[PATCH 14/25] powerpc: map vma key-protection bits to pte key bits.

[Balbir Singh]

On Fri,  8 Sep 2017 15:45:02 -0700
Ram Pai <linuxram at us.ibm.com> wrote:

> map  the  key  protection  bits of the vma to the pkey bits in
> the PTE.
> 
> The Pte  bits used  for pkey  are  3,4,5,6  and 57. The  first
> four bits are the same four bits that were freed up  initially
> in this patch series. remember? :-) Without those four bits
> this patch would'nt be possible.
> 
> BUT, On 4k kernel, bit 3, and 4 could not be freed up. remember?
> Hence we have to be satisfied with 5,6 and 7.
> 
> Signed-off-by: Ram Pai <linuxram at us.ibm.com>
> ---
>  arch/powerpc/include/asm/book3s/64/pgtable.h |   25 ++++++++++++++++++++++++-
>  arch/powerpc/include/asm/mman.h              |    8 ++++++++
>  arch/powerpc/include/asm/pkeys.h             |   12 ++++++++++++
>  3 files changed, 44 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
> index 73ed52c..5935d4e 100644
> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
> @@ -38,6 +38,7 @@
>  #define _RPAGE_RSV2		0x0800000000000000UL
>  #define _RPAGE_RSV3		0x0400000000000000UL
>  #define _RPAGE_RSV4		0x0200000000000000UL
> +#define _RPAGE_RSV5		0x00040UL
>  
>  #define _PAGE_PTE		0x4000000000000000UL	/* distinguishes PTEs from pointers */
>  #define _PAGE_PRESENT		0x8000000000000000UL	/* pte contains a translation */
> @@ -57,6 +58,25 @@
>  /* Max physical address bit as per radix table */
>  #define _RPAGE_PA_MAX		57
>  
> +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
> +#ifdef CONFIG_PPC_64K_PAGES
> +#define H_PAGE_PKEY_BIT0	_RPAGE_RSV1
> +#define H_PAGE_PKEY_BIT1	_RPAGE_RSV2
> +#else /* CONFIG_PPC_64K_PAGES */
> +#define H_PAGE_PKEY_BIT0	0 /* _RPAGE_RSV1 is not available */
> +#define H_PAGE_PKEY_BIT1	0 /* _RPAGE_RSV2 is not available */
> +#endif /* CONFIG_PPC_64K_PAGES */
> +#define H_PAGE_PKEY_BIT2	_RPAGE_RSV3
> +#define H_PAGE_PKEY_BIT3	_RPAGE_RSV4
> +#define H_PAGE_PKEY_BIT4	_RPAGE_RSV5
> +#else /*  CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
> +#define H_PAGE_PKEY_BIT0	0
> +#define H_PAGE_PKEY_BIT1	0
> +#define H_PAGE_PKEY_BIT2	0
> +#define H_PAGE_PKEY_BIT3	0
> +#define H_PAGE_PKEY_BIT4	0
> +#endif /*  CONFIG_PPC64_MEMORY_PROTECTION_KEYS */

H_PTE_PKEY_BITX?

> +
>  /*
>   * Max physical address bit we will use for now.
>   *
> @@ -120,13 +140,16 @@
>  #define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
>  			 _PAGE_ACCESSED | _PAGE_SPECIAL | _PAGE_PTE |	\
>  			 _PAGE_SOFT_DIRTY)
> +
> +#define H_PAGE_PKEY  (H_PAGE_PKEY_BIT0 | H_PAGE_PKEY_BIT1 | H_PAGE_PKEY_BIT2 | \
> +			H_PAGE_PKEY_BIT3 | H_PAGE_PKEY_BIT4)
>  /*
>   * Mask of bits returned by pte_pgprot()
>   */
>  #define PAGE_PROT_BITS  (_PAGE_SAO | _PAGE_NON_IDEMPOTENT | _PAGE_TOLERANT | \
>  			 H_PAGE_4K_PFN | _PAGE_PRIVILEGED | _PAGE_ACCESSED | \
>  			 _PAGE_READ | _PAGE_WRITE |  _PAGE_DIRTY | _PAGE_EXEC | \
> -			 _PAGE_SOFT_DIRTY)
> +			 _PAGE_SOFT_DIRTY | H_PAGE_PKEY)
>  /*
>   * We define 2 sets of base prot bits, one for basic pages (ie,
>   * cacheable kernel and user pages) and one for non cacheable
> diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
> index 067eec2..3f7220f 100644
> --- a/arch/powerpc/include/asm/mman.h
> +++ b/arch/powerpc/include/asm/mman.h
> @@ -32,12 +32,20 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
>  }
>  #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
>  
> +
>  static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
>  {
> +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
> +	return (vm_flags & VM_SAO) ?
> +		__pgprot(_PAGE_SAO | vmflag_to_page_pkey_bits(vm_flags)) :
> +		__pgprot(0 | vmflag_to_page_pkey_bits(vm_flags));
> +#else
>  	return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
> +#endif
>  }
>  #define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
>  
> +
>  static inline bool arch_validate_prot(unsigned long prot)
>  {
>  	if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO))
> diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
> index d2fffef..0d2488a 100644
> --- a/arch/powerpc/include/asm/pkeys.h
> +++ b/arch/powerpc/include/asm/pkeys.h
> @@ -41,6 +41,18 @@ static inline u64 pkey_to_vmflag_bits(u16 pkey)
>  		((pkey & 0x10UL) ? VM_PKEY_BIT4 : 0x0UL));
>  }
>  
> +static inline u64 vmflag_to_page_pkey_bits(u64 vm_flags)

vmflag_to_pte_pkey_bits?

> +{
> +	if (!pkey_inited)
> +		return 0x0UL;
> +
> +	return (((vm_flags & VM_PKEY_BIT0) ? H_PAGE_PKEY_BIT4 : 0x0UL) |
> +		((vm_flags & VM_PKEY_BIT1) ? H_PAGE_PKEY_BIT3 : 0x0UL) |
> +		((vm_flags & VM_PKEY_BIT2) ? H_PAGE_PKEY_BIT2 : 0x0UL) |
> +		((vm_flags & VM_PKEY_BIT3) ? H_PAGE_PKEY_BIT1 : 0x0UL) |
> +		((vm_flags & VM_PKEY_BIT4) ? H_PAGE_PKEY_BIT0 : 0x0UL));
> +}
> +
>  #define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \
>  				VM_PKEY_BIT3 | VM_PKEY_BIT4)
>  

Balbir Singh.