Messages in this thread | | | From | FUJITA Tomonori <> | Subject | [PATCH 0/10] x86: handle HW IOMMU initialization failure gracely | Date | Wed, 28 Oct 2009 15:47:34 +0900 |
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If HW IOMMU initialization fails (Intel VT-d often does typically due to BIOS bugs), we fall back to nommu. It doesn't work for the majority since nowadays we have more than 4GB memory so we must use swiotlb instead of nommu.
The problem is that it's too late to initialize swiotlb when HW IOMMU initialization fails. We need to allocate swiotlb memory earlier from bootmem allocator. Chris explained the issue in detail:
http://marc.info/?l=linux-kernel&m=125657444317079&w=2
The current x86 IOMMU initialization sequence is too complicated and handling the above issue makes it more hacky.
This series changes x86 IOMMU initialization sequence to handle the above issue cleanly.
The new x86 IOMMU initialization sequence are:
1. initializing swiotlb (and setting swiotlb to 1) in the case of (max_pfn > MAX_DMA32_PFN && !no_iommu). dma_ops is set to swiotlb_dma_ops or nommu_dma_ops.
2. calling the detection functions of all the IOMMUs
3. the detection function sets x86_init.iommu.iommu_init to the IOMMU initialization function (so we can avoid calling the initialization functions of all the IOMMUs needlessly).
4. if the IOMMU initialization function doesn't need to swiotlb then sets swiotlb to zero (e.g. the initialization is sucessful).
5. if we find that swiotlb is set to zero, we free swiotlb resource.
= arch/ia64/kernel/pci-swiotlb.c | 4 +- arch/powerpc/kernel/setup_32.c | 2 +- arch/powerpc/kernel/setup_64.c | 2 +- arch/x86/include/asm/amd_iommu.h | 2 - arch/x86/include/asm/calgary.h | 2 - arch/x86/include/asm/gart.h | 5 +-- arch/x86/include/asm/iommu.h | 2 +- arch/x86/include/asm/x86_init.h | 9 ++++ arch/x86/kernel/amd_iommu.c | 2 +- arch/x86/kernel/amd_iommu_init.c | 19 ++------ arch/x86/kernel/aperture_64.c | 4 +- arch/x86/kernel/pci-calgary_64.c | 19 ++----- arch/x86/kernel/pci-dma.c | 23 ++++----- arch/x86/kernel/pci-gart_64.c | 16 ++---- arch/x86/kernel/pci-nommu.c | 9 ---- arch/x86/kernel/pci-swiotlb.c | 8 ++-- arch/x86/kernel/x86_init.c | 5 ++ drivers/pci/dmar.c | 7 ++- drivers/pci/intel-iommu.c | 4 +- include/linux/bootmem.h | 1 + include/linux/dmar.h | 10 ---- include/linux/swiotlb.h | 5 +- lib/swiotlb.c | 45 +++++++++++++++--- mm/bootmem.c | 98 +++++++++++++++++++++++++++++--------- 24 files changed, 177 insertions(+), 126 deletions(-)
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