xsk: Move queue_id, dev and need_wakeup to buffer pool

Move queue_id, dev, and need_wakeup from the umem to the
buffer pool. This so that we in a later commit can share the umem
between multiple HW queues. There is one buffer pool per dev and
queue id, so these variables should belong to the buffer pool, not
the umem. Need_wakeup is also something that is set on a per napi
level, so there is usually one per device and queue id. So move
this to the buffer pool too.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/1598603189-32145-6-git-send-email-magnus.karlsson@intel.com

1 files changed, 22 insertions, 17 deletions

diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index 36287d2c5095..436648a04f6a 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -95,10 +95,9 @@ void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
 }
 EXPORT_SYMBOL(xp_set_rxq_info);
 
-int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev,
+int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *netdev,
 		  u16 queue_id, u16 flags)
 {
-	struct xdp_umem *umem = pool->umem;
 	bool force_zc, force_copy;
 	struct netdev_bpf bpf;
 	int err = 0;
@@ -111,27 +110,30 @@ int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev,
 	if (force_zc && force_copy)
 		return -EINVAL;
 
-	if (xsk_get_pool_from_qid(dev, queue_id))
+	if (xsk_get_pool_from_qid(netdev, queue_id))
 		return -EBUSY;
 
-	err = xsk_reg_pool_at_qid(dev, pool, queue_id);
+	err = xsk_reg_pool_at_qid(netdev, pool, queue_id);
 	if (err)
 		return err;
 
 	if (flags & XDP_USE_NEED_WAKEUP) {
-		umem->flags |= XDP_UMEM_USES_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().
 		 */
-		umem->need_wakeup = XDP_WAKEUP_TX;
+		pool->cached_need_wakeup = XDP_WAKEUP_TX;
 	}
 
+	dev_hold(netdev);
+
 	if (force_copy)
 		/* For copy-mode, we are done. */
 		return 0;
 
-	if (!dev->netdev_ops->ndo_bpf || !dev->netdev_ops->ndo_xsk_wakeup) {
+	if (!netdev->netdev_ops->ndo_bpf ||
+	    !netdev->netdev_ops->ndo_xsk_wakeup) {
 		err = -EOPNOTSUPP;
 		goto err_unreg_pool;
 	}
@@ -140,44 +142,47 @@ int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev,
 	bpf.xsk.pool = pool;
 	bpf.xsk.queue_id = queue_id;
 
-	err = dev->netdev_ops->ndo_bpf(dev, &bpf);
+	err = netdev->netdev_ops->ndo_bpf(netdev, &bpf);
 	if (err)
 		goto err_unreg_pool;
 
-	umem->zc = true;
+	pool->netdev = netdev;
+	pool->queue_id = queue_id;
+	pool->umem->zc = true;
 	return 0;
 
 err_unreg_pool:
 	if (!force_zc)
 		err = 0; /* fallback to copy mode */
 	if (err)
-		xsk_clear_pool_at_qid(dev, queue_id);
+		xsk_clear_pool_at_qid(netdev, queue_id);
 	return err;
 }
 
 void xp_clear_dev(struct xsk_buff_pool *pool)
 {
-	struct xdp_umem *umem = pool->umem;
 	struct netdev_bpf bpf;
 	int err;
 
 	ASSERT_RTNL();
 
-	if (!umem->dev)
+	if (!pool->netdev)
 		return;
 
-	if (umem->zc) {
+	if (pool->umem->zc) {
 		bpf.command = XDP_SETUP_XSK_POOL;
 		bpf.xsk.pool = NULL;
-		bpf.xsk.queue_id = umem->queue_id;
+		bpf.xsk.queue_id = pool->queue_id;
 
-		err = umem->dev->netdev_ops->ndo_bpf(umem->dev, &bpf);
+		err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf);
 
 		if (err)
-			WARN(1, "failed to disable umem!\n");
+			WARN(1, "Failed to disable zero-copy!\n");
 	}
 
-	xsk_clear_pool_at_qid(umem->dev, umem->queue_id);
+	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)