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
22static void __iomem *_iobase;
23static spinlock_t lock;
24
25/* Write a 128 bit field (either a writable key or IV) */
26static 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) */
36static 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
45static int
46do_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
68static void
69geode_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
109static 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
114	tctx->keylen = len;
115
116	if (len == AES_KEYSIZE_128) {
117		memcpy(tctx->key, key, len);
118		return 0;
119	}
120
121	if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256)
122		/* not supported at all */
123		return -EINVAL;
124
125	/*
126	 * The requested key size is not supported by HW, do a fallback
127	 */
128	tctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
129	tctx->fallback.cip->base.crt_flags |=
130		(tfm->crt_flags & CRYPTO_TFM_REQ_MASK);
131
132	return crypto_cipher_setkey(tctx->fallback.cip, key, len);
133}
134
135static int geode_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
136				 unsigned int len)
137{
138	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
139
140	tctx->keylen = len;
141
142	if (len == AES_KEYSIZE_128) {
143		memcpy(tctx->key, key, len);
144		return 0;
145	}
146
147	if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256)
148		/* not supported at all */
149		return -EINVAL;
150
151	/*
152	 * The requested key size is not supported by HW, do a fallback
153	 */
154	crypto_skcipher_clear_flags(tctx->fallback.skcipher,
155				    CRYPTO_TFM_REQ_MASK);
156	crypto_skcipher_set_flags(tctx->fallback.skcipher,
157				  crypto_skcipher_get_flags(tfm) &
158				  CRYPTO_TFM_REQ_MASK);
159	return crypto_skcipher_setkey(tctx->fallback.skcipher, key, len);
160}
161
162static void
163geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
164{
165	const struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
166
167	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
168		crypto_cipher_encrypt_one(tctx->fallback.cip, out, in);
169		return;
170	}
171
172	geode_aes_crypt(tctx, in, out, AES_BLOCK_SIZE, NULL,
173			AES_MODE_ECB, AES_DIR_ENCRYPT);
174}
175
176
177static void
178geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
179{
180	const struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
181
182	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
183		crypto_cipher_decrypt_one(tctx->fallback.cip, out, in);
184		return;
185	}
186
187	geode_aes_crypt(tctx, in, out, AES_BLOCK_SIZE, NULL,
188			AES_MODE_ECB, AES_DIR_DECRYPT);
189}
190
191static int fallback_init_cip(struct crypto_tfm *tfm)
192{
193	const char *name = crypto_tfm_alg_name(tfm);
194	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
195
196	tctx->fallback.cip = crypto_alloc_cipher(name, 0,
197						 CRYPTO_ALG_NEED_FALLBACK);
198
199	if (IS_ERR(tctx->fallback.cip)) {
200		printk(KERN_ERR "Error allocating fallback algo %s\n", name);
201		return PTR_ERR(tctx->fallback.cip);
202	}
203
204	return 0;
205}
206
207static void fallback_exit_cip(struct crypto_tfm *tfm)
208{
209	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
210
211	crypto_free_cipher(tctx->fallback.cip);
212}
213
214static struct crypto_alg geode_alg = {
215	.cra_name			=	"aes",
216	.cra_driver_name	=	"geode-aes",
217	.cra_priority		=	300,
218	.cra_alignmask		=	15,
219	.cra_flags			=	CRYPTO_ALG_TYPE_CIPHER |
220							CRYPTO_ALG_NEED_FALLBACK,
221	.cra_init			=	fallback_init_cip,
222	.cra_exit			=	fallback_exit_cip,
223	.cra_blocksize		=	AES_BLOCK_SIZE,
224	.cra_ctxsize		=	sizeof(struct geode_aes_tfm_ctx),
225	.cra_module			=	THIS_MODULE,
226	.cra_u				=	{
227		.cipher	=	{
228			.cia_min_keysize	=	AES_MIN_KEY_SIZE,
229			.cia_max_keysize	=	AES_MAX_KEY_SIZE,
230			.cia_setkey			=	geode_setkey_cip,
231			.cia_encrypt		=	geode_encrypt,
232			.cia_decrypt		=	geode_decrypt
233		}
234	}
235};
236
237static int geode_init_skcipher(struct crypto_skcipher *tfm)
238{
239	const char *name = crypto_tfm_alg_name(&tfm->base);
240	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
241
242	tctx->fallback.skcipher =
243		crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK |
244				      CRYPTO_ALG_ASYNC);
245	if (IS_ERR(tctx->fallback.skcipher)) {
246		printk(KERN_ERR "Error allocating fallback algo %s\n", name);
247		return PTR_ERR(tctx->fallback.skcipher);
248	}
249
250	crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
251				    crypto_skcipher_reqsize(tctx->fallback.skcipher));
252	return 0;
253}
254
255static void geode_exit_skcipher(struct crypto_skcipher *tfm)
256{
257	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
258
259	crypto_free_skcipher(tctx->fallback.skcipher);
260}
261
262static int geode_skcipher_crypt(struct skcipher_request *req, int mode, int dir)
263{
264	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
265	const struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
266	struct skcipher_walk walk;
267	unsigned int nbytes;
268	int err;
269
270	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
271		struct skcipher_request *subreq = skcipher_request_ctx(req);
272
273		*subreq = *req;
274		skcipher_request_set_tfm(subreq, tctx->fallback.skcipher);
275		if (dir == AES_DIR_DECRYPT)
276			return crypto_skcipher_decrypt(subreq);
277		else
278			return crypto_skcipher_encrypt(subreq);
279	}
280
281	err = skcipher_walk_virt(&walk, req, false);
282
283	while ((nbytes = walk.nbytes) != 0) {
284		geode_aes_crypt(tctx, walk.src.virt.addr, walk.dst.virt.addr,
285				round_down(nbytes, AES_BLOCK_SIZE),
286				walk.iv, mode, dir);
287		err = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE);
288	}
289
290	return err;
291}
292
293static int geode_cbc_encrypt(struct skcipher_request *req)
294{
295	return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_ENCRYPT);
296}
297
298static int geode_cbc_decrypt(struct skcipher_request *req)
299{
300	return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_DECRYPT);
301}
302
303static int geode_ecb_encrypt(struct skcipher_request *req)
304{
305	return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_ENCRYPT);
306}
307
308static int geode_ecb_decrypt(struct skcipher_request *req)
309{
310	return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_DECRYPT);
311}
312
313static struct skcipher_alg geode_skcipher_algs[] = {
314	{
315		.base.cra_name		= "cbc(aes)",
316		.base.cra_driver_name	= "cbc-aes-geode",
317		.base.cra_priority	= 400,
318		.base.cra_flags		= CRYPTO_ALG_KERN_DRIVER_ONLY |
319					  CRYPTO_ALG_NEED_FALLBACK,
320		.base.cra_blocksize	= AES_BLOCK_SIZE,
321		.base.cra_ctxsize	= sizeof(struct geode_aes_tfm_ctx),
322		.base.cra_alignmask	= 15,
323		.base.cra_module	= THIS_MODULE,
324		.init			= geode_init_skcipher,
325		.exit			= geode_exit_skcipher,
326		.setkey			= geode_setkey_skcipher,
327		.encrypt		= geode_cbc_encrypt,
328		.decrypt		= geode_cbc_decrypt,
329		.min_keysize		= AES_MIN_KEY_SIZE,
330		.max_keysize		= AES_MAX_KEY_SIZE,
331		.ivsize			= AES_BLOCK_SIZE,
332	}, {
333		.base.cra_name		= "ecb(aes)",
334		.base.cra_driver_name	= "ecb-aes-geode",
335		.base.cra_priority	= 400,
336		.base.cra_flags		= CRYPTO_ALG_KERN_DRIVER_ONLY |
337					  CRYPTO_ALG_NEED_FALLBACK,
338		.base.cra_blocksize	= AES_BLOCK_SIZE,
339		.base.cra_ctxsize	= sizeof(struct geode_aes_tfm_ctx),
340		.base.cra_alignmask	= 15,
341		.base.cra_module	= THIS_MODULE,
342		.init			= geode_init_skcipher,
343		.exit			= geode_exit_skcipher,
344		.setkey			= geode_setkey_skcipher,
345		.encrypt		= geode_ecb_encrypt,
346		.decrypt		= geode_ecb_decrypt,
347		.min_keysize		= AES_MIN_KEY_SIZE,
348		.max_keysize		= AES_MAX_KEY_SIZE,
349	},
350};
351
352static void geode_aes_remove(struct pci_dev *dev)
353{
354	crypto_unregister_alg(&geode_alg);
355	crypto_unregister_skciphers(geode_skcipher_algs,
356				    ARRAY_SIZE(geode_skcipher_algs));
357
358	pci_iounmap(dev, _iobase);
359	_iobase = NULL;
360
361	pci_release_regions(dev);
362	pci_disable_device(dev);
363}
364
365
366static int geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
367{
368	int ret;
369
370	ret = pci_enable_device(dev);
371	if (ret)
372		return ret;
373
374	ret = pci_request_regions(dev, "geode-aes");
375	if (ret)
376		goto eenable;
377
378	_iobase = pci_iomap(dev, 0, 0);
379
380	if (_iobase == NULL) {
381		ret = -ENOMEM;
382		goto erequest;
383	}
384
385	spin_lock_init(&lock);
386
387	/* Clear any pending activity */
388	iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);
389
390	ret = crypto_register_alg(&geode_alg);
391	if (ret)
392		goto eiomap;
393
394	ret = crypto_register_skciphers(geode_skcipher_algs,
395					ARRAY_SIZE(geode_skcipher_algs));
396	if (ret)
397		goto ealg;
398
399	dev_notice(&dev->dev, "GEODE AES engine enabled.\n");
400	return 0;
401
402 ealg:
403	crypto_unregister_alg(&geode_alg);
404
405 eiomap:
406	pci_iounmap(dev, _iobase);
407
408 erequest:
409	pci_release_regions(dev);
410
411 eenable:
412	pci_disable_device(dev);
413
414	dev_err(&dev->dev, "GEODE AES initialization failed.\n");
415	return ret;
416}
417
418static struct pci_device_id geode_aes_tbl[] = {
419	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_LX_AES), },
420	{ 0, }
421};
422
423MODULE_DEVICE_TABLE(pci, geode_aes_tbl);
424
425static struct pci_driver geode_aes_driver = {
426	.name = "Geode LX AES",
427	.id_table = geode_aes_tbl,
428	.probe = geode_aes_probe,
429	.remove = geode_aes_remove,
430};
431
432module_pci_driver(geode_aes_driver);
433
434MODULE_AUTHOR("Advanced Micro Devices, Inc.");
435MODULE_DESCRIPTION("Geode LX Hardware AES driver");
436MODULE_LICENSE("GPL");
437