[PATCH net-next v2 1/2] xsk: do not enable/disable irq when grabbing/releasing xsk_tx_list_lock

[Jason Xing <kerneljasonxing@gmail.com>]

From: Jason Xing <kernelxing@tencent.com>

The commit ac98d8aab61b ("xsk: wire upp Tx zero-copy functions")
originally introducing this lock put the deletion process in the
sk_destruct which can run in irq context obviously, so the
xxx_irqsave()/xxx_irqrestore() pair was used. But later another
commit 541d7fdd7694 ("xsk: proper AF_XDP socket teardown ordering")
moved the deletion into xsk_release() that only happens in process
context. It means that since this commit, it doesn't necessarily
need that pair.

Now, there are two places that use this xsk_tx_list_lock and only
run in the process context. So avoid manipulating the irq then.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
---
 net/xdp/xsk_buff_pool.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index aa9788f20d0d..309075050b2a 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -12,26 +12,22 @@
 
 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);
+	spin_lock(&pool->xsk_tx_list_lock);
 	list_add_rcu(&xs->tx_list, &pool->xsk_tx_list);
-	spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags);
+	spin_unlock(&pool->xsk_tx_list_lock);
 }
 
 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);
+	spin_lock(&pool->xsk_tx_list_lock);
 	list_del_rcu(&xs->tx_list);
-	spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags);
+	spin_unlock(&pool->xsk_tx_list_lock);
 }
 
 void xp_destroy(struct xsk_buff_pool *pool)
-- 
2.41.3