xref: /openbmc/u-boot/drivers/crypto/ace_sha.c (revision 8ee59472)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Advanced Crypto Engine - SHA Firmware
4  * Copyright (c) 2012  Samsung Electronics
5  */
6 #include <common.h>
7 #include "ace_sha.h"
8 
9 #ifdef CONFIG_SHA_HW_ACCEL
10 #include <u-boot/sha256.h>
11 #include <u-boot/sha1.h>
12 #include <linux/errno.h>
13 
14 /* SHA1 value for the message of zero length */
15 static const unsigned char sha1_digest_emptymsg[SHA1_SUM_LEN] = {
16 	0xDA, 0x39, 0xA3, 0xEE, 0x5E, 0x6B, 0x4B, 0x0D,
17 	0x32, 0x55, 0xBF, 0xFF, 0x95, 0x60, 0x18, 0x90,
18 	0xAF, 0xD8, 0x07, 0x09};
19 
20 /* SHA256 value for the message of zero length */
21 static const unsigned char sha256_digest_emptymsg[SHA256_SUM_LEN] = {
22 	0xE3, 0xB0, 0xC4, 0x42, 0x98, 0xFC, 0x1C, 0x14,
23 	0x9A, 0xFB, 0xF4, 0xC8, 0x99, 0x6F, 0xB9, 0x24,
24 	0x27, 0xAE, 0x41, 0xE4, 0x64, 0x9B, 0x93, 0x4C,
25 	0xA4, 0x95, 0x99, 0x1B, 0x78, 0x52, 0xB8, 0x55};
26 
27 int ace_sha_hash_digest(const unsigned char *pbuf, unsigned int buf_len,
28 			unsigned char *pout, unsigned int hash_type)
29 {
30 	unsigned int i, reg, len;
31 	unsigned int *pdigest;
32 	struct exynos_ace_sfr *ace_sha_reg =
33 		(struct exynos_ace_sfr *)samsung_get_base_ace_sfr();
34 
35 	if (buf_len == 0) {
36 		/* ACE H/W cannot compute hash value for empty string */
37 		if (hash_type == ACE_SHA_TYPE_SHA1)
38 			memcpy(pout, sha1_digest_emptymsg, SHA1_SUM_LEN);
39 		else
40 			memcpy(pout, sha256_digest_emptymsg, SHA256_SUM_LEN);
41 		return 0;
42 	}
43 
44 	/* Flush HRDMA */
45 	writel(ACE_FC_HRDMACFLUSH_ON, &ace_sha_reg->fc_hrdmac);
46 	writel(ACE_FC_HRDMACFLUSH_OFF, &ace_sha_reg->fc_hrdmac);
47 
48 	/* Set byte swap of data in */
49 	writel(ACE_HASH_SWAPDI_ON | ACE_HASH_SWAPDO_ON | ACE_HASH_SWAPIV_ON,
50 	       &ace_sha_reg->hash_byteswap);
51 
52 	/* Select Hash input mux as external source */
53 	reg = readl(&ace_sha_reg->fc_fifoctrl);
54 	reg = (reg & ~ACE_FC_SELHASH_MASK) | ACE_FC_SELHASH_EXOUT;
55 	writel(reg, &ace_sha_reg->fc_fifoctrl);
56 
57 	/* Set Hash as SHA1 or SHA256 and start Hash engine */
58 	reg = (hash_type == ACE_SHA_TYPE_SHA1) ?
59 		ACE_HASH_ENGSEL_SHA1HASH : ACE_HASH_ENGSEL_SHA256HASH;
60 	reg |= ACE_HASH_STARTBIT_ON;
61 	writel(reg, &ace_sha_reg->hash_control);
62 
63 	/* Enable FIFO mode */
64 	writel(ACE_HASH_FIFO_ON, &ace_sha_reg->hash_fifo_mode);
65 
66 	/* Set message length */
67 	writel(buf_len, &ace_sha_reg->hash_msgsize_low);
68 	writel(0, &ace_sha_reg->hash_msgsize_high);
69 
70 	/* Set HRDMA */
71 	writel((unsigned int)pbuf, &ace_sha_reg->fc_hrdmas);
72 	writel(buf_len, &ace_sha_reg->fc_hrdmal);
73 
74 	while ((readl(&ace_sha_reg->hash_status) & ACE_HASH_MSGDONE_MASK) ==
75 		ACE_HASH_MSGDONE_OFF) {
76 		/*
77 		 * PRNG error bit goes HIGH if a PRNG request occurs without
78 		 * a complete seed setup. We are using this bit to check h/w
79 		 * fault because proper setup is not expected in that case.
80 		 */
81 		if ((readl(&ace_sha_reg->hash_status)
82 			& ACE_HASH_PRNGERROR_MASK) == ACE_HASH_PRNGERROR_ON)
83 			return -EBUSY;
84 	}
85 
86 	/* Clear MSG_DONE bit */
87 	writel(ACE_HASH_MSGDONE_ON, &ace_sha_reg->hash_status);
88 
89 	/* Read hash result */
90 	pdigest = (unsigned int *)pout;
91 	len = (hash_type == ACE_SHA_TYPE_SHA1) ? SHA1_SUM_LEN : SHA256_SUM_LEN;
92 
93 	for (i = 0; i < len / 4; i++)
94 		pdigest[i] = readl(&ace_sha_reg->hash_result[i]);
95 
96 	/* Clear HRDMA pending bit */
97 	writel(ACE_FC_HRDMA, &ace_sha_reg->fc_intpend);
98 
99 	return 0;
100 }
101 
102 void hw_sha256(const unsigned char *pbuf, unsigned int buf_len,
103 			unsigned char *pout, unsigned int chunk_size)
104 {
105 	if (ace_sha_hash_digest(pbuf, buf_len, pout, ACE_SHA_TYPE_SHA256))
106 		debug("ACE was not setup properly or it is faulty\n");
107 }
108 
109 void hw_sha1(const unsigned char *pbuf, unsigned int buf_len,
110 			unsigned char *pout, unsigned int chunk_size)
111 {
112 	if (ace_sha_hash_digest(pbuf, buf_len, pout, ACE_SHA_TYPE_SHA1))
113 		debug("ACE was not setup properly or it is faulty\n");
114 }
115 #endif /* CONFIG_SHA_HW_ACCEL */
116 
117 #ifdef CONFIG_LIB_HW_RAND
118 static unsigned int seed_done;
119 
120 void srand(unsigned int seed)
121 {
122 	struct exynos_ace_sfr *reg =
123 		(struct exynos_ace_sfr *)samsung_get_base_ace_sfr();
124 	int i, status;
125 
126 	/* Seed data */
127 	for (i = 0; i < ACE_HASH_PRNG_REG_NUM; i++)
128 		writel(seed << i, &reg->hash_seed[i]);
129 
130 	/* Wait for seed setup done */
131 	while (1) {
132 		status = readl(&reg->hash_status);
133 		if ((status & ACE_HASH_SEEDSETTING_MASK) ||
134 		    (status & ACE_HASH_PRNGERROR_MASK))
135 			break;
136 	}
137 
138 	seed_done = 1;
139 }
140 
141 unsigned int rand(void)
142 {
143 	struct exynos_ace_sfr *reg =
144 		(struct exynos_ace_sfr *)samsung_get_base_ace_sfr();
145 	int i, status;
146 	unsigned int seed = (unsigned int)&status;
147 	unsigned int ret = 0;
148 
149 	if (!seed_done)
150 		srand(seed);
151 
152 	/* Start PRNG */
153 	writel(ACE_HASH_ENGSEL_PRNG | ACE_HASH_STARTBIT_ON, &reg->hash_control);
154 
155 	/* Wait for PRNG done */
156 	while (1) {
157 		status = readl(&reg->hash_status);
158 		if (status & ACE_HASH_PRNGDONE_MASK)
159 			break;
160 		if (status & ACE_HASH_PRNGERROR_MASK) {
161 			seed_done = 0;
162 			return 0;
163 		}
164 	}
165 
166 	/* Clear Done IRQ */
167 	writel(ACE_HASH_PRNGDONE_MASK, &reg->hash_status);
168 
169 	/* Read a PRNG result */
170 	for (i = 0; i < ACE_HASH_PRNG_REG_NUM; i++)
171 		ret += readl(&reg->hash_prng[i]);
172 
173 	seed_done = 0;
174 	return ret;
175 }
176 
177 unsigned int rand_r(unsigned int *seedp)
178 {
179 	srand(*seedp);
180 
181 	return rand();
182 }
183 #endif /* CONFIG_LIB_HW_RAND */
184