1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * sun8i-ce-prng.c - hardware cryptographic offloader for
4 * Allwinner H3/A64/H5/H2+/H6/R40 SoC
5 *
6 * Copyright (C) 2015-2020 Corentin Labbe <clabbe@baylibre.com>
7 *
8 * This file handle the PRNG
9 *
10 * You could find a link for the datasheet in Documentation/arm/sunxi.rst
11 */
12 #include "sun8i-ce.h"
13 #include <linux/dma-mapping.h>
14 #include <linux/pm_runtime.h>
15 #include <crypto/internal/rng.h>
16
sun8i_ce_prng_init(struct crypto_tfm * tfm)17 int sun8i_ce_prng_init(struct crypto_tfm *tfm)
18 {
19 struct sun8i_ce_rng_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
20
21 memset(ctx, 0, sizeof(struct sun8i_ce_rng_tfm_ctx));
22 return 0;
23 }
24
sun8i_ce_prng_exit(struct crypto_tfm * tfm)25 void sun8i_ce_prng_exit(struct crypto_tfm *tfm)
26 {
27 struct sun8i_ce_rng_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
28
29 memzero_explicit(ctx->seed, ctx->slen);
30 kfree(ctx->seed);
31 ctx->seed = NULL;
32 ctx->slen = 0;
33 }
34
sun8i_ce_prng_seed(struct crypto_rng * tfm,const u8 * seed,unsigned int slen)35 int sun8i_ce_prng_seed(struct crypto_rng *tfm, const u8 *seed,
36 unsigned int slen)
37 {
38 struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(tfm);
39
40 if (ctx->seed && ctx->slen != slen) {
41 memzero_explicit(ctx->seed, ctx->slen);
42 kfree(ctx->seed);
43 ctx->slen = 0;
44 ctx->seed = NULL;
45 }
46 if (!ctx->seed)
47 ctx->seed = kmalloc(slen, GFP_KERNEL | GFP_DMA);
48 if (!ctx->seed)
49 return -ENOMEM;
50
51 memcpy(ctx->seed, seed, slen);
52 ctx->slen = slen;
53
54 return 0;
55 }
56
sun8i_ce_prng_generate(struct crypto_rng * tfm,const u8 * src,unsigned int slen,u8 * dst,unsigned int dlen)57 int sun8i_ce_prng_generate(struct crypto_rng *tfm, const u8 *src,
58 unsigned int slen, u8 *dst, unsigned int dlen)
59 {
60 struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(tfm);
61 struct rng_alg *alg = crypto_rng_alg(tfm);
62 struct sun8i_ce_alg_template *algt;
63 struct sun8i_ce_dev *ce;
64 dma_addr_t dma_iv, dma_dst;
65 int err = 0;
66 int flow = 3;
67 unsigned int todo;
68 struct sun8i_ce_flow *chan;
69 struct ce_task *cet;
70 u32 common, sym;
71 void *d;
72
73 algt = container_of(alg, struct sun8i_ce_alg_template, alg.rng);
74 ce = algt->ce;
75
76 if (ctx->slen == 0) {
77 dev_err(ce->dev, "not seeded\n");
78 return -EINVAL;
79 }
80
81 /* we want dlen + seedsize rounded up to a multiple of PRNG_DATA_SIZE */
82 todo = dlen + ctx->slen + PRNG_DATA_SIZE * 2;
83 todo -= todo % PRNG_DATA_SIZE;
84
85 d = kzalloc(todo, GFP_KERNEL | GFP_DMA);
86 if (!d) {
87 err = -ENOMEM;
88 goto err_mem;
89 }
90
91 dev_dbg(ce->dev, "%s PRNG slen=%u dlen=%u todo=%u multi=%u\n", __func__,
92 slen, dlen, todo, todo / PRNG_DATA_SIZE);
93
94 #ifdef CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG
95 algt->stat_req++;
96 algt->stat_bytes += todo;
97 #endif
98
99 dma_iv = dma_map_single(ce->dev, ctx->seed, ctx->slen, DMA_TO_DEVICE);
100 if (dma_mapping_error(ce->dev, dma_iv)) {
101 dev_err(ce->dev, "Cannot DMA MAP IV\n");
102 err = -EFAULT;
103 goto err_iv;
104 }
105
106 dma_dst = dma_map_single(ce->dev, d, todo, DMA_FROM_DEVICE);
107 if (dma_mapping_error(ce->dev, dma_dst)) {
108 dev_err(ce->dev, "Cannot DMA MAP DST\n");
109 err = -EFAULT;
110 goto err_dst;
111 }
112
113 err = pm_runtime_get_sync(ce->dev);
114 if (err < 0) {
115 pm_runtime_put_noidle(ce->dev);
116 goto err_pm;
117 }
118
119 mutex_lock(&ce->rnglock);
120 chan = &ce->chanlist[flow];
121
122 cet = &chan->tl[0];
123 memset(cet, 0, sizeof(struct ce_task));
124
125 cet->t_id = cpu_to_le32(flow);
126 common = ce->variant->prng | CE_COMM_INT;
127 cet->t_common_ctl = cpu_to_le32(common);
128
129 /* recent CE (H6) need length in bytes, in word otherwise */
130 if (ce->variant->prng_t_dlen_in_bytes)
131 cet->t_dlen = cpu_to_le32(todo);
132 else
133 cet->t_dlen = cpu_to_le32(todo / 4);
134
135 sym = PRNG_LD;
136 cet->t_sym_ctl = cpu_to_le32(sym);
137 cet->t_asym_ctl = 0;
138
139 cet->t_key = cpu_to_le32(dma_iv);
140 cet->t_iv = cpu_to_le32(dma_iv);
141
142 cet->t_dst[0].addr = cpu_to_le32(dma_dst);
143 cet->t_dst[0].len = cpu_to_le32(todo / 4);
144 ce->chanlist[flow].timeout = 2000;
145
146 err = sun8i_ce_run_task(ce, 3, "PRNG");
147 mutex_unlock(&ce->rnglock);
148
149 pm_runtime_put(ce->dev);
150
151 err_pm:
152 dma_unmap_single(ce->dev, dma_dst, todo, DMA_FROM_DEVICE);
153 err_dst:
154 dma_unmap_single(ce->dev, dma_iv, ctx->slen, DMA_TO_DEVICE);
155
156 if (!err) {
157 memcpy(dst, d, dlen);
158 memcpy(ctx->seed, d + dlen, ctx->slen);
159 }
160 memzero_explicit(d, todo);
161 err_iv:
162 kfree(d);
163 err_mem:
164 return err;
165 }
166