[PATCH v20 2/5] arm64: kdump: introduce some macros for crash kernel reservation

[Leizhen (ThunderTown) <thunder.leizhen@huawei.com>]

On 2022/2/21 11:22, Baoquan He wrote:
> On 02/14/22 at 02:22pm, Leizhen (ThunderTown) wrote:
>>
>>
>> On 2022/2/11 18:39, Baoquan He wrote:
>>> On 01/24/22 at 04:47pm, 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.
>>>>
>>>> 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>
>>>> ---
>>>>  arch/arm64/mm/init.c | 11 ++++++++---
>>>>  1 file changed, 8 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
>>>> index 90f276d46b93bc6..6c653a2c7cff052 100644
>>>> --- a/arch/arm64/mm/init.c
>>>> +++ b/arch/arm64/mm/init.c
>>>> @@ -65,6 +65,12 @@ EXPORT_SYMBOL(memstart_addr);
>>>>  phys_addr_t arm64_dma_phys_limit __ro_after_init;
>>>>  
>>>>  #ifdef CONFIG_KEXEC_CORE
>>>> +/* Current arm64 boot protocol requires 2MB alignment */
>>>> +#define CRASH_ALIGN		SZ_2M
>>>> +
>>>> +#define CRASH_ADDR_LOW_MAX	arm64_dma_phys_limit
>>>> +#define CRASH_ADDR_HIGH_MAX	MEMBLOCK_ALLOC_ACCESSIBLE
>>>
>>> MEMBLOCK_ALLOC_ACCESSIBLE is obvoiously a alloc flag for memblock
>>> allocator, I don't think it's appropriate to make HIGH_MAX get its value.
>>
>> Right, thanks.
>>
>>> You can make it as memblock.current_limit, or do not define it, but using
>>> MEMBLOCK_ALLOC_ACCESSIBLE direclty in memblock_phys_alloc_range() with
>>> a code comment. 
>>
>> This patch is not required at present. These macros are added to eliminate
>> differences to share code with x86.
> 
> So this patch may not be needed in this series. It can be added in
> another post when you start to do the clean up and code unification
> among ARCHes, with my udnerstanding. At that time you can consider how
> to abstract the common code to handle the difference.

Yes, it should be merged with the v20 3/5.

> 
> .
> 

-- 
Regards,
  Zhen Lei