static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src,
unsigned int nbytes, int enc)
{
int ret;
u8 tweak[AES_BLOCK_SIZE];
u8 *iv;
struct blkcipher_walk walk;
struct p8_aes_xts_ctx *ctx =
crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
if (in_interrupt()) {
SKCIPHER_REQUEST_ON_STACK(req, ctx->fallback);
skcipher_request_set_tfm(req, ctx->fallback);
skcipher_request_set_callback(req, desc->flags, NULL, NULL);
skcipher_request_set_crypt(req, src, dst, nbytes, desc->info);
ret = enc? crypto_skcipher_encrypt(req) : crypto_skcipher_decrypt(req);
skcipher_request_zero(req);
} else {
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
blkcipher_walk_init(&walk, dst, src, nbytes);
ret = blkcipher_walk_virt(desc, &walk);
iv = walk.iv;
memset(tweak, 0, AES_BLOCK_SIZE);
aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
while ((nbytes = walk.nbytes)) {
if (enc)
aes_p8_xts_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK, &ctx->enc_key, NULL, tweak);
else
aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
}
return ret;
}
static void p8_aes_ctr_final(struct p8_aes_ctr_ctx *ctx,
struct blkcipher_walk *walk)
{
u8 *ctrblk = walk->iv;
u8 keystream[AES_BLOCK_SIZE];
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
unsigned int nbytes = walk->nbytes;
pagefault_disable();
enable_kernel_altivec();
aes_p8_encrypt(ctrblk, keystream, &ctx->enc_key);
pagefault_enable();
crypto_xor(keystream, src, nbytes);
memcpy(dst, keystream, nbytes);
crypto_inc(ctrblk, AES_BLOCK_SIZE);
}
