Re: [PATCH v12 01/14] ARM: mm: add missing pud_page define to 2-level page tables

[Ding Tianhong]

On 2021/2/2 19:47, Ding Tianhong wrote:
> On 2021/2/2 19:13, Russell King - ARM Linux admin wrote:
>> On Tue, Feb 02, 2021 at 09:05:02PM +1000, Nicholas Piggin wrote:
>>> diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
>>> index c02f24400369..d63a5bb6bd0c 100644
>>> --- a/arch/arm/include/asm/pgtable.h
>>> +++ b/arch/arm/include/asm/pgtable.h
>>> @@ -166,6 +166,9 @@ extern struct page *empty_zero_page;
>>>  
>>>  extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
>>>  
>>> +#define pud_page(pud)		pmd_page(__pmd(pud_val(pud)))
>>> +#define pud_write(pud)		pmd_write(__pmd(pud_val(pud)))
>>
>> As there is no PUD, does it really make sense to return a valid
>> struct page (which will be the PTE page) for pud_page(), which is
>> several tables above?
>>
> --- a/arch/arm/include/asm/pgtable-2level.h
> +++ b/arch/arm/include/asm/pgtable-2level.h
> 
> +static inline int pud_none(pud_t pud)
> +{
> +          return 0;
> +}
> 
 --- a/arch/arm/include/asm/pgtable-2level.h
 +++ b/arch/arm/include/asm/pgtable-2level.h>
 +static inline int pud_page(pud_t pud)
 +{
 +          return 0;
 +}

> I think it could be fix like this.
> 
> Ding
>