diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/xdp.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/net/core/xdp.c b/net/core/xdp.c index f1165a35411b..67b53fc7191e 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -535,6 +535,17 @@ void xdp_return_frame_bulk(struct xdp_frame *xdpf, } EXPORT_SYMBOL_GPL(xdp_return_frame_bulk); +/** + * xdp_return_frag -- free one XDP frag or decrement its refcount + * @netmem: network memory reference to release + * @xdp: &xdp_buff to release the frag for + */ +void xdp_return_frag(netmem_ref netmem, const struct xdp_buff *xdp) +{ + __xdp_return(netmem, xdp->rxq->mem.type, true, NULL); +} +EXPORT_SYMBOL_GPL(xdp_return_frag); + void xdp_return_buff(struct xdp_buff *xdp) { struct skb_shared_info *sinfo; @@ -618,6 +629,173 @@ int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp) } EXPORT_SYMBOL_GPL(xdp_alloc_skb_bulk); +/** + * xdp_build_skb_from_buff - create an skb from &xdp_buff + * @xdp: &xdp_buff to convert to an skb + * + * Perform common operations to create a new skb to pass up the stack from + * &xdp_buff: allocate an skb head from the NAPI percpu cache, initialize + * skb data pointers and offsets, set the recycle bit if the buff is + * PP-backed, Rx queue index, protocol and update frags info. + * + * Return: new &sk_buff on success, %NULL on error. + */ +struct sk_buff *xdp_build_skb_from_buff(const struct xdp_buff *xdp) +{ + const struct xdp_rxq_info *rxq = xdp->rxq; + const struct skb_shared_info *sinfo; + struct sk_buff *skb; + u32 nr_frags = 0; + int metalen; + + if (unlikely(xdp_buff_has_frags(xdp))) { + sinfo = xdp_get_shared_info_from_buff(xdp); + nr_frags = sinfo->nr_frags; + } + + skb = napi_build_skb(xdp->data_hard_start, xdp->frame_sz); + if (unlikely(!skb)) + return NULL; + + skb_reserve(skb, xdp->data - xdp->data_hard_start); + __skb_put(skb, xdp->data_end - xdp->data); + + metalen = xdp->data - xdp->data_meta; + if (metalen > 0) + skb_metadata_set(skb, metalen); + + if (rxq->mem.type == MEM_TYPE_PAGE_POOL) + skb_mark_for_recycle(skb); + + skb_record_rx_queue(skb, rxq->queue_index); + + if (unlikely(nr_frags)) { + u32 tsize; + + tsize = sinfo->xdp_frags_truesize ? : nr_frags * xdp->frame_sz; + xdp_update_skb_shared_info(skb, nr_frags, + sinfo->xdp_frags_size, tsize, + xdp_buff_is_frag_pfmemalloc(xdp)); + } + + skb->protocol = eth_type_trans(skb, rxq->dev); + + return skb; +} +EXPORT_SYMBOL_GPL(xdp_build_skb_from_buff); + +/** + * xdp_copy_frags_from_zc - copy frags from XSk buff to skb + * @skb: skb to copy frags to + * @xdp: XSk &xdp_buff from which the frags will be copied + * @pp: &page_pool backing page allocation, if available + * + * Copy all frags from XSk &xdp_buff to the skb to pass it up the stack. + * Allocate a new buffer for each frag, copy it and attach to the skb. + * + * Return: true on success, false on netmem allocation fail. + */ +static noinline bool xdp_copy_frags_from_zc(struct sk_buff *skb, + const struct xdp_buff *xdp, + struct page_pool *pp) +{ + struct skb_shared_info *sinfo = skb_shinfo(skb); + const struct skb_shared_info *xinfo; + u32 nr_frags, tsize = 0; + bool pfmemalloc = false; + + xinfo = xdp_get_shared_info_from_buff(xdp); + nr_frags = xinfo->nr_frags; + + for (u32 i = 0; i < nr_frags; i++) { + u32 len = skb_frag_size(&xinfo->frags[i]); + u32 offset, truesize = len; + netmem_ref netmem; + + netmem = page_pool_dev_alloc_netmem(pp, &offset, &truesize); + if (unlikely(!netmem)) { + sinfo->nr_frags = i; + return false; + } + + memcpy(__netmem_address(netmem), + __netmem_address(xinfo->frags[i].netmem), + LARGEST_ALIGN(len)); + __skb_fill_netmem_desc_noacc(sinfo, i, netmem, offset, len); + + tsize += truesize; + pfmemalloc |= netmem_is_pfmemalloc(netmem); + } + + xdp_update_skb_shared_info(skb, nr_frags, xinfo->xdp_frags_size, + tsize, pfmemalloc); + + return true; +} + +/** + * xdp_build_skb_from_zc - create an skb from XSk &xdp_buff + * @xdp: source XSk buff + * + * Similar to xdp_build_skb_from_buff(), but for XSk frames. Allocate an skb + * head, new buffer for the head, copy the data and initialize the skb fields. + * If there are frags, allocate new buffers for them and copy. + * Buffers are allocated from the system percpu pools to try recycling them. + * If new skb was built successfully, @xdp is returned to XSk pool's freelist. + * On error, it remains untouched and the caller must take care of this. + * + * Return: new &sk_buff on success, %NULL on error. + */ +struct sk_buff *xdp_build_skb_from_zc(struct xdp_buff *xdp) +{ + struct page_pool *pp = this_cpu_read(system_page_pool); + const struct xdp_rxq_info *rxq = xdp->rxq; + u32 len = xdp->data_end - xdp->data_meta; + u32 truesize = xdp->frame_sz; + struct sk_buff *skb; + int metalen; + void *data; + + if (!IS_ENABLED(CONFIG_PAGE_POOL)) + return NULL; + + data = page_pool_dev_alloc_va(pp, &truesize); + if (unlikely(!data)) + return NULL; + + skb = napi_build_skb(data, truesize); + if (unlikely(!skb)) { + page_pool_free_va(pp, data, true); + return NULL; + } + + skb_mark_for_recycle(skb); + skb_reserve(skb, xdp->data_meta - xdp->data_hard_start); + + memcpy(__skb_put(skb, len), xdp->data_meta, LARGEST_ALIGN(len)); + + metalen = xdp->data - xdp->data_meta; + if (metalen > 0) { + skb_metadata_set(skb, metalen); + __skb_pull(skb, metalen); + } + + skb_record_rx_queue(skb, rxq->queue_index); + + if (unlikely(xdp_buff_has_frags(xdp)) && + unlikely(!xdp_copy_frags_from_zc(skb, xdp, pp))) { + napi_consume_skb(skb, true); + return NULL; + } + + xsk_buff_free(xdp); + + skb->protocol = eth_type_trans(skb, rxq->dev); + + return skb; +} +EXPORT_SYMBOL_GPL(xdp_build_skb_from_zc); + struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, struct sk_buff *skb, struct net_device *dev) |