From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- net/core/xdp.c | 711 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 711 insertions(+) create mode 100644 net/core/xdp.c (limited to 'net/core/xdp.c') diff --git a/net/core/xdp.c b/net/core/xdp.c new file mode 100644 index 000000000..844c9d99d --- /dev/null +++ b/net/core/xdp.c @@ -0,0 +1,711 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* net/core/xdp.c + * + * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include /* struct xdp_mem_allocator */ +#include +#include + +#define REG_STATE_NEW 0x0 +#define REG_STATE_REGISTERED 0x1 +#define REG_STATE_UNREGISTERED 0x2 +#define REG_STATE_UNUSED 0x3 + +static DEFINE_IDA(mem_id_pool); +static DEFINE_MUTEX(mem_id_lock); +#define MEM_ID_MAX 0xFFFE +#define MEM_ID_MIN 1 +static int mem_id_next = MEM_ID_MIN; + +static bool mem_id_init; /* false */ +static struct rhashtable *mem_id_ht; + +static u32 xdp_mem_id_hashfn(const void *data, u32 len, u32 seed) +{ + const u32 *k = data; + const u32 key = *k; + + BUILD_BUG_ON(sizeof_field(struct xdp_mem_allocator, mem.id) + != sizeof(u32)); + + /* Use cyclic increasing ID as direct hash key */ + return key; +} + +static int xdp_mem_id_cmp(struct rhashtable_compare_arg *arg, + const void *ptr) +{ + const struct xdp_mem_allocator *xa = ptr; + u32 mem_id = *(u32 *)arg->key; + + return xa->mem.id != mem_id; +} + +static const struct rhashtable_params mem_id_rht_params = { + .nelem_hint = 64, + .head_offset = offsetof(struct xdp_mem_allocator, node), + .key_offset = offsetof(struct xdp_mem_allocator, mem.id), + .key_len = sizeof_field(struct xdp_mem_allocator, mem.id), + .max_size = MEM_ID_MAX, + .min_size = 8, + .automatic_shrinking = true, + .hashfn = xdp_mem_id_hashfn, + .obj_cmpfn = xdp_mem_id_cmp, +}; + +static void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu) +{ + struct xdp_mem_allocator *xa; + + xa = container_of(rcu, struct xdp_mem_allocator, rcu); + + /* Allow this ID to be reused */ + ida_simple_remove(&mem_id_pool, xa->mem.id); + + kfree(xa); +} + +static void mem_xa_remove(struct xdp_mem_allocator *xa) +{ + trace_mem_disconnect(xa); + + if (!rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params)) + call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free); +} + +static void mem_allocator_disconnect(void *allocator) +{ + struct xdp_mem_allocator *xa; + struct rhashtable_iter iter; + + mutex_lock(&mem_id_lock); + + rhashtable_walk_enter(mem_id_ht, &iter); + do { + rhashtable_walk_start(&iter); + + while ((xa = rhashtable_walk_next(&iter)) && !IS_ERR(xa)) { + if (xa->allocator == allocator) + mem_xa_remove(xa); + } + + rhashtable_walk_stop(&iter); + + } while (xa == ERR_PTR(-EAGAIN)); + rhashtable_walk_exit(&iter); + + mutex_unlock(&mem_id_lock); +} + +void xdp_unreg_mem_model(struct xdp_mem_info *mem) +{ + struct xdp_mem_allocator *xa; + int type = mem->type; + int id = mem->id; + + /* Reset mem info to defaults */ + mem->id = 0; + mem->type = 0; + + if (id == 0) + return; + + if (type == MEM_TYPE_PAGE_POOL) { + rcu_read_lock(); + xa = rhashtable_lookup(mem_id_ht, &id, mem_id_rht_params); + page_pool_destroy(xa->page_pool); + rcu_read_unlock(); + } +} +EXPORT_SYMBOL_GPL(xdp_unreg_mem_model); + +void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq) +{ + if (xdp_rxq->reg_state != REG_STATE_REGISTERED) { + WARN(1, "Missing register, driver bug"); + return; + } + + xdp_unreg_mem_model(&xdp_rxq->mem); +} +EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg_mem_model); + +void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq) +{ + /* Simplify driver cleanup code paths, allow unreg "unused" */ + if (xdp_rxq->reg_state == REG_STATE_UNUSED) + return; + + xdp_rxq_info_unreg_mem_model(xdp_rxq); + + xdp_rxq->reg_state = REG_STATE_UNREGISTERED; + xdp_rxq->dev = NULL; +} +EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg); + +static void xdp_rxq_info_init(struct xdp_rxq_info *xdp_rxq) +{ + memset(xdp_rxq, 0, sizeof(*xdp_rxq)); +} + +/* Returns 0 on success, negative on failure */ +int __xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq, + struct net_device *dev, u32 queue_index, + unsigned int napi_id, u32 frag_size) +{ + if (!dev) { + WARN(1, "Missing net_device from driver"); + return -ENODEV; + } + + if (xdp_rxq->reg_state == REG_STATE_UNUSED) { + WARN(1, "Driver promised not to register this"); + return -EINVAL; + } + + if (xdp_rxq->reg_state == REG_STATE_REGISTERED) { + WARN(1, "Missing unregister, handled but fix driver"); + xdp_rxq_info_unreg(xdp_rxq); + } + + /* State either UNREGISTERED or NEW */ + xdp_rxq_info_init(xdp_rxq); + xdp_rxq->dev = dev; + xdp_rxq->queue_index = queue_index; + xdp_rxq->napi_id = napi_id; + xdp_rxq->frag_size = frag_size; + + xdp_rxq->reg_state = REG_STATE_REGISTERED; + return 0; +} +EXPORT_SYMBOL_GPL(__xdp_rxq_info_reg); + +void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq) +{ + xdp_rxq->reg_state = REG_STATE_UNUSED; +} +EXPORT_SYMBOL_GPL(xdp_rxq_info_unused); + +bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq) +{ + return (xdp_rxq->reg_state == REG_STATE_REGISTERED); +} +EXPORT_SYMBOL_GPL(xdp_rxq_info_is_reg); + +static int __mem_id_init_hash_table(void) +{ + struct rhashtable *rht; + int ret; + + if (unlikely(mem_id_init)) + return 0; + + rht = kzalloc(sizeof(*rht), GFP_KERNEL); + if (!rht) + return -ENOMEM; + + ret = rhashtable_init(rht, &mem_id_rht_params); + if (ret < 0) { + kfree(rht); + return ret; + } + mem_id_ht = rht; + smp_mb(); /* mutex lock should provide enough pairing */ + mem_id_init = true; + + return 0; +} + +/* Allocate a cyclic ID that maps to allocator pointer. + * See: https://www.kernel.org/doc/html/latest/core-api/idr.html + * + * Caller must lock mem_id_lock. + */ +static int __mem_id_cyclic_get(gfp_t gfp) +{ + int retries = 1; + int id; + +again: + id = ida_simple_get(&mem_id_pool, mem_id_next, MEM_ID_MAX, gfp); + if (id < 0) { + if (id == -ENOSPC) { + /* Cyclic allocator, reset next id */ + if (retries--) { + mem_id_next = MEM_ID_MIN; + goto again; + } + } + return id; /* errno */ + } + mem_id_next = id + 1; + + return id; +} + +static bool __is_supported_mem_type(enum xdp_mem_type type) +{ + if (type == MEM_TYPE_PAGE_POOL) + return is_page_pool_compiled_in(); + + if (type >= MEM_TYPE_MAX) + return false; + + return true; +} + +static struct xdp_mem_allocator *__xdp_reg_mem_model(struct xdp_mem_info *mem, + enum xdp_mem_type type, + void *allocator) +{ + struct xdp_mem_allocator *xdp_alloc; + gfp_t gfp = GFP_KERNEL; + int id, errno, ret; + void *ptr; + + if (!__is_supported_mem_type(type)) + return ERR_PTR(-EOPNOTSUPP); + + mem->type = type; + + if (!allocator) { + if (type == MEM_TYPE_PAGE_POOL) + return ERR_PTR(-EINVAL); /* Setup time check page_pool req */ + return NULL; + } + + /* Delay init of rhashtable to save memory if feature isn't used */ + if (!mem_id_init) { + mutex_lock(&mem_id_lock); + ret = __mem_id_init_hash_table(); + mutex_unlock(&mem_id_lock); + if (ret < 0) { + WARN_ON(1); + return ERR_PTR(ret); + } + } + + xdp_alloc = kzalloc(sizeof(*xdp_alloc), gfp); + if (!xdp_alloc) + return ERR_PTR(-ENOMEM); + + mutex_lock(&mem_id_lock); + id = __mem_id_cyclic_get(gfp); + if (id < 0) { + errno = id; + goto err; + } + mem->id = id; + xdp_alloc->mem = *mem; + xdp_alloc->allocator = allocator; + + /* Insert allocator into ID lookup table */ + ptr = rhashtable_insert_slow(mem_id_ht, &id, &xdp_alloc->node); + if (IS_ERR(ptr)) { + ida_simple_remove(&mem_id_pool, mem->id); + mem->id = 0; + errno = PTR_ERR(ptr); + goto err; + } + + if (type == MEM_TYPE_PAGE_POOL) + page_pool_use_xdp_mem(allocator, mem_allocator_disconnect, mem); + + mutex_unlock(&mem_id_lock); + + return xdp_alloc; +err: + mutex_unlock(&mem_id_lock); + kfree(xdp_alloc); + return ERR_PTR(errno); +} + +int xdp_reg_mem_model(struct xdp_mem_info *mem, + enum xdp_mem_type type, void *allocator) +{ + struct xdp_mem_allocator *xdp_alloc; + + xdp_alloc = __xdp_reg_mem_model(mem, type, allocator); + if (IS_ERR(xdp_alloc)) + return PTR_ERR(xdp_alloc); + return 0; +} +EXPORT_SYMBOL_GPL(xdp_reg_mem_model); + +int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq, + enum xdp_mem_type type, void *allocator) +{ + struct xdp_mem_allocator *xdp_alloc; + + if (xdp_rxq->reg_state != REG_STATE_REGISTERED) { + WARN(1, "Missing register, driver bug"); + return -EFAULT; + } + + xdp_alloc = __xdp_reg_mem_model(&xdp_rxq->mem, type, allocator); + if (IS_ERR(xdp_alloc)) + return PTR_ERR(xdp_alloc); + + if (trace_mem_connect_enabled() && xdp_alloc) + trace_mem_connect(xdp_alloc, xdp_rxq); + return 0; +} + +EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model); + +/* XDP RX runs under NAPI protection, and in different delivery error + * scenarios (e.g. queue full), it is possible to return the xdp_frame + * while still leveraging this protection. The @napi_direct boolean + * is used for those calls sites. Thus, allowing for faster recycling + * of xdp_frames/pages in those cases. + */ +void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct, + struct xdp_buff *xdp) +{ + struct page *page; + + switch (mem->type) { + case MEM_TYPE_PAGE_POOL: + page = virt_to_head_page(data); + if (napi_direct && xdp_return_frame_no_direct()) + napi_direct = false; + /* No need to check ((page->pp_magic & ~0x3UL) == PP_SIGNATURE) + * as mem->type knows this a page_pool page + */ + page_pool_put_full_page(page->pp, page, napi_direct); + break; + case MEM_TYPE_PAGE_SHARED: + page_frag_free(data); + break; + case MEM_TYPE_PAGE_ORDER0: + page = virt_to_page(data); /* Assumes order0 page*/ + put_page(page); + break; + case MEM_TYPE_XSK_BUFF_POOL: + /* NB! Only valid from an xdp_buff! */ + xsk_buff_free(xdp); + break; + default: + /* Not possible, checked in xdp_rxq_info_reg_mem_model() */ + WARN(1, "Incorrect XDP memory type (%d) usage", mem->type); + break; + } +} + +void xdp_return_frame(struct xdp_frame *xdpf) +{ + struct skb_shared_info *sinfo; + int i; + + if (likely(!xdp_frame_has_frags(xdpf))) + goto out; + + sinfo = xdp_get_shared_info_from_frame(xdpf); + for (i = 0; i < sinfo->nr_frags; i++) { + struct page *page = skb_frag_page(&sinfo->frags[i]); + + __xdp_return(page_address(page), &xdpf->mem, false, NULL); + } +out: + __xdp_return(xdpf->data, &xdpf->mem, false, NULL); +} +EXPORT_SYMBOL_GPL(xdp_return_frame); + +void xdp_return_frame_rx_napi(struct xdp_frame *xdpf) +{ + struct skb_shared_info *sinfo; + int i; + + if (likely(!xdp_frame_has_frags(xdpf))) + goto out; + + sinfo = xdp_get_shared_info_from_frame(xdpf); + for (i = 0; i < sinfo->nr_frags; i++) { + struct page *page = skb_frag_page(&sinfo->frags[i]); + + __xdp_return(page_address(page), &xdpf->mem, true, NULL); + } +out: + __xdp_return(xdpf->data, &xdpf->mem, true, NULL); +} +EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi); + +/* XDP bulk APIs introduce a defer/flush mechanism to return + * pages belonging to the same xdp_mem_allocator object + * (identified via the mem.id field) in bulk to optimize + * I-cache and D-cache. + * The bulk queue size is set to 16 to be aligned to how + * XDP_REDIRECT bulking works. The bulk is flushed when + * it is full or when mem.id changes. + * xdp_frame_bulk is usually stored/allocated on the function + * call-stack to avoid locking penalties. + */ +void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq) +{ + struct xdp_mem_allocator *xa = bq->xa; + + if (unlikely(!xa || !bq->count)) + return; + + page_pool_put_page_bulk(xa->page_pool, bq->q, bq->count); + /* bq->xa is not cleared to save lookup, if mem.id same in next bulk */ + bq->count = 0; +} +EXPORT_SYMBOL_GPL(xdp_flush_frame_bulk); + +/* Must be called with rcu_read_lock held */ +void xdp_return_frame_bulk(struct xdp_frame *xdpf, + struct xdp_frame_bulk *bq) +{ + struct xdp_mem_info *mem = &xdpf->mem; + struct xdp_mem_allocator *xa; + + if (mem->type != MEM_TYPE_PAGE_POOL) { + xdp_return_frame(xdpf); + return; + } + + xa = bq->xa; + if (unlikely(!xa)) { + xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); + bq->count = 0; + bq->xa = xa; + } + + if (bq->count == XDP_BULK_QUEUE_SIZE) + xdp_flush_frame_bulk(bq); + + if (unlikely(mem->id != xa->mem.id)) { + xdp_flush_frame_bulk(bq); + bq->xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); + } + + if (unlikely(xdp_frame_has_frags(xdpf))) { + struct skb_shared_info *sinfo; + int i; + + sinfo = xdp_get_shared_info_from_frame(xdpf); + for (i = 0; i < sinfo->nr_frags; i++) { + skb_frag_t *frag = &sinfo->frags[i]; + + bq->q[bq->count++] = skb_frag_address(frag); + if (bq->count == XDP_BULK_QUEUE_SIZE) + xdp_flush_frame_bulk(bq); + } + } + bq->q[bq->count++] = xdpf->data; +} +EXPORT_SYMBOL_GPL(xdp_return_frame_bulk); + +void xdp_return_buff(struct xdp_buff *xdp) +{ + struct skb_shared_info *sinfo; + int i; + + if (likely(!xdp_buff_has_frags(xdp))) + goto out; + + sinfo = xdp_get_shared_info_from_buff(xdp); + for (i = 0; i < sinfo->nr_frags; i++) { + struct page *page = skb_frag_page(&sinfo->frags[i]); + + __xdp_return(page_address(page), &xdp->rxq->mem, true, xdp); + } +out: + __xdp_return(xdp->data, &xdp->rxq->mem, true, xdp); +} +EXPORT_SYMBOL_GPL(xdp_return_buff); + +/* Only called for MEM_TYPE_PAGE_POOL see xdp.h */ +void __xdp_release_frame(void *data, struct xdp_mem_info *mem) +{ + struct xdp_mem_allocator *xa; + struct page *page; + + rcu_read_lock(); + xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); + page = virt_to_head_page(data); + if (xa) + page_pool_release_page(xa->page_pool, page); + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(__xdp_release_frame); + +void xdp_attachment_setup(struct xdp_attachment_info *info, + struct netdev_bpf *bpf) +{ + if (info->prog) + bpf_prog_put(info->prog); + info->prog = bpf->prog; + info->flags = bpf->flags; +} +EXPORT_SYMBOL_GPL(xdp_attachment_setup); + +struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp) +{ + unsigned int metasize, totsize; + void *addr, *data_to_copy; + struct xdp_frame *xdpf; + struct page *page; + + /* Clone into a MEM_TYPE_PAGE_ORDER0 xdp_frame. */ + metasize = xdp_data_meta_unsupported(xdp) ? 0 : + xdp->data - xdp->data_meta; + totsize = xdp->data_end - xdp->data + metasize; + + if (sizeof(*xdpf) + totsize > PAGE_SIZE) + return NULL; + + page = dev_alloc_page(); + if (!page) + return NULL; + + addr = page_to_virt(page); + xdpf = addr; + memset(xdpf, 0, sizeof(*xdpf)); + + addr += sizeof(*xdpf); + data_to_copy = metasize ? xdp->data_meta : xdp->data; + memcpy(addr, data_to_copy, totsize); + + xdpf->data = addr + metasize; + xdpf->len = totsize - metasize; + xdpf->headroom = 0; + xdpf->metasize = metasize; + xdpf->frame_sz = PAGE_SIZE; + xdpf->mem.type = MEM_TYPE_PAGE_ORDER0; + + xsk_buff_free(xdp); + return xdpf; +} +EXPORT_SYMBOL_GPL(xdp_convert_zc_to_xdp_frame); + +/* Used by XDP_WARN macro, to avoid inlining WARN() in fast-path */ +void xdp_warn(const char *msg, const char *func, const int line) +{ + WARN(1, "XDP_WARN: %s(line:%d): %s\n", func, line, msg); +}; +EXPORT_SYMBOL_GPL(xdp_warn); + +int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp) +{ + n_skb = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, + n_skb, skbs); + if (unlikely(!n_skb)) + return -ENOMEM; + + return 0; +} +EXPORT_SYMBOL_GPL(xdp_alloc_skb_bulk); + +struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, + struct sk_buff *skb, + struct net_device *dev) +{ + struct skb_shared_info *sinfo = xdp_get_shared_info_from_frame(xdpf); + unsigned int headroom, frame_size; + void *hard_start; + u8 nr_frags; + + /* xdp frags frame */ + if (unlikely(xdp_frame_has_frags(xdpf))) + nr_frags = sinfo->nr_frags; + + /* Part of headroom was reserved to xdpf */ + headroom = sizeof(*xdpf) + xdpf->headroom; + + /* Memory size backing xdp_frame data already have reserved + * room for build_skb to place skb_shared_info in tailroom. + */ + frame_size = xdpf->frame_sz; + + hard_start = xdpf->data - headroom; + skb = build_skb_around(skb, hard_start, frame_size); + if (unlikely(!skb)) + return NULL; + + skb_reserve(skb, headroom); + __skb_put(skb, xdpf->len); + if (xdpf->metasize) + skb_metadata_set(skb, xdpf->metasize); + + if (unlikely(xdp_frame_has_frags(xdpf))) + xdp_update_skb_shared_info(skb, nr_frags, + sinfo->xdp_frags_size, + nr_frags * xdpf->frame_sz, + xdp_frame_is_frag_pfmemalloc(xdpf)); + + /* Essential SKB info: protocol and skb->dev */ + skb->protocol = eth_type_trans(skb, dev); + + /* Optional SKB info, currently missing: + * - HW checksum info (skb->ip_summed) + * - HW RX hash (skb_set_hash) + * - RX ring dev queue index (skb_record_rx_queue) + */ + + /* Until page_pool get SKB return path, release DMA here */ + xdp_release_frame(xdpf); + + /* Allow SKB to reuse area used by xdp_frame */ + xdp_scrub_frame(xdpf); + + return skb; +} +EXPORT_SYMBOL_GPL(__xdp_build_skb_from_frame); + +struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf, + struct net_device *dev) +{ + struct sk_buff *skb; + + skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC); + if (unlikely(!skb)) + return NULL; + + memset(skb, 0, offsetof(struct sk_buff, tail)); + + return __xdp_build_skb_from_frame(xdpf, skb, dev); +} +EXPORT_SYMBOL_GPL(xdp_build_skb_from_frame); + +struct xdp_frame *xdpf_clone(struct xdp_frame *xdpf) +{ + unsigned int headroom, totalsize; + struct xdp_frame *nxdpf; + struct page *page; + void *addr; + + headroom = xdpf->headroom + sizeof(*xdpf); + totalsize = headroom + xdpf->len; + + if (unlikely(totalsize > PAGE_SIZE)) + return NULL; + page = dev_alloc_page(); + if (!page) + return NULL; + addr = page_to_virt(page); + + memcpy(addr, xdpf, totalsize); + + nxdpf = addr; + nxdpf->data = addr + headroom; + nxdpf->frame_sz = PAGE_SIZE; + nxdpf->mem.type = MEM_TYPE_PAGE_ORDER0; + nxdpf->mem.id = 0; + + return nxdpf; +} -- cgit v1.2.3