Re: [PATCH V4 00/26] mm/mmap: Drop __SXXX/__PXXX macros from across platforms

[Anshuman Khandual]

On 6/24/22 10:42, Christoph Hellwig wrote:
> On Fri, Jun 24, 2022 at 10:13:13AM +0530, Anshuman Khandual wrote:
>> vm_get_page_prot(), in order for it to be reused on platforms that do not
>> require custom implementation. Finally, ARCH_HAS_VM_GET_PAGE_PROT can just
>> be dropped, as all platforms now define and export vm_get_page_prot(), via
>> looking up a private and static protection_map[] array. protection_map[]
>> data type is the following for all platforms without deviation (except the
>> powerpc one which is shared between 32 and 64 bit platforms), keeping it
>> unchanged for now.
>>
>> static pgprot_t protection_map[16] __ro_after_init
> 
> On most architectures this should be const now, only very few ever
> modify it.

Will make it a 'static const pgprot_t protection_map[16] __ro_after_init'
on platforms that do not change the protection_map[] even during boot.