1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * crc32.c - CRC32 and CRC32C using LoongArch crc* instructions
4  *
5  * Module based on mips/crypto/crc32-mips.c
6  *
7  * Copyright (C) 2014 Linaro Ltd <yazen.ghannam@linaro.org>
8  * Copyright (C) 2018 MIPS Tech, LLC
9  * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
10  */
11 
12 #include <linux/module.h>
13 #include <crypto/internal/hash.h>
14 
15 #include <asm/cpu-features.h>
16 #include <asm/unaligned.h>
17 
18 #define _CRC32(crc, value, size, type)			\
19 do {							\
20 	__asm__ __volatile__(				\
21 		#type ".w." #size ".w" " %0, %1, %0\n\t"\
22 		: "+r" (crc)				\
23 		: "r" (value)				\
24 		: "memory");				\
25 } while (0)
26 
27 #define CRC32(crc, value, size)		_CRC32(crc, value, size, crc)
28 #define CRC32C(crc, value, size)	_CRC32(crc, value, size, crcc)
29 
30 static u32 crc32_loongarch_hw(u32 crc_, const u8 *p, unsigned int len)
31 {
32 	u32 crc = crc_;
33 
34 	while (len >= sizeof(u64)) {
35 		u64 value = get_unaligned_le64(p);
36 
37 		CRC32(crc, value, d);
38 		p += sizeof(u64);
39 		len -= sizeof(u64);
40 	}
41 
42 	if (len & sizeof(u32)) {
43 		u32 value = get_unaligned_le32(p);
44 
45 		CRC32(crc, value, w);
46 		p += sizeof(u32);
47 		len -= sizeof(u32);
48 	}
49 
50 	if (len & sizeof(u16)) {
51 		u16 value = get_unaligned_le16(p);
52 
53 		CRC32(crc, value, h);
54 		p += sizeof(u16);
55 	}
56 
57 	if (len & sizeof(u8)) {
58 		u8 value = *p++;
59 
60 		CRC32(crc, value, b);
61 	}
62 
63 	return crc;
64 }
65 
66 static u32 crc32c_loongarch_hw(u32 crc_, const u8 *p, unsigned int len)
67 {
68 	u32 crc = crc_;
69 
70 	while (len >= sizeof(u64)) {
71 		u64 value = get_unaligned_le64(p);
72 
73 		CRC32C(crc, value, d);
74 		p += sizeof(u64);
75 		len -= sizeof(u64);
76 	}
77 
78 	if (len & sizeof(u32)) {
79 		u32 value = get_unaligned_le32(p);
80 
81 		CRC32C(crc, value, w);
82 		p += sizeof(u32);
83 		len -= sizeof(u32);
84 	}
85 
86 	if (len & sizeof(u16)) {
87 		u16 value = get_unaligned_le16(p);
88 
89 		CRC32C(crc, value, h);
90 		p += sizeof(u16);
91 	}
92 
93 	if (len & sizeof(u8)) {
94 		u8 value = *p++;
95 
96 		CRC32C(crc, value, b);
97 	}
98 
99 	return crc;
100 }
101 
102 #define CHKSUM_BLOCK_SIZE	1
103 #define CHKSUM_DIGEST_SIZE	4
104 
105 struct chksum_ctx {
106 	u32 key;
107 };
108 
109 struct chksum_desc_ctx {
110 	u32 crc;
111 };
112 
113 static int chksum_init(struct shash_desc *desc)
114 {
115 	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
116 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
117 
118 	ctx->crc = mctx->key;
119 
120 	return 0;
121 }
122 
123 /*
124  * Setting the seed allows arbitrary accumulators and flexible XOR policy
125  * If your algorithm starts with ~0, then XOR with ~0 before you set the seed.
126  */
127 static int chksum_setkey(struct crypto_shash *tfm, const u8 *key, unsigned int keylen)
128 {
129 	struct chksum_ctx *mctx = crypto_shash_ctx(tfm);
130 
131 	if (keylen != sizeof(mctx->key))
132 		return -EINVAL;
133 
134 	mctx->key = get_unaligned_le32(key);
135 
136 	return 0;
137 }
138 
139 static int chksum_update(struct shash_desc *desc, const u8 *data, unsigned int length)
140 {
141 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
142 
143 	ctx->crc = crc32_loongarch_hw(ctx->crc, data, length);
144 	return 0;
145 }
146 
147 static int chksumc_update(struct shash_desc *desc, const u8 *data, unsigned int length)
148 {
149 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
150 
151 	ctx->crc = crc32c_loongarch_hw(ctx->crc, data, length);
152 	return 0;
153 }
154 
155 static int chksum_final(struct shash_desc *desc, u8 *out)
156 {
157 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
158 
159 	put_unaligned_le32(ctx->crc, out);
160 	return 0;
161 }
162 
163 static int chksumc_final(struct shash_desc *desc, u8 *out)
164 {
165 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
166 
167 	put_unaligned_le32(~ctx->crc, out);
168 	return 0;
169 }
170 
171 static int __chksum_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
172 {
173 	put_unaligned_le32(crc32_loongarch_hw(crc, data, len), out);
174 	return 0;
175 }
176 
177 static int __chksumc_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
178 {
179 	put_unaligned_le32(~crc32c_loongarch_hw(crc, data, len), out);
180 	return 0;
181 }
182 
183 static int chksum_finup(struct shash_desc *desc, const u8 *data, unsigned int len, u8 *out)
184 {
185 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
186 
187 	return __chksum_finup(ctx->crc, data, len, out);
188 }
189 
190 static int chksumc_finup(struct shash_desc *desc, const u8 *data, unsigned int len, u8 *out)
191 {
192 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
193 
194 	return __chksumc_finup(ctx->crc, data, len, out);
195 }
196 
197 static int chksum_digest(struct shash_desc *desc, const u8 *data, unsigned int length, u8 *out)
198 {
199 	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
200 
201 	return __chksum_finup(mctx->key, data, length, out);
202 }
203 
204 static int chksumc_digest(struct shash_desc *desc, const u8 *data, unsigned int length, u8 *out)
205 {
206 	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
207 
208 	return __chksumc_finup(mctx->key, data, length, out);
209 }
210 
211 static int chksum_cra_init(struct crypto_tfm *tfm)
212 {
213 	struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
214 
215 	mctx->key = 0;
216 	return 0;
217 }
218 
219 static int chksumc_cra_init(struct crypto_tfm *tfm)
220 {
221 	struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
222 
223 	mctx->key = ~0;
224 	return 0;
225 }
226 
227 static struct shash_alg crc32_alg = {
228 	.digestsize		=	CHKSUM_DIGEST_SIZE,
229 	.setkey			=	chksum_setkey,
230 	.init			=	chksum_init,
231 	.update			=	chksum_update,
232 	.final			=	chksum_final,
233 	.finup			=	chksum_finup,
234 	.digest			=	chksum_digest,
235 	.descsize		=	sizeof(struct chksum_desc_ctx),
236 	.base			=	{
237 		.cra_name		=	"crc32",
238 		.cra_driver_name	=	"crc32-loongarch",
239 		.cra_priority		=	300,
240 		.cra_flags		=	CRYPTO_ALG_OPTIONAL_KEY,
241 		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
242 		.cra_alignmask		=	0,
243 		.cra_ctxsize		=	sizeof(struct chksum_ctx),
244 		.cra_module		=	THIS_MODULE,
245 		.cra_init		=	chksum_cra_init,
246 	}
247 };
248 
249 static struct shash_alg crc32c_alg = {
250 	.digestsize		=	CHKSUM_DIGEST_SIZE,
251 	.setkey			=	chksum_setkey,
252 	.init			=	chksum_init,
253 	.update			=	chksumc_update,
254 	.final			=	chksumc_final,
255 	.finup			=	chksumc_finup,
256 	.digest			=	chksumc_digest,
257 	.descsize		=	sizeof(struct chksum_desc_ctx),
258 	.base			=	{
259 		.cra_name		=	"crc32c",
260 		.cra_driver_name	=	"crc32c-loongarch",
261 		.cra_priority		=	300,
262 		.cra_flags		=	CRYPTO_ALG_OPTIONAL_KEY,
263 		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
264 		.cra_alignmask		=	0,
265 		.cra_ctxsize		=	sizeof(struct chksum_ctx),
266 		.cra_module		=	THIS_MODULE,
267 		.cra_init		=	chksumc_cra_init,
268 	}
269 };
270 
271 static int __init crc32_mod_init(void)
272 {
273 	int err;
274 
275 	if (!cpu_has(CPU_FEATURE_CRC32))
276 		return 0;
277 
278 	err = crypto_register_shash(&crc32_alg);
279 	if (err)
280 		return err;
281 
282 	err = crypto_register_shash(&crc32c_alg);
283 	if (err)
284 		return err;
285 
286 	return 0;
287 }
288 
289 static void __exit crc32_mod_exit(void)
290 {
291 	if (!cpu_has(CPU_FEATURE_CRC32))
292 		return;
293 
294 	crypto_unregister_shash(&crc32_alg);
295 	crypto_unregister_shash(&crc32c_alg);
296 }
297 
298 module_init(crc32_mod_init);
299 module_exit(crc32_mod_exit);
300 
301 MODULE_AUTHOR("Min Zhou <zhoumin@loongson.cn>");
302 MODULE_AUTHOR("Huacai Chen <chenhuacai@loongson.cn>");
303 MODULE_DESCRIPTION("CRC32 and CRC32C using LoongArch crc* instructions");
304 MODULE_LICENSE("GPL v2");
305