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); }