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Diffstat (limited to 'include/net/libeth/xsk.h')
| -rw-r--r-- | include/net/libeth/xsk.h | 685 |
1 files changed, 685 insertions, 0 deletions
diff --git a/include/net/libeth/xsk.h b/include/net/libeth/xsk.h new file mode 100644 index 000000000000..481a7b28e6f2 --- /dev/null +++ b/include/net/libeth/xsk.h @@ -0,0 +1,685 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright (C) 2025 Intel Corporation */ + +#ifndef __LIBETH_XSK_H +#define __LIBETH_XSK_H + +#include <net/libeth/xdp.h> +#include <net/xdp_sock_drv.h> + +/* ``XDP_TXMD_FLAGS_VALID`` is defined only under ``CONFIG_XDP_SOCKETS`` */ +#ifdef XDP_TXMD_FLAGS_VALID +static_assert(XDP_TXMD_FLAGS_VALID <= LIBETH_XDP_TX_XSKMD); +#endif + +/* ``XDP_TX`` bulking */ + +/** + * libeth_xsk_tx_queue_head - internal helper for queueing XSk ``XDP_TX`` head + * @bq: XDP Tx bulk to queue the head frag to + * @xdp: XSk buffer with the head to queue + * + * Return: false if it's the only frag of the frame, true if it's an S/G frame. + */ +static inline bool libeth_xsk_tx_queue_head(struct libeth_xdp_tx_bulk *bq, + struct libeth_xdp_buff *xdp) +{ + bq->bulk[bq->count++] = (typeof(*bq->bulk)){ + .xsk = xdp, + __libeth_xdp_tx_len(xdp->base.data_end - xdp->data, + LIBETH_XDP_TX_FIRST), + }; + + if (likely(!xdp_buff_has_frags(&xdp->base))) + return false; + + bq->bulk[bq->count - 1].flags |= LIBETH_XDP_TX_MULTI; + + return true; +} + +/** + * libeth_xsk_tx_queue_frag - internal helper for queueing XSk ``XDP_TX`` frag + * @bq: XDP Tx bulk to queue the frag to + * @frag: XSk frag to queue + */ +static inline void libeth_xsk_tx_queue_frag(struct libeth_xdp_tx_bulk *bq, + struct libeth_xdp_buff *frag) +{ + bq->bulk[bq->count++] = (typeof(*bq->bulk)){ + .xsk = frag, + __libeth_xdp_tx_len(frag->base.data_end - frag->data), + }; +} + +/** + * libeth_xsk_tx_queue_bulk - internal helper for queueing XSk ``XDP_TX`` frame + * @bq: XDP Tx bulk to queue the frame to + * @xdp: XSk buffer to queue + * @flush_bulk: driver callback to flush the bulk to the HW queue + * + * Return: true on success, false on flush error. + */ +static __always_inline bool +libeth_xsk_tx_queue_bulk(struct libeth_xdp_tx_bulk *bq, + struct libeth_xdp_buff *xdp, + bool (*flush_bulk)(struct libeth_xdp_tx_bulk *bq, + u32 flags)) +{ + bool ret = true; + + if (unlikely(bq->count == LIBETH_XDP_TX_BULK) && + unlikely(!flush_bulk(bq, LIBETH_XDP_TX_XSK))) { + libeth_xsk_buff_free_slow(xdp); + return false; + } + + if (!libeth_xsk_tx_queue_head(bq, xdp)) + goto out; + + for (const struct libeth_xdp_buff *head = xdp; ; ) { + xdp = container_of(xsk_buff_get_frag(&head->base), + typeof(*xdp), base); + if (!xdp) + break; + + if (unlikely(bq->count == LIBETH_XDP_TX_BULK) && + unlikely(!flush_bulk(bq, LIBETH_XDP_TX_XSK))) { + ret = false; + break; + } + + libeth_xsk_tx_queue_frag(bq, xdp); + } + +out: + bq->bulk[bq->count - 1].flags |= LIBETH_XDP_TX_LAST; + + return ret; +} + +/** + * libeth_xsk_tx_fill_buf - internal helper to fill XSk ``XDP_TX`` &libeth_sqe + * @frm: XDP Tx frame from the bulk + * @i: index on the HW queue + * @sq: XDPSQ abstraction for the queue + * @priv: private data + * + * Return: XDP Tx descriptor with the synced DMA and other info to pass to + * the driver callback. + */ +static inline struct libeth_xdp_tx_desc +libeth_xsk_tx_fill_buf(struct libeth_xdp_tx_frame frm, u32 i, + const struct libeth_xdpsq *sq, u64 priv) +{ + struct libeth_xdp_buff *xdp = frm.xsk; + struct libeth_xdp_tx_desc desc = { + .addr = xsk_buff_xdp_get_dma(&xdp->base), + .opts = frm.opts, + }; + struct libeth_sqe *sqe; + + xsk_buff_raw_dma_sync_for_device(sq->pool, desc.addr, desc.len); + + sqe = &sq->sqes[i]; + sqe->xsk = xdp; + + if (!(desc.flags & LIBETH_XDP_TX_FIRST)) { + sqe->type = LIBETH_SQE_XSK_TX_FRAG; + return desc; + } + + sqe->type = LIBETH_SQE_XSK_TX; + libeth_xdp_tx_fill_stats(sqe, &desc, + xdp_get_shared_info_from_buff(&xdp->base)); + + return desc; +} + +/** + * libeth_xsk_tx_flush_bulk - wrapper to define flush of XSk ``XDP_TX`` bulk + * @bq: bulk to flush + * @flags: Tx flags, see __libeth_xdp_tx_flush_bulk() + * @prep: driver callback to prepare the queue + * @xmit: driver callback to fill a HW descriptor + * + * Use via LIBETH_XSK_DEFINE_FLUSH_TX() to define an XSk ``XDP_TX`` driver + * callback. + */ +#define libeth_xsk_tx_flush_bulk(bq, flags, prep, xmit) \ + __libeth_xdp_tx_flush_bulk(bq, (flags) | LIBETH_XDP_TX_XSK, prep, \ + libeth_xsk_tx_fill_buf, xmit) + +/* XSk TMO */ + +/** + * libeth_xsktmo_req_csum - XSk Tx metadata op to request checksum offload + * @csum_start: unused + * @csum_offset: unused + * @priv: &libeth_xdp_tx_desc from the filling helper + * + * Generic implementation of ::tmo_request_checksum. Works only when HW doesn't + * require filling checksum offsets and other parameters beside the checksum + * request bit. + * Consider using within @libeth_xsktmo unless the driver requires HW-specific + * callbacks. + */ +static inline void libeth_xsktmo_req_csum(u16 csum_start, u16 csum_offset, + void *priv) +{ + ((struct libeth_xdp_tx_desc *)priv)->flags |= LIBETH_XDP_TX_CSUM; +} + +/* Only to inline the callbacks below, use @libeth_xsktmo in drivers instead */ +static const struct xsk_tx_metadata_ops __libeth_xsktmo = { + .tmo_request_checksum = libeth_xsktmo_req_csum, +}; + +/** + * __libeth_xsk_xmit_fill_buf_md - internal helper to prepare XSk xmit w/meta + * @xdesc: &xdp_desc from the XSk buffer pool + * @sq: XDPSQ abstraction for the queue + * @priv: XSk Tx metadata ops + * + * Same as __libeth_xsk_xmit_fill_buf(), but requests metadata pointer and + * fills additional fields in &libeth_xdp_tx_desc to ask for metadata offload. + * + * Return: XDP Tx descriptor with the DMA, metadata request bits, and other + * info to pass to the driver callback. + */ +static __always_inline struct libeth_xdp_tx_desc +__libeth_xsk_xmit_fill_buf_md(const struct xdp_desc *xdesc, + const struct libeth_xdpsq *sq, + u64 priv) +{ + const struct xsk_tx_metadata_ops *tmo = libeth_xdp_priv_to_ptr(priv); + struct libeth_xdp_tx_desc desc; + struct xdp_desc_ctx ctx; + + ctx = xsk_buff_raw_get_ctx(sq->pool, xdesc->addr); + desc = (typeof(desc)){ + .addr = ctx.dma, + __libeth_xdp_tx_len(xdesc->len), + }; + + BUILD_BUG_ON(!__builtin_constant_p(tmo == libeth_xsktmo)); + tmo = tmo == libeth_xsktmo ? &__libeth_xsktmo : tmo; + + xsk_tx_metadata_request(ctx.meta, tmo, &desc); + + return desc; +} + +/* XSk xmit implementation */ + +/** + * __libeth_xsk_xmit_fill_buf - internal helper to prepare XSk xmit w/o meta + * @xdesc: &xdp_desc from the XSk buffer pool + * @sq: XDPSQ abstraction for the queue + * + * Return: XDP Tx descriptor with the DMA and other info to pass to + * the driver callback. + */ +static inline struct libeth_xdp_tx_desc +__libeth_xsk_xmit_fill_buf(const struct xdp_desc *xdesc, + const struct libeth_xdpsq *sq) +{ + return (struct libeth_xdp_tx_desc){ + .addr = xsk_buff_raw_get_dma(sq->pool, xdesc->addr), + __libeth_xdp_tx_len(xdesc->len), + }; +} + +/** + * libeth_xsk_xmit_fill_buf - internal helper to prepare an XSk xmit + * @frm: &xdp_desc from the XSk buffer pool + * @i: index on the HW queue + * @sq: XDPSQ abstraction for the queue + * @priv: XSk Tx metadata ops + * + * Depending on the metadata ops presence (determined at compile time), calls + * the quickest helper to build a libeth XDP Tx descriptor. + * + * Return: XDP Tx descriptor with the synced DMA, metadata request bits, + * and other info to pass to the driver callback. + */ +static __always_inline struct libeth_xdp_tx_desc +libeth_xsk_xmit_fill_buf(struct libeth_xdp_tx_frame frm, u32 i, + const struct libeth_xdpsq *sq, u64 priv) +{ + struct libeth_xdp_tx_desc desc; + + if (priv) + desc = __libeth_xsk_xmit_fill_buf_md(&frm.desc, sq, priv); + else + desc = __libeth_xsk_xmit_fill_buf(&frm.desc, sq); + + desc.flags |= xsk_is_eop_desc(&frm.desc) ? LIBETH_XDP_TX_LAST : 0; + + xsk_buff_raw_dma_sync_for_device(sq->pool, desc.addr, desc.len); + + return desc; +} + +/** + * libeth_xsk_xmit_do_bulk - send XSk xmit frames + * @pool: XSk buffer pool containing the frames to send + * @xdpsq: opaque pointer to driver's XDPSQ struct + * @budget: maximum number of frames can be sent + * @tmo: optional XSk Tx metadata ops + * @prep: driver callback to build a &libeth_xdpsq + * @xmit: driver callback to put frames to a HW queue + * @finalize: driver callback to start a transmission + * + * Implements generic XSk xmit. Always turns on XSk Tx wakeup as it's assumed + * lazy cleaning is used and interrupts are disabled for the queue. + * HW descriptor filling is unrolled by ``LIBETH_XDP_TX_BATCH`` to optimize + * writes. + * Note that unlike other XDP Tx ops, the queue must be locked and cleaned + * prior to calling this function to already know available @budget. + * @prepare must only build a &libeth_xdpsq and return ``U32_MAX``. + * + * Return: false if @budget was exhausted, true otherwise. + */ +static __always_inline bool +libeth_xsk_xmit_do_bulk(struct xsk_buff_pool *pool, void *xdpsq, u32 budget, + const struct xsk_tx_metadata_ops *tmo, + u32 (*prep)(void *xdpsq, struct libeth_xdpsq *sq), + void (*xmit)(struct libeth_xdp_tx_desc desc, u32 i, + const struct libeth_xdpsq *sq, u64 priv), + void (*finalize)(void *xdpsq, bool sent, bool flush)) +{ + const struct libeth_xdp_tx_frame *bulk; + bool wake; + u32 n; + + wake = xsk_uses_need_wakeup(pool); + if (wake) + xsk_clear_tx_need_wakeup(pool); + + n = xsk_tx_peek_release_desc_batch(pool, budget); + bulk = container_of(&pool->tx_descs[0], typeof(*bulk), desc); + + libeth_xdp_tx_xmit_bulk(bulk, xdpsq, n, true, + libeth_xdp_ptr_to_priv(tmo), prep, + libeth_xsk_xmit_fill_buf, xmit); + finalize(xdpsq, n, true); + + if (wake) + xsk_set_tx_need_wakeup(pool); + + return n < budget; +} + +/* Rx polling path */ + +/** + * libeth_xsk_tx_init_bulk - initialize XDP Tx bulk for an XSk Rx NAPI poll + * @bq: bulk to initialize + * @prog: RCU pointer to the XDP program (never %NULL) + * @dev: target &net_device + * @xdpsqs: array of driver XDPSQ structs + * @num: number of active XDPSQs, the above array length + * + * Should be called on an onstack XDP Tx bulk before the XSk NAPI polling loop. + * Initializes all the needed fields to run libeth_xdp functions. + * Never checks if @prog is %NULL or @num == 0 as XDP must always be enabled + * when hitting this path. + */ +#define libeth_xsk_tx_init_bulk(bq, prog, dev, xdpsqs, num) \ + __libeth_xdp_tx_init_bulk(bq, prog, dev, xdpsqs, num, true, \ + __UNIQUE_ID(bq_), __UNIQUE_ID(nqs_)) + +struct libeth_xdp_buff *libeth_xsk_buff_add_frag(struct libeth_xdp_buff *head, + struct libeth_xdp_buff *xdp); + +/** + * libeth_xsk_process_buff - attach XSk Rx buffer to &libeth_xdp_buff + * @head: head XSk buffer to attach the XSk buffer to (or %NULL) + * @xdp: XSk buffer to process + * @len: received data length from the descriptor + * + * If @head == %NULL, treats the XSk buffer as head and initializes + * the required fields. Otherwise, attaches the buffer as a frag. + * Already performs DMA sync-for-CPU and frame start prefetch + * (for head buffers only). + * + * Return: head XSk buffer on success or if the descriptor must be skipped + * (empty), %NULL if there is no space for a new frag. + */ +static inline struct libeth_xdp_buff * +libeth_xsk_process_buff(struct libeth_xdp_buff *head, + struct libeth_xdp_buff *xdp, u32 len) +{ + if (unlikely(!len)) { + libeth_xsk_buff_free_slow(xdp); + return head; + } + + xsk_buff_set_size(&xdp->base, len); + xsk_buff_dma_sync_for_cpu(&xdp->base); + + if (head) + return libeth_xsk_buff_add_frag(head, xdp); + + prefetch(xdp->data); + + return xdp; +} + +void libeth_xsk_buff_stats_frags(struct libeth_rq_napi_stats *rs, + const struct libeth_xdp_buff *xdp); + +u32 __libeth_xsk_run_prog_slow(struct libeth_xdp_buff *xdp, + const struct libeth_xdp_tx_bulk *bq, + enum xdp_action act, int ret); + +/** + * __libeth_xsk_run_prog - run XDP program on XSk buffer + * @xdp: XSk buffer to run the prog on + * @bq: buffer bulk for ``XDP_TX`` queueing + * + * Internal inline abstraction to run XDP program on XSk Rx path. Handles + * only the most common ``XDP_REDIRECT`` inline, the rest is processed + * externally. + * Reports an XDP prog exception on errors. + * + * Return: libeth_xdp prog verdict depending on the prog's verdict. + */ +static __always_inline u32 +__libeth_xsk_run_prog(struct libeth_xdp_buff *xdp, + const struct libeth_xdp_tx_bulk *bq) +{ + enum xdp_action act; + int ret = 0; + + act = bpf_prog_run_xdp(bq->prog, &xdp->base); + if (unlikely(act != XDP_REDIRECT)) +rest: + return __libeth_xsk_run_prog_slow(xdp, bq, act, ret); + + ret = xdp_do_redirect(bq->dev, &xdp->base, bq->prog); + if (unlikely(ret)) + goto rest; + + return LIBETH_XDP_REDIRECT; +} + +/** + * libeth_xsk_run_prog - run XDP program on XSk path and handle all verdicts + * @xdp: XSk buffer to process + * @bq: XDP Tx bulk to queue ``XDP_TX`` buffers + * @fl: driver ``XDP_TX`` bulk flush callback + * + * Run the attached XDP program and handle all possible verdicts. + * Prefer using it via LIBETH_XSK_DEFINE_RUN{,_PASS,_PROG}(). + * + * Return: libeth_xdp prog verdict depending on the prog's verdict. + */ +#define libeth_xsk_run_prog(xdp, bq, fl) \ + __libeth_xdp_run_flush(xdp, bq, __libeth_xsk_run_prog, \ + libeth_xsk_tx_queue_bulk, fl) + +/** + * __libeth_xsk_run_pass - helper to run XDP program and handle the result + * @xdp: XSk buffer to process + * @bq: XDP Tx bulk to queue ``XDP_TX`` frames + * @napi: NAPI to build an skb and pass it up the stack + * @rs: onstack libeth RQ stats + * @md: metadata that should be filled to the XSk buffer + * @prep: callback for filling the metadata + * @run: driver wrapper to run XDP program + * @populate: driver callback to populate an skb with the HW descriptor data + * + * Inline abstraction, XSk's counterpart of __libeth_xdp_run_pass(), see its + * doc for details. + * + * Return: false if the polling loop must be exited due to lack of free + * buffers, true otherwise. + */ +static __always_inline bool +__libeth_xsk_run_pass(struct libeth_xdp_buff *xdp, + struct libeth_xdp_tx_bulk *bq, struct napi_struct *napi, + struct libeth_rq_napi_stats *rs, const void *md, + void (*prep)(struct libeth_xdp_buff *xdp, + const void *md), + u32 (*run)(struct libeth_xdp_buff *xdp, + struct libeth_xdp_tx_bulk *bq), + bool (*populate)(struct sk_buff *skb, + const struct libeth_xdp_buff *xdp, + struct libeth_rq_napi_stats *rs)) +{ + struct sk_buff *skb; + u32 act; + + rs->bytes += xdp->base.data_end - xdp->data; + rs->packets++; + + if (unlikely(xdp_buff_has_frags(&xdp->base))) + libeth_xsk_buff_stats_frags(rs, xdp); + + if (prep && (!__builtin_constant_p(!!md) || md)) + prep(xdp, md); + + act = run(xdp, bq); + if (likely(act == LIBETH_XDP_REDIRECT)) + return true; + + if (act != LIBETH_XDP_PASS) + return act != LIBETH_XDP_ABORTED; + + skb = xdp_build_skb_from_zc(&xdp->base); + if (unlikely(!skb)) { + libeth_xsk_buff_free_slow(xdp); + return true; + } + + if (unlikely(!populate(skb, xdp, rs))) { + napi_consume_skb(skb, true); + return true; + } + + napi_gro_receive(napi, skb); + + return true; +} + +/** + * libeth_xsk_run_pass - helper to run XDP program and handle the result + * @xdp: XSk buffer to process + * @bq: XDP Tx bulk to queue ``XDP_TX`` frames + * @napi: NAPI to build an skb and pass it up the stack + * @rs: onstack libeth RQ stats + * @desc: pointer to the HW descriptor for that frame + * @run: driver wrapper to run XDP program + * @populate: driver callback to populate an skb with the HW descriptor data + * + * Wrapper around the underscored version when "fill the descriptor metadata" + * means just writing the pointer to the HW descriptor as @xdp->desc. + */ +#define libeth_xsk_run_pass(xdp, bq, napi, rs, desc, run, populate) \ + __libeth_xsk_run_pass(xdp, bq, napi, rs, desc, libeth_xdp_prep_desc, \ + run, populate) + +/** + * libeth_xsk_finalize_rx - finalize XDPSQ after an XSk NAPI polling loop + * @bq: ``XDP_TX`` frame bulk + * @flush: driver callback to flush the bulk + * @finalize: driver callback to start sending the frames and run the timer + * + * Flush the bulk if there are frames left to send, kick the queue and flush + * the XDP maps. + */ +#define libeth_xsk_finalize_rx(bq, flush, finalize) \ + __libeth_xdp_finalize_rx(bq, LIBETH_XDP_TX_XSK, flush, finalize) + +/* + * Helpers to reduce boilerplate code in drivers. + * + * Typical driver XSk Rx flow would be (excl. bulk and buff init, frag attach): + * + * LIBETH_XDP_DEFINE_START(); + * LIBETH_XSK_DEFINE_FLUSH_TX(static driver_xsk_flush_tx, driver_xsk_tx_prep, + * driver_xdp_xmit); + * LIBETH_XSK_DEFINE_RUN(static driver_xsk_run, driver_xsk_run_prog, + * driver_xsk_flush_tx, driver_populate_skb); + * LIBETH_XSK_DEFINE_FINALIZE(static driver_xsk_finalize_rx, + * driver_xsk_flush_tx, driver_xdp_finalize_sq); + * LIBETH_XDP_DEFINE_END(); + * + * This will build a set of 4 static functions. The compiler is free to decide + * whether to inline them. + * Then, in the NAPI polling function: + * + * while (packets < budget) { + * // ... + * if (!driver_xsk_run(xdp, &bq, napi, &rs, desc)) + * break; + * } + * driver_xsk_finalize_rx(&bq); + */ + +/** + * LIBETH_XSK_DEFINE_FLUSH_TX - define a driver XSk ``XDP_TX`` flush function + * @name: name of the function to define + * @prep: driver callback to clean an XDPSQ + * @xmit: driver callback to write a HW Tx descriptor + */ +#define LIBETH_XSK_DEFINE_FLUSH_TX(name, prep, xmit) \ + __LIBETH_XDP_DEFINE_FLUSH_TX(name, prep, xmit, xsk) + +/** + * LIBETH_XSK_DEFINE_RUN_PROG - define a driver XDP program run function + * @name: name of the function to define + * @flush: driver callback to flush an XSk ``XDP_TX`` bulk + */ +#define LIBETH_XSK_DEFINE_RUN_PROG(name, flush) \ + u32 __LIBETH_XDP_DEFINE_RUN_PROG(name, flush, xsk) + +/** + * LIBETH_XSK_DEFINE_RUN_PASS - define a driver buffer process + pass function + * @name: name of the function to define + * @run: driver callback to run XDP program (above) + * @populate: driver callback to fill an skb with HW descriptor info + */ +#define LIBETH_XSK_DEFINE_RUN_PASS(name, run, populate) \ + bool __LIBETH_XDP_DEFINE_RUN_PASS(name, run, populate, xsk) + +/** + * LIBETH_XSK_DEFINE_RUN - define a driver buffer process, run + pass function + * @name: name of the function to define + * @run: name of the XDP prog run function to define + * @flush: driver callback to flush an XSk ``XDP_TX`` bulk + * @populate: driver callback to fill an skb with HW descriptor info + */ +#define LIBETH_XSK_DEFINE_RUN(name, run, flush, populate) \ + __LIBETH_XDP_DEFINE_RUN(name, run, flush, populate, XSK) + +/** + * LIBETH_XSK_DEFINE_FINALIZE - define a driver XSk NAPI poll finalize function + * @name: name of the function to define + * @flush: driver callback to flush an XSk ``XDP_TX`` bulk + * @finalize: driver callback to finalize an XDPSQ and run the timer + */ +#define LIBETH_XSK_DEFINE_FINALIZE(name, flush, finalize) \ + __LIBETH_XDP_DEFINE_FINALIZE(name, flush, finalize, xsk) + +/* Refilling */ + +/** + * struct libeth_xskfq - structure representing an XSk buffer (fill) queue + * @fp: hotpath part of the structure + * @pool: &xsk_buff_pool for buffer management + * @fqes: array of XSk buffer pointers + * @descs: opaque pointer to the HW descriptor array + * @ntu: index of the next buffer to poll + * @count: number of descriptors/buffers the queue has + * @pending: current number of XSkFQEs to refill + * @thresh: threshold below which the queue is refilled + * @buf_len: HW-writeable length per each buffer + * @nid: ID of the closest NUMA node with memory + */ +struct libeth_xskfq { + struct_group_tagged(libeth_xskfq_fp, fp, + struct xsk_buff_pool *pool; + struct libeth_xdp_buff **fqes; + void *descs; + + u32 ntu; + u32 count; + ); + + /* Cold fields */ + u32 pending; + u32 thresh; + + u32 buf_len; + int nid; +}; + +int libeth_xskfq_create(struct libeth_xskfq *fq); +void libeth_xskfq_destroy(struct libeth_xskfq *fq); + +/** + * libeth_xsk_buff_xdp_get_dma - get DMA address of XSk &libeth_xdp_buff + * @xdp: buffer to get the DMA addr for + */ +#define libeth_xsk_buff_xdp_get_dma(xdp) \ + xsk_buff_xdp_get_dma(&(xdp)->base) + +/** + * libeth_xskfqe_alloc - allocate @n XSk Rx buffers + * @fq: hotpath part of the XSkFQ, usually onstack + * @n: number of buffers to allocate + * @fill: driver callback to write DMA addresses to HW descriptors + * + * Note that @fq->ntu gets updated, but ::pending must be recalculated + * by the caller. + * + * Return: number of buffers refilled. + */ +static __always_inline u32 +libeth_xskfqe_alloc(struct libeth_xskfq_fp *fq, u32 n, + void (*fill)(const struct libeth_xskfq_fp *fq, u32 i)) +{ + u32 this, ret, done = 0; + struct xdp_buff **xskb; + + this = fq->count - fq->ntu; + if (likely(this > n)) + this = n; + +again: + xskb = (typeof(xskb))&fq->fqes[fq->ntu]; + ret = xsk_buff_alloc_batch(fq->pool, xskb, this); + + for (u32 i = 0, ntu = fq->ntu; likely(i < ret); i++) + fill(fq, ntu + i); + + done += ret; + fq->ntu += ret; + + if (likely(fq->ntu < fq->count) || unlikely(ret < this)) + goto out; + + fq->ntu = 0; + + if (this < n) { + this = n - this; + goto again; + } + +out: + return done; +} + +/* .ndo_xsk_wakeup */ + +void libeth_xsk_init_wakeup(call_single_data_t *csd, struct napi_struct *napi); +void libeth_xsk_wakeup(call_single_data_t *csd, u32 qid); + +/* Pool setup */ + +int libeth_xsk_setup_pool(struct net_device *dev, u32 qid, bool enable); + +#endif /* __LIBETH_XSK_H */ |