Commit ae9ef589 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

softirq: Move related code into one section 



To prepare for adding a RT aware variant of softirq serialization and
processing move related code into one section so the necessary #ifdeffery
is reduced to one.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20201113141733.974214480@linutronix.de
parent 15115830

kernel/softirq.c

+54 −53
Original line number Diff line number Diff line
@@ -92,6 +92,13 @@ static bool ksoftirqd_running(unsigned long pending) 
		!__kthread_should_park(tsk);

}



#ifdef CONFIG_TRACE_IRQFLAGS

DEFINE_PER_CPU(int, hardirqs_enabled);

DEFINE_PER_CPU(int, hardirq_context);

EXPORT_PER_CPU_SYMBOL_GPL(hardirqs_enabled);

EXPORT_PER_CPU_SYMBOL_GPL(hardirq_context);

#endif



/*

 * preempt_count and SOFTIRQ_OFFSET usage:

 * - preempt_count is changed by SOFTIRQ_OFFSET on entering or leaving
@@ -102,17 +109,11 @@ static bool ksoftirqd_running(unsigned long pending) 
 * softirq and whether we just have bh disabled.

 */



#ifdef CONFIG_TRACE_IRQFLAGS

/*

 * This one is for softirq.c-internal use,

 * where hardirqs are disabled legitimately:

 * This is for softirq.c-internal use, where hardirqs are disabled

 * legitimately:

 */

#ifdef CONFIG_TRACE_IRQFLAGS



DEFINE_PER_CPU(int, hardirqs_enabled);

DEFINE_PER_CPU(int, hardirq_context);

EXPORT_PER_CPU_SYMBOL_GPL(hardirqs_enabled);

EXPORT_PER_CPU_SYMBOL_GPL(hardirq_context);



void __local_bh_disable_ip(unsigned long ip, unsigned int cnt)

{

	unsigned long flags;
@@ -203,6 +204,50 @@ void __local_bh_enable_ip(unsigned long ip, unsigned int cnt) 
}

EXPORT_SYMBOL(__local_bh_enable_ip);



static inline void invoke_softirq(void)

{

	if (ksoftirqd_running(local_softirq_pending()))

		return;



	if (!force_irqthreads) {

#ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK

		/*

		 * We can safely execute softirq on the current stack if

		 * it is the irq stack, because it should be near empty

		 * at this stage.

		 */

		__do_softirq();

#else

		/*

		 * Otherwise, irq_exit() is called on the task stack that can

		 * be potentially deep already. So call softirq in its own stack

		 * to prevent from any overrun.

		 */

		do_softirq_own_stack();

#endif

	} else {

		wakeup_softirqd();

	}

}



asmlinkage __visible void do_softirq(void)

{

	__u32 pending;

	unsigned long flags;



	if (in_interrupt())

		return;



	local_irq_save(flags);



	pending = local_softirq_pending();



	if (pending && !ksoftirqd_running(pending))

		do_softirq_own_stack();



	local_irq_restore(flags);

}



/*

 * We restart softirq processing for at most MAX_SOFTIRQ_RESTART times,

 * but break the loop if need_resched() is set or after 2 ms.
@@ -327,24 +372,6 @@ asmlinkage __visible void __softirq_entry __do_softirq(void) 
	current_restore_flags(old_flags, PF_MEMALLOC);

}



asmlinkage __visible void do_softirq(void)

{

	__u32 pending;

	unsigned long flags;



	if (in_interrupt())

		return;



	local_irq_save(flags);



	pending = local_softirq_pending();



	if (pending && !ksoftirqd_running(pending))

		do_softirq_own_stack();



	local_irq_restore(flags);

}



/**

 * irq_enter_rcu - Enter an interrupt context with RCU watching

 */
@@ -371,32 +398,6 @@ void irq_enter(void) 
	irq_enter_rcu();

}



static inline void invoke_softirq(void)

{

	if (ksoftirqd_running(local_softirq_pending()))

		return;



	if (!force_irqthreads) {

#ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK

		/*

		 * We can safely execute softirq on the current stack if

		 * it is the irq stack, because it should be near empty

		 * at this stage.

		 */

		__do_softirq();

#else

		/*

		 * Otherwise, irq_exit() is called on the task stack that can

		 * be potentially deep already. So call softirq in its own stack

		 * to prevent from any overrun.

		 */

		do_softirq_own_stack();

#endif

	} else {

		wakeup_softirqd();

	}

}



static inline void tick_irq_exit(void)

{

#ifdef CONFIG_NO_HZ_COMMON