| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Cryptographic scatter and gather helpers. |
| 3 | * |
| 4 | * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> |
| 5 | * Copyright (c) 2002 Adam J. Richter <adam@yggdrasil.com> |
| 6 | * Copyright (c) 2004 Jean-Luc Cooke <jlcooke@certainkey.com> |
| 7 | * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au> |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify it |
| 10 | * under the terms of the GNU General Public License as published by the Free |
| 11 | * Software Foundation; either version 2 of the License, or (at your option) |
| 12 | * any later version. |
| 13 | * |
| 14 | */ |
| 15 | |
| 16 | #ifndef _CRYPTO_SCATTERWALK_H |
| 17 | #define _CRYPTO_SCATTERWALK_H |
| 18 | |
| 19 | #include <asm/kmap_types.h> |
| 20 | #include <crypto/algapi.h> |
| 21 | #include <linux/hardirq.h> |
| 22 | #include <linux/highmem.h> |
| 23 | #include <linux/kernel.h> |
| 24 | #include <linux/mm.h> |
| 25 | #include <linux/scatterlist.h> |
| 26 | #include <linux/sched.h> |
| 27 | |
| 28 | static inline void crypto_yield(u32 flags) |
| 29 | { |
| 30 | if (flags & CRYPTO_TFM_REQ_MAY_SLEEP) |
| 31 | cond_resched(); |
| 32 | } |
| 33 | |
| 34 | static inline void scatterwalk_sg_chain(struct scatterlist *sg1, int num, |
| 35 | struct scatterlist *sg2) |
| 36 | { |
| 37 | sg_set_page(&sg1[num - 1], (void *)sg2, 0, 0); |
| 38 | sg1[num - 1].page_link &= ~0x02; |
| 39 | sg1[num - 1].page_link |= 0x01; |
| 40 | } |
| 41 | |
| 42 | static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg) |
| 43 | { |
| 44 | if (sg_is_last(sg)) |
| 45 | return NULL; |
| 46 | |
| 47 | return (++sg)->length ? sg : sg_chain_ptr(sg); |
| 48 | } |
| 49 | |
| 50 | static inline void scatterwalk_crypto_chain(struct scatterlist *head, |
| 51 | struct scatterlist *sg, |
| 52 | int chain, int num) |
| 53 | { |
| 54 | if (chain) { |
| 55 | head->length += sg->length; |
| 56 | sg = scatterwalk_sg_next(sg); |
| 57 | } |
| 58 | |
| 59 | if (sg) |
| 60 | scatterwalk_sg_chain(head, num, sg); |
| 61 | else |
| 62 | sg_mark_end(head); |
| 63 | } |
| 64 | |
| 65 | static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in, |
| 66 | struct scatter_walk *walk_out) |
| 67 | { |
| 68 | return !(((sg_page(walk_in->sg) - sg_page(walk_out->sg)) << PAGE_SHIFT) + |
| 69 | (int)(walk_in->offset - walk_out->offset)); |
| 70 | } |
| 71 | |
| 72 | static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk) |
| 73 | { |
| 74 | unsigned int len = walk->sg->offset + walk->sg->length - walk->offset; |
| 75 | unsigned int len_this_page = offset_in_page(~walk->offset) + 1; |
| 76 | return len_this_page > len ? len : len_this_page; |
| 77 | } |
| 78 | |
| 79 | static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk, |
| 80 | unsigned int nbytes) |
| 81 | { |
| 82 | unsigned int len_this_page = scatterwalk_pagelen(walk); |
| 83 | return nbytes > len_this_page ? len_this_page : nbytes; |
| 84 | } |
| 85 | |
| 86 | static inline void scatterwalk_advance(struct scatter_walk *walk, |
| 87 | unsigned int nbytes) |
| 88 | { |
| 89 | walk->offset += nbytes; |
| 90 | } |
| 91 | |
| 92 | static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk, |
| 93 | unsigned int alignmask) |
| 94 | { |
| 95 | return !(walk->offset & alignmask); |
| 96 | } |
| 97 | |
| 98 | static inline struct page *scatterwalk_page(struct scatter_walk *walk) |
| 99 | { |
| 100 | return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT); |
| 101 | } |
| 102 | |
| 103 | static inline void scatterwalk_unmap(void *vaddr) |
| 104 | { |
| 105 | kunmap_atomic(vaddr); |
| 106 | } |
| 107 | |
| 108 | void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg); |
| 109 | void scatterwalk_copychunks(void *buf, struct scatter_walk *walk, |
| 110 | size_t nbytes, int out); |
| 111 | void *scatterwalk_map(struct scatter_walk *walk); |
| 112 | void scatterwalk_done(struct scatter_walk *walk, int out, int more); |
| 113 | |
| 114 | void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg, |
| 115 | unsigned int start, unsigned int nbytes, int out); |
| 116 | |
| 117 | #endif /* _CRYPTO_SCATTERWALK_H */ |