1 /* Glue code to lib/swiotlb-xen.c */
3 #include <linux/dma-mapping.h>
5 #include <xen/swiotlb-xen.h>
7 #include <asm/xen/hypervisor.h>
9 #include <asm/iommu_table.h>
12 #include <asm/iommu.h>
15 #include <linux/export.h>
16 int xen_swiotlb __read_mostly;
18 static struct dma_map_ops xen_swiotlb_dma_ops = {
19 .mapping_error = xen_swiotlb_dma_mapping_error,
20 .alloc = xen_swiotlb_alloc_coherent,
21 .free = xen_swiotlb_free_coherent,
22 .sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu,
23 .sync_single_for_device = xen_swiotlb_sync_single_for_device,
24 .sync_sg_for_cpu = xen_swiotlb_sync_sg_for_cpu,
25 .sync_sg_for_device = xen_swiotlb_sync_sg_for_device,
26 .map_sg = xen_swiotlb_map_sg_attrs,
27 .unmap_sg = xen_swiotlb_unmap_sg_attrs,
28 .map_page = xen_swiotlb_map_page,
29 .unmap_page = xen_swiotlb_unmap_page,
30 .dma_supported = xen_swiotlb_dma_supported,
34 * pci_xen_swiotlb_detect - set xen_swiotlb to 1 if necessary
36 * This returns non-zero if we are forced to use xen_swiotlb (by the boot
39 int __init pci_xen_swiotlb_detect(void)
45 /* If running as PV guest, either iommu=soft, or swiotlb=force will
46 * activate this IOMMU. If running as PV privileged, activate it
49 if ((xen_initial_domain() || swiotlb || swiotlb_force))
52 /* If we are running under Xen, we MUST disable the native SWIOTLB.
53 * Don't worry about swiotlb_force flag activating the native, as
54 * the 'swiotlb' flag is the only one turning it on. */
58 /* pci_swiotlb_detect_4gb turns on native SWIOTLB if no_iommu == 0
59 * (so no iommu=X command line over-writes).
60 * Considering that PV guests do not want the *native SWIOTLB* but
61 * only Xen SWIOTLB it is not useful to us so set no_iommu=1 here.
63 if (max_pfn > MAX_DMA32_PFN)
69 void __init pci_xen_swiotlb_init(void)
72 xen_swiotlb_init(1, true /* early */);
73 dma_ops = &xen_swiotlb_dma_ops;
75 /* Make sure ACS will be enabled */
80 int pci_xen_swiotlb_init_late(void)
87 rc = xen_swiotlb_init(1, false /* late */);
91 dma_ops = &xen_swiotlb_dma_ops;
92 /* Make sure ACS will be enabled */
97 EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late);
99 IOMMU_INIT_FINISH(pci_xen_swiotlb_detect,
101 pci_xen_swiotlb_init,