summaryrefslogtreecommitdiffstats
path: root/arch/c6x/kernel/dma.c
blob: 9fff8be75f585a8bf961aa5173b0957bf0ab7d31 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
/*
 *  Copyright (C) 2011 Texas Instruments Incorporated
 *  Author: Mark Salter <msalter@redhat.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <linux/mm.h>
#include <linux/mm_types.h>
#include <linux/scatterlist.h>

#include <asm/cacheflush.h>

static void c6x_dma_sync(dma_addr_t handle, size_t size,
			 enum dma_data_direction dir)
{
	unsigned long paddr = handle;

	BUG_ON(!valid_dma_direction(dir));

	switch (dir) {
	case DMA_FROM_DEVICE:
		L2_cache_block_invalidate(paddr, paddr + size);
		break;
	case DMA_TO_DEVICE:
		L2_cache_block_writeback(paddr, paddr + size);
		break;
	case DMA_BIDIRECTIONAL:
		L2_cache_block_writeback_invalidate(paddr, paddr + size);
		break;
	default:
		break;
	}
}

static dma_addr_t c6x_dma_map_page(struct device *dev, struct page *page,
		unsigned long offset, size_t size, enum dma_data_direction dir,
		unsigned long attrs)
{
	dma_addr_t handle = virt_to_phys(page_address(page) + offset);

	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
		c6x_dma_sync(handle, size, dir);

	return handle;
}

static void c6x_dma_unmap_page(struct device *dev, dma_addr_t handle,
		size_t size, enum dma_data_direction dir, unsigned long attrs)
{
	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
		c6x_dma_sync(handle, size, dir);
}

static int c6x_dma_map_sg(struct device *dev, struct scatterlist *sglist,
		int nents, enum dma_data_direction dir, unsigned long attrs)
{
	struct scatterlist *sg;
	int i;

	for_each_sg(sglist, sg, nents, i) {
		sg->dma_address = sg_phys(sg);
		if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
			c6x_dma_sync(sg->dma_address, sg->length, dir);
	}

	return nents;
}

static void c6x_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
		  int nents, enum dma_data_direction dir, unsigned long attrs)
{
	struct scatterlist *sg;
	int i;

	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
		return;

	for_each_sg(sglist, sg, nents, i)
		c6x_dma_sync(sg_dma_address(sg), sg->length, dir);
}

static void c6x_dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle,
		size_t size, enum dma_data_direction dir)
{
	c6x_dma_sync(handle, size, dir);

}

static void c6x_dma_sync_single_for_device(struct device *dev,
		dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
	c6x_dma_sync(handle, size, dir);

}

static void c6x_dma_sync_sg_for_cpu(struct device *dev,
		struct scatterlist *sglist, int nents,
		enum dma_data_direction dir)
{
	struct scatterlist *sg;
	int i;

	for_each_sg(sglist, sg, nents, i)
		c6x_dma_sync_single_for_cpu(dev, sg_dma_address(sg),
					sg->length, dir);

}

static void c6x_dma_sync_sg_for_device(struct device *dev,
		struct scatterlist *sglist, int nents,
		enum dma_data_direction dir)
{
	struct scatterlist *sg;
	int i;

	for_each_sg(sglist, sg, nents, i)
		c6x_dma_sync_single_for_device(dev, sg_dma_address(sg),
					   sg->length, dir);

}

const struct dma_map_ops c6x_dma_ops = {
	.alloc			= c6x_dma_alloc,
	.free			= c6x_dma_free,
	.map_page		= c6x_dma_map_page,
	.unmap_page		= c6x_dma_unmap_page,
	.map_sg			= c6x_dma_map_sg,
	.unmap_sg		= c6x_dma_unmap_sg,
	.sync_single_for_device	= c6x_dma_sync_single_for_device,
	.sync_single_for_cpu	= c6x_dma_sync_single_for_cpu,
	.sync_sg_for_device	= c6x_dma_sync_sg_for_device,
	.sync_sg_for_cpu	= c6x_dma_sync_sg_for_cpu,
};
EXPORT_SYMBOL(c6x_dma_ops);

/* Number of entries preallocated for DMA-API debugging */
#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)

static int __init dma_init(void)
{
	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);

	return 0;
}
fs_initcall(dma_init);