On 06/13/22 at 04:09pm, Zhen Lei wrote:
> arm64_memblock_init()
> if (!IS_ENABLED(CONFIG_ZONE_DMA/DMA32))
> reserve_crashkernel()
> //initialize crashk_res when
> //"crashkernel=" is correctly specified
> paging_init()
> map_mem()
>
> As shown in the above pseudo code, the crashk_res.end can only be
> initialized to non-zero when both "!IS_ENABLED(CONFIG_ZONE_DMA/DMA32)"
> and crash_mem_map are true. So some checks in map_mem() can be adjusted
> or optimized.
LGTM,
Acked-by: Baoquan He <bhe@xxxxxxxxxx>
>
> Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
> ---
> arch/arm64/mm/mmu.c | 25 +++++++++++--------------
> 1 file changed, 11 insertions(+), 14 deletions(-)
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index 626ec32873c6c36..6028a5757e4eae2 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -529,12 +529,12 @@ static void __init map_mem(pgd_t *pgdp)
>
> #ifdef CONFIG_KEXEC_CORE
> if (crash_mem_map) {
> - if (IS_ENABLED(CONFIG_ZONE_DMA) ||
> - IS_ENABLED(CONFIG_ZONE_DMA32))
> - flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
> - else if (crashk_res.end)
> + if (crashk_res.end)
> memblock_mark_nomap(crashk_res.start,
> resource_size(&crashk_res));
> + else if (IS_ENABLED(CONFIG_ZONE_DMA) ||
> + IS_ENABLED(CONFIG_ZONE_DMA32))
> + flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
> }
> #endif
>
> @@ -571,16 +571,13 @@ static void __init map_mem(pgd_t *pgdp)
> * through /sys/kernel/kexec_crash_size interface.
> */
> #ifdef CONFIG_KEXEC_CORE
> - if (crash_mem_map &&
> - !IS_ENABLED(CONFIG_ZONE_DMA) && !IS_ENABLED(CONFIG_ZONE_DMA32)) {
> - if (crashk_res.end) {
> - __map_memblock(pgdp, crashk_res.start,
> - crashk_res.end + 1,
> - PAGE_KERNEL,
> - NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS);
> - memblock_clear_nomap(crashk_res.start,
> - resource_size(&crashk_res));
> - }
> + if (crashk_res.end) {
> + __map_memblock(pgdp, crashk_res.start,
> + crashk_res.end + 1,
> + PAGE_KERNEL,
> + NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS);
> + memblock_clear_nomap(crashk_res.start,
> + resource_size(&crashk_res));
> }
> #endif
> }
> --
> 2.25.1
>
