xref: /linux/arch/riscv/crypto/aes-riscv64-glue.c (revision 6e7fd890f1d6ac83805409e9c346240de2705584)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AES using the RISC-V vector crypto extensions.  Includes the bare block
4  * cipher and the ECB, CBC, CBC-CTS, CTR, and XTS modes.
5  *
6  * Copyright (C) 2023 VRULL GmbH
7  * Author: Heiko Stuebner <heiko.stuebner@vrull.eu>
8  *
9  * Copyright (C) 2023 SiFive, Inc.
10  * Author: Jerry Shih <jerry.shih@sifive.com>
11  *
12  * Copyright 2024 Google LLC
13  */
14 
15 #include <asm/simd.h>
16 #include <asm/vector.h>
17 #include <crypto/aes.h>
18 #include <crypto/internal/cipher.h>
19 #include <crypto/internal/simd.h>
20 #include <crypto/internal/skcipher.h>
21 #include <crypto/scatterwalk.h>
22 #include <crypto/xts.h>
23 #include <linux/linkage.h>
24 #include <linux/module.h>
25 
26 asmlinkage void aes_encrypt_zvkned(const struct crypto_aes_ctx *key,
27 				   const u8 in[AES_BLOCK_SIZE],
28 				   u8 out[AES_BLOCK_SIZE]);
29 asmlinkage void aes_decrypt_zvkned(const struct crypto_aes_ctx *key,
30 				   const u8 in[AES_BLOCK_SIZE],
31 				   u8 out[AES_BLOCK_SIZE]);
32 
33 asmlinkage void aes_ecb_encrypt_zvkned(const struct crypto_aes_ctx *key,
34 				       const u8 *in, u8 *out, size_t len);
35 asmlinkage void aes_ecb_decrypt_zvkned(const struct crypto_aes_ctx *key,
36 				       const u8 *in, u8 *out, size_t len);
37 
38 asmlinkage void aes_cbc_encrypt_zvkned(const struct crypto_aes_ctx *key,
39 				       const u8 *in, u8 *out, size_t len,
40 				       u8 iv[AES_BLOCK_SIZE]);
41 asmlinkage void aes_cbc_decrypt_zvkned(const struct crypto_aes_ctx *key,
42 				       const u8 *in, u8 *out, size_t len,
43 				       u8 iv[AES_BLOCK_SIZE]);
44 
45 asmlinkage void aes_cbc_cts_crypt_zvkned(const struct crypto_aes_ctx *key,
46 					 const u8 *in, u8 *out, size_t len,
47 					 const u8 iv[AES_BLOCK_SIZE], bool enc);
48 
49 asmlinkage void aes_ctr32_crypt_zvkned_zvkb(const struct crypto_aes_ctx *key,
50 					    const u8 *in, u8 *out, size_t len,
51 					    u8 iv[AES_BLOCK_SIZE]);
52 
53 asmlinkage void aes_xts_encrypt_zvkned_zvbb_zvkg(
54 			const struct crypto_aes_ctx *key,
55 			const u8 *in, u8 *out, size_t len,
56 			u8 tweak[AES_BLOCK_SIZE]);
57 
58 asmlinkage void aes_xts_decrypt_zvkned_zvbb_zvkg(
59 			const struct crypto_aes_ctx *key,
60 			const u8 *in, u8 *out, size_t len,
61 			u8 tweak[AES_BLOCK_SIZE]);
62 
63 static int riscv64_aes_setkey(struct crypto_aes_ctx *ctx,
64 			      const u8 *key, unsigned int keylen)
65 {
66 	/*
67 	 * For now we just use the generic key expansion, for these reasons:
68 	 *
69 	 * - zvkned's key expansion instructions don't support AES-192.
70 	 *   So, non-zvkned fallback code would be needed anyway.
71 	 *
72 	 * - Users of AES in Linux usually don't change keys frequently.
73 	 *   So, key expansion isn't performance-critical.
74 	 *
75 	 * - For single-block AES exposed as a "cipher" algorithm, it's
76 	 *   necessary to use struct crypto_aes_ctx and initialize its 'key_dec'
77 	 *   field with the round keys for the Equivalent Inverse Cipher.  This
78 	 *   is because with "cipher", decryption can be requested from a
79 	 *   context where the vector unit isn't usable, necessitating a
80 	 *   fallback to aes_decrypt().  But, zvkned can only generate and use
81 	 *   the normal round keys.  Of course, it's preferable to not have
82 	 *   special code just for "cipher", as e.g. XTS also uses a
83 	 *   single-block AES encryption.  It's simplest to just use
84 	 *   struct crypto_aes_ctx and aes_expandkey() everywhere.
85 	 */
86 	return aes_expandkey(ctx, key, keylen);
87 }
88 
89 static int riscv64_aes_setkey_cipher(struct crypto_tfm *tfm,
90 				     const u8 *key, unsigned int keylen)
91 {
92 	struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
93 
94 	return riscv64_aes_setkey(ctx, key, keylen);
95 }
96 
97 static int riscv64_aes_setkey_skcipher(struct crypto_skcipher *tfm,
98 				       const u8 *key, unsigned int keylen)
99 {
100 	struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
101 
102 	return riscv64_aes_setkey(ctx, key, keylen);
103 }
104 
105 /* Bare AES, without a mode of operation */
106 
107 static void riscv64_aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
108 {
109 	const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
110 
111 	if (crypto_simd_usable()) {
112 		kernel_vector_begin();
113 		aes_encrypt_zvkned(ctx, src, dst);
114 		kernel_vector_end();
115 	} else {
116 		aes_encrypt(ctx, dst, src);
117 	}
118 }
119 
120 static void riscv64_aes_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
121 {
122 	const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
123 
124 	if (crypto_simd_usable()) {
125 		kernel_vector_begin();
126 		aes_decrypt_zvkned(ctx, src, dst);
127 		kernel_vector_end();
128 	} else {
129 		aes_decrypt(ctx, dst, src);
130 	}
131 }
132 
133 /* AES-ECB */
134 
135 static inline int riscv64_aes_ecb_crypt(struct skcipher_request *req, bool enc)
136 {
137 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
138 	const struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
139 	struct skcipher_walk walk;
140 	unsigned int nbytes;
141 	int err;
142 
143 	err = skcipher_walk_virt(&walk, req, false);
144 	while ((nbytes = walk.nbytes) != 0) {
145 		kernel_vector_begin();
146 		if (enc)
147 			aes_ecb_encrypt_zvkned(ctx, walk.src.virt.addr,
148 					       walk.dst.virt.addr,
149 					       nbytes & ~(AES_BLOCK_SIZE - 1));
150 		else
151 			aes_ecb_decrypt_zvkned(ctx, walk.src.virt.addr,
152 					       walk.dst.virt.addr,
153 					       nbytes & ~(AES_BLOCK_SIZE - 1));
154 		kernel_vector_end();
155 		err = skcipher_walk_done(&walk, nbytes & (AES_BLOCK_SIZE - 1));
156 	}
157 
158 	return err;
159 }
160 
161 static int riscv64_aes_ecb_encrypt(struct skcipher_request *req)
162 {
163 	return riscv64_aes_ecb_crypt(req, true);
164 }
165 
166 static int riscv64_aes_ecb_decrypt(struct skcipher_request *req)
167 {
168 	return riscv64_aes_ecb_crypt(req, false);
169 }
170 
171 /* AES-CBC */
172 
173 static int riscv64_aes_cbc_crypt(struct skcipher_request *req, bool enc)
174 {
175 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
176 	const struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
177 	struct skcipher_walk walk;
178 	unsigned int nbytes;
179 	int err;
180 
181 	err = skcipher_walk_virt(&walk, req, false);
182 	while ((nbytes = walk.nbytes) != 0) {
183 		kernel_vector_begin();
184 		if (enc)
185 			aes_cbc_encrypt_zvkned(ctx, walk.src.virt.addr,
186 					       walk.dst.virt.addr,
187 					       nbytes & ~(AES_BLOCK_SIZE - 1),
188 					       walk.iv);
189 		else
190 			aes_cbc_decrypt_zvkned(ctx, walk.src.virt.addr,
191 					       walk.dst.virt.addr,
192 					       nbytes & ~(AES_BLOCK_SIZE - 1),
193 					       walk.iv);
194 		kernel_vector_end();
195 		err = skcipher_walk_done(&walk, nbytes & (AES_BLOCK_SIZE - 1));
196 	}
197 
198 	return err;
199 }
200 
201 static int riscv64_aes_cbc_encrypt(struct skcipher_request *req)
202 {
203 	return riscv64_aes_cbc_crypt(req, true);
204 }
205 
206 static int riscv64_aes_cbc_decrypt(struct skcipher_request *req)
207 {
208 	return riscv64_aes_cbc_crypt(req, false);
209 }
210 
211 /* AES-CBC-CTS */
212 
213 static int riscv64_aes_cbc_cts_crypt(struct skcipher_request *req, bool enc)
214 {
215 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
216 	const struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
217 	struct scatterlist sg_src[2], sg_dst[2];
218 	struct skcipher_request subreq;
219 	struct scatterlist *src, *dst;
220 	struct skcipher_walk walk;
221 	unsigned int cbc_len;
222 	int err;
223 
224 	if (req->cryptlen < AES_BLOCK_SIZE)
225 		return -EINVAL;
226 
227 	err = skcipher_walk_virt(&walk, req, false);
228 	if (err)
229 		return err;
230 	/*
231 	 * If the full message is available in one step, decrypt it in one call
232 	 * to the CBC-CTS assembly function.  This reduces overhead, especially
233 	 * on short messages.  Otherwise, fall back to doing CBC up to the last
234 	 * two blocks, then invoke CTS just for the ciphertext stealing.
235 	 */
236 	if (unlikely(walk.nbytes != req->cryptlen)) {
237 		cbc_len = round_down(req->cryptlen - AES_BLOCK_SIZE - 1,
238 				     AES_BLOCK_SIZE);
239 		skcipher_walk_abort(&walk);
240 		skcipher_request_set_tfm(&subreq, tfm);
241 		skcipher_request_set_callback(&subreq,
242 					      skcipher_request_flags(req),
243 					      NULL, NULL);
244 		skcipher_request_set_crypt(&subreq, req->src, req->dst,
245 					   cbc_len, req->iv);
246 		err = riscv64_aes_cbc_crypt(&subreq, enc);
247 		if (err)
248 			return err;
249 		dst = src = scatterwalk_ffwd(sg_src, req->src, cbc_len);
250 		if (req->dst != req->src)
251 			dst = scatterwalk_ffwd(sg_dst, req->dst, cbc_len);
252 		skcipher_request_set_crypt(&subreq, src, dst,
253 					   req->cryptlen - cbc_len, req->iv);
254 		err = skcipher_walk_virt(&walk, &subreq, false);
255 		if (err)
256 			return err;
257 	}
258 	kernel_vector_begin();
259 	aes_cbc_cts_crypt_zvkned(ctx, walk.src.virt.addr, walk.dst.virt.addr,
260 				 walk.nbytes, req->iv, enc);
261 	kernel_vector_end();
262 	return skcipher_walk_done(&walk, 0);
263 }
264 
265 static int riscv64_aes_cbc_cts_encrypt(struct skcipher_request *req)
266 {
267 	return riscv64_aes_cbc_cts_crypt(req, true);
268 }
269 
270 static int riscv64_aes_cbc_cts_decrypt(struct skcipher_request *req)
271 {
272 	return riscv64_aes_cbc_cts_crypt(req, false);
273 }
274 
275 /* AES-CTR */
276 
277 static int riscv64_aes_ctr_crypt(struct skcipher_request *req)
278 {
279 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
280 	const struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
281 	unsigned int nbytes, p1_nbytes;
282 	struct skcipher_walk walk;
283 	u32 ctr32, nblocks;
284 	int err;
285 
286 	/* Get the low 32-bit word of the 128-bit big endian counter. */
287 	ctr32 = get_unaligned_be32(req->iv + 12);
288 
289 	err = skcipher_walk_virt(&walk, req, false);
290 	while ((nbytes = walk.nbytes) != 0) {
291 		if (nbytes < walk.total) {
292 			/* Not the end yet, so keep the length block-aligned. */
293 			nbytes = round_down(nbytes, AES_BLOCK_SIZE);
294 			nblocks = nbytes / AES_BLOCK_SIZE;
295 		} else {
296 			/* It's the end, so include any final partial block. */
297 			nblocks = DIV_ROUND_UP(nbytes, AES_BLOCK_SIZE);
298 		}
299 		ctr32 += nblocks;
300 
301 		kernel_vector_begin();
302 		if (ctr32 >= nblocks) {
303 			/* The low 32-bit word of the counter won't overflow. */
304 			aes_ctr32_crypt_zvkned_zvkb(ctx, walk.src.virt.addr,
305 						    walk.dst.virt.addr, nbytes,
306 						    req->iv);
307 		} else {
308 			/*
309 			 * The low 32-bit word of the counter will overflow.
310 			 * The assembly doesn't handle this case, so split the
311 			 * operation into two at the point where the overflow
312 			 * will occur.  After the first part, add the carry bit.
313 			 */
314 			p1_nbytes = min_t(unsigned int, nbytes,
315 					  (nblocks - ctr32) * AES_BLOCK_SIZE);
316 			aes_ctr32_crypt_zvkned_zvkb(ctx, walk.src.virt.addr,
317 						    walk.dst.virt.addr,
318 						    p1_nbytes, req->iv);
319 			crypto_inc(req->iv, 12);
320 
321 			if (ctr32) {
322 				aes_ctr32_crypt_zvkned_zvkb(
323 					ctx,
324 					walk.src.virt.addr + p1_nbytes,
325 					walk.dst.virt.addr + p1_nbytes,
326 					nbytes - p1_nbytes, req->iv);
327 			}
328 		}
329 		kernel_vector_end();
330 
331 		err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
332 	}
333 
334 	return err;
335 }
336 
337 /* AES-XTS */
338 
339 struct riscv64_aes_xts_ctx {
340 	struct crypto_aes_ctx ctx1;
341 	struct crypto_aes_ctx ctx2;
342 };
343 
344 static int riscv64_aes_xts_setkey(struct crypto_skcipher *tfm, const u8 *key,
345 				  unsigned int keylen)
346 {
347 	struct riscv64_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
348 
349 	return xts_verify_key(tfm, key, keylen) ?:
350 	       riscv64_aes_setkey(&ctx->ctx1, key, keylen / 2) ?:
351 	       riscv64_aes_setkey(&ctx->ctx2, key + keylen / 2, keylen / 2);
352 }
353 
354 static int riscv64_aes_xts_crypt(struct skcipher_request *req, bool enc)
355 {
356 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
357 	const struct riscv64_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
358 	int tail = req->cryptlen % AES_BLOCK_SIZE;
359 	struct scatterlist sg_src[2], sg_dst[2];
360 	struct skcipher_request subreq;
361 	struct scatterlist *src, *dst;
362 	struct skcipher_walk walk;
363 	int err;
364 
365 	if (req->cryptlen < AES_BLOCK_SIZE)
366 		return -EINVAL;
367 
368 	/* Encrypt the IV with the tweak key to get the first tweak. */
369 	kernel_vector_begin();
370 	aes_encrypt_zvkned(&ctx->ctx2, req->iv, req->iv);
371 	kernel_vector_end();
372 
373 	err = skcipher_walk_virt(&walk, req, false);
374 
375 	/*
376 	 * If the message length isn't divisible by the AES block size and the
377 	 * full message isn't available in one step of the scatterlist walk,
378 	 * then separate off the last full block and the partial block.  This
379 	 * ensures that they are processed in the same call to the assembly
380 	 * function, which is required for ciphertext stealing.
381 	 */
382 	if (unlikely(tail > 0 && walk.nbytes < walk.total)) {
383 		skcipher_walk_abort(&walk);
384 
385 		skcipher_request_set_tfm(&subreq, tfm);
386 		skcipher_request_set_callback(&subreq,
387 					      skcipher_request_flags(req),
388 					      NULL, NULL);
389 		skcipher_request_set_crypt(&subreq, req->src, req->dst,
390 					   req->cryptlen - tail - AES_BLOCK_SIZE,
391 					   req->iv);
392 		req = &subreq;
393 		err = skcipher_walk_virt(&walk, req, false);
394 	} else {
395 		tail = 0;
396 	}
397 
398 	while (walk.nbytes) {
399 		unsigned int nbytes = walk.nbytes;
400 
401 		if (nbytes < walk.total)
402 			nbytes = round_down(nbytes, AES_BLOCK_SIZE);
403 
404 		kernel_vector_begin();
405 		if (enc)
406 			aes_xts_encrypt_zvkned_zvbb_zvkg(
407 				&ctx->ctx1, walk.src.virt.addr,
408 				walk.dst.virt.addr, nbytes, req->iv);
409 		else
410 			aes_xts_decrypt_zvkned_zvbb_zvkg(
411 				&ctx->ctx1, walk.src.virt.addr,
412 				walk.dst.virt.addr, nbytes, req->iv);
413 		kernel_vector_end();
414 		err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
415 	}
416 
417 	if (err || likely(!tail))
418 		return err;
419 
420 	/* Do ciphertext stealing with the last full block and partial block. */
421 
422 	dst = src = scatterwalk_ffwd(sg_src, req->src, req->cryptlen);
423 	if (req->dst != req->src)
424 		dst = scatterwalk_ffwd(sg_dst, req->dst, req->cryptlen);
425 
426 	skcipher_request_set_crypt(req, src, dst, AES_BLOCK_SIZE + tail,
427 				   req->iv);
428 
429 	err = skcipher_walk_virt(&walk, req, false);
430 	if (err)
431 		return err;
432 
433 	kernel_vector_begin();
434 	if (enc)
435 		aes_xts_encrypt_zvkned_zvbb_zvkg(
436 			&ctx->ctx1, walk.src.virt.addr,
437 			walk.dst.virt.addr, walk.nbytes, req->iv);
438 	else
439 		aes_xts_decrypt_zvkned_zvbb_zvkg(
440 			&ctx->ctx1, walk.src.virt.addr,
441 			walk.dst.virt.addr, walk.nbytes, req->iv);
442 	kernel_vector_end();
443 
444 	return skcipher_walk_done(&walk, 0);
445 }
446 
447 static int riscv64_aes_xts_encrypt(struct skcipher_request *req)
448 {
449 	return riscv64_aes_xts_crypt(req, true);
450 }
451 
452 static int riscv64_aes_xts_decrypt(struct skcipher_request *req)
453 {
454 	return riscv64_aes_xts_crypt(req, false);
455 }
456 
457 /* Algorithm definitions */
458 
459 static struct crypto_alg riscv64_zvkned_aes_cipher_alg = {
460 	.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
461 	.cra_blocksize = AES_BLOCK_SIZE,
462 	.cra_ctxsize = sizeof(struct crypto_aes_ctx),
463 	.cra_priority = 300,
464 	.cra_name = "aes",
465 	.cra_driver_name = "aes-riscv64-zvkned",
466 	.cra_cipher = {
467 		.cia_min_keysize = AES_MIN_KEY_SIZE,
468 		.cia_max_keysize = AES_MAX_KEY_SIZE,
469 		.cia_setkey = riscv64_aes_setkey_cipher,
470 		.cia_encrypt = riscv64_aes_encrypt,
471 		.cia_decrypt = riscv64_aes_decrypt,
472 	},
473 	.cra_module = THIS_MODULE,
474 };
475 
476 static struct skcipher_alg riscv64_zvkned_aes_skcipher_algs[] = {
477 	{
478 		.setkey = riscv64_aes_setkey_skcipher,
479 		.encrypt = riscv64_aes_ecb_encrypt,
480 		.decrypt = riscv64_aes_ecb_decrypt,
481 		.min_keysize = AES_MIN_KEY_SIZE,
482 		.max_keysize = AES_MAX_KEY_SIZE,
483 		.walksize = 8 * AES_BLOCK_SIZE, /* matches LMUL=8 */
484 		.base = {
485 			.cra_blocksize = AES_BLOCK_SIZE,
486 			.cra_ctxsize = sizeof(struct crypto_aes_ctx),
487 			.cra_priority = 300,
488 			.cra_name = "ecb(aes)",
489 			.cra_driver_name = "ecb-aes-riscv64-zvkned",
490 			.cra_module = THIS_MODULE,
491 		},
492 	}, {
493 		.setkey = riscv64_aes_setkey_skcipher,
494 		.encrypt = riscv64_aes_cbc_encrypt,
495 		.decrypt = riscv64_aes_cbc_decrypt,
496 		.min_keysize = AES_MIN_KEY_SIZE,
497 		.max_keysize = AES_MAX_KEY_SIZE,
498 		.ivsize = AES_BLOCK_SIZE,
499 		.base = {
500 			.cra_blocksize = AES_BLOCK_SIZE,
501 			.cra_ctxsize = sizeof(struct crypto_aes_ctx),
502 			.cra_priority = 300,
503 			.cra_name = "cbc(aes)",
504 			.cra_driver_name = "cbc-aes-riscv64-zvkned",
505 			.cra_module = THIS_MODULE,
506 		},
507 	}, {
508 		.setkey = riscv64_aes_setkey_skcipher,
509 		.encrypt = riscv64_aes_cbc_cts_encrypt,
510 		.decrypt = riscv64_aes_cbc_cts_decrypt,
511 		.min_keysize = AES_MIN_KEY_SIZE,
512 		.max_keysize = AES_MAX_KEY_SIZE,
513 		.ivsize = AES_BLOCK_SIZE,
514 		.walksize = 4 * AES_BLOCK_SIZE, /* matches LMUL=4 */
515 		.base = {
516 			.cra_blocksize = AES_BLOCK_SIZE,
517 			.cra_ctxsize = sizeof(struct crypto_aes_ctx),
518 			.cra_priority = 300,
519 			.cra_name = "cts(cbc(aes))",
520 			.cra_driver_name = "cts-cbc-aes-riscv64-zvkned",
521 			.cra_module = THIS_MODULE,
522 		},
523 	}
524 };
525 
526 static struct skcipher_alg riscv64_zvkned_zvkb_aes_skcipher_alg = {
527 	.setkey = riscv64_aes_setkey_skcipher,
528 	.encrypt = riscv64_aes_ctr_crypt,
529 	.decrypt = riscv64_aes_ctr_crypt,
530 	.min_keysize = AES_MIN_KEY_SIZE,
531 	.max_keysize = AES_MAX_KEY_SIZE,
532 	.ivsize = AES_BLOCK_SIZE,
533 	.chunksize = AES_BLOCK_SIZE,
534 	.walksize = 4 * AES_BLOCK_SIZE, /* matches LMUL=4 */
535 	.base = {
536 		.cra_blocksize = 1,
537 		.cra_ctxsize = sizeof(struct crypto_aes_ctx),
538 		.cra_priority = 300,
539 		.cra_name = "ctr(aes)",
540 		.cra_driver_name = "ctr-aes-riscv64-zvkned-zvkb",
541 		.cra_module = THIS_MODULE,
542 	},
543 };
544 
545 static struct skcipher_alg riscv64_zvkned_zvbb_zvkg_aes_skcipher_alg = {
546 	.setkey = riscv64_aes_xts_setkey,
547 	.encrypt = riscv64_aes_xts_encrypt,
548 	.decrypt = riscv64_aes_xts_decrypt,
549 	.min_keysize = 2 * AES_MIN_KEY_SIZE,
550 	.max_keysize = 2 * AES_MAX_KEY_SIZE,
551 	.ivsize = AES_BLOCK_SIZE,
552 	.chunksize = AES_BLOCK_SIZE,
553 	.walksize = 4 * AES_BLOCK_SIZE, /* matches LMUL=4 */
554 	.base = {
555 		.cra_blocksize = AES_BLOCK_SIZE,
556 		.cra_ctxsize = sizeof(struct riscv64_aes_xts_ctx),
557 		.cra_priority = 300,
558 		.cra_name = "xts(aes)",
559 		.cra_driver_name = "xts-aes-riscv64-zvkned-zvbb-zvkg",
560 		.cra_module = THIS_MODULE,
561 	},
562 };
563 
564 static inline bool riscv64_aes_xts_supported(void)
565 {
566 	return riscv_isa_extension_available(NULL, ZVBB) &&
567 	       riscv_isa_extension_available(NULL, ZVKG) &&
568 	       riscv_vector_vlen() < 2048 /* Implementation limitation */;
569 }
570 
571 static int __init riscv64_aes_mod_init(void)
572 {
573 	int err = -ENODEV;
574 
575 	if (riscv_isa_extension_available(NULL, ZVKNED) &&
576 	    riscv_vector_vlen() >= 128) {
577 		err = crypto_register_alg(&riscv64_zvkned_aes_cipher_alg);
578 		if (err)
579 			return err;
580 
581 		err = crypto_register_skciphers(
582 			riscv64_zvkned_aes_skcipher_algs,
583 			ARRAY_SIZE(riscv64_zvkned_aes_skcipher_algs));
584 		if (err)
585 			goto unregister_zvkned_cipher_alg;
586 
587 		if (riscv_isa_extension_available(NULL, ZVKB)) {
588 			err = crypto_register_skcipher(
589 				&riscv64_zvkned_zvkb_aes_skcipher_alg);
590 			if (err)
591 				goto unregister_zvkned_skcipher_algs;
592 		}
593 
594 		if (riscv64_aes_xts_supported()) {
595 			err = crypto_register_skcipher(
596 				&riscv64_zvkned_zvbb_zvkg_aes_skcipher_alg);
597 			if (err)
598 				goto unregister_zvkned_zvkb_skcipher_alg;
599 		}
600 	}
601 
602 	return err;
603 
604 unregister_zvkned_zvkb_skcipher_alg:
605 	if (riscv_isa_extension_available(NULL, ZVKB))
606 		crypto_unregister_skcipher(&riscv64_zvkned_zvkb_aes_skcipher_alg);
607 unregister_zvkned_skcipher_algs:
608 	crypto_unregister_skciphers(riscv64_zvkned_aes_skcipher_algs,
609 				    ARRAY_SIZE(riscv64_zvkned_aes_skcipher_algs));
610 unregister_zvkned_cipher_alg:
611 	crypto_unregister_alg(&riscv64_zvkned_aes_cipher_alg);
612 	return err;
613 }
614 
615 static void __exit riscv64_aes_mod_exit(void)
616 {
617 	if (riscv64_aes_xts_supported())
618 		crypto_unregister_skcipher(&riscv64_zvkned_zvbb_zvkg_aes_skcipher_alg);
619 	if (riscv_isa_extension_available(NULL, ZVKB))
620 		crypto_unregister_skcipher(&riscv64_zvkned_zvkb_aes_skcipher_alg);
621 	crypto_unregister_skciphers(riscv64_zvkned_aes_skcipher_algs,
622 				    ARRAY_SIZE(riscv64_zvkned_aes_skcipher_algs));
623 	crypto_unregister_alg(&riscv64_zvkned_aes_cipher_alg);
624 }
625 
626 module_init(riscv64_aes_mod_init);
627 module_exit(riscv64_aes_mod_exit);
628 
629 MODULE_DESCRIPTION("AES-ECB/CBC/CTS/CTR/XTS (RISC-V accelerated)");
630 MODULE_AUTHOR("Jerry Shih <jerry.shih@sifive.com>");
631 MODULE_LICENSE("GPL");
632 MODULE_ALIAS_CRYPTO("aes");
633 MODULE_ALIAS_CRYPTO("ecb(aes)");
634 MODULE_ALIAS_CRYPTO("cbc(aes)");
635 MODULE_ALIAS_CRYPTO("cts(cbc(aes))");
636 MODULE_ALIAS_CRYPTO("ctr(aes)");
637 MODULE_ALIAS_CRYPTO("xts(aes)");
638