1 /*
2 * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
3 *
4 * Provide default implementations of the DMA mapping callbacks for
5 * busses using the iommu infrastructure
6 */
7
8 #include <asm/iommu.h>
9
10 /*
11 * Generic iommu implementation
12 */
13
14 /* Allocates a contiguous real buffer and creates mappings over it.
15 * Returns the virtual address of the buffer and sets dma_handle
16 * to the dma address (mapping) of the first page.
17 */
dma_iommu_alloc_coherent(struct device * dev,size_t size,dma_addr_t * dma_handle,gfp_t flag)18 static void *dma_iommu_alloc_coherent(struct device *dev, size_t size,
19 dma_addr_t *dma_handle, gfp_t flag)
20 {
21 return iommu_alloc_coherent(dev, dev->archdata.dma_data, size,
22 dma_handle, device_to_mask(dev), flag,
23 dev_to_node(dev));
24 }
25
dma_iommu_free_coherent(struct device * dev,size_t size,void * vaddr,dma_addr_t dma_handle)26 static void dma_iommu_free_coherent(struct device *dev, size_t size,
27 void *vaddr, dma_addr_t dma_handle)
28 {
29 iommu_free_coherent(dev->archdata.dma_data, size, vaddr, dma_handle);
30 }
31
32 /* Creates TCEs for a user provided buffer. The user buffer must be
33 * contiguous real kernel storage (not vmalloc). The address passed here
34 * comprises a page address and offset into that page. The dma_addr_t
35 * returned will point to the same byte within the page as was passed in.
36 */
dma_iommu_map_page(struct device * dev,struct page * page,unsigned long offset,size_t size,enum dma_data_direction direction,struct dma_attrs * attrs)37 static dma_addr_t dma_iommu_map_page(struct device *dev, struct page *page,
38 unsigned long offset, size_t size,
39 enum dma_data_direction direction,
40 struct dma_attrs *attrs)
41 {
42 return iommu_map_page(dev, dev->archdata.dma_data, page, offset, size,
43 device_to_mask(dev), direction, attrs);
44 }
45
46
dma_iommu_unmap_page(struct device * dev,dma_addr_t dma_handle,size_t size,enum dma_data_direction direction,struct dma_attrs * attrs)47 static void dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle,
48 size_t size, enum dma_data_direction direction,
49 struct dma_attrs *attrs)
50 {
51 iommu_unmap_page(dev->archdata.dma_data, dma_handle, size, direction,
52 attrs);
53 }
54
55
dma_iommu_map_sg(struct device * dev,struct scatterlist * sglist,int nelems,enum dma_data_direction direction,struct dma_attrs * attrs)56 static int dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist,
57 int nelems, enum dma_data_direction direction,
58 struct dma_attrs *attrs)
59 {
60 return iommu_map_sg(dev, dev->archdata.dma_data, sglist, nelems,
61 device_to_mask(dev), direction, attrs);
62 }
63
dma_iommu_unmap_sg(struct device * dev,struct scatterlist * sglist,int nelems,enum dma_data_direction direction,struct dma_attrs * attrs)64 static void dma_iommu_unmap_sg(struct device *dev, struct scatterlist *sglist,
65 int nelems, enum dma_data_direction direction,
66 struct dma_attrs *attrs)
67 {
68 iommu_unmap_sg(dev->archdata.dma_data, sglist, nelems, direction,
69 attrs);
70 }
71
72 /* We support DMA to/from any memory page via the iommu */
dma_iommu_dma_supported(struct device * dev,u64 mask)73 static int dma_iommu_dma_supported(struct device *dev, u64 mask)
74 {
75 struct iommu_table *tbl = dev->archdata.dma_data;
76
77 if (!tbl || tbl->it_offset > mask) {
78 printk(KERN_INFO
79 "Warning: IOMMU offset too big for device mask\n");
80 if (tbl)
81 printk(KERN_INFO
82 "mask: 0x%08llx, table offset: 0x%08lx\n",
83 mask, tbl->it_offset);
84 else
85 printk(KERN_INFO "mask: 0x%08llx, table unavailable\n",
86 mask);
87 return 0;
88 } else
89 return 1;
90 }
91
92 struct dma_mapping_ops dma_iommu_ops = {
93 .alloc_coherent = dma_iommu_alloc_coherent,
94 .free_coherent = dma_iommu_free_coherent,
95 .map_sg = dma_iommu_map_sg,
96 .unmap_sg = dma_iommu_unmap_sg,
97 .dma_supported = dma_iommu_dma_supported,
98 .map_page = dma_iommu_map_page,
99 .unmap_page = dma_iommu_unmap_page,
100 };
101 EXPORT_SYMBOL(dma_iommu_ops);
102