geode-aes.c revision b7a30da61adc5f252ee97b2a4f3fc23c9d06a08a 
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#include <crypto/aes.h>
17
18#include <asm/io.h>
19#include <asm/delay.h>
20
21#include "geode-aes.h"
22
23/* Static structures */
24
25static void __iomem * _iobase;
26static spinlock_t lock;
27
28/* Write a 128 bit field (either a writable key or IV) */
29static inline void
30_writefield(u32 offset, void *value)
31{
32	int i;
33	for(i = 0; i < 4; i++)
34		iowrite32(((u32 *) value)[i], _iobase + offset + (i * 4));
35}
36
37/* Read a 128 bit field (either a writable key or IV) */
38static inline void
39_readfield(u32 offset, void *value)
40{
41	int i;
42	for(i = 0; i < 4; i++)
43		((u32 *) value)[i] = ioread32(_iobase + offset + (i * 4));
44}
45
46static int
47do_crypt(void *src, void *dst, int len, u32 flags)
48{
49	u32 status;
50	u32 counter = AES_OP_TIMEOUT;
51
52	iowrite32(virt_to_phys(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
69static unsigned int
70geode_aes_crypt(struct geode_aes_op *op)
71{
72	u32 flags = 0;
73	unsigned long iflags;
74	int ret;
75
76	if (op->len == 0)
77		return 0;
78
79	/* If the source and destination is the same, then
80	 * we need to turn on the coherent flags, otherwise
81	 * we don't need to worry
82	 */
83
84	flags |= (AES_CTRL_DCA | AES_CTRL_SCA);
85
86	if (op->dir == AES_DIR_ENCRYPT)
87		flags |= AES_CTRL_ENCRYPT;
88
89	/* Start the critical section */
90
91	spin_lock_irqsave(&lock, iflags);
92
93	if (op->mode == AES_MODE_CBC) {
94		flags |= AES_CTRL_CBC;
95		_writefield(AES_WRITEIV0_REG, op->iv);
96	}
97
98	if (!(op->flags & AES_FLAGS_HIDDENKEY)) {
99		flags |= AES_CTRL_WRKEY;
100		_writefield(AES_WRITEKEY0_REG, op->key);
101	}
102
103	ret = do_crypt(op->src, op->dst, op->len, flags);
104	BUG_ON(ret);
105
106	if (op->mode == AES_MODE_CBC)
107		_readfield(AES_WRITEIV0_REG, op->iv);
108
109	spin_unlock_irqrestore(&lock, iflags);
110
111	return op->len;
112}
113
114/* CRYPTO-API Functions */
115
116static int
117geode_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int len)
118{
119	struct geode_aes_op *op = crypto_tfm_ctx(tfm);
120
121	if (len != AES_KEY_LENGTH) {
122		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
123		return -EINVAL;
124	}
125
126	memcpy(op->key, key, len);
127	return 0;
128}
129
130static void
131geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
132{
133	struct geode_aes_op *op = crypto_tfm_ctx(tfm);
134
135	if ((out == NULL) || (in == NULL))
136		return;
137
138	op->src = (void *) in;
139	op->dst = (void *) out;
140	op->mode = AES_MODE_ECB;
141	op->flags = 0;
142	op->len = AES_MIN_BLOCK_SIZE;
143	op->dir = AES_DIR_ENCRYPT;
144
145	geode_aes_crypt(op);
146}
147
148
149static void
150geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
151{
152	struct geode_aes_op *op = crypto_tfm_ctx(tfm);
153
154	if ((out == NULL) || (in == NULL))
155		return;
156
157	op->src = (void *) in;
158	op->dst = (void *) out;
159	op->mode = AES_MODE_ECB;
160	op->flags = 0;
161	op->len = AES_MIN_BLOCK_SIZE;
162	op->dir = AES_DIR_DECRYPT;
163
164	geode_aes_crypt(op);
165}
166
167
168static struct crypto_alg geode_alg = {
169	.cra_name               =       "aes",
170	.cra_driver_name	=       "geode-aes-128",
171	.cra_priority           =       300,
172	.cra_alignmask          =       15,
173	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
174	.cra_blocksize		=	AES_MIN_BLOCK_SIZE,
175	.cra_ctxsize		=	sizeof(struct geode_aes_op),
176	.cra_module		=	THIS_MODULE,
177	.cra_list		=	LIST_HEAD_INIT(geode_alg.cra_list),
178	.cra_u			=	{
179		.cipher = {
180			.cia_min_keysize	=  AES_KEY_LENGTH,
181			.cia_max_keysize	=  AES_KEY_LENGTH,
182			.cia_setkey		=  geode_setkey,
183			.cia_encrypt		=  geode_encrypt,
184			.cia_decrypt		=  geode_decrypt
185		}
186	}
187};
188
189static int
190geode_cbc_decrypt(struct blkcipher_desc *desc,
191		  struct scatterlist *dst, struct scatterlist *src,
192		  unsigned int nbytes)
193{
194	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
195	struct blkcipher_walk walk;
196	int err, ret;
197
198	blkcipher_walk_init(&walk, dst, src, nbytes);
199	err = blkcipher_walk_virt(desc, &walk);
200	memcpy(op->iv, walk.iv, AES_IV_LENGTH);
201
202	while((nbytes = walk.nbytes)) {
203		op->src = walk.src.virt.addr,
204		op->dst = walk.dst.virt.addr;
205		op->mode = AES_MODE_CBC;
206		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
207		op->dir = AES_DIR_DECRYPT;
208
209		ret = geode_aes_crypt(op);
210
211		nbytes -= ret;
212		err = blkcipher_walk_done(desc, &walk, nbytes);
213	}
214
215	memcpy(walk.iv, op->iv, AES_IV_LENGTH);
216	return err;
217}
218
219static int
220geode_cbc_encrypt(struct blkcipher_desc *desc,
221		  struct scatterlist *dst, struct scatterlist *src,
222		  unsigned int nbytes)
223{
224	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
225	struct blkcipher_walk walk;
226	int err, ret;
227
228	blkcipher_walk_init(&walk, dst, src, nbytes);
229	err = blkcipher_walk_virt(desc, &walk);
230	memcpy(op->iv, walk.iv, AES_IV_LENGTH);
231
232	while((nbytes = walk.nbytes)) {
233		op->src = walk.src.virt.addr,
234		op->dst = walk.dst.virt.addr;
235		op->mode = AES_MODE_CBC;
236		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
237		op->dir = AES_DIR_ENCRYPT;
238
239		ret = geode_aes_crypt(op);
240		nbytes -= ret;
241		err = blkcipher_walk_done(desc, &walk, nbytes);
242	}
243
244	memcpy(walk.iv, op->iv, AES_IV_LENGTH);
245	return err;
246}
247
248static struct crypto_alg geode_cbc_alg = {
249	.cra_name		=	"cbc(aes)",
250	.cra_driver_name	=	"cbc-aes-geode-128",
251	.cra_priority		=	400,
252	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
253	.cra_blocksize		=	AES_MIN_BLOCK_SIZE,
254	.cra_ctxsize		=	sizeof(struct geode_aes_op),
255	.cra_alignmask		=	15,
256	.cra_type		=	&crypto_blkcipher_type,
257	.cra_module		=	THIS_MODULE,
258	.cra_list		=	LIST_HEAD_INIT(geode_cbc_alg.cra_list),
259	.cra_u			=	{
260		.blkcipher = {
261			.min_keysize		=	AES_KEY_LENGTH,
262			.max_keysize		=	AES_KEY_LENGTH,
263			.setkey			=	geode_setkey,
264			.encrypt		=	geode_cbc_encrypt,
265			.decrypt		=	geode_cbc_decrypt,
266			.ivsize			=	AES_IV_LENGTH,
267		}
268	}
269};
270
271static int
272geode_ecb_decrypt(struct blkcipher_desc *desc,
273		  struct scatterlist *dst, struct scatterlist *src,
274		  unsigned int nbytes)
275{
276	struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
277	struct blkcipher_walk walk;
278	int err, ret;
279
280	blkcipher_walk_init(&walk, dst, src, nbytes);
281	err = blkcipher_walk_virt(desc, &walk);
282
283	while((nbytes = walk.nbytes)) {
284		op->src = walk.src.virt.addr,
285		op->dst = walk.dst.virt.addr;
286		op->mode = AES_MODE_ECB;
287		op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
288		op->dir = AES_DIR_DECRYPT;
289
290		ret = geode_aes_crypt(op);
291		nbytes -= ret;
292		err = blkcipher_walk_done(desc, &walk, nbytes);
293	}
294
295	return err;
296}
297
298static int
299geode_ecb_encrypt(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_ENCRYPT;
316
317		ret = geode_aes_crypt(op);
318		nbytes -= ret;
319		ret =  blkcipher_walk_done(desc, &walk, nbytes);
320	}
321
322	return err;
323}
324
325static struct crypto_alg geode_ecb_alg = {
326	.cra_name		=	"ecb(aes)",
327	.cra_driver_name	=	"ecb-aes-geode-128",
328	.cra_priority		=	400,
329	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
330	.cra_blocksize		=	AES_MIN_BLOCK_SIZE,
331	.cra_ctxsize		=	sizeof(struct geode_aes_op),
332	.cra_alignmask		=	15,
333	.cra_type		=	&crypto_blkcipher_type,
334	.cra_module		=	THIS_MODULE,
335	.cra_list		=	LIST_HEAD_INIT(geode_ecb_alg.cra_list),
336	.cra_u			=	{
337		.blkcipher = {
338			.min_keysize		=	AES_KEY_LENGTH,
339			.max_keysize		=	AES_KEY_LENGTH,
340			.setkey			=	geode_setkey,
341			.encrypt		=	geode_ecb_encrypt,
342			.decrypt		=	geode_ecb_decrypt,
343		}
344	}
345};
346
347static void
348geode_aes_remove(struct pci_dev *dev)
349{
350	crypto_unregister_alg(&geode_alg);
351	crypto_unregister_alg(&geode_ecb_alg);
352	crypto_unregister_alg(&geode_cbc_alg);
353
354	pci_iounmap(dev, _iobase);
355	_iobase = NULL;
356
357	pci_release_regions(dev);
358	pci_disable_device(dev);
359}
360
361
362static int
363geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
364{
365	int ret;
366
367	if ((ret = pci_enable_device(dev)))
368		return ret;
369
370	if ((ret = pci_request_regions(dev, "geode-aes-128")))
371		goto eenable;
372
373	_iobase = pci_iomap(dev, 0, 0);
374
375	if (_iobase == NULL) {
376		ret = -ENOMEM;
377		goto erequest;
378	}
379
380	spin_lock_init(&lock);
381
382	/* Clear any pending activity */
383	iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);
384
385	if ((ret = crypto_register_alg(&geode_alg)))
386		goto eiomap;
387
388	if ((ret = crypto_register_alg(&geode_ecb_alg)))
389		goto ealg;
390
391	if ((ret = crypto_register_alg(&geode_cbc_alg)))
392		goto eecb;
393
394	printk(KERN_NOTICE "geode-aes: GEODE AES engine enabled.\n");
395	return 0;
396
397 eecb:
398	crypto_unregister_alg(&geode_ecb_alg);
399
400 ealg:
401	crypto_unregister_alg(&geode_alg);
402
403 eiomap:
404	pci_iounmap(dev, _iobase);
405
406 erequest:
407	pci_release_regions(dev);
408
409 eenable:
410	pci_disable_device(dev);
411
412	printk(KERN_ERR "geode-aes:  GEODE AES initialization failed.\n");
413	return ret;
414}
415
416static struct pci_device_id geode_aes_tbl[] = {
417	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_LX_AES, PCI_ANY_ID, PCI_ANY_ID} ,
418	{ 0, }
419};
420
421MODULE_DEVICE_TABLE(pci, geode_aes_tbl);
422
423static struct pci_driver geode_aes_driver = {
424	.name = "Geode LX AES",
425	.id_table = geode_aes_tbl,
426	.probe = geode_aes_probe,
427	.remove = __devexit_p(geode_aes_remove)
428};
429
430static int __init
431geode_aes_init(void)
432{
433	return pci_register_driver(&geode_aes_driver);
434}
435
436static void __exit
437geode_aes_exit(void)
438{
439	pci_unregister_driver(&geode_aes_driver);
440}
441
442MODULE_AUTHOR("Advanced Micro Devices, Inc.");
443MODULE_DESCRIPTION("Geode LX Hardware AES driver");
444MODULE_LICENSE("GPL");
445
446module_init(geode_aes_init);
447module_exit(geode_aes_exit);
448