[PATCHv3 3/3] arm64/entry-common: supplement irq accounting

[Pingfan Liu]

At present, the irq entry/exit accounting, which is performed by
handle_domain_irq(), overlaps with arm64 exception entry code somehow.

By supplementing irq accounting on arm64 exception entry code, the
accounting in handle_domain_irq() can be dropped totally by selecting
the macro HAVE_ARCH_IRQENTRY.

Signed-off-by: Pingfan Liu <kernelfans at gmail.com>
Cc: "Paul E. McKenney" <paulmck at kernel.org>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Will Deacon <will at kernel.org>
Cc: Mark Rutland <mark.rutland at arm.com>
Cc: Marc Zyngier <maz at kernel.org>
Cc: Joey Gouly <joey.gouly at arm.com>
Cc: Sami Tolvanen <samitolvanen at google.com>
Cc: Julien Thierry <julien.thierry at arm.com>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: Yuichi Ito <ito-yuichi at fujitsu.com>
Cc: linux-kernel at vger.kernel.org
To: linux-arm-kernel at lists.infradead.org
---
 arch/arm64/Kconfig               | 1 +
 arch/arm64/kernel/entry-common.c | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 5c7ae4c3954b..d29bae38a951 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -98,6 +98,7 @@ config ARM64
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
 	select ARM_AMBA
 	select ARM_ARCH_TIMER
+	select HAVE_ARCH_IRQENTRY
 	select ARM_GIC
 	select AUDIT_ARCH_COMPAT_GENERIC
 	select ARM_GIC_V2M if PCI
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index 5f1473319fb0..6d4dc3b3799f 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -428,7 +428,9 @@ static __always_inline void
 __el1_interrupt(struct pt_regs *regs, void (*handler)(struct pt_regs *))
 {
 	enter_from_kernel_mode(regs);
+	irq_enter_rcu();
 	do_interrupt_handler(regs, handler);
+	irq_exit_rcu();
 	/*
 	 * Note: thread_info::preempt_count includes both thread_info::count
 	 * and thread_info::need_resched, and is not equivalent to
@@ -667,7 +669,9 @@ static void noinstr el0_interrupt(struct pt_regs *regs,
 	if (regs->pc & BIT(55))
 		arm64_apply_bp_hardening();
 
+	irq_enter_rcu();
 	do_interrupt_handler(regs, handler);
+	irq_exit_rcu();
 
 	exit_to_user_mode(regs);
 }
-- 
2.31.1