static int p8_aes_ctr_crypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
int ret;
struct blkcipher_walk walk;
struct p8_aes_ctr_ctx *ctx = crypto_tfm_ctx(
crypto_blkcipher_tfm(desc->tfm));
struct blkcipher_desc fallback_desc = {
.tfm = ctx->fallback,
.info = desc->info,
.flags = desc->flags
};
if (in_interrupt()) {
ret = crypto_blkcipher_encrypt(&fallback_desc, dst, src, nbytes);
} else {
blkcipher_walk_init(&walk, dst, src, nbytes);
ret = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
pagefault_disable();
enable_kernel_altivec();
aes_p8_ctr32_encrypt_blocks(walk.src.virt.addr, walk.dst.virt.addr,
(nbytes & AES_BLOCK_MASK)/AES_BLOCK_SIZE, &ctx->enc_key, walk.iv);
pagefault_enable();
crypto_inc(walk.iv, AES_BLOCK_SIZE);
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
if (walk.nbytes) {
p8_aes_ctr_final(ctx, &walk);
ret = blkcipher_walk_done(desc, &walk, 0);
}
}
return ret;
}
struct crypto_alg p8_aes_ctr_alg = {
.cra_name = "ctr(aes)",
.cra_driver_name = "p8_aes_ctr",
.cra_module = THIS_MODULE,
.cra_priority = 1000,
.cra_type = &crypto_blkcipher_type,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK,
.cra_alignmask = 0,
.cra_blocksize = 1,
.cra_ctxsize = sizeof(struct p8_aes_ctr_ctx),
.cra_init = p8_aes_ctr_init,
.cra_exit = p8_aes_ctr_exit,
.cra_blkcipher = {
.ivsize = 0,
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.setkey = p8_aes_ctr_setkey,
.encrypt = p8_aes_ctr_crypt,
.decrypt = p8_aes_ctr_crypt,
},
};
static int p8_aes_ctr_crypt(struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
int ret;
u64 inc;
struct blkcipher_walk walk;
struct p8_aes_ctr_ctx *ctx =
crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
if (in_interrupt()) {
SYNC_SKCIPHER_REQUEST_ON_STACK(req, ctx->fallback);
skcipher_request_set_sync_tfm(req, ctx->fallback);
skcipher_request_set_callback(req, desc->flags, NULL, NULL);
skcipher_request_set_crypt(req, src, dst, nbytes, desc->info);
ret = crypto_skcipher_encrypt(req);
skcipher_request_zero(req);
} else {
blkcipher_walk_init(&walk, dst, src, nbytes);
ret = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
aes_p8_ctr32_encrypt_blocks(walk.src.virt.addr,
walk.dst.virt.addr,
(nbytes &
AES_BLOCK_MASK) /
AES_BLOCK_SIZE,
&ctx->enc_key,
walk.iv);
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
/* We need to update IV mostly for last bytes/round */
inc = (nbytes & AES_BLOCK_MASK) / AES_BLOCK_SIZE;
if (inc > 0)
while (inc--)
crypto_inc(walk.iv, AES_BLOCK_SIZE);
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
if (walk.nbytes) {
p8_aes_ctr_final(ctx, &walk);
ret = blkcipher_walk_done(desc, &walk, 0);
}
}
return ret;
}