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9#include <linux/types.h>
10#include <linux/mm.h>
11#include <linux/string.h>
12#include <linux/bootmem.h>
13#include <linux/spinlock.h>
14#include <linux/device.h>
15#include <linux/dma-mapping.h>
16#include <linux/io.h>
17#include <linux/scatterlist.h>
18#include <asm/cacheflush.h>
19#include <asm/bfin-global.h>
20
21static spinlock_t dma_page_lock;
22static unsigned int *dma_page;
23static unsigned int dma_pages;
24static unsigned long dma_base;
25static unsigned long dma_size;
26static unsigned int dma_initialized;
27
28void dma_alloc_init(unsigned long start, unsigned long end)
29{
30 spin_lock_init(&dma_page_lock);
31 dma_initialized = 0;
32
33 dma_page = (unsigned int *)__get_free_page(GFP_KERNEL);
34 memset(dma_page, 0, PAGE_SIZE);
35 dma_base = PAGE_ALIGN(start);
36 dma_size = PAGE_ALIGN(end) - PAGE_ALIGN(start);
37 dma_pages = dma_size >> PAGE_SHIFT;
38 memset((void *)dma_base, 0, DMA_UNCACHED_REGION);
39 dma_initialized = 1;
40
41 printk(KERN_INFO "%s: dma_page @ 0x%p - %d pages at 0x%08lx\n", __func__,
42 dma_page, dma_pages, dma_base);
43}
44
45static inline unsigned int get_pages(size_t size)
46{
47 return ((size - 1) >> PAGE_SHIFT) + 1;
48}
49
50static unsigned long __alloc_dma_pages(unsigned int pages)
51{
52 unsigned long ret = 0, flags;
53 int i, count = 0;
54
55 if (dma_initialized == 0)
56 dma_alloc_init(_ramend - DMA_UNCACHED_REGION, _ramend);
57
58 spin_lock_irqsave(&dma_page_lock, flags);
59
60 for (i = 0; i < dma_pages;) {
61 if (dma_page[i++] == 0) {
62 if (++count == pages) {
63 while (count--)
64 dma_page[--i] = 1;
65 ret = dma_base + (i << PAGE_SHIFT);
66 break;
67 }
68 } else
69 count = 0;
70 }
71 spin_unlock_irqrestore(&dma_page_lock, flags);
72 return ret;
73}
74
75static void __free_dma_pages(unsigned long addr, unsigned int pages)
76{
77 unsigned long page = (addr - dma_base) >> PAGE_SHIFT;
78 unsigned long flags;
79 int i;
80
81 if ((page + pages) > dma_pages) {
82 printk(KERN_ERR "%s: freeing outside range.\n", __func__);
83 BUG();
84 }
85
86 spin_lock_irqsave(&dma_page_lock, flags);
87 for (i = page; i < page + pages; i++) {
88 dma_page[i] = 0;
89 }
90 spin_unlock_irqrestore(&dma_page_lock, flags);
91}
92
93void *dma_alloc_coherent(struct device *dev, size_t size,
94 dma_addr_t * dma_handle, gfp_t gfp)
95{
96 void *ret;
97
98 ret = (void *)__alloc_dma_pages(get_pages(size));
99
100 if (ret) {
101 memset(ret, 0, size);
102 *dma_handle = virt_to_phys(ret);
103 }
104
105 return ret;
106}
107EXPORT_SYMBOL(dma_alloc_coherent);
108
109void
110dma_free_coherent(struct device *dev, size_t size, void *vaddr,
111 dma_addr_t dma_handle)
112{
113 __free_dma_pages((unsigned long)vaddr, get_pages(size));
114}
115EXPORT_SYMBOL(dma_free_coherent);
116
117
118
119
120
121dma_addr_t
122dma_map_single(struct device *dev, void *ptr, size_t size,
123 enum dma_data_direction direction)
124{
125 BUG_ON(direction == DMA_NONE);
126
127 invalidate_dcache_range((unsigned long)ptr,
128 (unsigned long)ptr + size);
129
130 return (dma_addr_t) ptr;
131}
132EXPORT_SYMBOL(dma_map_single);
133
134int
135dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
136 enum dma_data_direction direction)
137{
138 int i;
139
140 BUG_ON(direction == DMA_NONE);
141
142 for (i = 0; i < nents; i++, sg++) {
143 sg->dma_address = (dma_addr_t) sg_virt(sg);
144
145 invalidate_dcache_range(sg_dma_address(sg),
146 sg_dma_address(sg) +
147 sg_dma_len(sg));
148 }
149
150 return nents;
151}
152EXPORT_SYMBOL(dma_map_sg);
153
154void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
155 enum dma_data_direction direction)
156{
157 BUG_ON(direction == DMA_NONE);
158}
159EXPORT_SYMBOL(dma_unmap_single);
160
161void dma_unmap_sg(struct device *dev, struct scatterlist *sg,
162 int nhwentries, enum dma_data_direction direction)
163{
164 BUG_ON(direction == DMA_NONE);
165}
166EXPORT_SYMBOL(dma_unmap_sg);
167
