Re: [PATCH V2 06/19] csky: Cache and TLB routines

[Peter Zijlstra]

On Mon, Jul 02, 2018 at 01:30:09AM +0800, Guo Ren wrote:
> diff --git a/arch/csky/include/asm/barrier.h b/arch/csky/include/asm/barrier.h
> new file mode 100644
> index 0000000..7254527
> --- /dev/null
> +++ b/arch/csky/include/asm/barrier.h
> @@ -0,0 +1,19 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
> +#ifndef __ASM_CSKY_BARRIER_H
> +#define __ASM_CSKY_BARRIER_H
> +
> +#ifndef __ASSEMBLY__
> +
> +#define nop()	asm volatile ("nop")
> +
> +#ifdef CONFIG_SMP
> +#define mb()	asm volatile ("sync.is":::"memory")
> +#else
> +#define mb()	asm volatile ("sync":::"memory")
> +#endif

This is very suspect, please elaborate.

What I would've expected is:

#define mb() asm volatile ("sync" ::: "memory")

#ifdef CONFIG_SMP
#define __smp_mb() asm volatile ("sync.is" ::: "memory")
#endif

Is that in fact what you meant?

Do you have a reference to your architecture manual and memory model
description somewhere?


> +
> +#include <asm-generic/barrier.h>
> +
> +#endif /* __ASSEMBLY__ */
> +#endif /* __ASM_CSKY_BARRIER_H */