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Groups > linux.kernel > #1244859
| From | Nishanth Aravamudan <nacc@linux.vnet.ibm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 1/2] powerpc/iommu: expose IOMMU page shift |
| Date | 2015-10-12 18:10 +0200 |
| Message-ID | <qiNPI-3X3-17@gated-at.bofh.it> (permalink) |
| References | <qfc9X-1mW-5@gated-at.bofh.it> <qfc9Y-1mW-23@gated-at.bofh.it> <qgr6V-2iB-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 06.10.2015 [14:19:43 +1100], David Gibson wrote: > On Fri, Oct 02, 2015 at 10:18:00AM -0700, Nishanth Aravamudan wrote: > > We will leverage this macro in the NVMe driver, which needs to know the > > configured IOMMU page shift to properly configure its device's page > > size. > > > > Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> > > > > --- > > Given this is available, it seems reasonable to expose -- and it doesn't > > really make sense to make the driver do a log2 call on the existing > > IOMMU_PAGE_SIZE() value. > > > > diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h > > index ca18cff..6fdf857 100644 > > --- a/arch/powerpc/include/asm/iommu.h > > +++ b/arch/powerpc/include/asm/iommu.h > > @@ -36,6 +36,7 @@ > > #define IOMMU_PAGE_MASK_4K (~((1 << IOMMU_PAGE_SHIFT_4K) - 1)) > > #define IOMMU_PAGE_ALIGN_4K(addr) _ALIGN_UP(addr, IOMMU_PAGE_SIZE_4K) > > > > +#define IOMMU_PAGE_SHIFT(tblptr) (tblptr)->it_page_shift > > #define IOMMU_PAGE_SIZE(tblptr) (ASM_CONST(1) << (tblptr)->it_page_shift) > > Seems like it would be a touch safer to alter IOMMU_PAGE_SIZE so it > uses the new IOMMU_PAGE_SHIFT macro. Yes absolutely! Sorry, I initially didn't add the first macro, so didn't think that through. Will update. -Nish -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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Re: [PATCH 1/2] powerpc/iommu: expose IOMMU page shift David Gibson <david@gibson.dropbear.id.au> - 2015-10-06 05:30 +0200
Re: [PATCH 1/2] powerpc/iommu: expose IOMMU page shift Nishanth Aravamudan <nacc@linux.vnet.ibm.com> - 2015-10-12 18:10 +0200
Re: [PATCH 1/2] powerpc/iommu: expose IOMMU page shift Nishanth Aravamudan <nacc@linux.vnet.ibm.com> - 2015-10-12 23:20 +0200
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