Re: Where do we stand with the Xen patches?

[FUJITA Tomonori]

On Thu, 21 May 2009 11:28:53 +0100
Ian Campbell <ijc@xxxxxxxxxxxxxx> wrote:

> On Thu, 2009-05-21 at 11:27 +0100, Ian Campbell wrote:
> > The corresponding the Xen updates will...
> ...follow.
> 
> Subject:swiotlb/xen: add implementation of swiotlb_range_needs_mapping hook
> 
> This function is now implemented via asm/dma-mapping.h rather than as
> a weak hook in swiotlb.c
> 
> Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> 
> diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
> index a80139a..ed51bd1 100644
> --- a/arch/x86/include/asm/dma-mapping.h
> +++ b/arch/x86/include/asm/dma-mapping.h
> @@ -315,9 +315,15 @@ static inline int is_buffer_dma_capable(struct device *dev, u64 mask,
>  	return addr + size <= mask;
>  }
>  
> +#ifdef CONFIG_PCI_XEN
> +extern int xen_range_needs_mapping(phys_addr_t paddr, size_t size);
> +#else
> +static inline int xen_range_needs_mapping(phys_addr_t paddr, size_t size) { return 0; }
> +#endif

I know Xen can do something like this but you think that this is
clean?

In addition, you also the similar hack in
arch/ia64/include/asm/dma-mapping.h for ia64's dom0 support, I think.


IMO, your patch just moves the ugly hacks from lib/swiotlb.c to
arch/{x86|ia64}/include/asm/dma-mapping.h.
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