diff options
Diffstat (limited to 'arch/x86/xen/pci-swiotlb-xen.c')
| -rw-r--r-- | arch/x86/xen/pci-swiotlb-xen.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c index b6a534002ab2..1c1722761eec 100644 --- a/arch/x86/xen/pci-swiotlb-xen.c +++ b/arch/x86/xen/pci-swiotlb-xen.c @@ -8,6 +8,11 @@ #include <xen/xen.h> #include <asm/iommu_table.h> +#ifdef CONFIG_X86_64 +#include <asm/iommu.h> +#include <asm/dma.h> +#endif + int xen_swiotlb __read_mostly; static struct dma_map_ops xen_swiotlb_dma_ops = { @@ -49,6 +54,15 @@ int __init pci_xen_swiotlb_detect(void) * the 'swiotlb' flag is the only one turning it on. */ swiotlb = 0; +#ifdef CONFIG_X86_64 + /* pci_swiotlb_detect_4gb turns on native SWIOTLB if no_iommu == 0 + * (so no iommu=X command line over-writes). + * Considering that PV guests do not want the *native SWIOTLB* but + * only Xen SWIOTLB it is not useful to us so set no_iommu=1 here. + */ + if (max_pfn > MAX_DMA32_PFN) + no_iommu = 1; +#endif return xen_swiotlb; } |