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

[john.p.donnelly at oracle.com]

On 12/10/21 12:55 AM, Zhen Lei wrote:
> From: Chen Zhou <chenzhou10 at 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 at huawei.com>
> Signed-off-by: Zhen Lei <thunder.leizhen at huawei.com>
> Tested-by: John Donnelly <John.p.donnelly at oracle.com>
> Tested-by: Dave Kleikamp <dave.kleikamp at oracle.com>

  Acked-by: John Donnelly <john.p.donnelly at 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",