1/* SPDX-License-Identifier: GPL-2.0 */
 2
 3#ifndef _CRYPTO_ECB_CBC_HELPER_H
 4#define _CRYPTO_ECB_CBC_HELPER_H
 5
 6#include <crypto/internal/skcipher.h>
 7#include <asm/fpu/api.h>
 8
 9/*
10 * Mode helpers to instantiate parameterized skcipher ECB/CBC modes without
11 * having to rely on indirect calls and retpolines.
12 */
13
14#define ECB_WALK_START(req, bsize, fpu_blocks) do {			\
15	void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));	\
16	const int __bsize = (bsize);					\
17	struct skcipher_walk walk;					\
18	int err = skcipher_walk_virt(&walk, (req), false);		\
19	while (walk.nbytes > 0) {					\
20		unsigned int nbytes = walk.nbytes;			\
21		bool do_fpu = (fpu_blocks) != -1 &&			\
22			      nbytes >= (fpu_blocks) * __bsize;		\
23		const u8 *src = walk.src.virt.addr;			\
24		u8 *dst = walk.dst.virt.addr;				\
25		u8 __maybe_unused buf[(bsize)];				\
26		if (do_fpu) kernel_fpu_begin()
27
28#define CBC_WALK_START(req, bsize, fpu_blocks)				\
29	ECB_WALK_START(req, bsize, fpu_blocks)
30
31#define ECB_WALK_ADVANCE(blocks) do {					\
32	dst += (blocks) * __bsize;					\
33	src += (blocks) * __bsize;					\
34	nbytes -= (blocks) * __bsize;					\
35} while (0)
36
37#define ECB_BLOCK(blocks, func) do {					\
38	while (nbytes >= (blocks) * __bsize) {				\
39		(func)(ctx, dst, src);					\
40		ECB_WALK_ADVANCE(blocks);				\
41	}								\
42} while (0)
43
44#define CBC_ENC_BLOCK(func) do {					\
45	const u8 *__iv = walk.iv;					\
46	while (nbytes >= __bsize) {					\
47		crypto_xor_cpy(dst, src, __iv, __bsize);		\
48		(func)(ctx, dst, dst);					\
49		__iv = dst;						\
50		ECB_WALK_ADVANCE(1);					\
51	}								\
52	memcpy(walk.iv, __iv, __bsize);					\
53} while (0)
54
55#define CBC_DEC_BLOCK(blocks, func) do {				\
56	while (nbytes >= (blocks) * __bsize) {				\
57		const u8 *__iv = src + ((blocks) - 1) * __bsize;	\
58		if (dst == src)						\
59			__iv = memcpy(buf, __iv, __bsize);		\
60		(func)(ctx, dst, src);					\
61		crypto_xor(dst, walk.iv, __bsize);			\
62		memcpy(walk.iv, __iv, __bsize);				\
63		ECB_WALK_ADVANCE(blocks);				\
64	}								\
65} while (0)
66
67#define ECB_WALK_END()							\
68		if (do_fpu) kernel_fpu_end();				\
69		err = skcipher_walk_done(&walk, nbytes);		\
70	}								\
71	return err;							\
72} while (0)
73
74#define CBC_WALK_END() ECB_WALK_END()
75
76#endif