1/*
2 * Cryptographic API.
3 *
4 * Support for VIA PadLock hardware crypto engine.
5 *
6 * Copyright (c) 2006  Michal Ludvig <michal@logix.cz>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 */
14
15#include <crypto/internal/hash.h>
16#include <crypto/padlock.h>
17#include <crypto/sha.h>
18#include <linux/err.h>
19#include <linux/module.h>
20#include <linux/init.h>
21#include <linux/errno.h>
22#include <linux/interrupt.h>
23#include <linux/kernel.h>
24#include <linux/scatterlist.h>
25#include <asm/cpu_device_id.h>
26#include <asm/i387.h>
27
28struct padlock_sha_desc {
29	struct shash_desc fallback;
30};
31
32struct padlock_sha_ctx {
33	struct crypto_shash *fallback;
34};
35
36static int padlock_sha_init(struct shash_desc *desc)
37{
38	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
39	struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
40
41	dctx->fallback.tfm = ctx->fallback;
42	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
43	return crypto_shash_init(&dctx->fallback);
44}
45
46static int padlock_sha_update(struct shash_desc *desc,
47			      const u8 *data, unsigned int length)
48{
49	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
50
51	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
52	return crypto_shash_update(&dctx->fallback, data, length);
53}
54
55static int padlock_sha_export(struct shash_desc *desc, void *out)
56{
57	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
58
59	return crypto_shash_export(&dctx->fallback, out);
60}
61
62static int padlock_sha_import(struct shash_desc *desc, const void *in)
63{
64	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
65	struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
66
67	dctx->fallback.tfm = ctx->fallback;
68	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
69	return crypto_shash_import(&dctx->fallback, in);
70}
71
72static inline void padlock_output_block(uint32_t *src,
73		 	uint32_t *dst, size_t count)
74{
75	while (count--)
76		*dst++ = swab32(*src++);
77}
78
79static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in,
80			      unsigned int count, u8 *out)
81{
82	/* We can't store directly to *out as it may be unaligned. */
83	/* BTW Don't reduce the buffer size below 128 Bytes!
84	 *     PadLock microcode needs it that big. */
85	char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
86		((aligned(STACK_ALIGN)));
87	char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
88	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
89	struct sha1_state state;
90	unsigned int space;
91	unsigned int leftover;
92	int ts_state;
93	int err;
94
95	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
96	err = crypto_shash_export(&dctx->fallback, &state);
97	if (err)
98		goto out;
99
100	if (state.count + count > ULONG_MAX)
101		return crypto_shash_finup(&dctx->fallback, in, count, out);
102
103	leftover = ((state.count - 1) & (SHA1_BLOCK_SIZE - 1)) + 1;
104	space =  SHA1_BLOCK_SIZE - leftover;
105	if (space) {
106		if (count > space) {
107			err = crypto_shash_update(&dctx->fallback, in, space) ?:
108			      crypto_shash_export(&dctx->fallback, &state);
109			if (err)
110				goto out;
111			count -= space;
112			in += space;
113		} else {
114			memcpy(state.buffer + leftover, in, count);
115			in = state.buffer;
116			count += leftover;
117			state.count &= ~(SHA1_BLOCK_SIZE - 1);
118		}
119	}
120
121	memcpy(result, &state.state, SHA1_DIGEST_SIZE);
122
123	/* prevent taking the spurious DNA fault with padlock. */
124	ts_state = irq_ts_save();
125	asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
126		      : \
127		      : "c"((unsigned long)state.count + count), \
128			"a"((unsigned long)state.count), \
129			"S"(in), "D"(result));
130	irq_ts_restore(ts_state);
131
132	padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
133
134out:
135	return err;
136}
137
138static int padlock_sha1_final(struct shash_desc *desc, u8 *out)
139{
140	u8 buf[4];
141
142	return padlock_sha1_finup(desc, buf, 0, out);
143}
144
145static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in,
146				unsigned int count, u8 *out)
147{
148	/* We can't store directly to *out as it may be unaligned. */
149	/* BTW Don't reduce the buffer size below 128 Bytes!
150	 *     PadLock microcode needs it that big. */
151	char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
152		((aligned(STACK_ALIGN)));
153	char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
154	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
155	struct sha256_state state;
156	unsigned int space;
157	unsigned int leftover;
158	int ts_state;
159	int err;
160
161	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
162	err = crypto_shash_export(&dctx->fallback, &state);
163	if (err)
164		goto out;
165
166	if (state.count + count > ULONG_MAX)
167		return crypto_shash_finup(&dctx->fallback, in, count, out);
168
169	leftover = ((state.count - 1) & (SHA256_BLOCK_SIZE - 1)) + 1;
170	space =  SHA256_BLOCK_SIZE - leftover;
171	if (space) {
172		if (count > space) {
173			err = crypto_shash_update(&dctx->fallback, in, space) ?:
174			      crypto_shash_export(&dctx->fallback, &state);
175			if (err)
176				goto out;
177			count -= space;
178			in += space;
179		} else {
180			memcpy(state.buf + leftover, in, count);
181			in = state.buf;
182			count += leftover;
183			state.count &= ~(SHA1_BLOCK_SIZE - 1);
184		}
185	}
186
187	memcpy(result, &state.state, SHA256_DIGEST_SIZE);
188
189	/* prevent taking the spurious DNA fault with padlock. */
190	ts_state = irq_ts_save();
191	asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
192		      : \
193		      : "c"((unsigned long)state.count + count), \
194			"a"((unsigned long)state.count), \
195			"S"(in), "D"(result));
196	irq_ts_restore(ts_state);
197
198	padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
199
200out:
201	return err;
202}
203
204static int padlock_sha256_final(struct shash_desc *desc, u8 *out)
205{
206	u8 buf[4];
207
208	return padlock_sha256_finup(desc, buf, 0, out);
209}
210
211static int padlock_cra_init(struct crypto_tfm *tfm)
212{
213	struct crypto_shash *hash = __crypto_shash_cast(tfm);
214	const char *fallback_driver_name = crypto_tfm_alg_name(tfm);
215	struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);
216	struct crypto_shash *fallback_tfm;
217	int err = -ENOMEM;
218
219	/* Allocate a fallback and abort if it failed. */
220	fallback_tfm = crypto_alloc_shash(fallback_driver_name, 0,
221					  CRYPTO_ALG_NEED_FALLBACK);
222	if (IS_ERR(fallback_tfm)) {
223		printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
224		       fallback_driver_name);
225		err = PTR_ERR(fallback_tfm);
226		goto out;
227	}
228
229	ctx->fallback = fallback_tfm;
230	hash->descsize += crypto_shash_descsize(fallback_tfm);
231	return 0;
232
233out:
234	return err;
235}
236
237static void padlock_cra_exit(struct crypto_tfm *tfm)
238{
239	struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);
240
241	crypto_free_shash(ctx->fallback);
242}
243
244static struct shash_alg sha1_alg = {
245	.digestsize	=	SHA1_DIGEST_SIZE,
246	.init   	= 	padlock_sha_init,
247	.update 	=	padlock_sha_update,
248	.finup  	=	padlock_sha1_finup,
249	.final  	=	padlock_sha1_final,
250	.export		=	padlock_sha_export,
251	.import		=	padlock_sha_import,
252	.descsize	=	sizeof(struct padlock_sha_desc),
253	.statesize	=	sizeof(struct sha1_state),
254	.base		=	{
255		.cra_name		=	"sha1",
256		.cra_driver_name	=	"sha1-padlock",
257		.cra_priority		=	PADLOCK_CRA_PRIORITY,
258		.cra_flags		=	CRYPTO_ALG_TYPE_SHASH |
259						CRYPTO_ALG_NEED_FALLBACK,
260		.cra_blocksize		=	SHA1_BLOCK_SIZE,
261		.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
262		.cra_module		=	THIS_MODULE,
263		.cra_init		=	padlock_cra_init,
264		.cra_exit		=	padlock_cra_exit,
265	}
266};
267
268static struct shash_alg sha256_alg = {
269	.digestsize	=	SHA256_DIGEST_SIZE,
270	.init   	= 	padlock_sha_init,
271	.update 	=	padlock_sha_update,
272	.finup  	=	padlock_sha256_finup,
273	.final  	=	padlock_sha256_final,
274	.export		=	padlock_sha_export,
275	.import		=	padlock_sha_import,
276	.descsize	=	sizeof(struct padlock_sha_desc),
277	.statesize	=	sizeof(struct sha256_state),
278	.base		=	{
279		.cra_name		=	"sha256",
280		.cra_driver_name	=	"sha256-padlock",
281		.cra_priority		=	PADLOCK_CRA_PRIORITY,
282		.cra_flags		=	CRYPTO_ALG_TYPE_SHASH |
283						CRYPTO_ALG_NEED_FALLBACK,
284		.cra_blocksize		=	SHA256_BLOCK_SIZE,
285		.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
286		.cra_module		=	THIS_MODULE,
287		.cra_init		=	padlock_cra_init,
288		.cra_exit		=	padlock_cra_exit,
289	}
290};
291
292/* Add two shash_alg instance for hardware-implemented *
293* multiple-parts hash supported by VIA Nano Processor.*/
294static int padlock_sha1_init_nano(struct shash_desc *desc)
295{
296	struct sha1_state *sctx = shash_desc_ctx(desc);
297
298	*sctx = (struct sha1_state){
299		.state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
300	};
301
302	return 0;
303}
304
305static int padlock_sha1_update_nano(struct shash_desc *desc,
306			const u8 *data,	unsigned int len)
307{
308	struct sha1_state *sctx = shash_desc_ctx(desc);
309	unsigned int partial, done;
310	const u8 *src;
311	/*The PHE require the out buffer must 128 bytes and 16-bytes aligned*/
312	u8 buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
313		((aligned(STACK_ALIGN)));
314	u8 *dst = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
315	int ts_state;
316
317	partial = sctx->count & 0x3f;
318	sctx->count += len;
319	done = 0;
320	src = data;
321	memcpy(dst, (u8 *)(sctx->state), SHA1_DIGEST_SIZE);
322
323	if ((partial + len) >= SHA1_BLOCK_SIZE) {
324
325		/* Append the bytes in state's buffer to a block to handle */
326		if (partial) {
327			done = -partial;
328			memcpy(sctx->buffer + partial, data,
329				done + SHA1_BLOCK_SIZE);
330			src = sctx->buffer;
331			ts_state = irq_ts_save();
332			asm volatile (".byte 0xf3,0x0f,0xa6,0xc8"
333			: "+S"(src), "+D"(dst) \
334			: "a"((long)-1), "c"((unsigned long)1));
335			irq_ts_restore(ts_state);
336			done += SHA1_BLOCK_SIZE;
337			src = data + done;
338		}
339
340		/* Process the left bytes from the input data */
341		if (len - done >= SHA1_BLOCK_SIZE) {
342			ts_state = irq_ts_save();
343			asm volatile (".byte 0xf3,0x0f,0xa6,0xc8"
344			: "+S"(src), "+D"(dst)
345			: "a"((long)-1),
346			"c"((unsigned long)((len - done) / SHA1_BLOCK_SIZE)));
347			irq_ts_restore(ts_state);
348			done += ((len - done) - (len - done) % SHA1_BLOCK_SIZE);
349			src = data + done;
350		}
351		partial = 0;
352	}
353	memcpy((u8 *)(sctx->state), dst, SHA1_DIGEST_SIZE);
354	memcpy(sctx->buffer + partial, src, len - done);
355
356	return 0;
357}
358
359static int padlock_sha1_final_nano(struct shash_desc *desc, u8 *out)
360{
361	struct sha1_state *state = (struct sha1_state *)shash_desc_ctx(desc);
362	unsigned int partial, padlen;
363	__be64 bits;
364	static const u8 padding[64] = { 0x80, };
365
366	bits = cpu_to_be64(state->count << 3);
367
368	/* Pad out to 56 mod 64 */
369	partial = state->count & 0x3f;
370	padlen = (partial < 56) ? (56 - partial) : ((64+56) - partial);
371	padlock_sha1_update_nano(desc, padding, padlen);
372
373	/* Append length field bytes */
374	padlock_sha1_update_nano(desc, (const u8 *)&bits, sizeof(bits));
375
376	/* Swap to output */
377	padlock_output_block((uint32_t *)(state->state), (uint32_t *)out, 5);
378
379	return 0;
380}
381
382static int padlock_sha256_init_nano(struct shash_desc *desc)
383{
384	struct sha256_state *sctx = shash_desc_ctx(desc);
385
386	*sctx = (struct sha256_state){
387		.state = { SHA256_H0, SHA256_H1, SHA256_H2, SHA256_H3, \
388				SHA256_H4, SHA256_H5, SHA256_H6, SHA256_H7},
389	};
390
391	return 0;
392}
393
394static int padlock_sha256_update_nano(struct shash_desc *desc, const u8 *data,
395			  unsigned int len)
396{
397	struct sha256_state *sctx = shash_desc_ctx(desc);
398	unsigned int partial, done;
399	const u8 *src;
400	/*The PHE require the out buffer must 128 bytes and 16-bytes aligned*/
401	u8 buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
402		((aligned(STACK_ALIGN)));
403	u8 *dst = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
404	int ts_state;
405
406	partial = sctx->count & 0x3f;
407	sctx->count += len;
408	done = 0;
409	src = data;
410	memcpy(dst, (u8 *)(sctx->state), SHA256_DIGEST_SIZE);
411
412	if ((partial + len) >= SHA256_BLOCK_SIZE) {
413
414		/* Append the bytes in state's buffer to a block to handle */
415		if (partial) {
416			done = -partial;
417			memcpy(sctx->buf + partial, data,
418				done + SHA256_BLOCK_SIZE);
419			src = sctx->buf;
420			ts_state = irq_ts_save();
421			asm volatile (".byte 0xf3,0x0f,0xa6,0xd0"
422			: "+S"(src), "+D"(dst)
423			: "a"((long)-1), "c"((unsigned long)1));
424			irq_ts_restore(ts_state);
425			done += SHA256_BLOCK_SIZE;
426			src = data + done;
427		}
428
429		/* Process the left bytes from input data*/
430		if (len - done >= SHA256_BLOCK_SIZE) {
431			ts_state = irq_ts_save();
432			asm volatile (".byte 0xf3,0x0f,0xa6,0xd0"
433			: "+S"(src), "+D"(dst)
434			: "a"((long)-1),
435			"c"((unsigned long)((len - done) / 64)));
436			irq_ts_restore(ts_state);
437			done += ((len - done) - (len - done) % 64);
438			src = data + done;
439		}
440		partial = 0;
441	}
442	memcpy((u8 *)(sctx->state), dst, SHA256_DIGEST_SIZE);
443	memcpy(sctx->buf + partial, src, len - done);
444
445	return 0;
446}
447
448static int padlock_sha256_final_nano(struct shash_desc *desc, u8 *out)
449{
450	struct sha256_state *state =
451		(struct sha256_state *)shash_desc_ctx(desc);
452	unsigned int partial, padlen;
453	__be64 bits;
454	static const u8 padding[64] = { 0x80, };
455
456	bits = cpu_to_be64(state->count << 3);
457
458	/* Pad out to 56 mod 64 */
459	partial = state->count & 0x3f;
460	padlen = (partial < 56) ? (56 - partial) : ((64+56) - partial);
461	padlock_sha256_update_nano(desc, padding, padlen);
462
463	/* Append length field bytes */
464	padlock_sha256_update_nano(desc, (const u8 *)&bits, sizeof(bits));
465
466	/* Swap to output */
467	padlock_output_block((uint32_t *)(state->state), (uint32_t *)out, 8);
468
469	return 0;
470}
471
472static int padlock_sha_export_nano(struct shash_desc *desc,
473				void *out)
474{
475	int statesize = crypto_shash_statesize(desc->tfm);
476	void *sctx = shash_desc_ctx(desc);
477
478	memcpy(out, sctx, statesize);
479	return 0;
480}
481
482static int padlock_sha_import_nano(struct shash_desc *desc,
483				const void *in)
484{
485	int statesize = crypto_shash_statesize(desc->tfm);
486	void *sctx = shash_desc_ctx(desc);
487
488	memcpy(sctx, in, statesize);
489	return 0;
490}
491
492static struct shash_alg sha1_alg_nano = {
493	.digestsize	=	SHA1_DIGEST_SIZE,
494	.init		=	padlock_sha1_init_nano,
495	.update		=	padlock_sha1_update_nano,
496	.final		=	padlock_sha1_final_nano,
497	.export		=	padlock_sha_export_nano,
498	.import		=	padlock_sha_import_nano,
499	.descsize	=	sizeof(struct sha1_state),
500	.statesize	=	sizeof(struct sha1_state),
501	.base		=	{
502		.cra_name		=	"sha1",
503		.cra_driver_name	=	"sha1-padlock-nano",
504		.cra_priority		=	PADLOCK_CRA_PRIORITY,
505		.cra_flags		=	CRYPTO_ALG_TYPE_SHASH,
506		.cra_blocksize		=	SHA1_BLOCK_SIZE,
507		.cra_module		=	THIS_MODULE,
508	}
509};
510
511static struct shash_alg sha256_alg_nano = {
512	.digestsize	=	SHA256_DIGEST_SIZE,
513	.init		=	padlock_sha256_init_nano,
514	.update		=	padlock_sha256_update_nano,
515	.final		=	padlock_sha256_final_nano,
516	.export		=	padlock_sha_export_nano,
517	.import		=	padlock_sha_import_nano,
518	.descsize	=	sizeof(struct sha256_state),
519	.statesize	=	sizeof(struct sha256_state),
520	.base		=	{
521		.cra_name		=	"sha256",
522		.cra_driver_name	=	"sha256-padlock-nano",
523		.cra_priority		=	PADLOCK_CRA_PRIORITY,
524		.cra_flags		=	CRYPTO_ALG_TYPE_SHASH,
525		.cra_blocksize		=	SHA256_BLOCK_SIZE,
526		.cra_module		=	THIS_MODULE,
527	}
528};
529
530static struct x86_cpu_id padlock_sha_ids[] = {
531	X86_FEATURE_MATCH(X86_FEATURE_PHE),
532	{}
533};
534MODULE_DEVICE_TABLE(x86cpu, padlock_sha_ids);
535
536static int __init padlock_init(void)
537{
538	int rc = -ENODEV;
539	struct cpuinfo_x86 *c = &cpu_data(0);
540	struct shash_alg *sha1;
541	struct shash_alg *sha256;
542
543	if (!x86_match_cpu(padlock_sha_ids) || !cpu_has_phe_enabled)
544		return -ENODEV;
545
546	/* Register the newly added algorithm module if on *
547	* VIA Nano processor, or else just do as before */
548	if (c->x86_model < 0x0f) {
549		sha1 = &sha1_alg;
550		sha256 = &sha256_alg;
551	} else {
552		sha1 = &sha1_alg_nano;
553		sha256 = &sha256_alg_nano;
554	}
555
556	rc = crypto_register_shash(sha1);
557	if (rc)
558		goto out;
559
560	rc = crypto_register_shash(sha256);
561	if (rc)
562		goto out_unreg1;
563
564	printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
565
566	return 0;
567
568out_unreg1:
569	crypto_unregister_shash(sha1);
570
571out:
572	printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
573	return rc;
574}
575
576static void __exit padlock_fini(void)
577{
578	struct cpuinfo_x86 *c = &cpu_data(0);
579
580	if (c->x86_model >= 0x0f) {
581		crypto_unregister_shash(&sha1_alg_nano);
582		crypto_unregister_shash(&sha256_alg_nano);
583	} else {
584		crypto_unregister_shash(&sha1_alg);
585		crypto_unregister_shash(&sha256_alg);
586	}
587}
588
589module_init(padlock_init);
590module_exit(padlock_fini);
591
592MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
593MODULE_LICENSE("GPL");
594MODULE_AUTHOR("Michal Ludvig");
595
596MODULE_ALIAS_CRYPTO("sha1-all");
597MODULE_ALIAS_CRYPTO("sha256-all");
598MODULE_ALIAS_CRYPTO("sha1-padlock");
599MODULE_ALIAS_CRYPTO("sha256-padlock");
600