summaryrefslogtreecommitdiff
path: root/drivers/crypto/geode-aes.c
blob: 6d3840e629de550c0b3de37a2090788cb6180351 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
 /* Copyright (C) 2004-2006, Advanced Micro Devices, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/crypto.h>
#include <linux/spinlock.h>
#include <crypto/algapi.h>

#include <asm/io.h>
#include <asm/delay.h>

#include "geode-aes.h"

/* Register definitions */

#define AES_CTRLA_REG  0x0000

#define AES_CTRL_START     0x01
#define AES_CTRL_DECRYPT   0x00
#define AES_CTRL_ENCRYPT   0x02
#define AES_CTRL_WRKEY     0x04
#define AES_CTRL_DCA       0x08
#define AES_CTRL_SCA       0x10
#define AES_CTRL_CBC       0x20

#define AES_INTR_REG  0x0008

#define AES_INTRA_PENDING (1 << 16)
#define AES_INTRB_PENDING (1 << 17)

#define AES_INTR_PENDING  (AES_INTRA_PENDING | AES_INTRB_PENDING)
#define AES_INTR_MASK     0x07

#define AES_SOURCEA_REG   0x0010
#define AES_DSTA_REG      0x0014
#define AES_LENA_REG      0x0018
#define AES_WRITEKEY0_REG 0x0030
#define AES_WRITEIV0_REG  0x0040

/*  A very large counter that is used to gracefully bail out of an
 *  operation in case of trouble
 */

#define AES_OP_TIMEOUT    0x50000

/* Static structures */

static void __iomem * _iobase;
static spinlock_t lock;

/* Write a 128 bit field (either a writable key or IV) */
static inline void
_writefield(u32 offset, void *value)
{
	int i;
	for(i = 0; i < 4; i++)
		iowrite32(((u32 *) value)[i], _iobase + offset + (i * 4));
}

/* Read a 128 bit field (either a writable key or IV) */
static inline void
_readfield(u32 offset, void *value)
{
	int i;
	for(i = 0; i < 4; i++)
		((u32 *) value)[i] = ioread32(_iobase + offset + (i * 4));
}

static int
do_crypt(void *src, void *dst, int len, u32 flags)
{
	u32 status;
	u32 counter = AES_OP_TIMEOUT;

	iowrite32(virt_to_phys(src), _iobase + AES_SOURCEA_REG);
	iowrite32(virt_to_phys(dst), _iobase + AES_DSTA_REG);
	iowrite32(len,  _iobase + AES_LENA_REG);

	/* Start the operation */
	iowrite32(AES_CTRL_START | flags, _iobase + AES_CTRLA_REG);

	do
		status = ioread32(_iobase + AES_INTR_REG);
	while(!(status & AES_INTRA_PENDING) && --counter);

	/* Clear the event */
	iowrite32((status & 0xFF) | AES_INTRA_PENDING, _iobase + AES_INTR_REG);
	return counter ? 0 : 1;
}

static unsigned int
geode_aes_crypt(struct geode_aes_op *op)
{
	u32 flags = 0;
	unsigned long iflags;

	if (op->len == 0 || op->src == op->dst)
		return 0;

	if (op->flags & AES_FLAGS_COHERENT)
		flags |= (AES_CTRL_DCA | AES_CTRL_SCA);

	if (op->dir == AES_DIR_ENCRYPT)
		flags |= AES_CTRL_ENCRYPT;

	/* Start the critical section */

	spin_lock_irqsave(&lock, iflags);

	if (op->mode == AES_MODE_CBC) {
		flags |= AES_CTRL_CBC;
		_writefield(AES_WRITEIV0_REG, op->iv);
	}

	if (op->flags & AES_FLAGS_USRKEY) {
		flags |= AES_CTRL_WRKEY;
		_writefield(AES_WRITEKEY0_REG, op->key);
	}

	do_crypt(op->src, op->dst, op->len, flags);

	if (op->mode == AES_MODE_CBC)
		_readfield(AES_WRITEIV0_REG, op->iv);

	spin_unlock_irqrestore(&lock, iflags);

	return op->len;
}

/* CRYPTO-API Functions */

static int
geode_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int len)
{
	struct geode_aes_op *op = crypto_tfm_ctx(tfm);

	if (len != AES_KEY_LENGTH) {
		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
		return -EINVAL;
	}

	memcpy(op->key, key, len);
	return 0;
}

static void
geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
	struct geode_aes_op *op = crypto_tfm_ctx(tfm);

	if ((out == NULL) || (in == NULL))
		return;

	op->src = (void *) in;
	op->dst = (void *) out;
	op->mode = AES_MODE_ECB;
	op->flags = 0;
	op->len = AES_MIN_BLOCK_SIZE;
	op->dir = AES_DIR_ENCRYPT;

	geode_aes_crypt(op);
}


static void
geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
	struct geode_aes_op *op = crypto_tfm_ctx(tfm);

	if ((out == NULL) || (in == NULL))
		return;

	op->src = (void *) in;
	op->dst = (void *) out;
	op->mode = AES_MODE_ECB;
	op->flags = 0;
	op->len = AES_MIN_BLOCK_SIZE;
	op->dir = AES_DIR_DECRYPT;

	geode_aes_crypt(op);
}


static struct crypto_alg geode_alg = {
	.cra_name               =       "aes",
	.cra_driver_name	=       "geode-aes-128",
	.cra_priority           =       300,
	.cra_alignmask          =       15,
	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
	.cra_blocksize		=	AES_MIN_BLOCK_SIZE,
	.cra_ctxsize		=	sizeof(struct geode_aes_op),
	.cra_module		=	THIS_MODULE,
	.cra_list		=	LIST_HEAD_INIT(geode_alg.cra_list),
	.cra_u			=	{
		.cipher = {
			.cia_min_keysize	=  AES_KEY_LENGTH,
			.cia_max_keysize	=  AES_KEY_LENGTH,
			.cia_setkey		=  geode_setkey,
			.cia_encrypt		=  geode_encrypt,
			.cia_decrypt		=  geode_decrypt
		}
	}
};

static int
geode_cbc_decrypt(struct blkcipher_desc *desc,
		  struct scatterlist *dst, struct scatterlist *src,
		  unsigned int nbytes)
{
	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;
	int err, ret;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while((nbytes = walk.nbytes)) {
		op->src = walk.src.virt.addr,
		op->dst = walk.dst.virt.addr;
		op->mode = AES_MODE_CBC;
		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
		op->dir = AES_DIR_DECRYPT;

		memcpy(op->iv, walk.iv, AES_IV_LENGTH);

		ret = geode_aes_crypt(op);

		memcpy(walk.iv, op->iv, AES_IV_LENGTH);
		nbytes -= ret;

		err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
}

static int
geode_cbc_encrypt(struct blkcipher_desc *desc,
		  struct scatterlist *dst, struct scatterlist *src,
		  unsigned int nbytes)
{
	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;
	int err, ret;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while((nbytes = walk.nbytes)) {
		op->src = walk.src.virt.addr,
		op->dst = walk.dst.virt.addr;
		op->mode = AES_MODE_CBC;
		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
		op->dir = AES_DIR_ENCRYPT;

		memcpy(op->iv, walk.iv, AES_IV_LENGTH);

		ret = geode_aes_crypt(op);
		nbytes -= ret;
		err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
}

static struct crypto_alg geode_cbc_alg = {
	.cra_name		=	"cbc(aes)",
	.cra_driver_name	=	"cbc-aes-geode-128",
	.cra_priority		=	400,
	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		=	AES_MIN_BLOCK_SIZE,
	.cra_ctxsize		=	sizeof(struct geode_aes_op),
	.cra_alignmask		=	15,
	.cra_type		=	&crypto_blkcipher_type,
	.cra_module		=	THIS_MODULE,
	.cra_list		=	LIST_HEAD_INIT(geode_cbc_alg.cra_list),
	.cra_u			=	{
		.blkcipher = {
			.min_keysize		=	AES_KEY_LENGTH,
			.max_keysize		=	AES_KEY_LENGTH,
			.setkey			=	geode_setkey,
			.encrypt		=	geode_cbc_encrypt,
			.decrypt		=	geode_cbc_decrypt,
		}
	}
};

static int
geode_ecb_decrypt(struct blkcipher_desc *desc,
		  struct scatterlist *dst, struct scatterlist *src,
		  unsigned int nbytes)
{
	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;
	int err, ret;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while((nbytes = walk.nbytes)) {
		op->src = walk.src.virt.addr,
		op->dst = walk.dst.virt.addr;
		op->mode = AES_MODE_ECB;
		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
		op->dir = AES_DIR_DECRYPT;

		ret = geode_aes_crypt(op);
		nbytes -= ret;
		err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
}

static int
geode_ecb_encrypt(struct blkcipher_desc *desc,
		  struct scatterlist *dst, struct scatterlist *src,
		  unsigned int nbytes)
{
	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;
	int err, ret;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while((nbytes = walk.nbytes)) {
		op->src = walk.src.virt.addr,
		op->dst = walk.dst.virt.addr;
		op->mode = AES_MODE_ECB;
		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
		op->dir = AES_DIR_ENCRYPT;

		ret = geode_aes_crypt(op);
		nbytes -= ret;
		ret =  blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
}

static struct crypto_alg geode_ecb_alg = {
	.cra_name		=	"ecb(aes)",
	.cra_driver_name	=	"ecb-aes-geode-128",
	.cra_priority		=	400,
	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		=	AES_MIN_BLOCK_SIZE,
	.cra_ctxsize		=	sizeof(struct geode_aes_op),
	.cra_alignmask		=	15,
	.cra_type		=	&crypto_blkcipher_type,
	.cra_module		=	THIS_MODULE,
	.cra_list		=	LIST_HEAD_INIT(geode_ecb_alg.cra_list),
	.cra_u			=	{
		.blkcipher = {
			.min_keysize		=	AES_KEY_LENGTH,
			.max_keysize		=	AES_KEY_LENGTH,
			.setkey			=	geode_setkey,
			.encrypt		=	geode_ecb_encrypt,
			.decrypt		=	geode_ecb_decrypt,
		}
	}
};

static void
geode_aes_remove(struct pci_dev *dev)
{
	crypto_unregister_alg(&geode_alg);
	crypto_unregister_alg(&geode_ecb_alg);
	crypto_unregister_alg(&geode_cbc_alg);

	pci_iounmap(dev, _iobase);
	_iobase = NULL;

	pci_release_regions(dev);
	pci_disable_device(dev);
}


static int
geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
	int ret;

	if ((ret = pci_enable_device(dev)))
		return ret;

	if ((ret = pci_request_regions(dev, "geode-aes-128")))
		goto eenable;

	_iobase = pci_iomap(dev, 0, 0);

	if (_iobase == NULL) {
		ret = -ENOMEM;
		goto erequest;
	}

	spin_lock_init(&lock);

	/* Clear any pending activity */
	iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);

	if ((ret = crypto_register_alg(&geode_alg)))
		goto eiomap;

	if ((ret = crypto_register_alg(&geode_ecb_alg)))
		goto ealg;

	if ((ret = crypto_register_alg(&geode_cbc_alg)))
		goto eecb;

	printk(KERN_NOTICE "geode-aes: GEODE AES engine enabled.\n");
	return 0;

 eecb:
	crypto_unregister_alg(&geode_ecb_alg);

 ealg:
	crypto_unregister_alg(&geode_alg);

 eiomap:
	pci_iounmap(dev, _iobase);

 erequest:
	pci_release_regions(dev);

 eenable:
	pci_disable_device(dev);

	printk(KERN_ERR "geode-aes:  GEODE AES initialization failed.\n");
	return ret;
}

static struct pci_device_id geode_aes_tbl[] = {
	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_LX_AES, PCI_ANY_ID, PCI_ANY_ID} ,
	{ 0, }
};

MODULE_DEVICE_TABLE(pci, geode_aes_tbl);

static struct pci_driver geode_aes_driver = {
	.name = "Geode LX AES",
	.id_table = geode_aes_tbl,
	.probe = geode_aes_probe,
	.remove = __devexit_p(geode_aes_remove)
};

static int __init
geode_aes_init(void)
{
	return pci_register_driver(&geode_aes_driver);
}

static void __exit
geode_aes_exit(void)
{
	pci_unregister_driver(&geode_aes_driver);
}

MODULE_AUTHOR("Advanced Micro Devices, Inc.");
MODULE_DESCRIPTION("Geode LX Hardware AES driver");
MODULE_LICENSE("GPL");

module_init(geode_aes_init);
module_exit(geode_aes_exit);