[PATCH v6 08/10] of: reserved_mem: mark /reserved-memory entries with MEMBLOCK_NODUMP

[Marek Szyprowski]

On 02.09.2026 09:31, Wandun Chen wrote:
> From: Wandun Chen <chenwandun at lixiang.com>
>
> Mark non-dumpable reserved-memory regions with MEMBLOCK_NODUMP so
> kdump can omit them from the vmcore.
>
> The marking is guarded by CONFIG_CRASH_DUMP so non-kdump kernels do not
> pay the cost of splitting memblock.memory entries at NODUMP boundaries.
>
> Signed-off-by: Wandun Chen <chenwandun at lixiang.com>
> Tested-by: Meijing Zhao <zhaomeijing at lixiang.com>

Acked-by: Marek Szyprowski <m.szyprowski at samsung.com>

> ---
>  drivers/of/fdt.c             |  1 +
>  drivers/of/of_private.h      |  1 +
>  drivers/of/of_reserved_mem.c | 15 +++++++++++++++
>  3 files changed, 17 insertions(+)
>
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index a64afc3ded3d..286fd4db6312 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -1285,6 +1285,7 @@ void __init unflatten_device_tree(void)
>  
>  	/* Save the statically-placed regions in the reserved_mem array */
>  	fdt_scan_reserved_mem_late();
> +	fdt_mark_reserve_mem_nodump();
>  
>  	/* Populate an empty root node when bootloader doesn't provide one */
>  	if (!fdt) {
> diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
> index 0ae16da066e2..505735732c13 100644
> --- a/drivers/of/of_private.h
> +++ b/drivers/of/of_private.h
> @@ -187,6 +187,7 @@ static inline struct device_node *__of_get_dma_parent(const struct device_node *
>  
>  int fdt_scan_reserved_mem(void);
>  void __init fdt_scan_reserved_mem_late(void);
> +void __init fdt_mark_reserve_mem_nodump(void);
>  
>  bool of_fdt_device_is_available(const void *blob, unsigned long node);
>  
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> index 8c9d6395d6a3..f29a07e8fb23 100644
> --- a/drivers/of/of_reserved_mem.c
> +++ b/drivers/of/of_reserved_mem.c
> @@ -677,6 +677,21 @@ static void __init fdt_init_reserved_mem_node(unsigned long node, const char *un
>  	reserved_mem_count++;
>  }
>  
> +void __init fdt_mark_reserve_mem_nodump(void)
> +{
> +	struct reserved_mem *rmem;
> +	int i;
> +
> +	if (!IS_ENABLED(CONFIG_CRASH_DUMP))
> +		return;
> +
> +	for (i = 0; i < reserved_mem_count; i++) {
> +		rmem = &reserved_mem[i];
> +		if (rmem->size && !rmem->dumpable)
> +			memblock_mark_nodump(rmem->base, rmem->size);
> +	}
> +}
> +
>  struct rmem_assigned_device {
>  	struct device *dev;
>  	struct reserved_mem *rmem;

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