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;
                 }