linux-kernel - [PATCH v4 08/26] arm64: daifflags: Use irqflags functions for daifflags

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Message-Id: <1527241772-48007-9-git-send-email-julien.thierry@arm.com>
Date:   Fri, 25 May 2018 10:49:14 +0100
From:   Julien Thierry <julien.thierry@....com>
To:     linux-arm-kernel@...ts.infradead.org
Cc:     linux-kernel@...r.kernel.org, daniel.thompson@...aro.org,
        joel@...lfernandes.org, marc.zyngier@....com, mark.rutland@....com,
        christoffer.dall@....com, james.morse@....com,
        catalin.marinas@....com, will.deacon@....com,
        Julien Thierry <julien.thierry@....com>
Subject: [PATCH v4 08/26] arm64: daifflags: Use irqflags functions for daifflags

Some of the work done in daifflags save/restore is already provided
by irqflags functions. Daifflags should always be a superset of irqflags
(it handles irq status + status of other flags). Modifying behaviour of
irqflags should alter the behaviour of daifflags.

Use irqflags_save/restore functions for the corresponding daifflags
operation.

Signed-off-by: Julien Thierry <julien.thierry@....com>
Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Will Deacon <will.deacon@....com>
Cc: James Morse <james.morse@....com>
---
 arch/arm64/include/asm/daifflags.h | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

Note:
A latter patch changes the behaviour of arch_local_flags but the daif
flag still need to follow the semantics of arch_local_flags.

diff --git a/arch/arm64/include/asm/daifflags.h b/arch/arm64/include/asm/daifflags.h
index 22e4c83..8d91f22 100644
--- a/arch/arm64/include/asm/daifflags.h
+++ b/arch/arm64/include/asm/daifflags.h
@@ -36,11 +36,8 @@ static inline unsigned long local_daif_save(void)
 {
 	unsigned long flags;

-	asm volatile(
-		"mrs	%0, daif		// local_daif_save\n"
-		: "=r" (flags)
-		:
-		: "memory");
+	flags = arch_local_save_flags();
+
 	local_daif_mask();

 	return flags;
@@ -60,11 +57,9 @@ static inline void local_daif_restore(unsigned long flags)
 {
 	if (!arch_irqs_disabled_flags(flags))
 		trace_hardirqs_on();
-	asm volatile(
-		"msr	daif, %0		// local_daif_restore"
-		:
-		: "r" (flags)
-		: "memory");
+
+	arch_local_irq_restore(flags);
+
 	if (arch_irqs_disabled_flags(flags))
 		trace_hardirqs_off();
 }
--
1.9.1