2019-06-11 09:53:23

by Julien Thierry

Subject: [PATCH v4 2/8] arm64: irqflags: Pass flags as readonly operand to restore instruction

Flags are only read by the instructions doing the irqflags restore
operation. Pass the operand as read only to the asm inline instead of
read-write.

Signed-off-by: Julien Thierry <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
---
arch/arm64/include/asm/irqflags.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/irqflags.h b/arch/arm64/include/asm/irqflags.h
index 62996318..9c93152 100644
--- a/arch/arm64/include/asm/irqflags.h
+++ b/arch/arm64/include/asm/irqflags.h
@@ -119,8 +119,8 @@ static inline void arch_local_irq_restore(unsigned long flags)
__msr_s(SYS_ICC_PMR_EL1, "%0")
"dsb sy",
ARM64_HAS_IRQ_PRIO_MASKING)
- : "+r" (flags)
:
+ : "r" (flags)
: "memory");
}

--
1.9.1

2019-06-11 12:47:17

by Mark Rutland

Subject: Re: [PATCH v4 2/8] arm64: irqflags: Pass flags as readonly operand to restore instruction

On Tue, Jun 11, 2019 at 10:38:07AM +0100, Julien Thierry wrote:
> Flags are only read by the instructions doing the irqflags restore
> operation. Pass the operand as read only to the asm inline instead of
> read-write.
>
> Signed-off-by: Julien Thierry <[email protected]>
> Cc: Catalin Marinas <[email protected]>
> Cc: Will Deacon <[email protected]>

Acked-by: Mark Rutland <[email protected]>

Mark.

> ---
> arch/arm64/include/asm/irqflags.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/include/asm/irqflags.h b/arch/arm64/include/asm/irqflags.h
> index 62996318..9c93152 100644
> --- a/arch/arm64/include/asm/irqflags.h
> +++ b/arch/arm64/include/asm/irqflags.h
> @@ -119,8 +119,8 @@ static inline void arch_local_irq_restore(unsigned long flags)
> __msr_s(SYS_ICC_PMR_EL1, "%0")
> "dsb sy",
> ARM64_HAS_IRQ_PRIO_MASKING)
> - : "+r" (flags)
> :
> + : "r" (flags)
> : "memory");
> }
>
> --
> 1.9.1