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)			\
19do {							\
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
30static 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
65static 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
103struct chksum_ctx {
104	u32 key;
105};
106
107struct chksum_desc_ctx {
108	u32 crc;
109};
110
111static 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 */
125static 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
137static 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
145static 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
153static 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
161static 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
169static 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
175static 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
181static 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
188static 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
195static 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
202static 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
209static 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
217static 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
225static 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_ctxsize		=	sizeof(struct chksum_ctx),
241		.cra_module		=	THIS_MODULE,
242		.cra_init		=	chksum_cra_init,
243	}
244};
245
246static struct shash_alg crc32c_alg = {
247	.digestsize		=	CHKSUM_DIGEST_SIZE,
248	.setkey			=	chksum_setkey,
249	.init			=	chksum_init,
250	.update			=	chksumc_update,
251	.final			=	chksumc_final,
252	.finup			=	chksumc_finup,
253	.digest			=	chksumc_digest,
254	.descsize		=	sizeof(struct chksum_desc_ctx),
255	.base			=	{
256		.cra_name		=	"crc32c",
257		.cra_driver_name	=	"crc32c-loongarch",
258		.cra_priority		=	300,
259		.cra_flags		=	CRYPTO_ALG_OPTIONAL_KEY,
260		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
261		.cra_ctxsize		=	sizeof(struct chksum_ctx),
262		.cra_module		=	THIS_MODULE,
263		.cra_init		=	chksumc_cra_init,
264	}
265};
266
267static int __init crc32_mod_init(void)
268{
269	int err;
270
271	if (!cpu_has(CPU_FEATURE_CRC32))
272		return 0;
273
274	err = crypto_register_shash(&crc32_alg);
275	if (err)
276		return err;
277
278	err = crypto_register_shash(&crc32c_alg);
279	if (err)
280		return err;
281
282	return 0;
283}
284
285static void __exit crc32_mod_exit(void)
286{
287	if (!cpu_has(CPU_FEATURE_CRC32))
288		return;
289
290	crypto_unregister_shash(&crc32_alg);
291	crypto_unregister_shash(&crc32c_alg);
292}
293
294module_init(crc32_mod_init);
295module_exit(crc32_mod_exit);
296
297MODULE_AUTHOR("Min Zhou <zhoumin@loongson.cn>");
298MODULE_AUTHOR("Huacai Chen <chenhuacai@loongson.cn>");
299MODULE_DESCRIPTION("CRC32 and CRC32C using LoongArch crc* instructions");
300MODULE_LICENSE("GPL v2");
301