Re: [PATCH V4 08/26] microblaze/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

Christophe Leroy
2022-06-24T05:24:50Z

Le 24/06/2022 à 06:43, Anshuman Khandual a écrit :
> This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports standard
> vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT, which looks
> up a private and static protection_map[] array. Subsequently all __SXXX and
> __PXXX macros can be dropped which are no longer needed.

In this patch and all following ones, can't protection_map[] be const
instead of __ro_after_init ?

>
> Cc: Michal Simek <monstr@monstr.eu>
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> arch/microblaze/Kconfig | 1 +
> arch/microblaze/include/asm/pgtable.h | 17 -----------------
> arch/microblaze/mm/init.c | 20 ++++++++++++++++++++
> 3 files changed, 21 insertions(+), 17 deletions(-)
>
> diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
> index 8cf429ad1c84..15f91ba8a0c4 100644
> --- a/arch/microblaze/Kconfig
> +++ b/arch/microblaze/Kconfig
> @@ -7,6 +7,7 @@ config MICROBLAZE
> 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_MIGHT_HAVE_PC_PARPORT
> select ARCH_WANT_IPC_PARSE_VERSION
> select BUILDTIME_TABLE_SORT
> diff --git a/arch/microblaze/include/asm/pgtable.h b/arch/microblaze/include/asm/pgtable.h
> index 0c72646370e1..ba348e997dbb 100644
> --- a/arch/microblaze/include/asm/pgtable.h
> +++ b/arch/microblaze/include/asm/pgtable.h
> @@ -204,23 +204,6 @@ extern pte_t *va_to_pte(unsigned long address);
> * We consider execute permission the same as read.
> * Also, write permissions imply read permissions.
> */
> -#define __P000 PAGE_NONE
> -#define __P001 PAGE_READONLY_X
> -#define __P010 PAGE_COPY
> -#define __P011 PAGE_COPY_X
> -#define __P100 PAGE_READONLY
> -#define __P101 PAGE_READONLY_X
> -#define __P110 PAGE_COPY
> -#define __P111 PAGE_COPY_X
> -
> -#define __S000 PAGE_NONE
> -#define __S001 PAGE_READONLY_X
> -#define __S010 PAGE_SHARED
> -#define __S011 PAGE_SHARED_X
> -#define __S100 PAGE_READONLY
> -#define __S101 PAGE_READONLY_X
> -#define __S110 PAGE_SHARED
> -#define __S111 PAGE_SHARED_X
>
> #ifndef __ASSEMBLY__
> /*
> diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
> index f4e503461d24..315fd5024f00 100644
> --- a/arch/microblaze/mm/init.c
> +++ b/arch/microblaze/mm/init.c
> @@ -285,3 +285,23 @@ void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask)
>
> return p;
> }
> +
> +static pgprot_t protection_map[16] __ro_after_init = {
> + [VM_NONE] = PAGE_NONE,
> + [VM_READ] = PAGE_READONLY_X,
> + [VM_WRITE] = PAGE_COPY,
> + [VM_WRITE | VM_READ] = PAGE_COPY_X,
> + [VM_EXEC] = PAGE_READONLY,
> + [VM_EXEC | VM_READ] = PAGE_READONLY_X,
> + [VM_EXEC | VM_WRITE] = PAGE_COPY,
> + [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_X,
> + [VM_SHARED] = PAGE_NONE,
> + [VM_SHARED | VM_READ] = PAGE_READONLY_X,
> + [VM_SHARED | VM_WRITE] = PAGE_SHARED,
> + [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED_X,
> + [VM_SHARED | VM_EXEC] = PAGE_READONLY,
> + [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_X,
> + [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED,
> + [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_X
> +};
> +DECLARE_VM_GET_PAGE_PROT