From 65f87d8a8a6e1b560c61951d0a68ed80f7c8ff19 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sat, 29 Jul 2006 21:42:49 +0200 Subject: [PATCH] [PATCH] x86_64: Fix swiotlb=force It was broken before. But having it is important as possible hardware bug workaround. And previously there was no way to force swiotlb if there is another IOMMU. Side effect is that iommu=force won't force swiotlb anymore even if there isn't another IOMMU. Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/pci-swiotlb.c | 5 +++-- include/asm-x86_64/swiotlb.h | 2 ++ 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86_64/kernel/pci-swiotlb.c b/arch/x86_64/kernel/pci-swiotlb.c index ebdb77fe20..6a55f87ba9 100644 --- a/arch/x86_64/kernel/pci-swiotlb.c +++ b/arch/x86_64/kernel/pci-swiotlb.c @@ -31,9 +31,10 @@ struct dma_mapping_ops swiotlb_dma_ops = { void pci_swiotlb_init(void) { /* don't initialize swiotlb if iommu=off (no_iommu=1) */ - if (!iommu_detected && !no_iommu && - (end_pfn > MAX_DMA32_PFN || force_iommu)) + if (!iommu_detected && !no_iommu && end_pfn > MAX_DMA32_PFN) swiotlb = 1; + if (swiotlb_force) + swiotlb = 1; if (swiotlb) { printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n"); swiotlb_init(); diff --git a/include/asm-x86_64/swiotlb.h b/include/asm-x86_64/swiotlb.h index 5f9a018058..ba94ab3d26 100644 --- a/include/asm-x86_64/swiotlb.h +++ b/include/asm-x86_64/swiotlb.h @@ -42,6 +42,8 @@ extern void swiotlb_free_coherent (struct device *hwdev, size_t size, extern int swiotlb_dma_supported(struct device *hwdev, u64 mask); extern void swiotlb_init(void); +extern int swiotlb_force; + #ifdef CONFIG_SWIOTLB extern int swiotlb; #else -- 2.39.5