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Date:   Mon, 19 Jun 2023 14:09:58 +0800
From:   Baoquan He <bhe@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     catalin.marinas@arm.com, thunder.leizhen@huawei.com,
        John.p.donnelly@oracle.com, kexec@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, horms@kernel.org,
        chenjiahao16@huawei.com, linux-riscv@lists.infradead.org,
        x86@kernel.org, bp@alien8.de
Subject: Re: [RFC PATCH 0/4] kdump: add generic functions to simplify
 crashkernel crashkernel in architecture
Message-ID: <ZI/xNm23BCNcB0+v@MiWiFi-R3L-srv>
References: <20230619055951.45620-1-bhe@redhat.com>
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On 06/19/23 at 01:59pm, Baoquan He wrote:
> In the current arm64, crashkernel=,high support has been finished after
> several rounds of posting and careful reviewing. The code in arm64 which
> parses crashkernel kernel parameters firstly, then reserve memory can be
> a good example for other ARCH to refer to.
> 
> Whereas in x86_64, the code mixing crashkernel parameter parsing and
> memory reserving is twisted, and looks messy. Refactoring the code to
> make it more readable maintainable is necessary.
                       ^ 'and' missed
> 
> Here, try to abstract the crashkernel parameter parsing code into a
> generic function parse_crashkernel_generic(), and the crashkernel memory
> reserving code into a generic function reserve_crashkernel_generic().
> Then, in ARCH which crashkernel=,high support is needed, a simple
> arch_reserve_crashkernel() can be added to call above two generic
> functions. This can remove the duplicated implmentation code in each
> ARCH, like arm64, x86_64.
> 
> I only change the arm64 and x86_64 implementation to make use of the
> generic functions to simplify code. Risc-v can be done very easily refer
> to the steps in arm64 and x86_64. I leave this to Jiahao or other risc-v
> developer since Jiahao have posted a patchset to add crashkernel=,high
> support to risc-v.
> 
> This patchset is based on the latest linus's tree, and on top of below
> patch:
> 
> arm64: kdump: simplify the reservation behaviour of crashkernel=,high
>       https://git.kernel.org/arm64/c/6c4dcaddbd36
> 
> 
> Baoquan He (4):
>   kdump: rename parse_crashkernel() to parse_crashkernel_common()
>   kdump: add generic functions to parse crashkernel and do reservation
>   arm64: kdump: use generic interfaces to simplify crashkernel
>     reservation code
>   x86: kdump: use generic interfaces to simplify crashkernel reservation
>     code
> 
>  arch/arm/kernel/setup.c              |   4 +-
>  arch/arm64/Kconfig                   |   3 +
>  arch/arm64/include/asm/kexec.h       |   8 ++
>  arch/arm64/mm/init.c                 | 141 ++----------------------
>  arch/ia64/kernel/setup.c             |   4 +-
>  arch/loongarch/kernel/setup.c        |   3 +-
>  arch/mips/cavium-octeon/setup.c      |   2 +-
>  arch/mips/kernel/setup.c             |   4 +-
>  arch/powerpc/kernel/fadump.c         |   5 +-
>  arch/powerpc/kexec/core.c            |   4 +-
>  arch/powerpc/mm/nohash/kaslr_booke.c |   4 +-
>  arch/riscv/mm/init.c                 |   5 +-
>  arch/s390/kernel/setup.c             |   4 +-
>  arch/sh/kernel/machine_kexec.c       |   5 +-
>  arch/x86/Kconfig                     |   3 +
>  arch/x86/include/asm/kexec.h         |  32 ++++++
>  arch/x86/kernel/setup.c              | 141 +++---------------------
>  include/linux/crash_core.h           |  33 +++++-
>  kernel/crash_core.c                  | 158 +++++++++++++++++++++++++--
>  19 files changed, 274 insertions(+), 289 deletions(-)
> 
> -- 
> 2.34.1
>