Re: [PATCH V6 4/7] sparc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

[Anshuman Khandual]

On 4/13/22 11:43, Christophe Leroy wrote:
> 
> 
> Le 13/04/2022 à 07:58, Anshuman Khandual a écrit :
>> This defines and exports a platform specific custom vm_get_page_prot() via
>> subscribing ARCH_HAS_VM_GET_PAGE_PROT. It localizes arch_vm_get_page_prot()
>> as sparc_vm_get_page_prot() and moves near vm_get_page_prot().
>>
>> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
>> Cc: Khalid Aziz <khalid.aziz@xxxxxxxxxx>
>> Cc: sparclinux@xxxxxxxxxxxxxxx
>> Cc: linux-kernel@xxxxxxxxxxxxxxx
>> Reviewed-by: Khalid Aziz <khalid.aziz@xxxxxxxxxx>
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
>> ---
>>   arch/sparc/Kconfig            |  1 +
>>   arch/sparc/include/asm/mman.h |  6 ------
>>   arch/sparc/mm/init_64.c       | 13 +++++++++++++
>>   3 files changed, 14 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
>> index 9200bc04701c..85b573643af6 100644
>> --- a/arch/sparc/Kconfig
>> +++ b/arch/sparc/Kconfig
>> @@ -84,6 +84,7 @@ config SPARC64
>>   	select PERF_USE_VMALLOC
>>   	select ARCH_HAVE_NMI_SAFE_CMPXCHG
>>   	select HAVE_C_RECORDMCOUNT
>> +	select ARCH_HAS_VM_GET_PAGE_PROT
>>   	select HAVE_ARCH_AUDITSYSCALL
>>   	select ARCH_SUPPORTS_ATOMIC_RMW
>>   	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
>> diff --git a/arch/sparc/include/asm/mman.h b/arch/sparc/include/asm/mman.h
>> index 274217e7ed70..af9c10c83dc5 100644
>> --- a/arch/sparc/include/asm/mman.h
>> +++ b/arch/sparc/include/asm/mman.h
>> @@ -46,12 +46,6 @@ static inline unsigned long sparc_calc_vm_prot_bits(unsigned long prot)
>>   	}
>>   }
>>   
>> -#define arch_vm_get_page_prot(vm_flags) sparc_vm_get_page_prot(vm_flags)
>> -static inline pgprot_t sparc_vm_get_page_prot(unsigned long vm_flags)
>> -{
>> -	return (vm_flags & VM_SPARC_ADI) ? __pgprot(_PAGE_MCD_4V) : __pgprot(0);
>> -}
>> -
>>   #define arch_validate_prot(prot, addr) sparc_validate_prot(prot, addr)
>>   static inline int sparc_validate_prot(unsigned long prot, unsigned long addr)
>>   {
>> diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
>> index 8b1911591581..dcb17763c1f2 100644
>> --- a/arch/sparc/mm/init_64.c
>> +++ b/arch/sparc/mm/init_64.c
>> @@ -3184,3 +3184,16 @@ void copy_highpage(struct page *to, struct page *from)
>>   	}
>>   }
>>   EXPORT_SYMBOL(copy_highpage);
>> +
>> +static pgprot_t sparc_vm_get_page_prot(unsigned long vm_flags)
>> +{
>> +	return (vm_flags & VM_SPARC_ADI) ? __pgprot(_PAGE_MCD_4V) : __pgprot(0);
>> +}
>> +
>> +pgprot_t vm_get_page_prot(unsigned long vm_flags)
>> +{
>> +	return __pgprot(pgprot_val(protection_map[vm_flags &
>> +			(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
>> +			pgprot_val(sparc_vm_get_page_prot(vm_flags)));
>> +}
>> +EXPORT_SYMBOL(vm_get_page_prot);
> 
> 
> sparc is now the only one with two functions. You can most likely do 
> like you did for ARM and POWERPC: merge into a single function:

I was almost about to do this one as well but as this patch has already been
reviewed with a tag, just skipped it. I will respin the series once more :)

Khalid,

Could I keep your review tag after the following change ?

> 
> pgprot_t vm_get_page_prot(unsigned long vm_flags)
> {
> 	unsigned long prot = pgprot_val(protection_map[vm_flags &
> 		(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]);
> 
> 	if (vm_flags & VM_SPARC_ADI)
> 		prot |= _PAGE_MCD_4V;
> 
> 	return __pgprot(prot);
> }
> EXPORT_SYMBOL(vm_get_page_prot);

- Anshuman