Messages in this thread |  | | Date | Tue, 14 Oct 2014 17:12:12 +0100 | From | David Vrabel <> | Subject | Re: [PATCH v4 6/7] xen/arm/arm64: introduce xen_arch_need_swiotlb |
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On 14/10/14 17:03, Konrad Rzeszutek Wilk wrote: > On Fri, Oct 10, 2014 at 12:51:47PM +0100, Stefano Stabellini wrote: >> Introduce an arch specific function to find out whether a particular dma >> mapping operation needs to bounce on the swiotlb buffer. >> >> On ARM and ARM64, if the page involved is a foreign page and the device >> is not coherent, we need to bounce because at unmap time we cannot >> execute any required cache maintenance operations (we don't know how to >> find the pfn from the mfn). ... >> --- a/arch/x86/include/asm/xen/page.h >> +++ b/arch/x86/include/asm/xen/page.h >> @@ -236,4 +236,11 @@ void make_lowmem_page_readwrite(void *vaddr); >> #define xen_remap(cookie, size) ioremap((cookie), (size)); >> #define xen_unmap(cookie) iounmap((cookie)) >> >> +static inline bool xen_arch_need_swiotlb(struct device *dev, >> + unsigned long pfn, >> + unsigned long mfn) >> +{ >> + return false; >> +} > > Why not make this an macro?
Because macros are evil and inline functions are preferred.
David
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