Messages in this thread | | | Date | Wed, 12 Nov 2014 15:55:24 +0000 | From | "Jan Beulich" <> | Subject | Re: [Xen-devel] [PATCH 3/3] x86/xen: use the maximum MFN to calculate the required DMA mask |
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>>> On 12.11.14 at 16:25, <david.vrabel@citrix.com> wrote: > +u64 > +xen_swiotlb_get_required_mask(struct device *dev) > +{ > + u64 max_mfn; > + > + max_mfn = HYPERVISOR_memory_op(XENMEM_maximum_ram_page, NULL); > + > + return DMA_BIT_MASK(fls64(max_mfn << PAGE_SHIFT) + 1); > +}
The value the hypercall returns is exclusive and an unsigned long. Hence I'd suggest
u64 xen_swiotlb_get_required_mask(struct device *dev) { unsigned long max_mfn;
max_mfn = HYPERVISOR_memory_op(XENMEM_maximum_ram_page, NULL);
return DMA_BIT_MASK(__fls(max_mfn - 1) + 1 + PAGE_SHIFT); }
Jan
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