Add linux-next specific files for 20110831
[linux-2.6/next.git] / arch / powerpc / kernel / dma.c
blobb04e01f303a9e26610e58ece4ca625aa305e1846
1 /*
2 * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
4 * Provide default implementations of the DMA mapping callbacks for
5 * directly mapped busses.
6 */
8 #include <linux/device.h>
9 #include <linux/dma-mapping.h>
10 #include <linux/dma-debug.h>
11 #include <linux/gfp.h>
12 #include <linux/memblock.h>
13 #include <linux/export.h>
14 #include <asm/bug.h>
15 #include <asm/abs_addr.h>
16 #include <asm/machdep.h>
19 * Generic direct DMA implementation
21 * This implementation supports a per-device offset that can be applied if
22 * the address at which memory is visible to devices is not 0. Platform code
23 * can set archdata.dma_data to an unsigned long holding the offset. By
24 * default the offset is PCI_DRAM_OFFSET.
28 void *dma_direct_alloc_coherent(struct device *dev, size_t size,
29 dma_addr_t *dma_handle, gfp_t flag)
31 void *ret;
32 #ifdef CONFIG_NOT_COHERENT_CACHE
33 ret = __dma_alloc_coherent(dev, size, dma_handle, flag);
34 if (ret == NULL)
35 return NULL;
36 *dma_handle += get_dma_offset(dev);
37 return ret;
38 #else
39 struct page *page;
40 int node = dev_to_node(dev);
42 /* ignore region specifiers */
43 flag &= ~(__GFP_HIGHMEM);
45 page = alloc_pages_node(node, flag, get_order(size));
46 if (page == NULL)
47 return NULL;
48 ret = page_address(page);
49 memset(ret, 0, size);
50 *dma_handle = virt_to_abs(ret) + get_dma_offset(dev);
52 return ret;
53 #endif
56 void dma_direct_free_coherent(struct device *dev, size_t size,
57 void *vaddr, dma_addr_t dma_handle)
59 #ifdef CONFIG_NOT_COHERENT_CACHE
60 __dma_free_coherent(size, vaddr);
61 #else
62 free_pages((unsigned long)vaddr, get_order(size));
63 #endif
66 static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
67 int nents, enum dma_data_direction direction,
68 struct dma_attrs *attrs)
70 struct scatterlist *sg;
71 int i;
73 for_each_sg(sgl, sg, nents, i) {
74 sg->dma_address = sg_phys(sg) + get_dma_offset(dev);
75 sg->dma_length = sg->length;
76 __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
79 return nents;
82 static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg,
83 int nents, enum dma_data_direction direction,
84 struct dma_attrs *attrs)
88 static int dma_direct_dma_supported(struct device *dev, u64 mask)
90 #ifdef CONFIG_PPC64
91 /* Could be improved so platforms can set the limit in case
92 * they have limited DMA windows
94 return mask >= get_dma_offset(dev) + (memblock_end_of_DRAM() - 1);
95 #else
96 return 1;
97 #endif
100 static inline dma_addr_t dma_direct_map_page(struct device *dev,
101 struct page *page,
102 unsigned long offset,
103 size_t size,
104 enum dma_data_direction dir,
105 struct dma_attrs *attrs)
107 BUG_ON(dir == DMA_NONE);
108 __dma_sync_page(page, offset, size, dir);
109 return page_to_phys(page) + offset + get_dma_offset(dev);
112 static inline void dma_direct_unmap_page(struct device *dev,
113 dma_addr_t dma_address,
114 size_t size,
115 enum dma_data_direction direction,
116 struct dma_attrs *attrs)
120 #ifdef CONFIG_NOT_COHERENT_CACHE
121 static inline void dma_direct_sync_sg(struct device *dev,
122 struct scatterlist *sgl, int nents,
123 enum dma_data_direction direction)
125 struct scatterlist *sg;
126 int i;
128 for_each_sg(sgl, sg, nents, i)
129 __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
132 static inline void dma_direct_sync_single(struct device *dev,
133 dma_addr_t dma_handle, size_t size,
134 enum dma_data_direction direction)
136 __dma_sync(bus_to_virt(dma_handle), size, direction);
138 #endif
140 struct dma_map_ops dma_direct_ops = {
141 .alloc_coherent = dma_direct_alloc_coherent,
142 .free_coherent = dma_direct_free_coherent,
143 .map_sg = dma_direct_map_sg,
144 .unmap_sg = dma_direct_unmap_sg,
145 .dma_supported = dma_direct_dma_supported,
146 .map_page = dma_direct_map_page,
147 .unmap_page = dma_direct_unmap_page,
148 #ifdef CONFIG_NOT_COHERENT_CACHE
149 .sync_single_for_cpu = dma_direct_sync_single,
150 .sync_single_for_device = dma_direct_sync_single,
151 .sync_sg_for_cpu = dma_direct_sync_sg,
152 .sync_sg_for_device = dma_direct_sync_sg,
153 #endif
155 EXPORT_SYMBOL(dma_direct_ops);
157 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
159 int dma_set_mask(struct device *dev, u64 dma_mask)
161 struct dma_map_ops *dma_ops = get_dma_ops(dev);
163 if (ppc_md.dma_set_mask)
164 return ppc_md.dma_set_mask(dev, dma_mask);
165 if ((dma_ops != NULL) && (dma_ops->set_dma_mask != NULL))
166 return dma_ops->set_dma_mask(dev, dma_mask);
167 if (!dev->dma_mask || !dma_supported(dev, dma_mask))
168 return -EIO;
169 *dev->dma_mask = dma_mask;
170 return 0;
172 EXPORT_SYMBOL(dma_set_mask);
174 static int __init dma_init(void)
176 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
178 return 0;
180 fs_initcall(dma_init);
182 int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
183 void *cpu_addr, dma_addr_t handle, size_t size)
185 unsigned long pfn;
187 #ifdef CONFIG_NOT_COHERENT_CACHE
188 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
189 pfn = __dma_get_coherent_pfn((unsigned long)cpu_addr);
190 #else
191 pfn = page_to_pfn(virt_to_page(cpu_addr));
192 #endif
193 return remap_pfn_range(vma, vma->vm_start,
194 pfn + vma->vm_pgoff,
195 vma->vm_end - vma->vm_start,
196 vma->vm_page_prot);
198 EXPORT_SYMBOL_GPL(dma_mmap_coherent);