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McKenney" , Linus Torvalds , Anna-Maria Behnsen , Eric Dumazet Subject: [RFC PATCH 2/6] softirq: Make softirq handling entry/exit generally available Date: Tue, 1 Aug 2023 15:24:37 +0200 Message-Id: <20230801132441.559222-3-frederic@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230801132441.559222-1-frederic@kernel.org> References: <20230801132441.559222-1-frederic@kernel.org> MIME-Version: 1.0 X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1773033944777229915 X-GMAIL-MSGID: 1773033944777229915 In order to prepare for re-enabling softirqs from vector callbacks that are known safe, make the code incrementing the preempt count while servicing softirqs more generally available. No intended behaviour change. Signed-off-by: Frederic Weisbecker --- include/linux/bottom_half.h | 7 +++++++ kernel/softirq.c | 22 ++++++++++++++++------ 2 files changed, 23 insertions(+), 6 deletions(-) diff --git a/include/linux/bottom_half.h b/include/linux/bottom_half.h index fc53e0ad56d9..2243c7de4917 100644 --- a/include/linux/bottom_half.h +++ b/include/linux/bottom_half.h @@ -33,6 +33,13 @@ static inline void local_bh_enable(void) __local_bh_enable_ip(_THIS_IP_, SOFTIRQ_DISABLE_OFFSET); } +static inline void local_bh_enter(void) +{ + __local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET); +} + +extern void local_bh_exit(void); + #ifdef CONFIG_PREEMPT_RT extern bool local_bh_blocked(void); #else diff --git a/kernel/softirq.c b/kernel/softirq.c index 1a3c3fe341ea..ba998d572ef4 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -247,21 +247,26 @@ void __local_bh_enable_ip(unsigned long ip, unsigned int cnt) } EXPORT_SYMBOL(__local_bh_enable_ip); +inline void local_bh_exit(void) +{ + __local_bh_enable(SOFTIRQ_OFFSET, true); + WARN_ON_ONCE(in_interrupt()); +} + /* * Invoked from ksoftirqd_run() outside of the interrupt disabled section * to acquire the per CPU local lock for reentrancy protection. */ static inline void ksoftirqd_run_begin(void) { - __local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET); + local_bh_enter(); local_irq_disable(); } /* Counterpart to ksoftirqd_run_begin() */ static inline void ksoftirqd_run_end(void) { - __local_bh_enable(SOFTIRQ_OFFSET, true); - WARN_ON_ONCE(in_interrupt()); + local_bh_exit(); local_irq_enable(); } @@ -389,15 +394,20 @@ void __local_bh_enable_ip(unsigned long ip, unsigned int cnt) } EXPORT_SYMBOL(__local_bh_enable_ip); +inline void local_bh_exit(void) +{ + __local_bh_enable(SOFTIRQ_OFFSET); + WARN_ON_ONCE(in_interrupt()); +} + static inline void softirq_handle_begin(void) { - __local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET); + local_bh_enter(); } static inline void softirq_handle_end(void) { - __local_bh_enable(SOFTIRQ_OFFSET); - WARN_ON_ONCE(in_interrupt()); + local_bh_exit(); } static inline void ksoftirqd_run_begin(void)