From: Andi Kleen Date: Sat, 29 Jul 2006 19:42:49 +0000 (+0200) Subject: [PATCH] x86_64: Fix swiotlb=force X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=65f87d8a8a6e1b560c61951d0a68ed80f7c8ff19;p=linux-beck.git [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 --- diff --git a/arch/x86_64/kernel/pci-swiotlb.c b/arch/x86_64/kernel/pci-swiotlb.c index ebdb77fe2057..6a55f87ba97f 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 5f9a01805821..ba94ab3d2673 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