cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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scatterwalk.h (3009B)

      1/* SPDX-License-Identifier: GPL-2.0-or-later */
      2/*
      3 * Cryptographic scatter and gather helpers.
      4 *
      5 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
      6 * Copyright (c) 2002 Adam J. Richter <adam@yggdrasil.com>
      7 * Copyright (c) 2004 Jean-Luc Cooke <jlcooke@certainkey.com>
      8 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
      9 */
     10
     11#ifndef _CRYPTO_SCATTERWALK_H
     12#define _CRYPTO_SCATTERWALK_H
     13
     14#include <crypto/algapi.h>
     15
     16#include <linux/highmem.h>
     17#include <linux/mm.h>
     18#include <linux/scatterlist.h>
     19
     20static inline void scatterwalk_crypto_chain(struct scatterlist *head,
     21					    struct scatterlist *sg, int num)
     22{
     23	if (sg)
     24		sg_chain(head, num, sg);
     25	else
     26		sg_mark_end(head);
     27}
     28
     29static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
     30{
     31	unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
     32	unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
     33	return len_this_page > len ? len : len_this_page;
     34}
     35
     36static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
     37					     unsigned int nbytes)
     38{
     39	unsigned int len_this_page = scatterwalk_pagelen(walk);
     40	return nbytes > len_this_page ? len_this_page : nbytes;
     41}
     42
     43static inline void scatterwalk_advance(struct scatter_walk *walk,
     44				       unsigned int nbytes)
     45{
     46	walk->offset += nbytes;
     47}
     48
     49static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
     50					       unsigned int alignmask)
     51{
     52	return !(walk->offset & alignmask);
     53}
     54
     55static inline struct page *scatterwalk_page(struct scatter_walk *walk)
     56{
     57	return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
     58}
     59
     60static inline void scatterwalk_unmap(void *vaddr)
     61{
     62	kunmap_atomic(vaddr);
     63}
     64
     65static inline void scatterwalk_start(struct scatter_walk *walk,
     66				     struct scatterlist *sg)
     67{
     68	walk->sg = sg;
     69	walk->offset = sg->offset;
     70}
     71
     72static inline void *scatterwalk_map(struct scatter_walk *walk)
     73{
     74	return kmap_atomic(scatterwalk_page(walk)) +
     75	       offset_in_page(walk->offset);
     76}
     77
     78static inline void scatterwalk_pagedone(struct scatter_walk *walk, int out,
     79					unsigned int more)
     80{
     81	if (out) {
     82		struct page *page;
     83
     84		page = sg_page(walk->sg) + ((walk->offset - 1) >> PAGE_SHIFT);
     85		flush_dcache_page(page);
     86	}
     87
     88	if (more && walk->offset >= walk->sg->offset + walk->sg->length)
     89		scatterwalk_start(walk, sg_next(walk->sg));
     90}
     91
     92static inline void scatterwalk_done(struct scatter_walk *walk, int out,
     93				    int more)
     94{
     95	if (!more || walk->offset >= walk->sg->offset + walk->sg->length ||
     96	    !(walk->offset & (PAGE_SIZE - 1)))
     97		scatterwalk_pagedone(walk, out, more);
     98}
     99
    100void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
    101			    size_t nbytes, int out);
    102void *scatterwalk_map(struct scatter_walk *walk);
    103
    104void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
    105			      unsigned int start, unsigned int nbytes, int out);
    106
    107struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2],
    108				     struct scatterlist *src,
    109				     unsigned int len);
    110
    111#endif  /* _CRYPTO_SCATTERWALK_H */