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