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1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file COPYING in the main directory of this archive
4  * for more details.
5  */
6 
7 #undef DEBUG
8 
9 #include <linux/dma-mapping.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/scatterlist.h>
13 #include <linux/vmalloc.h>
14 
15 #include <asm/pgalloc.h>
16 
dma_alloc_coherent(struct device * dev,size_t size,dma_addr_t * handle,gfp_t flag)17 void *dma_alloc_coherent(struct device *dev, size_t size,
18 			 dma_addr_t *handle, gfp_t flag)
19 {
20 	struct page *page, **map;
21 	pgprot_t pgprot;
22 	void *addr;
23 	int i, order;
24 
25 	pr_debug("dma_alloc_coherent: %d,%x\n", size, flag);
26 
27 	size = PAGE_ALIGN(size);
28 	order = get_order(size);
29 
30 	page = alloc_pages(flag, order);
31 	if (!page)
32 		return NULL;
33 
34 	*handle = page_to_phys(page);
35 	map = kmalloc(sizeof(struct page *) << order, flag & ~__GFP_DMA);
36 	if (!map) {
37 		__free_pages(page, order);
38 		return NULL;
39 	}
40 	split_page(page, order);
41 
42 	order = 1 << order;
43 	size >>= PAGE_SHIFT;
44 	map[0] = page;
45 	for (i = 1; i < size; i++)
46 		map[i] = page + i;
47 	for (; i < order; i++)
48 		__free_page(page + i);
49 	pgprot = __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
50 	if (CPU_IS_040_OR_060)
51 		pgprot_val(pgprot) |= _PAGE_GLOBAL040 | _PAGE_NOCACHE_S;
52 	else
53 		pgprot_val(pgprot) |= _PAGE_NOCACHE030;
54 	addr = vmap(map, size, VM_MAP, pgprot);
55 	kfree(map);
56 
57 	return addr;
58 }
59 EXPORT_SYMBOL(dma_alloc_coherent);
60 
dma_free_coherent(struct device * dev,size_t size,void * addr,dma_addr_t handle)61 void dma_free_coherent(struct device *dev, size_t size,
62 		       void *addr, dma_addr_t handle)
63 {
64 	pr_debug("dma_free_coherent: %p, %x\n", addr, handle);
65 	vfree(addr);
66 }
67 EXPORT_SYMBOL(dma_free_coherent);
68 
dma_sync_single_for_device(struct device * dev,dma_addr_t handle,size_t size,enum dma_data_direction dir)69 void dma_sync_single_for_device(struct device *dev, dma_addr_t handle,
70 				size_t size, enum dma_data_direction dir)
71 {
72 	switch (dir) {
73 	case DMA_TO_DEVICE:
74 		cache_push(handle, size);
75 		break;
76 	case DMA_FROM_DEVICE:
77 		cache_clear(handle, size);
78 		break;
79 	default:
80 		if (printk_ratelimit())
81 			printk("dma_sync_single_for_device: unsupported dir %u\n", dir);
82 		break;
83 	}
84 }
85 EXPORT_SYMBOL(dma_sync_single_for_device);
86 
dma_sync_sg_for_device(struct device * dev,struct scatterlist * sg,int nents,enum dma_data_direction dir)87 void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
88 			    enum dma_data_direction dir)
89 {
90 	int i;
91 
92 	for (i = 0; i < nents; sg++, i++)
93 		dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir);
94 }
95 EXPORT_SYMBOL(dma_sync_sg_for_device);
96 
dma_map_single(struct device * dev,void * addr,size_t size,enum dma_data_direction dir)97 dma_addr_t dma_map_single(struct device *dev, void *addr, size_t size,
98 			  enum dma_data_direction dir)
99 {
100 	dma_addr_t handle = virt_to_bus(addr);
101 
102 	dma_sync_single_for_device(dev, handle, size, dir);
103 	return handle;
104 }
105 EXPORT_SYMBOL(dma_map_single);
106 
dma_map_page(struct device * dev,struct page * page,unsigned long offset,size_t size,enum dma_data_direction dir)107 dma_addr_t dma_map_page(struct device *dev, struct page *page,
108 			unsigned long offset, size_t size,
109 			enum dma_data_direction dir)
110 {
111 	dma_addr_t handle = page_to_phys(page) + offset;
112 
113 	dma_sync_single_for_device(dev, handle, size, dir);
114 	return handle;
115 }
116 EXPORT_SYMBOL(dma_map_page);
117 
dma_map_sg(struct device * dev,struct scatterlist * sg,int nents,enum dma_data_direction dir)118 int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
119 	       enum dma_data_direction dir)
120 {
121 	int i;
122 
123 	for (i = 0; i < nents; sg++, i++) {
124 		sg->dma_address = sg_phys(sg);
125 		dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir);
126 	}
127 	return nents;
128 }
129 EXPORT_SYMBOL(dma_map_sg);
130