Re: [PATCH V3 19/30] csky/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

[Guo Ren]

Acked-by: Guo Ren <guoren@xxxxxxxxxx>

On Mon, Feb 28, 2022 at 7:10 PM Anshuman Khandual
<anshuman.khandual@xxxxxxx> wrote:
>
> This defines and exports a platform specific custom vm_get_page_prot() via
> subscribing ARCH_HAS_VM_GET_PAGE_PROT. Subsequently all __SXXX and __PXXX
> macros can be dropped which are no longer needed.
>
> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Cc: linux-csky@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> ---
>  arch/csky/Kconfig               |  1 +
>  arch/csky/include/asm/pgtable.h | 18 ------------------
>  arch/csky/mm/init.c             | 32 ++++++++++++++++++++++++++++++++
>  3 files changed, 33 insertions(+), 18 deletions(-)
>
> diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
> index 132f43f12dd8..209dac5686dd 100644
> --- a/arch/csky/Kconfig
> +++ b/arch/csky/Kconfig
> @@ -6,6 +6,7 @@ config CSKY
>         select ARCH_HAS_GCOV_PROFILE_ALL
>         select ARCH_HAS_SYNC_DMA_FOR_CPU
>         select ARCH_HAS_SYNC_DMA_FOR_DEVICE
> +       select ARCH_HAS_VM_GET_PAGE_PROT
>         select ARCH_USE_BUILTIN_BSWAP
>         select ARCH_USE_QUEUED_RWLOCKS
>         select ARCH_WANT_FRAME_POINTERS if !CPU_CK610 && $(cc-option,-mbacktrace)
> diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h
> index 151607ed5158..2c6b1cfb1cce 100644
> --- a/arch/csky/include/asm/pgtable.h
> +++ b/arch/csky/include/asm/pgtable.h
> @@ -76,24 +76,6 @@
>  #define MAX_SWAPFILES_CHECK() \
>                 BUILD_BUG_ON(MAX_SWAPFILES_SHIFT != 5)
>
> -#define __P000 PAGE_NONE
> -#define __P001 PAGE_READ
> -#define __P010 PAGE_READ
> -#define __P011 PAGE_READ
> -#define __P100 PAGE_READ
> -#define __P101 PAGE_READ
> -#define __P110 PAGE_READ
> -#define __P111 PAGE_READ
> -
> -#define __S000 PAGE_NONE
> -#define __S001 PAGE_READ
> -#define __S010 PAGE_WRITE
> -#define __S011 PAGE_WRITE
> -#define __S100 PAGE_READ
> -#define __S101 PAGE_READ
> -#define __S110 PAGE_WRITE
> -#define __S111 PAGE_WRITE
> -
>  extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
>  #define ZERO_PAGE(vaddr)       (virt_to_page(empty_zero_page))
>
> diff --git a/arch/csky/mm/init.c b/arch/csky/mm/init.c
> index bf2004aa811a..f9babbed17d4 100644
> --- a/arch/csky/mm/init.c
> +++ b/arch/csky/mm/init.c
> @@ -197,3 +197,35 @@ void __init fixaddr_init(void)
>         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
>         fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir);
>  }
> +
> +pgprot_t vm_get_page_prot(unsigned long vm_flags)
> +{
> +       switch (vm_flags & (VM_READ | VM_WRITE | VM_EXEC | VM_SHARED)) {
> +       case VM_NONE:
> +               return PAGE_NONE;
> +       case VM_READ:
> +       case VM_WRITE:
> +       case VM_WRITE | VM_READ:
> +       case VM_EXEC:
> +       case VM_EXEC | VM_READ:
> +       case VM_EXEC | VM_WRITE:
> +       case VM_EXEC | VM_WRITE | VM_READ:
> +               return PAGE_READ;
> +       case VM_SHARED:
> +               return PAGE_NONE;
> +       case VM_SHARED | VM_READ:
> +               return PAGE_READ;
> +       case VM_SHARED | VM_WRITE:
> +       case VM_SHARED | VM_WRITE | VM_READ:
> +               return PAGE_WRITE;
> +       case VM_SHARED | VM_EXEC:
> +       case VM_SHARED | VM_EXEC | VM_READ:
> +               return PAGE_READ;
> +       case VM_SHARED | VM_EXEC | VM_WRITE:
> +       case VM_SHARED | VM_EXEC | VM_WRITE | VM_READ:
> +               return PAGE_WRITE;
> +       default:
> +               BUILD_BUG();
> +       }
> +}
> +EXPORT_SYMBOL(vm_get_page_prot);
> --
> 2.25.1
>


-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/