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

[Khalid Aziz]

On 4/13/22 00:22, Anshuman Khandual wrote:
> 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 ?

Hi Anshuman,

Yes, this change makes sense.

--
Khalid

> > 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