xref: /openbmc/u-boot/drivers/crypto/ace_sha.c (revision 274bced8)
1 /*
2  * Advanced Crypto Engine - SHA Firmware
3  * Copyright (c) 2012  Samsung Electronics
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 #include <common.h>
8 #include "ace_sha.h"
9 
10 #ifdef CONFIG_SHA_HW_ACCEL
11 #include <u-boot/sha256.h>
12 #include <u-boot/sha1.h>
13 #include <linux/errno.h>
14 
15 /* SHA1 value for the message of zero length */
16 static const unsigned char sha1_digest_emptymsg[SHA1_SUM_LEN] = {
17 	0xDA, 0x39, 0xA3, 0xEE, 0x5E, 0x6B, 0x4B, 0x0D,
18 	0x32, 0x55, 0xBF, 0xFF, 0x95, 0x60, 0x18, 0x90,
19 	0xAF, 0xD8, 0x07, 0x09};
20 
21 /* SHA256 value for the message of zero length */
22 static const unsigned char sha256_digest_emptymsg[SHA256_SUM_LEN] = {
23 	0xE3, 0xB0, 0xC4, 0x42, 0x98, 0xFC, 0x1C, 0x14,
24 	0x9A, 0xFB, 0xF4, 0xC8, 0x99, 0x6F, 0xB9, 0x24,
25 	0x27, 0xAE, 0x41, 0xE4, 0x64, 0x9B, 0x93, 0x4C,
26 	0xA4, 0x95, 0x99, 0x1B, 0x78, 0x52, 0xB8, 0x55};
27 
28 int ace_sha_hash_digest(const unsigned char *pbuf, unsigned int buf_len,
29 			unsigned char *pout, unsigned int hash_type)
30 {
31 	unsigned int i, reg, len;
32 	unsigned int *pdigest;
33 	struct exynos_ace_sfr *ace_sha_reg =
34 		(struct exynos_ace_sfr *)samsung_get_base_ace_sfr();
35 
36 	if (buf_len == 0) {
37 		/* ACE H/W cannot compute hash value for empty string */
38 		if (hash_type == ACE_SHA_TYPE_SHA1)
39 			memcpy(pout, sha1_digest_emptymsg, SHA1_SUM_LEN);
40 		else
41 			memcpy(pout, sha256_digest_emptymsg, SHA256_SUM_LEN);
42 		return 0;
43 	}
44 
45 	/* Flush HRDMA */
46 	writel(ACE_FC_HRDMACFLUSH_ON, &ace_sha_reg->fc_hrdmac);
47 	writel(ACE_FC_HRDMACFLUSH_OFF, &ace_sha_reg->fc_hrdmac);
48 
49 	/* Set byte swap of data in */
50 	writel(ACE_HASH_SWAPDI_ON | ACE_HASH_SWAPDO_ON | ACE_HASH_SWAPIV_ON,
51 	       &ace_sha_reg->hash_byteswap);
52 
53 	/* Select Hash input mux as external source */
54 	reg = readl(&ace_sha_reg->fc_fifoctrl);
55 	reg = (reg & ~ACE_FC_SELHASH_MASK) | ACE_FC_SELHASH_EXOUT;
56 	writel(reg, &ace_sha_reg->fc_fifoctrl);
57 
58 	/* Set Hash as SHA1 or SHA256 and start Hash engine */
59 	reg = (hash_type == ACE_SHA_TYPE_SHA1) ?
60 		ACE_HASH_ENGSEL_SHA1HASH : ACE_HASH_ENGSEL_SHA256HASH;
61 	reg |= ACE_HASH_STARTBIT_ON;
62 	writel(reg, &ace_sha_reg->hash_control);
63 
64 	/* Enable FIFO mode */
65 	writel(ACE_HASH_FIFO_ON, &ace_sha_reg->hash_fifo_mode);
66 
67 	/* Set message length */
68 	writel(buf_len, &ace_sha_reg->hash_msgsize_low);
69 	writel(0, &ace_sha_reg->hash_msgsize_high);
70 
71 	/* Set HRDMA */
72 	writel((unsigned int)pbuf, &ace_sha_reg->fc_hrdmas);
73 	writel(buf_len, &ace_sha_reg->fc_hrdmal);
74 
75 	while ((readl(&ace_sha_reg->hash_status) & ACE_HASH_MSGDONE_MASK) ==
76 		ACE_HASH_MSGDONE_OFF) {
77 		/*
78 		 * PRNG error bit goes HIGH if a PRNG request occurs without
79 		 * a complete seed setup. We are using this bit to check h/w
80 		 * fault because proper setup is not expected in that case.
81 		 */
82 		if ((readl(&ace_sha_reg->hash_status)
83 			& ACE_HASH_PRNGERROR_MASK) == ACE_HASH_PRNGERROR_ON)
84 			return -EBUSY;
85 	}
86 
87 	/* Clear MSG_DONE bit */
88 	writel(ACE_HASH_MSGDONE_ON, &ace_sha_reg->hash_status);
89 
90 	/* Read hash result */
91 	pdigest = (unsigned int *)pout;
92 	len = (hash_type == ACE_SHA_TYPE_SHA1) ? SHA1_SUM_LEN : SHA256_SUM_LEN;
93 
94 	for (i = 0; i < len / 4; i++)
95 		pdigest[i] = readl(&ace_sha_reg->hash_result[i]);
96 
97 	/* Clear HRDMA pending bit */
98 	writel(ACE_FC_HRDMA, &ace_sha_reg->fc_intpend);
99 
100 	return 0;
101 }
102 
103 void hw_sha256(const unsigned char *pbuf, unsigned int buf_len,
104 			unsigned char *pout, unsigned int chunk_size)
105 {
106 	if (ace_sha_hash_digest(pbuf, buf_len, pout, ACE_SHA_TYPE_SHA256))
107 		debug("ACE was not setup properly or it is faulty\n");
108 }
109 
110 void hw_sha1(const unsigned char *pbuf, unsigned int buf_len,
111 			unsigned char *pout, unsigned int chunk_size)
112 {
113 	if (ace_sha_hash_digest(pbuf, buf_len, pout, ACE_SHA_TYPE_SHA1))
114 		debug("ACE was not setup properly or it is faulty\n");
115 }
116 #endif /* CONFIG_SHA_HW_ACCEL */
117 
118 #ifdef CONFIG_LIB_HW_RAND
119 static unsigned int seed_done;
120 
121 void srand(unsigned int seed)
122 {
123 	struct exynos_ace_sfr *reg =
124 		(struct exynos_ace_sfr *)samsung_get_base_ace_sfr();
125 	int i, status;
126 
127 	/* Seed data */
128 	for (i = 0; i < ACE_HASH_PRNG_REG_NUM; i++)
129 		writel(seed << i, &reg->hash_seed[i]);
130 
131 	/* Wait for seed setup done */
132 	while (1) {
133 		status = readl(&reg->hash_status);
134 		if ((status & ACE_HASH_SEEDSETTING_MASK) ||
135 		    (status & ACE_HASH_PRNGERROR_MASK))
136 			break;
137 	}
138 
139 	seed_done = 1;
140 }
141 
142 unsigned int rand(void)
143 {
144 	struct exynos_ace_sfr *reg =
145 		(struct exynos_ace_sfr *)samsung_get_base_ace_sfr();
146 	int i, status;
147 	unsigned int seed = (unsigned int)&status;
148 	unsigned int ret = 0;
149 
150 	if (!seed_done)
151 		srand(seed);
152 
153 	/* Start PRNG */
154 	writel(ACE_HASH_ENGSEL_PRNG | ACE_HASH_STARTBIT_ON, &reg->hash_control);
155 
156 	/* Wait for PRNG done */
157 	while (1) {
158 		status = readl(&reg->hash_status);
159 		if (status & ACE_HASH_PRNGDONE_MASK)
160 			break;
161 		if (status & ACE_HASH_PRNGERROR_MASK) {
162 			seed_done = 0;
163 			return 0;
164 		}
165 	}
166 
167 	/* Clear Done IRQ */
168 	writel(ACE_HASH_PRNGDONE_MASK, &reg->hash_status);
169 
170 	/* Read a PRNG result */
171 	for (i = 0; i < ACE_HASH_PRNG_REG_NUM; i++)
172 		ret += readl(&reg->hash_prng[i]);
173 
174 	seed_done = 0;
175 	return ret;
176 }
177 
178 unsigned int rand_r(unsigned int *seedp)
179 {
180 	srand(*seedp);
181 
182 	return rand();
183 }
184 #endif /* CONFIG_LIB_HW_RAND */
185