From: Tudor Ambarus Subject: [PATCH 1/3] crypto: scatterwak - Add scatterwalk_sg_copychunks Date: Mon, 22 Feb 2016 11:16:15 +0200 Message-ID: <1456132577-332-1-git-send-email-tudor-dan.ambarus@nxp.com> Mime-Version: 1.0 Content-Type: text/plain Cc: , , , , Tudor Ambarus To: Return-path: Received: from mail-bn1on0080.outbound.protection.outlook.com ([157.56.110.80]:37351 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753198AbcBVJa7 (ORCPT ); Mon, 22 Feb 2016 04:30:59 -0500 Sender: linux-crypto-owner@vger.kernel.org List-ID: This patch adds the function scatterwalk_sg_copychunks which writes a chunk of data from a scatterwalk to another scatterwalk. It will be used by caam driver to remove the leading zeros of RSA's algorithm output. Signed-off-by: Tudor Ambarus --- crypto/scatterwalk.c | 26 ++++++++++++++++++++++++++ include/crypto/scatterwalk.h | 2 ++ 2 files changed, 28 insertions(+) diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c index ea5815c..bc3222d 100644 --- a/crypto/scatterwalk.c +++ b/crypto/scatterwalk.c @@ -125,6 +125,32 @@ void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg, } EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy); +void scatterwalk_sg_copychunks(struct scatter_walk *dest, + struct scatter_walk *src, size_t nbytes) +{ + for (;;) { + unsigned int len_this_page = scatterwalk_pagelen(dest); + u8 *vaddr; + + if (len_this_page > nbytes) + len_this_page = nbytes; + + vaddr = scatterwalk_map(dest); + scatterwalk_copychunks(vaddr, src, len_this_page, 0); + scatterwalk_unmap(vaddr); + + scatterwalk_advance(dest, len_this_page); + + if (nbytes == len_this_page) + break; + + nbytes -= len_this_page; + + scatterwalk_pagedone(dest, 0, 1); + } +} +EXPORT_SYMBOL_GPL(scatterwalk_sg_copychunks); + int scatterwalk_bytes_sglen(struct scatterlist *sg, int num_bytes) { int offset = 0, n = 0; diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h index 35f99b6..8b799c5 100644 --- a/include/crypto/scatterwalk.h +++ b/include/crypto/scatterwalk.h @@ -86,6 +86,8 @@ static inline void scatterwalk_unmap(void *vaddr) void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg); void scatterwalk_copychunks(void *buf, struct scatter_walk *walk, size_t nbytes, int out); +void scatterwalk_sg_copychunks(struct scatter_walk *dest, + struct scatter_walk *src, size_t nbytes); void *scatterwalk_map(struct scatter_walk *walk); void scatterwalk_done(struct scatter_walk *walk, int out, int more); -- 1.8.3.1