Re: [PATCH RFC 5/6] arm64/xen: implement xen_remap on arm64

From: Catalin Marinas
Date: Fri May 31 2013 - 07:00:05 EST


On Thu, May 30, 2013 at 05:18:32PM +0100, Stefano Stabellini wrote:
> --- a/arch/arm/include/asm/xen/page.h
> +++ b/arch/arm/include/asm/xen/page.h
> @@ -90,6 +90,10 @@ static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
> return __set_phys_to_machine(pfn, mfn);
> }
>
> +#ifdef CONFIG_ARM64
> +#define xen_remap(cookie, size) __ioremap((cookie), (size), __pgprot(PROT_NORMAL))
> +#else
> #define xen_remap(cookie, size) __arm_ioremap((cookie), (size), MT_MEMORY);
> +#endif

Now I saw the ARM-specific part. Can you not use something like
ioremap_cached() which would give normal cacheable memory (at least on
ARMv7).

> #endif /* _ASM_ARM_XEN_PAGE_H */
> diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
> index 2e12258..0e9c9ac 100644
> --- a/arch/arm64/include/asm/io.h
> +++ b/arch/arm64/include/asm/io.h
> @@ -228,6 +228,7 @@ extern void __iounmap(volatile void __iomem *addr);
> #define PROT_DEFAULT (PTE_TYPE_PAGE | PTE_AF | PTE_DIRTY)
> #define PROT_DEVICE_nGnRE (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRE))
> #define PROT_NORMAL_NC (PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL_NC))
> +#define PROT_NORMAL (PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL))
>
> #define ioremap(addr, size) __ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRE))
> #define ioremap_nocache(addr, size) __ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRE))

Of course we need to add ioremap_cached() for arm64 but until now we
didn't need it.

--
Catalin
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