Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 1 | /* |
| 2 | * File: arch/blackfin/kernel/dma-mapping.c |
| 3 | * Based on: |
| 4 | * Author: |
| 5 | * |
| 6 | * Created: |
| 7 | * Description: Dynamic DMA mapping support. |
| 8 | * |
| 9 | * Modified: |
| 10 | * Copyright 2004-2006 Analog Devices Inc. |
| 11 | * |
| 12 | * Bugs: Enter bugs at http://blackfin.uclinux.org/ |
| 13 | * |
| 14 | * This program is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License as published by |
| 16 | * the Free Software Foundation; either version 2 of the License, or |
| 17 | * (at your option) any later version. |
| 18 | * |
| 19 | * This program is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public License |
| 25 | * along with this program; if not, see the file COPYING, or write |
| 26 | * to the Free Software Foundation, Inc., |
| 27 | * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 28 | */ |
| 29 | |
| 30 | #include <linux/types.h> |
| 31 | #include <linux/mm.h> |
| 32 | #include <linux/string.h> |
| 33 | #include <linux/bootmem.h> |
| 34 | #include <linux/spinlock.h> |
| 35 | #include <linux/device.h> |
| 36 | #include <linux/dma-mapping.h> |
Mike Frysinger | 1f83b8f | 2007-07-12 22:58:21 +0800 | [diff] [blame] | 37 | #include <linux/io.h> |
Adrian Bunk | 8286192 | 2007-10-24 14:09:25 +0200 | [diff] [blame] | 38 | #include <linux/scatterlist.h> |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 39 | #include <asm/cacheflush.h> |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 40 | #include <asm/bfin-global.h> |
| 41 | |
| 42 | static spinlock_t dma_page_lock; |
| 43 | static unsigned int *dma_page; |
| 44 | static unsigned int dma_pages; |
| 45 | static unsigned long dma_base; |
| 46 | static unsigned long dma_size; |
| 47 | static unsigned int dma_initialized; |
| 48 | |
| 49 | void dma_alloc_init(unsigned long start, unsigned long end) |
| 50 | { |
| 51 | spin_lock_init(&dma_page_lock); |
| 52 | dma_initialized = 0; |
| 53 | |
| 54 | dma_page = (unsigned int *)__get_free_page(GFP_KERNEL); |
| 55 | memset(dma_page, 0, PAGE_SIZE); |
| 56 | dma_base = PAGE_ALIGN(start); |
| 57 | dma_size = PAGE_ALIGN(end) - PAGE_ALIGN(start); |
| 58 | dma_pages = dma_size >> PAGE_SHIFT; |
| 59 | memset((void *)dma_base, 0, DMA_UNCACHED_REGION); |
| 60 | dma_initialized = 1; |
| 61 | |
Harvey Harrison | b85d858 | 2008-04-23 09:39:01 +0800 | [diff] [blame] | 62 | printk(KERN_INFO "%s: dma_page @ 0x%p - %d pages at 0x%08lx\n", __func__, |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 63 | dma_page, dma_pages, dma_base); |
| 64 | } |
| 65 | |
| 66 | static inline unsigned int get_pages(size_t size) |
| 67 | { |
| 68 | return ((size - 1) >> PAGE_SHIFT) + 1; |
| 69 | } |
| 70 | |
| 71 | static unsigned long __alloc_dma_pages(unsigned int pages) |
| 72 | { |
| 73 | unsigned long ret = 0, flags; |
| 74 | int i, count = 0; |
| 75 | |
| 76 | if (dma_initialized == 0) |
| 77 | dma_alloc_init(_ramend - DMA_UNCACHED_REGION, _ramend); |
| 78 | |
| 79 | spin_lock_irqsave(&dma_page_lock, flags); |
| 80 | |
| 81 | for (i = 0; i < dma_pages;) { |
| 82 | if (dma_page[i++] == 0) { |
| 83 | if (++count == pages) { |
| 84 | while (count--) |
| 85 | dma_page[--i] = 1; |
| 86 | ret = dma_base + (i << PAGE_SHIFT); |
| 87 | break; |
| 88 | } |
| 89 | } else |
| 90 | count = 0; |
| 91 | } |
| 92 | spin_unlock_irqrestore(&dma_page_lock, flags); |
| 93 | return ret; |
| 94 | } |
| 95 | |
| 96 | static void __free_dma_pages(unsigned long addr, unsigned int pages) |
| 97 | { |
| 98 | unsigned long page = (addr - dma_base) >> PAGE_SHIFT; |
| 99 | unsigned long flags; |
| 100 | int i; |
| 101 | |
| 102 | if ((page + pages) > dma_pages) { |
Harvey Harrison | b85d858 | 2008-04-23 09:39:01 +0800 | [diff] [blame] | 103 | printk(KERN_ERR "%s: freeing outside range.\n", __func__); |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 104 | BUG(); |
| 105 | } |
| 106 | |
| 107 | spin_lock_irqsave(&dma_page_lock, flags); |
| 108 | for (i = page; i < page + pages; i++) { |
| 109 | dma_page[i] = 0; |
| 110 | } |
| 111 | spin_unlock_irqrestore(&dma_page_lock, flags); |
| 112 | } |
| 113 | |
| 114 | void *dma_alloc_coherent(struct device *dev, size_t size, |
| 115 | dma_addr_t * dma_handle, gfp_t gfp) |
| 116 | { |
| 117 | void *ret; |
| 118 | |
| 119 | ret = (void *)__alloc_dma_pages(get_pages(size)); |
| 120 | |
| 121 | if (ret) { |
| 122 | memset(ret, 0, size); |
| 123 | *dma_handle = virt_to_phys(ret); |
| 124 | } |
| 125 | |
| 126 | return ret; |
| 127 | } |
| 128 | EXPORT_SYMBOL(dma_alloc_coherent); |
| 129 | |
| 130 | void |
| 131 | dma_free_coherent(struct device *dev, size_t size, void *vaddr, |
| 132 | dma_addr_t dma_handle) |
| 133 | { |
| 134 | __free_dma_pages((unsigned long)vaddr, get_pages(size)); |
| 135 | } |
| 136 | EXPORT_SYMBOL(dma_free_coherent); |
| 137 | |
| 138 | /* |
| 139 | * Dummy functions defined for some existing drivers |
| 140 | */ |
| 141 | |
| 142 | dma_addr_t |
| 143 | dma_map_single(struct device *dev, void *ptr, size_t size, |
| 144 | enum dma_data_direction direction) |
| 145 | { |
| 146 | BUG_ON(direction == DMA_NONE); |
| 147 | |
| 148 | invalidate_dcache_range((unsigned long)ptr, |
| 149 | (unsigned long)ptr + size); |
| 150 | |
| 151 | return (dma_addr_t) ptr; |
| 152 | } |
| 153 | EXPORT_SYMBOL(dma_map_single); |
| 154 | |
| 155 | int |
| 156 | dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, |
| 157 | enum dma_data_direction direction) |
| 158 | { |
| 159 | int i; |
| 160 | |
| 161 | BUG_ON(direction == DMA_NONE); |
| 162 | |
Sonic Zhang | b07af76 | 2007-07-12 12:18:08 +0800 | [diff] [blame] | 163 | for (i = 0; i < nents; i++, sg++) { |
Jens Axboe | 58b053e | 2007-10-22 20:02:46 +0200 | [diff] [blame] | 164 | sg->dma_address = (dma_addr_t) sg_virt(sg); |
Sonic Zhang | b07af76 | 2007-07-12 12:18:08 +0800 | [diff] [blame] | 165 | |
| 166 | invalidate_dcache_range(sg_dma_address(sg), |
| 167 | sg_dma_address(sg) + |
| 168 | sg_dma_len(sg)); |
| 169 | } |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 170 | |
| 171 | return nents; |
| 172 | } |
| 173 | EXPORT_SYMBOL(dma_map_sg); |
| 174 | |
| 175 | void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size, |
| 176 | enum dma_data_direction direction) |
| 177 | { |
| 178 | BUG_ON(direction == DMA_NONE); |
| 179 | } |
| 180 | EXPORT_SYMBOL(dma_unmap_single); |
| 181 | |
| 182 | void dma_unmap_sg(struct device *dev, struct scatterlist *sg, |
| 183 | int nhwentries, enum dma_data_direction direction) |
| 184 | { |
| 185 | BUG_ON(direction == DMA_NONE); |
| 186 | } |
| 187 | EXPORT_SYMBOL(dma_unmap_sg); |