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>
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 choosen to
36 * process a 512 byte disk block in one or a large 1400 bytes IPsec network
43 u32 key_enc[AES_MAX_KEYLENGTH_U32];
44 u32 key_dec[AES_MAX_KEYLENGTH_U32];
49 u32 key_enc[AES_MAX_KEYLENGTH_U32];
50 u32 key_dec[AES_MAX_KEYLENGTH_U32];
51 u32 key_twk[AES_MAX_KEYLENGTH_U32];
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,
59 extern void ppc_decrypt_ecb(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
61 extern void ppc_encrypt_cbc(u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
63 extern void ppc_decrypt_cbc(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
65 extern void ppc_crypt_ctr (u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
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);
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);
76 extern void ppc_generate_decrypt_key(u32 *key_dec,u32 *key_enc,
77 unsigned int key_len);
79 static void spe_begin(void)
81 /* disable preemption and save users SPE registers if required */
86 static void spe_end(void)
88 /* reenable preemption */
92 static int ppc_aes_setkey(struct crypto_tfm *tfm, const u8 *in_key,
95 struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
97 if (key_len != AES_KEYSIZE_128 &&
98 key_len != AES_KEYSIZE_192 &&
99 key_len != AES_KEYSIZE_256) {
100 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
105 case AES_KEYSIZE_128:
107 ppc_expand_key_128(ctx->key_enc, in_key);
109 case AES_KEYSIZE_192:
111 ppc_expand_key_192(ctx->key_enc, in_key);
113 case AES_KEYSIZE_256:
115 ppc_expand_key_256(ctx->key_enc, in_key);
119 ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);
124 static int ppc_xts_setkey(struct crypto_tfm *tfm, const u8 *in_key,
125 unsigned int key_len)
127 struct ppc_xts_ctx *ctx = crypto_tfm_ctx(tfm);
131 if (key_len != AES_KEYSIZE_128 &&
132 key_len != AES_KEYSIZE_192 &&
133 key_len != AES_KEYSIZE_256) {
134 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
139 case AES_KEYSIZE_128:
141 ppc_expand_key_128(ctx->key_enc, in_key);
142 ppc_expand_key_128(ctx->key_twk, in_key + AES_KEYSIZE_128);
144 case AES_KEYSIZE_192:
146 ppc_expand_key_192(ctx->key_enc, in_key);
147 ppc_expand_key_192(ctx->key_twk, in_key + AES_KEYSIZE_192);
149 case AES_KEYSIZE_256:
151 ppc_expand_key_256(ctx->key_enc, in_key);
152 ppc_expand_key_256(ctx->key_twk, in_key + AES_KEYSIZE_256);
156 ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);
161 static void ppc_aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
163 struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
166 ppc_encrypt_aes(out, in, ctx->key_enc, ctx->rounds);
170 static void ppc_aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
172 struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
175 ppc_decrypt_aes(out, in, ctx->key_dec, ctx->rounds);
179 static int ppc_ecb_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
180 struct scatterlist *src, unsigned int nbytes)
182 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
183 struct blkcipher_walk walk;
187 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
188 blkcipher_walk_init(&walk, dst, src, nbytes);
189 err = blkcipher_walk_virt(desc, &walk);
191 while ((nbytes = walk.nbytes)) {
192 ubytes = nbytes > MAX_BYTES ?
193 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
197 ppc_encrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
198 ctx->key_enc, ctx->rounds, nbytes);
201 err = blkcipher_walk_done(desc, &walk, ubytes);
207 static int ppc_ecb_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
208 struct scatterlist *src, unsigned int nbytes)
210 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
211 struct blkcipher_walk walk;
215 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
216 blkcipher_walk_init(&walk, dst, src, nbytes);
217 err = blkcipher_walk_virt(desc, &walk);
219 while ((nbytes = walk.nbytes)) {
220 ubytes = nbytes > MAX_BYTES ?
221 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
225 ppc_decrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
226 ctx->key_dec, ctx->rounds, nbytes);
229 err = blkcipher_walk_done(desc, &walk, ubytes);
235 static int ppc_cbc_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
236 struct scatterlist *src, unsigned int nbytes)
238 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
239 struct blkcipher_walk walk;
243 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
244 blkcipher_walk_init(&walk, dst, src, nbytes);
245 err = blkcipher_walk_virt(desc, &walk);
247 while ((nbytes = walk.nbytes)) {
248 ubytes = nbytes > MAX_BYTES ?
249 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
253 ppc_encrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
254 ctx->key_enc, ctx->rounds, nbytes, walk.iv);
257 err = blkcipher_walk_done(desc, &walk, ubytes);
263 static int ppc_cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
264 struct scatterlist *src, unsigned int nbytes)
266 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
267 struct blkcipher_walk walk;
271 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
272 blkcipher_walk_init(&walk, dst, src, nbytes);
273 err = blkcipher_walk_virt(desc, &walk);
275 while ((nbytes = walk.nbytes)) {
276 ubytes = nbytes > MAX_BYTES ?
277 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
281 ppc_decrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
282 ctx->key_dec, ctx->rounds, nbytes, walk.iv);
285 err = blkcipher_walk_done(desc, &walk, ubytes);
291 static int ppc_ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
292 struct scatterlist *src, unsigned int nbytes)
294 struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
295 struct blkcipher_walk walk;
296 unsigned int pbytes, ubytes;
299 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
300 blkcipher_walk_init(&walk, dst, src, nbytes);
301 err = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
303 while ((pbytes = walk.nbytes)) {
304 pbytes = pbytes > MAX_BYTES ? MAX_BYTES : pbytes;
305 pbytes = pbytes == nbytes ?
306 nbytes : pbytes & ~(AES_BLOCK_SIZE - 1);
307 ubytes = walk.nbytes - pbytes;
310 ppc_crypt_ctr(walk.dst.virt.addr, walk.src.virt.addr,
311 ctx->key_enc, ctx->rounds, pbytes , walk.iv);
315 err = blkcipher_walk_done(desc, &walk, ubytes);
321 static int ppc_xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
322 struct scatterlist *src, unsigned int nbytes)
324 struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
325 struct blkcipher_walk walk;
330 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
331 blkcipher_walk_init(&walk, dst, src, nbytes);
332 err = blkcipher_walk_virt(desc, &walk);
335 while ((nbytes = walk.nbytes)) {
336 ubytes = nbytes > MAX_BYTES ?
337 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
341 ppc_encrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
342 ctx->key_enc, ctx->rounds, nbytes, walk.iv, twk);
346 err = blkcipher_walk_done(desc, &walk, ubytes);
352 static int ppc_xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
353 struct scatterlist *src, unsigned int nbytes)
355 struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
356 struct blkcipher_walk walk;
361 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
362 blkcipher_walk_init(&walk, dst, src, nbytes);
363 err = blkcipher_walk_virt(desc, &walk);
366 while ((nbytes = walk.nbytes)) {
367 ubytes = nbytes > MAX_BYTES ?
368 nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1);
372 ppc_decrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
373 ctx->key_dec, ctx->rounds, nbytes, walk.iv, twk);
377 err = blkcipher_walk_done(desc, &walk, ubytes);
384 * Algorithm definitions. Disabling alignment (cra_alignmask=0) was chosen
385 * because the e500 platform can handle unaligned reads/writes very efficently.
386 * This improves IPsec thoughput by another few percent. Additionally we assume
387 * that AES context is always aligned to at least 8 bytes because it is created
388 * with kmalloc() in the crypto infrastructure
391 static struct crypto_alg aes_algs[] = { {
393 .cra_driver_name = "aes-ppc-spe",
395 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
396 .cra_blocksize = AES_BLOCK_SIZE,
397 .cra_ctxsize = sizeof(struct ppc_aes_ctx),
399 .cra_module = THIS_MODULE,
402 .cia_min_keysize = AES_MIN_KEY_SIZE,
403 .cia_max_keysize = AES_MAX_KEY_SIZE,
404 .cia_setkey = ppc_aes_setkey,
405 .cia_encrypt = ppc_aes_encrypt,
406 .cia_decrypt = ppc_aes_decrypt
410 .cra_name = "ecb(aes)",
411 .cra_driver_name = "ecb-ppc-spe",
413 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
414 .cra_blocksize = AES_BLOCK_SIZE,
415 .cra_ctxsize = sizeof(struct ppc_aes_ctx),
417 .cra_type = &crypto_blkcipher_type,
418 .cra_module = THIS_MODULE,
421 .min_keysize = AES_MIN_KEY_SIZE,
422 .max_keysize = AES_MAX_KEY_SIZE,
423 .ivsize = AES_BLOCK_SIZE,
424 .setkey = ppc_aes_setkey,
425 .encrypt = ppc_ecb_encrypt,
426 .decrypt = ppc_ecb_decrypt,
430 .cra_name = "cbc(aes)",
431 .cra_driver_name = "cbc-ppc-spe",
433 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
434 .cra_blocksize = AES_BLOCK_SIZE,
435 .cra_ctxsize = sizeof(struct ppc_aes_ctx),
437 .cra_type = &crypto_blkcipher_type,
438 .cra_module = THIS_MODULE,
441 .min_keysize = AES_MIN_KEY_SIZE,
442 .max_keysize = AES_MAX_KEY_SIZE,
443 .ivsize = AES_BLOCK_SIZE,
444 .setkey = ppc_aes_setkey,
445 .encrypt = ppc_cbc_encrypt,
446 .decrypt = ppc_cbc_decrypt,
450 .cra_name = "ctr(aes)",
451 .cra_driver_name = "ctr-ppc-spe",
453 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
455 .cra_ctxsize = sizeof(struct ppc_aes_ctx),
457 .cra_type = &crypto_blkcipher_type,
458 .cra_module = THIS_MODULE,
461 .min_keysize = AES_MIN_KEY_SIZE,
462 .max_keysize = AES_MAX_KEY_SIZE,
463 .ivsize = AES_BLOCK_SIZE,
464 .setkey = ppc_aes_setkey,
465 .encrypt = ppc_ctr_crypt,
466 .decrypt = ppc_ctr_crypt,
470 .cra_name = "xts(aes)",
471 .cra_driver_name = "xts-ppc-spe",
473 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
474 .cra_blocksize = AES_BLOCK_SIZE,
475 .cra_ctxsize = sizeof(struct ppc_xts_ctx),
477 .cra_type = &crypto_blkcipher_type,
478 .cra_module = THIS_MODULE,
481 .min_keysize = AES_MIN_KEY_SIZE * 2,
482 .max_keysize = AES_MAX_KEY_SIZE * 2,
483 .ivsize = AES_BLOCK_SIZE,
484 .setkey = ppc_xts_setkey,
485 .encrypt = ppc_xts_encrypt,
486 .decrypt = ppc_xts_decrypt,
491 static int __init ppc_aes_mod_init(void)
493 return crypto_register_algs(aes_algs, ARRAY_SIZE(aes_algs));
496 static void __exit ppc_aes_mod_fini(void)
498 crypto_unregister_algs(aes_algs, ARRAY_SIZE(aes_algs));
501 module_init(ppc_aes_mod_init);
502 module_exit(ppc_aes_mod_fini);
504 MODULE_LICENSE("GPL");
505 MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS, SPE optimized");
507 MODULE_ALIAS_CRYPTO("aes");
508 MODULE_ALIAS_CRYPTO("ecb(aes)");
509 MODULE_ALIAS_CRYPTO("cbc(aes)");
510 MODULE_ALIAS_CRYPTO("ctr(aes)");
511 MODULE_ALIAS_CRYPTO("xts(aes)");
512 MODULE_ALIAS_CRYPTO("aes-ppc-spe");