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

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

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.