1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * bignum support for Rockchip crypto
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (c) 2020 Rockchip Electronics Co., Ltd.
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Author: Lin Jinhan <troy.lin@rock-chips.com>
8*4882a593Smuzhiyun *
9*4882a593Smuzhiyun */
10*4882a593Smuzhiyun #include <linux/slab.h>
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun #include "rk_crypto_bignum.h"
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun #define DEFAULT_ENDIAN RK_BG_LITTILE_ENDIAN
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun #define BYTES2WORDS(bytes) (round_up((bytes), sizeof(u32)) / sizeof(u32))
17*4882a593Smuzhiyun #define WORDS2BYTES(words) ((words) * sizeof(u32))
18*4882a593Smuzhiyun #define RK_WORD_SIZE 32
19*4882a593Smuzhiyun
rk_reverse_memcpy(void * dst,const void * src,u32 size)20*4882a593Smuzhiyun static void rk_reverse_memcpy(void *dst, const void *src, u32 size)
21*4882a593Smuzhiyun {
22*4882a593Smuzhiyun char *_dst = (char *)dst, *_src = (char *)src;
23*4882a593Smuzhiyun u32 i;
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun if (!dst || !src || !size)
26*4882a593Smuzhiyun return;
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun for (i = 0; i < size; ++i)
29*4882a593Smuzhiyun _dst[size - i - 1] = _src[i];
30*4882a593Smuzhiyun }
31*4882a593Smuzhiyun
rk_bn_alloc(u32 max_size)32*4882a593Smuzhiyun struct rk_bignum *rk_bn_alloc(u32 max_size)
33*4882a593Smuzhiyun {
34*4882a593Smuzhiyun struct rk_bignum *bn;
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun bn = kzalloc(sizeof(*bn), GFP_KERNEL);
37*4882a593Smuzhiyun if (!bn)
38*4882a593Smuzhiyun return NULL;
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun bn->data = kzalloc(round_up(max_size, sizeof(u32)), GFP_KERNEL);
41*4882a593Smuzhiyun if (!bn->data) {
42*4882a593Smuzhiyun kfree(bn);
43*4882a593Smuzhiyun return NULL;
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun bn->n_words = BYTES2WORDS(max_size);
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun return bn;
49*4882a593Smuzhiyun }
50*4882a593Smuzhiyun
rk_bn_free(struct rk_bignum * bn)51*4882a593Smuzhiyun void rk_bn_free(struct rk_bignum *bn)
52*4882a593Smuzhiyun {
53*4882a593Smuzhiyun if (!bn)
54*4882a593Smuzhiyun return;
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun if (bn->data) {
57*4882a593Smuzhiyun memset(bn->data, 0x00, WORDS2BYTES(bn->n_words));
58*4882a593Smuzhiyun kfree(bn->data);
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun kfree(bn);
62*4882a593Smuzhiyun }
63*4882a593Smuzhiyun
rk_bn_set_data(struct rk_bignum * bn,const u8 * data,u32 size,enum bignum_endian endian)64*4882a593Smuzhiyun int rk_bn_set_data(struct rk_bignum *bn, const u8 *data, u32 size, enum bignum_endian endian)
65*4882a593Smuzhiyun {
66*4882a593Smuzhiyun if (!bn || !data)
67*4882a593Smuzhiyun return -EINVAL;
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun if (BYTES2WORDS(size) > bn->n_words)
70*4882a593Smuzhiyun return -EINVAL;
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun if (endian == DEFAULT_ENDIAN)
73*4882a593Smuzhiyun memcpy(bn->data, data, size);
74*4882a593Smuzhiyun else
75*4882a593Smuzhiyun rk_reverse_memcpy(bn->data, data, size);
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun return 0;
78*4882a593Smuzhiyun }
79*4882a593Smuzhiyun
rk_bn_get_data(const struct rk_bignum * bn,u8 * data,u32 size,enum bignum_endian endian)80*4882a593Smuzhiyun int rk_bn_get_data(const struct rk_bignum *bn, u8 *data, u32 size, enum bignum_endian endian)
81*4882a593Smuzhiyun {
82*4882a593Smuzhiyun if (!bn || !data)
83*4882a593Smuzhiyun return -EINVAL;
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun if (size < WORDS2BYTES(bn->n_words))
86*4882a593Smuzhiyun return -EINVAL;
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun memset(data, 0x00, size);
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun if (endian == DEFAULT_ENDIAN)
91*4882a593Smuzhiyun memcpy(data + size - WORDS2BYTES(bn->n_words), bn->data, bn->n_words);
92*4882a593Smuzhiyun else
93*4882a593Smuzhiyun rk_reverse_memcpy(data + size - WORDS2BYTES(bn->n_words),
94*4882a593Smuzhiyun bn->data, WORDS2BYTES(bn->n_words));
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun return 0;
97*4882a593Smuzhiyun }
98*4882a593Smuzhiyun
rk_bn_get_size(const struct rk_bignum * bn)99*4882a593Smuzhiyun u32 rk_bn_get_size(const struct rk_bignum *bn)
100*4882a593Smuzhiyun {
101*4882a593Smuzhiyun if (!bn)
102*4882a593Smuzhiyun return 0;
103*4882a593Smuzhiyun
104*4882a593Smuzhiyun return WORDS2BYTES(bn->n_words);
105*4882a593Smuzhiyun }
106*4882a593Smuzhiyun
107*4882a593Smuzhiyun /*
108*4882a593Smuzhiyun * @brief Returns the index of the highest 1 in |bn|.
109*4882a593Smuzhiyun * @param bn: the point of input data bignum.
110*4882a593Smuzhiyun * @return The index starts at 0 for the least significant bit.
111*4882a593Smuzhiyun * If src == zero, it will return -1
112*4882a593Smuzhiyun */
rk_bn_highest_bit(const struct rk_bignum * bn)113*4882a593Smuzhiyun int rk_bn_highest_bit(const struct rk_bignum *bn)
114*4882a593Smuzhiyun {
115*4882a593Smuzhiyun u32 w;
116*4882a593Smuzhiyun u32 b;
117*4882a593Smuzhiyun
118*4882a593Smuzhiyun if (!bn || !bn->data || !bn->n_words)
119*4882a593Smuzhiyun return -1;
120*4882a593Smuzhiyun
121*4882a593Smuzhiyun w = bn->data[bn->n_words - 1];
122*4882a593Smuzhiyun
123*4882a593Smuzhiyun for (b = 0; b < RK_WORD_SIZE; b++) {
124*4882a593Smuzhiyun w >>= 1;
125*4882a593Smuzhiyun if (w == 0)
126*4882a593Smuzhiyun break;
127*4882a593Smuzhiyun }
128*4882a593Smuzhiyun
129*4882a593Smuzhiyun return (int)(bn->n_words - 1) * RK_WORD_SIZE + b;
130*4882a593Smuzhiyun }
131