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

6 files changed, 39 insertions, 71 deletions

diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index 7d86a637367f..3e612fc818fa 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -63,26 +63,9 @@ static void xdp_umem_unaccount_pages(struct xdp_umem *umem)
 	}
 }
 
-void xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
-			 u16 queue_id)
-{
-	umem->dev = dev;
-	umem->queue_id = queue_id;
-
-	dev_hold(dev);
-}
-
-void xdp_umem_clear_dev(struct xdp_umem *umem)
-{
-	dev_put(umem->dev);
-	umem->dev = NULL;
-	umem->zc = false;
-}
-
 static void xdp_umem_release(struct xdp_umem *umem)
 {
-	xdp_umem_clear_dev(umem);
-
+	umem->zc = false;
 	ida_simple_remove(&umem_ida, umem->id);
 
 	xdp_umem_unpin_pages(umem);
@@ -181,8 +164,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
 		return -EINVAL;
 	}
 
-	if (mr->flags & ~(XDP_UMEM_UNALIGNED_CHUNK_FLAG |
-			XDP_UMEM_USES_NEED_WAKEUP))
+	if (mr->flags & ~XDP_UMEM_UNALIGNED_CHUNK_FLAG)
 		return -EINVAL;
 
 	if (!unaligned_chunks && !is_power_of_2(chunk_size))
diff --git a/net/xdp/xdp_umem.h b/net/xdp/xdp_umem.h
index 93e96be6f4de..67bf3f34d6c2 100644
--- a/net/xdp/xdp_umem.h
+++ b/net/xdp/xdp_umem.h
@@ -8,10 +8,6 @@
 
 #include <net/xdp_sock_drv.h>
 
-void xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
-			 u16 queue_id);
-void xdp_umem_clear_dev(struct xdp_umem *umem);
-bool xdp_umem_validate_queues(struct xdp_umem *umem);
 void xdp_get_umem(struct xdp_umem *umem);
 void xdp_put_umem(struct xdp_umem *umem);
 void xdp_add_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs);
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index dacd34034973..9f1b906ed0e7 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -41,13 +41,11 @@ bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)
 
 void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool)
 {
-	struct xdp_umem *umem = pool->umem;
-
-	if (umem->need_wakeup & XDP_WAKEUP_RX)
+	if (pool->cached_need_wakeup & XDP_WAKEUP_RX)
 		return;
 
 	pool->fq->ring->flags |= XDP_RING_NEED_WAKEUP;
-	umem->need_wakeup |= XDP_WAKEUP_RX;
+	pool->cached_need_wakeup |= XDP_WAKEUP_RX;
 }
 EXPORT_SYMBOL(xsk_set_rx_need_wakeup);
 
@@ -56,7 +54,7 @@ void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool)
 	struct xdp_umem *umem = pool->umem;
 	struct xdp_sock *xs;
 
-	if (umem->need_wakeup & XDP_WAKEUP_TX)
+	if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
 		return;
 
 	rcu_read_lock();
@@ -65,19 +63,17 @@ void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool)
 	}
 	rcu_read_unlock();
 
-	umem->need_wakeup |= XDP_WAKEUP_TX;
+	pool->cached_need_wakeup |= XDP_WAKEUP_TX;
 }
 EXPORT_SYMBOL(xsk_set_tx_need_wakeup);
 
 void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool)
 {
-	struct xdp_umem *umem = pool->umem;
-
-	if (!(umem->need_wakeup & XDP_WAKEUP_RX))
+	if (!(pool->cached_need_wakeup & XDP_WAKEUP_RX))
 		return;
 
 	pool->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP;
-	umem->need_wakeup &= ~XDP_WAKEUP_RX;
+	pool->cached_need_wakeup &= ~XDP_WAKEUP_RX;
 }
 EXPORT_SYMBOL(xsk_clear_rx_need_wakeup);
 
@@ -86,7 +82,7 @@ void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool)
 	struct xdp_umem *umem = pool->umem;
 	struct xdp_sock *xs;
 
-	if (!(umem->need_wakeup & XDP_WAKEUP_TX))
+	if (!(pool->cached_need_wakeup & XDP_WAKEUP_TX))
 		return;
 
 	rcu_read_lock();
@@ -95,13 +91,13 @@ void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool)
 	}
 	rcu_read_unlock();
 
-	umem->need_wakeup &= ~XDP_WAKEUP_TX;
+	pool->cached_need_wakeup &= ~XDP_WAKEUP_TX;
 }
 EXPORT_SYMBOL(xsk_clear_tx_need_wakeup);
 
 bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool)
 {
-	return pool->umem->flags & XDP_UMEM_USES_NEED_WAKEUP;
+	return pool->uses_need_wakeup;
 }
 EXPORT_SYMBOL(xsk_uses_need_wakeup);
 
@@ -478,16 +474,16 @@ static __poll_t xsk_poll(struct file *file, struct socket *sock,
 	__poll_t mask = datagram_poll(file, sock, wait);
 	struct sock *sk = sock->sk;
 	struct xdp_sock *xs = xdp_sk(sk);
-	struct xdp_umem *umem;
+	struct xsk_buff_pool *pool;
 
 	if (unlikely(!xsk_is_bound(xs)))
 		return mask;
 
-	umem = xs->umem;
+	pool = xs->pool;
 
-	if (umem->need_wakeup) {
+	if (pool->cached_need_wakeup) {
 		if (xs->zc)
-			xsk_wakeup(xs, umem->need_wakeup);
+			xsk_wakeup(xs, pool->cached_need_wakeup);
 		else
 			/* Poll needs to drive Tx also in copy mode */
 			__xsk_sendmsg(sk);
@@ -731,11 +727,9 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 		goto out_unlock;
 	} else {
 		/* This xsk has its own umem. */
-		xdp_umem_assign_dev(xs->umem, dev, qid);
 		xs->pool = xp_create_and_assign_umem(xs, xs->umem);
 		if (!xs->pool) {
 			err = -ENOMEM;
-			xdp_umem_clear_dev(xs->umem);
 			goto out_unlock;
 		}
 
@@ -743,7 +737,6 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 		if (err) {
 			xp_destroy(xs->pool);
 			xs->pool = NULL;
-			xdp_umem_clear_dev(xs->umem);
 			goto out_unlock;
 		}
 	}
@@ -1089,7 +1082,6 @@ static int xsk_notifier(struct notifier_block *this,
 
 				/* Clear device references. */
 				xp_clear_dev(xs->pool);
-				xdp_umem_clear_dev(xs->umem);
 			}
 			mutex_unlock(&xs->mutex);
 		}
diff --git a/net/xdp/xsk.h b/net/xdp/xsk.h
index a00e3e2a9ef1..da1f73e43924 100644
--- a/net/xdp/xsk.h
+++ b/net/xdp/xsk.h
@@ -11,13 +11,6 @@
 #define XSK_NEXT_PG_CONTIG_SHIFT 0
 #define XSK_NEXT_PG_CONTIG_MASK BIT_ULL(XSK_NEXT_PG_CONTIG_SHIFT)
 
-/* Flags for the umem flags field.
- *
- * The NEED_WAKEUP flag is 1 due to the reuse of the flags field for public
- * flags. See inlude/uapi/include/linux/if_xdp.h.
- */
-#define XDP_UMEM_USES_NEED_WAKEUP BIT(1)
-
 struct xdp_ring_offset_v1 {
 	__u64 producer;
 	__u64 consumer;
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)
diff --git a/net/xdp/xsk_diag.c b/net/xdp/xsk_diag.c
index 52675ea067bf..5bd8ea9d206a 100644
--- a/net/xdp/xsk_diag.c
+++ b/net/xdp/xsk_diag.c
@@ -59,8 +59,8 @@ static int xsk_diag_put_umem(const struct xdp_sock *xs, struct sk_buff *nlskb)
 	du.num_pages = umem->npgs;
 	du.chunk_size = umem->chunk_size;
 	du.headroom = umem->headroom;
-	du.ifindex = umem->dev ? umem->dev->ifindex : 0;
-	du.queue_id = umem->queue_id;
+	du.ifindex = pool->netdev ? pool->netdev->ifindex : 0;
+	du.queue_id = pool->queue_id;
 	du.flags = 0;
 	if (umem->zc)
 		du.flags |= XDP_DU_F_ZEROCOPY;