+int lrw_crypt(struct blkcipher_desc *desc, struct scatterlist *sdst,
+ struct scatterlist *ssrc, unsigned int nbytes,
+ struct lrw_crypt_req *req)
+{
+ const unsigned int bsize = LRW_BLOCK_SIZE;
+ const unsigned int max_blks = req->tbuflen / bsize;
+ struct lrw_table_ctx *ctx = req->table_ctx;
+ struct blkcipher_walk walk;
+ unsigned int nblocks;
+ be128 *iv, *src, *dst, *t;
+ be128 *t_buf = req->tbuf;
+ int err, i;
+
+ BUG_ON(max_blks < 1);
+
+ blkcipher_walk_init(&walk, sdst, ssrc, nbytes);
+
+ err = blkcipher_walk_virt(desc, &walk);
+ nbytes = walk.nbytes;
+ if (!nbytes)
+ return err;
+
+ nblocks = min(walk.nbytes / bsize, max_blks);
+ src = (be128 *)walk.src.virt.addr;
+ dst = (be128 *)walk.dst.virt.addr;
+
+ /* calculate first value of T */
+ iv = (be128 *)walk.iv;
+ t_buf[0] = *iv;
+
+ /* T <- I*Key2 */
+ gf128mul_64k_bbe(&t_buf[0], ctx->table);
+
+ i = 0;
+ goto first;
+
+ for (;;) {
+ do {
+ for (i = 0; i < nblocks; i++) {
+ /* T <- I*Key2, using the optimization
+ * discussed in the specification */
+ be128_xor(&t_buf[i], t,
+ &ctx->mulinc[get_index128(iv)]);
+ inc(iv);
+first:
+ t = &t_buf[i];
+
+ /* PP <- T xor P */
+ be128_xor(dst + i, t, src + i);
+ }
+
+ /* CC <- E(Key2,PP) */
+ req->crypt_fn(req->crypt_ctx, (u8 *)dst,
+ nblocks * bsize);
+
+ /* C <- T xor CC */
+ for (i = 0; i < nblocks; i++)
+ be128_xor(dst + i, dst + i, &t_buf[i]);
+
+ src += nblocks;
+ dst += nblocks;
+ nbytes -= nblocks * bsize;
+ nblocks = min(nbytes / bsize, max_blks);
+ } while (nblocks > 0);
+
+ err = blkcipher_walk_done(desc, &walk, nbytes);
+ nbytes = walk.nbytes;
+ if (!nbytes)
+ break;
+
+ nblocks = min(nbytes / bsize, max_blks);
+ src = (be128 *)walk.src.virt.addr;
+ dst = (be128 *)walk.dst.virt.addr;
+ }
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(lrw_crypt);
+