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74ed87e7 TK |
1 | /* |
2 | * OMAP Crypto driver common support routines. | |
3 | * | |
4 | * Copyright (c) 2017 Texas Instruments Incorporated | |
5 | * Tero Kristo <t-kristo@ti.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as published | |
9 | * by the Free Software Foundation. | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/scatterlist.h> | |
15 | #include <crypto/scatterwalk.h> | |
16 | ||
17 | #include "omap-crypto.h" | |
18 | ||
19 | static int omap_crypto_copy_sg_lists(int total, int bs, | |
20 | struct scatterlist **sg, | |
21 | struct scatterlist *new_sg, u16 flags) | |
22 | { | |
23 | int n = sg_nents(*sg); | |
24 | struct scatterlist *tmp; | |
25 | ||
26 | if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY)) { | |
27 | new_sg = kmalloc_array(n, sizeof(*sg), GFP_KERNEL); | |
28 | if (!new_sg) | |
29 | return -ENOMEM; | |
30 | ||
31 | sg_init_table(new_sg, n); | |
32 | } | |
33 | ||
34 | tmp = new_sg; | |
35 | ||
36 | while (*sg && total) { | |
37 | int len = (*sg)->length; | |
38 | ||
39 | if (total < len) | |
40 | len = total; | |
41 | ||
42 | if (len > 0) { | |
43 | total -= len; | |
44 | sg_set_page(tmp, sg_page(*sg), len, (*sg)->offset); | |
45 | if (total <= 0) | |
46 | sg_mark_end(tmp); | |
47 | tmp = sg_next(tmp); | |
48 | } | |
49 | ||
50 | *sg = sg_next(*sg); | |
51 | } | |
52 | ||
53 | *sg = new_sg; | |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
58 | static int omap_crypto_copy_sgs(int total, int bs, struct scatterlist **sg, | |
59 | struct scatterlist *new_sg, u16 flags) | |
60 | { | |
61 | void *buf; | |
62 | int pages; | |
63 | int new_len; | |
64 | ||
65 | new_len = ALIGN(total, bs); | |
66 | pages = get_order(new_len); | |
67 | ||
68 | buf = (void *)__get_free_pages(GFP_ATOMIC, pages); | |
69 | if (!buf) { | |
70 | pr_err("%s: Couldn't allocate pages for unaligned cases.\n", | |
71 | __func__); | |
72 | return -ENOMEM; | |
73 | } | |
74 | ||
75 | if (flags & OMAP_CRYPTO_COPY_DATA) { | |
76 | scatterwalk_map_and_copy(buf, *sg, 0, total, 0); | |
77 | if (flags & OMAP_CRYPTO_ZERO_BUF) | |
78 | memset(buf + total, 0, new_len - total); | |
79 | } | |
80 | ||
81 | if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY)) | |
82 | sg_init_table(new_sg, 1); | |
83 | ||
84 | sg_set_buf(new_sg, buf, new_len); | |
85 | ||
86 | *sg = new_sg; | |
87 | ||
88 | return 0; | |
89 | } | |
90 | ||
91 | static int omap_crypto_check_sg(struct scatterlist *sg, int total, int bs, | |
92 | u16 flags) | |
93 | { | |
94 | int len = 0; | |
95 | int num_sg = 0; | |
96 | ||
97 | if (!IS_ALIGNED(total, bs)) | |
98 | return OMAP_CRYPTO_NOT_ALIGNED; | |
99 | ||
100 | while (sg) { | |
101 | num_sg++; | |
102 | ||
103 | if (!IS_ALIGNED(sg->offset, 4)) | |
104 | return OMAP_CRYPTO_NOT_ALIGNED; | |
105 | if (!IS_ALIGNED(sg->length, bs)) | |
106 | return OMAP_CRYPTO_NOT_ALIGNED; | |
107 | ||
108 | len += sg->length; | |
109 | sg = sg_next(sg); | |
110 | ||
111 | if (len >= total) | |
112 | break; | |
113 | } | |
114 | ||
115 | if ((flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) && num_sg > 1) | |
116 | return OMAP_CRYPTO_NOT_ALIGNED; | |
117 | ||
118 | if (len != total) | |
119 | return OMAP_CRYPTO_BAD_DATA_LENGTH; | |
120 | ||
121 | return 0; | |
122 | } | |
123 | ||
124 | int omap_crypto_align_sg(struct scatterlist **sg, int total, int bs, | |
125 | struct scatterlist *new_sg, u16 flags, | |
126 | u8 flags_shift, unsigned long *dd_flags) | |
127 | { | |
128 | int ret; | |
129 | ||
130 | *dd_flags &= ~(OMAP_CRYPTO_COPY_MASK << flags_shift); | |
131 | ||
132 | if (flags & OMAP_CRYPTO_FORCE_COPY) | |
133 | ret = OMAP_CRYPTO_NOT_ALIGNED; | |
134 | else | |
135 | ret = omap_crypto_check_sg(*sg, total, bs, flags); | |
136 | ||
137 | if (ret == OMAP_CRYPTO_NOT_ALIGNED) { | |
138 | ret = omap_crypto_copy_sgs(total, bs, sg, new_sg, flags); | |
139 | if (ret) | |
140 | return ret; | |
141 | *dd_flags |= OMAP_CRYPTO_DATA_COPIED << flags_shift; | |
142 | } else if (ret == OMAP_CRYPTO_BAD_DATA_LENGTH) { | |
143 | ret = omap_crypto_copy_sg_lists(total, bs, sg, new_sg, flags); | |
144 | if (ret) | |
145 | return ret; | |
146 | if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY)) | |
147 | *dd_flags |= OMAP_CRYPTO_SG_COPIED << flags_shift; | |
148 | } else if (flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) { | |
149 | sg_set_buf(new_sg, sg_virt(*sg), (*sg)->length); | |
150 | } | |
151 | ||
152 | return 0; | |
153 | } | |
154 | EXPORT_SYMBOL_GPL(omap_crypto_align_sg); | |
155 | ||
156 | void omap_crypto_cleanup(struct scatterlist *sg, struct scatterlist *orig, | |
157 | int offset, int len, u8 flags_shift, | |
158 | unsigned long flags) | |
159 | { | |
160 | void *buf; | |
161 | int pages; | |
162 | ||
163 | flags >>= flags_shift; | |
164 | flags &= OMAP_CRYPTO_COPY_MASK; | |
165 | ||
166 | if (!flags) | |
167 | return; | |
168 | ||
169 | buf = sg_virt(sg); | |
170 | pages = get_order(len); | |
171 | ||
172 | if (orig && (flags & OMAP_CRYPTO_COPY_MASK)) | |
173 | scatterwalk_map_and_copy(buf, orig, offset, len, 1); | |
174 | ||
175 | if (flags & OMAP_CRYPTO_DATA_COPIED) | |
176 | free_pages((unsigned long)buf, pages); | |
177 | else if (flags & OMAP_CRYPTO_SG_COPIED) | |
178 | kfree(sg); | |
179 | } | |
180 | EXPORT_SYMBOL_GPL(omap_crypto_cleanup); | |
181 | ||
182 | MODULE_DESCRIPTION("OMAP crypto support library."); | |
183 | MODULE_LICENSE("GPL v2"); | |
184 | MODULE_AUTHOR("Tero Kristo <t-kristo@ti.com>"); |