Re: [RFC PATCH v2 00/12] Rewrite asm-generic/bitops/{atomic,lock}.h and use on arm64

From: Masahiro Yamada <yamada.masahiro@socionext.com>
To: Will Deacon <will.deacon@arm.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [RFC PATCH v2 00/12] Rewrite asm-generic/bitops/{atomic,lock}.h and use on arm64
Date: Thu, 1 Mar 2018 16:16:25 +0900	[thread overview]
Message-ID: <CAK7LNATktPPTHDDhS0i=3o8p=XoVXBJ1KB+3VmDp_iqn239Z8g@mail.gmail.com> (raw)
In-Reply-To: <1519657500-15094-1-git-send-email-will.deacon@arm.com>

2018-02-27 0:04 GMT+09:00 Will Deacon <will.deacon@arm.com>:
> Hi everyone,
>
> This is version two of the RFC I previously posted here:
>
>   https://www.spinics.net/lists/arm-kernel/msg634719.html
>
> Changes since v1 include:
>
>   * Fixed __clear_bit_unlock to work on archs with lock-based atomics
>   * Moved lock ops into bitops/lock.h
>   * Fixed build breakage on lesser-spotted architectures
>
> Trying to fix the circular #includes introduced by pulling atomic.h
> into btops/lock.h has been driving me insane. I've ended up moving some
> basic BIT definitions into bits.h, but this might all be better in
> const.h which is being proposed by Masahiro. Feedback is especially
> welcome on this part.

Info for reviewers:

You can see my patches at the following:

1/5: https://patchwork.kernel.org/patch/10235457/
2/5: https://patchwork.kernel.org/patch/10235461/
3/5: https://patchwork.kernel.org/patch/10235463/
4/5: https://patchwork.kernel.org/patch/10235469/
5/5: https://patchwork.kernel.org/patch/10235471/

5/5 has conflict with Will's 2/12.

Fortunately, it is at the tail of the series.
It is easy to pick/drop/change
when we decide how to organize it.

> I've not bothered optimising for the case of a 64-bit, big-endian
> architecture that uses the generic implementation of atomic64_t because
> it's both messy and hypothetical. The code here should still work
> correctly for that case, it just sucks (as does the implementation
> currently in mainline).
>
> Cheers,
>
> Will
>
> --->8
>
> Will Deacon (12):
>   h8300: Don't include linux/kernel.h in asm/atomic.h
>   m68k: Don't use asm-generic/bitops/lock.h
>   asm-generic: Move some macros from linux/bitops.h to a new bits.h file
>   openrisc: Don't pull in all of linux/bitops.h in asm/cmpxchg.h
>   sh: Don't pull in all of linux/bitops.h in asm/cmpxchg-xchg.h
>   arm64: fpsimd: include <linux/init.h> in fpsimd.h
>   arm64: lse: Include compiler_types.h and export.h for out-of-line
>     LL/SC
>   arm64: cmpxchg: Include build_bug.h instead of bug.h for BUILD_BUG
>   asm-generic/bitops/atomic.h: Rewrite using atomic_fetch_*
>   asm-generic/bitops/lock.h: Rewrite using atomic_fetch_*
>   arm64: Replace our atomic/lock bitop implementations with asm-generic
>   arm64: bitops: Include <asm-generic/bitops/ext2-atomic-setbit.h>
>
>  arch/arm64/include/asm/bitops.h     |  21 +---
>  arch/arm64/include/asm/cmpxchg.h    |   2 +-
>  arch/arm64/include/asm/fpsimd.h     |   1 +
>  arch/arm64/include/asm/lse.h        |   2 +
>  arch/arm64/lib/Makefile             |   2 +-
>  arch/arm64/lib/bitops.S             |  76 ---------------
>  arch/h8300/include/asm/atomic.h     |   4 +-
>  arch/m68k/include/asm/bitops.h      |   6 +-
>  arch/openrisc/include/asm/cmpxchg.h |   3 +-
>  arch/sh/include/asm/cmpxchg-xchg.h  |   3 +-
>  include/asm-generic/bitops/atomic.h | 188 +++++++-----------------------------
>  include/asm-generic/bitops/lock.h   |  68 ++++++++++---
>  include/asm-generic/bits.h          |  26 +++++
>  include/linux/bitops.h              |  22 +----
>  14 files changed, 135 insertions(+), 289 deletions(-)
>  delete mode 100644 arch/arm64/lib/bitops.S
>  create mode 100644 include/asm-generic/bits.h
>
> --
> 2.1.4
>

-- 
Best Regards
Masahiro Yamada