2 * Glue code for AES implementation for SPE instructions (PPC)
4 * Based on generic implementation. The assembler module takes care
5 * about the SPE registers so it can run from interrupt context.
7 * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
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)
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 #include <crypto/xts.h>
28 * MAX_BYTES defines the number of bytes that are allowed to be processed
29 * between preempt_disable() and preempt_enable(). e500 cores can issue two
30 * instructions per clock cycle using one 32/64 bit unit (SU1) and one 32
31 * bit unit (SU2). One of these can be a memory access that is executed via
32 * a single load and store unit (LSU). XTS-AES-256 takes ~780 operations per
33 * 16 byte block block or 25 cycles per byte. Thus 768 bytes of input data
34 * will need an estimated maximum of 20,000 cycles. Headroom for cache misses
35 * included. Even with the low end model clocked at 667 MHz this equals to a
36 * critical time window of less than 30us. The value has been choosen to
37 * process a 512 byte disk block in one or a large 1400 bytes IPsec network
44 u32 key_enc[AES_MAX_KEYLENGTH_U32];
45 u32 key_dec[AES_MAX_KEYLENGTH_U32];
50 u32 key_enc[AES_MAX_KEYLENGTH_U32];
51 u32 key_dec[AES_MAX_KEYLENGTH_U32];
52 u32 key_twk[AES_MAX_KEYLENGTH_U32];
56 extern void ppc_encrypt_aes(u8 *out, const u8 *in, u32 *key_enc, u32 rounds);
57 extern void ppc_decrypt_aes(u8 *out, const u8 *in, u32 *key_dec, u32 rounds);
58 extern void ppc_encrypt_ecb(u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
60 extern void ppc_decrypt_ecb(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
62 extern void ppc_encrypt_cbc(u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
64 extern void ppc_decrypt_cbc(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
66 extern void ppc_crypt_ctr (u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
68 extern void ppc_encrypt_xts(u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
69 u32 bytes, u8 *iv, u32 *key_twk);
70 extern void ppc_decrypt_xts(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
71 u32 bytes, u8 *iv, u32 *key_twk);
73 extern void ppc_expand_key_128(u32 *key_enc, const u8 *key);
74 extern void ppc_expand_key_192(u32 *key_enc, const u8 *key);
75 extern void ppc_expand_key_256(u32 *key_enc, const u8 *key);
77 extern void ppc_generate_decrypt_key(u32 *key_dec,u32 *key_enc,
78 unsigned int key_len);
80 static void spe_begin(void)
82 /* disable preemption and save users SPE registers if required */
87 static void spe_end(void)
90 /* reenable preemption */
94 static int ppc_aes_setkey(struct crypto_tfm *tfm, const u8 *in_key,
97 struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
99 if (key_len != AES_KEYSIZE_128 &&
100 key_len != AES_KEYSIZE_192 &&
101 key_len != AES_KEYSIZE_256) {
102 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
107 case AES_KEYSIZE_128:
109 ppc_expand_key_128(ctx->key_enc, in_key);
111 case AES_KEYSIZE_192:
113 ppc_expand_key_192(ctx->key_enc, in_key);
115 case AES_KEYSIZE_256:
117 ppc_expand_key_256(ctx->key_enc, in_key);
121 ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);
126 static int ppc_xts_setkey(struct crypto_tfm *tfm, const u8 *in_key,
127 unsigned int key_len)
129 struct ppc_xts_ctx *ctx = crypto_tfm_ctx(tfm);
132 err = xts_check_key(tfm, in_key, key_len);
138 if (key_len != AES_KEYSIZE_128 &&
139 key_len != AES_KEYSIZE_192 &&
140 key_len != AES_KEYSIZE_256) {
141 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
146 case AES_KEYSIZE_128:
148 ppc_expand_key_128(ctx->key_enc, in_key);
149 ppc_expand_key_128(ctx->key_twk, in_key + AES_KEYSIZE_128);
151 case AES_KEYSIZE_192:
153 ppc_expand_key_192(ctx->key_enc, in_key);
154 ppc_expand_key_192(ctx->key_twk, in_key + AES_KEYSIZE_192);
156 case AES_KEYSIZE_256:
158 ppc_expand_key_256(ctx->key_enc, in_key);
159 ppc_expand_key_256(ctx->key_twk, in_key + AES_KEYSIZE_256);
163 ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);
168 static void ppc_aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
170 struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
173 ppc_encrypt_aes(out, in, ctx->key_enc, ctx->rounds);
177 static void ppc_aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
179 struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
182 ppc_decrypt_aes(out, in, ctx->key_dec, ctx->rounds);
186 static int ppc_ecb_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
187 struct scatterlist *src, unsigned int nbytes)
189 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
190 struct blkcipher_walk walk;
194 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
195 blkcipher_walk_init(&walk, dst, src, nbytes);
196 err = blkcipher_walk_virt(desc, &walk);
198 while ((nbytes = walk.nbytes)) {
199 ubytes = nbytes > MAX_BYTES ?
200 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
204 ppc_encrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
205 ctx->key_enc, ctx->rounds, nbytes);
208 err = blkcipher_walk_done(desc, &walk, ubytes);
214 static int ppc_ecb_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
215 struct scatterlist *src, unsigned int nbytes)
217 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
218 struct blkcipher_walk walk;
222 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
223 blkcipher_walk_init(&walk, dst, src, nbytes);
224 err = blkcipher_walk_virt(desc, &walk);
226 while ((nbytes = walk.nbytes)) {
227 ubytes = nbytes > MAX_BYTES ?
228 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
232 ppc_decrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
233 ctx->key_dec, ctx->rounds, nbytes);
236 err = blkcipher_walk_done(desc, &walk, ubytes);
242 static int ppc_cbc_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
243 struct scatterlist *src, unsigned int nbytes)
245 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
246 struct blkcipher_walk walk;
250 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
251 blkcipher_walk_init(&walk, dst, src, nbytes);
252 err = blkcipher_walk_virt(desc, &walk);
254 while ((nbytes = walk.nbytes)) {
255 ubytes = nbytes > MAX_BYTES ?
256 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
260 ppc_encrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
261 ctx->key_enc, ctx->rounds, nbytes, walk.iv);
264 err = blkcipher_walk_done(desc, &walk, ubytes);
270 static int ppc_cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
271 struct scatterlist *src, unsigned int nbytes)
273 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
274 struct blkcipher_walk walk;
278 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
279 blkcipher_walk_init(&walk, dst, src, nbytes);
280 err = blkcipher_walk_virt(desc, &walk);
282 while ((nbytes = walk.nbytes)) {
283 ubytes = nbytes > MAX_BYTES ?
284 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
288 ppc_decrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
289 ctx->key_dec, ctx->rounds, nbytes, walk.iv);
292 err = blkcipher_walk_done(desc, &walk, ubytes);
298 static int ppc_ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
299 struct scatterlist *src, unsigned int nbytes)
301 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
302 struct blkcipher_walk walk;
303 unsigned int pbytes, ubytes;
306 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
307 blkcipher_walk_init(&walk, dst, src, nbytes);
308 err = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
310 while ((pbytes = walk.nbytes)) {
311 pbytes = pbytes > MAX_BYTES ? MAX_BYTES : pbytes;
312 pbytes = pbytes == nbytes ?
313 nbytes : pbytes & ~(AES_BLOCK_SIZE - 1);
314 ubytes = walk.nbytes - pbytes;
317 ppc_crypt_ctr(walk.dst.virt.addr, walk.src.virt.addr,
318 ctx->key_enc, ctx->rounds, pbytes , walk.iv);
322 err = blkcipher_walk_done(desc, &walk, ubytes);
328 static int ppc_xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
329 struct scatterlist *src, unsigned int nbytes)
331 struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
332 struct blkcipher_walk walk;
337 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
338 blkcipher_walk_init(&walk, dst, src, nbytes);
339 err = blkcipher_walk_virt(desc, &walk);
342 while ((nbytes = walk.nbytes)) {
343 ubytes = nbytes > MAX_BYTES ?
344 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
348 ppc_encrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
349 ctx->key_enc, ctx->rounds, nbytes, walk.iv, twk);
353 err = blkcipher_walk_done(desc, &walk, ubytes);
359 static int ppc_xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
360 struct scatterlist *src, unsigned int nbytes)
362 struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
363 struct blkcipher_walk walk;
368 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
369 blkcipher_walk_init(&walk, dst, src, nbytes);
370 err = blkcipher_walk_virt(desc, &walk);
373 while ((nbytes = walk.nbytes)) {
374 ubytes = nbytes > MAX_BYTES ?
375 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
379 ppc_decrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
380 ctx->key_dec, ctx->rounds, nbytes, walk.iv, twk);
384 err = blkcipher_walk_done(desc, &walk, ubytes);
391 * Algorithm definitions. Disabling alignment (cra_alignmask=0) was chosen
392 * because the e500 platform can handle unaligned reads/writes very efficently.
393 * This improves IPsec thoughput by another few percent. Additionally we assume
394 * that AES context is always aligned to at least 8 bytes because it is created
395 * with kmalloc() in the crypto infrastructure
398 static struct crypto_alg aes_algs[] = { {
400 .cra_driver_name = "aes-ppc-spe",
402 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
403 .cra_blocksize = AES_BLOCK_SIZE,
404 .cra_ctxsize = sizeof(struct ppc_aes_ctx),
406 .cra_module = THIS_MODULE,
409 .cia_min_keysize = AES_MIN_KEY_SIZE,
410 .cia_max_keysize = AES_MAX_KEY_SIZE,
411 .cia_setkey = ppc_aes_setkey,
412 .cia_encrypt = ppc_aes_encrypt,
413 .cia_decrypt = ppc_aes_decrypt
417 .cra_name = "ecb(aes)",
418 .cra_driver_name = "ecb-ppc-spe",
420 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
421 .cra_blocksize = AES_BLOCK_SIZE,
422 .cra_ctxsize = sizeof(struct ppc_aes_ctx),
424 .cra_type = &crypto_blkcipher_type,
425 .cra_module = THIS_MODULE,
428 .min_keysize = AES_MIN_KEY_SIZE,
429 .max_keysize = AES_MAX_KEY_SIZE,
430 .ivsize = AES_BLOCK_SIZE,
431 .setkey = ppc_aes_setkey,
432 .encrypt = ppc_ecb_encrypt,
433 .decrypt = ppc_ecb_decrypt,
437 .cra_name = "cbc(aes)",
438 .cra_driver_name = "cbc-ppc-spe",
440 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
441 .cra_blocksize = AES_BLOCK_SIZE,
442 .cra_ctxsize = sizeof(struct ppc_aes_ctx),
444 .cra_type = &crypto_blkcipher_type,
445 .cra_module = THIS_MODULE,
448 .min_keysize = AES_MIN_KEY_SIZE,
449 .max_keysize = AES_MAX_KEY_SIZE,
450 .ivsize = AES_BLOCK_SIZE,
451 .setkey = ppc_aes_setkey,
452 .encrypt = ppc_cbc_encrypt,
453 .decrypt = ppc_cbc_decrypt,
457 .cra_name = "ctr(aes)",
458 .cra_driver_name = "ctr-ppc-spe",
460 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
462 .cra_ctxsize = sizeof(struct ppc_aes_ctx),
464 .cra_type = &crypto_blkcipher_type,
465 .cra_module = THIS_MODULE,
468 .min_keysize = AES_MIN_KEY_SIZE,
469 .max_keysize = AES_MAX_KEY_SIZE,
470 .ivsize = AES_BLOCK_SIZE,
471 .setkey = ppc_aes_setkey,
472 .encrypt = ppc_ctr_crypt,
473 .decrypt = ppc_ctr_crypt,
477 .cra_name = "xts(aes)",
478 .cra_driver_name = "xts-ppc-spe",
480 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
481 .cra_blocksize = AES_BLOCK_SIZE,
482 .cra_ctxsize = sizeof(struct ppc_xts_ctx),
484 .cra_type = &crypto_blkcipher_type,
485 .cra_module = THIS_MODULE,
488 .min_keysize = AES_MIN_KEY_SIZE * 2,
489 .max_keysize = AES_MAX_KEY_SIZE * 2,
490 .ivsize = AES_BLOCK_SIZE,
491 .setkey = ppc_xts_setkey,
492 .encrypt = ppc_xts_encrypt,
493 .decrypt = ppc_xts_decrypt,
498 static int __init ppc_aes_mod_init(void)
500 return crypto_register_algs(aes_algs, ARRAY_SIZE(aes_algs));
503 static void __exit ppc_aes_mod_fini(void)
505 crypto_unregister_algs(aes_algs, ARRAY_SIZE(aes_algs));
508 module_init(ppc_aes_mod_init);
509 module_exit(ppc_aes_mod_fini);
511 MODULE_LICENSE("GPL");
512 MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS, SPE optimized");
514 MODULE_ALIAS_CRYPTO("aes");
515 MODULE_ALIAS_CRYPTO("ecb(aes)");
516 MODULE_ALIAS_CRYPTO("cbc(aes)");
517 MODULE_ALIAS_CRYPTO("ctr(aes)");
518 MODULE_ALIAS_CRYPTO("xts(aes)");
519 MODULE_ALIAS_CRYPTO("aes-ppc-spe");