diff options
Diffstat (limited to 'include/net/libeth')
| -rw-r--r-- | include/net/libeth/cache.h | 66 | ||||
| -rw-r--r-- | include/net/libeth/rx.h | 261 | ||||
| -rw-r--r-- | include/net/libeth/tx.h | 129 | ||||
| -rw-r--r-- | include/net/libeth/types.h | 25 |
4 files changed, 481 insertions, 0 deletions
diff --git a/include/net/libeth/cache.h b/include/net/libeth/cache.h new file mode 100644 index 000000000000..bdb0c043ce61 --- /dev/null +++ b/include/net/libeth/cache.h @@ -0,0 +1,66 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright (C) 2024 Intel Corporation */ + +#ifndef __LIBETH_CACHE_H +#define __LIBETH_CACHE_H + +#include <linux/cache.h> + +/** + * libeth_cacheline_group_assert - make sure cacheline group size is expected + * @type: type of the structure containing the group + * @grp: group name inside the struct + * @sz: expected group size + */ +#if defined(CONFIG_64BIT) && SMP_CACHE_BYTES == 64 +#define libeth_cacheline_group_assert(type, grp, sz) \ + static_assert(offsetof(type, __cacheline_group_end__##grp) - \ + offsetofend(type, __cacheline_group_begin__##grp) == \ + (sz)) +#define __libeth_cacheline_struct_assert(type, sz) \ + static_assert(sizeof(type) == (sz)) +#else /* !CONFIG_64BIT || SMP_CACHE_BYTES != 64 */ +#define libeth_cacheline_group_assert(type, grp, sz) \ + static_assert(offsetof(type, __cacheline_group_end__##grp) - \ + offsetofend(type, __cacheline_group_begin__##grp) <= \ + (sz)) +#define __libeth_cacheline_struct_assert(type, sz) \ + static_assert(sizeof(type) <= (sz)) +#endif /* !CONFIG_64BIT || SMP_CACHE_BYTES != 64 */ + +#define __libeth_cls1(sz1) SMP_CACHE_ALIGN(sz1) +#define __libeth_cls2(sz1, sz2) (SMP_CACHE_ALIGN(sz1) + SMP_CACHE_ALIGN(sz2)) +#define __libeth_cls3(sz1, sz2, sz3) \ + (SMP_CACHE_ALIGN(sz1) + SMP_CACHE_ALIGN(sz2) + SMP_CACHE_ALIGN(sz3)) +#define __libeth_cls(...) \ + CONCATENATE(__libeth_cls, COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__) + +/** + * libeth_cacheline_struct_assert - make sure CL-based struct size is expected + * @type: type of the struct + * @...: from 1 to 3 CL group sizes (read-mostly, read-write, cold) + * + * When a struct contains several CL groups, it's difficult to predict its size + * on different architectures. The macro instead takes sizes of all of the + * groups the structure contains and generates the final struct size. + */ +#define libeth_cacheline_struct_assert(type, ...) \ + __libeth_cacheline_struct_assert(type, __libeth_cls(__VA_ARGS__)); \ + static_assert(__alignof(type) >= SMP_CACHE_BYTES) + +/** + * libeth_cacheline_set_assert - make sure CL-based struct layout is expected + * @type: type of the struct + * @ro: expected size of the read-mostly group + * @rw: expected size of the read-write group + * @c: expected size of the cold group + * + * Check that each group size is expected and then do final struct size check. + */ +#define libeth_cacheline_set_assert(type, ro, rw, c) \ + libeth_cacheline_group_assert(type, read_mostly, ro); \ + libeth_cacheline_group_assert(type, read_write, rw); \ + libeth_cacheline_group_assert(type, cold, c); \ + libeth_cacheline_struct_assert(type, ro, rw, c) + +#endif /* __LIBETH_CACHE_H */ diff --git a/include/net/libeth/rx.h b/include/net/libeth/rx.h new file mode 100644 index 000000000000..43574bd6612f --- /dev/null +++ b/include/net/libeth/rx.h @@ -0,0 +1,261 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright (C) 2024 Intel Corporation */ + +#ifndef __LIBETH_RX_H +#define __LIBETH_RX_H + +#include <linux/if_vlan.h> + +#include <net/page_pool/helpers.h> +#include <net/xdp.h> + +/* Rx buffer management */ + +/* Space reserved in front of each frame */ +#define LIBETH_SKB_HEADROOM (NET_SKB_PAD + NET_IP_ALIGN) +/* Maximum headroom for worst-case calculations */ +#define LIBETH_MAX_HEADROOM LIBETH_SKB_HEADROOM +/* Link layer / L2 overhead: Ethernet, 2 VLAN tags (C + S), FCS */ +#define LIBETH_RX_LL_LEN (ETH_HLEN + 2 * VLAN_HLEN + ETH_FCS_LEN) +/* Maximum supported L2-L4 header length */ +#define LIBETH_MAX_HEAD roundup_pow_of_two(max(MAX_HEADER, 256)) + +/* Always use order-0 pages */ +#define LIBETH_RX_PAGE_ORDER 0 +/* Pick a sane buffer stride and align to a cacheline boundary */ +#define LIBETH_RX_BUF_STRIDE SKB_DATA_ALIGN(128) +/* HW-writeable space in one buffer: truesize - headroom/tailroom, aligned */ +#define LIBETH_RX_PAGE_LEN(hr) \ + ALIGN_DOWN(SKB_MAX_ORDER(hr, LIBETH_RX_PAGE_ORDER), \ + LIBETH_RX_BUF_STRIDE) + +/** + * struct libeth_fqe - structure representing an Rx buffer (fill queue element) + * @page: page holding the buffer + * @offset: offset from the page start (to the headroom) + * @truesize: total space occupied by the buffer (w/ headroom and tailroom) + * + * Depending on the MTU, API switches between one-page-per-frame and shared + * page model (to conserve memory on bigger-page platforms). In case of the + * former, @offset is always 0 and @truesize is always ```PAGE_SIZE```. + */ +struct libeth_fqe { + struct page *page; + u32 offset; + u32 truesize; +} __aligned_largest; + +/** + * enum libeth_fqe_type - enum representing types of Rx buffers + * @LIBETH_FQE_MTU: buffer size is determined by MTU + * @LIBETH_FQE_SHORT: buffer size is smaller than MTU, for short frames + * @LIBETH_FQE_HDR: buffer size is ```LIBETH_MAX_HEAD```-sized, for headers + */ +enum libeth_fqe_type { + LIBETH_FQE_MTU = 0U, + LIBETH_FQE_SHORT, + LIBETH_FQE_HDR, +}; + +/** + * struct libeth_fq - structure representing a buffer (fill) queue + * @fp: hotpath part of the structure + * @pp: &page_pool for buffer management + * @fqes: array of Rx buffers + * @truesize: size to allocate per buffer, w/overhead + * @count: number of descriptors/buffers the queue has + * @type: type of the buffers this queue has + * @hsplit: flag whether header split is enabled + * @buf_len: HW-writeable length per each buffer + * @nid: ID of the closest NUMA node with memory + */ +struct libeth_fq { + struct_group_tagged(libeth_fq_fp, fp, + struct page_pool *pp; + struct libeth_fqe *fqes; + + u32 truesize; + u32 count; + ); + + /* Cold fields */ + enum libeth_fqe_type type:2; + bool hsplit:1; + + u32 buf_len; + int nid; +}; + +int libeth_rx_fq_create(struct libeth_fq *fq, struct napi_struct *napi); +void libeth_rx_fq_destroy(struct libeth_fq *fq); + +/** + * libeth_rx_alloc - allocate a new Rx buffer + * @fq: fill queue to allocate for + * @i: index of the buffer within the queue + * + * Return: DMA address to be passed to HW for Rx on successful allocation, + * ```DMA_MAPPING_ERROR``` otherwise. + */ +static inline dma_addr_t libeth_rx_alloc(const struct libeth_fq_fp *fq, u32 i) +{ + struct libeth_fqe *buf = &fq->fqes[i]; + + buf->truesize = fq->truesize; + buf->page = page_pool_dev_alloc(fq->pp, &buf->offset, &buf->truesize); + if (unlikely(!buf->page)) + return DMA_MAPPING_ERROR; + + return page_pool_get_dma_addr(buf->page) + buf->offset + + fq->pp->p.offset; +} + +void libeth_rx_recycle_slow(struct page *page); + +/** + * libeth_rx_sync_for_cpu - synchronize or recycle buffer post DMA + * @fqe: buffer to process + * @len: frame length from the descriptor + * + * Process the buffer after it's written by HW. The regular path is to + * synchronize DMA for CPU, but in case of no data it will be immediately + * recycled back to its PP. + * + * Return: true when there's data to process, false otherwise. + */ +static inline bool libeth_rx_sync_for_cpu(const struct libeth_fqe *fqe, + u32 len) +{ + struct page *page = fqe->page; + + /* Very rare, but possible case. The most common reason: + * the last fragment contained FCS only, which was then + * stripped by the HW. + */ + if (unlikely(!len)) { + libeth_rx_recycle_slow(page); + return false; + } + + page_pool_dma_sync_for_cpu(page->pp, page, fqe->offset, len); + + return true; +} + +/* Converting abstract packet type numbers into a software structure with + * the packet parameters to do O(1) lookup on Rx. + */ + +enum { + LIBETH_RX_PT_OUTER_L2 = 0U, + LIBETH_RX_PT_OUTER_IPV4, + LIBETH_RX_PT_OUTER_IPV6, +}; + +enum { + LIBETH_RX_PT_NOT_FRAG = 0U, + LIBETH_RX_PT_FRAG, +}; + +enum { + LIBETH_RX_PT_TUNNEL_IP_NONE = 0U, + LIBETH_RX_PT_TUNNEL_IP_IP, + LIBETH_RX_PT_TUNNEL_IP_GRENAT, + LIBETH_RX_PT_TUNNEL_IP_GRENAT_MAC, + LIBETH_RX_PT_TUNNEL_IP_GRENAT_MAC_VLAN, +}; + +enum { + LIBETH_RX_PT_TUNNEL_END_NONE = 0U, + LIBETH_RX_PT_TUNNEL_END_IPV4, + LIBETH_RX_PT_TUNNEL_END_IPV6, +}; + +enum { + LIBETH_RX_PT_INNER_NONE = 0U, + LIBETH_RX_PT_INNER_UDP, + LIBETH_RX_PT_INNER_TCP, + LIBETH_RX_PT_INNER_SCTP, + LIBETH_RX_PT_INNER_ICMP, + LIBETH_RX_PT_INNER_TIMESYNC, +}; + +#define LIBETH_RX_PT_PAYLOAD_NONE PKT_HASH_TYPE_NONE +#define LIBETH_RX_PT_PAYLOAD_L2 PKT_HASH_TYPE_L2 +#define LIBETH_RX_PT_PAYLOAD_L3 PKT_HASH_TYPE_L3 +#define LIBETH_RX_PT_PAYLOAD_L4 PKT_HASH_TYPE_L4 + +struct libeth_rx_pt { + u32 outer_ip:2; + u32 outer_frag:1; + u32 tunnel_type:3; + u32 tunnel_end_prot:2; + u32 tunnel_end_frag:1; + u32 inner_prot:3; + enum pkt_hash_types payload_layer:2; + + u32 pad:2; + enum xdp_rss_hash_type hash_type:16; +}; + +void libeth_rx_pt_gen_hash_type(struct libeth_rx_pt *pt); + +/** + * libeth_rx_pt_get_ip_ver - get IP version from a packet type structure + * @pt: packet type params + * + * Wrapper to compile out the IPv6 code from the drivers when not supported + * by the kernel. + * + * Return: @pt.outer_ip or stub for IPv6 when not compiled-in. + */ +static inline u32 libeth_rx_pt_get_ip_ver(struct libeth_rx_pt pt) +{ +#if !IS_ENABLED(CONFIG_IPV6) + switch (pt.outer_ip) { + case LIBETH_RX_PT_OUTER_IPV4: + return LIBETH_RX_PT_OUTER_IPV4; + default: + return LIBETH_RX_PT_OUTER_L2; + } +#else + return pt.outer_ip; +#endif +} + +/* libeth_has_*() can be used to quickly check whether the HW metadata is + * available to avoid further expensive processing such as descriptor reads. + * They already check for the corresponding netdev feature to be enabled, + * thus can be used as drop-in replacements. + */ + +static inline bool libeth_rx_pt_has_checksum(const struct net_device *dev, + struct libeth_rx_pt pt) +{ + /* Non-zero _INNER* is only possible when _OUTER_IPV* is set, + * it is enough to check only for the L4 type. + */ + return likely(pt.inner_prot > LIBETH_RX_PT_INNER_NONE && + (dev->features & NETIF_F_RXCSUM)); +} + +static inline bool libeth_rx_pt_has_hash(const struct net_device *dev, + struct libeth_rx_pt pt) +{ + return likely(pt.payload_layer > LIBETH_RX_PT_PAYLOAD_NONE && + (dev->features & NETIF_F_RXHASH)); +} + +/** + * libeth_rx_pt_set_hash - fill in skb hash value basing on the PT + * @skb: skb to fill the hash in + * @hash: 32-bit hash value from the descriptor + * @pt: packet type + */ +static inline void libeth_rx_pt_set_hash(struct sk_buff *skb, u32 hash, + struct libeth_rx_pt pt) +{ + skb_set_hash(skb, hash, pt.payload_layer); +} + +#endif /* __LIBETH_RX_H */ diff --git a/include/net/libeth/tx.h b/include/net/libeth/tx.h new file mode 100644 index 000000000000..35614f9523f6 --- /dev/null +++ b/include/net/libeth/tx.h @@ -0,0 +1,129 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright (C) 2024 Intel Corporation */ + +#ifndef __LIBETH_TX_H +#define __LIBETH_TX_H + +#include <linux/skbuff.h> + +#include <net/libeth/types.h> + +/* Tx buffer completion */ + +/** + * enum libeth_sqe_type - type of &libeth_sqe to act on Tx completion + * @LIBETH_SQE_EMPTY: unused/empty, no action required + * @LIBETH_SQE_CTX: context descriptor with empty SQE, no action required + * @LIBETH_SQE_SLAB: kmalloc-allocated buffer, unmap and kfree() + * @LIBETH_SQE_FRAG: mapped skb frag, only unmap DMA + * @LIBETH_SQE_SKB: &sk_buff, unmap and napi_consume_skb(), update stats + */ +enum libeth_sqe_type { + LIBETH_SQE_EMPTY = 0U, + LIBETH_SQE_CTX, + LIBETH_SQE_SLAB, + LIBETH_SQE_FRAG, + LIBETH_SQE_SKB, +}; + +/** + * struct libeth_sqe - represents a Send Queue Element / Tx buffer + * @type: type of the buffer, see the enum above + * @rs_idx: index of the last buffer from the batch this one was sent in + * @raw: slab buffer to free via kfree() + * @skb: &sk_buff to consume + * @dma: DMA address to unmap + * @len: length of the mapped region to unmap + * @nr_frags: number of frags in the frame this buffer belongs to + * @packets: number of physical packets sent for this frame + * @bytes: number of physical bytes sent for this frame + * @priv: driver-private scratchpad + */ +struct libeth_sqe { + enum libeth_sqe_type type:32; + u32 rs_idx; + + union { + void *raw; + struct sk_buff *skb; + }; + + DEFINE_DMA_UNMAP_ADDR(dma); + DEFINE_DMA_UNMAP_LEN(len); + + u32 nr_frags; + u32 packets; + u32 bytes; + + unsigned long priv; +} __aligned_largest; + +/** + * LIBETH_SQE_CHECK_PRIV - check the driver's private SQE data + * @p: type or name of the object the driver wants to fit into &libeth_sqe + * + * Make sure the driver's private data fits into libeth_sqe::priv. To be used + * right after its declaration. + */ +#define LIBETH_SQE_CHECK_PRIV(p) \ + static_assert(sizeof(p) <= sizeof_field(struct libeth_sqe, priv)) + +/** + * struct libeth_cq_pp - completion queue poll params + * @dev: &device to perform DMA unmapping + * @ss: onstack NAPI stats to fill + * @napi: whether it's called from the NAPI context + * + * libeth uses this structure to access objects needed for performing full + * Tx complete operation without passing lots of arguments and change the + * prototypes each time a new one is added. + */ +struct libeth_cq_pp { + struct device *dev; + struct libeth_sq_napi_stats *ss; + + bool napi; +}; + +/** + * libeth_tx_complete - perform Tx completion for one SQE + * @sqe: SQE to complete + * @cp: poll params + * + * Do Tx complete for all the types of buffers, incl. freeing, unmapping, + * updating the stats etc. + */ +static inline void libeth_tx_complete(struct libeth_sqe *sqe, + const struct libeth_cq_pp *cp) +{ + switch (sqe->type) { + case LIBETH_SQE_EMPTY: + return; + case LIBETH_SQE_SKB: + case LIBETH_SQE_FRAG: + case LIBETH_SQE_SLAB: + dma_unmap_page(cp->dev, dma_unmap_addr(sqe, dma), + dma_unmap_len(sqe, len), DMA_TO_DEVICE); + break; + default: + break; + } + + switch (sqe->type) { + case LIBETH_SQE_SKB: + cp->ss->packets += sqe->packets; + cp->ss->bytes += sqe->bytes; + + napi_consume_skb(sqe->skb, cp->napi); + break; + case LIBETH_SQE_SLAB: + kfree(sqe->raw); + break; + default: + break; + } + + sqe->type = LIBETH_SQE_EMPTY; +} + +#endif /* __LIBETH_TX_H */ diff --git a/include/net/libeth/types.h b/include/net/libeth/types.h new file mode 100644 index 000000000000..603825e45133 --- /dev/null +++ b/include/net/libeth/types.h @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright (C) 2024 Intel Corporation */ + +#ifndef __LIBETH_TYPES_H +#define __LIBETH_TYPES_H + +#include <linux/types.h> + +/** + * struct libeth_sq_napi_stats - "hot" counters to update in Tx completion loop + * @packets: completed frames counter + * @bytes: sum of bytes of completed frames above + * @raw: alias to access all the fields as an array + */ +struct libeth_sq_napi_stats { + union { + struct { + u32 packets; + u32 bytes; + }; + DECLARE_FLEX_ARRAY(u32, raw); + }; +}; + +#endif /* __LIBETH_TYPES_H */ |