geode-aes.c revision 761e784673d79c8ea9befdad31e30c65e0d20b82 
1 /* Copyright (C) 2004-2006, Advanced Micro Devices, Inc.
2 *
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or
6 * (at your option) any later version.
7 */
8
9#include <linux/module.h>
10#include <linux/kernel.h>
11#include <linux/pci.h>
12#include <linux/pci_ids.h>
13#include <linux/crypto.h>
14#include <linux/spinlock.h>
15#include <crypto/algapi.h>
16
17#include <asm/io.h>
18#include <asm/delay.h>
19
20#include "geode-aes.h"
21
22/* Register definitions */
23
24#define AES_CTRLA_REG  0x0000
25
26#define AES_CTRL_START     0x01
27#define AES_CTRL_DECRYPT   0x00
28#define AES_CTRL_ENCRYPT   0x02
29#define AES_CTRL_WRKEY     0x04
30#define AES_CTRL_DCA       0x08
31#define AES_CTRL_SCA       0x10
32#define AES_CTRL_CBC       0x20
33
34#define AES_INTR_REG  0x0008
35
36#define AES_INTRA_PENDING (1 << 16)
37#define AES_INTRB_PENDING (1 << 17)
38
39#define AES_INTR_PENDING  (AES_INTRA_PENDING | AES_INTRB_PENDING)
40#define AES_INTR_MASK     0x07
41
42#define AES_SOURCEA_REG   0x0010
43#define AES_DSTA_REG      0x0014
44#define AES_LENA_REG      0x0018
45#define AES_WRITEKEY0_REG 0x0030
46#define AES_WRITEIV0_REG  0x0040
47
48/*  A very large counter that is used to gracefully bail out of an
49 *  operation in case of trouble
50 */
51
52#define AES_OP_TIMEOUT    0x50000
53
54/* Static structures */
55
56static void __iomem * _iobase;
57static spinlock_t lock;
58
59/* Write a 128 bit field (either a writable key or IV) */
60static inline void
61_writefield(u32 offset, void *value)
62{
63	int i;
64	for(i = 0; i < 4; i++)
65		iowrite32(((u32 *) value)[i], _iobase + offset + (i * 4));
66}
67
68/* Read a 128 bit field (either a writable key or IV) */
69static inline void
70_readfield(u32 offset, void *value)
71{
72	int i;
73	for(i = 0; i < 4; i++)
74		((u32 *) value)[i] = ioread32(_iobase + offset + (i * 4));
75}
76
77static int
78do_crypt(void *src, void *dst, int len, u32 flags)
79{
80	u32 status;
81	u32 counter = AES_OP_TIMEOUT;
82
83	iowrite32(virt_to_phys(src), _iobase + AES_SOURCEA_REG);
84	iowrite32(virt_to_phys(dst), _iobase + AES_DSTA_REG);
85	iowrite32(len,  _iobase + AES_LENA_REG);
86
87	/* Start the operation */
88	iowrite32(AES_CTRL_START | flags, _iobase + AES_CTRLA_REG);
89
90	do
91		status = ioread32(_iobase + AES_INTR_REG);
92	while(!(status & AES_INTRA_PENDING) && --counter);
93
94	/* Clear the event */
95	iowrite32((status & 0xFF) | AES_INTRA_PENDING, _iobase + AES_INTR_REG);
96	return counter ? 0 : 1;
97}
98
99static unsigned int
100geode_aes_crypt(struct geode_aes_op *op)
101{
102	u32 flags = 0;
103	unsigned long iflags;
104
105	if (op->len == 0)
106		return 0;
107
108	/* If the source and destination is the same, then
109	 * we need to turn on the coherent flags, otherwise
110	 * we don't need to worry
111	 */
112
113	if (op->src == op->dst)
114		flags |= (AES_CTRL_DCA | AES_CTRL_SCA);
115
116	if (op->dir == AES_DIR_ENCRYPT)
117		flags |= AES_CTRL_ENCRYPT;
118
119	/* Start the critical section */
120
121	spin_lock_irqsave(&lock, iflags);
122
123	if (op->mode == AES_MODE_CBC) {
124		flags |= AES_CTRL_CBC;
125		_writefield(AES_WRITEIV0_REG, op->iv);
126	}
127
128	if (!(op->flags & AES_FLAGS_HIDDENKEY)) {
129		flags |= AES_CTRL_WRKEY;
130		_writefield(AES_WRITEKEY0_REG, op->key);
131	}
132
133	do_crypt(op->src, op->dst, op->len, flags);
134
135	if (op->mode == AES_MODE_CBC)
136		_readfield(AES_WRITEIV0_REG, op->iv);
137
138	spin_unlock_irqrestore(&lock, iflags);
139
140	return op->len;
141}
142
143/* CRYPTO-API Functions */
144
145static int
146geode_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int len)
147{
148	struct geode_aes_op *op = crypto_tfm_ctx(tfm);
149
150	if (len != AES_KEY_LENGTH) {
151		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
152		return -EINVAL;
153	}
154
155	memcpy(op->key, key, len);
156	return 0;
157}
158
159static void
160geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
161{
162	struct geode_aes_op *op = crypto_tfm_ctx(tfm);
163
164	if ((out == NULL) || (in == NULL))
165		return;
166
167	op->src = (void *) in;
168	op->dst = (void *) out;
169	op->mode = AES_MODE_ECB;
170	op->flags = 0;
171	op->len = AES_MIN_BLOCK_SIZE;
172	op->dir = AES_DIR_ENCRYPT;
173
174	geode_aes_crypt(op);
175}
176
177
178static void
179geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
180{
181	struct geode_aes_op *op = crypto_tfm_ctx(tfm);
182
183	if ((out == NULL) || (in == NULL))
184		return;
185
186	op->src = (void *) in;
187	op->dst = (void *) out;
188	op->mode = AES_MODE_ECB;
189	op->flags = 0;
190	op->len = AES_MIN_BLOCK_SIZE;
191	op->dir = AES_DIR_DECRYPT;
192
193	geode_aes_crypt(op);
194}
195
196
197static struct crypto_alg geode_alg = {
198	.cra_name               =       "aes",
199	.cra_driver_name	=       "geode-aes-128",
200	.cra_priority           =       300,
201	.cra_alignmask          =       15,
202	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
203	.cra_blocksize		=	AES_MIN_BLOCK_SIZE,
204	.cra_ctxsize		=	sizeof(struct geode_aes_op),
205	.cra_module		=	THIS_MODULE,
206	.cra_list		=	LIST_HEAD_INIT(geode_alg.cra_list),
207	.cra_u			=	{
208		.cipher = {
209			.cia_min_keysize	=  AES_KEY_LENGTH,
210			.cia_max_keysize	=  AES_KEY_LENGTH,
211			.cia_setkey		=  geode_setkey,
212			.cia_encrypt		=  geode_encrypt,
213			.cia_decrypt		=  geode_decrypt
214		}
215	}
216};
217
218static int
219geode_cbc_decrypt(struct blkcipher_desc *desc,
220		  struct scatterlist *dst, struct scatterlist *src,
221		  unsigned int nbytes)
222{
223	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
224	struct blkcipher_walk walk;
225	int err, ret;
226
227	blkcipher_walk_init(&walk, dst, src, nbytes);
228	err = blkcipher_walk_virt(desc, &walk);
229
230	while((nbytes = walk.nbytes)) {
231		op->src = walk.src.virt.addr,
232		op->dst = walk.dst.virt.addr;
233		op->mode = AES_MODE_CBC;
234		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
235		op->dir = AES_DIR_DECRYPT;
236
237		memcpy(op->iv, walk.iv, AES_IV_LENGTH);
238
239		ret = geode_aes_crypt(op);
240
241		memcpy(walk.iv, op->iv, AES_IV_LENGTH);
242		nbytes -= ret;
243
244		err = blkcipher_walk_done(desc, &walk, nbytes);
245	}
246
247	return err;
248}
249
250static int
251geode_cbc_encrypt(struct blkcipher_desc *desc,
252		  struct scatterlist *dst, struct scatterlist *src,
253		  unsigned int nbytes)
254{
255	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
256	struct blkcipher_walk walk;
257	int err, ret;
258
259	blkcipher_walk_init(&walk, dst, src, nbytes);
260	err = blkcipher_walk_virt(desc, &walk);
261
262	while((nbytes = walk.nbytes)) {
263		op->src = walk.src.virt.addr,
264		op->dst = walk.dst.virt.addr;
265		op->mode = AES_MODE_CBC;
266		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
267		op->dir = AES_DIR_ENCRYPT;
268
269		memcpy(op->iv, walk.iv, AES_IV_LENGTH);
270
271		ret = geode_aes_crypt(op);
272		nbytes -= ret;
273		err = blkcipher_walk_done(desc, &walk, nbytes);
274	}
275
276	return err;
277}
278
279static struct crypto_alg geode_cbc_alg = {
280	.cra_name		=	"cbc(aes)",
281	.cra_driver_name	=	"cbc-aes-geode-128",
282	.cra_priority		=	400,
283	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
284	.cra_blocksize		=	AES_MIN_BLOCK_SIZE,
285	.cra_ctxsize		=	sizeof(struct geode_aes_op),
286	.cra_alignmask		=	15,
287	.cra_type		=	&crypto_blkcipher_type,
288	.cra_module		=	THIS_MODULE,
289	.cra_list		=	LIST_HEAD_INIT(geode_cbc_alg.cra_list),
290	.cra_u			=	{
291		.blkcipher = {
292			.min_keysize		=	AES_KEY_LENGTH,
293			.max_keysize		=	AES_KEY_LENGTH,
294			.setkey			=	geode_setkey,
295			.encrypt		=	geode_cbc_encrypt,
296			.decrypt		=	geode_cbc_decrypt,
297			.ivsize			=	AES_IV_LENGTH,
298		}
299	}
300};
301
302static int
303geode_ecb_decrypt(struct blkcipher_desc *desc,
304		  struct scatterlist *dst, struct scatterlist *src,
305		  unsigned int nbytes)
306{
307	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
308	struct blkcipher_walk walk;
309	int err, ret;
310
311	blkcipher_walk_init(&walk, dst, src, nbytes);
312	err = blkcipher_walk_virt(desc, &walk);
313
314	while((nbytes = walk.nbytes)) {
315		op->src = walk.src.virt.addr,
316		op->dst = walk.dst.virt.addr;
317		op->mode = AES_MODE_ECB;
318		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
319		op->dir = AES_DIR_DECRYPT;
320
321		ret = geode_aes_crypt(op);
322		nbytes -= ret;
323		err = blkcipher_walk_done(desc, &walk, nbytes);
324	}
325
326	return err;
327}
328
329static int
330geode_ecb_encrypt(struct blkcipher_desc *desc,
331		  struct scatterlist *dst, struct scatterlist *src,
332		  unsigned int nbytes)
333{
334	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
335	struct blkcipher_walk walk;
336	int err, ret;
337
338	blkcipher_walk_init(&walk, dst, src, nbytes);
339	err = blkcipher_walk_virt(desc, &walk);
340
341	while((nbytes = walk.nbytes)) {
342		op->src = walk.src.virt.addr,
343		op->dst = walk.dst.virt.addr;
344		op->mode = AES_MODE_ECB;
345		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
346		op->dir = AES_DIR_ENCRYPT;
347
348		ret = geode_aes_crypt(op);
349		nbytes -= ret;
350		ret =  blkcipher_walk_done(desc, &walk, nbytes);
351	}
352
353	return err;
354}
355
356static struct crypto_alg geode_ecb_alg = {
357	.cra_name		=	"ecb(aes)",
358	.cra_driver_name	=	"ecb-aes-geode-128",
359	.cra_priority		=	400,
360	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
361	.cra_blocksize		=	AES_MIN_BLOCK_SIZE,
362	.cra_ctxsize		=	sizeof(struct geode_aes_op),
363	.cra_alignmask		=	15,
364	.cra_type		=	&crypto_blkcipher_type,
365	.cra_module		=	THIS_MODULE,
366	.cra_list		=	LIST_HEAD_INIT(geode_ecb_alg.cra_list),
367	.cra_u			=	{
368		.blkcipher = {
369			.min_keysize		=	AES_KEY_LENGTH,
370			.max_keysize		=	AES_KEY_LENGTH,
371			.setkey			=	geode_setkey,
372			.encrypt		=	geode_ecb_encrypt,
373			.decrypt		=	geode_ecb_decrypt,
374		}
375	}
376};
377
378static void
379geode_aes_remove(struct pci_dev *dev)
380{
381	crypto_unregister_alg(&geode_alg);
382	crypto_unregister_alg(&geode_ecb_alg);
383	crypto_unregister_alg(&geode_cbc_alg);
384
385	pci_iounmap(dev, _iobase);
386	_iobase = NULL;
387
388	pci_release_regions(dev);
389	pci_disable_device(dev);
390}
391
392
393static int
394geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
395{
396	int ret;
397
398	if ((ret = pci_enable_device(dev)))
399		return ret;
400
401	if ((ret = pci_request_regions(dev, "geode-aes-128")))
402		goto eenable;
403
404	_iobase = pci_iomap(dev, 0, 0);
405
406	if (_iobase == NULL) {
407		ret = -ENOMEM;
408		goto erequest;
409	}
410
411	spin_lock_init(&lock);
412
413	/* Clear any pending activity */
414	iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);
415
416	if ((ret = crypto_register_alg(&geode_alg)))
417		goto eiomap;
418
419	if ((ret = crypto_register_alg(&geode_ecb_alg)))
420		goto ealg;
421
422	if ((ret = crypto_register_alg(&geode_cbc_alg)))
423		goto eecb;
424
425	printk(KERN_NOTICE "geode-aes: GEODE AES engine enabled.\n");
426	return 0;
427
428 eecb:
429	crypto_unregister_alg(&geode_ecb_alg);
430
431 ealg:
432	crypto_unregister_alg(&geode_alg);
433
434 eiomap:
435	pci_iounmap(dev, _iobase);
436
437 erequest:
438	pci_release_regions(dev);
439
440 eenable:
441	pci_disable_device(dev);
442
443	printk(KERN_ERR "geode-aes:  GEODE AES initialization failed.\n");
444	return ret;
445}
446
447static struct pci_device_id geode_aes_tbl[] = {
448	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_LX_AES, PCI_ANY_ID, PCI_ANY_ID} ,
449	{ 0, }
450};
451
452MODULE_DEVICE_TABLE(pci, geode_aes_tbl);
453
454static struct pci_driver geode_aes_driver = {
455	.name = "Geode LX AES",
456	.id_table = geode_aes_tbl,
457	.probe = geode_aes_probe,
458	.remove = __devexit_p(geode_aes_remove)
459};
460
461static int __init
462geode_aes_init(void)
463{
464	return pci_register_driver(&geode_aes_driver);
465}
466
467static void __exit
468geode_aes_exit(void)
469{
470	pci_unregister_driver(&geode_aes_driver);
471}
472
473MODULE_AUTHOR("Advanced Micro Devices, Inc.");
474MODULE_DESCRIPTION("Geode LX Hardware AES driver");
475MODULE_LICENSE("GPL");
476
477module_init(geode_aes_init);
478module_exit(geode_aes_exit);
479