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  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 <asm/unaligned.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_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)		\
 47do {							\
 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
 76static u32 crc32_mips_le_hw(u32 crc_, const u8 *p, unsigned int len)
 77{
 78	u32 crc = crc_;
 79
 80#ifdef CONFIG_64BIT
 81	while (len >= sizeof(u64)) {
 82		u64 value = get_unaligned_le64(p);
 83
 84		CRC32(crc, value, d);
 85		p += sizeof(u64);
 86		len -= sizeof(u64);
 87	}
 88
 89	if (len & sizeof(u32)) {
 90#else /* !CONFIG_64BIT */
 91	while (len >= sizeof(u32)) {
 92#endif
 93		u32 value = get_unaligned_le32(p);
 94
 95		CRC32(crc, value, w);
 96		p += sizeof(u32);
 97		len -= sizeof(u32);
 98	}
 99
100	if (len & sizeof(u16)) {
101		u16 value = get_unaligned_le16(p);
102
103		CRC32(crc, value, h);
104		p += sizeof(u16);
105	}
106
107	if (len & sizeof(u8)) {
108		u8 value = *p++;
109
110		CRC32(crc, value, b);
111	}
112
113	return crc;
114}
115
116static u32 crc32c_mips_le_hw(u32 crc_, const u8 *p, unsigned int len)
117{
118	u32 crc = crc_;
119
120#ifdef CONFIG_64BIT
121	while (len >= sizeof(u64)) {
122		u64 value = get_unaligned_le64(p);
123
124		CRC32C(crc, value, d);
125		p += sizeof(u64);
126		len -= sizeof(u64);
127	}
128
129	if (len & sizeof(u32)) {
130#else /* !CONFIG_64BIT */
131	while (len >= sizeof(u32)) {
132#endif
133		u32 value = get_unaligned_le32(p);
134
135		CRC32C(crc, value, w);
136		p += sizeof(u32);
137		len -= sizeof(u32);
138	}
139
140	if (len & sizeof(u16)) {
141		u16 value = get_unaligned_le16(p);
142
143		CRC32C(crc, value, h);
144		p += sizeof(u16);
145	}
146
147	if (len & sizeof(u8)) {
148		u8 value = *p++;
149
150		CRC32C(crc, value, b);
151	}
152	return crc;
153}
154
155#define CHKSUM_BLOCK_SIZE	1
156#define CHKSUM_DIGEST_SIZE	4
157
158struct chksum_ctx {
159	u32 key;
160};
161
162struct chksum_desc_ctx {
163	u32 crc;
164};
165
166static int chksum_init(struct shash_desc *desc)
167{
168	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
169	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
170
171	ctx->crc = mctx->key;
172
173	return 0;
174}
175
176/*
177 * Setting the seed allows arbitrary accumulators and flexible XOR policy
178 * If your algorithm starts with ~0, then XOR with ~0 before you set
179 * the seed.
180 */
181static int chksum_setkey(struct crypto_shash *tfm, const u8 *key,
182			 unsigned int keylen)
183{
184	struct chksum_ctx *mctx = crypto_shash_ctx(tfm);
185
186	if (keylen != sizeof(mctx->key))
187		return -EINVAL;
188	mctx->key = get_unaligned_le32(key);
189	return 0;
190}
191
192static int chksum_update(struct shash_desc *desc, const u8 *data,
193			 unsigned int length)
194{
195	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
196
197	ctx->crc = crc32_mips_le_hw(ctx->crc, data, length);
198	return 0;
199}
200
201static int chksumc_update(struct shash_desc *desc, const u8 *data,
202			 unsigned int length)
203{
204	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
205
206	ctx->crc = crc32c_mips_le_hw(ctx->crc, data, length);
207	return 0;
208}
209
210static int chksum_final(struct shash_desc *desc, u8 *out)
211{
212	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
213
214	put_unaligned_le32(ctx->crc, out);
215	return 0;
216}
217
218static int chksumc_final(struct shash_desc *desc, u8 *out)
219{
220	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
221
222	put_unaligned_le32(~ctx->crc, out);
223	return 0;
224}
225
226static int __chksum_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
227{
228	put_unaligned_le32(crc32_mips_le_hw(crc, data, len), out);
229	return 0;
230}
231
232static int __chksumc_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
233{
234	put_unaligned_le32(~crc32c_mips_le_hw(crc, data, len), out);
235	return 0;
236}
237
238static int chksum_finup(struct shash_desc *desc, const u8 *data,
239			unsigned int len, u8 *out)
240{
241	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
242
243	return __chksum_finup(ctx->crc, data, len, out);
244}
245
246static int chksumc_finup(struct shash_desc *desc, const u8 *data,
247			unsigned int len, u8 *out)
248{
249	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
250
251	return __chksumc_finup(ctx->crc, data, len, out);
252}
253
254static int chksum_digest(struct shash_desc *desc, const u8 *data,
255			 unsigned int length, u8 *out)
256{
257	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
258
259	return __chksum_finup(mctx->key, data, length, out);
260}
261
262static int chksumc_digest(struct shash_desc *desc, const u8 *data,
263			 unsigned int length, u8 *out)
264{
265	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
266
267	return __chksumc_finup(mctx->key, data, length, out);
268}
269
270static int chksum_cra_init(struct crypto_tfm *tfm)
271{
272	struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
273
274	mctx->key = ~0;
275	return 0;
276}
277
278static struct shash_alg crc32_alg = {
279	.digestsize		=	CHKSUM_DIGEST_SIZE,
280	.setkey			=	chksum_setkey,
281	.init			=	chksum_init,
282	.update			=	chksum_update,
283	.final			=	chksum_final,
284	.finup			=	chksum_finup,
285	.digest			=	chksum_digest,
286	.descsize		=	sizeof(struct chksum_desc_ctx),
287	.base			=	{
288		.cra_name		=	"crc32",
289		.cra_driver_name	=	"crc32-mips-hw",
290		.cra_priority		=	300,
291		.cra_flags		=	CRYPTO_ALG_OPTIONAL_KEY,
292		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
293		.cra_ctxsize		=	sizeof(struct chksum_ctx),
294		.cra_module		=	THIS_MODULE,
295		.cra_init		=	chksum_cra_init,
296	}
297};
298
299static struct shash_alg crc32c_alg = {
300	.digestsize		=	CHKSUM_DIGEST_SIZE,
301	.setkey			=	chksum_setkey,
302	.init			=	chksum_init,
303	.update			=	chksumc_update,
304	.final			=	chksumc_final,
305	.finup			=	chksumc_finup,
306	.digest			=	chksumc_digest,
307	.descsize		=	sizeof(struct chksum_desc_ctx),
308	.base			=	{
309		.cra_name		=	"crc32c",
310		.cra_driver_name	=	"crc32c-mips-hw",
311		.cra_priority		=	300,
312		.cra_flags		=	CRYPTO_ALG_OPTIONAL_KEY,
313		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
314		.cra_ctxsize		=	sizeof(struct chksum_ctx),
315		.cra_module		=	THIS_MODULE,
316		.cra_init		=	chksum_cra_init,
317	}
318};
319
320static int __init crc32_mod_init(void)
321{
322	int err;
323
324	err = crypto_register_shash(&crc32_alg);
325
326	if (err)
327		return err;
328
329	err = crypto_register_shash(&crc32c_alg);
330
331	if (err) {
332		crypto_unregister_shash(&crc32_alg);
333		return err;
334	}
335
336	return 0;
337}
338
339static void __exit crc32_mod_exit(void)
340{
341	crypto_unregister_shash(&crc32_alg);
342	crypto_unregister_shash(&crc32c_alg);
343}
344
345MODULE_AUTHOR("Marcin Nowakowski <marcin.nowakowski@mips.com");
346MODULE_DESCRIPTION("CRC32 and CRC32C using optional MIPS instructions");
347MODULE_LICENSE("GPL v2");
348
349module_cpu_feature_match(MIPS_CRC32, crc32_mod_init);
350module_exit(crc32_mod_exit);