xref: /linux/drivers/crypto/geode-aes.c (revision 9a6b55ac) 
1 // SPDX-License-Identifier: GPL-2.0-or-later
2  /* Copyright (C) 2004-2006, Advanced Micro Devices, Inc.
3   */
4 
5 #include <linux/module.h>
6 #include <linux/kernel.h>
7 #include <linux/pci.h>
8 #include <linux/pci_ids.h>
9 #include <linux/crypto.h>
10 #include <linux/spinlock.h>
11 #include <crypto/algapi.h>
12 #include <crypto/aes.h>
13 #include <crypto/internal/skcipher.h>
14 
15 #include <linux/io.h>
16 #include <linux/delay.h>
17 
18 #include "geode-aes.h"
19 
20 /* Static structures */
21 
22 static void __iomem *_iobase;
23 static spinlock_t lock;
24 
25 /* Write a 128 bit field (either a writable key or IV) */
26 static inline void
27 _writefield(u32 offset, const void *value)
28 {
29 	int i;
30 
31 	for (i = 0; i < 4; i++)
32 		iowrite32(((const u32 *) value)[i], _iobase + offset + (i * 4));
33 }
34 
35 /* Read a 128 bit field (either a writable key or IV) */
36 static inline void
37 _readfield(u32 offset, void *value)
38 {
39 	int i;
40 
41 	for (i = 0; i < 4; i++)
42 		((u32 *) value)[i] = ioread32(_iobase + offset + (i * 4));
43 }
44 
45 static int
46 do_crypt(const void *src, void *dst, u32 len, u32 flags)
47 {
48 	u32 status;
49 	u32 counter = AES_OP_TIMEOUT;
50 
51 	iowrite32(virt_to_phys((void *)src), _iobase + AES_SOURCEA_REG);
52 	iowrite32(virt_to_phys(dst), _iobase + AES_DSTA_REG);
53 	iowrite32(len,  _iobase + AES_LENA_REG);
54 
55 	/* Start the operation */
56 	iowrite32(AES_CTRL_START | flags, _iobase + AES_CTRLA_REG);
57 
58 	do {
59 		status = ioread32(_iobase + AES_INTR_REG);
60 		cpu_relax();
61 	} while (!(status & AES_INTRA_PENDING) && --counter);
62 
63 	/* Clear the event */
64 	iowrite32((status & 0xFF) | AES_INTRA_PENDING, _iobase + AES_INTR_REG);
65 	return counter ? 0 : 1;
66 }
67 
68 static void
69 geode_aes_crypt(const struct geode_aes_tfm_ctx *tctx, const void *src,
70 		void *dst, u32 len, u8 *iv, int mode, int dir)
71 {
72 	u32 flags = 0;
73 	unsigned long iflags;
74 	int ret;
75 
76 	/* If the source and destination is the same, then
77 	 * we need to turn on the coherent flags, otherwise
78 	 * we don't need to worry
79 	 */
80 
81 	flags |= (AES_CTRL_DCA | AES_CTRL_SCA);
82 
83 	if (dir == AES_DIR_ENCRYPT)
84 		flags |= AES_CTRL_ENCRYPT;
85 
86 	/* Start the critical section */
87 
88 	spin_lock_irqsave(&lock, iflags);
89 
90 	if (mode == AES_MODE_CBC) {
91 		flags |= AES_CTRL_CBC;
92 		_writefield(AES_WRITEIV0_REG, iv);
93 	}
94 
95 	flags |= AES_CTRL_WRKEY;
96 	_writefield(AES_WRITEKEY0_REG, tctx->key);
97 
98 	ret = do_crypt(src, dst, len, flags);
99 	BUG_ON(ret);
100 
101 	if (mode == AES_MODE_CBC)
102 		_readfield(AES_WRITEIV0_REG, iv);
103 
104 	spin_unlock_irqrestore(&lock, iflags);
105 }
106 
107 /* CRYPTO-API Functions */
108 
109 static int geode_setkey_cip(struct crypto_tfm *tfm, const u8 *key,
110 		unsigned int len)
111 {
112 	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
113 	unsigned int ret;
114 
115 	tctx->keylen = len;
116 
117 	if (len == AES_KEYSIZE_128) {
118 		memcpy(tctx->key, key, len);
119 		return 0;
120 	}
121 
122 	if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256) {
123 		/* not supported at all */
124 		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
125 		return -EINVAL;
126 	}
127 
128 	/*
129 	 * The requested key size is not supported by HW, do a fallback
130 	 */
131 	tctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
132 	tctx->fallback.cip->base.crt_flags |=
133 		(tfm->crt_flags & CRYPTO_TFM_REQ_MASK);
134 
135 	ret = crypto_cipher_setkey(tctx->fallback.cip, key, len);
136 	if (ret) {
137 		tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
138 		tfm->crt_flags |= (tctx->fallback.cip->base.crt_flags &
139 				   CRYPTO_TFM_RES_MASK);
140 	}
141 	return ret;
142 }
143 
144 static int geode_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
145 				 unsigned int len)
146 {
147 	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
148 	unsigned int ret;
149 
150 	tctx->keylen = len;
151 
152 	if (len == AES_KEYSIZE_128) {
153 		memcpy(tctx->key, key, len);
154 		return 0;
155 	}
156 
157 	if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256) {
158 		/* not supported at all */
159 		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
160 		return -EINVAL;
161 	}
162 
163 	/*
164 	 * The requested key size is not supported by HW, do a fallback
165 	 */
166 	crypto_skcipher_clear_flags(tctx->fallback.skcipher,
167 				    CRYPTO_TFM_REQ_MASK);
168 	crypto_skcipher_set_flags(tctx->fallback.skcipher,
169 				  crypto_skcipher_get_flags(tfm) &
170 				  CRYPTO_TFM_REQ_MASK);
171 	ret = crypto_skcipher_setkey(tctx->fallback.skcipher, key, len);
172 	crypto_skcipher_set_flags(tfm,
173 				  crypto_skcipher_get_flags(tctx->fallback.skcipher) &
174 				  CRYPTO_TFM_RES_MASK);
175 	return ret;
176 }
177 
178 static void
179 geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
180 {
181 	const struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
182 
183 	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
184 		crypto_cipher_encrypt_one(tctx->fallback.cip, out, in);
185 		return;
186 	}
187 
188 	geode_aes_crypt(tctx, in, out, AES_BLOCK_SIZE, NULL,
189 			AES_MODE_ECB, AES_DIR_ENCRYPT);
190 }
191 
192 
193 static void
194 geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
195 {
196 	const struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
197 
198 	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
199 		crypto_cipher_decrypt_one(tctx->fallback.cip, out, in);
200 		return;
201 	}
202 
203 	geode_aes_crypt(tctx, in, out, AES_BLOCK_SIZE, NULL,
204 			AES_MODE_ECB, AES_DIR_DECRYPT);
205 }
206 
207 static int fallback_init_cip(struct crypto_tfm *tfm)
208 {
209 	const char *name = crypto_tfm_alg_name(tfm);
210 	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
211 
212 	tctx->fallback.cip = crypto_alloc_cipher(name, 0,
213 						 CRYPTO_ALG_NEED_FALLBACK);
214 
215 	if (IS_ERR(tctx->fallback.cip)) {
216 		printk(KERN_ERR "Error allocating fallback algo %s\n", name);
217 		return PTR_ERR(tctx->fallback.cip);
218 	}
219 
220 	return 0;
221 }
222 
223 static void fallback_exit_cip(struct crypto_tfm *tfm)
224 {
225 	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
226 
227 	crypto_free_cipher(tctx->fallback.cip);
228 }
229 
230 static struct crypto_alg geode_alg = {
231 	.cra_name			=	"aes",
232 	.cra_driver_name	=	"geode-aes",
233 	.cra_priority		=	300,
234 	.cra_alignmask		=	15,
235 	.cra_flags			=	CRYPTO_ALG_TYPE_CIPHER |
236 							CRYPTO_ALG_NEED_FALLBACK,
237 	.cra_init			=	fallback_init_cip,
238 	.cra_exit			=	fallback_exit_cip,
239 	.cra_blocksize		=	AES_BLOCK_SIZE,
240 	.cra_ctxsize		=	sizeof(struct geode_aes_tfm_ctx),
241 	.cra_module			=	THIS_MODULE,
242 	.cra_u				=	{
243 		.cipher	=	{
244 			.cia_min_keysize	=	AES_MIN_KEY_SIZE,
245 			.cia_max_keysize	=	AES_MAX_KEY_SIZE,
246 			.cia_setkey			=	geode_setkey_cip,
247 			.cia_encrypt		=	geode_encrypt,
248 			.cia_decrypt		=	geode_decrypt
249 		}
250 	}
251 };
252 
253 static int geode_init_skcipher(struct crypto_skcipher *tfm)
254 {
255 	const char *name = crypto_tfm_alg_name(&tfm->base);
256 	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
257 
258 	tctx->fallback.skcipher =
259 		crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK |
260 				      CRYPTO_ALG_ASYNC);
261 	if (IS_ERR(tctx->fallback.skcipher)) {
262 		printk(KERN_ERR "Error allocating fallback algo %s\n", name);
263 		return PTR_ERR(tctx->fallback.skcipher);
264 	}
265 
266 	crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
267 				    crypto_skcipher_reqsize(tctx->fallback.skcipher));
268 	return 0;
269 }
270 
271 static void geode_exit_skcipher(struct crypto_skcipher *tfm)
272 {
273 	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
274 
275 	crypto_free_skcipher(tctx->fallback.skcipher);
276 }
277 
278 static int geode_skcipher_crypt(struct skcipher_request *req, int mode, int dir)
279 {
280 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
281 	const struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
282 	struct skcipher_walk walk;
283 	unsigned int nbytes;
284 	int err;
285 
286 	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
287 		struct skcipher_request *subreq = skcipher_request_ctx(req);
288 
289 		*subreq = *req;
290 		skcipher_request_set_tfm(subreq, tctx->fallback.skcipher);
291 		if (dir == AES_DIR_DECRYPT)
292 			return crypto_skcipher_decrypt(subreq);
293 		else
294 			return crypto_skcipher_encrypt(subreq);
295 	}
296 
297 	err = skcipher_walk_virt(&walk, req, false);
298 
299 	while ((nbytes = walk.nbytes) != 0) {
300 		geode_aes_crypt(tctx, walk.src.virt.addr, walk.dst.virt.addr,
301 				round_down(nbytes, AES_BLOCK_SIZE),
302 				walk.iv, mode, dir);
303 		err = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE);
304 	}
305 
306 	return err;
307 }
308 
309 static int geode_cbc_encrypt(struct skcipher_request *req)
310 {
311 	return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_ENCRYPT);
312 }
313 
314 static int geode_cbc_decrypt(struct skcipher_request *req)
315 {
316 	return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_DECRYPT);
317 }
318 
319 static int geode_ecb_encrypt(struct skcipher_request *req)
320 {
321 	return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_ENCRYPT);
322 }
323 
324 static int geode_ecb_decrypt(struct skcipher_request *req)
325 {
326 	return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_DECRYPT);
327 }
328 
329 static struct skcipher_alg geode_skcipher_algs[] = {
330 	{
331 		.base.cra_name		= "cbc(aes)",
332 		.base.cra_driver_name	= "cbc-aes-geode",
333 		.base.cra_priority	= 400,
334 		.base.cra_flags		= CRYPTO_ALG_KERN_DRIVER_ONLY |
335 					  CRYPTO_ALG_NEED_FALLBACK,
336 		.base.cra_blocksize	= AES_BLOCK_SIZE,
337 		.base.cra_ctxsize	= sizeof(struct geode_aes_tfm_ctx),
338 		.base.cra_alignmask	= 15,
339 		.base.cra_module	= THIS_MODULE,
340 		.init			= geode_init_skcipher,
341 		.exit			= geode_exit_skcipher,
342 		.setkey			= geode_setkey_skcipher,
343 		.encrypt		= geode_cbc_encrypt,
344 		.decrypt		= geode_cbc_decrypt,
345 		.min_keysize		= AES_MIN_KEY_SIZE,
346 		.max_keysize		= AES_MAX_KEY_SIZE,
347 		.ivsize			= AES_BLOCK_SIZE,
348 	}, {
349 		.base.cra_name		= "ecb(aes)",
350 		.base.cra_driver_name	= "ecb-aes-geode",
351 		.base.cra_priority	= 400,
352 		.base.cra_flags		= CRYPTO_ALG_KERN_DRIVER_ONLY |
353 					  CRYPTO_ALG_NEED_FALLBACK,
354 		.base.cra_blocksize	= AES_BLOCK_SIZE,
355 		.base.cra_ctxsize	= sizeof(struct geode_aes_tfm_ctx),
356 		.base.cra_alignmask	= 15,
357 		.base.cra_module	= THIS_MODULE,
358 		.init			= geode_init_skcipher,
359 		.exit			= geode_exit_skcipher,
360 		.setkey			= geode_setkey_skcipher,
361 		.encrypt		= geode_ecb_encrypt,
362 		.decrypt		= geode_ecb_decrypt,
363 		.min_keysize		= AES_MIN_KEY_SIZE,
364 		.max_keysize		= AES_MAX_KEY_SIZE,
365 	},
366 };
367 
368 static void geode_aes_remove(struct pci_dev *dev)
369 {
370 	crypto_unregister_alg(&geode_alg);
371 	crypto_unregister_skciphers(geode_skcipher_algs,
372 				    ARRAY_SIZE(geode_skcipher_algs));
373 
374 	pci_iounmap(dev, _iobase);
375 	_iobase = NULL;
376 
377 	pci_release_regions(dev);
378 	pci_disable_device(dev);
379 }
380 
381 
382 static int geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
383 {
384 	int ret;
385 
386 	ret = pci_enable_device(dev);
387 	if (ret)
388 		return ret;
389 
390 	ret = pci_request_regions(dev, "geode-aes");
391 	if (ret)
392 		goto eenable;
393 
394 	_iobase = pci_iomap(dev, 0, 0);
395 
396 	if (_iobase == NULL) {
397 		ret = -ENOMEM;
398 		goto erequest;
399 	}
400 
401 	spin_lock_init(&lock);
402 
403 	/* Clear any pending activity */
404 	iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);
405 
406 	ret = crypto_register_alg(&geode_alg);
407 	if (ret)
408 		goto eiomap;
409 
410 	ret = crypto_register_skciphers(geode_skcipher_algs,
411 					ARRAY_SIZE(geode_skcipher_algs));
412 	if (ret)
413 		goto ealg;
414 
415 	dev_notice(&dev->dev, "GEODE AES engine enabled.\n");
416 	return 0;
417 
418  ealg:
419 	crypto_unregister_alg(&geode_alg);
420 
421  eiomap:
422 	pci_iounmap(dev, _iobase);
423 
424  erequest:
425 	pci_release_regions(dev);
426 
427  eenable:
428 	pci_disable_device(dev);
429 
430 	dev_err(&dev->dev, "GEODE AES initialization failed.\n");
431 	return ret;
432 }
433 
434 static struct pci_device_id geode_aes_tbl[] = {
435 	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_LX_AES), },
436 	{ 0, }
437 };
438 
439 MODULE_DEVICE_TABLE(pci, geode_aes_tbl);
440 
441 static struct pci_driver geode_aes_driver = {
442 	.name = "Geode LX AES",
443 	.id_table = geode_aes_tbl,
444 	.probe = geode_aes_probe,
445 	.remove = geode_aes_remove,
446 };
447 
448 module_pci_driver(geode_aes_driver);
449 
450 MODULE_AUTHOR("Advanced Micro Devices, Inc.");
451 MODULE_DESCRIPTION("Geode LX Hardware AES driver");
452 MODULE_LICENSE("GPL");
453