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
crc32_mips_le_hw(u32 crc_,const u8 * p,unsigned int len)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
crc32c_mips_le_hw(u32 crc_,const u8 * p,unsigned int len)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 CRC32(crc, value, d);
127 }
128
129 if (len & sizeof(u32)) {
130 u32 value = get_unaligned_le32(p);
131
132 CRC32(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 CRC32(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
chksum_init(struct shash_desc * desc)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 */
chksum_setkey(struct crypto_shash * tfm,const u8 * key,unsigned int keylen)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
chksum_update(struct shash_desc * desc,const u8 * data,unsigned int length)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
chksumc_update(struct shash_desc * desc,const u8 * data,unsigned int length)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
chksum_final(struct shash_desc * desc,u8 * out)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
chksumc_final(struct shash_desc * desc,u8 * out)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
__chksum_finup(u32 crc,const u8 * data,unsigned int len,u8 * out)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
__chksumc_finup(u32 crc,const u8 * data,unsigned int len,u8 * out)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
chksum_finup(struct shash_desc * desc,const u8 * data,unsigned int len,u8 * out)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
chksumc_finup(struct shash_desc * desc,const u8 * data,unsigned int len,u8 * out)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
chksum_digest(struct shash_desc * desc,const u8 * data,unsigned int length,u8 * out)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
chksumc_digest(struct shash_desc * desc,const u8 * data,unsigned int length,u8 * out)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
chksum_cra_init(struct crypto_tfm * tfm)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
crc32_mod_init(void)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
crc32_mod_exit(void)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