Re: [PATCH v17 06/10] arm64: kdump: introduce some macros for crash kernel reservation

john.p.donnelly
2021-12-13T14:30:54Z

On 12/10/21 12:55 AM, Zhen Lei wrote:
> From: Chen Zhou <chenzhou10@huawei.com>
>
> Introduce macro CRASH_ALIGN for alignment, macro CRASH_ADDR_LOW_MAX
> for upper bound of low crash memory, macro CRASH_ADDR_HIGH_MAX for
> upper bound of high crash memory, use macros instead.
>
> Besides, keep consistent with x86, use CRASH_ALIGN as the lower bound
> of crash kernel reservation.
>
> Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> Tested-by: John Donnelly <John.p.donnelly@oracle.com>
> Tested-by: Dave Kleikamp <dave.kleikamp@oracle.com>

Acked-by: John Donnelly <john.p.donnelly@oracle.com>

> ---
> arch/arm64/include/asm/kexec.h | 6 ++++++
> arch/arm64/mm/init.c | 4 ++--
> 2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
> index 9839bfc163d7147..1b9edc69f0244ca 100644
> --- a/arch/arm64/include/asm/kexec.h
> +++ b/arch/arm64/include/asm/kexec.h
> @@ -25,6 +25,12 @@
>
> #define KEXEC_ARCH KEXEC_ARCH_AARCH64
>
> +/* 2M alignment for crash kernel regions */
> +#define CRASH_ALIGN SZ_2M
> +
> +#define CRASH_ADDR_LOW_MAX arm64_dma_phys_limit
> +#define CRASH_ADDR_HIGH_MAX MEMBLOCK_ALLOC_ACCESSIBLE
> +
> #ifndef __ASSEMBLY__
>
> /**
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index a8834434af99ae0..be4595dc7459115 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -75,7 +75,7 @@ phys_addr_t arm64_dma_phys_limit __ro_after_init;
> static void __init reserve_crashkernel(void)
> {
> unsigned long long crash_base, crash_size;
> - unsigned long long crash_max = arm64_dma_phys_limit;
> + unsigned long long crash_max = CRASH_ADDR_LOW_MAX;
> int ret;
>
> ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
> @@ -91,7 +91,7 @@ static void __init reserve_crashkernel(void)
> crash_max = crash_base + crash_size;
>
> /* Current arm64 boot protocol requires 2MB alignment */
> - crash_base = memblock_phys_alloc_range(crash_size, SZ_2M,
> + crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
> crash_base, crash_max);
> if (!crash_base) {
> pr_warn("cannot allocate crashkernel (size:0x%llx)\n",