Re: [PATCH V7 4/5] arm64: apei: implement arch_apei_get_mem_attributes()

[Will Deacon <will.deacon@arm.com>]

On Fri, Jul 24, 2015 at 05:21:49PM +0100, Catalin Marinas wrote:
> On Fri, Jul 24, 2015 at 03:57:08PM +0100, Will Deacon wrote:
> > On Tue, Jul 21, 2015 at 10:59:19PM +0100, Jonathan (Zhixiong) Zhang wrote:
> > > diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> > > +static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)
> > > +{
> > > +	pgprot_t prot;
> > > +
> > > +	prot = efi_mem_attributes(addr);
> > > +	if (prot & EFI_MEMORY_UC)
> > > +		return PROT_DEVICE_nGnRnE;
> > > +	if (prot & EFI_MEMORY_WC)
> > > +		return PROT_NORMAL_NC;
> > 
> > Can we not use pgprot_noncached and pgprot_writecombine for these two?
> 
> Actually, why do we even use pgprot_t for prot here? EFI_MEMORY_* don't
> have anything to do with the arch-specific pgprot_t.

Good point; the pgprot_t confused me, so my suggestion is much use after
ll. We're better off with a u64 to avoid further confusion.

Will