[PATCH v2 3/8] of: reserved_mem: add dumpable flag to opt-in vmcore

[Marek Szyprowski]

On 20.05.2026 11:18, Wandun Chen wrote:
> From: Wandun Chen <chenwandun1 at gmail.com>
>
> From: Wandun Chen <chenwandun at lixiang.com>
>
> Add a 'dumpable' flag to struct reserved_mem so the kernel can decide
> whether a reserved area should be included in the kdump vmcore. Most
> reserved regions are owned by devices and do not contain data useful
> for kernel crash analysis, so excluding them by default is the right
> behaviour.
>
> Reusable CMA regions are different: pages in a CMA region are handed
> back to the buddy allocator and may contain key data for crash
> analysis, so set dumpable to true in rmem_cma_setup().
>
> Suggested-by: Rob Herring <robh at kernel.org>
> Signed-off-by: Wandun Chen <chenwandun at lixiang.com>
> Tested-by: Meijing Zhao <zhaomeijing at lixiang.com>
> Link: https://lore.kernel.org/all/20260506144542.GA2072596-robh@kernel.org/
Acked-by: Marek Szyprowski <m.szyprowski at samsung.com>
> ---
>  include/linux/of_reserved_mem.h | 1 +
>  kernel/dma/contiguous.c         | 1 +
>  2 files changed, 2 insertions(+)
>
> diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
> index e8b20b29fa68..55a67cee41ea 100644
> --- a/include/linux/of_reserved_mem.h
> +++ b/include/linux/of_reserved_mem.h
> @@ -15,6 +15,7 @@ struct reserved_mem {
>  	phys_addr_t			base;
>  	phys_addr_t			size;
>  	void				*priv;
> +	bool				dumpable;
>  };
>  
>  struct reserved_mem_ops {
> diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
> index 03f52bd17120..eddec89eb414 100644
> --- a/kernel/dma/contiguous.c
> +++ b/kernel/dma/contiguous.c
> @@ -579,6 +579,7 @@ static int __init rmem_cma_setup(unsigned long node, struct reserved_mem *rmem)
>  		dma_contiguous_default_area = cma;
>  
>  	rmem->priv = cma;
> +	rmem->dumpable = true;
>  
>  	pr_info("Reserved memory: created CMA memory pool at %pa, size %ld MiB\n",
>  		&rmem->base, (unsigned long)rmem->size / SZ_1M);

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland