load_stash(xdp, stash);
+	libeth_xdp_return_buff_slow(xdp);
+
+	stash->data = NULL;
+}
+EXPORT_SYMBOL_GPL(__libeth_xdp_return_stash);
+
+/**
+ * libeth_xdp_return_buff_slow - free &libeth_xdp_buff
+ * @xdp: buffer to free/return
+ *
+ * Slowpath version of libeth_xdp_return_buff() to be called on exceptions,
+ * queue clean-ups etc., without unwanted inlining.
+ */
+void __cold libeth_xdp_return_buff_slow(struct libeth_xdp_buff *xdp)
+{
+	__libeth_xdp_return_buff(xdp, false);
+}
+EXPORT_SYMBOL_GPL(libeth_xdp_return_buff_slow);
+
+/**
+ * libeth_xdp_buff_add_frag - add frag to XDP buffer
+ * @xdp: head XDP buffer
+ * @fqe: Rx buffer containing the frag
+ * @len: frag length reported by HW
+ *
+ * External helper used by libeth_xdp_process_buff(), do not call directly.
+ * Frees both head and frag buffers on error.
+ *
+ * Return: true success, false on error (no space for a new frag).
+ */
+bool libeth_xdp_buff_add_frag(struct libeth_xdp_buff *xdp,
+			      const struct libeth_fqe *fqe,
+			      u32 len)
+{
+	netmem_ref netmem = fqe->netmem;
+
+	if (!xdp_buff_add_frag(&xdp->base, netmem,
+			       fqe->offset + netmem_get_pp(netmem)->p.offset,
+			       len, fqe->truesize))
+		goto recycle;
+
+	return true;
+
+recycle:
+	libeth_rx_recycle_slow(netmem);
+	libeth_xdp_return_buff_slow(xdp);
+
+	return false;
+}
+EXPORT_SYMBOL_GPL(libeth_xdp_buff_add_frag);
+
+/**
+ * libeth_xdp_prog_exception - handle XDP prog exceptions
+ * @bq: XDP Tx bulk
+ * @xdp: buffer to process
+ * @act: original XDP prog verdict
+ * @ret: error code if redirect failed
+ *
+ * External helper used by __libeth_xdp_run_prog() and
+ * __libeth_xsk_run_prog_slow(), do not call directly.
+ * Reports invalid @act, XDP exception trace event and frees the buffer.
+ *
+ * Return: libeth_xdp XDP prog verdict.
+ */
+u32 __cold libeth_xdp_prog_exception(const struct libeth_xdp_tx_bulk *bq,
+				     struct libeth_xdp_buff *xdp,
+				     enum xdp_action act, int ret)
+{
+	if (act > XDP_REDIRECT)
+		bpf_warn_invalid_xdp_action(bq->dev, bq->prog, act);
+
+	libeth_trace_xdp_exception(bq->dev, bq->prog, act);
+
+	if (xdp->base.rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL)
+		return libeth_xsk_prog_exception(xdp, act, ret);
+
+	libeth_xdp_return_buff_slow(xdp);
+
+	return LIBETH_XDP_DROP;
+}
+EXPORT_SYMBOL_GPL(libeth_xdp_prog_exception);
+
+/* Tx buffer completion */
+
+static void libeth_xdp_put_netmem_bulk(netmem_ref netmem,
+				       struct xdp_frame_bulk *bq)
+{
+	if (unlikely(bq->count == XDP_BULK_QUEUE_SIZE))
+		xdp_flush_frame_bulk(bq);
+
+	bq->q[bq->count++] = netmem;
+}
+
+/**
+ * libeth_xdp_return_buff_bulk - free &xdp_buff as part of a bulk
+ * @sinfo: shared info corresponding to the buffer
+ * @bq: XDP frame bulk to store the buffer
+ * @frags: whether the buffer has frags
+ *
+ * Same as xdp_return_frame_bulk(), but for &libeth_xdp_buff, speeds up Tx
+ * completion of ``XDP_TX`` buffers and allows to free them in same bulks
+ * with &xdp_frame buffers.
+ */
+void libeth_xdp_return_buff_bulk(const struct skb_shared_info *sinfo,
+				 struct xdp_frame_bulk *bq, bool frags)
+{
+	if (!frags)
+		goto head;
+
+	for (u32 i = 0; i < sinfo->nr_frags; i++)
+		libeth_xdp_put_netmem_bulk(skb_frag_netmem(&sinfo->frags[i]),
+					   bq);
+
+head:
+	libeth_xdp_put_netmem_bulk(virt_to_netmem(sinfo), bq);
+}
+EXPORT_SYMBOL_GPL(libeth_xdp_return_buff_bulk);
+
+/* Misc */
+
+/**
+ * libeth_xdp_queue_threshold - calculate XDP queue clean/refill threshold
+ * @count: number of descriptors in the queue
+ *
+ * The threshold is the limit at which RQs start to refill (when the number of
+ * empty buffers exceeds it) and SQs get cleaned up (when the number of free
+ * descriptors goes below it). To speed up hotpath processing, threshold is
+ * always pow-2, closest to 1/4 of the queue length.
+ * Don't call it on hotpath, calculate and cache the threshold during the
+ * queue initialization.
+ *
+ * Return: the calculated threshold.
+ */
+u32 libeth_xdp_queue_threshold(u32 count)
+{
+	u32 quarter, low, high;
+
+	if (likely(is_power_of_2(count)))
+		return count >> 2;
+
+	quarter = DIV_ROUND_CLOSEST(count, 4);
+	low = rounddown_pow_of_two(quarter);
+	high = roundup_pow_of_two(quarter);
+
+	return high - quarter <= quarter - low ? high : low;
+}
+EXPORT_SYMBOL_GPL(libeth_xdp_queue_threshold);
+
+/**
+ * __libeth_xdp_set_features - set XDP features for netdev
+ * @dev: &net_device to configure
+ * @xmo: XDP metadata ops (Rx hints)
+ * @zc_segs: maximum number of S/G frags the HW can transmit
+ * @tmo: XSk Tx metadata ops (Tx hints)
+ *
+ * Set all the features libeth_xdp supports. Only the first argument is
+ * necessary; without the third one (zero), XSk support won't be advertised.
+ * Use the non-underscored versions in drivers instead.
+ */
+void __libeth_xdp_set_features(struct net_device *dev,
+			       const struct xdp_metadata_ops *xmo,
+			       u32 zc_segs,
+			       const struct xsk_tx_metadata_ops *tmo)
+{
+	xdp_set_features_flag(dev,
+			      NETDEV_XDP_ACT_BASIC |
+			      NETDEV_XDP_ACT_REDIRECT |
+			      NETDEV_XDP_ACT_NDO_XMIT |
+			      (zc_segs ? NETDEV_XDP_ACT_XSK_ZEROCOPY : 0) |
+			      NETDEV_XDP_ACT_RX_SG |
+			      NETDEV_XDP_ACT_NDO_XMIT_SG);
+	dev->xdp_metadata_ops = xmo;
+
+	tmo = tmo == libeth_xsktmo ? &libeth_xsktmo_slow : tmo;
+
+	dev->xdp_zc_max_segs = zc_segs ? : 1;
+	dev->xsk_tx_metadata_ops = zc_segs ? tmo : NULL;
+}
+EXPORT_SYMBOL_GPL(__libeth_xdp_set_features);
+
+/**
+ * libeth_xdp_set_redirect - toggle the XDP redirect feature
+ * @dev: &net_device to configure
+ * @enable: whether XDP is enabled
+ *
+ * Use this when XDPSQs are not always available to dynamically enable
+ * and disable redirect feature.
+ */
+void libeth_xdp_set_redirect(struct net_device *dev, bool enable)
+{
+	if (enable)
+		xdp_features_set_redirect_target(dev, true);
+	else
+		xdp_features_clear_redirect_target(dev);
+}
+EXPORT_SYMBOL_GPL(libeth_xdp_set_redirect);
+
+/* Module */
+
+static const struct libeth_xdp_ops xdp_ops __initconst = {
+	.bulk	= libeth_xdp_return_buff_bulk,
+	.xsk	= libeth_xsk_buff_free_slow,
+};
+
+static int __init libeth_xdp_module_init(void)
+{
+	libeth_attach_xdp(&xdp_ops);
+
+	return 0;
+}
+module_init(libeth_xdp_module_init);
+
+static void __exit libeth_xdp_module_exit(void)
+{
+	libeth_detach_xdp();
+}
+module_exit(libeth_xdp_module_exit);
+
+MODULE_DESCRIPTION("Common Ethernet library - XDP infra");
+MODULE_IMPORT_NS("LIBETH");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/net/ethernet/intel/libeth/xsk.c

@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2025 Intel Corporation */
+
+#define DEFAULT_SYMBOL_NAMESPACE	"LIBETH_XDP"
+
+#include <linux/export.h>
+
+#include <net/libeth/xsk.h>
+
+#include "priv.h"
+
+/* ``XDP_TX`` bulking */
+
+void __cold libeth_xsk_tx_return_bulk(const struct libeth_xdp_tx_frame *bq,
+				      u32 count)
+{
+	for (u32 i = 0; i < count; i++)
+		libeth_xsk_buff_free_slow(bq[i].xsk);
+}
+
+/* XSk TMO */
+
+const struct xsk_tx_metadata_ops libeth_xsktmo_slow = {
+	.tmo_request_checksum		= libeth_xsktmo_req_csum,
+};
+
+/* Rx polling path */
+
+/**
+ * libeth_xsk_buff_free_slow - free an XSk Rx buffer
+ * @xdp: buffer to free
+ *
+ * Slowpath version of xsk_buff_free() to be used on exceptions, cleanups etc.
+ * to avoid unwanted inlining.
+ */
+void libeth_xsk_buff_free_slow(struct libeth_xdp_buff *xdp)
+{
+	xsk_buff_free(&xdp->base);
+}
+EXPORT_SYMBOL_GPL(libeth_xsk_buff_free_slow);
+
+/**
+ * libeth_xsk_buff_add_frag - add frag to XSk Rx buffer
+ * @head: head buffer
+ * @xdp: frag buffer
+ *
+ * External helper used by libeth_xsk_process_buff(), do not call directly.
+ * Frees both main and frag buffers on error.
+ *
+ * Return: main buffer with attached frag on success, %NULL on error (no space
+ * for a new frag).
+ */
+struct libeth_xdp_buff *libeth_xsk_buff_add_frag(struct libeth_xdp_buff *head,
+						 struct libeth_xdp_buff *xdp)
+{
+	if (!xsk_buff_add_frag(&head->base, &xdp->base))
+		goto free;
+
+	return head;
+
+free:
+	libeth_xsk_buff_free_slow(xdp);
+	libeth_xsk_buff_free_slow(head);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(libeth_xsk_buff_add_frag);
+
+/**
+ * libeth_xsk_buff_stats_frags - update onstack RQ stats with XSk frags info
+ * @rs: onstack stats to update
+ * @xdp: buffer to account
+ *
+ * External helper used by __libeth_xsk_run_pass(), do not call directly.
+ * Adds buffer's frags count and total len to the onstack stats.
+ */
+void libeth_xsk_buff_stats_frags(struct libeth_rq_napi_stats *rs,
+				 const struct libeth_xdp_buff *xdp)
+{
+	libeth_xdp_buff_stats_frags(rs, xdp);
+}
+EXPORT_SYMBOL_GPL(libeth_xsk_buff_stats_frags);
+
+/**
+ * __libeth_xsk_run_prog_slow - process the non-``XDP_REDIRECT`` verdicts
+ * @xdp: buffer to process
+ * @bq: Tx bulk for queueing on ``XDP_TX``
+ * @act: verdict to process
+ * @ret: error code if ``XDP_REDIRECT`` failed
+ *
+ * External helper used by __libeth_xsk_run_prog(), do not call directly.
+ * ``XDP_REDIRECT`` is the most common and hottest verdict on XSk, thus
+ * it is processed inline. The rest goes here for out-of-line processing,
+ * together with redirect errors.
+ *
+ * Return: libeth_xdp XDP prog verdict.
+ */
+u32 __libeth_xsk_run_prog_slow(struct libeth_xdp_buff *xdp,
+			       const struct libeth_xdp_tx_bulk *bq,
+			       enum xdp_action act, int ret)
+{
+	switch (act) {
+	case XDP_DROP:
+		xsk_buff_free(&xdp->base);
+
+		return LIBETH_XDP_DROP;
+	case XDP_TX:
+		return LIBETH_XDP_TX;
+	case XDP_PASS:
+		return LIBETH_XDP_PASS;
+	default:
+		break;
+	}
+
+	return libeth_xdp_prog_exception(bq, xdp, act, ret);
+}
+EXPORT_SYMBOL_GPL(__libeth_xsk_run_prog_slow);
+
+/**
+ * libeth_xsk_prog_exception - handle XDP prog exceptions on XSk
+ * @xdp: buffer to process
+ * @act: verdict returned by the prog
+ * @ret: error code if ``XDP_REDIRECT`` failed
+ *
+ * Internal. Frees the buffer and, if the queue uses XSk wakeups, stop the
+ * current NAPI poll when there are no free buffers left.
+ *
+ * Return: libeth_xdp's XDP prog verdict.
+ */
+u32 __cold libeth_xsk_prog_exception(struct libeth_xdp_buff *xdp,
+				     enum xdp_action act, int ret)
+{
+	const struct xdp_buff_xsk *xsk;
+	u32 __ret = LIBETH_XDP_DROP;
+
+	if (act != XDP_REDIRECT)
+		goto drop;
+
+	xsk = container_of(&xdp->base, typeof(*xsk), xdp);
+	if (xsk_uses_need_wakeup(xsk->pool) && ret == -ENOBUFS)
+		__ret = LIBETH_XDP_ABORTED;
+
+drop:
+	libeth_xsk_buff_free_slow(xdp);
+
+	return __ret;
+}
+
+/* Refill */
+
+/**
+ * libeth_xskfq_create - create an XSkFQ
+ * @fq: fill queue to initialize
+ *
+ * Allocates the FQEs and initializes the fields used by libeth_xdp: number
+ * of buffers to refill, refill threshold and buffer len.
+ *
+ * Return: %0 on success, -errno otherwise.
+ */
+int libeth_xskfq_create(struct libeth_xskfq *fq)
+{
+	fq->fqes = kvcalloc_node(fq->count, sizeof(*fq->fqes), GFP_KERNEL,
+				 fq->nid);
+	if (!fq->fqes)
+		return -ENOMEM;
+
+	fq->pending = fq->count;
+	fq->thresh = libeth_xdp_queue_threshold(fq->count);
+	fq->buf_len = xsk_pool_get_rx_frame_size(fq->pool);
+	fq->truesize = xsk_pool_get_rx_frag_step(fq->pool);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(libeth_xskfq_create);
+
+/**
+ * libeth_xskfq_destroy - destroy an XSkFQ
+ * @fq: fill queue to destroy
+ *
+ * Zeroes the used fields and frees the FQEs array.
+ */
+void libeth_xskfq_destroy(struct libeth_xskfq *fq)
+{
+	fq->buf_len = 0;
+	fq->thresh = 0;
+	fq->pending = 0;
+
+	kvfree(fq->fqes);
+}
+EXPORT_SYMBOL_GPL(libeth_xskfq_destroy);
+
+/* .ndo_xsk_wakeup */
+
+static void libeth_xsk_napi_sched(void *info)
+{
+	__napi_schedule_irqoff(info);
+}
+
+/**
+ * libeth_xsk_init_wakeup - initialize libeth XSk wakeup structure
+ * @csd: struct to initialize
+ * @napi: NAPI corresponding to this queue
+ *
+ * libeth_xdp uses inter-processor interrupts to perform XSk wakeups. In order
+ * to do that, the corresponding CSDs must be initialized when creating the
+ * queues.
+ */
+void libeth_xsk_init_wakeup(call_single_data_t *csd, struct napi_struct *napi)
+{
+	INIT_CSD(csd, libeth_xsk_napi_sched, napi);
+}
+EXPORT_SYMBOL_GPL(libeth_xsk_init_wakeup);
+
+/**
+ * libeth_xsk_wakeup - perform an XSk wakeup
+ * @csd: CSD corresponding to the queue
+ * @qid: the stack queue index
+ *
+ * Try to mark the NAPI as missed first, so that it could be rescheduled.
+ * If it's not, schedule it on the corresponding CPU using IPIs (or directly
+ * if already running on it).
+ */
+void libeth_xsk_wakeup(call_single_data_t *csd, u32 qid)
+{
+	struct napi_struct *napi = csd->info;
+
+	if (napi_if_scheduled_mark_missed(napi) ||
+	    unlikely(!napi_schedule_prep(napi)))
+		return;
+
+	if (unlikely(qid >= nr_cpu_ids))
+		qid %= nr_cpu_ids;
+
+	if (qid != raw_smp_processor_id() && cpu_online(qid))
+		smp_call_function_single_async(qid, csd);
+	else
+		__napi_schedule(napi);
+}
+EXPORT_SYMBOL_GPL(libeth_xsk_wakeup);
+
+/* Pool setup */
+
+#define LIBETH_XSK_DMA_ATTR					\
+	(DMA_ATTR_WEAK_ORDERING | DMA_ATTR_SKIP_CPU_SYNC)
+
+/**
+ * libeth_xsk_setup_pool - setup or destroy an XSk pool for a queue
+ * @dev: target &net_device
+ * @qid: stack queue index to configure
+ * @enable: whether to enable or disable the pool
+ *
+ * Check that @qid is valid and then map or unmap the pool.
+ *
+ * Return: %0 on success, -errno otherwise.
+ */
+int libeth_xsk_setup_pool(struct net_device *dev, u32 qid, bool enable)
+{
+	struct xsk_buff_pool *pool;
+
+	pool = xsk_get_pool_from_qid(dev, qid);
+	if (!pool)
+		return -EINVAL;
+
+	if (enable)
+		return xsk_pool_dma_map(pool, dev->dev.parent,
+					LIBETH_XSK_DMA_ATTR);
+	else
+		xsk_pool_dma_unmap(pool, LIBETH_XSK_DMA_ATTR);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(libeth_xsk_setup_pool);