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gerrit-public.fairphone.software / kernel / msm-4.9 / ccfe27d7000668b02d10fc3e06aa49e3e3603162 / . / arch / microblaze / kernel / dma.c
blob: 300fea46737e0a9baa3b2ca88776dc62f9c9cff0 [file] [log] [blame]
Michal Simekccfe27d2010-01-14 11:21:02 +0100[diff] [blame^]1/*
2 * Copyright (C) 2009-2010 PetaLogix
3 * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
4 *
5 * Provide default implementations of the DMA mapping callbacks for
6 * directly mapped busses.
7 */
8
9#include <linux/device.h>
10#include <linux/dma-mapping.h>
11#include <linux/dma-debug.h>
12#include <asm/bug.h>
13
14/*
15 * Generic direct DMA implementation
16 *
17 * This implementation supports a per-device offset that can be applied if
18 * the address at which memory is visible to devices is not 0. Platform code
19 * can set archdata.dma_data to an unsigned long holding the offset. By
20 * default the offset is PCI_DRAM_OFFSET.
21 */
22
23static unsigned long get_dma_direct_offset(struct device *dev)
24{
25 if (dev)
26 return (unsigned long)dev->archdata.dma_data;
27
28 return PCI_DRAM_OFFSET; /* FIXME Not sure if is correct */
29}
30
31void *dma_direct_alloc_coherent(struct device *dev, size_t size,
32 dma_addr_t *dma_handle, gfp_t flag)
33{
34 void *ret;
35 struct page *page;
36 int node = dev_to_node(dev);
37
38 /* ignore region specifiers */
39 flag &= ~(__GFP_HIGHMEM);
40
41 page = alloc_pages_node(node, flag, get_order(size));
42 if (page == NULL)
43 return NULL;
44 ret = page_address(page);
45 memset(ret, 0, size);
46 *dma_handle = virt_to_phys(ret) + get_dma_direct_offset(dev);
47
48 return ret;
49}
50
51void dma_direct_free_coherent(struct device *dev, size_t size,
52 void *vaddr, dma_addr_t dma_handle)
53{
54 free_pages((unsigned long)vaddr, get_order(size));
55}
56
57static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
58 int nents, enum dma_data_direction direction,
59 struct dma_attrs *attrs)
60{
61 struct scatterlist *sg;
62 int i;
63
64 for_each_sg(sgl, sg, nents, i) {
65 sg->dma_address = sg_phys(sg) + get_dma_direct_offset(dev);
66 sg->dma_length = sg->length;
67 __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
68 }
69
70 return nents;
71}
72
73static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg,
74 int nents, enum dma_data_direction direction,
75 struct dma_attrs *attrs)
76{
77}
78
79static int dma_direct_dma_supported(struct device *dev, u64 mask)
80{
81 return 1;
82}
83
84static inline dma_addr_t dma_direct_map_page(struct device *dev,
85 struct page *page,
86 unsigned long offset,
87 size_t size,
88 enum dma_data_direction dir,
89 struct dma_attrs *attrs)
90{
91 BUG_ON(dir == DMA_NONE);
92 __dma_sync_page(page, offset, size, dir);
93 return page_to_phys(page) + offset + get_dma_direct_offset(dev);
94}
95
96static inline void dma_direct_unmap_page(struct device *dev,
97 dma_addr_t dma_address,
98 size_t size,
99 enum dma_data_direction direction,
100 struct dma_attrs *attrs)
101{
102}
103
104struct dma_map_ops dma_direct_ops = {
105 .alloc_coherent = dma_direct_alloc_coherent,
106 .free_coherent = dma_direct_free_coherent,
107 .map_sg = dma_direct_map_sg,
108 .unmap_sg = dma_direct_unmap_sg,
109 .dma_supported = dma_direct_dma_supported,
110 .map_page = dma_direct_map_page,
111 .unmap_page = dma_direct_unmap_page,
112};
113EXPORT_SYMBOL(dma_direct_ops);
114
115/* Number of entries preallocated for DMA-API debugging */
116#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
117
118static int __init dma_init(void)
119{
120 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
121
122 return 0;
123}
124fs_initcall(dma_init);