diff options
Diffstat (limited to 'include/net/libeth/xdp.h')
| -rw-r--r-- | include/net/libeth/xdp.h | 151 |
1 files changed, 151 insertions, 0 deletions
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, |