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Diffstat (limited to 'arch/x86/kernel/pci-swiotlb.c')
-rw-r--r--arch/x86/kernel/pci-swiotlb.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index aaa6b7839f1..e3c0a66b9e7 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -42,18 +42,28 @@ static struct dma_map_ops swiotlb_dma_ops = {
.dma_supported = NULL,
};
-void __init pci_swiotlb_init(void)
+/*
+ * pci_swiotlb_init - initialize swiotlb if necessary
+ *
+ * This returns non-zero if we are forced to use swiotlb (by the boot
+ * option).
+ */
+int __init pci_swiotlb_init(void)
{
+ int use_swiotlb = swiotlb | swiotlb_force;
+
/* don't initialize swiotlb if iommu=off (no_iommu=1) */
#ifdef CONFIG_X86_64
- if ((!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN))
+ if (!no_iommu && max_pfn > MAX_DMA32_PFN)
swiotlb = 1;
#endif
if (swiotlb_force)
swiotlb = 1;
+
if (swiotlb) {
- printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
- swiotlb_init();
+ swiotlb_init(0);
dma_ops = &swiotlb_dma_ops;
}
+
+ return use_swiotlb;
}