diff options
Diffstat (limited to 'include/net/libeth/xdp.h')
| -rw-r--r-- | include/net/libeth/xdp.h | 1879 |
1 files changed, 1879 insertions, 0 deletions
diff --git a/include/net/libeth/xdp.h b/include/net/libeth/xdp.h new file mode 100644 index 000000000000..f4880b50e804 --- /dev/null +++ b/include/net/libeth/xdp.h @@ -0,0 +1,1879 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright (C) 2025 Intel Corporation */ + +#ifndef __LIBETH_XDP_H +#define __LIBETH_XDP_H + +#include <linux/bpf_trace.h> +#include <linux/unroll.h> + +#include <net/libeth/rx.h> +#include <net/libeth/tx.h> +#include <net/xsk_buff_pool.h> + +/* + * Defined as bits to be able to use them as a mask on Rx. + * Also used as internal return values on Tx. + */ +enum { + LIBETH_XDP_PASS = 0U, + LIBETH_XDP_DROP = BIT(0), + LIBETH_XDP_ABORTED = BIT(1), + LIBETH_XDP_TX = BIT(2), + LIBETH_XDP_REDIRECT = BIT(3), +}; + +/* + * &xdp_buff_xsk is the largest structure &libeth_xdp_buff gets casted to, + * pick maximum pointer-compatible alignment. + */ +#define __LIBETH_XDP_BUFF_ALIGN \ + (IS_ALIGNED(sizeof(struct xdp_buff_xsk), 16) ? 16 : \ + IS_ALIGNED(sizeof(struct xdp_buff_xsk), 8) ? 8 : \ + sizeof(long)) + +/** + * struct libeth_xdp_buff - libeth extension over &xdp_buff + * @base: main &xdp_buff + * @data: shortcut for @base.data + * @desc: RQ descriptor containing metadata for this buffer + * @priv: driver-private scratchspace + * + * The main reason for this is to have a pointer to the descriptor to be able + * to quickly get frame metadata from xdpmo and driver buff-to-xdp callbacks + * (as well as bigger alignment). + * Pointer/layout-compatible with &xdp_buff and &xdp_buff_xsk. + */ +struct libeth_xdp_buff { + union { + struct xdp_buff base; + void *data; + }; + + const void *desc; + unsigned long priv[] + __aligned(__LIBETH_XDP_BUFF_ALIGN); +} __aligned(__LIBETH_XDP_BUFF_ALIGN); +static_assert(offsetof(struct libeth_xdp_buff, data) == + offsetof(struct xdp_buff_xsk, xdp.data)); +static_assert(offsetof(struct libeth_xdp_buff, desc) == + offsetof(struct xdp_buff_xsk, cb)); +static_assert(IS_ALIGNED(sizeof(struct xdp_buff_xsk), + __alignof(struct libeth_xdp_buff))); + +/** + * __LIBETH_XDP_ONSTACK_BUFF - declare a &libeth_xdp_buff on the stack + * @name: name of the variable to declare + * @...: sizeof() of the driver-private data + */ +#define __LIBETH_XDP_ONSTACK_BUFF(name, ...) \ + ___LIBETH_XDP_ONSTACK_BUFF(name, ##__VA_ARGS__) +/** + * LIBETH_XDP_ONSTACK_BUFF - declare a &libeth_xdp_buff on the stack + * @name: name of the variable to declare + * @...: type or variable name of the driver-private data + */ +#define LIBETH_XDP_ONSTACK_BUFF(name, ...) \ + __LIBETH_XDP_ONSTACK_BUFF(name, __libeth_xdp_priv_sz(__VA_ARGS__)) + +#define ___LIBETH_XDP_ONSTACK_BUFF(name, ...) \ + __DEFINE_FLEX(struct libeth_xdp_buff, name, priv, \ + LIBETH_XDP_PRIV_SZ(__VA_ARGS__ + 0), \ + __uninitialized); \ + LIBETH_XDP_ASSERT_PRIV_SZ(__VA_ARGS__ + 0) + +#define __libeth_xdp_priv_sz(...) \ + CONCATENATE(__libeth_xdp_psz, COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__) + +#define __libeth_xdp_psz0(...) +#define __libeth_xdp_psz1(...) sizeof(__VA_ARGS__) + +#define LIBETH_XDP_PRIV_SZ(sz) \ + (ALIGN(sz, __alignof(struct libeth_xdp_buff)) / sizeof(long)) + +/* Performs XSK_CHECK_PRIV_TYPE() */ +#define LIBETH_XDP_ASSERT_PRIV_SZ(sz) \ + static_assert(offsetofend(struct xdp_buff_xsk, cb) >= \ + struct_size_t(struct libeth_xdp_buff, priv, \ + LIBETH_XDP_PRIV_SZ(sz))) + +/* XDPSQ sharing */ + +DECLARE_STATIC_KEY_FALSE(libeth_xdpsq_share); + +/** + * libeth_xdpsq_num - calculate optimal number of XDPSQs for this device + sys + * @rxq: current number of active Rx queues + * @txq: current number of active Tx queues + * @max: maximum number of Tx queues + * + * Each RQ must have its own XDPSQ for XSk pairs, each CPU must have own XDPSQ + * for lockless sending (``XDP_TX``, .ndo_xdp_xmit()). Cap the maximum of these + * two with the number of SQs the device can have (minus used ones). + * + * Return: number of XDP Tx queues the device needs to use. + */ +static inline u32 libeth_xdpsq_num(u32 rxq, u32 txq, u32 max) +{ + return min(max(nr_cpu_ids, rxq), max - txq); +} + +/** + * libeth_xdpsq_shared - whether XDPSQs can be shared between several CPUs + * @num: number of active XDPSQs + * + * Return: true if there's no 1:1 XDPSQ/CPU association, false otherwise. + */ +static inline bool libeth_xdpsq_shared(u32 num) +{ + return num < nr_cpu_ids; +} + +/** + * libeth_xdpsq_id - get XDPSQ index corresponding to this CPU + * @num: number of active XDPSQs + * + * Helper for libeth_xdp routines, do not use in drivers directly. + * + * Return: XDPSQ index needs to be used on this CPU. + */ +static inline u32 libeth_xdpsq_id(u32 num) +{ + u32 ret = raw_smp_processor_id(); + + if (static_branch_unlikely(&libeth_xdpsq_share) && + libeth_xdpsq_shared(num)) + ret %= num; + + return ret; +} + +void __libeth_xdpsq_get(struct libeth_xdpsq_lock *lock, + const struct net_device *dev); +void __libeth_xdpsq_put(struct libeth_xdpsq_lock *lock, + const struct net_device *dev); + +/** + * libeth_xdpsq_get - initialize &libeth_xdpsq_lock + * @lock: lock to initialize + * @dev: netdev which this lock belongs to + * @share: whether XDPSQs can be shared + * + * Tracks the current XDPSQ association and enables the static lock + * if needed. + */ +static inline void libeth_xdpsq_get(struct libeth_xdpsq_lock *lock, + const struct net_device *dev, + bool share) +{ + if (unlikely(share)) + __libeth_xdpsq_get(lock, dev); +} + +/** + * libeth_xdpsq_put - deinitialize &libeth_xdpsq_lock + * @lock: lock to deinitialize + * @dev: netdev which this lock belongs to + * + * Tracks the current XDPSQ association and disables the static lock + * if needed. + */ +static inline void libeth_xdpsq_put(struct libeth_xdpsq_lock *lock, + const struct net_device *dev) +{ + if (static_branch_unlikely(&libeth_xdpsq_share) && lock->share) + __libeth_xdpsq_put(lock, dev); +} + +void __libeth_xdpsq_lock(struct libeth_xdpsq_lock *lock); +void __libeth_xdpsq_unlock(struct libeth_xdpsq_lock *lock); + +/** + * libeth_xdpsq_lock - grab &libeth_xdpsq_lock if needed + * @lock: lock to take + * + * Touches the underlying spinlock only if the static key is enabled + * and the queue itself is marked as shareable. + */ +static inline void libeth_xdpsq_lock(struct libeth_xdpsq_lock *lock) +{ + if (static_branch_unlikely(&libeth_xdpsq_share) && lock->share) + __libeth_xdpsq_lock(lock); +} + +/** + * libeth_xdpsq_unlock - free &libeth_xdpsq_lock if needed + * @lock: lock to free + * + * Touches the underlying spinlock only if the static key is enabled + * and the queue itself is marked as shareable. + */ +static inline void libeth_xdpsq_unlock(struct libeth_xdpsq_lock *lock) +{ + if (static_branch_unlikely(&libeth_xdpsq_share) && lock->share) + __libeth_xdpsq_unlock(lock); +} + +/* XDPSQ clean-up timers */ + +void libeth_xdpsq_init_timer(struct libeth_xdpsq_timer *timer, void *xdpsq, + struct libeth_xdpsq_lock *lock, + void (*poll)(struct work_struct *work)); + +/** + * libeth_xdpsq_deinit_timer - deinitialize &libeth_xdpsq_timer + * @timer: timer to deinitialize + * + * Flush and disable the underlying workqueue. + */ +static inline void libeth_xdpsq_deinit_timer(struct libeth_xdpsq_timer *timer) +{ + cancel_delayed_work_sync(&timer->dwork); +} + +/** + * libeth_xdpsq_queue_timer - run &libeth_xdpsq_timer + * @timer: timer to queue + * + * Should be called after the queue was filled and the transmission was run + * to complete the pending buffers if no further sending will be done in a + * second (-> lazy cleaning won't happen). + * If the timer was already run, it will be requeued back to one second + * timeout again. + */ +static inline void libeth_xdpsq_queue_timer(struct libeth_xdpsq_timer *timer) +{ + mod_delayed_work_on(raw_smp_processor_id(), system_bh_highpri_wq, + &timer->dwork, HZ); +} + +/** + * libeth_xdpsq_run_timer - wrapper to run a queue clean-up on a timer event + * @work: workqueue belonging to the corresponding timer + * @poll: driver-specific completion queue poll function + * + * Run the polling function on the locked queue and requeue the timer if + * there's more work to do. + * Designed to be used via LIBETH_XDP_DEFINE_TIMER() below. + */ +static __always_inline void +libeth_xdpsq_run_timer(struct work_struct *work, + u32 (*poll)(void *xdpsq, u32 budget)) +{ + struct libeth_xdpsq_timer *timer = container_of(work, typeof(*timer), + dwork.work); + + libeth_xdpsq_lock(timer->lock); + + if (poll(timer->xdpsq, U32_MAX)) + libeth_xdpsq_queue_timer(timer); + + libeth_xdpsq_unlock(timer->lock); +} + +/* Common Tx bits */ + +/** + * enum - libeth_xdp internal Tx flags + * @LIBETH_XDP_TX_BULK: one bulk size at which it will be flushed to the queue + * @LIBETH_XDP_TX_BATCH: batch size for which the queue fill loop is unrolled + * @LIBETH_XDP_TX_DROP: indicates the send function must drop frames not sent + * @LIBETH_XDP_TX_NDO: whether the send function is called from .ndo_xdp_xmit() + * @LIBETH_XDP_TX_XSK: whether the function is called for ``XDP_TX`` for XSk + */ +enum { + LIBETH_XDP_TX_BULK = DEV_MAP_BULK_SIZE, + LIBETH_XDP_TX_BATCH = 8, + + LIBETH_XDP_TX_DROP = BIT(0), + LIBETH_XDP_TX_NDO = BIT(1), + LIBETH_XDP_TX_XSK = BIT(2), +}; + +/** + * enum - &libeth_xdp_tx_frame and &libeth_xdp_tx_desc flags + * @LIBETH_XDP_TX_LEN: only for ``XDP_TX``, [15:0] of ::len_fl is actual length + * @LIBETH_XDP_TX_CSUM: for XSk xmit, enable checksum offload + * @LIBETH_XDP_TX_XSKMD: for XSk xmit, mask of the metadata bits + * @LIBETH_XDP_TX_FIRST: indicates the frag is the first one of the frame + * @LIBETH_XDP_TX_LAST: whether the frag is the last one of the frame + * @LIBETH_XDP_TX_MULTI: whether the frame contains several frags + * @LIBETH_XDP_TX_FLAGS: only for ``XDP_TX``, [31:16] of ::len_fl is flags + */ +enum { + LIBETH_XDP_TX_LEN = GENMASK(15, 0), + + LIBETH_XDP_TX_CSUM = XDP_TXMD_FLAGS_CHECKSUM, + LIBETH_XDP_TX_XSKMD = LIBETH_XDP_TX_LEN, + + LIBETH_XDP_TX_FIRST = BIT(16), + LIBETH_XDP_TX_LAST = BIT(17), + LIBETH_XDP_TX_MULTI = BIT(18), + + LIBETH_XDP_TX_FLAGS = GENMASK(31, 16), +}; + +/** + * struct libeth_xdp_tx_frame - represents one XDP Tx element + * @data: frame start pointer for ``XDP_TX`` + * @len_fl: ``XDP_TX``, combined flags [31:16] and len [15:0] field for speed + * @soff: ``XDP_TX``, offset from @data to the start of &skb_shared_info + * @frag: one (non-head) frag for ``XDP_TX`` + * @xdpf: &xdp_frame for the head frag for .ndo_xdp_xmit() + * @dma: DMA address of the non-head frag for .ndo_xdp_xmit() + * @xsk: ``XDP_TX`` for XSk, XDP buffer for any frag + * @len: frag length for XSk ``XDP_TX`` and .ndo_xdp_xmit() + * @flags: Tx flags for the above + * @opts: combined @len + @flags for the above for speed + * @desc: XSk xmit descriptor for direct casting + */ +struct libeth_xdp_tx_frame { + union { + /* ``XDP_TX`` */ + struct { + void *data; + u32 len_fl; + u32 soff; + }; + + /* ``XDP_TX`` frag */ + skb_frag_t frag; + + /* .ndo_xdp_xmit(), XSk ``XDP_TX`` */ + struct { + union { + struct xdp_frame *xdpf; + dma_addr_t dma; + + struct libeth_xdp_buff *xsk; + }; + union { + struct { + u32 len; + u32 flags; + }; + aligned_u64 opts; + }; + }; + + /* XSk xmit */ + struct xdp_desc desc; + }; +} __aligned(sizeof(struct xdp_desc)); +static_assert(offsetof(struct libeth_xdp_tx_frame, frag.len) == + offsetof(struct libeth_xdp_tx_frame, len_fl)); +static_assert(sizeof(struct libeth_xdp_tx_frame) == sizeof(struct xdp_desc)); + +/** + * struct libeth_xdp_tx_bulk - XDP Tx frame bulk for bulk sending + * @prog: corresponding active XDP program, %NULL for .ndo_xdp_xmit() + * @dev: &net_device which the frames are transmitted on + * @xdpsq: shortcut to the corresponding driver-specific XDPSQ structure + * @act_mask: Rx only, mask of all the XDP prog verdicts for that NAPI session + * @count: current number of frames in @bulk + * @bulk: array of queued frames for bulk Tx + * + * All XDP Tx operations except XSk xmit queue each frame to the bulk first + * and flush it when @count reaches the array end. Bulk is always placed on + * the stack for performance. One bulk element contains all the data necessary + * for sending a frame and then freeing it on completion. + * For XSk xmit, Tx descriptor array from &xsk_buff_pool is casted directly + * to &libeth_xdp_tx_frame as they are compatible and the bulk structure is + * not used. + */ +struct libeth_xdp_tx_bulk { + const struct bpf_prog *prog; + struct net_device *dev; + void *xdpsq; + + u32 act_mask; + u32 count; + struct libeth_xdp_tx_frame bulk[LIBETH_XDP_TX_BULK]; +} __aligned(sizeof(struct libeth_xdp_tx_frame)); + +/** + * LIBETH_XDP_ONSTACK_BULK - declare &libeth_xdp_tx_bulk on the stack + * @bq: name of the variable to declare + * + * Helper to declare a bulk on the stack with a compiler hint that it should + * not be initialized automatically (with `CONFIG_INIT_STACK_ALL_*`) for + * performance reasons. + */ +#define LIBETH_XDP_ONSTACK_BULK(bq) \ + struct libeth_xdp_tx_bulk bq __uninitialized + +/** + * struct libeth_xdpsq - abstraction for an XDPSQ + * @pool: XSk buffer pool for XSk ``XDP_TX`` and xmit + * @sqes: array of Tx buffers from the actual queue struct + * @descs: opaque pointer to the HW descriptor array + * @ntu: pointer to the next free descriptor index + * @count: number of descriptors on that queue + * @pending: pointer to the number of sent-not-completed descs on that queue + * @xdp_tx: pointer to the above, but only for non-XSk-xmit frames + * @lock: corresponding XDPSQ lock + * + * Abstraction for driver-independent implementation of Tx. Placed on the stack + * and filled by the driver before the transmission, so that the generic + * functions can access and modify driver-specific resources. + */ +struct libeth_xdpsq { + struct xsk_buff_pool *pool; + struct libeth_sqe *sqes; + void *descs; + + u32 *ntu; + u32 count; + + u32 *pending; + u32 *xdp_tx; + struct libeth_xdpsq_lock *lock; +}; + +/** + * struct libeth_xdp_tx_desc - abstraction for an XDP Tx descriptor + * @addr: DMA address of the frame + * @len: length of the frame + * @flags: XDP Tx flags + * @opts: combined @len + @flags for speed + * + * Filled by the generic functions and then passed to driver-specific functions + * to fill a HW Tx descriptor, always placed on the [function] stack. + */ +struct libeth_xdp_tx_desc { + dma_addr_t addr; + union { + struct { + u32 len; + u32 flags; + }; + aligned_u64 opts; + }; +} __aligned_largest; + +/** + * libeth_xdp_ptr_to_priv - convert pointer to a libeth_xdp u64 priv + * @ptr: pointer to convert + * + * The main sending function passes private data as the largest scalar, u64. + * Use this helper when you want to pass a pointer there. + */ +#define libeth_xdp_ptr_to_priv(ptr) ({ \ + typecheck_pointer(ptr); \ + ((u64)(uintptr_t)(ptr)); \ +}) +/** + * libeth_xdp_priv_to_ptr - convert libeth_xdp u64 priv to a pointer + * @priv: private data to convert + * + * The main sending function passes private data as the largest scalar, u64. + * Use this helper when your callback takes this u64 and you want to convert + * it back to a pointer. + */ +#define libeth_xdp_priv_to_ptr(priv) ({ \ + static_assert(__same_type(priv, u64)); \ + ((const void *)(uintptr_t)(priv)); \ +}) + +/* + * On 64-bit systems, assigning one u64 is faster than two u32s. When ::len + * occupies lowest 32 bits (LE), whole ::opts can be assigned directly instead. + */ +#ifdef __LITTLE_ENDIAN +#define __LIBETH_WORD_ACCESS 1 +#endif +#ifdef __LIBETH_WORD_ACCESS +#define __libeth_xdp_tx_len(flen, ...) \ + .opts = ((flen) | FIELD_PREP(GENMASK_ULL(63, 32), (__VA_ARGS__ + 0))) +#else +#define __libeth_xdp_tx_len(flen, ...) \ + .len = (flen), .flags = (__VA_ARGS__ + 0) +#endif + +/** + * libeth_xdp_tx_xmit_bulk - main XDP Tx function + * @bulk: array of frames to send + * @xdpsq: pointer to the driver-specific XDPSQ struct + * @n: number of frames to send + * @unroll: whether to unroll the queue filling loop for speed + * @priv: driver-specific private data + * @prep: callback for cleaning the queue and filling abstract &libeth_xdpsq + * @fill: internal callback for filling &libeth_sqe and &libeth_xdp_tx_desc + * @xmit: callback for filling a HW descriptor with the frame info + * + * Internal abstraction for placing @n XDP Tx frames on the HW XDPSQ. Used for + * all types of frames: ``XDP_TX``, .ndo_xdp_xmit(), XSk ``XDP_TX``, and XSk + * xmit. + * @prep must lock the queue as this function releases it at the end. @unroll + * greatly increases the object code size, but also greatly increases XSk xmit + * performance; for other types of frames, it's not enabled. + * The compilers inline all those onstack abstractions to direct data accesses. + * + * Return: number of frames actually placed on the queue, <= @n. The function + * can't fail, but can send less frames if there's no enough free descriptors + * available. The actual free space is returned by @prep from the driver. + */ +static __always_inline u32 +libeth_xdp_tx_xmit_bulk(const struct libeth_xdp_tx_frame *bulk, void *xdpsq, + u32 n, bool unroll, u64 priv, + u32 (*prep)(void *xdpsq, struct libeth_xdpsq *sq), + struct libeth_xdp_tx_desc + (*fill)(struct libeth_xdp_tx_frame frm, u32 i, + const struct libeth_xdpsq *sq, u64 priv), + void (*xmit)(struct libeth_xdp_tx_desc desc, u32 i, + const struct libeth_xdpsq *sq, u64 priv)) +{ + struct libeth_xdpsq sq __uninitialized; + u32 this, batched, off = 0; + u32 ntu, i = 0; + + n = min(n, prep(xdpsq, &sq)); + if (unlikely(!n)) + goto unlock; + + ntu = *sq.ntu; + + this = sq.count - ntu; + if (likely(this > n)) + this = n; + +again: + if (!unroll) + goto linear; + + batched = ALIGN_DOWN(this, LIBETH_XDP_TX_BATCH); + + for ( ; i < off + batched; i += LIBETH_XDP_TX_BATCH) { + u32 base = ntu + i - off; + + unrolled_count(LIBETH_XDP_TX_BATCH) + for (u32 j = 0; j < LIBETH_XDP_TX_BATCH; j++) + xmit(fill(bulk[i + j], base + j, &sq, priv), + base + j, &sq, priv); + } + + if (batched < this) { +linear: + for ( ; i < off + this; i++) + xmit(fill(bulk[i], ntu + i - off, &sq, priv), + ntu + i - off, &sq, priv); + } + + ntu += this; + if (likely(ntu < sq.count)) + goto out; + + ntu = 0; + + if (i < n) { + this = n - i; + off = i; + + goto again; + } + +out: + *sq.ntu = ntu; + *sq.pending += n; + if (sq.xdp_tx) + *sq.xdp_tx += n; + +unlock: + libeth_xdpsq_unlock(sq.lock); + + return n; +} + +/* ``XDP_TX`` bulking */ + +void libeth_xdp_return_buff_slow(struct libeth_xdp_buff *xdp); + +/** + * libeth_xdp_tx_queue_head - internal helper for queueing one ``XDP_TX`` head + * @bq: XDP Tx bulk to queue the head frag to + * @xdp: XDP 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_xdp_tx_queue_head(struct libeth_xdp_tx_bulk *bq, + const struct libeth_xdp_buff *xdp) +{ + const struct xdp_buff *base = &xdp->base; + + bq->bulk[bq->count++] = (typeof(*bq->bulk)){ + .data = xdp->data, + .len_fl = (base->data_end - xdp->data) | LIBETH_XDP_TX_FIRST, + .soff = xdp_data_hard_end(base) - xdp->data, + }; + + if (!xdp_buff_has_frags(base)) + return false; + + bq->bulk[bq->count - 1].len_fl |= LIBETH_XDP_TX_MULTI; + + return true; +} + +/** + * libeth_xdp_tx_queue_frag - internal helper for queueing one ``XDP_TX`` frag + * @bq: XDP Tx bulk to queue the frag to + * @frag: frag to queue + */ +static inline void libeth_xdp_tx_queue_frag(struct libeth_xdp_tx_bulk *bq, + const skb_frag_t *frag) +{ + bq->bulk[bq->count++].frag = *frag; +} + +/** + * libeth_xdp_tx_queue_bulk - internal helper for queueing one ``XDP_TX`` frame + * @bq: XDP Tx bulk to queue the frame to + * @xdp: XDP 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_xdp_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)) +{ + const struct skb_shared_info *sinfo; + bool ret = true; + u32 nr_frags; + + if (unlikely(bq->count == LIBETH_XDP_TX_BULK) && + unlikely(!flush_bulk(bq, 0))) { + libeth_xdp_return_buff_slow(xdp); + return false; + } + + if (!libeth_xdp_tx_queue_head(bq, xdp)) + goto out; + + sinfo = xdp_get_shared_info_from_buff(&xdp->base); + nr_frags = sinfo->nr_frags; + + for (u32 i = 0; i < nr_frags; i++) { + if (unlikely(bq->count == LIBETH_XDP_TX_BULK) && + unlikely(!flush_bulk(bq, 0))) { + ret = false; + break; + } + + libeth_xdp_tx_queue_frag(bq, &sinfo->frags[i]); + } + +out: + bq->bulk[bq->count - 1].len_fl |= LIBETH_XDP_TX_LAST; + xdp->data = NULL; + + return ret; +} + +/** + * libeth_xdp_tx_fill_stats - fill &libeth_sqe with ``XDP_TX`` frame stats + * @sqe: SQ element to fill + * @desc: libeth_xdp Tx descriptor + * @sinfo: &skb_shared_info for this frame + * + * Internal helper for filling an SQE with the frame stats, do not use in + * drivers. Fills the number of frags and bytes for this frame. + */ +#define libeth_xdp_tx_fill_stats(sqe, desc, sinfo) \ + __libeth_xdp_tx_fill_stats(sqe, desc, sinfo, __UNIQUE_ID(sqe_), \ + __UNIQUE_ID(desc_), __UNIQUE_ID(sinfo_)) + +#define __libeth_xdp_tx_fill_stats(sqe, desc, sinfo, ue, ud, us) do { \ + const struct libeth_xdp_tx_desc *ud = (desc); \ + const struct skb_shared_info *us; \ + struct libeth_sqe *ue = (sqe); \ + \ + ue->nr_frags = 1; \ + ue->bytes = ud->len; \ + \ + if (ud->flags & LIBETH_XDP_TX_MULTI) { \ + us = (sinfo); \ + ue->nr_frags += us->nr_frags; \ + ue->bytes += us->xdp_frags_size; \ + } \ +} while (0) + +/** + * libeth_xdp_tx_fill_buf - internal helper to fill one ``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_xdp_tx_fill_buf(struct libeth_xdp_tx_frame frm, u32 i, + const struct libeth_xdpsq *sq, u64 priv) +{ + struct libeth_xdp_tx_desc desc; + struct skb_shared_info *sinfo; + skb_frag_t *frag = &frm.frag; + struct libeth_sqe *sqe; + netmem_ref netmem; + + if (frm.len_fl & LIBETH_XDP_TX_FIRST) { + sinfo = frm.data + frm.soff; + skb_frag_fill_netmem_desc(frag, virt_to_netmem(frm.data), + offset_in_page(frm.data), + frm.len_fl); + } else { + sinfo = NULL; + } + + netmem = skb_frag_netmem(frag); + desc = (typeof(desc)){ + .addr = page_pool_get_dma_addr_netmem(netmem) + + skb_frag_off(frag), + .len = skb_frag_size(frag) & LIBETH_XDP_TX_LEN, + .flags = skb_frag_size(frag) & LIBETH_XDP_TX_FLAGS, + }; + + dma_sync_single_for_device(__netmem_get_pp(netmem)->p.dev, desc.addr, + desc.len, DMA_BIDIRECTIONAL); + + if (!sinfo) + return desc; + + sqe = &sq->sqes[i]; + sqe->type = LIBETH_SQE_XDP_TX; + sqe->sinfo = sinfo; + libeth_xdp_tx_fill_stats(sqe, &desc, sinfo); + + return desc; +} + +void libeth_xdp_tx_exception(struct libeth_xdp_tx_bulk *bq, u32 sent, + u32 flags); + +/** + * __libeth_xdp_tx_flush_bulk - internal helper to flush one XDP Tx bulk + * @bq: bulk to flush + * @flags: XDP TX flags (.ndo_xdp_xmit(), XSk etc.) + * @prep: driver-specific callback to prepare the queue for sending + * @fill: libeth_xdp callback to fill &libeth_sqe and &libeth_xdp_tx_desc + * @xmit: driver callback to fill a HW descriptor + * + * Internal abstraction to create bulk flush functions for drivers. Used for + * everything except XSk xmit. + * + * Return: true if anything was sent, false otherwise. + */ +static __always_inline bool +__libeth_xdp_tx_flush_bulk(struct libeth_xdp_tx_bulk *bq, u32 flags, + u32 (*prep)(void *xdpsq, struct libeth_xdpsq *sq), + struct libeth_xdp_tx_desc + (*fill)(struct libeth_xdp_tx_frame frm, u32 i, + const struct libeth_xdpsq *sq, u64 priv), + void (*xmit)(struct libeth_xdp_tx_desc desc, u32 i, + const struct libeth_xdpsq *sq, + u64 priv)) +{ + u32 sent, drops; + int err = 0; + + sent = libeth_xdp_tx_xmit_bulk(bq->bulk, bq->xdpsq, + min(bq->count, LIBETH_XDP_TX_BULK), + false, 0, prep, fill, xmit); + drops = bq->count - sent; + + if (unlikely(drops)) { + libeth_xdp_tx_exception(bq, sent, flags); + err = -ENXIO; + } else { + bq->count = 0; + } + + trace_xdp_bulk_tx(bq->dev, sent, drops, err); + + return likely(sent); +} + +/** + * libeth_xdp_tx_flush_bulk - wrapper to define flush of one ``XDP_TX`` bulk + * @bq: bulk to flush + * @flags: Tx flags, see above + * @prep: driver callback to prepare the queue + * @xmit: driver callback to fill a HW descriptor + * + * Use via LIBETH_XDP_DEFINE_FLUSH_TX() to define an ``XDP_TX`` driver + * callback. + */ +#define libeth_xdp_tx_flush_bulk(bq, flags, prep, xmit) \ + __libeth_xdp_tx_flush_bulk(bq, flags, prep, libeth_xdp_tx_fill_buf, \ + xmit) + +/* .ndo_xdp_xmit() implementation */ + +/** + * libeth_xdp_xmit_init_bulk - internal helper to initialize bulk for XDP xmit + * @bq: bulk to initialize + * @dev: target &net_device + * @xdpsqs: array of driver-specific XDPSQ structs + * @num: number of active XDPSQs (the above array length) + */ +#define libeth_xdp_xmit_init_bulk(bq, dev, xdpsqs, num) \ + __libeth_xdp_xmit_init_bulk(bq, dev, (xdpsqs)[libeth_xdpsq_id(num)]) + +static inline void __libeth_xdp_xmit_init_bulk(struct libeth_xdp_tx_bulk *bq, + struct net_device *dev, + void *xdpsq) +{ + bq->dev = dev; + bq->xdpsq = xdpsq; + bq->count = 0; +} + +/** + * libeth_xdp_xmit_frame_dma - internal helper to access DMA of an &xdp_frame + * @xf: pointer to the XDP frame + * + * There's no place in &libeth_xdp_tx_frame to store DMA address for an + * &xdp_frame head. The headroom is used then, the address is placed right + * after the frame struct, naturally aligned. + * + * Return: pointer to the DMA address to use. + */ +#define libeth_xdp_xmit_frame_dma(xf) \ + _Generic((xf), \ + const struct xdp_frame *: \ + (const dma_addr_t *)__libeth_xdp_xmit_frame_dma(xf), \ + struct xdp_frame *: \ + (dma_addr_t *)__libeth_xdp_xmit_frame_dma(xf) \ + ) + +static inline void *__libeth_xdp_xmit_frame_dma(const struct xdp_frame *xdpf) +{ + void *addr = (void *)(xdpf + 1); + + if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && + __alignof(*xdpf) < sizeof(dma_addr_t)) + addr = PTR_ALIGN(addr, sizeof(dma_addr_t)); + + return addr; +} + +/** + * libeth_xdp_xmit_queue_head - internal helper for queueing one XDP xmit head + * @bq: XDP Tx bulk to queue the head frag to + * @xdpf: XDP frame with the head to queue + * @dev: device to perform DMA mapping + * + * Return: ``LIBETH_XDP_DROP`` on DMA mapping error, + * ``LIBETH_XDP_PASS`` if it's the only frag in the frame, + * ``LIBETH_XDP_TX`` if it's an S/G frame. + */ +static inline u32 libeth_xdp_xmit_queue_head(struct libeth_xdp_tx_bulk *bq, + struct xdp_frame *xdpf, + struct device *dev) +{ + dma_addr_t dma; + + dma = dma_map_single(dev, xdpf->data, xdpf->len, DMA_TO_DEVICE); + if (dma_mapping_error(dev, dma)) + return LIBETH_XDP_DROP; + + *libeth_xdp_xmit_frame_dma(xdpf) = dma; + + bq->bulk[bq->count++] = (typeof(*bq->bulk)){ + .xdpf = xdpf, + __libeth_xdp_tx_len(xdpf->len, LIBETH_XDP_TX_FIRST), + }; + + if (!xdp_frame_has_frags(xdpf)) + return LIBETH_XDP_PASS; + + bq->bulk[bq->count - 1].flags |= LIBETH_XDP_TX_MULTI; + + return LIBETH_XDP_TX; +} + +/** + * libeth_xdp_xmit_queue_frag - internal helper for queueing one XDP xmit frag + * @bq: XDP Tx bulk to queue the frag to + * @frag: frag to queue + * @dev: device to perform DMA mapping + * + * Return: true on success, false on DMA mapping error. + */ +static inline bool libeth_xdp_xmit_queue_frag(struct libeth_xdp_tx_bulk *bq, + const skb_frag_t *frag, + struct device *dev) +{ + dma_addr_t dma; + + dma = skb_frag_dma_map(dev, frag); + if (dma_mapping_error(dev, dma)) + return false; + + bq->bulk[bq->count++] = (typeof(*bq->bulk)){ + .dma = dma, + __libeth_xdp_tx_len(skb_frag_size(frag)), + }; + + return true; +} + +/** + * libeth_xdp_xmit_queue_bulk - internal helper for queueing one XDP xmit frame + * @bq: XDP Tx bulk to queue the frame to + * @xdpf: XDP frame to queue + * @flush_bulk: driver callback to flush the bulk to the HW queue + * + * Return: ``LIBETH_XDP_TX`` on success, + * ``LIBETH_XDP_DROP`` if the frame should be dropped by the stack, + * ``LIBETH_XDP_ABORTED`` if the frame will be dropped by libeth_xdp. + */ +static __always_inline u32 +libeth_xdp_xmit_queue_bulk(struct libeth_xdp_tx_bulk *bq, + struct xdp_frame *xdpf, + bool (*flush_bulk)(struct libeth_xdp_tx_bulk *bq, + u32 flags)) +{ + u32 head, nr_frags, i, ret = LIBETH_XDP_TX; + struct device *dev = bq->dev->dev.parent; + const struct skb_shared_info *sinfo; + + if (unlikely(bq->count == LIBETH_XDP_TX_BULK) && + unlikely(!flush_bulk(bq, LIBETH_XDP_TX_NDO))) + return LIBETH_XDP_DROP; + + head = libeth_xdp_xmit_queue_head(bq, xdpf, dev); + if (head == LIBETH_XDP_PASS) + goto out; + else if (head == LIBETH_XDP_DROP) + return LIBETH_XDP_DROP; + + sinfo = xdp_get_shared_info_from_frame(xdpf); + nr_frags = sinfo->nr_frags; + + for (i = 0; i < nr_frags; i++) { + if (unlikely(bq->count == LIBETH_XDP_TX_BULK) && + unlikely(!flush_bulk(bq, LIBETH_XDP_TX_NDO))) + break; + + if (!libeth_xdp_xmit_queue_frag(bq, &sinfo->frags[i], dev)) + break; + } + + if (unlikely(i < nr_frags)) + ret = LIBETH_XDP_ABORTED; + +out: + bq->bulk[bq->count - 1].flags |= LIBETH_XDP_TX_LAST; + + return ret; +} + +/** + * libeth_xdp_xmit_fill_buf - internal helper to fill one XDP xmit &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 mapped DMA and other info to pass to + * the driver callback. + */ +static inline struct libeth_xdp_tx_desc +libeth_xdp_xmit_fill_buf(struct libeth_xdp_tx_frame frm, u32 i, + const struct libeth_xdpsq *sq, u64 priv) +{ + struct libeth_xdp_tx_desc desc; + struct libeth_sqe *sqe; + struct xdp_frame *xdpf; + + if (frm.flags & LIBETH_XDP_TX_FIRST) { + xdpf = frm.xdpf; + desc.addr = *libeth_xdp_xmit_frame_dma(xdpf); + } else { + xdpf = NULL; + desc.addr = frm.dma; + } + desc.opts = frm.opts; + + sqe = &sq->sqes[i]; + dma_unmap_addr_set(sqe, dma, desc.addr); + dma_unmap_len_set(sqe, len, desc.len); + + if (!xdpf) { + sqe->type = LIBETH_SQE_XDP_XMIT_FRAG; + return desc; + } + + sqe->type = LIBETH_SQE_XDP_XMIT; + sqe->xdpf = xdpf; + libeth_xdp_tx_fill_stats(sqe, &desc, + xdp_get_shared_info_from_frame(xdpf)); + + return desc; +} + +/** + * libeth_xdp_xmit_flush_bulk - wrapper to define flush of one XDP xmit 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_XDP_DEFINE_FLUSH_XMIT() to define an XDP xmit driver + * callback. + */ +#define libeth_xdp_xmit_flush_bulk(bq, flags, prep, xmit) \ + __libeth_xdp_tx_flush_bulk(bq, (flags) | LIBETH_XDP_TX_NDO, prep, \ + libeth_xdp_xmit_fill_buf, xmit) + +u32 libeth_xdp_xmit_return_bulk(const struct libeth_xdp_tx_frame *bq, + u32 count, const struct net_device *dev); + +/** + * __libeth_xdp_xmit_do_bulk - internal function to implement .ndo_xdp_xmit() + * @bq: XDP Tx bulk to queue frames to + * @frames: XDP frames passed by the stack + * @n: number of frames + * @flags: flags passed by the stack + * @flush_bulk: driver callback to flush an XDP xmit bulk + * @finalize: driver callback to finalize sending XDP Tx frames on the queue + * + * Perform common checks, map the frags and queue them to the bulk, then flush + * the bulk to the XDPSQ. If requested by the stack, finalize the queue. + * + * Return: number of frames send or -errno on error. + */ +static __always_inline int +__libeth_xdp_xmit_do_bulk(struct libeth_xdp_tx_bulk *bq, + struct xdp_frame **frames, u32 n, u32 flags, + bool (*flush_bulk)(struct libeth_xdp_tx_bulk *bq, + u32 flags), + void (*finalize)(void *xdpsq, bool sent, bool flush)) +{ + u32 nxmit = 0; + + if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) + return -EINVAL; + + for (u32 i = 0; likely(i < n); i++) { + u32 ret; + + ret = libeth_xdp_xmit_queue_bulk(bq, frames[i], flush_bulk); + if (unlikely(ret != LIBETH_XDP_TX)) { + nxmit += ret == LIBETH_XDP_ABORTED; + break; + } + + nxmit++; + } + + if (bq->count) { + flush_bulk(bq, LIBETH_XDP_TX_NDO); + if (unlikely(bq->count)) + nxmit -= libeth_xdp_xmit_return_bulk(bq->bulk, + bq->count, + bq->dev); + } + + finalize(bq->xdpsq, nxmit, flags & XDP_XMIT_FLUSH); + + return nxmit; +} + +/** + * libeth_xdp_xmit_do_bulk - implement full .ndo_xdp_xmit() in driver + * @dev: target &net_device + * @n: number of frames to send + * @fr: XDP frames to send + * @f: flags passed by the stack + * @xqs: array of XDPSQs driver structs + * @nqs: number of active XDPSQs, the above array length + * @fl: driver callback to flush an XDP xmit bulk + * @fin: driver cabback to finalize the queue + * + * If the driver has active XDPSQs, perform common checks and send the frames. + * Finalize the queue, if requested. + * + * Return: number of frames sent or -errno on error. + */ +#define libeth_xdp_xmit_do_bulk(dev, n, fr, f, xqs, nqs, fl, fin) \ + _libeth_xdp_xmit_do_bulk(dev, n, fr, f, xqs, nqs, fl, fin, \ + __UNIQUE_ID(bq_), __UNIQUE_ID(ret_), \ + __UNIQUE_ID(nqs_)) + +#define _libeth_xdp_xmit_do_bulk(d, n, fr, f, xqs, nqs, fl, fin, ub, ur, un) \ +({ \ + u32 un = (nqs); \ + int ur; \ + \ + if (likely(un)) { \ + LIBETH_XDP_ONSTACK_BULK(ub); \ + \ + libeth_xdp_xmit_init_bulk(&ub, d, xqs, un); \ + ur = __libeth_xdp_xmit_do_bulk(&ub, fr, n, f, fl, fin); \ + } else { \ + ur = -ENXIO; \ + } \ + \ + ur; \ +}) + +/* Rx polling path */ + +/** + * libeth_xdp_tx_init_bulk - initialize an XDP Tx bulk for Rx NAPI poll + * @bq: bulk to initialize + * @prog: RCU pointer to the XDP program (can be %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 NAPI polling loop. + * Initializes all the needed fields to run libeth_xdp functions. If @num == 0, + * assumes XDP is not enabled. + * Do not use for XSk, it has its own optimized helper. + */ +#define libeth_xdp_tx_init_bulk(bq, prog, dev, xdpsqs, num) \ + __libeth_xdp_tx_init_bulk(bq, prog, dev, xdpsqs, num, false, \ + __UNIQUE_ID(bq_), __UNIQUE_ID(nqs_)) + +#define __libeth_xdp_tx_init_bulk(bq, pr, d, xdpsqs, num, xsk, ub, un) do { \ + typeof(bq) ub = (bq); \ + u32 un = (num); \ + \ + rcu_read_lock(); \ + \ + if (un || (xsk)) { \ + ub->prog = rcu_dereference(pr); \ + ub->dev = (d); \ + ub->xdpsq = (xdpsqs)[libeth_xdpsq_id(un)]; \ + } else { \ + ub->prog = NULL; \ + } \ + \ + ub->act_mask = 0; \ + ub->count = 0; \ +} while (0) + +void libeth_xdp_load_stash(struct libeth_xdp_buff *dst, + const struct libeth_xdp_buff_stash *src); +void libeth_xdp_save_stash(struct libeth_xdp_buff_stash *dst, + const struct libeth_xdp_buff *src); +void __libeth_xdp_return_stash(struct libeth_xdp_buff_stash *stash); + +/** + * libeth_xdp_init_buff - initialize a &libeth_xdp_buff for Rx NAPI poll + * @dst: onstack buffer to initialize + * @src: XDP buffer stash placed on the queue + * @rxq: registered &xdp_rxq_info corresponding to this queue + * + * Should be called before the main NAPI polling loop. Loads the content of + * the previously saved stash or initializes the buffer from scratch. + * Do not use for XSk. + */ +static inline void +libeth_xdp_init_buff(struct libeth_xdp_buff *dst, + const struct libeth_xdp_buff_stash *src, + struct xdp_rxq_info *rxq) +{ + if (likely(!src->data)) + dst->data = NULL; + else + libeth_xdp_load_stash(dst, src); + + dst->base.rxq = rxq; +} + +/** + * libeth_xdp_save_buff - save a partially built buffer on a queue + * @dst: XDP buffer stash placed on the queue + * @src: onstack buffer to save + * + * Should be called after the main NAPI polling loop. If the loop exited before + * the buffer was finished, saves its content on the queue, so that it can be + * completed during the next poll. Otherwise, clears the stash. + */ +static inline void libeth_xdp_save_buff(struct libeth_xdp_buff_stash *dst, + const struct libeth_xdp_buff *src) +{ + if (likely(!src->data)) + dst->data = NULL; + else + libeth_xdp_save_stash(dst, src); +} + +/** + * libeth_xdp_return_stash - free an XDP buffer stash from a queue + * @stash: stash to free + * + * If the queue is about to be destroyed, but it still has an incompleted + * buffer stash, this helper should be called to free it. + */ +static inline void libeth_xdp_return_stash(struct libeth_xdp_buff_stash *stash) +{ + if (stash->data) + __libeth_xdp_return_stash(stash); +} + +static inline void libeth_xdp_return_va(const void *data, bool napi) +{ + netmem_ref netmem = virt_to_netmem(data); + + page_pool_put_full_netmem(__netmem_get_pp(netmem), netmem, napi); +} + +static inline void libeth_xdp_return_frags(const struct skb_shared_info *sinfo, + bool napi) +{ + for (u32 i = 0; i < sinfo->nr_frags; i++) { + netmem_ref netmem = skb_frag_netmem(&sinfo->frags[i]); + + page_pool_put_full_netmem(netmem_get_pp(netmem), netmem, napi); + } +} + +/** + * libeth_xdp_return_buff - free/recycle &libeth_xdp_buff + * @xdp: buffer to free + * + * Hotpath helper to free &libeth_xdp_buff. Comparing to xdp_return_buff(), + * it's faster as it gets inlined and always assumes order-0 pages and safe + * direct recycling. Zeroes @xdp->data to avoid UAFs. + */ +#define libeth_xdp_return_buff(xdp) __libeth_xdp_return_buff(xdp, true) + +static inline void __libeth_xdp_return_buff(struct libeth_xdp_buff *xdp, + bool napi) +{ + if (!xdp_buff_has_frags(&xdp->base)) + goto out; + + libeth_xdp_return_frags(xdp_get_shared_info_from_buff(&xdp->base), + napi); + +out: + libeth_xdp_return_va(xdp->data, napi); + xdp->data = NULL; +} + +bool libeth_xdp_buff_add_frag(struct libeth_xdp_buff *xdp, + const struct libeth_fqe *fqe, + u32 len); + +/** + * libeth_xdp_prepare_buff - fill &libeth_xdp_buff with head FQE data + * @xdp: XDP buffer to attach the head to + * @fqe: FQE containing the head buffer + * @len: buffer len passed from HW + * + * Internal, use libeth_xdp_process_buff() instead. Initializes XDP buffer + * head with the Rx buffer data: data pointer, length, headroom, and + * truesize/tailroom. Zeroes the flags. + * Uses faster single u64 write instead of per-field access. + */ +static inline void libeth_xdp_prepare_buff(struct libeth_xdp_buff *xdp, + const struct libeth_fqe *fqe, + u32 len) +{ + const struct page *page = __netmem_to_page(fqe->netmem); + +#ifdef __LIBETH_WORD_ACCESS + static_assert(offsetofend(typeof(xdp->base), flags) - + offsetof(typeof(xdp->base), frame_sz) == + sizeof(u64)); + + *(u64 *)&xdp->base.frame_sz = fqe->truesize; +#else + xdp_init_buff(&xdp->base, fqe->truesize, xdp->base.rxq); +#endif + xdp_prepare_buff(&xdp->base, page_address(page) + fqe->offset, + pp_page_to_nmdesc(page)->pp->p.offset, len, true); +} + +/** + * libeth_xdp_process_buff - attach Rx buffer to &libeth_xdp_buff + * @xdp: XDP buffer to attach the Rx buffer to + * @fqe: Rx buffer to process + * @len: received data length from the descriptor + * + * If the XDP buffer is empty, attaches the Rx 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: true on success, false if the descriptor must be skipped (empty or + * no space for a new frag). + */ +static inline bool libeth_xdp_process_buff(struct libeth_xdp_buff *xdp, + const struct libeth_fqe *fqe, + u32 len) +{ + if (!libeth_rx_sync_for_cpu(fqe, len)) + return false; + + if (xdp->data) + return libeth_xdp_buff_add_frag(xdp, fqe, len); + + libeth_xdp_prepare_buff(xdp, fqe, len); + + prefetch(xdp->data); + + return true; +} + +/** + * libeth_xdp_buff_stats_frags - update onstack RQ stats with XDP frags info + * @ss: onstack stats to update + * @xdp: buffer to account + * + * Internal helper used by __libeth_xdp_run_pass(), do not call directly. + * Adds buffer's frags count and total len to the onstack stats. + */ +static inline void +libeth_xdp_buff_stats_frags(struct libeth_rq_napi_stats *ss, + const struct libeth_xdp_buff *xdp) +{ + const struct skb_shared_info *sinfo; + + sinfo = xdp_get_shared_info_from_buff(&xdp->base); + ss->bytes += sinfo->xdp_frags_size; + ss->fragments += sinfo->nr_frags + 1; +} + +u32 libeth_xdp_prog_exception(const struct libeth_xdp_tx_bulk *bq, + struct libeth_xdp_buff *xdp, + enum xdp_action act, int ret); + +/** + * __libeth_xdp_run_prog - run XDP program on an XDP buffer + * @xdp: XDP buffer to run the prog on + * @bq: buffer bulk for ``XDP_TX`` queueing + * + * Internal inline abstraction to run XDP program. Handles ``XDP_DROP`` + * and ``XDP_REDIRECT`` only, the rest is processed levels up. + * Reports an XDP prog exception on errors. + * + * Return: libeth_xdp prog verdict depending on the prog's verdict. + */ +static __always_inline u32 +__libeth_xdp_run_prog(struct libeth_xdp_buff *xdp, + const struct libeth_xdp_tx_bulk *bq) +{ + enum xdp_action act; + + act = bpf_prog_run_xdp(bq->prog, &xdp->base); + if (unlikely(act < XDP_DROP || act > XDP_REDIRECT)) + goto out; + + switch (act) { + case XDP_PASS: + return LIBETH_XDP_PASS; + case XDP_DROP: + libeth_xdp_return_buff(xdp); + + return LIBETH_XDP_DROP; + case XDP_TX: + return LIBETH_XDP_TX; + case XDP_REDIRECT: + if (unlikely(xdp_do_redirect(bq->dev, &xdp->base, bq->prog))) + break; + + xdp->data = NULL; + + return LIBETH_XDP_REDIRECT; + default: + break; + } + +out: + return libeth_xdp_prog_exception(bq, xdp, act, 0); +} + +/** + * __libeth_xdp_run_flush - run XDP program and handle ``XDP_TX`` verdict + * @xdp: XDP buffer to run the prog on + * @bq: buffer bulk for ``XDP_TX`` queueing + * @run: internal callback for running XDP program + * @queue: internal callback for queuing ``XDP_TX`` frame + * @flush_bulk: driver callback for flushing a bulk + * + * Internal inline abstraction to run XDP program and additionally handle + * ``XDP_TX`` verdict. Used by both XDP and XSk, hence @run and @queue. + * Do not use directly. + * + * Return: libeth_xdp prog verdict depending on the prog's verdict. + */ +static __always_inline u32 +__libeth_xdp_run_flush(struct libeth_xdp_buff *xdp, + struct libeth_xdp_tx_bulk *bq, + u32 (*run)(struct libeth_xdp_buff *xdp, + const struct libeth_xdp_tx_bulk *bq), + bool (*queue)(struct libeth_xdp_tx_bulk *bq, + struct libeth_xdp_buff *xdp, + bool (*flush_bulk) + (struct libeth_xdp_tx_bulk *bq, + u32 flags)), + bool (*flush_bulk)(struct libeth_xdp_tx_bulk *bq, + u32 flags)) +{ + u32 act; + + act = run(xdp, bq); + if (act == LIBETH_XDP_TX && unlikely(!queue(bq, xdp, flush_bulk))) + act = LIBETH_XDP_DROP; + + bq->act_mask |= act; + + return act; +} + +/** + * libeth_xdp_run_prog - run XDP program (non-XSk path) and handle all verdicts + * @xdp: XDP 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. XSk has its + * own version. + * Prefer using it via LIBETH_XDP_DEFINE_RUN{,_PASS,_PROG}(). + * + * Return: true if the buffer should be passed up the stack, false if the poll + * should go to the next buffer. + */ +#define libeth_xdp_run_prog(xdp, bq, fl) \ + (__libeth_xdp_run_flush(xdp, bq, __libeth_xdp_run_prog, \ + libeth_xdp_tx_queue_bulk, \ + fl) == LIBETH_XDP_PASS) + +/** + * __libeth_xdp_run_pass - helper to run XDP program and handle the result + * @xdp: XDP 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 XDP 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 that does the following (non-XSk path): + * 1) adds frame size and frag number (if needed) to the onstack stats; + * 2) fills the descriptor metadata to the onstack &libeth_xdp_buff + * 3) runs XDP program if present; + * 4) handles all possible verdicts; + * 5) on ``XDP_PASS`, builds an skb from the buffer; + * 6) populates it with the descriptor metadata; + * 7) passes it up the stack. + * + * In most cases, number 2 means just writing the pointer to the HW descriptor + * to the XDP buffer. If so, please use LIBETH_XDP_DEFINE_RUN{,_PASS}() + * wrappers to build a driver function. + */ +static __always_inline void +__libeth_xdp_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), + bool (*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; + + rs->bytes += xdp->base.data_end - xdp->data; + rs->packets++; + + if (xdp_buff_has_frags(&xdp->base)) + libeth_xdp_buff_stats_frags(rs, xdp); + + if (prep && (!__builtin_constant_p(!!md) || md)) + prep(xdp, md); + + if (!bq || !run || !bq->prog) + goto build; + + if (!run(xdp, bq)) + return; + +build: + skb = xdp_build_skb_from_buff(&xdp->base); + if (unlikely(!skb)) { + libeth_xdp_return_buff_slow(xdp); + return; + } + + xdp->data = NULL; + + if (unlikely(!populate(skb, xdp, rs))) { + napi_consume_skb(skb, true); + return; + } + + napi_gro_receive(napi, skb); +} + +static inline void libeth_xdp_prep_desc(struct libeth_xdp_buff *xdp, + const void *desc) +{ + xdp->desc = desc; +} + +/** + * libeth_xdp_run_pass - helper to run XDP program and handle the result + * @xdp: XDP buffer to process + * @bq: XDP Tx bulk to queue ``XDP_TX`` frames + * @napi: NAPI to build an skb and pass it up the stack + * @ss: 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_xdp_run_pass(xdp, bq, napi, ss, desc, run, populate) \ + __libeth_xdp_run_pass(xdp, bq, napi, ss, desc, libeth_xdp_prep_desc, \ + run, populate) + +/** + * libeth_xdp_finalize_rx - finalize XDPSQ after a NAPI polling loop (non-XSk) + * @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_xdp_finalize_rx(bq, flush, finalize) \ + __libeth_xdp_finalize_rx(bq, 0, flush, finalize) + +static __always_inline void +__libeth_xdp_finalize_rx(struct libeth_xdp_tx_bulk *bq, u32 flags, + bool (*flush_bulk)(struct libeth_xdp_tx_bulk *bq, + u32 flags), + void (*finalize)(void *xdpsq, bool sent, bool flush)) +{ + if (bq->act_mask & LIBETH_XDP_TX) { + if (bq->count) + flush_bulk(bq, flags | LIBETH_XDP_TX_DROP); + finalize(bq->xdpsq, true, true); + } + if (bq->act_mask & LIBETH_XDP_REDIRECT) + xdp_do_flush(); + + rcu_read_unlock(); +} + +/* + * Helpers to reduce boilerplate code in drivers. + * + * Typical driver Rx flow would be (excl. bulk and buff init, frag attach): + * + * LIBETH_XDP_DEFINE_START(); + * LIBETH_XDP_DEFINE_FLUSH_TX(static driver_xdp_flush_tx, driver_xdp_tx_prep, + * driver_xdp_xmit); + * LIBETH_XDP_DEFINE_RUN(static driver_xdp_run, driver_xdp_run_prog, + * driver_xdp_flush_tx, driver_populate_skb); + * LIBETH_XDP_DEFINE_FINALIZE(static driver_xdp_finalize_rx, + * driver_xdp_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) { + * // ... + * driver_xdp_run(xdp, &bq, napi, &rs, desc); + * } + * driver_xdp_finalize_rx(&bq); + */ + +#define LIBETH_XDP_DEFINE_START() \ + __diag_push(); \ + __diag_ignore(GCC, 8, "-Wold-style-declaration", \ + "Allow specifying \'static\' after the return type") + +/** + * LIBETH_XDP_DEFINE_TIMER - define a driver XDPSQ cleanup timer callback + * @name: name of the function to define + * @poll: Tx polling/completion function + */ +#define LIBETH_XDP_DEFINE_TIMER(name, poll) \ +void name(struct work_struct *work) \ +{ \ + libeth_xdpsq_run_timer(work, poll); \ +} + +/** + * LIBETH_XDP_DEFINE_FLUSH_TX - define a driver ``XDP_TX`` bulk 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_XDP_DEFINE_FLUSH_TX(name, prep, xmit) \ + __LIBETH_XDP_DEFINE_FLUSH_TX(name, prep, xmit, xdp) + +#define __LIBETH_XDP_DEFINE_FLUSH_TX(name, prep, xmit, pfx) \ +bool name(struct libeth_xdp_tx_bulk *bq, u32 flags) \ +{ \ + return libeth_##pfx##_tx_flush_bulk(bq, flags, prep, xmit); \ +} + +/** + * LIBETH_XDP_DEFINE_FLUSH_XMIT - define a driver XDP xmit bulk 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_XDP_DEFINE_FLUSH_XMIT(name, prep, xmit) \ +bool name(struct libeth_xdp_tx_bulk *bq, u32 flags) \ +{ \ + return libeth_xdp_xmit_flush_bulk(bq, flags, prep, xmit); \ +} + +/** + * LIBETH_XDP_DEFINE_RUN_PROG - define a driver XDP program run function + * @name: name of the function to define + * @flush: driver callback to flush an ``XDP_TX`` bulk + */ +#define LIBETH_XDP_DEFINE_RUN_PROG(name, flush) \ + bool __LIBETH_XDP_DEFINE_RUN_PROG(name, flush, xdp) + +#define __LIBETH_XDP_DEFINE_RUN_PROG(name, flush, pfx) \ +name(struct libeth_xdp_buff *xdp, struct libeth_xdp_tx_bulk *bq) \ +{ \ + return libeth_##pfx##_run_prog(xdp, bq, flush); \ +} + +/** + * LIBETH_XDP_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_XDP_DEFINE_RUN_PASS(name, run, populate) \ + void __LIBETH_XDP_DEFINE_RUN_PASS(name, run, populate, xdp) + +#define __LIBETH_XDP_DEFINE_RUN_PASS(name, run, populate, pfx) \ +name(struct libeth_xdp_buff *xdp, struct libeth_xdp_tx_bulk *bq, \ + struct napi_struct *napi, struct libeth_rq_napi_stats *ss, \ + const void *desc) \ +{ \ + return libeth_##pfx##_run_pass(xdp, bq, napi, ss, desc, run, \ + populate); \ +} + +/** + * LIBETH_XDP_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 ``XDP_TX`` bulk + * @populate: driver callback to fill an skb with HW descriptor info + */ +#define LIBETH_XDP_DEFINE_RUN(name, run, flush, populate) \ + __LIBETH_XDP_DEFINE_RUN(name, run, flush, populate, XDP) + +#define __LIBETH_XDP_DEFINE_RUN(name, run, flush, populate, pfx) \ + LIBETH_##pfx##_DEFINE_RUN_PROG(static run, flush); \ + LIBETH_##pfx##_DEFINE_RUN_PASS(name, run, populate) + +/** + * LIBETH_XDP_DEFINE_FINALIZE - define a driver Rx NAPI poll finalize function + * @name: name of the function to define + * @flush: driver callback to flush an ``XDP_TX`` bulk + * @finalize: driver callback to finalize an XDPSQ and run the timer + */ +#define LIBETH_XDP_DEFINE_FINALIZE(name, flush, finalize) \ + __LIBETH_XDP_DEFINE_FINALIZE(name, flush, finalize, xdp) + +#define __LIBETH_XDP_DEFINE_FINALIZE(name, flush, finalize, pfx) \ +void name(struct libeth_xdp_tx_bulk *bq) \ +{ \ + libeth_##pfx##_finalize_rx(bq, flush, finalize); \ +} + +#define LIBETH_XDP_DEFINE_END() __diag_pop() + +/* XMO */ + +/** + * libeth_xdp_buff_to_rq - get RQ pointer from an XDP buffer pointer + * @xdp: &libeth_xdp_buff corresponding to the queue + * @type: typeof() of the driver Rx queue structure + * @member: name of &xdp_rxq_info inside @type + * + * Often times, pointer to the RQ is needed when reading/filling metadata from + * HW descriptors. The helper can be used to quickly jump from an XDP buffer + * to the queue corresponding to its &xdp_rxq_info without introducing + * additional fields (&libeth_xdp_buff is precisely 1 cacheline long on x64). + */ +#define libeth_xdp_buff_to_rq(xdp, type, member) \ + container_of_const((xdp)->base.rxq, type, member) + +/** + * libeth_xdpmo_rx_hash - convert &libeth_rx_pt to an XDP RSS hash metadata + * @hash: pointer to the variable to write the hash to + * @rss_type: pointer to the variable to write the hash type to + * @val: hash value from the HW descriptor + * @pt: libeth parsed packet type + * + * Handle zeroed/non-available hash and convert libeth parsed packet type to + * the corresponding XDP RSS hash type. To be called at the end of + * xdp_metadata_ops idpf_xdpmo::xmo_rx_hash() implementation. + * Note that if the driver doesn't use a constant packet type lookup table but + * generates it at runtime, it must call libeth_rx_pt_gen_hash_type(pt) to + * generate XDP RSS hash type for each packet type. + * + * Return: 0 on success, -ENODATA when the hash is not available. + */ +static inline int libeth_xdpmo_rx_hash(u32 *hash, + enum xdp_rss_hash_type *rss_type, + u32 val, struct libeth_rx_pt pt) +{ + if (unlikely(!val)) + return -ENODATA; + + *hash = val; + *rss_type = pt.hash_type; + + return 0; +} + +/* Tx buffer completion */ + +void libeth_xdp_return_buff_bulk(const struct skb_shared_info *sinfo, + struct xdp_frame_bulk *bq, bool frags); +void libeth_xsk_buff_free_slow(struct libeth_xdp_buff *xdp); + +/** + * __libeth_xdp_complete_tx - complete sent XDPSQE + * @sqe: SQ element / Tx buffer to complete + * @cp: Tx polling/completion params + * @bulk: internal callback to bulk-free ``XDP_TX`` buffers + * @xsk: internal callback to free XSk ``XDP_TX`` buffers + * + * Use the non-underscored version in drivers instead. This one is shared + * internally with libeth_tx_complete_any(). + * Complete an XDPSQE of any type of XDP frame. This includes DMA unmapping + * when needed, buffer freeing, stats update, and SQE invalidation. + */ +static __always_inline void +__libeth_xdp_complete_tx(struct libeth_sqe *sqe, struct libeth_cq_pp *cp, + typeof(libeth_xdp_return_buff_bulk) bulk, + typeof(libeth_xsk_buff_free_slow) xsk) +{ + enum libeth_sqe_type type = sqe->type; + + switch (type) { + case LIBETH_SQE_EMPTY: + return; + case LIBETH_SQE_XDP_XMIT: + case LIBETH_SQE_XDP_XMIT_FRAG: + dma_unmap_page(cp->dev, dma_unmap_addr(sqe, dma), + dma_unmap_len(sqe, len), DMA_TO_DEVICE); + break; + default: + break; + } + + switch (type) { + case LIBETH_SQE_XDP_TX: + bulk(sqe->sinfo, cp->bq, sqe->nr_frags != 1); + break; + case LIBETH_SQE_XDP_XMIT: + xdp_return_frame_bulk(sqe->xdpf, cp->bq); + break; + case LIBETH_SQE_XSK_TX: + case LIBETH_SQE_XSK_TX_FRAG: + xsk(sqe->xsk); + break; + default: + break; + } + + switch (type) { + case LIBETH_SQE_XDP_TX: + case LIBETH_SQE_XDP_XMIT: + case LIBETH_SQE_XSK_TX: + cp->xdp_tx -= sqe->nr_frags; + + cp->xss->packets++; + cp->xss->bytes += sqe->bytes; + break; + default: + break; + } + + sqe->type = LIBETH_SQE_EMPTY; +} + +static inline void libeth_xdp_complete_tx(struct libeth_sqe *sqe, + struct libeth_cq_pp *cp) +{ + __libeth_xdp_complete_tx(sqe, cp, libeth_xdp_return_buff_bulk, + libeth_xsk_buff_free_slow); +} + +/* Misc */ + +u32 libeth_xdp_queue_threshold(u32 count); + +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); +void libeth_xdp_set_redirect(struct net_device *dev, bool enable); + +/** + * libeth_xdp_set_features - set XDP features for netdev + * @dev: &net_device to configure + * @...: optional params, see __libeth_xdp_set_features() + * + * Set all the features libeth_xdp supports, including .ndo_xdp_xmit(). That + * said, it should be used only when XDPSQs are always available regardless + * of whether an XDP prog is attached to @dev. + */ +#define libeth_xdp_set_features(dev, ...) \ + CONCATENATE(__libeth_xdp_feat, \ + COUNT_ARGS(__VA_ARGS__))(dev, ##__VA_ARGS__) + +#define __libeth_xdp_feat0(dev) \ + __libeth_xdp_set_features(dev, NULL, 0, NULL) +#define __libeth_xdp_feat1(dev, xmo) \ + __libeth_xdp_set_features(dev, xmo, 0, NULL) +#define __libeth_xdp_feat2(dev, xmo, zc_segs) \ + __libeth_xdp_set_features(dev, xmo, zc_segs, NULL) +#define __libeth_xdp_feat3(dev, xmo, zc_segs, tmo) \ + __libeth_xdp_set_features(dev, xmo, zc_segs, tmo) + +/** + * libeth_xdp_set_features_noredir - enable all libeth_xdp features w/o redir + * @dev: target &net_device + * @...: optional params, see __libeth_xdp_set_features() + * + * Enable everything except the .ndo_xdp_xmit() feature, use when XDPSQs are + * not available right after netdev registration. + */ +#define libeth_xdp_set_features_noredir(dev, ...) \ + __libeth_xdp_set_features_noredir(dev, __UNIQUE_ID(dev_), \ + ##__VA_ARGS__) + +#define __libeth_xdp_set_features_noredir(dev, ud, ...) do { \ + struct net_device *ud = (dev); \ + \ + libeth_xdp_set_features(ud, ##__VA_ARGS__); \ + libeth_xdp_set_redirect(ud, false); \ +} while (0) + +#define libeth_xsktmo ((const void *)GOLDEN_RATIO_PRIME) + +#endif /* __LIBETH_XDP_H */ |