OSCL-LXR linux-6.0.1/​net/​xdp/​xsk_buff_pool.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // 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->tx_descs);
     kvfree(pool->heads);
     kvfree(pool);
 }
 
 int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs)
 {
     pool->tx_descs = kvcalloc(xs->tx->nentries, sizeof(*pool->tx_descs),
                   GFP_KERNEL);
     if (!pool->tx_descs)
         return -ENOMEM;
 
     return 0;
 }
 
 struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
                         struct xdp_umem *umem)
 {
     bool unaligned = umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG;
     struct xsk_buff_pool *pool;
     struct xdp_buff_xsk *xskb;
     u32 i, entries;
 
     entries = unaligned ? umem->chunks : 0;
     pool = kvzalloc(struct_size(pool, free_heads, entries), GFP_KERNEL);
     if (!pool)
         goto out;
 
     pool->heads = kvcalloc(umem->chunks, sizeof(*pool->heads), GFP_KERNEL);
     if (!pool->heads)
         goto out;
 
     if (xs->tx)
         if (xp_alloc_tx_descs(pool, xs))
             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->chunk_shift = ffs(umem->chunk_size) - 1;
     pool->unaligned = unaligned;
     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);
     spin_lock_init(&pool->cq_lock);
     refcount_set(&pool->users, 1);
 
     pool->fq = xs->fq_tmp;
     pool->cq = xs->cq_tmp;
 
     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;
         INIT_LIST_HEAD(&xskb->free_list_node);
         if (pool->unaligned)
             pool->free_heads[i] = xskb;
         else
             xp_init_xskb_addr(xskb, pool, i * pool->chunk_size);
     }
 
     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");
     }
 }
 
 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() or poll().
      */
     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");
         err = -EINVAL;
         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);
         dev_put(netdev);
     }
     return err;
 }
 
 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
              struct net_device *dev, u16 queue_id)
 {
     u16 flags;
     struct xdp_umem *umem = umem_xs->umem;
 
     /* 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 (umem_xs->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, false);
     xp_destroy(pool);
 }
 
 void xp_get_pool(struct xsk_buff_pool *pool)
 {
     refcount_inc(&pool->users);
 }
 
 bool xp_put_pool(struct xsk_buff_pool *pool)
 {
     if (!pool)
         return false;
 
     if (refcount_dec_and_test(&pool->users)) {
         INIT_WORK(&pool->work, xp_release_deferred);
         schedule_work(&pool->work);
         return true;
     }
 
     return false;
 }
 
 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 &= ~XSK_NEXT_PG_CONTIG_MASK;
             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)
 {
     if (!pool->unaligned) {
         u32 i;
 
         for (i = 0; i < pool->heads_cnt; i++) {
             struct xdp_buff_xsk *xskb = &pool->heads[i];
 
             xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, xskb->orig_addr);
         }
     }
 
     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;
 
     for (;;) {
         if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
             pool->fq->queue_empty_descs++;
             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;
     }
 
     if (pool->unaligned) {
         xskb = pool->free_heads[--pool->free_heads_cnt];
         xp_init_xskb_addr(xskb, pool, addr);
         if (pool->dma_pages_cnt)
             xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
     } else {
         xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
     }
 
     xskq_cons_release(pool->fq);
     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_init(&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);
 
 static u32 xp_alloc_new_from_fq(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
 {
     u32 i, cached_cons, nb_entries;
 
     if (max > pool->free_heads_cnt)
         max = pool->free_heads_cnt;
     max = xskq_cons_nb_entries(pool->fq, max);
 
     cached_cons = pool->fq->cached_cons;
     nb_entries = max;
     i = max;
     while (i--) {
         struct xdp_buff_xsk *xskb;
         u64 addr;
         bool ok;
 
         __xskq_cons_read_addr_unchecked(pool->fq, cached_cons++, &addr);
 
         ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
             xp_check_aligned(pool, &addr);
         if (unlikely(!ok)) {
             pool->fq->invalid_descs++;
             nb_entries--;
             continue;
         }
 
         if (pool->unaligned) {
             xskb = pool->free_heads[--pool->free_heads_cnt];
             xp_init_xskb_addr(xskb, pool, addr);
             if (pool->dma_pages_cnt)
                 xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
         } else {
             xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
         }
 
         *xdp = &xskb->xdp;
         xdp++;
     }
 
     xskq_cons_release_n(pool->fq, max);
     return nb_entries;
 }
 
 static u32 xp_alloc_reused(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 nb_entries)
 {
     struct xdp_buff_xsk *xskb;
     u32 i;
 
     nb_entries = min_t(u32, nb_entries, pool->free_list_cnt);
 
     i = nb_entries;
     while (i--) {
         xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, free_list_node);
         list_del_init(&xskb->free_list_node);
 
         *xdp = &xskb->xdp;
         xdp++;
     }
     pool->free_list_cnt -= nb_entries;
 
     return nb_entries;
 }
 
 u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
 {
     u32 nb_entries1 = 0, nb_entries2;
 
     if (unlikely(pool->dma_need_sync)) {
         struct xdp_buff *buff;
 
         /* Slow path */
         buff = xp_alloc(pool);
         if (buff)
             *xdp = buff;
         return !!buff;
     }
 
     if (unlikely(pool->free_list_cnt)) {
         nb_entries1 = xp_alloc_reused(pool, xdp, max);
         if (nb_entries1 == max)
             return nb_entries1;
 
         max -= nb_entries1;
         xdp += nb_entries1;
     }
 
     nb_entries2 = xp_alloc_new_from_fq(pool, xdp, max);
     if (!nb_entries2)
         pool->fq->queue_empty_descs++;
 
     return nb_entries1 + nb_entries2;
 }
 EXPORT_SYMBOL(xp_alloc_batch);
 
 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)
 {
     if (!list_empty(&xskb->free_list_node))
         return;
 
     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);

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