diff mbox

[v2,1/3] crypto: scatterwak - Add scatterwalk_sg_copychunks

Message ID 1458745539-1252-2-git-send-email-tudor-dan.ambarus@nxp.com (mailing list archive)
State Changes Requested
Delegated to: Herbert Xu
Headers show

Commit Message

Tudor Ambarus March 23, 2016, 3:05 p.m. UTC
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 <tudor-dan.ambarus@nxp.com>
---
 crypto/scatterwalk.c         | 26 ++++++++++++++++++++++++++
 include/crypto/scatterwalk.h |  2 ++
 2 files changed, 28 insertions(+)

Comments

Cristian Stoica March 28, 2016, 4:48 p.m. UTC | #1
> -----Original Message-----
> From: linux-crypto-owner@vger.kernel.org [mailto:linux-crypto-
> owner@vger.kernel.org] On Behalf Of Tudor Ambarus
> Sent: Wednesday, March 23, 2016 5:06 PM
> To: herbert@gondor.apana.org.au
> Cc: tadeusz.struk@intel.com; linux-crypto@vger.kernel.org;
> smueller@chronox.de; Horia Ioan Geanta Neag <horia.geanta@nxp.com>;
> Tudor-Dan Ambarus <tudor-dan.ambarus@nxp.com>
> Subject: [PATCH v2 1/3] crypto: scatterwak - Add scatterwalk_sg_copychunks
> 
> 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 <tudor-dan.ambarus@nxp.com>

Acked-by: Cristian Stoica <cristian.stoica@nxp.com>

> ---
>  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
> 
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diff mbox

Patch

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);