// SPDX-License-Identifier: GPL-2.0 #include <net/xsk_buff_pool.h> #include <net/xdp_sock.h> #include <net/xdp_sock_drv.h> #include "xsk_queue.h" #include "xdp_umem.h" #include "xsk.h" void xp_add_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs) { unsigned long flags; if (!xs->tx) return; spin_lock_irqsave(&pool->xsk_tx_list_lock, flags); list_add_rcu(&xs->tx_list, &pool->xsk_tx_list); spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags); } void xp_del_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs) { unsigned long flags; if (!xs->tx) return; spin_lock_irqsave(&pool->xsk_tx_list_lock, flags); list_del_rcu(&xs->tx_list); spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags); } void xp_destroy(struct xsk_buff_pool *pool) { if (!pool) return; kvfree(pool->heads); kvfree(pool); } struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs, struct xdp_umem *umem) { struct xsk_buff_pool *pool; struct xdp_buff_xsk *xskb; u32 i; pool = kvzalloc(struct_size(pool, free_heads, umem->chunks), GFP_KERNEL); if (!pool) goto out; pool->heads = kvcalloc(umem->chunks, sizeof(*pool->heads), GFP_KERNEL); if (!pool->heads) goto out; pool->chunk_mask = ~((u64)umem->chunk_size - 1); pool->addrs_cnt = umem->size; pool->heads_cnt = umem->chunks; pool->free_heads_cnt = umem->chunks; pool->headroom = umem->headroom; pool->chunk_size = umem->chunk_size; pool->unaligned = umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG; pool->frame_len = umem->chunk_size - umem->headroom - XDP_PACKET_HEADROOM; pool->umem = umem; pool->addrs = umem->addrs; INIT_LIST_HEAD(&pool->free_list); INIT_LIST_HEAD(&pool->xsk_tx_list); spin_lock_init(&pool->xsk_tx_list_lock); refcount_set(&pool->users, 1); pool->fq = xs->fq_tmp; pool->cq = xs->cq_tmp; xs->fq_tmp = NULL; xs->cq_tmp = NULL; for (i = 0; i < pool->free_heads_cnt; i++) { xskb = &pool->heads[i]; xskb->pool = pool; xskb->xdp.frame_sz = umem->chunk_size - umem->headroom; pool->free_heads[i] = xskb; } return pool; out: xp_destroy(pool); return NULL; } void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq) { u32 i; for (i = 0; i < pool->heads_cnt; i++) pool->heads[i].xdp.rxq = rxq; } EXPORT_SYMBOL(xp_set_rxq_info); static void xp_disable_drv_zc(struct xsk_buff_pool *pool) { struct netdev_bpf bpf; int err; ASSERT_RTNL(); if (pool->umem->zc) { bpf.command = XDP_SETUP_XSK_POOL; bpf.xsk.pool = NULL; bpf.xsk.queue_id = pool->queue_id; err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf); if (err) WARN(1, "Failed to disable zero-copy!\n"); } } static int __xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *netdev, u16 queue_id, u16 flags) { bool force_zc, force_copy; struct netdev_bpf bpf; int err = 0; ASSERT_RTNL(); force_zc = flags & XDP_ZEROCOPY; force_copy = flags & XDP_COPY; if (force_zc && force_copy) return -EINVAL; if (xsk_get_pool_from_qid(netdev, queue_id)) return -EBUSY; pool->netdev = netdev; pool->queue_id = queue_id; err = xsk_reg_pool_at_qid(netdev, pool, queue_id); if (err) return err; if (flags & XDP_USE_NEED_WAKEUP) { pool->uses_need_wakeup = true; /* Tx needs to be explicitly woken up the first time. * Also for supporting drivers that do not implement this * feature. They will always have to call sendto(). */ pool->cached_need_wakeup = XDP_WAKEUP_TX; } dev_hold(netdev); if (force_copy) /* For copy-mode, we are done. */ return 0; if (!netdev->netdev_ops->ndo_bpf || !netdev->netdev_ops->ndo_xsk_wakeup) { err = -EOPNOTSUPP; goto err_unreg_pool; } bpf.command = XDP_SETUP_XSK_POOL; bpf.xsk.pool = pool; bpf.xsk.queue_id = queue_id; err = netdev->netdev_ops->ndo_bpf(netdev, &bpf); if (err) goto err_unreg_pool; if (!pool->dma_pages) { WARN(1, "Driver did not DMA map zero-copy buffers"); goto err_unreg_xsk; } pool->umem->zc = true; return 0; err_unreg_xsk: xp_disable_drv_zc(pool); err_unreg_pool: if (!force_zc) err = 0; /* fallback to copy mode */ if (err) xsk_clear_pool_at_qid(netdev, queue_id); return err; } int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev, u16 queue_id, u16 flags) { return __xp_assign_dev(pool, dev, queue_id, flags); } int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem, struct net_device *dev, u16 queue_id) { u16 flags; /* One fill and completion ring required for each queue id. */ if (!pool->fq || !pool->cq) return -EINVAL; flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY; if (pool->uses_need_wakeup) flags |= XDP_USE_NEED_WAKEUP; return __xp_assign_dev(pool, dev, queue_id, flags); } void xp_clear_dev(struct xsk_buff_pool *pool) { if (!pool->netdev) return; xp_disable_drv_zc(pool); xsk_clear_pool_at_qid(pool->netdev, pool->queue_id); dev_put(pool->netdev); pool->netdev = NULL; } static void xp_release_deferred(struct work_struct *work) { struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool, work); rtnl_lock(); xp_clear_dev(pool); rtnl_unlock(); if (pool->fq) { xskq_destroy(pool->fq); pool->fq = NULL; } if (pool->cq) { xskq_destroy(pool->cq); pool->cq = NULL; } xdp_put_umem(pool->umem); xp_destroy(pool); } void xp_get_pool(struct xsk_buff_pool *pool) { refcount_inc(&pool->users); } void xp_put_pool(struct xsk_buff_pool *pool) { if (!pool) return; if (refcount_dec_and_test(&pool->users)) { INIT_WORK(&pool->work, xp_release_deferred); schedule_work(&pool->work); } } static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool) { struct xsk_dma_map *dma_map; list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) { if (dma_map->netdev == pool->netdev) return dma_map; } return NULL; } static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev, u32 nr_pages, struct xdp_umem *umem) { struct xsk_dma_map *dma_map; dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL); if (!dma_map) return NULL; dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL); if (!dma_map->dma_pages) { kfree(dma_map); return NULL; } dma_map->netdev = netdev; dma_map->dev = dev; dma_map->dma_need_sync = false; dma_map->dma_pages_cnt = nr_pages; refcount_set(&dma_map->users, 1); list_add(&dma_map->list, &umem->xsk_dma_list); return dma_map; } static void xp_destroy_dma_map(struct xsk_dma_map *dma_map) { list_del(&dma_map->list); kvfree(dma_map->dma_pages); kfree(dma_map); } static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs) { dma_addr_t *dma; u32 i; for (i = 0; i < dma_map->dma_pages_cnt; i++) { dma = &dma_map->dma_pages[i]; if (*dma) { dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE, DMA_BIDIRECTIONAL, attrs); *dma = 0; } } xp_destroy_dma_map(dma_map); } void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs) { struct xsk_dma_map *dma_map; if (pool->dma_pages_cnt == 0) return; dma_map = xp_find_dma_map(pool); if (!dma_map) { WARN(1, "Could not find dma_map for device"); return; } if (!refcount_dec_and_test(&dma_map->users)) return; __xp_dma_unmap(dma_map, attrs); kvfree(pool->dma_pages); pool->dma_pages_cnt = 0; pool->dev = NULL; } EXPORT_SYMBOL(xp_dma_unmap); static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map) { u32 i; for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) { if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1]) dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK; else dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK; } } static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map) { pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL); if (!pool->dma_pages) return -ENOMEM; pool->dev = dma_map->dev; pool->dma_pages_cnt = dma_map->dma_pages_cnt; pool->dma_need_sync = dma_map->dma_need_sync; memcpy(pool->dma_pages, dma_map->dma_pages, pool->dma_pages_cnt * sizeof(*pool->dma_pages)); return 0; } int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev, unsigned long attrs, struct page **pages, u32 nr_pages) { struct xsk_dma_map *dma_map; dma_addr_t dma; int err; u32 i; dma_map = xp_find_dma_map(pool); if (dma_map) { err = xp_init_dma_info(pool, dma_map); if (err) return err; refcount_inc(&dma_map->users); return 0; } dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem); if (!dma_map) return -ENOMEM; for (i = 0; i < dma_map->dma_pages_cnt; i++) { dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE, DMA_BIDIRECTIONAL, attrs); if (dma_mapping_error(dev, dma)) { __xp_dma_unmap(dma_map, attrs); return -ENOMEM; } if (dma_need_sync(dev, dma)) dma_map->dma_need_sync = true; dma_map->dma_pages[i] = dma; } if (pool->unaligned) xp_check_dma_contiguity(dma_map); err = xp_init_dma_info(pool, dma_map); if (err) { __xp_dma_unmap(dma_map, attrs); return err; } return 0; } EXPORT_SYMBOL(xp_dma_map); static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool, u64 addr) { return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size); } static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr) { *addr = xp_unaligned_extract_addr(*addr); if (*addr >= pool->addrs_cnt || *addr + pool->chunk_size > pool->addrs_cnt || xp_addr_crosses_non_contig_pg(pool, *addr)) return false; return true; } static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr) { *addr = xp_aligned_extract_addr(pool, *addr); return *addr < pool->addrs_cnt; } static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool) { struct xdp_buff_xsk *xskb; u64 addr; bool ok; if (pool->free_heads_cnt == 0) return NULL; xskb = pool->free_heads[--pool->free_heads_cnt]; for (;;) { if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) { pool->fq->queue_empty_descs++; xp_release(xskb); return NULL; } ok = pool->unaligned ? xp_check_unaligned(pool, &addr) : xp_check_aligned(pool, &addr); if (!ok) { pool->fq->invalid_descs++; xskq_cons_release(pool->fq); continue; } break; } xskq_cons_release(pool->fq); xskb->orig_addr = addr; xskb->xdp.data_hard_start = pool->addrs + addr + pool->headroom; if (pool->dma_pages_cnt) { xskb->frame_dma = (pool->dma_pages[addr >> PAGE_SHIFT] & ~XSK_NEXT_PG_CONTIG_MASK) + (addr & ~PAGE_MASK); xskb->dma = xskb->frame_dma + pool->headroom + XDP_PACKET_HEADROOM; } return xskb; } struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool) { struct xdp_buff_xsk *xskb; if (!pool->free_list_cnt) { xskb = __xp_alloc(pool); if (!xskb) return NULL; } else { pool->free_list_cnt--; xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, free_list_node); list_del(&xskb->free_list_node); } xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM; xskb->xdp.data_meta = xskb->xdp.data; if (pool->dma_need_sync) { dma_sync_single_range_for_device(pool->dev, xskb->dma, 0, pool->frame_len, DMA_BIDIRECTIONAL); } return &xskb->xdp; } EXPORT_SYMBOL(xp_alloc); bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count) { if (pool->free_list_cnt >= count) return true; return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt); } EXPORT_SYMBOL(xp_can_alloc); void xp_free(struct xdp_buff_xsk *xskb) { xskb->pool->free_list_cnt++; list_add(&xskb->free_list_node, &xskb->pool->free_list); } EXPORT_SYMBOL(xp_free); void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr) { addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr; return pool->addrs + addr; } EXPORT_SYMBOL(xp_raw_get_data); dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr) { addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr; return (pool->dma_pages[addr >> PAGE_SHIFT] & ~XSK_NEXT_PG_CONTIG_MASK) + (addr & ~PAGE_MASK); } EXPORT_SYMBOL(xp_raw_get_dma); void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb) { dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0, xskb->pool->frame_len, DMA_BIDIRECTIONAL); } EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow); void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma, size_t size) { dma_sync_single_range_for_device(pool->dev, dma, 0, size, DMA_BIDIRECTIONAL); } EXPORT_SYMBOL(xp_dma_sync_for_device_slow);