xref: /openbmc/linux/arch/s390/crypto/paes_s390.c (revision 5a158981)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Cryptographic API.
4  *
5  * s390 implementation of the AES Cipher Algorithm with protected keys.
6  *
7  * s390 Version:
8  *   Copyright IBM Corp. 2017,2019
9  *   Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
10  *		Harald Freudenberger <freude@de.ibm.com>
11  */
12 
13 #define KMSG_COMPONENT "paes_s390"
14 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15 
16 #include <crypto/aes.h>
17 #include <crypto/algapi.h>
18 #include <linux/bug.h>
19 #include <linux/err.h>
20 #include <linux/module.h>
21 #include <linux/cpufeature.h>
22 #include <linux/init.h>
23 #include <linux/spinlock.h>
24 #include <crypto/internal/skcipher.h>
25 #include <crypto/xts.h>
26 #include <asm/cpacf.h>
27 #include <asm/pkey.h>
28 
29 /*
30  * Key blobs smaller/bigger than these defines are rejected
31  * by the common code even before the individual setkey function
32  * is called. As paes can handle different kinds of key blobs
33  * and padding is also possible, the limits need to be generous.
34  */
35 #define PAES_MIN_KEYSIZE 64
36 #define PAES_MAX_KEYSIZE 256
37 
38 static u8 *ctrblk;
39 static DEFINE_SPINLOCK(ctrblk_lock);
40 
41 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions;
42 
43 struct key_blob {
44 	/*
45 	 * Small keys will be stored in the keybuf. Larger keys are
46 	 * stored in extra allocated memory. In both cases does
47 	 * key point to the memory where the key is stored.
48 	 * The code distinguishes by checking keylen against
49 	 * sizeof(keybuf). See the two following helper functions.
50 	 */
51 	u8 *key;
52 	u8 keybuf[128];
53 	unsigned int keylen;
54 };
55 
56 static inline int _copy_key_to_kb(struct key_blob *kb,
57 				  const u8 *key,
58 				  unsigned int keylen)
59 {
60 	if (keylen <= sizeof(kb->keybuf))
61 		kb->key = kb->keybuf;
62 	else {
63 		kb->key = kmalloc(keylen, GFP_KERNEL);
64 		if (!kb->key)
65 			return -ENOMEM;
66 	}
67 	memcpy(kb->key, key, keylen);
68 	kb->keylen = keylen;
69 
70 	return 0;
71 }
72 
73 static inline void _free_kb_keybuf(struct key_blob *kb)
74 {
75 	if (kb->key && kb->key != kb->keybuf
76 	    && kb->keylen > sizeof(kb->keybuf)) {
77 		kfree(kb->key);
78 		kb->key = NULL;
79 	}
80 }
81 
82 struct s390_paes_ctx {
83 	struct key_blob kb;
84 	struct pkey_protkey pk;
85 	unsigned long fc;
86 };
87 
88 struct s390_pxts_ctx {
89 	struct key_blob kb[2];
90 	struct pkey_protkey pk[2];
91 	unsigned long fc;
92 };
93 
94 static inline int __paes_convert_key(struct key_blob *kb,
95 				     struct pkey_protkey *pk)
96 {
97 	int i, ret;
98 
99 	/* try three times in case of failure */
100 	for (i = 0; i < 3; i++) {
101 		ret = pkey_keyblob2pkey(kb->key, kb->keylen, pk);
102 		if (ret == 0)
103 			break;
104 	}
105 
106 	return ret;
107 }
108 
109 static int __paes_set_key(struct s390_paes_ctx *ctx)
110 {
111 	unsigned long fc;
112 
113 	if (__paes_convert_key(&ctx->kb, &ctx->pk))
114 		return -EINVAL;
115 
116 	/* Pick the correct function code based on the protected key type */
117 	fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KM_PAES_128 :
118 		(ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KM_PAES_192 :
119 		(ctx->pk.type == PKEY_KEYTYPE_AES_256) ? CPACF_KM_PAES_256 : 0;
120 
121 	/* Check if the function code is available */
122 	ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
123 
124 	return ctx->fc ? 0 : -EINVAL;
125 }
126 
127 static int ecb_paes_init(struct crypto_skcipher *tfm)
128 {
129 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
130 
131 	ctx->kb.key = NULL;
132 
133 	return 0;
134 }
135 
136 static void ecb_paes_exit(struct crypto_skcipher *tfm)
137 {
138 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
139 
140 	_free_kb_keybuf(&ctx->kb);
141 }
142 
143 static int ecb_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
144 			    unsigned int key_len)
145 {
146 	int rc;
147 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
148 
149 	_free_kb_keybuf(&ctx->kb);
150 	rc = _copy_key_to_kb(&ctx->kb, in_key, key_len);
151 	if (rc)
152 		return rc;
153 
154 	if (__paes_set_key(ctx)) {
155 		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
156 		return -EINVAL;
157 	}
158 	return 0;
159 }
160 
161 static int ecb_paes_crypt(struct skcipher_request *req, unsigned long modifier)
162 {
163 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
164 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
165 	struct skcipher_walk walk;
166 	unsigned int nbytes, n, k;
167 	int ret;
168 
169 	ret = skcipher_walk_virt(&walk, req, false);
170 	while ((nbytes = walk.nbytes) != 0) {
171 		/* only use complete blocks */
172 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
173 		k = cpacf_km(ctx->fc | modifier, ctx->pk.protkey,
174 			     walk.dst.virt.addr, walk.src.virt.addr, n);
175 		if (k)
176 			ret = skcipher_walk_done(&walk, nbytes - k);
177 		if (k < n) {
178 			if (__paes_set_key(ctx) != 0)
179 				return skcipher_walk_done(&walk, -EIO);
180 		}
181 	}
182 	return ret;
183 }
184 
185 static int ecb_paes_encrypt(struct skcipher_request *req)
186 {
187 	return ecb_paes_crypt(req, 0);
188 }
189 
190 static int ecb_paes_decrypt(struct skcipher_request *req)
191 {
192 	return ecb_paes_crypt(req, CPACF_DECRYPT);
193 }
194 
195 static struct skcipher_alg ecb_paes_alg = {
196 	.base.cra_name		=	"ecb(paes)",
197 	.base.cra_driver_name	=	"ecb-paes-s390",
198 	.base.cra_priority	=	401,	/* combo: aes + ecb + 1 */
199 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
200 	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
201 	.base.cra_module	=	THIS_MODULE,
202 	.base.cra_list		=	LIST_HEAD_INIT(ecb_paes_alg.base.cra_list),
203 	.init			=	ecb_paes_init,
204 	.exit			=	ecb_paes_exit,
205 	.min_keysize		=	PAES_MIN_KEYSIZE,
206 	.max_keysize		=	PAES_MAX_KEYSIZE,
207 	.setkey			=	ecb_paes_set_key,
208 	.encrypt		=	ecb_paes_encrypt,
209 	.decrypt		=	ecb_paes_decrypt,
210 };
211 
212 static int cbc_paes_init(struct crypto_skcipher *tfm)
213 {
214 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
215 
216 	ctx->kb.key = NULL;
217 
218 	return 0;
219 }
220 
221 static void cbc_paes_exit(struct crypto_skcipher *tfm)
222 {
223 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
224 
225 	_free_kb_keybuf(&ctx->kb);
226 }
227 
228 static int __cbc_paes_set_key(struct s390_paes_ctx *ctx)
229 {
230 	unsigned long fc;
231 
232 	if (__paes_convert_key(&ctx->kb, &ctx->pk))
233 		return -EINVAL;
234 
235 	/* Pick the correct function code based on the protected key type */
236 	fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KMC_PAES_128 :
237 		(ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KMC_PAES_192 :
238 		(ctx->pk.type == PKEY_KEYTYPE_AES_256) ? CPACF_KMC_PAES_256 : 0;
239 
240 	/* Check if the function code is available */
241 	ctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0;
242 
243 	return ctx->fc ? 0 : -EINVAL;
244 }
245 
246 static int cbc_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
247 			    unsigned int key_len)
248 {
249 	int rc;
250 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
251 
252 	_free_kb_keybuf(&ctx->kb);
253 	rc = _copy_key_to_kb(&ctx->kb, in_key, key_len);
254 	if (rc)
255 		return rc;
256 
257 	if (__cbc_paes_set_key(ctx)) {
258 		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
259 		return -EINVAL;
260 	}
261 	return 0;
262 }
263 
264 static int cbc_paes_crypt(struct skcipher_request *req, unsigned long modifier)
265 {
266 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
267 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
268 	struct skcipher_walk walk;
269 	unsigned int nbytes, n, k;
270 	int ret;
271 	struct {
272 		u8 iv[AES_BLOCK_SIZE];
273 		u8 key[MAXPROTKEYSIZE];
274 	} param;
275 
276 	ret = skcipher_walk_virt(&walk, req, false);
277 	if (ret)
278 		return ret;
279 	memcpy(param.iv, walk.iv, AES_BLOCK_SIZE);
280 	memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
281 	while ((nbytes = walk.nbytes) != 0) {
282 		/* only use complete blocks */
283 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
284 		k = cpacf_kmc(ctx->fc | modifier, &param,
285 			      walk.dst.virt.addr, walk.src.virt.addr, n);
286 		if (k) {
287 			memcpy(walk.iv, param.iv, AES_BLOCK_SIZE);
288 			ret = skcipher_walk_done(&walk, nbytes - k);
289 		}
290 		if (k < n) {
291 			if (__cbc_paes_set_key(ctx) != 0)
292 				return skcipher_walk_done(&walk, -EIO);
293 			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
294 		}
295 	}
296 	return ret;
297 }
298 
299 static int cbc_paes_encrypt(struct skcipher_request *req)
300 {
301 	return cbc_paes_crypt(req, 0);
302 }
303 
304 static int cbc_paes_decrypt(struct skcipher_request *req)
305 {
306 	return cbc_paes_crypt(req, CPACF_DECRYPT);
307 }
308 
309 static struct skcipher_alg cbc_paes_alg = {
310 	.base.cra_name		=	"cbc(paes)",
311 	.base.cra_driver_name	=	"cbc-paes-s390",
312 	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
313 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
314 	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
315 	.base.cra_module	=	THIS_MODULE,
316 	.base.cra_list		=	LIST_HEAD_INIT(cbc_paes_alg.base.cra_list),
317 	.init			=	cbc_paes_init,
318 	.exit			=	cbc_paes_exit,
319 	.min_keysize		=	PAES_MIN_KEYSIZE,
320 	.max_keysize		=	PAES_MAX_KEYSIZE,
321 	.ivsize			=	AES_BLOCK_SIZE,
322 	.setkey			=	cbc_paes_set_key,
323 	.encrypt		=	cbc_paes_encrypt,
324 	.decrypt		=	cbc_paes_decrypt,
325 };
326 
327 static int xts_paes_init(struct crypto_skcipher *tfm)
328 {
329 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
330 
331 	ctx->kb[0].key = NULL;
332 	ctx->kb[1].key = NULL;
333 
334 	return 0;
335 }
336 
337 static void xts_paes_exit(struct crypto_skcipher *tfm)
338 {
339 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
340 
341 	_free_kb_keybuf(&ctx->kb[0]);
342 	_free_kb_keybuf(&ctx->kb[1]);
343 }
344 
345 static int __xts_paes_set_key(struct s390_pxts_ctx *ctx)
346 {
347 	unsigned long fc;
348 
349 	if (__paes_convert_key(&ctx->kb[0], &ctx->pk[0]) ||
350 	    __paes_convert_key(&ctx->kb[1], &ctx->pk[1]))
351 		return -EINVAL;
352 
353 	if (ctx->pk[0].type != ctx->pk[1].type)
354 		return -EINVAL;
355 
356 	/* Pick the correct function code based on the protected key type */
357 	fc = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? CPACF_KM_PXTS_128 :
358 		(ctx->pk[0].type == PKEY_KEYTYPE_AES_256) ?
359 		CPACF_KM_PXTS_256 : 0;
360 
361 	/* Check if the function code is available */
362 	ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
363 
364 	return ctx->fc ? 0 : -EINVAL;
365 }
366 
367 static int xts_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
368 			    unsigned int xts_key_len)
369 {
370 	int rc;
371 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
372 	u8 ckey[2 * AES_MAX_KEY_SIZE];
373 	unsigned int ckey_len, key_len;
374 
375 	if (xts_key_len % 2)
376 		return -EINVAL;
377 
378 	key_len = xts_key_len / 2;
379 
380 	_free_kb_keybuf(&ctx->kb[0]);
381 	_free_kb_keybuf(&ctx->kb[1]);
382 	rc = _copy_key_to_kb(&ctx->kb[0], in_key, key_len);
383 	if (rc)
384 		return rc;
385 	rc = _copy_key_to_kb(&ctx->kb[1], in_key + key_len, key_len);
386 	if (rc)
387 		return rc;
388 
389 	if (__xts_paes_set_key(ctx)) {
390 		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
391 		return -EINVAL;
392 	}
393 
394 	/*
395 	 * xts_check_key verifies the key length is not odd and makes
396 	 * sure that the two keys are not the same. This can be done
397 	 * on the two protected keys as well
398 	 */
399 	ckey_len = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ?
400 		AES_KEYSIZE_128 : AES_KEYSIZE_256;
401 	memcpy(ckey, ctx->pk[0].protkey, ckey_len);
402 	memcpy(ckey + ckey_len, ctx->pk[1].protkey, ckey_len);
403 	return xts_verify_key(tfm, ckey, 2*ckey_len);
404 }
405 
406 static int xts_paes_crypt(struct skcipher_request *req, unsigned long modifier)
407 {
408 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
409 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
410 	struct skcipher_walk walk;
411 	unsigned int keylen, offset, nbytes, n, k;
412 	int ret;
413 	struct {
414 		u8 key[MAXPROTKEYSIZE];	/* key + verification pattern */
415 		u8 tweak[16];
416 		u8 block[16];
417 		u8 bit[16];
418 		u8 xts[16];
419 	} pcc_param;
420 	struct {
421 		u8 key[MAXPROTKEYSIZE];	/* key + verification pattern */
422 		u8 init[16];
423 	} xts_param;
424 
425 	ret = skcipher_walk_virt(&walk, req, false);
426 	if (ret)
427 		return ret;
428 	keylen = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? 48 : 64;
429 	offset = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? 16 : 0;
430 retry:
431 	memset(&pcc_param, 0, sizeof(pcc_param));
432 	memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak));
433 	memcpy(pcc_param.key + offset, ctx->pk[1].protkey, keylen);
434 	cpacf_pcc(ctx->fc, pcc_param.key + offset);
435 
436 	memcpy(xts_param.key + offset, ctx->pk[0].protkey, keylen);
437 	memcpy(xts_param.init, pcc_param.xts, 16);
438 
439 	while ((nbytes = walk.nbytes) != 0) {
440 		/* only use complete blocks */
441 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
442 		k = cpacf_km(ctx->fc | modifier, xts_param.key + offset,
443 			     walk.dst.virt.addr, walk.src.virt.addr, n);
444 		if (k)
445 			ret = skcipher_walk_done(&walk, nbytes - k);
446 		if (k < n) {
447 			if (__xts_paes_set_key(ctx) != 0)
448 				return skcipher_walk_done(&walk, -EIO);
449 			goto retry;
450 		}
451 	}
452 	return ret;
453 }
454 
455 static int xts_paes_encrypt(struct skcipher_request *req)
456 {
457 	return xts_paes_crypt(req, 0);
458 }
459 
460 static int xts_paes_decrypt(struct skcipher_request *req)
461 {
462 	return xts_paes_crypt(req, CPACF_DECRYPT);
463 }
464 
465 static struct skcipher_alg xts_paes_alg = {
466 	.base.cra_name		=	"xts(paes)",
467 	.base.cra_driver_name	=	"xts-paes-s390",
468 	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
469 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
470 	.base.cra_ctxsize	=	sizeof(struct s390_pxts_ctx),
471 	.base.cra_module	=	THIS_MODULE,
472 	.base.cra_list		=	LIST_HEAD_INIT(xts_paes_alg.base.cra_list),
473 	.init			=	xts_paes_init,
474 	.exit			=	xts_paes_exit,
475 	.min_keysize		=	2 * PAES_MIN_KEYSIZE,
476 	.max_keysize		=	2 * PAES_MAX_KEYSIZE,
477 	.ivsize			=	AES_BLOCK_SIZE,
478 	.setkey			=	xts_paes_set_key,
479 	.encrypt		=	xts_paes_encrypt,
480 	.decrypt		=	xts_paes_decrypt,
481 };
482 
483 static int ctr_paes_init(struct crypto_skcipher *tfm)
484 {
485 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
486 
487 	ctx->kb.key = NULL;
488 
489 	return 0;
490 }
491 
492 static void ctr_paes_exit(struct crypto_skcipher *tfm)
493 {
494 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
495 
496 	_free_kb_keybuf(&ctx->kb);
497 }
498 
499 static int __ctr_paes_set_key(struct s390_paes_ctx *ctx)
500 {
501 	unsigned long fc;
502 
503 	if (__paes_convert_key(&ctx->kb, &ctx->pk))
504 		return -EINVAL;
505 
506 	/* Pick the correct function code based on the protected key type */
507 	fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KMCTR_PAES_128 :
508 		(ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KMCTR_PAES_192 :
509 		(ctx->pk.type == PKEY_KEYTYPE_AES_256) ?
510 		CPACF_KMCTR_PAES_256 : 0;
511 
512 	/* Check if the function code is available */
513 	ctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0;
514 
515 	return ctx->fc ? 0 : -EINVAL;
516 }
517 
518 static int ctr_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
519 			    unsigned int key_len)
520 {
521 	int rc;
522 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
523 
524 	_free_kb_keybuf(&ctx->kb);
525 	rc = _copy_key_to_kb(&ctx->kb, in_key, key_len);
526 	if (rc)
527 		return rc;
528 
529 	if (__ctr_paes_set_key(ctx)) {
530 		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
531 		return -EINVAL;
532 	}
533 	return 0;
534 }
535 
536 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes)
537 {
538 	unsigned int i, n;
539 
540 	/* only use complete blocks, max. PAGE_SIZE */
541 	memcpy(ctrptr, iv, AES_BLOCK_SIZE);
542 	n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1);
543 	for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) {
544 		memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE);
545 		crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE);
546 		ctrptr += AES_BLOCK_SIZE;
547 	}
548 	return n;
549 }
550 
551 static int ctr_paes_crypt(struct skcipher_request *req)
552 {
553 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
554 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
555 	u8 buf[AES_BLOCK_SIZE], *ctrptr;
556 	struct skcipher_walk walk;
557 	unsigned int nbytes, n, k;
558 	int ret, locked;
559 
560 	locked = spin_trylock(&ctrblk_lock);
561 
562 	ret = skcipher_walk_virt(&walk, req, false);
563 	while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
564 		n = AES_BLOCK_SIZE;
565 		if (nbytes >= 2*AES_BLOCK_SIZE && locked)
566 			n = __ctrblk_init(ctrblk, walk.iv, nbytes);
567 		ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk.iv;
568 		k = cpacf_kmctr(ctx->fc, ctx->pk.protkey, walk.dst.virt.addr,
569 				walk.src.virt.addr, n, ctrptr);
570 		if (k) {
571 			if (ctrptr == ctrblk)
572 				memcpy(walk.iv, ctrptr + k - AES_BLOCK_SIZE,
573 				       AES_BLOCK_SIZE);
574 			crypto_inc(walk.iv, AES_BLOCK_SIZE);
575 			ret = skcipher_walk_done(&walk, nbytes - n);
576 		}
577 		if (k < n) {
578 			if (__ctr_paes_set_key(ctx) != 0) {
579 				if (locked)
580 					spin_unlock(&ctrblk_lock);
581 				return skcipher_walk_done(&walk, -EIO);
582 			}
583 		}
584 	}
585 	if (locked)
586 		spin_unlock(&ctrblk_lock);
587 	/*
588 	 * final block may be < AES_BLOCK_SIZE, copy only nbytes
589 	 */
590 	if (nbytes) {
591 		while (1) {
592 			if (cpacf_kmctr(ctx->fc, ctx->pk.protkey, buf,
593 					walk.src.virt.addr, AES_BLOCK_SIZE,
594 					walk.iv) == AES_BLOCK_SIZE)
595 				break;
596 			if (__ctr_paes_set_key(ctx) != 0)
597 				return skcipher_walk_done(&walk, -EIO);
598 		}
599 		memcpy(walk.dst.virt.addr, buf, nbytes);
600 		crypto_inc(walk.iv, AES_BLOCK_SIZE);
601 		ret = skcipher_walk_done(&walk, 0);
602 	}
603 
604 	return ret;
605 }
606 
607 static struct skcipher_alg ctr_paes_alg = {
608 	.base.cra_name		=	"ctr(paes)",
609 	.base.cra_driver_name	=	"ctr-paes-s390",
610 	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
611 	.base.cra_blocksize	=	1,
612 	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
613 	.base.cra_module	=	THIS_MODULE,
614 	.base.cra_list		=	LIST_HEAD_INIT(ctr_paes_alg.base.cra_list),
615 	.init			=	ctr_paes_init,
616 	.exit			=	ctr_paes_exit,
617 	.min_keysize		=	PAES_MIN_KEYSIZE,
618 	.max_keysize		=	PAES_MAX_KEYSIZE,
619 	.ivsize			=	AES_BLOCK_SIZE,
620 	.setkey			=	ctr_paes_set_key,
621 	.encrypt		=	ctr_paes_crypt,
622 	.decrypt		=	ctr_paes_crypt,
623 	.chunksize		=	AES_BLOCK_SIZE,
624 };
625 
626 static inline void __crypto_unregister_skcipher(struct skcipher_alg *alg)
627 {
628 	if (!list_empty(&alg->base.cra_list))
629 		crypto_unregister_skcipher(alg);
630 }
631 
632 static void paes_s390_fini(void)
633 {
634 	if (ctrblk)
635 		free_page((unsigned long) ctrblk);
636 	__crypto_unregister_skcipher(&ctr_paes_alg);
637 	__crypto_unregister_skcipher(&xts_paes_alg);
638 	__crypto_unregister_skcipher(&cbc_paes_alg);
639 	__crypto_unregister_skcipher(&ecb_paes_alg);
640 }
641 
642 static int __init paes_s390_init(void)
643 {
644 	int ret;
645 
646 	/* Query available functions for KM, KMC and KMCTR */
647 	cpacf_query(CPACF_KM, &km_functions);
648 	cpacf_query(CPACF_KMC, &kmc_functions);
649 	cpacf_query(CPACF_KMCTR, &kmctr_functions);
650 
651 	if (cpacf_test_func(&km_functions, CPACF_KM_PAES_128) ||
652 	    cpacf_test_func(&km_functions, CPACF_KM_PAES_192) ||
653 	    cpacf_test_func(&km_functions, CPACF_KM_PAES_256)) {
654 		ret = crypto_register_skcipher(&ecb_paes_alg);
655 		if (ret)
656 			goto out_err;
657 	}
658 
659 	if (cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_128) ||
660 	    cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_192) ||
661 	    cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_256)) {
662 		ret = crypto_register_skcipher(&cbc_paes_alg);
663 		if (ret)
664 			goto out_err;
665 	}
666 
667 	if (cpacf_test_func(&km_functions, CPACF_KM_PXTS_128) ||
668 	    cpacf_test_func(&km_functions, CPACF_KM_PXTS_256)) {
669 		ret = crypto_register_skcipher(&xts_paes_alg);
670 		if (ret)
671 			goto out_err;
672 	}
673 
674 	if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_128) ||
675 	    cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_192) ||
676 	    cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_256)) {
677 		ret = crypto_register_skcipher(&ctr_paes_alg);
678 		if (ret)
679 			goto out_err;
680 		ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
681 		if (!ctrblk) {
682 			ret = -ENOMEM;
683 			goto out_err;
684 		}
685 	}
686 
687 	return 0;
688 out_err:
689 	paes_s390_fini();
690 	return ret;
691 }
692 
693 module_init(paes_s390_init);
694 module_exit(paes_s390_fini);
695 
696 MODULE_ALIAS_CRYPTO("paes");
697 
698 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm with protected keys");
699 MODULE_LICENSE("GPL");
700