[PATCH -next v3 2/2] docs: kdump: Update the crashkernel description for riscv

[Guo Ren]

Reviewed-by: Guo Ren <guoren at kernel.org>

On Thu, Apr 6, 2023 at 10:05 PM Chen Jiahao <chenjiahao16 at huawei.com> wrote:
>
> Now "crashkernel=" parameter on riscv has been updated to support
> crashkernel=X,[high,low]. Through which we can reserve memory region
> above/within 32bit addressible DMA zone.
>
> Here update the parameter description accordingly.
>
> Signed-off-by: Chen Jiahao <chenjiahao16 at huawei.com>
> ---
>  Documentation/admin-guide/kernel-parameters.txt | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 54702bd488eb..41865aae9eaa 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -866,7 +866,7 @@
>                         memory region [offset, offset + size] for that kernel
>                         image. If '@offset' is omitted, then a suitable offset
>                         is selected automatically.
> -                       [KNL, X86-64, ARM64] Select a region under 4G first, and
> +                       [KNL, X86-64, ARM64, RISCV] Select a region under 4G first, and
>                         fall back to reserve region above 4G when '@offset'
>                         hasn't been specified.
>                         See Documentation/admin-guide/kdump/kdump.rst for further details.
> @@ -879,14 +879,14 @@
>                         Documentation/admin-guide/kdump/kdump.rst for an example.
>
>         crashkernel=size[KMG],high
> -                       [KNL, X86-64, ARM64] range could be above 4G. Allow kernel
> -                       to allocate physical memory region from top, so could
> -                       be above 4G if system have more than 4G ram installed.
> -                       Otherwise memory region will be allocated below 4G, if
> -                       available.
> +                       [KNL, X86-64, ARM64, RISCV] range could be above 4G.
> +                       Allow kernel to allocate physical memory region from top,
> +                       so could be above 4G if system have more than 4G ram
> +                       installed. Otherwise memory region will be allocated
> +                       below 4G, if available.
>                         It will be ignored if crashkernel=X is specified.
>         crashkernel=size[KMG],low
> -                       [KNL, X86-64, ARM64] range under 4G. When crashkernel=X,high
> +                       [KNL, X86-64, ARM64, RISCV] range under 4G. When crashkernel=X,high
>                         is passed, kernel could allocate physical memory region
>                         above 4G, that cause second kernel crash on system
>                         that require some amount of low memory, e.g. swiotlb
> @@ -897,6 +897,7 @@
>                         size is platform dependent.
>                           --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB)
>                           --> arm64: 128MiB
> +                         --> riscv: 128MiB
>                         This one lets the user specify own low range under 4G
>                         for second kernel instead.
>                         0: to disable low allocation.
> --
> 2.31.1
>


-- 
Best Regards
 Guo Ren