RE: [PATCH V5 12/26] hexagon/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

[Brian Cain <bcain@quicinc.com>]

> -----Original Message-----
> From: Anshuman Khandual <anshuman.khandual@arm.com>
...
> WARNING: This email originated from outside of Qualcomm. Please be wary
> of any links or attachments, and do not enable macros.
> 
> 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.
> 
> Cc: Brian Cain <bcain@codeaurora.org>
> Cc: linux-hexagon@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
>  arch/hexagon/Kconfig               |  1 +
>  arch/hexagon/include/asm/pgtable.h | 27 -------------------
>  arch/hexagon/mm/init.c             | 42 ++++++++++++++++++++++++++++++
>  3 files changed, 43 insertions(+), 27 deletions(-)
> 
> diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
> index 54eadf265178..bc4ceecd0588 100644
> --- a/arch/hexagon/Kconfig
> +++ b/arch/hexagon/Kconfig
> @@ -6,6 +6,7 @@ config HEXAGON
>         def_bool y
>         select ARCH_32BIT_OFF_T
>         select ARCH_HAS_SYNC_DMA_FOR_DEVICE
> +       select ARCH_HAS_VM_GET_PAGE_PROT
>         select ARCH_NO_PREEMPT
>         select DMA_GLOBAL_POOL
>         # Other pending projects/to-do items.
> diff --git a/arch/hexagon/include/asm/pgtable.h
> b/arch/hexagon/include/asm/pgtable.h
> index 0610724d6a28..f7048c18b6f9 100644
> --- a/arch/hexagon/include/asm/pgtable.h
> +++ b/arch/hexagon/include/asm/pgtable.h
> @@ -126,33 +126,6 @@ extern unsigned long _dflt_cache_att;
>   */
>  #define CACHEDEF       (CACHE_DEFAULT << 6)
> 
> -/* Private (copy-on-write) page protections. */
> -#define __P000 __pgprot(_PAGE_PRESENT | _PAGE_USER | CACHEDEF)
> -#define __P001 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ |
> CACHEDEF)
> -#define __P010 __P000  /* Write-only copy-on-write */
> -#define __P011 __P001  /* Read/Write copy-on-write */
> -#define __P100 __pgprot(_PAGE_PRESENT | _PAGE_USER | \
> -                       _PAGE_EXECUTE | CACHEDEF)
> -#define __P101 __pgprot(_PAGE_PRESENT | _PAGE_USER |
> _PAGE_EXECUTE | \
> -                       _PAGE_READ | CACHEDEF)
> -#define __P110 __P100  /* Write/execute copy-on-write */
> -#define __P111 __P101  /* Read/Write/Execute, copy-on-write */
> -
> -/* Shared page protections. */
> -#define __S000 __P000
> -#define __S001 __P001
> -#define __S010 __pgprot(_PAGE_PRESENT | _PAGE_USER | \
> -                       _PAGE_WRITE | CACHEDEF)
> -#define __S011 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ |
> \
> -                       _PAGE_WRITE | CACHEDEF)
> -#define __S100 __pgprot(_PAGE_PRESENT | _PAGE_USER | \
> -                       _PAGE_EXECUTE | CACHEDEF)
> -#define __S101 __P101
> -#define __S110 __pgprot(_PAGE_PRESENT | _PAGE_USER | \
> -                       _PAGE_EXECUTE | _PAGE_WRITE | CACHEDEF)
> -#define __S111 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ |
> \
> -                       _PAGE_EXECUTE | _PAGE_WRITE | CACHEDEF)
> -
>  extern pgd_t swapper_pg_dir[PTRS_PER_PGD];  /* located in head.S */
> 
>  /*  HUGETLB not working currently  */
> diff --git a/arch/hexagon/mm/init.c b/arch/hexagon/mm/init.c
> index 3167a3b5c97b..146115c9de61 100644
> --- a/arch/hexagon/mm/init.c
> +++ b/arch/hexagon/mm/init.c
> @@ -234,3 +234,45 @@ void __init setup_arch_memory(void)
>          *  which is called by start_kernel() later on in the process
>          */
>  }
> +
> +static const pgprot_t protection_map[16] = {
> +       [VM_NONE]                                       = __pgprot(_PAGE_PRESENT |
> _PAGE_USER |
> +                                                                  CACHEDEF),
> +       [VM_READ]                                       = __pgprot(_PAGE_PRESENT |
> _PAGE_USER |
> +                                                                  _PAGE_READ | CACHEDEF),
> +       [VM_WRITE]                                      = __pgprot(_PAGE_PRESENT |
> _PAGE_USER |
> +                                                                  CACHEDEF),
> +       [VM_WRITE | VM_READ]                            = __pgprot(_PAGE_PRESENT |
> _PAGE_USER |
> +                                                                  _PAGE_READ | CACHEDEF),
> +       [VM_EXEC]                                       = __pgprot(_PAGE_PRESENT |
> _PAGE_USER |
> +                                                                  _PAGE_EXECUTE | CACHEDEF),
> +       [VM_EXEC | VM_READ]                             = __pgprot(_PAGE_PRESENT |
> _PAGE_USER |
> +                                                                  _PAGE_EXECUTE | _PAGE_READ |
> +                                                                  CACHEDEF),
> +       [VM_EXEC | VM_WRITE]                            = __pgprot(_PAGE_PRESENT |
> _PAGE_USER |
> +                                                                  _PAGE_EXECUTE | CACHEDEF),
> +       [VM_EXEC | VM_WRITE | VM_READ]                  =
> __pgprot(_PAGE_PRESENT | _PAGE_USER |
> +                                                                  _PAGE_EXECUTE | _PAGE_READ |
> +                                                                  CACHEDEF),
> +       [VM_SHARED]                                     = __pgprot(_PAGE_PRESENT |
> _PAGE_USER |
> +                                                                  CACHEDEF),
> +       [VM_SHARED | VM_READ]                           = __pgprot(_PAGE_PRESENT |
> _PAGE_USER |
> +                                                                  _PAGE_READ | CACHEDEF),
> +       [VM_SHARED | VM_WRITE]                          = __pgprot(_PAGE_PRESENT |
> _PAGE_USER |
> +                                                                  _PAGE_WRITE | CACHEDEF),
> +       [VM_SHARED | VM_WRITE | VM_READ]                =
> __pgprot(_PAGE_PRESENT | _PAGE_USER |
> +                                                                  _PAGE_READ | _PAGE_WRITE |
> +                                                                  CACHEDEF),
> +       [VM_SHARED | VM_EXEC]                           = __pgprot(_PAGE_PRESENT |
> _PAGE_USER |
> +                                                                  _PAGE_EXECUTE | CACHEDEF),
> +       [VM_SHARED | VM_EXEC | VM_READ]                 =
> __pgprot(_PAGE_PRESENT | _PAGE_USER |
> +                                                                  _PAGE_EXECUTE | _PAGE_READ |
> +                                                                  CACHEDEF),
> +       [VM_SHARED | VM_EXEC | VM_WRITE]                =
> __pgprot(_PAGE_PRESENT | _PAGE_USER |
> +                                                                  _PAGE_EXECUTE | _PAGE_WRITE |
> +                                                                  CACHEDEF),
> +       [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]      =
> __pgprot(_PAGE_PRESENT | _PAGE_USER |
> +                                                                  _PAGE_READ | _PAGE_EXECUTE |
> +                                                                  _PAGE_WRITE | CACHEDEF)
> +};
> +DECLARE_VM_GET_PAGE_PROT
> --
> 2.25.1

Acked-by: Brian Cain <bcain@quicinc.com>