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From 7f3eb2174512fe6c9c0f062e96eccb0d3cc6d5cd Mon Sep 17 00:00:00 2001
From: Christian Marangi <ansuelsmth@gmail.com>
Date: Wed, 18 Oct 2023 14:35:47 +0200
Subject: [PATCH] net: introduce napi_is_scheduled helper
We currently have napi_if_scheduled_mark_missed that can be used to
check if napi is scheduled but that does more thing than simply checking
it and return a bool. Some driver already implement custom function to
check if napi is scheduled.
Drop these custom function and introduce napi_is_scheduled that simply
check if napi is scheduled atomically.
Update any driver and code that implement a similar check and instead
use this new helper.
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
drivers/net/ethernet/chelsio/cxgb3/sge.c | 8 --------
drivers/net/wireless/realtek/rtw89/core.c | 2 +-
include/linux/netdevice.h | 23 +++++++++++++++++++++++
net/core/dev.c | 2 +-
4 files changed, 25 insertions(+), 10 deletions(-)
--- a/drivers/net/ethernet/chelsio/cxgb3/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb3/sge.c
@@ -2501,14 +2501,6 @@ static int napi_rx_handler(struct napi_s
return work_done;
}
-/*
- * Returns true if the device is already scheduled for polling.
- */
-static inline int napi_is_scheduled(struct napi_struct *napi)
-{
- return test_bit(NAPI_STATE_SCHED, &napi->state);
-}
-
/**
* process_pure_responses - process pure responses from a response queue
* @adap: the adapter
--- a/drivers/net/wireless/realtek/rtw89/core.c
+++ b/drivers/net/wireless/realtek/rtw89/core.c
@@ -1744,7 +1744,7 @@ static void rtw89_core_rx_to_mac80211(st
struct napi_struct *napi = &rtwdev->napi;
/* In low power mode, napi isn't scheduled. Receive it to netif. */
- if (unlikely(!test_bit(NAPI_STATE_SCHED, &napi->state)))
+ if (unlikely(!napi_is_scheduled(napi)))
napi = NULL;
rtw89_core_hw_to_sband_rate(rx_status);
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -480,6 +480,29 @@ static inline bool napi_prefer_busy_poll
return test_bit(NAPI_STATE_PREFER_BUSY_POLL, &n->state);
}
+/**
+ * napi_is_scheduled - test if NAPI is scheduled
+ * @n: NAPI context
+ *
+ * This check is "best-effort". With no locking implemented,
+ * a NAPI can be scheduled or terminate right after this check
+ * and produce not precise results.
+ *
+ * NAPI_STATE_SCHED is an internal state, napi_is_scheduled
+ * should not be used normally and napi_schedule should be
+ * used instead.
+ *
+ * Use only if the driver really needs to check if a NAPI
+ * is scheduled for example in the context of delayed timer
+ * that can be skipped if a NAPI is already scheduled.
+ *
+ * Return True if NAPI is scheduled, False otherwise.
+ */
+static inline bool napi_is_scheduled(struct napi_struct *n)
+{
+ return test_bit(NAPI_STATE_SCHED, &n->state);
+}
+
bool napi_schedule_prep(struct napi_struct *n);
/**
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6610,7 +6610,7 @@ static int __napi_poll(struct napi_struc
* accidentally calling ->poll() when NAPI is not scheduled.
*/
work = 0;
- if (test_bit(NAPI_STATE_SCHED, &n->state)) {
+ if (napi_is_scheduled(n)) {
work = n->poll(n, weight);
trace_napi_poll(n, work, weight);
}
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