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/unaligned/access_ok.h>
 12#include <linux/cpufeature.h>
 13#include <linux/init.h>
 14#include <linux/kernel.h>
 15#include <linux/module.h>
 16#include <linux/string.h>
 17#include <asm/mipsregs.h>
 18
 19#include <crypto/internal/hash.h>
 20
 21enum crc_op_size {
 22	b, h, w, d,
 23};
 24
 25enum crc_type {
 26	crc32,
 27	crc32c,
 28};
 29
 30#ifndef TOOLCHAIN_SUPPORTS_CRC
 31#define _ASM_MACRO_CRC32(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_ASM_MACRO_CRC32(crc32b,  0, 0);
 41_ASM_MACRO_CRC32(crc32h,  1, 0);
 42_ASM_MACRO_CRC32(crc32w,  2, 0);
 43_ASM_MACRO_CRC32(crc32d,  3, 0);
 44_ASM_MACRO_CRC32(crc32cb, 0, 1);
 45_ASM_MACRO_CRC32(crc32ch, 1, 1);
 46_ASM_MACRO_CRC32(crc32cw, 2, 1);
 47_ASM_MACRO_CRC32(crc32cd, 3, 1);
 48#define _ASM_SET_CRC ""
 49#else /* !TOOLCHAIN_SUPPORTS_CRC */
 50#define _ASM_SET_CRC ".set\tcrc\n\t"
 51#endif
 52
 53#define _CRC32(crc, value, size, type)		\
 54do {						\
 55	__asm__ __volatile__(			\
 56		".set	push\n\t"		\
 57		_ASM_SET_CRC			\
 58		#type #size "	%0, %1, %0\n\t"	\
 59		".set	pop"			\
 60		: "+r" (crc)			\
 61		: "r" (value));			\
 62} while (0)
 63
 64#define CRC32(crc, value, size) \
 65	_CRC32(crc, value, size, crc32)
 66
 67#define CRC32C(crc, value, size) \
 68	_CRC32(crc, value, size, crc32c)
 69
 70static u32 crc32_mips_le_hw(u32 crc_, const u8 *p, unsigned int len)
 71{
 72	u32 crc = crc_;
 73
 74#ifdef CONFIG_64BIT
 75	while (len >= sizeof(u64)) {
 76		u64 value = get_unaligned_le64(p);
 77
 78		CRC32(crc, value, d);
 79		p += sizeof(u64);
 80		len -= sizeof(u64);
 81	}
 82
 83	if (len & sizeof(u32)) {
 84#else /* !CONFIG_64BIT */
 85	while (len >= sizeof(u32)) {
 86#endif
 87		u32 value = get_unaligned_le32(p);
 88
 89		CRC32(crc, value, w);
 90		p += sizeof(u32);
 91		len -= sizeof(u32);
 92	}
 93
 94	if (len & sizeof(u16)) {
 95		u16 value = get_unaligned_le16(p);
 96
 97		CRC32(crc, value, h);
 98		p += sizeof(u16);
 99	}
100
101	if (len & sizeof(u8)) {
102		u8 value = *p++;
103
104		CRC32(crc, value, b);
105	}
106
107	return crc;
108}
109
110static u32 crc32c_mips_le_hw(u32 crc_, const u8 *p, unsigned int len)
111{
112	u32 crc = crc_;
113
114#ifdef CONFIG_64BIT
115	while (len >= sizeof(u64)) {
116		u64 value = get_unaligned_le64(p);
117
118		CRC32C(crc, value, d);
119		p += sizeof(u64);
120		len -= sizeof(u64);
121	}
122
123	if (len & sizeof(u32)) {
124#else /* !CONFIG_64BIT */
125	while (len >= sizeof(u32)) {
126#endif
127		u32 value = get_unaligned_le32(p);
128
129		CRC32C(crc, value, w);
130		p += sizeof(u32);
131		len -= sizeof(u32);
132	}
133
134	if (len & sizeof(u16)) {
135		u16 value = get_unaligned_le16(p);
136
137		CRC32C(crc, value, h);
138		p += sizeof(u16);
139	}
140
141	if (len & sizeof(u8)) {
142		u8 value = *p++;
143
144		CRC32C(crc, value, b);
145	}
146	return crc;
147}
148
149#define CHKSUM_BLOCK_SIZE	1
150#define CHKSUM_DIGEST_SIZE	4
151
152struct chksum_ctx {
153	u32 key;
154};
155
156struct chksum_desc_ctx {
157	u32 crc;
158};
159
160static int chksum_init(struct shash_desc *desc)
161{
162	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
163	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
164
165	ctx->crc = mctx->key;
166
167	return 0;
168}
169
170/*
171 * Setting the seed allows arbitrary accumulators and flexible XOR policy
172 * If your algorithm starts with ~0, then XOR with ~0 before you set
173 * the seed.
174 */
175static int chksum_setkey(struct crypto_shash *tfm, const u8 *key,
176			 unsigned int keylen)
177{
178	struct chksum_ctx *mctx = crypto_shash_ctx(tfm);
179
180	if (keylen != sizeof(mctx->key)) {
181		crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
182		return -EINVAL;
183	}
184	mctx->key = get_unaligned_le32(key);
185	return 0;
186}
187
188static int chksum_update(struct shash_desc *desc, const u8 *data,
189			 unsigned int length)
190{
191	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
192
193	ctx->crc = crc32_mips_le_hw(ctx->crc, data, length);
194	return 0;
195}
196
197static int chksumc_update(struct shash_desc *desc, const u8 *data,
198			 unsigned int length)
199{
200	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
201
202	ctx->crc = crc32c_mips_le_hw(ctx->crc, data, length);
203	return 0;
204}
205
206static int chksum_final(struct shash_desc *desc, u8 *out)
207{
208	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
209
210	put_unaligned_le32(ctx->crc, out);
211	return 0;
212}
213
214static int chksumc_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
222static int __chksum_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
223{
224	put_unaligned_le32(crc32_mips_le_hw(crc, data, len), out);
225	return 0;
226}
227
228static int __chksumc_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
229{
230	put_unaligned_le32(~crc32c_mips_le_hw(crc, data, len), out);
231	return 0;
232}
233
234static int chksum_finup(struct shash_desc *desc, const u8 *data,
235			unsigned int len, u8 *out)
236{
237	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
238
239	return __chksum_finup(ctx->crc, data, len, out);
240}
241
242static int chksumc_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 __chksumc_finup(ctx->crc, data, len, out);
248}
249
250static int chksum_digest(struct shash_desc *desc, const u8 *data,
251			 unsigned int length, u8 *out)
252{
253	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
254
255	return __chksum_finup(mctx->key, data, length, out);
256}
257
258static int chksumc_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 __chksumc_finup(mctx->key, data, length, out);
264}
265
266static int chksum_cra_init(struct crypto_tfm *tfm)
267{
268	struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
269
270	mctx->key = ~0;
271	return 0;
272}
273
274static struct shash_alg crc32_alg = {
275	.digestsize		=	CHKSUM_DIGEST_SIZE,
276	.setkey			=	chksum_setkey,
277	.init			=	chksum_init,
278	.update			=	chksum_update,
279	.final			=	chksum_final,
280	.finup			=	chksum_finup,
281	.digest			=	chksum_digest,
282	.descsize		=	sizeof(struct chksum_desc_ctx),
283	.base			=	{
284		.cra_name		=	"crc32",
285		.cra_driver_name	=	"crc32-mips-hw",
286		.cra_priority		=	300,
287		.cra_flags		=	CRYPTO_ALG_OPTIONAL_KEY,
288		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
289		.cra_alignmask		=	0,
290		.cra_ctxsize		=	sizeof(struct chksum_ctx),
291		.cra_module		=	THIS_MODULE,
292		.cra_init		=	chksum_cra_init,
293	}
294};
295
296static struct shash_alg crc32c_alg = {
297	.digestsize		=	CHKSUM_DIGEST_SIZE,
298	.setkey			=	chksum_setkey,
299	.init			=	chksum_init,
300	.update			=	chksumc_update,
301	.final			=	chksumc_final,
302	.finup			=	chksumc_finup,
303	.digest			=	chksumc_digest,
304	.descsize		=	sizeof(struct chksum_desc_ctx),
305	.base			=	{
306		.cra_name		=	"crc32c",
307		.cra_driver_name	=	"crc32c-mips-hw",
308		.cra_priority		=	300,
309		.cra_flags		=	CRYPTO_ALG_OPTIONAL_KEY,
310		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
311		.cra_alignmask		=	0,
312		.cra_ctxsize		=	sizeof(struct chksum_ctx),
313		.cra_module		=	THIS_MODULE,
314		.cra_init		=	chksum_cra_init,
315	}
316};
317
318static int __init crc32_mod_init(void)
319{
320	int err;
321
322	err = crypto_register_shash(&crc32_alg);
323
324	if (err)
325		return err;
326
327	err = crypto_register_shash(&crc32c_alg);
328
329	if (err) {
330		crypto_unregister_shash(&crc32_alg);
331		return err;
332	}
333
334	return 0;
335}
336
337static void __exit crc32_mod_exit(void)
338{
339	crypto_unregister_shash(&crc32_alg);
340	crypto_unregister_shash(&crc32c_alg);
341}
342
343MODULE_AUTHOR("Marcin Nowakowski <marcin.nowakowski@mips.com");
344MODULE_DESCRIPTION("CRC32 and CRC32C using optional MIPS instructions");
345MODULE_LICENSE("GPL v2");
346
347module_cpu_feature_match(MIPS_CRC32, crc32_mod_init);
348module_exit(crc32_mod_exit);