Commit 3c973c51 authored by Jinjie Ruan's avatar Jinjie Ruan Committed by Will Deacon
Browse files

entry: Add arch_irqentry_exit_need_resched() for arm64 



Compared to the generic entry code, ARM64 does additional checks
when deciding to reschedule on return from interrupt. So introduce
arch_irqentry_exit_need_resched() in the need_resched()
condition of the generic raw_irqentry_exit_cond_resched(), with
a NOP default. This will allow ARM64 to implement the architecture
specific version for switching over to the generic entry code.

Suggested-by: default avatarAda Couprie Diaz <ada.coupriediaz@arm.com>
Suggested-by: default avatarMark Rutland <mark.rutland@arm.com>
Suggested-by: default avatarKevin Brodsky <kevin.brodsky@arm.com>
Suggested-by: default avatarThomas Gleixner <tglx@linutronix.de>
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 c74c44c6

kernel/entry/common.c

+15 −1
Original line number Diff line number Diff line
@@ -143,6 +143,20 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs) 
	return ret;

}



/**

 * arch_irqentry_exit_need_resched - Architecture specific need resched function

 *

 * Invoked from raw_irqentry_exit_cond_resched() to check if resched is needed.

 * Defaults return true.

 *

 * The main purpose is to permit arch to avoid preemption of a task from an IRQ.

 */

static inline bool arch_irqentry_exit_need_resched(void);



#ifndef arch_irqentry_exit_need_resched

static inline bool arch_irqentry_exit_need_resched(void) { return true; }

#endif



void raw_irqentry_exit_cond_resched(void)

{

	if (!preempt_count()) {
@@ -150,7 +164,7 @@ void raw_irqentry_exit_cond_resched(void) 
		rcu_irq_exit_check_preempt();

		if (IS_ENABLED(CONFIG_DEBUG_ENTRY))

			WARN_ON_ONCE(!on_thread_stack());

		if (need_resched())

		if (need_resched() && arch_irqentry_exit_need_resched())

			preempt_schedule_irq();

	}

}