RT-AC56 3.0.0.4.374.37 core
[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / drivers / crypto / padlock-aes.c
blob8a515baa38f7c2d554e786bb33ab6979d770bc00
1 /*
2 * Cryptographic API.
4 * Support for VIA PadLock hardware crypto engine.
6 * Copyright (c) 2004 Michal Ludvig <michal@logix.cz>
8 */
10 #include <crypto/algapi.h>
11 #include <crypto/aes.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/types.h>
15 #include <linux/errno.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel.h>
18 #include <linux/percpu.h>
19 #include <linux/smp.h>
20 #include <linux/slab.h>
21 #include <asm/byteorder.h>
22 #include <asm/processor.h>
23 #include <asm/i387.h>
24 #include "padlock.h"
27 * Number of data blocks actually fetched for each xcrypt insn.
28 * Processors with prefetch errata will fetch extra blocks.
30 static unsigned int ecb_fetch_blocks = 2;
31 #define MAX_ECB_FETCH_BLOCKS (8)
32 #define ecb_fetch_bytes (ecb_fetch_blocks * AES_BLOCK_SIZE)
34 static unsigned int cbc_fetch_blocks = 1;
35 #define MAX_CBC_FETCH_BLOCKS (4)
36 #define cbc_fetch_bytes (cbc_fetch_blocks * AES_BLOCK_SIZE)
38 /* Control word. */
39 struct cword {
40 unsigned int __attribute__ ((__packed__))
41 rounds:4,
42 algo:3,
43 keygen:1,
44 interm:1,
45 encdec:1,
46 ksize:2;
47 } __attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));
49 /* Whenever making any changes to the following
50 * structure *make sure* you keep E, d_data
51 * and cword aligned on 16 Bytes boundaries and
52 * the Hardware can access 16 * 16 bytes of E and d_data
53 * (only the first 15 * 16 bytes matter but the HW reads
54 * more).
56 struct aes_ctx {
57 u32 E[AES_MAX_KEYLENGTH_U32]
58 __attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));
59 u32 d_data[AES_MAX_KEYLENGTH_U32]
60 __attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));
61 struct {
62 struct cword encrypt;
63 struct cword decrypt;
64 } cword;
65 u32 *D;
68 static DEFINE_PER_CPU(struct cword *, paes_last_cword);
70 /* Tells whether the ACE is capable to generate
71 the extended key for a given key_len. */
72 static inline int
73 aes_hw_extkey_available(uint8_t key_len)
75 /* TODO: We should check the actual CPU model/stepping
76 as it's possible that the capability will be
77 added in the next CPU revisions. */
78 if (key_len == 16)
79 return 1;
80 return 0;
83 static inline struct aes_ctx *aes_ctx_common(void *ctx)
85 unsigned long addr = (unsigned long)ctx;
86 unsigned long align = PADLOCK_ALIGNMENT;
88 if (align <= crypto_tfm_ctx_alignment())
89 align = 1;
90 return (struct aes_ctx *)ALIGN(addr, align);
93 static inline struct aes_ctx *aes_ctx(struct crypto_tfm *tfm)
95 return aes_ctx_common(crypto_tfm_ctx(tfm));
98 static inline struct aes_ctx *blk_aes_ctx(struct crypto_blkcipher *tfm)
100 return aes_ctx_common(crypto_blkcipher_ctx(tfm));
103 static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
104 unsigned int key_len)
106 struct aes_ctx *ctx = aes_ctx(tfm);
107 const __le32 *key = (const __le32 *)in_key;
108 u32 *flags = &tfm->crt_flags;
109 struct crypto_aes_ctx gen_aes;
110 int cpu;
112 if (key_len % 8) {
113 *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
114 return -EINVAL;
118 * If the hardware is capable of generating the extended key
119 * itself we must supply the plain key for both encryption
120 * and decryption.
122 ctx->D = ctx->E;
124 ctx->E[0] = le32_to_cpu(key[0]);
125 ctx->E[1] = le32_to_cpu(key[1]);
126 ctx->E[2] = le32_to_cpu(key[2]);
127 ctx->E[3] = le32_to_cpu(key[3]);
129 /* Prepare control words. */
130 memset(&ctx->cword, 0, sizeof(ctx->cword));
132 ctx->cword.decrypt.encdec = 1;
133 ctx->cword.encrypt.rounds = 10 + (key_len - 16) / 4;
134 ctx->cword.decrypt.rounds = ctx->cword.encrypt.rounds;
135 ctx->cword.encrypt.ksize = (key_len - 16) / 8;
136 ctx->cword.decrypt.ksize = ctx->cword.encrypt.ksize;
138 /* Don't generate extended keys if the hardware can do it. */
139 if (aes_hw_extkey_available(key_len))
140 goto ok;
142 ctx->D = ctx->d_data;
143 ctx->cword.encrypt.keygen = 1;
144 ctx->cword.decrypt.keygen = 1;
146 if (crypto_aes_expand_key(&gen_aes, in_key, key_len)) {
147 *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
148 return -EINVAL;
151 memcpy(ctx->E, gen_aes.key_enc, AES_MAX_KEYLENGTH);
152 memcpy(ctx->D, gen_aes.key_dec, AES_MAX_KEYLENGTH);
155 for_each_online_cpu(cpu)
156 if (&ctx->cword.encrypt == per_cpu(paes_last_cword, cpu) ||
157 &ctx->cword.decrypt == per_cpu(paes_last_cword, cpu))
158 per_cpu(paes_last_cword, cpu) = NULL;
160 return 0;
163 /* ====== Encryption/decryption routines ====== */
165 /* These are the real call to PadLock. */
166 static inline void padlock_reset_key(struct cword *cword)
168 int cpu = raw_smp_processor_id();
170 if (cword != per_cpu(paes_last_cword, cpu))
171 #ifndef CONFIG_X86_64
172 asm volatile ("pushfl; popfl");
173 #else
174 asm volatile ("pushfq; popfq");
175 #endif
178 static inline void padlock_store_cword(struct cword *cword)
180 per_cpu(paes_last_cword, raw_smp_processor_id()) = cword;
184 * While the padlock instructions don't use FP/SSE registers, they
185 * generate a spurious DNA fault when cr0.ts is '1'. These instructions
186 * should be used only inside the irq_ts_save/restore() context
189 static inline void rep_xcrypt_ecb(const u8 *input, u8 *output, void *key,
190 struct cword *control_word, int count)
192 asm volatile (".byte 0xf3,0x0f,0xa7,0xc8" /* rep xcryptecb */
193 : "+S"(input), "+D"(output)
194 : "d"(control_word), "b"(key), "c"(count));
197 static inline u8 *rep_xcrypt_cbc(const u8 *input, u8 *output, void *key,
198 u8 *iv, struct cword *control_word, int count)
200 asm volatile (".byte 0xf3,0x0f,0xa7,0xd0" /* rep xcryptcbc */
201 : "+S" (input), "+D" (output), "+a" (iv)
202 : "d" (control_word), "b" (key), "c" (count));
203 return iv;
206 static void ecb_crypt_copy(const u8 *in, u8 *out, u32 *key,
207 struct cword *cword, int count)
210 * Padlock prefetches extra data so we must provide mapped input buffers.
211 * Assume there are at least 16 bytes of stack already in use.
213 u8 buf[AES_BLOCK_SIZE * (MAX_ECB_FETCH_BLOCKS - 1) + PADLOCK_ALIGNMENT - 1];
214 u8 *tmp = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
216 memcpy(tmp, in, count * AES_BLOCK_SIZE);
217 rep_xcrypt_ecb(tmp, out, key, cword, count);
220 static u8 *cbc_crypt_copy(const u8 *in, u8 *out, u32 *key,
221 u8 *iv, struct cword *cword, int count)
224 * Padlock prefetches extra data so we must provide mapped input buffers.
225 * Assume there are at least 16 bytes of stack already in use.
227 u8 buf[AES_BLOCK_SIZE * (MAX_CBC_FETCH_BLOCKS - 1) + PADLOCK_ALIGNMENT - 1];
228 u8 *tmp = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
230 memcpy(tmp, in, count * AES_BLOCK_SIZE);
231 return rep_xcrypt_cbc(tmp, out, key, iv, cword, count);
234 static inline void ecb_crypt(const u8 *in, u8 *out, u32 *key,
235 struct cword *cword, int count)
237 /* Padlock in ECB mode fetches at least ecb_fetch_bytes of data.
238 * We could avoid some copying here but it's probably not worth it.
240 if (unlikely(((unsigned long)in & ~PAGE_MASK) + ecb_fetch_bytes > PAGE_SIZE)) {
241 ecb_crypt_copy(in, out, key, cword, count);
242 return;
245 rep_xcrypt_ecb(in, out, key, cword, count);
248 static inline u8 *cbc_crypt(const u8 *in, u8 *out, u32 *key,
249 u8 *iv, struct cword *cword, int count)
251 /* Padlock in CBC mode fetches at least cbc_fetch_bytes of data. */
252 if (unlikely(((unsigned long)in & ~PAGE_MASK) + cbc_fetch_bytes > PAGE_SIZE))
253 return cbc_crypt_copy(in, out, key, iv, cword, count);
255 return rep_xcrypt_cbc(in, out, key, iv, cword, count);
258 static inline void padlock_xcrypt_ecb(const u8 *input, u8 *output, void *key,
259 void *control_word, u32 count)
261 u32 initial = count & (ecb_fetch_blocks - 1);
263 if (count < ecb_fetch_blocks) {
264 ecb_crypt(input, output, key, control_word, count);
265 return;
268 if (initial)
269 asm volatile (".byte 0xf3,0x0f,0xa7,0xc8" /* rep xcryptecb */
270 : "+S"(input), "+D"(output)
271 : "d"(control_word), "b"(key), "c"(initial));
273 asm volatile (".byte 0xf3,0x0f,0xa7,0xc8" /* rep xcryptecb */
274 : "+S"(input), "+D"(output)
275 : "d"(control_word), "b"(key), "c"(count - initial));
278 static inline u8 *padlock_xcrypt_cbc(const u8 *input, u8 *output, void *key,
279 u8 *iv, void *control_word, u32 count)
281 u32 initial = count & (cbc_fetch_blocks - 1);
283 if (count < cbc_fetch_blocks)
284 return cbc_crypt(input, output, key, iv, control_word, count);
286 if (initial)
287 asm volatile (".byte 0xf3,0x0f,0xa7,0xd0" /* rep xcryptcbc */
288 : "+S" (input), "+D" (output), "+a" (iv)
289 : "d" (control_word), "b" (key), "c" (initial));
291 asm volatile (".byte 0xf3,0x0f,0xa7,0xd0" /* rep xcryptcbc */
292 : "+S" (input), "+D" (output), "+a" (iv)
293 : "d" (control_word), "b" (key), "c" (count-initial));
294 return iv;
297 static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
299 struct aes_ctx *ctx = aes_ctx(tfm);
300 int ts_state;
302 padlock_reset_key(&ctx->cword.encrypt);
303 ts_state = irq_ts_save();
304 ecb_crypt(in, out, ctx->E, &ctx->cword.encrypt, 1);
305 irq_ts_restore(ts_state);
306 padlock_store_cword(&ctx->cword.encrypt);
309 static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
311 struct aes_ctx *ctx = aes_ctx(tfm);
312 int ts_state;
314 padlock_reset_key(&ctx->cword.encrypt);
315 ts_state = irq_ts_save();
316 ecb_crypt(in, out, ctx->D, &ctx->cword.decrypt, 1);
317 irq_ts_restore(ts_state);
318 padlock_store_cword(&ctx->cword.encrypt);
321 static struct crypto_alg aes_alg = {
322 .cra_name = "aes",
323 .cra_driver_name = "aes-padlock",
324 .cra_priority = PADLOCK_CRA_PRIORITY,
325 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
326 .cra_blocksize = AES_BLOCK_SIZE,
327 .cra_ctxsize = sizeof(struct aes_ctx),
328 .cra_alignmask = PADLOCK_ALIGNMENT - 1,
329 .cra_module = THIS_MODULE,
330 .cra_list = LIST_HEAD_INIT(aes_alg.cra_list),
331 .cra_u = {
332 .cipher = {
333 .cia_min_keysize = AES_MIN_KEY_SIZE,
334 .cia_max_keysize = AES_MAX_KEY_SIZE,
335 .cia_setkey = aes_set_key,
336 .cia_encrypt = aes_encrypt,
337 .cia_decrypt = aes_decrypt,
342 static int ecb_aes_encrypt(struct blkcipher_desc *desc,
343 struct scatterlist *dst, struct scatterlist *src,
344 unsigned int nbytes)
346 struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
347 struct blkcipher_walk walk;
348 int err;
349 int ts_state;
351 padlock_reset_key(&ctx->cword.encrypt);
353 blkcipher_walk_init(&walk, dst, src, nbytes);
354 err = blkcipher_walk_virt(desc, &walk);
356 ts_state = irq_ts_save();
357 while ((nbytes = walk.nbytes)) {
358 padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr,
359 ctx->E, &ctx->cword.encrypt,
360 nbytes / AES_BLOCK_SIZE);
361 nbytes &= AES_BLOCK_SIZE - 1;
362 err = blkcipher_walk_done(desc, &walk, nbytes);
364 irq_ts_restore(ts_state);
366 padlock_store_cword(&ctx->cword.encrypt);
368 return err;
371 static int ecb_aes_decrypt(struct blkcipher_desc *desc,
372 struct scatterlist *dst, struct scatterlist *src,
373 unsigned int nbytes)
375 struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
376 struct blkcipher_walk walk;
377 int err;
378 int ts_state;
380 padlock_reset_key(&ctx->cword.decrypt);
382 blkcipher_walk_init(&walk, dst, src, nbytes);
383 err = blkcipher_walk_virt(desc, &walk);
385 ts_state = irq_ts_save();
386 while ((nbytes = walk.nbytes)) {
387 padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr,
388 ctx->D, &ctx->cword.decrypt,
389 nbytes / AES_BLOCK_SIZE);
390 nbytes &= AES_BLOCK_SIZE - 1;
391 err = blkcipher_walk_done(desc, &walk, nbytes);
393 irq_ts_restore(ts_state);
395 padlock_store_cword(&ctx->cword.encrypt);
397 return err;
400 static struct crypto_alg ecb_aes_alg = {
401 .cra_name = "ecb(aes)",
402 .cra_driver_name = "ecb-aes-padlock",
403 .cra_priority = PADLOCK_COMPOSITE_PRIORITY,
404 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
405 .cra_blocksize = AES_BLOCK_SIZE,
406 .cra_ctxsize = sizeof(struct aes_ctx),
407 .cra_alignmask = PADLOCK_ALIGNMENT - 1,
408 .cra_type = &crypto_blkcipher_type,
409 .cra_module = THIS_MODULE,
410 .cra_list = LIST_HEAD_INIT(ecb_aes_alg.cra_list),
411 .cra_u = {
412 .blkcipher = {
413 .min_keysize = AES_MIN_KEY_SIZE,
414 .max_keysize = AES_MAX_KEY_SIZE,
415 .setkey = aes_set_key,
416 .encrypt = ecb_aes_encrypt,
417 .decrypt = ecb_aes_decrypt,
422 static int cbc_aes_encrypt(struct blkcipher_desc *desc,
423 struct scatterlist *dst, struct scatterlist *src,
424 unsigned int nbytes)
426 struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
427 struct blkcipher_walk walk;
428 int err;
429 int ts_state;
431 padlock_reset_key(&ctx->cword.encrypt);
433 blkcipher_walk_init(&walk, dst, src, nbytes);
434 err = blkcipher_walk_virt(desc, &walk);
436 ts_state = irq_ts_save();
437 while ((nbytes = walk.nbytes)) {
438 u8 *iv = padlock_xcrypt_cbc(walk.src.virt.addr,
439 walk.dst.virt.addr, ctx->E,
440 walk.iv, &ctx->cword.encrypt,
441 nbytes / AES_BLOCK_SIZE);
442 memcpy(walk.iv, iv, AES_BLOCK_SIZE);
443 nbytes &= AES_BLOCK_SIZE - 1;
444 err = blkcipher_walk_done(desc, &walk, nbytes);
446 irq_ts_restore(ts_state);
448 padlock_store_cword(&ctx->cword.decrypt);
450 return err;
453 static int cbc_aes_decrypt(struct blkcipher_desc *desc,
454 struct scatterlist *dst, struct scatterlist *src,
455 unsigned int nbytes)
457 struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
458 struct blkcipher_walk walk;
459 int err;
460 int ts_state;
462 padlock_reset_key(&ctx->cword.encrypt);
464 blkcipher_walk_init(&walk, dst, src, nbytes);
465 err = blkcipher_walk_virt(desc, &walk);
467 ts_state = irq_ts_save();
468 while ((nbytes = walk.nbytes)) {
469 padlock_xcrypt_cbc(walk.src.virt.addr, walk.dst.virt.addr,
470 ctx->D, walk.iv, &ctx->cword.decrypt,
471 nbytes / AES_BLOCK_SIZE);
472 nbytes &= AES_BLOCK_SIZE - 1;
473 err = blkcipher_walk_done(desc, &walk, nbytes);
476 irq_ts_restore(ts_state);
478 padlock_store_cword(&ctx->cword.encrypt);
480 return err;
483 static struct crypto_alg cbc_aes_alg = {
484 .cra_name = "cbc(aes)",
485 .cra_driver_name = "cbc-aes-padlock",
486 .cra_priority = PADLOCK_COMPOSITE_PRIORITY,
487 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
488 .cra_blocksize = AES_BLOCK_SIZE,
489 .cra_ctxsize = sizeof(struct aes_ctx),
490 .cra_alignmask = PADLOCK_ALIGNMENT - 1,
491 .cra_type = &crypto_blkcipher_type,
492 .cra_module = THIS_MODULE,
493 .cra_list = LIST_HEAD_INIT(cbc_aes_alg.cra_list),
494 .cra_u = {
495 .blkcipher = {
496 .min_keysize = AES_MIN_KEY_SIZE,
497 .max_keysize = AES_MAX_KEY_SIZE,
498 .ivsize = AES_BLOCK_SIZE,
499 .setkey = aes_set_key,
500 .encrypt = cbc_aes_encrypt,
501 .decrypt = cbc_aes_decrypt,
506 static int __init padlock_init(void)
508 int ret;
509 struct cpuinfo_x86 *c = &cpu_data(0);
511 if (!cpu_has_xcrypt) {
512 printk(KERN_NOTICE PFX "VIA PadLock not detected.\n");
513 return -ENODEV;
516 if (!cpu_has_xcrypt_enabled) {
517 printk(KERN_NOTICE PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
518 return -ENODEV;
521 if ((ret = crypto_register_alg(&aes_alg)))
522 goto aes_err;
524 if ((ret = crypto_register_alg(&ecb_aes_alg)))
525 goto ecb_aes_err;
527 if ((ret = crypto_register_alg(&cbc_aes_alg)))
528 goto cbc_aes_err;
530 printk(KERN_NOTICE PFX "Using VIA PadLock ACE for AES algorithm.\n");
532 if (c->x86 == 6 && c->x86_model == 15 && c->x86_mask == 2) {
533 ecb_fetch_blocks = MAX_ECB_FETCH_BLOCKS;
534 cbc_fetch_blocks = MAX_CBC_FETCH_BLOCKS;
535 printk(KERN_NOTICE PFX "VIA Nano stepping 2 detected: enabling workaround.\n");
538 out:
539 return ret;
541 cbc_aes_err:
542 crypto_unregister_alg(&ecb_aes_alg);
543 ecb_aes_err:
544 crypto_unregister_alg(&aes_alg);
545 aes_err:
546 printk(KERN_ERR PFX "VIA PadLock AES initialization failed.\n");
547 goto out;
550 static void __exit padlock_fini(void)
552 crypto_unregister_alg(&cbc_aes_alg);
553 crypto_unregister_alg(&ecb_aes_alg);
554 crypto_unregister_alg(&aes_alg);
557 module_init(padlock_init);
558 module_exit(padlock_fini);
560 MODULE_DESCRIPTION("VIA PadLock AES algorithm support");
561 MODULE_LICENSE("GPL");
562 MODULE_AUTHOR("Michal Ludvig");
564 MODULE_ALIAS("aes");