GNU Linux-libre 4.19.314-gnu1
[releases.git] / arch / arm / crypto / crc32-ce-glue.c
1 /*
2  * Accelerated CRC32(C) using ARM CRC, NEON and Crypto Extensions instructions
3  *
4  * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10
11 #include <linux/cpufeature.h>
12 #include <linux/crc32.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/string.h>
17
18 #include <crypto/internal/hash.h>
19
20 #include <asm/hwcap.h>
21 #include <asm/neon.h>
22 #include <asm/simd.h>
23 #include <asm/unaligned.h>
24
25 #define PMULL_MIN_LEN           64L     /* minimum size of buffer
26                                          * for crc32_pmull_le_16 */
27 #define SCALE_F                 16L     /* size of NEON register */
28
29 asmlinkage u32 crc32_pmull_le(const u8 buf[], u32 len, u32 init_crc);
30 asmlinkage u32 crc32_armv8_le(u32 init_crc, const u8 buf[], u32 len);
31
32 asmlinkage u32 crc32c_pmull_le(const u8 buf[], u32 len, u32 init_crc);
33 asmlinkage u32 crc32c_armv8_le(u32 init_crc, const u8 buf[], u32 len);
34
35 static u32 (*fallback_crc32)(u32 init_crc, const u8 buf[], u32 len);
36 static u32 (*fallback_crc32c)(u32 init_crc, const u8 buf[], u32 len);
37
38 static int crc32_cra_init(struct crypto_tfm *tfm)
39 {
40         u32 *key = crypto_tfm_ctx(tfm);
41
42         *key = 0;
43         return 0;
44 }
45
46 static int crc32c_cra_init(struct crypto_tfm *tfm)
47 {
48         u32 *key = crypto_tfm_ctx(tfm);
49
50         *key = ~0;
51         return 0;
52 }
53
54 static int crc32_setkey(struct crypto_shash *hash, const u8 *key,
55                         unsigned int keylen)
56 {
57         u32 *mctx = crypto_shash_ctx(hash);
58
59         if (keylen != sizeof(u32)) {
60                 crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
61                 return -EINVAL;
62         }
63         *mctx = le32_to_cpup((__le32 *)key);
64         return 0;
65 }
66
67 static int crc32_init(struct shash_desc *desc)
68 {
69         u32 *mctx = crypto_shash_ctx(desc->tfm);
70         u32 *crc = shash_desc_ctx(desc);
71
72         *crc = *mctx;
73         return 0;
74 }
75
76 static int crc32_update(struct shash_desc *desc, const u8 *data,
77                         unsigned int length)
78 {
79         u32 *crc = shash_desc_ctx(desc);
80
81         *crc = crc32_armv8_le(*crc, data, length);
82         return 0;
83 }
84
85 static int crc32c_update(struct shash_desc *desc, const u8 *data,
86                          unsigned int length)
87 {
88         u32 *crc = shash_desc_ctx(desc);
89
90         *crc = crc32c_armv8_le(*crc, data, length);
91         return 0;
92 }
93
94 static int crc32_final(struct shash_desc *desc, u8 *out)
95 {
96         u32 *crc = shash_desc_ctx(desc);
97
98         put_unaligned_le32(*crc, out);
99         return 0;
100 }
101
102 static int crc32c_final(struct shash_desc *desc, u8 *out)
103 {
104         u32 *crc = shash_desc_ctx(desc);
105
106         put_unaligned_le32(~*crc, out);
107         return 0;
108 }
109
110 static int crc32_pmull_update(struct shash_desc *desc, const u8 *data,
111                               unsigned int length)
112 {
113         u32 *crc = shash_desc_ctx(desc);
114         unsigned int l;
115
116         if (may_use_simd()) {
117                 if ((u32)data % SCALE_F) {
118                         l = min_t(u32, length, SCALE_F - ((u32)data % SCALE_F));
119
120                         *crc = fallback_crc32(*crc, data, l);
121
122                         data += l;
123                         length -= l;
124                 }
125
126                 if (length >= PMULL_MIN_LEN) {
127                         l = round_down(length, SCALE_F);
128
129                         kernel_neon_begin();
130                         *crc = crc32_pmull_le(data, l, *crc);
131                         kernel_neon_end();
132
133                         data += l;
134                         length -= l;
135                 }
136         }
137
138         if (length > 0)
139                 *crc = fallback_crc32(*crc, data, length);
140
141         return 0;
142 }
143
144 static int crc32c_pmull_update(struct shash_desc *desc, const u8 *data,
145                                unsigned int length)
146 {
147         u32 *crc = shash_desc_ctx(desc);
148         unsigned int l;
149
150         if (may_use_simd()) {
151                 if ((u32)data % SCALE_F) {
152                         l = min_t(u32, length, SCALE_F - ((u32)data % SCALE_F));
153
154                         *crc = fallback_crc32c(*crc, data, l);
155
156                         data += l;
157                         length -= l;
158                 }
159
160                 if (length >= PMULL_MIN_LEN) {
161                         l = round_down(length, SCALE_F);
162
163                         kernel_neon_begin();
164                         *crc = crc32c_pmull_le(data, l, *crc);
165                         kernel_neon_end();
166
167                         data += l;
168                         length -= l;
169                 }
170         }
171
172         if (length > 0)
173                 *crc = fallback_crc32c(*crc, data, length);
174
175         return 0;
176 }
177
178 static struct shash_alg crc32_pmull_algs[] = { {
179         .setkey                 = crc32_setkey,
180         .init                   = crc32_init,
181         .update                 = crc32_update,
182         .final                  = crc32_final,
183         .descsize               = sizeof(u32),
184         .digestsize             = sizeof(u32),
185
186         .base.cra_ctxsize       = sizeof(u32),
187         .base.cra_init          = crc32_cra_init,
188         .base.cra_name          = "crc32",
189         .base.cra_driver_name   = "crc32-arm-ce",
190         .base.cra_priority      = 200,
191         .base.cra_flags         = CRYPTO_ALG_OPTIONAL_KEY,
192         .base.cra_blocksize     = 1,
193         .base.cra_module        = THIS_MODULE,
194 }, {
195         .setkey                 = crc32_setkey,
196         .init                   = crc32_init,
197         .update                 = crc32c_update,
198         .final                  = crc32c_final,
199         .descsize               = sizeof(u32),
200         .digestsize             = sizeof(u32),
201
202         .base.cra_ctxsize       = sizeof(u32),
203         .base.cra_init          = crc32c_cra_init,
204         .base.cra_name          = "crc32c",
205         .base.cra_driver_name   = "crc32c-arm-ce",
206         .base.cra_priority      = 200,
207         .base.cra_flags         = CRYPTO_ALG_OPTIONAL_KEY,
208         .base.cra_blocksize     = 1,
209         .base.cra_module        = THIS_MODULE,
210 } };
211
212 static int __init crc32_pmull_mod_init(void)
213 {
214         if (elf_hwcap2 & HWCAP2_PMULL) {
215                 crc32_pmull_algs[0].update = crc32_pmull_update;
216                 crc32_pmull_algs[1].update = crc32c_pmull_update;
217
218                 if (elf_hwcap2 & HWCAP2_CRC32) {
219                         fallback_crc32 = crc32_armv8_le;
220                         fallback_crc32c = crc32c_armv8_le;
221                 } else {
222                         fallback_crc32 = crc32_le;
223                         fallback_crc32c = __crc32c_le;
224                 }
225         } else if (!(elf_hwcap2 & HWCAP2_CRC32)) {
226                 return -ENODEV;
227         }
228
229         return crypto_register_shashes(crc32_pmull_algs,
230                                        ARRAY_SIZE(crc32_pmull_algs));
231 }
232
233 static void __exit crc32_pmull_mod_exit(void)
234 {
235         crypto_unregister_shashes(crc32_pmull_algs,
236                                   ARRAY_SIZE(crc32_pmull_algs));
237 }
238
239 static const struct cpu_feature __maybe_unused crc32_cpu_feature[] = {
240         { cpu_feature(CRC32) }, { cpu_feature(PMULL) }, { }
241 };
242 MODULE_DEVICE_TABLE(cpu, crc32_cpu_feature);
243
244 module_init(crc32_pmull_mod_init);
245 module_exit(crc32_pmull_mod_exit);
246
247 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
248 MODULE_LICENSE("GPL v2");
249 MODULE_ALIAS_CRYPTO("crc32");
250 MODULE_ALIAS_CRYPTO("crc32c");