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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 <linux/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	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
118static 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
162struct chksum_ctx {
163	u32 key;
164};
165
166struct chksum_desc_ctx {
167	u32 crc;
168};
169
170static 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 */
185static 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
196static 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
205static 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
214static 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
222static 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
230static 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
236static 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
242static 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
250static 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
258static 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
266static 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
274static 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
282static 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
303static 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
324static 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
343static void __exit crc32_mod_exit(void)
344{
345	crypto_unregister_shash(&crc32_alg);
346	crypto_unregister_shash(&crc32c_alg);
347}
348
349MODULE_AUTHOR("Marcin Nowakowski <marcin.nowakowski@mips.com");
350MODULE_DESCRIPTION("CRC32 and CRC32C using optional MIPS instructions");
351MODULE_LICENSE("GPL v2");
352
353module_cpu_feature_match(MIPS_CRC32, crc32_mod_init);
354module_exit(crc32_mod_exit);