Messages in this thread | | | Date | Thu, 13 Aug 2009 15:03:20 +0800 | Subject | Re: [RFC patch] init default dma_ops to prepare intel_iommu_init failure | From | Luming Yu <> |
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Thanks for another workaround, we should be working on deleting wrong assumption of"iommu_deteced == iommu working", Not just workaround. My patch could break something.. but it is just a start towards right goal..
On Thu, Aug 13, 2009 at 2:52 PM, FUJITA Tomonori<fujita.tomonori@lab.ntt.co.jp> wrote: > On Thu, 13 Aug 2009 13:48:45 +0800 > Luming Yu <luming.yu@gmail.com> wrote: > >> >> >> >> This check can not be removed. Otherwise, swiotlb_dma_ops will always override >> >> previous dma_ops value. >> > >> > Yeah. >> >> I think pci_swiotlb_init needs to be cleaned up for both x86_{32,64} and ia64. >> it should be used to init default dma_ops, and the call site of it should be >> as early as platform_dma_init in mem_init. SInce swiotlb_dma_ops is pitched as >> default dma_ops for x86, ia64, we really don't need to let pci_swiotlb_init >> know iommu_deteced, dmar_disabled or iommu_passthrough...and anything >> like that.. >> Please note the major wrong assumption of the current implementation is >> "iommu_deteced == iommu working" that I was trying to fix. > > How about this? > > You can work around that assumption, I guess. > > > diff --git a/arch/ia64/kernel/pci-dma.c b/arch/ia64/kernel/pci-dma.c > index f6b1ff0..48caafa 100644 > --- a/arch/ia64/kernel/pci-dma.c > +++ b/arch/ia64/kernel/pci-dma.c > @@ -20,6 +20,8 @@ > > #include <asm/page.h> > > +extern int swiotlb_late_init_with_default_size (size_t size); > + > dma_addr_t bad_dma_address __read_mostly; > EXPORT_SYMBOL(bad_dma_address); > > @@ -44,11 +46,25 @@ struct device fallback_dev = { > }; > > extern struct dma_map_ops intel_dma_ops; > +extern struct dma_map_ops swiotlb_dma_ops; > > static int __init pci_iommu_init(void) > { > - if (iommu_detected) > - intel_iommu_init(); > + int ret; > + > + if (iommu_detected) { > + ret = intel_iommu_init(); > + if (ret) { > +#ifdef CONFIG_IA64_GENERIC > + dma_ops = &swiotlb_dma_ops; > + if (swiotlb_late_init_with_default_size(64 * (1<<20))) > + panic("failed to initialize swiotlb"); > + machvec_init("dig"); > +#else > + panic("Unable to find Intel IOMMU"); > +#endif > + } > + } > > return 0; > } > -- 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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