Re: [RFC v2 06/12] powerpc: Program HPTE key protection bits.

[Anshuman Khandual]

On 06/17/2017 09:22 AM, Ram Pai wrote:
> Map the PTE protection key bits to the HPTE key protection bits,
> while creatiing HPTE  entries.
> 
> Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
> ---
>  arch/powerpc/include/asm/book3s/64/mmu-hash.h | 5 +++++
>  arch/powerpc/include/asm/pkeys.h              | 7 +++++++
>  arch/powerpc/mm/hash_utils_64.c               | 5 +++++
>  3 files changed, 17 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
> index cfb8169..3d7872c 100644
> --- a/arch/powerpc/include/asm/book3s/64/mmu-hash.h
> +++ b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
> @@ -90,6 +90,8 @@
>  #define HPTE_R_PP0		ASM_CONST(0x8000000000000000)
>  #define HPTE_R_TS		ASM_CONST(0x4000000000000000)
>  #define HPTE_R_KEY_HI		ASM_CONST(0x3000000000000000)
> +#define HPTE_R_KEY_BIT0		ASM_CONST(0x2000000000000000)
> +#define HPTE_R_KEY_BIT1		ASM_CONST(0x1000000000000000)
>  #define HPTE_R_RPN_SHIFT	12
>  #define HPTE_R_RPN		ASM_CONST(0x0ffffffffffff000)
>  #define HPTE_R_RPN_3_0		ASM_CONST(0x01fffffffffff000)
> @@ -104,6 +106,9 @@
>  #define HPTE_R_C		ASM_CONST(0x0000000000000080)
>  #define HPTE_R_R		ASM_CONST(0x0000000000000100)
>  #define HPTE_R_KEY_LO		ASM_CONST(0x0000000000000e00)
> +#define HPTE_R_KEY_BIT2		ASM_CONST(0x0000000000000800)
> +#define HPTE_R_KEY_BIT3		ASM_CONST(0x0000000000000400)
> +#define HPTE_R_KEY_BIT4		ASM_CONST(0x0000000000000200)
> 

Should we indicate/document how these 5 bits are not contiguous
in the HPTE format for any given real page ?

>  #define HPTE_V_1TB_SEG		ASM_CONST(0x4000000000000000)
>  #define HPTE_V_VRMA_MASK	ASM_CONST(0x4001ffffff000000)
> diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
> index 0f3dca8..9b6820d 100644
> --- a/arch/powerpc/include/asm/pkeys.h
> +++ b/arch/powerpc/include/asm/pkeys.h
> @@ -27,6 +27,13 @@
>  		((vm_flags & VM_PKEY_BIT3) ? H_PAGE_PKEY_BIT1 : 0x0UL) |     \
>  		((vm_flags & VM_PKEY_BIT4) ? H_PAGE_PKEY_BIT0 : 0x0UL))
> 
> +#define calc_pte_to_hpte_pkey_bits(pteflags)	\
> +	(((pteflags & H_PAGE_PKEY_BIT0) ? HPTE_R_KEY_BIT0 : 0x0UL) |	\
> +	((pteflags & H_PAGE_PKEY_BIT1) ? HPTE_R_KEY_BIT1 : 0x0UL) |	\
> +	((pteflags & H_PAGE_PKEY_BIT2) ? HPTE_R_KEY_BIT2 : 0x0UL) |	\
> +	((pteflags & H_PAGE_PKEY_BIT3) ? HPTE_R_KEY_BIT3 : 0x0UL) |	\
> +	((pteflags & H_PAGE_PKEY_BIT4) ? HPTE_R_KEY_BIT4 : 0x0UL))
> +

We can drop calc_ in here. pte_to_hpte_pkey_bits should be
sufficient.