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/cipher.h>
14#include <crypto/internal/skcipher.h>
15
16#include <linux/io.h>
17#include <linux/delay.h>
18
19#include "geode-aes.h"
20
21/* Static structures */
22
23static void __iomem *_iobase;
24static DEFINE_SPINLOCK(lock);
25
26/* Write a 128 bit field (either a writable key or IV) */
27static inline void
28_writefield(u32 offset, const void *value)
29{
30	int i;
31
32	for (i = 0; i < 4; i++)
33		iowrite32(((const u32 *) value)[i], _iobase + offset + (i * 4));
34}
35
36/* Read a 128 bit field (either a writable key or IV) */
37static inline void
38_readfield(u32 offset, void *value)
39{
40	int i;
41
42	for (i = 0; i < 4; i++)
43		((u32 *) value)[i] = ioread32(_iobase + offset + (i * 4));
44}
45
46static int
47do_crypt(const void *src, void *dst, u32 len, u32 flags)
48{
49	u32 status;
50	u32 counter = AES_OP_TIMEOUT;
51
52	iowrite32(virt_to_phys((void *)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 void
70geode_aes_crypt(const struct geode_aes_tfm_ctx *tctx, const void *src,
71		void *dst, u32 len, u8 *iv, int mode, int dir)
72{
73	u32 flags = 0;
74	unsigned long iflags;
75	int ret;
76
77	/* If the source and destination is the same, then
78	 * we need to turn on the coherent flags, otherwise
79	 * we don't need to worry
80	 */
81
82	flags |= (AES_CTRL_DCA | AES_CTRL_SCA);
83
84	if (dir == AES_DIR_ENCRYPT)
85		flags |= AES_CTRL_ENCRYPT;
86
87	/* Start the critical section */
88
89	spin_lock_irqsave(&lock, iflags);
90
91	if (mode == AES_MODE_CBC) {
92		flags |= AES_CTRL_CBC;
93		_writefield(AES_WRITEIV0_REG, iv);
94	}
95
96	flags |= AES_CTRL_WRKEY;
97	_writefield(AES_WRITEKEY0_REG, tctx->key);
98
99	ret = do_crypt(src, dst, len, flags);
100	BUG_ON(ret);
101
102	if (mode == AES_MODE_CBC)
103		_readfield(AES_WRITEIV0_REG, iv);
104
105	spin_unlock_irqrestore(&lock, iflags);
106}
107
108/* CRYPTO-API Functions */
109
110static int geode_setkey_cip(struct crypto_tfm *tfm, const u8 *key,
111		unsigned int len)
112{
113	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
114
115	tctx->keylen = len;
116
117	if (len == AES_KEYSIZE_128) {
118		memcpy(tctx->key, key, len);
119		return 0;
120	}
121
122	if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256)
123		/* not supported at all */
124		return -EINVAL;
125
126	/*
127	 * The requested key size is not supported by HW, do a fallback
128	 */
129	tctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
130	tctx->fallback.cip->base.crt_flags |=
131		(tfm->crt_flags & CRYPTO_TFM_REQ_MASK);
132
133	return crypto_cipher_setkey(tctx->fallback.cip, key, len);
134}
135
136static int geode_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
137				 unsigned int len)
138{
139	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
140
141	tctx->keylen = len;
142
143	if (len == AES_KEYSIZE_128) {
144		memcpy(tctx->key, key, len);
145		return 0;
146	}
147
148	if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256)
149		/* not supported at all */
150		return -EINVAL;
151
152	/*
153	 * The requested key size is not supported by HW, do a fallback
154	 */
155	crypto_skcipher_clear_flags(tctx->fallback.skcipher,
156				    CRYPTO_TFM_REQ_MASK);
157	crypto_skcipher_set_flags(tctx->fallback.skcipher,
158				  crypto_skcipher_get_flags(tfm) &
159				  CRYPTO_TFM_REQ_MASK);
160	return crypto_skcipher_setkey(tctx->fallback.skcipher, key, len);
161}
162
163static void
164geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
165{
166	const struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
167
168	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
169		crypto_cipher_encrypt_one(tctx->fallback.cip, out, in);
170		return;
171	}
172
173	geode_aes_crypt(tctx, in, out, AES_BLOCK_SIZE, NULL,
174			AES_MODE_ECB, AES_DIR_ENCRYPT);
175}
176
177
178static void
179geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
180{
181	const struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
182
183	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
184		crypto_cipher_decrypt_one(tctx->fallback.cip, out, in);
185		return;
186	}
187
188	geode_aes_crypt(tctx, in, out, AES_BLOCK_SIZE, NULL,
189			AES_MODE_ECB, AES_DIR_DECRYPT);
190}
191
192static int fallback_init_cip(struct crypto_tfm *tfm)
193{
194	const char *name = crypto_tfm_alg_name(tfm);
195	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
196
197	tctx->fallback.cip = crypto_alloc_cipher(name, 0,
198						 CRYPTO_ALG_NEED_FALLBACK);
199
200	if (IS_ERR(tctx->fallback.cip)) {
201		printk(KERN_ERR "Error allocating fallback algo %s\n", name);
202		return PTR_ERR(tctx->fallback.cip);
203	}
204
205	return 0;
206}
207
208static void fallback_exit_cip(struct crypto_tfm *tfm)
209{
210	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
211
212	crypto_free_cipher(tctx->fallback.cip);
213}
214
215static struct crypto_alg geode_alg = {
216	.cra_name			=	"aes",
217	.cra_driver_name	=	"geode-aes",
218	.cra_priority		=	300,
219	.cra_alignmask		=	15,
220	.cra_flags			=	CRYPTO_ALG_TYPE_CIPHER |
221							CRYPTO_ALG_NEED_FALLBACK,
222	.cra_init			=	fallback_init_cip,
223	.cra_exit			=	fallback_exit_cip,
224	.cra_blocksize		=	AES_BLOCK_SIZE,
225	.cra_ctxsize		=	sizeof(struct geode_aes_tfm_ctx),
226	.cra_module			=	THIS_MODULE,
227	.cra_u				=	{
228		.cipher	=	{
229			.cia_min_keysize	=	AES_MIN_KEY_SIZE,
230			.cia_max_keysize	=	AES_MAX_KEY_SIZE,
231			.cia_setkey			=	geode_setkey_cip,
232			.cia_encrypt		=	geode_encrypt,
233			.cia_decrypt		=	geode_decrypt
234		}
235	}
236};
237
238static int geode_init_skcipher(struct crypto_skcipher *tfm)
239{
240	const char *name = crypto_tfm_alg_name(&tfm->base);
241	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
242
243	tctx->fallback.skcipher =
244		crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK |
245				      CRYPTO_ALG_ASYNC);
246	if (IS_ERR(tctx->fallback.skcipher)) {
247		printk(KERN_ERR "Error allocating fallback algo %s\n", name);
248		return PTR_ERR(tctx->fallback.skcipher);
249	}
250
251	crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
252				    crypto_skcipher_reqsize(tctx->fallback.skcipher));
253	return 0;
254}
255
256static void geode_exit_skcipher(struct crypto_skcipher *tfm)
257{
258	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
259
260	crypto_free_skcipher(tctx->fallback.skcipher);
261}
262
263static int geode_skcipher_crypt(struct skcipher_request *req, int mode, int dir)
264{
265	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
266	const struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
267	struct skcipher_walk walk;
268	unsigned int nbytes;
269	int err;
270
271	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
272		struct skcipher_request *subreq = skcipher_request_ctx(req);
273
274		*subreq = *req;
275		skcipher_request_set_tfm(subreq, tctx->fallback.skcipher);
276		if (dir == AES_DIR_DECRYPT)
277			return crypto_skcipher_decrypt(subreq);
278		else
279			return crypto_skcipher_encrypt(subreq);
280	}
281
282	err = skcipher_walk_virt(&walk, req, false);
283
284	while ((nbytes = walk.nbytes) != 0) {
285		geode_aes_crypt(tctx, walk.src.virt.addr, walk.dst.virt.addr,
286				round_down(nbytes, AES_BLOCK_SIZE),
287				walk.iv, mode, dir);
288		err = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE);
289	}
290
291	return err;
292}
293
294static int geode_cbc_encrypt(struct skcipher_request *req)
295{
296	return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_ENCRYPT);
297}
298
299static int geode_cbc_decrypt(struct skcipher_request *req)
300{
301	return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_DECRYPT);
302}
303
304static int geode_ecb_encrypt(struct skcipher_request *req)
305{
306	return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_ENCRYPT);
307}
308
309static int geode_ecb_decrypt(struct skcipher_request *req)
310{
311	return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_DECRYPT);
312}
313
314static struct skcipher_alg geode_skcipher_algs[] = {
315	{
316		.base.cra_name		= "cbc(aes)",
317		.base.cra_driver_name	= "cbc-aes-geode",
318		.base.cra_priority	= 400,
319		.base.cra_flags		= CRYPTO_ALG_KERN_DRIVER_ONLY |
320					  CRYPTO_ALG_NEED_FALLBACK,
321		.base.cra_blocksize	= AES_BLOCK_SIZE,
322		.base.cra_ctxsize	= sizeof(struct geode_aes_tfm_ctx),
323		.base.cra_alignmask	= 15,
324		.base.cra_module	= THIS_MODULE,
325		.init			= geode_init_skcipher,
326		.exit			= geode_exit_skcipher,
327		.setkey			= geode_setkey_skcipher,
328		.encrypt		= geode_cbc_encrypt,
329		.decrypt		= geode_cbc_decrypt,
330		.min_keysize		= AES_MIN_KEY_SIZE,
331		.max_keysize		= AES_MAX_KEY_SIZE,
332		.ivsize			= AES_BLOCK_SIZE,
333	}, {
334		.base.cra_name		= "ecb(aes)",
335		.base.cra_driver_name	= "ecb-aes-geode",
336		.base.cra_priority	= 400,
337		.base.cra_flags		= CRYPTO_ALG_KERN_DRIVER_ONLY |
338					  CRYPTO_ALG_NEED_FALLBACK,
339		.base.cra_blocksize	= AES_BLOCK_SIZE,
340		.base.cra_ctxsize	= sizeof(struct geode_aes_tfm_ctx),
341		.base.cra_alignmask	= 15,
342		.base.cra_module	= THIS_MODULE,
343		.init			= geode_init_skcipher,
344		.exit			= geode_exit_skcipher,
345		.setkey			= geode_setkey_skcipher,
346		.encrypt		= geode_ecb_encrypt,
347		.decrypt		= geode_ecb_decrypt,
348		.min_keysize		= AES_MIN_KEY_SIZE,
349		.max_keysize		= AES_MAX_KEY_SIZE,
350	},
351};
352
353static void geode_aes_remove(struct pci_dev *dev)
354{
355	crypto_unregister_alg(&geode_alg);
356	crypto_unregister_skciphers(geode_skcipher_algs,
357				    ARRAY_SIZE(geode_skcipher_algs));
358
359	pci_iounmap(dev, _iobase);
360	_iobase = NULL;
361
362	pci_release_regions(dev);
363	pci_disable_device(dev);
364}
365
366
367static int geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
368{
369	int ret;
370
371	ret = pci_enable_device(dev);
372	if (ret)
373		return ret;
374
375	ret = pci_request_regions(dev, "geode-aes");
376	if (ret)
377		goto eenable;
378
379	_iobase = pci_iomap(dev, 0, 0);
380
381	if (_iobase == NULL) {
382		ret = -ENOMEM;
383		goto erequest;
384	}
385
386	/* Clear any pending activity */
387	iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);
388
389	ret = crypto_register_alg(&geode_alg);
390	if (ret)
391		goto eiomap;
392
393	ret = crypto_register_skciphers(geode_skcipher_algs,
394					ARRAY_SIZE(geode_skcipher_algs));
395	if (ret)
396		goto ealg;
397
398	dev_notice(&dev->dev, "GEODE AES engine enabled.\n");
399	return 0;
400
401 ealg:
402	crypto_unregister_alg(&geode_alg);
403
404 eiomap:
405	pci_iounmap(dev, _iobase);
406
407 erequest:
408	pci_release_regions(dev);
409
410 eenable:
411	pci_disable_device(dev);
412
413	dev_err(&dev->dev, "GEODE AES initialization failed.\n");
414	return ret;
415}
416
417static struct pci_device_id geode_aes_tbl[] = {
418	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_LX_AES), },
419	{ 0, }
420};
421
422MODULE_DEVICE_TABLE(pci, geode_aes_tbl);
423
424static struct pci_driver geode_aes_driver = {
425	.name = "Geode LX AES",
426	.id_table = geode_aes_tbl,
427	.probe = geode_aes_probe,
428	.remove = geode_aes_remove,
429};
430
431module_pci_driver(geode_aes_driver);
432
433MODULE_AUTHOR("Advanced Micro Devices, Inc.");
434MODULE_DESCRIPTION("Geode LX Hardware AES driver");
435MODULE_LICENSE("GPL");
436MODULE_IMPORT_NS(CRYPTO_INTERNAL);
437