linux/include/crypto/scatterwalk.h
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

116 lines
3.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Cryptographic scatter and gather helpers.
*
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
* Copyright (c) 2002 Adam J. Richter <adam@yggdrasil.com>
* Copyright (c) 2004 Jean-Luc Cooke <jlcooke@certainkey.com>
* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
*/
#ifndef _CRYPTO_SCATTERWALK_H
#define _CRYPTO_SCATTERWALK_H
#include <crypto/algapi.h>
#include <linux/highmem.h>
#include <linux/kernel.h>
#include <linux/scatterlist.h>
static inline void scatterwalk_crypto_chain(struct scatterlist *head,
struct scatterlist *sg, int num)
{
if (sg)
sg_chain(head, num, sg);
else
sg_mark_end(head);
}
static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
{
unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
return len_this_page > len ? len : len_this_page;
}
static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
unsigned int nbytes)
{
unsigned int len_this_page = scatterwalk_pagelen(walk);
return nbytes > len_this_page ? len_this_page : nbytes;
}
static inline void scatterwalk_advance(struct scatter_walk *walk,
unsigned int nbytes)
{
walk->offset += nbytes;
}
static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
unsigned int alignmask)
{
return !(walk->offset & alignmask);
}
static inline struct page *scatterwalk_page(struct scatter_walk *walk)
{
return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
}
static inline void scatterwalk_unmap(void *vaddr)
{
kunmap_atomic(vaddr);
}
static inline void scatterwalk_start(struct scatter_walk *walk,
struct scatterlist *sg)
{
walk->sg = sg;
walk->offset = sg->offset;
}
static inline void *scatterwalk_map(struct scatter_walk *walk)
{
return kmap_atomic(scatterwalk_page(walk)) +
offset_in_page(walk->offset);
}
static inline void scatterwalk_pagedone(struct scatter_walk *walk, int out,
unsigned int more)
{
if (out) {
struct page *page;
page = sg_page(walk->sg) + ((walk->offset - 1) >> PAGE_SHIFT);
/* Test ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE first as
* PageSlab cannot be optimised away per se due to
* use of volatile pointer.
*/
if (ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE && !PageSlab(page))
flush_dcache_page(page);
}
if (more && walk->offset >= walk->sg->offset + walk->sg->length)
scatterwalk_start(walk, sg_next(walk->sg));
}
static inline void scatterwalk_done(struct scatter_walk *walk, int out,
int more)
{
if (!more || walk->offset >= walk->sg->offset + walk->sg->length ||
!(walk->offset & (PAGE_SIZE - 1)))
scatterwalk_pagedone(walk, out, more);
}
void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
size_t nbytes, int out);
void *scatterwalk_map(struct scatter_walk *walk);
void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
unsigned int start, unsigned int nbytes, int out);
struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2],
struct scatterlist *src,
unsigned int len);
#endif /* _CRYPTO_SCATTERWALK_H */