From 7f3eb2174512fe6c9c0f062e96eccb0d3cc6d5cd Mon Sep 17 00:00:00 2001 From: Christian Marangi 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 Signed-off-by: Paolo Abeni --- 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 @@ -2507,14 +2507,6 @@ 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 @@ -1479,7 +1479,7 @@ 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 @@ -468,6 +468,29 @@ 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 @@ -6533,7 +6533,7 @@ 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); }