Re: [PATCH 0/2] Allow assembly code to use BIT(), GENMASK(), etc. and clean-up arm64 header

From: Catalin Marinas
Date: Wed Jun 05 2019 - 03:38:11 EST


On Mon, May 27, 2019 at 05:34:10PM +0900, Masahiro Yamada wrote:
> Some in-kernel headers use _BITUL() instead of BIT().
>
> arch/arm64/include/asm/sysreg.h
> arch/s390/include/asm/*.h
>
> I think the reason is because BIT() is currently not available
> in assembly. It hard-codes 1UL, which is not available in assembly.
[...]
> Masahiro Yamada (2):
> linux/bits.h: make BIT(), GENMASK(), and friends available in assembly
> arm64: replace _BITUL() with BIT()
>
> arch/arm64/include/asm/sysreg.h | 82 ++++++++++++++++-----------------
> include/linux/bits.h | 17 ++++---

I'm not sure it's worth the hassle. It's nice to have the same BIT macro
but a quick grep shows arc, arm64, s390 and x86 using _BITUL. Maybe a
tree-wide clean-up would be more appropriate.

--
Catalin