1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Cryptographic API.
4 *
5 * Support for VIA PadLock hardware crypto engine.
6 *
7 * Copyright (c) 2006  Michal Ludvig <michal@logix.cz>
8 */
9
10#include <crypto/internal/hash.h>
11#include <crypto/padlock.h>
12#include <crypto/sha1.h>
13#include <crypto/sha2.h>
14#include <linux/err.h>
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/errno.h>
18#include <linux/interrupt.h>
19#include <linux/kernel.h>
20#include <linux/scatterlist.h>
21#include <asm/cpu_device_id.h>
22#include <asm/fpu/api.h>
23
24struct padlock_sha_desc {
25	struct shash_desc fallback;
26};
27
28struct padlock_sha_ctx {
29	struct crypto_shash *fallback;
30};
31
32static int padlock_sha_init(struct shash_desc *desc)
33{
34	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
35	struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
36
37	dctx->fallback.tfm = ctx->fallback;
38	return crypto_shash_init(&dctx->fallback);
39}
40
41static int padlock_sha_update(struct shash_desc *desc,
42			      const u8 *data, unsigned int length)
43{
44	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
45
46	return crypto_shash_update(&dctx->fallback, data, length);
47}
48
49static int padlock_sha_export(struct shash_desc *desc, void *out)
50{
51	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
52
53	return crypto_shash_export(&dctx->fallback, out);
54}
55
56static int padlock_sha_import(struct shash_desc *desc, const void *in)
57{
58	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
59	struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
60
61	dctx->fallback.tfm = ctx->fallback;
62	return crypto_shash_import(&dctx->fallback, in);
63}
64
65static inline void padlock_output_block(uint32_t *src,
66		 	uint32_t *dst, size_t count)
67{
68	while (count--)
69		*dst++ = swab32(*src++);
70}
71
72static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in,
73			      unsigned int count, u8 *out)
74{
75	/* We can't store directly to *out as it may be unaligned. */
76	/* BTW Don't reduce the buffer size below 128 Bytes!
77	 *     PadLock microcode needs it that big. */
78	char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
79		((aligned(STACK_ALIGN)));
80	char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
81	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
82	struct sha1_state state;
83	unsigned int space;
84	unsigned int leftover;
85	int err;
86
87	err = crypto_shash_export(&dctx->fallback, &state);
88	if (err)
89		goto out;
90
91	if (state.count + count > ULONG_MAX)
92		return crypto_shash_finup(&dctx->fallback, in, count, out);
93
94	leftover = ((state.count - 1) & (SHA1_BLOCK_SIZE - 1)) + 1;
95	space =  SHA1_BLOCK_SIZE - leftover;
96	if (space) {
97		if (count > space) {
98			err = crypto_shash_update(&dctx->fallback, in, space) ?:
99			      crypto_shash_export(&dctx->fallback, &state);
100			if (err)
101				goto out;
102			count -= space;
103			in += space;
104		} else {
105			memcpy(state.buffer + leftover, in, count);
106			in = state.buffer;
107			count += leftover;
108			state.count &= ~(SHA1_BLOCK_SIZE - 1);
109		}
110	}
111
112	memcpy(result, &state.state, SHA1_DIGEST_SIZE);
113
114	asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
115		      : \
116		      : "c"((unsigned long)state.count + count), \
117			"a"((unsigned long)state.count), \
118			"S"(in), "D"(result));
119
120	padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
121
122out:
123	return err;
124}
125
126static int padlock_sha1_final(struct shash_desc *desc, u8 *out)
127{
128	u8 buf[4];
129
130	return padlock_sha1_finup(desc, buf, 0, out);
131}
132
133static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in,
134				unsigned int count, u8 *out)
135{
136	/* We can't store directly to *out as it may be unaligned. */
137	/* BTW Don't reduce the buffer size below 128 Bytes!
138	 *     PadLock microcode needs it that big. */
139	char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
140		((aligned(STACK_ALIGN)));
141	char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
142	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
143	struct sha256_state state;
144	unsigned int space;
145	unsigned int leftover;
146	int err;
147
148	err = crypto_shash_export(&dctx->fallback, &state);
149	if (err)
150		goto out;
151
152	if (state.count + count > ULONG_MAX)
153		return crypto_shash_finup(&dctx->fallback, in, count, out);
154
155	leftover = ((state.count - 1) & (SHA256_BLOCK_SIZE - 1)) + 1;
156	space =  SHA256_BLOCK_SIZE - leftover;
157	if (space) {
158		if (count > space) {
159			err = crypto_shash_update(&dctx->fallback, in, space) ?:
160			      crypto_shash_export(&dctx->fallback, &state);
161			if (err)
162				goto out;
163			count -= space;
164			in += space;
165		} else {
166			memcpy(state.buf + leftover, in, count);
167			in = state.buf;
168			count += leftover;
169			state.count &= ~(SHA1_BLOCK_SIZE - 1);
170		}
171	}
172
173	memcpy(result, &state.state, SHA256_DIGEST_SIZE);
174
175	asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
176		      : \
177		      : "c"((unsigned long)state.count + count), \
178			"a"((unsigned long)state.count), \
179			"S"(in), "D"(result));
180
181	padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
182
183out:
184	return err;
185}
186
187static int padlock_sha256_final(struct shash_desc *desc, u8 *out)
188{
189	u8 buf[4];
190
191	return padlock_sha256_finup(desc, buf, 0, out);
192}
193
194static int padlock_init_tfm(struct crypto_shash *hash)
195{
196	const char *fallback_driver_name = crypto_shash_alg_name(hash);
197	struct padlock_sha_ctx *ctx = crypto_shash_ctx(hash);
198	struct crypto_shash *fallback_tfm;
199
200	/* Allocate a fallback and abort if it failed. */
201	fallback_tfm = crypto_alloc_shash(fallback_driver_name, 0,
202					  CRYPTO_ALG_NEED_FALLBACK);
203	if (IS_ERR(fallback_tfm)) {
204		printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
205		       fallback_driver_name);
206		return PTR_ERR(fallback_tfm);
207	}
208
209	ctx->fallback = fallback_tfm;
210	hash->descsize += crypto_shash_descsize(fallback_tfm);
211	return 0;
212}
213
214static void padlock_exit_tfm(struct crypto_shash *hash)
215{
216	struct padlock_sha_ctx *ctx = crypto_shash_ctx(hash);
217
218	crypto_free_shash(ctx->fallback);
219}
220
221static struct shash_alg sha1_alg = {
222	.digestsize	=	SHA1_DIGEST_SIZE,
223	.init   	= 	padlock_sha_init,
224	.update 	=	padlock_sha_update,
225	.finup  	=	padlock_sha1_finup,
226	.final  	=	padlock_sha1_final,
227	.export		=	padlock_sha_export,
228	.import		=	padlock_sha_import,
229	.init_tfm	=	padlock_init_tfm,
230	.exit_tfm	=	padlock_exit_tfm,
231	.descsize	=	sizeof(struct padlock_sha_desc),
232	.statesize	=	sizeof(struct sha1_state),
233	.base		=	{
234		.cra_name		=	"sha1",
235		.cra_driver_name	=	"sha1-padlock",
236		.cra_priority		=	PADLOCK_CRA_PRIORITY,
237		.cra_flags		=	CRYPTO_ALG_NEED_FALLBACK,
238		.cra_blocksize		=	SHA1_BLOCK_SIZE,
239		.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
240		.cra_module		=	THIS_MODULE,
241	}
242};
243
244static struct shash_alg sha256_alg = {
245	.digestsize	=	SHA256_DIGEST_SIZE,
246	.init   	= 	padlock_sha_init,
247	.update 	=	padlock_sha_update,
248	.finup  	=	padlock_sha256_finup,
249	.final  	=	padlock_sha256_final,
250	.export		=	padlock_sha_export,
251	.import		=	padlock_sha_import,
252	.init_tfm	=	padlock_init_tfm,
253	.exit_tfm	=	padlock_exit_tfm,
254	.descsize	=	sizeof(struct padlock_sha_desc),
255	.statesize	=	sizeof(struct sha256_state),
256	.base		=	{
257		.cra_name		=	"sha256",
258		.cra_driver_name	=	"sha256-padlock",
259		.cra_priority		=	PADLOCK_CRA_PRIORITY,
260		.cra_flags		=	CRYPTO_ALG_NEED_FALLBACK,
261		.cra_blocksize		=	SHA256_BLOCK_SIZE,
262		.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
263		.cra_module		=	THIS_MODULE,
264	}
265};
266
267/* Add two shash_alg instance for hardware-implemented *
268* multiple-parts hash supported by VIA Nano Processor.*/
269static int padlock_sha1_init_nano(struct shash_desc *desc)
270{
271	struct sha1_state *sctx = shash_desc_ctx(desc);
272
273	*sctx = (struct sha1_state){
274		.state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
275	};
276
277	return 0;
278}
279
280static int padlock_sha1_update_nano(struct shash_desc *desc,
281			const u8 *data,	unsigned int len)
282{
283	struct sha1_state *sctx = shash_desc_ctx(desc);
284	unsigned int partial, done;
285	const u8 *src;
286	/*The PHE require the out buffer must 128 bytes and 16-bytes aligned*/
287	u8 buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
288		((aligned(STACK_ALIGN)));
289	u8 *dst = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
290
291	partial = sctx->count & 0x3f;
292	sctx->count += len;
293	done = 0;
294	src = data;
295	memcpy(dst, (u8 *)(sctx->state), SHA1_DIGEST_SIZE);
296
297	if ((partial + len) >= SHA1_BLOCK_SIZE) {
298
299		/* Append the bytes in state's buffer to a block to handle */
300		if (partial) {
301			done = -partial;
302			memcpy(sctx->buffer + partial, data,
303				done + SHA1_BLOCK_SIZE);
304			src = sctx->buffer;
305			asm volatile (".byte 0xf3,0x0f,0xa6,0xc8"
306			: "+S"(src), "+D"(dst) \
307			: "a"((long)-1), "c"((unsigned long)1));
308			done += SHA1_BLOCK_SIZE;
309			src = data + done;
310		}
311
312		/* Process the left bytes from the input data */
313		if (len - done >= SHA1_BLOCK_SIZE) {
314			asm volatile (".byte 0xf3,0x0f,0xa6,0xc8"
315			: "+S"(src), "+D"(dst)
316			: "a"((long)-1),
317			"c"((unsigned long)((len - done) / SHA1_BLOCK_SIZE)));
318			done += ((len - done) - (len - done) % SHA1_BLOCK_SIZE);
319			src = data + done;
320		}
321		partial = 0;
322	}
323	memcpy((u8 *)(sctx->state), dst, SHA1_DIGEST_SIZE);
324	memcpy(sctx->buffer + partial, src, len - done);
325
326	return 0;
327}
328
329static int padlock_sha1_final_nano(struct shash_desc *desc, u8 *out)
330{
331	struct sha1_state *state = (struct sha1_state *)shash_desc_ctx(desc);
332	unsigned int partial, padlen;
333	__be64 bits;
334	static const u8 padding[64] = { 0x80, };
335
336	bits = cpu_to_be64(state->count << 3);
337
338	/* Pad out to 56 mod 64 */
339	partial = state->count & 0x3f;
340	padlen = (partial < 56) ? (56 - partial) : ((64+56) - partial);
341	padlock_sha1_update_nano(desc, padding, padlen);
342
343	/* Append length field bytes */
344	padlock_sha1_update_nano(desc, (const u8 *)&bits, sizeof(bits));
345
346	/* Swap to output */
347	padlock_output_block((uint32_t *)(state->state), (uint32_t *)out, 5);
348
349	return 0;
350}
351
352static int padlock_sha256_init_nano(struct shash_desc *desc)
353{
354	struct sha256_state *sctx = shash_desc_ctx(desc);
355
356	*sctx = (struct sha256_state){
357		.state = { SHA256_H0, SHA256_H1, SHA256_H2, SHA256_H3, \
358				SHA256_H4, SHA256_H5, SHA256_H6, SHA256_H7},
359	};
360
361	return 0;
362}
363
364static int padlock_sha256_update_nano(struct shash_desc *desc, const u8 *data,
365			  unsigned int len)
366{
367	struct sha256_state *sctx = shash_desc_ctx(desc);
368	unsigned int partial, done;
369	const u8 *src;
370	/*The PHE require the out buffer must 128 bytes and 16-bytes aligned*/
371	u8 buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
372		((aligned(STACK_ALIGN)));
373	u8 *dst = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
374
375	partial = sctx->count & 0x3f;
376	sctx->count += len;
377	done = 0;
378	src = data;
379	memcpy(dst, (u8 *)(sctx->state), SHA256_DIGEST_SIZE);
380
381	if ((partial + len) >= SHA256_BLOCK_SIZE) {
382
383		/* Append the bytes in state's buffer to a block to handle */
384		if (partial) {
385			done = -partial;
386			memcpy(sctx->buf + partial, data,
387				done + SHA256_BLOCK_SIZE);
388			src = sctx->buf;
389			asm volatile (".byte 0xf3,0x0f,0xa6,0xd0"
390			: "+S"(src), "+D"(dst)
391			: "a"((long)-1), "c"((unsigned long)1));
392			done += SHA256_BLOCK_SIZE;
393			src = data + done;
394		}
395
396		/* Process the left bytes from input data*/
397		if (len - done >= SHA256_BLOCK_SIZE) {
398			asm volatile (".byte 0xf3,0x0f,0xa6,0xd0"
399			: "+S"(src), "+D"(dst)
400			: "a"((long)-1),
401			"c"((unsigned long)((len - done) / 64)));
402			done += ((len - done) - (len - done) % 64);
403			src = data + done;
404		}
405		partial = 0;
406	}
407	memcpy((u8 *)(sctx->state), dst, SHA256_DIGEST_SIZE);
408	memcpy(sctx->buf + partial, src, len - done);
409
410	return 0;
411}
412
413static int padlock_sha256_final_nano(struct shash_desc *desc, u8 *out)
414{
415	struct sha256_state *state =
416		(struct sha256_state *)shash_desc_ctx(desc);
417	unsigned int partial, padlen;
418	__be64 bits;
419	static const u8 padding[64] = { 0x80, };
420
421	bits = cpu_to_be64(state->count << 3);
422
423	/* Pad out to 56 mod 64 */
424	partial = state->count & 0x3f;
425	padlen = (partial < 56) ? (56 - partial) : ((64+56) - partial);
426	padlock_sha256_update_nano(desc, padding, padlen);
427
428	/* Append length field bytes */
429	padlock_sha256_update_nano(desc, (const u8 *)&bits, sizeof(bits));
430
431	/* Swap to output */
432	padlock_output_block((uint32_t *)(state->state), (uint32_t *)out, 8);
433
434	return 0;
435}
436
437static int padlock_sha_export_nano(struct shash_desc *desc,
438				void *out)
439{
440	int statesize = crypto_shash_statesize(desc->tfm);
441	void *sctx = shash_desc_ctx(desc);
442
443	memcpy(out, sctx, statesize);
444	return 0;
445}
446
447static int padlock_sha_import_nano(struct shash_desc *desc,
448				const void *in)
449{
450	int statesize = crypto_shash_statesize(desc->tfm);
451	void *sctx = shash_desc_ctx(desc);
452
453	memcpy(sctx, in, statesize);
454	return 0;
455}
456
457static struct shash_alg sha1_alg_nano = {
458	.digestsize	=	SHA1_DIGEST_SIZE,
459	.init		=	padlock_sha1_init_nano,
460	.update		=	padlock_sha1_update_nano,
461	.final		=	padlock_sha1_final_nano,
462	.export		=	padlock_sha_export_nano,
463	.import		=	padlock_sha_import_nano,
464	.descsize	=	sizeof(struct sha1_state),
465	.statesize	=	sizeof(struct sha1_state),
466	.base		=	{
467		.cra_name		=	"sha1",
468		.cra_driver_name	=	"sha1-padlock-nano",
469		.cra_priority		=	PADLOCK_CRA_PRIORITY,
470		.cra_blocksize		=	SHA1_BLOCK_SIZE,
471		.cra_module		=	THIS_MODULE,
472	}
473};
474
475static struct shash_alg sha256_alg_nano = {
476	.digestsize	=	SHA256_DIGEST_SIZE,
477	.init		=	padlock_sha256_init_nano,
478	.update		=	padlock_sha256_update_nano,
479	.final		=	padlock_sha256_final_nano,
480	.export		=	padlock_sha_export_nano,
481	.import		=	padlock_sha_import_nano,
482	.descsize	=	sizeof(struct sha256_state),
483	.statesize	=	sizeof(struct sha256_state),
484	.base		=	{
485		.cra_name		=	"sha256",
486		.cra_driver_name	=	"sha256-padlock-nano",
487		.cra_priority		=	PADLOCK_CRA_PRIORITY,
488		.cra_blocksize		=	SHA256_BLOCK_SIZE,
489		.cra_module		=	THIS_MODULE,
490	}
491};
492
493static const struct x86_cpu_id padlock_sha_ids[] = {
494	X86_MATCH_FEATURE(X86_FEATURE_PHE, NULL),
495	{}
496};
497MODULE_DEVICE_TABLE(x86cpu, padlock_sha_ids);
498
499static int __init padlock_init(void)
500{
501	int rc = -ENODEV;
502	struct cpuinfo_x86 *c = &cpu_data(0);
503	struct shash_alg *sha1;
504	struct shash_alg *sha256;
505
506	if (!x86_match_cpu(padlock_sha_ids) || !boot_cpu_has(X86_FEATURE_PHE_EN))
507		return -ENODEV;
508
509	/* Register the newly added algorithm module if on *
510	* VIA Nano processor, or else just do as before */
511	if (c->x86_model < 0x0f) {
512		sha1 = &sha1_alg;
513		sha256 = &sha256_alg;
514	} else {
515		sha1 = &sha1_alg_nano;
516		sha256 = &sha256_alg_nano;
517	}
518
519	rc = crypto_register_shash(sha1);
520	if (rc)
521		goto out;
522
523	rc = crypto_register_shash(sha256);
524	if (rc)
525		goto out_unreg1;
526
527	printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
528
529	return 0;
530
531out_unreg1:
532	crypto_unregister_shash(sha1);
533
534out:
535	printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
536	return rc;
537}
538
539static void __exit padlock_fini(void)
540{
541	struct cpuinfo_x86 *c = &cpu_data(0);
542
543	if (c->x86_model >= 0x0f) {
544		crypto_unregister_shash(&sha1_alg_nano);
545		crypto_unregister_shash(&sha256_alg_nano);
546	} else {
547		crypto_unregister_shash(&sha1_alg);
548		crypto_unregister_shash(&sha256_alg);
549	}
550}
551
552module_init(padlock_init);
553module_exit(padlock_fini);
554
555MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
556MODULE_LICENSE("GPL");
557MODULE_AUTHOR("Michal Ludvig");
558
559MODULE_ALIAS_CRYPTO("sha1-all");
560MODULE_ALIAS_CRYPTO("sha256-all");
561MODULE_ALIAS_CRYPTO("sha1-padlock");
562MODULE_ALIAS_CRYPTO("sha256-padlock");
563