xref: /linux/arch/mips/crypto/crc32-mips.c (revision 7f71507851fc7764b36a3221839607d3a45c2025) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * crc32-mips.c - CRC32 and CRC32C using optional MIPSr6 instructions
4  *
5  * Module based on arm64/crypto/crc32-arm.c
6  *
7  * Copyright (C) 2014 Linaro Ltd <yazen.ghannam@linaro.org>
8  * Copyright (C) 2018 MIPS Tech, LLC
9  */
10 
11 #include <linux/cpufeature.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/string.h>
16 #include <asm/mipsregs.h>
17 #include <linux/unaligned.h>
18 
19 #include <crypto/internal/hash.h>
20 
21 enum crc_op_size {
22 	b, h, w, d,
23 };
24 
25 enum crc_type {
26 	crc32,
27 	crc32c,
28 };
29 
30 #ifndef TOOLCHAIN_SUPPORTS_CRC
31 #define _ASM_SET_CRC(OP, SZ, TYPE)					  \
32 _ASM_MACRO_3R(OP, rt, rs, rt2,						  \
33 	".ifnc	\\rt, \\rt2\n\t"					  \
34 	".error	\"invalid operands \\\"" #OP " \\rt,\\rs,\\rt2\\\"\"\n\t" \
35 	".endif\n\t"							  \
36 	_ASM_INSN_IF_MIPS(0x7c00000f | (__rt << 16) | (__rs << 21) |	  \
37 			  ((SZ) <<  6) | ((TYPE) << 8))			  \
38 	_ASM_INSN32_IF_MM(0x00000030 | (__rs << 16) | (__rt << 21) |	  \
39 			  ((SZ) << 14) | ((TYPE) << 3)))
40 #define _ASM_UNSET_CRC(op, SZ, TYPE) ".purgem " #op "\n\t"
41 #else /* !TOOLCHAIN_SUPPORTS_CRC */
42 #define _ASM_SET_CRC(op, SZ, TYPE) ".set\tcrc\n\t"
43 #define _ASM_UNSET_CRC(op, SZ, TYPE)
44 #endif
45 
46 #define __CRC32(crc, value, op, SZ, TYPE)		\
47 do {							\
48 	__asm__ __volatile__(				\
49 		".set	push\n\t"			\
50 		_ASM_SET_CRC(op, SZ, TYPE)		\
51 		#op "	%0, %1, %0\n\t"			\
52 		_ASM_UNSET_CRC(op, SZ, TYPE)		\
53 		".set	pop"				\
54 		: "+r" (crc)				\
55 		: "r" (value));				\
56 } while (0)
57 
58 #define _CRC32_crc32b(crc, value)	__CRC32(crc, value, crc32b, 0, 0)
59 #define _CRC32_crc32h(crc, value)	__CRC32(crc, value, crc32h, 1, 0)
60 #define _CRC32_crc32w(crc, value)	__CRC32(crc, value, crc32w, 2, 0)
61 #define _CRC32_crc32d(crc, value)	__CRC32(crc, value, crc32d, 3, 0)
62 #define _CRC32_crc32cb(crc, value)	__CRC32(crc, value, crc32cb, 0, 1)
63 #define _CRC32_crc32ch(crc, value)	__CRC32(crc, value, crc32ch, 1, 1)
64 #define _CRC32_crc32cw(crc, value)	__CRC32(crc, value, crc32cw, 2, 1)
65 #define _CRC32_crc32cd(crc, value)	__CRC32(crc, value, crc32cd, 3, 1)
66 
67 #define _CRC32(crc, value, size, op) \
68 	_CRC32_##op##size(crc, value)
69 
70 #define CRC32(crc, value, size) \
71 	_CRC32(crc, value, size, crc32)
72 
73 #define CRC32C(crc, value, size) \
74 	_CRC32(crc, value, size, crc32c)
75 
76 static u32 crc32_mips_le_hw(u32 crc_, const u8 *p, unsigned int len)
77 {
78 	u32 crc = crc_;
79 
80 	if (IS_ENABLED(CONFIG_64BIT)) {
81 		for (; len >= sizeof(u64); p += sizeof(u64), len -= sizeof(u64)) {
82 			u64 value = get_unaligned_le64(p);
83 
84 			CRC32(crc, value, d);
85 		}
86 
87 		if (len & sizeof(u32)) {
88 			u32 value = get_unaligned_le32(p);
89 
90 			CRC32(crc, value, w);
91 			p += sizeof(u32);
92 		}
93 	} else {
94 		for (; len >= sizeof(u32); len -= sizeof(u32)) {
95 			u32 value = get_unaligned_le32(p);
96 
97 			CRC32(crc, value, w);
98 			p += sizeof(u32);
99 		}
100 	}
101 
102 	if (len & sizeof(u16)) {
103 		u16 value = get_unaligned_le16(p);
104 
105 		CRC32(crc, value, h);
106 		p += sizeof(u16);
107 	}
108 
109 	if (len & sizeof(u8)) {
110 		u8 value = *p++;
111 
112 		CRC32(crc, value, b);
113 	}
114 
115 	return crc;
116 }
117 
118 static u32 crc32c_mips_le_hw(u32 crc_, const u8 *p, unsigned int len)
119 {
120 	u32 crc = crc_;
121 
122 	if (IS_ENABLED(CONFIG_64BIT)) {
123 		for (; len >= sizeof(u64); p += sizeof(u64), len -= sizeof(u64)) {
124 			u64 value = get_unaligned_le64(p);
125 
126 			CRC32C(crc, value, d);
127 		}
128 
129 		if (len & sizeof(u32)) {
130 			u32 value = get_unaligned_le32(p);
131 
132 			CRC32C(crc, value, w);
133 			p += sizeof(u32);
134 		}
135 	} else {
136 		for (; len >= sizeof(u32); len -= sizeof(u32)) {
137 			u32 value = get_unaligned_le32(p);
138 
139 			CRC32C(crc, value, w);
140 			p += sizeof(u32);
141 		}
142 	}
143 
144 	if (len & sizeof(u16)) {
145 		u16 value = get_unaligned_le16(p);
146 
147 		CRC32C(crc, value, h);
148 		p += sizeof(u16);
149 	}
150 
151 	if (len & sizeof(u8)) {
152 		u8 value = *p++;
153 
154 		CRC32C(crc, value, b);
155 	}
156 	return crc;
157 }
158 
159 #define CHKSUM_BLOCK_SIZE	1
160 #define CHKSUM_DIGEST_SIZE	4
161 
162 struct chksum_ctx {
163 	u32 key;
164 };
165 
166 struct chksum_desc_ctx {
167 	u32 crc;
168 };
169 
170 static int chksum_init(struct shash_desc *desc)
171 {
172 	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
173 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
174 
175 	ctx->crc = mctx->key;
176 
177 	return 0;
178 }
179 
180 /*
181  * Setting the seed allows arbitrary accumulators and flexible XOR policy
182  * If your algorithm starts with ~0, then XOR with ~0 before you set
183  * the seed.
184  */
185 static int chksum_setkey(struct crypto_shash *tfm, const u8 *key,
186 			 unsigned int keylen)
187 {
188 	struct chksum_ctx *mctx = crypto_shash_ctx(tfm);
189 
190 	if (keylen != sizeof(mctx->key))
191 		return -EINVAL;
192 	mctx->key = get_unaligned_le32(key);
193 	return 0;
194 }
195 
196 static int chksum_update(struct shash_desc *desc, const u8 *data,
197 			 unsigned int length)
198 {
199 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
200 
201 	ctx->crc = crc32_mips_le_hw(ctx->crc, data, length);
202 	return 0;
203 }
204 
205 static int chksumc_update(struct shash_desc *desc, const u8 *data,
206 			 unsigned int length)
207 {
208 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
209 
210 	ctx->crc = crc32c_mips_le_hw(ctx->crc, data, length);
211 	return 0;
212 }
213 
214 static int chksum_final(struct shash_desc *desc, u8 *out)
215 {
216 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
217 
218 	put_unaligned_le32(ctx->crc, out);
219 	return 0;
220 }
221 
222 static int chksumc_final(struct shash_desc *desc, u8 *out)
223 {
224 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
225 
226 	put_unaligned_le32(~ctx->crc, out);
227 	return 0;
228 }
229 
230 static int __chksum_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
231 {
232 	put_unaligned_le32(crc32_mips_le_hw(crc, data, len), out);
233 	return 0;
234 }
235 
236 static int __chksumc_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
237 {
238 	put_unaligned_le32(~crc32c_mips_le_hw(crc, data, len), out);
239 	return 0;
240 }
241 
242 static int chksum_finup(struct shash_desc *desc, const u8 *data,
243 			unsigned int len, u8 *out)
244 {
245 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
246 
247 	return __chksum_finup(ctx->crc, data, len, out);
248 }
249 
250 static int chksumc_finup(struct shash_desc *desc, const u8 *data,
251 			unsigned int len, u8 *out)
252 {
253 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
254 
255 	return __chksumc_finup(ctx->crc, data, len, out);
256 }
257 
258 static int chksum_digest(struct shash_desc *desc, const u8 *data,
259 			 unsigned int length, u8 *out)
260 {
261 	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
262 
263 	return __chksum_finup(mctx->key, data, length, out);
264 }
265 
266 static int chksumc_digest(struct shash_desc *desc, const u8 *data,
267 			 unsigned int length, u8 *out)
268 {
269 	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
270 
271 	return __chksumc_finup(mctx->key, data, length, out);
272 }
273 
274 static int chksum_cra_init(struct crypto_tfm *tfm)
275 {
276 	struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
277 
278 	mctx->key = ~0;
279 	return 0;
280 }
281 
282 static struct shash_alg crc32_alg = {
283 	.digestsize		=	CHKSUM_DIGEST_SIZE,
284 	.setkey			=	chksum_setkey,
285 	.init			=	chksum_init,
286 	.update			=	chksum_update,
287 	.final			=	chksum_final,
288 	.finup			=	chksum_finup,
289 	.digest			=	chksum_digest,
290 	.descsize		=	sizeof(struct chksum_desc_ctx),
291 	.base			=	{
292 		.cra_name		=	"crc32",
293 		.cra_driver_name	=	"crc32-mips-hw",
294 		.cra_priority		=	300,
295 		.cra_flags		=	CRYPTO_ALG_OPTIONAL_KEY,
296 		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
297 		.cra_ctxsize		=	sizeof(struct chksum_ctx),
298 		.cra_module		=	THIS_MODULE,
299 		.cra_init		=	chksum_cra_init,
300 	}
301 };
302 
303 static struct shash_alg crc32c_alg = {
304 	.digestsize		=	CHKSUM_DIGEST_SIZE,
305 	.setkey			=	chksum_setkey,
306 	.init			=	chksum_init,
307 	.update			=	chksumc_update,
308 	.final			=	chksumc_final,
309 	.finup			=	chksumc_finup,
310 	.digest			=	chksumc_digest,
311 	.descsize		=	sizeof(struct chksum_desc_ctx),
312 	.base			=	{
313 		.cra_name		=	"crc32c",
314 		.cra_driver_name	=	"crc32c-mips-hw",
315 		.cra_priority		=	300,
316 		.cra_flags		=	CRYPTO_ALG_OPTIONAL_KEY,
317 		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
318 		.cra_ctxsize		=	sizeof(struct chksum_ctx),
319 		.cra_module		=	THIS_MODULE,
320 		.cra_init		=	chksum_cra_init,
321 	}
322 };
323 
324 static int __init crc32_mod_init(void)
325 {
326 	int err;
327 
328 	err = crypto_register_shash(&crc32_alg);
329 
330 	if (err)
331 		return err;
332 
333 	err = crypto_register_shash(&crc32c_alg);
334 
335 	if (err) {
336 		crypto_unregister_shash(&crc32_alg);
337 		return err;
338 	}
339 
340 	return 0;
341 }
342 
343 static void __exit crc32_mod_exit(void)
344 {
345 	crypto_unregister_shash(&crc32_alg);
346 	crypto_unregister_shash(&crc32c_alg);
347 }
348 
349 MODULE_AUTHOR("Marcin Nowakowski <marcin.nowakowski@mips.com");
350 MODULE_DESCRIPTION("CRC32 and CRC32C using optional MIPS instructions");
351 MODULE_LICENSE("GPL v2");
352 
353 module_cpu_feature_match(MIPS_CRC32, crc32_mod_init);
354 module_exit(crc32_mod_exit);
355