summaryrefslogtreecommitdiffstats
path: root/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
blob: b3cc43ea6c8a69db03844222696bdb738ab3eb87 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
// SPDX-License-Identifier: GPL-2.0
/*
 * sun8i-ce-prng.c - hardware cryptographic offloader for
 * Allwinner H3/A64/H5/H2+/H6/R40 SoC
 *
 * Copyright (C) 2015-2020 Corentin Labbe <clabbe@baylibre.com>
 *
 * This file handle the PRNG
 *
 * You could find a link for the datasheet in Documentation/arm/sunxi.rst
 */
#include "sun8i-ce.h"
#include <linux/dma-mapping.h>
#include <linux/pm_runtime.h>
#include <crypto/internal/rng.h>

int sun8i_ce_prng_init(struct crypto_tfm *tfm)
{
	struct sun8i_ce_rng_tfm_ctx *ctx = crypto_tfm_ctx(tfm);

	memset(ctx, 0, sizeof(struct sun8i_ce_rng_tfm_ctx));
	return 0;
}

void sun8i_ce_prng_exit(struct crypto_tfm *tfm)
{
	struct sun8i_ce_rng_tfm_ctx *ctx = crypto_tfm_ctx(tfm);

	kfree_sensitive(ctx->seed);
	ctx->seed = NULL;
	ctx->slen = 0;
}

int sun8i_ce_prng_seed(struct crypto_rng *tfm, const u8 *seed,
		       unsigned int slen)
{
	struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(tfm);

	if (ctx->seed && ctx->slen != slen) {
		kfree_sensitive(ctx->seed);
		ctx->slen = 0;
		ctx->seed = NULL;
	}
	if (!ctx->seed)
		ctx->seed = kmalloc(slen, GFP_KERNEL | GFP_DMA);
	if (!ctx->seed)
		return -ENOMEM;

	memcpy(ctx->seed, seed, slen);
	ctx->slen = slen;

	return 0;
}

int sun8i_ce_prng_generate(struct crypto_rng *tfm, const u8 *src,
			   unsigned int slen, u8 *dst, unsigned int dlen)
{
	struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(tfm);
	struct rng_alg *alg = crypto_rng_alg(tfm);
	struct sun8i_ce_alg_template *algt;
	struct sun8i_ce_dev *ce;
	dma_addr_t dma_iv, dma_dst;
	int err = 0;
	int flow = 3;
	unsigned int todo;
	struct sun8i_ce_flow *chan;
	struct ce_task *cet;
	u32 common, sym;
	void *d;

	algt = container_of(alg, struct sun8i_ce_alg_template, alg.rng);
	ce = algt->ce;

	if (ctx->slen == 0) {
		dev_err(ce->dev, "not seeded\n");
		return -EINVAL;
	}

	/* we want dlen + seedsize rounded up to a multiple of PRNG_DATA_SIZE */
	todo = dlen + ctx->slen + PRNG_DATA_SIZE * 2;
	todo -= todo % PRNG_DATA_SIZE;

	d = kzalloc(todo, GFP_KERNEL | GFP_DMA);
	if (!d) {
		err = -ENOMEM;
		goto err_mem;
	}

	dev_dbg(ce->dev, "%s PRNG slen=%u dlen=%u todo=%u multi=%u\n", __func__,
		slen, dlen, todo, todo / PRNG_DATA_SIZE);

#ifdef CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG
	algt->stat_req++;
	algt->stat_bytes += todo;
#endif

	dma_iv = dma_map_single(ce->dev, ctx->seed, ctx->slen, DMA_TO_DEVICE);
	if (dma_mapping_error(ce->dev, dma_iv)) {
		dev_err(ce->dev, "Cannot DMA MAP IV\n");
		err = -EFAULT;
		goto err_iv;
	}

	dma_dst = dma_map_single(ce->dev, d, todo, DMA_FROM_DEVICE);
	if (dma_mapping_error(ce->dev, dma_dst)) {
		dev_err(ce->dev, "Cannot DMA MAP DST\n");
		err = -EFAULT;
		goto err_dst;
	}

	err = pm_runtime_resume_and_get(ce->dev);
	if (err < 0)
		goto err_pm;

	mutex_lock(&ce->rnglock);
	chan = &ce->chanlist[flow];

	cet = &chan->tl[0];
	memset(cet, 0, sizeof(struct ce_task));

	cet->t_id = cpu_to_le32(flow);
	common = ce->variant->prng | CE_COMM_INT;
	cet->t_common_ctl = cpu_to_le32(common);

	/* recent CE (H6) need length in bytes, in word otherwise */
	if (ce->variant->prng_t_dlen_in_bytes)
		cet->t_dlen = cpu_to_le32(todo);
	else
		cet->t_dlen = cpu_to_le32(todo / 4);

	sym = PRNG_LD;
	cet->t_sym_ctl = cpu_to_le32(sym);
	cet->t_asym_ctl = 0;

	cet->t_key = cpu_to_le32(dma_iv);
	cet->t_iv = cpu_to_le32(dma_iv);

	cet->t_dst[0].addr = cpu_to_le32(dma_dst);
	cet->t_dst[0].len = cpu_to_le32(todo / 4);
	ce->chanlist[flow].timeout = 2000;

	err = sun8i_ce_run_task(ce, 3, "PRNG");
	mutex_unlock(&ce->rnglock);

	pm_runtime_put(ce->dev);

err_pm:
	dma_unmap_single(ce->dev, dma_dst, todo, DMA_FROM_DEVICE);
err_dst:
	dma_unmap_single(ce->dev, dma_iv, ctx->slen, DMA_TO_DEVICE);

	if (!err) {
		memcpy(dst, d, dlen);
		memcpy(ctx->seed, d + dlen, ctx->slen);
	}
err_iv:
	kfree_sensitive(d);
err_mem:
	return err;
}