[PATCH net-next v2] net: use napi_id_valid helper

[PATCH net-next v2] net: use napi_id_valid helper

[Stefano Jordhani]

In commit 6597e8d35851 ("netdev-genl: Elide napi_id when not present"),
napi_id_valid function was added. Use the helper to refactor open-coded
checks in the source.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Stefano Jordhani <sjordhani@gmail.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk> # for iouring
---
v2:
 - Added Joe's and Jens' (for iouring) Reviewed-by tags. 
 - Respinning because my email client mangled my previous patch.

 fs/eventpoll.c            | 8 ++++----
 include/net/busy_poll.h   | 4 ++--
 io_uring/napi.c           | 4 ++--
 net/core/dev.c            | 6 +++---
 net/core/netdev-genl.c    | 2 +-
 net/core/page_pool_user.c | 2 +-
 net/core/sock.c           | 2 +-
 net/xdp/xsk.c             | 2 +-
 8 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 7c0980db77b3..2fecf66661e9 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -447,7 +447,7 @@ static bool ep_busy_loop(struct eventpoll *ep, int nonblock)
 	if (!budget)
 		budget = BUSY_POLL_BUDGET;
 
-	if (napi_id >= MIN_NAPI_ID && ep_busy_loop_on(ep)) {
+	if (napi_id_valid(napi_id) && ep_busy_loop_on(ep)) {
 		napi_busy_loop(napi_id, nonblock ? NULL : ep_busy_loop_end,
 			       ep, prefer_busy_poll, budget);
 		if (ep_events_available(ep))
@@ -492,7 +492,7 @@ static inline void ep_set_busy_poll_napi_id(struct epitem *epi)
 	 *	or
 	 * Nothing to do if we already have this ID
 	 */
-	if (napi_id < MIN_NAPI_ID || napi_id == ep->napi_id)
+	if (!napi_id_valid(napi_id) || napi_id == ep->napi_id)
 		return;
 
 	/* record NAPI ID for use in next busy poll */
@@ -546,7 +546,7 @@ static void ep_suspend_napi_irqs(struct eventpoll *ep)
 {
 	unsigned int napi_id = READ_ONCE(ep->napi_id);
 
-	if (napi_id >= MIN_NAPI_ID && READ_ONCE(ep->prefer_busy_poll))
+	if (napi_id_valid(napi_id) && READ_ONCE(ep->prefer_busy_poll))
 		napi_suspend_irqs(napi_id);
 }
 
@@ -554,7 +554,7 @@ static void ep_resume_napi_irqs(struct eventpoll *ep)
 {
 	unsigned int napi_id = READ_ONCE(ep->napi_id);
 
-	if (napi_id >= MIN_NAPI_ID && READ_ONCE(ep->prefer_busy_poll))
+	if (napi_id_valid(napi_id) && READ_ONCE(ep->prefer_busy_poll))
 		napi_resume_irqs(napi_id);
 }
 
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index 741fa7754700..cab6146a510a 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -119,7 +119,7 @@ static inline void sk_busy_loop(struct sock *sk, int nonblock)
 #ifdef CONFIG_NET_RX_BUSY_POLL
 	unsigned int napi_id = READ_ONCE(sk->sk_napi_id);
 
-	if (napi_id >= MIN_NAPI_ID)
+	if (napi_id_valid(napi_id))
 		napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk,
 			       READ_ONCE(sk->sk_prefer_busy_poll),
 			       READ_ONCE(sk->sk_busy_poll_budget) ?: BUSY_POLL_BUDGET);
@@ -134,7 +134,7 @@ static inline void skb_mark_napi_id(struct sk_buff *skb,
 	/* If the skb was already marked with a valid NAPI ID, avoid overwriting
 	 * it.
 	 */
-	if (skb->napi_id < MIN_NAPI_ID)
+	if (!napi_id_valid(skb->napi_id))
 		skb->napi_id = napi->napi_id;
 #endif
 }
diff --git a/io_uring/napi.c b/io_uring/napi.c
index b1ade3fda30f..4a10de03e426 100644
--- a/io_uring/napi.c
+++ b/io_uring/napi.c
@@ -44,7 +44,7 @@ int __io_napi_add_id(struct io_ring_ctx *ctx, unsigned int napi_id)
 	struct io_napi_entry *e;
 
 	/* Non-NAPI IDs can be rejected. */
-	if (napi_id < MIN_NAPI_ID)
+	if (!napi_id_valid(napi_id))
 		return -EINVAL;
 
 	hash_list = &ctx->napi_ht[hash_min(napi_id, HASH_BITS(ctx->napi_ht))];
@@ -87,7 +87,7 @@ static int __io_napi_del_id(struct io_ring_ctx *ctx, unsigned int napi_id)
 	struct io_napi_entry *e;
 
 	/* Non-NAPI IDs can be rejected. */
-	if (napi_id < MIN_NAPI_ID)
+	if (!napi_id_valid(napi_id))
 		return -EINVAL;
 
 	hash_list = &ctx->napi_ht[hash_min(napi_id, HASH_BITS(ctx->napi_ht))];
diff --git a/net/core/dev.c b/net/core/dev.c
index d5ab9a4b318e..bcb266ab2912 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1008,7 +1008,7 @@ struct net_device *dev_get_by_napi_id(unsigned int napi_id)
 
 	WARN_ON_ONCE(!rcu_read_lock_held());
 
-	if (napi_id < MIN_NAPI_ID)
+	if (!napi_id_valid(napi_id))
 		return NULL;
 
 	napi = napi_by_id(napi_id);
@@ -6740,7 +6740,7 @@ static void napi_hash_add(struct napi_struct *napi)
 
 	/* 0..NR_CPUS range is reserved for sender_cpu use */
 	do {
-		if (unlikely(++napi_gen_id < MIN_NAPI_ID))
+		if (unlikely(!napi_id_valid(++napi_gen_id)))
 			napi_gen_id = MIN_NAPI_ID;
 	} while (napi_by_id(napi_gen_id));
 
@@ -6911,7 +6911,7 @@ netif_napi_dev_list_add(struct net_device *dev, struct napi_struct *napi)
 
 	higher = &dev->napi_list;
 	list_for_each_entry(pos, &dev->napi_list, dev_list) {
-		if (pos->napi_id >= MIN_NAPI_ID)
+		if (napi_id_valid(pos->napi_id))
 			pos_id = pos->napi_id;
 		else if (pos->config)
 			pos_id = pos->config->napi_id;
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index c18bb53d13fd..22ac51356d9f 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -267,7 +267,7 @@ netdev_nl_napi_dump_one(struct net_device *netdev, struct sk_buff *rsp,
 
 	prev_id = UINT_MAX;
 	list_for_each_entry(napi, &netdev->napi_list, dev_list) {
-		if (napi->napi_id < MIN_NAPI_ID)
+		if (!napi_id_valid(napi->napi_id))
 			continue;
 
 		/* Dump continuation below depends on the list being sorted */
diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
index 9d8a3d8597fa..c82a95beceff 100644
--- a/net/core/page_pool_user.c
+++ b/net/core/page_pool_user.c
@@ -233,7 +233,7 @@ page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
 		goto err_cancel;
 
 	napi_id = pool->p.napi ? READ_ONCE(pool->p.napi->napi_id) : 0;
-	if (napi_id >= MIN_NAPI_ID &&
+	if (napi_id_valid(napi_id) &&
 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_NAPI_ID, napi_id))
 		goto err_cancel;
 
diff --git a/net/core/sock.c b/net/core/sock.c
index a197f0a0b878..53c7af0038c4 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2042,7 +2042,7 @@ int sk_getsockopt(struct sock *sk, int level, int optname,
 		v.val = READ_ONCE(sk->sk_napi_id);
 
 		/* aggregate non-NAPI IDs down to 0 */
-		if (v.val < MIN_NAPI_ID)
+		if (!napi_id_valid(v.val))
 			v.val = 0;
 
 		break;
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 89d2bef96469..0edf25973072 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -875,7 +875,7 @@ static bool xsk_no_wakeup(struct sock *sk)
 #ifdef CONFIG_NET_RX_BUSY_POLL
 	/* Prefer busy-polling, skip the wakeup. */
 	return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) &&
-		READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID;
+		napi_id_valid(READ_ONCE(sk->sk_napi_id));
 #else
 	return false;
 #endif

base-commit: 7a7e0197133d18cfd9931e7d3a842d0f5730223f
-- 
2.43.0

Re: [PATCH net-next v2] net: use napi_id_valid helper

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Fri, 14 Feb 2025 18:17:51 +0000 you wrote:
> In commit 6597e8d35851 ("netdev-genl: Elide napi_id when not present"),
> napi_id_valid function was added. Use the helper to refactor open-coded
> checks in the source.
> 
> Suggested-by: Paolo Abeni <pabeni@redhat.com>
> Signed-off-by: Stefano Jordhani <sjordhani@gmail.com>
> Reviewed-by: Joe Damato <jdamato@fastly.com>
> Reviewed-by: Jens Axboe <axboe@kernel.dk> # for iouring
> 
> [...]

Here is the summary with links:
  - [net-next,v2] net: use napi_id_valid helper
    https://git.kernel.org/netdev/net-next/c/b9d752105e5f

You are awesome, thank you!
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