The following commit has been merged into the x86/entry branch of tip: Commit-ID: a59262f6413b82992626754b46383a615bfac152 Gitweb: https://git.kernel.org/tip/a59262f6413b82992626754b46383a615bfac152 Author: Thomas Gleixner <t...@linutronix.de> AuthorDate: Thu, 21 May 2020 22:05:21 +02:00 Committer: Ingo Molnar <mi...@kernel.org> CommitterDate: Tue, 26 May 2020 19:06:27 +02:00
genirq: Provide irq_enter/exit_rcu() irq_enter()/exit() currently include RCU handling. To properly separate the RCU handling code, provide variants which contain only the non-RCU related functionality. Signed-off-by: Thomas Gleixner <t...@linutronix.de> Signed-off-by: Ingo Molnar <mi...@kernel.org> Reviewed-by: Andy Lutomirski <l...@kernel.org> Link: https://lore.kernel.org/r/20200521202117.567023...@linutronix.de --- include/linux/hardirq.h | 13 +++++++++++-- kernel/softirq.c | 35 +++++++++++++++++++++++++++-------- 2 files changed, 38 insertions(+), 10 deletions(-) diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 29b862a..3dc9102 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -40,7 +40,11 @@ static __always_inline void rcu_irq_enter_check_tick(void) /* * Enter irq context (on NO_HZ, update jiffies): */ -extern void irq_enter(void); +void irq_enter(void); +/* + * Like irq_enter(), but RCU is already watching. + */ +void irq_enter_rcu(void); /* * Exit irq context without processing softirqs: @@ -55,7 +59,12 @@ extern void irq_enter(void); /* * Exit irq context and process softirqs if needed: */ -extern void irq_exit(void); +void irq_exit(void); + +/* + * Like irq_exit(), but return with RCU watching. + */ +void irq_exit_rcu(void); #ifndef arch_nmi_enter #define arch_nmi_enter() do { } while (0) diff --git a/kernel/softirq.c b/kernel/softirq.c index a47c6dd..beb8e3a 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -339,12 +339,11 @@ asmlinkage __visible void do_softirq(void) local_irq_restore(flags); } -/* - * Enter an interrupt context. +/** + * irq_enter_rcu - Enter an interrupt context with RCU watching */ -void irq_enter(void) +void irq_enter_rcu(void) { - rcu_irq_enter(); if (is_idle_task(current) && !in_interrupt()) { /* * Prevent raise_softirq from needlessly waking up ksoftirqd @@ -354,10 +353,18 @@ void irq_enter(void) tick_irq_enter(); _local_bh_enable(); } - __irq_enter(); } +/** + * irq_enter - Enter an interrupt context including RCU update + */ +void irq_enter(void) +{ + rcu_irq_enter(); + irq_enter_rcu(); +} + static inline void invoke_softirq(void) { if (ksoftirqd_running(local_softirq_pending())) @@ -397,10 +404,12 @@ static inline void tick_irq_exit(void) #endif } -/* - * Exit an interrupt context. Process softirqs if needed and possible: +/** + * irq_exit_rcu() - Exit an interrupt context without updating RCU + * + * Also processes softirqs if needed and possible. */ -void irq_exit(void) +void irq_exit_rcu(void) { #ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED local_irq_disable(); @@ -413,6 +422,16 @@ void irq_exit(void) invoke_softirq(); tick_irq_exit(); +} + +/** + * irq_exit - Exit an interrupt context, update RCU and lockdep + * + * Also processes softirqs if needed and possible. + */ +void irq_exit(void) +{ + irq_exit_rcu(); rcu_irq_exit(); /* must be last! */ lockdep_hardirq_exit();
