xref: /openbmc/linux/drivers/crypto/geode-aes.c (revision 2cf1c348)
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/cipher.h>
14 #include <crypto/internal/skcipher.h>
15 
16 #include <linux/io.h>
17 #include <linux/delay.h>
18 
19 #include "geode-aes.h"
20 
21 /* Static structures */
22 
23 static void __iomem *_iobase;
24 static DEFINE_SPINLOCK(lock);
25 
26 /* Write a 128 bit field (either a writable key or IV) */
27 static inline void
28 _writefield(u32 offset, const void *value)
29 {
30 	int i;
31 
32 	for (i = 0; i < 4; i++)
33 		iowrite32(((const u32 *) value)[i], _iobase + offset + (i * 4));
34 }
35 
36 /* Read a 128 bit field (either a writable key or IV) */
37 static inline void
38 _readfield(u32 offset, void *value)
39 {
40 	int i;
41 
42 	for (i = 0; i < 4; i++)
43 		((u32 *) value)[i] = ioread32(_iobase + offset + (i * 4));
44 }
45 
46 static int
47 do_crypt(const void *src, void *dst, u32 len, u32 flags)
48 {
49 	u32 status;
50 	u32 counter = AES_OP_TIMEOUT;
51 
52 	iowrite32(virt_to_phys((void *)src), _iobase + AES_SOURCEA_REG);
53 	iowrite32(virt_to_phys(dst), _iobase + AES_DSTA_REG);
54 	iowrite32(len,  _iobase + AES_LENA_REG);
55 
56 	/* Start the operation */
57 	iowrite32(AES_CTRL_START | flags, _iobase + AES_CTRLA_REG);
58 
59 	do {
60 		status = ioread32(_iobase + AES_INTR_REG);
61 		cpu_relax();
62 	} while (!(status & AES_INTRA_PENDING) && --counter);
63 
64 	/* Clear the event */
65 	iowrite32((status & 0xFF) | AES_INTRA_PENDING, _iobase + AES_INTR_REG);
66 	return counter ? 0 : 1;
67 }
68 
69 static void
70 geode_aes_crypt(const struct geode_aes_tfm_ctx *tctx, const void *src,
71 		void *dst, u32 len, u8 *iv, int mode, int dir)
72 {
73 	u32 flags = 0;
74 	unsigned long iflags;
75 	int ret;
76 
77 	/* If the source and destination is the same, then
78 	 * we need to turn on the coherent flags, otherwise
79 	 * we don't need to worry
80 	 */
81 
82 	flags |= (AES_CTRL_DCA | AES_CTRL_SCA);
83 
84 	if (dir == AES_DIR_ENCRYPT)
85 		flags |= AES_CTRL_ENCRYPT;
86 
87 	/* Start the critical section */
88 
89 	spin_lock_irqsave(&lock, iflags);
90 
91 	if (mode == AES_MODE_CBC) {
92 		flags |= AES_CTRL_CBC;
93 		_writefield(AES_WRITEIV0_REG, iv);
94 	}
95 
96 	flags |= AES_CTRL_WRKEY;
97 	_writefield(AES_WRITEKEY0_REG, tctx->key);
98 
99 	ret = do_crypt(src, dst, len, flags);
100 	BUG_ON(ret);
101 
102 	if (mode == AES_MODE_CBC)
103 		_readfield(AES_WRITEIV0_REG, iv);
104 
105 	spin_unlock_irqrestore(&lock, iflags);
106 }
107 
108 /* CRYPTO-API Functions */
109 
110 static int geode_setkey_cip(struct crypto_tfm *tfm, const u8 *key,
111 		unsigned int len)
112 {
113 	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
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 		return -EINVAL;
125 
126 	/*
127 	 * The requested key size is not supported by HW, do a fallback
128 	 */
129 	tctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
130 	tctx->fallback.cip->base.crt_flags |=
131 		(tfm->crt_flags & CRYPTO_TFM_REQ_MASK);
132 
133 	return crypto_cipher_setkey(tctx->fallback.cip, key, len);
134 }
135 
136 static int geode_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
137 				 unsigned int len)
138 {
139 	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
140 
141 	tctx->keylen = len;
142 
143 	if (len == AES_KEYSIZE_128) {
144 		memcpy(tctx->key, key, len);
145 		return 0;
146 	}
147 
148 	if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256)
149 		/* not supported at all */
150 		return -EINVAL;
151 
152 	/*
153 	 * The requested key size is not supported by HW, do a fallback
154 	 */
155 	crypto_skcipher_clear_flags(tctx->fallback.skcipher,
156 				    CRYPTO_TFM_REQ_MASK);
157 	crypto_skcipher_set_flags(tctx->fallback.skcipher,
158 				  crypto_skcipher_get_flags(tfm) &
159 				  CRYPTO_TFM_REQ_MASK);
160 	return crypto_skcipher_setkey(tctx->fallback.skcipher, key, len);
161 }
162 
163 static void
164 geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
165 {
166 	const struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
167 
168 	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
169 		crypto_cipher_encrypt_one(tctx->fallback.cip, out, in);
170 		return;
171 	}
172 
173 	geode_aes_crypt(tctx, in, out, AES_BLOCK_SIZE, NULL,
174 			AES_MODE_ECB, AES_DIR_ENCRYPT);
175 }
176 
177 
178 static void
179 geode_decrypt(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_decrypt_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_DECRYPT);
190 }
191 
192 static int fallback_init_cip(struct crypto_tfm *tfm)
193 {
194 	const char *name = crypto_tfm_alg_name(tfm);
195 	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
196 
197 	tctx->fallback.cip = crypto_alloc_cipher(name, 0,
198 						 CRYPTO_ALG_NEED_FALLBACK);
199 
200 	if (IS_ERR(tctx->fallback.cip)) {
201 		printk(KERN_ERR "Error allocating fallback algo %s\n", name);
202 		return PTR_ERR(tctx->fallback.cip);
203 	}
204 
205 	return 0;
206 }
207 
208 static void fallback_exit_cip(struct crypto_tfm *tfm)
209 {
210 	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
211 
212 	crypto_free_cipher(tctx->fallback.cip);
213 }
214 
215 static struct crypto_alg geode_alg = {
216 	.cra_name			=	"aes",
217 	.cra_driver_name	=	"geode-aes",
218 	.cra_priority		=	300,
219 	.cra_alignmask		=	15,
220 	.cra_flags			=	CRYPTO_ALG_TYPE_CIPHER |
221 							CRYPTO_ALG_NEED_FALLBACK,
222 	.cra_init			=	fallback_init_cip,
223 	.cra_exit			=	fallback_exit_cip,
224 	.cra_blocksize		=	AES_BLOCK_SIZE,
225 	.cra_ctxsize		=	sizeof(struct geode_aes_tfm_ctx),
226 	.cra_module			=	THIS_MODULE,
227 	.cra_u				=	{
228 		.cipher	=	{
229 			.cia_min_keysize	=	AES_MIN_KEY_SIZE,
230 			.cia_max_keysize	=	AES_MAX_KEY_SIZE,
231 			.cia_setkey			=	geode_setkey_cip,
232 			.cia_encrypt		=	geode_encrypt,
233 			.cia_decrypt		=	geode_decrypt
234 		}
235 	}
236 };
237 
238 static int geode_init_skcipher(struct crypto_skcipher *tfm)
239 {
240 	const char *name = crypto_tfm_alg_name(&tfm->base);
241 	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
242 
243 	tctx->fallback.skcipher =
244 		crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK |
245 				      CRYPTO_ALG_ASYNC);
246 	if (IS_ERR(tctx->fallback.skcipher)) {
247 		printk(KERN_ERR "Error allocating fallback algo %s\n", name);
248 		return PTR_ERR(tctx->fallback.skcipher);
249 	}
250 
251 	crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
252 				    crypto_skcipher_reqsize(tctx->fallback.skcipher));
253 	return 0;
254 }
255 
256 static void geode_exit_skcipher(struct crypto_skcipher *tfm)
257 {
258 	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
259 
260 	crypto_free_skcipher(tctx->fallback.skcipher);
261 }
262 
263 static int geode_skcipher_crypt(struct skcipher_request *req, int mode, int dir)
264 {
265 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
266 	const struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
267 	struct skcipher_walk walk;
268 	unsigned int nbytes;
269 	int err;
270 
271 	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
272 		struct skcipher_request *subreq = skcipher_request_ctx(req);
273 
274 		*subreq = *req;
275 		skcipher_request_set_tfm(subreq, tctx->fallback.skcipher);
276 		if (dir == AES_DIR_DECRYPT)
277 			return crypto_skcipher_decrypt(subreq);
278 		else
279 			return crypto_skcipher_encrypt(subreq);
280 	}
281 
282 	err = skcipher_walk_virt(&walk, req, false);
283 
284 	while ((nbytes = walk.nbytes) != 0) {
285 		geode_aes_crypt(tctx, walk.src.virt.addr, walk.dst.virt.addr,
286 				round_down(nbytes, AES_BLOCK_SIZE),
287 				walk.iv, mode, dir);
288 		err = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE);
289 	}
290 
291 	return err;
292 }
293 
294 static int geode_cbc_encrypt(struct skcipher_request *req)
295 {
296 	return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_ENCRYPT);
297 }
298 
299 static int geode_cbc_decrypt(struct skcipher_request *req)
300 {
301 	return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_DECRYPT);
302 }
303 
304 static int geode_ecb_encrypt(struct skcipher_request *req)
305 {
306 	return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_ENCRYPT);
307 }
308 
309 static int geode_ecb_decrypt(struct skcipher_request *req)
310 {
311 	return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_DECRYPT);
312 }
313 
314 static struct skcipher_alg geode_skcipher_algs[] = {
315 	{
316 		.base.cra_name		= "cbc(aes)",
317 		.base.cra_driver_name	= "cbc-aes-geode",
318 		.base.cra_priority	= 400,
319 		.base.cra_flags		= CRYPTO_ALG_KERN_DRIVER_ONLY |
320 					  CRYPTO_ALG_NEED_FALLBACK,
321 		.base.cra_blocksize	= AES_BLOCK_SIZE,
322 		.base.cra_ctxsize	= sizeof(struct geode_aes_tfm_ctx),
323 		.base.cra_alignmask	= 15,
324 		.base.cra_module	= THIS_MODULE,
325 		.init			= geode_init_skcipher,
326 		.exit			= geode_exit_skcipher,
327 		.setkey			= geode_setkey_skcipher,
328 		.encrypt		= geode_cbc_encrypt,
329 		.decrypt		= geode_cbc_decrypt,
330 		.min_keysize		= AES_MIN_KEY_SIZE,
331 		.max_keysize		= AES_MAX_KEY_SIZE,
332 		.ivsize			= AES_BLOCK_SIZE,
333 	}, {
334 		.base.cra_name		= "ecb(aes)",
335 		.base.cra_driver_name	= "ecb-aes-geode",
336 		.base.cra_priority	= 400,
337 		.base.cra_flags		= CRYPTO_ALG_KERN_DRIVER_ONLY |
338 					  CRYPTO_ALG_NEED_FALLBACK,
339 		.base.cra_blocksize	= AES_BLOCK_SIZE,
340 		.base.cra_ctxsize	= sizeof(struct geode_aes_tfm_ctx),
341 		.base.cra_alignmask	= 15,
342 		.base.cra_module	= THIS_MODULE,
343 		.init			= geode_init_skcipher,
344 		.exit			= geode_exit_skcipher,
345 		.setkey			= geode_setkey_skcipher,
346 		.encrypt		= geode_ecb_encrypt,
347 		.decrypt		= geode_ecb_decrypt,
348 		.min_keysize		= AES_MIN_KEY_SIZE,
349 		.max_keysize		= AES_MAX_KEY_SIZE,
350 	},
351 };
352 
353 static void geode_aes_remove(struct pci_dev *dev)
354 {
355 	crypto_unregister_alg(&geode_alg);
356 	crypto_unregister_skciphers(geode_skcipher_algs,
357 				    ARRAY_SIZE(geode_skcipher_algs));
358 
359 	pci_iounmap(dev, _iobase);
360 	_iobase = NULL;
361 
362 	pci_release_regions(dev);
363 	pci_disable_device(dev);
364 }
365 
366 
367 static int geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
368 {
369 	int ret;
370 
371 	ret = pci_enable_device(dev);
372 	if (ret)
373 		return ret;
374 
375 	ret = pci_request_regions(dev, "geode-aes");
376 	if (ret)
377 		goto eenable;
378 
379 	_iobase = pci_iomap(dev, 0, 0);
380 
381 	if (_iobase == NULL) {
382 		ret = -ENOMEM;
383 		goto erequest;
384 	}
385 
386 	/* Clear any pending activity */
387 	iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);
388 
389 	ret = crypto_register_alg(&geode_alg);
390 	if (ret)
391 		goto eiomap;
392 
393 	ret = crypto_register_skciphers(geode_skcipher_algs,
394 					ARRAY_SIZE(geode_skcipher_algs));
395 	if (ret)
396 		goto ealg;
397 
398 	dev_notice(&dev->dev, "GEODE AES engine enabled.\n");
399 	return 0;
400 
401  ealg:
402 	crypto_unregister_alg(&geode_alg);
403 
404  eiomap:
405 	pci_iounmap(dev, _iobase);
406 
407  erequest:
408 	pci_release_regions(dev);
409 
410  eenable:
411 	pci_disable_device(dev);
412 
413 	dev_err(&dev->dev, "GEODE AES initialization failed.\n");
414 	return ret;
415 }
416 
417 static struct pci_device_id geode_aes_tbl[] = {
418 	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_LX_AES), },
419 	{ 0, }
420 };
421 
422 MODULE_DEVICE_TABLE(pci, geode_aes_tbl);
423 
424 static struct pci_driver geode_aes_driver = {
425 	.name = "Geode LX AES",
426 	.id_table = geode_aes_tbl,
427 	.probe = geode_aes_probe,
428 	.remove = geode_aes_remove,
429 };
430 
431 module_pci_driver(geode_aes_driver);
432 
433 MODULE_AUTHOR("Advanced Micro Devices, Inc.");
434 MODULE_DESCRIPTION("Geode LX Hardware AES driver");
435 MODULE_LICENSE("GPL");
436 MODULE_IMPORT_NS(CRYPTO_INTERNAL);
437