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powerpc: Fix misspellings in comments.
[linux-2.6/btrfs-unstable.git] / arch / powerpc / crypto / aes-spe-glue.c
blob6d99ebf2ea152e374fa0c46380eda9ff8c96f00b
1 /*
2 * Glue code for AES implementation for SPE instructions (PPC)
3 *
4 * Based on generic implementation. The assembler module takes care
5 * about the SPE registers so it can run from interrupt context.
6 *
7 * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the Free
11 * Software Foundation; either version 2 of the License, or (at your option)
12 * any later version.
13 *
14 */
15
16 #include <crypto/aes.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/types.h>
20 #include <linux/errno.h>
21 #include <linux/crypto.h>
22 #include <asm/byteorder.h>
23 #include <asm/switch_to.h>
24 #include <crypto/algapi.h>
25
26 /*
27 * MAX_BYTES defines the number of bytes that are allowed to be processed
28 * between preempt_disable() and preempt_enable(). e500 cores can issue two
29 * instructions per clock cycle using one 32/64 bit unit (SU1) and one 32
30 * bit unit (SU2). One of these can be a memory access that is executed via
31 * a single load and store unit (LSU). XTS-AES-256 takes ~780 operations per
32 * 16 byte block block or 25 cycles per byte. Thus 768 bytes of input data
33 * will need an estimated maximum of 20,000 cycles. Headroom for cache misses
34 * included. Even with the low end model clocked at 667 MHz this equals to a
35 * critical time window of less than 30us. The value has been chosen to
36 * process a 512 byte disk block in one or a large 1400 bytes IPsec network
37 * packet in two runs.
38 *
39 */
40 #define MAX_BYTES 768
41
42 struct ppc_aes_ctx {
43 u32 key_enc[AES_MAX_KEYLENGTH_U32];
44 u32 key_dec[AES_MAX_KEYLENGTH_U32];
45 u32 rounds;
46 };
47
48 struct ppc_xts_ctx {
49 u32 key_enc[AES_MAX_KEYLENGTH_U32];
50 u32 key_dec[AES_MAX_KEYLENGTH_U32];
51 u32 key_twk[AES_MAX_KEYLENGTH_U32];
52 u32 rounds;
53 };
54
55 extern void ppc_encrypt_aes(u8 *out, const u8 *in, u32 *key_enc, u32 rounds);
56 extern void ppc_decrypt_aes(u8 *out, const u8 *in, u32 *key_dec, u32 rounds);
57 extern void ppc_encrypt_ecb(u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
58 u32 bytes);
59 extern void ppc_decrypt_ecb(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
60 u32 bytes);
61 extern void ppc_encrypt_cbc(u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
62 u32 bytes, u8 *iv);
63 extern void ppc_decrypt_cbc(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
64 u32 bytes, u8 *iv);
65 extern void ppc_crypt_ctr (u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
66 u32 bytes, u8 *iv);
67 extern void ppc_encrypt_xts(u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
68 u32 bytes, u8 *iv, u32 *key_twk);
69 extern void ppc_decrypt_xts(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
70 u32 bytes, u8 *iv, u32 *key_twk);
71
72 extern void ppc_expand_key_128(u32 *key_enc, const u8 *key);
73 extern void ppc_expand_key_192(u32 *key_enc, const u8 *key);
74 extern void ppc_expand_key_256(u32 *key_enc, const u8 *key);
75
76 extern void ppc_generate_decrypt_key(u32 *key_dec,u32 *key_enc,
77 unsigned int key_len);
78
79 static void spe_begin(void)
80 {
81 /* disable preemption and save users SPE registers if required */
82 preempt_disable();
83 enable_kernel_spe();
84 }
85
86 static void spe_end(void)
87 {
88 disable_kernel_spe();
89 /* reenable preemption */
90 preempt_enable();
91 }
92
93 static int ppc_aes_setkey(struct crypto_tfm *tfm, const u8 *in_key,
94 unsigned int key_len)
95 {
96 struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
97
98 if (key_len != AES_KEYSIZE_128 &&
99 key_len != AES_KEYSIZE_192 &&
100 key_len != AES_KEYSIZE_256) {
101 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
102 return -EINVAL;
103 }
104
105 switch (key_len) {
106 case AES_KEYSIZE_128:
107 ctx->rounds = 4;
108 ppc_expand_key_128(ctx->key_enc, in_key);
109 break;
110 case AES_KEYSIZE_192:
111 ctx->rounds = 5;
112 ppc_expand_key_192(ctx->key_enc, in_key);
113 break;
114 case AES_KEYSIZE_256:
115 ctx->rounds = 6;
116 ppc_expand_key_256(ctx->key_enc, in_key);
117 break;
118 }
119
120 ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);
121
122 return 0;
123 }
124
125 static int ppc_xts_setkey(struct crypto_tfm *tfm, const u8 *in_key,
126 unsigned int key_len)
127 {
128 struct ppc_xts_ctx *ctx = crypto_tfm_ctx(tfm);
129
130 key_len >>= 1;
131
132 if (key_len != AES_KEYSIZE_128 &&
133 key_len != AES_KEYSIZE_192 &&
134 key_len != AES_KEYSIZE_256) {
135 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
136 return -EINVAL;
137 }
138
139 switch (key_len) {
140 case AES_KEYSIZE_128:
141 ctx->rounds = 4;
142 ppc_expand_key_128(ctx->key_enc, in_key);
143 ppc_expand_key_128(ctx->key_twk, in_key + AES_KEYSIZE_128);
144 break;
145 case AES_KEYSIZE_192:
146 ctx->rounds = 5;
147 ppc_expand_key_192(ctx->key_enc, in_key);
148 ppc_expand_key_192(ctx->key_twk, in_key + AES_KEYSIZE_192);
149 break;
150 case AES_KEYSIZE_256:
151 ctx->rounds = 6;
152 ppc_expand_key_256(ctx->key_enc, in_key);
153 ppc_expand_key_256(ctx->key_twk, in_key + AES_KEYSIZE_256);
154 break;
155 }
156
157 ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);
158
159 return 0;
160 }
161
162 static void ppc_aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
163 {
164 struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
165
166 spe_begin();
167 ppc_encrypt_aes(out, in, ctx->key_enc, ctx->rounds);
168 spe_end();
169 }
170
171 static void ppc_aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
172 {
173 struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
174
175 spe_begin();
176 ppc_decrypt_aes(out, in, ctx->key_dec, ctx->rounds);
177 spe_end();
178 }
179
180 static int ppc_ecb_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
181 struct scatterlist *src, unsigned int nbytes)
182 {
183 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
184 struct blkcipher_walk walk;
185 unsigned int ubytes;
186 int err;
187
188 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
189 blkcipher_walk_init(&walk, dst, src, nbytes);
190 err = blkcipher_walk_virt(desc, &walk);
191
192 while ((nbytes = walk.nbytes)) {
193 ubytes = nbytes > MAX_BYTES ?
194 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
195 nbytes -= ubytes;
196
197 spe_begin();
198 ppc_encrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
199 ctx->key_enc, ctx->rounds, nbytes);
200 spe_end();
201
202 err = blkcipher_walk_done(desc, &walk, ubytes);
203 }
204
205 return err;
206 }
207
208 static int ppc_ecb_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
209 struct scatterlist *src, unsigned int nbytes)
210 {
211 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
212 struct blkcipher_walk walk;
213 unsigned int ubytes;
214 int err;
215
216 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
217 blkcipher_walk_init(&walk, dst, src, nbytes);
218 err = blkcipher_walk_virt(desc, &walk);
219
220 while ((nbytes = walk.nbytes)) {
221 ubytes = nbytes > MAX_BYTES ?
222 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
223 nbytes -= ubytes;
224
225 spe_begin();
226 ppc_decrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
227 ctx->key_dec, ctx->rounds, nbytes);
228 spe_end();
229
230 err = blkcipher_walk_done(desc, &walk, ubytes);
231 }
232
233 return err;
234 }
235
236 static int ppc_cbc_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
237 struct scatterlist *src, unsigned int nbytes)
238 {
239 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
240 struct blkcipher_walk walk;
241 unsigned int ubytes;
242 int err;
243
244 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
245 blkcipher_walk_init(&walk, dst, src, nbytes);
246 err = blkcipher_walk_virt(desc, &walk);
247
248 while ((nbytes = walk.nbytes)) {
249 ubytes = nbytes > MAX_BYTES ?
250 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
251 nbytes -= ubytes;
252
253 spe_begin();
254 ppc_encrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
255 ctx->key_enc, ctx->rounds, nbytes, walk.iv);
256 spe_end();
257
258 err = blkcipher_walk_done(desc, &walk, ubytes);
259 }
260
261 return err;
262 }
263
264 static int ppc_cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
265 struct scatterlist *src, unsigned int nbytes)
266 {
267 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
268 struct blkcipher_walk walk;
269 unsigned int ubytes;
270 int err;
271
272 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
273 blkcipher_walk_init(&walk, dst, src, nbytes);
274 err = blkcipher_walk_virt(desc, &walk);
275
276 while ((nbytes = walk.nbytes)) {
277 ubytes = nbytes > MAX_BYTES ?
278 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
279 nbytes -= ubytes;
280
281 spe_begin();
282 ppc_decrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
283 ctx->key_dec, ctx->rounds, nbytes, walk.iv);
284 spe_end();
285
286 err = blkcipher_walk_done(desc, &walk, ubytes);
287 }
288
289 return err;
290 }
291
292 static int ppc_ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
293 struct scatterlist *src, unsigned int nbytes)
294 {
295 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
296 struct blkcipher_walk walk;
297 unsigned int pbytes, ubytes;
298 int err;
299
300 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
301 blkcipher_walk_init(&walk, dst, src, nbytes);
302 err = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
303
304 while ((pbytes = walk.nbytes)) {
305 pbytes = pbytes > MAX_BYTES ? MAX_BYTES : pbytes;
306 pbytes = pbytes == nbytes ?
307 nbytes : pbytes & ~(AES_BLOCK_SIZE - 1);
308 ubytes = walk.nbytes - pbytes;
309
310 spe_begin();
311 ppc_crypt_ctr(walk.dst.virt.addr, walk.src.virt.addr,
312 ctx->key_enc, ctx->rounds, pbytes , walk.iv);
313 spe_end();
314
315 nbytes -= pbytes;
316 err = blkcipher_walk_done(desc, &walk, ubytes);
317 }
318
319 return err;
320 }
321
322 static int ppc_xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
323 struct scatterlist *src, unsigned int nbytes)
324 {
325 struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
326 struct blkcipher_walk walk;
327 unsigned int ubytes;
328 int err;
329 u32 *twk;
330
331 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
332 blkcipher_walk_init(&walk, dst, src, nbytes);
333 err = blkcipher_walk_virt(desc, &walk);
334 twk = ctx->key_twk;
335
336 while ((nbytes = walk.nbytes)) {
337 ubytes = nbytes > MAX_BYTES ?
338 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
339 nbytes -= ubytes;
340
341 spe_begin();
342 ppc_encrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
343 ctx->key_enc, ctx->rounds, nbytes, walk.iv, twk);
344 spe_end();
345
346 twk = NULL;
347 err = blkcipher_walk_done(desc, &walk, ubytes);
348 }
349
350 return err;
351 }
352
353 static int ppc_xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
354 struct scatterlist *src, unsigned int nbytes)
355 {
356 struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
357 struct blkcipher_walk walk;
358 unsigned int ubytes;
359 int err;
360 u32 *twk;
361
362 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
363 blkcipher_walk_init(&walk, dst, src, nbytes);
364 err = blkcipher_walk_virt(desc, &walk);
365 twk = ctx->key_twk;
366
367 while ((nbytes = walk.nbytes)) {
368 ubytes = nbytes > MAX_BYTES ?
369 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
370 nbytes -= ubytes;
371
372 spe_begin();
373 ppc_decrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
374 ctx->key_dec, ctx->rounds, nbytes, walk.iv, twk);
375 spe_end();
376
377 twk = NULL;
378 err = blkcipher_walk_done(desc, &walk, ubytes);
379 }
380
381 return err;
382 }
383
384 /*
385 * Algorithm definitions. Disabling alignment (cra_alignmask=0) was chosen
386 * because the e500 platform can handle unaligned reads/writes very efficently.
387 * This improves IPsec thoughput by another few percent. Additionally we assume
388 * that AES context is always aligned to at least 8 bytes because it is created
389 * with kmalloc() in the crypto infrastructure
390 *
391 */
392 static struct crypto_alg aes_algs[] = { {
393 .cra_name = "aes",
394 .cra_driver_name = "aes-ppc-spe",
395 .cra_priority = 300,
396 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
397 .cra_blocksize = AES_BLOCK_SIZE,
398 .cra_ctxsize = sizeof(struct ppc_aes_ctx),
399 .cra_alignmask = 0,
400 .cra_module = THIS_MODULE,
401 .cra_u = {
402 .cipher = {
403 .cia_min_keysize = AES_MIN_KEY_SIZE,
404 .cia_max_keysize = AES_MAX_KEY_SIZE,
405 .cia_setkey = ppc_aes_setkey,
406 .cia_encrypt = ppc_aes_encrypt,
407 .cia_decrypt = ppc_aes_decrypt
408 }
409 }
410 }, {
411 .cra_name = "ecb(aes)",
412 .cra_driver_name = "ecb-ppc-spe",
413 .cra_priority = 300,
414 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
415 .cra_blocksize = AES_BLOCK_SIZE,
416 .cra_ctxsize = sizeof(struct ppc_aes_ctx),
417 .cra_alignmask = 0,
418 .cra_type = &crypto_blkcipher_type,
419 .cra_module = THIS_MODULE,
420 .cra_u = {
421 .blkcipher = {
422 .min_keysize = AES_MIN_KEY_SIZE,
423 .max_keysize = AES_MAX_KEY_SIZE,
424 .ivsize = AES_BLOCK_SIZE,
425 .setkey = ppc_aes_setkey,
426 .encrypt = ppc_ecb_encrypt,
427 .decrypt = ppc_ecb_decrypt,
428 }
429 }
430 }, {
431 .cra_name = "cbc(aes)",
432 .cra_driver_name = "cbc-ppc-spe",
433 .cra_priority = 300,
434 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
435 .cra_blocksize = AES_BLOCK_SIZE,
436 .cra_ctxsize = sizeof(struct ppc_aes_ctx),
437 .cra_alignmask = 0,
438 .cra_type = &crypto_blkcipher_type,
439 .cra_module = THIS_MODULE,
440 .cra_u = {
441 .blkcipher = {
442 .min_keysize = AES_MIN_KEY_SIZE,
443 .max_keysize = AES_MAX_KEY_SIZE,
444 .ivsize = AES_BLOCK_SIZE,
445 .setkey = ppc_aes_setkey,
446 .encrypt = ppc_cbc_encrypt,
447 .decrypt = ppc_cbc_decrypt,
448 }
449 }
450 }, {
451 .cra_name = "ctr(aes)",
452 .cra_driver_name = "ctr-ppc-spe",
453 .cra_priority = 300,
454 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
455 .cra_blocksize = 1,
456 .cra_ctxsize = sizeof(struct ppc_aes_ctx),
457 .cra_alignmask = 0,
458 .cra_type = &crypto_blkcipher_type,
459 .cra_module = THIS_MODULE,
460 .cra_u = {
461 .blkcipher = {
462 .min_keysize = AES_MIN_KEY_SIZE,
463 .max_keysize = AES_MAX_KEY_SIZE,
464 .ivsize = AES_BLOCK_SIZE,
465 .setkey = ppc_aes_setkey,
466 .encrypt = ppc_ctr_crypt,
467 .decrypt = ppc_ctr_crypt,
468 }
469 }
470 }, {
471 .cra_name = "xts(aes)",
472 .cra_driver_name = "xts-ppc-spe",
473 .cra_priority = 300,
474 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
475 .cra_blocksize = AES_BLOCK_SIZE,
476 .cra_ctxsize = sizeof(struct ppc_xts_ctx),
477 .cra_alignmask = 0,
478 .cra_type = &crypto_blkcipher_type,
479 .cra_module = THIS_MODULE,
480 .cra_u = {
481 .blkcipher = {
482 .min_keysize = AES_MIN_KEY_SIZE * 2,
483 .max_keysize = AES_MAX_KEY_SIZE * 2,
484 .ivsize = AES_BLOCK_SIZE,
485 .setkey = ppc_xts_setkey,
486 .encrypt = ppc_xts_encrypt,
487 .decrypt = ppc_xts_decrypt,
488 }
489 }
490 } };
491
492 static int __init ppc_aes_mod_init(void)
493 {
494 return crypto_register_algs(aes_algs, ARRAY_SIZE(aes_algs));
495 }
496
497 static void __exit ppc_aes_mod_fini(void)
498 {
499 crypto_unregister_algs(aes_algs, ARRAY_SIZE(aes_algs));
500 }
501
502 module_init(ppc_aes_mod_init);
503 module_exit(ppc_aes_mod_fini);
504
505 MODULE_LICENSE("GPL");
506 MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS, SPE optimized");
507
508 MODULE_ALIAS_CRYPTO("aes");
509 MODULE_ALIAS_CRYPTO("ecb(aes)");
510 MODULE_ALIAS_CRYPTO("cbc(aes)");
511 MODULE_ALIAS_CRYPTO("ctr(aes)");
512 MODULE_ALIAS_CRYPTO("xts(aes)");
513 MODULE_ALIAS_CRYPTO("aes-ppc-spe");
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