1 /* pci-dma-nommu.c: Dynamic DMA mapping support for the FRV
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Woodhouse (dwmw2@infradead.org)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/types.h>
13 #include <linux/slab.h>
14 #include <linux/export.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/list.h>
17 #include <linux/pci.h>
21 #define DMA_SRAM_START dma_coherent_mem_start
22 #define DMA_SRAM_END dma_coherent_mem_end
23 #else // Use video RAM on Matrox
24 #define DMA_SRAM_START 0xe8900000
25 #define DMA_SRAM_END 0xe8a00000
28 struct dma_alloc_record {
29 struct list_head list;
34 static DEFINE_SPINLOCK(dma_alloc_lock);
35 static LIST_HEAD(dma_alloc_list);
37 void *dma_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t gfp)
39 struct dma_alloc_record *new;
40 struct list_head *this = &dma_alloc_list;
42 unsigned long start = DMA_SRAM_START;
45 if (!DMA_SRAM_START) {
46 printk("%s called without any DMA area reserved!\n", __func__);
50 new = kmalloc(sizeof (*new), GFP_ATOMIC);
54 /* Round up to a reasonable alignment */
55 new->len = (size + 31) & ~31;
57 spin_lock_irqsave(&dma_alloc_lock, flags);
59 list_for_each (this, &dma_alloc_list) {
60 struct dma_alloc_record *this_r = list_entry(this, struct dma_alloc_record, list);
63 if (end - start >= size)
66 start = this_r->ofs + this_r->len;
68 /* Reached end of list. */
70 this = &dma_alloc_list;
72 if (end - start >= size) {
75 list_add_tail(&new->list, this);
76 spin_unlock_irqrestore(&dma_alloc_lock, flags);
83 spin_unlock_irqrestore(&dma_alloc_lock, flags);
87 EXPORT_SYMBOL(dma_alloc_coherent);
89 void dma_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle)
91 struct dma_alloc_record *rec;
94 spin_lock_irqsave(&dma_alloc_lock, flags);
96 list_for_each_entry(rec, &dma_alloc_list, list) {
97 if (rec->ofs == dma_handle) {
100 spin_unlock_irqrestore(&dma_alloc_lock, flags);
104 spin_unlock_irqrestore(&dma_alloc_lock, flags);
108 EXPORT_SYMBOL(dma_free_coherent);
110 dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
111 enum dma_data_direction direction)
113 BUG_ON(direction == DMA_NONE);
115 frv_cache_wback_inv((unsigned long) ptr, (unsigned long) ptr + size);
117 return virt_to_bus(ptr);
120 EXPORT_SYMBOL(dma_map_single);
122 int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
123 enum dma_data_direction direction)
127 for (i=0; i<nents; i++)
128 frv_cache_wback_inv(sg_dma_address(&sg[i]),
129 sg_dma_address(&sg[i]) + sg_dma_len(&sg[i]));
131 BUG_ON(direction == DMA_NONE);
136 EXPORT_SYMBOL(dma_map_sg);
138 dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
139 size_t size, enum dma_data_direction direction)
141 BUG_ON(direction == DMA_NONE);
142 flush_dcache_page(page);
143 return (dma_addr_t) page_to_phys(page) + offset;
146 EXPORT_SYMBOL(dma_map_page);