summaryrefslogtreecommitdiffstats
path: root/drivers/crypto/omap-crypto.c
blob: 2c42e4b4a6e9d15f3c84c985096dd772b6884db7 (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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
/*
 * OMAP Crypto driver common support routines.
 *
 * Copyright (c) 2017 Texas Instruments Incorporated
 *   Tero Kristo <t-kristo@ti.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/kernel.h>
#include <linux/scatterlist.h>
#include <crypto/scatterwalk.h>

#include "omap-crypto.h"

static int omap_crypto_copy_sg_lists(int total, int bs,
				     struct scatterlist **sg,
				     struct scatterlist *new_sg, u16 flags)
{
	int n = sg_nents(*sg);
	struct scatterlist *tmp;

	if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY)) {
		new_sg = kmalloc_array(n, sizeof(*sg), GFP_KERNEL);
		if (!new_sg)
			return -ENOMEM;

		sg_init_table(new_sg, n);
	}

	tmp = new_sg;

	while (*sg && total) {
		int len = (*sg)->length;

		if (total < len)
			len = total;

		if (len > 0) {
			total -= len;
			sg_set_page(tmp, sg_page(*sg), len, (*sg)->offset);
			if (total <= 0)
				sg_mark_end(tmp);
			tmp = sg_next(tmp);
		}

		*sg = sg_next(*sg);
	}

	*sg = new_sg;

	return 0;
}

static int omap_crypto_copy_sgs(int total, int bs, struct scatterlist **sg,
				struct scatterlist *new_sg, u16 flags)
{
	void *buf;
	int pages;
	int new_len;

	new_len = ALIGN(total, bs);
	pages = get_order(new_len);

	buf = (void *)__get_free_pages(GFP_ATOMIC, pages);
	if (!buf) {
		pr_err("%s: Couldn't allocate pages for unaligned cases.\n",
		       __func__);
		return -ENOMEM;
	}

	if (flags & OMAP_CRYPTO_COPY_DATA) {
		scatterwalk_map_and_copy(buf, *sg, 0, total, 0);
		if (flags & OMAP_CRYPTO_ZERO_BUF)
			memset(buf + total, 0, new_len - total);
	}

	if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY))
		sg_init_table(new_sg, 1);

	sg_set_buf(new_sg, buf, new_len);

	*sg = new_sg;

	return 0;
}

static int omap_crypto_check_sg(struct scatterlist *sg, int total, int bs,
				u16 flags)
{
	int len = 0;
	int num_sg = 0;

	if (!IS_ALIGNED(total, bs))
		return OMAP_CRYPTO_NOT_ALIGNED;

	while (sg) {
		num_sg++;

		if (!IS_ALIGNED(sg->offset, 4))
			return OMAP_CRYPTO_NOT_ALIGNED;
		if (!IS_ALIGNED(sg->length, bs))
			return OMAP_CRYPTO_NOT_ALIGNED;
#ifdef CONFIG_ZONE_DMA
		if (page_zonenum(sg_page(sg)) != ZONE_DMA)
			return OMAP_CRYPTO_NOT_ALIGNED;
#endif

		len += sg->length;
		sg = sg_next(sg);

		if (len >= total)
			break;
	}

	if ((flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) && num_sg > 1)
		return OMAP_CRYPTO_NOT_ALIGNED;

	if (len != total)
		return OMAP_CRYPTO_BAD_DATA_LENGTH;

	return 0;
}

int omap_crypto_align_sg(struct scatterlist **sg, int total, int bs,
			 struct scatterlist *new_sg, u16 flags,
			 u8 flags_shift, unsigned long *dd_flags)
{
	int ret;

	*dd_flags &= ~(OMAP_CRYPTO_COPY_MASK << flags_shift);

	if (flags & OMAP_CRYPTO_FORCE_COPY)
		ret = OMAP_CRYPTO_NOT_ALIGNED;
	else
		ret = omap_crypto_check_sg(*sg, total, bs, flags);

	if (ret == OMAP_CRYPTO_NOT_ALIGNED) {
		ret = omap_crypto_copy_sgs(total, bs, sg, new_sg, flags);
		if (ret)
			return ret;
		*dd_flags |= OMAP_CRYPTO_DATA_COPIED << flags_shift;
	} else if (ret == OMAP_CRYPTO_BAD_DATA_LENGTH) {
		ret = omap_crypto_copy_sg_lists(total, bs, sg, new_sg, flags);
		if (ret)
			return ret;
		if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY))
			*dd_flags |= OMAP_CRYPTO_SG_COPIED << flags_shift;
	} else if (flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) {
		sg_set_buf(new_sg, sg_virt(*sg), (*sg)->length);
	}

	return 0;
}
EXPORT_SYMBOL_GPL(omap_crypto_align_sg);

void omap_crypto_cleanup(struct scatterlist *sg, struct scatterlist *orig,
			 int offset, int len, u8 flags_shift,
			 unsigned long flags)
{
	void *buf;
	int pages;

	flags >>= flags_shift;
	flags &= OMAP_CRYPTO_COPY_MASK;

	if (!flags)
		return;

	buf = sg_virt(sg);
	pages = get_order(len);

	if (orig && (flags & OMAP_CRYPTO_COPY_MASK))
		scatterwalk_map_and_copy(buf, orig, offset, len, 1);

	if (flags & OMAP_CRYPTO_DATA_COPIED)
		free_pages((unsigned long)buf, pages);
	else if (flags & OMAP_CRYPTO_SG_COPIED)
		kfree(sg);
}
EXPORT_SYMBOL_GPL(omap_crypto_cleanup);

MODULE_DESCRIPTION("OMAP crypto support library.");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Tero Kristo <t-kristo@ti.com>");
OpenPOWER on IntegriCloud