From 240a23a21ba64ff51801c32adad6c2a6e8addc27 Mon Sep 17 00:00:00 2001
From: Dominique Martinet <dominique.martinet@cea.fr>
Date: Fri, 27 Jul 2018 14:49:06 +0900
Subject: [PATCH] arch-lock: tentative implementation of irqflags_can_interrupt
 for arm64

Change-Id: I814e02e757039cab8c142c0b774ad470154454c1
---
 arch/arm64/kernel/include/arch-lock.h | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/include/arch-lock.h b/arch/arm64/kernel/include/arch-lock.h
index 10930016..e53f2532 100644
--- a/arch/arm64/kernel/include/arch-lock.h
+++ b/arch/arm64/kernel/include/arch-lock.h
@@ -607,8 +607,13 @@ __mcs_rwlock_reader_unlock(struct mcs_rwlock_lock *lock, struct mcs_rwlock_node_
 
 static inline int irqflags_can_interrupt(unsigned long flags)
 {
-#warning "arm64 irqflags_can_interrupt not implemented"
-	return true;
+#ifdef CONFIG_HAS_NMI
+#warning irqflags_can_interrupt needs testing/fixing on such a target
+	return flags > ICC_PMR_EL1_MASKED;
+#else
+	// PSTATE.DAIF I bit clear means interrupt is possible
+	return !(flags & (1 << 7));
+#endif
 }