geode-aes.c revision 9fe757b0cfcee0724027a675c533077287a21b96 
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/sched.h>
12#include <linux/pci.h>
13#include <linux/pci_ids.h>
14#include <linux/crypto.h>
15#include <linux/spinlock.h>
16#include <crypto/algapi.h>
17
18#include <asm/io.h>
19#include <asm/delay.h>
20
21#include "geode-aes.h"
22
23/* Register definitions */
24
25#define AES_CTRLA_REG  0x0000
26
27#define AES_CTRL_START     0x01
28#define AES_CTRL_DECRYPT   0x00
29#define AES_CTRL_ENCRYPT   0x02
30#define AES_CTRL_WRKEY     0x04
31#define AES_CTRL_DCA       0x08
32#define AES_CTRL_SCA       0x10
33#define AES_CTRL_CBC       0x20
34
35#define AES_INTR_REG  0x0008
36
37#define AES_INTRA_PENDING (1 << 16)
38#define AES_INTRB_PENDING (1 << 17)
39
40#define AES_INTR_PENDING  (AES_INTRA_PENDING | AES_INTRB_PENDING)
41#define AES_INTR_MASK     0x07
42
43#define AES_SOURCEA_REG   0x0010
44#define AES_DSTA_REG      0x0014
45#define AES_LENA_REG      0x0018
46#define AES_WRITEKEY0_REG 0x0030
47#define AES_WRITEIV0_REG  0x0040
48
49/*  A very large counter that is used to gracefully bail out of an
50 *  operation in case of trouble
51 */
52
53#define AES_OP_TIMEOUT    0x50000
54
55/* Static structures */
56
57static void __iomem * _iobase;
58static spinlock_t lock;
59
60/* Write a 128 bit field (either a writable key or IV) */
61static inline void
62_writefield(u32 offset, void *value)
63{
64	int i;
65	for(i = 0; i < 4; i++)
66		iowrite32(((u32 *) value)[i], _iobase + offset + (i * 4));
67}
68
69/* Read a 128 bit field (either a writable key or IV) */
70static inline void
71_readfield(u32 offset, void *value)
72{
73	int i;
74	for(i = 0; i < 4; i++)
75		((u32 *) value)[i] = ioread32(_iobase + offset + (i * 4));
76}
77
78static int
79do_crypt(void *src, void *dst, int len, u32 flags)
80{
81	u32 status;
82	u32 counter = AES_OP_TIMEOUT;
83
84	iowrite32(virt_to_phys(src), _iobase + AES_SOURCEA_REG);
85	iowrite32(virt_to_phys(dst), _iobase + AES_DSTA_REG);
86	iowrite32(len,  _iobase + AES_LENA_REG);
87
88	/* Start the operation */
89	iowrite32(AES_CTRL_START | flags, _iobase + AES_CTRLA_REG);
90
91	do
92		status = ioread32(_iobase + AES_INTR_REG);
93	while(!(status & AES_INTRA_PENDING) && --counter);
94
95	/* Clear the event */
96	iowrite32((status & 0xFF) | AES_INTRA_PENDING, _iobase + AES_INTR_REG);
97	return counter ? 0 : 1;
98}
99
100unsigned int
101geode_aes_crypt(struct geode_aes_op *op)
102{
103
104	u32 flags = 0;
105	int iflags;
106
107	if (op->len == 0 || op->src == op->dst)
108		return 0;
109
110	if (op->flags & AES_FLAGS_COHERENT)
111		flags |= (AES_CTRL_DCA | AES_CTRL_SCA);
112
113	if (op->dir == AES_DIR_ENCRYPT)
114		flags |= AES_CTRL_ENCRYPT;
115
116	/* Start the critical section */
117
118	spin_lock_irqsave(&lock, iflags);
119
120	if (op->mode == AES_MODE_CBC) {
121		flags |= AES_CTRL_CBC;
122		_writefield(AES_WRITEIV0_REG, op->iv);
123	}
124
125	if (op->flags & AES_FLAGS_USRKEY) {
126		flags |= AES_CTRL_WRKEY;
127		_writefield(AES_WRITEKEY0_REG, op->key);
128	}
129
130	do_crypt(op->src, op->dst, op->len, flags);
131
132	if (op->mode == AES_MODE_CBC)
133		_readfield(AES_WRITEIV0_REG, op->iv);
134
135	spin_unlock_irqrestore(&lock, iflags);
136
137	return op->len;
138}
139
140/* CRYPTO-API Functions */
141
142static int
143geode_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int len)
144{
145	struct geode_aes_op *op = crypto_tfm_ctx(tfm);
146
147	if (len != AES_KEY_LENGTH) {
148		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
149		return -EINVAL;
150	}
151
152	memcpy(op->key, key, len);
153	return 0;
154}
155
156static void
157geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
158{
159	struct geode_aes_op *op = crypto_tfm_ctx(tfm);
160
161	if ((out == NULL) || (in == NULL))
162		return;
163
164	op->src = (void *) in;
165	op->dst = (void *) out;
166	op->mode = AES_MODE_ECB;
167	op->flags = 0;
168	op->len = AES_MIN_BLOCK_SIZE;
169	op->dir = AES_DIR_ENCRYPT;
170
171	geode_aes_crypt(op);
172}
173
174
175static void
176geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
177{
178	struct geode_aes_op *op = crypto_tfm_ctx(tfm);
179
180	if ((out == NULL) || (in == NULL))
181		return;
182
183	op->src = (void *) in;
184	op->dst = (void *) out;
185	op->mode = AES_MODE_ECB;
186	op->flags = 0;
187	op->len = AES_MIN_BLOCK_SIZE;
188	op->dir = AES_DIR_DECRYPT;
189
190	geode_aes_crypt(op);
191}
192
193
194static struct crypto_alg geode_alg = {
195	.cra_name               =       "aes",
196	.cra_driver_name	=       "geode-aes-128",
197	.cra_priority           =       300,
198	.cra_alignmask          =       15,
199	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
200	.cra_blocksize		=	AES_MIN_BLOCK_SIZE,
201	.cra_ctxsize		=	sizeof(struct geode_aes_op),
202	.cra_module		=	THIS_MODULE,
203	.cra_list		=	LIST_HEAD_INIT(geode_alg.cra_list),
204	.cra_u			=	{
205		.cipher = {
206			.cia_min_keysize	=  AES_KEY_LENGTH,
207			.cia_max_keysize	=  AES_KEY_LENGTH,
208			.cia_setkey		=  geode_setkey,
209			.cia_encrypt		=  geode_encrypt,
210			.cia_decrypt		=  geode_decrypt
211		}
212	}
213};
214
215static int
216geode_cbc_decrypt(struct blkcipher_desc *desc,
217		  struct scatterlist *dst, struct scatterlist *src,
218		  unsigned int nbytes)
219{
220	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
221	struct blkcipher_walk walk;
222	int err, ret;
223
224	blkcipher_walk_init(&walk, dst, src, nbytes);
225	err = blkcipher_walk_virt(desc, &walk);
226
227	while((nbytes = walk.nbytes)) {
228		op->src = walk.src.virt.addr,
229		op->dst = walk.dst.virt.addr;
230		op->mode = AES_MODE_CBC;
231		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
232		op->dir = AES_DIR_DECRYPT;
233
234		memcpy(op->iv, walk.iv, AES_IV_LENGTH);
235
236		ret = geode_aes_crypt(op);
237
238		memcpy(walk.iv, op->iv, AES_IV_LENGTH);
239		nbytes -= ret;
240
241		err = blkcipher_walk_done(desc, &walk, nbytes);
242	}
243
244	return err;
245}
246
247static int
248geode_cbc_encrypt(struct blkcipher_desc *desc,
249		  struct scatterlist *dst, struct scatterlist *src,
250		  unsigned int nbytes)
251{
252	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
253	struct blkcipher_walk walk;
254	int err, ret;
255
256	blkcipher_walk_init(&walk, dst, src, nbytes);
257	err = blkcipher_walk_virt(desc, &walk);
258
259	while((nbytes = walk.nbytes)) {
260		op->src = walk.src.virt.addr,
261		op->dst = walk.dst.virt.addr;
262		op->mode = AES_MODE_CBC;
263		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
264		op->dir = AES_DIR_ENCRYPT;
265
266		memcpy(op->iv, walk.iv, AES_IV_LENGTH);
267
268		ret = geode_aes_crypt(op);
269		nbytes -= ret;
270		err = blkcipher_walk_done(desc, &walk, nbytes);
271	}
272
273	return err;
274}
275
276static struct crypto_alg geode_cbc_alg = {
277	.cra_name		=	"cbc(aes)",
278	.cra_driver_name	=	"cbc-aes-geode-128",
279	.cra_priority		=	400,
280	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
281	.cra_blocksize		=	AES_MIN_BLOCK_SIZE,
282	.cra_ctxsize		=	sizeof(struct geode_aes_op),
283	.cra_alignmask		=	15,
284	.cra_type		=	&crypto_blkcipher_type,
285	.cra_module		=	THIS_MODULE,
286	.cra_list		=	LIST_HEAD_INIT(geode_cbc_alg.cra_list),
287	.cra_u			=	{
288		.blkcipher = {
289			.min_keysize		=	AES_KEY_LENGTH,
290			.max_keysize		=	AES_KEY_LENGTH,
291			.setkey			=	geode_setkey,
292			.encrypt		=	geode_cbc_encrypt,
293			.decrypt		=	geode_cbc_decrypt,
294		}
295	}
296};
297
298static int
299geode_ecb_decrypt(struct blkcipher_desc *desc,
300		  struct scatterlist *dst, struct scatterlist *src,
301		  unsigned int nbytes)
302{
303	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
304	struct blkcipher_walk walk;
305	int err, ret;
306
307	blkcipher_walk_init(&walk, dst, src, nbytes);
308	err = blkcipher_walk_virt(desc, &walk);
309
310	while((nbytes = walk.nbytes)) {
311		op->src = walk.src.virt.addr,
312		op->dst = walk.dst.virt.addr;
313		op->mode = AES_MODE_ECB;
314		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
315		op->dir = AES_DIR_DECRYPT;
316
317		ret = geode_aes_crypt(op);
318		nbytes -= ret;
319		err = blkcipher_walk_done(desc, &walk, nbytes);
320	}
321
322	return err;
323}
324
325static int
326geode_ecb_encrypt(struct blkcipher_desc *desc,
327		  struct scatterlist *dst, struct scatterlist *src,
328		  unsigned int nbytes)
329{
330	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
331	struct blkcipher_walk walk;
332	int err, ret;
333
334	blkcipher_walk_init(&walk, dst, src, nbytes);
335	err = blkcipher_walk_virt(desc, &walk);
336
337	while((nbytes = walk.nbytes)) {
338		op->src = walk.src.virt.addr,
339		op->dst = walk.dst.virt.addr;
340		op->mode = AES_MODE_ECB;
341		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
342		op->dir = AES_DIR_ENCRYPT;
343
344		ret = geode_aes_crypt(op);
345		nbytes -= ret;
346		ret =  blkcipher_walk_done(desc, &walk, nbytes);
347	}
348
349	return err;
350}
351
352static struct crypto_alg geode_ecb_alg = {
353	.cra_name		=	"ecb(aes)",
354	.cra_driver_name	=	"ecb-aes-geode-128",
355	.cra_priority		=	400,
356	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
357	.cra_blocksize		=	AES_MIN_BLOCK_SIZE,
358	.cra_ctxsize		=	sizeof(struct geode_aes_op),
359	.cra_alignmask		=	15,
360	.cra_type		=	&crypto_blkcipher_type,
361	.cra_module		=	THIS_MODULE,
362	.cra_list		=	LIST_HEAD_INIT(geode_ecb_alg.cra_list),
363	.cra_u			=	{
364		.blkcipher = {
365			.min_keysize		=	AES_KEY_LENGTH,
366			.max_keysize		=	AES_KEY_LENGTH,
367			.setkey			=	geode_setkey,
368			.encrypt		=	geode_ecb_encrypt,
369			.decrypt		=	geode_ecb_decrypt,
370		}
371	}
372};
373
374static void
375geode_aes_remove(struct pci_dev *dev)
376{
377	crypto_unregister_alg(&geode_alg);
378	crypto_unregister_alg(&geode_ecb_alg);
379	crypto_unregister_alg(&geode_cbc_alg);
380
381	pci_iounmap(dev, _iobase);
382	_iobase = NULL;
383
384	pci_release_regions(dev);
385	pci_disable_device(dev);
386}
387
388
389static int
390geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
391{
392	int ret;
393
394	if ((ret = pci_enable_device(dev)))
395		return ret;
396
397	if ((ret = pci_request_regions(dev, "geode-aes-128")))
398		goto eenable;
399
400	_iobase = pci_iomap(dev, 0, 0);
401
402	if (_iobase == NULL) {
403		ret = -ENOMEM;
404		goto erequest;
405	}
406
407	spin_lock_init(&lock);
408
409	/* Clear any pending activity */
410	iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);
411
412	if ((ret = crypto_register_alg(&geode_alg)))
413		goto eiomap;
414
415	if ((ret = crypto_register_alg(&geode_ecb_alg)))
416		goto ealg;
417
418	if ((ret = crypto_register_alg(&geode_cbc_alg)))
419		goto eecb;
420
421	printk(KERN_NOTICE "geode-aes: GEODE AES engine enabled.\n");
422	return 0;
423
424 eecb:
425	crypto_unregister_alg(&geode_ecb_alg);
426
427 ealg:
428	crypto_unregister_alg(&geode_alg);
429
430 eiomap:
431	pci_iounmap(dev, _iobase);
432
433 erequest:
434	pci_release_regions(dev);
435
436 eenable:
437	pci_disable_device(dev);
438
439	printk(KERN_ERR "geode-aes:  GEODE AES initialization failed.\n");
440	return ret;
441}
442
443static struct pci_device_id geode_aes_tbl[] = {
444	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_LX_AES, PCI_ANY_ID, PCI_ANY_ID} ,
445	{ 0, }
446};
447
448MODULE_DEVICE_TABLE(pci, geode_aes_tbl);
449
450static struct pci_driver geode_aes_driver = {
451	.name = "Geode LX AES",
452	.id_table = geode_aes_tbl,
453	.probe = geode_aes_probe,
454	.remove = __devexit_p(geode_aes_remove)
455};
456
457static int __init
458geode_aes_init(void)
459{
460	return pci_module_init(&geode_aes_driver);
461}
462
463static void __exit
464geode_aes_exit(void)
465{
466	pci_unregister_driver(&geode_aes_driver);
467}
468
469MODULE_AUTHOR("Advanced Micro Devices, Inc.");
470MODULE_DESCRIPTION("Geode LX Hardware AES driver");
471MODULE_LICENSE("GPL");
472
473module_init(geode_aes_init);
474module_exit(geode_aes_exit);
475