[PATCH v8 1/3] crypto: scatterwak - Add scatterwalk_sg_copychunks
From: Tudor Ambarus <hidden>
Date: 2016-06-15 14:52:54
Subsystem:
crypto api, the rest · Maintainers:
Herbert Xu, "David S. Miller", Linus Torvalds
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 for the output data of the RSA algorithm, after the computation completes. Signed-off-by: Tudor Ambarus <redacted> --- 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