diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/devmap.c | 74 |
1 files changed, 70 insertions, 4 deletions
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 06c400e7e4ff..15293b9dfb77 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -55,10 +55,17 @@ #define DEV_CREATE_FLAG_MASK \ (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) +#define DEV_MAP_BULK_SIZE 16 +struct xdp_bulk_queue { + struct xdp_frame *q[DEV_MAP_BULK_SIZE]; + unsigned int count; +}; + struct bpf_dtab_netdev { struct net_device *dev; /* must be first member, due to tracepoint */ struct bpf_dtab *dtab; unsigned int bit; + struct xdp_bulk_queue __percpu *bulkq; struct rcu_head rcu; }; @@ -208,6 +215,34 @@ void __dev_map_insert_ctx(struct bpf_map *map, u32 bit) __set_bit(bit, bitmap); } +static int bq_xmit_all(struct bpf_dtab_netdev *obj, + struct xdp_bulk_queue *bq) +{ + struct net_device *dev = obj->dev; + int i; + + if (unlikely(!bq->count)) + return 0; + + for (i = 0; i < bq->count; i++) { + struct xdp_frame *xdpf = bq->q[i]; + + prefetch(xdpf); + } + + for (i = 0; i < bq->count; i++) { + struct xdp_frame *xdpf = bq->q[i]; + int err; + + err = dev->netdev_ops->ndo_xdp_xmit(dev, xdpf); + if (err) + xdp_return_frame(xdpf); + } + bq->count = 0; + + return 0; +} + /* __dev_map_flush is called from xdp_do_flush_map() which _must_ be signaled * from the driver before returning from its napi->poll() routine. The poll() * routine is called either from busy_poll context or net_rx_action signaled @@ -223,6 +258,7 @@ void __dev_map_flush(struct bpf_map *map) for_each_set_bit(bit, bitmap, map->max_entries) { struct bpf_dtab_netdev *dev = READ_ONCE(dtab->netdev_map[bit]); + struct xdp_bulk_queue *bq; struct net_device *netdev; /* This is possible if the dev entry is removed by user space @@ -232,6 +268,9 @@ void __dev_map_flush(struct bpf_map *map) continue; __clear_bit(bit, bitmap); + + bq = this_cpu_ptr(dev->bulkq); + bq_xmit_all(dev, bq); netdev = dev->dev; if (likely(netdev->netdev_ops->ndo_xdp_flush)) netdev->netdev_ops->ndo_xdp_flush(netdev); @@ -254,6 +293,20 @@ struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key) return obj; } +/* Runs under RCU-read-side, plus in softirq under NAPI protection. + * Thus, safe percpu variable access. + */ +static int bq_enqueue(struct bpf_dtab_netdev *obj, struct xdp_frame *xdpf) +{ + struct xdp_bulk_queue *bq = this_cpu_ptr(obj->bulkq); + + if (unlikely(bq->count == DEV_MAP_BULK_SIZE)) + bq_xmit_all(obj, bq); + + bq->q[bq->count++] = xdpf; + return 0; +} + int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp) { struct net_device *dev = dst->dev; @@ -266,8 +319,7 @@ int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp) if (unlikely(!xdpf)) return -EOVERFLOW; - /* TODO: implement a bulking/enqueue step later */ - return dev->netdev_ops->ndo_xdp_xmit(dev, xdpf); + return bq_enqueue(dst, xdpf); } static void *dev_map_lookup_elem(struct bpf_map *map, void *key) @@ -282,13 +334,18 @@ static void dev_map_flush_old(struct bpf_dtab_netdev *dev) { if (dev->dev->netdev_ops->ndo_xdp_flush) { struct net_device *fl = dev->dev; + struct xdp_bulk_queue *bq; unsigned long *bitmap; + int cpu; for_each_online_cpu(cpu) { bitmap = per_cpu_ptr(dev->dtab->flush_needed, cpu); __clear_bit(dev->bit, bitmap); + bq = per_cpu_ptr(dev->bulkq, cpu); + bq_xmit_all(dev, bq); + fl->netdev_ops->ndo_xdp_flush(dev->dev); } } @@ -300,6 +357,7 @@ static void __dev_map_entry_free(struct rcu_head *rcu) dev = container_of(rcu, struct bpf_dtab_netdev, rcu); dev_map_flush_old(dev); + free_percpu(dev->bulkq); dev_put(dev->dev); kfree(dev); } @@ -332,6 +390,7 @@ static int dev_map_update_elem(struct bpf_map *map, void *key, void *value, { struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); struct net *net = current->nsproxy->net_ns; + gfp_t gfp = GFP_ATOMIC | __GFP_NOWARN; struct bpf_dtab_netdev *dev, *old_dev; u32 i = *(u32 *)key; u32 ifindex = *(u32 *)value; @@ -346,13 +405,20 @@ static int dev_map_update_elem(struct bpf_map *map, void *key, void *value, if (!ifindex) { dev = NULL; } else { - dev = kmalloc_node(sizeof(*dev), GFP_ATOMIC | __GFP_NOWARN, - map->numa_node); + dev = kmalloc_node(sizeof(*dev), gfp, map->numa_node); if (!dev) return -ENOMEM; + dev->bulkq = __alloc_percpu_gfp(sizeof(*dev->bulkq), + sizeof(void *), gfp); + if (!dev->bulkq) { + kfree(dev); + return -ENOMEM; + } + dev->dev = dev_get_by_index(net, ifindex); if (!dev->dev) { + free_percpu(dev->bulkq); kfree(dev); return -EINVAL; } |