Commit 77c19539 authored by Jinjie Ruan's avatar Jinjie Ruan Committed by Will Deacon
Browse files

arm64: entry: Rework arm64_preempt_schedule_irq() 



The generic entry code has the form:

| raw_irqentry_exit_cond_resched()
| {
| 	if (!preempt_count()) {
| 		...
| 		if (need_resched())
| 			preempt_schedule_irq();
| 	}
| }

In preparation for moving arm64 over to the generic entry code, align
the structure of the arm64 code with raw_irqentry_exit_cond_resched() from
the generic entry code.

Reviewed-by: default avatarAda Couprie Diaz <ada.coupriediaz@arm.com>
Signed-off-by: default avatarJinjie Ruan <ruanjinjie@huawei.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent ee776d68

arch/arm64/kernel/entry-common.c

+10 −7
Original line number Diff line number Diff line
@@ -294,10 +294,10 @@ DEFINE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched); 
#define need_irq_preemption()	(IS_ENABLED(CONFIG_PREEMPTION))

#endif



static void __sched arm64_preempt_schedule_irq(void)

static inline bool arm64_preempt_schedule_irq(void)

{

	if (!need_irq_preemption())

		return;

		return false;



	/*

	 * Note: thread_info::preempt_count includes both thread_info::count
@@ -305,7 +305,7 @@ static void __sched arm64_preempt_schedule_irq(void) 
	 * preempt_count().

	 */

	if (READ_ONCE(current_thread_info()->preempt_count) != 0)

		return;

		return false;



	/*

	 * DAIF.DA are cleared at the start of IRQ/FIQ handling, and when GIC
@@ -314,7 +314,7 @@ static void __sched arm64_preempt_schedule_irq(void) 
	 * DAIF we must have handled an NMI, so skip preemption.

	 */

	if (system_uses_irq_prio_masking() && read_sysreg(daif))

		return;

		return false;



	/*

	 * Preempting a task from an IRQ means we leave copies of PSTATE
@@ -324,8 +324,10 @@ static void __sched arm64_preempt_schedule_irq(void) 
	 * Only allow a task to be preempted once cpufeatures have been

	 * enabled.

	 */

	if (system_capabilities_finalized())

		preempt_schedule_irq();

	if (!system_capabilities_finalized())

		return false;



	return true;

}



static void do_interrupt_handler(struct pt_regs *regs,
@@ -699,7 +701,8 @@ static __always_inline void __el1_irq(struct pt_regs *regs, 
	do_interrupt_handler(regs, handler);

	irq_exit_rcu();



	arm64_preempt_schedule_irq();

	if (arm64_preempt_schedule_irq())

		preempt_schedule_irq();



	exit_to_kernel_mode(regs, state);

}