compat: generic compat get/settimeofday
[linux-2.6] / arch / powerpc / kernel / dma.c
1 /*
2  * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
3  *
4  * Provide default implementations of the DMA mapping callbacks for
5  * directly mapped busses.
6  */
7
8 #include <linux/device.h>
9 #include <linux/dma-mapping.h>
10 #include <asm/bug.h>
11 #include <asm/abs_addr.h>
12
13 /*
14  * Generic direct DMA implementation
15  *
16  * This implementation supports a per-device offset that can be applied if
17  * the address at which memory is visible to devices is not 0. Platform code
18  * can set archdata.dma_data to an unsigned long holding the offset. By
19  * default the offset is PCI_DRAM_OFFSET.
20  */
21
22 static unsigned long get_dma_direct_offset(struct device *dev)
23 {
24         if (dev)
25                 return (unsigned long)dev->archdata.dma_data;
26
27         return PCI_DRAM_OFFSET;
28 }
29
30 void *dma_direct_alloc_coherent(struct device *dev, size_t size,
31                                 dma_addr_t *dma_handle, gfp_t flag)
32 {
33         void *ret;
34 #ifdef CONFIG_NOT_COHERENT_CACHE
35         ret = __dma_alloc_coherent(size, dma_handle, flag);
36         if (ret == NULL)
37                 return NULL;
38         *dma_handle += get_dma_direct_offset(dev);
39         return ret;
40 #else
41         struct page *page;
42         int node = dev_to_node(dev);
43
44         /* ignore region specifiers */
45         flag  &= ~(__GFP_HIGHMEM);
46
47         page = alloc_pages_node(node, flag, get_order(size));
48         if (page == NULL)
49                 return NULL;
50         ret = page_address(page);
51         memset(ret, 0, size);
52         *dma_handle = virt_to_abs(ret) + get_dma_direct_offset(dev);
53
54         return ret;
55 #endif
56 }
57
58 void dma_direct_free_coherent(struct device *dev, size_t size,
59                               void *vaddr, dma_addr_t dma_handle)
60 {
61 #ifdef CONFIG_NOT_COHERENT_CACHE
62         __dma_free_coherent(size, vaddr);
63 #else
64         free_pages((unsigned long)vaddr, get_order(size));
65 #endif
66 }
67
68 static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
69                              int nents, enum dma_data_direction direction,
70                              struct dma_attrs *attrs)
71 {
72         struct scatterlist *sg;
73         int i;
74
75         for_each_sg(sgl, sg, nents, i) {
76                 sg->dma_address = sg_phys(sg) + get_dma_direct_offset(dev);
77                 sg->dma_length = sg->length;
78         }
79
80         return nents;
81 }
82
83 static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg,
84                                 int nents, enum dma_data_direction direction,
85                                 struct dma_attrs *attrs)
86 {
87 }
88
89 static int dma_direct_dma_supported(struct device *dev, u64 mask)
90 {
91 #ifdef CONFIG_PPC64
92         /* Could be improved to check for memory though it better be
93          * done via some global so platforms can set the limit in case
94          * they have limited DMA windows
95          */
96         return mask >= DMA_32BIT_MASK;
97 #else
98         return 1;
99 #endif
100 }
101
102 static inline dma_addr_t dma_direct_map_page(struct device *dev,
103                                              struct page *page,
104                                              unsigned long offset,
105                                              size_t size,
106                                              enum dma_data_direction dir,
107                                              struct dma_attrs *attrs)
108 {
109         BUG_ON(dir == DMA_NONE);
110         __dma_sync_page(page, offset, size, dir);
111         return page_to_phys(page) + offset + get_dma_direct_offset(dev);
112 }
113
114 static inline void dma_direct_unmap_page(struct device *dev,
115                                          dma_addr_t dma_address,
116                                          size_t size,
117                                          enum dma_data_direction direction,
118                                          struct dma_attrs *attrs)
119 {
120 }
121
122 struct dma_mapping_ops dma_direct_ops = {
123         .alloc_coherent = dma_direct_alloc_coherent,
124         .free_coherent  = dma_direct_free_coherent,
125         .map_sg         = dma_direct_map_sg,
126         .unmap_sg       = dma_direct_unmap_sg,
127         .dma_supported  = dma_direct_dma_supported,
128         .map_page       = dma_direct_map_page,
129         .unmap_page     = dma_direct_unmap_page,
130 };
131 EXPORT_SYMBOL(dma_direct_ops);