module: cleanup FIXME comments about trimming exception table entries.
[linux-2.6] / arch / m68k / kernel / dma.c
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
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
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
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
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
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
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
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);