diff options
| -rw-r--r-- | drivers/net/ethernet/intel/libeth/xdp.c | 90 | ||||
| -rw-r--r-- | include/net/libeth/types.h | 23 | ||||
| -rw-r--r-- | include/net/libeth/xdp.h | 151 |
3 files changed, 264 insertions, 0 deletions
diff --git a/drivers/net/ethernet/intel/libeth/xdp.c b/drivers/net/ethernet/intel/libeth/xdp.c index 6f62603cf568..d0669f1f02f3 100644 --- a/drivers/net/ethernet/intel/libeth/xdp.c +++ b/drivers/net/ethernet/intel/libeth/xdp.c @@ -175,6 +175,64 @@ 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 * @@ -187,6 +245,38 @@ void __cold libeth_xdp_return_buff_slow(struct libeth_xdp_buff *xdp) } 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); + /* Tx buffer completion */ static void libeth_xdp_put_netmem_bulk(netmem_ref netmem, diff --git a/include/net/libeth/types.h b/include/net/libeth/types.h index 4df703a9eb59..7b27c1966d45 100644 --- a/include/net/libeth/types.h +++ b/include/net/libeth/types.h @@ -79,4 +79,27 @@ struct libeth_xdpsq_timer { struct delayed_work dwork; }; +/* Rx polling path */ + +/** + * struct libeth_xdp_buff_stash - struct for stashing &xdp_buff onto a queue + * @data: pointer to the start of the frame, xdp_buff.data + * @headroom: frame headroom, xdp_buff.data - xdp_buff.data_hard_start + * @len: frame linear space length, xdp_buff.data_end - xdp_buff.data + * @frame_sz: truesize occupied by the frame, xdp_buff.frame_sz + * @flags: xdp_buff.flags + * + * &xdp_buff is 56 bytes long on x64, &libeth_xdp_buff is 64 bytes. This + * structure carries only necessary fields to save/restore a partially built + * frame on the queue structure to finish it during the next NAPI poll. + */ +struct libeth_xdp_buff_stash { + void *data; + u16 headroom; + u16 len; + + u32 frame_sz:24; + u32 flags:8; +} __aligned_largest; + #endif /* __LIBETH_TYPES_H */ diff --git a/include/net/libeth/xdp.h b/include/net/libeth/xdp.h index 22bd038decb6..780447cdabc1 100644 --- a/include/net/libeth/xdp.h +++ b/include/net/libeth/xdp.h @@ -60,6 +60,42 @@ static_assert(offsetof(struct libeth_xdp_buff, desc) == 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); @@ -963,6 +999,65 @@ __libeth_xdp_xmit_do_bulk(struct libeth_xdp_tx_bulk *bq, /* Rx polling path */ +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. + */ +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); @@ -1004,6 +1099,62 @@ out: 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. + */ +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); + + xdp_init_buff(&xdp->base, fqe->truesize, xdp->base.rxq); + xdp_prepare_buff(&xdp->base, page_address(page) + fqe->offset, + 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; +} + /* Tx buffer completion */ void libeth_xdp_return_buff_bulk(const struct skb_shared_info *sinfo, |