2 * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
4 * Provide default implementations of the DMA mapping callbacks for
5 * directly mapped busses.
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>
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
,
30 struct dma_attrs
*attrs
)
33 #ifdef CONFIG_NOT_COHERENT_CACHE
34 ret
= __dma_alloc_coherent(dev
, size
, dma_handle
, flag
);
37 *dma_handle
+= get_dma_offset(dev
);
41 int node
= dev_to_node(dev
);
43 /* ignore region specifiers */
44 flag
&= ~(__GFP_HIGHMEM
);
46 page
= alloc_pages_node(node
, flag
, get_order(size
));
49 ret
= page_address(page
);
51 *dma_handle
= virt_to_abs(ret
) + get_dma_offset(dev
);
57 void dma_direct_free_coherent(struct device
*dev
, size_t size
,
58 void *vaddr
, dma_addr_t dma_handle
,
59 struct dma_attrs
*attrs
)
61 #ifdef CONFIG_NOT_COHERENT_CACHE
62 __dma_free_coherent(size
, vaddr
);
64 free_pages((unsigned long)vaddr
, get_order(size
));
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
)
72 struct scatterlist
*sg
;
75 for_each_sg(sgl
, sg
, nents
, i
) {
76 sg
->dma_address
= sg_phys(sg
) + get_dma_offset(dev
);
77 sg
->dma_length
= sg
->length
;
78 __dma_sync_page(sg_page(sg
), sg
->offset
, sg
->length
, direction
);
84 static void dma_direct_unmap_sg(struct device
*dev
, struct scatterlist
*sg
,
85 int nents
, enum dma_data_direction direction
,
86 struct dma_attrs
*attrs
)
90 static int dma_direct_dma_supported(struct device
*dev
, u64 mask
)
93 /* Could be improved so platforms can set the limit in case
94 * they have limited DMA windows
96 return mask
>= get_dma_offset(dev
) + (memblock_end_of_DRAM() - 1);
102 static u64
dma_direct_get_required_mask(struct device
*dev
)
106 end
= memblock_end_of_DRAM() + get_dma_offset(dev
);
108 mask
= 1ULL << (fls64(end
) - 1);
114 static inline dma_addr_t
dma_direct_map_page(struct device
*dev
,
116 unsigned long offset
,
118 enum dma_data_direction dir
,
119 struct dma_attrs
*attrs
)
121 BUG_ON(dir
== DMA_NONE
);
122 __dma_sync_page(page
, offset
, size
, dir
);
123 return page_to_phys(page
) + offset
+ get_dma_offset(dev
);
126 static inline void dma_direct_unmap_page(struct device
*dev
,
127 dma_addr_t dma_address
,
129 enum dma_data_direction direction
,
130 struct dma_attrs
*attrs
)
134 #ifdef CONFIG_NOT_COHERENT_CACHE
135 static inline void dma_direct_sync_sg(struct device
*dev
,
136 struct scatterlist
*sgl
, int nents
,
137 enum dma_data_direction direction
)
139 struct scatterlist
*sg
;
142 for_each_sg(sgl
, sg
, nents
, i
)
143 __dma_sync_page(sg_page(sg
), sg
->offset
, sg
->length
, direction
);
146 static inline void dma_direct_sync_single(struct device
*dev
,
147 dma_addr_t dma_handle
, size_t size
,
148 enum dma_data_direction direction
)
150 __dma_sync(bus_to_virt(dma_handle
), size
, direction
);
154 struct dma_map_ops dma_direct_ops
= {
155 .alloc
= dma_direct_alloc_coherent
,
156 .free
= dma_direct_free_coherent
,
157 .map_sg
= dma_direct_map_sg
,
158 .unmap_sg
= dma_direct_unmap_sg
,
159 .dma_supported
= dma_direct_dma_supported
,
160 .map_page
= dma_direct_map_page
,
161 .unmap_page
= dma_direct_unmap_page
,
162 .get_required_mask
= dma_direct_get_required_mask
,
163 #ifdef CONFIG_NOT_COHERENT_CACHE
164 .sync_single_for_cpu
= dma_direct_sync_single
,
165 .sync_single_for_device
= dma_direct_sync_single
,
166 .sync_sg_for_cpu
= dma_direct_sync_sg
,
167 .sync_sg_for_device
= dma_direct_sync_sg
,
170 EXPORT_SYMBOL(dma_direct_ops
);
172 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
174 int dma_set_mask(struct device
*dev
, u64 dma_mask
)
176 struct dma_map_ops
*dma_ops
= get_dma_ops(dev
);
178 if (ppc_md
.dma_set_mask
)
179 return ppc_md
.dma_set_mask(dev
, dma_mask
);
180 if ((dma_ops
!= NULL
) && (dma_ops
->set_dma_mask
!= NULL
))
181 return dma_ops
->set_dma_mask(dev
, dma_mask
);
182 if (!dev
->dma_mask
|| !dma_supported(dev
, dma_mask
))
184 *dev
->dma_mask
= dma_mask
;
187 EXPORT_SYMBOL(dma_set_mask
);
189 u64
dma_get_required_mask(struct device
*dev
)
191 struct dma_map_ops
*dma_ops
= get_dma_ops(dev
);
193 if (ppc_md
.dma_get_required_mask
)
194 return ppc_md
.dma_get_required_mask(dev
);
196 if (unlikely(dma_ops
== NULL
))
199 if (dma_ops
->get_required_mask
)
200 return dma_ops
->get_required_mask(dev
);
202 return DMA_BIT_MASK(8 * sizeof(dma_addr_t
));
204 EXPORT_SYMBOL_GPL(dma_get_required_mask
);
206 static int __init
dma_init(void)
208 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES
);
212 fs_initcall(dma_init
);
214 int dma_mmap_coherent(struct device
*dev
, struct vm_area_struct
*vma
,
215 void *cpu_addr
, dma_addr_t handle
, size_t size
)
219 #ifdef CONFIG_NOT_COHERENT_CACHE
220 vma
->vm_page_prot
= pgprot_noncached(vma
->vm_page_prot
);
221 pfn
= __dma_get_coherent_pfn((unsigned long)cpu_addr
);
223 pfn
= page_to_pfn(virt_to_page(cpu_addr
));
225 return remap_pfn_range(vma
, vma
->vm_start
,
227 vma
->vm_end
- vma
->vm_start
,
230 EXPORT_SYMBOL_GPL(dma_mmap_coherent
);