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Diffstat (limited to 'arch/x86/kernel/pci-swiotlb.c')
-rw-r--r--arch/x86/kernel/pci-swiotlb.c46
1 files changed, 15 insertions, 31 deletions
diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 6af96ee44200..e3c0a66b9e77 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -13,31 +13,6 @@
int swiotlb __read_mostly;
-void * __init swiotlb_alloc_boot(size_t size, unsigned long nslabs)
-{
- return alloc_bootmem_low_pages(size);
-}
-
-void *swiotlb_alloc(unsigned order, unsigned long nslabs)
-{
- return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
-}
-
-dma_addr_t swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
-{
- return paddr;
-}
-
-phys_addr_t swiotlb_bus_to_phys(struct device *hwdev, dma_addr_t baddr)
-{
- return baddr;
-}
-
-int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
-{
- return 0;
-}
-
static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags)
{
@@ -67,19 +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) ||
- iommu_pass_through)
- swiotlb = 1;
+ 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;
}