From 8d4f6b93a4aaa6b56b600cd1165c971f4395e4b3 Mon Sep 17 00:00:00 2001 From: Jon Mason Date: Mon, 26 Jun 2006 13:58:05 +0200 Subject: [PATCH] x86_64: Calgary IOMMU - introduce iommu_detected swiotlb relies on the gart specific iommu_aperture variable to know if we discovered a hardware IOMMU before swiotlb initialization. Introduce iommu_detected to do the same thing, but in a HW IOMMU neutral manner, in preparation for adding the Calgary HW IOMMU. Signed-Off-By: Muli Ben-Yehuda Signed-Off-By: Jon Mason Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/aperture.c | 1 + arch/x86_64/kernel/pci-dma.c | 3 +++ arch/x86_64/kernel/pci-gart.c | 4 ++++ arch/x86_64/kernel/pci-swiotlb.c | 2 +- 4 files changed, 9 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/x86_64/kernel/aperture.c b/arch/x86_64/kernel/aperture.c index 9ea723bab16..a195ef06ec5 100644 --- a/arch/x86_64/kernel/aperture.c +++ b/arch/x86_64/kernel/aperture.c @@ -209,6 +209,7 @@ void __init iommu_hole_init(void) if (!early_is_k8_nb(read_pci_config(0, num, 3, 0x00))) continue; + iommu_detected = 1; iommu_aperture = 1; aper_order = (read_pci_config(0, num, 3, 0x90) >> 1) & 7; diff --git a/arch/x86_64/kernel/pci-dma.c b/arch/x86_64/kernel/pci-dma.c index 33926c36725..7edd1a40fab 100644 --- a/arch/x86_64/kernel/pci-dma.c +++ b/arch/x86_64/kernel/pci-dma.c @@ -33,6 +33,9 @@ int panic_on_overflow __read_mostly = 0; int force_iommu __read_mostly= 0; #endif +/* Set this to 1 if there is a HW IOMMU in the system */ +int iommu_detected __read_mostly = 0; + /* Dummy device used for NULL arguments (normally ISA). Better would be probably a smaller DMA mask, but this is bug-to-bug compatible to i386. */ diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c index 82a346e6e2e..4f67957d2b4 100644 --- a/arch/x86_64/kernel/pci-gart.c +++ b/arch/x86_64/kernel/pci-gart.c @@ -597,6 +597,10 @@ static int __init pci_iommu_init(void) if (swiotlb) return -ENODEV; + /* Did we detect a different HW IOMMU? */ + if (iommu_detected && !iommu_aperture) + return -1; + if (no_iommu || (!force_iommu && end_pfn <= MAX_DMA32_PFN) || !iommu_aperture || diff --git a/arch/x86_64/kernel/pci-swiotlb.c b/arch/x86_64/kernel/pci-swiotlb.c index 990ed67896f..ebdb77fe205 100644 --- a/arch/x86_64/kernel/pci-swiotlb.c +++ b/arch/x86_64/kernel/pci-swiotlb.c @@ -31,7 +31,7 @@ struct dma_mapping_ops swiotlb_dma_ops = { void pci_swiotlb_init(void) { /* don't initialize swiotlb if iommu=off (no_iommu=1) */ - if (!iommu_aperture && !no_iommu && + if (!iommu_detected && !no_iommu && (end_pfn > MAX_DMA32_PFN || force_iommu)) swiotlb = 1; if (swiotlb) { -- cgit v1.2.3-70-g09d2