[PATCH v5 4/4] riscv: kexec: Add support for crashkernel CMA reservation

[Paul Walmsley]

On Thu, 12 Feb 2026, Jinjie Ruan wrote:

> Commit 35c18f2933c5 ("Add a new optional ",cma" suffix to the
> crashkernel= command line option") and commit ab475510e042 ("kdump:
> implement reserve_crashkernel_cma") added CMA support for kdump
> crashkernel reservation. This allows the kernel to dynamically allocate
> contiguous memory for crash dumping when needed, rather than permanently
> reserving a fixed region at boot time.
> 
> So extend crashkernel CMA reservation support to riscv. The following
> changes are made to enable CMA reservation:
> 
> - Parse and obtain the CMA reservation size along with other crashkernel
>   parameters.
> - Call reserve_crashkernel_cma() to allocate the CMA region for kdump.
> - Include the CMA-reserved ranges for kdump kernel to use.
> - Exclude the CMA-reserved ranges from the crash kernel memory to
>   prevent them from being exported through /proc/vmcore, which is already
>   done in the crash core.
> 
> Update kernel-parameters.txt to document CMA support for crashkernel on
> riscv architecture.
> 
> Signed-off-by: Jinjie Ruan <ruanjinjie at huawei.com>

Looks reasonable.  If the plan is to have the kdump maintainers merge 
this, then:

Acked-by: Paul Walmsley <pjw at kernel.org> # arch/riscv


- Paul